• 전기학회논문지P
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• 제61권3호
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• pp.111-115
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• 2012

Generally, brushless DC motor(BLDCM) driving system uses hall sensors or encoders as the mechanical position or speed sensor. It is necessary to achieve the informations of rotor position for driving trapezoidal type brushless DC motor without any position sensor. In this paper, the commutation signals are obtained without the motor neutral voltage, multistage analog filters, A/D converters, or the complex digital phase shift circuits which are indispensable in the conventional sensorless control algorithms. In the proposed method, in stead of detecting the zero crossing point of the nonexcited motor back electromagnetic force for the average motor terminal to neutral voltage, the commutation signal are extracted directly from the specific average line to line voltage with low-pass filter, adder and comparators circuit. In contrast to conventional methods, the neutral voltage is not need; therefore, the commutation signals are insensitive to the common mode noise. Moreover, the complex phase shift circuit can be eliminated. The effectiveness of the proposed method is verified through simulation results.

• 한국자동차공학회논문집
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• 제7권9호
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• pp.75-81
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• 1999

In this paper, the details of electronically controlled CVT is described , which Kia Motor company recently developed in prototype form for hybrid passenger car. This transmission has two input shafts, one for engine and the other for traction motor. The shaft for traction motor is located at rear side which is extended from primary pulley shaft and connected to traction motor through adapter gear box. Adopting two input system, various driving mode is available such as motor alone driving in hybrid vehicle application. As far as electrohydraulic system concerned , this transmission uses two bleed type variable force solenoids for line pressure and ratio control, and one on-off solenoid for clutch control. Another feature for this transmission is that oil pump for transmission is separate from CVT for supplying oil pressure even at vehicle standstill.

• Journal of Astronomy and Space Sciences
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• 제12권1호
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• pp.54-65
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• 1995

We present a design study for a remote sensing camera system which can be operated in multi-channel mode simultaneously with several bandpass filters. The camera control electronics is based on the multiplexed driving concept, which can provide a variety of flexibility for system control parameters and its individual optimisation. The design can also be applied to any system with linear sensors or frame sensors according to its functional requirements. The system design parameters have been examined, including modification of driving waveforms for different types of sensors, waveforms for low-nosie readout circuit in analog chain, and synchronisation with other signal processing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1224-1226
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• 2000

In this paper, load paralleled type FB series resonant inverter of a new novel type is proposed. In the output control method, phase-shift driving signal control method with CVCF introduces. Also by driving signal patterns, the operation principle of the proposed circuit in detail is described and its characteristics are compared on separated ratio(n). According to each the mode in order to the analysis and characteristic evaluation of the circuit state equations are derived and presented using normalized parameter. To verify the theoretical analysis result, experimental results are provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.486-488
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• 1999

This paper shows the form of the optimal solution and how to minimize energy of train driving control using SA(simulated annealing). In this paper, we consider the case where a train is to be driven by automatic operation mode along a non-constant gradient, curve and with speed limits. Using the combinational optimal technique, SA, we constructed optimal train driving strategy.

• 전기학회논문지
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• 제66권5호
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• pp.792-799
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• 2017

The real time unmanned monitoring system of an equipment's internal parts and condition requires the monitoring device to be able to stop at a set location on the rail. However, due to the slip between the driving surface and the roller, an error occurs between the actual position and the command position. In this paper, a method to compensate the position error due to the roller slip is proposed. A proximity sensor located at both ends of the rail detects the starting point and the maximum position pulse, linearly compensating the error between the angular position of the motor and the mechanically fixed starting and maximum position pulse of the rail in forward and reverse direction. Moreover, unlike the existing servo position controller, the motor adopts the position detection method of Hall sensor in BLDC (Brushless DC) and applies an algorithm for low-speed driving so that a stable position control is possible. The proposed rail guided unmanned monitoring system with driving slip compensator was tested to verify the effectiveness.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.403-405
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• 2007

This paper presents the over-modulation strategy and indirect vector control drive of NPC type PWM inverter. NPC inverter has three level phase voltage output.It can perform in high voltage through assembling switching components. It has less harmonics and surge voltage stress at motor terminals than the 2 level inverter in same switching frequency through 3 level voltage. The conventional railway vehicle has used the vector control to MI=0.907 and the slip-frequency control from MI=0.907 to six-step mode. The slip-frequency control has bad motive power and slow torque control response. But vector control has good motive power and can instant torque control. In this paper, output voltage is controlled linearly from linear region to six-step mode by using over-modulation strategy. And NPC inverter is used.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.353-358
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• 2001

Turbo-charging or Super-charging has been used to boost engine power for Gasoline Engine and Diesel Engine came to the world at the beginning of $20^{th}$ century. So far Turbo-Charger has enjoyed a high reputation in the charging filed for its technical advantages such as no demand of operation power from engine and an excellent charging effect in the event of a static operation at mid- and high engine speed. A mechanically driven Super-Charger, however, is now emerging in order to meet demands of the age of speed such as high engine power for a quick change of the driving mode - high engine torque even at low engine speed. Since Super-Charger needs driving power from engine, it cannot improve its relatively higher fuel consumption against that of Turbo-Charger. This negative point is still an obstacle to the wide use of Super-Charger. Super-Charger using Screw-type compressor which has already had a considerable base in air compressor market will fulfill this purpose of improving fuel consumption by minimizing operation power owing to no charging at idling or partially loading driving. This study aims to develop power control concept to achieve this minimization of operation power.

• 제어로봇시스템학회논문지
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• 제11권8호
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• pp.696-703
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• 2005

Since most autonomous mobile robots are powered by a battery, it is important to increase the continuous operating time without recharging. This can be achieved by improving the energy efficiency of a mobile robot, but little research on energy efficiency has been performed. This paper proposes two methods for improving the energy efficiency of an omnidirectional mobile robot.. One method is to realize a continuously variable transmission (CVT) by adopting the mechanism of steerable omnidirectional wheels. The other is the proposed steering algorithm in which wheel arrangement of the mobile robot is continuously adjusted so as to obtain the maximum energy efficiency of the motors during navigation. In addition, new omnidirectional wheels which can be transformed to the conventional wheels depending on the driving conditions are proposed to compensate for less efficient omnidirectional drive mode. Various tests show that motion control of the OMR-SOW works satisfactorily and the proposed steering algorithm for CVT can provide higher energy efficiency than the algorithm using a fixed steering angle. In addition, it is shown that the differential drive mode can give better energy efficiency than the omnidirectional drive mode.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.276-279
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• 1997

When a magnetostrictive material is exposed to a magnetic field, its geometry changes due to a magnetostrictive effect. The magnetostriction is analogous to the piezoeletricity. The displacement of the magnetostrictive material is proportional to the applied current while that of the piezoelectric material is proportional to the voltage. A magnetostrictive material generates large displacement and higher compressive force compared with a piezoeletric material. These advantages provide a good performance of a vibration isolation of a platform. In this work, it is applied to a driving actuator for vibration isolation of a platform. The properties of a magnetostrictive material are investigated in terms of hysteresis and displacement vs. applied current for a various preload. Modeling of the displacement of the vibration isolating actuator is performed as it behaves as a flow source. A sliding mode controller is designed to demonstrate the ability of the magnetostrictive actuator to reduce the vibration at the platform. The effectiveness of the proposed scheme is demonstrated through experimental works. The experimental results of the vibration of the platform axe presented in terms of time response and frequency response.