A nonlinear dynamic hysteresis model and dynamic performance of the piezoelectric ring bending actuator

A piezoelectric ring-bending actuator with a piezoelectric ring bender as the core component has the merits of fast response, high control accuracy, high driving frequency, and compact size. Therefore, it has broad application prospects. However, the relationship between its output displacement and driving voltage is nonlinear, and it is important to establish a nonlinear hysteresis dynamic model for its applications. First, the structure and working principle of the piezoelectric ring-bending actuator are presented. Second, an improved model of the piezoelectric ring bending actuator was developed based on the Bouc–Wen model, and its parameters were identified by the particle swarm optimization algorithm. Third, an equivalent dynamic model of mechanical transmission is established, and its nonlinear hysteresis dynamic model is established by combining the improved model. Finally, the model was experimentally verified under different driving frequencies. The comparison shows that the model has a high accuracy at 300 Hz. Finally, the step-response and frequency-response performances of the piezoelectric ring-bending actuator were experimentally determined. The results show that the output displacement is 31.2 μm at 100 V, the response time is less than 0.5 ms, the amplitude bandwidth is close to 700 Hz, and the phase bandwidth is ∼300 Hz.