Aircraft Electric Brake System Control Law

The analysis and study of aircraft all-electric braking system and hydraulic braking system is presented. Aiming at some kind of aircraft, the piston and valve actuated housing for hydraulic braking system is replaced by electro-mechanical actuated housing, and the project of all-elctric braking system is realized.By analyzing frictional characteristics between the tyre and the runway conditions, we get the relation of the speed of the aircraft and μ_max , μ_slide mμ_max /σ_p based on the experimental data. An on-line parameter identification method that is least-square is presented because the coefficient between tyre and runway hasn't been got. The mathematical models of aircraft electric braking system comprising aircraft dynamics model, wheel model and braking device are built correctly. On the basis of these models, the nonlinear iterative learning controller is designed which control variable is slip ratio. The PBM control of hydraulic braking system is different from electric braking system which control variable is velocity dispersion. At last, these two methods are compared.The results of simulating indicate that the electric braking system is more excellent than hydraulic system on braking time, braking distance and braking efficiency and iterative learning control (ILC) method is better than PBM control.