Research On Autonomous Despun Of Rolling Target Based On Flexible Brush

In recent years,with the rapid development of space industry and the increasing number of space exploration missions,space debris such as spacecraft left in space threatens the subsequent on-orbit spacecraft.Space debris is mostly non-cooperative targets.Due to long-term runaway,it is affected by solar pressure,gravity gradient and residual angular momentum,and finally presents a free rolling state.Therefore,it is necessary to study the autonomous despun technology of space rolling target,which provides necessary conditions for subsequent on-orbit capture tasks.The space free rolling targets mostly exhibit two kinds of motions:spin and nutation.By establishing the attitude dynamics model,the motion laws of target attitude and marker point under the two states are analyzed.The space rolling target is a non-cooperative target,and the despun robot cannot accurately obtain the attitude motion information,so it is necessary to estimate and predict the target motion.By establishing the attitude equation of quaternion form,the system model and the observation model related to the marker point are derived.Based on the third-order spherical-phase cubature rule,a Cubature Kalman Filter is designed to estimate the attitude motion of the target.Under the condition that the target motion state is known,the flexible deceleration brush is used to perform the derotation of the tumbling target.By establishing the kinematics and dynamics model of the space robot,the parameters of the space robot are designed.The dynamic model and contact collision model of the flexible deceleration brush are established.Based on this,a generalized despun strategy for rolling targets is proposed,and the performance of depun is designed.When the flexible deceleration brush is used to race the space roll target,the contact collision in the race process will cause greater interference.Therefore,the H_?robust optimal controller is designed.The correctness and effectiveness of the controller are verified by simulation by comparing with the sliding mode robust controller.The despun strategy for the spin target and the nutation target is completed by using the despun strategy,CKF and H_?robust optimal control.The simulation results verify the effectiveness of the flexible deceleration brush,the despun strategy and the controller.