航天级双读数多圈绝对式光电编码器设计

Design for Spaceborne Multi-Turn Photoelectric Encoder of Dual Numerical System

利用多圈光电编码器具有体积小、量程大以及数字量输出等优点,设计了基于双读数系统的航天级多圈绝对式光电编码器。根据航天相机的精度要求,采用精度高、分辨率高的绝对式矩阵玻璃码盘作为一级码盘完成角度测量;根据电机转动的计数要求,采用重量轻,体积小的绝对式矩阵金属码盘作为二级码盘完成对一级码盘的转动圈数计数;其具有的双狭缝及双读数系统可实现信号处理电路冷备份。按照鉴定级航天产品要求,通过热学环境实验和力学环境实验对编码器性能进行了验证。实验结果表明,所设计的编码器精度范围为±100″内、分辨率为80″、测量圈数为16圈、外形尺寸为φ50 mm×50 mm、重量为270 g,稳定性高、可靠性强,且满足高分辨率航天设备设计指标。

According to the requirements of high- resolution spaceborne camera focusing mechanism, a dual readings multi- turn absolute encoder is designed. Accuracy and high- resolution glass plate is the first level absolute matrix optical code disc; metal plate with light weight and small size is the second level absolute matrix optical code disc which completes the count of the number of first level disc turns; double slit and double reading system to meet the circuit cold backup. The encoder can offer that resolution of 80″, accuracy between ±100″, cylinder number is 16, its dimensions for φ50 mm×50 mm, weight of 270 g. According to the requirements of identified spaceborne product, the function of encoder is verified through kinds of experiments. The experimental result shows that the encoder is stable, reliable and satisfies for the requirement of highresolution spaceborne focusing mechanism.