Parameter optimization for spray coating

The aim of planning path-oriented spray-coating processes is to find a time-dependent continuous sequence of spray gun configurations so that a coating of desired thickness is achieved when executing the sequence. A novel approach to solving the planning task, called "geometry-last", is outlined which leads to a more general gun configuration cover problem. The gun configuration cover problem is to find a finite set of spray gun configurations, which minimizes the error between a target coating and the coating induced by simultaneously activating those configurations. A suitable objective function for gun configuration covers is defined, and algorithmic solutions for the optimization problem are presented, including speed-up by hierarchization and use of graphics hardware. An experimental evaluation shows that good approximations of the desired coatings can be achieved within reasonable computing times. In contrast to other approaches, geometry-last gains additional flexibility required to find complex paths for free-form workpieces. (C) 2009 Elsevier Ltd. All rights reserved.