Abstract
Dynamic hybrid position and contact force control is examined for open-chain manipulators that are constrained at one or several points. Both position variables and contact forces are defined as controllable output variables. They are partitioned into functional output variables with values specified by the particular task and redundant output variables with unspecified values. By means of exact input-output linearization the dynamics of the manipulator is transferred into a decoupled linear dynamics in the subspace of the functional output variables and a still nonlinear dynamics in the subspace of the redundant output variables. By projecting artificial potential and damping forces into the subspace of the redundant position variables, it is possible e. g. to realize repeatable motions in the joint space for cyclic trajectories or to avoid collisions with obstacles in the workspace. Redundant contact forces are used to minimize control torques.
