Dissertation > Aviation, aerospace > Aviation > Aircraft instrumentation,avionics, flight control and navigation > Flight control system and navigation > Flight control

Research on BTT Vehicle Robust Control Method Based on μ Synthesis

Author SunZhongXu
Tutor WangZiCai
School Harbin Institute of Technology
Course Control Science and Engineering
Keywords μ synthesis attitude control controller reduction gap metrics
CLC V249.1
Type Master's thesis
Year 2012
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Recently hypersonic vehicles have attracted more and more attention and beenstudied by more and more researchers. This type of vehicle has dynamicuncertainties and environment uncertainties,and usually uses the bank-to-turncontrol mode leading to serious coupling characteristics. Considering of thesecharacteristics of the BTT vehicle,the attitude control system design method isinvestigated to guarante the stability and track performance of the system.First,the kinematic model of BTT vehicle is built up to analyse the motioncharacteristics. Then the actuator model and the uncertainties are established,andthe formulas of some auxiliary angles are given. This part of research gives thefoundation of the whole work.Second, the kinematic model of the BTT vehicle is linearized and thendecoupled into the longitudinal model and the latitudinal model. Analyse theinfluence of the uncertainties to the system. A BTT vehicle attitude control methodusing the dual-loop control mode based on μ synthesis is presented. The feedbackparameters of the inner loop are optimized by using the genetic algorithm toguarante the track performance. And the controller of the outside loop is designed byμ synthesis method. Using the genetic algorithm to determine weight functionsensures the close-loop system robust and the order of the controller is not too high.Then,a controller reduction method based on Hankel norm and gap metrics isproposed to reduce the order of the robust controller. Use Hankel norm to measurethe system error and use gap metrics to test the robustness of the close-loop systemafter order reduction. Finally a lower order robust controller guaranteeing thestability and track performance of the close-loop system is obtained.Finally,according to the task of flight attitude control,the simulation for theBTT vehicle attitude control is performed. During the simulation,the dynamicuncertainties and the flight environment uncertainties,including wind and initialconditions,are taking into account. The simulation result shows the proposed designmethod is effective in BTT vehicle attitude control while dynamic uncertainties andenvironment uncertainties exist.

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