• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.659-666
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• 2006

Servo-motors are used as key components of automated system by performing precise motion control as accurate positioning and accurate speed regulation in response to the commands from computers and sensors. Especially, the linear brushless servo-motors have numerous advantages over the rotary servo motors which have connection with the friction induced transfer mechanism such as ball screws, timing belts, rack/pinion. This paper proposes an estimation method of unknown motor system parameters using the informations from the sinusoidal driving type linear brushless DC motor dynamics and outputs. The estimated parameters can be used to tune the controller gain and a disturbance observer. In order to meet this purpose high performance Digital Signal Processor, TMS320F240, designed originally for implementation of a Field Oriented Control(FOC) technology is adopted as a controller of the liner BLDC servo motor. Having A/D converters, PWM generators, rich I/O port internally, this servo motor application specific DSP play an important role in servo motor controller. This linear BLDC servo motor system also contains IPM(Intelligent Power Module) driver and hail sensor type current sensor module, photocoupler module for isolation of gate signals and fault signals.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.6
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• pp.500-509
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• 2007

In this paper, we propose a novel pc-based 8-channel USB interface digital multi-controller (DMC) has capacity to be able to adjust ultrasonic motor's (USM's) the parameters-frequency, amplitude, phase difference using FPGA. The proposed DMC can control parameters directly by digital logic through a FPGA. Since it has counter circuit for rotary encoder to measure position and velocity of USM, the other separate circuits are unnecessary. Therefore, it could reduce the size of controller and the production cost. Finally, to verify the performance of proposed DMC, we tested the speed characteristic of two types USM with no-load as adjusting the parameters.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.613-627
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• 2019

The purpose of this study was to design a powertrain for a 78 kW AWD (all wheel drive) electric tractor by analyzing the combination of various reduction gear ratios on a commercial motor using data from actual agricultural work and driving conditions. A load measurement system was constructed to collect data using wheel torque meters, proximity sensors, and a data acquisition system. Field experiments for measuring load data were performed for two environmental driving conditions (on asphalt and soil) and four agricultural operations (plow tillage, rotary tillage, loader operation, and baler operation). The attached implements and gear stages were selected through farmer surveys. The range of the reduction ratio was determined by selecting the minimum reduction ratio needed to satisfy the torque condition required for agricultural operations and the maximum reduction gear ratio to satisfy the maximum travel speed. The minimum reduction gear ratio selected was 57 in consideration of the working load condition and the maximum reduction gear ratio selected was 62 considering the maximum running speed. In the range of the reduction gear ratio 57 - 62, the selected motor satisfied all working torque conditions. As a result, the combination of the selected motor and reduction gear ratio was applicable for satisfying the loads required during agricultural operation and driving operation.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.173-175
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• 2006

소형화 되어 가는 전기기기에 따른 소형 모터가 요구되고 있다. 소형 모터 중 높은 정지 토크 및 높은 효율 등의 장점을 가진 소형 로터리 초음파 모터는 여러 목적에 쓰이고 있다. 하지만 주로 경험적인 방법 또는 상용 해석툴이 소형 로터리 초음파 모터의 해석에 주로 사용되었다. 따라서 소형 로터리 초음파 모터의 체계적인 해석 방법이 필요하다. 본 논문에서는 우선 소형 로터리 초음파 모터의 동작 원리를 통해 진행파의 존재를 확인하였고, 유한요소법 해석법을 통해 과도 및 정상 상태의 소형 로터리 초음파모터를 설계하고 해석하였다. 이 해석결과를 이용하여 소형 로터리 초음파 모터의 동작 특성 또한 해석하였다.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.110-112
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• 2008

A linear generator driven by a hydrogen combustion engine has been developed. Unlike rotary engine-generator systems, the linear counterpart is inherently unable to start by itself unless external force is provided for initial compression/ignition cycle. When the generator is connected to utility power lines through a bidirectional power conversion system, however, the self start-up can be done by driving the generator as a motor. This paper introduces a prototype 1kW linear hydrogen engine-generator system being developed and shows the self start-up is possible with proper motoring mode.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.470-472
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• 1996

In this paper, we proposed a new speed control algorithm based on the least-order observer theory. The proposed system using the new algorithm can estimate the instantaneous speed accurately even at low speed by using a load torgue observer estimating the torgue component of indirect-vector controlled induction motor. Thus the stable characteristics of speed control are possible at low speed even in the case of using low-resolution rotary encoder. Also, the system becomes robust against disturbance by feedforward control the load torque estimated automatically at the speed observer.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.65-69
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• 1997

Generally, we often use a speed sensor based on a rotary encoder and we can obtain a speed information by counting the increased or decreased number of encoder pulses in a sampling period. However, these speed measurement systems do not inherently produce a true, instantaneous speed information and them the speed ripple is generated by speed measurement errors. In order to overcome this problem, speed observer is used for the accurate speed measurement and improvement of speed ripple for Permanent Magnet Synchronous Motor (PMSM) in this paper. Speed observer estimates the instantaneous speed at each sampling instant. This estimated speed signal is then used as the speed feedback signal for the speed loop control. The proposed speed observer system is proved simulation using SABER simulation S/W.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.68-70
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• 2006

전기기기가 다양해짐에 따른 여러 종류의 모터가 요구되고 있다. 모터 중에서 높은 정지 토크 및 높은 효율 등의 장점을 가진 로터리 초음파 모터는 여러 목적에 쓰이고 있다. 하지만 초음파 모터의 중요한 부분인 teeth는 경험적인 방법으로 설계되어 문제점이 자주 발생하였다. 따라서 로터리 초음파 모터의 teeth에 대한 설계 최적화가 필요하다. 본 논문에서는 우선 3차원 유한요소법 해석법을 통해 로터리 초음파 모터를 해석하였고, 이 해석결과와 ES 알고리즘을 이용하여 로터리 초음파 모터의 teeth를 최적 설계하였다.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.316-320
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• 2004

This paper presents an advanced method for an initial pole position estimation of a PMLSM (Permanent Magnet Linear Synchronous Motor) that has an incremental encoder for servo applications but does not have Hall sensors as a magnetic pole sensor. The proposed algorithm finds either of two zero force positions and then the correct d-axis by appropriately using the secant method as a numerical method. It only requires the tuned current controller and the relative position information and so it can be simply applicable to a rotary PMSM. The experimental results show the validity of the proposed method with respect to accurate pole position estimation under the minimal moving distance during estimation process.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.507-514
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• 2001

Direct drive servovalve(DDV) is a kind of one-stage valve since the rotary motion of DC motor is directly transferred to the linear motion of valve spool through the link. Since the structure of DDV is simple, it is less expensive, more reliable and offers reduced internal leakage and reduced sensitivity to fluid contamination. However, the flow force effect on the spool motion is significant such that it induces large steady-state error in a step response. If the proportional control gain is increased to reduce the steady-state error, the system becomes unstable. In order to satisfy the system design requirements, the classical controller is designed using the analytical Bode method.