基于STM32微控制器的电容式微位移测量系统的设计

Design of Capacitance Micro-Displacement Measurement System Based on STM32 Microcontroller

基于STM32微控制器构建了电容式微位移测量系统,该系统由电容传感器、数据采集电路以及主控系统组成.基于传感器电容梯度理论模型,分析计算了圆筒形电容式传感器下的电容梯度,对系统关键部件电容式位移传感器探头进行变面积型结构设计.通过对电容梯度与位移的变化进行精密测量,对位移与电容梯度之间的理论数值关系进行实验验证.实验数据证明了变面积型电容式传感器探头设计与测量方案的可行性.在当前的电容式传感器条件下,该测量系统量程达到4.6 mm,精度为10μm,具有较大的测量范围和较高的精度.

In this article,a capacitive micro-displacement measurement system is constructed based on STM32 microcontroller,which is composed of capacitance sensor,data acquisition circuit and master control system. Based on the theoretical model,the capacitance gradient of the cylindrical capacitive displacement sensor is analyzed and calculated,and the capacitive displacement sensor probe of the key component of the system is designed with variable area. The theoretical numerical relationship between the displacement and capacitance gradient is calibrated by experiments through precise measurement of capacitance gradient and displacement. The experimental data have proved the feasibility of the design and measurement scheme of capacitive sensor probe with variable area. Under the current capacitive sensor condition,the measuring system has a range of 4.6 mm and an accuracy of 10 μm,with large measuring range and high accuracy.