Joint driver simulation test platform based on magnetorheological device

Abstract

The invention discloses a joint driver simulation test platform based on a magnetorheological device, and belongs to the technical field of test and control. The platform comprises an adjustable load unit, a sensor unit, a control system and an upper computer. The magneto-rheological device serves as an adjustable load element, controllable force or torque load output is achieved by adjusting the magnitude of exciting current, the actual working condition of the tested joint driver is reproduced, and therefore the response of the corresponding joint driving unit is simulated and tested. Besides, in order to compensate mechanical friction and liquid viscous force of the magneto-rheological device, a motor active driving unit is installed on the magneto-rheological device in parallel, so that the test interval of the simulation test platform is remarkably improved. The device is compact in structure, high in response speed and easy to control, and can be widely applied to dynamic performance test and characteristic research of joint motors, joint actuators, joint brakes and other parts of humanoid robots, human exoskeletons and human prostheses.

Description

Technical Field

[0001] This invention belongs to the field of testing and measurement technology in mechanical engineering, and specifically relates to a joint actuator simulation test platform based on a magnetorheological device. Background Technology

[0002] In the field of modern robotics, high-performance joint actuators are the core of achieving flexible movement and precise control of devices. In recent years, especially in applications such as humanoid robots and exoskeleton robots, joint actuators not only need to output precise position and torque, but also must have good dynamic response capabilities to cope with unstructured external interference. To ensure the reliability of joint actuators, rigorous load simulation tests must be conducted during the research and development phase to reproduce complex working conditions such as gravitational torque, inertial force, friction, and human-robot interaction forces in real-world scenarios.

[0003] Traditional load simulation platforms are mainly divided into two types based on the loading components: electro-hydraulic loading systems and electric loading systems. Electro-hydraulic loading systems use servo valves to control hydraulic cylinders or hydraulic motors to generate corresponding thrust or torque to simulate loads. These systems have large output torque and high operating frequency bands, but also have large friction / torque, making them unsuitable for small loads. They also have a slow response speed. Electric loading systems mainly use torque motors, electromagnetic clutches, and magnetic powder brakes. These systems have better stability, but the coupling between electricity and magnetism leads to higher control complexity. They are mainly suitable for constant torque or linear load conditions and are difficult to implement complex nonlinear loads. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a joint actuator simulation test platform based on a magnetorheological device. This platform incorporates a magnetorheological device as an adjustable load element, achieving controllable force or torque load output by adjusting the excitation current, thus replicating the actual operating conditions of the joint actuator under test and simulating the response of the corresponding joint drive unit. Furthermore, to compensate for the mechanical friction and fluid viscosity of the magnetorheological device, this invention connects a motor active drive unit in parallel with the magnetorheological device, significantly expanding the test range of the simulation test platform.

[0005] The technical solution of this invention to solve the above problems is: a joint actuator simulation test platform based on a magnetorheological device, characterized in that it includes: An adjustable load unit is used to drive the joint actuator under test in linear or rotary motion. The adjustable load unit is used to generate controllable damping force or damping torque, thereby accurately testing the driving performance of the joint actuator under test under different loads.

[0006] The sensor unit is used to collect system status data in real time, providing feedback for control and testing.

[0007] The control system is used to execute real-time control algorithms, complete sensor data acquisition, signal filtering and communication, and control the output of the adjustable load unit according to the target characteristics.

[0008] The host computer is used to control system parameters and issue commands, display the system status in real time, and collect test data.

[0009] Preferably, the joint actuator under test can be a rotary active / passive element.

[0010] Preferably, the rotating active and passive components include one or more of the following: a rotary motor, a point drive unit, a transmission system, a joint module, a brake, a clutch, a flywheel, or a moment of inertia testing device.

[0011] Preferably, the joint actuator under test can be a linear active / passive element.

[0012] Preferably, the linear active and passive components include one or more of the following: hydraulic cylinder, push rod, linear motor, linear joint, telescopic unit, suspension, and shock absorber.

[0013] Preferably, the adjustable load unit can reproduce one or more of the following: a torque curve that is constant or variable with time, a torque curve that is constant or variable with angle, a torque curve that is constant or variable with angular velocity, a force curve that is constant or variable with time, a torque curve that is constant or variable with displacement, and a torque curve that is constant or variable with velocity.

[0014] Preferably, the main structure of the adjustable load unit can be a magnetorheological device connected in parallel with an active drive element via a transmission unit.

[0015] Preferably, the main structure of the adjustable load unit can also be a direct drive of a magnetorheological device.

[0016] Preferably, the magnetorheological brake includes one or more of the following: a magnetorheological rotary brake, a magnetorheological linear damper, a magnetorheological clutch, and a magnetorheological hydraulic valve.

[0017] Preferably, the magnetorheological rotary brake is one or more of a disc brake, a drum brake, and a hybrid brake.

[0018] Preferably, the magnetorheological rotary brake includes a stator, a rotor, an excitation coil, a magnetorheological fluid, a magnetic circuit structure, and a housing.

[0019] Preferably, the magnetorheological linear damper is one or more of a single-tube damper, a double-tube damper, and a double-ended damper.

[0020] Preferably, the magnetorheological linear damper includes a piston rod, a piston head, a coil, a magnetorheological fluid, a magnetic circuit structure, and a housing.

[0021] Preferably, the magnetorheological clutch is typically used to transmit or disconnect power to the drive element.

[0022] Preferably, the magnetorheological hydraulic valve is connected to the hydraulic cylinder via a bypass arrangement to convert hydraulic pressure into damping force / damping torque.

[0023] Preferably, the magnetorheological hydraulic valve includes a valve core, valve body, coil, magnetorheological fluid, magnetic circuit structure, and outer shell.

[0024] Preferably, the active drive element can be used to compensate for the inherent fluid flow damping and mechanical friction damping of the magnetohydrodynamic fluid, and can also provide controllable driving force to achieve positive angle / torque output.

[0025] Preferably, the active drive element is one or more of various types of motors, electro-hydraulic active elements, pneumatic active elements, and smart material active elements.

[0026] Preferably, the transmission unit is used to transmit and amplify (or regulate) the output of the magnetorheological device and the active drive element.

[0027] Preferably, the transmission unit can be one or more of the following: direct-drive transmission, speed reduction transmission mechanism, ball screw mechanism, series-parallel transmission, and gear / differential transmission mechanism.

[0028] Preferably, the sensor unit is used to monitor and provide feedback on the system operating parameters in real time, providing closed-loop control signals and performance monitoring data to the control system and the host computer.

[0029] Preferably, the sensor unit includes one or more of the following: torque sensor, angular velocity sensor / encoder, displacement sensor, force sensor, current sensor, and pressure sensor.

[0030] Preferably, the torque sensor is used to measure the output torque, thereby realizing closed-loop torque control and torque superposition or compensation.

[0031] Preferably, the angular velocity sensor / encoder is used to provide velocity feedback for dynamic control and data acquisition.

[0032] Preferably, the displacement sensor is used to detect the displacement of the linear drive element.

[0033] Preferably, the force sensor is used to measure the applied force for force control and calibration.

[0034] Preferably, the current sensor is used to detect the magnetic field strength and derive the output force / torque of the magnetorheological device.

[0035] Preferably, the pressure sensor is used to detect the pressure in the magnetorheological cavity and analyze the fluid characteristics and stability.

[0036] Preferably, the control system is used to execute real-time control algorithms, complete sensor data acquisition and filtering, communicate and record with the host computer, and control the load requirements of the host computer to control the output force / torque of the adjustable load unit.

[0037] Preferably, the hardware components of the control system include a real-time controller, an analog-to-digital / digital-to-analog converter module, a driver, a communication interface, and a safety protection unit.

[0038] Preferably, the real-time controller is used for closed-loop control, signal processing, I / O processing, and communication with a host computer.

[0039] Preferably, the analog-to-digital converter module is used to convert the sensor's analog signal into a digital signal for the controller.

[0040] Preferably, the digital-to-analog converter module is used to convert digital signals into analog signals for the driver.

[0041] Preferably, the driver includes a coil drive for a magnetorheological device and a servo drive for an active element such as a motor.

[0042] Preferably, the magnetorheological device has a coil drive support current loop.

[0043] Preferably, the servo drive of the motor supports one or more of the following: current loop, speed loop, position loop, and torque loop.

[0044] Preferably, the communication interface is used to realize information transmission between the host computer, the driver, and the slave computer.

[0045] Preferably, the safety protection unit supports one or more of the following: hardware and software limit switches, emergency stop, electrical protection, and overcurrent alarm.

[0046] Preferably, the control system software comprises a bottom-level architecture, a middle-level architecture, and a top-level architecture.

[0047] Preferably, the underlying architecture directly controls the current and voltage of the driver.

[0048] Preferably, the mid-level architecture control structure includes torque closed-loop control and compensation control algorithms.

[0049] Preferably, the upper-layer architecture mainly performs task target generation and system management.

[0050] Advantages of this invention: This invention proposes a joint actuator simulation test platform based on a magnetorheological device. The platform uses a magnetorheological device as an adjustable load unit and achieves controllable force / torque load output by adjusting the magnetic field strength through current. Compared to electro-hydraulic loading systems, this platform offers faster response times and a more compact layout; compared to electric loading systems, it consumes less power and is easier to control. To address the issues of fluid resistance and mechanical friction, the platform proposed in this invention introduces an active driving element, which can effectively counteract or reduce the noise of the system caused by the fluid resistance and mechanical friction of the magnetorheological device, and expand the test range of the test platform. This invention can be used not only for testing the load characteristics of motors, but also for testing components such as joint motors, joint actuators, and joint brakes in humanoid robots, human exoskeletons, and human prostheses. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the principle framework of an embodiment of the present invention (parallel motor); Figure 2 This is a schematic diagram of the principle framework of an embodiment of the present invention (non-parallel motors); Figure 3 An isometric view (parallel motor) of a torque load simulation platform for an embodiment of the present invention; Figure 4 An isometric view of the torque load simulation platform (without parallel motors) as an embodiment of the present invention; Figure 5 An isometric view of the force load simulation platform (parallel motor) for an embodiment of the present invention; Figure 6 This is an isometric view of the force load simulation platform (without parallel motors) as an embodiment of the present invention; Figure 7 This is an example diagram of a magnetorheological rotary brake according to an embodiment of the present invention; Figure 8 An example diagram of an adjustable magnetorheological rotary brake (large gear engagement) is shown as an embodiment of the present invention. Figure 9 An example diagram (small engagement) of an adjustable magnetorheological rotary brake is shown as an embodiment of the present invention. Figure 10 This is an example diagram of a magnetorheological linear damper according to an embodiment of the present invention; Figure 11 This is an example diagram of a magnetorheological hydraulic valve according to an embodiment of the present invention; Figure 12 Example diagram of an adjustable magnetorheological hydraulic valve (large clearance) as an embodiment of the present invention; Figure 13 Example diagram of an adjustable magnetorheological hydraulic valve (small clearance) as an embodiment of the present invention; Figure 14 This is a dynamic model diagram of a magnetorheological device according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the user interface of an embodiment of the present invention; Figure 16 Example simulation scenario one of the joint actuators in this embodiment of the invention; Figure 17 Example simulation scenario two of the joint actuator in this embodiment of the invention; Figure 18 This is an example of a torque curve in an embodiment of the present invention; Figure 19 This is an example of a force curve in an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1. Elevating platform; 2. Rotary element mounting bracket; 3. Gear set; 4. Magnetorheological rotary brake; 5. Brake mounting bracket; 6. Servo motor I; 7. Reducer; 8. Servo motor mounting bracket; 9. Torque sensor; 10. Rotary element under test; 11. Damper mounting bracket; 12. Damper elevation plate; 13. Magnetorheological linear damper; 14. Coupling; 15. Linear element mounting bracket; 16. Linear element under test; 17. Transmission unit; 18. Force sensor; 19. Linear module; 20. Servo motor I; 21. Motor II; 22. Magnetofluid I; 23. Rotor; 24. Stator; 25. Excitation coil I; 26. Multilayer rotor; 27. Excitation core; 28. Magnetofluid II; 29. ​​Gear structure; 30. Housing I; 31. Multilayer stator; 32. Excitation coil II; 33. Piston; 34. Housing II; 35. Piston rod; 36. Magnetofluid III; 37. Excitation coil III; 38. Valve core; 39. Housing III; 40. Hydraulic pipe; 41. Magnetofluid IV; 42. Displacement sensor. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0053] This invention proposes a joint actuator simulation test platform based on a magnetorheological device, comprising: an adjustable load unit, a sensor unit, a control system, and a host computer.

[0054] The tested joint actuator, as the loaded object, is used to drive the linear or rotary motion of the adjustable load unit. The adjustable load unit is used to generate controllable damping force or damping torque, thereby accurately testing the driving performance of the tested joint actuator under different loads. The sensor unit is used to collect system status variables in real time, providing feedback for control and testing. The control system is used to execute real-time control algorithms, complete sensor data acquisition, signal filtering and communication, and control the output of the adjustable load unit according to the target characteristics. The host computer is used to control system parameter setting and command issuance, and to display the system status in real time and collect test data.

[0055] The joint actuator under test can be a rotary active / passive element.

[0056] Specifically, the rotating active and passive components include one or more of the following: a rotary motor, a point drive unit, a transmission system, a joint module, a brake, a clutch, a flywheel, or a moment of inertia testing device.

[0057] The joint actuator under test can be a linear active / passive element.

[0058] Specifically, the linear active and passive components include one or more of the following: hydraulic cylinder, push rod, linear motor, linear joint, telescopic unit, suspension, and shock absorber.

[0059] In a preferred embodiment of the present invention, the adjustable load unit can reproduce one or more of the following: torque curves that are constant or variable with time, torque curves that are constant or variable with angle, torque curves that are constant or variable with angular velocity, force curves that are constant or variable with time, torque curves that are constant or variable with displacement, and torque curves that are constant or variable with velocity.

[0060] In a preferred embodiment of the present invention, the main structure of the adjustable load unit can be a magnetorheological device connected in parallel with an active drive element through a transmission unit, or it can be a magnetorheological device directly connected to a drive unit.

[0061] Specifically, the magnetorheological brake includes one or more of the following: a magnetorheological rotary brake, a magnetorheological linear damper, a magnetorheological clutch, and a magnetorheological hydraulic valve. The magnetorheological rotary brake can be one or more of the following: a disc brake, a drum brake, and a hybrid brake.

[0062] As a preferred embodiment of the present invention, the magnetorheological rotary brake includes a stator, a rotor, an excitation coil, a magnetorheological fluid, a magnetic circuit structure, a housing, etc.

[0063] In a preferred embodiment of the present invention, the magnetorheological linear damper is one or more of a single-tube damper, a double-tube damper, and a double-ended damper.

[0064] In a preferred embodiment of the present invention, the magnetorheological linear damper includes a piston rod, a piston head, a coil, a magnetorheological fluid, a magnetic circuit structure, and a housing.

[0065] As a preferred embodiment of the present invention, the magnetorheological clutch is typically used to transmit or disconnect the power of a drive element.

[0066] In a preferred embodiment of the present invention, the magnetorheological hydraulic valve is connected to the hydraulic cylinder via a bypass arrangement to convert hydraulic pressure into damping force / damping torque.

[0067] In a preferred embodiment of the present invention, the active driving element can be used to compensate for the inherent fluid flow damping and mechanical friction damping of the magnetohydrodynamic fluid, and can also provide controllable driving force to achieve positive angle / torque output.

[0068] In a preferred embodiment of the present invention, the active driving element is a servo motor. In a preferred embodiment of the present invention, the transmission unit is used to transmit and amplify (or adjust) the output of the magnetorheological device and the active driving element.

[0069] In a preferred embodiment of the present invention, the transmission unit is a parallel transmission.

[0070] Specifically, the transmission unit of the test rotary active-passive component is a gear transmission mechanism, and the transmission unit of the test linear active-passive component is a ball screw mechanism.

[0071] In a preferred embodiment of the present invention, the sensor unit is used to monitor and provide feedback on the system operating parameters in real time, and to provide closed-loop control signals and performance monitoring data to the control system and the host computer.

[0072] In a preferred embodiment of the present invention, the sensor unit includes a torque sensor, an angular velocity sensor / encoder, a displacement sensor, a force sensor, and a current sensor.

[0073] Specifically, the torque sensor is used to measure the output torque, realize torque closed-loop control, and torque superposition or compensation.

[0074] The angular velocity sensor / encoder is used to provide velocity feedback for dynamic control and data acquisition.

[0075] The displacement sensor is used to detect the displacement of the linear drive element.

[0076] The force sensor is used to measure the applied force for force control and calibration.

[0077] The current sensor is used to detect the magnetic field strength and derive the output force / torque of the magnetorheological device.

[0078] In a preferred embodiment of the present invention, the control system is used to execute a real-time control algorithm, complete sensor data acquisition and filtering, communicate and record with the host computer, and control the load requirements of the host computer to control the output force / torque of the adjustable load unit.

[0079] In a preferred embodiment of the present invention, the hardware components of the control system include a real-time controller, an analog-to-digital / digital-to-analog converter module, a driver, a communication interface, and a safety protection unit.

[0080] Furthermore, the real-time controller is used for closed-loop control, signal processing, I / O processing, and communication with the host computer.

[0081] The analog-to-digital converter module is used to convert the sensor's analog signals into digital signals for the controller. The digital-to-analog converter module is used to convert the digital signals into analog signals for the driver.

[0082] The driver includes a coil drive for a magnetorheological device and an active element, such as a servo drive for a motor.

[0083] Specifically, the magnetorheological device has a coil drive support current loop.

[0084] The servo drive of the motor supports current loop, speed loop, position loop, and torque loop.

[0085] The communication interface is used to realize information transmission between the host computer, the driver, and the slave computer.

[0086] The safety protection unit supports hardware and software limits, emergency stop, electrical protection, and overcurrent alarm.

[0087] In a preferred embodiment of the present invention, the control system software comprises a bottom-level architecture, a middle-level architecture, and a top-level architecture.

[0088] Specifically, the underlying architecture directly controls the current and voltage of the driver. The middle-layer architecture control structure includes torque closed-loop control and compensation control algorithms. The upper-layer architecture mainly performs task target generation and system management.

[0089] Figure 1 and Figure 2This is a schematic diagram of the principle framework of the joint actuator simulation test platform based on a magnetorheological device proposed in this invention. The main working principle is as follows: The housing of the joint actuator under test is fixed, the transmission shaft is connected to the sensor, and the linear element is used in conjunction with the force sensor and the displacement sensor. The force sensor detects the load force signal, and the displacement sensor detects the element displacement signal. The control system feeds back the collected tension / compression and displacement signals to the adjustable load unit, and the adjustable load unit outputs damping force or active angle. The rotary element is used in conjunction with the torque sensor and the angle sensor. The torque sensor collects torque and angle signals, and the control system feeds back the collected torque and angle signals to the adjustable load unit. The linear adjustable load unit outputs damping torque or active angle. The main structure of the adjustable load unit can be a magnetorheological device connected in parallel with a motor through a transmission unit, or it can be a magnetorheological device directly connected to a drive.

[0090] See Figures 3-6 This invention proposes a joint actuator simulation test platform based on a magnetorheological device. The test platform can be divided into a rotating element test system and a linear element test system, which are placed on a raised platform 1.

[0091] See Figure 3 The structure of the rotating element testing system (parallel motor) is as follows: the housing of the magnetorheological rotary brake 4 of the adjustable load unit is fixed on the brake mounting bracket 5, and the output shaft of the magnetorheological rotary brake 4 is connected to the gear set 3 of the transmission unit; the servo motor I 6 together with the reducer 7 is fixed on the servo motor bracket 8 and is also connected to the gear set 3; the brake and the motor transmit the superimposed torque to the output gear of the gear set 3, and the output gear is connected to the torque sensor 9 for detecting the torque signal; the housing of the rotating element 10 under test is fixed on the rotating element mounting bracket 2, and its output shaft is connected to the torque sensor 9 through a coupling.

[0092] See Figure 4 The structure of the rotating element testing system (non-parallel motor) is as follows: the housing of the magnetorheological rotary brake 4 of the adjustable load unit is fixed on the brake mounting bracket 5, the output shaft of the magnetorheological rotary brake 4 is directly connected to the torque sensor 9 for detecting torque signal, the housing of the rotating element 10 under test is fixed on the rotating element mounting bracket 2, and the output shaft is connected to the torque sensor 9 through a coupling.

[0093] See Figure 5The structure of the linear element testing system (parallel motor) is as follows: the housing of the magnetorheological linear damper 13 of the adjustable load unit is fixed on the riser platform 1 through the damper mounting bracket 11 and the damper riser plate 12; the piston rod of the magnetorheological linear damper 13 is connected to one end of the linear transmission unit 17 through the coupling 14; the servo motor II 20 is connected to the other end of the linear transmission unit 17 through the linear module 19; the linear transmission unit 17 transmits the superimposed force to the linear element 16 under test; the force sensor 18 detects the force signal; the displacement sensor 42 detects the displacement signal; and the linear element 16 under test is fixed on the riser platform 1 through the linear element mounting bracket 15.

[0094] See Figure 6 The structure of the linear element testing system (non-parallel motor) is as follows: the housing of the magnetorheological linear damper 13 of the adjustable load unit is fixed on the riser platform 1 through the damper mounting bracket 11 and the riser plate 12. The piston rod of the magnetorheological linear damper 13 is connected to the force sensor 18, which transmits the force to the linear element 16 under test. The force sensor 18 detects the force signal, and the displacement sensor 42 detects the displacement signal. One end of the housing of the linear element 16 under test is fixed on the riser platform 1, and the output shaft is connected to the force sensor 18.

[0095] Figures 7-13 The magnetorheological device used in the preferred embodiment includes: a magnetorheological rotary brake, a magnetorheological linear damper, and a magnetorheological hydraulic valve.

[0096] Figure 7 This is a schematic diagram and magnetic field distribution diagram of a magnetorheological disc brake. The disc brake is mainly composed of magnetorheological fluid I21, rotor 22, stator 23, and excitation coil I24. The magnetic circuit is along the white dashed line, and the direction of motion is along the black arrow. After the excitation coil I24 is energized, a magnetic field is generated inside. The magnetorheological fluid I21 between rotor 22 and stator 23 changes from liquid to solid, the viscosity increases, which hinders the rotation of rotor 22 and outputs damping torque. Figure 7 The right figure shows the magnetic field distribution, which passes through the rotor, stator, and the magnetofluid between them.

[0097] In particular, Figure 8 and Figure 9 This diagram shows a schematic of an adjustable magnetorheological brake and its magnetic field distribution (under large and small engagement lengths). It mainly consists of a multi-layer rotor 25, an excitation core 26, a magnetorheological fluid II 27, an engagement unit 28, a housing I 29, a multi-layer stator 30, and an excitation coil II 31. The magnetic circuit is along the white dashed line, and the direction of motion is along the black arrow. The brake can adjust the working width and length of the magnetorheological fluid through the engagement structure 28, thereby expanding the controllable torque range of the brake.

[0098] See Figure 8This is a schematic diagram and magnetic field distribution diagram of the brake under the large engagement length. At this time, the multi-layer rotor 25 and the multi-layer stator 30 approach each other and mesh. After the excitation coil II 31 is energized, a magnetic field is generated from the excitation core 26. The magnetofluid II 27 between the multi-layer rotor 25 and the multi-layer stator 23 changes from liquid to solid, the viscosity increases, which hinders the rotation of the multi-layer rotor 25 and outputs a large damping torque. Figure 8 The middle right figure shows the magnetic field distribution, which passes through the rotor, stator, and the magnetofluid between them.

[0099] See Figure 9 This diagram shows the brake in the short engagement length and the magnetic field distribution. At this time, the multi-layer rotor 25 and the multi-layer stator 30 are separated from each other or partially separated. When the excitation coil II 31 is not energized, the magnetofluid II 27 is mainly in a liquid state with low viscosity and will not hinder the rotation of the multi-layer rotor 25. When the excitation coil II 31 is energized, the output damping torque will also decrease accordingly. Figure 9 The middle right figure shows the magnetic field distribution. The magnetic field passes through the rotor, stator, and the magnetofluid between them, but produces a magnetic field weaker than that at small engagement lengths.

[0100] Figure 10 This diagram shows the magnetic field distribution of a magnetorheological damper. The damper mainly consists of an excitation coil Ⅲ32, a piston 33, a housing Ⅱ34, a piston rod 35, and a magnetorheological fluid Ⅲ36. The magnetic circuit is along the white dashed line, and the direction of motion is along the straight line of the black arrow. When the excitation coil Ⅲ32 is energized, a magnetic field is generated inside. The magnetorheological fluid Ⅲ36 between the piston 33 and the housing Ⅱ34 changes from a liquid state to a solid state, increasing the viscosity and hindering the movement of the piston 33, thus outputting a damping force. Figure 10 The right image shows the magnetic field distribution, with the magnetic field passing through the piston, the outer shell, and the magnetofluid between them.

[0101] Figure 11 This diagram shows the magnetic field distribution of a magnetorheological hydraulic valve. The valve mainly consists of an excitation coil IV 37, a valve core 38, a housing III 39, a hydraulic pipe 40, and a magnetorheological fluid IV 41. The magnetic circuit is along the white dashed line, and the hydraulic medium magnetorheological fluid IV flows along the black arrow. When the excitation coil IV 37 is energized, a magnetic field is generated inside. The magnetorheological fluid IV 41 between the valve core 38 and the housing III 39 changes from a liquid state to a solid state, increasing the viscosity and hindering the flow of the hydraulic medium between the valve core 38 and the housing III 39, thus creating a pressure drop. Figure 11 The right figure shows the magnetic field distribution, with the magnetic field passing through the valve core, the housing, and the magnetofluid between them.

[0102] In particular, Figure 12 and Figure 13This diagram shows an adjustable magnetorheological hydraulic valve and its magnetic field distribution (small and large gaps). The hydraulic valve mainly consists of an excitation coil IV 37, a valve core 38, a housing III 39, a hydraulic pipe 40, and a magnetorheological fluid IV 41. The magnetic circuit is along the white dashed line, and the hydraulic medium magnetorheological fluid IV flows along the black arrow. The valve core 38 and the housing III 39 of this hydraulic valve are machined into a conical shape. The working gap of the magnetorheological fluid can be adjusted by changing the position of the valve core 38, thereby expanding the controllable pressure drop range of the hydraulic valve.

[0103] See Figure 12 This diagram illustrates the hydraulic valve in a small clearance configuration and its magnetic field distribution. At this point, the gap between the valve core 38 and the outer casing Ⅲ39 is small. After the excitation coil Ⅳ37 is energized, the magnetofluid Ⅳ41 between the valve core 38 and the outer casing Ⅲ39 changes from a liquid to a solid state, increasing the viscosity and hindering the flow of hydraulic media between the valve core 38 and the outer casing Ⅲ39, thus creating a pressure drop. (See also...) Figure 12 (2) shows the magnetic field distribution diagram, with the magnetic field passing through the valve core, the outer shell, and the magnetofluid between them.

[0104] See Figure 13 This diagram illustrates the hydraulic valve under large clearance conditions and its magnetic field distribution. In this state, the gap between the valve core 38 and the outer casing III 39 is large. With the excitation coil IV 37 de-energized, the magnetofluid IV 41 between the valve core 38 and the outer casing III 39 primarily functions as a liquid, not hindering the flow of hydraulic media between them. When the excitation coil IV 37 is energized, the resulting pressure drop is small. (See also...) Figure 13 (2) shows the magnetic field distribution diagram. The magnetic field passes through the valve core, the outer shell, and the magnetofluid between them, but produces a magnetic field weaker than that under small gap length.

[0105] Figure 14 A schematic diagram of the dynamic model of the magnetorheological device in an embodiment of the present invention is shown below:

[0106]

[0107]

[0108]

[0109]

[0110]

[0111] in, Damping for the magnetorheological device, This refers to relative displacement or angle. and These are the evolutionary parameters in the model. This represents the coil current in the damper. and These are model parameters, obtained through experimental tuning.

[0112] Figure 15 This is a schematic diagram of the user interface displayed on the host computer in an embodiment of the present invention. The interface mainly reflects the following information: the type and parameters of the input signal, the address where the data is stored, and the curves of the angle, torque, displacement, and force signals collected by the sensor.

[0113] Figure 16 and Figure 17 The example simulation scenario of the joint actuator is an embodiment of the present invention. The test platform proposed in the present invention can reproduce the complex working conditions of the joint actuator in real-world scenarios.

[0114] Figure 16 When a person wears an upper limb exoskeleton and swings their arm, the change curve of the elbow shows a sinusoidal motion of the angle over time, exhibiting a trend of gradually decreasing amplitude; the torque is mainly manifested as resistive torque, presenting a characteristic decaying oscillation waveform.

[0115] Figure 17 When a person walks wearing a lower limb exoskeleton, the knee joint changes in the following curves: the angle shows a tendency for slight flexion in the support phase and large flexion in the swing phase; the torque shows a large resistance torque in the support phase and a small swing active torque in the swing phase.

[0116] Figure 18 The torque curve example is an embodiment of the present invention. It can reproduce torque curves that are constant or change with time, torque curves that are constant or change with angle, and torque curves that are constant or change with angular velocity, such as sine waves, triangular waves, and user-defined curves.

[0117] Figure 19 Examples of force curves in the embodiments of the invention can reproduce force curves that are constant or changeable with time, force curves that are constant or changeable with displacement, and force curves that are constant or changeable with velocity, such as sine waves, triangular waves, and user-defined curves.

[0118] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related system fields, are similarly included within the scope of protection of the present invention.

Claims

1. A magneto-rheological device based joint actuator simulation test platform, characterized in that, The adjustable load unit is driven by the measured joint driver to generate linear or rotary motion, and is used to generate controllable damping force or damping torque, so as to accurately test the driving performance of the measured joint driver under different loads. The sensor unit is used for real-time acquisition of system state quantities, providing feedback for control and testing. The control system is used to execute real-time control algorithms, complete sensor unit data acquisition, signal filtering and communication, and control the output of the adjustable load unit according to the target characteristics. The host computer is used for system parameter setting and command issuing, and real-time display of system state and test data acquisition. The adjustable load unit can reproduce one or more of the following torque curves: constant or varying torque curve over time, constant or varying torque curve over angle, constant or varying torque curve over angular velocity, constant or varying force curve over time, constant or varying torque curve over displacement, and constant or varying torque curve over speed.

2. The magneto-rheological device based joint actuator analog test platform of claim 1, wherein: The main structure of the adjustable load unit is that the magneto-rheological device is connected in parallel with the active driving element through the transmission unit; or the magneto-rheological device is directly connected with the transmission.

3. The magneto-rheological device based joint actuator analog test platform of claim 1, wherein: The magneto-rheological device includes one or more of a magneto-rheological rotary brake, a magneto-rheological linear damper, a magneto-rheological clutch, and a magneto-rheological hydraulic valve.

4. The magneto-rheological device based joint actuator analog test platform of claim 3, wherein: The magneto-rheological rotary brake is one or more of a disc brake, a drum brake, and a hybrid brake.

5. The magneto-rheological device based joint actuator analog test platform of claim 4, wherein: The magneto-rheological rotary brake includes a stator, a rotor, an excitation coil, a magnetic fluid, a magnetic circuit structure, and a housing.

6. The magneto-rheological device based joint actuator analog test platform of claim 4, wherein: The magneto-rheological linear damper is one or more of a single-cylinder damper, a double-cylinder damper, and a double-end damper.

7. The magneto-rheological device based joint actuator analog test platform of claim 4, wherein: The magneto-rheological linear damper includes a piston rod, a piston head, a coil, a magnetic fluid, a magnetic circuit structure, and a housing.

8. The magneto-rheological device based joint actuator analog test platform of claim 4, wherein: The magneto-rheological clutch is used to transmit or cut off the power of the driving element.

9. The magneto-rheological device based joint actuator analog test platform of claim 4, wherein: The magneto-rheological hydraulic valve converts hydraulic pressure into damping force / damping torque through a bypass arrangement connected with a hydraulic cylinder. The active driving element can be used to compensate for the inherent liquid flow damping and mechanical friction damping of the magnetic fluid, and can also provide controllable driving force to realize positive angle / torque output.

10. The magneto-rheological device based joint actuator analog test platform of claim 3, wherein: The active driving element is one or more of various types of motors, electro-hydraulic active elements, pneumatic active elements, and intelligent material active elements. The transmission unit is used to transmit and adjust the output of the magneto-rheological device and the active driving element.

11. The magneto-rheological device based joint actuator analog test platform of claim 3, wherein: The transmission unit is one or more of a direct transmission, a speed reduction transmission mechanism, a ball screw mechanism, a series-parallel transmission, and a gear / differential transmission mechanism. The sensor unit is used for real-time monitoring and feedback of system operating parameters, providing closed-loop control signals and performance monitoring data for the control system and the host computer.

12. The magneto-rheological device based joint actuator analog test platform of claim 1, wherein: The sensor unit includes one or more of a torque sensor, an angular velocity sensor / encoder, a displacement sensor, a force sensor, a current sensor, and a pressure sensor. The torque sensor is used to measure the output torque, realize torque closed-loop control, and realize torque superposition or compensation.

13. The magneto-rheological device based joint actuator analog test platform of claim 12, wherein: The angular velocity sensor / encoder is used to provide speed feedback for dynamic control and data acquisition. ​ The displacement sensor is used for detecting the displacement of the linear driving element. The force sensor is used for measuring the loading force for force control and calibration. The current sensor is used for detecting the magnetic field intensity to derive the output force / torque of the magneto-rheological device. The pressure sensor is used for detecting the pressure of the magneto-rheological cavity to analyze the fluid characteristics and stability.

14. The magneto-rheological device based joint actuator analog test platform of claim 1, wherein: The control system is used for executing real-time control algorithm to complete sensor data acquisition and filtering, communication and recording with the upper computer, and control of the load requirement of the upper computer to adjust the output force / torque of the load unit.

15. The magneto-rheological device based joint actuator analog test platform of claim 1, wherein: The hardware components of the control system include a real-time controller, an analog / digital conversion module, a driver, a communication interface and a safety protection unit; the real-time controller is used for closed-loop control, signal processing, IO processing and communication with the upper computer. The analog / digital conversion module is used for converting the analog signals of the sensors into digital signals for the controller. The digital / analog conversion module is used for converting the digital signals into analog signals for the driver. The communication interface is used for realizing information transmission among the upper computer, the driver and the lower computer. The safety protection unit supports one or more of the following: software and hardware limiting, emergency stop, electrical protection and overcurrent alarm. The software components of the control system include a bottom layer architecture, a middle layer architecture and an upper layer architecture. The bottom layer architecture directly controls the current and voltage of the driver. The control structure of the middle layer architecture includes torque closed-loop control and compensation control algorithm. The upper layer architecture generates task targets and manages the system.

16. The magneto-rheological device based joint actuator analog test platform of claim 15, wherein: The driver includes the coil drive of the magneto-rheological device and the active element; the coil drive of the magneto-rheological device supports the current loop; the active element includes the servo drive of the motor, which supports one or more of the current loop, the speed loop, the position loop and the torque loop.

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