基于小波分析的交流伺服系统摩擦特征的研究

Research on the Friction for AC Servo Systems Based on Wavelet Analysis

摩擦是影响XY交流伺服工作台定位精度的重要因素。采用扭矩测量方式对交流伺服工作台的摩擦进行了研究,利用小波变换对测量信号进行多分辨率分析,从中识别出静摩擦力到动摩擦力变化过程中的特征信息。对比分析了扭矩测量方式和电流检测方式两种实验方法,结果表明,扭矩信号和伺服电流都包含了反映系统运行状态的丰富信息。与位移输出信号的对比分析表明,这两种实验方法均能有效地提取出摩擦影响的特征信息,但两者存在一定差别,充分利用这些特征可建立更有效的补偿控制模型。

Friction is an important factor influencing positioning precision of the AC servo controlled XY worktable.The friction in XY worktable was researched by means of torsion measurement.Multi-resolution analysis was performed upon the signals based on wavelet transform,from which the feature of transformation information from static friction to dynamic friction was detected.The experiments of torsion measurement were compared with ones of current measurement.Results show that lots of states information of the system is involved in torsion and current signals.Compared with the output signals of displacement,it is shown that information influenced by friction can both be extracted effectively from the torsion signals and current sig- nals.There are differences in a certain extent.Effective compensation and control models can be built by u- sing these characteristics sufficiently.