|
The mechatronics brake automotive anti-lock braking system, the abbreviation ABS (Anti-lock braking system) is a brake to automatically adjust the size of the wheel braking force to prevent the wheels from locking for best braking effect systems. The system is capable of effectively improving directional stability when braking and steering ability to shorten the braking distance, the car's ride safety plays an important role, has become the important automotive active safety devices, an important research topic in the automotive industry at home and abroad and the Key Project in China. Semitrailer train is composed of two parts of the tractor-trailer and semi-trailer car vehicle with a large amount of cargo transport efficiency, etc., is the backbone of the long-distance trucking and major trends. In recent years, both the proportion of the number of trucks, or bear the proportion of freight traffic in the road freight has increased year by year. Tractor - semitrailer body length, quality, speed, traffic safety, more and more attention. In order to solve the problem of the service brake directional stability, the paper analyzes the tractor - semitrailer pneumatic ABS control method. In the study discussed in detail the basic theory of the Auto ABS, the general structure of the main types and working principle. Tractor - semitrailer, its pneumatic braking system is characterized by; tractor - semitrailer pneumatic ABS structure of the program and control methods. Fuzzy adaptive control strategy based on reference slip rate control parameters. The establishment of a fuzzy control system, computer simulation, and simulation results are analyzed and discussed. Tractor - semitrailer pneumatic ABS divided into semi-trailer tractor and semi-trailer two parts: tractor part with the same general cargo vehicles, the use of two-channel sensor structure of the program: the two front wheels, the principle of independent control individually controlled, two after round, round (semi-trailer road trains) using the unified control of the principle of low-election. Trailer wheels (rear wheels of the tractor - semitrailer) ABS system SL structure. In accordance with the requirements of the simulation modeling, corresponding tractor - semitrailer vehicle model, the model of the single wheel brake model, tire model of four mathematical models, and made a more detailed exposition of the principle of fuzzy control, followed by the use of MATLAB Fuzzy toolbox establish ABS adaptive fuzzy controller, and the use of a mathematical model in MATLAB / Simulink straight line braking of the tractor - semitrailer simulation, simulation results show that the pneumatic ABS prevents the wheels from locking, less small braking distance had a marked effect, can improve the tractor - semitrailer directional stability during braking and steering ability. According to the simulation results, the analysis of the main factors that affect pressure ABS effect and the standard atmosphere ABS improvements proposed feasibility proposal.
|