AUTOMATED CAD BASED TRAJECTORY FOR SPRAY PAINTING ROBOT: VARIABLE VELOCITY APPROACH

This paper proposes a new automated offline trajectory generation approach for free form surfaces targeted towards spray painting application. The spray gun trajectory is generated from the computer aided design (CAD) model of the surface to be painted for a structured environment. A variable velocity approach is proposed to overcome the effect of surface curvature on the desired paint thickness. The proposed approach is divided into three problems: paint pass generation, optimal gun velocity and overlap distance computation. These problems are solved independently of each other using standard optimization techniques. The paint passes consisting of points and corresponding normals are generated using a 'section' based approach. An optimal variable spray gun velocity depending on the surface curvature is calculated based on the paint thickness function using genetic algorithm and curve fitting technique. The overlap distance is calculated depending on paint thickness of every paint pass. The approach was implemented on test surfaces and the simulation and experimental results reveal that minimal paint thickness deviation is obtained for simple as well as highly curved surfaces.