• 대한기계학회논문집A
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• 제30권9호
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• pp.1041-1048
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• 2006

The pulley is one of core mechanical elements in the power steering system for vehicles. The pulley operates under both the compressive loading and the torque. Therefore, to assure the safety of the power steering system, it is very important to investigate the durability and the optimization of the pulley. In this study, the applied stress distribution of the pulley under high tension and torsion loads was obtained by using finite element analysis. Based on these results the fatigue life of the pulley with the variation of the fatigue strength was evaluated by a durability analysis simulator. The results at 50% and 1% for the failure probability were compared with respect to the fatigue life. In addition to the optimum design for the fatigue life is obtained by the response surface method. The response function utilizes the function of the life and weight factors. Within range for design life condition the minimization of the weight, one of the formulation, is obtained by the optimal design. Moreover the optimum design by considering its durability and validity is verified by the durability test.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.1195-1202
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• 2017

Induction motors often reach their maximum efficiency at the nominal load. In most applications, the machine load is not equal to the nominal load, thus reduces the motor efficiency and turns a greater percent of power into loss. In this paper, the induction motor control problem has been investigated to reduce the system losses. The Field Oriented Control method (FOC) has been employed in this paper. In this research, the mathematical equations related to system losses are calculated in relation to torque and speed, and then the q- and d-axis are summarized according to the current components. After that, the proposed method is applied along with d- and q-axis. In the recent three decades, many techniques have been suggested to improve the induction motor performance using smart and non-smart methods. In this paper, a new PSO-Fuzzy method have used in real time. The fuzzy logic method serves as speed controller in q-axis and PSO algorithm controls the optimum flux in d-axis. It will be proved that the use of this combined method will lead to a significant improvement in motor efficiency.

• 한국정밀공학회지
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• 제29권7호
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• pp.745-752
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• 2012

The pivot steering of an individual wheel motor drive vehicle is an effective steering maneuver in the narrow road, but it has become a matter of concern that the torque input of each wheel is very difficult to determine. In this study, the independent yaw moment control was proposed for the smooth pivot steering control of an in-wheel drive vehicle. For this control method, the vertical forces of tires were estimated from the trailing arm dynamic model, and the yaw moments of individual wheels were calculated from the vehicle dynamic model. Dynamic simulation results showed that the independent yaw moment control was much more effective on the minimization of the instabilities of pivot steering in comparison with the conventional direct yaw moment control with yaw rate feedback.

• 대한전기학회논문지
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• 제38권3호
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• pp.155-165
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• 1989

본 논문은 페라이트 자석 직류전동기의 치수제원 및 특성계산에 필요한 설계식을 도출하고 이로부터 파라메타 서베이법을 적용한 반복계산에 의해 치수설계를 행하는 방법을 제시하였다. 그 계산결과와 공시 전동기와의 치수제원을 비교, 검토하여 다음과 같은 사실과 설계방법의 타당성을 밝혔다. (1)파라메터로 설정한 치수비 $\mathfrak$ 및 극호비 ${\alpha}_2$는 치수제원 및 전동기 성능에 밀접한 관계사 있으며, 이 값들이 합리적인 치수결정에 있어 중요한 요소가 된다. (2)페라이트 자석의 동작점 퍼미언스계수를 자속밀도비 ${\gamma}$만의 함수로 표시함으로써 자석부피의 최소화를 가능하게 하였다. (3)슬롯 내에 잇는 도체의 동손면적밀도를 고려하여 제시한 토오크 식은 페라이트 자석 직류정동기의 치수결정에 유용함을 보였다.