• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1068-1074
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• 2010

In high speed railway, event recorder is essential system for analyzing the cause of train accident. It stores train operation sent by train control system in safe memory unit. Crash protected memory, the safe memory unit for event recorder, keeps the stored contents from severe environment. For crash protected memory, we have designed the architecture of concrete enclosure and controller board. Proposed system provides large volume of memory capacity and fault tolerance architecture. For checking the characteristics of proposed crash protected memory specification, the simulation is executed. Simulation results shows the designed crash protected memory meets all requirements.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.148-156
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• 2003

Many car manufacturers have frequently adopted an aggressive inflator and a lower threshold speed for airbag deployment in order to meet an injury requirement for unbolted occupant at high speed crash test. Consequently, today's occupant safety restraint system has a weakness due to an airbag induced injury at low speed crash event. This paper proposes a new crash algorithm to improve the weakness by suppressing airbag deployment at low speed crash event in case of belted condition. The proposed algorithm consists of two major blocks-crash severity algorithm and deployment logic block. The first block decides crash severity with two levels by means of velocity and crash energy calculation from acceleration signal. The second block implemented by simple AND/OR logic combines the crash severity level and seat belt status information to generate firing commands for airbag and belt pretensioner. Furthermore, it can be extended to adopt additional sensor information from passenger presence detection sensor and safing sensor. A simulation using real crash data for a 1,800cc passenger vehicle has been conducted to verify the performance of proposed algorithm.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.93-99
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• 2020

A majority of car crash is affected by careless driving that causes extensive economic and social costs, as well as injuries and fatalities. Thus, the research of precise crash detection systems is very significant issues in automotive safety. A lot of crash detection algorithms have been developed, but the coverage of these algorithms has been limited to few scenarios. Road scenes and situations need to be considered in order to expand the scope of a collision detection system to include a variety of collision modes. The proposed algorithm effectively handles the x, y, and z axes of the sensor, while considering time and suggests a method suitable for various real worlds. To reduce nuisance and false crash detection events, the algorithm discriminated between driving mode and parking mode. The performance of the suggested algorithm was evaluated under various scenarios, and it successfully discriminated between driving and parking modes, and it adjusted crash detection events depending on the real scenario. The proposed algorithm is expected to efficiently manage the space and lifespan of the storage device by allowing the vehicle's black box system to store only necessary crash event's videos.

• 자동차안전학회지
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• 제13권4호
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• pp.66-72
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• 2021

This study was initiated to improve of the defect investigation method using event data recorders (EDR) and suggested a solution through the regulation and system analysis of EDR. The EDR data has been used for various purposes such as the vehicle defect investigation and the traffic accident investigation. However the EDR regulation has not been updated since the implementation in 2012. "Trigger Threshold" can be used to analyze a single accident such as the frontal crash, the side crash, and the rollover. In the case of a complex accident in which a rollover accident and a crash accident occur simultaneously, it is difficult to analyze a complex accident due to current "Trigger Threshold". This study proposed the method of separating the "Trigger Threshold" into a crash accident and a rollover accident so that accidents can be analyzed using the EDR data even when a complex accident occurs. In addition, it proposed the improvement method to quickly use the data of EDR in accident reconstruction software.

• 자동차안전학회지
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• 제12권3호
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• pp.52-60
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• 2020

Usage of EDR(Event Data Recorder) report for traffic accident analysis is currently increasing due to government regulation of EDR data release. Nevertheless, a lot of investigators simply adopt by comparing the number of ignition cycles(crash) at event to the number of ignition cycles(download) without an exact judgment whether event data occurred by this accident or not. In the EDR report, besides ignition cycles, there are many factors such as event record type, algorithm active(rear/rollover/side/frontal), time between events, event severity status(rollover/rear/right side/reft side/frontal), belt switch circuit status, driver/passenger pretensioner/air-bag deployment, PDOF(Principal Direction of Force) by ΔV to be able to decide whether or not to adopt. also the event data is considered enough to vehicle damaged state, accident situation at the scene of the accident. and there is described in "all data should be examined in conjunction with other available physical evidence from the vehicle and scene" in the CDR(Crash Data Retrieval) report. Therefore many investigators have to decide whether or not to adopt after they consider sufficiently to above factors when they are the traffic accident analysis and investigate the causes of a accident on the adopted event data. In this paper, we report to traffic accident investigators notable points and analysis methods on the basis of thousands of cases and the results of one's own experiment in NFS(National Forensic Service).

• 한국자동차공학회논문집
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• 제25권3호
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• pp.317-325
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• 2017

The EDR(Event Data Recorder) is a part of the ACU(Airbag Control Unit) functions mounted on a vehicle. EDR data have pre-crash data and post-crash data. Pre-crash data are recorded within 5 sec from time zero(AE) with 0.5 sec resolution, and reveal vehicle speed, engine rotation speed, throttle opening, brake pedal operation, acceleration pedal position and steering angle, etc. Using this EDR data, the investigation of a traffic accident can become more objective and scientific. Crash tests of three vehicles equipped with EDR function had been performed successfully. Evaluation of EDR data reliability had also been performed using Vbox and PC-Crash's sequence table function. Based on the results, we could confirm EDR data's reliability and availability for Traffic Accident Analysis by the series of this process.

• 한국자동차공학회논문집
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• 제11권1호
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• pp.128-136
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• 2003

In today's design trend of vehicle structure, crush zone is fiequently reinforced by adding a box-shaped sub-frame in order to avoid an excessive deformation against a high-speed offset barrier such as EU Directive 96/97 EC, IIHS offset test. That kind of vehicle structure design results in a relatively monotonic crash pulse for airbag ECU(Electronic Control Unit) located at non-crush zone. As for an angular crash event, the measured crash signal using a single-axis accelerometer in a longitudinal direction is usually weaker than that of frontal barrier crash. Therefore, it is not so easy task to achieve a satisfactory crash discrimination performance for offset and angular crash events. In this paper, we introduce a new crash discrimination algorithm using an electronic X-Y 2-axis accelerometer in order to improve crash discrimination performance especially for those crash events. The proposed method uses a crash signal in lateral direction(Y-axis) as well as in longitudinal direction(X-axis). A crash severity measure obtained from Y-axis acceleration is used to improve the discrimination between fire and no-fire events. The result obtained by the proposed measure is logically ORed with an existing algorithm block using X-axis crash signal. Simulation and pulse injection test have been conducted to verify the performance of proposed algorithm by using real crash data of a 2,000cc passenger vehicle.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1581-1586
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• 2009

The CEM (Crash Energy Management) concept is getting important in rail vehicle design to minimize Injury on passengers and drivers on crash event. In this paper, the accuracy of the FEA analysis result was verified through the crush test on the front part of a non-CEM based carbody. Using the verified FEA analysis method, the energy absorbing capability of the CEM based carbody was estimated.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.115-126
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• 2009

This paper studied on the application of the crashworthiness regulations of Korean Railway Safety Law and Urban Transit Safety Law to the urban Maglev vehicle of KIMM. The Urban Maglev vehicle has to comply with the crashworthiness regulations for urban transit vehicles. The collision load cases have been simulated by using explicit finite element analysis. From the numerical results, the crashworthiness regulations of the Urban Transit Safety Law were completely satisfied, but maximum crash pulse requirement in 25 km/h crash event and no plastic deformation requirement in 10 km/h crash event in the Korean Railway Safety Law were not. If a commercial urban Maglev vehicle is developed in the near future, it is necessary that some soft buffing and energy absorbing devices are adopted in its front end so as to satisfy the crashworthiness regulations of the Korean Railway Safety Law.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1182-1188
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• 2011

By storing various train information in running high speed train, we can analyze the cause of train accident efficiently. we have developed the smart and high available control method to control and manage the hardware modules. The hardware modules for event recorder consist CPU, Digital Input and Output, Pulse Input, Communication, Control Panel and Crash Protected Memory. The real time operation system is used to totally control and manage the various hardware modules. The main function of control method is collection of train information, calculation of train speed, interface with other on-board control system, storing and retrieving train information, and communication with Control Panel. In Control Panel, it displays the current train speed and the status of event recorder effectively. Also user interface is provided in Control Panel.