Comprehensive Method Of QFT And H_∞for Helicopter Flight Control Research

When control helicopter pilots, due to excessive coordinated action, the operationresponse has been delayed so that the pilots in a highly nervous state, under a lot ofworkload. In this regard, said the helicopter more difficult to operate than fixed-wingaircraft, the use of helicopter flight control system to improve the quality, ease thepressure on the pilot’s operation is very necessary. For modern helicopters, whether hasexcellent flight control system has become an important indicator to judge theperformance of the helicopter. Helicopters are high order nonlinear systems,time-varying and highly coupled, but also because of the dynamic model of thehelicopter flying state of change and a huge perturbation, these conditions gave theall-inclusive helicopter flight control system design brings great difficulties. In thiscontext, we use a combination of QFT and H∞Methods helicopter flight controllers doa design study. The main contents can be divided into the following three parts:1. Through the UH-60A helicopter flight dynamics modeling analysis wasnonlinear dynamic model of the helicopter, after linearization order to get the28helicopter when linearized model. Analysis of stability and pole position of the model,the results showed that the helicopter itself has no stability, and modal coupling betweenthe situation is very serious. The last part of the military rotorcraft handling qualitiesrequirements of the relevant performance indicators ADS-33E are analyzed.2. Were analyzed quantitative feedback theory (QFT) and H∞loop-formingmethods by inner/outer loop design ideas,. Quantitative feedback theory when appliedto multiple-input multiple-output (MIMO) systems need to first multiple-inputmultiple-output (MIMO) system is equivalent transformation of multi-inputsingle-output (MISO) system, because the object of this study is the high-order28helicopters order model, so this is a very tedious equivalent conversion. The use ofhelicopters inner/outer loop design ideas, using loop shaping method can be decoupledfour-channel helicopter systems, complete the equivalent transformation MIMOsystems. If you combine the two, then the first decoupling internal closed-loop system/outer loop design carried out after the formation of QFT design, will greatly simplifythe design process of QFT MIMO systems, improve design efficiency. 3. Use the28helicopter order linear model for the study, the first conducted by themethod of forming the inner loop circuit design, and then extended to the outer loop.Quantitative feedback theory then the entire closed-loop system design approach afterinternal/external circuit design formed to design, get the flight controllers. Finally, thecontroller performance indicators to meet the requirements of the standard HQR level1.