Generation of temporal sequences using local dynamic-programming

The generation of a sequence of control actions to move a system from an initial state to a final one is an ill-posed problem because the solution is not unique. Soft constraints like the minimization of a cost associated to control actions makes the problem mathematically solvable in the framework of optimal control theory. The authors present here a method to approximate the solution of the problems of this category based on heuristic dynamic programming proposed by Werbos: local dynamic programming. Its main features are the exploration of a volume around the actual trajectory and the introduction of a set of correcting functions. Its application to the generation of a trajectory whose kinematics is minimum jerk is presented; in this situation, the introduction of a short-term temporal credit assignment improves the convergence tackling the lack of controllability in the plant.