Computation of spraying deposition thickness on parametrized surfaces using moving frame method

This paper discusses the difficulties and current limitations of approaches which use static reference coordinates when planning appropriate trajectories for robotic spray guns as they attempt to apply even coating thicknesses to curved surfaces. It then proposes a calculative method, using moving frame of method, which can be used for successfully modeling such trajectories for continuous spraying onto parametric surfaces. Two coefficients are defined. The first is the ratio of the velocity of accumulation of coating thickness at any point in the sprayed area compared with that the spraying center, another one relates the position and orientation at any point relative to the spray gun. Taking a surface of rotation as an example, and considering the travel velocity of the spray gun and the spraying space as variables, we apply the method to compute the continuous-spraying deposition thickness, in order to allow trajectory optimization to minimize coating thickness deviation on the sprayed surface. We also apply Matlab programming to conduct a numerical computation verification, the result of which shows that this computing method represents an improvement over static coordinate methods in terms both of applicability and validity for spray-trajectory planning for the parametrized surfaces.