Smart knee joint for a human lower limb exoskeleton, a prosthesis and an orthosis

Patent metadata

Field	Value
Publication number	US-2023025654-A1
Application number	US-202117453600-A
Country	US
Kind code	A1
Filing date	Nov 4, 2021
Priority date	Jul 21, 2021
Publication date	Jan 26, 2023
Grant date	—

Abstract

The present application relates to a smart knee joint for a human lower limb exoskeleton, a prosthesis, and an orthosis. The smart knee joint reproduces part or all of the biomechanics of the knee joint of the human body by using a motor driving unit and a controllable elastic energy storage unit based on a magnetorheological damper. The motor driving unit here can be replaced with a controllable damping unit. The smart knee joint is developed for helping amputees or patients with impaired mobility regain/repair natural gaits and also reduce their burden of walking. The motor drive unit operates in a generator mode and an actuator mode. Energy harvesting technologies are exploited to reduce the power consumption of the smart knee joint then to prolong the working time. In addition, the controllable elastic energy storage unit based on the magnetorheological damper can further reduce the energy consumption of the smart knee joint, and also simplify the control of the knee joint.

First claim

What is claimed is:

1 . A smart knee joint for a human lower limb exoskeleton, a prosthesis, and an orthosis, attached to a knee joint, comprising:
1) a motor driving unit or a controllable damping unit, the motor driving unit including a motor and a transmission, and having two working modes: a generator mode and an actuator mode, the motor driving unit being adjusted to a corresponding working mode based on states and walking modes of the knee joint; 2) an elastic energy storage unit including an elastic element, a transmission, and a working mode regulator, the elastic energy storage unit having three working modes: being locked mode, free mode, and energy dissipation mode, the elastic energy storage unit being adjusted to a corresponding working mode based on states and walking modes of the knee joint; 3) sensors for detecting the motion of the knee joint; 4) a controller for monitoring the states and the walking modes of the knee joint in real-time based on signals of the sensors, and generating control signals for the elastic energy storage unit and the motor driving unit or the controllable damping unit; 5) a power supply for powering the motor driving unit, the controllable damping unit, the elastic energy storage unit, the sensors, and the controller, and storing electric energy recovered by the motor, the power supply being one or both of a battery and a supercapacitor; and 6) connecting devices comprising a thigh connecting device and a shank connecting device.

2 . The smart knee joint of claim 1 , wherein the motor driving unit comprises a motor, a gear reduction box, and a bevel gear transmission.

3 . A smart knee joint of claim 1 , wherein the motor drive unit comprises a motor and a harmonic gear transmission.

4 . The smart knee joint of claim 1 , wherein the motor driving unit comprises a motor, a gear transmission, a ball-screw transmission, and a slider-crank mechanism.

5 . The smart knee joint of claim 1 , wherein the motor driving unit comprises a motor, a timing-belt transmission, a ball-screw transmission, and a slider-crank mechanism.

6 . The smart knee joint of claim 1 , wherein the elastic energy storage unit is configured in parallel with the motor driving unit.

7 . A smart knee joint of claim 1 , wherein the elastic element, the transmission, and the working mode regulator are arranged in series.

8 . The smart knee joint of claim 1 , wherein 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 smart knee joint of claim 1 , wherein the transmission in the elastic energy storage unit is one or more of a pulley rope mechanism, a slider-crank mechanism, and a cam mechanism.

10 . A smart knee joint of claim 9 , wherein a cam profile of the cam is arranged to satisfy a specific elastic torque-angle curve.

11 . The smart knee joint of claim 1 , wherein the working mode regulator in the elastic energy storage unit comprises a motor, and a ball-screw transmission or a screw transmission.

12 . An smart knee joint of claim 11 , wherein when the elastic energy storage unit operates in the being locked mode, the elastic element is compressed or stretched to store energy, and the motor in the working mode regulator is powered to held in a constant position.

13 . A smart knee joint of claim 11 , wherein when the elastic energy storage unit operates in the free mode, the motor in the working mode regulator is de-energized and the motor is free to rotate.

14 . A smart knee joint of claim 11 , wherein the motor in the working mode regulator is energized to provide a controllable damping torque when the elastic energy storage unit operates in the energy dissipation mode.

15 . The smart knee joint of claim 14 , wherein the motor is used as a generator to recover electrical energy.

16 . The smart knee joint of claim 1 , wherein the working mode regulator comprises a clutch, a gear transmission, a ball-screw transmission, and a restoring spring.

17 . A smart knee joint of claim 16 , wherein the clutch engages in the event of power loss or energization.

18 . A smart knee joint of claim 16 , wherein when the elastic energy storage unit operates in the being locked mode, the clutch in the working mode regulator is energized or de-energized to engage, and the ball-screw transmission in the working mode regulator is locked.

19 . A smart knee joint of claim 16 , wherein when the elastic energy storage unit operates in the free mode, the clutch in the working mode regulator is energized or de-energized to be fully released and disengaged, and the ball-screw transmission in the working mode regulator is free to rotate.

20 . The smart knee joint of claim 16 , wherein when the elastic energy storage unit operates in the energy dissipation mode, the clutch is powered on, and the damping force of the clutch is controlled by adjusting the current of the clutch.

21 . The smart knee joint of claim 1 , wherein the working mode regulator comprises a magnetorheological damper and a restoring spring.

22 . A smart knee joint of claim 21 , wherein when the elastic energy storage unit operates in the being locked mode, the magnetorheological damper in the working mode regulator is energized to be locked.

23 . A smart knee joint of claim 21 , wherein the magnetorheological damper in the working mode regulator is de-energized when the elastic energy storage unit is operating in the free mode.

24 . The smart knee joint of claim 21 , wherein when the elastic energy storage unit operates in the energy dissipation mode, the magnetorheological damper in the working mode regulator is energized, but there is a relative motion between the damper piston and the damper housing, the damping force is regulated by adjusting the current applied to the magnetorheological damper.

25 . The smart knee joint of claim 1 , wherein the working mode regulator comprises a hydraulic cylinder, a hydraulic valve, and a restoring spring, and the working mode of the elastic energy storage unit is adjusted by controlling the hydraulic valve.

26 . The smart knee joint of claim 1 , wherein the sensors comprise one or more of an axial force sensor, a torque sensor, a knee angle sensor, an inertial measurement unit for measuring the motion of the thigh, an inertial measurement unit for measuring the motion of the shank, and electromyographic signal sensors.

27 . The smart knee joint of claim 1 , wherein the controller detects the motion states and the walking modes of the knee joint based on the signals of the sensors, and generates one or both of a reference angle or a reference torque for the motor driving unit.

28 . The smart knee joint of claim 1 , wherein the knee joint is enabled to fully or partially reproduce the biomechanics of the human knee joint by controlling the motor driving unit, the controllable damping unit, and the elastic energy storage unit.

29 . The smart knee joint of claim 28 , wherein the biomechanics of the human knee joint is a torque-angle curve during the stance phase and an angle curve during the swing phase.

30 . The smart knee joint of claim 1 , wherein the controllable damping unit is a magnetorheological rotary brake capable of adjusting an impedance torque of the controllable damping unit by

Assignees

• Univ Hong Kong Chinese

Inventors

• Liao Wei-Hsin
• Gao Fei

Classifications

• A61F2/64 Primary

  Knee joints · CPC title

• A61F2/68 Primary

  Operating or control means · CPC title

• A61F2002/5003

  having damping means, e.g. shock absorbers · CPC title

• A61B5/1071

  measuring angles, e.g. using goniometers (A61B5/1123 takes precedence) · CPC title

• A61F2005/0155

  with actuating means · CPC title