• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.212-217
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• 2004

In general, the braking system of high speed train has an important role for the safety of the train. To stop safely train at its pre-decided position, it is necessary to combine properly the various brakes. The prototype of Korean high speed train (KHST) has been designed, fabricated and tested by the domestic researchers. It has adopted a combined electrical brakes, such as rheostatic brake, regenerative brake and eddy current brake, and mechanical brakes composed of disc brake, wheel disc brake and tread brake. In this paper, the performances and control algorithms of braking system have been reviewed by the experimental method.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.299-300
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• 2007

In this paper, slip wear phenomenon of train was studied by traction force of acceleration and braking force of deceleration. First, the slip wear phenomenon on train operation mode was analyzed when powering, coasting and braking each and then rail wear was analyzed from the slip wear data. Especially, the data proved correlation between slip wear and deceleration rather than acceleration. Second, If velocity of a train is constant, even though the velocity is high, ATO logging data and measurement data proved that the rail wear is not serious. It will help for efficient braking force operation providing fundamental data to braking step control.

• International Journal of Automotive Technology
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• v.5 no.2
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• pp.89-94
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• 2004

In this paper, a safe control strategy is considered in the situation when a platoon of vehicles need to decelerate rapidly. When the vehicles ate spaced closely, it is known that the reference information should be transmitted to the whole platoon to minimize the undesirable effects of small leader disturbances. However, the vehicle control should also depend on the preceding vehicle position to maintain the desired distance. Tracking the preceding vehicle position can lead to amplification of the control input along the following vehicles, therefore the vehicles in the rearward generally exert larger maximum control input than the vehicles in the front. The theoretical bounds for the $i^{th}$ vehicle control input are calculated using a linear vehicle and controller model. In the simple illustrative example, the designed controller maintains string stability, and the control inputs of the following vehicles stay within bounds.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.649-663
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• 2004

While a great number of studies on human motor control have provided a wide variety of viewpoints concerning the strategy of the central nervous system (CNS) in controlling limb movement, none were able to reveal the exact methods how the movement command from CNS is mapped onto the neuromuscular activity. As a preliminary study of human-machine interface design, the characteristics of human leg motion and its underlying motor control scheme are studied through experiments and simulations in this paper. The findings in this study suggest a simple open-loop motor control scheme in leg motion. As a possible candidate, an equilibrium point control model appears consistent in recreating the experimental data in numerical simulations. Based on the general leg motion analysis, the braking motion by the driver's leg is modeled.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.177-181
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• 1992

For this study, a new hydraulic control unit which designed in compact compared to the currently manufactured hydraulic control unit for ABS has been introduced and its experimental model has been made. Based on the basic principle as ABS using braking force characteristics against slip ratio of tire, half car model bench tester were designed and made to make an analysis of braking effect of the new hydraulic control unit. Experiment for slip ratio characteristics of tire has been carried out using half car model bench tester and with the results of this experiment and control experiment of the new hyraulic control unit, the experiment result of the characteristics of tire and control experiment were compared to find out their correspondence. And furthermore, slip ratio characteristics of the new hydraulic control unit has been studied based on the experiment result of slip ratio characteristics of tire through simulation and compared with experiment result.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.83-89
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• 2005

This paper presents vehicle stability control algorithm based on 3-DOF vehicle model. The brake control inputs have been directly derived from the sliding control law based on a three degree of freedom plane vehicle model with differential braking. The simulation has performed using a full nonlinear 3-dimensional vehicle model and the performance of the controller has been compared to that of a direct yaw moment controller. Simulation results show that the proposed controller can provide a vehicle with better performance than conventional controller with respect to brake actuation without compromising stability at critical driving conditions.

• Journal of IKEEE
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• v.21 no.3
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• pp.174-184
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• 2017

This paper proposes a torque predictive control for dynamic performance improvement of clamping force in electro-mechanical brake (EMB) for railroad cars. In general, pneumatic braking system (PBS) is used for railroad cars. It is sensitive depending on environmental changes and it has increasing idle running time because of slow dynamic response. Additionally, the PBS has low braking efficiency in case braking torque more than standard value is applied to the brake system such as emergency braking. In order to overcome these disadvantages of the PBS, the EMB is used for the railroad cars. The EMB for railroad cars has advantages that increasing the fuel efficiency and design flexibility because it is able to decrease vehicle weight of railroad cars and secure space for design. In this paper, control method for dynamic performance improvement of clamping force in EMB for railroad car is proposed. The effectiveness of the proposed control method is verified by the simulation results.

• Journal of Korean Physical Therapy Science
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• v.29 no.4
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• pp.43-53
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• 2022

Background: It is suggested that the decline in functional level due to aging influences the increase in traffic accidents among elderly drivers. Among the functions related to the driving behavior of older drivers, physical function is related to muscle strength and motor control, and aging causes deterioration of motor control and a defect in motor output variability. Method: Data Search The online databases used for literature search are PubMed, ProQuest(PML), NDSL, and literature searches were conducted from April 19 to April 26, 2022. For the search, 'aging', 'driving', and 'braking' were used in the investigation. Results: The physical functions related to the braking ability of elderly drivers were analyzed in muscle strength, reaction ability, motor control, and other related factors. In terms of muscle strength, 3 studies analyzed the above factors. 8 studies analyzed the above factors for response ability. For motor control, two studies analyzed the above factors. In addition, related factors were analyzed in one piece. Conclusion: As a result of the analysis, physical function for reaction ability showed the highest frequency, followed by the strength item with the highest frequency. This study suggests that factors that can increase physical function must be included in the development of a rehabilitation program for the driving ability of the elderly.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.7
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• pp.535-540
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• 2016

The braking device in railway vehicles decelerates or stops the train by dissipating the thermal energy converted from kinetic energy into the air. Therefore, the brake system is crucial for safety. In this paper, we performed a study on an electromechanical brake actuator using an electrical motor as an alternative to pneumatic air cylinders to reduce the idle running time in braking, which subsequently increases braking distance, and to ensure reliable response characteristics. Especially, to analyze the response characteristics of the electromechanical brake actuator, we measure the delay time, response time and power consumption compared to the air cylinder. It is confirmed that the electromechanical brake actuator can reduce reaction time by 0.1 seconds (Braking Action) and 0.46 seconds (Brake Release) compared to the air cylinder.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.653-661
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• 2016

This paper proposes a capacitance estimation method of the dc-link capacitor for brushless DC motor (BLDCM) drive systems. In order to estimate the dc-link capacitance, the BLDCM is operated in quadrant-II or -IV among four-quadrant operation. Quadrant-II and -IV are called reverse braking and forward braking, respectively. During the braking operation of the BLDCM, the capacitor is charged by the phase current and then the voltage is increased during the braking operation time. The capacitor current and voltage can be obtained by using the phase current sensor of BLDCM and the dc-link voltage sensor. The capacitance and be easily obtained by the voltage equation of the capacitor. The proposed method guarantees the reliable and simple calculation of the dc-link capacitance without additional hardware system except several the sensors already installed for the motor control system. The effectiveness of the proposed method is verified through both the simulation and experimental results.