Research On Dynamical Modeling And Control Of Flexible Manipulators

With the rapid development of aerospace industry and the deepening of space exploration techniques, space technology and robot technology also have a great development. Space flexible manipulator, due to its light weight, fast speed, high precision, low power consumption and better work adaptability, is widely adopted in the fields of aerospace, aviation and robot. It is significant to complete some tasks using space manipulator, and it has become an important research topic in the field of space technology.In the project, research comes to the so-called flexible multibody dynamic system or rigid-flexible coupling dynamic system which features large-scale movement of rigid body and small elastic vibration of flexible components. Since the flexible multibody dynamic system has lots of applications in high tech engineering areas, it is of great importance, both theoretically and practically, to study its dynamic modeling and active control method. The flexible manipulator is a typical application in this area. It has simple structure but includes highly nonlinear coupled dynamic characteristics. This paper studies the dynamic properties and vibration active control, including the below contents:(1) Current research progress of the tip trajectory tracking of flexible manipulators is summarized. The methods of modeling of flexible manipulators are introduced, the background and meaning of tip trajectory tracking is analyzed, and the existing problems as well as strategies of the tip trajectory tracking flexible manipulators are discussed and compared.(2) The dynamic modeling of flexible manipulators is studied. Flexible manipulators are complicated system of nonlinear, tight-coupling and time-varying. Based on the model of Euler-Bernoulli beam, lump mass method is used to describe the flexible deflection and Lagrange equation is introduced to develop the dynamic equation of flexible manipulators.(3) The linear quadratic optimal control and variable integration PID control algorithms are studied respectively. Computer simulations are performed to evaluate the behavior of the two control schemes. Results from the simulation demonstrate that it is important to select proper weighing matrices in using linear quadratic optimal control. The variable integration PID control is analyzed on the basis of traditional PID control. Moreover, the control performance based on variable integration PID control is superior to traditional PID controls. The results may be used to provide a basis for vibration control experiments and applications of a flexible manipulator.(4) The design methods of sliding mode variable structure control are studied. The traditional proportion switch sliding mode control and integral type switching gain sliding mode control are studied and compared. Moreover, the control performance based on integral-type switching gain sliding mode control is superior to the traditional proportion switch sliding mode controls. The results may be used to provide a basis for vibration control experiments and applications of a flexible manipulator. The results may be used to provide a basis for vibration control experiments and applications of a flexible manipulator.