The Research Of Control Method For Aircraft Anti-Skid Braking System

For aircraft, anti-skid braking control system is important airborne equipment, and it plays very important role in safe takeoff and landing. With the increasing weight, landing speed and the more complicated landing environment, the issues of reliability and safety during aircraft taking off and landing will become more prominent. Therefore, it has great significance of researching advanced control algorithms and designing high-performance digital anti-skid braking system.Since aircraft anti-skid braking system is a time-varying nonlinear system, traditional PID control is difficult to get predictive results. Currently, many aircrafts use a slip-velocity controlled system which include pressure-bias-modulated (PD+PBM). This control algorithm performs well on dry roads, but its performance will degrade when adverse road conditions are encountered. Aiming at the deficiencies of the traditional PD + PBM control law, a new composite control strategy with intelligent immune PID for aircraft anti-skid braking system combined with the advantages of PBM is presented in this paper, which is suitable for the future aircraft braking system. In addition, a balance regulation unit is designed for the phenomenon that the aircraft is easy to sideslip on the runway with non-uniform coefficients. In order to verify the effectiveness of the proposed control strategy, the aircraft braking system is tested firstly in ADAMS software simulation environment, based on the aircraft model which is established by ADAMS. After that, a digital anti-skid braking controller based on high-performance digital signal processor core TMS320LF2407 is designed, and the controller is connected to the simulation circuit to form a semi-physical simulation test system. The semi-physical simulation system can simulate the dynamic process of aircraft braking truthfully, and provide a more effective test platform for the research of aircraft anti-skid braking system.The simulations carried on different runway to test aircraft braking performance of new control strategy, and the results were analyzed and compared with the traditional control methods. It indicated that the control strategy proposed in the paper can improve the deficiencies of traditional control method effectively, enhance the ability to adapt to runway and improve the braking performance.