Attitude Maneuver Path Planning And Optimization Of Spacecraft Under Multiple Constraints

In orbit operation,spacecraft needs continuous attitude maneuver to adjust its attitude pointing.During attitude maneuver process,not only the dynamic constraints caused by internal environment need to be met,but also the pointing constraints caused by external environment should be considered.For example,in observation of objects,cameras or other remote sensors must orient these objects;some optical sensors(such as infrared or weak light sensor components)must not orient celestial bodies.When the complex attitude pointing constraints couples with dynamic constraints,it is very difficult to plan out reasonable attitude maneuver path.Meanwhile,as the consisting development of space industry,the capability of spacecraft attitude maneuver should be improved.Especially when being applied to undertake the tasks of catastrophe early warnings,scientific detection and military applications,it requires spacecraft consume limited energy to switch from current attitude to the expected attitude in the shortest time.So this thesis researches on problem of optimal attitude maneuver under multiple constraints,and works on planning attitude maneuver path that meets complex attitude constraints and tasks demands.The research mainly concludes the following parts.Path-optimal attitude maneuver problem of spacecraft under multiple constraints is investigated and a rapid attitude maneuver planning method based on CE-RRT(Comparative Evaluation-Rapidly Exploring Random Tree)is proposed.By using CE-RRT as the global planner,the method is to randomize samples of uniformly distributed nodes of attitude space to enlarge the amount in safe space,ensuring the meets of pointing constraints;or switch dynamic constraints into linear constraints of local enlargement’s second time plan,ensuring to meet the different layers of orientation constraints and dynamical constraints.Meanwhile,introduce comparative evaluation strategy to screen unwinding nodes for solving the problems of path unwinding and twining caused by random plan methods,and delete unnecessary middle nodes,avoiding circuitousness of routes.Eventually,this method was validated through contrast simulation.Compared with the RRT,it can not only shorten maneuver path distance to avoid unwinding phenomena and increase the computational efficiency by 106.62%.Energy-optimal attitude maneuver problem of spacecraft under multiple constraints is investigated.Started with the views of energy optimal,attitude maneuver problem is concluded into NQCQP problem,by using state-space method.Firstly,the linear relaxation technique is introduced,the problem is converted into a bilinear programming problem,in which convex envelope and concave envelope of one variable could be obtained.By this theory the complexity of solving is reduced and a linear relaxation of the original problem can be obtained.And then,based on the previous linear relaxation programming and evaluation function,a resolve method based on the branch and bound technique is proposed,which adopts hyper rectangle division method to reduce comparatively large nodes of indexes,and put forward the principles of algorithm convergence.Finally,an optimal solution of the original problem is found out.Time-optimal attitude maneuver problem of spacecraft under multiple constraints is investigated.This constraint maneuver problem briefly is concluded into time-optimal path planning problem.Firstly,through Gauss pseudospectra method is employed to find out the solution of attitude maneuver problem under forbidden constraint.But this method has not given out the proper deal with the constraints of nodes,which caused the nodes’ dissatisfaction of constraints,especially for the middle sparse nodes.To solve this problem,a time-optimal attitude maneuver based on ATDE,adopting the methods of angular velocity and time coding,building the evaluation function of algorithm from complicate constraints,switching optimal path planning problems to optimal problems of intermediate nodes.And then adopt differential evolution method to optimize and find out the attitude maneuver path which meets complex constraints.Finally,based on research of optimal attitude maneuver under multiple constraints and combining with autonomous planning methods,on-board controller simulation system,real time dynamic simulation system and simulation control system are developed,and simulation testing system for spacecraft attitude maneuver are build,in order to undertake the principle simulation tests for the designed attitude maneuver plan algorithm and control methods.