Dynamic Characteristic Analysis Of Piezoelectric Torque Sensor

The dynamic characteristics of the torque sensor can be obtained by using the method of negative step signal excitation,but this method is not easy to stimulate the high-frequency working mode of the torque sensor,and can not effectively analyze the high-frequency dynamic characteristics of the sensor,In order to solve this problem,the step excitation method with shock tube as excitation source is used to analyze the dynamic characteristics of torque sensor,and the following research contents are carried out.Firstly,according to the response characteristics of piezoelectric torque sensor under the condition of shock tube as excitation source,the least square residual variance method is used to determine the order of its mathematical model,and then the differential method is selected as the method to obtain the dynamic nonparametric model of the sensor,The differential method solves the problems of a large number of burr interference and high-frequency distortion in the non parametric model image obtained by other methods.Then,the rise time,overshoot and natural frequency are analyzed to explain the influence of each index on the output signal.Finally,based on the Labview software design platform,a dynamic characteristic analysis system with shock tube as excitation source is designed,which solves the problem that the shock tube test system contains multiple equipment and parts are scattered,and the function is single,which is not suitable for installation and disassembly.It integrates data acquisition,signal processing,input / output control and signal generation,which greatly reduces the difficulty of operation,The virtualization,generalization and automation of the test process are realized.According to this test platform,the rise time,overshoot,dynamic sensitivity,installation resonance frequency,natural frequency and other parameters of the sensor are measured,and the repeatability of each parameter is calculated to verify the reliability of the data.The maximum frequency of the measured signal is 7.42 k Hz,which shows that the shock tube dynamic characteristic analysis system can excite the frequency response of the sensor whose working frequency is much higher than 1k Hz of the negative step device.The dynamic characteristic analysis method using shock tube as the excitation source can better obtain the dynamic characteristics of the measured sensor.