Calculation Method and Simulation for Workspace of Arm–Rail Coordinated Spray Painting Robot

To address the need for improving the efficiency of spray painting large and complex curved surfaces, this study investigates the arm–rail coordinated spray painting operation method and proposes a robot workspace calculation method for efficient spray area partitioning. The steps for calculating the workspace under the constraints of the principal normal vector and the conical pose domain are introduced, along with an analysis of the robot’s forward and inverse kinematics. Simulation validation was conducted using a wind turbine blade as the target object. The results show that the workspace based on conical pose domain constraints outperforms both the reachable workspace and the full-orientation workspace in terms of validity and coverage, significantly enhancing spray painting efficiency. Compared to traditional fixed-station spray painting systems, the arm–rail coordinated robot can expand the workspace, reduce the number of stations and spray overlap areas, thereby improving efficiency while ensuring coating uniformity.