标定偏心下压电力传感器测试精度研究

面向大型薄壁构件自寻位加工检测一体化测控原理,研发了一种小型化多维压电力传感器并进行标定研究。分析静态标定时,偏载对压电传感器多维力测试精度的影响。通过对静态标定加载有偏差时传感器受力的理论推导得到,加载偏差使传感器的转换系数改变,导致向间干扰补偿系数失真,影响了横向干扰输出,降低了测试精度;分析了偏载程度对传感器测试精度的影响,提出了衡量加载点偏差程度的判别方法,发现微小加载偏心带来的附加干扰会超出传感器自身向间干扰指标规定的5%;针对机械连接偏载不可避免事实,找到了克服偏载对转换系数影响的输出比例归一化法,将向间干扰降到5%内。

Study on Test Precision of Piezoelectric Force Sensor Under Load Deviation Calibration

Facing the large thin-walled member integration measurement principle of auto-orientation processing and testing, a kind of miniaturized multi-dimensional piezoelectric sensor is developed and calibrated. Based on the static calibration, the influence of the piezoelectric force sensor load deviation on the test precision of the multi-dimensional force is analyzed. The theoretical derivation results show that the static calibration load deviation changes the conversion coefficient, causes compensation coefficient of transverse interference to distortion and influences the output of transverse interference, resulting in measuring deviation of multidimensional force and lower test precision; the influence of the load deviation degree on the test precision of the multidimensional force is analyzed. A method to measure the deviation degree of loading point is put forward. It is found that the additional interference caused by little load deviation is much more than 5% of the sensor itself indicators. According to the fact that the load deviation in mechanical connection is unavoidable, the output proportion normalization method is used to overcome the influence of load deviation on the conversion coefficient, and the transverse interference is reduced to less than 5%.