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Wheel-slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional ABS systems. But, in order to achieve the superior braking performance, real-time information about the vehicle status variables such as wheel slip ratio, tire force, etc is required. In this paper, a wheel slip controller based on the estimated braking force is developed for brake-by-wire systems. The proposed wheel slip control system is composed of the braking force monitor and robust slip controller. In the brake force monitor, the tire braking forces as well as the brake disk-pad friction coefficient are estimated. The robust wheel slip controller using the estimated tire braking force is designed based on the sliding mode control technique. This system determines the braking pressure as the control input and maintains the wheel slip at any given target slip.

This paper proposes a control and fault diagnosis method for a pressure sensor based brake control system. The proposed wheel brake pressure control method consists of feedforward and feedback controller, respectively. The main purpose of the feedforward controller is to set the operating point of the feedback control, and the purpose of feedback controller is to improve the control response and the steady state error characteristic. Also, the proposed fault diagnosis method consists of three processes: a fault detection process, a fault isolation process and a fault identification process. In the fault detection process, a fault is detected by the difference between the estimated signal and the measured signal. Then, in the fault isolation process, the location of the fault is determined. Finally, in the identification process, the size and effect of the fault are evaluated.

Recently, wheel slip controllers with controlling the wheel slip directly have been studied using the brake-by-wire actuator. The wheel slip controller is able to control the braking force more accurately and can be adapted to various different vehicles more easily than the conventional ABS systems. The wheel slip controller requires the information about the tire braking force and road condition in order to achieve the braking and stability control performance. In this paper, the tire braking forces are estimated considering the variation of the friction between brake pad and disk due to aging of the brake, moisture on the contact area or heating. In addition, the road friction coefficient is estimated without using tire models. The estimated performance of tire braking forces and the road friction coefficient is evaluated in simulations.

This paper describes the MANDO MGH ESP (Electronic Stability Program) and consists of the control philosophy, hydraulic actuator and the simulation and test results. The ESP system controls the dynamic vehicle motion in the emergency situation such as the final oversteer and understeer and allows the vehicle to follow the course as desired by the driver. The MANDO MGH ESP is integrated with the existing MANDO MGH ABS/TCS, which is improved with the more information and controls both brake pressure and engine torque for the optimal performance. The look-up tables are emphasized to have the accurate target yaw rate of the vehicle and obtained from vehicle test for the whole operation range of the steering wheel angle and vehicle speed. The wheel slip control is applied for the yaw compensation and the target wheel slip is determined by error between the target yaw rate and actual yaw rate.