• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.4
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• pp.32-38
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• 2010

A semi-active suspension is an automotive technology that controls the vertical movement of the vehicle while the car is driving. The system therefore virtually eliminates body roll and pitch variation in many driving situations including cornering, accelerating, and braking. This technology allows car manufacturers to achieve a higher degree of both ride quality and car handling by keeping the tires perpendicular to the road in corners, allowing for much higher levels of grip and control. An onboard computer detects body movement from sensors located throughout the vehicle and, using data calculated by opportune control techniques, controls the action of the suspension. Semi-active systems can change the viscous damping coefficient of the shock absorber, and do not add energy to the suspension system. Though limited in their intervention (for example, the control force can never have different direction than that of the current speed of the suspension), semi-active suspensions are less expensive to design and consume far less energy. In recent time, the research in semi-active suspensions has continued to advance with respect to their capabilities, narrowing the gap between semi-active and fully active suspension systems. In this paper we are studied the characteristics of vehicle movement during the field test with conventional and semi-active suspension system.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2345-2347
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• 2000

ABS(Antilock Brake System) prevents the wheels from "locking" and improve "handling" during braking. Currently, safety and environmental issues are a major concern in the automotive industry. ABS has become the vital brake system. ABS is composed of sensors for wheel speed, a pressure modulator for controlling the brake pressures in the wheel brake cylinders, and an electronic control unit(ECU) which evaluates the signals from the wheel speed sensors and converts these to commands to control the pressure of modulator. In this paper, ECU developed for commercial vehicles is described. Detection of wheel slip, control algorithms of ABS, and diagnosis method of ECU are presented.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.111-111
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• 2000

The research of network system, being used to reduce automotive wiring harness, is reaching to the development of by-wire system. It is by-wire system that apply IVN(In-Vehicle-Network) to steering, braking system, and it has the advantage of mass-decreasing, easy to diagnose fault and so on. But until now, many developed device can't satisfied with reliability that system have ever had. So redundancy of each network module, i.e., It is only way to make backup module. This paper researches development of network module and redundancy management of backup module when error occurred for implementation of brake-by-wire system.

• Journal of the Korean Institute of Gas
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• v.20 no.6
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• pp.37-42
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• 2016

The purpose of this paper is to study for the emission gas control of passenger car. The first example, the PCSV never open when operating condition, but it opened by causing malfunction because of trouble. As a result, the purge gas entered into surge tank, a mount of fuel was displayed with excessive supply on tester. Therefore, it certified the bad-condition of the engine when idling by decreasing of fuel injection quantity from engine ECU. The second example, the hose activating a EGR valve didn't supply the vacuum pressure because of assembling the other part. Thus, it knew the bad-condition of engine that the EGR valve would not work normally by leaking with the other port. The third example, as the rear oxygen sensor of two sensor were fault-installing by changing the sensor of other a car it could not detect of oxygen quantity. Finally, it found the phenomenon of abruptly decreasing vehicle speed when braking a car. Therefore, the system including with emission control has to drastically manage by maximizing condition to role decreasing the emission gas.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.527-534
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• 2015

This paper presents an integrated chassis control with electronic stability control (ESC) and active front steering (AFS) under lateral force constraint on AFS. The control yaw moment is calculated using a sliding mode control. The tire forces generated by ESC and AFS are determined using weighted pseudo-inverse based control allocation (WPCA) in order to generate the control yaw moment. On a low friction road, AFS is not effective when the lateral tire forces of front wheels are easily saturated. To solve problem, the lateral force of AFS is limited to its maximum and the braking of ESC is applied with WPCA. To evaluate the effectiveness of the proposed method, a simulation was performed on the vehicle simulation package, $CarSim^{(R)}$. From the simulation, it was verified that the proposed method could enhance the maneuverability and lateral stability if the lateral force of AFS exceeds its maximum.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.13-19
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• 2017

In this paper, study of vehicle fire cases caused by connector and power wiring of anti-lock brake system(ABS) module damage is presented. The purpose of ABS module is to improve braking and steering ability under sudden stop of the vehicle by repeatedly activating and releasing the brake with electric signal via electric control unit. The electric control unit for ABS may experience incomplete contact between power line and signal line or electrical breakdown on the printed circuit board by undergoing repetitive signal change which would consequently result in electrical heat and spark, eventually leading to automotive fire. Therefore, the purpose of this paper is to provide fundamental data by analyzing connector and power wiring of ABS module damage conducive to the precise investigation on the cause of vehicle fire.

• Journal of Auto-vehicle Safety Association
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• v.14 no.3
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• pp.60-64
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• 2022

In the automotive industry, the development of automobiles to meet safety requirements is becoming increasingly complex. This is because quality evaluation agencies in each country are continually strengthening new safety standards for vehicles. Among these various requirements, collision safety must be satisfied by controlling airbags, seat belts, etc., and can be defined as post-crash safety. Apart from this safety system, the Advanced Driver Assistance Systems (ADAS) use advanced detection sensors, GPS, communication, and video equipment to detect the hazard and notify driver before the collision. However, research to improve passenger safety in case of an accident by using the sensor of active safety represented by ADAS in the existing passive safety is limited to the level that utilizes the sudden braking level of the FCA (Forward Collision-avoidance Assist) system. Therefore, this study aims to develop logic that can improve passenger protection in case of an accident by using ADAS information and driving information secured before a collision. The proposed logic was constructed based on LSTM deep learning techniques and trained using crash test data.

• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.28-38
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• 2019

In the world, traffic accidents and environmental pollution caused by the increase of vehicles are becoming a serious social problem. According to the 2016 data published by the Korea Highway Traffic Authority, Korea owns 49.9 vehicles per 100 people. This is the 28th largest number among the 35 OECD member countries. In addition, the number of deaths from traffic accidents in Korea totaled 4,292, of which 1,714 were caused by traffic accidents involving vehicles and pedestrians. To reduce these human casualties, the automotive industry is constantly working on the development and commercialization of Adaptive Driver Assist System (ADAS). ADAS is the system providing convenience and safeness for drivers. In general, ADAS consists of Autonomous Emergency Braking (AEB), Highway Driving Assist (HDA), Adaptive Cruise Control (ACC), Lane Keeping Assist System (LKAS). Among them, the AEB detects the possibility of collision by the vehicle itself and plays a role of avoiding the collision or reducing the damage through active braking. For such AEB, Euro NCAP has been developing test-evaluation methods for the vulnerable since 2017. Therefore, In this paper analyzes the scenario of Euro NCAP VRU Test Protocol v3.0.1, which will be established in 2020, and proposes test conditions according to the Korean road traffic law. In addition, the reliability of the proposed scenario and test conditions was verified by comparing and analyzing the proposed theoretical evaluation formulas and actual test results.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.609-617
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• 2016

Belt-driven Starter Generator (BSG) differs from other mild hybrid systems as the crankshaft of vehicle are not run off. Motor permits a low-cost method of adding mild hybrid capabilities such as start-stop, power assist, and mild levels of regenerative braking. Wound rotor synchronous motor (WRSM) could be adopted in BSG system for HEV e-Assisted application instead of the interior permanent magnet synchronous motor (IPMSM). In practice, adequate torque is indispensable for starter assist system, and energy conversion should be taken into account for the HEV or EV as well. Particularly, flux weakening control is possible to realize by adjusting both direct axis components of current and field current in WRSM. Accordingly, this paper present an off-line current acquisition algorithm that can reasonably combine the stator and field current to acquire the maximum torque, meanwhile the energy conversion is taken into consideration by losses. Besides, on account of inductance influence by non-uniform air gap around rotor, nonlinear inductances and armature flux linkage against current variation are proposed to guarantee the results closer to reality. A computer-aided method for proposed algorithm are present and results are given in form of the Look-up table (LUT). The experiment shows the validity of algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.57-64
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• 2020

The leading technologies of the ADAS (Advanced Driver Assist System) are ACC (Advanced Cruise Control), LKAS (Lane Keeping Assist System), and AEB (Autonomous Emergency Braking). LKAS is a system that uses cameras and infrared sensors to control steering and return to its running lane in the event of unintentional deviations. The actual test is performed for a safety evaluation and verification of the system. On the other hand, research on the system evaluation method is insufficient when an additional steering angle is applied. In this study, a model using Prescan was developed and simulated for the scenarios proposed in the preceding study. Comparative analyses of the simulation and the actual test were performed. As a result, the modeling validity was verified. A difference between the front wheels and the lane occurred due to the return velocity. The results revealed a maximum error of 0.56 m. The error occurred because the lateral velocity of the car was relatively small. On the other hand, the distance from wheels to the lanes displayed a tendency of approximately 0.5 m. This can be verified reliably.