Kinematic control for redundant manipulators with time dependent constraints: General-Weighted Least-Norm method

This paper extends the General-Weighted Least-Norm (GWLN) method to the control problem of redundant manipulators with time dependent constraints. By defining virtual joints presenting the time dependent constraint and a time-dependent coordinates transformation, a middle kinematic control problem with only joint limits is obtained. We then apply the GWLN method on the middle problem that is time independent. We also improve the GWLN method by replacing the prediction step in implementation algorithm of the GWLN method with a new weighted matrix. To demonstrate the efficacy of the method, simulations are carried out on five-link welding manipulator to track welding trajectory meanwhile guaranteeing time dependent orientation constraint and keeping away from joint limits.