CN121127381A

CN121127381A - Disengagement and/or engagement of a controllable transmission system

Info

Publication number: CN121127381A
Application number: CN202580001301.2A
Authority: CN
Inventors: 史蒂文·M·托马斯
Original assignee: Means Industries Inc
Current assignee: Means Industries Inc
Priority date: 2024-04-11
Filing date: 2025-04-08
Publication date: 2025-12-12
Also published as: WO2025217144A1

Abstract

A system and method for controlling the engagement of a vehicle's drivetrain. The system is configured to perform the method, which includes one or more of the following: determining when the vehicle transitions to an off state; disengaging the vehicle's wheels from the vehicle's drivetrain by actuating a clutch on an axle connecting the wheels to the vehicle's drivetrain in response to the vehicle transitioning to the off state; determining when the vehicle transitions to an on state; engaging the vehicle's wheels with the vehicle's drivetrain by actuating a clutch in response to the vehicle transitioning to the on state; determining whether the vehicle is in a traction mode; and/or disengaging the vehicle's wheels from the vehicle's drivetrain by actuating a clutch in response to determining that the vehicle has transitioned to the off state and that the vehicle is in a traction mode.

Description

Disengagement and/or engagement of a controllable transmission system

Technical Field

The present disclosure relates generally to vehicle drive trains, and more particularly, to controlling engagement and/or disengagement of wheels with drive trains of large trucks and/or other vehicles.

Background

A wheeled vehicle includes wheels and one or more prime movers (like an internal combustion engine and/or an electric motor) to rotatably drive the wheels. Some such vehicles are capable of driving the wheels directly with an electric motor. Other such vehicles may also or alternatively include a driveline located between the prime mover and the wheels and including an axle (axle) for changing drive rotation from a longitudinal direction along the length of the vehicle to a transverse direction. The other such vehicles may also include a drive shaft coupled to the input side of the axle and a half shaft (axle shaft) extending laterally away from the axle and coupled to the wheels. Some vehicles may also include multiple sets of wheels and multiple axles, typically two rear axles and two sets of wheels driven via the axles. In any event, all such wheels include a hub that couples the wheel (e.g., a rim and a tire mounted on the rim) to a drivetrain half shaft or a motor shaft. Some hubs include a hub clutch configured to disconnect (and reconnect) the wheels from the prime mover, for example, to improve fuel economy when a vehicle having a plurality of driven rear axles is traveling at highway speeds, or to switch the vehicle from a four-wheel drive mode to a two-wheel drive mode.

Disclosure of Invention

In accordance with an embodiment, a system and method for controlling driveline engagement of a vehicle is disclosed. The system is configured to perform the method including one or more of determining when the vehicle transitions to an off state, disengaging a wheel of the vehicle from a driveline of the vehicle by actuating a clutch for coupling the wheel to an axle of the driveline of the vehicle in response to the vehicle transitioning to the off state, determining when the vehicle transitions to an on state, and engaging the wheel of the vehicle with the driveline of the vehicle by actuation of the clutch in response to the vehicle transitioning to the on state, determining whether the vehicle is in a traction mode, and/or disengaging the wheel of the vehicle from the driveline of the vehicle by actuation of the clutch in response to the vehicle transitioning to the off state and determining that the vehicle is in the traction mode.

Drawings

Fig. 1 is a perspective view of an illustrative embodiment of a truck according to the present disclosure, and including a vehicle system, particularly a driveline disengage system for controlling engagement of one or more wheel end hubs with one or more axles according to the present disclosure.

Fig. 2 is a perspective view of another truck according to the present disclosure and shows additional tractors according to the present disclosure, each of which may incorporate the automatic transmission system of fig. 1 according to the present disclosure.

FIG. 3 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein in accordance with a first embodiment of the vehicle system.

FIG. 4 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein, in accordance with a second embodiment of the vehicle system.

FIG. 5 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein, in accordance with a third embodiment of the vehicle system.

FIG. 6 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein, in accordance with a fourth embodiment of the vehicle system.

FIG. 7 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein, in accordance with a fifth embodiment of the vehicle system.

FIG. 8 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein, according to a sixth embodiment of the vehicle system.

FIG. 9 is a schematic block diagram of a vehicle system configured according to one or more methods disclosed herein, in accordance with a seventh embodiment of the vehicle system.

Fig. 10 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a first embodiment.

Fig. 11 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a second embodiment.

Fig. 12 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a third embodiment.

Fig. 13 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a fourth embodiment.

Fig. 14 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a fifth embodiment.

FIG. 15 is a schematic block diagram of a vehicle having a plurality of axles, each of the plurality of axles being configured to drive a wheel of the vehicle and further configured to control disengagement or engagement of one or more wheels on the plurality of axles of the vehicle.

FIG. 16 is a schematic block diagram of a vehicle having a plurality of axles, each of the plurality of axles being configured to drive a wheel of the vehicle and further configured to control disengagement or engagement of one or more central axles of the vehicle.

Fig. 17 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a sixth embodiment.

Fig. 18 is a flowchart showing a method of controlling driveline engagement of a vehicle according to a seventh embodiment.

Fig. 19 is a flowchart showing a method of controlling driveline engagement of a vehicle according to an eighth embodiment.

Detailed Description

Generally, systems and methods for controlling the disengagement of a driveline of a vehicle, and in particular disengaging wheels from a driveline of a vehicle, will be described using one or more examples of illustrative embodiments of a truck having a control subsystem or vehicle driveline control system, which may be more generally referred to as a vehicle system. According to an embodiment, an automatic transmission system disengagement system is provided that may be used to perform the methods described herein. According to an embodiment, an automatic driveline disconnect system includes a controller configured to send control signals to one or more Dynamically Controllable Clutches (DCCs) to control whether associated wheels are engaged to a driveline of a vehicle.

One or more example embodiments will be described with reference to use in a truck or tractor (e.g., a class 8 tractor). However, it will be appreciated that as the description proceeds, aspects of the invention are useful in many different applications and may be implemented in many other embodiments. In this regard, and as used herein and in the claims, it will be understood that the term "vehicle" refers not only to commercial truck applications, but also to passenger vehicle applications, agricultural vehicle applications, military vehicle applications, or any other vehicle applications, whether or not the vehicle includes a non-driven front axle and/or one or more driven rear axles. Similarly, the term axle includes a structure that rotatably supports a wheel on a vehicle, the structure including an axle housing that couples the axle to a structural member of the vehicle, a hub that is configured to be removably secured to the wheel, and a spindle that rotatably supports the hub relative to the axle housing.

A Dynamically Controllable Clutch (DCC) (i.e., a hub clutch) is used to disengage and engage a hub with an axle of a driveline of a vehicle. An illustrative DCC is shown and described in WO 2023/048826A1 and in its U.S. national stage patent US12,054,041, which patent US12,054,041 is incorporated herein by reference in its entirety.

According to an embodiment, such as in the case of the illustrative hub clutch discussed above, engagement and disengagement between the hub and the vehicle driveline is achieved through a hub clutch or DCC. According to an embodiment, a DCC includes a notch plate having a notch and a hub mount and a slot cavity plate having a corresponding slot cavity and plunger channel. Further, such an illustrative DCC includes a locking member in the slot cavity that engages the recess to provide an efficient wheel end system, axle and driveline configuration.

Referring now specifically to the drawings, FIG. 1 shows an illustrative embodiment of a vehicle (e.g., truck 10) that may be electric and that may include a chassis 12, a driveline disengage control subsystem 13, a cab or body 14 that may be carried by a front portion of the chassis 12, a non-driven front axle 16 coupled to a front portion of the chassis 12, and front wheels 18 carried by the front axle 16. The truck 10 further includes at least one driven rear axle, which may include a main rear axle 20 coupled to a rear portion of the chassis 12, a prime mover 22 drivingly coupled to the main rear axle 20, a hub 24 coupled to the main rear axle 20, and a main rear wheel 26 coupled to the hub 24. Similarly, the at least one rear axle 20 may further include a secondary rear axle 28 coupled to a rear portion of the chassis 12. The secondary rear axle 28 is coupled to the hub 30, and the secondary rear wheel 32 is coupled to the hub 30.

In this embodiment, the prime mover 22 is or includes an Internal Combustion Engine (ICE), such as a diesel engine commonly found in class 8 trucks. However, in other embodiments, for example, the prime mover 22 is or includes an electric motor, such as in the case of an Electric Vehicle (EV) or hybrid truck. In embodiments where prime mover 22 is or includes an ICE, for example, as described above, the introduction of a Dynamically Controllable Clutch (DCC) arranged as a hub clutch can decouple the individual wheels from the driveline of the vehicle. It has been found that such a feature enables automatic disengagement and engagement of the wheels by automatically controlling actuation of the DCC between the engaged and disengaged positions.

In addition, the truck 10 includes a processing subsystem 34 for controlling actuation of the hubs 24, 30. The processing subsystem 34 includes at least one processor 36 and a memory 37 storing computer instructions that, when executed by the at least one processor 36, cause the functions attributed to the processing subsystem 34 to be performed, such as one or more of the methods described herein. The communication or control connection is shown as a hard wire from the processing subsystem 34 (as indicated by the cubic housing) to each of the hub clutches. According to an embodiment, the processing subsystem 34 includes the various vehicle electronics of the vehicle (such as an infotainment unit for receiving user input), and/or non-vehicle components (such as a smart phone or other handheld mobile device for receiving user input and providing the user input to the vehicle controller of the processing subsystem 34).

According to various embodiments, the hub 24 for the primary rear axle 20 and/or the hub 30 for the secondary rear axle 28 are disengageable hubs in that the respective hub clutch is coupled between the respective axle 20, 28 and the respective hub 30. In the embodiment shown in fig. 1, hub 24 is a conventional or non-disengageable hub and hubs 30 are disengageable hubs because each hub 30 includes DCC 38. In other embodiments, hub 24 may be a disengageable hub each having DCC, and may be communicatively coupled and controlled by processing subsystem 34 (such as in the same or similar manner as disengageable hub 30).

In an embodiment, the axial length of one or more of the disengageable hubs is longer than the axial length of the non-disengageable hubs, but shorter than the axial overhang of the rim of the wheel, the disengageable hubs being used with the rim of the wheel such that those hubs fit axially within the rim overhang and thus do not protrude axially beyond the rim of the wheel.

In accordance with at least one embodiment, a power source (not shown) (which may include a battery, fuel cell, etc.), a power regulator, a power transformer, etc. is used to provide power to DCC 38.

The disengageable hubs 30 each include DCCs 38, which DCCs 38 enable decoupling of the auxiliary rear wheels 32 from the auxiliary rear axle 28 to allow freewheeling of the rear wheels 32. The truck 10 may include a drivetrain that is at least partially formed by one or both of the rear axles 20, 28 and one or both of the hubs 24, 30. In other embodiments, the main rear axle 20 may include a disengageable hub instead of the conventional hub 24.

The disengageable hub 30 operates based on or in response to control signals received from the processing subsystem 34. The disengageable hubs 30 are examples of dynamically controllable hubs, and the disengageable hubs 30 are each used to couple a wheel to an axle of a driveline of the truck 10. Control signals may be sent from the automated transmission disengagement control subsystem 13 to the control components of DCC 38 via wiring.

Similarly, referring to FIG. 2, the disengageable hub may be used with one or more vehicles, such as three trucks 10', 10", 10'" towed by a vehicle 10"" as shown in the embodiment illustrated in FIG. 2. Each of the trucks 10', 10", 10'" is similar to the truck 10 of fig. 1 and the truck 10"" may also be similar to the truck 10 or may be a conventional truck without DCC or a disengageable hub. The truck 10', 10", 10'" may have a plurality of rear axles including a primary rear axle and a secondary rear axle. The engine may provide power to drive both the primary rear axle and the secondary rear axle via the primary rear axle, or the engine may provide power to drive only the primary rear axle and another prime mover (e.g., an electric motor) may provide power to drive the secondary rear axle. The truck 10', 10", 10'" may include a powertrain at least partially composed of one or both of the rear axle and hubs 24, 30. Likewise, the truck 10', 10", 10'" may include a powertrain comprised of an internal combustion engine and/or an electric motor, one or more transmissions coupled to the engine, and a driveline coupled to the engine and/or the electric motor via the transmissions. As will become apparent from the following description, the disengageable hub 30 allows one or more additional trucks 10', 10", 10'" to be towed by the truck 10"" without having to manually remove or disengage the axle shafts from the drivetrain as is conventionally done. Furthermore, according to an embodiment, the disengageable hub 30 may be automatically operated to disengage the wheels 32 from the driveline of the vehicle. In embodiments, the disengageable hub 30 may also be used for other purposes, such as to allow the wheels 32 to be decoupled from the driveline at highway speeds for better fuel economy.

Referring to fig. 3-9, various embodiments of a vehicle system configured in accordance with one or more methods disclosed herein are shown, including a first embodiment of the vehicle system 100 (fig. 3), a second embodiment of the vehicle system 200 (fig. 4), a third embodiment of the vehicle system 300 (fig. 5), a fourth embodiment of the vehicle system 400 (fig. 6), a fifth embodiment of the vehicle system 500 (fig. 7), a sixth embodiment of the vehicle system 600 (fig. 8), and a seventh embodiment of the vehicle system 700 (fig. 9). According to an embodiment, any of the vehicle systems 100, 200, 300, 400, 500, 600, 700 may be used with any one or more of the trucks discussed herein, such as with any of the trucks 10, 10', 10", 10'". In the illustrated embodiment, and in particular in the embodiments of the figures 3-9, the following notation is used, with the dotted line indicating a hardwired control signal path or other communication channel, the dotted line indicating a wireless communication channel, the line with a double composite type (two parallel lines) indicating a power transmission path, the dotted line with a double coupling type indicating both a hardwired communication channel and a power transmission path, and the dotted line with a double coupling type indicating both a wireless communication channel and a power transmission path.

It will be appreciated that fig. 3-9 are schematic in nature and that the implementation of the communication connection and power transmission path may vary depending on different factors. In one embodiment, the communication connection is a wired connection, such as a hardwired Controller Area Network (CAN), a hardwired Local Area Network (LAN) connection (e.g., an Ethernet connection), or a hardwired local area Internet (LIN), and in other embodiments, wireless communication may be used, such as Wi-Fi ^TM, bluetooth ^TM, or other wireless technology. In one embodiment, the power transmission path is an electrical power transmission path through which electrical power is transmitted (such as through solid or stranded copper wire). In another embodiment, the power transmission path is a pneumatic power transmission path through which pneumatic power is transmitted (such as through a conduit carrying pressurized air). Also, in another embodiment, the power transmission path is a hydraulic power transmission path through which hydraulic power is transmitted (such as through a conduit carrying hydraulic fluid). While the specific embodiments discussed below teach or suggest the use of specific communication channel types (e.g., hardwired, wired) and power transmission types (e.g., electrical, pneumatic, hydraulic), those skilled in the art will appreciate that different communication channel types and techniques, as well as different power transmission types and techniques, may be used according to various embodiments.

Referring now specifically to fig. 3, a vehicle system 100 is shown in accordance with a first embodiment, the vehicle system 100 including a left disengageable hub 102 and a right disengageable hub 102, each of the left disengageable hub 102 and the right disengageable hub 102 being comprised of a DCC 104 and a linear actuator 106. The disengageable hubs 102 are each coupled to a wheel (not shown) and an axle 108. The vehicle system 100 also includes a processing subsystem 110, the processing subsystem 110 including a controller 112, the controller 112 being implementable using at least one processor and memory, such as those discussed above in connection with the processing subsystem 34. Further, the vehicle system 100 includes a battery 114, the battery 114 being configured to provide power to the controller and/or the disengageable hub 102, as shown in phantom. The vehicle system 100 may be configured to perform embodiments of the methods discussed herein, particularly by using the processing subsystem 110.

Referring now specifically to FIG. 4, a vehicle system 200 according to a second embodiment is shown, the vehicle system 200 including the same components 102-114 as the vehicle system 100 according to the first embodiment, but further including a user interface 116 for providing input to a processing subsystem 210. Processing subsystem 210 is similar to processing subsystem 110 except for its configuration as discussed herein. In the embodiment shown in fig. 4, the user interface 116 is depicted as a button 116. For example, the buttons 116 may be physical buttons or tactile switches for providing input to the controller 112, or may be graphical buttons on a touch screen or other Graphical User Interface (GUI). The vehicle system 200 may be configured to perform the methods discussed herein, particularly by using the processing subsystem 210. In embodiments, the button 116 is a button within the cab of a truck or vehicle, and in other embodiments, the button 116 is outside the cab, such as at or near an axle or a disengageable hub on the exterior of the vehicle.

Referring now specifically to FIG. 5, a vehicle system 300 according to a third embodiment is shown, the vehicle system 300 including the same components 102-116 as the vehicle system 200 according to the second embodiment, but also including a power system control module (PCM) 118 for providing input to the controller 112 and being considered part of a processing subsystem 310, the processing subsystem 310 being similar to the processing subsystem 210 except for its configuration discussed more below. In the illustrated embodiment of fig. 5, PCM 118 is depicted as being communicatively coupled to a controller, as indicated by the dashed line therebetween. PCM 118 is an Electronic Control Unit (ECU) that manages and regulates various aspects of the vehicle's powertrain. In an embodiment, PCM 118 serves as a central control unit for the engine, transmission, and other related components, and may be responsible for coordinating and optimizing operation of the powertrain components to ensure efficient performance, emissions control, and overall vehicle reliability. PCM 118 may receive inputs from various sensors throughout the vehicle, such as those measuring engine speed, throttle position, temperature, and exhaust composition. Based on the sensor inputs, PCM 118 makes real-time adjustments to control parameters such as fuel injection timing, spark timing, transmission shift points, and torque converter lock-up. PCM 118 also monitors and diagnoses any faults or malfunctions in the power system, and may activate warning indicators or initiate protective measures to prevent further damage in various other potential functions, as will be appreciated by those skilled in the art, according to an embodiment.

In accordance with at least one embodiment, PCM 118 is configured to obtain a signal or data indicating whether the vehicle has transitioned to an off state or an on state, and this signal or data is referred to as vehicle state transition data. In an embodiment, the vehicle state transition data is or is based on an ignition signal indicative of an ignition state of the vehicle. An ignition signal may be received at PCM 118 from an ignition unit (not shown). For example, when the key is turned to an "on" position, or an engine start button is pressed (assuming it is in an activatable state), a signal is sent to the electrical system of the vehicle and various components including, for example, PCM 118 are activated. PCM 118 then initiates a start-up sequence, which may include powering up the engine, fuel system, and other related systems. Conversely, when the key is turned to the "off" position or the engine start button is released (or depressed assuming it is in an actuatable/receptive state), PCM 118 receives a signal to shut down the engine and other systems. This may involve shutting off the fuel supply, disabling the ignition, and powering down various electrical components. In addition, modern class 8 trucks may also have sensors or switches to detect the position of keys or buttons, thereby ensuring that the engine cannot be started or run without proper authorization. In general, the determination of whether a class 8 truck is on or off is based primarily on the status of the ignition system and the signals received by the powertrain control module. The vehicle system 300 may be configured to perform embodiments of the methods discussed herein, particularly through the use of the processing subsystem 310.

Referring now in particular to fig. 6, a vehicle system 400 according to a fourth embodiment is shown, the vehicle system 400 comprising the same components 102-114, 118 as the vehicle system 300 according to the third embodiment, but not the user interface 116. The vehicle system 400 may be configured to perform embodiments of the methods discussed herein, particularly by using the processing subsystem 410. In the embodiment illustrated in fig. 6, PCM 118 is configured to obtain a signal or data indicating whether the vehicle has transitioned to an off state or an on state, and this signal or data is referred to as vehicle state transition data, which may be or may be based on an ignition signal indicating an ignition state of the vehicle, as discussed above. In other embodiments, other Electronic Control Units (ECUs) of the vehicle, such as an Engine Control Module (ECM), may be used to provide vehicle state transition signals or data. PCM 118 provides vehicle state transition data to controller 112, which controller 112 then automatically disengages one or more hub clutches by actuating its linear actuator 106. In an embodiment, the vehicle system 400 is an automatic hub disengagement system, and in an embodiment is also an automatic traction mode preparation system by which the vehicle system 400 automatically places the vehicle in a traction preparation state. As used herein, the term "traction ready state" when used in connection with a vehicle refers to a state of the vehicle in which the driveline of the vehicle is ready to be towed by a tractor or other towing vehicle, and such preparation includes disengagement of two or more wheels of the vehicle from the driveline of the vehicle.

Referring now in particular to fig. 7, a vehicle system 500 according to a fifth embodiment is shown, the vehicle system 500 comprising the same components 102-112 as the vehicle system 100 according to the first embodiment, but also comprising a jumper box 120 and not necessarily a battery, such as battery 114. However, in embodiments, the battery 114 is included in the vehicle system 500 and is used to power the controller 112, and in other embodiments, the controller 112 is powered by the jumper box 120, as will be discussed more below. The vehicle system 500 may be configured to perform embodiments of the methods discussed herein, particularly by using the processing subsystem 510. In the embodiment shown in fig. 7, power is provided by the jumper box 120 to each of the left and right disengageable hubs 102, 102 and routed through a processing subsystem 510, where the controller 112 regulates or otherwise controls the power delivery from the jumper box 120 to the disengageable hub 102. As used herein, the term "jumper box" refers to a device or system that delivers, transmits, or otherwise outputs power that may be used to actuate a physical component, such as for actuating the linear actuator 106.

In one embodiment, the power output by the jumper box 120 is electrical power. In such an embodiment, power is delivered from the jumper box 120 via a hardwired connection (such as a connection with a copper core). In another embodiment, the power output by the jumper box 120 is pneumatic power, and in such embodiments, the tubing, connectors for tubing, valves, and other suitable components are used to provide an electronically controllable fluid path that extends from the jumper box 120 through the components and ultimately to the disengageable hub 102 where the controllable power is ultimately delivered, such as for controlling the linear actuator 106. In another embodiment, the power output by the jumper box 120 is hydraulic power, and in such an embodiment, the tubing, connectors for the tubing, valves, and other suitable components are used to provide an electronically controllable fluid path through which hydraulic fluid flows. The fluid or hydraulic path extends from the jumper box 120 through the components and ultimately to the disengageable hub 102, where the controllable power is ultimately delivered, such as for controlling the linear actuator 106.

Referring now in particular to fig. 8, a vehicle system 600 according to a sixth embodiment is shown, which vehicle system 600 comprises the same components 102-112, 120 as the vehicle system 500 according to the fifth embodiment, but also comprises a user interface 116, which user interface 116 is shown as a button in the present embodiment. The vehicle system 600 may be configured to perform embodiments of the methods discussed herein, particularly through the use of the processing subsystem 610.

Referring now in particular to fig. 9, a vehicle system 700 according to a seventh embodiment is shown, the vehicle system 700 comprising the same components 102-112, 120 as the vehicle system 500 according to the fifth embodiment, but further instead of a single jumper box 120, the vehicle system 700 comprises two jumper boxes 120', each of the two jumper boxes 120' being shown as being in wireless connection or communication with the controller 112. The jumper box 120' provides power directly to one of the disengageable hubs 102, particularly the left jumper box 120' to the left disengageable hub 102 and the right jumper box 120' to the right disengageable hub 102. As used herein, the term "directly providing" when used in connection with power delivered by a jumper box to a power end point, which in this embodiment is a disengageable hub 102, refers to power delivered via a power transmission path that is not interruptible by another control device or system (e.g., controller 112) such that the power output from the jumper box is directly proportional to and generally the same as the power delivered to the power end point. Thus, the power provided by the jumper box 120' is accomplished directly and without interruption by the controller 112. Thus, control of the power delivery of the disengageable hub 102 is determined by the jumper box 120', which jumper box 120' may effectuate the determination based on information received from the controller 112 via the wireless communication path (or, in fact, based on a determination of computer instructions, for example). In other embodiments, a wired communication path may be used to communicate information between controller 112 and jumper box 120'. The vehicle system 700 may be configured to perform embodiments of the methods discussed herein, particularly through the use of the processing subsystem 710.

Referring to fig. 10-14, various processes or methods are shown that may be performed by one or more of the previously described vehicle systems 100, 200, 300, 400, 500, 600, 700, as will be appreciated by those skilled in the art in light of the teachings herein.

The methods 1000, 1100, 1200, 1300, 1400 refer to the "on state" and "off state" of the vehicle. As used herein, the term "off state" when used in connection with a vehicle (such as a class 8 truck) refers to a state of the vehicle in which the primary propulsion system (such as an ignition system) is deactivated, which results in a shutdown of the engine (or other primary propulsion system) and often accompanied by shutdown of other related vehicle systems when a transition from an on state to an off state occurs. On the other hand, as used herein, the term "on state" when used in connection with a vehicle (such as a class 8 truck) refers to a vehicle state in which a primary propulsion system (such as an ignition system) is activated, which results in the start of a previously shut-down engine (or other primary propulsion system) when a transition from an off state to an on state occurs, and typically accompanied by the start of other related vehicle systems.

In the context of class 8 trucks, air brakes are braking systems that utilize compressed air. The vehicle may include an air brake that is operated between an applied braking state and a released braking state by applying air pressure, and wherein the air brake is biased to the applied braking state when positive air pressure is not applied. The air brake may be used to provide braking force to the brakes of two or more wheels of the vehicle, and wherein the two or more wheels of the vehicle are in a freewheel state due to positive air pressure being applied to and disengaging the two or more wheels of the vehicle. During the active state, when the air brake is pressurized and active, there is a bias towards the brake being engaged or in a stationary state. This biasing may be achieved by using a spring within the brake chamber. In the active state, the compressed air holds the brake chamber in a released or rest position, allowing the vehicle to move freely. When the driver applies the brake pedal, air pressure is released and the springs within the brake chamber push the brake shoes or pads against the brake drum or rotor, creating the necessary friction for braking. Conversely, during the inactive state, when the brake pedal is not subjected to a force applied by the driver, the air brake is pressurized and forced toward the disengaged or released brake. In the absence of air pressure, the springs within the brake chambers expand, pushing the brake shoes or pads toward the brake drum or rotor, and when air pressure is applied, the brake shoes or pads are forced away from the brake drum or rotor, and this disengages the brakes and allows the wheels to freely rotate. This biasing of the brake towards being engaged during the active state and disengaged during the inactive state is designed to ensure safety and practicality in real life situations. When the vehicle is in motion, the brake is in a stationary state and ready to be engaged when needed, and when the vehicle is parked or stationary, the brake is disengaged to prevent, for example, unnecessary wear and heat generation.

According to an embodiment, and as will become apparent from the following discussion of a method for controlling wheel-drive-train engagement of a vehicle, there is provided a vehicle system configured to control wheel-drive-train engagement, the vehicle system comprising:

TABLE 1

In the above table, an embodiment of a configuration for a vehicle system is presented. According to this configuration, when the key is off and the engine is off, the air brake is on (applied), releasing the air pressure, as discussed above. When the key is placed in the assist mode ("Acc") but the engine or prime mover is still off, the air brake remains engaged, but can be operated by the user. The DCC or wheel end hub clutch remains disengaged or free in these first two initial states, at least in accordance with this embodiment. Then, when the key is turned to the start position and the engine is started, the air brake is pressurized and disengaged or closed, while the DCC or wheel end hub clutch is engaged to be coupled to the driveline of the vehicle and drivable by the engine. When the vehicle remains on but is placed in neutral or assist mode, the DCC or wheel end hub clutch remains engaged even though the air brake may be on or off. Then, when the vehicle's engine is off, the DCC or wheel end hub clutch is disengaged so that the vehicle is traction-ready, as discussed in more detail below. This enables the tractor driver or other operator to simply hang onto the vehicle and disengage the parking brake, and for trucks with air brakes, the parking brake is released by supplying air to the system as described above.

Referring specifically to fig. 10, a process or method 1000 for controlling wheel-drive system engagement of a vehicle is illustrated. The method 1000 is performed by the vehicle system 100, 400, 500, 700 as an automatic wheel-drive-train disengagement system, and in particular wherein the control of the engagement of the individual wheels with the drive-train of the vehicle is automatically controllable, thereby also constituting an automatic hub disengagement system. Further, according to an embodiment, the vehicle system 100, 400, 500, 700 automatically places the vehicle in a traction ready state (whereby the driveline of the vehicle is ready to be towed by a tractor) in response to the vehicle transitioning to a closed state by the method 1000, as discussed below. By configuring the system to take action to place the vehicle in traction ready state without user input, automating the system is achieved.

The method 1000 begins at step 1010 where it is determined that the vehicle transitions to a closed state. In an embodiment, this includes receiving an indication from an Electronic Control Unit (ECU) of the vehicle, such as PCM 118 or an ignition unit or other ECU capable of accessing the ignition state or state of the main propulsion system. The method 1000 continues to step 1020.

In step 1020, one or more wheels of a vehicle (such as a pair of left-right wheels) are disengaged from a driveline of the vehicle by actuation of one or more DCCs for coupling the two or more wheels to an axle of the driveline of the vehicle. As used herein, a "pair of left-right wheels" when used in connection with a vehicle having a longitudinal axis extending directly through the center and in the main direction of travel refers to the left wheel of the vehicle and the right wheel of the vehicle that spans the longitudinal axis from the left wheel of the vehicle. In fig. 1, the wheel 30 is a pair of left-right wheels. Also, in fig. 1, the wheel 30 is a pair of left-right wheels.

In an embodiment, each disengageable hub includes a microcontroller that controls the linear actuator 106 or other mechanism that controls DCC engagement. In such an embodiment, disengaging the wheels of the vehicle from the driveline of the vehicle is accomplished by sending a control signal to the DCC of the disengageable hub, which then actuates the linear actuator 106, thereby disengaging the DCC and decoupling the wheels from the driveline of the vehicle.

However, in other embodiments, the disengageable hub may not include a separate controller, but rather may be controlled, for example, by the controller 112 or other ECU of the processing subsystem, or even by the application or modification of the force applied by the jumper boxes 120, 120'. For example, referring to the vehicle system 700 of fig. 9, in one embodiment, hydraulic pressure is applied through the jumper box 120' to actuate the linear actuator 106 to disengage the wheels from the driveline of the vehicle. The method 1000 ends.

Referring specifically to FIG. 11, a process or method 1100 for controlling wheel-drive system engagement of a vehicle is illustrated. The method 1100 is performed by the vehicle system 100, 400, 500, 700 as an automatic wheel-drive-train disengagement system, and in particular, wherein the control of the engagement of the individual wheels with the drive-train of the vehicle is automatically controllable, thereby also constituting an automatic hub disengagement system. In other embodiments, the method 1100 is performed by the vehicle system 200, 300, 600, and in such embodiments, the method 1100 is configured to place the vehicle in a driving readiness state when the vehicle transitions to an on state. However, in some embodiments, separate inputs are provided to the vehicle systems 200, 300, 600 in order to place the vehicle in a driving readiness state, such as a traction readiness mode exit input provided by the user via the user interface 116. Further, according to an embodiment, the vehicle system 100, 400, 500, 700 automatically places the vehicle in a driving ready state (whereby the driveline of the vehicle is ready to be driven by the vehicle rather than the tractor) in response to the vehicle transitioning to an on state by the method 1100, as discussed below.

Method 1100 begins at step 1110, where it is determined when a vehicle transitions to an on state. This step is similar to step 1010 (fig. 10) of method 1000, except that instead of detecting or otherwise determining whether the vehicle transitions to the off state, it detects or otherwise determines when the vehicle transitions to the on state. In one embodiment, PCM 118 or an ignition unit or other ECU having access to the ignition status or the status of the main propulsion system informs controller 112 of this information, allowing it to determine that the vehicle has transitioned to an on state. The method 1100 continues to step 1120.

In step 1120, one or more wheels of the vehicle, such as a pair of left-right wheels, are engaged to a driveline of the vehicle by actuating one or more Dynamically Controllable Clutches (DCCs) for coupling the two or more wheels to axles of the driveline of the vehicle. In an embodiment, a pair of left-right wheels (such as hub 24 or wheels 30) are engaged to the driveline of the vehicle.

As described above, in embodiments in which each disengageable hub includes a microcontroller that controls the linear actuator 106 or other mechanism that controls engagement of the DCC, engaging the wheels of the vehicle from the driveline of the vehicle is accomplished by sending control signals to the DCC of the disengageable hub, which then actuates the linear actuator 106 to engage the DCC and decouple the wheels from the driveline of the vehicle.

However, as also discussed above, in other embodiments, the disengageable hub may not include a separate controller, and instead may be a controller controlled, for example, by the controller 112 or other ECU of the processing subsystem 110, or even by the application or change of force applied by the jumper boxes 120, 120'. For example, referring to the vehicle system 700 of fig. 9, in one embodiment, hydraulic pressure is applied by the jumper box 120' to actuate the linear actuator 106 to engage wheels from the driveline of the vehicle. The method 1100 ends.

According to an embodiment, method 1100 includes receiving a user input indicating that the vehicle is placed in a drive-ready mode, and responsive to receiving this input and/or determining that the vehicle transitions to an on state, executing step 1120.

Referring to fig. 12, a process or method 1200 for controlling wheel-drive system engagement of a vehicle is illustrated. The method 1100 is performed by the vehicle system 100, 400, 500, 700 as an automatic wheel-drive-train disengagement system, and in particular, wherein the control of the engagement of the individual wheels with the drive-train of the vehicle is automatically controllable, thereby also constituting an automatic hub disengagement system. Further, according to an embodiment, the vehicle system 100, 400, 500, 700 automatically places the vehicle in a traction ready state in response to the vehicle transitioning to an off state by the method 1000 and automatically places the vehicle in a driving ready state in response to the vehicle transitioning to an on state by the method 1100.

Method 1200 begins at step 1210, wherein the steps of method 1000 are performed as process 1000 to disengage a wheel from a driveline of a vehicle in response to determining to transition to a closed state. Method 1200 then continues to step 1220.

In step 1220, the steps of method 1100 are performed as process 1100 to engage wheels to a driveline of a vehicle in response to determining to transition to an on state. The method 1200 may be continuously performed as the vehicle cycles between the on and off states, as indicated by the long dashed and dotted lines in fig. 12.

Referring to fig. 13, a process or method 1300 for controlling wheel-drive system engagement of a vehicle is illustrated. The method 1300 is performed by the vehicle system 200, 300, 600 being a wheel-driveline disengage system, wherein control of engagement of each wheel with the driveline of the vehicle may be controlled in response to user input, such as a traction mode input that provides an indication, requests, or places the vehicle in a traction ready mode.

The method 1300 begins at step 1310, where it is determined that the vehicle transitions to a closed state. This step is similar to step 1010 and the discussion is incorporated herein and attributed to step 1310. The method 1300 continues to step 1320.

In step 1320, it is determined that the vehicle is in traction mode. As used herein, when used in connection with a vehicle, a "traction mode" refers to a mode of the vehicle in which the vehicle is in or is to be placed in a traction ready state, such as when a user provides user input indicating that the vehicle enters the traction ready mode. Further, as used herein, such input for placing the vehicle in a traction ready state is referred to as traction mode input. For example, the vehicle system 200, 300, 600 receives traction mode input from a user in the form of the user pressing the button 116. In some embodiments, the user interface 116 takes the form of a Graphical User Interface (GUI) presented on an electronic display screen, such as an infotainment display screen of a vehicle or a touch screen of a smart phone or other handheld device. In another embodiment, tactile buttons are used as buttons 116 and for receiving traction mode input from a user. According to an embodiment, the traction mode input is received before the vehicle transitions to the off state, such as for a predetermined period of time before the vehicle transitions to the off state. In another embodiment, the traction mode input is received after the vehicle transitions to the off state. When the vehicle has transitioned to the off state and the traction mode input has been received, method 1300 continues to step 1330.

In step 1330, one or more wheels of the vehicle, such as a pair of left-right wheels, are disengaged from the driveline of the vehicle by actuating one or more Dynamically Controllable Clutches (DCCs) for coupling the two or more wheels to axles of the driveline of the vehicle. This step is similar to step 1020 and the discussion is incorporated herein and attributed to step 1330. The method 1300 ends.

Referring to fig. 14, a process or method 1400 for controlling wheel-drive system engagement of a vehicle is illustrated. The method 1400 is performed by the vehicle system 200, 300, 600 being a wheel-drive-train engagement system, wherein control of engagement of the respective wheels with the driveline of the vehicle may be controlled in response to a user input, such as a traction mode input that provides an indication, requests, or places the vehicle in a traction ready mode.

Method 1400 begins at step 1410, wherein steps of method 1300 are performed as process 1300 to disengage a wheel from a driveline of a vehicle in response to determining to transition to a closed state. Method 1400 then continues with step 1420.

In step 1420, the steps of method 1100 are performed as process 1100 to engage wheels to a driveline of a vehicle in response to determining to transition to an on state. The method 1400 may be continuously performed as the vehicle cycles between the on and off states, as indicated by the long dashed and dotted lines in fig. 14.

Referring to fig. 15, a vehicle system 1500 is shown in which a disengageable hub for wheels on a plurality of different axles, including a first axle 1508 and a second axle 1510, is controlled, in accordance with an embodiment. The vehicle system 1500 includes a first pair of disengageable hubs 1502 (where each disengageable hub 1503 includes a DCC 1504 and a linear actuator 1506) and a second pair of disengageable hubs 1512 (where each disengageable hub 1513 includes a DCC 1514 and a linear actuator 1516). Each of the disengageable hubs 1502, 1512 has the same configuration and is each similar to the disengageable hub 102 discussed above. The disengageable hubs 1502, 1512 are coupled to wheels (not shown) and axles 1508, 1510, respectively. The vehicle system 1500 also includes a processing subsystem 1520, the processing subsystem 1520 including a controller 1518, the controller 1518 being implemented using at least one processor and memory, such as those discussed above in connection with the processing subsystems 34, 110. The components 1502-1508 form a first disengageable axle subsystem 1501, and the components 1510-1516 form a second disengageable axle subsystem 1509. Further, the vehicle system 1500 may include a battery for providing power to the controller and/or to the disengageable hubs 1502, 1512, as indicated by the dashed lines.

In the illustrated embodiment, the first disengageable axle subsystem 1501 is an automatic or controller-based disengageable hub axle system, as discussed above, and the second disengageable axle subsystem 1509 is also an automatic or controller-based disengageable hub axle system. In another embodiment, the first disengageable axle subsystem 1501 is an automatic or controller-based disengageable hub axle system, as discussed above, and the second disengageable axle subsystem 1509 is a manually disengageable axle system, as the disengageable hub is manually disengageable, such as by manual actuation and/or other manipulation of the disengageable hub by an operator. The vehicle system 1500 may be configured to perform embodiments of the methods discussed herein, particularly through the use of a processing subsystem 1520. Further, the vehicle system 1500 may be adapted or configured in accordance with any one or more of the embodiments discussed above (including those with respect to the vehicle systems 100, 200, 300, 400, 500, 600, 700). Furthermore, according to an embodiment, the vehicle system 1500 includes one or more additional disengageable axle subsystems, each of which is for an additional axle of the vehicle. Also, according to various embodiments, the vehicle system 1500 is configured to perform one or more of the methods discussed herein (such as, for example, one or more of the methods 1000, 1100, 1200, 1300, 1400).

Referring to fig. 16, a vehicle system 1600 is shown in which disengageable hubs for wheels on a plurality of different axles (including a first axle 1508 and a second axle 1510) are controlled, however, the vehicle system 1600 also includes an automatic or controller-based central axle disconnect system 1601 having a central axle disconnect subsystem 1602, and this central axle disconnect subsystem 1602 has a DCC 1604 disposed between a first axle differential 1606 and a first central axle 1608 that is connected to a second axle differential 1610 for the second axle 1510. Drive unit 1612 is provided for transmitting torque to first axle differential 1606 via drive shaft 1614, whereby the torque is then transmitted to first axle 1508 and DCC 1604. When the DCC is in the engaged position, the first central axle 1608 is engaged with the first axle differential 1606 and drive axle 1614 to receive torque from the drive unit 1612, thereby causing the second axle 1510 to rotate. The drive unit 1612 may be an internal combustion engine, such as a diesel engine, an electric propulsion system, a hybrid propulsion system, or other suitable main propulsion system.

In an embodiment, the automatic central axle disconnect system 1601 uses an electronic controller (such as controller 1518) to control engagement and disengagement of DCC 1604. According to an embodiment, control of DCC 1604 may be achieved by various means, such as any of those discussed above with respect to vehicle systems 100, 200, 300, 400, 500, 600, 700. In one embodiment, controller 1518 is used to control DCC 1604 and wheel end DCCs, such as DCCs 1504, 1514. In another embodiment, the controller 1518 for the wheel end DCC is separate from the controller for controlling the central axle DCC 1604. In some embodiments (such as those employing separate controllers for different DCCs), the separate controllers may communicate with each other in a point-to-point manner or with a master controller or central controller that may provide control, status, or other information to the individual DCCs. Thus, the vehicle system 1600 may be adapted or configured in accordance with any one or more of the embodiments discussed above (including those embodiments with respect to the vehicle systems 100, 200, 300, 400, 500, 600, 700, 1500). Further, according to an embodiment, the vehicle system 1600 includes one or more additional central axle disconnect subsystems and/or one or more disengageable axle subsystems (each for additional axles of the vehicle). For example, a third axle (not shown) parallel to the first axle 1508 and the second axle 1510 is used to transfer torque to a third pair of wheel end hubs, and is coupled to the powertrain via a third axle differential (not shown), which in turn is coupled to the second axle differential 1610 via a second center axle and a second center axle DCC (not shown). Thus, such a second central axle DCC is located between second axle differential 1610 and the second central axle. In such embodiments, the first central axle DCC may be controlled separately from the second axle DCC (and/or the third, fourth central axles DCC, etc.). Also, according to various embodiments, the vehicle system 1600 is configured to perform one or more methods discussed herein (such as, for example, one or more of methods 1000, 1100, 1200, 1300, 1400 and methods 1700, 1800, 1900), which will be discussed below with reference to fig. 17, 18, 19, respectively.

Referring to fig. 17, a process or method 1700 for controlling axle-to-driveline engagement of a vehicle is illustrated. Method 1700 is performed by a vehicle system 1600, and in particular an automatic center axle disconnect system 1601, wherein control of engagement of a center axle to a driveline of a vehicle is electronically controllable, such as in response to a vehicle condition and/or in response to a user input. According to an embodiment, the method 1700 is useful for dynamically controlling engagement of one or more central axles from a powertrain of a vehicle, such that the method 1700 may be used to improve fuel efficiency and range of the vehicle. The method 1700 assumes that the central axle is disengaged from the driveline of the vehicle prior to step 1710.

The method 1700 begins with step 1710, wherein it is determined whether to engage a central axle of the vehicle based on vehicle information and/or user input. In one embodiment, the central axle control signal is a signal that is automatically generated based on one or more predetermined criteria (such as one or more predetermined vehicle conditions). For example, information from a Powertrain Control Module (PCM), an ignition control unit, and/or an Engine Control Module (ECM) may be used to determine whether to engage the central axle, and the details of such control may depend on the desired operation of the vehicle, such as, for example, desired fuel efficiency. Other information, such as on-board vehicle sensors, may provide information for determining whether to engage the central axle, such as, for example, whether the vehicle is on a slope exceeding a predetermined amount. In an embodiment, control of the central axle DCC may depend at least in part on user input received from a user, such as the user input discussed above. When it is determined to engage the central axle of the vehicle, then the method 1700 proceeds to step 1720.

In step 1720, the central axle of the vehicle is engaged by sending a control signal to control the DCC. The control signal may be an electronic or electrical signal indicative of engaging the DCC (such as a signal sent from the controller 1518 to the DCC 1604) that may be controlled between its engaged and disengaged positions via an electronically controllable linear actuator. A solenoid or other mechanism for performing mechanical engagement of the race or other component to place DCC 1604 in its engaged position may be used. The method 1700 then ends.

Referring to FIG. 18, a process or method 1800 for controlling axle-to-driveline engagement of a vehicle is illustrated. The method 1800 is performed by the vehicle system 1600, and in particular the automatic center axle disconnect system 1601, where control of engagement of the center axle with the driveline of the vehicle is electronically controllable, such as in response to a vehicle condition and/or in response to a user input. According to an embodiment, method 1800 is useful for dynamically controlling engagement of one or more central axles from a driveline of a vehicle, such that method 1800 may be used to improve fuel efficiency and range of the vehicle. The method 1800 assumes that the central axle is engaged to the driveline of the vehicle prior to step 1810.

The method 1800 begins at step 1810, where it is determined whether to disengage the central axle of the vehicle based on vehicle information and/or user input. In one embodiment, the central axle control signal is a signal that is automatically generated based on one or more predetermined criteria, such as one or more predetermined vehicle states (such as those discussed in connection with step 1710), but that is configured to determine when to disengage the central axle rather than engaging the central axle. In an embodiment, control of the central axle DCC may depend at least in part on user input received from a user, such as the user input discussed above. When it is determined to disengage the central axle of the vehicle, then method 1800 proceeds to step 1820.

In step 1820, the central axle of the vehicle is disengaged by sending a control signal to control the DCC. The control signal may be an electronic or electrical signal indicating the disengaged DCC, such as a signal sent from the controller 1518 to the DCC 1604. As discussed above in connection with step 1720, a solenoid or other mechanism for performing mechanical engagement of a race or other component to place DCC 1604 in its engaged position may be used. The method 1800 then ends.

Referring to fig. 19, a process or method 1900 for controlling wheel-drive system engagement of a vehicle is shown. Method 1900 is performed by a vehicle system 1600 that is a wheel-driveline engagement system, wherein control of engagement of each wheel with the driveline of the vehicle is controllable in response to user input, such as a user providing an indication, requesting, or placing the vehicle in a traction mode input in a traction ready mode.

Method 1900 begins with step 1910 where the steps of method 1700 are performed as process 1700 to engage a center axle to a driveline of a vehicle in response to determining to transition to an engaged state. Method 1900 then proceeds to step 1920.

In step 1920, the steps of method 1800 are performed as process 1800 to disengage the center axle from the driveline of the vehicle in response to determining to transition to the disengaged state. Method 1900 may be performed continuously as the vehicle cycles between an on state and an off state, as indicated by the long dashed and dotted lines in fig. 19. In embodiments where the vehicle system includes a plurality of central axle DCCs, methods 1700, 1800, 1900 may be performed for controlling each of the plurality of central axle DCCs.

As used herein, the terms "for example," "e.g.," e.g., (for instance), "as used herein, when used with a list of one or more elements, are to be construed as open ended, meaning that the list does not exclude additional elements. Moreover, as used herein, the term "may" is merely indicative of convenience of the alternatives such as the disclosed embodiments, elements, features, etc., and should not be interpreted as making any disclosure herein ambiguous. Moreover, directional words such as front, rear, top, bottom, upper, lower, radial, circumferential, axial, lateral, longitudinal, vertical, horizontal, transverse, and the like are used by way of example and not limitation. The term "and/OR" should be interpreted as an inclusive OR. Thus, for example, the phrase "A, B and/or C" should be construed to cover all of the following terms "A", "B", "C", "A and B", "A and C", "B and C", and "A, B, and C".

Finally, various terms are presently used in connection with a number of explicitly described embodiments and modifications of those embodiments to disclose the subject matter of the present application. Unless used in a context where a different interpretation is required, all terms used herein are intended to be descriptive only and not necessarily limiting and are illustrated and interpreted in accordance with their ordinary and customary meaning in the art. And each explicit illustrative embodiment and modification is incorporated herein by reference in its entirety into one or more other explicit illustrative embodiments and modifications for convenience. Thus, many other embodiments, modifications and equivalents thereof now exist or remain to be discovered, and thus, it is neither intended nor possible to describe all such subject matter at present, which would be readily suggested to one of ordinary skill in the art in light of this disclosure. On the contrary, the present disclosure is intended to cover all embodiments and modifications of the subject matter of the present application, and equivalents thereof, which fall within the broad scope of the appended claims.

Claims

1. A method for controlling the engagement of a vehicle's transmission system, comprising:

Determine when the vehicle transitions to at least one of the off or on states; and

At least one of the following:

In response to the vehicle switching to the closed state, one or more clutches on the axles of the vehicle that connect two or more wheels to the vehicle's powertrain are actuated to disengage the two or more wheels from the vehicle's powertrain.

In response to the vehicle switching to the open state, the two or more wheels of the vehicle are engaged with the powertrain by actuating one or more clutches on the axles of the vehicle's powertrain.

2. The method of claim 1, wherein disengaging the two or more wheels of the vehicle results in the vehicle being in a traction-ready state, in which the powertrain of the vehicle is prepared to be towed by a tractor, and wherein, when the vehicle is in the traction-ready state, an air compressor carried by the tractor is used to provide positive air pressure to the air brakes of the two or more wheels, thereby placing the two or more wheels of the vehicle in a freewheel state so that the vehicle can be towed.

3. A method for controlling the disconnection of a vehicle's transmission system, comprising:

Determine when the vehicle will switch to the off state;

Determine whether the vehicle is in traction mode; and

In response to determining that the vehicle has switched to the off state and that the vehicle is in the traction mode, one or more clutches for connecting two or more wheels to the axles of the vehicle's powertrain are actuated to disengage the two or more wheels from the vehicle's powertrain.

4. The method of claim 3, further comprising receiving user input from an operator of the vehicle, wherein the user input is used to determine whether the vehicle is in the traction mode.

5. The method of claim 4, wherein the user input is a traction mode input that places the vehicle in a traction preparation state, and wherein the traction preparation state is a state of the vehicle in which the vehicle's powertrain is ready to be towed by a tractor, the traction preparation state including the disengagement of the two or more wheels of the vehicle from the vehicle's powertrain.

6. The method of claim 3, further comprising receiving user input from an operator of the vehicle, wherein the user input is for placing the vehicle in a driving-ready mode, and wherein the driving-ready mode is a mode in which the two or more wheels of the vehicle are connected to the axles of the powertrain.

7. A vehicle transmission system control system, comprising:

Wheel end, the wheel end including a hub;

axle;

A clutch, connected between the axle and the wheel hub, for controlling the engagement of the wheel hub and the axle; and

Processing subsystem, the processing subsystem being configured to:

At least one of the following:

In response to the vehicle switching to the closed state, the wheels of the vehicle are disengaged from the vehicle's powertrain by actuation of the clutch, or

In response to the vehicle switching to the open state, the wheels of the vehicle are engaged with the powertrain of the vehicle by actuation of the clutch.

8. A vehicle having a vehicle transmission system control system according to claim 7.

9. The vehicle transmission system control system of claim 7, wherein the processing subsystem includes at least one controller, and wherein the at least one controller has at least one processor and a memory storing computer instructions, wherein when the at least one processor executes the computer instructions, the computer instructions cause the vehicle transmission system control system to determine whether the vehicle has transitioned to the off state, and in response to the vehicle transitioning to the off state, to disengage two or more wheels.

10. The vehicle drivetrain control system of claim 7, wherein the vehicle includes an air brake that operates between an applied braking state and a released braking state by applying air pressure, and wherein the air brake is biased to the applied braking state when no positive air pressure is applied.

11. The vehicle transmission system control system of claim 7, wherein the air brake is used to provide braking force to the brakes of two or more wheels of the vehicle, and wherein the two or more wheels of the vehicle are in a freewheel state due to the application of positive air pressure to the brakes of the two or more wheels of the vehicle and the disengagement of the two or more wheels of the vehicle.

12. The vehicle transmission system control system of claim 8, wherein disengaging the wheels of the vehicle causes the vehicle to be in a traction preparation state, in which the powertrain of the vehicle is prepared to be towed by a tractor, and wherein, when the vehicle is in the traction preparation state, an air compressor carried by the tractor provides positive air pressure to the brakes of the wheels, thereby placing the wheels of the vehicle in a freewheel state so as to enable traction of the vehicle, and wherein engaging the wheels of the vehicle with the powertrain of the vehicle causes the vehicle to disengage from the traction preparation state.

13. The vehicle transmission system control system of claim 7, wherein at least one clutch comprises a plurality of clutches, wherein the wheels of the vehicle are connected to the powertrain of the vehicle via a single clutch of the plurality of clutches, and wherein each of the plurality of clutches is controlled by a linear actuator between an engaged position and a disengaged position.

14. The vehicle transmission system control system of claim 13, wherein the plurality of clutches includes four clutches, wherein the power transmission system includes a first axle connected to two wheels of the vehicle, wherein the power transmission system includes a second axle connected to two other wheels of the vehicle, and wherein each wheel of the vehicle is connected to the first axle or the second axle of the power transmission system of the vehicle via a single clutch of the plurality of clutches.

15. The vehicle drivetrain control system according to claim 14, wherein the electronically controllable central axle disconnector is controllable between an engaged state and a disengaged state, such that power from the vehicle's powertrain is selectively transmitted to the first axle of the drivetrain depending on whether the electronically controllable central axle disconnector is in the engaged state or the disengaged state.

16. The vehicle transmission system control system according to claim 13, wherein the linear actuator is an electronically controllable linear actuator, a pneumatically controllable linear actuator, or a hydraulically controllable linear actuator.

17. The vehicle transmission system control system of claim 7, wherein the jumper box is used to provide input to the linear actuator for controlling the clutch between an engaged position and a disengaged position.

18. The vehicle transmission system control system according to claim 7, wherein the clutch includes a dynamically controllable clutch (DCC).

19. The vehicle drivetrain control system of claim 18, further comprising at least one other wheel hub and at least one other dynamically controllable clutch, the at least one other dynamically controllable clutch being configured to engage with the at least one other wheel hub.

20. A vehicle transmission system control system, comprising:

Wheel end, the wheel end including a hub;

axle;

A clutch, connected between the wheel hub and the axle to control engagement between the wheel hub and the axle; and

A processing subsystem is configured to:

Determine when the vehicle should be switched to the off state;

Determine whether the vehicle is in traction mode; and

In response to determining that the vehicle has switched to the off state and that the vehicle is in the traction mode, the wheels of the vehicle are disengaged from the vehicle's powertrain by actuation of the clutch.