Spacecraft's Coupled Attitude And Orbit Control For Flying Around A Tumbling Object

The non-cooperative targets in space are important studies of orbital service,and it is the key and difficult point in this field.Something like debris and fault spacecraft are tumbling when they move freely on orbit,therefore a control system must be established for approaching and flying around before the task of capture,which conducts the research of this paper.First,In view of relatively flying around a tumbling target problem,a coupled attitude and orbit Newton-Euler equation is derived to analyze the movement characteristics.Simulations induct the main attitude motion forms of these objects.Then,both dual quaternion and screw methods are applied to the relative dynamic model and a dual quaternion's double-loop sliding mode controller is designed for a chaser craft to execute the task.Not only the distance between chaser and target space craft are stabilized,but also the posture of them kept the same.Numerical simulations test the effectiveness of the controller established.In the end,by changing the form and rate of tumble in the experiment,the adaptive capacity of controller is analyzed which shows the pros and cons of the system.