The Effect of Robot Kinematics on the Coating Thickness Uniformity

The torch speed is one of the most important operating parameters in thermal spraying. Generally, in order to keep a uniform coating thickness, the movement of the torch should be constant. Nevertheless, when the torch follows a large trajectory angle, the torch speed will decrease significantly, which leads to an irregular coating thickness. This phenomenon is caused by the weight of different devices fixed on the robot and the combination of the robot’s six axes. It is therefore necessary to optimize robot kinematics behaviors in this case. In this paper, the works concentrate mainly on the relationship between the robot kinematics property and the coating quality to find an adequate model for the torch speed optimization. An add-in program based on RobotStudio™ (ABB, Sweden) is developed to determine and optimize the spray trajectory. The optimal trajectory was verified by both the simulations and the experiments.