Dual-Amplifier Driving in Sequence Method with Switches for Piezoelectric Stack Actuators to Reduce Hysteresis

Piezoelectric actuators have been widely applied to precision positioning platforms. However, the positioning accuracy of piezoelectric ceramic has been significantly affected by its characteristics of hysteresis. Owing to the voltage-keeping feature of capacitive load for piezoelectric ceramic, this paper has proposed a switch-based driving in sequence method, which alternately drives each layer of PZT by using switches. Based on the driving in sequence method, the proposed method is capable of reducing the hysteresis to 1/N of the hysteresis under traditional voltage driving method, while significantly lowering the scale and cost of hardware, compared with the previous driving in sequence method. Thus, it allows for application to hundreds of layers of piezoelectric ceramic. According to experiment results, the hysteresis under different frequencies from 0.1 to 500 Hz for homemade seven-layer piezoelectric ceramic can be reduced from 12.5 to 2.1%. Furtherly, the residual hysteresis can be corrected by applying a simple quadratic-polynomial feedforward control, and the hysteresis is constrained within 0.8%, even with feedforward parameters that are not strictly calibrated. The dual-amplifier driving in sequence method proposed in this paper can significantly reduce the hysteresis in open-loop control of piezoelectric stack actuators, effectively improving the positioning and driving performance and saving cost.