• Journal of Power Electronics
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• v.5 no.1
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• pp.36-44
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• 2005

This paper presents an implementation of high performance control of a reluctance synchronous motor (RSM) using a neural network with a direct torque control. The equivalent circuit in a RSM, which considers iron losses, is theoretically analyzed. Also, the optimal current ratio between torque current and exiting current is analytically derived. In the case of a RSM, unlike an induction motor, torque dynamics can only be maintained by controlling the flux level because torque is directly proportional to the stator current. The neural network is used to efficiently drive the RSM. The TMS320C3l is employed as a control driver to implement complex control algorithms. The experimental results are presented to validate the applicability of the proposed method. The developed control system shows high efficiency and good dynamic response features for a 1.0 [kW] RSM having a 2.57 ratio of d/q.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.803-812
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• 2006

In order to reduce the negative effects of dynamic coupling among vehicle subsystems and improve the handling performance of vehicle under severe driving conditions, a vehicle chassis control integration approach based on a main-loop and servo-loop structure is proposed. In the main-loop, in order to achieve satisfactory longitudinal, lateral and yaw response, a sliding mode controller is used to calculate the desired longitudinal, lateral forces and yaw moment of the vehicle; and in the servo-loop, a nonlinear optimizing method is adopted to compute the optimal control inputs, i.e. wheel control torques and active steering angles, and thus distributes the forces and moment to four tire/road contact patches. Simulation results indicate that significant improvement in vehicle handling and stability can be expected from the proposed chassis control integration.

• International Journal of Control, Automation, and Systems
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• v.4 no.1
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• pp.53-62
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• 2006

In this paper, ATM network congestion control with explicit rate feedback is considered. In ATM networks, delays commonly appear in data transmission and have to be considered in congestion control design. In this paper, a bounded single round delay on the return path is considered. Our objective is to design an explicit rate feedback control that achieves a robust optimal $H_2$ performance regardless of the bounded time-varying delays. An optimization approach in terms of linear matrix inequalities (LMIs) is given. Saturation in source rate and queue buffer is also taken into consideration in the proposed design. Simulations for the cases of single source and multiple sources are presented to demonstrate the effectiveness of the design.

• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.79-84
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• 2000

This paper presents an implementation of digital position control system for an induction motor vector drives by a direct torque control(DTC) using the 16bit DSP TMS320 F240. The DSP controller enable enhanced real time algorithm and cost-effective design of intelligent controller for motors which can be yield enhanced operation, fewer system components, lower system cost, increased efficiency and high performance. The system presented are stator flux and torque observer using current model that inputs are current sensing of motor terminal and rotor angle for a low speed operating area, two hysteresis controller, optimal switching look-up table, and IGBT voltage source inverter by fully integrated control software. The developed control system are shown a good motion control response characteristic results and high performance features using 2.2Kw general purposed induction motor.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.675-684
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• 2004

The Helicopter system has a non-linearity and complexity. Futhermore, because of absence of its correct mathematical model. it is difficult to control accurately its attitudes for elevation angle and azimuth one. Therefore, we proposed a GA-PID control technique to control these angles efficiently. The proposed GA-PID controller can systematically generate optimal PID parameters by applying GA theory to a helicopter attitude control system. Through the computer simulation, the GA-PID technique shows better attitude control characteristic than traditional PID control technique.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.453-458
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• 2000

Design of an in-process feedback control system has been studied for precision grinding. A grinding system consists of a grinding tool, a turn table and a disk-shaped workpiece on the table is taken as an object. A grinding process model has been deduced which gives some reasoning about the process errors. In the control system the tool position is actively controlled by an electro-magnetic actuator in-process. The ground error is feedback to compose a closed-loop control system and an optimal PID controller is applied. Some control performances such as transient response and disturbance such as transient response and disturbance attenuation have been examined, which convinces the effectiveness of the control. Some methods for implementation of the control. Some methods for implementation of the control have been suggested from a standpoint of practical application.

• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1240-1247
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• 2001

A robust control design scheme using well-developed SISO techniques is proposed for maglev vehicles that are inherently unstable MIMO systems. The proposed separate control method has basically two control loops: a stabilizing loop by a pole-placement technique, and a performance loop using a novel optimal LQ loop-shaping technique. This paper shows that the coupling terms involved in maglev vehicles with multimagnets should not be neglected but compensated for their stability and performance robustness. The robustness properties of the proposed control system are then evaluated under variations of vehicle masses and air gaps through a computer simulation. This paper also describes the reason why the proposed control technique can be suggested as a tool using only SISO techniques in controlling unstable MIMO systems such as maglev vehicles.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2251-2253
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• 2003

This paper is concerned with the active vibration control of flexible cantilever beam system using electromagnetic force actuator. The main objective of this paper is to propose the control algorithms and implement the experimental setups for active vibration control. Several control algorithms are proposed and implemented on the experimental setups to show their efficacy. These include a PID control design, an optimal $H_2$ control design, and a fuzzy PID control design. Effectiveness and performance of the designed controller were verified by both simulation and experiment results.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.482-496
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• 2016

Algal blooms of cyanobacteria (blue-green Algae) due to the eutrophication of rivers and lakes can cause not only the damage by its biological toxins but also the economic loss in drinking water treatment. The natural algae coagulant, a commercial product known as W.H. containing the algicidal and allelopathic material derived from oak, can control algal problems proactively through the coagulation flotation process. However, because there have been no applications of the process for pre-treatment in drinking water plants, we could find no report on the optimum injection dose of W.H.. In this study, we have conducted several sets of jar-tests while changing W.H. dose and concentration of chl-a for (1) Han-river samples and (2) subcultured cyanobacteria samples, and monitored the removal mechanisms of algae intensively. Based on these jar-test results, two linear equations with variables of chl-a and turbidity have been deduced to predict the optimal W.H. dose after the multiple regression analysis using IBM-SPSS. Also, prototypes of automatic control logic have been suggested to inject the optimal W.H. dose promptly in response to the variation of water quality.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.847-858
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• 2015

Control strategy and corresponding parameters have significant impacts on the overall technical and economic characteristics of composite energy storage systems (CESS). A better control strategy and optimized control parameters can be used to improve the economic and technical characteristics of CESS, and determine the maximum power and stored energy capacity of CESS. A novel coordinated control strategy is proposed considering the coordination of various energy storage systems in CESS. To describe the degree of coordination, a new index, i.e. state of charge coordinated response margin of supercapacitor energy storage system, is presented. Based on the proposed control strategy and index, an optimization model was formulated to minimize the total equivalent cost in a given period for two purposes. The one is to obtain optimal control parameters of an existing CESS, and the other is to obtain the integrated optimal results of control parameters, maximum power and stored energy capacity for CESS in a given period. Case studies indicate that the developed index, control strategy and optimization model can be extensively applied to optimize the economic and technical characteristics of CESS. In addition, impacts of control parameters are discussed in detail.