• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.22-27
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• 2003

The roller machines installed in the industrial field are operated under hazardous conditions due to no safety devices available, human error during operation, defective safety devices, and inadequate regulation even in case that safety devices are provided. Up to now, most roller machines installed in domestic field are provides with band breaking system as a safety device. In this study, the emergency stop distance is measured within the limit of domestic regulation but violates a foreign regulation(EN1417). Consequently, it is concluded that the roller machines with a band breaking system have high possibility of death or serious injury of the operator and the system should be improved with the introduction of additional safety devices. This thesis suggests the safety measures suitable for the roller machines with different drive systems based on the experiment results. The use of the newly developed safety system has been tested on many cases.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.1
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• pp.19-27
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• 2017

In this paper, a simulator hardware and control design for an electronic parking brake (EPB) are proposed for emergency vehicle braking when the hydraulic break and anti-lock brake systems (ABS) fail to function. EPB systems are designed specifically for park braking and are usually installed on the rear wheels. However, in an emergency situation when all vehicle brake systems fail, the EPB can be utilized to stop the vehicle and track the target slip ratio as the ABS. This paper analyzed the non-linear EBP of the type of motor on caliper (MoC) based on experiments. A simulator hardware is also designed to validate the performance of the designed EPB controller in terms of braking distance and performance in tracking the target slip ratio. Through the experimental analysis, it is confirmed that a sliding mode controller can be applied on a non-linear EPB to track the target slip ratio.

• Journal of Auto-vehicle Safety Association
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• v.10 no.2
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• pp.20-28
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• 2018

Currently, sharp increase of car is on the rise as a serious social problem due to loss of lives from car accident and environmental pollution. There is a study on ITS (Intelligent Transportation System) to seek coping measures. As for the commercialization of ITS, we aim for occupancy of world market through ASV (Advanced Safety Vehicle) related system development and international standardization. However, the domestic environment is very insufficient. Core factor technologies of ITS are Adaptive Cruise Control, Lane Keeping Assist System, Forward Collision Warning System, AEB (Autonomous Emergency Braking) system etc. These technologies are applied to cars to support driving of a driver. AEB system is stop the car automatically based on the result decided by the relative speed and distance with obstacle detected through sensor attached on car rather than depending on the driver. The purpose of AEB system is to measure the distance and speed of car and to prevent accident. Thus, AEB will be a system useful for prevention of accident by decreasing car accident along with the development of automobile technology. This study suggests a scenario to suggest a test evaluation method that accords with domestic environment and active response of international standard regarding the test evaluation method of AEB. Also, by setting the goal with function for distance, it suggests theoretic model according to the result. And the study aims to verify the theoretic evaluation standard per proposed scenario using car which is installed with AEB device through field car driving test on test road. It will be useful to utilize the suggested scenario and theoretical model when conducting AEB test evaluation.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.68-76
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• 2007

In general, the braking system of a high speed train has an important role for the safety of the train. To stop safely the train at its pre-decided position, it is necessary to properly combine the various brakes. The train has adopted a combined electrical and mechanical (friction) braking systems. In order to design a good brake system, it is essential for designers to predict the brake performance. In this paper, the braking performance analysis program has been developed and verified by comparing the simulation results with the brake test results of HSR-350x; both results match very well. Also, the brake performances of high speed trains can be predicted by using this program under various conditions.

• International Journal of Aerospace System Engineering
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• v.2 no.1
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• pp.1-5
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• 2015

The Unmanned Air Vehicle (UAV) systems are indispensable tools of air surveillance and reconnaissance nowadays. Via this systems, hazardous end risky intelligence gathering activities are handled easily. Although they are named as "Unmanned" the UAV systems are commanded by pilots/operators. So, because of weather conditions, enemy attacks etc. as well as pilot error it is possible to face with sudden Round per Minute (RPM) drops and subsequently engine cut/stop during a mission flight at high altitudes. In this case, there are some very urgent decisions to make and rapid "emergency procedure" steps to take in a very short time before Line of Sight (LOS) is lost. The time before crash and the distance to landing air base need to be calculated, the Return Home route need to be checked and the landing/crash side need to be determined. Therefore it is a vital necessity that UAV pilots have some extra qualifications like being determined, well instructed and trained, experienced apart from operating ability. Within this scope, for an education process of a UAV pilot experience sharing and lessons learned are as important as simulators even more. By means of lessons learned it is possible to find out the reasons, mistakes and prevent the likely UAV accidents. In this study it is told about a real UAV crash, experienced of the pilot, the dos and don'ts and the difficulties. Thus it is aimed to help the people who can experience the same or similar situations in future.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.809-810
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• 2016

In this study, Speed-sensitive vehicle brake using the LED, When the driver presses the brake pedal, range step while being turned in connection taillights brake of the vehicle, such as speed-sensitive vehicle brake using the LED, It is turned on according to the deceleration of the vehicle to be series of points are displayed. The rear vehicle can prevent collision about an abrupt stop of preceding vehicle by perceiving deceleration state of preceding vehicle easier and faster. Also, if the inter-vehicle distance by using an ultrasonic sensor is closer than a certain distance, the emergency light turns on to convey the situation to the driver of the rear vehicle with a buzzer.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.11-22
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• 2018

The safety of tunnels is quantified by quantitative risk assessment when planning the disaster prevention facilities of railway tunnels, and it is decided whether they are appropriate. The purpose of this study is to estimate the probability of the train stopping in the tunnels at train fire, which has a significant effect on the results of quantitative risk assessment for tunnel fires. For this purpose, a model was developed to calculate the coasting distance of the train considering the coefficient of train running resistance. The probability of stopping in case of train fire in the tunnel is predicted by the Monte Carlo simulation method with the coasting distance and the emergency braking distance as parameters of the tunnel lengths and slopes, train initial driving speeds. The kinetic equations for predicting the coasting distance were analyzed by reflecting the coefficient train running resistance of KTX II. In the case of KTX II trains, the coasting distance is reduced as the slope increases in a tunnel with an upward slope, but it is possible to continue driving without stopping in a slope downward. The probability of the train stopping in the case of train fire in tunnel decreases as the train speed increases and the slope of the tunnel decreases. If human error is not taken into account, the probability that a high-speed train traveling at a speed of 250 km/h or above will stop in a tunnel due to a fire is 0% when the slope of the tunnel is 0.5% or less, and the probability of stopping increases rapidly as the tunnel slope increases and the tunnel length increases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.102-109
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• 2019

This paper describes the design of the circuit card assembly to eliminate the communication error on a servo control unit installed in the automated resupply vehicle K56. K56 is a weapon system that automates the supply and loading of ammunition on the K-55A1 self-propelled artillery. As the core item responsible for ammunition movement control, the servo control unit is required to have good communication stability and reliability, but the conventional unit has recognized a problem that communication error intermittently occurs, resulting in an emergency stop phenomenon. We analyzed the communication signal of the servo control unit and identified the failure cause of the circuit card assembly to solve this problem. In addition, the signal interference in data/address line of the circuit card assembly was confirmed through analysis of the failure cause, and redesigned to avoid the interference, such as adjustment of the distance between communication lines and position change. Finally, the proposed cause analysis and redesign were verified through the component of servo control unit and attachment test on K56. We expected these study results to be used as reference for the design of other similar items.