Time-Optimal Trajectory Planning for Anti-Sloshing 2-Dimensional Motions of an Industrial Robot

When considering industrial applications in which liquid-filled containers are transported by a robot, the performed motions can cause undesired liquid stirring inside the container (also known as liquid sloshing), especially when the robot end-effector reaches high accelerations. The use of a simple sloshing-dynamics prediction model can be used for constrained-optimization purposes. The aim of this work is the time-optimal trajectory planning of an industrial robot carrying a cylindrical container filled with liquid, imposing limits on the liquid's sloshing for 1D and 2D planar motions of the container. Experimental tests taking into account three different paths are described, considering both non-optimized and optimized motions. Results from the experiments are illustrated and discussed, thus proving the effectiveness of the optimization.