Control system and method for non-gait ankle and foot motion in human assistance device

Patent metadata

Field	Value
Publication number	US-10307271-B2
Application number	US-201615341817-A
Country	US
Kind code	B2
Filing date	Nov 2, 2016
Priority date	Feb 17, 2012
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A human assistance device has a rate gyro, first accelerometer, and second accelerometer disposed on a mobile body for sensing a physical state of the mobile body to provide a physical state measurement. The human assistance device can be a prosthetic, orthotic, and robotic device. An ATAN2 function is performed on an output of the first accelerometer and an output of the second accelerometer. An output of the rate gyro and an output of the ATAN2 function is filtered to provide a filtered physical state measurement. The filtered physical state measurement is applied to a reference function to generate a reference command to control a non-gait motion of an actuator in the human assistance device. The reference command controls the human assistance device, for example to provide a shifting foot position while seated, with a natural, biological motion, without an artificial or mechanical appearance.

First claim

What is claimed:

1. A method of controlling a human assistance device, comprising:
disposing a rate gyro, first accelerometer, and second accelerometer on a mobile body of the human assistance device for sensing a physical state of the mobile body to provide a physical state measurement;
performing an ATAN2 function based on an output of the first accelerometer and an output of the second accelerometer;
filtering electronically an output of the rate gyro and an output of the ATAN2 function using a controller of the human assistance device to provide a filtered physical state measurement, wherein the filtering is implemented according to A 1 *(θ PREV +{dot over (θ)} s *Δt)+(1−A 1 )*β, where A1 is a calibration coefficient, θ PREV is a previous output of the filtering, Δt is a rate of time change of {dot over (θ)} s , {dot over (θ)} s is the output of the rate gyro, and β is the output of the ATAN2 function;
providing a reference function based on a non-gait activity; and
applying the filtered physical state measurement to the reference function to generate a reference command using the controller to control a non-gait motion of the human assistance device.

2. The method of claim 1 , wherein the reference command controls an actuator in the human assistance device.

3. The method of claim 2 , further including applying a signal representative of a position of the actuator to the reference function to generate the reference command.

4. The method of claim 1 , further including:
measuring an ankle moment, wherein the human assistance device comprises an ankle prosthesis;
applying a gain to the ankle moment; and
summing the ankle moment after gain with an output of the reference function to generate the reference command.

5. The method of claim 4 , wherein the gain is implemented as A 2 cos

(

M
A

M
T

*
π

)

-

A
2

,

where A 2 is a calibration coefficient, M A is the ankle moment, and M T is a maximum ankle moment.

6. A method of controlling a human assistance device, comprising:
disposing a plurality of sensors on a mobile body of the human assistance device to measure a physical state of the mobile body and obtain a physical state measurement from the sensors;
filtering electronically the physical state measurement from the sensors using a controller of the human assistance device to provide a filtered physical state measurement, wherein the filtering is implemented according to A 1 *(θ PREV +{dot over (θ)} s *Δt)+(1−A 1 )*β, where A1 is a calibration coefficient, θ PREV is a previous output of the filtering, Δt is a rate of time change of {dot over (θ)} s , {dot over (θ)} s is an output of a rate gyro on the mobile body, and β is an output of an ATAN2 function;
providing a reference function based on a non-gait activity; and
applying the filtered physical state measurement to the reference function to generate a reference command using the controller to control a non-gait motion of the human assistance device.

7. The method of claim 6 , wherein the sensors include the rate gyro, a first accelerometer, and a second accelerometer.

8. The method of claim 7 , further including performing the ATAN2 function based on an output of the first accelerometer and an output of the second accelerometer, wherein filtering the physical state measurement includes filtering an output of the rate gyro and an output of the ATAN2 function.

9. The method of claim 6 , wherein the reference command controls an actuator in the human assistance device, and a signal representative of a position of the actuator is applied to the reference function to generate the reference command.

10. The method of claim 6 , further including:
measuring an ankle moment, wherein the human assistance device comprises an ankle prosthesis;
applying a gain to the ankle moment; and
summing the ankle moment after gain with an output of the reference function to generate the reference command.

11. The method of claim 10 , wherein the gain is implemented as A 2 cos

(

M
A

M
T

*
π

)

-

A
2

,

where A 2 is a calibration coefficient, M A is the ankle moment, and M T is a maximum ankle moment.

12. A method of controlling a human assistance device, comprising:
sensing a physical state of a mobile body of the human assistance device by providing a physical state measurement of the physical state;
filtering electronically the physical state measurement of the physical state of the mobile body using a controller of the human assistance device to provide a filtered physical state measurement, wherein the filtering is implemented according to A 1 *(θ PREV +{dot over (θ)} s *Δt)+(1−A 1 )*β, where A1 is a calibration coefficient, θ PREV is a previous output of the filtering, Δt is a rate of time change of {dot over (θ)} s , {dot over (θ)} s is an output of a rate gyro on the mobile body, and β is an output of an ATAN2 function;
providing a reference function based on a non-gait activity; and
applying the filtered physical state measurement to the reference function to generate a reference command using the controller to control a non-gait motion of the human assistance device.

13. The method of claim 12 , further including disposing the rate gyro, a first accelerometer, and a second accelerometer on the mobile body for sensing the physical state of the mobile body.

14. The method of claim 13 , further including performing an ATAN2 function based on an output of the first accelerometer and an output of the second accelerometer, wherein filtering the physical state measurement includes filtering an output of the rate gyro and an output of the ATAN2 function.

15. The method of claim 12 , wherein the reference command controls an actuator in the human assistance device, and a signal representative of a position of the actuator is applied to the reference function to generate the reference command.

16. The method of claim 12 , further including:
measuring an ankle moment, wherein the human assistance device comprises an ankle prosthesis;
applying a gain to the ankle moment; and
summing the ankle moment after gain with an output of the reference function to generate the reference command.

17. The method of claim 16 , wherein the gain is implemented as A 2 cos

(

Assignees

• Oessur Iceland Ehf

Inventors

• Holgate Matthew A
• Wheeler Chase

Classifications

• A61F2002/7645

  for measuring torque, e.g. hinge or turning moment, moment of force · CPC title

• A61F2002/764

  for measuring acceleration · CPC title

• A61F2002/7635

  for measuring force, pressure or mechanical tension · CPC title

• A61F2002/7625

  for measuring angular position · CPC title

• A61F2002/762

  for measuring dimensions, e.g. a distance · CPC title