PID composite vibration control and simulation analysis of an active and passive integrated vibration isolator

In order to resist the effect from harsh dynamic load, and ensure mechanical environment for navigation, guiding and other sensitive devices on hypersonic flight vehicles, a new vibration isolation technology applicable on wide band and high precision is exigently required. Aiming at strict vibration control requirements on high and low frequencies for sensitive devices, this paper presents a new active and passive integrated vibration isolator based on piezoelectric stack, which includes both passive isolator's features of simple structure, high reliability, being good at restraining high frequency vibration and active isolator's advantages of fast response, being smart, being good at restraining low frequency vibration. Firstly, the paper builds up the coupling dynamic model of piezoelectric stack rubber integrated isolator, and carries out a transmissibility comparison analysis of different feedback forms for this 2 DOF system. Then, a feedforward-feedback PID composite control scheme for the active and passive integrated isolator is presented, with the close loop transfer function deduced and different parameters' effects on transfer characteristics of the control system analyzed. Lastly, a simulation analysis on vibration control effect of the integrated isolator under pulse, harmonic, and random stimulation is presented, whose response signal result proves the validity of the PID composite controller.