• 대한기계학회논문집A
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• 제25권9호
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• pp.1468-1474
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• 2001

In this paper, a new fuzzy-logic anti-swing control scheme is proposed for a three-dimensional overhead crane. The proposed control consists of a position servo control and a fuzzy-logic control. The position servo control is used to control the trolley position and rope length, and the fuzzy-logic control is used to suppress load swing. The proposed control guarantees not only prompt suppression of load swing but also accurate control of trolley position and rope length for the simultaneous travel, traverse, and hoisting motions of the crane. The effectiveness of the proposed control is shown by experiments with a prototype three-dimensional overhead crane.

• Journal of international Conference on Electrical Machines and Systems
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• 제1권1호
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• pp.84-90
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• 2012

Various methods have been proposed to identify the flux position in an interior permanent magnet synchronous motor (IPMSM) without the use of mechanical sensors. To achieve this, a method that uses both the back electromotive force (EMF) and the saliency to identify the flux position in the IPMSM without the injection of high-frequency components at low speeds has been reported. This method was then extended in order to drive the motor with no load to a light load. We propose a combination of these methods with different proportional-integral (PI) controllers for controlling $di_{dest}$/dt and $di_{qest}$/dt. We also introduce compensation values $F_L$ and $F_H$ to reduce the position error when the estimation rule is being selected.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 정기총회 및 학술대회 전문대학교육위원
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• pp.95-97
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• 2008

The binary observer estimates the rotor position and rotor flux with alleviation of the high-frequency chattering, and retains the benefits achieved in the conventional sliding observer, such as robustness to parameter and disturbance variations. The position sensorless control of SRM under the load and inductance variation is verified by the experimental results.

• 한국전문물리치료학회지
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• 제25권2호
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• pp.71-77
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• 2018

Background: There are insufficient objective or quantitative evidence for the better intervention to improve proprioception particularly for the application of external load. There are conflicting opinions whether the external load is effective for proprioception improvement or not. Objects: The purpose of this study was to investigate effects of external load on proprioception of shoulder joint quantitatively using 3D motion capture system. Methods: Nine healthy adults joined for this study. They were asked to perform scapular plane abduction motion with attaching reflective markers on the trunk and upper limb. The 3D positions of finger marker, while they performed the same task with and without external load, were recorded and analyzed. Results: All participants showed decreased variable errors in the vertical direction when the external load was applied (p<.02). Even though other directions (y, z) and absolute errors increased, they did not have statistical significances. Conclusion: Based on this study results, the external load application would be effective for shoulder joint position sense improvement.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권3호
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• pp.188-195
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• 2004

This paper presents neural load torque observer that is used to deadbeat load torque observer and gain compensation by parameter estimator As a result, the response of the PMSM(permanent magnet synchronous motor) follows that nominal plant. The load torque compensation method is composed of a neural deadbeat observer To reduce the noise effect, the post-filter implemented by MA(moving average) process, is adopted. The parameter compensator with RLSM (recursive least square method) parameter estimator is adopted to increase the performance of the load torque observer and main controller The parameter estimator is combined with a high performance neural load torque observer to resolve the problems. The neural network is trained in on-line phases and it is composed by a feed forward recall and error back-propagation training. During the normal operation, the input-output response is sampled and the weighting value is trained multi-times by error back-propagation method at each sample period to accommodate the possible variations in the parameters or load torque. As a result, the proposed control system has a robust and precise system against the load torque and the Parameter variation. A stability and usefulness are verified by computer simulation and experiment.

• Smart Structures and Systems
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• 제12권6호
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• pp.661-678
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• 2013

In this paper, a wireless sensing system for structural field evaluation and rating of bridges is presented. The system uses a wireless platform integrated with traditional analogue sensors including strain gages and accelerometers along with the operating software. A wireless vehicle position indicator is developed using a tri-axial accelerometer node that is mounted on the test vehicle, and was used for identifying the moving truck position during load testing. The developed software is capable of calculating the theoretical bridge rating factors based on AASHTO Load and Resistance Factor Rating specifications, and automatically produces the field adjustment factor through load testing data. The sensing system along with its application in bridge deck rating was successfully demonstrated on the Evansville Bridge in West Virginia. A finite element model was conducted for the test bridge, and was used to calculate the load distribution factors of the bridge deck after verifying its results using field data. A confirmation field test was conducted on the same bridge and its results varied by only 3% from the first test. The proposed wireless sensing system proved to be a reliable tool that overcomes multiple drawbacks of conventional wired sensing platforms designed for structural load evaluation of bridges.

• 한국생산제조학회지
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• 제25권2호
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• pp.97-104
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• 2016

In this study, the qualitative effects of the positional error of carrier pin holes on the planet load sharing characteristics of the three-point suspension gearbox of wind turbines were investigated experimentally. A 35-kW gearbox comprising two planetary gear stages and a parallel gear stage and size one-fourth of that of a 2-MW three-point suspension gearbox was used as the test gearbox. The strain gauges attached to the ring gear teeth of the input planetary gear stage were used for the purpose of this study. The applied loading conditions were 50%, 75%, and 100% of the rated torque, and the mesh load factor was used as the load sharing index. The experimental results indicated that both the magnitude and direction of the positional error of pin holes had a significant effect on the planet load sharing characteristics of the three-point suspension gearbox. In addition, an increase in the applied torque results in uniform load sharing.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.289-293
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• 2004

The sensorless speed control technique for BLDCM using digital IP control is proposed in this paper for advanced speed characteristic which is robust for loads. The sensorless drive of BLDCM using terminal voltages is affected by load or speed because it uses analog filters to estimate the rotor position. For this reason, the robust speed controller with the accurate rotor position estimator is needed for sensorless control which is robust to load and insensitive to motor parameters. The constant speeds robust to load variation and the stable sensorless control of BLDCM robust to the increase or decrease of speed with constant load are implemented using digital IP control in this paper. The validity to these is established with experimentation.

• Structural Engineering and Mechanics
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• 제4권2호
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• pp.163-176
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• 1996

The tension and compression buckling behaviour of a square plate with localized zones of damage and subjected to non-uniform loading is studied using a finite element analysis. The influence of parameters such as position of damage, extent of damage, size of damage and position of load on instability behaviour are discussed. The dynamic behaviour for certain load and damage parameters are also presented. It is observed that the presence of damage has a marked effect on the static buckling load and natural frequency of the plate.

• 한국기계가공학회지
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• 제2권4호
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• pp.46-52
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• 2003

For position control of electro-hydraulic servo system, single rod cylinders and double rod cylinders are used. Single rod cylinders have simple structure for manufacturing but different volume ratio of two sides induce to non-linearity in process of then mathematical modeling. So only with conventional PID control method it is difficult to control single rod cylinders precisely. For mole precise position control of single rod cylinders, a controller which is inserted a velocity feedback PID controller and MRAC controller are proposed. With experiment control performances of three control methods are compared. In case of experiment, for external varying load to the system, a hydraulic cylinder and a pressure control valve are used. In conclusion a MRAC is considered a suitable control method for external varying load.