• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.1
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• pp.18-24
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• 2007

The continuously variable transmission (CVT) of which speed ratio can change continuously in a fixed range has the benefits of low fuel consumption and exhaust gas because it enables the engine of a vehicle to operate in a high efficiency range regardless of vehicle speed. The speed ratio of belt type CVT is controlled by adjusting line pressure. The one of the line pressure control methods, mechanical-hydraulic control is usually adopting VDT's control method, in which the secondary solenoid valve has two functions both a regulator and a line pressure controller. However, this control method could not show the high performance of CVT with optimal driving capability because of the limitation of simple control algorithm, and it could not gain market share sufficiently in spite of the advantage of CVT with low fuel consumption. On the other hand, the electro-hydraulic control method gives the enhancement of power performance and low fuel consumption by implementing various driving mode using the proportional control or PWM control. The key of CVT technique is to develop a control algorithm of the electro-hydraulic solenoid valve in order to implement the speed ratio efficiently. In this paper, the line pressure control algorithm is proposed and the hydraulic system is controlled using metal belt type CVT test rig and the embedded ECU platform.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1448-1453
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• 2015

In this paper, we propose an alternative method of communication to improve the reliability of in-vehicle networks by jointly using wireless communication networks. Wired Communication networks have been used in vehicles for the monitoring and the control of vehicle motion, however, the disconnection of wires or hardware fault of networks may cause a critical problem in vehicles. If the network manager detects a disconnection or faults in wired in-vehicle network like the Controller Area Network(CAN), it can redirect the communication path from the wired to the wireless communication like the Zigbee network. To show the validity and the effectiveness of the proposed in-vehicle network architecture, we implement the Electronic Stability Control(ESC) system as ECU-In-the-Loop Simulation(EILS) and verify that the control performance can be kept well even if some hardware faults like disconnection of wires occur.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.113-120
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• 2014

In this paper, we examine Asymmetric Multi-Processing Environment to provide LDW service. Asymmetric Multi-Processing Environment consists of high-speed MCU to support rapid image processing and low-speed MCU for controlling with other ECU at the control domain. Also we designed rapid image process application and LDW application Software Component(SW-C) according to the development process rule of AUTOSAR. To communicate between two MCUs, timer based polling based IPC was designed. Also to communicate with other ECUs(Electronic Control Units), we designed CAN messages to provide alarm information and receiving CAN message to catch the Turn signal. We confirm the possibility of the various ADAS development using an Asymmetric Multi-Processing Environment and AUTOSAR platform. We also expect providing ISO 26262 functional safety.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.9 s.351
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• pp.80-87
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• 2006

In this paper, we analyze the performance of IEEE 802.11b WLAN communication between access point(AP) and mobile equipment(ME) in 2.4 GHz band with noise and interference factors. WLAN communication at in-vehicle environment is assumed as the communication between main vehicle controller and electronic device such as sensor, ECU (Electrical Control Unit) in vehicle on telematics field for implementing wireless vehicle control system. Received interference level from other system's mobile equipment in the same band and automobile noise from each part of vehicle can be the main factors that can cause increasing error rate of control signal. With these (actors, we focus on the Eb/No the BER performance of WLAN for analyzing the characteristic of interference factors by the measured bit error rate.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2380-2382
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• 2004

In this paper, Web server is built up using PXA255, 32bit RISC processor with porting Embedded Linux and GoAhead, HTTP(Hyper Text Transfer Protocol) web server, and the system with can monitor and control the environment and condition for AICC(Automatic Intelligent Cruise Control) is realized. For sending the operation condition and change of vehicle the desired data is derived by interacting ECU(Electric Control Unit) and Embedded system and the rpm of engine is controlled by step motor connected to throttle value.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.307-308
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• 2007

At present, there are unnecessary electrical consumes and a lot of fuel-losses by the vaporized gas due to the rising of fuel temperature because the fuel pump of the fuel supply system rotates regularly regardless to the driving condition. In this paper, we designed the multi-step controller for controlling fuel pump to supply fuel according to RPM of each moment by measuring the real time RPM of the engine at ECU of the vehicle. Also, it can judge the existence or nonexistence of disorder by measuring the pressure of the fuel supply line, in case of abnormal state, it can supply the fuel intelligently by changing the mode to self-compensation mode.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.422-424
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• 2010

Recently the car attached many ECUs and entertainment devices to provide the easiness maintenance and driver's convenience. CAN and MOST networks have been used to manage and control those devices in the car. Wireless network also has been established to receive information from external. These days a car navigation system with GPS is being integrated with CAN, MOST and Wireless network. In these circumstances, the car navigation system can have HMI function to integrate and control the car networks' devices. To solve the GPS problems such as positioning errors or losing signals from satellites in the tunnels and urban canyons, this paper designs and implements a method for positioning vehicle by using the sensing data of sensors and Wi-Fi devices based on this integrated environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.105-108
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• 2010

The vehicle navigation system is a representative driver supporting system that available to present searching and guiding path functions, have been increased for usability. Under competition situation because of following the spreaded navigation market, to meet customer's needs about new given services, there are need differentiated services increasing dramatically. Also now, dash board indicates various vehicle's status and driver can aware of that. However it is not easy to know where is abnormal essentially and there are no devices to give warning to driver. Therefore, It is difficult to preserve accidents because it can't deal with various abnormal functions immediately on driving. In this paper, we proposed vehicle diagnosis program within navigation that is available to manage and to make a diagnosis of vehicle. And this program conform OBD-II standard, so it can transmit diagnosis data from ECU to navigation system using Bluetooth wireless communication protocol. Thus this program give enhanced services to customer as well as multimedia and geometry information services.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.2
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• pp.47-54
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• 2012

An oxygen sensor installed in vehicle exhaust systems enables to measure the amount of oxygen in the exhaust gas, in which the measured data are collected and analyzed in ECU(Engine Control Unit). The oxygen sensor is exposed to the high speed exhaust gas at high temperature circumstance, so that protection caps are required not only to protect the susceptible measuring part, but also to provide the real time measurement without time delay. In this study, a new oxygen sensor with one protection cap was proposed, and the CFD analysis was carried out in order to compare the performance characteristics, such as flow speed and ratio of AOA(Age of Air), for the conventional and new oxygen sensor. The numerical results of CFD analysis provided the flow speed of 1.34m/s and the ratio of AOA of 3.43. The similar features obtained from the numerical results showed that the new oxygen sensor guarantees the same performance characteristics of the conventional ones.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.67 no.2
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• pp.100-105
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• 2018

In this paper, we determined the driver's stress and fatigue level through physiological signals of a driver in the connected car environment, accordingly designing and implementing the architecture of the connected cars' platforms needed to provide services to make the driving environments comfortable and reduce the driver's fatigue level. It includes a gateway between AVN and ECU for the vehicle control, a framework for native applications and web applications based on AVN, and a sensing device and an emotion estimation engine for application services. This paper will provide the element technologies for the connected car-based convergence services and their implementation methods, and reference models for the service design.