Research On Attitude Dynamics And Control Of Spacecraft Multibody System

The attitude dynamics and control problem of multibody system of spacecraft are researched. The fundamental purpose of analysis of kinematics and dynamics is to provide support for products and equipment in these areas of mechanical design and control and achieve high efficiency, low cost product development purposes.Aerospace engineering are high input, high-risk areas, which cover a very wide range of subject areas, not only related closely to aviation aerospace science and technology, but also with the Control Science and Engineering, Information and Communication Engineering, Electronic Science and Technology, and weapons science and technology, Materials Science and Engineering, as well as the instruments science and technology and so on. Spacecraft multibody system is an important branch of mechanical multibody system. Space Station, space robot, satellite with solar panels are all the rootless tree multibody system. The attitude of base body of spacecraft multibody system will change during the process of the expand of satellite's Solar panels, Docking process of space station,and the time of implementation mission of Services in-orbit space robot. However connected to the base body's solar panels must always towards the sun, and the antenna must towards the ground receiver, which required the spacecraft to adjust its attitude of base body. With the development of science and technologies, docking technology of spacecraft enables the scale and degree of freedom of spacecraft multibody system are becoming more increasingly than before, and the attitude dynamics and control of the system is also becoming increasingly complex. Along with the development of China's manned space, modeling and analysis techniques of large-scale and complex multibody spacecraft system will surely develop towards the direction of high efficiency, high precision, automation and adaptive.The attitude motion of Spacecraft includes the motion of overall spacecraft around its center of mass, and the relative movement of the various parts of the spacecraft. In this paper, the following aspects were studied:(1) The topology of spacecraft multibody system is described by shift operator which contains the characteristics of correlation matrix and path matrix method. That has Advantages of simple forms and small memory space, Easy to realize computer programming.(2)model of kinematics and dynamics. Efficient dynamic modeling method of spacecraft multibody system is studied based on spatial operator algebra. The method is applied to modeling of kinematics and dynamics combination of kinematics, dynamics equivalent manipulator of spacecraft multibody system. By combining the quasi-velocities and recursive calculation of screws, efficient dynamic modeling is researched. The definition and classification of quasi-velocities, and the dynamic modeling methods and analysis of their advantanges and comparative computation based on quasi-velocities are studied. Quasi-velocities can be apart from greater freedom to select the independent variables, but also contains the kinematic parameters or dynamic parameters directly obtained for computing the first-order dynamic differential equations, to avoid unnecessary cross-operator, saving the computer's computing time and space. And it can be used to design decoupling control or non-interactive control. (3) The drift-free model of spacecraft defined as in the manifold SO (3) (?) T~M is studied. Controllability of the structure of arguments and procedures are received by Lie algebra method. The relationship between spacecraft attitude dynamics and shape dynamics is researched. The attitude of base body can be controlled by attachment (flywheel or arm) articulated in Spacecraft. This can be looked as As a complementary way to adjust the attitude of spacecraft. (4) The nonholonomic spacecraft attitude of multibody system optimal control problems, and based on the Hamiltonian equations of spacecraft nonholonomic system stability problem are studied. (5) Symbolic programming dynamics of spacecraft multibody system is researched, which is that the spacecraft kinematics, dynamics, control is realized through symbolic programming software mathematica. (6) The design of full-physics simulation of spacecraft attitude control system by magnetic suspension.The main innovation as follows: (1) The topology of spacecraft multibody system is described by shift operator which contains the characteristics of correlation matrix and path matrix method. (2) By addition, multiplication to replace the traditional kinetic modeling of time-consuming, laborious derivation operator. (3) By combining the quasi-velocities and recursive calculation of screws, efficient dynamic modeling is researched. (4) The drift-free model of spacecraft defined as in the manifold is studied. (5) The nonholonomic spacecraft attitude of multibody system optimal control problems on quaternion, and based on the Hamiltonian equations of spacecraft nonholonomic system stability problem are studied. (6) Application of magnetic levitation to achieve physical simulation of spacecraft attitude control system.