• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.36 no.10
• /
• pp.703-712
• /
• 1987

A position detection method for 2 phase bifilar permanent magnet step motors is proposed. The back emfgenerated on 2 phase windings by rotor permanent magnet is calculated using motor terminal voltage and current by analog circuit, and the rotor position output is obtained from tese back emf signals through some logical manipulation circuit. This position detector functionally acts like a 2 channel optical incremental encoder, and it is also shown by experimental results that it works well over wide range of speed or under resonant condition where the rotor rings around the detent position. Its resolution is twice of the number of steps per revolution. Bu software implemented on micro-processor, the reliability of position output is enhanced, detecting and correcting error dut to external and/ or internal noise.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.11 no.5
• /
• pp.65-72
• /
• 2002

In this study, actuator, sensor, guide, power transmission element and control method are considered for ultra-precision positioning apparatus. Through previous process, single plane X-Y stage with ultra-precision positioning is manufactured. Global stage for the purpose of materialization with robust system, is combined by using AC servo motor and ball screw and rolling guide. And ultra-precision positioning system is developed by micro stage with elastic hinge type and piezo element. global servo and micro servo for the purpose of materialization positioning accuracy with nm(nanometer) are controlled simultaneously by using incremental encoder and laser interferometer as displacement measurement sensor. Through previous process, ultra-precision positioning system(100mm stroke and $\pm$ l0nm positioning accuracy) with single plane X-Y stage are materialized.

• Proceedings of the IEEK Conference
• /
• 2003.07a
• /
• pp.97-100
• /
• 2003

The quasi-complementary turbo codes (QCTC) proposed by Kim [1] is used for a fast hybrid ARQ scheme with incremental redundancy and adaptive modulation coding in the cdma2000 1xEV-DV [2]. The QCTC provides various code rates with good performance, a very simple encoder structure, and an inherent channel interleaving. It is shown that the QCTC is a unified scheme of channel coding and channel interleaving. In this paper, we introduce the properties of QCTC and various hybrid ARQ-QCTC schemes for the system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.441-441
• /
• 2012

Noise and vibration performance plays an important role in the development of rotating components, such as engines, drivelines, transmission systems, compressors and pumps. The presence of torsional vibrations and other specific phenomena require the dynamic behaviour of systems and components to be designed accurately in order to avoid comfort and durability related problems. This paper provides an overview of the instrumentation and challenges related to torsional vibration testing. The accuracy and performance of five measurement techniques (high-speed incremental encoder, dual beam laser interferometer, zebra tape, zebra disc, direct pulse measurements with magnetic probe) is investigated by measurements on a Fiat Punto 1.4 liter engine. The potential sources of error are discussed to explain the inaccuracies of each technique.

• Proceedings of the KIPE Conference
• /
• 2003.11a
• /
• pp.127-131
• /
• 2003

This paper describes an initial pole position estimation method of a magnetic pole sensorless permanent magnet synchronous motor(PMSM) with an incremental encoder, The accurate initial pole position is estimated by using an efficient numerical method of Secant Method, which finds either of two zero torque/force positions and then the correct d-axis. It can be simply applicable to both rotary and linear PMSM because it only requires the tuned current controller and the relative position information. The experimental results show the validity of the proposed method with respect to highly accurate pole position estimation under the moderate moving distance and convergence time.

• Proceedings of the KIPE Conference
• /
• 2003.11a
• /
• pp.104-108
• /
• 2003

This paper explained algorithm for a initial pole position estimation of a permanent magnet linear synchronous motor(PMLSM). Generally this motor is considered initial pole position with a position sensor such as incremental encoder for the precise initial pole position estimation and high performance. But this is based on the principle that the initial pole position is accomplished by the PI controller using the maximum values of a position error generated by the new proposed two reference frames and also by using a rated force for input. the proposed algorithm does not utilize the general methods such as impedance ratio, EMF and using the magnetic saturation. In other words, this can be applied without respect to variety of the motor structure because of insensitivity to the motor parameters. In conclusion, simulation results are presented to confirm performance of initial pole position estimation method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1989.10a
• /
• pp.51-58
• /
• 1989

In this paper, the technique of particular harmonics elimination in three-phase PWM Inver-ter output waveform and the method for speed control of a squirrel cage I.M. are introduces. The required switching patterns are determind on personal computer and the results are stored in look-up table in EPROM for controlling the switching of the Inverter devices. In this system, the microprocessor(Intel 8086)computes the actual Motor speed from the pulses generated in a Incremental Encoder, compares the actual speed with the reference speed. And the PI(Proportional-Integral) controller is used to adjust the frequency of the Inverter that feeds the Motor.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.355-358
• /
• 1987

A design of digital position control system with DC Motor is presented. The digital position control system is constructed by power circuits, interface circuits and control circuits using single chip microprocessor (8096). All control functions are implemented on the 16 bit micro-processor requiring only on incremental encoder for speed and position sensing. The control schemes are used by the proportional control for some modifications and braking algorithms. This digital position system offered to the fast response, good steady-state accuracy, flexibility and reliability, Hardware, software features and experimental results of this system are described.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.1 no.1
• /
• pp.12-19
• /
• 1996

The purpose of this paper is the improvement of the speed control characteristics of induction machines suited the low resolution incremental-type encoder in a low speed region. In order to improve the control characteristics in a low speed range, we propose that the instantaneous speed control method by the instantaneous speed detection which is implemented by the disturbance torque observer. Also, in case of the speed control by the instantaneous speed detection, the simple estimation method of the mechanical inertia moment is proposed. We will the carry out the mathematical verification of the proposed theory by the theoretic advisement connected with the convergence relationship of the estimated inertia moment to the real mechanical inertia moment. Computer simulations and experiments by the IGBT inverter adopting DSP is performed to verify the proposed method.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.54 no.1
• /
• pp.26-32
• /
• 2005

Rotor position information is essential in the operation of the switched reluctance motor(SRM) drive for generation the phase current switching signals. When an incremental encoder is used as a rotor position sensor, the initial rotor position can not be detected. Some sensorless rotor position estimation methods also have the same problem. In these systems, to initially align the rotor, the forced alignment method has a delay and reverse rotation before the motor can start. Therefore it can not be acceptable for unidirectional drive systems. So the forced alignment method is not desirable in all drive systems and the research on the SRM drives should be directed to a system without rotor alignment. In this paper, a new detection method of initial rotor position using the rate of change of current is suggested. Firstly, di/dt versus θ/sub R/ reference table, which is the relation between the rate of change of current and rotor position, is generated and then the squared Euclidean distance method is used to estimate the rotor position based on the table. The simulated and experimental results are presented demonstrating the feasibility and accuracy of this method.