Biomimetic joint actuators
AssigneeOtto Bock Healthcare GmbH
InventorsHugh Miller Herr, Jeff Anthony Weber, Richard James Casler, Jr.
Life of this patent
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Abstract
In a powered actuator for supplying torque, joint equilibrium, and/or impedance to a joint, a motor is directly coupled to a low-reduction ratio transmission, e.g., a transmission having a gear ratio less than about 80 to 1. The motor has a low dissipation constant, e.g., less than about 50 W/(Nm)2. The transmission is serially connected to an elastic element that is also coupled to the joint, thereby supplying torque, joint equilibrium, and/or impedance to the joint while minimizing the power consumption and/or acoustic noise of the actuator.
Claims20
A powered human augmentation device comprising:
- a low revolutions-per-minute (RPM) motor having an RPM less than 1500 configured to apply torque to a joint of the human augmentation device during a phase of a gait cycle to modulate at least one of joint augmentation torque, joint impedance, or joint equilibrium during the phase of the gait cycle;
- a transmission coupled directly to the low RPM motor;
- and
- a controller configured to short leads of the motor to exert a viscous damping torque on the motor proportional to a motor dissipation constant given by R/kt2, where R refers to a stator winding resistance and kt refers to a motor torque constant, the dissipation constant being less than 50 W/(Nm)2.
A method for augmenting joint function using a powered human augmentation device, the method comprising:
- energizing a low revolutions-per-minute (RPM) motor having an RPM less than 1500 to apply torque to a joint of the human augmentation device during a phase of a gait cycle to modulate at least one of joint augmentation torque, joint impedance, or joint equilibrium during the phase of the gait cycle, the motor coupled directly to a transmission;
- and
- shorting leads of the motor to exert a viscous damping torque on the motor proportional to a motor dissipation constant given by R/kt2, where R refers to a stator winding resistance and kt refers to a motor torque constant, the dissipation constant being less than 50 W/(Nm)2.
A powered human augmentation device comprising:
- a low revolutions-per-minute (RPM) motor having an RPM less than 1500 configured to apply torque to a joint of the human augmentation device during a phase of a gait cycle to modulate at least one of joint augmentation torque, joint impedance, or joint equilibrium during the phase of the gait cycle;
- a transmission coupled directly to the low RPM motor;
- an elastic element serially coupled to the transmission, the elastic element coupled to the joint;
- and
- a controller configured to short leads of the motor to exert a viscous damping torque on the motor.
Dependencies are inferred from the claim text.