• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.3
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• pp.403-411
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• 2015

In this paper, we propose a design method for the position and speed controller, current control of a Brushless Direct Current(BLDC) motor using back-stepping design techniques. Further, to stabilize the whole system, and proposes a method for setting the appropriate gain control to improve the tracking performance. By applying the proposed controller to 120W BLDC motors were tested for the ability to follow the position, velocity and current reference. Since the simulation results of the steady state error is within 1%, we were able to show the usefulness of the tracking performance of the proposed controller.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.613-619
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• 2010

The stationary discontinuous armatures that are used in permanent magnet linear synchronous motors (PM-LSMs) have been proposed as a driving source for transportation systems. However, the stationary discontinuous armature PM-LSM contains the outlet edges which always exist as a result of the discontinuous arrangement of the armature. For this reason, the outlet edge cogging force generated between the armature's core and the mover's permanent magnet. This paper contemplated the outlet cogging for ceaccording to 2-D numerical analysis by FEM. We installed the auxiliary pole for in order to minimize the outlet cogging force.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.603-610
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• 2001

Industrial processes are normally operated by skilled humans who have the cumulative and logical information about the system. Fuzzy control has been investigated for many application. Intelligent control approaches based on fuzzy logic have a chance to include human thinking. This paper represents modeling approach based upon operators knowledge without mathematical model of the system and optimize the controller. The experimented system is constructed for sending a ball to the goal position using wind of two DC motors in the predefined path. A vision camera to mimic human eyes detects the ball position. The system used in this experiment could be hardly modeled by mathematical methods and ould not be easily controlled by conventional manners. The controller is designed based on the input-output data and experimental knowledge obtained by trials, and optimized under the predefined performance criterion. And this paper shows the data adaptation for changeable operating condition. When the system is driven in the abnormal condition with unconsidered noise, the new optimal operating parameters could be defined by adjusting membership functions. Thus, this technique could be applied in industrial fields.

• International Journal of Fluid Machinery and Systems
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• v.4 no.2
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• pp.255-261
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• 2011

Recently, as global-scale problems, such as global warming and energy depletion, have attracted attention, the importance of future environmental preservation has been emphasized worldwide, and various measures have been proposed and implemented. This study focuses on water hammer pumps that can effectively use the water hammer phenomenon and allow fluid transport without drive sources, such as electric motors. An understanding of operating conditions of water hammer pumps and an evaluation of their basic hydrodynamic characteristics are significant for determining whether they can be widely used as an energy-saving device in the future. However, conventional studies have not described the pump performance in terms of pump head and flow rate, common measures indicating the performance of pumps. As a first stage for the understanding of water hammer pump performance in comparison to the characteristics of typical turbo pumps, the previous study focused on understanding the basic hydrodynamic characteristics of water hammer pumps and experimentally examined how the hydrodynamic characteristics were affected by the inner diameters of the drive and lift pipes and the angle of the drive pipe. This paper suggests the effect of the air volume in the air chamber that affects the hydrodynamic characteristics and operating conditions of the water hammer pump.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.52-57
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• 2007

This paper presents the design of intelligent moving machine control system using a real time speech recognition. The proposed moving machine control system is composed of four separated module, which are main control module, speech recognition module, servo motor driving module and sensor module. In main control module with microprocessor(80C196KC), one part of the artificial intelligences, fuzzy logic, was applied to the proposed intelligent control system. In order to improve the non-linear characteristic which depend on an user's weight and variable environment, encoder attached to the servo motors was used for feedback control. The proposed system is tested using 9 words lot control of the mobile robot, and the performance of a mobile robot using voice and joystick command is also evaluated.

• Journal of Drive and Control
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• v.16 no.4
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• pp.80-86
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• 2019

The gerotor type device is mainly used in low-speed, high-torque hydraulic motors, and is also applied as a small priming hydraulic pump. For this reason, many studies have been conducted to increase the efficiency of the gerotor pump. In this paper, we propose a new tooth profile design method different from the existing method. The new tooth design is made by modifying the tooth surface using the amplification function of the trajectories, created along the inner and outer rolling circles around the base circle. The shape of the mate rotor is then created using rotation simulation techniques. Such shapes are described as hypercloid. The designed hypercloid rotor is compared with the existing trochoid rotor, and the characteristics of the parameters and volumetric displacements are analyzed. Through this process, the optimum design with larger volumetric displacement than the existing rotor is achieved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1291-1296
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• 2003

This paper deals with efficient diagnostic for stator winding fault of 3-phase induction motor using a current Park's vector approach. This method firstly transforms 3-phase stator current to vertical axis current and horizontal axis current of Park's Vector, and then obtains the each Park's Vector Pattern and detects stator winding fault by comparing to Park's Vector Pattern of healthy and fault. Experimental results, obtained by using induction motor having inter-turn fault of 2, 10, 20 turn, demonstrate the effectiveness of the proposed technique, for detecting the presence of stator winding fault under 25%, 50%, and 100% of full load condition.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.167-172
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• 2017

In this study, high performance patching repair mortars with light weight and sulfuric acid resistance properties were suggested. Their performance estimation were investigated based on KS F 4042 using patching repair mortar with light weight aggregate and soluble polymer of Type I and sulfuric acid resistance mortar of Type II, From these results, it was confirmed that these motors were satisficed and improved by all standard tests of KS F 4042.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.290-295
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• 2005

The incremental encoder has been mostly used to measure the speed and position of the motor. As the output signals of encoder are high frequency digital signals, they have much influence on radiation noises due to switching of the power semiconductor circuits. It is so difficult to suppress the noises with the conventional LPF. In this paper, the hardware digital filter for suppressing noises in the output signals of the encoder signals is developed. As both the clock frequency and counter in the digital filter for encoder are easily adjusted according to the kinds of noises, any noises in the encoder can be entirely eliminated. The performance of the digital filter has been verified by simulation and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.233-240
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• 2005

In this paper, AC electric vehicle propulsion system(Converter/Inverter) using high power semiconductor, IPM is proposed. 2-Parallel operation of two PWM converter is adopted for increasing capacity of system and the harmonic content is eliminated by the phase shaft between two PWM converters switching phase. VVVF inverter control is used a mixed control algorithm, where the vector control strategy at low speed region and slip-frequency control strategy at high speed region. The proposed propulsion system is verified by experimental results with a 1,350kW converter and 1,100kVA inverter with four 210kW traction motors.