Adaptive Control Of Post-Boost Vehicle Using Multiple Models

Post-boost vehicle is a new kind of astronautic vehicle and is produced withthe development of the modern astronautic. Compared with the traditional vehicles,the post-boost vehicle releases loads in the course of ?ight. At the moment when itreleases loads, there are sudden changes on the mass and the distribution of the mass ofit, which lead to the sudden changes on the location of the mass center and the inertiamatrix. Besides, modern vehicles are characterized by high maneuvers, so there arestrongly nonlinear and coupled problems on the dynamic and kinematic equations ofthem. Therefore some new methods must be found to design the attitude trackingcontroller for the post-boost vehicle. Considering the post-boost vehicle as the rigidbody with loads released, this paper studies the attitude dynamic and relative attitudekinematic equations of the rigid body and designs the attitude tracking controller forpost-boost vehicle according to the adaptive control using multiple models and sometheories of nonlinear systems. The main results can be given as follows:Firstly, the dynamic and the kinematic equations for the motion of the masscenter and rotation of the vehicle around the mass center are built. The particularityis presented on the model of post-boost vehicle. Unit quaternions are introduced todescribe all of the attitudes concerning the post-boost vehicle.Secondly, with a linear filter introduced, an adaptive controller using singlemodel is designed for the post-boost vehicle in view of the linear relationship be-tween the parameter and the control torque in the dynamic equations. According tothe particularity of the model for the post-boost vehicle and theory of switched sys-tems, the adaptive controllers using multiple models are also built for the post-boostvehicle to increase the transient performance of the system.At last, if there exists disturbance in the dynamic equations of the vehicle, thelinear relationship between the parameter and the control torque is destroyed. Thenby Assuming that the inertia matrix is known and the parameter adjusted in the singlemodel adaptive controller is replaced by the real value, the attenuation of the distur-bance is studied on the attitude tracking system which is controlled by the controller.Theory of input-to-state stability is a key to the study here. At last, Ballistic simulation on the post-boost vehicle for a release of the load is done.