阀体焊接机器人运动性能分析

基于弗莱那-雪列（Frenet-Serret）矢量理论，获得了离散焊点处的切向、法向和次法向矢量，据此可求得焊枪-焊点间的相对位姿。基于变位机-机器人主从运动链末端的耦合约束关系，提出以船型焊为最佳焊位时的协同焊接运动学模型及参数求解流程。在求解焊接机器人工作空间的基础上，依据球形手腕六关节串联机器人处于奇异位形的几何条件，归纳得出焊接机器人的10种独立的奇异位形。协同焊接阀体密封面的运动仿真和现场试验表明，该变位机-机器人焊接系统能够平稳、准确地完成预期焊接任务，证实了提出的协同焊接运动学模型及参数求解方法正确可行。

Motion Performance Analyses of Valve Welding Robots

The tangential vectors, normal vectors and auxiliary normal vectors of the discrete solder joints were solved based on Frenet-Serret's vector theory. Thus the relative positions and orientations between welding point and welding torch will be derived more easily. Based on the coupling constraint relationship between the ends of the active positioner kinematic chain and the driven robot kinematic chain, the coordinated welding kinematic model and the corresponding parameter solving process were presented for the optimum ship-welding position. On the basis of solving the working space of the welding robot, according to the geometric conditions of the singular positions for the spherical wrist 6-joint series robot, 10 independent singular positions of the welding robot were obtained. The motion simulation and field tests of the robot-positioner coordinated welding operation show that the system may smoothly and accurately complete the coordinated welding tasks of valve sealing surface. These results confirm that the proposed kinematic model and parameter solving process are correct and feasible.