Biomimetic joint actuators
AssigneeiWalk, Inc.
InventorsHugh M. Herr, Jeff A. Weber, David A. Garlow, Richard J. Casler, Jr.
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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.
Claims21
A powered actuator for supplying to a joint augmented by a powered human augmentation device at least one of an augmentation torque, joint equilibrium, and an impedance, the powered actuator comprising:
- a motor having a dissipation constant less than about 50 W/(Nm)2, wherein the dissipation constant is given by R/kt2, where R refers to stator winding resistance and kt refers to motor torque constant;
- a transmission coupled directly to the motor;
- and
- an elastic element coupled to the joint and coupled, in series, to the transmission,
- to generate a normalized joint torque in a range from about −2.8 to about 2.8 Nm/kg.
A powered human augmentation device, comprising:
- an artificial joint;
- a motor constructed and arranged to supply torque to the artificial joint, the motor having a dissipation constant of less than about 50 W/(Nm)2, wherein the dissipation constant is given by R/kt2, where R refers to stator winding resistance and kt refers to motor torque constant;
- a transmission coupled directly to the motor;
- and
- an elastic element coupled to the joint and coupled, in series, to the transmission, to generate a normalized joint torque in a range from about −2.8 to about 2.8 Nm/kg.
Dependencies are inferred from the claim text.