复杂空间轨迹焊接过程运动规划方法

Motion planning method for complex three dimensional path welding

在复杂空间轨迹构件自动焊接场合,对执行机构运动参量的合理、准确规划是保证良好焊缝成形质量和冶金质量的前提。针对已有的运动规划方法未能在空间轨迹焊接中满足焊接速度和位姿恒定等工艺要求问题,该文提出了一种适用于任意复杂空间轨迹焊接的运动规划方法。该方法首先对待焊轨迹上的离散点进行B样条插补,然后建立空间轨迹焊接运动学模型并进行逆运动学求解,获得每个时刻各关节的位移和瞬时速度。仿真计算结果表明:该方法可保证在整个焊接过程中焊接区始终处于水平状态,且焊接速度、焊炬倾角、焊炬末端与焊接区距离保持恒定的预设值。该文提出的焊接运动规划可应用于复杂空间轨迹电弧焊、激光焊和搅拌摩擦焊等自动焊接场合。

Good forming and metallurgical quality in complex three dimensional welds requires accurate motion planning. Existing planning methods do not provide uniform welding speeds and stable positioning and pose between the torch and the workpiece. This paper presents a motion planning method for complex three dimensional path welding that first uses a B-spline curve to connect selected points along the seam. Then, a kinematic model is used to calculate the displacements and velocities of each joint at each time using an inverse kinematic method. Simulations show that this method keeps the welding region horizontal during the entire welding process and keeps the welding speed, inclination angle and distance between the welding region and the end of the welding torch equal to the predetermined values. This welding path planning method can be applied to complex three dimensional path planning for arc welding, laser welding and friction stir welding.