• 한국자동차공학회논문집
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• 제5권6호
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• pp.192-201
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• 1997

The feedback control scheme of the pressure control system of the rear wheel steering gear which has relatively large volume and sprung load was built up in order to improve th response characteristic of the system. The control algorithm chosen was a feedback compensator joined by a feedfoward compensator and the model matching method was used in the process of control system design. The structures and properties of the reference models were inspected and the parameters of the controller were decided. The improvement of the response characteristic of the pressure control valve by means of the feedback control is affirmed. Particularly, when the order of the system model is higher than the 2nd order, the effectiveness of the feedback control on the improvement of the response characteristic of the valve is distinct. And the convenience of the model matching method is the process of control system design is confirmed as well.

• 수산해양기술연구
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• 제34권2호
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• pp.231-237
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• 1998

Generally, the three position solenoid valve has veen used for the hydraulic steering gear on account of it’s low cost, simplicity in device, etc. But, there is some off-set because of dead-zone which exists in on-off valves. In this paper, we proposed a combined controller which was added an integral controller to an only on-off one in hydraulic steering gear control system used low speed three position solenoid valve. Experimental results show that the off-set is removed, and the number of valve switching is reduced considerable. The validity of proposed method comparing with an only on-off control was proved by the response experiments.

• International Journal of Automotive Technology
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• 제7권3호
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• pp.321-327
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• 2006

The previous paper described the logic tuning, the vehicle manufacture and the evaluation in the HILS system for the purpose of the development of a Steer-By-Wire(SBW) system. This paper describes the content of applying to a new HILS system, the vehicle manufacture and the result of the evaluation performed in Independent-type SBW(I-SBW) system. Here, the SBW indicates the method of steering both tires by using one motor as the steering gear actuator, similar to the conventional steering system. On the other hand, the I-SBW means the method of steering both front tires independently by using dual motors as the steering gear actuator. As a result, the layout and the kinematical mechanism of the I-SBW system are quite different from those of the typical steering mechanism. Nevertheless, there is no change in the steering column motor system. In the report, we first describe the structure and control logic of the I-SBW system, and then the control effect on this system as applied for both the HILS system and a vehicle. Furthermore, our HILS system involves the actuator mechanism which realizes the reaction force of the road surface with a minimized frictional force in operation. Therefore, it is possible for us to tune the control logic via the HILS system and confirm the effect of the tuned control logic by applying it to a vehicle with the I-SBW system.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.199-205
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• 2002

The scale of repair parts market reached 0.1 billion won. Above all, it is remarkable that the automotive insurance business world is paying f3r 40 ~5o% of the whole repair cost. The repair parts consist of a genuine parts, non-genuine parts, recycling used parts. It is the recent trend that recycled parts are more popular than the genuine parts f3r repairing crashed cars due to the cost. Performance of recycled continuous velocity(CV) joints and power steering(PS) gear box as replacement parts was tested and analysed in this study. To examine the durability of the recycled parts, the replaced CV joints and PS gear box after repair were tested and analysed periodically. The results were showed that basic performance of the recycled parts was normal. However the ball cage of CV joints was more frequently damaged than genuine parts. We concluded that a test standard and amendment of related laws for recycled parts is required to get a safe and durable parts.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년 추계학술발표대회 개요집
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• pp.152-154
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• 2006

• Tribology and Lubricants
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• 제26권1호
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• pp.61-67
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• 2010

The purpose of this paper is to study and analyze the failure examples on tribological characteristics of an automotive steering system. In this failure study, the grease leakage may stick leaked grease, dust, and wear particles between pinion and rack gears in mechanical steering system. In the case of seal failures such as a rod seal, o-ring and oil seals, the gear box and oil pump do not operate properly due to lack of oils. This means that oil pump does not supply a working fluid and produce a normal oil pressure of the steering system. This leads to leak a working fluid from the seals and produce a wear between pinion and rack gears. Especially, the leaked oil is usually mixed with internal wear particles and foreign dust/fine sands. Thus no leakage of working oils is very important design concepts, which is strongly related to the sealing components and smoothly operating of the mechanical friction parts of power steering system.

• 한국자동차공학회논문집
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• 제16권4호
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• pp.135-142
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• 2008

Hydraulic power steering system has been adopted in seniority passenger and commercial vehicle system for an easy maneuverability and a smoother ride. In this study, hydraulic power steering system analysis model which includes hydraulics and mechanical sub-systems was developed using commercial software, AMESim in order to predict characteristics for various steering components. Each component which constructs system was modeled and verified by experimentally obtained characteristics curves of each components. The parameter sensitivity analysis such as valve opening area, torsional stiffness of torsion bar for system design are carried out by the analysis and experimental method. The predicted results by the development model were a good agreement with experimentally obtained results. The sensitivity investigation results rotary torque when changing an input shaft edge width, was most sensitive, to change in angle and slot width and supply flow of input shaft edge is not a lot sensitively.

• 한국지능시스템학회논문지
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• 제12권5호
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• pp.417-423
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• 2002

본 논문에서는 자연언어를 이용하는 인간의 학습방법에 기초한 LIBL방법을 선박의 조타 시스템에 적용하여, 항해사의 조타명령과 같은 언어적 지시가 조타수를 경유하여 수행되는 과정을 대체하는 지능형 조타 제어 시스템을 제안하고자 한다. 구체적인 연구방법으로는 조타수의 적절한 조타조작모델을 퍼지추론 규칙을 이용하여 구현하고, 적절한 의미소 및 평가규칙을 제시한 언어지시 기반 학습방법을 선박의 조타시스템에 적용하여, 항해사의 언어지시에 보다 효율적으로 응답하는 지능형 조타기 제어 시스템을 구현한다. 퍼지추론을 이용하여 조타수의 경험을 바탕으로 한 타 조작 모델을 구축하였고, 지능형 조타 시스템을 위한 타각, 방위도달시간, 정상상태의 의미소를 제안하여, 조타수 조작 모델 규칙을 수정하기 위한 평가 규칙을 제시하였다. 또한, 구축된 선박조종 시뮬레이터에 제안된 시스템을 적용하여 그 유효성을 확인하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2002년도 추계학술대회 및 정기총회
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• pp.93-97
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• 2002

본 논문에서는 자연언어를 이용하는 인간의 학습방법에 기초한 LIBL방법을 선박의 조타 시스템에 적용하여, 항해사의 조타명령과 같은 언어적 지시가 조타수를 경유하여 수행되는 과정을 대체하는 지능형 조타 제어 시스템을 제안하고자 한다. 구체적인 연구방법으로는 조타수의 적절한 조타조작모델을 퍼지추론규칙을 이용하여 구현하고, 적절한 의미소 및 평가규칙을 제시한 언어지시 기반 학습방법을 선박의 조타시스템에 적용하여, 항해사의 언어지시에 보다 효율적으로 응답하는 지능형 조타기 제어 시스템을 구현한다. 퍼지추론을 이용하여 조타수의 경험을 바탕으로 한 타 조작 모델을 구축하였고, 지능형 조타 시스템을 위한 타각, 방위도달시간, 정상상태의 의미소를 제안하여, 조타수 조작 모델 규칙을 수정하기 위한 평가규칙을 제시하였다. 또한, 구축된 선박조종 시뮬레이터에 제안된 시스템을 적용하여 그 유효성을 확인하였다.

• 한국정밀공학회지
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• 제16권12호
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• pp.214-221
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• 1999

In this research, a power-assisted steering system is modeled as a part of a full vehicle dynamic model. The dynamic model of the steering system incorporates hydraulic and dynamic relations between major parts of a steering system, such as steering column, control valve, rack and pinion gear. Through an experimental setup of the steering system, the steering system model is validated. The steering model is included in a full vehicle dynamic model of a car, where kinematic relations between steering and suspension system are defined, and various simulations are performed to evaluate the performance of steering system in conjunction with overall dynamic performance of the vehicle.