Vibration Control Study Of Flexible Manipulator

With the rapid development of aerospace industry and the deepening of space exploration, 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 direction in space technology field.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 based on PZT actuators, including the below contents:Firstly, the elasticity deformation problem of flexible manipulator is analyzed. And the dynamic model is established, obtaining its natural frequency and vibration mode. Meanwhile, Modal truncation method facing vibration control of flexible manipulator is proposed.Secondly, for the study of dynamic characteristic and vibration control of flexible manipulator, it is compared linearized model with nonlinearity model of the flexible manipulator. On the condition of the same parameters, the nonlinearized model is proved to be more precise. Using the nonlinearized model of flexible manipulator the vibration changing regularity is researched considering different mode orders, different structure parameters, different driven torques and with or without tip additional mass. And several ways in compressing vibration of flexible manipulator are proposed.Then, this paper adopts PZT material to control the vibration of flexible manipulator. The inverse piezoelectric effect of the PZT material, the principle of compressing vibration and optimal sticky location on the flexible manipulator are studied.Finally, this paper describes an approach for the use of smart materials, specifically, piezoelectric(PZT) materials, in control of a single-link flexible manipulator. It is investigated by a Lyapunov approach that a combined scheme of PD feedback and command voltages applied to segmented PZT actuators. By comparison, only PD feedback control is also considered to control the flexible manipulator. And it is proved to be effective to compress the vibration of flexible manipulator with PZT actuators control.