Hybrid control of flexible manipulators with multiple contact

A hybrid position/force controller is proposed for flexible link manipulators that make contact with the environment at more than one point. The dynamic equations of the motion with multiple contact constraints are derived. The dynamic equations are transformed into two subspaces (the constrained and constraint-free subspace) using singular value decomposition of the constraint equations. Each force and position controller is developed based on the orthogonality of these two subspaces. A hybrid controller is proposed from the new coordinates. Its stability is proved analytically under the quasi-static condition. An experimental study is carried out to justify the feasibility and application of the proposed ideas