Design Of The Low-altitude Sea-skimming UAVS' Safety Control System Based On Switching Technique

With the rapid development of aerospace science and technology and the rapid ascension of defense industry,unmanned flight control technique is increasingly becoming the focus of development in this field.Compared with the techniques of unmanned aerial vehicles(UAVS)at the end of the last century,new type of unmanned aerial vehicles present a"fast","high power","high precision" and many other new features.For this kind of low-level sea-skimming UAVS,it also has a "low","stealth" and other obvious characteristics.At the same time,the flight test environment of unmanned aircraft is also more complex than before and,complex electromagnetic environment and many protected targets around the area make greater demands on the safety and reliability of Aircraft Test.The existing safety control mode of UAVS cannot fully meet the relatively complex test environment and the stringent security requirements.The current problem aircraft safety control technique urgently needs to solve is that how to improve the reliability and effectiveness of the safety control system on the basis of the existing security conditions in order to adapt to the safety requirements for flight test under the new situations.This thesis studies unmanned spacecraft test environment and the working principle of safety control systems.Such a safety control system which includes discrete and continuous dynamic behavior is decomposed.A reasonable safety control system submode and the switching rules are designed and a hybrid system based on the switching technique,through three lays of sources of information input,switching rules design and,the subpattern output is built.Simulation experiments are included for verifying the effectiveness of the proposed method.The thesis include the following main contents.Firstly,we briefly review the unmanned aircraft safety control system's structure,working principle and mode,as well as security control behavior relevant test flight zoning,security control to protect the principle of targeting other basics,related coordinate system and transform relations.This analysis builds safety control systems theoretical foundation.Secondly,for the performance characteristics of safety control systems,control structures and other aspects,the thesis makes a further analysis of the existing safety control system hybrid characteristics and determines the parameters for confounding variables,and then builds a reasonable model of security control switching system.Again,according to the actual work process of the safety control system of unmanned aircraft,the thesis studies the aircraft control dynamics model of the processes involved,the control channel model,height control model and the steering engine model,and provide a theoretical basis for the final implementation of the system simulation.Then,according to the difference of security sources and safety control execution mode,the safety working mode can be break up into non-safety mode,standby mode,attitude angle self-destruction mode,position circumvention mode,positioning unbalanced mode,positioning overtravel mode,artificial circumvention mode and artificial destruction mode,etc.Then,simulation experiments are conducted for verifying the effectiveness of the method proposed.At the same time,according to the actual security control unmanned aircraft demand,well-designed security control mode switching strategy is carried out.Finally,on the basis of the sub-mode and switching rules of the safety control system,the thesis selects a proper system hardware and software work platform,sets up safety control hybrid system model,carries out the simulations and partly physical simulation,and then tests results are analyzed.