Impedance simulating motion controller for orthotic and prosthetic applications

• US 9,060,884 B2
• Filed: 05/03/2011
• Issued: 06/23/2015
• Est. Priority Date: 05/03/2011
• Status: Active Grant

• Current Assignee: Victhom Laboratory Inc (Ergoresearch Ltd.)
• Original Assignee: Victhom Human Bionics Inc. (Ergoresearch Ltd.)
• Inventors: Langlois, David
• Primary Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US13/099,961
• Publication Number:
  US 20120283844A1
• Time in Patent Office: 1,512 Days
• Field of Search: 623/24, 623/50
• US Class Current: 1/1
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/5038 Hinged joint, e.g. with transverse axle restricting the movement for implantable joints A61F2002/30624
• CPC Class Codes: A61F 2002/701 operated by electrically controlled means, e.g. solenoids or torque motors
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/7615 Measuring means for implanting artificial joints A61F2/4657
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/764 for measuring acceleration
• CPC Class Codes: A61F 5/0102 specially adapted for correcting deformities of the limbs or for supporting them; Ortheses, e.g. with articulations
• CPC Class Codes: G05B 15/02 electric

Abstract

An impedance simulating motion controller for orthotic and prosthetic devices includes an equilibrium trajectory generator that receives locomotion data regarding the locomotion of a user, a dynamic trajectory compensator that generates one or more control parameters based on the locomotion data and one or more physiological characteristics of the user, and a dynamic gain tuner that adjusts the one or more control parameters based on a gain scaling factor that is calculated using a measured deflection point and an expected deflection point. The adjusted control parameters are used to control movement of an actuator of an orthotic or prosthetic device.

Claims

1. A method of controlling a motorized prosthetic or orthotic device provided with a joint, the method comprising:

measuring a joint angle of a joint of a motorized prosthetic or orthotic device during a gait cycle;

determining one or more control signals that control a stiffness of one or more actuators of the motorized prosthetic or orthotic device based at least on a difference of the measured joint angle from an equilibrium joint angle during stance phase of the gait cycle, wherein the equilibrium joint angle is approximately constant during at least a majority of the stance phase; and

transmitting the one or more control signals to the one or more actuators to control the stiffness of the one or more actuators.

2. The method of claim 1, wherein the equilibrium joint angle is determined using a regression line of torque-angle during stance phase of a gait cycle.

3. The method of claim 1, wherein the equilibrium joint angle during the stance phase is different from an expected joint angle during the stance phase.

4. The method of claim 3, further comprising:

altering the one or more control signals upon determining that a difference between the measured joint angle and the expected joint angle satisfies a threshold tolerance level; and

transmitting the one or more altered control signals to the one or more actuators to alter the stiffness of the one or more actuators.

5. The method of claim 3, wherein the expected joint angle is calculated using Winter'"'"'s kinematic data.

6. The method of claim 1, wherein the stiffness of the one or more actuators causes the measured joint angle to approximate a kinematic reference model during the stance phase.

7. The method of claim 6, wherein the kinematic reference model is Winter'"'"'s Reference Trajectory.

8. The method of claim 1, wherein the one or more control signals are based on at least a position set-point, a proportional gain, and a derivative gain.

9. The method of claim 1, wherein the one or more control signals are based on one or more control parameters that are generated based on general characteristics of human locomotion using non-complex mathematical relationships.

10. The method of claim 9, wherein the one or more control parameters comprise at least one of a desired position, a proportional gain, and a derivative gain.

11. The method of claim 1, wherein the one or more control signals are determined based on least one of body mass and weight.

12. The method of claim 1, wherein the one or more control signals are updated between gait cycles during movement of the user.

13. The method of claim 1, wherein the measured joint angle is a maximum joint angle during the stance phase.

14. The method of claim 1, wherein the equilibrium joint angle changes during the stance phase.