基于位姿在线反馈调整的大型法兰对装

Assemblage of Large Flange Based on Attitued Vector and Position Online Feedback

为解决工业结构中大型法兰对接装配存在的低精度、低效率等问题,提出一种基于姿态矢量及LD-PSD在线反馈的对装方法.首先,以关节臂测量机获取标定块测量点的实际坐标值,与理论坐标值对比形成拟合误差矩阵,以该矩阵2范数最小为优化目标,利用奇异值分解法(SVD)建立全局坐标系与测量坐标系映射关系,并获取全局坐标系下待装配件若干点空间坐标,结合最小二乘法及随机霍夫变换(RHT)建立待装配体当前位姿数学模型.设计六自由度位姿调整装置,以静法兰为目标位姿,依据关键姿态矢量信息解算动法兰位姿调整参量,实现位姿预调整.LD-PSD在线反馈系统检测并反馈装配质量评价指标,规划微转动及微平动路径,对静法兰位姿多次纠偏以满足对接装配精度.试验结果表明:装配过程高效,装配精度高,能够实现法兰连接结构的精确对装.设计的LD-PSD在线反馈系统可实现位姿的调整、检测、反馈再调整的闭环装配操作.

In order to solve the problems of low precision and low efficiency in the assemblage of large flange, a new method was considered on the basis of the key attitude vector and LD-PSD online feedback for the assemblage of large flange. Firstly, joint arm measuring machine was used to measure the actual coordinates of calibration block, which was compared with the theoretical values to build fitting error matrix. Taking the least 2-norm of the error matrix as optimization objective, a mapping relation between the global coordinate system and measuring coordinate system with SVD was then established. Secondly, the space coordinates of several points in the parts to be assembled under global coordinate system, and the mathematical model of the current position of the parts by the combination of the least square and RHT the key attitude vector information for the position and attitude adjustment parameters of tail nozzle were calculated. Lastly, the LD-PSD online correction system detected and feedbacked the quality evaluation index of the assembly to plan the micro motion and rotation path and adjust nozzle position in order to satisfy the assembly accuracy. According to the results of experiment, the assemble process through the proposed method is stable and efficient, the assemble precision is high, and the precise assemble of nozzle and combustion chamber is realized. LD-PSD system can realize a closed-loop operation of tail nozzle, such as adjustment, detection, feedback, and readjustment.