基于误差补偿的光源调频非线性校正研究

Correction of nonlinear frequency modulation of laser source based on error compensation

由于FMCW光源非线性频率调制的影响,其差频信号的频谱会出现展宽,降低频谱分辨率,因此光源非线性校正是该体制激光雷达精确测距的前提。为了避免现有非线性校正技术系统结构复杂,测量成本高的缺陷,本文提出了基于误差补偿的FMCW光源非线性校正法。该方法通过输出信号与线性回归数据之间的误差,构建与输出信号频率变化趋势相反的校正数据作为激光器的调制信号源。经过若干次循环补偿,逐步将输出信号频率与线性回归数据之间的决定系数提高到0.9995以上。最终通过距离测量实验,验证了该方法的有效性和可行性。

Due to the effect of nonlinear frequency modulation of FMCW laser source,the spectrum of beat frequency appears to be broadened,which reduces spectral resolution,so the nonlinear correction of the light source is a prerequisite for the accurate ranging of this system LIDAR.To avoid the defects of the existing nonlinear correction technology with complex system structure and high measurement cost,a nonlinear correction method of FMCW laser source based on error compensation is proposed in this paper.Through the error between the output signal and the linear regression data,correction data with the opposite trend of change in the output signal frequency is constructed as the modulation signal source of the laser.After several cycles of compensation,the coefficient of determination between the output signal frequency and the linear regression data is gradually improved to more than O.9995.At last,the effectiveness and feasibility of this method is verified by range measurement experiments.