Active control of an ankle-foot orthosis

• US 7,650,204 B2
• Filed: 04/11/2006
• Issued: 01/19/2010
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Dariush, Behzad
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Holwerda; Stephen
• Application Number:
  US11/402,487
• Publication Number:
  US 20060270950A1
• Time in Patent Office: 1,379 Days
• Field of Search: 623/24, 623/47, 623/50, 602/26, 192/81.C, 738/620.8, 482/1, 600/587, 600/595, 601/27, 601/33, 601/34, 601/35, 700/245, 700/247, 700/260, 700/261
• US Class Current: 700/245
• CPC Class Codes: A61B 5/1036 Measuring load distribution, e.g. podologic studies
• CPC Class Codes: A61B 5/1071 measuring angles, e.g. using goniometers A61B5/1123 takes precedence
• CPC Class Codes: A61H 1/0266 Foot
• CPC Class Codes: A61H 2003/007 secured to the patient, e.g. with belts
• CPC Class Codes: A61H 2201/50 Control means thereof
• CPC Class Codes: A61H 2201/5061 Force sensors
• CPC Class Codes: A61H 3/00 Appliances for aiding patients or disabled persons to walk about apparatus for helping babies to walk A47D13/04 ; applying electrical currents by contact electrodes for stimulating motor muscles, e.g. walking assistance A61N1/36003
• CPC Class Codes: A61H 3/008 using suspension devices for supporting the body in an upright walking or standing position, e.g. harnesses
• CPC Class Codes: B25J 9/0006 Exoskeletons, i.e. resembling a human figure
• CPC Class Codes: B62D 57/032 with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid B62D57/024 takes precedence

Abstract

Techniques are provided for controlling a human-exoskeleton system including an ankle-foot orthosis by receiving system parameters for the human-exoskeleton system, receiving generalized coordinates such as an orientation of the foot, and determining a joint torque for controlling the ankle-foot orthosis to compensate for one or more components of forces acting on the foot. Forces selected for compensation include gravitational forces as well as external forces such as ground reaction forces. Techniques are provided for determining an ankle joint torque for partial or complete compensation of forces acting on the foot about an axis of rotation. The provided techniques mitigate the amount of interference between voluntary control and assist control, thereby allowing humans to quickly humans adapt to an exoskeleton system.

Claims

1. A computer based method of controlling a human-exoskeleton system comprising an ankle-foot orthosis at an ankle joint, the method comprising:

receiving a system parameter for the human-exoskeleton system;

receiving an orientation of a foot connected to the ankle joint;

determining a control torque for controlling the ankle-foot orthosis to compensate for a component of a ground reaction force acting on the foot, the control torque determined by setting a value of one of a linear velocity associated with the foot and a linear acceleration associated with the foot to zero and

controlling the ankle-foot orthosis according to the control torque to compensate for the component of the ground reaction force acting on the foot.

3. The method of claim 1, further comprising determining the control torque for controlling the ankle-foot orthosis to compensate for the component of the ground reaction force about an axis of rotation of the ankle-foot orthosis.

4. The method of claim 1, further comprising determining the control torque for controlling the ankle-foot orthosis to provide partial compensation for the component of the ground reaction force acting on the foot.

5. The method of claim 1, wherein no online measurement information is needed to determine the control torque for controlling the ankle-foot orthosis.

2. A computer based method of controlling a human-exoskeleton system comprising an ankle-foot orthosis at an ankle joint, the method comprising:

receiving a system parameter for the human-exoskeleton system;

receiving an orientation of a foot connected to the ankle joint;

determining a control torque for controlling the ankle-foot orthosis to compensate for a component of a ground reaction force acting on the foot, the control torque determined by setting a value of one of an angular velocity associated with the foot and an angular acceleration associated with the foot to zero and

controlling the ankle-foot orthosis according to the control torque to compensate for the component of the ground reaction force acting on the foot.

14. The method of claim 2, further comprising determining the control torque for controlling the ankle-foot orthosis to compensate for the component of the ground reaction force about an axis of rotation of the ankle-foot orthosis.

15. The method of claim 2, further comprising determining the control torque for controlling the ankle-foot orthosis to provide partial compensation for the component of the ground reaction force acting on the foot.

16. The method of claim 2, wherein no online measurement information is needed to determine the control torque for controlling the ankle-foot orthosis.

6. A computer based method of controlling a human-exoskeleton system comprising an ankle-foot orthosis at an ankle joint, the method comprising:

receiving a system parameter for the human-exoskeleton system;

receiving an orientation of a foot connected to the ankle joint;

determining a control torque for controlling the ankle-foot orthosis to compensate for a vertical component of a force acting on the foot; and

controlling the ankle-foot orthosis according to the control torque to compensate for the vertical component of the force acting on the foot.

7. The method of claim 6, wherein the vertical component of the force acting on the foot comprises one of:

a force due to gravity acting on the foot; and

a vertical component of a ground reaction force acting on the foot.

8. The method of claim 6, wherein the vertical component of the ground reaction force is measured using one of:

a force sensor; and

a pressure sensor.

9. A system for automatically controlling an ankle-foot orthosis at an ankle joint, comprising:

first receiving means for receiving a system parameter;

second receiving means for receiving an orientation of a foot connected to the ankle joint; and

first determining means for determining a control torque for controlling the ankle-foot orthosis to compensate for a component of a ground reaction force acting on the foot, the control torque determined by setting a value of one of a linear velocity associated with the foot and a linear acceleration associated with the foot to zero.

10. The system of claim 9, wherein the component of the ground reaction force comprises a vertical component of the ground reaction force.

11. The system of claim 9, wherein the component of the ground reaction force comprises a dynamic component of a vertical ground reaction force.

12. The system of claim 9, further comprising second determining means for determining the control torque for controlling the ankle-foot orthosis to compensate for the component of the ground reaction force about an axis of rotation of the ankle-foot orthosis.

13. The system of claim 9, further comprising second determining means for determining the control torque for controlling the ankle-foot orthosis to provide partial compensation for the component of the ground reaction force acting on the foot.

17. A system for automatically controlling an ankle-foot orthosis at an ankle joint, comprising:

first receiving means for receiving a system parameter;

second receiving means for receiving an orientation of a foot connected to the ankle joint; and

first determining means for determining a control torque for controlling the ankle-foot orthosis to compensate for a component of a ground reaction force acting on the foot, the control torque determined by setting a value of one of an angular velocity associated with the foot and an angular acceleration associated with the foot to zero.

18. The system of claim 17, wherein the component of the ground reaction force comprises a vertical component of the ground reaction force.

19. The system of claim 17, wherein the component of the ground reaction force comprises a dynamic component of a vertical ground reaction force.

20. The system of claim 17, further comprising second determining means for determining the control torque for controlling the ankle-foot orthosis to compensate for the component of the ground reaction force about an axis of rotation of the ankle-foot orthosis.

21. The system of claim 17, further comprising second determining means for determining the control torque for controlling the ankle-foot orthosis to provide partial compensation for the component of the ground reaction force acting on the foot.