Study On The Simulation Model Of Attitude Control Of Rendezvous Docking And Combination Body During Lunar Exploration

The central task of the third period of the lunar exploration project of our country is that the prober takes the specimens back to Earth after sampling on the moonscape. Once the sampling subsystem of the prober having sampled enough specimens, the ascender will take these specimens back to the combination of the orbiter and the returner. The rendezvous and docking of the ascender and the combination will be the key that if the specimens can be transfered successfully.This paper carries on a study on the simulation model of attitude control of the ascender and the combination during the rendezvous and docking, including the attitude determination, attitude acquisition, attitude hold and attitude maneuver during the long and short distance guidance and docking and separation of the ascender and the combination.And all the modules have been built with c++, which have already been used in the flighting simulation platform of rendezvous and docking at lunar orbit.Firstly, this paper introduced the algorithms of attitude dynamics, which attitude control relies on. Secondly, this paper analyzes and discusses the approach of the modeling of the spacecraft attitude control particularly, giving out the mathematical model of attitude sensors including solar sensors, star sensors, ultraviolet sensors and gyro sensors, and putting forward a double-vector attitude determination model by combining the output vector of the solar sensor and the ultraviolet sensor, then building a mathematical model of highly accurate attitude determination of gyro sensor and star sensor. Then, contraposing the attitude control tasks like attitude acquisition, attitude hold and attitude maneuver during the rendezvous and docking of the ascender and the combination, and the actuators using in these tasks, including flywheels and thrusters, this paper gives out the mathematical models of them. After that, the redundancy of the sensors and thrusters is studied and analyzed in this paper, and the primary algorithms of redundant information fusion and distribution of actuators are gave out for future use in realization of redundant information fusion and distribution of actuators in this subject.Finally, this paper gives out the results of numerical simulation of the attitude control model, and then verifies the validity and accuracy of this attitude control model built in this paper.