不同作用点下压电测力仪灵敏度规律及其预测

Sensitivity laws and prediction of piezoelectric force sensors at different loading points

为了测量作用位置可变的大量程矢量力,设计了多点支撑式压电测力仪。对不同作用点下测力仪的灵敏度差异性进行分析和预测,以实现精准测量变作用位置的大量程矢量力的目标。对造成测力仪不同测试位置的灵敏度差异的影响因素进行分析,得到测力仪工作面域内不同作用点下的灵敏度与测力单元力电转换系数之间的关系。进行三向变加载点标定实验,获得不同作用点下测力仪的灵敏度实验值。建立LS-SVM预测模型,利用变加载点实验结果对模型进行训练。验证实验表明,该模型预测的不同作用点下的测力仪灵敏度值与真实值的偏差小于3%。采用LS-SVM模型对不同作用点下的多点支撑式压电测力仪灵敏度进行预测具有快速、可靠和高精度的特点,该方法用于定量分析复杂关系量是有效的。

A multi-point supported piezoelectric force sensor was designed to measure a wide range of vec⁃tor forces with variable application points.More specifically,this study focused on analyzing and predict⁃ing sensitivity variations of the force sensor at various application points to ensure precise measurements of vector forces at different loading points.The factors that cause sensitivity variations of the force sensor at different test positions were analyzed,and the relationship between the sensitivity at such points within the working surface of the force sensor and the force-electricity conversion coefficient of the force measuring unit was derived.A least-squares support vector machine(LS-SVM)prediction model was established.Verification experiments showed that this model accurately predicts sensitivity values for the force sensor at different application points,with an error below 3%compared to actual values.The LS-SVM model of⁃fers the advantages of speed,reliability,and high precision in predicting sensitivity for multi-point support⁃ed piezoelectric force sensors at various application points,indicating its efficacy in quantitatively analyzing complex variable relationships.