基于光敏阵列直接调制的单栅式时栅位移传感器

针对传统叠栅形式光栅存在制造难度大、安装要求高等缺点,提出了一种用时间细分空间的单栅式时栅位移传感器。从光的粒子性出发,分析了用正交变化的光场信号合成光场电行波的方法;用点阵发光二极管(LED)模块作为交变光源,用空间正交的光敏阵列直接耦合光强信号获取了反应空间位移的电行波信号;最后,通过检测电行波信号与激励信号过零点之间的时间差,实现了对空间直线位移的测量。研制了原理样机,采用普通机械加工方法对其进行了实验验证。结果表明,在440mm测量范围内,样机的测量精度可达±2μm。该单栅式时栅位移传感器减少了叠栅式传感器对安装工艺的要求,提高了抗干扰能力;采用的测量技术避免了传统粗光栅技术存在的精度难以提高、动态特性差等缺点,为光学位移测量提供了一种不通过精密机械细分来提高测量精度的方法。

Single grate type time-grating displacement sensor based on photosensitive array direct modulation

Because conventional Moiré fringe gratings are difficult to be manufactured and assembled, this paper proposes a single grate type time-grating displacement sensor based on a time subdivision space. Based on the particle characteristics of light, a generation method of light field electronic traveling wave by light field signal with orthogonal transform was analyzed. Then, by using dot matrix Light Emitting Diode(LED) modules as alternating light sources,the electronic traveling wave signals to response the displacement values were obtained by coupling the space orthogonal photosensitive array with the receiving device. Finally, the space linear displacement was measured by detecting the time difference of zero-crossing between electronic traveling wave signal and excitation signal. A principle prototype was developed and validated experimentally by using a common mechanical processing method. The testing results demonstrate that measuring errors of the developed prototype are controlled within ±2 μm after error correction in a measuring range of 440 mm. The single grate type time-grating displacement sensor relaxes the requirements for installation process and improves its anti-interference ability. Moreover, the measurement technique avoids the weaknesses of traditional coarse grating technologies such as difficult to improve measuring accuracy and poor dynamic characteristics and provides a new method not to be depend on mechanical subdivision for improving the precision of optical displacement measurement.