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Research On Robust Control Method For Hypersonic Vehicle Based On Event Triggered Mechanism

Posted on:2018-06-28Degree:MasterType:Thesis
Country:ChinaCandidate:J P LiFull Text:PDF
GTID:2382330572465580Subject:Control theory and control engineering
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Considering the outstanding penetration ability and detection performance,the hypersonic vehicle techniques have been a research focus throughout the world.This kind of vehicles is also an important development direction for the future defense equipment and civil aviation technology in our country.Different from the common aircrafts,the integration of design scheme make the hypersonic vehicles have the features of fast-time variations,system nonlinearities,uncertainties and coupling effects.Moreover,the complex flight environment makes the time-varying parameters exercise greater influence on the system stability.All this complex factors make it more challenging to obtain the dynamic mode and to design useful control system.In the past 20 years,the robust control method has been the international research focus in the control group.However,it is worth noting that the traditional robust control methods based on the time require the real-time transmission of the sensor data,which will take up a lot of unnecessary communication resources.Event-based robust control methods not only have the advantages of robust control methods bust also can significantly reduce the amount of data transmission between the sensor and controller,which provides a new train of thought for researching the robust control of uncertain systems.In this thesis,the generic hypersonic vehicle longitudinal model developed by NASA Langley research center is considered.The related researches are carried out to analyze the model of the hypersonic vehicle and to design the event-based robust controller.The main work is as follows:Firstly,based on the full-state differential equations of the hypersonic vehicle model,the basic structural parameters and each sub-models of the hypersonic vehicle are analyzed.Then,the longitudinal dynamics equations under the usual coordinates are presented,which provides the targeted application object for the proposed control methods.Secondly,based on some reasonable assumptions,one local linear model is obtained by linearizing the longitudinal model of the hypersonic vehicle.For the obtained linear system,the observer based output feedback event triggered control problem is investigated.Different from the existing static event triggering scheme,one integral form event triggering scheme is proposed and the exponential convergence of the state can be guaranteed.From the simulation results,the number of the data transmission can be reduced obviously based on the proposed method.Thirdly,considering the linearization longitudinal model of the hypersonic vehicle with the time-varying uncertainties,the event trigger based adaptive robust varying gain tracking control problem is investigated.Because only the sampled data at the triggering instant can be used for the controller,the common robust varying gain control method cannot be used directly.To overcome this difficulty,one event triggered adaptive control method is proposed.The estimations of the uncertain parameters in the controller are only updated at the triggering instant,which together with the system state at the triggering instant are used to generate the control input and guarantee the robust tracking performance of the hypersonic vehicle.The effectiveness of the proposed method is testified by the simulation results.Concluding remarks are given at the end of this thesis.Some future research works are also pointed out.
Keywords/Search Tags:hypersonic vehicle, robust control, event triggered control, output feedback control, time-varying uncertainties, controller with variable gains
PDF Full Text Request
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