基于机器视觉的航天器密封舱内结构装配精度检测系统设计

Design of the precision detection system for the assembly accuracy of the spacecraft sealed cabin structure based on machine vision

摘要:

目前航天器机械加工装配作业依赖人工操作，影响航天器密封舱内结构装配精度。为此，设计了航天器密封舱内结构装配精度检测系统，为高精度装配航天器密封舱内结构提供基础。由于航天器密封舱舱内结构较为复杂，为了保证使用电池供电时，检测系统能够保持稳定可靠工作模式，应保证电池电量充足前提下，系统发出预警信息，以便工作人员及时采取相应解决措施。在电池供电电路中，设计欠电压电路监测形式，该电路主要是由电压比较器LM393和555和谐振电路构成。当电池供电量不足时，谐振电路中的微电流高效率650nm谐振腔发光二极管会出现闪烁报警信号。以STC89C52RC-40I-PDIP40单片机中央控制单元为核心芯片，检测航天器密封舱密封性能。依据机器视觉检测原理，使用非线性滤波算法增强图像，避免外界噪声对图像采集结果造成影响，滤除图像上若干白点。设计检测流程可得到仪器板安装精度和设备安装支架装调检测结果。由实验结果可知，该系统检测精度最高与实测值一致，为航天器密封舱内结构优化提供设备支持。

Abstract:

At present, the machining and assembly operations of spacecraft rely on manual operation, which affects the assembly accuracy of the structure inside the sealed cabin of the spacecraft. To this end, an assembly precision detection system for the spacecraft sealed cabin structure was designed to provide a basis for high-precision assembly of the spacecraft sealed cabin structure. Due to the complicated structure of the spacecraft's sealed cabin, in order to ensure that the detection system can maintain a stable and reliable working mode when using battery power, the system should issue an early warning message on the premise of sufficient battery power, so that the staff can take corresponding solutions in time. In the battery-powered circuit, the monitoring form of the undervoltage circuit is designed. The circuit is mainly composed of voltage comparators LM393 and 555 and a resonant circuit. When the battery power supply is insufficient, the micro-current high-efficiency 650nm resonant cavity LED in the resonant circuit will flash a warning signal. The STC89C52RC-40I-PDIP40 single-chip microcomputer central control unit is used as the core chip to test the sealing performance of the spacecraft sealed cabin. According to the principle of machine vision detection, a nonlinear filtering algorithm is used to enhance the image, to avoid the influence of external noise on the image acquisition result, and to filter out some white spots on the image. The testing process can be designed to obtain the test results of the installation accuracy of the instrument board and the installation and adjustment of the equipment mounting bracket. It can be seen from the experimental results that the highest detection accuracy of the system is consistent with the measured values, which provides equipment support for the optimization of the structure of the spacecraft sealed cabin.