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Vehicle stability control system can enhance the vehicle stability and handling in the emergency situations through the control of traction and braking forces at the individual wheels. Because this system needs to handle the nonlinear and complex vehicle dynamics, the controller is required to have the robustness and the simple structure for practical applications in order to achieve the desired performance. This paper proposes a new controller based on the multiple sliding mode control theory for vehicle stability control system to satisfy these requirements. The proposed controller for the lateral motion makes use of both the sideslip angle and the yaw rate. It brings the vehicle sideslip angle and the yaw rate close to the desired ones so that the vehicle dynamics becomes stable and the vehicle traces the desired course even in limit cornering.

Vehicle stability control system is a new idea which can enhance the vehicle stability and handling in the emergency situation. This system requires of the yaw rate, side slip angle, and road friction in order to control the traction force and the braking force at the individual wheels. This paper proposes an observer for vehicle stability control system. This observer consisted of the state observer for vehicle motion identification and the road condition estimator for the identification of the road friction coefficient. The state observer uses 2 degree-of-freedom bicycle model with the Dugoff tire and estimates the system variables based on the Kalman filter. The road condition estimator uses the same vehicle model and identifies the tire-road friction based on the recursive least square method. Both estimators make use of each other information.

This paper presents the integrated chassis control (ICC) system under development at MANDO. By sharing the sensor and control information through the communication link among the existing 2 or more chassis subsystems, the integrated chassis control system improves vehicle performance and reduces cost for the sensors and related wiring. ICC consists of continuously variable damping control system(CDC), rear toe angle control system(AGCS) and electronic stability program (ESP). In ICC, the steering angle and yaw control information of ESP are delivered to the other systems through the CAN interface, and co-operative control strategy overrides each subsystem to improve the vehicle handling performance and stability. The effectiveness of both integrated chassis control systems are illustrated by a computer simulation and vehicle test on dry asphalt, snow road surface and so on.

Conventional steering system has a mechanical connection between the driver and the front tires of the vehicle, but in steer-by-wire system, there is no such a connection. Instead, actuators, positioned in the vehicle's front corners receive input from the control module and turn the front wheels accordingly. In steer-by-wire system, steering wheel is an important part that not only transfers driver's steering input to the controller but also provides a road feedback feeling to the driver's hand. Thus the reactive torque actuator, providing road feedback, plays an important role in steer-by-wire system. In conventional steer-by-wire-system, a motor was used as a reactive torque actuator. But using motor has some disadvantages such as an oscillatory feeling, and improper and potentially dangerous acceleration of the steering wheel by the motor when driver's hands are released from steering wheel abruptly.

This paper focuses on clamping force control of electronic wedge brakes without additional sensors for cost-effectiveness and system simplicity. Brake-by-wire systems can be used for enhanced, safe braking of intelligent and environmentally friendly vehicles such as gas-electric hybrid and electric vehicles. For implementation of the electronic wedge brake, the clamping force should be controlled properly even though model uncertainty and parameter variations exist due to the environment or system characteristics changes, e.g., temperature variations, pad wear, and nonlinear friction. In this paper, the electronic wedge brake is modeled to include the wedge dynamics as well as the nonlinearities such as backlash and friction in mechanical connections and clearance between the brake disk and pad. An on-line status monitoring algorithm using the simplified mathematical models is designed to estimate the mechanical system parameters.

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.

This paper describes the development of Mando's new continuously controlled semi-active suspension system. The goals for the new system are 1) enhanced control performance and functionality for customer satisfaction and added value, 2) optimal design of variable valve for compact size, light weight and fast response. Based on the system requirements established from benchmarking and market needs, design of variable dampers, an ECU, sensors and control algorithms is carried out. Skyhook control is applied with a better road detection algorithm by using vertical wheel G sensors. New “Comfort” mode biased toward smooth ride adds more value to the vehicle. Co-operation with ESP helps increase the vehicle stability. Well-defined design procedure and test methods for verification and validation are followed. Simulation study, rig and vehicle integration test prove that the design goals are met.

The semi-active damping control system with continuously variable shock absorber is widely used to improve the vehicle dynamic characteristics such as ride comfort and driving safety. To achieve better vehicle performance, the continuously variable shock absorber must have a fast response time with wide range of damping force variation. In this paper, the analytic model is developed to estimate the effect of various parameters on dynamic behavior of the variable shock absorber, such as electromagnetic properties of solenoid, vibration of moving valve body and pressure prevailing time at damper stage due to compressibility of oil and container. By analyzing the derived model and carrying out the parametric studies, the response time of the shock absorber was reduced and it was verified by rig test.

An electric motor for regenerative braking in front-wheel-drive hybrid electric vehicle is only connected to the front axle, and mechanical friction braking can be independently applied on each of the 4 wheels. Excessive regenerative braking only at front wheels to improve fuel economy can cause under-steer and eventually vehicle instability. Nonlinear tire characteristic may cause this vehicle instability in severe cornering with hard braking. Therefore, cooperative braking control strategy has to be considered nonlinear tire characteristic for guaranteeing the vehicle stability while enhancing the braking energy recovery. This paper is to compare the performance of cooperative braking control strategy according to consider the influence of braking force on the lateral force. Carsim™ software is used to evaluate the performance of cooperative regenerative braking control regarding to the vehicle stability and regenerative braking efficiency.