Research On A Simulation And Analysis System For ABS Of Heavy Vehicle With Multi-axle Based On The AOH Brake System

Heavy-duty vehicle with multi-axle plays an important role in the national transportation and engineering construction, because of its good cross-country performance and road adaptability. It is significant of studying the vehicle's braking dynamics to improve the driving safety and reducing the amount of traffic accidents. Anti-lock braking system(ABS), a represent in the vehicle's active safety control domain, has tended to be the compulsory equipment with the standard for N3 vehicles both in domestic and abroad. The development process of the ABS system for the multi-axle vehicle lasts much longer on account of the complicated structure, various influencing factors and more constraints with the ABS test on the vehicle level. It is very necessary to do theoretical research for the application of ABS on the heavy-duty vehicle with multi-axle and to investigate the effect of ABS on improving the braking performance.Based on the realistic significance of improving driving safety and research efficiency, study on the Air-over-Hydraulic(AOH) braking system, ABS technique and braking characteristic are carried out and an ABS simulation analysis system for the multi-axle vehicle is developed. Some functions can be realized with the developed system, such as model construction and simulation, parameters inputting, simulation results outputting and braking performance evaluation, etc. Braking characteristics of the multi-axle vehicle under different road conditions can be studied further with the developed system.In the way of modulation, the sub-system model for the multi-axle vehicle and AOH braking system are built to constitute a complete simulation model for braking performance analysis. Meanwhile, simulations are conducted to optimize the static and dynamic characteristics for those braking valves models. On the basis of comparing its basic arrangement and control algorithm, research on the application and control technique of ABS on a six-axle vehicle is implemented. Several different schemes of ABS channel layout are proposed and the feasibility is also analyzed. The logical control algorithms under different road conditions are presented in detail. Based what has been studied above, an ABS simulation system for the multi-axle vehicle is developed. Designing of overall structure and function definitions for the whole system are explained. Development tool is determined to realize the interface design and the communication between outside input and inside model parameters. Then the system's operation process is clearly presented.With the developed system, simulation tests are implemented with different ABS layout schemes under high adhesion condition, slippery road and bisectional road condition. The correctness of the developed system and its functional effectiveness are verified according to the obtained results. The better ABS layout scheme is determined and the braking performance analysis and evaluation of a multi-axle vehicle are conducted with reference to the national standards.The research results show the developed system can be used to conduct the simulation of ABS performance for the multi-axle vehicle with high efficiency and it is greatly beneficial for the designing of braking system and developing of braking performance for multi-axle vehicle. The proposed scheme and the obtained results in the paper can provide good reference for the application of ABS on the heavy-duty vehicle with multi-axle and for related experimental study.