介绍了基于四象限探测器的激光跟踪仪目标脱靶量测量系统。根据四象限探测器的工作原理和跟踪激光的光斑特性，分析得出目标脱靶量与四象限探测器输出电流信号的关系为非线性。针对非线性关系不易快速解算的难题，文中采用了分段线性插值算法。使用高精度位移平台对测量系统进行标定并开展了测量实验。结果表明，该系统测量速度快，每秒测量次数可达 600次以上；测量精度高，在±500 μm量程范围内测量精度可达 5 μm。该系统可以广泛应用于需要微小位移测量的相关领域。

The measurement system for laser tracker’s target-missing quantity based on four-quadrant detectorsis introduced. According to the operation principle of the detector and the facula characteristic of tracking laser, the re.lationship between target-missing quantity and the output current of the four-quadrant detector is nonlinear. Accord.ing to the problem, piecewise linear interpolated algorithm is adopted. The measurement system is calibrated by ahigh-precision displacement platform and measurement experiments are performed. The results show that the systemhas a fast measurement speed and high measurement accuracy. The time of measurement per second is up to 600times or more and the accuracy is 5 m within ±500 m measurement range. The system can be widely applied in the re.lated fields.