• Journal of information and communication convergence engineering
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• 제8권5호
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• pp.591-594
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• 2010

Control devices perform various works for us in many areas. The device is being utilized for precision movement of certain object. In as much as control devices are activated by means of motors, motor control is important.[1][2] Generally, servo motors capable of precision control are more frequently used than DC motors. Use of 3 motors allows 3- way movement. Medical controllers for surgical operation require high precision. [3][4][5][6] AX-12, a servo motor can realize various types of movement. AX-12 can be easily manufactured in the form of a robotic arm and has features that MCU and its peripheral circuits are simple. For precision movement, 3 motors can be controlled by use of a single joystick and 2 buttons, with movement angles being adjusted by having preset values in the program changed.[7][8] By virtue of this study, we have realized small precision robotic arm system utilizing single joystick and 2 buttons. This system can control the robotic arm in the direction desired by the user. The system has been designed such that a joystick controls 2 motors with the remaining motor being controlled by a button. Single MCU is tasked with both control and movement.[9] We have shown precision robotic arm system in the Figure contained in the conclusion part and made reference to results of analysis in there. It has also been demonstrated that the system can be utilized in the industry.[8]

• 제어로봇시스템학회논문지
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• 제11권7호
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• pp.602-608
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• 2005

In the virtual environment, force feedback to the human operator makes virtual experiences more realistic. To ensure the safe operation and enhance the haptic feeling, stability should be guaranteed. Both motors and brakes are commonly used for haptic devices. Motors can generate a torque in any direction, but they can make the system active during operation, thus leading to instability. Brakes can generate a torque only against their rotation, but they dissipate energy during operation, which makes the system intrinsically stable. Consequently, motors and brakes are complementing each other. In this research, a two degree-of-freedom (DOF) haptic device equipped with motors and brakes has been developed to provide better haptic effects. Each DOF is actuated by a pair of motor and brake. Modeling of the environment and the control method are needed to utilize both actuators. Among various haptic effects, contact with the virtual wall, representation of friction and representation of plastic deformation have been investigated extensively in this paper. It is shown that the hybrid haptic device is more suited to some applications than the motor-based haptic device.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 후기공동학술대회 논문집
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• pp.73-73
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• 2011

In fact, asynchronous motors are used widely. Asynchronous motors which have large power (compared to the source supplies) is needed to start them in various methods. The theory of application reduced voltage to motor's stator or variable resistor fed rotor for the purpose of altering the motor's torque and power consumption characteristics is an idea that has existed for many years. These concepts have flourished mainly due to the need to limit torque and limited generator/power distribution capabilities. However, how can know exactly the time of switching steps with different types of motors as well as load characteristics is very difficult. This paper focuses on the design and development mathematical models of motor[1][2], load, ACB, asynchronous machine and then is implemented in SIMULINK in order to calculate this time, special on ships where power generation station is limited. The simulation results are both compared and discussed in detail so that it can apply to conclude the most suitable and applicable starting time for new system with various motors and load.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.338-345
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• 2013

Induction motors play an increasing importance in industrial manufacturing. Therefore, the state monitoring systems also have been considering as the key in dealing with their negative effect by absorbing faulty symptoms in motors. There are numerous proposed systems in literature, in which, several kinds of signals are utilized as the input. To solve the multiple faults problem of induction motors, like the proposed system, the vibration signals is good candidate. In this study, a new signal processing scheme was utilized, which transforms the time domain vibration signal into the spatial domain as an image. Then the spatial features of converted image then have been extracted by applying the dominant neighbourhood structure (DNS) algorithm. In addition, these feature vectors were evaluated to obtain the fruitful dimensions, which support to discriminate between states of motors. Because of reliability, the conventional one-against-all (OAA) multi-class support vector machines (MCSVM) have been utilized in the proposed system as classifier module. Even though examined in severity levels of signal-to-noise ratio (SNR), up to 15dB, the proposed system still reliable in term of two criteria: true positive (TF) and false positive (FP). Furthermore, it also offers better performance than five state-of-the-art systems.

• 한국정밀공학회지
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• 제17권8호
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• pp.60-70
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• 2000

In this paper a 3D position measuring device that finds the 3D position of an arbitarily placed object using a camersa system is introduced. The camera system consists of three stepping motors and a CCD camera and a laser. The viewing direction of the camera is controlled by two stepping motors (pan and tilt motors) and the direction of a laser is also controlled by a stepping motors(laser motor). If an object in a remote place is selected from a live video image the x,y,z coordinates of the object with respect to the reference coordinate system can be obtained by calculating the distance from the camera to the object using a structured light scheme and by obtaining the orientation of the camera that is controlled by two stepping motors. The angles o f stepping motors are controlled by a SGI O2 workstation through a parallel port. The mathematical model of the camera and the distance measuring system are calibrated to calculate an accurate position of the object. This 3D position measuring device can be used to acquire information that is necessary to monitor a remote place.

• 한국철도학회논문집
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• 제13권2호
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• pp.173-178
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• 2010

전기철도는 전력공급시스템과 전기차로 구성되어 있다. 전기철도의 전기차는 대규모의 견인력을 얻을 수 있어 대량수송과 고속운전에 적합하다. 전기차는 모터블록과 견인전동기에 의해서 구동되며, 지령속도에 따라 모터블록에서 견인전동기에 전력을 공급하여 속도가 제어된다. 전기차의 속도제어는 모터블록과 견인전동기의 최소 에너지로 속도를 제어하는 것이 목표이다. 최근의 견인전동기는 직류 및 동기전동기에서 유도전동기를 사용하고 있다. 대부분의 유도전동기는 벡터제어기법을 사용하여 유도전동기의 속도를 제어한다. 본 논문에서는 유도전동기의 벡터제어기법을 이용하여 유도전동기의 속도를 제어하였다. Simulink를 이용하여 제어시스템을 모델링하고, PI 제어기와 Hysteresis 제어기를 이용하여 펄스를 제어하여 전동기의 속도를 제어하였다. 실시간 제어를 위해 IGBT 인버터를 사용하였고, 유도전동기 구동실험에 의해 시스템 성능을 입증하였다.

• 전력전자학회논문지
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• 제8권6호
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• pp.534-542
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• 2003

현재 차량에 사용되는 전동기는 대부분 직류전동기로, 12V또는 24V 밧데리 전원으로 구동되는 엔진 냉각 팬, 오일 펌프 및 공조시스템 등에 적용되고 있다 그러나 직류전동기의 경우 효율, 수명, 내구성에 취약한 단점을 지니고 있다. 따라서, 자동차용 전동기로써 구조가 간단하고 내구성이 우수한 SRM(Switched Reluctance Motor)의 관심이 매우 높아지고 있다. SRM을 차량용으로 사용하기 위해서는 고성능 제어와 12V 전윈 구동에 모두 우수한 성능을 갖는 구동 컨버터의 선정이 매우 중요하다. 여러 종류의 구동 컨버터는 각각의 장단점을 갖고 있어, 차량에 적용시 여러 가지 제약 조건이 따른다. 일반적으로 많이 사용되고 있는 비대칭 컨버터는 제어성능이 우수하지만, 각 상당 스위치가 가장 많이 필요하고, 상당 2개의 스위치에 의한 전압강하가 발생하는 단점을 지니고 있어, 차량의 12V 전원에는 부적절하다 구조가 간단하고, 스위치 수가 적은 컨버터로 차량의 환경과 여러 요구조건을 충족시킬 수 있는 컨버터로써 Modified C-dump 컨버터와 Energy efficient C-dump 컨버터를 선정하였다. 제안된 두 컨버터를 시뮬레이션과 실험을 통해 비교 검토하여, 차량용 SRM 구동 컨버터로써 Energy efficient C-dump 컨버터의 우수한 제어성능을 증명하였다.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1621-1625
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• 2015

Power quality has always been a concern of power engineers. Certainly an argument can be successfully made that most parts of power engineering have the ultimate objective to improve power quality. AC motors were widely used in industrial and domestic applications. Generally, AC motors were of two types: Induction and Synchronous motors. In motor many parameters like different load cycling, switching, working in hot weather and unbalances creates harmonics which creates major reasons for temperature rise of the motors. Due to high peak value of voltage, harmonics can weaken insulation in cables, windings and capacitors and different electronic components. Higher value of harmonics increase the motor current and decrease the power factor which will reduce the life time of the motor and increase the overall rating of all electrical equipments. Harmonics reduction of all the motors in India will save more power. Coating of windings of the motor with nano fillers will reduce the amount of harmonics in the motor. Based on the previous project works, actions were taken to use the enamel filled with various nano fillers for the coating of the windings of the different AC motors. Ball mill method was used to convert the micro particles of Al₂O₃, SiO₂, TiO₂, ZrO₂ and ZnO into nano particles. SEM, TEM and XRD were used to augment the particle size of the powder. The synthesized nano powders were mixed with the enamel by using ultrasonic vibrator. Then the enamel mixed with the nano fillers was coated to the windings of the several AC motors. Harmonics were measured in terms of various indices like THD, VHD, CHD and DIN by using Harmonic analyzer. There are many other measures and indices to describe power quality, but none is applicable in all cases and in many instances, these indices may hide more than they show. Sometimes power quality indices were used as a basis of comparison and standardization. The efficiency of the motors was increased by 5 – 10 %. The thermal withstanding capacity of the motor was increased by 5º to 15º C. The harmonics of the motors were reduced by 10 – 50%.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.676-678
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• 2002

This paper deals with the design and characteristic analysis of a coreless an axial flux permanent magnet (AFPM) motor. Axial-flux permanent magnet motors prove to be the best candidate for application in electric vehicles (EVs) as direct-drive wheel motors, as in comparison with conventional motors they allow design with higher compactness, lightness and efficiency. Recently, issues regarding environment and the diversification of dependence in oil are watched with keen interest. In this theses, through the simulation of AFPM for low and high torque which has stator in the center and two rotors each side, understand its specialty, with this, make a prototype motor and design drive which can enhance the motors stability in low speed. Especially, specialty of motors torque power output will be mainly talked and based on this, possibility of application in EVs will be inspected by the theoretical study and the test.

• 한국소음진동공학회논문집
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• 제19권8호
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• pp.759-763
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• 2009

The goal of this study is to examine the effect of the number of slots on the noise from BLDC motors. To this end, the number of poles was fixed to 4 and the number of the slots was set to 6 or 24 before noise was measured. Motors having different numbers of slots showed clear differences in noise. Cogging torque, torque ripple and normal local force were interpreted, analyzed and compared to determine the reason for the differences. To determine the cause of the noise, cogging torque, torque ripple and normal local force were calculated, which are representative noise sources of BLDC motors, and FFT was performed to analyze their frequency components(harmonics). The results show that torque ripple and normal local force were the dominant factors in the noise difference between the 6-slot and 24-pole motors. As the number of the slots increased, the number of harmonics decreased and their amplitude of harmonic were reduced, which was attributed as the reason for the noise differences.