Total energy shaping control methods and devices for powered orthosis
Total energy shaping control methods and devices for powered orthosis for controlling the device to counteract forces exerted on the person including inertial forces.
1. An orthosis device comprising:
a first support member;
a second support member;
a plurality of sensors configured to measure a plurality of parameters, wherein the plurality of parameters includes:
an angle between the first support member and the second support member; and
an orientation of the first support member or the second support member;
an actuator configured to apply a torque to the first or second support member; and
a controller, wherein:
the controller is configured to calculate a plurality of forces exerted on a person coupled to the orthosis device, wherein:
the plurality of forces include an inertial force and a gravitational force; and
the plurality of forces are calculated based on the angle between the first support member and the second support member and based on the orientation of the first support member or the second support member;
the controller is configured to control the torque applied by the actuator; and
the torque applied by the actuator is controlled to:
counteract the plurality of forces exerted on the person and device, wherein:
the plurality of forces exerted on the person and the device include an inertial force exerted on the person and the device; and
the plurality of forces exerted on the person and the device include a gravitational force exerted on the person and the device;
compensate for lower-limb inertia via kinetic energy shaping; and
provide body weight support via potential energy shaping.
2. The orthosis device of claim 1 wherein the plurality of sensors includes an inertial measurement unit (IMU) coupled to the first support member or the second support member.
3. The orthosis device of claim 1 wherein the plurality of sensors includes a joint encoder configured to measure the angle between the first support member and the second support member.
4. The orthosis device of claim 3 wherein the joint encoder is an optical encoder.
5. The orthosis device of claim 3 wherein the joint encoder is a magnetic encoder.
6. The orthosis device of claim 1 wherein the torque applied by the actuator is kinetically controlled via a nonlinear control method.
7. The orthosis device of claim 1 wherein the actuator comprises an electric motor, and wherein the controller is configured to vary an electric current to the electric motor.
8. The orthosis device of claim 1 wherein:
the first support member is configured to be coupled to a shin of a person;
the second support member is configured to be coupled to a thigh of a person; and
the actuator is configured to vary the angle between the first support member and the second support member.
9. The orthosis device of claim 1 wherein:
the first support member is configured to be coupled to a thigh of a person; and
the second support member is configured to be coupled to a hip of a person; and
the actuator is configured to vary the angle between the first support member and the second support member.
10. The orthosis device of claim 1 wherein:
the first support member is configured to be placed under a foot of a person;
the second support member is configured to be coupled to a shin of a person; and
the actuator is configured to vary the angle between the first support member and the second support member.
11. The orthosis device of claim 10 wherein the plurality of sensors comprises a first sensor in the first support member configured to measure a force in a ball area of the foot of the person.
12. The orthosis device of claim 11 wherein the plurality of sensors comprises a second sensor in the first support member configured to measure a force in a heel area of the foot of the person.
13. The orthosis device of claim 1 wherein:
the actuator comprises an electric motor coupled to a gearbox and a first sprocket;
the orthosis device comprises a second sprocket coupled to the first support member; and
the orthosis device comprises a belt coupling the first sprocket and the second sprocket.
14. The orthosis device of claim 13 further comprising a reaction torque sensor coupled to the gearbox.
15. The orthosis device of claim 14 wherein the gearbox comprises a planetary gear transmission, and wherein the reaction torque sensor is configured to measure torque at an end of the planetary gear transmission.
16. The orthosis device of claim 1 wherein the orthosis device comprises:
an electric motor, a first sprocket, a second sprocket, a belt and a gearbox, wherein:
the electric motor is coupled to the first sprocket;
the belt couples the first sprocket and the second sprocket; and
the gearbox is located inside the second sprocket.
17. The orthosis device of claim 16 wherein the gearbox is configured to be coupled to a joint of a person.
18. The orthosis device of claim 1 wherein the orthosis device comprises:
an electric motor and a gearbox, wherein:
the electric motor is directly coupled to the gearbox.
19. The orthosis device of claim 18 wherein the gearbox is a single-stage planetary gearbox.
20. The orthosis device of claim 19 wherein the gearbox is configured to be coupled to a joint of a person.
21. A method for controlling an orthosis device coupled to a person, the method comprising:
measuring a plurality of parameters, wherein:
the orthosis device comprises a first support member, a second support member, an actuator and a controller; and
the plurality of parameters includes:
an angle between the first support member and the second support member; and
an orientation of the first support member or the second support member;
applying a torque to one of the plurality of support members via the actuator; and
controlling the torque applied via the actuator, wherein:
the torque applied via the actuator is controlled to counteract a plurality of forces exerted on the person and the orthosis device;
the plurality of forces exerted on the person and the device include an inertial force exerted on the person and the device; and
the plurality of forces exerted on the person and the device include a gravitational force exerted on the person and the device;
torque applied via the actuator is not controlled to direct the orthosis device in a pre-determined pattern of motion;
the torque applied via the actuator is controlled to compensate for lower-limb inertia via kinetic energy shaping; and
the torque applied via the actuator is controlled to provide body weight support via potential energy shaping.
22. The method of claim 21 wherein the orientation of the first support member or the second support member is measured via an inertial measurement unit (IMU).
23. The method of claim 21 wherein the angle between the first support member and the second support member is measured via an optical encoder.
24. The method of claim 21 wherein the torque is kinetically controlled via a nonlinear control method.
25. The method of claim 21 wherein the actuator comprises an electric motor, and wherein the controller varies an electric current to the electric motor to control the torque applied via the actuator.
26. The method of claim 21 wherein:
the first support member is coupled to a shin of a person;
the second support member is coupled to a thigh of a person; and
the actuator varies the angle between the first support member and the second support member.
27. The method of claim 21 wherein:
the first support member is placed under a foot of a person;
the second support member is coupled to a shin of a person; and
the actuator varies the angle between the first support member and the second support member.
28. The method of claim 27 wherein:
the plurality of sensors comprises a first sensor in the first support member; and
the first sensor in the first support member measures a force in a ball area of the foot of the person.
29. The method of claim 28 wherein:
the plurality of sensors comprises a second sensor in the first support member; and
the second sensor in the first support member measures a force in a heel area of the foot of the person.
30. The method of claim 21 wherein:
the actuator comprises an electric motor coupled to a gearbox and a first sprocket;
the orthosis device comprises a second sprocket coupled to the first support member; and
the orthosis device comprises a belt coupling the first sprocket and the second sprocket.
31. The method of claim 30 wherein the orthosis device comprises a reaction torque sensor coupled to the gearbox.
32. The method of claim 30 wherein the gearbox comprises a planetary gear transmission, and wherein the reaction torque sensor measures torque at an end of the planetary gear transmission.