小型化的高重频多脉冲激光测距机采用数字化处理确定目标距离,接收电路带宽、数字化采样精度以及滤波算法等因素会影响测距的精度,文中在对测距误差分析的基础上提出改进测距精度的算法。首先,在对激光回波信号积累以提高信噪比的基础上,对回波信号波形进行中心差分处理、斜率阈值和幅度阈值条件处理,剔除伪峰值点,初步确定峰值点位置。然后,根据初定位后的波形特点,选择相应的指数函数进行非对称sinc函数波形拟合修正,估计波峰点相对准确位置,从而输出较为精确的目标距离。最后,将改进算法在matlab中仿真,实验结果验证了文中提出的修正算法对提高激光测距精度的有效性。
On the basis of the fact that digital processing algorithm is used by high repetition frequency multi pulse laser rangefinder, the bandwidth of the receiving circuit, the digital sampling accuracy and the filtering algorithm affect the accuracy of ranging. The algorithm of improving measuring precision was put forward by analyzing the error of ranging. Firstly, based on the accumulation of the laser echo signal to improve the signal to noise ratio (SNR),it was followed by the processing of center differential signal, slope threshold condition of echo signal and eliminated the pseudo peak point, thus peak position was determined preliminarily; and then according to the characteristics of the waveform after initial positioning, the corresponding exponential function was selected to modify the waveform of the asymmetric sinc function to obtain the relative exact position of the crest point, so as to calculate the more accurate target distance. Finally, the improved algorithm was simulated in MATLAB, the simulation results show that the proposed algorithm can improve the accuracy of laser range accuracy.