Compliant motion control and redundancy resolution for kinematically redundant manipulators

An augmented hybrid impedance control (AHIC) scheme is proposed for kinematically redundant manipulators. The hybrid impedance control (HIC) scheme, which has been used in the past for compliant motion control of non-redundant manipulators, is extended to the redundant case. It is shown that by appropriately combining redundancy resolution with the hybrid impedance control scheme, one can simultaneously achieve the regulation of the end-effector interaction with the environment and satisfy user defined additional tasks. This is done by augmenting the task space by additional constraints. An augmented Cartesian target acceleration (ACTA) trajectory is generated in real-time. An extension of the configuration control approach at the acceleration level is then used to find the joint target acceleration (JTA) trajectory. A feedback linearization loop is implemented in joint space to ensure the tracking of the JTA trajectory. Different additional tasks are represented by appropriate kinematic functions and the possibility of having a multi-point force-control scheme is presented.