Torque-position transformer for task control of position controlled robots

US7405531B2 · kind B2 · utility

Assignee

• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Oussama Khatib · Stanford, US
• Peter Thaulad · Santa Clara, US
• Jaehoung Park · Palo Alto, US

Key dates

• Filing date: Apr 25, 2007
• Grant date: Jul 29, 2008
• Expiry date: Apr 25, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G05B2219/39261
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

Torque control capability is provided to a position controlled robot by calculating joint position inputs from transformation of the desired joint torques. This is based on calculating the transfer function 1/E(s), which relates the desired joint torque to joint position. Here E(s) is a servo transfer function D(s) or an effective servo transfer function D*(s). The use of an effective servo transfer function D*s) is helpful in cases where joint nonlinearities are significant. The effective servo transfer function D*(s) is defined with respect to an ideal joint transfer function G*(s)=1/(Ieffs2+beffs), where Ieff is an effective moment of inertia and beff is an effective damping coefficient.