Modeling And Simulation Of Aircraft Brake System

With the evolution of the aviation industry, modern aircrafts are designed and developed to be able to carry more weight, to cruise at higher speed and to be more reliable. For the sake of aircraft running safely, it demands greater brake performance of brake system. Moreover, research and improving of control law of anti-skid brake is a guarantee for improving brake performance. An adaptive fuzzy brake control arithmetic based on genetic algorithm is presented aiming at characteristic of aircraft anti-skid brake system.On the basis of analyzing principle of anti-skid braking system, composition and dynamic characteristic of landing gear, numeric model for the entire braking system is completed in the paper, including dynamic model of aircraft, wheel and type model, landing gear model, hydraulic system model and so on. In perspective of complexity, nonlinear and uncertainty of aircraft anti-skid braking system, a combination control algorithm derived from genetic algorithm and adaptive: fuzzy algorithm has been proposed. This method combines the merits of the GA and AF, the shape of fuzzy controlling membership grade function is optimized by genetic algorithm, and adaptive and robustness of fuzzy controlling is improved, then performance of braking system is improved.Finally, the numeric model of the proposed system has been verified in Matlab software. Braking characteristics on dry runway, wet runway and ice runway is analyzed. The results have been compared to the traditional PID+PBM algorithm's results. The results demonstrate that the braking performance can be greatly improved when GA+AF method is employed.