Reactive Layer Control System for Prosthetic and Orthotic Devices

• US 20110125290A1
• Filed: 01/21/2008
• Published: 05/26/2011
• Est. Priority Date: 01/19/2007
• Status: Active Grant

• Current Assignee: Victhom Laboratory Inc (Ergoresearch Ltd.)
• Original Assignee: Victhom Human Bionics Inc. (Ergoresearch Ltd.)
• Inventors: Langlois, David
• Granted Patent: US 9,808,357 B2
• Time in Patent Office: Days
• US Class Current: 623/27
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/68 Operating or control means
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/5033 for adjusting damping damping means A61F2002/5003
• CPC Class Codes: A61F 2002/6818 for braking
• 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 2002/762 for measuring dimensions, e.g. a distance
• 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 2002/7645 for measuring torque, e.g. hinge or turning moment, moment of force

Abstract

A variable gain impedance controller for use in a control system for controlling a motorized prosthetic or orthotic apparatus provided with a joint The controller comprises a sensor input for receiving a signal indicative of an interaction between the apparatus and the ground, a torque sensor input for receiving a signal indicative of the torque at the joint and a variable gain scheduler in communication with the sensor input so as to receive data therefrom thereby providing a variable torque gain. The variable gain impedance controller adjusts its control on the apparatus based on the variable torque gain and the indicated torque so as to a) increase the joint resistance to motion when the signal received from the sensor input indicates an interaction between the apparatus and the ground and b) decrease the joint resistance to motion when the signal received from the sensor input indicates an absence of interaction between the apparatus and the ground.

Claims

1-84. -84. (canceled)

85. A variable gain impedance controller for use in a control system for controlling a motorized prosthetic or orthotic apparatus provided with a joint, the controller comprising:

a sensor input for receiving a signal indicative of an interaction between the apparatus and the ground;

a torque sensor input for receiving a signal indicative of the torque at the joint; and

a variable gain scheduler in communication with the sensor input so as to receive data therefrom thereby providing a variable torque gain;

wherein the variable gain impedance controller adjusts its control on the apparatus based on the variable torque gain and the indicated torque so as to adjust the joint resistance to motion depending on the received signal indication of interaction between the apparatus an the ground.

86. A variable gain impedance controller according to claim 85, further comprising:

a position sensor input for receiving a signal indicative of the position of the joint;

wherein the variable gain scheduler further provides a variable velocity gain and a variable position gain, and

wherein the variable gain impedance controller adjusts its control on the apparatus based on the variable velocity gain, a difference between a velocity set-point and a velocity estimation, the variable position gain, a difference between a position set-point and the indicated position, the variable torque gain and the indicated torque so as to adjust the joint resistance based on the state of the signal received from the sensor input indicates an interaction between the apparatus and the ground.

87. A variable gain impedance controller according to claim 86, wherein the velocity estimation is obtained by an ARMA process applied to the signal indicative of the position.

88. A variable gain impedance controller according to claim 86, further comprising a braking mechanism providing a braking feedback value when the indicated velocity is greater than a first threshold and the indicated position is greater than a second threshold, wherein the variable gain impedance controller adjusts its control on the apparatus based on the braking feedback value so as to increase the joint resistance to motion.

89. A variable gain impedance controller according to claim 88, wherein the braking feedback value is based on a ratio of the indicated velocity to the square of an indicated position offset with a motion stop target of the apparatus.

90. A variable gain impedance controller according to claim 88, wherein the motion stop target of the apparatus is dynamically adjustable.

91. A variable gain impedance controller according to claim 88, further comprising a force injection mechanism providing a pulse when the signal received from the sensor input indicates a transition from an interaction between the apparatus and the ground to an absence of interaction between the apparatus and the ground, wherein the variable gain impedance controller adjusts its control on the apparatus based on the pulse so as to ensure minimal joint flexion.

92. A variable gain impedance controller according to claim 91, wherein characteristics of the pulse are dynamically adjustable.

93. A variable gain impedance controller according to claim 92, wherein the dynamically adjustable characteristics of the pulse include at least one element selected from a group consisting of an amplitude, a duration and a timing.

94. A variable gain impedance controller according to claim 85, wherein the signal indicative of an interaction between the apparatus and the ground is a measure of load at a shank portion of the motorized prosthetic or orthotic apparatus, and wherein the interaction between the apparatus and the ground is determined by a single value hysteretic thresholding of the signal received from the sensor input.

95. A variable gain impedance controller according to claim 85, wherein the variable gain impedance controller increases joint resistance to motion when the signal received from the sensor input indicates an interaction between the apparatus and the ground and the variable gain impedance controller decreases joint resistance to motion when the signal received from the sensor input indicates an absence of interaction between the apparatus and the ground.

96. A variable gain impedance controller according to claim 85, wherein the variable torque gain is a) a substantially unitary positive value when the signal received from the sensor input indicates an interaction between the apparatus and the ground, and b) a substantially unitary negative value when the signal received from the sensor input indicates an absence of interaction between the apparatus and the ground.

97. A method of modifying the feedback of an impedance controller for use in a control system for controlling a motorized prosthetic or orthotic apparatus provided with a joint, the method comprising:

receiving a signal indicative of an interaction between the apparatus and the ground;

receiving a signal indicative of the torque at the joint; and

based on the signal indicative of an interaction between the apparatus and the ground calculating a result by multiplying the signal indicative of the torque by a value, and providing the result to the controller.

98. A method according to claim 97, wherein the value is a positive value and substantially unitary when the signal indicative of the interaction between the apparatus and the ground indicates an interaction and the value is a negative value and substantially unitary when the signal indicative of the interaction between the apparatus and the ground indicates an absence of interaction.

99. A method according to claim 97, further comprising:

receiving a signal indicative of the position of the joint;

when the signal indicative of an interaction between the apparatus and the ground indicates an interaction;

multiplying the signal indicative of the torque by a positive value and providing the result to the controller;

estimating a velocity of the joint from the signal indicative of the position of the joint;

multiplying the difference between a velocity set-point and the estimated velocity by a velocity gain value and providing the result to the controller;

multiplying the difference between a position set-point and the signal indicative of the position by a position gain value and providing the result to the controller.

100. A method according to claim 97, further comprising:

when the signal indicative of velocity is greater than a first threshold and the signal indicative of position is greater than a second threshold;

providing a braking feedback value to the controller so as to increase the joint resistance to motion.

101. A method according to claim 97, wherein the braking feedback value is based on a ratio of the signal indicative of velocity to the square of an indicated position offset with a motion stop target of the apparatus.

102. A method according to claim 97, further comprising dynamically adjusting the motion stop target.

103. A method according to claim 101, further comprising:

when the signal received from the sensor input indicates a transition from an interaction between the apparatus and the ground to an absence of interaction between the apparatus and the ground;

providing a pulse to controller so as to ensure minimal joint flexion.

104. A method according to claim 97, further comprising dynamically adjusting characteristics of the pulse.

105. A method according to claim 97, wherein the dynamically adjusted characteristics of the pulse include at least one element selected from a group consisting of an amplitude, a duration and a timing.

106. A method according to claim 97, wherein the signal indicative of an interaction between the apparatus and the ground is a measure of load at a shank portion of the motorized prosthetic. or orthotic apparatus, and wherein the interaction between the apparatus and the ground is determined by a single value hysteretic thresholding of the signal received from the sensor input.

107. A method according to claim 97, further comprising:

receiving a signal indicative of the position of the joint;

when the signal indicative of an interaction between the apparatus and the ground indicates an absence of interaction;

multiplying the signal indicative of the torque by a negative value and providing the result to the controller;

estimating a velocity of the joint from the signal indicative of the position of the joint;

multiplying the difference between a velocity set-point and the estimated velocity by a velocity gain value and providing the result to the controller;

multiplying the difference between a position set-point and the signal indicative of the position by a position gain value and providing the result to the controller.

108. A method according to claim 97, further comprising:

receiving a signal indicative of the velocity of the joint;

receiving a signal indicative of the position of the joint;

when the signal indicative of an interaction between the apparatus and the ground indicates an absence of interaction;

multiplying the signal indicative of the torque by a negative value and providing the result to the controller;

multiplying the difference between a velocity set-point and the signal indicative of velocity by a velocity gain value and providing the result to the controller;

multiplying the difference between a position set-point and the signal indicative of the position by a position gain value and providing the result to the controller.