基于分时方法的高精度反射绝对式 纳米时栅位移传感器设计

本文提出了一种反射绝对式纳米时栅位移传感器的传感方法。采用反射单列式传感器作为反射绝对式传感器的精密测量部分,记为传感器A。为了实现绝对位移测量,设计了一个与传感器A相差一个周期的反射单列式传感器,记为传感器B,利用传感器A与传感器B相位作差实现绝对位移测量。采用标准印刷电路板技术制作了传感器样机,搭建了实验平台,进行了实验测试。测试结果表明,激励电极引线方式对接收电极带来干扰,从而造成一次谐波误差。为了抑制误差,提出了交叉反射结构和分时方法,交叉反射结构将感应电极与另一端的反射电极引线相连,增大激励电极和接收电极的距离,分时方法通过不同时间段对传感器A和传感器B施加激励信号,并把不工作的电极接地。实验表明该结构和方法相互配合有效的抑制了干扰,最终在400 mm范围内,补偿后实现了±300 nm的测量精度。

Design of high-precision reflective absolute nanometer time-grating displacement sensor based on time-division method

This article presents a sensing method of the reflective absolute nanometer time-grating displacement sensor. The reflective single-row sensor is used as the precision measurement part of the reflective absolute sensor, which is marked as sensor A. To achieve absolute displacement measurement, a reflective single-row sensor with a period of difference from sensor A is designed, which is marked as sensor B. The phase difference between sensor A and sensor B is utilized to achieve absolute displacement measurement. The sensor prototype is made by using standard printed circuit board technology. An experimental platform is established, and evaluation experiments are carried out. Results show that the lead method of the excitation electrode brings interference to the receiving electrode, which causes the first-order harmonic error. To suppress error, a cross-reflective structure and a time-division method are proposed. The cross-reflective structure connects the sensing electrode with the reflective electrode lead at the other end to increase the distance between the excitation electrode and the receiving electrode. The time-division method applies an excitation signal to sensor A and sensor B at different time. In addition, it connects the inoperative electrode to the ground. Experimental results show that the structure and method cooperate with each other to effectively suppress the interference. Finally, within the range of 400 mm, the measurement accuracy of ±300 nm is achieved after compensation.