Trajectory-tracking control of a multiple flexible joint robot based on singular perturbation

The trajectory-tracking control of a typical industrial robot with six revolute joints is studied, where the joint flexibility is taken into account. An explicit form of the control law is obtained by using the composite control technique to guarantee the global convergence of tracking error. This method has a unique advantage in handling a multiple flexible joint robot as well as a hybrid rigid/flexible joint robot. Numerical simulation on a PUMA-600 robot arm has been done to verify the control algorithm for both set-point and time-varying trajectory tracking operations. Some important issues related to the validity of the algorithm are discussed.