Inverse Jacobian based hybrid impedance control of redundant manipulators

Abstract

This paper presents an efficient control scheme for compliant motion control of kinematically redundant manipulators and its evaluation using an experimental 7 degrees-of-freedom manipulator, REDIESTRO (a redundant dexterous isotropically enhanced, seven turning-pair robot). An inverse Jacobian based hybrid impedance control (IJ-HIC) scheme is proposed that provides a unified approach for combining compliant motion control, redundancy resolution, and user defined secondary tasks in a single methodology. The IJ-HIC uses the inverse of the manipulator Jacobian together with PD control and feed-forward computed torque to track desired force and position trajectories. The scheme is capable of controlling force and position of redundant manipulators and utilizes the manipulator redundancy by achieving user-defined additional tasks. The IJ-HIC is implemented for real-time control of REDIESTRO. Simulation and experimental results validate the IJ-HIC scheme, and demonstrate its capabilities for performing various tasks.