Research On High Accuracy Control Technology In The Mars Orbit Insertion

With the development of the space technology,human is more and more interested in space exploration.And the Mars becomes the key mission of deep space exploration.The Mars' features are very similar to earth in many ways and some people believe that the Mars is the future of the earth.Therefore,it is very important to do exploration and research of the Mars.China's first Mars missions has been set up.The major problems include large communication time delay,low ground control precision,high in-orbit key process of autonomous management performance requirements.Mars brake capture process,in particular,the process has the characteristics of the "uniqueness",short braking time will cause probe over Mars,braking time and Mars collided.High accuracy control techniques of Mars orbit insertion are the key point of the Mars exploration.And it is an important technical foundation of further exploration.This paper firstly analyzes the main factors of the Mars orbit insertion process: 1)orbit insertion strategy;2)orbit insertion attitude and orbit control.The above process includes key techniques of autonomous navigation,the intelligent optimization of mars orbit insertion,and high precision closed-loop feedback orbit control.High precision orbit determination is the prerequisite of the intelligent optimization of mars orbit insertion.An autonomous navigation strategy is proposed based on optical navigation sensor measuring planetary direction and sight distance.And accuracy requirements are identified based on the orbit and the technical index of the optical navigation sensor is proposed.The intelligent optimization searching algorithm is the main method of optimization.The mars orbit insertion optimization searching algorithm is proposed based on “particle swarm”.Directional control,inertia and angular rate control and along the trace in the opposite direction control strategy are analyzed.Considering the factors of attitude control accuracy,the precision of orbit recursive and the most superior factor of energy consumption,homogeneous angular rate control strategy is selected.A solid-liquid-flexibility spacecraft control under a big thruster is the security of the mars orbit insertion strategy.Considering the orbit control precision and the reliability needs of the project,attitude control uses the PID controller.The output of jet uses stopping processing,thereby inhibiting the liquid sloshing,antenna and the wing of the flexible vibration caused byinstability,different from low-earth orbit control of the satellite ground remote means of implementing open loop using accelerometer measurement,introducing methods of track control strategy in real time.To sum up,this paper from the point of view of engineering application proposes autonomous navigation + closed-loop position track coupling control technology.It is low brake and acquisition process surface measurement and control precision,large time delay and the problem of low autonomy,and it realizes high precision autonomous brake and acquisition control.This paper firstly discusses the application performance of deep space exploration autonomous navigation,and it analyzes the principle of autonomous navigation based on planetary optical measurement,and it elaborates the process of autonomous navigation.Then,a mars orbit insertion optimization searching algorithm based on autonomous navigation,and the final mars orbit insertion control strategy is determined.On this basis,considering the thruster error,such as liquid sloshing,flexible interference effects,it puts forward the closed-loop attitude orbit coupling high accuracy control technology.It improves the precision and safety of mars orbit insertion control.