Workspace safe operation of a force- or impedance-controlled robot

US8483877B2 · kind B2 · utility

Assignees

• GM GLOBAL TECHNOLOGY OPERATIONS LLC · US
• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Muhammad E. Abdallah · Houston, US
• Brian Hargrave · Dallas, US
• John D. Yamokoski · Houston, US
• Philip A. Strawser · Houston, US

Key dates

• Filing date: Sep 3, 2010
• Grant date: Jul 9, 2013
• Expiry date: Jul 29, 2031

Classification

• Technology area (CPC G): Physics
• CPC primary: G05B2219/39505
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

A method of controlling a robotic manipulator of a force- or impedance-controlled robot within an unstructured workspace includes imposing a saturation limit on a static force applied by the manipulator to its surrounding environment, and may include determining a contact force between the manipulator and an object in the unstructured workspace, and executing a dynamic reflex when the contact force exceeds a threshold to thereby alleviate an inertial impulse not addressed by the saturation limited static force. The method may include calculating a required reflex torque to be imparted by a joint actuator to a robotic joint. A robotic system includes a robotic manipulator having an unstructured workspace and a controller that is electrically connected to the manipulator, and which controls the manipulator using force- or impedance-based commands. The controller, which is also disclosed herein, automatically imposes the saturation limit and may execute the dynamic reflex noted above.