大型筒体-尾喷管位姿建模与精确装配方法

针对大型筒体-尾喷管对接装配的现场特点及安全性要求,为提高其装配精度及效率,提出一种基于关键位姿矢量及LD－PSD多参量在线检测反馈的精确装配新方法.利用跟踪仪获取标定块上标记点的实际坐标,依据其理论坐标和实测坐标的偏差建立最小二乘矩阵模型, 利用SVD法实现测量坐标系与全局坐标系空间配准.跟踪仪获取喷管、筒体关键点坐标,利用最小二乘及霍夫变换建立喷管、筒体当前位姿模型.研制六自由度装配设备,基于位姿矢量反解喷管位姿调整参量,完成姿态预调整.启动LD－PSD在线反馈系统,规划微调整路径,对喷管位姿多次纠偏以满足给定装配精度要求.在某动力厂的试验表明:装配过程平稳、高效,实现了筒体-尾喷管的精准对接.

Research on Pose Modeling and Precise Assembly Method for Large Cylinder-Tail Nozzles

According to the setting and safety of docking assembly for large cylinder-tail nozzles, a new method for precise docking assembly is proposed based on LD-PSD to improve the assembly accuracy and efficiency. First, the calibration block marker coordinates are obtained by using laser trackers, and the least square model is established according to the deviation between theoretical coordinate and the measured coordinate of the mark point. Precise spatial registration is implemented between measured coordinate and global coordinate by using singular value decomposition(SVD). Then, the tracking instrument is used to obtain the coordinate of the key point of the nozzle and cylinder. The mathematical model of the current position of nozzle cylinder is established using the least squares and HSF. 6-DOF CNC equipment is developed, and taking the posture of the cylinder as a reference, posture preconditioning is done by the anti-solution of nozzle pose parameters. The online feedback system is launched to detect the pre-assembly error. By planning micro rotation and micro translational path, the position of the nozzle is corrected several times to meet the requirement of a given assembly accuracy. The test results in a power plant show that the assembly process is smooth and efficient, and it can realize the precise docking assembly of large cylinder-tail nozzles.