Mission Plan And Guidance For Rendezvous To Elliptical Targets

The autonomous rendezvous technology is crucial to on-orbit servicing, orbitcleanup, military application and deep space exploration, which is the trend ofrendezvous technology. Mission plan, orbit optimization, guidance and controlalgorithms for proximity to cooperative targets based on relative dynamics model ofelliptical orbit, guidance and control algorithms for proximity to uncooperative targetsbased on the line of sight model are studied. The main results achieved in this paper aresummarized as follows.Design strategy of mission plan for phasing maneuvers is researched.1) Thetracking area and the encountering area are defined, and the method to determine theareas is studied with limited consumption and determinate transfer time, which could beused to analyze the feasibility of the mission, performing occasion and the largest fuelconsumption.2) A mission assignment problem is solved based on multi-objectiveoptimization method, taking the finishing time, consumption and priority into account.3)A two-layer model is formulated, of which the inner is to achieve the exact rendezvousconsidering the J2disturbance and the outer is to find the optimal trajectory based on thegenetic algorithm.Guidance and control algorithms for proximity to cooperative targets are developedwith the foundation of elliptical dynamics model.1) The glideslope approaching phasebased on the TH equations is formulated, which can control the approaching time,direction and relative velocity.2) The flyaround phase based on theequal-angle-equal-time model is formulated with different forms in two planes.3) Thehovering phase based on the LQR control is developed, which can strengthen theanti-disturbance ability.Guidance and control algorithms for proximity to uncooperative targets aredeveloped with the line of sight model.1) Generalized True Proportional Navigation(GTPN) model to control the relative velocity in the direction of LOS is established.2)Improved GTPN model is developed to control the relative velocity in the direction ofLOS and normal to LOS separately.3) An inverse method to design the controlacceleration function is proposed according to the anticipative state, which can achievethe rendezvous and flyaround effectively.The mission plan and guidance method to targets in elliptical targets are thoroughlystudied in this dissertation, and the technologies such as phasing maneuvers, relativedynamics model of elliptical orbit, guidance algorithms for proximity to cooperativetargets, and guidance algorithms to uncooperative targets are developed. Some newapproaches and important conclusions of the mission design and the guidance algorithms are obtained, which can also be applied to the targets in circular or nearcircular orbits.