GB2623955A

GB2623955A - Motion generation apparatus

Info

Publication number: GB2623955A
Application number: GB2216097.2A
Authority: GB
Inventors: Kirkman David
Original assignee: Anthony Best Dynamics Ltd
Current assignee: Anthony Best Dynamics Ltd
Priority date: 2022-10-31
Filing date: 2022-10-31
Publication date: 2024-05-08
Also published as: CN120456963A; EP4611916A1; GB202216097D0; WO2024094960A1

Abstract

A motion generation apparatus 1000; 2000 is disclosed for a motion platform system. The apparatus comprises a plurality of motion control arrangements 1201, 1202, 1203 that include control members 1211, 1212, 1213 and couplings 1241, 1242, 1243 configured to engage respective inclined portions 1251, 1252, 1253 of the control members. Laterally driving the or each respective control member laterally in multiple lateral directions forces the or each respective coupling in a direction along an inclined path P1, P2, P3 to impart a vertical force to a portion 1801, 1802, 1803 of a motion platform 1800. Motion and positioning of the platform 1800 is determined by the combined movement and/or positioning of the control members 1211, 1212, 1213.

Description

Motion generation apparatus

BACKGROUND OF THE INVENTION

[0001] The present invention relates to motion generation apparatus for a motion platform system. The invention may have particular application, for example, in motion platform systems for simulating motion relating to a vehicle, for example a land, air, space or sea vehicle, including a motorised land vehicle, aircraft, spacecraft, hovercraft or water craft. Some embodiments of the invention are of particular application to simulations in which a high frequency response with a high level of authority is desirable, for example motorsports simulations.

Background Art

[0002] Motion platform systems are known that provide for multiple degrees of freedom of movement, allowing an occupant to be subjected to a range of motions that provide a realistic sensation of being in the environment under simulation, such as a sensation of occupying and/or operating a land, sea, air or space vehicle. Such systems generally aim to generate motion of an occupant carrier that is closely aligned to the motion of a vehicle or vehicle type. The simulated motion can then facilitate stimulation of the somatosensory and vestibular systems of an occupant, and improve the occupant's ability to operate in and/or control a real vehicle that is the subject of the simulation.

[0003] For example, a motion platform system including an occupant carrier mounted to the platform may provide an occupant with an accurate sensation of being in a motor racing car. In a motion platform system having six degrees of freedom, there may be provided, for example, translational motion of the platform in the surge, sway, and heave directions, i.e. along respective x-, y-, and z-axes of the motion platform, and rotational motion in roll, pitch, and yaw, i.e. about the respective x-, y-, and z-axes of the platform. [0004] Some known motion platform systems use parallel manipulators. For example, Stewart platform hexapods have a platform connected to a base unit by six telescopic struts or actuators. Due to the large range of telescopic movement provided by the struts, the apparatus is very tall. Typically, a large space is required underneath the platform.

The struts must be relatively powerful and heavy with this type of platform to both hold the static mass of the payload and move the payload if it is desired to provide high frequency response and good authority, and it is difficult to provide a high frequency response for all desirable translational and rotational motions. While sometimes useful for simulating motion of some aircraft which do not require high magnitude and high frequency horizontal forces and accelerations to be simulated, use of such arrangements is not cost efficient or practical for simulating motions requiring very high forces in both the horizontal (when braking, accelerating or cornering) and vertical/rotational (ride handling) directions, such as those that arise for example in motor racing.

[0005] The 'Williams' motion platform system, described in WO 2014/087172, aims to alleviate some of the limitations of the Stewart platform. The height of an occupant carrier platform in Williams is adjusted by a set of first motors each of which drives a first support, or carriage, along an inclined surface of a second support, or wedge to independently control the height of respective occupant carrier support rails. The occupant carrier support rails slidably support the platform for relative sliding movement in a surge direction. The second supports are located on opposite sides of the occupant carrier support rails, and are driven by second motors movable along a transversely extending base track. Yaw and surge motions are provided by the second motors driving the second supports laterally along the base track to move the converging occupant carrier support rails laterally together or apart. Due to the nature of the arrangement of the convergently angled occupant carrier platform between the convergent occupant carrier support rails in the Williams platform system, for some applications there is insufficient authority (i.e. the ability to timely and accurately control the motion platform) and insufficiently long range of travel in the surge axis. Whilst it is possible to increase the "V" angle of the occupant support rails in the platform system design to increase authority, this negatively impacts overall surge travel.

[0006] In general, provision of insufficient surge travel may create a problem during sustained brake cueing which can lead to miscuing the occupant with a perception of brake fade as the travel runs out before the platform system has finished the cue. It can be impractical to extend the range of surge motion in known designs due to overhanging portions of the platform hitting the floor. Furthermore, when known motion platforms are at the extremities of surge, the centre of gravity of the moving mass is often in a substantially different location to when the platform is in a neutral position. Gas struts are often tuned to support the load primarily with the platform positioned relatively close to the neutral position, so that in extreme positions, the platform is inherently unbalanced and the support provided by the gas struts is sub-optimal. Control in such extreme positions of a platform system can then be difficult, as holding such positions typically creates a peak current demand in drive motors and can lead to system instability. Conventional motion platform systems also require a large physical footprint, particularly in the sway direction (i.e. along the y axis). The footprint is important when considering scaling the platform system with limited space available.

[0007] Other examples of prior art show multi-stage systems in which, for example, one stage provides yaw, surge and sway and another stage provides heave, pitch and roll. Multi-stage systems negatively impact the stiffness and high frequency response of the motion platform system. Those skilled in the art will appreciate that the frequency response of the motion platform system (i.e. its ability to make high speed movements such as to simulate a shock motion associated with hitting a bump in a road) is tied to the mechanical stiffness, the moving mass of the motion platform, and to the actuators used to impart motion. Such multi-stage platform systems are typically heavy, and excess weight and lack of stiffness has a significant negative effect on the frequency response of the motion platform, particularly impacting the high frequency response.

[0008] GB 2378687 discloses a motion simulator using a rocker arm arrangement. It has been found challenging with rocker arm arrangements to successfully provide high levels of heave and surge using relatively small motors. The challenges include having to make the rockers relatively large to achieve a desired range of motion but this increase in rocker size introduces a lack of stiffness into the system. The lack of stiffness makes it difficult to achieve good displacement, velocity and frequency response bandwidth in the system. The requirement for larger motors increases cost.

[0009] WO 2021/019213 discloses a motion platform having an occupant carrier portion comprising first, second and third guide portions pivotally connected by respective coupling members to first, second and third control pillars constrained for independent movement in a plane. The guide portions of the occupant carrier portion are angled with respect to the plane and with respect to each other, and constrain motion of the coupling members along the guide portions.

[0010] The present invention aims to facilitate the mitigation or overcoming of at least one problem of the prior art, and/or to provide a useful motion generation apparatus.

SUMMARY OF THE INVENTION

100111 According to a first aspect of the invention, there is provided motion generation apparatus for a motion platform system, the apparatus comprising: a platform for supporting an occupant carrier; a plurality of motion control arrangements each configured to independently provide motion control to a respective portion of the platform, and each comprising i) a respective control member and ii) a respective rotatable coupling coupled between the platform and the respective said control member; and a plurality of actuation arrangements each configured independently to drive a respective said control member laterally in multiple lateral directions; wherein at least one of the control members comprises an inclined portion, and a respective said coupling is configured to engage the respective inclined portion such that laterally driving the or each respective control member forces the or each respective coupling in a direction along an inclined path under control of the control member, to thereby impart a vertical component of drive force to a said respective portion of the platform; motion and positioning of the platform with multiple translational and rotational degrees of freedom being determined by the combined movement and/or positioning of the control members.

[0012] The use in this manner, of a control member having an inclined portion and independently driven in multidirectional lateral directions to independently transmit drive to a portion of the platform, facilitates the provision of motion generation apparatus that has a compact motion envelope vertically and/or laterally, and/or is robust for use in high performance environments.

[0013] Furthermore, the maintenance of a fixed motion ratio is facilitated across the extent of travel of the control members, that is, a substantially consistent ratio between the travel of a control member and the resulting vertical travel of its respective coupling. This mitigates the occurrence of peak loads in extreme positions of the motion platform, thus facilitating more effective utilisation of lower cost and/or lower weight linear actuators such as ironless or air-core linear motors in the actuation arrangements, and/or facilitating control of motion without the requirement for gas struts or other forms of assistance to support the actuation arrangements in dealing with such peak loads. The ability to use ironless linear motors in a motion generation apparatus is also advantageous due to such qualities as zero cogging, low noise, high speed, high positional accuracy, and better repeatability, for example in comparison to ball screw actuators typically used in hexapods. Thus, the provision of a high frequency response motion platform system with a high level of authority is facilitated, as is desirable for example for high performance simulation applications such as motorsports. Various embodiments of the invention thus facilitate the provision of higher performance and/or lower cost motion generation apparatus.

[0014] Still further, because the platform is constrained to move with multiple degrees of freedom as determined by the control members, the apparatus requires no further motors to separately drive the couplings relative to the inclined portion of the control members. [0015] Still further, there is facilitated the provision of a less costly and/or less heavy motion generation apparatus that is not over-constrained. Because the degrees of freedom of movement are not decoupled from one another, a more rigid and responsive generation of motion is facilitated. The robust and/or lighter design facilitates installation of the motion generation apparatus on a support surface more quickly and/or conveniently, without requirement for a time consuming highly accurate levelling process, and/or facilitates provision of a motion generation apparatus which is convenient to transport and to install.

[0016] Lateral, or horizontal directions or planes, as used herein with respect to the motion generation apparatus and components thereof, mean directions or planes generally parallel to the ground or other support surface, or surfaces, to which the motion generation apparatus or a control member is mounted, and laterally and horizontally are to be understood accordingly. Such support surface may be static or may be movable, for example rotatable, relative to a supporting ground surface. Vertical or vertically means perpendicular to such a lateral or horizontal direction or plane.

[0017] A plurality of the control members, for example three said control members, may each comprise a respective said inclined portion and be configured to engage with a respective said coupling, such that laterally driving each respective said control member causes each respective said coupling to be driven under control of the respective control member along the respective inclined portion in a direction along a respective inclined path, to thereby impart a vertical component of drive force to a said respective portion of the platform. Using multiple control members each having an inclined portion, and respectively independently driven in multidirectional lateral directions to independently transmit drive to a respective portion of the platform, further facilitates the provision of motion generation apparatus that has a compact motion envelope vertically and/or laterally, and/or is robust for use in high performance environments.

[0018] The inclined paths may extend generally towards an inner region of the platform in an at rest, or centred, or neutral, condition of the motion generation apparatus. That is, the paths may be generally convergent, towards a general region or area, although the paths' axes do not necessarily extend towards a common point of intersection. The inclined paths may lie not all in a common plane. The inclined paths may in some embodiments converge laterally and vertically towards an approximate intersection point of the path's axes, for example where the couplings are connected to a platform shaped generally as an equilateral triangle, at respective locations of the intersections of the sides of the platform, and the inclined paths have similar values of the angle of vertical inclination.

[0019] The motion generation apparatus may comprise two rear motion control arrangements, the directions of the respective inclined paths of the rear motion control arrangements having an angle therebetween of from about 200 to 1600, or from about 900 to 140°, or of about 1200 or 1000. While at least some of the aforementioned values of the angle have been shown to be an effective compromise resulting in a good level of authority in both surge and sway for some applications, for example in a motorsports simulation environment, the skilled person will appreciate that the optimal value of the angle will vary according to the desired application of the apparatus. In principle, a value of the angle between 10 and 1790 could have utility.

[0020] A respective angle vertically between the direction of a said inclined path and a laterally extending plane may lie in a range from about 100 to about 45°, and may be about 16°. The vertical angle of each said inclined path may be the same as the vertical angle of other said inclined paths, or alternatively at least one said inclined path may be inclined at a different vertical angle to that of at least one other said inclined path. While at least some of the aforementioned values of vertical angle have been shown to be effective, for example in a motorsports simulation environment, the skilled person will appreciate that the optimal value of vertical angle will vary according to the desired application of the apparatus. With the angle at about 16°, a lateral motion of about 3.5 units of distance of the coupling relative to the control member causes a relative vertical motion between the two of about 1 unit of distance i.e. a motion ratio of about 3.5 is provided. A higher motion ratio, such as a 3.5:1 motion ratio, facilitates the provision of smaller, lighter and/or cheaper motors relative to a similar arrangement that instead provides a lower motion ratio such as a 2:1 motion ratio, provided using a vertical angle of about 26.5°. A higher motion ratio, such as a 3,5:1 motion ratio, is suitable for simulations where large vertical displacements are not required, for example motorsports simulations. In general, a higher motion ratio provides a reduction in effort required to displace the load vertically, and facilitates the use of smaller and lighter motors while meeting motion envelope (displacement), velocity and acceleration requirements. This facilitates a reduction in cost and/or size whilst maintaining consistent performance as required for high frequency response simulations.

[0021] The or each said coupling that is configured to engage the respective inclined portion may be engaged so as to move freely along the respective said inclined path, motion of the or each said coupling being controlled by the or each respective control member. Motion of the or each said coupling along the inclined path may be controlled solely by the or each respective control member, subject only to force transmitted to the coupling through the platform as determined by the other control members. That is, there is no additional actuator or motor to directly drive the or each coupling along the respective inclined path. This facilitates a reduction in the moving mass and an increase in performance of the platform.

[0022] Each coupling may comprise a carriage connected to the platform through a respective rotatable connector joint disposed between the or each respective carriage and the respective portion of the platform.

[0023] The or each rotatable coupling may be fixed against translational movement of the or each coupling relative to the platform, while permitting rotational movement between the platform and the or each respective control member. That is, the or each coupling is mounted to the platform to resist or prevent such relative translation at the mounting location.

[0024] The or each rotatable coupling may provide 3 degrees of rotational freedom of movement relative to the or each respective portion of the platform. The coupling may comprise any suitable form of rotatable connector joint, such as a ball joint, or a gimbal or universal joint.

[0025] The motion generation apparatus may comprise three or more said motion control arrangements, each associated with a respective one of said actuation arrangements. [0026] The combined movement and/or positioning of all of the control members may control motion and positioning of the platform with three translational and three rotational degrees of freedom of movement.

[0027] The or each motion control arrangement may comprise a respective guide configured to constrain movement of a respective said coupling to translation along a respective said inclined path.

[0028] The or each control member may comprise a respective said guide, for example one or more rails, extending along a respective said inclined portion.

[0029] The or each coupling may comprise a respective engaging portion, comprising for example a carriage including one or more rotatable wheels, configured to engage with a respective said guide of a respective said control member so that the or each coupling is guided along a respective said inclined path with minimal friction. The guide may comprise one or more rails to receive one or more respective wheels of the engaging portion.

[0030] Tt will be apparent to the skilled person that alternative guide and/or engaging mechanisms are available to guide and constrain movement of the coupling relative to the control member, while facilitating low friction sliding movement therebetween, such as any suitable form of low friction bearing or sliding surface. The guide may be provided either at the control member or at the coupling, with the engaging portion provided at the other of the control member and the coupling.

[0031] The actuation arrangements may include respective linear actuation devices having respective drive axes arranged at angles that are laterally in alignment with the angles of the respective inclined paths.

[0032] Alternatively, the actuation arrangements may include respective linear actuation devices having respective drive axes arranged at angles so as to be laterally out of alignment with the respective inclined paths, for example by at least 30° or other significant amount, such that the inclined paths are aligned along offset lateral angles from the drive axes. In the design of such a motion generation apparatus, any desired angle can be selected at which the inclined paths can be orientated relative to each of the mutually orthogonal drive axes of the actuation arrangements, and the control members are movable in any lateral direction, including along either of the drive axes. Such an arrangement facilitates the sharing of vertical forces generated from the static mass between the linear actuation devices, and a reduction in size and/or cost of the linear actuation devices.

[0033] At least one of the actuation arrangements may comprise a respective plurality of stacked linear actuation devices, the or each actuation arrangement being independently connected, for independent force transmission, to the or each respective control member. By stacking, the moving mass may be kept down, which can be beneficial especially with a large motion envelope.

[0034] At least one of the actuation devices may comprise an electric linear motor, for example an ironless, or air core, linear motor. Alternatively, or additionally, iron core or magnet-free-track linear motors may be employed in the actuation devices.

[0035] Notwithstanding the above examples, the at least one control member can be laterally driven by any type of respective actuation device suitable for driving the control member in lateral directions. For example, a plurality of linear actuation devices, either stacked or laterally arranged in an XY table, may drive the control member along respective orthogonal linear axes. While electric linear motors have advantages in many motion platform system applications, alternative actuation devices may be employed in the form, for example, of hydraulic or gas piston actuators, or rotary electric motors with suitable gearing and arrangements to provide linear drive force.

[0036] Each actuation arrangement may be supported on a separate respective base support, to permit independent fixing and orientation of the base supports in relation to one another. This facilitates the mounting of the base supports and the motion generation apparatus to a support surface or location quickly, without the requirement for time a time consuming highly accurate levelling process, and/or facilitates the provision of a motion platform system that is convenient to transport and to install. The support surface may be flat, and may be static or may be movable, and may for example be a rotatable table to provide unlimited yaw. In some embodiments the base supports may be mounted to respective support surfaces that are not at the same height as each other and/or not parallel with the ground. In alternative embodiments, the base supports may be connected directly to one another, and not permit independent fixing, and/or the actuation arrangements may be supported on an integral base support and/or may be included in an integral XY table arrangement.

[0037] All of the actuation arrangements may include respective upper or lower linear actuation devices having respective drive axes arranged generally parallel with a front-back axis of the motion generation apparatus.

[0038] The motion generation apparatus may comprise two rear said actuation arrangements, each comprising a respective upper linear actuation device stacked on a respective portion of a common lower linear actuation device, the lower linear actuation device being arranged to independently drive the respective upper linear actuation devices along a common guide extending in a direction generally perpendicular to a front-back axis of the motion generation apparatus, for permitting an increased range of sway.

[0039] The motion generation apparatus may comprise two rear said actuation arrangements and a front said actuation arrangement, the front actuation arrangement providing a greater extent of travel than each of the rear actuator arrangements in a I0 direction generally perpendicular to a front-back axis of the motion generation platform, for permitting an increased range of sway.

[0040] The platform may comprise a rigid frame.

[0041] The motion generation apparatus may comprise an occupant carrier fixed for movement relative to platform, the occupant carrier including, for example, seating for a single occupant, or tandem, side by side, or multiple seating for multiple occupants. [0042] According to a further aspect of the invention, there is provided a motion platform system for simulating vehicular motion, comprising motion generation apparatus as described above in relation to the first aspect of the invention.

[0043] The motion platform system may be configured to simulate motion of a land, air, space or sea vehicle, including an aircraft, spacecraft, hovercraft, water craft or land vehicle, for example a land motor vehicle such as a single seat performance motor car, or a tracked or off-road vehicle.

[0044] According to a further aspect of the invention, there is provided a simulator for simulating vehicular motion, comprising: a movable frame to support occupant seating and controls; three inwardly pointing control wedges having respective inwardly and upwardly directed inclined wedge faces; three couplings each i) fixedly connected to a respective location on the frame by a respective 3 degrees of freedom rotatable joint and ii) engaged with a respective one of the inclined faces for guided relative translational movement along the face; and linear motors to respectively drive each of the respective wedges independently, in any desired lateral, or horizontal, direction; motion of the frame with three rotational degrees of freedom and three translational degrees of freedom being controlled solely by the linear motors through the control members.

[0045] The linear motors may have drive axes respectively extending along front-back and sideways directions of the simulator, each of which directions is arranged at a nonzero lateral angle (i.e. taken parallel to a lateral plane) relative to the respective directions of guided movement of the couplings along each of the inwardly directed faces.

Alternatively, the drive axes of the linear motors may be in alignment with the respective directions of guided movement of the couplings along each of the inwardly directed faces. [0046] Tt will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention.

DESCRIPTION OF THE DRAWINGS

100471 In order that the invention may be well understood, by way of example only, various embodiments of the present invention will now be described with reference to the accompanying schematic drawings of which: Figure 1 is a perspective view of a motion generation apparatus in a neutral state; Figure la is a plan view of portions of the apparatus; Figure 2 shows the motion generation apparatus in a state of maximum heave; Figure 2a is a plan view of portions of the apparatus in the state shown in Figure 2; Figure 3 shows the motion generation apparatus in a state of minimum heave; Figure 3a is a plan view of portions of the apparatus in the state shown in Figure 3; Figure 4 shows the motion generation apparatus in a pitch down state, Figure 4a is a plan view of portions of the apparatus in the state shown in Figure 4; Figure 5 shows the motion generation apparatus in a pitch up state; Figure 5a is a plan view of portions of the apparatus in the state shown in Figure 5; Figure 6 shows the motion generation apparatus rolled to the right; Figure 6a is a plan view of portions of the apparatus in the state shown in Figure 6; Figure 7 shows the motion generation apparatus rolled to the left; Figure 7a is a plan view of portions of the apparatus in the state shown in Figure 7; Figure 8 shows the motion generation apparatus yawed to the right; Figure 8a is a plan view of portions of the apparatus in the state shown in Figure 8; Figure 9 shows the motion generation apparatus yawed to the left; Figure 9a is a plan view of portions of the apparatus in the state shown in Figure 9; Figure 10 shows the motion generation apparatus swayed to the right; Figure 10a is a plan view of portions of the apparatus in the state shown in Figure 10; Figure 11 shows the motion generation apparatus surged forward; Figure 1 I a is a plan view of portions of the apparatus in the state shown in Figure Figure 12 shows an alternative motion generation apparatus in a neutral state; Figure 13 shows a motion generation apparatus in a motorsports configuration; and Figure 14 shows a motion generation apparatus in an automotive configuration.

DETAILED DESCRIPTION

100481 Figure 1 is a perspective view downwards from the front right of a motion generation apparatus 1000 in accordance with a first embodiment of the invention in an at rest, or neutral, position or state. The motion generation apparatus 1000 comprises a motion platform 1800 and a plurality of motion control arrangements 1201, 1202, 1203 each configured to independently provide motion control to a respective portion 1801, 1802, 1803 of the platform 1800. Each motion control arrangement 1201, 1202, 1203 comprises a respective control member 1211, 1212, 1213 and a respective rotatable coupling 1241, 1242, 1243 coupled between the platform 1800 and the respective control member 1211, 1212, 1213. The motion generation apparatus 1000 further comprises a plurality of actuation arrangements 1001, 1002, 1003, each configured independently to drive a respective one of the control members 1211, 1212, 1213 laterally in multiple lateral directions. That is, in the direction of mutually orthogonal laterally extending X and Y axes of the motion generation apparatus 1000 and, when the X and Y drives are combined, all other motions and directions therebetween, in or parallel to a plane containing the X and Y axes. In the embodiment of Figure 1 the X axis extends along a longitudinal centre axis, or front-back axis of the motion generation apparatus 1000, and the Y axis extends along a sideways, or left-right axis. Figure I also shows a Z axis extending orthogonally to a lateral plane containing the X and Y axes, in a generally vertical direction.

100491 The motion platform 1800 comprises a substantially rigid, generally triangular frame. The three sides of the platform 1800 are formed by beams 1806, 1807, 1808. Portions 1801, 1802, 1803 of the platform 1800, located in respective apical regions of the platform 1800, include respective connectors that connect each said portion 1801, 1802, 1803 with a respective one of the couplings 1241, 1242, 1243, to fixedly restrain a connected portion of each respective coupling 1241, 1242, 1243 against translational motion relative to the platform 1800. In the at rest position shown in Figure 1, a longitudinal centre axis, or surge axis xc, of the platform 1800 extends parallel to the front-back axis X of the motion generation apparatus 1000, with the forward apical portion 1801 forwardly directed in alignment with the X axis. A sway axis yc of the platform 1800 extends orthogonally to the surge axis xc. In the at rest position shown in Figure 1, the sway axis ye and surge axis xc of the platform 1800 extend parallel to the X and Y axes of the motion generation apparatus 1000, such that a heave axis zc of the platform 1800, which extends orthogonal to the sway and surge axes yc, xc, lies parallel to the Z axis of the motion generation apparatus 1000.

[0050] As shown in Figure 1, each control member 1211, 1212, 1213 comprises a respective laterally extending downwardly facing base portion and a respective face or faces, that face upwardly and inwardly so that each control member forms a general wedge shape, the wedge being directed inwardly of the apparatus 1000.

[0051] The upwardly and inwardly directed faces of the control members, or wedges, 1211, 1212, 1213 provide respective inclined portions 1251, 1252, 1253. Each respective inclined portion 1251, 1252, 1253 includes a respective guide, in the form of respective guide rails 1221, 1222; 1223, 1224; 1225, 1226. Each guide extends along its respective inclined portion 1251, 1252, 1253, and is configured to constrain movement of the respective couplings 1241, 1242, 1243 to translation along respective inclined paths P 1, P2, P3. The inclined portions 1251, 1252, 1253 and the respective inclined paths P!, P2, P3 extend upwardly and outwardly at respective angles 01, 02, 03 (see also Figure 14) measured vertically from the lateral, or XY, plane, and are generally inwardly convergent towards a laterally central region of the apparatus 1000. In the embodiment of Figure 1, each of the vertical angles 01, 02, 03 has equal value of about 16°. In alternative embodiments, different values of 01, 02, 03 may be used depending on the intended application for the motion generation apparatus 1000, for example selected in the range of from about 10° to about 45°, and the values of 01, 02, 03 may not all be the same.

[0052] The inclined paths P2, P3 of the right and left rear motion control arrangements 1202, 1203 extend in directions having an angle cp therebetween, as best shown in Figure la, which is a plan view illustrating positions of positions of the paths P1, P2, P3 relative to the apical portions 1801, 1802, 1803 of the platform 1800, in the neutral state of the motion generation apparatus 1000. In the embodiment, cp is 1200, with the rear inclined paths P2, P3 each lying 60° to the right and left respectively of the longitudinal centreline of the motion generation apparatus 1000. Values of y of about 90°, or about 100° have been shown to provide a good level of authority in both surge and sway in a motorsports simulation environment.

[0053] Each coupling 1241, 1242, 1243 includes a respective rigid body supporting a respective rotatable joint 1261, 1262, 1263 and a respective engaging portion 1231, 1232, 1233 that enables the coupling 1241, 1242, 1243 to slidably engage with the respective guide of a respective inclined portion 1251, 1252, 1253. In the embodiment shown in Figure 1, each engaging portion 1231, 1232, 1233 comprises a respective pair of carriages that engage with a respective pair of the guide rails 1221, 1222; 1223, 1224; 1225, 1226. Each carriage takes the form of an upturned generally U-shaped member having a wheel or wheels on its underside to engage a respective guide rail 1221, 1222; 1223, 1224; 1225, 1226 so as to restrain movement laterally of the rail while permitting low friction travel of the carriage along the rail. Alternative ways of providing low friction translational movement between the couplings 1241, 1242, 1243 and the respective inclined portions 1251, 1252, 1253 will be apparent to the skilled person. For example any suitable type of bearing and/or low friction sliding surface could be utilised in the engaging portions 1231, 1232, 1233 and/or the guides of the inclined portions 1251, 1252, 1253.

[0054] A lower portion of each rotatable joint 1261, 1262, 1263 is connected to an upper body portion of each respective coupling 1241, 1242, 1243. Each rotatable joint comprises a rod, or other rigid portion of the joint, that fixedly connects to a respective apical portion of platform 1801, 1802, 1803 and substantially prevents relative translational movement between the couplings 1241, 1242, 1243 and the platform 1800. The or each rotatable joint 1261, 1262, 1263 comprises a ball joint, which provides 3 degrees of rotational freedom of movement of the or each respective portion 1801, 1802, 1803 of the platform 1800 relative to each respective coupling 1241, 1242, 1243, and therefore relative to each respective control member 1211, 1212, 1213, to enable a specified range of rotational movement of the platform 1800 within a desired motion envelope. In alternative embodiments, other forms of rotatable connector joint could be employed, for example a gimbal or universal joint. The or each rotatable coupling 1241, 1242, 1243 is thus fixed against translational movement of the or each coupling relative to the platform 1800, while permitting rotational movement between the platform 1800 and the or each respective control member 1211, 1212, 1213.

[0055] Each control member 1211, 1212, 1213 is supported by a respective upper support, or table, 1146, 1147, 1148 for movement in a lateral plane. Each table 1146, 1147, 1148 carries on its upper face a respective upper guide. Each guide is directed inwardly of the motion generation apparatus 1000 and extends in a lateral plane, and is arranged such that respective longitudinal axes of the guides are in alignment with the angles of the respective inclined paths P1, P2, P3. Each guide comprises a respective pair of parallel guide rails 1121, 1122; 1123, 1124; 1125, 1126. The base portion of each control member 1211, 1212, 1213 is provided with a respective engager 1131, 1132, 1133. Each engager 1131, 1132, 1133 comprises a respective set of four carriages, and each respective set of carriages engages a respective pair of the guide rails 1121, 1122; 1123, 1124; 1125, 1126. Each carriage takes the form of an upturned generally U-shaped member having a wheel or wheels on its underside that engage with a respective one of the guide rails 1121, 1122; 1123, 1124; 1125, 1126 so as to restrain lateral movement relative to the rail while permitting low friction travel of the carriage along the rail. It will be apparent to the skilled person that, instead of wheeled carriages, many alternative ways of providing low friction translational engagement are available, for example any suitable type of bearing and/or low friction surface.

[0056] Each actuation arrangement 1001, 1002, 1003 is independently connected, for independent force transmission, to a respective control member 1211, 1212, 1213, and comprises a respective upper linear actuation device 1141, 1142, 1143 and a respective lower linear actuation device 1041, 1042, 1043. Each upper linear actuation device 1141, 1142, 1143 is supported by a respective one of the tables 1146, 1147, 1148 and is connected by its respective forcer (not shown) to a respective control member 1211, 1212, 1213. Lateral drive axes Ml, M2, M3 (see also Figure 14) of the upper linear actuation devices 1141, 1142, 1143 are directed inwardly of the motion generation apparatus 1000 so as to supply lateral drive to the respective control members 1211, 1212, 1213. The lateral drive axes Ml, M2, M3 are aligned with the guide rails 1121, 1122; 1123, 1124; 1125, 1126 and with the directions of the respective inclined paths P1, P2, P3. The upper linear actuation devices 1141, 1142, 1143 of the embodiment take the form of electric linear motors, in particular ironless, or air-core, electric linear motors.

[0057] Each of the tables 1146, 1147, 1148 is movably supported, or stacked, on a respective base support 1011, 1012, 1013 for movement in a direction substantially perpendicular to drive axes Ml, M2, M3 of the respective upper linear actuation devices 1141, 1142, 1143. Each base support 1011, 1012, 1013 comprises a respective pair of base guide rails 1021, 1022; 1023, 1024; 1025, 1026. Each base guide rail pair extends with its longitudinal axis perpendicular to the axis of the corresponding pair of upper guide rails 1121, 1122; 1123, 1124; 1125, 1126 of the corresponding stacked table 1146, 1147, 1148. Each table 1146, 1147, 1148, is provided on its underside with a respective base engager 1031, 1032, 1033. Each base engager 1031, 1032, 1033 comprises a respective set of four carriages, and each respective set of carriages engages a respective pair of the base guide rails 1021, 1022; 1023, 1024; 1025, 1026. Each carriage takes the form of an upturned generally U-shaped member having a wheel or wheels on its underside that engage with a respective one of the base guide rails 1021, 1022; 1023, 1024; 1025, 1026 so as to restrain lateral movement relative to the rail 1021, 1022; 1023, 1024; 1025, 1026 while permitting low friction travel of the carriage along the rail 1021, 1022; 1023, 1024; 1025, 1026.

[0058] Each lower linear actuation device 1041, 1042, 1043 is supported on a respective base support 1011, 1012, 1013 between a respective pair of the base guide rails 1021, 1022; 1023, 1024; 1025, 1026, with its drive axis parallel to the respective base guide rails 1021, 1022; 1023, 1024; 1025, 1026. The forcer of each lower linear actuation device 1041, 1042, 1043 is connected to the underside of a respective table 1146, 1147, 1148 for driving the respective table 1146, 1147, 1148 along the base guide rails 1021, 1022; 1023, 1024; 1025, 1026. Thus, each respective upper linear actuation device 1141, 1142, 1143 is effectively stacked above a respective lower linear actuation device 1041, 1042, 1043 for perpendicular movement relative thereto, and each control member 1211, 1212, 1213 is laterally drivable in any chosen lateral direction. The lower linear actuation devices 1041, 1042, 1043 of the embodiment take the form of electric linear motors, in particular ironless, or air-core, electric linear motors. The skilled person will be aware of suitable alternative types of actuation devices, for example, iron core or magnet-free-track linear motors, or any other pipe of actuation device capable of providing suitable lateral motion. [0059] Each actuation arrangement 1001, 1002, 1003 is supported on a separate respective base support 101 I, 1012, 1013, to permit independent fixing and orientation of the base supports 1011, 1012, 1013 in relation to one another. Each base support 1011, 1012, 1013 comprises a plate, for example a pre-stressed steel base plate attached to the floor with 4 anchor points. The motion generation apparatus 1000 further comprises various shock absorbers to mitigate shock and/or damage in case the tables 1146, 1147, 1148, control members 1211, 1212, 1213 and/or or couplings 1241, 1242, 1243 overshoot the limits of their designed travel, and emergency brakes (not shown) to provide safety in case of failure of electrical supply to the motors.

[0060] Longer base guide rails 1021, 1022 and a longer lower linear actuation device 1041 are provided in the front actuation arrangement 1001 than in the rear actuation arrangements 1002, 1003, and the sideways extent of the front actuation arrangement (in a direction of the Y axis) is greater than the sideways footprint of the rear actuation arrangements 1002, 1003. The front actuation arrangement 1001 provides a greater extent of travel than each of the rear actuator arrangements in 1002, 1003 along the Y axis, for permitting an increased range of sway.

[0061] The carriages 123 I, 1232, 1233 of the couplings 1241, 1242, 1243 respectively engage the rails 122 I, 1222; 1223, 1224; 1225, 1226 of the inclined portions 1251, 1252, 1253 such that lateral XY forces independently exerted on each of the control members 121 I, 12 I 2, 1213 by the respective actuation arrangements 1001, 1002, 1003 cause resulting forces on the respective couplings 1241, 1242, 1243 along the respective inclined paths P1, P2, P3, that drive the respective portions 1801, 1802, 1803 of the platform 1800 in a vertical direction 1 The motion and position of the platform 1800 with three translational and three rotational degrees of freedom along and about its axes xc, yc and zc is determined by the combined movement and/or positioning of the control members 1241, 1242, 1243 in the XY plane by the actuation arrangements 1001, 1002, 1003. Because the couplings 1241, 1242, 1243 are passively mounted on the inclined portions, that is, without any additional actuators to directly drive the couplings 1241, 1242, 1243 along the inclined paths PI, P2, P3, the position of each coupling 1241, 1242,

IS

1243 along a path P 1, P2, P3 depends solely on the balance of forces received by the coupling 1241, 1242, 1243 from i) its directly engaged control member 1241, 1242, 1243 and ii) the other control members 1241, 1242, 1243 via the platform 1800. Force transmission chains through the respective motion control arrangements 1201, 1202, I 203 are independent, i.e. decoupled from one another. The motion generation apparatus 1000 has a motion envelope suitable to provide excursions typically seen in motorsport and automotive cueing, and is compact as well as robust. At rest the apparatus 1000 has a height of approximately 400mm from the floor, and a footprint having maximum width and length of approximately 1900mm 2100mm respectively, although it will be appreciated that dimensions can be selected and varied in accordance with a desired application of the apparatus 1000.

[0062] Figures 2 to 11 and 2a to 1 la show the motion generation apparatus 1000 in various further states. Figures 2 and 2a show a state of maximum heave, wherein all of the control members 1211, 1212, 1213 are moved inwardly to the fullest extent. The couplings 1241, 1242, 1243 all lie at their highest points, at the outward ends of the paths P1, P2, P3, raising the overall height of the platform 1800 at all three of its apices.

[0063] Figures 3 and 3a show a state of minimum heave, wherein all of the control members 1211, 1212, 1213 are moved outwardly to the fullest extent. The couplings 1241, 1242, 1243 all lie at their lowest points, at the inward ends of the paths P 1, P2, P3, lowering the overall height of the platform 1800 at all three of its apices.

[0064] Figures 4 and 4a show a possible pitch down state, in which the front control member 1211 has been moved outwardly, forwards along the X axis. The forward coupling 1241 lies at its lowest, at the inward end of the path P1, lowering the height of the platform 1800 at its front apex 1801. The rear control members 1212, 1213 also move outwards. As the rotation centre is not fixed the motor positions may move to accommodate the variable rotation centre.

[0065] Figures 5 and 5a show a pitch up state, in which the front control member 1211 has been moved inwardly, rearwards along the X axis. The forward coupling 1241 lies at its highest, at the outward end of the path P1, raising the height of the platform 1800 at its front apex 1801. The rear control members 1212, 1213 maintain their neutral position.

[0066] Figures 6 and 6a show a rolled right state, wherein the rear right control member 1212 has been moved outwardly, and the rear left control member 1213 inwardly, thus causing the rear right coupling 1242 to drop to its lowest position, lowering the right rear apex 1802, and causing the rear left coupling 1243 to rise to its highest position, raising the rear left apex 1803. The front control member 1211 maintains its neutral position. [0067] Figures 7 and 7a show a rolled left state, wherein the rear right control member 1212 has been moved inwardly, and the rear left control member 1213 outwardly, thus causing the rear right coupling 1242 to rise to its highest position, raising the right rear apex 1802, and causing the rear left coupling 1243 to drop to its lowest position, lowering the rear left apex 1803. The front control member 1211 maintains its neutral position. [0068] Figures Sand 8a show a yawed right state, wherein the front control member 1211 is moved perpendicularly to its axis by driving the front support table 1146 to the right along the base rails 1021, 1022 in a direction of the Y axis. The rear right control member 1212 is moved perpendicularly to its axis by driving the rear right support table 1147 along the base rails 1023, 1024 rearwards and to the left. The rear left control member 1213 is moved perpendicularly to its axis by driving the rear left support table 1148 along the base rails 1025, 1026 forwards and to the left. The positions of the control members 1211, 1212, 1213 along the drive axes Ml, M2, M3 are adjusted to maintain the positions of the couplings 1241, 1242, 1243 along the paths P1, P2, P3 unchanged, so that the rear right control member 1212 moves along Its axis outwardly of the motion generation apparatus 1000 and the rear left control member 1213 moves along its axis inwardly of the motion generation apparatus 1000, thereby maintaining the heights of the apices 1801, 1802, 1803.

[0069] Figures 9 and 9a show a yawed left state wherein the front control member 1211 is moved perpendicularly to its axis by driving the front support table 1146 to the left along the base rails 1021, 1022 in a direction of the Y axis. The rear right control member 1212 is moved perpendicularly to its axis by driving the rear right support table 1147 along the base rails 1023, 1024 forwards and to the right. The rear left control member 1213 is moved perpendicularly to its axis by driving the rear left support table 1148 along the base rails 1025, 1026 rearwards and to the right. The positions of the control members 1211, 1212, 1213 along the drive axes Ml, M2, M3 are adjusted to maintain the positions of the couplings along the paths P I, P2, P3 unchanged, so that the rear right control member 1212 moves along its axis inwardly of the motion generation apparatus 1000 and the rear left control member 12 I 3 moves along its axis outwardly of the motion generation apparatus 1000, thereby maintaining the heights of the apices 1801, 1802, 1803.

[0070] Figures 10 and 10a show a swayed right state, wherein the front control member 1211 is moved perpendicularly to its axis by driving the front support table 1146 rightwardly along the base rails 1021, 1022, to move the front coupling 1241 and thus the front apex of the platform 1801 in a direction along the Y axis. The position of the front control member 1211 along its axis is maintained unchanged, or neutral, and the position of the front coupling 1241 along the front inclined path P1 is unchanged, thereby maintaining the height of the front apex 1801 unchanged. The rear right coupling 1242 and thus the rear right apex 1802 of the platform 1800 is moved rightwardly in the same direction and over the same distance as the front coupling 1241, by i) driving the rear right control member 1212 along the drive axis M2 outwardly and generally towards the right, resulting also in a rearward component of movement, and ii) to balance out this undesired rearward component of movement, moving the rear right control member 1212 forwards perpendicularly to its axis, by driving the rear right support table 1147 generally forwardly along the base rails 1023, 1024, which also provides a further movement to the right. The position of the rear right coupling 1232 along the rear right inclined path P2 is unchanged, thereby maintaining the height of the rear right apex 1802 unchanged. The rear left coupling 1243 and thus the rear left apex 1803 of the platform 1800 is moved rightwardly in the same direction and over the same distance as the other couplings 1241, 1242 by i) driving the rear left control member 1213 along the drive axis M3 inwardly and generally towards the right, resulting also in a forward component of movement, and ii) to balance out this undesired forward component of movement, moving the rear left control member 1213 rearwards perpendicularly to its axis, by driving the rear left support table 1148 generally rearwardly along the base rails 1025, 1026, which also provides a further movement to the right. The position of the rear left coupling 1233 along the rear left inclined path P3 is unchanged, thereby maintaining the height of the rear left apex 1803 unchanged.

[0071] Figures 11 and 11 a show a state of forward surge. The front control member 1211 is moved fully forwards along the drive axis MI along a direction of the X axis. The rear right table 1147 and rear left table 1148 are moved to their forwardmost positions along the respective pairs of rear base rails 1023, 1024; 1025, 1226. The rear right control member 1212 and rear left control member 1213 are moved inwardly along the respective drive axes M2, M3 in order to maintain the respective positions of the rear right and rear left couplings 1242, 1243 along the inclined paths P2, P3 as the tables 1147, 1148 move forwards, enabling the forward surge while maintaining the apices 1801, 1802, 1803 at the same height, and the platform 1800 horizontal.

[0072] Figure 12 shows an alternative embodiment of a motion generation apparatus 2000, comprising a plurality of actuation arrangements 1001, 2002, 2003, each configured independently to drive a respective control member 1211, 2212, 2213 laterally in multiple lateral directions. The construction and operation of the apparatus 2000 is similar to that of the apparatus 1000 described above with reference to Figures 1 to 11a, except for differences in the rear actuation arrangements. In describing construction and operation of the apparatus 2000, only the differences will be described. Where a feature of the apparatus 2000 of Figure 12 is the same as a feature of the apparatus 1000 already referred to, the same reference sign will be used.

[0073] Tn the motion generation apparatus 2000 of Figure 12, each of the rear control members 2212, 2213 is supported by a respective rear upper support, or table, 2147, 2148 for movement in a lateral plane along a longitudinal axis of the table 2147, 2148. The longitudinal axis of each rear table 2 I 47, 2148 extends parallel to the X axis. Each rear table 2147, 2148 comprises a respective upper guide. The longitudinal axis of each guide extends parallel to the X axis, in the lateral XY plane. Each guide comprises a respective pair of parallel upper guide rails 2 I 23, 2124; 2125, 2126. The base portion of each control member 1211, 2212, 2213 is provided with a respective upper engager The engagers of the rear control members 2212, 2213 are angled in the lateral XY plane relative to the longitudinal axes of the rear control members 2212, 2213 such that, when the upper engagers are engaged with the respective upper guides 2123, 2124; 2125, 2126, the longitudinal axes of the rear control members 2212, 2213 are inwardly angled, and the inclined paths P1, P2, P3 extend generally towards an inner region of the platform 1800 in the at rest condition of the motion generation apparatus 2000.

[0074] Each upper engager 2132, 2133 comprises a respective set of four carriages, and each respective set of carriages engages a respective pair of the guide rails 2123, 2124; 2125, 2126. Each carriage takes the form of an upturned generally U-shaped member having a wheel or wheels on its underside that engage with a respective one of the guide rails 2123, 2124; 2125, 2126 so as to restrain lateral movement relative to the rail while permitting low friction travel of the carriage along the rail.

[0075] Each actuation arrangement 1001, 2002, 2003 is independently connected, for independent force transmission, to a respective one of the control members 1211, 2212, 2213, and comprises a respective upper linear actuation device 1141, 2142, 2143. Each upper linear actuation device 1141, 2142, 2143 is supported by a respective one of the tables 1146, 2147, 2148 and is connected by its respective forcer to a respective control member 1211, 2212, 2213. Drive axes M5. M6 of the rear upper linear actuation devices 2142, 2143 are arranged generally parallel with the X axis of the motion generation apparatus 2000 so as to supply drive to the respective rear control members 2212, 2213, in alignment with the guide rails 2123, 2124; 2125, 2126. The upper linear actuation devices 1141, 2142, 2143 of the embodiment take the form of electric linear motors, in particular ironless, or air-core, electric linear motors.

[0076] The motion generation apparatus 2000 comprises a rear lower linear actuation device 2042 that extends in the Y direction substantially across the rear extent of the apparatus 2000, so as to be used in common by both the rear right and the rear left actuation arrangements 2002, 2003. The rear lower linear actuation device 2042 is supported between a respective pair of rear base guide rails 2023, 2023, with its drive axis parallel to the rails 2023, 2024, on a common base support 2012. Separate respective forcers (not shown) of the rear lower linear actuation device 2042 are connected to the undersides of the respective rear tables 2147, 2148 for independently driving the respective rear tables 2147, 2148 along the rear base guide rails 2023, 2024.

[0077] Each respective rear upper linear actuation device 2142, 2143 is thus stacked above the common rear lower linear actuation device 2042 for perpendicular movement relative thereto, and each rear control member 2212, 2213 is laterally drivable in any chosen lateral direction. The rear lower linear actuation device 2042 takes the form of an electric linear motor, in particular an ironless, or air-core, electric linear motor. The rear base support 2012 may comprise a pre-stressed steel base plate. It will be apparent that the motion generation apparatus 2000 comprises two rear actuation arrangements 2002, 2003, each having a respective rear upper linear actuation device 2142, 2143 stacked on a respective portion of the common rear lower linear actuation device 2042, the rear lower linear actuation device 2042 being arranged to independently drive each of the respective rear upper linear actuation devices 2142, 2143 along the common guide extending in a Y direction i.e. generally perpendicular to the front-back X axis of the motion generation apparatus 2000, for permitting an increased range of sway.

[0078] The principle of operation of the alternative apparatus 2000 is similar to that of the apparatus 1000, and the range of motions available to the apparatus 2000 is also similar except for additional capabilities due to the enhanced range of sway.

[0079] Figure 13 shows the motion generation apparatus 1000 further including an occupant carrier 1300 fixed to the motion platform 1800 so as to move with the platform 1800 and transmit motion to an occupant (not shown). The occupant carrier 1300 is for use in motorsports simulations, and provides seating for a single occupant. Figure 14 is a front left perspective view of the motion generation apparatus 1000, including an alternative occupant carrier 1400 fixed to the motion platform 1800 so as to move with the platform 1800 and transmit motion to an occupant (not shown). The occupant carrier 1400 is for use in more general automotive simulations.

[0080] Key components of the apparatus 1000, 2000 can be formed from any suitable engineering materials, for example metallic alloy or composite materials, that can provide relatively light weight structures for transmitting high forces, including transient forces, and support the weight of the platform 1800 and occupant carrier 1300; 1400, while providing mechanical stiffness. In general, suitable materials for components to support high bandwidth performance of the motion generation apparatus 1000, 2000 should provide sufficient stiffness to permit the actuation arrangements 1001, 1002, 1003; 2002, 2003 to drive the platform 1800 and occupant carrier 1300, 1400 via the motion control arrangements 1201, 1202, 1203 with minimal mechanical compliance of components, whether under shear, tensile or torsional loading. Where appropriate, relatively low weight fibrous composite materials can be employed with the fibres oriented so as to provide high stiffness. The rotatable joints 1261, 1262, 1263 can, for example, comprise or consist of heat treated high-carbon steel, and/or any other suitable material. Control members I 21 I, 1212, 1213; 2212, 2213 and/or tables 1146, 1147, 1148; 2147, 2148 can, for example, comprise or consist of aluminium, or of aluminium and composite, and/or any other suitable material. The base supports 1011,1012,1013; 2012 can, for example, comprise or consist of steel or aluminium, and/or any other suitable material.

100811 The motion generation apparatuses 1000, 2000 can be used for simulating vehicular motion such as motion of a ground based vehicle, or of an air, space or sea vehicle. In use, in a motion platform system for simulating vehicular motion, various mechanical and electronic controls (not shown) are provided in or on the occupant carrier, and various sensors and processors (not shown) are provided to sense parameters such as position, speed and/or acceleration of various components of the motion generation apparatus 1000. Such controls and sensors are connected to communicate control information to a system processor (not shown) for controlling the actuation arrangements 1001, 1002, 1003; 1001, 2002, 2003 in accordance with the commands from the controls. A display (not shown) controlled by the system processor to provide visual information during the simulation may also be provided. Such a motion platform system may be configured to simulate motion of a land, air, space or sea vehicle, including an aircraft, spacecraft, hovercraft, water craft or land vehicle, for example a land motor vehicle such as a single seat performance motor car, or a tracked or off-road vehicle The motion generation apparatuses 1000, 2000 of the embodiments have motion envelopes suitable to provide excursions typically seen in motorsport and automotive cueing. However, it will be apparent that many other types of motion envelope are obtainable using variations of the embodiments.

[0082] Whilst the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

CLAIMS1. Motion generation apparatus for a motion platform system, the apparatus comprising: a platform for supporting an occupant carrier; a plurality of motion control arrangements each configured to independently provide motion control to a respective portion of the platform, and each comprising i) a respective control member and ii) a respective rotatable coupling coupled between the platform and the respective said control member; and a plurality of actuation arrangements each configured independently to drive a respective said control member laterally in multiple lateral directions; wherein at least one of the control members comprises an inclined portion, and a respective said coupling is configured to engage the respective inclined portion such that laterally driving the or each respective control member forces the or each respective coupling to in a direction along an inclined path under control of the control member, to thereby impart a vertical component of drive force to a said respective portion of the platform; motion and positioning of the platform laterally and vertically with multiple degrees of freedom being determined by the combined movement and/or positioning of the control members.
2. Motion generation apparatus according to claim 1, wherein a plurality of the control members, for example three said control members, each comprises a respective said inclined portion and is configured to engage with a respective said coupling, such that laterally driving each respective said control member causes each respective said coupling to be driven under control of the respective control member along the respective inclined portion in a direction along a respective inclined path, to thereby impart a vertical component of drive force to a said respective portion of the platform.
3. Motion generation apparatus according to claim 2, wherein the inclined paths extend generally towards an inner region of the platform in an at rest condition of the motion generation apparatus.
4. Motion generation apparatus according to claim 2 or 3, comprising two rear motion control arrangements, the directions of the respective inclined paths of the rear motion control arrangements having an angle therebetween of from about 200 to 160°, preferably from about 900 to 140°, and more preferably of about 120°.
5. Motion generation apparatus according to claim 2, 3 or 4, wherein a respective angle vertically between the direction of a said inclined path and a laterally extending plane lies in a range from about 10° to about 45°, and preferably is about 16'.
6. Motion generation apparatus according to any of the preceding claims, wherein the or each said coupling that is configured to engage the respective inclined portion is engaged so as to move freely along the respective said inclined path, motion of the or each said coupling being controlled by the or each respective control member.
7. Motion generation apparatus according to any of the preceding claims, wherein each coupling comprises a carriage connected to the platform through a respective rotatable connector joint disposed between the or each respective carriage and the respective portion of the platform.
8. Motion generation apparatus according to any of the preceding claims, wherein the or each rotatable coupling is fixed against translational movement of the or each coupling relative to the platform, while permitting rotational movement between the platfonu and the or each respective control member.
9. Motion generation apparatus according to any of the preceding claims, wherein the or each rotatable coupling provides three degrees of rotational freedom of movement relative to the or each respective portion of the platform.
10. Motion generation apparatus according to any of the preceding claims, comprising three or more said motion control arrangements, each associated with a respective one of said actuation arrangements.
11. Motion generation apparatus according to any of the preceding claims, wherein the combined movement and/or positioning of all of the control members controls motion and positioning of the platform with three translational and three rotational degrees of freedom of movement.
12. Motion generation apparatus according to any of the preceding claims, wherein the or each motion control arrangement comprises a respective guide configured to constrain movement of a respective said coupling to translation along a respective said inclined path.
13. Motion generation apparatus according to claim 12, wherein the or each control member comprises a respective said guide, for example one or more rails, extending along a respective said inclined portion.
14. Motion generation apparatus according to claim 13, wherein the or each coupling comprises a respective engaging portion, comprising for example a carriage including one or more rotatable wheels, configured to engage with a respective said guide of a respective said control member so that the or each coupling is guided along a respective said inclined path.
Ii. Motion generation apparatus according to any of the preceding claims, wherein the actuation arrangements include respective linear actuation devices having respective drive axes arranged at angles so as to be laterally in alignment with the respective inclined paths.
16. Motion generation apparatus according to any of claims 1 to 14, wherein the actuation arrangements include respective linear actuation devices having respective drive axes arranged at angles so as to be laterally out of alignment with the respective inclined paths.
17. Motion generation apparatus according to any of the preceding claims, wherein at least one of the actuation arrangements comprises a respective plurality of stacked linear actuation devices, the or each actuation arrangement being independently connected, for independent force transmission, to the or each respective control member.
18. Motion generation apparatus according to any of the preceding claims, wherein at least one of the actuation devices comprises an electric linear motor.
19. Motion generation apparatus according to any of the preceding claims, wherein each actuation arrangement is supported on a separate respective base support, to permit independent fixing and orientation of the base supports in relation to one another.
20. Motion generation apparatus according to any of the preceding claims, wherein the actuation arrangements include respective linear actuation devices having respective drive axes arranged generally parallel with a front-back axis of the motion generation apparatus.
21. Motion generation apparatus according to any of the preceding claims, comprising two rear said actuation arrangements, each comprising a respective upper linear actuation device stacked on a respective portion of a common lower linear actuation device, the lower linear actuation device being arranged to independently drive the respective upper linear actuation devices along a common guide extending in a direction generally perpendicular to a front-back axis of the motion generation apparatus, for permitting an increased range of sway.
22. Motion generation apparatus according to any of the preceding claims, comprising two rear said actuation arrangements and a front said actuation arrangement, the front actuation arrangement providing a greater extent of travel than each of the rear actuator arrangements in a direction generally perpendicular to a front-back axis of the motion generation platform, for permitting an increased range of sway.
23. Motion generation apparatus according to any of the preceding claims, wherein the platform comprises a rigid frame.
24. Motion generation apparatus according to any of the preceding claims, further comprising an occupant carrier fixed for movement relative to platform, the occupant carrier including, for example, seating for a single occupant, or tandem, side by side, or multiple seating for multiple occupants.
25. A motion platform system for simulating vehicular motion, comprising motion generation apparatus according to any of the preceding claims.
26. A motion platform system as claimed in claim 24, configured to simulate motion of a land, air, space or sea vehicle, including an aircraft, spacecraft, hovercraft, water craft or land vehicle, for example a land motor vehicle such as a single seat performance motor car, or a tracked or off-road vehicle.
27. A simulator for simulating vehicular motion, comprising: a movable frame to support occupant seating and controls; three inwardly pointing control wedges having respective inwardly and upwardly directed inclined wedge faces; three couplings each i) connected to a respective fixed location on the frame by a respective rotatable joint having three degrees of rotational freedom of movement, and ii) engaged with a respective one of the inclined faces for guided relative translational movement along the face; and respective linear motors to respectively drive each of the respective wedges independently, in any desired horizontal direction; motion of the frame with three rotational degrees of freedom and three translational degrees of freedom being controlled by operation of the linear motors.
28. A simulator according to claim 27, the linear motors having drive axes respectively extending along front-back and sideways directions of the simulator, each of 3! which directions is arranged at a lateral angle relative to the respective directions of guided movement of the couplings along each of the inwardly directed faces.