基于比值线性化的高适应性光栅细分方法研究

电子细分是光栅位移传感器实现纳米级分辨率测量的关键,细分误差由细分方法和光栅信号质量共同决定。针对信号实时修正方法在小步距测量和一些复杂工况环境下的局限性,从提高细分方法对非理想光栅信号的适应性的角度出发,提出了基于信号比值线性化的新型电子细分方法,构建了2种实时补偿信号以进一步提高信号的线性度;详细阐述了所提细分方法的细分原理,分析了其在非理想光栅信号输入情况下的细分误差;实现了最高为0.003μm的理论细分精度和0.08μm的实际细分精度。数值仿真和对比实验结果表明,所提细分方法对非理想光栅信号的适应性明显优于常用的反正切细分法和正余弦绝对值相减细分法。

Research on Ratiometric Linearization Based High Adaptive Grating Signal Subdivision Method

Electronic subdivision is the key technology to achieving the nanometer resolution for the grating displacement sensors.And the error is caused by the subdivision method and the grating signal quality.Aiming at the limitations of real-time signal correction method in small-step measurement and some complicated working conditions, based on signal amplitude ratiometric, a new electronic subdivision linearization method is proposed from the perspective of improving the adaptability of subdivision method to non-ideal grating signals.In this way, two kinds of real-time signal compensation algorithms are constructed to further improve the linearity of the signal.Then, the principle of the proposed method is described, the error under the input of non-ideal grating signal is analyzed.And a theoretical accuracy of up to 0.003 μm and an actual accuracy of 0.08 μm are achieved.The numerical simulation and comparison experiments show that the proposed method has better adaptability to the non-ideal grating signals than the commonly used arctangent algorithm and linearization method based on the difference between the absolute values of the sine and cosine signals.