Residual vibration reduction of flexible joint systems using a frequency domain trajectory planning algorithm

Abstract

Fast motions of systems with constrained flexible dynamics often lead to residual vibrations. Established methods for compensating those vibrations such as input-shaping, filtering and feed-forward methods are already available. However, those methods do not explicitly consider input-constraints. As a consequence, they cannot effectively reduce residual vibrations if input-constraints are violated. This depends on the trajectory they are applied on, which is generated by a trajectory planning algorithm. In this paper, a trajectory planning algorithm is introduced which incorporates a residual vibration compensation procedure within the algorithm. In order to minimize the trajectory's excitation of the resonant frequency, a cost function is defined in the frequency domain and input-constraints are considered in the optimization algorithm. Hence, suppression of residual vibrations for fast motions can be achieved. The algorithm is implemented and tested on a robotic manipulator.