自适应线性倍频在双频激光定位系统中的应用研究

针对双频激光干涉测长系统中物体变速对信号线性倍频提高测量分辨率的影响，提出一种数字自适应线性倍频方法。该方法利用带基准时基的数字计数器实现周期内线性细分，当前周期信号将前一整周期的倍频数作为参考构成信号周期的小数部分。以匀加速-匀速-匀减速运动为例，分析了测量误差与加速度之间的关系，仿真结果验证了该方法的可行性。该方法采用硬件线性细分，为解决非等周期信号的倍频问题提供了一种简便易行的方案。

Adaptive Linear Frequency Multiplication in Double-frequency Laser Orientation System

In order to reduce the effect of variable speed on the resolution improvement via linear frequency multiplication in double-frequency laser interferometric system of displacement measurement, this paper presents a new adaptive digital linear frequency multiplication method. A counter with timing fiducial oscillator acts as a frequency multiplier, and the count value in the prior period is taken as the reference for the current period to give the decimal part of a signal period. From a numerical simulation on a practical possible mode: uniform acceleration-unifom speed-uniform deceleration, we obtain the relationship between the measurement error and the acceleration value. The simulation results show the feasibility of this method which provides a new and simple way through hardware linear multiplication for frequency multiplication of periodic signal with unequal periods.