Aircraft Brakes Semi-physical Simulation System Based On Real-time Linux System

The actual domestic statues of aircraft braking system study is analysed and the means of test have been compared. Considering the implementary conditions and the constraint of cost, a new aircraft braking hardware in the loop simulation system based on the Real-Time Linux system is designed, and the implementary process of the whole system in hardware and software.On the basis of analyzing dynamic characteristics of airplane slip, this paper sets up the ground adhesion coefficient-slip model, airplane dynamics model, the landing gears model, the brake equipments and the tire model etc. Aimed at the interface between the simulating computer to practicle hardware, the circuit of the hardware and software interface based on S-function is designed. Further more, the real time communication network of simulation system is completed.Secondly, aimed to characteristics of simulation system in real-time process, an scheme is given to generat the code for real-time simulation by Matlab\RTW. At the same time, a real-time network is built by Matlab\RTW on external customer mode. It is designed by S-function tools in Matlab that include the module of mulitithread on Linux OS.Moreover, the characteristics of parallel computation with symmetric multiple processors construction is discussed in details, and the method to build the parallel program with MPI(message passing interface) is introduced. An parallel arithmetic of evolution is applied to the model of frictional characteristics, and solved the real-time computation of complicated mathematical models in system simulation.Finally, according to the scheme of airplane braking simulation system, a experiment of an airplane braking system is given, and the results indicate that the experimental platform of the HIL simulation system of the aircraft brake is feasible, and the runway model improved via the parameters identified by genetic programming based on evolutional computation can describe the real frictional characteristics. The whole performance of the anti-skid braking system is demonstrated satisfyingly by the platform.