Swing-free trajectory generation for dual cooperative manipulators using dynamic programming

In the high speed transport of freely suspended objects, traditional methods of suppressing residual oscillations may not produce satisfactory results. Nonlinearities may exist to the point that the linearizing assumptions required by these methods may no longer be valid. The optimization algorithm of dynamic programming (DP) is advantageous for such intrinsically nonlinear applications. This paper will outline the development of the DP algorithm for discrete time systems. It also describe the application of the algorithm to a rapid maneuver of a long slender payload suspended by a cable at each end. The cables are each held by one of two independent robot manipulators. The DP algorithm will be used to generate optimal swing-free motion trajectories for the robots. Simulation and experimental results show that residual oscillations are virtually nonexistent