PIEZOELECTRIC ACTIVE CONTROL OF MICRO-VIBRATION OF CENTRAL RIGID BODY-FLEXIBLE ARM WITH DRIVING MECHANISM

This work studies the micro-vibration of a flexible arm rotating in space driven by a stepper motor and a harmonic reducer, and a piezoelectric patch is pasted at the root of the flexible arm for vibration control. First, based on the working principles of the stepper motor and the harmonic reducer, the theoretical and equivalent dynamic models of both components are derived. The driving mechanism is equivalent to a two-degree-of-freedom spring oscillator system which stepper motor and harmonic reducer are coupled, and the corresponding motion and torque equations are derived. Then, based on the modeling method of the Lagrange equation, the dynamic equation of the central rigid body-flexible cantilever beam system containing a piezoelectric actuator is established. The influence of rotational speed on the motion of the flexible arm is considered, and the control equation of the system is derived. A PID controller is employed to regulate the voltage across the piezoelectric actuator. A vibration control model is developed on the Simulink platform, and the control effectiveness is simulated and analyzed. The simulation results show that the piezoelectric mechanism designed in this study effectively suppresses the vibration of the flexible arm.