Studies the dynamic behavior of a near-minimum time controller for planar flexible manipulators using three control schemes: rigid manipulator control, passive flexible manipulator control and active flexible manipulator control. The Lagrange-Euler equation is employed to formulate workable state variable models for both rigid and flexible manipulators. The link flexibility is incorporated by using the method of assumed mode. Simulation results indicated that effects of small link flexibility could not be ignored. In the worst case, vibrations may even disable the controllers. Higher torque inputs produce larger tip displacements, and reduce execution times. Simulation results also indicated that tip deflections could be suppressed in highly flexible links with small applied modal torques. However, applied modal torques would prolong the execution time if they are too small.

The development of a near-minimum-time control for two coordinating robots manipulating an object in a workspace is addressed. Optimal control theory is used to derive a feedback controller which will enable the two robots to move an object from one place to another in near-minimum time. A dynamic model for the two robots and the load is established and then linearized using the average dynamics method. The model is continuously updated at every control interval, making it suitable for high-speed applications such as minimum-time problems. Bang-bang control theory in conjunction with synchronization of execution time for each joint is used to derive the near-minimum-time controller. The model and the control law are simulated for two distinct schemes. One is a master-slave configuration of the two robots, and the other is based on an optimal controller for both robots. The simulation results indicate that the proposed controller implemented for both schemes behaves favorably.>

A dynamic model for the Merline 6200 industrial robot system which is suitable for optimization and control studies is derived by making use of the Lagrange-Euler method. A controller that is based on ideas from sliding mode and optimal control theory is applied to the linearized dynamic model to enable the arm to track a preplanned trajectory with minimum error. The results of computer simulations indicate that the dynamic model derived is suitable for control studies and that the controller applied is an accurate one.>

The authors consider the development of a near-minimum-time suboptimal controller for a robot manipulator to follow a prespecified path which is designed to avoid obstacles in the workspace. A dynamic model for the manipulator, which is simple to manipulate, is established using the average dynamics method of linearization. The model has the advantage of being continuously updated over the control time periods. This makes it suitable for high-speed or variable-payload applications. Bang-bang control theory in conjunction with synchronization of executing time for each joint is used to derive the suboptimal controller. Simulation results under different conditions of obstacles and loads indicate that the desired controller moves the manipulator around the obstacles in near minimum time with an acceptable level of accuracy.>