基于试验的电动舵机模型辨识

摘要

目前电动舵机模型的建立基本上是基于理论的数学推导，所建立的舵机模型与实际舵机模型存在一定的误差。针对此问题，提出一种基于试验实测数据建立舵机模型的方法，搭建自动数据采集试验平台，采用组合窗法对实测数据进行频域转换，得到舵机的频率响应函数并采用非线性最小二乘法辨识舵机模型。对辨识得到的数学仿真结果与实际舵机响应比较，在频域，整个频段内幅频特性最大绝对误差＜1．9 dB；在时域，仿真模型跟踪实际舵机角度的最大误差＜1．5°，延迟时间＜10 ms。结果表明，基于试验数据建立的舵机仿真模型能很好地模拟实际舵机。%Model establishment of the electromechanical actuator is essentially based on the theory of mathematical derivation at present ,however ,the actuator model built by this method is not closed to the actual model.To solve this problem,the paper proposed a method to establish the model of the actuator based on the tested data ,and set up an experimental platform for data automatic collecting ,and also inno-vatively use combination window method to convert the data in the frequency domain ,get the frequency response function then use the nonlinear least squares method to identify the model of the actuator .By combination of the simulated results with the tested data ,it is shown that,in the frequency domain,the maximal absolute error of magnitude is less than 1.9 dB,in the time-domain,the error of angle is less than 1.5°,and the error of dely time is less than 10 ms,The result showed that the simulation model built by tested data is closed to the actuator .Therefore,this method can be applied well to model identification in the project .