Dynamics And Control Of Hovering And Flyover To Rotating Target

Recently significant attention has been devoted to autonomous rendezvous anddocking technology, but little attention has been given to missions with rotating target.Dynamic models, mission analysis and control methods are studied for hovering,flyover and approach to rotating target.The main achievements in this paper are summarized as follows.An analytical solution to free rotating rigid body and a model of relativemotion to rotating target are derived in this paper. An analytical solution to attitudemovement of free rotating target is derived. Models are established in both orbit andbody coordinate for relative motion, which lays the foundation for research on hovering,flyover and approach.Mission properties are studied for hovering over rotating target. Hoveringacceleration is derived in both orbit and body coordinates. The influence of orbit factors,moment of momentum, and hovering position on hovering acceleration is analyzedafterward. Finally, maximum distance, maximum thrust, periodicity of parameters,hovering velocity increment are analyzed. Conclusions are useful in plan design.Control of hove ring ove r rotating target is studied. Hovering controller isestablished based on fuzzy logic for three cases with targets of fixed axis rotation,regular procession and Euler-Poinsot rotation, and dynamic tracking is demonstratedand validated by simulation results in three cases with targets of fixed axis rotation,regular procession or Euler-Poinsot rotation. Factors and properties are analyzed innumerical simulation, conclusions are useful for controller design.Control method is developed for flyove r and approach to rotating targets.Dynamic model for flyover and approach is derived based on previous relative motionmodel. Fuzzy controllers are designed for flyover and approach, the controllers workwell in cases with targets of fixed axis rotation, regular procession and Euler-Poinsotrotation, and dynamic tracking is showed in numerical simulation. The influence offlyover radius and moment of momentum on flying period and velocity increment isanalyzed in simulation, which is useful in mission design.Some approaches are obtained in dynamic models and control methods forhovering, flyover and approach to rotating target, which are useful for autonomousrendezvous control method and mission design.