• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.640-643
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• 1997

This paper describes speed controller of a induction motor for electric vehicles using PLL and Fuzzy logic. The proposed system is combined precise speed control of PLL and robust, fast speed control of Fuzzy logic. The motor speed is adaptively incremented or decremented toward the PLL locking range by the Fuzzy logic using information of sampled speed errors and then is maintained accurately by PLL. The results of experiment show excellence of proposed system and that the proposed system is appropriates to control the speed of induction motor for electric vehicles.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.7
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• pp.437-442
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• 2005

In order to realize the speed control of an induction motor, the information of the rotor speed is needed. So the speed sensor as an encoder or a pulse generator is used to obtain it. But the use of speed sensor occur the some problems in the control system of an induction motor. To solve the problems, the appropriate speed estimation algorithm is used instead of the speed sensor. Also there is the limitation to improve the speed control performance of an induction motor using the existing speed estimation algorithm. Therefore, in this paper, intelligent speed estimator using Fuzzy-Neural systems as adaptive laws in Model Reference Adaptive System is proposed so as to improve the existing estimation algorithm and ,using the rotor speed estimated by the Proposed estimator, the speed control of an induction motor without speed sensor is performed. The computer simulation and the experiment is executed to prove the performance of the speed control system usinu the proposed speed estimator.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.754-758
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• 1996

In this paper, a new method of position synchronizing control is proposed for multi-axes driving system. The proposed synchronizing control system is constituted with speed and synchronizing controller. The structure of synchronizing control system is varied by sign of synchronizing error. When a disturbance input becomes added to one axis, this axis becomes slave axis. The other axis is master axis. Therefore, master axis is not influenced by the disturbance. The speed controller of the first axis is designed by $H_{\infty}$ control theory. The speed controller of the second axis is designed by inverse dynamics of speed control system of the first axis. The speed control system designed with $H_{\infty}$ controller guarantees low sensitivity for the disturbance as well as robustness against model uncertainties. Especially, the synchronizing controller is designed to keep position error to minimize by controlling speed of slave axis. The effectiveness of the proposed method is successfully confirmed through several experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.856-864
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• 2008

This paper describes a vehicle low speed driving assistant (VLDA) system that is composed of laser scanner. This vehicle is designed for following lead vehicle (LV) without driver's operation. The system is made up several component systems that are based on unmanned ground vehicle (UGV). Each component system is applied to use advanced safety vehicle developed to complete UGV system. VLDA system was divided into vehicle control system and obstacle detecting system. The obstacle detecting system calculate distance and angle of LV and transmit these data to vehicle control system using front, left and right laser scanners. Vehicle control system makes vehicle control values such as steering angle, acceleration and brake position and control vehicle's movement with steering, acceleration and brake actuators. In this research, we designed VLDA system like as low speed cruise control system and test it on real road environments.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.161-164
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• 2001

This paper presents a digital speed sensorless control system for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, rotor speed estimator, torque estimator two hysteresis band controllers, an optimal switching look-up table. IGBT voltage source inverter, and TMS320C31DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor speed is estimated by the observed stator flux-linkage space vector. The estimated rotor speed can be determinated by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. In order to prove the suggested speed sensorless control algorithm. There are some simulation and testing at actual experimental system. The developed digitally high- performance speed sensorless control system are shown a good speed control response characteristic results and high Performance features using 1.0Kw RSM.

• Journal of the Semiconductor & Display Technology
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• v.13 no.4
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• pp.71-76
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• 2014

This paper presents the implementation for the BLDC motor speed control system using VHDL and FPGA. The BLDC motor is widely used in automation for its good robustness and easy controllability. In order to control the speed of the BLDC motor, the PI controller used for static RPM output of the BLDC motor to variations in load. In addition, by using the DA converter, we were able to monitor the BLDC motor reference speed and the current speed through real time. The motor speed command and the parameters of the PI speed controller were modified easily by the FPGA and the AD converter. Finally, in order to show the feasibility of the control algorithm the speed control characteristics of the motor was monitored using an oscilloscope and the DA converter. Further, the speed control system was designed in this paper has shown the applicability of the drive system of the factory automation.

• Transactions of The Korea Fluid Power Systems Society
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• v.7 no.3
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• pp.13-19
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• 2010

Hydraulic systems are widely used as a power transfer and/or power control system due to its flexibility, controllability, accuracy and high power density. Valve controlled and/or pump capacity controlled systems are normally adopted as a control device, but nowadays pump speed controlled systems are emerging as a new energy-efficient hydraulic control system. In this paper the pump speed controlled system for the cylinder position control of a counter balance circuit is investigated by simulation study and position control experiments were carried out. As a result, the possibility and efficiency of the pump speed controlled system were verified.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.524-527
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• 2003

This paper proposes speed control system using a Fuzzy Logic Controller(FLC) in order to realize the speed control of Permanent Magnet AC Motor with no sensor. FLC based MRAS(Model Reference Adaptive System) estimates the speed of Permanent Magnet AC Motor. Using the estimated speed, speed control is performed. The experiment is executed to verify the propriety and the effectiveness of the proposed system.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.6
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• pp.1374-1381
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• 1994

This study suggests a new type shaft generating system driven by hydrostatic transmission suitable for small size vessels. In this system, the hydraulic motor speed is controlled by displacement adjustment using a 3-way high speed on/off valve. The 3-way high speed valve is operated by PWM control signal. In this study, a digital robust servo control algorithm is applied to the controller design of the system. By experiments and numerical computations, the frequency variation characteristics of the generating system under various disturbances are investigated. Conclusively, it is said that the shaft generating system proposed in this study shows excellent control performances.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.162-164
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• 1994

This paper proposes a servo control system of brushless motor at a low and high speed range. The control system is composed of the PI controller for high-speed control and the modified PI controller for low-speed control and the current controller using the hysteresis current control PWM method. The speed control performance is shown by the computer simulation.