基于坐标变换的压电陶瓷执行器迟滞非线性模型研究

Study of coordinate transform model for hysteresis nonlinearity in piezoceramic actuator

在实验测量的基础上,基于压电陶瓷执行器位移-电压曲线各升程之间、各回程之间的近似相似性,采用坐标变换方法,建立了压电陶瓷执行器位移-电压之间的迟滞非线性模型.该模型只用第1个升回程的实测值,便可实现对以后任意升回程各点的跟踪;其不仅适用于驱动电压为周期信号的情形,也适用于非周期信号的情形.实验研究了不同的电压驱动过程、驱动电压频率、驱动循环次数、晶片厚度对模型精度的影响.结果表明,当驱动次数不是很高时,模型相对于实测值的误差很小,为2.8%;当驱动次数很高时,模型相对于实测值的误差变大.

A new approach of coordinate transform to model the hysteresis nonlinearity between the displacement and the voltage across piezoceramic actuator is adopted, which takes advantage of the fact that there is approximate comparability among the ascending curves and among descending curves in a measured hysteresis loop. This model can predict any future ascending or descending displacement under a given voltage only employing the first ascending curve and the first descending curve and it is applicable to any circumstance no matter the driving voltage is periodical or not. The model accuracy is analyzed via experiments under different driving procedure, frequency, cycles and different width of wafer. Experiments show that the maximum prediction error is less than 2.8% under small driving cycles, and the error will increase along with the increasing of cycles.