基于激光扫描的自适应相贯线焊缝多层多道路径规划

Adaptive multi-path/multi-layer path planning of intersecting welding seams based on laser scanning

实际生产中管管相贯的多层多道焊接任务,存在工件一致性、焊缝位置差异、热变形影响等因素给轨迹规划带来偏差的难题,开发了一种四自由度焊接机器人,并提出了一种无需建立工件坐标系的基于激光测距传感器的关键点变位姿扫描加轨迹拟合插补的多层多道路径动态规划方法。首先对机器人结构合理简化建立了D-H连杆坐标系,通过齐次变化矩阵推导了机器人的运动学正解和逆解方程。接着制定了等分旋转每道等间隔逐层扫描规则,机器人焊枪携带激光测距传感器对相贯线焊缝轨迹上的若干点进行扫描,并在误差允许的范围内,采用修正的等距切线法及欧拉角线性插值,实现了无需纠偏的轨迹动态规划。通过试验验证,焊缝成型美观饱满致密,能自适应非一致性焊缝,可以满足工程领域大批量非标准工件的相贯线焊接质量要求。

In the actual production of multi-path/multi-layer welding tasks where pipe-pipe are intersected,poor workpiece consistency,large weld position differences,thermal deformation and other factors bring deviations to path planning.This paper develops a four Multi-Joints welding Robot,and proposed a multi-path/multi-layer path dynamic planning method based on distance laser sensor's key point variable pose scanning trajectory fitting and interpolation without the need to establish a workpiece coordinate system.Firstly,the D-H link coordinate system is established by rationally simplifying the structure of the robot,and the forward and inverse kinematics equations of the robot are derived through the homogeneous change matrix.Then,the rule of scanning layer by layer with equal rotation and equal intervals was formulated.The robot welding gun carries the distance laser sensor to scan several points on the intersecting weld seams,and within the allowable range of error,adopts the corrected isometric tangent method and Euler angle linear interpolation to realize the dynamic planning of the trajectory without correction.It is verified by experiments that the weld seam is beautiful,full and compact,and can adapt to non-uniform weld seams,which is able to meet the welding quality requirements of large quantities of non-standard workpieces in the engineering field.