• International Journal of Automotive Technology
• /
• 제7권3호
• /
• pp.315-320
• /
• 2006

We have developed an active front steering system(AFS) with a planetary gear train, which can vary the steering gear ratio according to the vehicle speed and improve vehicle stability by superimposing steering angle. We conducted vehicle tests showing that co-operated control of AFS with ESP can improve vehicle stability by direct control of tire slip angle and that steering reaction torque during AFS intervention can be compensated by torque compensation using electric power steering.

• 한국자동차공학회논문집
• /
• 제7권9호
• /
• pp.105-111
• /
• 1999

The paper presents development of a Hardware-In-the-Loop simulation (HILS) system for the purpose of testing performance, stability, and reliability of an electronic power steering system(EPS). In order to realistically test an EPS by the proposed HILS apparatus, a simulated uniaxial dynamic rack force is applied physically to the EPS hardware by a pnumatic actuator. An EPS hardware is composed of steering wheel &column, a rack & pinion mechanism, andas motor-driven power steering system. A command signal for a pneumatic rack-force actuator is generated from the vehicle handling lumped parameter dynamic model 9software) that is simulated in real time by using a very fast digital signal processor. The inputs to the real-time vehicle dynamic simulation model are a constant vehicle forward speed and from wheel steering angles driven through a steering system by a driver. The output from a real-time simulation model is an electric signal that is proportional to the uniaxial rack force. The vehicle handling lumped parameter dynamic model is validated by a fully nonlinear constrained multibody vehicle dynamic model. The HILS system simulation results sow that the proposed HILS system may be used to realistically test the performance stability , and reliability of an electronic power steering system is a repeated way.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.277-278
• /
• 2006

As a development of technology, electric power steering system which uses an electric motor came to use in recent and it can solve the problems with hydraulic power steering system. In this paper, vehicle model and electric power steering system are combined to fulfill full vehicle model. By simulation effect of motor torque assist through electric power steering revealed effective, and full vehicle model are proved reasonable through comparison with real car experimental datum.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
• /
• pp.698-703
• /
• 1990

This paper describes an Electronically-controlled Power Steering system which is developed by the modification of a conventional power steering based on so called rotary valve technology. The steering effort is influenced by the electrohydraulic flow rate control of the pressurized oil to rotary valve. The vehicle speed and the steering angular velocity are used to calculate and output a signal to proportional flow rate control valve by the Electronic Control Unit. The improvement of the steering feel was satisfactory compared with that of the original conventional power steering.

• 동력기계공학회지
• /
• 제12권6호
• /
• pp.83-87
• /
• 2008

EPS(Electric Power Steering) system, which has replaced the hydraulic steering system(HPS or HPAS) in many passenger cars recently, have many merits such as low energy consumption, easy mounting, light weight and improvement of environmental pollution. However, EPS system has the problem of motor noise when motor is rotated, which can make a driver feel uncomfortable. There are many techniques to solve those problems, but they are not clear. It is necessary to evaluate the mechanical noise in steering systems, because an EPS has vibration sources such as at the motor gear reducer, manual gears and intermediate joints. In this paper, reduction technique of EPS motor noise is introduced.

• 한국산학기술학회논문지
• /
• 제13권3호
• /
• pp.1008-1013
• /
• 2012

EHPS는 탈엔진형 조향기술로 BLDC 모터를 통해 유압펌프를 작동시켜 조향력을 보조하는 동력 조향장치이다. EHPS는 BLDC 모터, 기어펌프 및 유압회로, 파워 스티어링 등으로 이루어진 전기전자, 유압 및 기계시스템의 복합적 시스템으로 모델링이 어렵다. 본 논문에서는 EHPS 시스템의 구성 부품을 수학적 모델링 하였고, AMESim을 이용하여 multi-domain 시스템의 시뮬레이션 모델을 구축하였다. 이를 활용한 다양한 시뮬레이션을 통해 개발 초기단계에서의 시행착오를 줄이고 완성도 높은 EHPS 개발 업무를 수행하는 데 도움을 줄 수 있을 것으로 사료된다.

• 한국공작기계학회논문집
• /
• 제14권1호
• /
• pp.66-72
• /
• 2005

The working tactor of this study, an agriculture machine, is consisted of 4 wheel driving system with gear trains and 4-type wheel steering system. Since technological regions for 4 wheel driving system and 4-type wheel steering system are some large, we divide on two studies on 4 wheel driving system and 4-type wheel steering system This study develops transmission and axle that are very important units for strong working operation because the power of tractor is largely affected by transmission and axle. Even if the development of the power train is some common technology, it is very complicated work and needs many experience know-hows. So, for new given specifications fitted to the working tractor, a kind of new agriculture machine, this study haws out processes that are development of assembly drawing and strength analysis through classical method and CAE software for all internal parts and housing cases.

• Tribology and Lubricants
• /
• 제20권3호
• /
• pp.163-167
• /
• 2004

Reducing friction torque of the oil hydraulic vane pump used as the power source of power steering system should consider friction torque including viscous and mechanical friction torque according to the changes of rpm and pressure. This paper analyzes the forces acting on the vane to reduce the friction torque of the vane of the hydraulic vane pump used for Hydraulic Power Steering(HPS) system, and futhermore, the forces according to the shapes of cam profiles are analyzed.

• 제어로봇시스템학회논문지
• /
• 제21권2호
• /
• pp.95-101
• /
• 2015

In this paper, we develop a sliding mode control for steering wheel angle control based on torque overlay in order to resolve the problem of previous methods for Electric Power Steering (EPS) systems in the Lane Keeping System (LKS) of autonomous vehicles. For the controller design, we propose a 2nd order model of the electric power steering system in an autonomous LKS. The desired state model is designed to prevent a rapid change of the steering wheel angle. The sliding mode steering wheel angle controller is developed for the robustness of the disturbance. Since the proposed method is designed based on torque overlay, torque integration with basic functions of the EPS system for the steering wheel angle control is available for the driver's convenience. The performance of the proposed method was validated via experiments.

• 전기학회논문지
• /
• 제63권11호
• /
• pp.1511-1518
• /
• 2014

Demand for high fuel efficiency and smart features of the vehicles, research has been intensified. Hence, research and development on electric power steering (EPS) system to replace the existing hydraulic steering system has been actively conducted. Permanent magnet motors are widely used in automotive applications due to their high power density and high efficiency. However, increasing price and limited production of rare-earth permanent magnets has recently prompted the auto parts makers to substitute permanent magnet motors by non- or less rare earth magnet motors. Switched reluctance motors SRMs), known as typical non-rare earth motors have simple structure, low manufacturing cost, and high reliability. This paper discusses design, modeling, simulation, and experimental verification of a prototype SRM drive for electric power steering system.