摘要
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。
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.
出处
《南京理工大学学报》
EI
CAS
CSCD
北大核心
2005年第2期189-192,共4页
Journal of Nanjing University of Science and Technology
关键词
自适应线性倍频
双频激光干涉系统
非匀速运动
位移测量
adaptive linear frequency multiplication
double-frequency laser interferometric system
variable speed
displacement measurement
