为了在高温环境下测量角位移, 研制了一种基于光纤的耐高温增量式光电编码器。针对高温工作环境提出利用耐高温的光纤传输光, 在常温环境中采用FPGA处理增量式编码器的电信号, 并通过USB传输角度信息; 分析光源光束准直度对光电编码器的影响, 提出采用LED凸透镜光纤耦合的方式获得平行光; 最后, 使用自准直平行光管和23面体检测精度, 并对比LED凸透镜耦合方式和直接耦合方式的精度。实验结果表明: 该系统在100 ℃的高温环境下工作正常, 编码器头部外型尺寸为62 mm×42 mm, 分辨力为0.3″, 精度3σ=13.55″; 与LED直接耦合方式相比精度提高了20.8%, 满足高温环境下角位移测量的需求。

To measure the angle shift that occurs under high-temperature conditions, a fiber-based high-temperature-resistant incremental encoder was developed in this study. First, a high-temperature-resistant fiber was employed to transfer light under high-temperature conditions. A field programmable gate array was used to process the incremental encoder's electric signal, and a USB was used to transfer the angle in a normal temperature environment. Second, the effect of the collimation degree of a light beam on the performance of the optical encoder was analyzed, and then a light-emitting diode (LED) convex lens fiber couple was developed. Finally, 23 surface polyhedrons and autocollimations were used to test the accuracy, and the accuracies of the LED convex lens fiber couple and fiber direct couple were compared. The results show that this system can work normally in 100 ℃ conditions. The size of the encoder head is 62 mm× 42 mm, the resolution is 0.3", and the precision 3σ is 13.55 ″, which represent an improvement of 20.8% over that of the fiber direct couple. The system thus satisfies high-temperature conditions.