• Title, Summary, Keyword: Motor Point

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Validation of the Simplified Motor Score for the Triage after Traumatic Brain Injury (두부 외상 환자의 중증도 평가 시 단순운동점수의 유용성)

  • Lee, Sang Kyong;Ryoo, Hyun Wook;Park, Jung Bae;Seo, Kang Suk;Chung, Jae Myung
    • Journal of Trauma and Injury
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    • v.21 no.2
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    • pp.71-77
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    • 2008
  • Purpose: The Glasgow Coma Scale (GCS), though it is widely used for triage, has been criticized as being unnecessarily complex. Recently, a 3-point Simplified Motor Score (SMS, defined as obeys commands=2; localizes pain=1; withdrawals to pain or worse=0) was developed from the motor component of the GCS and was found to have a similar test performance for triage after traumatic brain injury when compared with the GCS as the criterion standard. The purpose of this study was to validate the SMS. Methods: We analyzed the patients who visited Kyungpook National University Hospital emergency center after traumatic brain injury from 2006 January to 2006 June. The test performance of the GCS, its motor component, and SMS relative to three clinically relevant traumatic brain injury outcomes (abnormal brain CT scans, Abbreviated Injury Scale $(AIS){\geq}4$, and mortality) were evaluated with areas under the receiver operating characteristic curves (AUCs). Results: Of 504 patients included in the analysis, 25.6% had an abnormal brain CT scans, 13.1% had $AIS{\geq}4$, and 5.0% died. The AUCs for the GCS, its motor component, and SMS with respect to the abnormal CT scans were 0.776, 0.715, and 0.716, and respectively, those for $AIS{\geq}4$ and mortality, were 0.969, 0.973, and 0.968, and 0.931, 0.909, and 0.909, respectively. Conclusion: The 3-point SMS demonstrated similar test performance when compared with the 15-point GCS score and its motor component for triage after traumatic brain injury in our populations.

Position Correction Method for Misaligned Hall-Effect Sensor of BLDC Motor using BACK-EMF Estimation (역기전력 추정법을 이용한 브러시리스 직류 전동기의 홀센서 상전류 전환시점 보상 방법)

  • Park, Je-Wook;Kim, Jong-Hoon;Kim, Jang-Mok
    • The Transactions of the Korean Institute of Power Electronics
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    • v.17 no.3
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    • pp.246-251
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    • 2012
  • This paper proposes a new position compensation method for misaligned Hall-effect sensors of BLDCM(Brushless DC Motor). If the Hall-effect sensors are installed at wrong position, the exact rotor position cannot be obtained. Therefore, when the BLDCM is controlled with this wrong position, the torque ripple can be increased and the average torque also decreases. The back-EMF of BLDCM can be obtained by using the voltage equation and by multiplying the back-EMF constant and rotor speed. At a constant speed, the estimated back-EMF by using the multiplication of the back-EMF constant and rotor speed is constant, but the estimated back-EMF from the voltage equation decreases at the commutation point because the line-to-line back-EMF of two conducting phases is start to decrease at this point. Therefore, by using the difference between these two estimated back-EMFs, the commutation point of the phase current can be determined and position compensation can be carried out. The proposed position correction method doesn't require additional hardware circuit and can be easily implemented. The validity of the proposed position compensation method is verified through several experiments.

Linear Pulse Motor Characteristics Analysis using Non-linear Simulation (비선형 시뮬레이션에 의한 리니어 펄스모터의 특성해석)

  • Lee, Je-Hie;Huh, Uk-Youl
    • Proceedings of the KIEE Conference
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    • pp.584-587
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    • 1992
  • Because linear motor directly drives linear motion, it does not need conversion equipment such as belt and gear. Especially linear pulse motor provide more precise positioning and large force of linear pulse motors. As current manufacture technic of linear pulse motor is much to be desired at home. This motor lay out to make use of computer aided design program, In this paper the experimental motor is 2-phases 4-poles hybrid pulse motor which has teeth per pole Simulation program is divided its function into 4 parts - air gap permeance analysis, permanent magnet & non-linear core operating point determine, winding configuration, leakage flux analysis. It is possible to make motor static and magnetic characteristics for this simulation program. Also, by varying input parameters of the program, experimental motor is to be compared to motor characteristics.

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A Study on Design of Linear Induction Motor in Dynamic Tester for Catenary-current Collection (주행 집전계 시험기의 주행 대차용 선형 유도전동기 설계에 관한 연구)

  • Ham, Sang-Hwan;Cho, Su-Yeon;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.4
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    • pp.771-775
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    • 2011
  • This paper presents design process of linear induction motor in dynamic tester for catenary-current collection. To minimize length of rail for dynamic tester for catenary-current collection, accelerating performance of the linear induction motor is very important. So the design process of linear induction motor considered in this paper is different with general design process of linear induction motor, because dynamic tester has three type driving region, as accelerating region, constant speed region, and braking region. Considering accelerating performance of motor, distance and time from starting point to constant speed region were concerned for load condition of motor. Designed linear induction motor was analyzed by 2-dimensional finite element method. Using mechanical dynamics simulation with analysis result of 2-dimensional finite element method and accelerating performance of designed motor was proved.

A Study on the Performance Analysis of Single-Phase Induction Motor Considering Asymmetrical Concept (비대칭성개념(非對稱性槪念)을 고려한 단상전원용유도전동기(單相電源用誘導電動機)의 특성해석(特性解析)에 관한 연구(硏究))

  • Lee, Il-Chun;Kim, Chul-Woo;Hwang, Young-Moon
    • Proceedings of the KIEE Conference
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    • pp.5-9
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    • 1989
  • In this paper, while 2-or 3-phase induction motor is driven with balance and no noise driving at dynamic and steady state condition. Single-phase induction motor is driven with pulsating torque except specific driving point. So we analyze the reason of producing pulsating torque with the view of unsymmetring concept. These results are applied to the design of high efficincy, high quality single-phase induction motor.

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콘덴서 런 단상유도전동기의 설계적 고찰

  • 원종수
    • 전기의세계
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    • v.31 no.2
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    • pp.132-140
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    • 1982
  • Designing the capacitor-run motor for balanced operation is accompanied with the excessive capacitor value and low capacitor terminal voltage of condenser. As a solution for this problems, It was reported the design by equal volt-ampere method. The running characteristics of capacitor-run motor by this method due to the balancing point selection, however, has a room to be studied further. This paper deals with the determination of the winding ratio and capacitor value of a permarient-split capacitor motor by balanced operation and equal volt-ampere method at the different load points. The analysis of the running characteristics of a motor and its designing method also presented for both cases. It concluded that the running characteristics due to the equal volt-ampere operation are very close to the balanced operation.

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Comparison of Characteristics between $L_1-B_4$ mode and $L_1-B_8$ mode Ultrasonic Motors ($L_1-B_4$모드와 $L_1-B_8$모드 초음파 선형 전동기의 특성 비교)

  • U, Sang-Ho;Kim, Dong-Yeon;Kim, Jin-Soo
    • Proceedings of the KIEE Conference
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    • pp.1518-1520
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    • 2002
  • Purpose of this research compares best transfer speed about applied frequency and voltage using characteristic of $L_1-B_4$ mode and $L_1-B_8$ mode linear ultrasonic motor that use piezoelectric effect. By method of study, analyzed best transfer speed measuring and comparison load status that use actuality telephone card in $L_1-B_4$ mode linear ultrasonic motor and no-load status of $L_1-B_8$ mode linear ultrasonic motor. Experiment result is applied frequency(58.4Hz) in $L_1-B_4$ mode linear ultrasonic motor (load state) and the best transfer speed by 19.8[cm/s] at applied voltage(56V) point. Also, $L_1-B_8$ mode linear ultrasonic motor (no-load state) is best transfer speed by applied frequency(27.9kHz) and 32.96[cm/s] at applied voltage (50V) point.

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Optimal Design of Stator Shape for Cogging Torque Reduction of Single-phase BLDC Motor (단상 BLDC 전동기의 코깅토크 저감을 위한 고정자 형상 최적설계)

  • Park, Young-Un;So, Ji-Young;Chung, Dong-Hwa;Yoo, Yong-Min;Cho, Ju-Hee;Ahn, Kang-Soon;Kim, Dae-Kyong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.11
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    • pp.1528-1534
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    • 2013
  • This paper proposes the optimal design of stator shape for cogging torque reduction of single-phase brushless DC (BLDC) motor with asymmetric notch. This method applied size and position of asymmetric notches to tapered teeth of stator for single-phase BLDC motor. Which affects the variation of the residual flux density of the permanent magnet. The process of optimal design included the extraction of the sampling point by using Latin Hypercube Sampling(LHS), and involved the creation of an approximation model by using kriging method. Also, the optimum point of the design variables were discovered by using the Genetic Algorithm(GA). Finite element analysis was used to calculate the characteristics analysis and cogging torque. As a result of finite element analysis, cogging torque were reduced approximately 39.2% lower than initial model. Also experimental result were approximately 38.5% lower than initial model. The period and magnitude of the cogging torque were similar to the results of FEA.

Design and Analysis of a L shape two touch point ultrasonic rotary motor (L형 2타점 회전모터의 설계와 해석)

  • Kim, Sung-Hyun;Park, Tae-Gone
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.85-88
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    • 2004
  • The piezoelectric ceramic is attached between 'L' type guide and 'L' type stator, This motor has rotary motion which is operated by longitudinal and bending mode. The basic structure of the two kinds of type motor that called one stator motor, two stator motor is same but we suggested a few parameters for considering their stator design and characteristics. As a result, the two stator type motor is much more useful than one stator type motor for hi-direction rotation.

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Analysis of Ultrasonic Linear Motor Using the Finite Element Method and Equivalent Circuit

  • Park, Jong-Seok;Joo, Hyun-Woo;Lee, Chang-Hwan;Jung, Hyun-Kyo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.3B no.4
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    • pp.159-164
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    • 2003
  • In this paper, a three-dimensional finite element method and construction of equivalent-circuit for a linear ultrasonic motor are presented. The validity of three-dimensional finite element routine in this paper is experimentally confirmed by analyzing impedance of a piezoelectric transducer. Using this confirmed finite element routine, impedance and vibration mode of a linear ultrasonic motor are calculated. Elliptical motion of contact point between vibrator and rail of the linear ultrasonic motor is shown for determination of contact points. By using the finite element method and analytic equations, characteristics of the linear ultrasonic motor, such as thrust force, speed, losses, powers and efficiency, are calculated. The results are confirmed by experiment. Finally, equivalent circuit parameters of the linear ultrasonic motor are obtained using the three-dimensional finite element method and analytic equations.