Trajectory optimization for spray-painting robot in Cartesian space based on consistency index of paint film thickness

In response to the issue of uneven paint film thickness in Z-shaped spray trajectories during camouflage coating operations, this paper presents a robot spray trajectory optimization method based on a consistency evaluation index of the paint film thickness. Firstly, for the Z-shaped spray trajectory of the robot spray gun, a linear trajectory with seventh-degree polynomial blends is used to generate multi-point spray trajectories within the camouflage color blocks. Then, based on the paint deposition model of the rectangular gun, a consistency evaluation index for the paint film thickness is established. Finally, with the minimization of the variance in paint thickness as the optimization objective, the optimal spray trajectory is generated based on a genetic algorithm, with the interpolation time interval as the decision variable. Simulation and experiment results validate the effectiveness of the proposed method, demonstrating its capability to achieve a relatively uniform paint thickness while realizing a Z-shaped spray trajectory planning for camouflage blocks in Cartesian space.