行波型超声电机基于输入电压变化的参数模型辨识

Identification for Rotary Traveling Wave Ultrasonic Motor Based on Input-Voltage-Dependent Parameters

针对超声电机具有很强的依赖于输入控制电压的非线性和时变特性,很难建立适合控制的完整而精确的动态数学模型的问题,在分析行波型超声电机接触机理的基础上,将输入控制电压对超声电机动态参数的影响转化为所建模型时间常数、系统增益和延时参数的变化,并使用函数插值原理辨识模型参数与输入电压之间的函数关系,建立了电机的整体数学模型。最后给出实验结果验证了模型的有效性。

The ultrasonic motor （USM） possesses highly nonlinear characteristics that vary with input driving voltages and time. Thus, it is difficult to derive an accurate dynamic mathematic model for control design. Based on the analysis of the working principle of the so-called rotary traveling wave type ultrasonic motor （RTWUSM）, an identification method for the model with the parameters depending on input voltages was proposed. The effect of the driving voltages on the dynamics of the RTWUSM was transformed to the changes of the parameters, i.e. time constants, gains and delays in the proposed model. The relations between the input voltage and the parameters were obtained by means of the interpolation principle. Finally, experimental results show the effectiveness of the proposed approach.