WO2025172919A2

WO2025172919A2 - Vehicle motion units, control units, and elevated track for self-steering suspended vehicles

Info

Publication number: WO2025172919A2
Application number: PCT/IB2025/051604
Authority: WO
Inventors: Andries Auret LOUW
Original assignee: Ev Podcars
Current assignee: Ev Podcars
Priority date: 2024-02-15
Filing date: 2025-02-14
Publication date: 2025-08-21
Anticipated expiration: 2026-08-15
Also published as: WO2025172919A3

Abstract

Techniques for assuring safety in operations of self-steering suspended vehicles operating on an elevated track are described Disclosed is a vehicle motion unit comprising wheel assemblies with sensing units to detect wheel set positions relative to a reference element on the track. An actuator may perform corrective actions based on the sensing unit determining that there is a misalignment either in between a leading wheel set and a trailing wheel set or within a single wheel set. A control unit receives signals from the sensing units, process the signals to determine misalignments, and triggers the corrective actions. For additional safety, the elevated track is provided with a channel formed by a vertical guide wall and a supplementary guide rail near track split junctions. The system includes mechanisms for continuous monitoring of wheel alignment and physical constraints for wheel movement.

Description

VEHICLE MOTION UNITS, CONTROL UNITS, AND ELEVATED TRACK FOR SELF-STEERING SUSPENDED VEHICLES

TECHNICAL FIELD

[0001 ] The present subject matter relates, in general, to self-steering vehicles suspended and moveable along an elevated track, and in particular, to techniques for assuring safety in operation of such self-steering vehicles.

BACKGROUND

[0002] Transportation systems have evolved over time, employing various means to move goods and individuals across distances. The transportation systems have undergone significant transformations, from early fuel-driven locomotives running on tracks that are laid on the ground to electronically controlled rapid transit vehicles that operate on elevated tracks. Such advancements in the transportation systems are a result of ongoing efforts to address the challenges of congestion, inefficiency, and environmental concerns that plague traditional ground-level transportation. One promising advancement in the field of transportation is the development of automated, elevated, and suspended transportation systems. In such transportation systems, vehicles are typically suspended from tracks and operate along an elevated network that spans across various geographic locations. Such suspended transportation systems have been implemented globally. Examples of the suspended transportation systems implemented globally include the hanging bus system in China, Japan, the Schwebebahn system in Wuppertal, Germany and the Panda system in Chengdu, China.

BRIEF DESCRIPTION OF DRAWINGS

[0003] The detailed description is provided with reference to the accompanying figures, wherein: [0004] Fig. 1A illustrates a perspective view of a vehicle motion unit, in accordance with an example implementation of the present subject matter. [0005] Fig. 1 B illustrates a schematic of the vehicle motion unit, in accordance with the example implementation of the present subject matter. [0006] Fig. 2 illustrates a control unit for controlling a self-steering suspended vehicle operating on an elevated track, in accordance with an example implementation of the present subject matter.

[0007] Fig. 3A illustrates an elevated track comprising a vertical guide wall, in accordance with an example implementation of the present subject matter.

[0008] Fig. 3B illustrates the elevated track comprising a channel, in accordance with the example implementation of the present subject matter. [0009] Fig. 4A illustrates different zones of an elevated track, in accordance with an example implementation of the present subject matter. [0010] Fig. 4B illustrates a movement of a vehicle motion unit in a first zone of the elevated track, in accordance with the example implementation of the present subject matter.

[0011 ] Fig. 4C illustrates a movement of the vehicle motion unit in a second zone of the elevated track, in accordance with the example implementation of the present subject matter.

[0012] Fig. 4D illustrates a movement of the vehicle motion unit in a third zone of the elevated track, in accordance with the example implementation of the present subject matter.

[0013] Fig. 4E illustrates a movement of the vehicle motion unit after crossing a track split junction, in accordance with the example implementation of the present subject matter.

[0014] Fig. 4F illustrates movement of a vehicle motion unit through a track split in a straight path, in accordance with the example implementation of the present subject matter. [0015] Fig. 4G illustrates movement of the vehicle motion unit through the track split along a track split section, in accordance with the example implementation of the present subject matter.

[0016] Fig. 5A illustrates a position of a wheel assembly with respect to a vertical guide wall, in accordance with an example implementation of the present subject matter.

[0017] Fig. 5B illustrates a position of a wheel assembly in a channel, in accordance with an example implementation of the present subject matter. [0018] Fig. 5C illustrates a position of a wheel assembly in a first zone of an elevated track, in accordance with an example implementation of the present subject matter.

[0019] Fig. 5D illustrates a swing in the wheel assembly in the first zone in a first direction, in accordance with an example implementation of the present subject matter.

[0020] Fig. 5E illustrates a swing in the wheel assembly in the first zone in a second direction, in accordance with an example implementation of the present subject matter.

[0021 ] Fig. 5F illustrates a position of a wheel assembly in a third zone in a first channel, in accordance with an example implementation of the present subject matter.

[0022] Fig. 5G illustrates a position of a wheel assembly in a third zone in a second channel, in accordance with an example implementation of the present subject matter.

[0023] Fig. 5H illustrates a swing in a first direction in the wheel assembly in the third zone in the first channel, in accordance with an example implementation of the present subject matter.

[0024] Fig. 5I illustrates a swing in a second direction in the wheel assembly in the third zone in the first channel, in accordance with an example implementation of the present subject matter. [0025] Fig. 5J illustrates a swing in the second direction in the wheel assembly in the third zone in the second channel, in accordance with an example implementation of the present subject matter.

[0026] Fig. 5K illustrates a swing in the first direction in the wheel assembly in the third zone in the second channel, in accordance with an example implementation of the present subject matter.

[0027] The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings.

DETAILED DESCRIPTION

[0028] Elevated transportation systems have become a prominent solution to address challenges arising from land saturation and the inefficiencies of expanding ground-level transportation networks. By relocating infrastructure from the ground, the elevated transportation systems alleviate congestion and reduce competition for land use, which are common issues in densely populated urban areas, and a common obstruction to expansion of ground-level transportation network. Examples of elevated systems include monorails, light rail transit, electrified rapid rail transit, and cable cars.

[0029] In addition to the examples described above, the elevated transportation systems also include suspended transportation systems which include vehicles that are suspended from an elevated track and move, autonomously, along the elevated track. The elevated tracks, for the suspended transportation systems, are formed to have a lower track surface facing the ground, an upper track surface opposite the lower track surface, and an elongated slot that runs throughout a length of the elevated track. Suspended vehicles are provided such that at least one wheel may be positioned on an upper surface of the elevated track, and at least one wheel may be positioned on a lower surface of the elevated track, and a load is suspended through a slot running along the elevated track. The suspended load may be attached to a hanging element coupled to a motorized unit. The motorized unit is powered to propel the suspended vehicle, such that the suspended load may be pulled along with the movement of the motorized unit. The suspended load may be a passenger cabin of a vehicle, a container for transportation of ores in mines, and any other load that may need transportation from one geographical location to another.

[0030] The suspended transportation systems have a vast potential for traversing long distances in a cost-effective manner, primarily as less infrastructure is needed to support the operations of the suspended vehicles. Unlike traditional elevated transportation systems that need extensive and broad structural frameworks for allowing the vehicles to travel thereon, the necessary infrastructure to suspend a vehicle therefrom includes relatively simple and narrow track design and support structures. However the operation of suspended vehicles moveable over elevated tracks is limited due to certain drawbacks.

[0031 ] Passengers are often reluctant to opt for the suspended vehicles as a means for regular transport, as the passengers find the operations of the suspended vehicles risky due to limited support in the suspended vehicles. One common safety concern in the operations of the suspended vehicles is a potential risk of instability as the vehicle may sway upon experiencing forces in directions other than the direction of motion. Such forces may arise, especially during operation, from external factors that are not in control of the suspended vehicle systems. The external factors can include a variety of elements such as wind, seismic activity, and movement of passengers within the vehicle body, such as a passenger cabin. For example, strong gusts of wind, particularly in elevated or open-air environments, can exert lateral forces on the suspended vehicle, leading to sways and vibrations in the vehicle body that may affect the stability of the suspended vehicle. As a result, the experience of the passengers of the suspended vehicle may be disrupted, thereby making the experience scary. Further, in suspended vehicles, passengers shifting their weight or moving within the passenger cabin may cause a shift in the vehicle's balance, contributing to further swaying of the passenger cabin, and consequently swaying of the entire suspended vehicle.

[0032] In situations where the swaying becomes severe, the sway may cause wheels running on the upper surface of the elevated track to tip from the track, which could disrupt the operations of the suspended vehicle systems and even pose safety risks. Thus, while suspended transportation systems are attractive due to their lower infrastructure costs, the need to address stability issues could introduce unexpected costs. For example, developing and implementing advanced stabilization mechanisms and more sophisticated track designs can increase the initial construction and maintenance costs. Such increase in the costs could diminish the economic advantages that make suspended transportation systems appealing in the first place.

[0033] Further, if the suspended transportation systems are to be expanded to cover a larger operating radius, the elevated track needs to be split at certain positions to allow movement of suspended vehicles from one point to another point in different directions. In a track split, a slot, through which the vehicle is suspended, widens to form an elongated slot. The widening of the slot occurs as the elongated slot has to be divided into at least two track sections therefrom, creating an independent slot for each track section. Where the slot is widened, especially at a junction where the track divides into multiple paths, the suspended vehicle may need to transition from one side of the split to the other.

[0034] In traditional track-based vehicular systems, a moveable element is used to manage the transition of vehicles from one track section to another, especially in cases of track splits. The moveable element may be a switch or a set of rails that can shift position, guiding the vehicle onto an intended track. For example, the intended track may be determined based on a destination of the vehicle. The moveable element may be mechanically operated, either manually or automatically, and is designed to ensure that the vehicle follows the intended track.

[0035] A similar moveable element is employed in the case of elevated tracks for suspended vehicles when the track splits into multiple directions. However, the use of moveable elements in suspended vehicles for elevated tracks imposes restrictions on the operational efficiency of the suspended vehicles. For instance, the introduction of moveable elements, such as switches or rails, that guide suspended vehicles onto different track sections, removes the autonomy of the suspended vehicles in terms of lane selection. The suspended vehicles no longer have control over their path but instead rely on external mechanical systems to direct them onto a correct track. As an extension thereto, the moveable element on the elevated track also needs a rail signaling mechanism to be deployed for coordinating the movement of different suspended vehicles across various paths. The dependency on the rail signaling mechanism introduces several limitations. For instance, the operation of suspended vehicles become dependent on the smooth operation of all components involved in the switching mechanisms and the rail signaling system. Any failure in such components, be it a mechanical fault in the track switches or a malfunction in the rail signaling system, can lead to delays, potential collisions, or system-wide disruptions. Further, the complexity of maintaining and ensuring the high availability of all the components increases operational costs and creates potential risks for the overall reliability of the transportation system.

[0036] An alternative to providing moveable elements in a track split is to provide a static track switch on the elevated tracks for autonomous vehicles. In such cases, the vehicles can retain autonomy in their operation. However, when a static track switch is used in a suspended vehicle system, the elongated slot provides a greater distance that is to be traversed between the upper track surfaces on either side while switching tracks. While traversing the elongated slot, as the wheels of the suspended vehicle system have to traverse the greater distance without support, the chances of instability are aggravated as the wheels may fall in the elongated slot during the track switch and may thereby tip or lose traction. Therefore, while the use of a static track switch eliminates the need for dynamic components like moveable elements and signaling mechanisms, the use of the static track switch has several safety risks associated therewith. Further, the chances of the tipping may be exacerbated in situations where the vehicle experiences swaying while traversing the track junction and over the elongated slot. While a steering system of the suspended vehicles may be capable of aligning the wheels, the steering system has no control over the external forces that may force the wheels out of alignment and cause the wheels to tip in the elongated slot. As a result, the safety of the vehicle is compromised.

[0037] According to examples of the present subject matter, techniques for assuring safety in operations of self-steering suspended vehicles are described.

[0038] In an example of the present subject matter, a vehicle motion unit for a self-steering vehicle suspended and moveable on an elevated track is described. The vehicle motion unit may be connected to a passenger cabin of a self-steering suspended vehicle and may be moveable to cause propulsion of the self-steering suspended vehicle along the elevated track. [0039] In an example, the vehicle motion unit includes a frame and a wheel assembly movably mounted to the frame, where the wheel assembly is swivelable for steering operation. The vehicle motion unit further includes a bracing structure and a wheel axle supported on the bracing structure. Further, the vehicle motion unit includes a wheel set mounted on each end of the wheel axle, where the wheel set is rotatable with respect to the bracing structure.

[0040] The vehicle motion unit further includes a sensing unit positioned on the wheel assembly in proximity of the wheel set to determine a position of the wheel set relative to a reference element. The vehicle motion control unit further includes an actuator actuable to perform a corrective action in response to the sensing unit indicating a misalignment in the wheel set.

[0041 ] During the operation of the self-steering suspended vehicle, the sensing unit may either instantaneously or continuously monitor the position of the wheel set from the reference element. By monitoring the position of the wheel set with respect to the reference element, the sensing unit may facilitate identification of any misalignment between the wheel set and the intended path and enable the actuation of the actuator to perform the corrective action. As a result, the vehicle motion unit may facilitate safe, stable, and efficient operation of the self-steering suspended vehicle.

[0042] In another example, the vehicle motion unit includes a frame and a set of wheel assemblies provided on the frame. The set of wheel assemblies includes a leading wheel assembly and a trailing wheel assembly, where the leading wheel assembly and the trailing wheel assembly are separated in a lateral direction. Further, the leading wheel assembly and the trailing wheel assembly are movably mounted to the frame to be swivelable for steering operation.

[0043] The leading wheel assembly includes a leading bracing structure and a leading wheel axle supported on the leading bracing structure. The leading wheel assembly further includes a leading wheel set mounted on each end of the leading wheel axle to be rotatable with respect to the leading bracing structure. Further, the leading wheel assembly includes a first sensing unit positioned on the leading wheel assembly in proximity to the leading wheel set to determine a position of the leading wheel set relative to a reference element. The trailing wheel assembly includes a trailing bracing structure and a trailing wheel axle supported on the trailing bracing structure. The trailing wheel assembly further includes a trailing wheel set mounted on each end of the trailing wheel axle to be rotatable with respect to the trailing bracing structure. Further, the trailing wheel assembly includes a second sensing unit positioned on the trailing wheel assembly in proximity of the trailing wheel set to determine a position of the trailing wheel set relative to the reference element.

[0044] The vehicle motion unit further includes an actuator that is actuable to perform a corrective action in response to at least one of the first sensing unit and the second sensing unit indicating a misalignment between the leading wheel set and the trailing wheel set.

[0045] During the operation of the self-steering suspended vehicle, the first sensing unit and the second sensing unit may either instantaneously or continuously monitor the position of the leading wheel set and the trailing wheel set from the reference element. By monitoring the position of the leading wheel set and the trailing wheel set with respect to the reference element, the first sensing unit and the second sensing unit may facilitate identification of any misalignment between the leading wheel set and the trailing wheel set and enable the actuation of the actuator to perform the corrective action. As a result, the vehicle motion unit may facilitate safe, stable, and efficient operation of the self-steering suspended vehicle. Preventing the misalignment is of further importance at critical positions on the elevated track, such as when the self-steering suspended vehicle has to traverse a track split junction. Therefore, any chances of any of the leading wheel set and the trailing wheel set missing an intended track section, for instance upon action from external swaying forces, may be avoided.

[0046] In another example of the present subject matter, a control unit for controlling the self-steering suspended vehicle is described. In operation, the control unit receives a first signal from a first sensing unit and a second signal from a second sensing unit, where the first signal and the second signal may be temporally synchronized. The first signal is indicative of a position of the leading wheel set relative to the elevated track and the second signal is indicative of a position of the trailing wheel set relative to the elevated track. Based on the first signal and the second signal, the control unit ascertains an instantaneous misalignment between the leading wheel set and the trailing wheel set along the elevated track, where the instantaneous misalignment is indicative of a condition preceding to an error situation associated with the self-steering suspended vehicle. In response to the ascertained instantaneous misalignment, the control unit identifies the corrective action to preemptively prevent the error situation. Subsequently, the control unit transmits the corrective signal to the actuator of the selfsteering vehicle for performing the corrective action. The control unit thus monitors the operation of the wheel set on the track to detect any misalignment and thus facilitate safe, stable, and efficient operation of the self-steering suspended vehicle.

[0047] In yet another example of the present subject matter, an elevated track for hoisting the self-steering suspended vehicle is described. The elevated track includes a channel along each longitudinal edge of the elevated track to support wheels of the self-steering suspended vehicle. The channel includes a vertical guide wall provided to define a lateral boundary of the channel for the wheels of the self-steering suspended vehicle. The channel further includes a supplementary vertical guide rail that is provided on the channel and is parallel to and offset with respect to the vertical guide wall. In an example, the wheels of the self-steering suspended vehicle are to be disposed on the channel between the vertical guide wall and the supplementary vertical guide rail. In the example, the supplementary vertical guide rail is provided on the channel in a track transit section immediately preceding and contiguous to a track split junction, where the tracking is divided into multiple track sections at the track split junction.

[0048] The elevated track, featuring both the vertical guide wall and the supplementary vertical guide rail, significantly improves the stability of the vehicle. For instance, by creating the channel for the wheels, the elevated track limits sideways movement of the wheels in both directions. The constrained motion within the channel reduces unwanted misalignments by providing a physical barrier, leading to smoother travel and lesser vibrations. Further, when unexpected external forces like wind push occur against the self-steering suspended vehicle, the elevated track forces the wheels to brace against either the vertical guide wall or the supplementary vertical guide rail, thereby countering such external forces efficiently.

[0049] Further, by positioning the supplementary vertical guide rail in the track transit section immediately preceding and contiguous to the track split junction, the elevated track enhances vehicle stability during a critical transition. As the self-steering suspended vehicle approaches the track split junction, the supplementary vertical guide rail provides extra guidance and support to the wheels. Such a configuration helps in maintaining proper wheel alignment as the self-steering suspended vehicle enters the track split junction, reducing the risk of misalignment or derailment. Further, while changing tracks at the track split junction, the wheels of the suspended vehicle can be locked in the channel towards which the vehicle is to move. Therefore, any chances of misalignment that may cause the vehicle operating on the elevated track to miss entering the intended track section may be prevented, and thereby tip in the elongated slot is avoided. The continuous guidance from the supplementary rail ensures a smoother transition between the single track and the track split junction. The extra support is particularly valuable in elongated slots where the tracks begin to separate, addressing a common weak point in traditional designs. Thus, the elevated track allows for more precise control of the path of the self-steering suspended vehicle as the self-steering suspended vehicle navigates the track split junction, thereby potentially enabling higher operational speeds through the track split junction.

[0050] The present subject matter is further described with reference to Figs. 1A-5K. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.

[0051 ] Fig. 1 A illustrates a perspective view of a vehicle motion unit 100, in accordance with an example implementation of the present subject matter. Fig. 1 B illustrates a schematic of the vehicle motion unit 100, in accordance with the example implementation of the present subject matter. For the sake of brevity, Figs. 1A-1 B have been explained in conjunction with each other.

[0052] Fig. 1 A depicts a perspective view of the vehicle motion unit 100 for a self-steering suspended vehicle. The self-steering suspended vehicle may be a vehicle that has a passenger cabin suspending from an elevated track. The elevated track may be a track at a height above the ground, and such tracks have become increasingly common in modem urban transportation systems, offering solutions to congestion and land use challenges in densely populated areas. Further, the self-steering suspended vehicle may be moveable along the elevated track. To facilitate the movement of the suspended vehicle on the elevated track, the vehicle may be provided with the vehicle motion unit 100. The vehicle motion unit 100 includes a frame 102, a set of wheel assemblies 104 provided on the frame 102, and an actuator (not shown in Fig. 1A and 1 B). The frame 102 serves as a primary structural component, providing a foundation for various elements of the vehicle motion unit 100 to be supported thereon. The set of wheel assemblies 104 may include a leading wheel assembly 104-1 and a trailing wheel assembly 104-2, where the leading wheel assembly 104-1 and the trailing wheel assembly 104-2 may be separated in a lateral direction. In an example where the vehicle motion unit 100 is mounted on the elevated track, the lateral direction may be along a length of the elevated track. Further, the leading wheel assembly 104-1 and the trailing wheel assembly 104-2 may be moveably mounted to the frame 102 to be swivelable for steering operation. [0053] Each wheel assembly of the set of wheel assemblies 104 includes a bracing structure 106, a wheel axle 108, a wheel set 110 mounted on each end of the wheel axle 108 to be rotatable with respect to the bracing structure 106, and a sensing unit (not shown in the Figs.). For instance, the leading wheel assembly 104-1 includes a leading bracing structure 106-1 , a leading wheel axle 108-1 , a leading wheel set 110-1 mounted on each end of the leading wheel axle 108-1 to be rotatable with respect to the leading bracing structure 106-1 , and a first sensing unit (not shown in the Figs.). The leading wheel axle 108-1 may be supported on the leading bracing structure 106-1. Further, the first sensing unit may be positioned on the leading wheel assembly 104-1 in proximity to the leading wheel set 110-1 to determine a position of the leading wheel set 110-1 relative to a reference element (not shown).

[0054] Similarly, the trailing wheel assembly 104-2 includes a trailing bracing structure 106-2, a trailing wheel axle 108-2, a trailing wheel set 110- 2 mounted on each end of the trailing wheel axle 108-2 to be rotatable with respect to the trailing bracing structure 106-2, and a second sensing unit (not shown in the Figs.). The trailing wheel axle 108-2 may be supported on the trailing bracing structure 106-2. Further, the second sensing unit may be positioned on the trailing wheel assembly 104-2 in proximity to the trailing wheel set 110-2 to determine a position of the trailing wheel set 110-2 relative to the reference element (not shown).

[0055] The first sensing unit and the second sensing unit may include a first sensing device and a second sensing device respectively. In an example, the first sensing device and the second sensing device may be positioned on the leading bracing structure 106-1 and the trailing bracing structure 106-2, respectively. In an example, the first sensing device and the second sensing device may be able to either instantaneously (based on an external trigger) or continuously (during operation) determine a distance of the corresponding wheel set relative to the reference element. By providing the sensing devices on the bracing structure 106, reliability of output from the sensing unit is ensured, as the bracing structure 106 is a stationary element, and thus it will always be exposed to the reference element. In scenarios, where the sensing unit is mounted to the wheel set 110, there may be no reliability of continuous output as the wheel is rotatable and thus a line of sight between the sensing unit and the reference element is likely to be obstructed at several intervals arbitrarily.

[0056] In an example, the first sensing unit may receive an input from the first sensing device that the leading wheel set 110-1 is at a first distance from the reference element. If the first distance is greater than a first threshold, it may be determined that there is a misalignment between the leading wheel set 110-1 and the trailing wheel set 110-2. Similarly, in another example, the misalignment between the leading wheel set 110-1 and the trailing wheel set 110-2 may also be determined based on an input from the second sensing device. In another example, the second sensing unit may receive the input from the second sensing device that the trailing wheel set 110-2 is at a second distance from the reference element. If the second distance is greater than a second threshold, it may be determined that there is a misalignment between the leading wheel set 110-1 and the trailing wheel set 110-2. In addition, the misalignment between the leading wheel set 110-1 and the trailing wheel set 110-2 based on inputs from both the first sensing unit and the second sensing unit, where there may be a breach of the first threshold at an instance of the first sensing unit and a breach of the second threshold at an instance of the second sensing unit, where the breaches at the instances of both sensing units are temporally synchronized.

[0057] During operation of the self-steering suspended vehicle on the elevated track, the leading wheel set 110-1 and the trailing wheel set 110-2 shall be maintained in alignment, to provide stability to the operation of the self-steering suspended vehicle. To maintain such alignment, both the leading wheel set 110-1 and the trailing wheel set 110-2, may be configured to operate at a predetermined distance from a boundary of the elevated track. In such cases, the boundary of the track may be understood as the reference element. The predetermined distance may be set as the first threshold and the second threshold, in instances where the first threshold and the second threshold are equal. At other instance, the first threshold and the second threshold may be different based on a design of the elevated track. In an example, tracks with sharp curves or varying elevations may cause to maintain different first threshold and the second threshold to ensure stability. By providing a provision to monitor the distance with the reference element, there is a timely detection of a misalignment before a mishap occurs and necessary corrective action may be undertaken to prevent the mishap. Therefore, when even one of the first sensing unit and the second sensing unit provides inputs that fulfil conditions amounting to a misalignment, the necessary corrective action may be performed. The sensing unit may be operated to monitor a distance with the reference element at real time, and therefore real-time corrective actions may be taken without disrupting the operations of the self-steering suspended vehicle. In an example, the actuator may be actuable to perform the corrective action. [0058] Maintaining alignment between the leading wheel set 110-1 and the trailing wheel set 110-2 may be of criticality in situations where a slight misalignment can cause catastrophic effects. For instance, in situations where the self-steering suspended vehicle is moving through a track split junction, maintaining the stability of the vehicle motion unit 100 is of utmost importance to prevent the wheels from tipping into a widened elongated slot between the elevated track, which could cause injury to passengers in a cabin of the self-steering suspended vehicle. The present subject matter, by being able to detect a misalignment at real time allows an opportunity to take a necessary corrective action that preemptively prevents an error situation. The track split junction for the above implementation may be understood as a position on the elevated track whereafter the tracking is divided into multiple track sections. [0059] In an example, the corrective action may be applying of brakes to constrain the movement of the self-steering suspended vehicle on the elevated track. Thus, the actuator is to cause a braking action to constrain the movement of the self-steering suspended vehicle on the elevated track. Therefore, for time critical emergency situations, the movement of the selfsteering suspended vehicle may be temporarily halted before the misalignment is corrected. This may be done in situations where there is no sufficient time to correct the misalignment as the vehicle may tip into the slot of the elevated track or may hit a boundary of the elevated track causing injury to the vehicle and/or the vehicles. Further, in situations where the time-criticality is not very high, the corrective action may pertain to causing at least one of the first leading wheel assembly 104-1 and the first trailing wheel assembly 104-2 to swivel for correcting the misalignment. The first leading wheel assembly 104-1 and the first trailing wheel assembly 104-2 may be made to swivel by a degree determined based upon a degree of misalignment.

[0060] In an example implementation of the present subject matter, the wheel assembly 104 may include a control wheel unit 112 mounted on the bracing structure 106. An axis of each wheel in the control wheel unit 112 is orthogonal to the wheel set 110. Therefore, the control wheel unit 112 is exposed along a circumferential direction thereof to an exterior of the vehicle motion unit 100, and thus in proximity to the reference element during operation of the self-steering suspended vehicle. In an example, the control wheel unit 112 may be stationary with respect to the bracing structure 106. In the present example implementation of the present subject matter, the sensing unit may have sensing devices that may be mounted to the control wheel unit 112.

[0061 ] In an example, the control wheel unit 112 may include a first control wheel 112-1 and a second control wheel 112-1. The first control wheel 112-1 and the second control wheel 112-2 may be mounted on the bracing structure 106 such that a span of the control wheel unit 112 is substantially equal to a diameter of the wheel set 110. In such examples, the sensing unit may be mounted either on the control wheel unit 112 or on the bracing structure 106 in proximity of the control wheel unit 112. By providing the control wheel units to span the diameter of a wheel in the wheel set, a swing in the wheel of the wheel set may be prevented. For instance, the sensing unit may comprise a third sensing device positioned on the bracing structure 106 and in proximity to the first control wheel 112- 1. In such a case, the sensing unit may receive an input from the third sensing device that the wheel set 110 is at a third distance from the reference element. If the third distance is greater than a third threshold, it may be determined that there is a misalignment in the wheel set 110.

[0062] Similarly, the sensing unit may comprise a fourth sensing device positioned on the bracing structure 106 and in proximity to the second control wheel 112-2. In such a case, the sensing unit may receive an input from the fourth sensing device that the wheel set 110 is at a fourth distance from the reference element. If the fourth distance is greater than a fourth threshold, it may be determined that there is a misalignment in the wheel set 110. Additionally, if the third distance and the fourth distance is not equal, it may represent a swing in the wheel set which can be easily addressed by the techniques of the present subject matter due to the presence of the control wheel unit 112 spanning a diameter of the wheel.

[0063] The control wheel unit 112 may include a leading control wheel 112-1 and a trailing control wheel 112-2. The leading control wheel unit 112- 1 may include a first leading control wheel 112-1 -A and a second leading control wheel 112-1 -B. The first leading control wheel 112-1 -A and the second leading control wheel 112-1 -B may be provided to span a diameter of the leading wheel set 110-1. In such examples, the first sensing unit may be mounted either on the leading control wheel unit 112-1 or on the leading bracing structure 106-1 in proximity of the leading control wheel unit 112-1 , for reasons discussed above. Similarly, the trailing control wheel unit 112-2 may include a first trailing control wheel 112-2 -A and a second trailing control wheel 112-2-B. The first trailing control wheel 112-2 -A and the second trailing control wheel 112-2-B may be provided to span a diameter of the trailing wheel set 110-2. In such examples, the first sensing unit may be mounted either on the trailing control wheel unit 112-2 or on the trailing bracing structure 106-2 in proximity of the trailing control wheel unit 112-2, for reasons discussed above. Therefore, in such an implementation the misalignment between the leading wheel set 110-1 and the trailing wheel set 110-2 and a misalignment within each of the leading wheel set 110-1 and the trailing wheel set 110-2 are simultaneously detected.

[0064]

[0065] In an example, to bias the wheel set 110 towards a surface of the elevated track, the vehicle motion unit 100 may be provided with a loading mechanism coupled to the wheel axle 108. The wheel axle 108 in such a scenario, be referred to as a weight-bearing wheel axle 108.

[0066] In addition to the above components, the vehicle motion unit 100 comprises a steering mechanism that may be coupled to the frame 102 to control the steering of the self-steering suspended vehicle along the elevated track. The steering mechanism assists in navigating the vehicle through various track configurations, including straight sections, curves, and track splits. In an example, the steering mechanism may be a motor including a main motor and a stepper motor.

[0067] Further, the vehicle motion unit 100, as depicted in Fig. 1A, includes two swivel arms, namely, a leading swivel arm 114-1 and a trailing swivel arm 114-2, both operably coupled with the steering mechanism. It should be noted that while the present embodiment depicts two swivel arms, alternative configurations with a single swivel arm 114 are also possible as depicted in Fig. 1 B. The choice of the number of swivel arms 114 and the number of wheel assemblies 104 to be mounted on the frame 102 may be made based on a size of the vehicle to be suspended from the elevated track and operational considerations for the self-steering suspended vehicle. Each swivel arm 114 is configured to translate inputs from the steering mechanism into directional changes of wheel sets 110 that may be coupled to the each swivel arm 114.

[0068] Further, the vehicle motion unit 100 may include an auxiliary wheel set 116 mounted on each end of an auxiliary wheel axle 118. The auxiliary wheel set 116 and the auxiliary wheel axle 118 may be provided opposite to the wheel set 110 and the wheel axle 108. The auxiliary wheel set 116 and the second wheel axle 118, respectively, may include a leading auxiliary wheel set 116-1 is mounted on each end of a leading auxiliary wheel axle 118-1 , while a trailing auxiliary wheel set 116-2 is mounted on each end of the trailing auxiliary wheel axle 118-1.

[0069] The leading wheel set 110-1 and the leading auxiliary wheel set 116-1 may be mounted in a manner that an imaginary plane containing central axes of the leading wheel axle 108-1 and the leading auxiliary wheel axle 118-1 is substantially perpendicular to a first tangent on a first wheel from amongst the leading wheel set 110-1 and a second tangent on a second wheel from amongst the leading auxiliary wheel set 116-1 . The first tangent may be understood as a tangent formed on the first wheel at a potential point of contact of the first wheel with the elevated track. Similarly, the second tangent may be understood as a tangent formed on the second wheel at a potential point of contact of the second wheel with the elevated track.

[0070] Correspondingly, an imaginary plane containing central axes of the trailing wheel axle 108-2 and the trailing auxiliary wheel axle 118-2 is substantially perpendicular to a third tangent on a first wheel from amongst the trailing wheel set 110-2 and a fourth tangent on a second wheel from amongst the trailing auxiliary wheel set 116-2. Again, these tangents are formed at the potential points of contact of the respective wheels with the elevated track. The vehicle motion unit 100 being mounted on the elevated track in a manner discussed above, causes the wheel set 110 and the auxiliary wheel set 116 to straddle the elevated track and maintain a secure grip on the elevated track while facilitating smooth movement of the vehicle motion unit 100 and the vehicle along the elevated track. Further, the configuration of the vehicle motion unit 100 effectively manages vertical forces during operation for maintaining track and preventing tipping and slippage over the elevated track, for instance during sharp turns or under influence of external forces.

[0071 ] Further, the vehicle motion unit 100 may include a mounting structure 120. In an example, the vehicle motion unit 100 may include a hanging bracket 122 extending from a portion of the vehicle motion unit 100 to couple the mounting structure 120 with the remaining components of the vehicle motion unit 100. The hanging bracket 122 may, in an example, extend from a reinforcement member 124 of the wheel-axle assembly to mount the mounting structure 120. In the example, the swivel arm 114 may be disposed between the hanging brackets 122 and allowed to swivel between the hanging brackets 122. In an embodiment having a leading end a trailing end as depicted in Fig. 1A and 1 B, the hanging bracket 122 may include a leading hanging bracket 122-1 and a trailing hanging bracket 122- 2. Similarly, the reinforcement member 124 may include a leading reinforcement member 124-1 and a trailing reinforcement member 124-2.

[0072] In some aspects, to enhance the vehicle's control and safety, various braking systems may be incorporated into the vehicle motion unit 100. These may include disk brakes mounted on the wheel axles or integrated into the wheel hubs, drum brakes, regenerative braking systems, or electromagnetic brakes. The braking systems may provide efficient stopping power and speed control when needed. In some cases, anti-lock braking systems (ABS) or electronic brake-force distribution (EBD) may also be implemented to further improve braking performance and safety.

[0073] The above provided steering mechanisms shall be construed as an exemplary implementations and additional steering mechanisms and configurations could be considered for enhanced maneuverability and adaptability to various track conditions. The vehicle motion unit 100, in an example, may also be coupled to a Global Positioning System (GPS) module to provide additional data for accurate steering and positioning. Further, in another example, cameras and image processing systems may be provided to detect track features and upcoming turns, allowing for predictive steering adjustments.

[0074] Fig. 1 B illustrates a schematic of the vehicle motion unit 100, in accordance with the example implementation of the present subject matter. The vehicle motion unit 100, as described with reference to Fig. 1 B, is provided for a vehicle to be suspended from and movable over an elevated track 126. Fig. 1 B may be understood as an example implementation where there is a single wheel assembly 104 and not two wheels assemblies 104, namely, the leading wheel assembly 104-1 and the trailing wheel assembly 104-2. The vehicle motion unit 100, as depicted in Fig. 1 B, may be used with vehicles carrying lighter loads.

[0075] Fig. 2 illustrates a control unit 200 for controlling a self-steering suspended vehicle operating on an elevated track, in accordance with an example implementation of the present subject matter. The control unit 200 may include a processor(s) 202 and a memory (not shown).

[0076] The processor(s) 202 may be configured to fetch and execute instructions stored in the memory. The processor(s) may be interpreted as one or more microprocessors, microcontrollers, or digital signal processors configured for automotive applications. When provided by the processor(s) 202, the functions may be delivered by a single dedicated processor or by a combination of shared processors. The term "processor(s)" should not be construed exclusively to refer to hardware executing machine-readable instructions; it may also encompass application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), and various types of memory such as read-only memory (ROM) and random access memory (RAM) that are crucial for storing operational code and data.

[0077] The processor(s) 202 may include routines, programs, objects, components, and data structures that perform specific tasks relevant to vehicle operation, such as controlling engine functions, managing safety systems, or facilitating communication between different vehicle components. Additionally, it may incorporate modules that enhance applications within the vehicle's control system, including those found in operating systems tailored for automotive environments.

[0078] In an example, the self-steering suspended vehicle may include a wheel assembly 104, as disclosed in relation to Fig. 1 B. In another example, the self-steering suspended vehicle may include a leading wheel assembly 104-1 and a trailing wheel assembly 104-2, as disclosed in relation to Fig. 1A. Accordingly, the self-steering suspended vehicle may include a leading wheel axle, a leading wheel set mounted on each end of the leading wheel axle, a trailing wheel axle separated from the leading wheel axle in a lateral direction, and a trailing wheel set mounted on each end of the trailing wheel axle. The leading wheel axle may be similar to the leading wheel axle 108-1 , the leading wheel set may be similar to the leading wheel set 110-1 , the trailing wheel axle 108-2, and the trailing wheel set 110-2 of the disclosure made in Fig. 1A and for the sake of clarity has been referenced herein with the same reference numerals. In an example, the control unit 200 may be provided to receive and interpret signals received from sensing units, as discussed in relation to Figs. 1A-1 B.

[0079] Accordingly, the control unit 200 is to receive a first signal from a first sensing unit and a second signal from a second sensing unit. The first signal may be indicative of a position of the leading wheel set 110-1 relative to the elevated track 126. Similarly, the second signal may be indicative of a position of the trailing wheel set 110-2 relative to the elevated track 126. In an example, the first signal and the second signal may be temporally synchronized. The temporal synchronization of the first signal and the second signal may allow for an instantaneous determination of a misalignment situation between the leading wheel set 110-1 and the trailing wheel set 110-2.

[0080] In an example, the first sensing unit comprises a first sensing device positioned in proximity to the leading wheel set 110-1. In the example, the control unit 200 is to determine, based on an input from the first sensing device, a first distance between the leading wheel set 110-1 and a reference element on the elevated track 126 being greater than a first threshold to indicate the misalignment between the leading wheel set 110- 1 and the trailing wheel set 110-2. Similarly, the second sensing unit comprises a second sensing device positioned in proximity to the trailing wheel set 110-2. In such a case, the control unit 200 is to determine, based on an input from the second sensing device, a second distance between the trailing wheel set and a reference element on the elevated track being greater than a second threshold to indicate the misalignment between the leading wheel set and the trailing wheel set.

[0081 ] The reference element may in an example be a boundary of a track. Further, in another example where the self-steering suspended vehicle has to steer through a track split junction, the reference element may be a supplementary vertical wall forming a channel with a boundary of the elevated track 126.

[0082] Further, the control unit 200 is to ascertain an instantaneous misalignment between the leading wheel set 110-1 and the trailing wheel set 110-2 along the elevated track 126. In an example, the instantaneous misalignment is indicative of a condition preceding to an error situation associated with the self-steering suspended vehicle. In an example, the error situation associated with the self-steering suspended vehicle is a situation where the leading wheel set 110-1 enters a channel at a track transit section immediately preceding and contiguous to a track split junction. The tracking is divided into multiple track sections at the track split junction, however the trailing wheel set 110-2 fails to enter the channel, during operation of the self-steering suspended vehicle.

[0083] In response to the instantaneous misalignment having been ascertained, the control unit 200 is to identify a corrective action. The corrective action may be an action to preemptively prevent the error situation. Additionally, the corrective signal that is generated based on the error situation is transmitted to an actuator of the self-steering suspended vehicle for performing the corrective action. In an example, the corrective action may be applying of brakes to constrain the movement of the selfsteering suspended vehicle on the elevated track. Thus, the control unit 200 is to control the actuator is to cause a braking action to constrain the movement of the self-steering suspended vehicle on the elevated track. Therefore, for time critical emergency situations, the movement of the selfsteering suspended vehicle may be temporarily halted before the misalignment is corrected. This may be done in situations where there is no sufficient time to correct the misalignment as the vehicle may tip into the slot of the elevated track or may hit a boundary of the elevated track causing injury to the vehicle and/or the vehicles. Further, in situations where the time-criticality is not very high, the corrective action may pertain to causing at least one of the first leading wheel assembly 104-1 and the first trailing wheel assembly 104-2 to swivel for correcting the misalignment. The first leading wheel assembly 104-1 and the first trailing wheel assembly 104-2 may be made to swivel by a degree determined based upon a degree of misalignment. Similar techniques may be applied to determine swing of a single wheel in the wheel set 110 by the control unit 200, in consideration of the control wheel unit 112 explained in conjunction to the description of Figs. 1A-1 B.

[0084] Fig. 3A illustrates an elevated track 300 comprising a vertical guide wall 302, in accordance with an example implementation of the present subject matter. Fig. 3B illustrates the elevated track 300 comprising a channel 304, in accordance with the example implementation of the present subject matter. The elevated track 300 may include the vertical guide wall 302. The vertical guide wall 302 may be provided to define a lateral boundary of the elevated track, in one instance, as depicted in Fig. 3A. Further, as the track approaches a track split junction wherefrom the tracking is divided into multiple track sections, there is provided a track transit section. A channel 304 is created along each longitudinal edge of the elevated track 300 in the track transit section. The channel 304 may be provided to support the wheels, such as a wheel from amongst the wheel set 110, of the self-steering suspended vehicle. The channel 304 may include the vertical guide wall 302 provided to define a lateral boundary of the channel 304 for the wheels of the self-steering suspended vehicle. Further, the channel 304 may include a supplementary vertical guide rail 306 provided on the channel 304. The supplementary vertical guide rail 306 may be provided parallel to and offset with respect to the vertical guide wall 302. In an example, the wheels of the self-steering suspended vehicle are to be disposed on the channel 304 between the vertical guide wall 302 and the supplementary vertical guide rail 306. Further, the supplementary vertical guide rail 306 is offset with respect to the vertical guide wall 302 by a distance greater than a width of the wheels of the self-steering suspended vehicle.

[0085] The supplementary vertical guide rail 306 may be provided on the channel 304 in the track transit section immediately preceding and contiguous to the track split junction. While the sensing units of the vehicle motion unit 100 are able to continuously monitor the distance with respect to the reference element, as discussed above, in order to counter situations of extreme sway, the channel 304 may be provided as an additional safety measure. The channel 304 provides a physical barrier to limit sideways movement of the wheels in both directions. The physical barrier becomes of great significance when unexpected external forces like strong winds push against the self-steering suspended vehicle as the channel 304 forces the wheels to brace against either the vertical guide wall 302 or the supplementary vertical guide rail 306, effectively countering such external forces. The channel 304 may be created at areas where the prevention of misalignment becomes supremely important such as when the vehicle approaches track split junctions, to provide extra guidance and support to maintain proper wheel alignment, thus reducing the risk of misalignment or derailment during critical transitions. [0086] In an example, a length of the channel 304 in the longitudinal direction may be determined based on an average travelling speed of the self-steering suspended vehicle on the elevated track. The average traveling speed may assist in determining a braking distance, should an error situation arise. For instance, if the self-steering suspended vehicle is being operated on the elevated track 300 to enter the track split junction, a situation may arise where the leading wheel set 110-1 enters the channel 304 but the trailing wheel set 110-2 misses the channel 304, for example due to an external force causing sway. In such a situation, a corrective action such as braking may have to be performed such that the self-steering suspended vehicle halts before entering the track split junction. Therefore, the braking distance is considered while determining the length of the channel 304, such that the length is at least greater than the breaking distance. In the example, the braking distance corresponds to a distance that would be travelled by the self-steering suspended vehicle after an instance of application of brakes and an instance of halting of operations. Further, in an example, the elevated track 300 may include a set of rails 308, including a left rail 308-1 and a right rail 308-2, and a slot 310 between the set of rails 308. The slot 310 may be provided to suspend the selfsteering suspended vehicle therefrom.

[0087] When operating on the elevated track 300, the vehicle motion unit 100 (as discussed in relation to Figs. 1A-1 B) may consider at least one of the vertical guide wall 302 as the reference element during a whole of a journey of the self-steering suspended vehicle. In addition, or alternatively, the vehicle motion unit 100 may consider the supplementary vertical guide rail 306 as the reference element while traversing through the track split junction.

[0088] In an example implementation of the present subject matter, the control wheel 112 may be equipped with suspension mechanisms, allowing it to be flexible when running against the vertical guide wall 302 or the supplementary vertical guide rail 306. Further, the stiffness of the control wheel 112 can be adjusted using either a roller bearing arrangement or a spring or suspension mechanism. A roller bearing arrangement will only allow the control wheel 112 to touch the vertical guide wall 302 or the supplementary vertical guide rail 306 if the self-steering suspended vehicle steers in that direction, while a spring or suspension mechanism will allow for variable movement so that the control wheel 112 can run permanently against these vertical elements and increase the pressure away from the vertical elements as the self-steering suspended vehicle moves closer to them.

[0089] Fig. 4A illustrates different zones of an elevated track 400, in accordance with an example implementation of the present subject matter. Fig. 4B illustrates a movement of a vehicle motion unit 100 in a first zone 400-1 of the elevated track 400, in accordance with the example implementation of the present subject matter. Fig. 4C illustrates a movement of the vehicle motion unit 100 in a second zone 400-2 of the elevated track 400, in accordance with the example implementation of the present subject matter. Fig. 4D illustrates a movement of the vehicle motion unit 100 in a third zone 400-3 of the elevated track 400, in accordance with the example implementation of the present subject matter. Fig. 4E illustrates a movement of the vehicle motion unit 100 after crossing a track split junction, in accordance with the example implementation of the present subject matter. Fig. 4F illustrates movement of a vehicle motion unit 100 through a track split in a straight path. Fig. 4G illustrates movement of the vehicle motion unit 100 through the track split along a track split section. For the sake of brevity, Figs. 4A-4G are explained in conjunction. For the sake of clarity and continuity, it should be noted that reference numerals from Figs. 1A-3B are utilized herein to denote common elements, without limiting the scope of the invention to the specific embodiments depicted in those figures. The elevated track 400 may be similar to the elevated track 300, as discussed in relation to Figs. 3A-3B. [0090] For the sake of explanation of variations in the track width and the provisioning of the channel 304 immediately preceding and contiguous to a track split junction, the elevated track 400 has been partitioned into three zones - a first zone 400-1 , a second zone 400-2, a third zone 400-3. The third zone 400-3 may be provisioned with the channel 304 to lock the wheels into either a right lane or a left lane, based on an intended direction of the self-steering suspended vehicle.

[0091 ] Fig. 4B illustrates a movement of the vehicle motion unit 100 in a first zone 400-1 of the elevated track 400. The first zone 400-1 may be understood as a single lane, single line track. The first zone 400-1 may be provided with the vertical guide wall 302 at each side of the elevated track 400 to define a longitudinal boundary of the elevated track 400. The vehicle motion unit 100 may operate on the elevated track 400 such that the wheel set 110 is operated at a first distance from the vertical guide wall 302. The first distance may be determined based on a freedom of movement that can be allowed to the vehicle motion unit 100 while ensuring safe operation. The freedom of movement, in an example, may be provided in consideration of a degree of rotation of the vehicle motion unit 100 until which a corrective action can be safely performed. The freedom of movement has been depicted by showing a position of the vehicle motion unit 100 at a first time instant T1 depicted by arrow 402-1 , a second time instant T2 depicted by arrow 402-2, and a third time instant T3 depicted by arrow 402-3. At the first time instant 402-1 , the vehicle motion unit 100 may be operating normally and parallel to the track. At the second time instant 402-2, the vehicle motion unit 100 may sway to a first degree of rotation until which a first wheel of the control wheel unit 112 on a first side of the vehicle motion unit 100 contacts the vertical guide wall 302 to physically constrain further rotation, thereby maintaining safe operation. At the same time, a first wheel of the control wheel unit 112 on a second side of the vehicle motion unit 100 contacts the vertical guide wall 302 at another edge of the elevated track 400. [0092] At the third time instant 402-3, the vehicle motion unit 100 may sway to a second degree of rotation, in a direction opposite to the first degree of rotation, such that a second wheel of the control wheel unit 112 at the first side of the vehicle motion unit 100 contacts the vertical guide wall 302. For reasons similar to the second time instant 402-2, the vehicle motion unit 100 may be restricted to sway beyond the safe freedom of movement by physically restraining the rotation due to physical contact between the control wheel unit 112 and the vertical guide wall 302 on each edge of the elevated track 400.

[0093] Crossing the first zone 400-1 , the vehicle motion unit 100 moves into a second zone 400-2 depicted in Fig. 4C. The second zone 400-2 is usually wider than the first zone 400-1 , as it has to allow the self-steering suspended vehicle to move either into a left-hand position before the track split, or into the right-hand position of the track, based on an intended direction for the self-steering suspended vehicle. Therefore, a freedom of movement in the second zone 400-2 is higher than a freedom of movement in the first zone 400-1. Similar to Fig. 4B, the freedom of movement in the second zone 400-2 has been depicted by showing a position of the vehicle motion unit 100 at a fourth time instant T4 depicted by arrow 404-1 , a fifth time instant T5 depicted by arrow 404-2, and a sixth time instant T6 depicted by arrow 404-3. At the third time instant 404-1 , the vehicle motion unit 100 may be operating normally and parallel to the track. However, a distance of separation between each wheel set 110 and the vertical guide wall 302 at the second zone 400-2 is greater than a distance of separation between each wheel set 110 and the vertical guide element at the first zone 400-1. At the fifth time instant 404-2, the vehicle motion unit 100 may sway to a third degree of rotation until which a first wheel of the control wheel unit 112 on a first side of the vehicle motion unit 100 contacts the vertical guide wall 302 to physically constrain further rotation, thereby maintaining safe operation. At the same time, a first wheel of the control wheel unit 112 on a second side of the vehicle motion unit 100 contacts the vertical guide wall 302 at another edge of the elevated track 400. It shall be understood that the third degree of rotation may be greater than the first degree of rotation shown in Fig. 4B.

[0094] At sixth time instant 404-3, the vehicle motion unit 100 may sway to a fourth degree of rotation, in a direction opposite to the third degree of rotation, such that a second wheel of the control wheel unit 112 at the first side of the vehicle motion unit 100 contacts the vertical guide wall 302. For reasons similar to the fifth time instant 404-2, the vehicle motion unit 100 may be restricted to sway beyond the safe freedom of movement by physically restraining the rotation due to physical contact between the control wheel unit 112 and the vertical guide wall 302 on each edge of the elevated track 400.

[0095] At seventh time instant 404-4, the vehicle motion unit 100 may begin to enter a track transit section, depicted as a third zone 400-3. The track transit section may be section immediately preceding and contiguous to a track split junction, where the tracking is divided into multiple track sections at the track split junction. As discussed in relation to Fig. 3B, the track transit section may be provided with the channel 304 on each longitudinal edge thereof. Based on an intended track section that is to be traversed, the vehicle motion unit 100 may move towards a left direction or a right direction by the time instant T6. For instance, the vehicle motion unit 100 may move towards the left direction after the time instant T5. Further, the vehicle motion unit 100 may move toward the right direction after the time instant T6.

[0096] At the third zone 400-3, at an eighth time instance 406-1 (T8), the vehicle motion unit 100 is depicted as located in a first channel 304-1 provided on one longitudinal edge of the track transit section, say the left longitudinal edge. Further, at a ninth time instance 406-2 (T9), the vehicle motion unit 100 is depicted as located in a second channel 304-2 provided on another longitudinal edge of the track transit section, say the right longitudinal edge. Therefore, the channel 304 is present at the track transit section immediately preceding the track junction

[0097] Further, the channel 304 may also be contiguous to the track split junction and into the track sections, as depicted in Fig. 4E. The channel 304- 1 on a left longitudinal edge may continue to a predetermined length in a left track section until the vehicle motion unit 100 reliable crosses the track split junction. Further, the channel 304-2 on a right longitudinal edge may continue to a further predetermined length in a right track section until the vehicle motion unit 100 reliable crosses the track split junction and the elevated track 400 further becomes straight, for instance similar to the first zone 400-1 .

[0098] Figs. 4F and 4G ilustrate a track split junction having a static switch 406. The wheel set 110 of the vehicle motion unit 100 includes a first wheel 408-1 and a second wheel 408-2 of the wheel set 110 on one end of the first wheel axle 108, and a third wheel 408-3 and a fourth wheel 408-4 of the wheel set 110 on another end of the first wheel axle 108. The first wheel 408-1 , the second wheel 408-2, the third wheel 408-3, and the fourth wheel 408-4 may be positioned such that a span between the outermost wheels (first wheel 408-1 and the second wheel 408-2 on one side, the third wheel 408-3 and the fourth wheel 408-4 on the other) is greater than the maximum width of the slot at any track split junction. Such an arrangement ensures that as the vehicle approaches and traverses a track split having a static triangular element 406, at least one wheel on each side of the wheel set 110 remains supported on the track surface. For instance, on one side, either the first wheel 408-1 of the wheel set or the second wheel 408-2 of the wheel set 110 will maintain contact with the track, when going through the left track section, as illustrated in Fig. 4F or going through the right track section, as illustrated in Fig. 4G. Simultaneously, on the opposite side, either the third wheel 408-3 of the first wheel set or the fourth wheel 408-4 of the wheel set 110 will remain supported when going through the left track section, as illustrated in Fig. 4F or going through the right track section, as illustrated in Fig. 4G. Therefore, calibrating the width of the wheel applies to movements through track splits and curved transitions to diverging paths. By maintaining the wheel span, as defined, the vehicle motion unit 100 can safely navigate track splits without risking misalignment or loss of support, thereby enhancing the overall stability and reliability of the suspended vehicle system. Additionally, as discussed above, the fourth wheel 408-4 may be locked in a first channel 304-1 when traversing towards the left track section or the first wheel 408-1 may be locked in a second channel 304-2 when traversing towards the right track section.

[0099] To summarize, the suspended vehicle sway arrest steering system described herein offers a robust solution for enhancing the stability, safety, and efficiency of elevated track transportation. By employing a unique wheel configuration and supporting elements, the system effectively mitigates sway and maintains consistent track contact, even when navigating challenging track splits and turns.

[00100] Fig. 5A illustrates a position of a wheel assembly 104 with respect to the vertical guide wall 302, in accordance with an example implementation of the present subject matter. Fig. 5B illustrates a position of a wheel assembly 104 in the channel 304, in accordance with an example implementation of the present subject matter. Fig. 5C illustrates a position of a wheel assembly in a first zone 400-1 of an elevated track 400, in accordance with an example implementation of the present subject matter. Fig. 5D illustrates a swing in the wheel assembly in the first zone 400-1 in a first direction, in accordance with an example implementation of the present subject matter. Fig. 5E illustrates a swing in the wheel assembly in the first zone 400-1 in a second direction, in accordance with an example implementation of the present subject matter. Fig. 5F illustrates a position of a wheel assembly in a third zone 400-3 in a first channel 304-1 , in accordance with an example implementation of the present subject matter. Fig. 5G illustrates a position of a wheel assembly in a third zone 400-4 in a second channel 304-2, in accordance with an example implementation of the present subject matter. Fig. 5H illustrates a swing in a first direction in the wheel assembly in the third zone 400-3 in the first channel 304-1 , in accordance with an example implementation of the present subject matter. Fig. 5I illustrates a swing in a second direction in the wheel assembly in the third zone 400-3 in the first channel 304-2, in accordance with an example implementation of the present subject matter. Fig. 5J illustrates a swing in a second direction in the wheel assembly in the third zone 400-3 in the second channel 304-1 , in accordance with an example implementation of the present subject matter. Fig. 5K illustrates a swing in the first direction in the wheel assembly in the third zone 400-3 in the second channel 304-2, in accordance with an example implementation of the present subject matter. For the sake of brevity, Figs. 5A-5K are explained in conjunction. For the sake of clarity and continuity, it should be noted that reference numerals from Figs. 1A-4G are utilized herein to denote common elements, without limiting the scope of the invention to the specific embodiments depicted in those figures.

[00101 ] Fig. 5A illustrates a position of a wheel assembly 104 with respect to the vertical guide wall 302, in accordance with an example implementation of the present subject matter. As discussed above, the wheel assembly 104 includes a wheel set 110 and a control wheel 112 mounted in proximity to and orthogonal to the wheel set 110. The vertical guide wall 302 provided at a longitudinal edge of the elevated track may not be provided to be very high. In an example, measure between 20mm and 60mm in height, providing an effective reference element for the sensing unit to determine the position of the wheel set 110. The control wheel 112 may be positioned to run approximately 5mm to 15mm above the track surface and has a diameter typically between 30mm to 70mm. In the example implementation shown in Fig. 5A, the diameter of the control wheel 112 is shown to be 50mm. In a safe operation, it is not intended for the control wheel 112 to interact with the vertical guide wall 302. Therefore, there may be a separation between a circumferential section of the control wheel 112 and the vertical guide wall 302. In the first zone 400-1 , the circumferential section of the control wheel 112 in proximity to the vertical guide wall 302 may be separated by constant 30mm at both longitudinal edges of the elevated track 400.

[00102] Further, in a third zone 400-3, a channel 304, formed by the vertical guide wall 302 and a supplementary vertical guide rail 306 is present, as depicted in Fig. 5B. The channel 304 is designed to be wider than the control wheel 112 to allow for free movement of the wheel set 110 in the channel 304. For instance, if the wheel set 110 is 20mm wide and the control wheel 112 is 50mm wide, the channel 304 is ideally between 70mm and 100mm wide. Having a width of the channel 304 to be greater than a width of the control wheel 112, provides lateral constraint for the wheel assembly 104 while still allowing necessary movement, thereby further improving smoother transitions on the elevated track and reducing the risk of misalignment. The necessary movement may be needed to slip the vehicle motion unit 100 towards either of the left longitudinal edge and the right longitudinal edge of the elevated track, based on an intended track section to be taken by the vehicle motion unit 100. Therefore, a margin may be provided on each side of the control wheel 112 in the channel 304. In an example, the margin may be of 20mm. Particularly, the margin of approximately 20mm may be provided on both sides of the control wheel 112, i.e. , with respect to the vertical guide wall 302 and another 20mm with respect to the supplementary vertical guide rail 306.

[00103] Fig. 5C illustrates a position of a wheel assembly 104 in a first zone 400-1 of an elevated track 400. In this zone, the wheel assembly 104 operates with a certain degree of freedom within the constraints provided by the vertical guide wall 302. The control wheel 112 is positioned to run as close as 10mm to 50mm from the vertical guide wall 302, allowing for limited lateral movement and twist of the wheel axles.

[00104] Figs. 5D and 5E illustrate swings in the wheel assembly 104 in the first zone 400-1 in opposite directions. These figures demonstrate how the wheel assembly 104 can tilt or rotate within the limits set by a width of the channel 304. If the rotation or the tilting is beyond an acceptable degree, the control wheel 112 may come into contact with the vertical guide wall 302, acting as a physical limit to prevent further tilting that would be dangerous. The channel width, being between 70mm and 100mm, allows for this controlled swing while preventing excessive movement. As shown in Fig. 5A, a separation between the vertical guide wall 302 and the proximate circumferential section of the control wheel 112 is 30mm at both longitudinal edges of the elevated track 400. Therefore, if the wheel assembly tilts more towards one longitudinal side than the other, a distance between the other longitudinal side and the proximate circumferential section of the control wheel 112 may be a maximum of 60mm, as has been shown in Fig. 5D and Fig. 5E.

[00105] Figs. 5F and 5G illustrate positions of a wheel assembly 104 in a third zone 400-3 in a first channel 304-1 and a second channel 304-2 respectively. In the third zone, representing a track transit section preceding a track split junction, the channels 304 provide additional guidance and constraint. The wheel set 110, being sufficiently narrow (e.g., 20mm wide) allows for selection between the left and right channels. The control wheel 112, being wider (e.g., 50mm wide), ensures stable guidance within the 80mm to 100mm wide channel. As shown in Fig. 5F and Fig. 5G, if a wheel of the wheel set is 20 mm wide, and the control wheels are 50 mm wide, then the channel 304 shall be wider than 50 mm in order to allow for the free movement of the control wheels 112 inside the channel 304. At the same time, it must be sufficiently narrow to limit the sway in body of the suspended vehicle resulting from swing in the wheel assembly 104 of the self-steering suspended vehicle inside this channel 304. For instance, if the control wheels are 50mm wide, the channel 304 should ideally be between 70mm and 100mm wide, as shown in Fig. 5F and Fig. 5G.

[00106] Figs. 5H-5K illustrate swings in the wheel assembly 104 in the third zone 400-3 in a first channel 304-1 (Figs. 5H-5I) and a second channel 304-2 (Figs. 5J-5K). These figures demonstrate how the channels constrain the swing of the wheel assembly 104 within safe limits. The control wheel 112 may engage with either the vertical guide wall 302 (shown in Fig. 5I and Fig. 5K) or the supplementary vertical guide rail 306 (shown in Fig. 5H and Fig. 5J), depending on the direction of the swing. The channel width of 80mm to 100mm allows for this controlled movement while ensuring the wheel set 110 remains properly aligned.

[00107] The configuration of the wheel assembly 104, including the narrow wheel set 110 (e.g., 20mm wide) and wider control wheel 112 (e.g., 50mm wide), in conjunction with the vertical guide wall 302, supplementary vertical guide rail 306, and channels 304 (80mm to 100mm wide), provides a comprehensive system for ensuring safe and stable operation of the suspended vehicle. The orthogonal mounting of the control wheel 112 relative to the wheel set 110 allows for effective interaction with the vertical guide surfaces, providing both guidance and a physical limit to lateral movement before the wheel set 110 contacts the vertical guide wall.

[00108] The use of channels 304 in the third zone 400-3 offers additional benefits. By constraining the wheel assembly 104 within a defined space of 80mm to 100mm, the system can ensure precise alignment and control as the vehicle approaches and traverses track split junctions. This precision is crucial for maintaining safe operations at higher speeds and allows for more efficient routing through complex track networks. Additionally, the swing capability demonstrated in Figs. 5D, 5E, 5H, and 5I showcases the system's resilience to external forces within the constraints of the channel 304. By allowing a controlled range of motion while providing definitive physical limits, the system can effectively manage the dynamic forces experienced during operation.

[00109] Although examples for the vehicle motion unit 100, elevated track 300, and the control unit 200 have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not limited to the specific features described.

Claims

I/We Claim:

1. A vehicle motion unit for a self-steering suspended vehicle suspended from and moveable along an elevated track, the vehicle motion unit comprising: a frame; a set of wheel assemblies provided on the frame, the set of wheel assemblies comprising a leading wheel assembly and a trailing wheel assembly, wherein the leading wheel assembly and the trailing wheel assembly are separated in a lateral direction, the leading wheel assembly movably mounted to the frame to be swivelable for steering operation, the leading wheel assembly comprising, a leading bracing structure; a leading wheel axle supported on the leading bracing structure; a leading wheel set mounted on each end of the leading wheel axle to be rotatable with respect to the leading bracing structure; and a first sensing unit positioned on the leading wheel assembly in proximity to the leading wheel set to determine a position of the leading wheel set relative to a reference element, and the trailing wheel assembly movably mounted to the frame to be swivelable for the steering operation, the trailing wheel assembly comprising, a trailing bracing structure; a trailing wheel axle supported on the trailing bracing structure; a trailing wheel set mounted on each end of the trailing wheel axle to be rotatable with respect to the trailing bracing structure; and a second sensing unit positioned on the trailing wheel assembly in proximity of the trailing wheel set to determine a position of the trailing wheel set relative to the reference element; and an actuator actuable to perform a corrective action, in response to at least one of the first sensing unit and the second sensing unit indicating a misalignment between the leading wheel set and the trailing wheel set.

2. The vehicle motion unit as claimed in claim 1 , wherein the first sensing unit comprises a first sensing device positioned on the leading bracing structure, wherein the first sensing unit is to determine, based on an input from the first sensing device, a first distance between the leading wheel set and the reference element being greater than a first threshold to indicate the misalignment between the leading wheel set and the trailing wheel set.

3. The vehicle motion unit as claimed in claim 1 , wherein the leading wheel assembly comprises a leading control wheel unit mounted on the leading bracing structure, wherein an axis of each wheel in the leading control wheel unit is orthogonal to the leading wheel axle.

4. The vehicle motion unit as claimed in claim 1 , wherein the second sensing unit comprises a second sensing device positioned on the trailing bracing structure, wherein the second sensing unit is to determine, based on an input from the second sensing device, a second distance between the trailing wheel set and the reference element being greater than a second threshold to indicate the misalignment between the leading wheel set and the trailing wheel set.

5. The vehicle motion unit as claimed in claim 1 , wherein the trailing wheel assembly comprises a trailing control wheel unit mounted on the trailing bracing structure, wherein an axis of each wheel in the trailing control wheel unit is orthogonal to the trailing wheel axle.

6. The vehicle motion unit as claimed in claim 1 , wherein the reference element is a vertical guide wall on the elevated track in a direction towards which the self-steering suspended vehicle has to steer at a track split junction, the track split junction being a position on the elevated track from where the track is divided into at least two track sections.

7. The vehicle motion unit as claimed in claim 1 , wherein the reference element is a supplementary vertical guide rail on the elevated track, the supplementary vertical guide rail being parallel and offset to a boundary of the elevated track and provided immediately preceding and contiguous to a track split junction, the track split junction being a position on the elevated track from where the track is divided into at least two track sections.

8. The vehicle motion unit as claimed in claim 1 , wherein to perform the corrective action, the actuator is to cause a braking action to constrain a movement of the self-steering suspended vehicle on the elevated track.

9. The vehicle motion unit as claimed in claim 1 , wherein to perform the corrective action, the actuator is to cause at least one of the first leading wheel assembly and the first trailing wheel assembly to swivel to correct the misalignment.

10. The vehicle motion unit as claimed in claim 1 , further comprising a loading mechanism coupled to at least one of the leading wheel axle and the trailing wheel axle to bias the at least one of the leading wheel axle and the trailing wheel axle towards a surface of the elevated track during a journey of the self-steering suspended vehicle.

11. A vehicle motion unit for a self-steering suspended vehicle suspended from and moveable along an elevated track, the vehicle motion unit comprising: a frame; a wheel assembly movably mounted to the frame to be swivelable for steering operation, the wheel assembly comprising, a bracing structure; a wheel axle supported on the bracing structure; a wheel set mounted on each end of the wheel axle to be rotatable with respect to the bracing structure; and a sensing unit positioned on the wheel assembly in proximity of the wheel set to determine a position of the wheel set relative to a reference element, and an actuator actuable to perform a corrective action, in response to the sensing unit indicating a misalignment in the wheel set.

12. The vehicle motion unit as claimed in claim 11 , wherein the wheel assembly comprises a control wheel unit mounted on the bracing structure, the control wheel unit comprising a first control wheel and a second control wheel, wherein the first control wheel and the second control wheel are mounted on the bracing structure to substantially span a diameter of a first wheel of the wheel set.

13. The vehicle motion unit as claimed in claim 12, wherein the sensing unit comprises a third sensing device positioned on the bracing structure in proximity to the first control wheel, and wherein the sensing unit is to determine, based on an input from the third sensing device, a third distance between the wheel set and the reference element being greater than a third threshold.

14. The vehicle motion unit as claimed in claim 12, wherein the sensing unit comprises a fourth sensing device positioned on the bracing structure in proximity to the second control wheel, wherein the sensing unit is to determine, based on an input from the fourth sensing device, a fourth distance between the wheel set and the reference element being greater than a fourth threshold.

15. The vehicle motion as claimed in claim 12, wherein an axis of first control wheel and an axis of the second control wheel is orthogonal to the wheel axle.

16. The vehicle motion unit as claimed in claim 11 , wherein the reference element is a vertical guide wall on the elevated track in a direction towards which the self-steering suspended vehicle has to steer at a track split junction, the track split junction being a position on the elevated track from where the track is divided into at least two track sections.

17. The vehicle motion unit as claimed in claim 11 , wherein the reference element is a supplementary vertical guide rail on the elevated track, the supplementary vertical guide rail being parallel and offset to a boundary of the elevated track and provided immediately preceding and contiguous to a track split junction, the track split junction being a position on the elevated track from where the track is divided into at least two track sections.

18. The vehicle motion unit as claimed in claim 11 , wherein to perform the corrective action, the actuator is to cause a braking action to constrain a movement of the self-steering suspended vehicle on the elevated track.

19. The vehicle motion unit as claimed in claim 11 , wherein to perform the corrective action, the actuator is to cause the wheel assembly to swivel to correct the misalignment.

20. An elevated track for hoisting a self-steering suspended vehicle moveable thereon, the elevated track comprising: a channel along each longitudinal edge of the elevated track to support wheels of the self-steering suspended vehicle, the channel having: a vertical guide wall provided to define a lateral boundary of the channel for the wheels of the self-steering suspended vehicle; and a supplementary vertical guide rail provided on the channel, parallel to and offset with respect to the vertical guide wall, wherein the wheels of the self-steering suspended vehicle are to be disposed on the channel between the vertical guide wall and the supplementary vertical guide rail; wherein the supplementary vertical guide rail is provided on the channel in a track transit section immediately preceding and contiguous to a track split junction, the tracking being divided into multiple track sections at the track split junction.

21 . The elevated track as claimed in claim 20, wherein the elevated track comprises a pair of rails having a slot therebetween to suspend the selfsteering vehicle therefrom.

22. The elevated track as claimed in claim 20, wherein the supplementary vertical guide rail is offset with respect to the vertical guide wall by a distance greater than a width of the wheels of the self-steering suspended vehicle.

23. The elevated track as claimed in claim 20, wherein a length of the channel is determined based on an average travelling speed of the selfsteering suspended vehicle on the elevated track.

24. A control unit for controlling a self-steering suspended vehicle operating on an elevated track, the self-steering suspended vehicle comprising a leading wheel axle, a leading wheel set mounted on each end of the leading wheel axle, a trailing wheel axle separated from the leading wheel axle in a lateral direction, and a trailing wheel set mounted on each end of the trailing wheel axle, wherein the control unit is to: receive a first signal from a first sensing unit indicative of a position of the leading wheel set relative to the track and a second signal from a second sensing unit indicative of a position of the trailing wheel set relative to the elevated track, the first signal and the second signal being temporally synchronized; ascertain, from the first signal and the second signal, an instantaneous misalignment between the leading wheel set and the trailing wheel set along the elevated track, the instantaneous misalignment is indicative of a condition preceding to an error situation associated with the self-steering suspended vehicle; identify a corrective action, in response to the instantaneous misalignment having been ascertained, the corrective action being an action to preemptively prevent the error situation; and transmit the corrective signal, generated based on the error situation, to an actuator of the self-steering suspended vehicle for performing the corrective action.

25. The control unit as claimed in claim 24, wherein the first sensing unit comprises a first sensing device positioned in proximity to the leading wheel set, wherein the control unit is to determine, based on an input from the first sensing device, a first distance between the leading wheel set and a reference element on the elevated track being greater than a first threshold to indicate the misalignment between the leading wheel set and the trailing wheel set.

26. The control unit as claimed in claim 24, wherein the second sensing unit comprises a second sensing device positioned in proximity to the trailing wheel set, wherein the control unit is to determine, based on an input from the second sensing device, a second distance between the trailing wheel set and a reference element on the elevated track being greater than a second threshold to indicate the misalignment between the leading wheel set and the trailing wheel set.

27. The control unit as claimed in claim 24, wherein the error situation associated with the self-steering suspended vehicle is a situation where the leading wheel set enters a channel at a track transit section immediately preceding and contiguous to a track split junction, the tracking being divided into multiple track sections at the track split junction, and the trailing wheel set fails to enter the channel, during operation of the self-steering suspended vehicle.

28. The control unit as claimed in claim 24, wherein to perform the corrective action, the control unit is to generate a signal to cause a braking action to constrain a movement of the self-steering suspended vehicle on the elevated track.

29. The control unit as claimed in claim 24, wherein to perform the corrective action, the control unit is to generate a signal to cause at least one of the leading wheel axle and the trailing wheel axle to swivel to correct the misalignment.