Study On Distributed Parameter Model And Cooperative Control Of Flexible Manipulators

This dissertation is supported by the project of National Natural ScienceFoundation of China "Studies on the distributed parameter model and controlmethod for multi-link constrained flexible manipulators cooperative motionsystem". This dissertation deeply studied the distributed parameter model andcontrol method of flexible manipulators cooperative system.With the development of robot and space technology, space robots havebeen required to offer more service. Such as, in order to get more precise andskillful manipulations, the use of two or more manipulators is necessary insuch various applications as material handling, assembling and large spacestructures constructing etc. On the other hand, many satellites have beenlaunched so far. Some of them have become uncontrolled and don't work in theorbit. Thus, replacing the failed parts, charging the exhausted batteries andrecovering the attitude of the satellites are the desired services to rescue them.As the task is dangerous for the astronauts, the space robots are expected to doit. It is hard for a single manipulator to accomplish the task, so the cooperativemanipulators system is required. In cooperative control of flexiblemanipulators, not only the position and force of the end-point but also thecooperative motion between the end-point and the object are concerned. It is asynthesis problem of position, force, vibration and cooperative control. Thedynamics of cooperating flexible manipulators is so complex that it is verydifficult to control them. It is presently to begin to study on the flexiblemanipulators cooperative motion system and there have few papers about it tillnow. And, there have many problems about modeling and control of flexiblemanipulators cooperative motion system.The flexible manipulators cooperative motion system is a typicalnonlinear system with distributed parameters. It must be expressed by themodel of infinite mode essentially. Thus, in this dissertation, flexiblemanipulators cooperative motion system is modeled as the distributedparameters system by virtue of the extended Hamilton's principle. Consideringthat the distributed parameters model of flexible manipulators cooperativemotion system is the hybrid partial differential and integral equations and itsdynamics is very complex to be controlled by one kind of control arithmetic,we introduce a small perturbation parameter, then, the obtained distributedparameter model of flexible manipulators cooperative motion system is dividedinto a lumped parameter subsystem expressing the whole rigid motion and adistributed parameter subsystem which describe the small vibration of thesystem by virtue of the singular perturbation method.For the lumped parameter subsystem has the same dynamics to the rigidmanipulators, we studied the hybrid position/force controller of the lumpedparameter subsystem.For the distributed parameter subsystem is the partial differential equationwith boundary conditions, we discussed the distributed parameter controlmethods to suppress the vibration. Then, the characteristic of the main operatorand c0 semigroup of the distributed parameter closed-loop subsystem wasstudied, and the distributed parameter closed-loop subsystem was proved to beasymptotic stable. The hybrid cooperative controller was discussed in thisdissertation.