一种X型梁电容式扭矩传感器设计

Design of an X-beam Capacitive Torque Sensor

为获得精确扭矩信息,通过对传感器传统十字型弹性梁结构分析,以等强度梁理论限定最小梁尺寸,进行不同尺寸梁结构拓扑优化求解,最终提出一种高灵敏度和良好抗串扰能力的X型弹性梁结构电容式扭矩传感器。传感器敏感元件为X型梁,此结构可以使传感器在满足强度条件下实现更小刚度以提高传感器的灵敏度;传感器转换元件为差动结构平行极板电容器,提高了传感器灵敏度并有效降低了传感器非线性误差,此外设计了带槽型孔的PCB板使得电容器初始极距可手动调节,更容易保证了电容器的初始极距;制作传感器并通过实验验证,结果显示,该传感器的灵敏度为871.9(CDC/N·m),迟滞为0.16%FS,串扰误差为0.73%FS。对实验结果采用最小二乘法进行三次多项式拟合,得到传感器符合度为0.14%FS。

In order to obtain accurate torque information,through the analysis of the traditional cross type elastic beam structure of the sensor,the maximum trabecular size is defined by the equal strength beam theory,and the topology optimization of beam structures of different sizes is solved.Finally,an X-type elastic beam structure capacitive torque sensor with high sensitivity and good crosstalk resistance is proposed.The sensitive element of the sensor is an X-type beam,able to achieve smaller stiffness to improve the sensitivity of the sensor while satisfying the strength requirements.The sensor conversion element is a differential structure parallel plate capacitor,which improves the sensitivity of the sensor and effectively reduces the nonlinear error of the sensor.In addition,the PCB board with groove holes is designed so that the initial pole distance of the capacitor can be adjusted manually,which ensures the initial pole distance of capacitor more easily.The results show that the sensitivity of the sensor is 871.9(CDC/N·m),the hysteresis is 0.16%FS,and the crosstalk error is 0.73%FS.The least square method is used to fit the experimental results,and the sensor conformity is 0.14%FS.