• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.2
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• pp.30-37
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• 2012

Pneumatic Active Engine Mount(PAEM) with open-loop control system has been developed to reduce the transmission of the idle-shake vibration induced by engine effectively and economically. A solenoid valve installed between PAEM and vacuum tank is on-off switched by the Pulse Width Modulate(PWM) control signal to decrease the dynamic stiffness of the engine mount. This paper presents the methodology to identify the optimal values of control parameters of a PAEM, i.e, turn-on timing and duty ratio of PWM signal for 6 different idle driving conditions. A scanning algorithm was first applied to the vehicle test to obtain the approximate optimal control parameters minimizing the vibration at front seat rail and at steering wheel. Then the PAEM system identification was fulfilled to find accurate optimal control parameters by using multi-layer neural networks of Levenberg-Marquardt algorithm with vehicle test data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3127-3134
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• 2013

This paper presents the verified results from the examination of the control algorithm, logic composition, and vehicle condition of the engine that has been adapted for DME fuel. It introduces the development process of the control structure and the logic control based on control map and auto-code generation, and finally verifies the reliability and performance of the overall control. The control structure largely consists of the injection control part that implements driver demand into an engine net torque and the air control system part that satisfies characteristics of exhaust gas and power performance. The control logic is designed with feedforward and feedback control for each of its control functions for an enhanced response. Moreover, the control map of the feedforward controller is created by the use of an engine model created by test data of mass product diesel engine, and it was subsequently calibrated in the test process of the engine and vehicle state. A test mode was completed by attaching the developed controller to the vehicle, and a reduction in gas emission is confirmed by the calibration of EGR, VGT, and injection times.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.282-283
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• 2008

According to the development of vehicle technique, the improved NVH performance is required in the vehicle which have the high effectiveness and the high output of the powertrain. This vehicle has to be adapted to active engine mounting system to reduce the vibration in accordance with various vehicle information. The pneumatic active engine mounting system is consist with engine mount, solenoid valve, air tank and control unit totally. The important technique of this system is to reduce the vibration by the air pressure. This paper contains the development process of the pneumatic active engine mounting system and confirm the performance of this system test and vehicle test.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.65-75
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• 2001

Modern vehicles require a high degree of refinement including good driveability. Vehicle driveability, which becomes a key decisive factor f3r marketability, is affected by many parameters such as engine control and the dynamic characteristics in drive lines. Therefore engine and drive train characteristics should be considered to achieve a well balanced vehicle response simultaneously. This paper describes experimental procedures which have been developed to measure engine torque and investigate shuffle characteristics. To analyze the vehicle dynamic behavior, fractional torques and inertia mass moment of engine, and drive train were measured. Shuffle characteristics during tip-in condition were investigated in an experimental vehicle at 2nd and 3rd gear stages. It was found that the shuffle characteristics were caused by sudden changes of engine torque and have a different vibration frequency with gear stage variation. Inertia mass moment of engine including flywheel rotation showed a key factor for the shuffle characteristics.

• Advances in aircraft and spacecraft science
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• v.7 no.6
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• pp.553-570
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• 2020

To address the problems caused by the strong coupling of an airbreathing hypersonic vehicle's airframe and propulsion to the integrated control system design, an integrated airframe-propulsion model is established, and the coupling characteristics between the aircraft and engine are analyzed. First, the airframe-propulsion integration model is established based on the typical nonlinear longitudinal dynamical model of an air-breathing hypersonic vehicle and the one-dimensional dual-mode scramjet model. Thrust, moment, angle of attack, altitude, and velocity are used as transfer variables between the aircraft model and the engine model. The one-dimensional scramjet model can accurately reflect the working state of the engine and provide data to support the coupling analysis. Second, owing to the static instability of the aircraft model, the linear quadratic regulator (LQR) controller of the aircraft is designed to ensure attitude stability and height tracking. Finally, the coupling relationship between the aircraft and the engine is revealed through simulation examples. The interaction between vehicle attitude and engine working condition is analyzed, and the influence of vehicle attitude on engine safety is considered. When the engine is in a critical working state, the attitude change of the aircraft will not affect the engine safety without considering coupling, whereas when coupling is considered, the attitude change of the aircraft may cause the engine unstart, which demonstrates the significance of considering coupling characteristics.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.325-332
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• 2017

The engine cooling system is a device that maintains the temperature in the engine room at an appropriate level by driving a cooling fan when the temperature in the engine room generated during the vehicle operation occurs over a certain temperature. In recent years, the vehicle cooling system has changed to an electronic system. Therefore, in this paper, we design and develop a hall sensor based electronic engine cooling system. In this paper, a hall sensor module and an actuator module for engine cooling control system are designed. In order to verify the performance of the designed module, the magnetic field control was verified through the simulation of the diameter and the head of the coil.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.73-81
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• 2006

A commercial diesel engine was converted into a dedicated natural gas engine to reduce the exhaust emissions in a retrofit of a diesel-fueled vehicle. The cylinder head and piston were remodeled into engine parts suited for a spark ignition engine using natural gas. The remodeling of the combustion chamber changed the compression ratio from 21.5 to 10.5. A multi-point port injection(MPI) system for a dedicated natural gas engine was also adopted to increase the engine power and torque through improved volumetric efficiency, to allow a rapid engine response to changes in throttle position, and to control the precise equivalence ratio during cold-start and engine warm-up. The performance and exhaust emissions of the retrofitted natural gas engine after remodeling a diesel engine are investigated. The emissions of the retrofitted natural gas engine were low enough to satisfy the limits for a transitional low emission vehicle(TLEV) in Korea. We concluded that a diesel engine can be effectively converted into a dedicated natural gas engine without any deterioration in engine performance or exhaust emissions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.1-8
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• 2018

This paper describes new communication methods for transmitting torque commands between the vehicle controller that determines the amount of power generation in a range-extended electric vehicle and the engine controller that performs it. Generally, vehicles use CAN communication, but in this case, the hardware and software of the existing engine controller must be modified. For this reason, it is not easy to apply CAN communication to small and medium sized automotive reorganize companies. Therefore, this research presents a pin-pin communication method for applying the existing mass produced engine controller to range-extended electric vehicles. The pin-pin communication method converts the driver's demand torque control map inside an mass produced engine controller into a virtual accelerator opening position according to the target speed and target torque of the engine, and converts this to a voltage signal for the existing mass produced engine controller to recognize it. The virtual accelerator opening positions are mounted in the form of a control map in the vehicle controller through the reverse conversion process in an offline environment and are determined by the engine generating power requirements and engine optimal operating point algorithm. These algorithms and signal conversion circuits for engine torque transmission have been mounted on the vehicle controller to conduct the virtual accelerator opening position conversion process according to the engine target torque and to establish the virtual accelerator voltage signal using the signal converter.

• Journal of the korean Society of Automotive Engineers
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• v.11 no.5
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• pp.1-12
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• 1989

This short report describes the trend of exhaust emission control of the diesel engine vehicles in Korea, which originally was motivated from the newly proposed Emission Control Regulation of Diesel Engine Vehicles possible to be activated in 1991 by Korean Environmental Protection Agency. This short survey report has been prepared by the special working group of The Korea Society of Automotive Engineers (KSAE) on this particular subject. This report includes (1) estimation of portions of contribution of diesel engine vehicle emission to total air pollution, (2) comparison of proposals of new articles/regulations/laws in Korea with those of other selected countries such as USA, European countries, and Japan, (3) comparison of vehical emission control regulations in Korea with those in other selected countries, (4) technical aspects of possibilities of reduction of diesel engine vehicle emissions, (5) additional administrational aspects of technology development program, (6) social impact resulted from the severe emission control regulation on diesel engine vehicles, and (7) proposals, prepared by the special working group of the KSAE, on the emission control regulation of diesel engine vehicles, which can possibly bring better cleaner air released from the air pollution resulted from diesel engine exhaust emissions in real sense with minimal financial contribution, with optimal technological efforts, with less social impacts, within five to ten year period.

• Journal of Mechanical Science and Technology
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• v.16 no.10
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• pp.1287-1295
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• 2002

In this work, the fuel economy of a parallel hybrid electric vehicle is investigated. A vehicle control algorithm which yields operating points where operational cost of HEV is minimal is suggested. The operational cost of HEV is decided considering both the cost of fossil fuel consumed by an engine and the cost of electricity consumed by an electric motor. A procedure for obtaining the operating points of minimal fuel consumption is introduced. Simulations are carried out for 3 variations of HEV and the results are compared to the fuel economy of a conventional vehicle in order to investigate the effect of hybridization. Simulation results show that HEV with the vehicle control algorithm suggested in this work has a fuel economy 45% better than the conventional vehicle if braking energy is recuperated fully by regeneration and idling of the engine is eliminated. The vehicle modification is also investigated to obtain the target fuel economy set in PNGV program.