• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.4
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• pp.393-401
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• 1995

In this paper, vector analysis on the novel quick torque control of Induction Motors(I.M) based on voltage-controlled type is conducted. It was very difficult to get a step response of torque when the primary voltage was selected as control input of induction motors in conventional quick torque control methods. To solve this problem, the new control method was developed using a new concept of pulse addition which can realize the stepwise torque response of a specified settling time of $\Delta$. The new method was successfully confirmed through DSP(Digital Signal Processor) system-based experiments. However, it was a little difficult to understand the control mechanism intutionally. The purpose of this paper is to provide more understanding about the quick torque control mechanism using the vector analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.2
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• pp.54-63
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• 2022

Among the various industrial robots, palletizing robots have received particular attention because of their higher productivity in accordance with technological progress. When designing a palletizing robot, the main components, such as the servo motors and reducers, should be properly selected to ensure its performance. In this study, a practical method for selecting the motors and reducers of a robot was proposed by performing the dynamic analysis of rigid-flexible multibody systems using ANSYS and ADAMS. In the first step, the links and frames were selected based on the structural analysis results obtained from ANSYS. Subsequently, a modal neutral file (MNF) with information on the flexible body was generated from the links and frames using modal analysis through ANSYS and APDL commands. Through a dynamic analysis of the flexible bodies, the specifications of the major components were finally determined by considering the required torque and power. To verify the effectiveness of the proposed method, the analysis results were compared with those of a rigid-body model. The comparison showed that rigid-flexible multibody dynamic analysis is much more useful than rigid body analysis, particularly for movements heavily influenced by gravity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.5
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• pp.14-21
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• 2002

This paper did the study target for modeling, characteristics analysis and harmonic reduce with the detent torque of a 4 phase and 5 phase hybrid type step motor. For this, it was attempted to derive the mathematical modeling and used the permeance method for flux field analysis. Through this analysis result, this paper acquired the detent torque of this model. To compare the characteristics analysis of phase difference with two motors structure it have obtained to derive the operating detent torque with this model. Here, 5 phase motor has known the harmonic reduce of detail torque compare with 4 phase motor. Also, that has showed to improved the step response. The analysis result has represent the effect that a fundamental component of the permeance distribution produces the average torque and that harmonic components produce the ripple torque.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.748-757
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• 2007

This paper is intended to solve the technical problem that fails in large-capacity induction motor starting due to serious voltage drop during starting period. One induction motor that is established already can reach in steady-state using reactor starting method but the voltage magnitude of PCC (point of common coupling) has dropped down a little. When the same capacity induction motor is installed additionally in the PCC, where the existing induction motor is operating, voltage drop becomes more serious by starting of additional induction motor. As a result, the additional induction motor fails in starting. Therefore, voltage compensation method is proposed so that all of two induction motors can be started completely. First, modeling technique is described in order to implement starting characteristics of large induction motor. And then, this paper proposes strategic starting scheme by proper voltage compensation that use no-load transformer tap control (NLTC) and step voltage regulator (SVR) for starting of two large induction motors successfully and improving the feeding network voltage profile during the starting period. The induction motor discussed in this paper is the pumped induction motor of 2500kVA capacity that is operating by KOWACO (Korea Water Resources Corporation). Modeling and simulation is conducted using PSCAD/EMTDC software.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.2
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• pp.104-115
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• 2002

Core is the main component of inductor. This core should be classified into around 10 classes according to the value of inductance and Q. The coil should be winded with the outer-boundary of this core by different number of turns. Theses kind of precise inductors would be required in the future environment which PCs and communication devices demand more high speed and lower voltage level. It would be quite unefficient that only one core is classified once a time. There, it will be developed so that 10 cores are classified simultaneously. For the operation of classifying 10 cores once in a time, suppose 10 test instruments could be used. In this case, it would take much cost since a test instrument Is expensive. So, by using only one test instrument, it is really more desirable that this system is developed. Each core classified by 10 different classes is to be stored into the corresponding box through the corresponding rubber hose. 10 cores are passed on a serial line and are placed on each testing slot. Here, each core located at each slot is tested, and then the bowl located on the top of a step motor is moved into the corresponding spot by rotating step motor with some angles. Each bowl connected with the corresponding box through rubber hose. Actually 100 hoses are connected, 10 step motors are rotated at 10 different angles, so the size is really so big, the shape of connecting 100 hoses is so complicated. Therefore it is anticipated that the system would be going to be easily out of ordered. In this paper the main purpose is to make several suggestions to be able to work well in these kinds of being affected by the abnormal operation of motors and the flow of cores.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.72-81
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• 2018

In this study, the sinusoidal-wave driving method, six-step driving method, and twelve-step driving method, which can be used in an inverter for permanent-magnet synchronous motors, were simulated, and the results were compared to review their operating performance. These driving methods were classified according to the electrical conduction angle and phase current of the motor. Conventionally, only the transition control technique between the sinusoidal-wave driving method and six-step driving method was studied for the efficiency of the inverter. In this paper, however, comparative analysis was focused on a variety of transition control applications to use the advantages of each driving method. For this purpose, computer simulations for these driving methods were carried out to obtain the motor torque, speed control characteristics, and THD of the motor phase currents. As a result, the sinusoidal-wave driving method showed the best performance in all respects. The six-step driving method has better speed control characteristics than the twelve-step driving method, and the twelve-step driving method has a lower THD of the motor phase currents than the six-step driving method.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.6
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• pp.389-395
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• 2019

This paper presents the sensorless position control of an auxiliary scaffolding step system for vehicles using DC motors. The designed auxiliary scaffolding step has a mechanical protector at the stop position. At this position, the scaffolding is forcibly stopped by the mechanical protector, and the motor current is dramatically increased to the stall current of the DC motor, thereby increasing the electrical damage. In this study, the estimated back EMF- and current model-based observers are proposed to estimate the motor speed and stop position. A simple V/F acceleration voltage pattern is used to operate the auxiliary scaffolding system. The estimated moving position is adopted to determine the stop position of the DC motor with the load current state. The operating current of the DC motor can be reduced by the estimated moving position and V/F acceleration pattern. At the stop position, the proposed sensorless position controller can smoothly stop the DC motor with the estimated moving position and reduced load current without any mechanical and electrical stress from the stall current from the mechanical protector. The proposed control scheme is verified by the comparison of simulations and experiments.

• Transactions on Control, Automation and Systems Engineering
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• v.3 no.4
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• pp.223-228
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• 2001

We have been developed an intelligent mobile robot with an artificial olfactory function to recognize odours and to track odour source location. This mobile robot also has ben installed an engine for speech recognition and synthesis and is controlled by wireless communication. An artificial olfactory system based on array of 7 gas sensors has been installed in the mobile robot for odour recognition, and 11 gas sensors also are located in the obttom of robot to track odour sources. 3 optical sensors are also in cluded in the intelligent mobile robot, which is driven by 2 D. C. motors, for clash avoidance in a way of direction toward an odour source. Throughout the experimental trails, it is confirmed that the intelligent mobile robot is capable of not only the odour recognition using artificial neural network algorithm, but also the tracking odour source using the step-by-step approach method. The preliminary results are promising that intelligent mobile robot, which has been developed, is applicable to service robot system for environmental monitoring, localization of odour source, odour tracking of hazardous areas etc.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.81-87
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• 2020

A stable rotational-to-linear motion transformation structure using a driving mechanism with 2 degrees of freedom was developed for an orthogonal mechanism to prevent the interference of each axis in 2D motion. In this mechanism, a step motor was used for precise position control. This structure was developed to maneuver workparts in micro particle blast machining experiments. To determine the real-time performance of micro particle blast machining, the control, input, and output were operated simultaneously and precise position control was implemented, using a timer interrupt with multiple execution codes. The two step motors obtained precise position control by removing backlash with a ball-screw mechanism. The device has menu-type control codes for user-friendliness, and real-time sequence control was simultaneously adopted for user control input.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.92-99
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• 2006

The swirl ratio of a charge in the cylinder was estimated by calculating the ratio of the rotary speed of charge which could be simulated from the rotary speed of paddle in the swirl measurement apparatus, to the engine speed which could be calculated by measuring intake air flow rate. The automation of the swirl ratio measurement for cylinder head was achieved by controling both valve lift in cylinder head and a suction pressure of surge tank using two step-motors. The number of measurement position for calculating mean swirl ratio was varied by adjusting the interval of valve lift. The mean swirl ratio with varying the number of measurement position showed nearly constant value. Two measurement methods for measuring the swirl ratio were compared, one was to control the suction pressure of the surge tank with PID (proportional, integral, differential) mode with by-pass valve controlled by the step motor and the other did not control the surge tank pressure by fixing the by-pass valve. The difference of the mean swirl ratio between the two measurement methods showed nearly constant value with varying the number of measurement position. This means that the w/o PID control method could be preferred to the PID control method which has been used, due to the simpleness of the swirl measurement.