Research On Attitude Control Of Spatial Non-Cooperative Rendezvous And Docking

With rapid development of space technology, reaearch on rendezvous and docking has taken a significant place. Under the background of non-cooperative rendezvous and docking, this paper has investigated the attitude control problems, including angular velocity estimation as well as velocity-free feedback control.Firstly, this thesis analysis the non-cooperative character of the target Space Craft(SC). Then modeling the attitude movement and give a brief introduction of state estimation theory as well as stability theory.Secondly, the paper studies the angular velocity estimation of the target SC. Usually, there are two ways to improve the performance of state estimation, which are the algorithm approach and the model approach. From the algorithm approach,the paper uses the attitude dynamics to estimate the angular velocity of non-cooperative target. And then design the parameters filter in the case that the capture SC does not have the information of the rotational inertial of the target SC.And design a strong tracking filter, which fits the case that the target SC may escape unknownly.From the model approach, the paper put forward the angular velocity estimation based on current statistical model. In this way, the angular velocity filter do not need to know the rotational inertial or the control torque of of the target SC. We also compares the performance of all these approaches. The angular velocity estimation supplies the needed information for the 6 DOF synchronous control.At last, we studies the relative attitude model and velocity-free control use MRP. The paper put forward two control laws based on passive filter, none of which usees angular velocity of capture SC. These control methods can be used on some small satellites which havn't carry gyros or as a backup control law in case of the breakdown of gyrounit. Numerical simulations has carried out to test and verify the put forward control laws.