Throwing motion generation using nonlinear optimization on a 6-degree-of-freedom robot manipulator

A 6-degree-of-freedom rigid robot arm and its throwing motion generation is described in this paper. The trajectories for the joint variables are generated off-line as a cubic spline obtained using general constrained nonlinear optimization, taking into consideration limitations (position, speed, acceleration and jerk) of the joint actuators, and the current limit of the whole structure. The obtained trajectories are previously checked to avoid collisions using oriented bounding boxes and their separating axis theorem tests. The trajectory tracking of the individual joint is done using a discrete-time constrained optimal control technique.