Nonlinear control with input preshaping for flexible-link manipulators

Input precompensators in conjunction with rigid body based controllers are considered for flexible-link manipulators. The objective is to preshape the reference input signals so that vibration free output is achieved. This control scheme is n open-loop one and is achieved by convolving the sequence of impulses with the reference input signal in real-time. Linear and nonlinear based rigid controllers are considered in the paper. Thereafter, the rigid body based control schemes are augmented with an input preshaper for vibration suppression along the links. Satisfactory performance has been achieved with input preshaping scheme in the case of one-link flexible arms. In the paper, the input preshaping is applied to the dynamics of two-link flexible under the control action of an inner-loop controller which corresponds to the rigid body motion of the manipulator. Experimental and simulation results on a two-link flexible manipulator are provided to show the effectiveness of the advocated controllers.<>