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The commercial vehicle is widely used in the overland transport. A prediction is given on the 9th annual China automotive industry forum that the number of the global commercial vehicles will reach eight million by the year of 2016. However, since the distance between its gravity centre and the ground is larger than that of the passenger vehicle, considering its comparatively short wheelbase, the rollover accident, which is fatal to the drivers and always makes enormous loss of merchandises, easily occurs in the case of commercial vehicles. As the number of the commercial vehicle is increasing fast, the accidents will occur more frequently, the losses will be increasingly enormous. To solve the problem, many researches about rollover early warning systems have been done. In most cases, it is assumed that the references of the vehicle are given.

The simulation of electro-pneumatic components used in brake systems of commercial vehicles is of great importance in order to understand their characteristics for developing a control logic and improve the braking performance. As the goal of improving the performance of the commercial vehicle pneumatic EBS(Electronically controlled Braking System), static and dynamic characteristics of proportional relay valve for commercial vehicle pneumatic EBS have been simulated by using MATLAB/Simulink environment and validated by testing on hardware-in-the-loop test bench focused on its pressure hysteresis characteristic. The simulation and test results show that the mathematic model for proportional relay valve characteristics is reasonable and reliable, and this simulation tool can be used for research and developing of pneumatic EBS system for commercial vehicle effectively.

In order to accurately characterize the dynamic characteristics of articulated heavy vehicles, 3-dof (degree of freedom) model and 5-dof simplified model of articulated heavy vehicle are established and key parameters of models are identified by the method which is to combine double models with genetic algorithm and by using Trucksim data. Simulation study, which combines 5-dof simplified model with the MAPs of key identified parameters, is carried out. Comparison, which is between simulation results and Trucksim data, indicates that the key parameters of simplified model can be accurately identified, the MAPs of key identified parameters can satisfy the demand of characterizing the actual state of vehicle and lay a foundation for vehicle stability control.

The paper describes an algorithm, which estimates the mass of large buses and axle load distribution using pedal position, wheel speed and the wheel cylinder pressure sensors. This algorithm is allowed to achieve the purpose without additional sensors by using the rotational speed sensors from ABS system and air pressure sensors in brake cylinders form ESP system. The axle load distribution algorithm mainly consists of three steps. Firstly, deceleration of the bus is estimated and then the mass of the bus is estimated. After that, the position of the mass centre is estimated. Taking account of the tire nonlinear characteristics under longitudinal forces and vertical forces, mass estimation, deceleration and the position of the mass centre of buses is corrected by the coefficient, which is determined by the wheel cylinder pressure, the wheel speed and mass estimation.

Electronic braking system (EBS) of commercial vehicle is developed from ABS to enhance the brake performance. Based on the early development of controller hardware, this paper starts with an analysis of the definition of EBS. It aims at the software design of electronic control unit, and makes it compiled into the controller in the form of C language by the in-depth study about control strategy of EBS in different braking conditions. Designed controller software is divided into two layers. The upper control strategy includes the recognition algorithm of driver's braking intention, estimation algorithm of the vehicle state, conventional braking strategy which consists of the algorithm of deceleration control and braking force distribution, and emergency braking strategy which consists of the algorithm of brake assist control and ABS control.