An On-Line Path Correction Method Based on 2D Laser Profile Measurement for Gluing Robot

Gluing is an essential fastening step in the field of aircraft assembly except for riveting and bolting. Generally, the robotic programs of gluing are generated in CAM environment. Due to the positioning errors and deformation of the workpiece to be glued in the fixture, the nominal pose and the actual pose of the workpiece are no longer consistent with each other. The Robot trajectory of dispensing glue is adjusted manually according to the actual pose of the workpiece by robot teaching. In this paper, an on-line gluing path correction method is developed by 2D laser profile measurement. A pose calibration method for 2D laser profiler integrated into a gluing robot by measuring a fixed center point of a standard ball is proposed to identify the position and orientation of the laser sensor, which enables the accurate transforming coordinates between the robot frame and the sensor frame. Since there are corner points in the cross-section between two workpieces to be glued together, an innovative method that can identify the corner point of the 2D point cloud is presented. After the cloud data is denoised, the curvature values concerning discrete cloud points are calculated in turn. By searching the local maximum values of the curvature in a specific length range, the corner points are obtained. A point-by-point correction method based on discretization of gluing path is put forward. The experiment results indicate that all the above measures ensure high accuracy and reliable gluing.