MOTION GENERATOR

Abstract

This invention relates to motion generators comprising: an end effector, a stationary support, a first set of elastic elements interconnecting the end effector and the stationary support; a set of tensile members; in which the end effector is supported within the stationary support by the elastic elements; and a set of actuators in which the motion generator further comprises at least six rockers each rocker being pivotally mounted at one end thereof on the stationary support, and each rocker having a free end; the set of tensile members comprising: at least six elongate tensile members, each elongate tensile member having one end connected to a rocker and the other end connected to one of a second set of elastic elements which are fixed; a set of connecting elements connecting each rocker to the end effector and in which each one of the set of tensile members is independently adjustably tensioned by an associated actuator to move the free end of the rocker, which rocker movement causes movement of a connected connecting element leading to movement of the end effector.

Claims

1-20. (canceled)

21. A backdriveable motion generator comprising: a moveable end effector; a frame; a first set of elastic elements interconnecting the end effector and the frame; a set of tensile members, in which the end effector is supported within the frame by the elastic elements; a set of actuators; and at least six rockers each being pivotally mounted at one end thereof on the frame, and each having a free end, wherein: the set of tensile members comprises: at least six elongate tensile members, each elongate tensile member having one end connected to a rocker and the other end connected to one of a second set of elastic elements, the second set of elastic elements being fixed to one of the frame or a base; and a set of connecting elements connecting each rocker to the end effector; and each one of the set of tensile members is independently adjustably tensioned by an associated actuator to move the free end of the rocker, which rocker movement causes movement of a connected connecting element leading to movement of the end effector.

22. The backdriveable motion generator according to claim 21 in which the effector includes or supports a platform, vehicle chassis, monocoque, or seat.

23. The backdriveable motion generator according to claim 21 in which motion of the effector may be controlled to produce high frequency motion of the effector of more than 50 Hz in six degrees of freedom.

24. The backdriveable motion generator according to claim 23 in which motion of the effector may be controlled to produce high frequency motion of the effector of up to 100 Hz.

25. The backdriveable motion generator according to claim 23 in which motion of the effector may be controlled to produce high frequency motion of the effector of more than 100 Hz.

26. A method of operating the backdriveable motion generator according to claim 21, and in which the actuators of the motion generator comprise rotary electric motors, the method of operating being such that when a user supported by the end effector moves, then forces applied by the user to the effector cause one or more of the electric motors to rotate.

27. The method according to claim 26 in which the rotation of the motors is measured and used to infer the user's position and movement.

28. A game apparatus for domestic or commercial use in a game or simulation, the game apparatus comprising the backdriveable motion generator according to claim 21, and in which a movement of a user on the effector is used as an input to the game or simulation.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0033] Motion generators, motion systems, and driving simulators and their operation, uses and production in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, FIGS. 1 to 10, in which:

[0034] FIG. 1A is an elevation from one side of a motion generator in accordance with the invention in a neutral configuration;

[0035] FIG. 1B is an elevation from the front of the motion generator as shown in FIG. 1A;

[0036] FIG. 1C is a simplified plan view from below of the motion generator as shown in FIG. 1A;

[0037] FIG. 1D is a perspective view of the motion on generator as shown in FIG. 1A from above, front and one side;

[0038] FIG. 2A is an elevation from one side of the motion generator of FIG. 1 when in a surge forward along the x-axis configuration;

[0039] FIG. 2B is an elevation from the front of the motion generator as shown in FIG. 2A;

[0040] FIG. 2C is a simplified plan view from below of the motion generator as shown in FIG. 2A;

[0041] FIG. 2D is a perspective view of the motion generator as shown in FIG. 2A;

[0042] FIG. 3A is an elevation from one side of the motion generator of FIG. 1 when in a sway laterally along the y-axis configuration;

[0043] FIG. 3B is an elevation from the front of the motion generator as shown in FIG. 2A;

[0044] FIG. 3C is a simplified plan view from below of the motion generator as shown FIG. 2A;

[0045] FIG. 3D is a perspective view of the motion generator as shown in FIG. 2A;

[0046] FIG. 4A is an elevation from one side of the motion generator of FIG. 1 when in a heave vertically along the z-axis configuration;

[0047] FIG. 4B is an elevation from the front of the motion generator as shown in FIG. 4A;

[0048] FIG. 4C is a simplified plan view from below of the motion generator as shown in FIG. 4A;

[0049] FIG. 4D is a schematic perspective view of a motion generator as shown in FIG. 4A;

[0050] FIG. 5A is an elevation from one side of the motion generator of FIG. 1 when in a roll about the x-axis configuration;

[0051] FIG. 5B is an elevation from the front of the motion generator as shown in FIG. 5A;

[0052] FIG. 5C is a simplified plan view from below of the motion generator as shown in FIG. 5A;

[0053] FIG. 5D is a schematic perspective view of a motion generator as shown in FIG. 5A;

[0054] FIG. 6A is an elevation from one side of the motion generator of FIG. 1 when in a pitch about the y-axis configuration;

[0055] FIG. 6B is an elevation from the front of the motion generator as shown in FIG. 6A;

[0056] FIG. 6C is a simplified plan view from below of the motion generator as shown in FIG. 6A;

[0057] FIG. 6D is a schematic perspective view of a motion generator as shown in FIG. 6A;

[0058] FIG. 7A is an elevation from one side of the motion generator of FIG. 7 when in a yaw about the z-axis configuration;

[0059] FIG. 7B is an elevation from the front of the motion generator as shown in FIG. 7A;

[0060] FIG. 7C is a simplified plan view from below of the motion generator as shown in FIG. 7A;

[0061] FIG. 7D is a schematic perspective view of a motion generator as shown in FIG. 7A;

[0062] FIG. 8A is an elevation from one side of the motion generator of FIG. 1 when in a combined surge, sway and yaw configuration

[0063] FIG. 8B is an elevation from the front of the motion generator as shown in FIG. 8A;

[0064] FIG. 8C is a simplified plan view from below of the motion generator as shown in FIG. 8A;

[0065] FIG. 8D is a schematic perspective view of a motion generator as shown in FIG. 8A;

[0066] FIG. 9A is an elevation from one side of the motion generator of FIG. 1 when in a combined pitch and roll configuration;

[0067] FIG. 9B is an elevation from the front of the motion generator as shown in FIG. 9A;

[0068] FIG. 9C is a simplified plan view from below of the motion generator as shown in FIG. 9A;

[0069] FIG. 9D is a schematic perspective view of a motion generator as shown in FIG. 9A; and

[0070] FIG. 10 is an elevation of a vehicle motion simulator incorporating a motion generator of FIG. 1 in use with a human user.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

[0071] A Motion Generator

[0072] A motion generator 10 in accordance with the invention is shown in FIGS. 1 to 9. The motion generator 10 is mounted on a surface such as floor 12. The floor 12 may be that of a test building in which the motion generator is located or may be an additional floor unit which overlays another floor in use.

[0073] The motion generator 10 comprises a rigid frame 14, of tubular space-frame type construction including lower elongate tubular elements 16, 18, 20, 22, 24, and 25, and longer tubular elements 26, 28, and 30, which each have a lower horizontal portion co-planar with tubular elements 16, 18, 20, 22, 24 and 25 to form the base of the frame 14 and which each also have an upstanding portion 27, 29, and 31 respectively. Although tubular components have been described, those components may be for example solid. The frame 14 may be made of materials such as steel, or other alloy, aluminium, aluminium alloy, titanium or carbon fibre and in the form of separate components joined rigidly together or could equally be moulded in one or more pieces. Suspended within the volume created by the frame 14 is a platform (or end effector) 32 which is sufficient to carry a significant load, for example a seat and a human user, or a vehicle chassis or monocoque. The platform 32 has a triangular planform. Other platforms are and anticipated for the platform.

[0074] Six rockers 36, 38, 40, 42, 44, and 45 are pivotally mounted by one end thereof on the ends of tubular elements 16, 18, 20, 22, 24, and 25 for movement in the horizontal plane only. More rockers may be used. In other embodiments the rockers may move in different planes according to the application and configuration. Whilst straight rockers have been shown in this example other shapes are contemplated for the rockers including L-shaped or V-shaped. Elongate struts 46, 48, 50, 52, 54, and 55 are in turn pivotally mounted on the other ends of the rockers 36, 38, 40, 42, 44, and 45 respectively by their lower ends. The opposing end of each strut 46, 48, 50, 52, 54, and 55 is pivotally mounted to the corners of the triangular motion platform 32 in pairs 46, 45; 48, 50, and 52, 54. The struts 46, 48, 50, 52, 54, and 55 could be replaced by tensile members such as ropes, wire ropes or belts. One example of a suitable rope is M-Rig Max made from Dyneema's DM20 by Marlow. A suitable wire rope is SS 1×7/1×19 Compacted made by Certex. A suitable belt is Conti® Synchrochain Carbon made by Continental.

[0075] As shown in FIG. 1A, the platform 32 is supported by three elastic cords 60, 62 and 64 which are fixed at one end to the ends of upstanding portions 27, 29 and 31 of the frame 14, and fixed at the other end to rigid elongate members 70, 72 and 74 which are fixed to and depend from the base of the platform 30. An example of a suitable elastic cord would be a Powerspring by Ibex Marina. Three or more elastic elements in the first set of elastic elements are preferred. Too many elastic elements may inhibit operation. Elastic cords 60, 62, 64 could be replaced by helically coiled springs, or wire ropes connected to another elastic energy storage device such as a torsion spring.

[0076] Six actuators, in the form of rotary electric motors, driving toothed capstans (one suitable example of which would be an AKM2G Servo Motor by Kollmorgan with a synchronous belt sprocket by Martin) 80 (referred to as “actuator 1” below), 82 (“actuator 2”), 84 (“actuator 3”), 86 (“actuator 4”), 88 (“actuator 5”),and 90 (“actuator 6”) are fixed to the base 12 or to the frame so that they are constrained from movement. The actuators drive toothed belts 92, 94, 96 98, 100, and 102 which connect at one end thereof to the rockers and at the other end to the frame 14 or base 12 via a second set of elastic elements in the form of elastic cords 104, 106, 108, 110, 112, and 114, which are anchored rigidly fixed to the frame 14 or base 12. Elastic cords 104, 106, 108, 110, 112, and 114 could be replaced by helically coiled springs, or wire ropes connected to another elastic energy storage device such as a torsion spring.

[0077] In use, each associated rocker, elastic cord, actuator and belt combination 36 104, 80, 92; 38, 106, 82, and 94; 40, 108, 84, 96; 42, 110, 86, 98; 44, 112, 88, 100; and 45, 114, 90, 102, (each combination being referred to in the description below by the actuator number mentioned above) is controlled by computing means (not shown) acting on the actuator to move the associated belt thus altering the state of the connected rocker and elastic cord which affects the motion/position of the platform 32.

[0078] Some basic configurations of the motion generator will now be described with reference to the further figures.

[0079] Neutral Configuration

[0080] In the neutral configuration illustrated in FIG. 1A-D the motion platform 32 is horizontal, suspended by the elastic cords 60, 62 and 64 with the rockers and elastic cords in a neutral state.

TABLE-US-00001 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Neutral Neutral 2 Neutral Neutral 3 Neutral Neutral 4 Neutral Neutral 5 Neutral Neutral 6 Neutral Neutral

[0081] Surge Forward Along the x-Axis Configuration

[0082] In the surge forward configuration shown in FIGS. 2A-D, the platform 32 is moved forward by actuator-controlled movement of the rockers and connected elastic cords into the states set out below.

TABLE-US-00002 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Anticlockwise Extended 2 Anticlockwise Contracted 3 Anticlockwise Extended 4 Clockwise Extended 5 Clockwise Contracted 6 Clockwise Extended

[0083] Sway Laterally Along the y-Axis Configuration

[0084] In the sway sideways configuration shown in FIGS. 3A-D, which may simulate sideways movement of a vehicle, the platform 32 is moved sideways by actuator-controlled movement of the rockers and connected elastic cords into the states set out below.

TABLE-US-00003 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Clockwise Contracted 2 Anticlockwise Contracted 3 Anticlockwise Extended 4 Anticlockwise Contracted 5 Anticlockwise Extended 6 Clockwise Extended

[0085] Heave Vertically Along the z Axis Configuration

[0086] In the heave upwards configuration shown in FIGS. 4A-D, the platform 32 is moved upwardly by actuator-controlled movement of the rockers and connected elastic cords into the states set out below.

TABLE-US-00004 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Anticlockwise Extended 2 Clockwise Extended 3 Anticlockwise Extended 4 Clockwise Extended 5 Anticlockwise Extended 6 Clockwise Extended

[0087] Roll About the x-Axis Configuration

[0088] In the roll configuration shown in FIG. 5A-D, the platform 32 rotates about its longitudinal axis by actuator-controlled movement of the rockers and connected elastic cords into the states set out below.

TABLE-US-00005 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Unchanged Unchanged 2 Clockwise Extended 3 Anticlockwise Extended 4 Anticlockwise Contracted 5 Clockwise Contracted 6 Unchanged Unchanged

[0089] Pitch About the y Axis Configuration

[0090] In the pitch configuration shown in FIG. 6A-D, the nose 33 of the platform 32, is lowered by actuator-controlled movement of the rockers and connected elastic cords into the states set out below

TABLE-US-00006 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Clockwise Contracted 2 Clockwise Extended 3 Anticlockwise Extended 4 Clockwise Extended 5 Anticlockwise Extended 6 Anticlockwise Contracted

[0091] Yaw About the z-Axis Configuration

[0092] In the configuration shown in FIG. 7A-D, the platform 32 rotates about a vertical axis by actuator-controlled movement of the rockers and connected elastic cords into the states set out below.

TABLE-US-00007 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Clockwise Contracted 2 Clockwise Extended 3 Clockwise Contracted 4 Clockwise Extended 5 Clockwise Contracted 6 Clockwise Extended

[0093] In the above description, a number of configurations for the motion generator are described. It will be appreciated that these two or more of these configurations can be combined in many different ways to simulate different motion events.

[0094] Combined Surge, Sway and Yaw

[0095] In the configuration shown in FIG. 8A-D, the motion generator is in a Combined Surge, Sway and Yaw configuration.

TABLE-US-00008 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Clockwise Contracted 2 Clockwise Extended 3 Clockwise Contracted 4 Clockwise Extended 5 Clockwise Contracted 6 Clockwise Extended

[0096] Combined Pitch and Roll

[0097] In the configuration shown in FIG. 9, the motion generator is in a combined pitch and roll. Configuration.

TABLE-US-00009 Actuator support Rocker position spring length Actuator relative to relative to number neutral state neutral state 1 Clockwise Contracted 2 Clockwise Extended 3 Anticlockwise Extended 4 Unchanged Unchanged 5 Unchanged Unchanged 6 Anticlockwise Contracted

[0098] Test Data

[0099] When a motion generator in accordance with the invention was tested it was found to be capable of creating movements in all six degrees of freedom with a bandwidth in excess of 50 Hz′.

[0100] The motion generator can accelerate at more than 10 m/s.sup.2 in each translational direction and at more than 1000°/s.sup.2 in each rotational direction. As the system is essentially a direct drive system, lacking gearboxes or ballscrews it is capable of being backdriven.

[0101] Specific practical applications of the motion generator described above are now disclosed below.

[0102] A Vehicle Simulator

[0103] A vehicle simulator 200 is shown in FIG. 10. The vehicle simulator comprises a motion generator 202 in which the platform (end effector) 204 supports a chassis replica including a cockpit 206. Foot controls (not shown) and steering wheel 208 are mounted within the cockpit 206. A user 112 sits in cockpit 206. A projection system including screen 210 is provided which displays a driving environment simulation to a user. In use, the user feels vibrations transmitted through the mo generator 202 to the cockpit 206. A feature of the motion generator of the present invention is that when the user moves in relation to the platform 204, for example lurching sideways against a rolling movement of the platform, the motion generator is backdriven.

[0104] Vehicle Design

[0105] In a method of designing a vehicle, using a motion generator in accordance with the invention in a vehicle simulator as described above, a change in a vehicle parameter may be simulated through operation of the motion generator in a particular manner to reflect the change, and feedback from an experienced user in the simulator, and measurements on the system are useful in determining whether the change results in an improvement in vehicle performance in some aspect.

[0106] An Arcade Game Apparatus

[0107] An arcade game apparatus, for example a racing car game apparatus, may have the same main features as the vehicle simulator 200, but might, for example use a lower cost virtual reality headset system to the projection system shown in FIG. 10. Furthermore, an arcade game apparatus might include apparatus for coin, token, electronic payment system or card-controlled operation.

[0108] A further application of the system could as an arcade apparatus in which the user's body movement are detected and acted upon by the system. For example, the use may be standing on a board (e.g. surfboard or skateboard) which is fixed to the table/end effector. By shifting their weight around and applying inertial forces to the board, the user may shove or tilt the board in different directions. These movements can be used as inputs to the simulation or game. The game may also still generate movements and forces that push the board and the user in different directions.

[0109] This is possible due to the “backdrivability” of the system, meaning that its state can easily be affected by movements or loads applied to the end effector. This is possibly due to the very low friction present in the actuators compared to a typical hexapod system which might use a ball-screw actuator.

[0110] It will be appreciated that arcade game apparatus could be adapted for domestic use.

[0111] While a number of embodiments have been disclosed by way of example in this specification, it should be understood that other variations are possible within the scope of the present invention. For example, in certain applications, some or all of the rockers may move in a non-horizontal plane. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.