Research On Multiple Models Predictive Control Of Guided Bomb

Last decades have witnessed the expansion of the systems with more complex strctures and broader working conditions, such as guided bombs. When they are in the status of shifting of different height, the guided bombs are often viewed as the systems with strong nonlinearity. For these systems needed to be controlled, the traditional control method may not achieve the satisfied performance. The multiple models control method and the model predictive control method thus appeared and filled the gap between the control theory and its application. These two methods themselves are also one of the most important parts of the current research in control theory.In this dissertation, research on guided bomb's control system is deeply developed on the background of project of transformging our conventional bomb into guided bomb by using multiple models predictive control method. The main contributions of this dissertation are summarized as follows:(1) The six-degree-of-freedom mathematical model of guided bomb's extended range motion was established based on its aerodynamic characteristics and its motive properties, based on that, the mathematical postural equation model of guided bomb was obtained.(2) Use the commonly time-varying parameter system as the research object, two issues were studied: the ascertainment of the characteristic points of the nonlinear system, and the linearization of the nonlinear system in these characteristic points. Via that, the acquirement of model set of nonlinear system was resolved, this method is effective when applied to the guided bomb.(3) Based on the eigenstructure assignment and model following theories for linear systems, a multiple models witching control strategy with the capability of chattering attenuation was proposed and applied to the pitch/yaw channel autopilot design of the guided bomb. Several characteristic operating points were selected along the guided bomb's whole flight trajectory, and the time-invariant systems, which describe the pitch/yaw motion of guided bomb, were then estabilished. For each separate time-invariant system, based on the eigenstructure assignment method, a feedback controller was designed to stabilize it, at the same time a feedforward controller was designed by using the model following method, so that the closed system was able to track the guidance command. While the guided bomb's flight states varys from the neighborhood of one operating point into that of the next, the controller switches from one into the other. Simulation results demonstrate the validity of the proposed method in command tracking and switching chattering attenuation, obviously have much more excellence than gain scheduling.(4) The application of multiple models switching predictive control in guided bomb was researched. Some issues of nonlinear system multiple models switching predictive control were studied: the design of generalized predictive controller, the multiple models referenced track and the models switching algorithm. The simulation results demonstrate that the flight states of guided bomb is stability, the following capability is favorable and the deflexion of rudder is logical.