Orientation Trajectory Planning Based on Unit Quaternions for Spray Painting Robots

In this paper, we present an approach for the orientation trajectory planning based on cubic B-splines with cumulative basis functions and unit quaternions for spray painting robots. The orientation representation based on unit quaternions avoids potential issues due to the representation singularity of Euler angles. Experimental results on an industrial spray painting robot demonstrate the feasibility of the proposed approach in obtaining a good approximation of the input orientations. Furthermore, continuity in velocity and acceleration is achieved, as well as limited values of the tangential velocity of the robot end-effector, as required in spray painting.