• Journal of Mechanical Science and Technology
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• 제14권6호
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• pp.645-654
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• 2000

In this paper, low level control algorithms of a metal belt CVT are suggested. A feedforward PID control algorithm is adopted for line pressure based on a steady state relationship between the input duty and the line pressure. Experimental results show that feedforward PID control of the line pressure guarantees a fast response while reducing the pressure undershoot which may result in belt slip. For ratio control, a fuzzy logic is suggested by considering the CVT shift dynamics and on-off characteristics of the ratio control valve. It is found from experimental results that a desired speed ratio can be achieved at steady state in spite of the fluctuating primary pressure. It is expected that the low level control algorithms for the line pressure and speed ratio suggested in this study can be implemented in a prototype CVT.

• 유공압시스템학회논문집
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• 제4권1호
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• pp.18-24
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• 2007

The continuously variable transmission (CVT) of which speed ratio can change continuously in a fixed range has the benefits of low fuel consumption and exhaust gas because it enables the engine of a vehicle to operate in a high efficiency range regardless of vehicle speed. The speed ratio of belt type CVT is controlled by adjusting line pressure. The one of the line pressure control methods, mechanical-hydraulic control is usually adopting VDT's control method, in which the secondary solenoid valve has two functions both a regulator and a line pressure controller. However, this control method could not show the high performance of CVT with optimal driving capability because of the limitation of simple control algorithm, and it could not gain market share sufficiently in spite of the advantage of CVT with low fuel consumption. On the other hand, the electro-hydraulic control method gives the enhancement of power performance and low fuel consumption by implementing various driving mode using the proportional control or PWM control. The key of CVT technique is to develop a control algorithm of the electro-hydraulic solenoid valve in order to implement the speed ratio efficiently. In this paper, the line pressure control algorithm is proposed and the hydraulic system is controlled using metal belt type CVT test rig and the embedded ECU platform.

• 제어로봇시스템학회논문지
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• 제3권4호
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• pp.357-362
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• 1997

This paper suggests an automatic calibration technique for piezoelectric low pressure transducer measuring a pressure blow 500psi. The present calibration system embedded with error correction algorithm generates it's best you don't cut parts of wards like so dynamic pressure and compensates offset voltage and pressure error. It is shown via experimental results that the instrumentation accuracy has been improved and mean time between calibrations has been shortened.

• 설비공학논문집
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• 제15권3호
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• pp.203-209
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• 2003

Control algorithms of an air handling unit by using the mixing box plenum pressures were developed and verified by experiments. Control algorithms developed for this study were the setpoint algorithms for the outdoor damper position, the outdoor/fixed plenum pressure, and the return/exhaust plenum pressure. The outdoor/fixed plenum pressure setpoint was used to control the bypass damper position, and the return/exhaust plenum pressure setpoint was used to control the return fan speed. Experimental results showed the good control of the required outdoor air demand. Therefore, setpoint algorithms developed for this study may effectively be applied for the control of the VAV air handling unit.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.699-703
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• 1993

When the error path can be modeled as a pure delay, an adaptive algorithm for slowly time varying system is proposed to minimize the sound pressure level. This algorithm makes it possible to use the fittered-x LMS algorithm with on-line delay modeling of the error path. Another simple adaptive algorithm for pure tone noise is proposed which eliminates the cross term in the multiple error filtered-x LMS algorithm.

• 대한기계학회논문집A
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• 제26권2호
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• pp.399-405
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• 2002

This paper proposes a new type of piezoactuator-driven valve system. The piezoceramic actuator bonded to both sides of a flexible beam surface makes a movement required to control the pressure at the flapper-nozzle of a pneumatic valve system. After establishing a dynamic model, an appropriate size of the valve system is designed and manufactured. Subsequently, a robust H$_{\infty}$ control algorithm is formulated in order to achieve accurate tracking control of the desired pressure. The controller is experimentally realized and control performance for the sinusoidal pressure trajectory is presented in time domain. The control bandwidth of the valve system, which directly represents the fastness, is also evaluated in the frequency domain.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.673-678
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• 2001

This paper proposes a new type of piezoactuator-driven valve system. The piezoceramic actuator bonded to both sides of a flexible beam surface makes a movement required to control the pressure at the flapper-nozzle of a pneumatic valve system. After establishing a dynamic model, an appropriate size of the valve system is designed and manufactured. Subsequently, a robust $H_{\infty}$ control algorithm is formulated in order to achieve accurate tracking control of the desired pressure. The controller is experimentally realized and control performance for the sinusoidal pressure trajectory is presented in time domain. The control bandwidth of the valve system, which directly represents the fastness, is also evaluated in the frequency domain.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.382-384
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• 1996

This paper introduces the controller development of booster multi-pump system with constantly estimated control algorithm. Through analyzing by the experiment of optimal pressure with a certain flow rate. The larger pressure processing apparatus in microprocessor makes optimal water-supplying. This method is implemented with the only pure control algorithm without any other mechanical or circuitry apparatus. Also, Pump's life is lengthened by exchanging simple on, off and rotational inverter control. Optimal condition for pump is adjusted by the inverter control, and compact control panel helps the booster system install in real field.

• 한국자동차공학회논문집
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• 제2권6호
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• pp.29-37
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• 1994

Active noise control of random noise which propatate in the vehicle cabin as a form of spherical wave is the target of this study. In the previous study, the adaptive algorithm for adaptive controller is presented for the application in active noise control system. And for the preliminary study of adaptive active noise control in vehicle cabin as a real system, a computer simulation is performed on the effectiveness of the adaptive algorithm in the amplitude of the pressure fluctuation. This work studies the implementation of multi-channel feedforward adaptive algorithm for the reduction of the noise inside a vehicle cabin using a number of secondary sources derived by adaptive filtering of reference noise source. Multi-channel adaptive feedforward algorithm are verified in numerical simulation and semi-experimental justification of developed system is made on a domestic passenger car. In the results of semi-experimental study, the noise of specific region in the interior of automobile are reduced for the appreciabe sound pressure level in the operating engine rpm and finally this study suggests the capabilities of the real time active noise control in 3 dimensional acoustic fields.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1294-1297
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• 2003

With the development of medical field, many kinds of operations have been performed on human articulation. Arthroscopic surgery, which has Irrigation Pumping System for security of operator vision and washing spaces of operation, has been used for more merits than others. In this paper, it is presented that the research on a reliable control algorithm of the pumping system instrument for arthroscopic surgery. Before clinical operation, the flexible artificial articulation model is used for realizing the model the most same as human's and the algorithm has been exploited for it. This system is considered of the following; limited sensing point, dynamic effect by compliance, time delay by fluid flow and so on. The system is composed with a pressure controller, a regulator for keeping air pressure, an airtight tank that can have distilled water packs, artificial articulation and a measuring system, and has controlled by the feedback of pressure sensor on the artificial articulation. Also the system has applied to Smith Predictor for time delay and the parameter estimation method for the most suitable system with both the experiment data and modeling. In this paper, the pressure error that is between an air pressure tank and an artificial articulation was measured so that the system could be presumed and then the controller had developed for performing State-Feedback. Finally, the controller with a real microprocessor has realized. The confidence of system can be proved by applying this control algorithm to an artificial articulation experiment material.