压电测力仪的联立标定方法研究

Research on simultaneous calibration for piezoelectric dynamometer

针对四支点布置形式压电测力仪标定时力解耦困难和测试受力状态与标定时不一致的问题,提出了联立标定法。基于测力仪测试模型,建立了力电关系方程组,推导出力电转换系数模型,并进行了扰动分析和误差传递分析。在测力仪上表面选取均布的21个特征点,进行加载实验,计算测试力值,并分析测试误差在上表面的分布情况。实验结果表明:在测力仪上表面,联立标定法最大测试误差仅为0. 376%,线性度在0. 33%以内,重复性在0. 26%以内。证明在测力仪上表面,联立标定法的测试精度均很高,标定方法有效。

Aiming at the problem of difficulty of force decoupling and inconformity between test stress state and calibration when piezoelectric dynamometer with four point layout is used,a simultaneous calibration is put forward.Based on the test model of dynamometer,a force-electricity equation is set up,the model for forceelectricity conversion coefficient is derived,and the disturbance analysis and error transfer analysis are carried out.21 characteristic points are selected on the surface of the dynamometer,the loading experiment is carried out,the test force value is calculated and the distribution of the test error on the upper surface is analyzed.Experimental results show that the maximum test error of the simultaneous calibration method is only 0.376%,the linearity is less than 0.33%,and the repeatability is less than 0.26%.It proves that the simultaneous calibration has high precision and the calibration method is effective on the upper surface of dynamometer.