• Title/Summary/Keyword: Average torque

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The Effect of a Taping on Muscle Strength, and Proprioception in Ankle (테이핑에 따른 발목 근력, 고유수용성감각에 미치는 영향)

  • Lee, Sang-Young
    • Journal of the Korean Society of Physical Medicine
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    • v.3 no.4
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    • pp.225-233
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    • 2008
  • Purpose : The purpose of this study was to investigate changes of muscle strength, ROM and proprioceptive function as before & after ankle taping in soccer players. For this study fifteen sports club whose had no ankle injuries were volunteered. Methode : Fifteen healthy male in soccer players participated in this study. Biodex pro system3 was used to measure isokinetic muscle strengths at $60^{\circ}$/sec angular velocity. Performances of ankle joint were measured peak torque, total work, average power, total work. To measure proprioceptive function used goniometer. Results : 1. proprioceptive sensation error were significantly differences by before & after taping(p<.05). 2. Compare of total work of dorsi flexion plantar flexion weren't significantly differences by before & after taping(p>.05). 3. Compare of average power of dorsi flexion weren't significantly differences by before & after taping(p>.05). 4. Compare average power of plantar flexion were significantly differences by before & after taping(p<.05). 5. Compare average peak torque of dorsi flexion weren't significantly differences by before & after taping(p>.05). 6. Compare average peak torque of plantar flexion were significantly differences by before & after taping(p<.05). Conclusion : Taping can have propriocetive aberrative angular measure, power & peak torque of plantar flexion were significantly differences. But, total work of dorsi flexion plantar flexion and power & peak torque of dorsi flexion weren't significantly differences.

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Maximization average torque control of Switched Reluctance Motor using least square method (최소자승법을 이용한 Switched Reluctance Motor의 최대 평균토오크 제어)

  • 김춘삼;정연석
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.5
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    • pp.61-65
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    • 2002
  • RM(Switched Reluctance Motor)'s Torque is generated by phase-current and inductance profile. A new analytical concept is proposed to determine the turn-off angle for maximization of the torque output. This paper describes a new method to maximization the average torque of a current control Switched Reluctance Motor. It is based on the simplified turn-off angle equation using least square method. Simulations carried out on a three-phase 6/4 pole SRM justify the algorithm is described. The suggested maximization average torque is verified by simulation in this paper.

A Comparison of Muscle Strength by Russian Current and Low Frequency Current Stimulation in Normal Adult (정상성인에서 러시안 전류와 저주파 전류 자극에 의한 근력 증가의 비교)

  • Kim, Jong-Youl
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.3
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    • pp.353-360
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    • 2011
  • Purpose : The purpose of this study was to compare the effect of muscle strength by stimulation of russian current and low frequency. Methods : The subjects were thirty young healthy volunteers who were divided into two groups including russian current group(n=15) and low frequency group(n=15). The intervention was applied totally 12 times (1 time, 10 minute) for 4weeks in each group. The peak torque and average power were measured and analysed using Biodex system 4 before the treatment, after 2 weeks, 4 weeks. Results : As a result, russians currents and low frequency stimulation increased significantly average power and peak torque with the lapse of time. However, there were not significant differences of the average power and peak torque between the groups in all periods. Conclusion : In conclusion, russians currents and low frequency stimulation had no differences in the increase of muscle strength.

Improvement of Torque Characteristics of a Rotatory Two-Phase Transverse Flux Machine Optimizing the shape of Rotor Pole (자석 형상 최적화를 통한 축방향 이상 횡자속형 전동기의 토크 특성 향상에 관한 연구)

  • Ahn, Hee-Tae;Jang, Gun-Hee;Chang, Jung-Hwan;Chung, Shi-Uk;Kang, Do-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.286-292
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    • 2008
  • Transverse flux machine (TFM) has been developed to drive a machine of large input power at low-speed. However, it has complicated structure and large torque ripple due to its inherent structure In this paper the characteristics of torque of a rotatory two-phase TFM are analyzed by using the 3-dimensional finite to element method and optimal design. This research shows that one of the effective design variables is the skew angle of permanent magnet. The skew angles of permanent magnet are optimized by using a Progressive Quadratic Response Surface Method (PQRSM). It also shows that the proposed optimal skew magnet not only increases average torque but also decreases torque ripple of a rotatory two-phase TFM.

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Study of Permanent Magnet Optimum Design on the PMa-SynRM (PMa-SynRM에서 영구자석 배치에 따른 최적 설계 연구)

  • Kim, Su-Yong;Kim, Won-Ho;Im, Jong-Bin;Lee, Ki-Deok;Ryu, Gwang-Hyeon;Lee, Ju
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.768_769
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    • 2009
  • Average torque of PMa-SynRM(Permanent Magnet-assisted Synchronous Reluctance Motor) is changed by magnet form inserted to the barrier. Because the magnet form influences to the magnet-torque and reluctance torque. Therefore, this paper present a suitable permanent magnet form design for maximum torque when the magnet quantites are always fixed. And each motor characteristic such as average torque, torque ripple, cogging torque and back-EMF are analyzed by FEM(Finite Element Method) for optimal design..

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Improvement of Torque Characteristics of a Rotatory Two-phase Transverse Flux Machine Optimizing the Shape of Rotor Pole (자석 형상 최적화를 통한 축방향 이상 횡자속형 전동기의 토크 특성 향상에 관한 연구)

  • Ahn, Hee-Tae;Jang, Gun-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.10
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    • pp.1003-1011
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    • 2009
  • Transverse flux machine(TFM) has been developed to drive a machine of large input power at low-speed. However, it has complicated structure and large torque ripple due to its inherent structure. In this paper the characteristics of torque of a rotatory two-phase TFM are analyzed by using the 3-dimensional finite element method and optimal design. This research shows that one of the effective design variables is the skew angle of permanent magnet. The skew angles of permanent magnet are optimized by using a genetic algorithm. It also shows that the proposed optimal skew magnet not only increases average torque but also decreases torque ripple of a rotatory two-phase TFM.

An Asymmetric Rotor Design of Interior Permanent Magnet Synchronous Motor for Improving Torque Performance

  • Yoon, Myung-Hwan;Kim, Doo-Young;Kim, Sung-Il;Hong, Jung-Pyo
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.387-393
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    • 2015
  • Torque ripple is necessarily generated in interior permanent magnet synchronous motors (IPMSMs) due to the non-sinusoidal distribution of flux density in the air gap and the magnetic reluctance by stator slots. This paper deals with an asymmetric rotor shape to reduce torque ripple which can make sinusoidal flux density distribution in the air gap. Meanwhile the average torque is relatively increased by the asymmetric rotor. Response surface method (RSM) is applied to find the optimum position of the permanent magnets for the IMPSM with improved torque performance. Consequently, an asymmetric structure is the result of RSM and the structure has disadvantage of a mechanical stiffness. Finally, the performance of suggested shape is verified by finite element analysis and structural analysis is conducted for the mechanical stiffness.

Study of Permanent Magnet Optimum Design on the Permanent Magnet assisted-Synchronous Reluctance Motor

  • Lee, Hyung-Woo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.11
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    • pp.28-33
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    • 2009
  • Average torque of PMa-SynRM(Permanent Magnet-assisted Synchronous Reluctance Motor) is changed by magnet form inserted to the barrier. Because the magnet structure inserted to the barrier influences to the magnet-torque and reluctance torque. Therefore, this paper present a suitable permanent magnet form design for maximum torque when the magnet quantites are always fixed. And each motor characteristic such as average torque, torque ripple, cogging torque and back-EMF are analyzed by FEM(Finite Element Method) for optimal design.

Immersion Ration Estimation Using Spindle Motor Current during Milling (밀링공정에서 주축모터전류를 이용한 절입비 추정)

  • Cho, K.-J.;Kwon, W.-T.;Cho, D.-W.;Chu, C.-N.
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.12
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    • pp.222-229
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    • 1999
  • In order to regulate cutting torque in milling, monitoring system should be set to a certain threshold. Radial immersion ratio is an important factor to determine the threshold and should be estimated in process for automatic regulation. In this paper, on-line estimation of the radial immersion ration using spindle motor current in face milling is presented. When a tooth finishes sweeping, a sudden drop of cutting torque occurs. This torque drop is equal to cutting torque acting on a single tooth at the swept angle of cut and can be acquired form cutting torque signals. Average cutting torque per revolution can also be calculate form cutting torque signals. The ratio of cutting torque acting on a single tooth at the swept angle of cut to the average cutting torque per revolution is a function of the swept angle of cut and the number of teeth. Using the magnitude of this ratio, the radial immersion ratio is estimated. Identical algorithm is adopted to estimate the immersion ratio based on the spindle motor current measurement. The experiments performed under different cutting conditions show that the radial immersion ratio can be estimated within 10% error range by the proposed method using spindle motor current.

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In-process Immersion Ratio Estimation Using Spindle Motor Current during Face Milling (정면밀링공정중 추축모터전류를 이용한 절입비의 실시간 추정)

  • 조규진;오영탁;권원태;주종남
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.6
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    • pp.57-64
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    • 2000
  • In order to regulate cutting torque in milling, monitoring system should be set to a certain threshold. Radial immersion ratio is an important factor to determine the threshold and should be estimated in process for automatic regulation. In this paper, on-line estimation of the radial immersion ratio using spindle motor current in face milling is presented. When a tooth finishes sweeping, a sudden drop of cutting torque occurs. This torque drop is equal to the cutting torque acting on a single tooth at the swept angle of cut and can be acquired from cutting torque signals. Average cutting torque per revolution can also be calculated from cutting torque signals. The ratio of cutting torque acting on a single tooth at the swept angle of cut to the average cutting torque per revolution is a function of the swept angle of cut and the number of teeth. Using the magnitude of this ratio, the radial immersion ratio is estimated. Identical algorithm is adopted to estimate the immersion ratio based on the spindle motor current measurement. The experiments performed under different cutting conditions show that the radial immersion ratio can be estimated within 10% error range by the proposed method using spindle motor current. Varying immersion ratio is also estimated well using the presented algorithm.

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