Adaptive And Optimal Control Of Dual-manipulator Systems Handling Flexible Payloads

Recently, robot manipulator has been used in many fields. There are many scholars who have done much work in manipulating rigid object, while in many fields, such as shipbuilding, car and air craft, flexible material has been used largely. So far, there are few scholars who have done such work. The system composed of robot manipulators and flexible payload has characteristics as following: exceeding nonlinearity, strong coupling and infinite degree of freedom. In the process of handling flexible two actions will happen that are rigid and vibration. Considering the current conditions domestic and abroad, the study of manipulating flexible payload is underway and the methods of control aren't perfect. There are many questions needed to be solved.In this paper the study of two manipulators handling a flexible payload has been done. The contributions of this paper are the modeling and the controller that is based on the other's work. Firstly, the background and significance are introduced. The system of manipulator manipulating flexible payload is divided into two species single and cooperative and the conditions are introduced singly. The characteristics of current methods are analyzed.In term of this paper, the structures that will appear in cooperative manipulation are analyzed and the structure we need in this paper is chose. Based on this structure, boundary condition is present to be the benchmark of flexible body. The object coordinate is located on this benchmark and the flexible payload is divided into four elements in the object coordinate. There is a special condition appearing when we define the flexible coordinates both sides of the object coordinate because of the choice of coordinates and the explanation is given. On the last basis the rigid dynamic equation and vibration equation are deduced. In this paper three kinds of coordinates will appear that are joint coordinates, end-effector coordinates and object coordinate. In order to have a uniform expression the relations of three coordinates are listed and the rigid dynamic equation and vibration equation of the system are derived in the object coordinate. The characteristics of the system are introduced.So far, there are few scholars who have studied the whole system and some scholars have only studied certain problem because of the complexity of the system. The control of vibration is very difficult because the state vibration is unmeasurable.Considering the uncertainties exist in both of the manipulators and flexible beams. In the design of control scheme, the cooperative trajectory tracking control method is designed based on the Adaptive Control Theory. Then the proof of the stability and global convergence is presented, global convergence in trajectory tracking errors is obtained. The tracking errors of the internal forces are bounded and the bound is proportional to the norm of the parameter errors. It has also been shown that if the desired trajectory is chosen to satisfy the PE condition as has been mentioned earlier, then the force errors will converge to zero along with the parameter errors.In connection with the influence that vibration moments on the trajectory control. A procedure to find an optimal input for point-to-point motions of cooperating robots carrying a flexible beam is presented basked on the Bang-Bang control of Optimal Control Theory. Both the time and vibration quantity are included in the performance index, the obtained robot's path can deliver the flexible object fast enough while suppressing its vibration during the motion. The emulation results demonstrate the effectiveness of the proposed manipulating strategy based on vibration control and trajectory tracking.Some prepared work was done for two manipulators handling a flexible payload. Because it's a very complex system many problems will appear in dealing with the system. This paper mostly solved the problem of model and designed a adaptive and optimal vibration controller while the manipulators handling the flexible beams to validate the veracity but there are many works remained needed to be solved.