• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1366-1370
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• 2005

As the development of microprocessor technology, electric power steering (EPS) system which uses an electric motor came to use a few years ago. It can solve the problems associated with hydraulic power steering. The motor only operates when steering assistance is needed, so it can save fuel and can reduce weight and cost by eliminating hydraulic pump and piping. As one of performance criteria of EPS systems, the transmissibility from road wheel load to steering wheel torque is considered in the paper. The transmissibility can be studied by fixing the steering wheel and calculating the torque needed to hold the steering wheel from road wheel load. A proportion-plus-derivative control is needed for EPS systems to generate desired static torque boost and avoid transmissibility of fluctuation. A pure proportion control can't satisfy both requirements.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.277-278
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• 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.

• Journal of Power Electronics
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• v.10 no.2
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• pp.176-180
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• 2010

This paper deals with a control method to reduce the torque ripple of a permanent magnet synchronous motor (PMSM) for electric power steering (EPS) systems. Such an application requires a very low torque ripple in order to maintain a good steering feel. However, because of spatial limitations, it cannot help having a partial saturation in the iron core of the PMSM for an EPS system, and this saturation results in a significant torque ripple. Thus, this paper analyzes the torque ripple caused by the magnetic saturation of a PMSM and proposes a method with respect to inductance measurement to verify the partial saturation. In addition, it is shown that a compensation current is needed in order to minimize the torque ripple when a PMSM is driven in the high torque region. The estimation process of the current and the torque ripple decreased by the current are presented and verified with test results.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.864-866
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• 2002

Power steering of a car is used to reduce driver's handle control power. It is usually operated by oil pressure of engine power. However, electrically power steering (EPS) is used recently instead of oil pressure type for environmental and economical reason. This paper presents structure design and characteristics analysis of SRM for EPS application.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.11
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• pp.1511-1518
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• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1403-1407
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• 2013

This paper presents the method to calculate the motor parameters considering skew in EPS Interior Permanent Magnet Synchronous Motor (IPMSM). The skew is applied to stator or rotor by general technology used for design of reducing noise and vibration in motor. The characteristics analysis of motor including the skew is mostly used by 3D Finite Element Analysis (FEA), though, this analysis is a very time-consuming to perform. Besides, The reliability lacks due to the considerable change of motor characteristics according to the number of elements in 3D FEA. However, analysis time and effort can be saved by characteristic analysis considering skew using 2D FEA. Therefore, in this paper, a quick and accurate method for the calculations of motor parameters considering skew is suggested. The proposed method is verified by the comparison of calculated and experimental results.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.2
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• pp.765-781
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• 2019

This study predicts the power consumption of an Electric Propulsion Ship (EPS) in marine environment. The EPS is driven by a propeller rotated by a propulsion motor, and the power consumption of the propeller changes by the marine environment. The propulsion motor consumes the highest percentage of the ships' total power. Therefore, it is necessary to predict the power consumption and determine the power generation capacity and the propeller capacity to design an efficient EPS. This study constructs a power estimation simulator for EPS by using a ship motion model including marine environment and an electric power consumption model. The usage factor that represents the relationship between power consumption and propulsion is applied to the simulator for power prediction. Four marine environment scenarios are set up and the power consumed by the propeller to maintain a constant ship speed according to the marine environment is predicted in each scenario.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.785-787
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• 2010

It is well known that most power steering systems obtain the power by a hydraulic mechanism. Therefore, it consumes more energy because the oil power should be sustained all the times. Recently, to solve this problem the Electric Power System(EPS) or Motor Driven Power System(MDPS) has widely equipped in passenger vehicles. In this research the concurrent simulation technique for an EPS system with MATLAB/SIMULINK and a full vehicle model has been developed. The dynamic responses of vehicle chassis and steering system are evaluated. Then, a full vehicle model interacted with EPS control is concurrently simulated with an impulsive steering wheel torque input to analyze the stability of 'free control' or hands free motion for SUV. This integrated method allows engineers to reduce the prototype testing cost and to shorten the developing period.

• Journal of Magnetics
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• v.17 no.4
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• pp.285-290
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• 2012

Electric Power Steering (EPS) system is superior to conventional Hydraulic Power Steering (HPS) system in aspect of fuel economy and environmental concerns. The EPS system consists of torque sensor, electric motor, ECU (Electric Control Unit), gears and etc. Among the elements, the torque sensor is one of the core technologies of which output signal is used for main input of EPS controller. Usually, the torque sensor has used torsion bar to transform torsion angle into torque and needs linear characteristic in terms of flux variation with respect to rotation angle of permanent magnet. The torsion angle of both ends of a torsion bar is measured by a contact variable resistor. In this paper, the sensor is accurately analyzed using 3D finite element method and its characteristics with respect to four different shapes of the stator teeth are compared. The four shapes are rectangular, triangular, trapezoidal and circular type.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1483-1488
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• 2005

As the development of microprocessor technology, electric power steering(EPS) system which uses an electric motor came to use a few years ago. It can solve the problems associated with hydraulic power steering. The motor only operates when steering assistance is needed, so it can save fuel and can reduce weight and cost by eliminating hydraulic pump and piping. As one of performance criteria of EPS systems, the transmissibility from road wheel load to steering wheel torque is considered in this paper. The transmissibility can be studied by fixing the steering wheel and calculating the torque needed to hold the steering wheel from road wheel load. A proportion-plus-derivative control is needed for EPS systems to generate desired static torque boost and avoid transmissibility of fluctuation. A pure proportion control can' satisfy both requirements.