• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.1
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• pp.99-111
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• 2016

This paper presents an integrated fault diagnosis algorithm for driving motor of In-wheel independent drive electric vehicle. Especially, this paper proposes a method that integrated the high level fault diagnosis and the low level fault diagnosis in order to improve a robustness and performance of the fault diagnosis system. The high level fault diagnosis is performed using the vehicle dynamics analysis and the low level fault diagnosis is carried using the motor system analysis. The validity of the high level fault diagnosis algorithms was verified through $Carsim^{(R)}$ and MATLAB/$Simulink^{(R)}$ cosimulation and the low level fault diagnosis's validity was shown by applying it to a MATLAB/$Simulink^{(R)}$ interior permanent magnet synchronous motor control system. Finally, this paper presents a fault diagnosis strategy by combining the high level fault diagnosis and the low level fault diagnosis.

• Tribology and Lubricants
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• v.24 no.6
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• pp.285-290
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• 2008

The purpose of this paper is to present the case study of tribological failure analysis on the gear damages, oil leakage, and sealant sealing in a manual transmission of front engine and front wheel drive vehicle. The manual transmission is to change the speed range and direction of the engines depending on the driving conditions by friction driving forces with input and output gear system. The material property and surface roughness of the gears are strongly related to the gear noise and micro-vibration, oil leakage and wear, which may decrease the real contact area of the gear and the strength of the oil film thickness between the driving gear and driven one. The O-ring damage of speedometer driven gear and bad sealant sealing of oil pan may produce oil leakage through the contact surfaces, which cause the oil shortage and seizure on the sliding surfaces of the transaxle gears. In the failure case study, the proper repair working and good lubrication are very important for the long life of the transaxle without any tribological failures and oil leakage.

• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.4
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• pp.9-14
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• 2010

Most power steering systems work by using a hydraulic system to turn the vehicle's wheels. The pressure is usually provided by a hydraulic pump driven by the vehicle's engine. A double-acting hydraulic cylinder applies a force to the steering gear, which in turn applies a torque to the steering axis of the road wheels. The flow to the cylinder is controlled by valves operated by the steering wheel ; the more torque the driver applies to the steering wheel and the shaft it is attached to, the more fluid the valves allow through to the cylinder, and so the more force is applied to steer the wheels in the appropriate direction. Since the pumps employed are of the positive displacement type, the flow rate they deliver is directly proportional to the speed of the engine. And for a long time, the type of hydraulic pump pulley was boss welding type. But recently, monolith type driving pulley is widely used. Therefore in this paper we studied the safety of monolith type driving pulley to the extracting force and endurance by FEM analysis and experiments.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.288-293
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• 2016

Purpose: The purpose of this study was to investigate the key factors in designing a three-wheeled two-row soybean reaper (riding type) that is suitable for soybean production, and ensure worker safety by proposing optimal work conditions for the prototype of the designed machine in relation to the slope of the road. Methods: A three-wheeled two-row soybean reaper (riding type) was designed and its prototype was fabricated based on the local soybean-production approach. This approach was considered to be closely related to the prototype-designing of the cutter and the wheel driving system of the reaper. Load distribution on the wheels of the prototype, its minimum turning radius, static lateral overturning angle, tilt angle during driving, and The working and rear overturning (back flip) angle were measured. Based on the gathered information, investigations were conducted regarding optimal work conditions for the prototype. The investigations took into account driving stability and worker safety. Results: The minimum ground clearance of the prototype was 0.5 m. The blade height of the prototype was adjusted such that the cutter was operated in line with the height of the ridges. The load distribution on the prototype's wheels was found to be 1 (front wheel: F): 1.35 (rear-left wheel: RL): 1.43 (rear-right wheel: RR). With the ratio of load distribution between the RL and RR wheels being 1: 1.05, the left-to-right lateral loads were found to be well-balanced. The minimum turning radius of the prototype was 2.0 m. Such a small turning radius was considered to be beneficial for cutting work on small-scale fields. The sliding of the prototype started at $25^{\circ}$, and its lateral overturning started at $39.3^{\circ}$. Further, the critical slope angle for the worker to drive the prototype in the direction of the contour line on an incline was found to be $12.8^{\circ}$, and the safe angle of slope for the cutting was measured to be less than $6^{\circ}$. The critical angle of slope that allowed for work was found to be $10^{\circ}$, at which point the prototype would overturn backward when given impact forces of 1,060 N on its front wheel. Conclusions: It was determined that farmers using the prototype would be able to work safely in most soybean production areas, provided that they complied with safe working conditions during driving and cutting.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.529-538
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• 2009

A trial run of locally-developed tilting train has been in process on Chungbuk line since the test vehicle was first produced. For the system stabilization, interface verification among the systems including track, structure, catenary and signaling system, not to mention the rolling stock, is very crucial. Therefore, in this study, the dynamic rail force of the tilting (Hanvit 200), high-speed (KTX) and general (Mugunghwa) vehicle caused by driving in transition curve track was measured. And, it compared the tilting response with the other by using the measured wheel load data in transition curve track, and then evaluated probability the range of wheel load fluctuation for the variable dynamic vertical and lateral wheel load. As a result, a range of wheel load by occured a change of cant from the high-speed and general vehicle which had fixed bogie structure was distributed throughout small deviation (${\Delta}8{\sim}13kN$). Otherwise, in case of the tilting train which was consisted of the pendulum bogie structure was distributed wide range about large deviation (${\Delta}25{\sim}28kN$) by changed of cant.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.6
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• pp.59-67
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• 2014

A numerical model and a controller of Active Front wheel Steer (AFS) system are designed in this study. The AFS model consists of four sub models, and the AFS controller uses sliding mode control and PID control methods. To test this model and controller an Integrated Dynamics Control with Steering (IDCS) system is also designed. The IDCS system integrates an AFS system and an ARS (Active Rear wheel Steering) system. The AFS controller and IDCS controller are compared under several driving and road conditions. An 8 degree of freedom vehicle model is also employed to test the controllers. The results show that the model of AFS system shows good kinematic steering assistance function. Steering ratio varies depends on vehicle velocity between 12 and 24. Kinematic stabilization function also shows good performance because yaw rate of AFS vehicle tracks the reference yaw rate. IDCS shows improved responses compared to AFS because body side slip angle is also reduced. This result also proves that AFS system shows satisfactory result when it is integrated with another chassis system. On a split-m road, two controllers forced the vehicle to proceed straight ahead.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.392-397
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• 2006

This paper proposed yaw moment control scheme using braking and active rear wheel steering for improving driving stability especially in high speed driving. Its characteristics the unified chassis control system of two equipment that 4WS(4 Wheel Steering) and ESP(Electronic Stability Program). in this study the performance of the vehicle was compared each equipment. And conventional ABS and TCS can only possible to control the longitudinal movement of braking equipment and drive which can only available to control of longitudinal direction. There after new braking system ESP was developed, which controls both of longitudinal and lateral, with adding of the function of controlling Active Yaw Moment. On this paper, we show about not only designing of improved braking and steering system through establishing of the integrated control system design of 4WS and ESP but also designing of the system contribute to precautious for advanced vehicle stability problem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.159-165
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• 2010

The moving object monitoring and transforming personal robot system based on remote controls is designed and implemented, and the performance of the system is analyzed in this paper. The major considering factors in the system design are such as 1) the control scheme design (button based and the remote control schemes); 2) the operation modes design (wheel driving mode/pedestrian mode/auto driving mode/observation mode); 3) the remote control function design; 4) the design of the monitoring function of the changes in neighbor environments; 5) the design of the detection of obstruction. From the experiments, it is assured that the developed personal robot can walk to the grounds that covered with doorsill or electric wires in indoors by control the leg articulations, and can escape from the obstruction using three infrared sensors in the 30cm*30cm obstruction styled space under the auto driving mode.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1695-1696
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• 2008

KRRI (Korea Railroad Research Institute) is developing a bimodal tram since the 2003s. The vehicle will be used in the public transportation system. The bimodal tram has the advantages of both bus and train. Bus system has the advantages of flexibility of the routes delivering passengers to the destination and easy accessibility. Train is to meet the scheduled arrival and massive public transportations. The vehicle is the rubber tired tram and is all wheel steered single articulation. The propulsion system is configured by CNG hybrid system. The length of the vehicle is 18m. The vehicle lanes will be marked with permanent magnets that are buried in the road. The vehicle can be automatically operated by navigation control system (NCS). In this paper, we introduce the driving system of the bimodal tram which is developed by KRRI.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.1
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• pp.40-45
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• 1982

The spring constant and damping coefficient are vital factors of ride comfort and driving stability in the vibration of the vehicle which is mainly induced by a variety of the surface irregularity. This paper reviewed the optimum condition of the damping factor derived from the typical model of two mass-two degrees of freedom. Through the evaluation and discussion, it was presented that the spring of the torsion bar type was not effective for the driving stability in the large displacement of the wheel, and also that the damper with progressive performance has to be fundamentally selected to meet the requirement of the driving suability when this kind of spring is used as a suspension system of the vehicle.