Cooperative control method of trajectory online dynamic planning and weld bead tracking in welding process

Abstract

The invention provides a cooperative control method for track online dynamic programming and weld pass tracking in a welding process and belongs to the technical field of movable welding robots. According to the method, the advantages that the joint welding groove detection in front of a welding area is achieved by a structured light visual sensor detecting area ahead of an electric arc, and welding torch poses are obtained by an electric arc sensor in real time are combined sufficiently; based on the weld pass isometric approximation theory, the cooperative decoupling control over the track online dynamic programming and weld pass tracking of a robot body is achieved. By means of the method, the welding speed stability and weld pass tracking accuracy of a movable welding robot in the large structure complex tracking welding joint welding process can be improved, and the local large curvature of the joint track and the welding joint forming quality in a bevel area are improved; the method can be applied to the movable robot welding process in equipment manufacturing of ships, energy sources, rail transit and the like and is especially applicable to the welding occasions of curved welding joints of large bevel or large curvature.

Description

technical field [0001] The invention belongs to the technical field of mobile (type) welding robots. The invention relates to a control method for the coordination of trajectory online dynamic planning and welding bead tracking in the welding process, and can be widely used in automatic welding of mobile robots and the like. Background technique [0002] In the welding of large components in the fields of energy equipment, heavy machinery, and shipbuilding, mobile welding robots have become an effective method for automatic welding of large-scale and complex space curve welds due to their advantages in large-scale motion capabilities. Limited by the working stroke of the airborne actuator device (such as the mechanical arm, Cartesian coordinate system X-Y carriage, etc.) installed on the robot body of the mobile welding robot, it is necessary to adjust its position and posture in real time in combination with the robot body to ensure that the welding torch is aligned. In th...

AI Technical Summary

Problems solved by technology

[0003] Existing mobile welding robots mainly use a single type of seam tracking sensor, including arc sensors and vision sensors. The mobile welding robot using arc sensors only detects the molten pool area and obtains welding deviation information from it. The real-time welding deviation information or the actual correction behavior of the airborne actuator to adjust the pose requires the airborne actuator to have a large effective working stroke; moreover, the following motion of the robot body to the welding bead is easily affected by the electromechanical inertia of the mobile welding robot system The impact leads to control lag, especially in areas with large curvature of the curved weld trajectory and knuckle areas where the mobile welding robot needs to perform large-angle turning motions to track the weld trajectory. Because it is difficult to adjust the pose in time, it is easy to produce partial welding defects , or the welding seam is poorly formed due to changes in welding speed; in order to avoid strong arc light interference, the mobile welding robot using visual sensors usually has a certain distance between the detection area of ​​the visual sensor and the arc molten pool area, and it is difficult to compensate in real time. Changes in seam position and size

[0004] In summary, the existing technologies are difficult to take into account the dynamic response and static accuracy of the mobile welding robot in the welding process of large-scale complex trajectory welds, and it is difficult to solve the technical problem of coupling the motion control of the robot body and the airborne actuator

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