基于超定方程组的相位激光测距解模糊算法

快速准确的测距解模糊算法是相位式激光测距仪实现快速测距的关键问题。研究了一种基于超定线性方程组的相位测距解模糊算法,该算法避免了对最优解的搜索,因而运算量小、求解速度快。首先使用差频测相法在较大的不模糊距离上捕获到目标,获得近似距离值,然后使用这一距离值准确求解出不同频率调制波之间的周期数之差,从而构建超定线性方程组,最后应用最小二乘法求解出准确距离。同时还对该算法的2种解法进行计算机仿真,比较仿真结果,选取用间接法求解目标距离,并对该解法进行了精度分析。对3台K-60系列激光测距仪在精度为0.18 mm的国家标准基线上进行了测距试验,结果表明,3台样机的平均测量误差小于2 mm,测量标准差小于1 mm,验证了该算法是有效的。

Resolution method of laser ranging ambiguity based on overdetermined equation system

Rapid and accurate resolution method of laser ranging ambiguity is important for phase-shift laser rangefinder to measure distances.Based on overdetermined linear equation system,an algorithm is presented to solve the laser ranging ambiguity.Because the algorithm avoids the optimal solution searching and requires a little computation task,the solution speed is very quick.First an approximate distance is acquired in the unambiguous range using differential frequency phase measurement method.Then the differences of the period numbers for the modulated signals with different frequencies are calculated using the measured distance.Thus an overdetermined linear equation system is designed.Using least squares method,the accurate distance can be calculated.Meanwhile computer simulations are carried out for two solutions of the algorithm.Simulation results are compared and their precisions are analyzed;the indirect solution is chosen to calculate the distance.Three phase-shift laser rangefinders were tested on the baseline accorded with the national standards.Experimental results show that the average measurement error of the three prototypes is less than 2mm,and the standard deviation is less than 1mm,which indicates that the algorithm based on overdetermined linear equation system is efficient for ranging ambiguity resolution.