• Title/Summary/Keyword: Shape control

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Technology of profile and shape control in the 6-high Tandem cold Rolling Mill (연속 6단 냉간압연기에서 Profile 및 형상제어 압연기술)

  • 박해두
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.08a
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    • pp.142-149
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    • 1999
  • Strip profile and shape control is one of the most important technologies in cold mill, especially for ultra-thin and wide cold strip. The 6-high mills, both of HCMW and UCMW mill, are known to be very effective for the shape controllability. The optimized values of these factors for set-up scheduling were analyzed and found that excellent strip control would be possible by controlling the combination of the influencing factors according to hot coil profile. The important considerations for operation were discussed for individual stand.

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Design and implementation of fast output sampling feedback control for shape memory alloy actuated structures

  • Dhanalakshmi, K.;Umapathy, M.;Ezhilarasi, D.;Bandyopadhyay, B.
    • Smart Structures and Systems
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    • v.8 no.4
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    • pp.367-384
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    • 2011
  • This paper presents the design and experimental evaluation of fast output sampling feedback controller to minimize structural vibration of a cantilever beam using Shape Memory Alloy (SMA) wires as control actuators and piezoceramics as sensor and disturbance actuator. Linear dynamic models of the smart cantilever beam are obtained using online recursive least square parameter estimation. A digital control system that consists of $Simulink^{TM}$ modeling software and dSPACE DS1104 controller board is used for identification and control. The effectiveness of the controller is shown through simulation and experimentation by exciting the structure at resonance.

Position Control of Shape Memory Alloy Actuators Using Self Tuning Fuzzy PID Controller

  • Ahn Kyoung-Kwan;Nguyen Bao Kha
    • International Journal of Control, Automation, and Systems
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    • v.4 no.6
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    • pp.756-762
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    • 2006
  • Shape Memory Alloy(SMA) actuators, which have the ability to return to a predetermined shape when heated, have many potential applications such as aeronautics, surgical tools, robotics and so on. Although the conventional PID controller can be used with slow response systems, there has been limited success in precise motion control of SMA actuators, since the systems are disturbed by unknown factors beside their inherent nonlinear hysteresis and changes in the surrounding environment of the systems. This paper presents a new development of a SMA position control system by using a self-tuning fuzzy PID controller. This control algorithm is used by tuning the parameters of the PID controller thereby integrating fuzzy inference and producing a fuzzy adaptive PID controller, which can then be used to improve the control performance of nonlinear systems. The experimental results of position control of SMA actuators using conventional and self-tuning fuzzy PID controllers are both included in this paper.

A Study on Body Image Perception and Obesity Stress by the Degree of Obesity in College Women

  • Lee, Ji-Eun;Kim, Jung-Hyun;Jung, In-Kyung
    • Preventive Nutrition and Food Science
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    • v.14 no.2
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    • pp.116-122
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    • 2009
  • The principal objective of this study was to assess the weight control behavior, body shape satisfaction, and obesity stress depending on the degree of obesity in college students who applied for a weight control program. The average BMI of the participants was $21.4\;kg/m^2$ which was in the normal range, and 76.3% of the participants were of normal body weight. Ideal BMI in this participant was $18.1\;kg/m^2$, which is in the underweight range. In terms of body perception, participants generally overestimated their body weight. The overweight and normal weight groups were less satisfied with their body shape than was the underweight group. The overweight group also expressed fears of showing their bodies to others. Additionally, the overweight and normal groups exhibited higher obesity stress than the underweight group. 97.0% of participants were interested in weight control as a way to improve their appearance. They usually obtained their weight control information from the internet and mass media. More than 80% of participants had weight control experience, having undergone weight control attempts for duration of less than a month. However, after the discontinuation of weight control efforts, these participants regained the weight. As a consequence, they were generally unsatisfied with the outcomes of weight control programs. This study demonstrated that the college women who had applied for the weight control program were unsatisfied with their body shape owing to distorted notions of the ideal body shape, and these women had generally undertaken frequent efforts to control their body weights. These results underline the importance of educating college-aged women on proper body perception and the maintenance of healthy body weight and shape.

Flatness Control System of the Hot Strip by Using Tension Profile between Stands (스탠드간 장력프로파일을 이용한 열연판 평탄도 제어시스템)

  • 홍완기;이준정
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.08a
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    • pp.27-36
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    • 1999
  • To have high flatness quality of hot rolled strip in the hot strip finishing mill train, a new inter-stand tension profile measuring device of segmented looper roll type(coined as Flatness Sensing Inter-stand Looper, FlatSIL) and a new flatness control system have been developed in this study. The device measures the strip tension profile across the strip width and informs the strip wave pattern to new flatness control system where work roll bending mode to relieve the strip wave is determined. The existing automatic shape control system which uses laser type shape-meter installed at the outlet of the last finishing mill stand strip tension between down coiler and last finishig mill since the latent wave concealed by the strip tension between down coiler and last finishing mill stand cannot be measured by the laser distance-meter. Thus the existing shape control system is not able to control the flatness through the full strip length. The new flatness control system, however, works for full strip length during strip rolling as far as the tension profile measuring device and work roll bender are on. With the new flatness control system, work roll bender is automatically controller to minimize the latent wave of the running strip and the flatness quality as well as strip travelling stability has been noticeably improved from strip head through body to tail.

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The Decision of the Optimal Shape of Inductive Loop for Real-Time Traffic Signal Control (실시간 교통신호제어를 위한 루프 검지기의 최적형태결정에 관한 연구)

  • 오영태;이철기
    • Journal of Korean Society of Transportation
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    • v.13 no.3
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    • pp.67-86
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    • 1995
  • It requires the detector system which can collect highly reliable traffic data in order to perform the real-time traffic signal control. This study is to decide the optimal shape of inductive loop for the real-time traffic signal control .This loop is located at the stopline in the signalized intersection for DS(Degree of Saturation) control. In order to find out the optimal shape of loop, 6types of experiments were performed . The results of the basic experiments of loops are as follows ; -the optimal number of turns for loop is 3 turns. -the impedance values of the loop detectors are similar to that of NEMA standards -the 1.8${\times}$4.5M loop is excellent for sensitivity in actual detection range of car length comparing to other shape of inductive loops. At the experimental of establishments of the optimal loop shape, it found that 1.8 4.5M loop has the highest values of $\DeltaL$ comparing to other types of loops, It means that the range of Lead-in cable length of this loop. And this loop is highly reliable in occpupancy time. Conclusivley, the 1.8${\times}$4.5M inductive loop is the optimal solution as a stop line loop detector for real -time traffic signal control.

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Spring Length Effect on the Flow Capacity of automatic Flow-Temperature Control Valve (자동 정유량 온도조절밸브의 스프링 길이가 밸브 용량에 미치는 영향)

  • Yoo, Seon-Hak;Kang, Seung-Duk;Park, Kyung-Am
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.174-177
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    • 2003
  • The automatic temperature control valve is used to control the flow rate of heating water in the large apartment complex and buildings. It is important to have simillar heating flow rate in the apartments, even though the apartment is top or bottom floors. To achieve those purposes, the automatic flow-temperature control valve was developed. The perfromance of this control valve is effected by the catridge shape and spring length. The flow capacity of this control valve is obtained with the different shape of catridges and with change of spring length.

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Active shape control of a cantilever by resistively interconnected piezoelectric patches

  • Schoeftner, J.;Buchberger, G.
    • Smart Structures and Systems
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    • v.12 no.5
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    • pp.501-521
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    • 2013
  • This paper is concerned with static and dynamic shape control of a laminated Bernoulli-Euler beam hosting a uniformly distributed array of resistively interconnected piezoelectric patches. We present an analytical one-dimensional model for a laminated piezoelectric beam with material discontinuities within the framework of Bernoulli-Euler and extent the model by a network of resistors which are connected to several piezoelectric patch actuators. The voltage of only one piezoelectric patch is prescribed: we answer the question how to design the interconnected resistive electric network in order to annihilate lateral vibrations of a cantilever. As a practical example, a cantilever with eight patch actuators under the influence of a tip-force is studied. It is found that the deflection at eight arbitrary points along the beam axis may be controlled independently, if the local action of the piezoelectric patches is equal in magnitude, but opposite in sign, to the external load. This is achieved by the proper design of the resistive network and a suitable choice of the input voltage signal. The validity of our method is exact in the static case for a Bernoulli-Euler beam, but it also gives satisfactory results at higher frequencies and for transient excitations. As long as a certain non-dimensional parameter, involving the number of the piezoelectric patches, the sum of the resistances in the electric network and the excitation frequency, is small, the proposed shape control method is approximately fulfilled for dynamic load excitations. We evaluate the feasibility of the proposed shape control method with a more refined model, by comparing the results of our one-dimensional calculations based on the extended Bernoulli-Euler equations to three-dimensional electromechanically coupled finite element results in ANSYS 12.0. The results with the simple Bernoulli-Euler model agree well with the three-dimensional finite element results.

Discontinuous Surface Profile measurement using Wavelength Scanning Interferometer(WSI)

  • Kang, Chul-Goo;Cho, Hyoung-Suck;Lee, Jae-Yong;Hahn, Jae-Won
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.127.4-127
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    • 2001
  • Inspection and shape measurement of three-dimensional objects are widely needed in industries for quality monitoring and control. A number of visual or optical technologies have been successfully applied to measure three dimensional surfaces. Especially, the shape measurement using an interferometric principle becomes a successful methodology. However, those conventional interferometric methods to measure surface profile have an inherent shortcoming, namely 2∏ ambiguity problem. The problem inevitably happens when the object to be measured has discontinuous shape due to the repetition of interferometric signal with phase period of 2∏. Therefore, in this paper, we choose as a shape measuring method, ...

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