摘要
精准的焊缝识别与自动跟踪控制是保证机器人焊接质量及作业效率的基础。为实现大型结构件弧面焊缝的高效自动化跟踪焊接,该文提出一种基于单激光传感器的爬行机器人双向自动跟踪技术和自适应权重的焊枪级联控制方法。针对爬行机器人建立运动学模型,分析了激光系统与焊缝的距离偏差预估方法和机器人与焊缝夹角修正方法,通过动态调整爬行机器人本体与焊缝的位置关系实现爬行机器人沿焊缝双向自动跟踪。基于焊接工艺参数和焊缝位置信息确定焊枪姿态和末端位置,通过执行机构的逆运动学模型求解得到焊枪传动关节的运动位移值,并基于运动位移值调整关节电机对焊枪位置进行实时校正。仿真分析了激光系统与机器人本体中心距离对直线焊缝路径跟踪的影响,发现该距离在0.35~0.5 m之间能够兼顾激光系统和机器人本体中心快速跟踪焊缝。初始距离偏差对激光系统与焊缝的距离偏差影响较小,但对机器人与焊缝的夹角偏差影响较大。分析了后退控制的系统稳定条件,并在5G和6G焊接位置开展机器人沿焊缝的双向跟踪性能测试,得到跟踪过程的激光系统与焊缝距离偏差值曲线以及机器人与焊缝夹角曲线,证明了控制系统的有效性。通过对执行机构进行运动学仿真,验证了焊枪定位的准确性。
[Objective]Accurate weld seam recognition and automatic tracking control are crucial for ensuring the welding quality and operational efficiency of crawling robots.To achieve the efficient and automatic tracking of curved surface welds on large structural components,this work proposes a crawling robot bidirectional automatic tracking technology based on a single laser sensor and an adaptive weight welding gun cascade control method.[Methods]A kinematic model was established for a crawling robot.The methods for estimating distance deviation between the laser system and the weld seam and correcting the angle between the robot and the weld seam were analyzed.By dynamically adjusting the position of the crawling robot with respect to the weld seam,the robot achieved bidirectional automatic tracking along the weld seam.Based on the welding process parameters and weld position information,the welding gun posture and end position were determined.The motion displacement value of the welding gun transmission joint was obtained by solving the inverse kinematics model of the actuator,and the joint motor was adjusted based on the motion displacement value for real-time welding gun calibration.[Results]The influence of the distance between the laser system and the center of the robot on the straight weld path tracking was simulated and analyzed.Distances between 35 and 50 cm enabled rapid tracking of the weld seam by the laser system and center of the robot.The initial distance deviation had a small impact on the deviation between the laser system and the weld seam but has a significant impact on the angle correction between the robot and the weld seam.The stability conditions of the cascade control system were analyzed,and the bidirectional tracking performance of the robot along the weld seam was tested at the 5G and 6G welding positions.The distance deviation curve between the laser system and the weld seam during the tracking process and the angle correction curve between the robot and the weld seam were obtained.The distance deviation between the laser system and the weld seam was less than 2 cm,and the angle correction between the robot and the weld seam was approximately 1°.[Conclusions]To ensure the stability of the cascade control system,the distance deviation between the laser system and the weld seam should be converted to the distance deviation of the robot tail for proportion integration differentiation(PID)input.The crawling robot motion control system satisfies the bidirectional automatic tracking along the weld seam in the 5G and 6G test scenarios,and the system has accurate welding gun positioning capability.Prealignment of the weld should be done before the welding operation of the crawling robot to further ensure operating stability.
作者
冯消冰
郑军
杨尚贤
潘百蛙
FENG Xiaobing;ZHENG Jun;YANG Shangxian;PAN Baiwa(Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;Beijing Botsing Technology Co.,Ltd.,Beijing 100176,China)
出处
《清华大学学报(自然科学版)》
北大核心
2025年第5期867-881,共15页
Journal of Tsinghua University(Science and Technology)
关键词
大型结构件
弧面焊缝
爬行机器人
单激光传感器
双向自动跟踪
large structural components
curved surface welds
crawling robot
single laser sensor
bidirectional automatic tracking
