An intelligent knee joint for human lower limb exoskeleton, prosthesis, orthosis

Abstract

The present application relates to an intelligent knee joint for human lower limb exoskeleton, prosthesis, or orthosis. The intelligent knee joint reproduces part or all of the biomechanical characteristics of the human knee joint by adopting a motor drive unit in combination with a controllable spring energy storage unit based on a magnetorheological damper, or adopts a controllable resistance unit in combination with a controllable elastic energy storage unit based on a magnetorheological damper, thereby helping the wearer to better reduce the burden of walking and regain or repair the walking function. The motor drive unit operates in generator mode and driver mode, and the energy recovery technology is used to reduce the power consumption of the intelligent knee joint and extend the working time of the device. In addition, the use of a controllable elastic energy storage unit based on a magnetorheological damper further reduces the energy consumption of the intelligent knee joint, while also simplifying the control difficulty of the knee joint.

Description

Technical Field

[0001] The present application relates to an intelligent knee joint, and more specifically, to an intelligent knee joint for use in human lower limb exoskeletons, prostheses, or orthoses. Furthermore, the present application also relates to a method for assisting a knee joint. Background Art

[0002] With the rapid development of the economy, people's living standards have gradually improved, and society has gradually increased its attention to the lives of people with disabilities. Due to the loss of motor function in some joints of the body, people with disabilities have reduced their ability to take care of themselves, resulting in a significant decrease in their sense of well-being and self-recognition. Currently, in order to help people with lower limb amputation or hemiplegia caused by stroke regain some or all of their walking function, research institutions and commercial companies have proposed lower limb prostheses, exoskeletons, and orthoses. This type of human motion assist / power device helps the wearer regain or repair walking function by actively or passively reproducing the biomechanical characteristics of the corresponding joint, such as torque-angle curve reproduction or angle tracking.

[0003] Lower limb exoskeletons are currently receiving widespread attention from the scientific and industrial communities, and researchers have proposed a variety of active and passive lower limb skeletons. Such devices are currently being used to help people with lower limb paraplegia stand up and walk independently again from wheelchairs, or to improve the load-bearing capacity of individual soldiers. In addition, powered lower limb prostheses have also made significant progress in the past 20 years. Traditional passive prostheses have a simple structure, are lightweight, and are inexpensive. However, because these prostheses do not include adjustable components, the mechanical properties of the mechanism are fixed, and therefore cannot well replicate the biomechanical characteristics of the corresponding joints. This can lead to clinical problems such as poor gait adaptability, gait asymmetry, and a significant increase in metabolism in the wearer.

[0004] To improve the shortcomings of traditional passive prostheses, powered prostheses use drivers, controllers, sensors, and power supplies to adjust the prosthetic output characteristics in real time, thereby completely mimicking or approximating the functions of corresponding human joints. Clinical trials have shown that compared with traditional passive prostheses, powered lower limb prostheses can significantly improve the walking gait of amputees and reduce their walking burden.

[0005] However, for power-assisted devices, drivers and power supplies still face significant challenges due to current technological limitations. Existing commercial drivers, such as DC motors, have a low power-to-weight ratio. Providing sufficient driving force while meeting the weight and size constraints of mobile devices is a major engineering challenge.

[0006] In addition, due to the limitation of lithium battery energy density, the energy consumption of the driver in mobile human assistive devices is also one of the main considerations during the equipment development process.

[0007] Composite actuators based on smart materials possess unique characteristics and advantages. For example, a composite actuator based on a magnetorheological damper / magnetorheological rotary brake, while taking into account the mechanical properties of the corresponding joint, can achieve relatively low power consumption compared to electric motor drives while meeting the required drive performance. This significantly reduces the size and weight of the battery and extends the time between recharges. Furthermore, the complementary performance of the various power units in the composite actuator can significantly reduce the control difficulty of the system and greatly improve its robustness.

[0008] Therefore, it is necessary and meaningful to seek an intelligent knee joint including a composite actuator based on smart materials to improve human lower limb exoskeletons, prostheses, and orthoses. Summary of the Invention

[0009] To eliminate or reduce the power, power consumption, and control challenges faced by knee joints in lower-limb exoskeletons, prosthetics, and orthoses, this application proposes an intelligent knee joint by employing energy recovery technology, utilizing elastic energy storage components, and intelligent actuators. This intelligent knee joint can replicate some or all of the biomechanical characteristics of the human knee joint while also offering low power consumption. Furthermore, the mechanical design of this intelligent knee joint reduces the difficulty of controlling the knee joint.

[0010] According to one aspect of the present application, a smart knee joint for a lower limb exoskeleton, prosthesis, or orthosis is provided. The smart knee joint is attached to a knee joint and may include:

[0011] 1) A motor drive unit or a controllable resistance unit, wherein the motor drive unit may include a motor and a transmission reduction device. The motor drive unit has two operating modes: a generator mode and a driver mode. The motor drive unit can be adjusted to a corresponding operating mode according to the motion mode and motion state of the knee joint;

[0012] 2) an elastic energy storage unit, which may include an elastic element, a transmission device, and an operating mode adjuster. The elastic energy storage unit has three operating modes: a locked energy storage mode, a free release mode, and an energy dissipation mode. The elastic energy storage unit can be adjusted to a corresponding operating mode according to the movement mode and movement state of the knee joint;

[0013] 3) a sensor for detecting a motion signal of the knee joint;

[0014] 4) a controller, which monitors the motion pattern and motion state of the knee joint in real time based on the feedback signal of the sensor, and provides a control signal to the elastic energy storage unit and the motor drive unit or the controllable resistance unit;

[0015] 5) a power supply, which supplies power to the motor drive unit, the controllable resistance unit, the elastic energy storage unit, the sensor, and the controller, and is also used to store the electric energy recovered by the motor, wherein the power supply is one or both of a battery and a supercapacitor; and

[0016] 6) Connecting devices, which may include thigh connecting devices and calf connecting devices.

[0017] According to an exemplary embodiment of the present application, the motor drive unit may include a motor, a gear reduction box, and a bevel gear transmission device.

[0018] According to an exemplary embodiment of the present application, the motor drive unit may include a motor and a harmonic gear transmission device.

[0019] According to an exemplary embodiment of the present application, the motor drive unit may include a motor, a gear transmission device, a ball screw transmission device, and a crank slider mechanism.

[0020] According to an exemplary embodiment of the present application, the motor drive unit may include a motor, a synchronous pulley transmission device, a ball screw transmission device, and a crank slider mechanism.

[0021] According to an exemplary embodiment of the present application, the elastic energy storage unit may be configured in parallel with the motor drive unit.

[0022] According to an exemplary embodiment of the present application, the elastic element, the transmission device, and the working mode adjuster may be configured in series.

[0023] According to an exemplary embodiment of the present application, the elastic element in the elastic energy storage unit may be one or more of a coil spring, a leaf spring, a gas spring, and a rubber spring.

[0024] According to an exemplary embodiment of the present application, the transmission device in the elastic energy storage unit may be one or more of a pulley and rope mechanism, a crank slider mechanism, and a cam mechanism.

[0025] According to an exemplary embodiment of the present application, the cam surface of the cam may be configured to satisfy a specific elastic torque-angle curve.

[0026] According to an exemplary embodiment of the present application, the working mode adjuster in the elastic energy storage unit may include a motor and a ball screw transmission device or a threaded screw transmission device.

[0027] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in a locked energy storage mode, the elastic element may be compressed or stretched to store energy, and the motor in the operating mode adjuster is energized to maintain a constant position.

[0028] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in a free release mode, the motor in the operating mode adjuster may be powered off and the motor may rotate freely.

[0029] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in the energy dissipation mode, the motor in the operating mode regulator is energized to provide resistance.

[0030] According to an exemplary embodiment of the present application, the motor can be used as a generator to recover electrical energy.

[0031] According to an exemplary embodiment of the present application, the working mode adjuster may include a clutch, a gear transmission device, a ball screw transmission device, and a spring return mechanism.

[0032] According to an exemplary embodiment of the present application, the clutch may be engaged in a power-off or power-on state.

[0033] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in a locked energy storage mode, the clutch in the working mode regulator is energized or de-energized to engage, and the ball screw transmission device in the working mode regulator is locked.

[0034] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in a free release mode, the clutch in the working mode regulator is fully released and disengaged when powered on or off, and the ball screw transmission device in the working mode regulator can transmit freely.

[0035] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in the energy dissipation mode, the clutch energization portion in the operating mode regulator is released and disengaged, and the friction resistance of the clutch is controlled by adjusting the energization current.

[0036] According to an exemplary embodiment of the present application, the operating mode adjuster may include a magnetorheological damper and a spring return mechanism.

[0037] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in a locked energy storage mode, the magnetorheological damper in the operating mode adjuster is energized and locked.

[0038] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in a free release mode, the magnetorheological damper in the operating mode adjuster is powered off.

[0039] According to an exemplary embodiment of the present application, when the elastic energy storage unit operates in the energy dissipation mode, the magnetorheological damper in the working mode regulator can be energized, and the resistance of the magnetorheological damper is adjusted by adjusting the power-on current of the magnetorheological damper, and the piston of the magnetorheological damper and the piston cylinder of the magnetorheological damper can move relative to each other.

[0040] According to an exemplary embodiment of the present application, the working mode adjuster may include a hydraulic cylinder, a hydraulic control valve, and a spring return mechanism, and the working mode of the elastic energy storage unit is adjusted by controlling the hydraulic control valve.

[0041] According to an exemplary embodiment of the present application, the sensor may include one or more of an axial force sensor, a torque sensor, a knee joint angle sensor, a thigh motion inertial measurement unit, a calf motion inertial measurement unit, and an electromyographic signal sensor.

[0042] According to an exemplary embodiment of the present application, the controller may detect the motion pattern and motion state of the knee joint based on the feedback signal of the sensor, and provide one or both of a reference angle and a reference torque to the motor drive unit.

[0043] According to an exemplary embodiment of the present application, by controlling the motor drive unit, the controllable resistance unit and the elastic energy storage unit, the knee joint can fully or partially reproduce the biomechanical characteristics of the human knee joint.

[0044] According to an exemplary embodiment of the present application, the biomechanical characteristics of the human knee joint may be torque-angle characteristics during the stance phase and angle tracking characteristics during the swing phase.

[0045] According to an exemplary embodiment of the present application, the controllable resistance unit is a magnetorheological rotation brake, and the magnetorheological rotation brake can adjust the impedance torque of the controllable resistance unit by controlling the power supply current.

[0046] According to an exemplary embodiment of the present application, the controllable resistance unit includes a magnetorheological damper and a crank slider mechanism, and the magnetorheological damper can adjust the impedance torque of the controllable resistance unit by controlling the power supply current.

[0047] According to an exemplary embodiment of the present application, the output of the magnetorheological rotary brake may be a rotational motion, and the output torque of the magnetorheological rotary brake may be controlled by controlling the power supply current of the magnetorheological rotary brake.

[0048] According to an exemplary embodiment of the present application, the output of the magnetorheological damper may be a linear motion, and the output resistance of the magnetorheological damper may be controlled by controlling the power supply current of the magnetorheological damper.

[0049] According to an exemplary embodiment of the present application, the controllable resistance unit may include a hydraulic cylinder, a hydraulic control valve, and a crank slider mechanism, and the impedance torque of the controllable resistance unit is controlled by adjusting the hydraulic control valve.

[0050] According to an exemplary embodiment of the present application, the controllable resistance unit may be connected in parallel with the elastic energy storage unit.

[0051] According to another aspect of the present application, a method for assisting a knee joint is provided, which may include: detecting the movement of the knee joint through a sensor; based on the feedback signal of the sensor, providing a control signal to the elastic energy storage unit and the motor drive unit and / or the controllable resistance unit according to the movement of the knee joint, wherein the motor drive unit is used for driving and generating electricity, the elastic energy storage unit is used for storing and releasing energy, and the controllable resistance unit is used for providing impedance torque; wherein the elastic energy storage unit is used to store and release energy, and the electric energy storage unit is used to store the electric energy recovered by the motor drive unit and to power the motor drive unit, the elastic energy storage unit, the sensor and the controller.

[0052] According to another aspect of the present application, a device for assisting walking is provided, which includes the intelligent knee joint as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The following, in conjunction with the accompanying drawings, describes non-limiting embodiments of the present application to explain the principles of the present invention. It should be understood that the drawings are intended to illustrate exemplary embodiments of the present application rather than to limit them. The drawings are used to provide a further understanding of the inventive concepts of the present application and are incorporated into and constitute a part of this specification. The same reference numerals in the drawings represent the same features. In the drawings:

[0054] Figure 1 shows an intelligent knee joint according to an exemplary embodiment of the present application;

[0055] Figure 2 shows a front view and a left view of a smart knee joint according to an exemplary embodiment of the present application;

[0056] Figure 3 Detailed description of some internal components of the smart knee joint according to an exemplary embodiment of the present application is shown;

[0057] Figure 4 shows a perspective exploded view of a motor drive unit of an intelligent knee joint according to an exemplary embodiment of the present application;

[0058] Figure 51. A knee joint axial force measuring device of an intelligent knee joint according to an exemplary embodiment of the present application is shown;

[0059] Figure 6 A driving principle diagram of an intelligent knee joint according to an exemplary embodiment of the present application is shown, which includes a motor drive unit;

[0060] Figure 7 A driving principle diagram of an intelligent knee joint according to an exemplary embodiment of the present application is shown, which includes a resistance unit - a magnetorheological rotation brake;

[0061] Figure 8 The angle curve, torque curve and power curve of the human knee joint in one cycle during walking on flat ground, climbing stairs and descending stairs are shown;

[0062] Figure 9 The figure shows the torque-angle curves of the human knee joint during walking on level ground, climbing stairs, and descending stairs.

[0063] Figure 10 The working principle of the intelligent knee joint during walking on flat ground according to an exemplary embodiment of the present application is shown. The intelligent knee joint includes the working principle of a motor, an elastic unit, and a magnetorheological damper;

[0064] Figure 11 The working principle of the smart knee joint according to an exemplary embodiment of the present application during stair climbing is shown. The smart knee joint includes a motor, an elastic unit, and a magnetorheological damper.

[0065] Figure 12 The working principle of the smart knee joint according to an exemplary embodiment of the present application in the process of going downstairs is shown, and the smart knee joint includes a motor, an elastic unit and a magnetorheological damper; and

[0066] Figure 13 The schematic diagram of the cam-leaf spring-magnetorheological damper device and the torque-angle curve output under three corresponding working modes are shown. DETAILED DESCRIPTION

[0067] To better understand the present application, various aspects of the present application will be described in more detail below with reference to the exemplary embodiments shown in the accompanying drawings. It should be understood that these detailed descriptions are merely descriptions of exemplary embodiments of the present application and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0068] It should be noted that in this specification and claims, the terms "first," "second," etc., are used solely to distinguish one feature from another and do not represent any limitation of the features. Therefore, without departing from the teachings of this application, the first rotor and the first guide slot discussed herein may also be referred to as the second rotor and the second guide slot, and vice versa.

[0069] In the accompanying drawings, the thickness, size, and shape of each component are slightly exaggerated for ease of explanation. Therefore, the accompanying drawings are only examples and are not drawn strictly to scale.

[0070] It should be understood that the expressions "comprise", "comprises", "has", "includes" and / or "comprising", when used in this specification, indicate the presence of the listed features, elements, parts and / or steps, but do not exclude the presence or addition of one or more other features, elements, parts, steps and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire listed features rather than modifying the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". Furthermore, the expression "exemplary" is intended to refer to an example of an embodiment or to illustrate an embodiment.

[0071] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which this application belongs. It should also be understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0072] The following describes various aspects of the present application in more detail with reference to the accompanying drawings and in combination with specific implementations, but the implementations of the present application are not limited thereto.

[0073] Figure 1 An intelligent knee joint according to an exemplary embodiment of the present application is shown. Figures 2 to 5 According to the intelligent knee joint of the exemplary embodiment of the present application. Figure 5 As shown, in this embodiment, the DC motor 8 is mounted on the motor sleeve 7 via the mounting bracket 9, and the motor sleeve 7 is connected to the right bracket 11. The output shaft of the DC motor 8 is connected to the input shaft of the harmonic gear 6 via the coupling 10, and the output shaft of the harmonic gear 6 is connected to the knee joint housing 3.

[0074] The knee joint housing 3 is mounted on the rotation axis of the bearing 2, and the bearing 2 is mounted on the fixing member 1. The fixing member 1 is mounted on the left bracket 12. The right bracket 11 and the left bracket 12 are simultaneously mounted on the bottom fixing member 14. The thigh connector 13 is mounted on the knee joint housing 3, and the calf connector 51 is mounted on the bottom fixing member 14. The cam 3x is mounted on the knee joint housing 3. The knee joint angle sensor 32 is mounted on the fixing member 1 via the sensor fixing member 47, and the rotation axis of the knee joint angle sensor 32 is connected to the rotation axis of the bearing 2 via the connecting shaft 46. The knee joint angle sensor 32 is used to measure the rotation angle of the knee joint housing 3 relative to the left bracket.

[0075] Rotating frame 17 is mounted on bottom fixture 14 and is rotatable about rotation axis 31. An angle sensor 32 measures the rotation angle of rotating frame 17 relative to bottom fixture 14. One end of leaf spring 18 is mounted on the left end of rotating frame 17, and the other end of leaf spring 18 is attached to roller bracket 19. Roller 20 rotates on roller bracket 19 about a fixed axis while in contact with cam 3x.

[0076] The MR damper's piston connecting shaft 23 is hinged to the right end of the rotating frame 17. The MR damper's housing 21 is hinged to the damper mounting bracket 28, which is mounted on the left bracket 12. A small return spring 42 is installed in parallel with the MR damper to help it return to its initial position.

[0077] Figure 5 The figure shows a device for measuring the knee joint axial force of an intelligent knee joint according to an exemplary embodiment of the present application. A cantilever beam structure is provided on the bottom fixing member 14, and the calf connector 51 is mounted on the cantilever beam. A strain gauge 52 is mounted at the base of the fixed end of the cantilever beam. When the knee joint axial force acts on the calf connector 51, the cantilever beam deforms. At this time, the resistance of the strain gauge 52 changes, allowing the magnitude of the knee joint axial force to be calculated based on the change in resistance.

[0078] Figure 6 A schematic diagram of the drive mechanism of an intelligent knee joint according to an exemplary embodiment of the present application is shown, including a motor drive unit. The motor drive unit can function as a driver to power the intelligent knee joint, or as a generator to generate electricity by recovering the mechanical negative work of the knee joint. When the knee joint flexes or extends, the cam rotates relative to the frame, causing the rollers at the ends of the leaf springs to slide along the cam surface.

[0079] When the magnetorheological damper is energized and locked, the rotating bracket is fixed and the leaf spring is compressed by the cam, thereby providing a biasing torque for the knee joint.

[0080] When the magnetorheological damper is de-energized, the rotating bracket will rotate freely and the leaf spring will not be compressed.

[0081] When the magnetorheological damper is energized and the damper piston and the damper housing can slide relative to each other, the leaf spring can be compressed by the cam, but the magnetorheological damper will consume some mechanical energy.

[0082] Figure 7 A schematic diagram of the drive mechanism of an intelligent knee joint according to an exemplary embodiment of the present application is shown, including a resistance unit—a magnetorheological rotary brake. The magnetorheological rotary brake adjusts its resistance torque by controlling its supply current. When the knee joint flexes or extends, the cam rotates relative to the frame, causing the rollers at the ends of the leaf springs to slide along the cam surface.

[0083] When the magnetorheological damper is energized and locked, the rotating bracket is fixed and the leaf spring is compressed by the cam, thereby providing a biasing torque for the knee joint.

[0084] When the magnetorheological damper is de-energized, the rotating bracket will rotate freely and the leaf spring will not be compressed.

[0085] When the magnetorheological damper is energized and the damper piston and the damper housing can slide relative to each other, the leaf spring can be compressed by the cam, but the magnetorheological damper will consume some mechanical energy.

[0086] Figure 8 The graph shows the angle curve, torque curve, and power curve of the human knee joint during one cycle of walking on flat ground, climbing stairs, and descending stairs. Figure 9 The figure shows the torque-angle curve of the human knee joint during walking on the ground, climbing and descending stairs. Figures 8 and 9 In the figure, the solid line indicates the stance phase, and the dashed line indicates the swing phase.

[0087] Figure 10 This figure illustrates the operating principle of the intelligent knee joint during level ground walking, according to an exemplary embodiment of the present application. During the initial stance flexion and extension phases, the magnetorheological damper is energized and locked, and the leaf spring is compressed and deformed by the cam, storing and releasing mechanical energy. Furthermore, during this process, the DC motor is de-energized.

[0088] During the later stance flexion and swing phases, the magnetorheological damper is de-energized, allowing the leaf spring to rotate freely without being compressed by the cam. During this process, the DC motor acts as a generator, recovering the negative mechanical work of the knee joint to generate electricity.

[0089] During the stance phase of walking on level ground, the knee joint will simulate Figure 9 The torque-angle curve of walking on flat ground (solid line). During the swing phase of walking on flat ground, the knee joint will Figure 8Angle tracking during mid-level walking. During the entire gait cycle, the above-mentioned torque-angle curve tracking and angle tracking can be achieved by controlling the DC motor current and the magnetorheological damper current.

[0090] Figure 11 The working principle of the intelligent knee joint according to an exemplary embodiment of the present application during stair climbing is shown. Since the power of the knee joint is positive work throughout the gait cycle, the DC motor is always used as a driver to provide positive work input.

[0091] Additionally, throughout the gait cycle, the magnetorheological damper is de-energized and the leaf spring is free to rotate without being compressed by the cam. During the stance phase of stair climbing, the knee joint will simulate Figure 9 The stair climbing torque-angle curve (solid line) is shown. During the swing phase of the stair climbing process, the knee joint will perform Figure 8 Angle tracking during stair climbing. During the entire gait cycle, the above-mentioned torque-angle curve tracking and angle tracking can be achieved by controlling the current of the DC motor.

[0092] Figure 12 The figure illustrates the operating principle of a smart knee joint according to an exemplary embodiment of the present application during stair descent. During the initial stance flexion phase, the magnetorheological damper is energized and locked, and the leaf spring is compressed by the cam to provide a biasing torque, thereby supporting the wearer's weight. Subsequently, during the later stance flexion phase, the magnetorheological damper remains energized, but the damper's piston moves relative to the damper housing to dissipate the mechanical energy stored in the leaf spring, thereby reducing the biasing torque provided by the leaf spring.

[0093] During the swing phase, the magnetorheological damper is de-energized, allowing the leaf spring to rotate freely without being compressed by the cam. Throughout the gait cycle, since the knee joint performs negative work, the DC motor can function as a generator, recovering the negative mechanical work of the knee joint and generating electricity.

[0094] During the stance phase of the stair descent, the knee joint will mimic Figure 9 The moment-angle curve of stair-walking (solid line). During the swing phase of the stair-walking process, the knee joint will perform Figure 8 The above-mentioned torque-angle curve tracking and angle tracking can be achieved by controlling the DC motor current and the magnetorheological damper current throughout the gait cycle.

[0095] It should be noted that during uphill and downhill walking, the knee joint's motion is similar to that of walking on flat ground. The operating principles of the various components are essentially the same as those described above for walking on flat ground, requiring only modifications to the torque-angle curve or angle tracking curve at each stage.

[0096] Figure 13The schematic diagram of the cam-leaf spring-MR damper device and the torque-angle output curves for three operating modes are shown. By controlling the MR damper, the cam-leaf spring-MR damper device can be used as a nonlinear spring mechanism to store and release mechanical energy (①); as a nonlinear damper to dissipate mechanical energy (②); or as a free-wheeling mechanism (③).

[0097] The exemplary embodiments of the present application have been described above with reference to the accompanying drawings. Those skilled in the art should understand that the above embodiments are examples given for illustrative purposes only and are not intended to limit the scope of the present application. The scope of the present application shall be defined by the appended claims and their equivalents. Any modifications, equivalent substitutions, etc. made under the teachings of this application and the scope of protection of the claims shall be included within the scope of protection claimed in this application.

Claims

1. An intelligent knee joint for a human lower limb exoskeleton, prosthesis, or orthosis, attached to a knee joint, comprising: 1) A motor drive unit or a controllable resistance unit, the motor drive unit comprising a motor and a transmission reduction device. The motor drive unit has two operating modes: a generator mode and a driver mode. The motor drive unit is adjusted to a corresponding operating mode according to the motion mode and motion state of the knee joint; 2) an elastic energy storage unit, comprising an elastic element, a transmission device, and an operating mode adjuster. The elastic energy storage unit has three operating modes: a locked energy storage mode, a free release mode, and an energy dissipation mode. The elastic energy storage unit is adjusted to a corresponding operating mode according to the motion mode and motion state of the knee joint. The operating mode adjuster includes a magnetorheological damper and a spring return mechanism. 3) a sensor for detecting a motion signal of the knee joint; 4) a controller, which monitors the motion pattern and motion state of the knee joint in real time based on feedback signals from the sensor, and provides control signals to the elastic energy storage unit and the motor drive unit or the controllable resistance unit; 5) a power supply, which supplies power to the motor drive unit, the controllable resistance unit, the elastic energy storage unit, the sensor, and the controller, and is also used to store the electric energy recovered by the motor, wherein the power supply is one or both of a battery and a supercapacitor; and 6) Connecting device, including a thigh connecting device and a calf connecting device.

2. The intelligent knee joint according to claim 1, characterized in that: The motor drive unit includes a motor, a gear reduction box and a bevel gear transmission device.

3. The intelligent knee joint according to claim 1, characterized in that: The motor drive unit includes a motor and a harmonic gear transmission device.

4. The intelligent knee joint according to claim 1, characterized in that: The motor drive unit includes a motor, a gear transmission device, a ball screw transmission device and a crank slider mechanism.

5. The intelligent knee joint according to claim 1, characterized in that: The motor drive unit includes a motor, a synchronous pulley transmission device, a ball screw transmission device and a crank slider mechanism.

6. The intelligent knee joint according to claim 1, characterized in that: The elastic energy storage unit is configured in parallel with the motor drive unit.

7. The intelligent knee joint according to claim 1, characterized in that: The elastic element, the transmission device and the working mode adjuster are arranged in series.

8. The intelligent knee joint according to claim 1, characterized in that: The elastic element in the elastic energy storage unit is one or more of a coil spring, a leaf spring, a gas spring and a rubber spring.

9. The intelligent knee joint according to claim 1, characterized in that: The transmission device in the elastic energy storage unit is one or more of a pulley and rope mechanism, a crank slider mechanism, and a cam mechanism.

10. The intelligent knee joint according to claim 9, characterized in that: The cam surface of the cam mechanism is configured to satisfy a specific elastic torque-angle curve.

11. The intelligent knee joint according to claim 1, characterized in that: The working mode regulator in the elastic energy storage unit includes a motor and a ball screw transmission device or a threaded screw transmission device.

12. The intelligent knee joint according to claim 11, characterized in that: When the elastic energy storage unit operates in the locked energy storage mode, the elastic element is compressed or stretched to store energy, and the motor in the operating mode adjuster is energized to maintain a constant position.

13. The intelligent knee joint according to claim 11, characterized in that: When the elastic energy storage unit operates in the free release mode, the motor in the operating mode regulator is powered off and can rotate freely.

14. The intelligent knee joint according to claim 11, characterized in that: When the elastic energy storage unit operates in the energy dissipation mode, the motor in the operating mode regulator is energized to provide resistance.

15. The intelligent knee joint according to claim 14, characterized in that: The motor is used as a generator to recover electrical energy.

16. The intelligent knee joint according to claim 1, characterized in that: The working mode regulator includes a clutch, a gear transmission device, a ball screw transmission device and a spring return mechanism.

17. The intelligent knee joint according to claim 16, characterized in that: The clutch is engaged when power is off or on.

18. The intelligent knee joint according to claim 16, characterized in that: When the elastic energy storage unit operates in the locked energy storage mode, the clutch in the working mode regulator is energized or de-energized to engage, and the ball screw transmission device in the working mode regulator is locked.

19. The intelligent knee joint according to claim 16, characterized in that: When the elastic energy storage unit operates in the free release mode, the clutch in the working mode regulator is fully released and disconnected when powered on or off, and the ball screw transmission device in the working mode regulator can transmit freely.

20. The intelligent knee joint according to claim 16, characterized in that: When the elastic energy storage unit operates in the energy dissipation mode, the energized portion of the clutch in the operating mode regulator is released and disengaged, and the friction resistance of the clutch is controlled by adjusting the energized current.

21. The intelligent knee joint according to claim 1, characterized in that: When the elastic energy storage unit operates in the locked energy storage mode, the magnetorheological damper in the operating mode adjuster is energized and locked.

22. The intelligent knee joint according to claim 1, characterized in that: When the elastic energy storage unit operates in a free release mode, the magnetorheological damper in the operating mode regulator is powered off.

23. The intelligent knee joint according to claim 1, characterized in that When the elastic energy storage unit operates in the energy dissipation mode, the magnetorheological damper in the working mode regulator is energized, and the resistance of the magnetorheological damper is adjusted by adjusting the power-on current of the magnetorheological damper, so that the piston of the magnetorheological damper and the piston cylinder of the magnetorheological damper can move relative to each other.

24. The intelligent knee joint according to claim 1, characterized in that The working mode regulator includes a hydraulic cylinder, a hydraulic control valve and a spring return mechanism, and the working mode of the elastic energy storage unit is adjusted by controlling the hydraulic control valve.

25. The intelligent knee joint according to claim 1, characterized in that The sensor includes one or more of an axial force sensor, a torque sensor, a knee joint angle sensor, a thigh motion inertial measurement unit, a calf motion inertial measurement unit, and an electromyographic signal sensor.

26. The intelligent knee joint according to claim 1, characterized in that: The controller detects the motion mode and motion state of the knee joint based on the feedback signal of the sensor, and provides one or both of a reference angle and a reference torque to the motor drive unit.

27. The intelligent knee joint according to claim 1, characterized in that: By controlling the motor drive unit, the controllable resistance unit and the elastic energy storage unit, the knee joint can completely or partially reproduce the biomechanical characteristics of the human knee joint.

28. The intelligent knee joint according to claim 27, characterized in that: The biomechanical characteristics of the human knee joint are torque-angle characteristics during the stance phase and angle tracking characteristics during the swing phase.

29. The intelligent knee joint according to claim 1, characterized in that: The controllable resistance unit is a magnetorheological rotation brake, and the magnetorheological rotation brake can adjust the impedance torque of the controllable resistance unit by controlling the power supply current.

30. The intelligent knee joint according to claim 1, characterized in that The controllable resistance unit includes a magnetorheological damper and a crank slider mechanism. The magnetorheological damper can adjust the impedance torque of the controllable resistance unit by controlling the power supply current.

31. The intelligent knee joint according to claim 1, characterized in that The controllable resistance unit includes a hydraulic cylinder, a hydraulic control valve and a crank slider mechanism, and the impedance torque of the controllable resistance unit is controlled by adjusting the hydraulic control valve.

32. The intelligent knee joint according to claim 1, characterized in that The controllable resistance unit is connected in parallel with the elastic energy storage unit.

33. A method for assisting a knee joint, comprising: detecting movement of the knee joint by a sensor included in an intelligent knee joint for a human lower limb exoskeleton, prosthesis, or orthosis, wherein the intelligent knee joint is attached to the knee joint and includes an elastic energy storage unit and a motor drive unit or a controllable resistance unit; as well as Based on the signal from the sensor, a control signal is provided to the elastic energy storage unit and the motor drive unit or the controllable resistance unit, wherein the motor drive unit includes a motor and a transmission reduction device and has two working modes: a generator mode and a driver mode. The motor drive unit is adjusted to a corresponding working mode according to the motion state and motion mode of the knee joint. The elastic energy storage unit includes an elastic element, a transmission device, and a working mode regulator. The elastic energy storage unit has three working modes: locked energy storage mode, free release mode, and energy dissipation mode. The elastic energy storage unit is adjusted to a corresponding working mode according to the motion state and motion mode of the knee joint. The working mode regulator includes a magnetorheological damper and a spring return mechanism. The control signal is generated by a controller included in the intelligent knee joint, and the controller is configured to monitor the motion state and motion mode of the knee joint in real time based on the signal from the sensor, and provide the control signal to the elastic energy storage unit and the motor drive unit or the controllable resistance unit; Among them, the intelligent knee joint also includes: a power supply, which supplies power to the motor drive unit, the controllable resistance unit, the elastic energy storage unit, the sensor and the controller, and is also used to store the electric energy recovered by the motor, the power supply being one or both of a battery or a supercapacitor; and a connecting device, including a thigh connecting device and a calf connecting device.

34. A device for assisting walking, comprising the intelligent knee joint according to any one of claims 1 to 32.

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