• Journal of Advanced Marine Engineering and Technology
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• v.24 no.1
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• pp.104-111
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• 2000

It is very difficult to maintain the desired tank level without any overflow or any shortage in a dangerous shemical plant and in a cooling one. Futhermore, because its dynamics are very complicate and nonlinear, it is impossible to realize the precise control using the accurate mathematical model which can be applied to the various peration modes. Nonetheless, the sliding mode controller(SMC) is known as having the robust variable structures for the nonlinear control system with the parametric perturbations and with the rapid disturbances. But the adaptive tuning algorithms for their parameters are not satisfactory. Therefore, in this paper, a Real Variable Elitist Genetic Algorithm based Sliding Mode Controller (RVEGA SMC) for the precise control of the coupled tank level was tried. The SMC's switching parameters were optimized easily and rapidly by RVEGA. The simulation results showed that the tank level could be satisfactorily controlled without and overshoot and any steady-state error by the proposed RVEGA SMC.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2002.05a
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• pp.239-244
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• 2002

Even though, tanks are used at the many industry plants, it is very difficult to control the tank level without any overflow and shortage; moreover, cause of its complication of dynamics and nonlinearity, it's impossible to realize the accurate control using the mathematical model which can be applied to the various operation modes. However, the sliding mode controller(SMC) is known as having the robust variable structures for the nonlinear control systems with the parametric perturbations and with the sudden disturbances, but the auto-tuning of parameters was a problem. Therefore, in this paper, a Genetic Algorithm based Sliding Mode Controller (GA-SMC) for the precise control of the coupled tank level was tried. GA optimized the SMCs switching parameters easily and rapidly. The simulation results are shown that the tank level could be satisfactorily controlled with less overshoot and steady-stale error by the proposed GA-SMC.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.102-108
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• 1999

The sliding rmde controller(SMC) is known as having the robust variable structures for the nonlinear control systems such as coupled tank system with the pararretric perturbations and with the rapid disturbances. But the adaptive tuning algorit1uns for their pararreters are not satisfactory. Therefore, in this paper, a Real Variable Elitist Genetic Algorithm based Sliding Mode Controller (RVEGA SMC) for the precise control of the coupled tank level was tried. The SMC's switching pararreters were optimized easily and rapidly by RVEGA The simulation results showed that the tank level could be satisfactorily controlled without any overshoot and any steady-state error by the proposed RVEGA SMC.GA SMC.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.550-552
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• 1999

This paper describes a control technique of coupled tank level using Evolutionary Neural Network. In general, the control of tank level without a dangerous overflow and with a high accuracy is difficult because of higher order time delay and nonlinearity. Nonetheless, proposed Evolution Neural Network controller in this paper was successfully implemented and simulation results of the superiority over a conventional PID one was investigated.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.966-968
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• 1999

It is very difficult to maintain the desired tank level without overflow or shortage in a dangerous chemical plant. and a cooling one. Futhermore, because its dynamics are very complicate and nonlinear, the accurate mathematical model cannot be technique acquired and also their problems cannot be solved easily. In this paper, a RVEGA SMC for the robust control of a coupled tank level was proposed. The simulation results were very appreciative.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.169-177
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• 2024

Interacting Spherical tank has maximum storage capacity is broadly utilized in industries because of its high storage capacity. This two tank level system has the nonlinear characteristics due to its varying surface area of cross section of tank. The challenging tasks in industries is to manage the flow rate of liquid. This proposed work plays a major role in controlling the liquid level in avoidance of time delay and error. Several researchers studied and investigated about reducing the nonlinearity problem and their approaches do not provide better result. Different types of controllers with various techniques are implemented by the proposed system. Intelligent Adaptive Neuro Fuzzy Inference System (ANFIS) based Sliding Mode Controller (SMC) with Fractional order PID controller is a novel technique which is developed for a liquid level control in a interacting spherical tank system to avoid the external disturbances perform better result in terms of rise time, settling time and overshoot reduction. The performance of the proposed system is obtained by analyzing the simulation result obtained from the controller. The simulation results are obtained with the help of FOMCON toolbox with MATLAB 2018. Finally, the performance of the conventional controller (FOPID, PID-SMC) and proposed ANFIS based SMC-FOPID controllers are compared and analyzed the performance indices.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1909-1910
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• 2006

산업 프로세스에서 볼 수 있는 이중탱크 시스템(Coupled Tank System)을 수학적으로 모델링하고 그에 대한 제어기를 구성하여 제어성능과 특성을 시뮬레이션을 통해 살펴 보고자 한다. 본 논문에서는, 다입력-다출력의 비선형적인 시스템에 대해서도 단순히 IF-THEN 형태의 규칙만으로 손쉽게 비선형 제어기를 구현할 수 있는 퍼지제어(fuzzy control)를 이용하고자 한다. 이중탱크 시스템은 단일탱크에 비하여 시간지연이 크고, 비선형성이 큰데, 이러한 경우에도 퍼지제어를 이용하여 손쉽게, 그리고 유용하게 제어기를 구성할 수 있음을 보이고자 한다. 특히, 첫번째 탱크에서 오버플로가 발생할 위험이 있는데, 이를 위해 본 논문에서는 이중 피드백 루프의 구조로 구성하여 레벨 제어를 하고자 한다.

• Journal of electromagnetic engineering and science
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• v.4 no.4
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• pp.168-174
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• 2004

A bandwidth-enhanced and phase noise-improved differential LC-tank VCO is proposed in this paper. By connecting the varactors to the bases of the cross-coupled transistors of the proposed LC-tank VCO, its input negative resistance has been widened. Also, the feedback capacitor Cc in the cross-coupling path of the proposed LC-tank VCO attenuates the output common-mode level modulated by the low-frequency noise because the modulated common-mode level jitters the varactor bias point and degrades phase noise. Compared with the fabricated conventional LC-tank VCO, the proposed LC-tank VCO demonstrates $200\;\%$ enhancement in tuning range, and 6 - dB improvement in phase noise at 6 MHz offset frequency from 5.4-GHz carrier. We achieved the phase noise of - 106 dBc/Hz at 6 MHz offset, and $10\;\%$ tuning range from the proposed LC-tank VCO. The proposed LC-tank VCO consumes 12 mA at 2.5 V supply voltage.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2192-2195
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• 2002

Even though, tanks are used at the many industry plants, it is very difficult to control the tank level without any overflow and shortage; moreover, cause of its complication of dynamics and nonlinearity, it's impossible to realize the accurate control using the mathematical model which can be applied to the various operation modes. However, the sliding mode controller(SMC) is known as having the robust variable structures for the nonlinear control systems with the parametric perturbations and with the sudden disturbances. It's difficult to find SMC's parameters, and SMC is bring chattering which injures actuator and increases error. In this paper, Genetic Aloglism based Fuzzy Sliding Mode Controller(GA-FSMC) for the precise control of the coupled tank level was proposed. Genetic Algolism and Fuzzy logic are adapted to find SMC's parameters and reduce the chattering. The simulation result is shown that the tank level could be satisfactorily controlled with less overshoot and steady-state error by the proposed GA-FSMC.

• ETRI Journal
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• v.27 no.5
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• pp.473-483
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• 2005

In this paper, we propose two LC voltage-controlled oscillators (VCOs) that improve both phase noise and tuning range. With both 1/f induced low-frequency noise and low-frequency thermal noise around DC or around harmonics suppressed significantly by the employment of a current-current negative feedback (CCNF) loop, the phase noise in the CCNF LC VCO has been improved by about 10 dB at 6 MHz offset compared to the conventional LC VCO. The phase noise of the CCNF VCO was measured as -112 dBc/Hz at 6 MHz offset from 5.5 GHz carrier frequency. Also, we present a bandwidth-enhanced LC VCO whose tuning range has been increased about 250 % by connecting the varactor to the bases of the cross-coupled pair. The phase noise of the bandwidth-enhanced LC-tank VCO has been improved by about 6 dB at 6 MHz offset compared to the conventional LC VCO. The phase noise reduction has been achieved because the DC-decoupling capacitor Cc prevents the output common-mode level from modulating the varactor bias point, and the signal power increases in the LC-tank resonator. The bandwidth-enhanced LC VCO represents a 12 % bandwidth and phase noise of -108 dBc/Hz at 6 MHz offset.