精密PSD微位移在线测量系统

为了满足工业现场微位移测量的精密性实时性和可靠性要求,设计并制作了位置敏感器件（PSD）激光微位移测量系统.系统将调制带通滤波峰值检测等信号处理技术运用于激光三角法中,并利用PSD信号单通道处理方式,提高了系统的抗干扰能力.同时,系统采用自适应控制方法改变激光的调制频率,从而调整电信号的增益系数以适应各种测量对象.实验表明,在没有滤光片的情况下,系统有效地消除了背景光和暗电流的影响,测量频率最高可达2,kHz,分辨率达到0.035%,稳定性误差小于0.090%,线性度好于1.2%,大大降低了温漂的影响.

Precise PSD Micro-Displacement Online Measurement System

In the industrial field, the online measurement of micro-displacement needs to be precise, real-time and reliable. In order to meet the requirements above, a position sensitive detector （PSD） laser micro-displacement meas- urement system was designed. In the system, many signal processing techniques, including modulation, band-pass filter and peak detection, were applied to laser triangulation method, and the PSD signal was processed in the single- channel way, all of which improved the anti-jamming capability. Meanwhile an adaptive control method was adopted to adjust the PSD signal gain coefficient by changing laser modulation frequency, which made the system suitable for various specific objects. Experimental results indicate that in the absence of filter, the system can effectively elimi- nate the impact of background light with dark current, with measurement frequency up to 2 kHz, resolution up to 0.035%, stability error better than 0.090%, and linearity better than 1.2%. The results also show that the impact of drift has been greatly reduced. Currently, the system has been applied to some online measurement systems.