Effective active vibration control of single link flexible manipulator with modified positive position feedback control in the presence of instrumentation phase lead/lag

Abstract

Accurate trajectory regulation of flexible link manipulators is a challenging task. The presence of hardware filters with the cut-off frequency near the resonant frequency cause an additional closed loop instability problem in the control system. This problem can be solved using modified Kalman filters along with certain hardware circuits called compensators. A linear quadratic Gaussian controller has been used to control the hub position. A positive position feedback (PPF) controller has been used at the piezoelectric actuators at the flexible link in the present work to minimize the end-effector vibrations. Normally the design parameters (i.e. coefficients of the numerator and denominator polynomial) of the PPF controller are selected by hit and trial. Pattern search technique has been used as an efficient design method to design these controllers which otherwise have no systematic way to design.