• Journal of Electrical Engineering and Technology
• /
• v.6 no.2
• /
• pp.226-232
• /
• 2011

The $H_{\infty}$ approach, adopted in this paper, is based on loop shaping using a normalized coprime factor combined with a field-oriented control to control induction motor. We develop two loops. The first one, the inner loop, controls the stator current by $H{\infty}$ controller in order to obtain good performance. The second loop, the outer one, guarantees stability and tracking performance of speed and rotor flux using a proportional integral controller. When the rotor flux cannot be measured, we introduce a flux observer to estimate the rotor flux. Simulation and experimental results are presented to validate the effectiveness and the good performance of this control technique.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.26 no.10
• /
• pp.766-770
• /
• 2013

This paper tried to develop a BLDC electric motor securing the 800 W-level watertight structure for driving the outboard motor. For this purpose, this paper developed a high-efficient controller-integrating BLDC electric motor system for underwater propulsion and designed and developed a triple watertight structure. Besides, this study developed a outboard motor integrating motor, propeller and controller based on the production of a controller for BLDC motor which can the speed control by selecting low-voltage, high-current power element. The characteristics of developed outboard motor were 24 V input voltage, over 800 W motor output, and max. 3,000 rpm motor, and 84.9% motor efficiency, and the developed outboard motor could secure the watertight structure in 5 m in water depth.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.19 no.4
• /
• pp.37-43
• /
• 2011

Lunar exploration program has been prepared with the aim of launch in the 2020's. As part of it, a lunar lander demonstrator has been developed which is the model for verifying all the system, such as structure, propulsion and control system before launch to deep space. After verifying all the system, the demonstrator will be evaluated by flight test. This paper deals with path tracking controller based on thrusters for the demonstrator. For this, first we derive equations of motion according to the allocation of thrusters and design the path tracking controller. The signal generated from the controller is continuous so PWPF(Pulse-Width Pulse-Frequency) modulator is adopted for generating on/off signal. Finally MATLAB simulation is performed for evaluating the path tracking ability and the final landing velocity.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.252-255
• /
• 2007

Recently military industrial company, utilizing company funded R&D and goverment and industry contracts, has developed ACTS/DACS technology. This technology can be utilized to rapidly steer "smart" bullets, "smart" rounds, tactical missile, cruise missile and kill vehicles for both endo- and exoatmospheric applications. The ACTS/DACS typically consists of a Smart Bus Controller(SCB), a proprietary network firing bus, Smart Pyrotechnic Devices(SPD), rocket motors, and a structure. The SCB communicates with the SPDs over the propretary network firing bus. Each rocket motor contains an SPD which provides rocket motor ignition. Firing energy is stored locally in the SPD so surge currents do not occur in the system as rocket motors are fired. This approach allows multiple, truly simultaneous firings without the need for large, dedicated batteries. Each SPD also functions as a network tranceiver and high reliability fir set all in the space of a single-sided 10 millimeter diameter circuit. The present work develops a new means for igniting explosive materials. The volume of semiconductor bridge (SCB) is over 30 times smaller than a conventional hot wire. We believe that the present work has a potential for development of a new igniter such as smart pyrotechnic device.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.19 no.3
• /
• pp.54-64
• /
• 2015

This paper deals with an acceleration controller design for a kill vehicle equipped with a divert and attitude control system (DACS). In the proposed method, the attitude control system (ACS) is used to produce the thrust command to nullify angle-of-attack. For the angle-of-attack control, a nonlinear angle-of-attack controller is proposed based on the feedback linearization methodology. Since the flight path angle is identical to the attitude angle under the condition of zero angle-of-attack, the divert control system (DCS) can directly produce the lateral acceleration which is demanded from the guidance loop. In the proposed method, we can minimize the aerodynamic uncertainty due to the propulsive force. Additionally, we can simplify the operation logic of DCS and ACS. In this paper, nonlinear simulations are performed to show the performance of the proposed method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.03a
• /
• pp.369-375
• /
• 2004

Gas turbine engine simulation in terms of transient, steady state performance and operational characteristics is complex work at the various engineering functions of aero engine manufacturers. Especially, efficiency of control system design and development in terms of cost, development period and technical relevance implies controlling diverse simulation and identification activities. The previous engine simulation has been accomplished within a limited analysis area such as fan, compressor, combustor, turbine, controller, etc. and this has resulted in improper engine performance and control characteristics because of limited interaction between analysis areas. In this paper, we propose a new simulation methodology for gas turbine engine performance analysis as well as its digital controller to solve difficulties as mentioned above. The novel method has particularities of (ⅰ) resulting in the integrated control simulation using almost every component/module analysis, (ⅱ) providing automated math model generation process of engine itself, various engine subsystems and control compensators/regulators, (ⅲ) presenting total sophisticated output results and easy understandable graphic display for a final user. We call this simulation system GT3GS (Gas Turbine 3D Graphic Simulator). GT3GS was built on both software and hardware technology for total simulation capable of high calculation flexibility as well as interface with real engine controller. All components in the simulator were implemented using COTS (Commercial Off the Shelf) modules. In addition, described here includes GT3GS main features and future works for better gas turbine engine simulation.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.4
• /
• pp.43-52
• /
• 2021

In this study, performance modeling and simulation of a gas turbine engine, a constituent module, was performed for the integrated control of the CODOG structure, mechanical propulsion systems. The engine model used MATLAB/Simulink to facilitate integration with the host controller and other components, and was configured to enable input/output settings suitable for the system configuration and purpose. In general, engine manufacturers do not provide performance data for the engine and components. Therefore, as a modeling method for a gas turbine, a CMF method that obtains performance data by scaling the map of components was applied. Using the generated model and simulation program, steady-state and dynamic simulation analysis tests were performed, and reliability within 5% of the maximum error was secured for the final output of power.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.3079-3085
• /
• 2011

Through Korean Urban Maglev Program started in 2006, an urban maglev train was developed and the demonstration line is under construction as of now in 2011. The target speed of the developed maglev train is 110km/h, and the core technologies for super speed maglev trains over 500km/h are being studied. The propulsion and levitation systems of the super speed maglev train under consideration consist of linear synchronous motors (LSM) and levitation electromagnets which also act as a mover of LSM. In addition, guidance electromagnets are used to ensure stable running on curved tracks during super speed operation. The levitation and guidance control is focused on in this paper. For experimental purpose, a small maglev train is being manufactured, and its levitation and guidance controller is studied. The main task of the controller is to maintain the gap between the corresponding electromagnet and the guideway constantly. In general, measurements of the gap, acceleration and current and so on are utilized, and the gap control is implemented independently for each electromagnet. In this paper, the levitation and guidance system is modelled considering mechanical interactions, and the levitation and guidance controller is proposed based on this model. The developed controller is verified by various simulations using MATLAB/Simulink.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.12 no.6
• /
• pp.125-131
• /
• 2013

This study was carried out to develop a diesel engine for marine propulsion. This marine diesel engine was developed based on a 500Ps vehicle diesel engine. Many main parts, such as the intercooler, radiator, and engine controller were designed for the marine diesel engine. The intercooler was designed to be of sea water cooling type; inlet air is cooled by sea water. Engine coolant is cooled by sea water in the radiator too. The water cooling heat exchanger has high cooling performance. In the cooling system, consists of the intercooler and the radiator, the sea water passes through the intercooler and then the radiator, in sequence. This process is very effective compared to the reverse method in which sea water passes through the radiator and then the intercooler, in sequence. The control performance of the engine controller and the fuel injection rate were improved using an engine speed controller. This system was tested on an engine dynamometer and an exhaust gas analyzer using the marine diesel engine test method. Test results show that the 500Ps marine diesel engine satisfied the IMO NOx regulations; Tier II.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.2
• /
• pp.944-949
• /
• 2017

Recently, the demand of maglev systems in the manufacturing industry for LCD and OLED display panels, which are required to be very clean and possess vacuum systems, has been increasing due to their characteristics such as being non-contact, noise free and eco-friendly. However, it is still a challenge to simultaneously control both the propulsion and levitation for their interactive effect difficult to be exactly measured. In this paper, we proposed a new tuning method for controlling the magnetic levitation force robustly against the levitation disturbance caused by a propulsion system, based on LQ servo optimal control. The disturbance torque of the LSM propulsion system is calculated through FEM analysis in such a way that the LQ servo controller is determined in order to minimize the effect of the disturbance. The robust performance of the proposed LQ servo control method for the in-track type magnetic levitation systems is demonstrated via simulations and experiments.