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EMB (Electro-Mechanical Brake) system that removes hydraulic brake device from conventional brake systems completely can be considered as BbW (Brake-by-Wire) system in the full sense. As the research on the EMB system is actively conducted, it is also required to establish the test methods for the performance verification and evaluation of developed EMB system. In fact, however, the characteristics of the EMB system makes it difficult to apply it to an actual vehicle test due to the expense and safety matters in the process of the test and evaluation. Thus, this study developed the EMB HILS (Hardware In the Loop Simulation) system in application of the actual EMB system in order to verify the actuating response characteristics and control logic performance of the EMB system before an actual vehicle test.

The automotive industry is replacing more and more hydraulic systems by electronic system. This not only reduces the weight of vehicles, but also has the potential for a large number of new features [1]. Such a change has led to researches on XbW(X-by-Wire) without the existing mechanical connection and hydraulic system, among which the study on BbW(Brake-by-Wire) in relation to brake devices proceeded to the point of EHB(Electro-Hydraulic-Brake) and then EMB(Electro-Mechanical-Brake). In replacement of existing CBS(Conventional Brake System) with EMB, various advantages such as improvement of response performance and easy combination with various brake applications including ABS and ESC have been found. In fact, however, the problem of fail-safe has remained. This study, therefore, is to develop the control strategy with which the vehicle's longitudinal and lateral motion can follow the driver's steering intention upon failure of one EMB actuator for braking in straight and corner.

In this paper, we suggest a new control algorithm for driver's intention judgment for collision avoidance using a steering system to improve the emergency steering system performance. Most of the collision avoidance systems proposed by previous works relied only on the braking systems. Recently the automotive industry began to consider ways to avoid collisions using the steering system. It is not hard to imagine that any steering-assisted collision avoidance algorithm must judge a driver's intention for lane change before any attempt at longitudinal avoidance is made. To improve the accuracy of driver's intention judgment and thus the performance of the emergency steering system, we developed a new algorithm based on on-center handling characteristics generated by the steering system. The performance of the proposed driver's intention algorithm was validated in the test of real vehicles as well as in the SILS environment.

In this paper, the hardware-in-the loop simulator which is used for evaluating performance of the EPS (Electric Power Steering) system has been developed. The HILS system consists of the steering system of the light commercial vehicle - the steering wheel, the EPS module, the universal joint, and the rack bar. These components were placed in proper spaces based on location of their hard points in an actual vehicle. An electric servo motor has been used for generating the road reaction force which is generated by vehicle's kingpin moment. A real-time simulation environment has been developed using CarSim to evaluate performance of EPS through various handling tests. For verifying reliability of the HILS system, various handling tests were performed and compared with the results of actual vehicle tests in the proving ground. Through the developed EPS HILS system, various handling tests were successfully performed in the laboratory.

In this paper, we suggest a new steering wheel returnability control strategy for EPS(Electric Power Steering) system to improve on-center handling performance. To improve steering wheel returnability for on-center handling performance, we developed a new control strategy based on estimation of alignment torque generated by tire and road surface. The returnability control algorithm only uses estimated values of the slip angle and the lateral acceleration that can be easily computed from sensor signals commonly available in passenger vehicles. The proposed algorithm was coded with Simulink, and it was cosimulated with the CarSim vehicle model. The performance of the proposed algorithm was compared with that of the conventional algorithm and it demonstrated improvement in both returnability and on-center handling performance.

In-vehicle driving tests for evaluating performance of vehicle control devices are often time-consuming, expensive, and not reproducible. Using hardware-in-the-loop simulation scheme, actual control devices can be easily tested in real time in a closed loop with a virtual vehicle. This advantage has made HILS systems popular as testbench lately in automotive industries. This paper describes a PC-based HILS system for ABS that has been developed in Matlab environment with real-time rapid prototyping tools. Also presented in this paper is a semi-empirical vehicle dynamic model that has been designed to account for kinematic and compliant characteristics of the suspension system from rig tests.

The continuously variable damper is widely used in the semi-active suspension system since it can yield various damping forces at a given damper velocity. By applying an appropriate control scheme to the damper, satisfaction of both ride comfort and driving safety can be realized. For successful development of the semi-active suspension system, a model that accurately describes the complex and nonlinear behavior of the continuously variable damper is crucial. In this research, a modeling technique for the continuously variable damper has been studied. Various damper components have been analyzed and their effects upon damper characteristics have been closely investigated. The effects of the damper characteristics change upon ride comfort and driving safety has also been investigated via simulations.