System and method of bidirectional compliant joint torque actuation
View Patent ↗A joint actuation device for adding torque to a joint of a user includes an actuation system having an actuator and a spring. A lever is configured to couple to the user's leg and to the actuation system. The lever configured to rotate at a device joint with respect to the actuation system. A first sensor measures a position of the device joint. A second sensor measures deflection in a spring. The actuator is positioned based on the position of the device joint and deflection in the spring. The actuator is configured to deflect the spring to apply a torque the device joint. The device joint aligns with the user's joint to add a torque to the user's joint during a gait activity. The actuator disengages the spring during a non-gait activity. The lever is configured to disengage from the actuator when the device joint exceeds a predetermined angle.
1. A method of adding torque to a joint of a user, comprising:
providing an actuation system including an actuator and a first and second spring;
coupling a lever to a leg of the user and to the actuation system;
measuring a position of the joint using a first sensor; and
positioning the actuator to compress the first or second spring based on the position of the joint.
2. The method of claim 1 , further including providing a control system to control the actuator based on the position of the joint.
3. The method of claim 1 , further including:
measuring a deflection in the first or second spring using a second sensor;
integrating the deflection measurement using an integration function; and
positioning the actuator based on the deflection measurement.
4. The method of claim 3 , further including:
determining a phase angle of the leg; and
selecting the integration function based on the phase angle of the leg.
5. The method of claim 1 , further including:
adding torque to the joint in a first direction by compressing a first spring; and
adding torque to the joint in a second direction by compressing a second spring.
6. The method of claim 5 , further including:
rotating the lever at a system joint of the actuation system; and
aligning the system joint with the joint of the user.
7. A method of adding torque to a joint of a user, comprising:
coupling a lever to a leg of the user;
providing an actuator including a spring with the actuator coupled to the lever;
measuring a position of the joint using a first sensor;
measuring a deflection in the spring using a second sensor;
integrating the deflection measurement using an integration function; and
positioning the actuator based on the deflection measurement to deflect the spring.
8. The method of claim 7 , further including coupling a control system to the actuator and the first sensor.
9. The method of claim 7 , further including:
determining a phase angle of the leg; and
selecting the integration function based on the phase angle of the leg.
10. A method of adding torque to a joint of a user, comprising:
coupling a lever to a leg of the user;
providing an actuator including a spring with the actuator coupled to the lever;
measuring a position of the joint using a first sensor;
positioning the actuator to deflect the spring based on the position of the joint; and
disengaging the spring during a non-gait activity.
11. The method of claim 10 , further including disengaging the lever from the actuator during the non-gait activity.
12. The method of claim 10 , further including:
adding torque to the joint in a first direction by deflecting the spring in a first direction; and
adding torque to the joint in a second direction by deflecting the spring in a second direction.
13. A joint actuation device, comprising:
an actuation system including an actuator and a spring;
a lever coupled to the actuation system and configured to couple to a leg of a user, the lever configured to rotate at a device joint with respect to the actuation system;
a first sensor configured to measure a physical characteristic of the leg; and
a control system configured to control the actuator based on the physical characteristic of the leg, wherein the actuator is configured to apply a torque to the device joint.
14. The joint actuation device of claim 13 , wherein actuation system is configured to couple to a torso of the user, and the actuation system spans a hip joint of the user.
15. The joint actuation device of claim 14 , wherein the torque at the device joint is aligned with the hip joint of the user.
16. The joint actuation device of claim 13 , wherein actuation system is configured to couple to a foot of the user, and the actuation system spans an ankle joint of the user.
17. The joint actuation device of claim 16 , wherein the torque at the device joint is positioned in proximity to the ankle joint of the user.
18. A joint actuation device, comprising:
an actuation system including an actuator and a spring; and
a lever coupled to the actuation system and configured to couple to a leg of a user, the lever configured to rotate at a device joint with respect to the actuation system, wherein the lever is configured to disengage from the actuation system during a non-gait activity.
19. The joint actuation device of claim 18 , wherein actuator is to disengage the spring during the non-gait activity.
20. The joint actuation device of claim 18 , further including:
a sensor configured to measure a position of the device joint; and
a control system coupled to the sensor and actuator, wherein the control system is configured to produce a command to control the actuator based on the position of the device joint.
21. The joint actuation device of claim 18 , wherein actuation system is configured to couple to a torso of the user, and the actuation system spans a hip joint of the user.
22. The joint actuation device of claim 18 , wherein actuation system is configured to couple to a foot of the user, and the actuation system spans an ankle joint of the user.