高精度多频调制实时激光测距系统

High-precision Real-time Multi-frequency Modulation Laser Ranging System

为了克服多频调制激光测距系统中相位检测算法复杂、实时性差、精度低的问题,提出一种距离测量方法。该方法将测距回波信号通过改进的正交计算模块得到精确的相位延迟正切值,再通过坐标旋转计算机(CORDIC)角度计算模块得到相应的角度,结合正交同相(I)和正交(Q)支路输出的符号位和相位测距解模糊算法计算出精确的距离。实验结果表明,系统测距误差与回波信号的信噪比和计算模块的字长有关,在SNR为10dB,字长为16bit时,相位精度为0.03°,距离精度为0.125mm。

To overcome the shortcomings of complex algorithm,low precision and poor real-time ability of phase detection in multi-frequency modulation laser ranging system,a new ranging method was designed.An improved orthogonal algorithm was used to calculate the tangent value of the ranging phase,and the angle could be calculated with cordic angle solver algorithm.Experiments indicate this method can effectively improve the ranging accuracy and greatly reduce the ranging error.Combined with the sign bit of I and Q outputs,the accurate distance can be obtained.In experiments,when the SNR is 10 dB and the word length is 16 bits,the phase difference resolution is higher than 0.03° and the distance accuracy is about 0.125 mm.