• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.706-708
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• 1998

Recently, it was very difficult for hydraulic governor to regulate the speed of high power engine with long stroke at low speed and low load, because of the jiggling phenomena by rough fluctuation of rotating torque and the hunting phenomena by long dead time occurred in fuel combustion process in the engine cylinder. In this paper, the influence of engine dead time is investigated by Nickels chart, and hybrid controller selected advantages of PID and fuzzy logic controller is provided to improve the performance of speed control of a low speed and long stroke diesel engine.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.319-326
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• 2006

In this paper, a fuzzy inference control system is proposed for a turbojet engine with fuel flow control input only. The proposed control system provides a practical fuel flow control method to prevent surge or flame out during engine acceleration or deceleration. A fuzzy logic is designed to obtain the fast acceleration and deceleration of the engine under the condition that the operating point should stay between the surge line and flame out control line. With using both engine rotating speed error and surge margin as fuzzy input variables, the desired engine rotating speed can be achieved to rapidly follow the engine control line without engine stall. Computer simulation using the MATLAB is realized to prove the proposed control performance to the turbojet engine which is linear modelized using DYGABCD program package.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.6
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• pp.502-508
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• 2001

In this paper, slack is computed from a comparison of the cable pay out rate and the ship ground speed in accordance with laying conditions, and the speed controller of the cable engine based on an H(sub)$\infty$ servo control id designed for adjusting the cable engine in order to lay a desired amount of slack. The controller is designed for robust tracking of the cable engine under disturbances. The performance of the designed controller is evaluated by computer simulation, and, consequently, a feasibility study for laying the submarine cable stably is done through analyzing simulation results.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.66-72
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• 1999

It is necessary to discuss lightening engine parts and reducing the friction of sliding parts to improve fuel consumption and combustion stability at idling condition. Lean best torque combustion which produce maximum power at a lean air-fuel ratio is effective for the reduction of exhaust gas emission and the improvement of fuel consumption. Accordingly, this study deals with the expansion of lean combustible limitation, the combustion stability and the reduction of idle speed through the analysis of combustion characteristics on the base of the control technique of precise air-fuel ratio because it does not need to maximum power at idling condition. The idle speed is increased proportional to ISC(Idle Speed Control) duty ratio. On the other hand the idle speed decreased by lean air-fuel ratio. The COV in engine speed is stable within maximum two percent up to 17.6 mixture ratio by the control of ISC duty ratio.

• Proceedings of the KIEE Conference
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• 1997.07b
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• pp.672-674
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• 1997

In this paper, we study the idle speed control of the spark ignition engine. Engine idle speed control is a difficult problem because of troublesome characteristics such as severe process nonlinearities, variable time delays, time-varying dynamics and unobservable internal system states and disturbances. We investigate the intelligent control algorithms such as neural network controller and fuzzy controller for 4-cylinder 4-stroke engine.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.430-433
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• 1989

This paper describes dynamic engine model that is appricable to idle speed control system development. A basic linear engine model responds to throttle and load torque Inputs to provide manifold pressure and speed outputs. Transfer functions are then derived for the modified linear engine model and significant dynamic characteristics are discussed. Lastly, the strategy for controlling idle speed uses the linear optimal control theory. The linear optimal regulator was designed using a state variable and the performance Index was minimized.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.579-583
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• 1997

A diesel Engine rotates vibratively because of alternative explosion strokes. Traditional measurement of a diesel engine speed is carried out by measuring output voltage of FV convertor from input signals of MPU(magnetic pickup unit) or of DC tachometer. Because these measurement include also vibrative rotation of a diesel engine, an analog filter is often used to eliminate high frequency noises due to periodic explosion stroke. But by this method these high frequency noises do not eliminated effectively because noise frequencies are changed according to diesel engine speed. In this paper, author proposes a new measurement method of a diesel engine revolution which read digital signal directly from MPU and prove the utility of proposed method through the real experiment.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.6
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• pp.631-637
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• 2002

Two stroke low speed diesel engines are used as a power supplier not only for marine vessel but also diesel power plant with a benefit of its higher mobility and durability than the other thermal engines. However, there are some disadvantages such as the bigger vibrating excitation forces generated by high combustion pressure in cylinders which various kinds of vibrations are caused. In this paper, it is theoretically studied to control engine body vibration using dynamic vibration absorber. As an actual case, dynamic absorbers are designed for controlling X-mode vibration of 9K80MC-S engine on the diesel power plant and its performance is identified by the vibration test both in shop and site

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.3
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• pp.40-49
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• 1994

This paper describes the method to investigate combustion pressure in the cylinder without modifications of engine. Assuming engine dynamics as a single degree of freedom cylinder pressure is estimated using the variation of crank shaft speed. For this study pressure, crank shaft sped, and load are sampled by the crank angle. This study suggests the variation of crank shaft speed can be used as parameters of feedback engine control.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.1
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• pp.82-87
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• 1997

This paper presents a method about the modeling of the medium - small diesel engine for the speed control and designs the robust speed control system by the $\mu$-synthesis, which has good performance, in spite of the existence of model uncertainities and the external disturbance. We confirmed the validity of the proposed modeling method and the designed control system by $\mu$-synthesis through the experimental responses.