高精度角度测量装置是保证旋转设备精度和性能的关键，广泛应用于测量跟踪仪器中，特别是对于大尺寸坐标测量仪器，测角相比于测距是制约坐标测量精度的瓶颈。在精密一维轴系平台上，采用高精度柱面光栅及四个读数头构建测角装置，对传感器本身、安装及轴系跳动等误差因素对测角精度的影响进行了详细分析。基于角度测量标准器具校准角度测量误差，对误差数据进行谐波分析。基于遗传算法提出了一种参数优化方法，建立误差补偿模型，对测角误差进行了补偿。实验结果显示，补偿后柱面光栅测角误差减少为±0.7″，证明了误差补偿算法的有效性，显著地提高了角度测量精度。

High precision angle measuring unit, which is the key to ensure accuracy and performance of rotary equipments, is extensively applied in measuring and tracking apparatuses. In regard to large-scale coordinate measuring instruments, angle measurement is the bottleneck to enhance instruments′ coordinate measurement accuracy by comparing with distance measurement. High accuracy cylindrical grating and four reading heads were adopted to build angle measuring unit for precise one-dimension turntable platform, then the influence on angle measuring accuracy by sensor itself, installation and axis shafting were analyzed in detail. Angle measuring error was calibrated by standard device and analyzed with harmonic method. A parameter optimization method based on genetic algorithm was proposed to develop error compensating model, by which angle measurement error was compensated. The experimental results show that cylindrical grating angle measuring error is reduced to ±0.7″ after compensation, which demonstrates that the compensation method is effective to improve accuracy obviously.