Experimental evaluation of flexible manipulator trajectory optimization

Experimental results showing the effectiveness of trajectory optimization for reducing vibration excitation in point-to-point maneuvers of flexible manipulators are presented. Joint trajectories are found as the solution to a functional (or global) optimization problem. To reduce vibration, the functional is chosen to be the strain energy of the manipulator integrated over the time interval of the motion. A numerical example is presented to help verify the algorithm. A laboratory-based flexible-link manipulator is then described, and a model of its dynamics is obtained by combining analysis with experimental parameter identification. Through the use of the model, the optimal trajectory is generated and compared, both in simulation and experimentally, to a polynomial trajectory and the globally optimal straight-line trajectory. The experiments agree with the simulation in confirming that joint trajectory optimization can significantly reduce the total strain energy incurred during point-to-point motions.