Apparatus and method for energy regulation and leg control for spring-mass walking machine

Patent metadata

Field	Value
Publication number	US-9789920-B2
Application number	US-201615076870-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Apr 1, 2015
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

A robot for legged locomotion incorporating passive dynamics with touchdown and takeoff control and method.

First claim

What is claimed is:

1. A robot incorporating passive dynamics for legged locomotion on a surface, comprising:
first and second extendable legs each having opposing first and second ends;
first and second leg motors each coupled to the first extendable leg, the motors operable to swing the first leg about the first end and extend or retract the first leg along a leg length direction;
at least one leg spring disposed in series between the leg motors and the first leg, the at least one leg spring configured to store energy therein during a touchdown part of a stance and configured to recover the stored energy during a liftoff part of the stance to provide passive dynamic locomotion;
one or more sensors configured to measure a torque in the leg angle direction of the first leg proximate the first end thereof and configured to measure a force in the leg length direction of the first leg; and
a controller in communication with the sensor and the motors, the controller configured to constrain the second end of the first leg to a column above a specified contact area of the surface at which the second end of the first leg is to be placed on touchdown.

2. A robot incorporating passive dynamics for legged locomotion on a surface, comprising:
first and second extendable legs each having opposing first and second ends;
first and second leg motors each coupled to the first extendable leg, the motors operable to swing the first leg about the first end and extend or retract the first leg along a leg length direction;
at least one leg spring disposed in series between the leg motors and the first leg, the at least one leg spring configured to store energy therein during a touchdown part of a stance and configured to recover the stored energy during a liftoff part of the stance to provide passive dynamic locomotion;
one or more sensors configured to measure a torque in the leg angle direction of the first leg proximate the first end thereof and configured to measure a force in the leg length direction of the first leg; and
a controller in communication with the sensor and the motors, the controller configured to scale the transition between a swing phase and a stance phase.

3. The robot according to claim 2 , wherein the controller is configured to scale the transition between a swing phase and a stance phase based on a defined component of a measured ground reaction force.

4. The robot according to claim 1 , wherein the controller configured to control the forward velocity of the robot by controlling the motors to retract or extend the first leg to remove or add energy, respectively, from the gait of the robot, the controller configured to scale the amount of leg retraction or extension as a direct function of a measured forward velocity and a desired forward velocity.

5. A robot incorporating passive dynamics for legged locomotion on a surface, comprising:
first and second extendable legs each having opposing first and second ends;
first and second leg motors each coupled to the first extendable leg, the motors operable to swing the first leg about the first end and extend or retract the first leg along a leg length direction;
at least one leg spring disposed in series between the leg motors and the first leg, the at least one leg spring configured to store energy therein during a touchdown part of a stance and configured to recover the stored energy during a liftoff part of the stance to provide passive dynamic locomotion;
one or more sensors configured to measure a torque in the leg angle direction of the first leg proximate the first end thereof and configured to measure a force in the leg length direction of the first leg; and
a controller in communication with the sensor and the motors, the controller configured to control the forward velocity of the robot by controlling the motors to retract or extend the first leg to remove or add energy, respectively, from the gait of the robot, the controller configured to scale the amount of leg retraction or extension as a direct function of a measured forward velocity and a desired forward velocity.

6. The robot according to claim 5 , wherein the first leg spring comprises a leaf spring.

7. The robot according to claim 5 , wherein the one or more sensors provide a measure of the angular displacement of the first leg about its first end, and wherein the one or more sensors provide a measure of the length of the first leg.

8. The robot according to claim 5 , wherein the controller is configured to determine the measured torque and force in the leg length direction and/or the leg angle direction from the displacement of the at least one leg spring.

9. A method for controlling the transition between leg swing and stance for legged robot locomotion on a surface, comprising:
providing a robot having first and second extendable legs with opposing first and second ends, and having first and second leg motors coupled to the first extendable leg, the motors operable to swing the first leg about the first end to extend or retract the first leg along a leg length direction, and at least one leg spring disposed in series between the leg motors and the first leg, the at least one leg spring configured to store energy therein during a touchdown part of a stance and configured to recover the stored energy during a liftoff part of the stance to provide passive dynamic locomotion;
measuring a force in the leg length direction of the first leg and measuring the torque in the leg angle direction of the first leg proximate the first end thereof; and
commanding the leg motors to constrain the second end of the first leg to a column above a specified contact area of the surface at which the second end of the first leg is to be placed on touchdown.

10. A method for controlling the transition between leg swing and stance for legged robot locomotion, comprising:
providing a robot having first and second extendable legs and first and second leg motors coupled to a first end of the first extendable leg, the motors operable to swing the first leg about the first end to extend or retract the first leg along a leg length direction, and at least one leg spring disposed in series between the leg motors and the first leg, the at least one leg spring configured to store energy therein during a touchdown part of a stance and configured to recover the stored energy during a liftoff part of the stance to provide passive dynamic locomotion;
measuring a force in the leg length direction of the first leg and measuring the torque in the leg angle direction of the first leg proximate the first end thereof; and
scaling the transition between a swing phase and a stance phase based on a defined component of a measured ground reaction force.

11. A method for controlling the transition between leg swing and stance for legged robot locomotion on a surface, comprising:
providing a robot having first and second extendable legs with opposing first and second ends, and having first and second leg motors coupled to the first extendable leg, the motors operable to swing the first leg about the first end to extend or retract the first leg along a leg length direction, and at least one leg spring disposed in series between the leg motors and the first leg, the at least one leg spring configured to store energy therein during a touchdown part of a stance and configured to recover the stored energy during a liftoff part of the stance to provide passive dynamic locomotion;
measuring a force in the leg length direction of the first leg and measuring the torque in the leg angle direction of the first leg proximate the first end thereof; and
commanding the leg motors control the forward velocity of the robot to re

Assignees

• Univ Oregon State

Inventors

• Hurst Jonathan
• Jones Mikhail
• Rezazadeh Siavash
• Noghreiyan Hamid Reza Vejdani
• Abate Andrew

Classifications

• B62D57/032 Primary

  with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) · CPC title

• Y10S901/01

  Mobile robot · CPC title

• G06N3/008

  based on physical entities controlled by simulated intelligence so as to replicate intelligent life forms, e.g. based on robots replicating pets or humans in their appearance or behaviour · CPC title