Design And Study Of Three-axis Flight Simulator Control System

The flight control technology is one of the key technologies in aircraft design. With the increasing development of flight control technology and the fusion of navigation, guidance and control technology,the flight control system which sets navigation, guidandce and control technology as a whole is a mainstream in the design of the control system of modern flight.And the flight control technology is taking a core position of increasing importance. Since the flight simulators can simulate the attitude motion of the aircraft in flight, the changes of attitude angle and attitude rate can be reproduced in the laboratory. Besides, the flight simulator which is an important device for testing the performance of flight control system and conducting simulation experiment, can provide an approximately real runtime environment for inertial sensor.This thesis does an research on the construction of the control system of HIL flight simulators on the basis of a systematic analysis on current studies of three axis simulators home and abroad, and put up with a control system of HIL simulator for the flight control system. The control system of three axis simulator mentioned here takes the ARM processor as the core controller and achieves a precise control of the rotation of three axis turntable by adopting a two level control made of upper computer and lower computer and using a PID control algorithm. The SINS is the test element of this system which is chosen after a synthesized consideration of actual requirements and the system accuracy and sensitivity. The control system adopts the modular design concept and designs a power supply, a attitude sensor, a stepper motor drive circuit, a LCD liquid crystal display, an encoder interface, and a serial communication.In order to improve the accuracy of the inertial navigation system and reduce errors, this thesis adopts quaternion after a thorough study on three kinds of attitude algorithm which are euler angles, the direction cosine law and the quaternion. Based on the static angular rate data collected by the gyro, this theis obtains the static attitude angle error diagram by combining the MATLAB with the quaternion.Apart from that, this thesis also conducts a research on the fuzzy PID control theory and build a mathematical model of the outer ring axis. It has designed a fuzzy PID control algorithm for the outer ring axis by using fuzzy control toolbox which provided by MATLAB. In the MATLAB environment we can get the input step function’s output response curve through simulation. By contrast with the output curve obtained by the traditional PID control algorithm, we found that the nonlinear properties of fuzzy PID algorithm is much better than that of the traditional PID method.For the software structure, this thesis has made a drive design for each of the bottom modules and done application tests for each modules by using the hardware circuit designed by myself. Through the development and debugging of softwares in upper computer, the control system of three axis flight simulator can realize the funtion of serial communicationm, turning control and displaying of attitude data.