Design And Research On μ-Synthesis Controller Of Air-to-Air Missile

Guaranteeing high maneuverability in the entire flight envelop is one feature of4thgenerationair-to-air missile autopilot,so that critical issues for controller design will not only be a fast responseto the required demands or to provide extreme maneuverability while maintaining stability,but also toguarantee robustness over a wide range of mission profiles.Classical control techniques which havedominated missile autopilot design over the past several decades fail to cope with the requirementabove,while robust μ-synthesis methodology which can take uncertainties account into control systemdesign is an effective approach to cope with controller design of4thgeneration air-to-air missile.A mathematic model was built for the sample air-to-air missile, then controllers were designedwith μ-synthesis methodology for longitudinal and lateral dynamic of the missile autopilot after allkinds of uncertainties were reshaped,μ-analysis was then applied to test robustness of these controllerssimultaneously.To achieve stability command flight, this paper fixed attention on studying again-scheduled autopilot based on interpolation for the missile using μ-synthesis control designtechniques.Two gain-scheduled methods which employ dynamic pressure as scheduling variable werepresented to interpolate controllers themselves and control signals between design points.Throughsimulation and analysis, an alterative approach called “conditioning/blending” achieved a smoothtransition between controllers.Secondly, controller reduction optimization and implementation were emphasized for thepurpose of controllers’ engineering realization.Controllers designed with μ-synthesis typically hadorders comparable to the plants.Balanced truncation and Hankel norm approximation methods wereapplied to reduce controller order,Hankel norm approximation was proved to be more suitable foroptimization of the sample missile. Due to stiff feature, a new difference algorithm called ‘ImplicitEuler and Extrapolate’ for implementing the μ-synthesis controller was introduced and was alsovalidated by real-time simulation the property of astringency and fast.Lastly, a platform for nonlinear simulation was constructed under Maltab/Simulink to verifyperformance and robustness of the gain-scheduling μ-synthesis controller of air-to-air missile throughone point simulation and whole ballistic trajectory simulation. It was proved that the controller can getfast response to command and obtain good robustness, simultaneously the gain-scheduled scheme alsoguarantees stability command flight through the whole flight envelope.