Motion generator

Abstract

The invention relates to a motion generator comprising an end effector that moves relative to a surface, the end effector being moved by at least six actuation mechanisms, wherein each actuation mechanism comprises an elongated tension member that is connected at one end thereof to the end effector, whereby the end effector is suspended above the surface by the tension member, and at the other end thereof to an associated rocker of the same actuation mechanism, whereby the rocker is mounted pivotable about an axis that is fixed relative to the surface, and wherein upon actuation of the rocker, the associated tension member and the end effector are caused to move. The invention further relates to a motion system and simulator comprising such a motion generator, and to methods of operation and production.

Description

TECHNICAL FIELD

[0001] The present invention relates to the field of motion systems. In particular, but not exclusively, the present invention relates to motion generators, and to motion systems comprising such motion generators, and to methods of using motion generators and motion systems. BACKGROUND

[0002] A motion generator is a device capable of applying forces and / or moments, motions and accelerations to a payload in the direction of one or more degrees of freedom. The payload can be, for example, a person experiencing a simulated experience in a motion simulator based on the motion generator. Motion generators are used in motion systems comprising a control system.

[0003] Motion systems are used for various applications, including motion simulation (e.g. flight simulators and driving simulators), robotics, 3D printing, vibration and seismic simulation. The most common type of motion system currently used in motion simulation is the Stewart platform (or “hexapod”). This is a parallel robot with six actuators (typically hydraulic rams) connected in pairs to three configurations on a platform base and spanning three mounting points on a top plate. A device or payload, e.g. a human user, placed on the top plate, typically in the form of a cockpit, driver area or model vehicle, can be moved in six degrees of freedom in which the freely suspended body can move, i.e. three linear motions x, y, z (lateral, longitudinal and vertical) and three rotations (pitch, roll and yaw).

[0004] A motion simulator is a mechanism comprising a motion system that can create the effect or sensation of being in a moving vehicle for an occupant. Motion simulators are used professionally for training drivers and pilots in the form of driving and flight simulators, respectively. They are also used industrially for the creation, design and testing of vehicles themselves. Professional motion simulators for driving and flight simulators typically synchronise visual displays - e.g. provided by a projection system and associated screen - and audio signals with the motion of the vehicle cabin (or chassis) occupied by the driver or pilot in order to provide a better sensation of the effect of the motion. Motion simulators are also used for leisure or gaming applications (e.g. arcade video driving games). The advent of virtual reality (VR) head-mounted displays (HMDs) has reduced the cost of immersive simulations with current motion systems and enabled the provision of virtual reality applications for leisure use, for example in passive amusement park or arcade driving, first-person cycling or flying rides, and in active games in which one or more players have some control over the driving, cycling, flying or first-person game experience.

[0005] Six-legged types commonly used for human participant motion simulation typically have a relatively low bandwidth of up to about 20 Hz. This means that they can produce oscillatory motion and vibration of consistent amplitude up to a frequency of 20 times per second, beyond which the amplitude of the motion decreases with increasing frequency. This is sufficient to replicate most car suspension motion, but it does not transmit frequency content associated with vibrations from the car engine, tyre vibrations, road noise and sharp kerbs on the race track. The low bandwidth also means signal delay, which means that the driver cannot respond quickly.

[0006] Current motion systems, especially those intended for high-end use motion systems such as military and commercial flight guidance and training applications, are typically very large, heavy, complex and very expensive. Their complexity requires a lot of programming and maintenance, further increasing the cost to the user. Specialised driving simulator motion systems have been developed by McLaren / MTS Williams / ABD and Ansible, but these systems tend to be mechanically extremely complex and therefore also very expensive, with precision machined custom components and often expensive linear motors. These specialised driving simulator motion systems are more sensitive than six-legged in some directions, but are still limited in others. The disadvantage of using ball screws in such systems is that while they establish positioning well, they dampen force transmission and can only achieve a lower bandwidth. This results in a less natural experience for the human user.

[0007] The applicant’s earlier patent publications WO2020 / 007506 and EP3591641 form part of the technical background to the present invention.

[0008] It is an object of the present invention to provide an improved motion generator, and an improved motion system and simulator incorporating such a motion generator. It is an object of the present invention to provide a motion generator operable to move an end effector in six degrees of freedom, which is less expensive to produce. It is a further object of the present invention to provide a motion generator suitable for leisure or gaming applications. SUMMARY

[0009] According to an aspect of the present invention, there is provided a motion generator according to claim 1. An advantage of such a motion generator can be that it is less expensive to produce. A further advantage of such a motion generator can be that it is suitable for leisure or gaming applications, for example because it is relatively simple to produce or it is particularly compact. The motion generator according to the present invention can still have a relatively high bandwidth. The motion generator can be backdrivable.

[0010] Further features of the motion generator according to the present invention are apparent from the individual claims 2 to 17 or combinations of claims 2 to 17.

[0011] According to another aspect of the present invention, a motion system is provided, the motion system including a motion generator and a control system according to the present invention.

[0012] Another aspect of the present invention provides a simulator comprising a motion generator according to the invention or a motion system and environment simulation device according to the invention.

[0013] Another aspect of the invention provides a motion simulator for gaming or leisure applications, including a motion generator according to the invention. Preferably, the motion generator includes an end effector weighing less than 200 kg, less than 100 kg, or less than 50 kg, which may be typical in gaming applications, and a motion generator control system.

[0014] The present invention also provides methods for using a motion generator or motion system, such as those set forth in any one of claims 21 to 23.

[0015] The present invention also provides a method for producing a motion generator or motion system according to any one of claims 24 to 25. Attached Figure Description

[0016] Now, we will refer to the appendix as an example only. Figures 1 to 11 The invention describes a motion generator, motion system, and driving simulator according to the present invention, as well as their operation and manufacture, wherein:

[0017] Figure 1 This is a perspective view of the motion generator according to the present invention in a neutral state, viewed from the front and one side.

[0018] Figure 1A yes Figure 1 A three-dimensional view of the motion generator viewed from the back and one side;

[0019] Figure 2 yes Figure 1 A three-dimensional view of the motion generator in a swaying state, viewed from the front and one side.

[0020] Figure 3 yes Figure 1 A three-dimensional view of the motion generator in a forward-swinging state, viewed from the front and one side.

[0021] Figure 4 This is a perspective view of the motion generator according to the present invention, viewed from the front and one side, generally as follows: Figure 1 As shown, one type of actuation mechanism is in a neutral state;

[0022] Figure 5 yes Figure 4 A detailed view of a portion of the motion generator actuation mechanism shown;

[0023] Figure 6 is a perspective view of a motion generator according to the application, seen from the front and one side, substantially as Figure 1 illustrated, with another type of actuation mechanism in a neutral state;

[0024] Figure 7 is a perspective view of a motion generator according to the application, seen from the front and one side, substantially as Figure 1 illustrated, with another type of actuation mechanism in a neutral state;

[0025] Figure 8 is a detailed view of the actuation mechanism illustrated in Figure 7

[0026] Figure 9 is a perspective schematic view of a motion simulator according to the application;

[0027] Figure 10 is a perspective view of another motion simulator according to the application; and

[0028] Figure 11 is a schematic view of a control system for use in a motion system according to the application. DETAILED DESCRIPTION

[0029] Motion generator

[0030] Figure 1 A motion generator 10 according to the application is shown. The motion generator 10 is mounted on a surface 12, for example the floor of a building in which the motion generator is located.

[0031] The motion generator 10 comprises an end effector in the form of a platform 14 for supporting a payload, here a user 16. The platform 14 is here a replica of a racing car cockpit suitable for, for example, a gaming or leisure application. The platform 14 is suspended on six elongate tension members T1-6 comprised in six actuation mechanisms (not fully shown). One end of each elongate tension member T1-6 in an actuation mechanism is connected to the platform 14 and the other end is connected to one end of an associated rocker R1-6 in the actuation mechanism, respectively. As Figure 1A illustrated, the rockers R1-6 are pivotally mounted on the surface 12 and are free to pivot or rock in a counterclockwise or clockwise direction, respectively, indicated by the curved arrows, about an axis A indicated by a straight line A1, A2, A3, A4, A5 or A6 under the control of an actuator, which is typically an electric motor (not shown). Examples of the actuator and the complete actuation mechanism are explained in detail below. In the illustrated embodiment, the rockers R1-6 are mounted on the surface 12. It will be appreciated that the rockers can be mounted on a frame supporting the motion generator or contained in the motion generator.

[0032] Method of using a motion generator ​

[0033] As shown, for example, in Figure 11 The motion generator 10 can be operated by actuation of the actuation mechanisms of the generator, typically under command of a control system, so that the suspended end effector 14 is moved in six degrees of freedom by the rocker drive motions of the six tension members in the six actuation mechanisms.

[0034] Figure 2 The motion generator 10 is shown with its end effector 14 in a left roll state. In this state, the displacement states of the rockers are as follows:

[0035]

[0036] Figure 3 The motion generator is shown with its end effector in a surge forward state. In this state, the displacement states of the rockers are as follows:

[0037]

[0038] While two states have been described above, it will be appreciated that the suspended end effector 14 can be moved in six degrees of freedom by the rocker drive motions of the six tension members in the six actuation mechanisms to other states, including a right sway, a heave up, a heave down, a surge back, and combinations of any such states.

[0039] Actuation mechanisms

[0040] Figure 4 and 5 An actuation mechanism of the type used in the motion generator of the application is shown. Figure 4 The motion generator 10 shown is as described above in relation to Figures 1-3 As generally described above, the motion generator comprises six actuation mechanisms, and like elements have like numbering. Figure 5 One actuation mechanism is shown in detail. In the following description of different types of actuation mechanisms, the elements of an actuation mechanism (e.g. X) are given the numbering of the actuation mechanism (e.g. X1, X2, X3, X4, X5 or X6). The motion generator is provided with six such actuation mechanisms. In this form of actuation mechanism, and as Figure 5In detail, a rocker R is associated with a motor M, which has a toothed capstan C (covered). An elongated toothed belt B is connected at one end to a spring S, which keeps the belt B in tension. The other end of the toothed belt B is connected to an elongated tension member TM, which in turn suspends the end effector 14. There are six such actuation mechanisms in the motion generator. Upon command from the control system, operation of the motor M displaces the "free end" (i.e. the non-pivotally mounted end) of the associated rocker R1-6 clockwise or counter-clockwise by the motion of the associated toothed belt B. This causes the motion of the tension member T connected to the rocker, such that the motion of the end effector is according to the displacement of the end effector caused by the rockers R1-6, for example, into the above-described pitch or heave forward configuration. Figure 2 and 3 the described pitch or heave forward configuration.

[0041] actuation mechanism

[0042] Figure 6 Another type of actuation mechanism is shown for use in the motion generator of the present invention. Figure 4 The shown motion generator 10 is again as generally described with respect to Figures 1-3 and like elements have like numbering. In this type of actuation mechanism, a pivotally mounted rocker R is associated with a motor RM, which is directly connected to the rocker by a shaft (covered). The free end of the rocker R is connected to a tension member, which in turn suspends the end effector 14. By virtue of this direct connection to the rocker, upon command from the control system, operation of the motor RM causes the clockwise or counter-clockwise displacement of the associated rocker R1-6 by the motion of the associated shaft.

[0043] actuation mechanism

[0044] Figure 7 and 8 Other actuation mechanisms are shown for use in the motion generator of the present invention. Figure 7 The shown motion generator 10 is again as generally described with respect to Figures 1-3 and like elements have like numbering. Figure 8 One actuation mechanism is shown in detail. In this form of actuation mechanism, and as Figure 8In detail, a rocker R pivotally mounted on a shaft A is associated with a motor M having a toothed capstan C (shrouded) on its shaft. Near the midpoint of the rocker, an elongate toothed belt TB is connected at both ends to the rocker R and is in mesh with the capstan C. It will be appreciated that the toothed belt TB can alternatively be continuous and fixed to the rocker R at one point. Other connection points are also conceivable. The connection point towards the free end of the rocker can be preferred. The idler P is biased by a spring S to keep the belt B under tension. The free end of the rocker R is connected to an elongate tension member TM which in turn suspends the end effector 14. There are six such actuation mechanisms in the motion generator. Upon command from the control system, operation of the motor M produces a clockwise or anti-clockwise displacement of the associated rocker R1-6 by the motion of the associated toothed belt B. This produces a motion of the tension member T such that the motion of the end effector 14 is according to the displacement of the end effector produced by the rockers R1-6 into the forward configuration described above with respect to Figure 2 and 3 the pitch or surge forward configuration.

[0045] Several different types of actuation mechanisms have been described above by way of example. It is possible that a motion generator according to the invention can comprise six actuation mechanisms of the same type, or a mix of actuation mechanisms of the types described above, for example. A motion generator according to the invention can comprise more than six such actuation mechanisms, possibly for reasons of redundancy.

[0046] Motion system

[0047] A motion system according to the invention comprises a motion generator according to the invention and an associated motion generator control system. Figure 11 An example of a control system suitable for use in the control operation of a motion generator according to the invention is shown. Figure 11 The control system 701 shown can receive input from a user. With respect to Figure 11The motion generator of the motion system is referred to as 702, but the control system 701 is applicable to other motion generators, motion systems, and motion simulators, such as the motion generator 10 and motion simulators 20, 30 described herein. The control system 701 includes a motion controller 704, which preferably executes a computer program in a deterministic or real-time manner, and obtains motion demand inputs 705 from a demand generator such as a simulation environment 703 or a setpoint generator 706. The motion controller calculates the position, acceleration, and / or force 707 that needs to be produced at each actuator 709 to produce the desired motion trajectory 705. The control system 701 also includes servo drives 708, which provide precisely controlled currents 710 to drive the actuators 709. In operation, the motion controller sends the desired position or force 707 to each servo drive 708. The actuators 709 have motion measuring devices 711, such as encoders, which optionally provide motion feedback 712 to the motion controller through the servo drives. The motion controller compares the desired motion trajectory 705 with the measured 712, and updates the actuator demand 707 accordingly. Figure 11 A control system is also shown with a simulation environment 703, such as a driving simulation, in which the physical properties of a simulated vehicle and its environment, such as a race track or city street, are computed. In this embodiment, the control system 701 receives motion demands from the simulation environment 703, which represent the motion of a virtual vehicle. A computer program determines the motion of the vehicle in the virtual world 714, and then applies a motion cueing algorithm 713 (MCA, also known as a washout filter) to convert the simulated vehicle motion into those that can be represented by the motion generator 701. These computed motions are then provided to the control system as motion demands 705. The MCA 713 can be part of the simulation environment 703 or the control system 701 or separate from both. The simulation environment 703 can receive input signals 715 from control devices 716, such as steering, throttle, or brake inputs, which are used by an operator, i.e., a human user such as a driver, passenger, or pilot, to control the virtual vehicle in the simulation environment. The operator can be a passenger on the motion generator 702. These inputs 715 can be passed back to the simulation environment through the control system or directly. The simulation environment can also produce outputs on a visual display 717 for the driver, passenger, or other user or operator. The simulation environment can also require additional data 718 from the control system, such as data related to the position of the motion generator or control device input signals.

[0048] Motion simulator

[0049] In Figure 9 and 10A motion simulator 20 and 30 according to the application are shown in Figs. 1 and 2. The motion simulator 20 comprises a motion system 21 according to the application (including a control system 20CS, e.g. as described above) and at least one environment simulation device.

[0050] In the motion simulator 20 of Fig. 1, the environment simulation device comprises a projection system 20PS and a screen 22. A separate environment simulation device in the form of an audio system can also be provided. Figure 9

[0051] In the motion simulator 30 of Fig. 2, the environment simulation device is in the form of a virtual reality headset 32 worn by the user 16. Figure 10 Figure 10 A user input device, here a joystick 34, 35, which can be used to provide input to the associated motion generator control system 30CS, is also shown.

[0052] Method of producing a motion generator

[0053] A method of producing a motion generator according to the application can comprise providing an end effector and at least six actuation mechanisms, wherein each actuation mechanism comprises an elongate tension member connected at one end thereof to the end effector, whereby the end effector is suspended above a surface by the tension member, and connected at the other end thereof to an associated rocker of the same actuation mechanism, whereby the rocker is mounted to be pivotable about an axis fixed relative to the surface, and wherein, when the rocker is actuated, the associated tension member and the end effector move; and assembling the above elements to produce the motion generator. The method can further comprise connecting a control system to the motion generator to produce a motion simulator.​​

Claims

1. A motion generator comprising an end effector that moves relative to a surface, the end effector being actuated by at least six actuation mechanisms, wherein each actuation mechanism includes an elongated tensioning member connected at its bottom end to the end effector and at its top end to an associated rocker arm of the same actuation mechanism, wherein the end effector is suspended above the surface by the tensioning member from the rocker arm, and wherein the rocker arm is mounted to be pivotable about a pivot axis fixed relative to the surface, the rocker arm having a non-pivotible mounted end that is displaceable by pivoting the rocker arm about the pivot axis, and wherein... When the rocker arm is actuated and its non-pivotable end is displaced, the associated tensioning member and end effector move.

2. The motion generator according to claim 1, wherein, The elongated tensioning member slopes downward from the top of the non-pivotable end of the rocker arm to the bottom of the end effector.

3. The motion generator according to claim 1, wherein, The rocker arm is pivotable about its pivot axis in both the clockwise and counterclockwise directions, and the elongated tensioning member is connected to either the first clockwise side of the rocker arm or the second counterclockwise side of the rocker arm.

4. The motion generator according to claim 1, wherein, When the given actuating mechanism is in a neutral state, the non-pivotable end of its rocker arm is positioned at a height above the connection between the slender tensioning member and the end effector.

5. The motion generator according to claim 1, wherein, Each slender tensioning member is connected to its associated rocker at a point between the pivot axis and the non-pivot mounting end along the length of the rocker associated in the same actuating mechanism.

6. The motion generator according to claim 5, wherein, Each elongated tensioning member is connected to its associated rocker arm at the non-pivotable end of the rocker arm.

7. The motion generator according to claim 6, wherein, Each rocker arm is pivotally mounted on a rotary joint or bearing.

8. The motion generator according to claim 1, wherein, At least one actuation mechanism includes a motor drivably connected to the rocker arm.

9. The motion generator according to claim 8, wherein, The motor is an electric motor, a torque motor, or a geared motor.

10. The motion generator according to claim 9, wherein, All actuation mechanisms include an electric motor, torque motor, or geared motor that is drivably connected to the rocker arm.

11. The motion generator according to claim 10, wherein, A motor of an actuation mechanism is connected to the rocker arm of the same actuation mechanism via a shaft drivably connected at its pivot point, thereby, in use, the rocker arm pivots by the rotation of the shaft.

12. The motion generator according to claim 11, wherein, The shaft is concentric with the pivot axis around which the rocker arm pivots.

13. The motion generator of claim 1, wherein at least one actuation mechanism includes a tension band connected to the rocker arm at a point along the length of the rocker arm between the pivot axis and the non-pivot mounting end.

14. The motion generator according to claim 13, wherein, All actuation mechanisms include a tension band connected to the rocker arm at a point along its length between the pivot axis and the non-pivot mounting end.

15. The motion generator according to claim 14, wherein, The point is oriented toward the non-pivotable end of the rocker arm.

16. The motion generator according to claim 15, wherein, The tension band is connected to the rocker arm at the end of the rocker arm.

17. The motion generator according to claim 13, wherein, The tensioning band is actuated by a winch or pulley, which is actuated by an associated motor or other drive device, and the tensioning band is kept taut by a spring or other elastic member attached to its other end.

18. The motion generator according to claim 1, wherein, At least one actuation mechanism includes an elongated tension band connected at both ends to the rocker arm and actuated by a winch or pulley or by a motor, and optionally kept tensioned by a guide wheel connected to a spring or other elastic member.

19. The motion generator according to claim 18, wherein, All actuation mechanisms include this thin tension band.

20. The motion generator according to claim 1, wherein, The surface is the ground or a support for the motion generator.

21. A motion system comprising a motion generator and a motion generator control system according to claim 1.

22. A motion simulator, comprising a motion generator according to claim 1 and at least one environmental simulation device.

23. A motion simulator for gaming or leisure use, comprising the motion generator according to claim 1, wherein the end effector weighs less than 200 kg, less than 100 kg, or less than 50 kg, and comprising a motion generator control system.

24. A method of operating a motion generator according to claim 1 or a motion simulator according to claim 22, the method comprising: Operate one or more of these actuators to make the end effector move in up to six degrees of freedom.

25. The method according to claim 24, wherein, Operation is performed using a motion generator control system connected to or within the motion generator system.

26. The method of claim 25, wherein, The control system is user-operated.

27. A method for producing a motion generator according to any one of claims 1 to 20, the method comprising: A component is provided comprising an end effector and at least six actuation mechanisms, wherein each actuation mechanism includes an elongated tensioning member connected at its bottom end to the end effector and at its top end to an associated rocker arm of the same actuation mechanism, wherein the end effector is suspended above a surface by the rocker arm via the tensioning member, wherein the rocker arm is mounted to be pivotable about a pivot axis fixed relative to the surface, the rocker arm having a non-pivotable end end that is displaceable by pivoting the rocker arm about the pivot axis, and wherein, when the rocker arm is actuated and its non-pivotable end end is displaced, the associated tensioning member and the suspended end effector are moved; and the above-described component is assembled to generate a motion generator.

28. A method for producing a motion system, the method comprising: Producing the motion generator according to claim 27; And, the control system is connected to the motion generator.

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