Neural network plus fuzzy PD control of tip vibration for flexible-link manipulators

A neural network (NN) plus fuzzy PD controller is presented in this paper for the trajectory tracking of a flexible-link manipulator, where the robot tip vibration is measured by an optical measurement device with position-sensitive detectors (PSD). Based on the singular perturbation method and two time-scale decompositions, the flexible-link robot model is decomposed into a slow subsystem of an equivalent rigid-link manipulator and a fast subsystem of flexible mode. An NN-based adaptive controller is used to implement the angle position control of the slow dynamics, while the fuzzy PD control with PSD tip deflection measurement is designed to suppress the vibration along with the robot control process. Finally, the control performance of the proposed control approach is illustrated by experimental research.