Visual Simulation Of Midcourse Guidance For Companion Aircraft

With the increasing frequency of human space activities,the problem of spacecraft flight companion is becoming more and more important,which has important applications in many scenarios.It is becoming a hot topic to study the guidance and control theory of the companion around the main aircraft.Firstly,this paper studies the guidance algorithm of the main aircraft from launch to the end of midcourse guidance.Based on the principle of minimum energy orbit,a universal iterative algorithm for elliptic,parabolic and hyperbolic orbits is used to solve the Lambert problem.A method based on C-W equation and state transition matrix to describe the relative motion relationship between two spacecraft is discussed to design relative motion guidance algorithm.This paper describes a velocity gain guidance algorithm which can be used in practice.In the flight process,by controlling the acceleration direction of the main aircraft and its companion,it can gradually enter the predetermined orbit.Secondly,the attitude tracking method of flight companion is studied.According to the attitude angle command of guidance algorithm,it is transformed into the quaternion-based attitude command,and the attitude tracking system based on error quaternion is established.The variable structure control method is used to design the thrust command of the orbit control and attitude control engines.Combined with the installation layout of the orbit control and attitude control engines,the working logic of each engine is obtained.Finally,simulation analysis is carried out to verify the performance of the guidance and control algorithm.Finally,based on unity3 d engine,a flight visualization system is created to display and evaluate the flight status of the main aircraft and its companion.In order to ensure the real-time display effect of the aircraft in the animation field of view,the motion algorithm of the tracking camera is studied,and the whole process trajectory and real-time attitude of the aircraft are skillfully displayed separately by using the principle of camera hierarchical rendering.Taking unity3 d world coordinate system as reference,the attitude and position data of the aircraft are calculated reasonably.In order to solve the chattering phenomenon of the display when the aircraft is far away from the origin,an effective algorithm is developed to deal with the problem.In order to simulate the flight process of the aircraft more realistically,the terrain module and particle system of unity3 d are used to create the launch site scene of the main aircraft and the engine plume of the main aircraft and its companion respectively.In order to meet the requirements of human-computer interaction,a GUI is developed to control the real-time flight simulation process.Finally,the method of publishing virtual simulation scene to Windows system is introduced.