The Research On The Optimal Trajectory Control Of The Aircraft Tactical Maneuver

Pilots are a core segment of the pilot-aircraft closed-loop systems. How to control flight riskfrom the perspective of operation of pilots is an important research direction. In an air combatsituation, the sequential execution of the tactical maneuvers will lead to the increase of the statedeviation of maneuvers, which results in larger flight risk. Therefore, to improve the pilots’operation ability of the maneuvers is an important issue in reducing flight risk. In this thesis, therisk quantitative assessment method and the optimal trajectory control model of the maneuver hasbeen proposed based on Bayesian theory, fuzzy analytical hierarchy process and multi-stageinfluence diagram. The main contents and contributions of the thesis are as follows:(1) The categories of the flight maneuvers and the characteristics of some typical maneuversare introduced. Then, the related research methods for the maneuver control law are reviewed.Moreover, the theoretical knowledge of influence diagram and its main applications aresummarized.(2) Aiming to evaluate the risk of the maneuver, a risk quantitative assessment model ispresented based on Bayesian theory and fuzzy analytical hierarchy process (FAHP). Themaneuver has been divided into several stages by the key points. Meanwhile, the definitions ofdifferent risk levels are given. For the uncertain problem of the relationship between risk levelsand parameter deviation, Bayesian theory is used to determine the probabilities of different risklevels. Considering the weights of different risk levels, the risk values of different key points canbe obtained. As the uncertainty of the judgment of different pilots, FAHP is used to determine theweights of the key points. Finally, the risk quantitative assessment of the maneuver is computed.Through the analysis of the real data of the maneuver, the effectiveness and feasibility of themodel is validated.(3) The optimal trajectory control model of the maneuver, taking the control rate of changeinto the optimization objective function, is proposed. The maneuver can be divided into differenttrajectory primitives, each of which has the identical control rate of change. The control rate ofchange reflects the pilots’ control condition of the maneuver. Niching steady-state geneticalgorithm (Niching SSGA) is adopted to solve the optimal control model and the optimal controlsequences of the maneuver are obtained. The control inputs of the maneuver corresponding to theoptimal control sequences are able to drive the aircraft to complete the optimal maneuver. Theoptimal maneuver control model are used to analyze the characteristic maneuvers, i.e. loop andbarrel roll, and the optimal control sequences of the maneuvers are obtained with the undisturbed or disturbed point mass model, respectively. Through comparison the actual data with thesimulation data, the effectiveness of the model is certified.(4) The optimal trajectory control of the maneuver considering the preference of the pilots ismodeled by adopting multi-stage influence diagram. And Niching SSGA is used to solve theoptimization model. Taking loop operation as example, three scenarios with different levels ofinitial state deviation are analyzed, and the optimal modified sequences of the maneuver areobtained. The characteristics of the pilots’ operation in the modified process are analyzed bycomparing the experimental results with the optimal control sequences of the loop. Moreover, theprobabilities of different risk levels and the risk values of the key points are derived.This thesis investigates the tactical maneuver. The risk quantitative assessment model and theoptimal trajectory control model of the maneuver have been proposed. The main contributions ofthis thesis include two parts, that is, reasonably evaluating the risk of the state deviations of themaneuver, providing decision supports for the pilots to complete the standard maneuver andmodify the state deviation in maneuver process.