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Nahian, S A,Truong, D Q,Ahn, K K SAGE Publications 2014 Proceedings of the Institution of Mechanical Engin Vol.228 No.7
<P>Realization of biologically motivated algorithms in industrial applications is becoming a new research, especially in the field of electrohydraulic systems. One of the recent innovations named brain emotional learning–based intelligent controller has been catching eyes of the researcher as a model-free adaptive controller, which has effective capabilities to handle nonlinearities and uncertainties of controlled systems. The aim of this article is to develop a so-called self-tuning brain emotional learning–based intelligent controller for tracking control of electrohydraulic actuators. Here, the main control unit brain emotional learning–based intelligent controller is used to drive the system to desired targets. Meanwhile, a fuzzy inference is designed to tune online the reward function (RF) parameter of the brain emotional learning–based intelligent controller, which enables the system robustness and stability. A test rig employing an electrohydraulic actuator is then setup to investigate the system control performance. The experimental results implied that proposed controller has strong ability to drive the system to follow different reference trajectories with minimal errors.</P>
Nahian, Syed Abu,Cheedarala, Ravi Kumar,Ahn, Kyoung Kwan unknown 2017 Nano energy Vol.38 No.-
<P><B>Abstract</B></P> <P>Recently, the triboelectric nanogenerator (TENG) has become a well-known energy harvester for ambient-resource energy harvesting for which the contact electrification between two different materials is employed. Alternatively, research has been carried out on the fluid-based TENG (FluTENG) for the replacement of the conventional solid-based TENG due to the destruction of the active surface by a long mechanical rupture that reduces the triboelectrical effect. For the first time, a simple, eco-friendly, very economical, and novel DI (deionized)-water commercial-polytetrafluoroethylene (cPTFE)-based FluTENG with contact-separation (CS-FluTENG) and lateral-sliding (LS-FluTENG) modes has been developed for this paper. Here, we examined the dynamic interaction between water and solid contact for each mode. During the study of the surface morphologies for both the CS-FluTENG and the LS-FluTENG, an FE-SEM analysis showed expansions of the fibril lengths in the film network. Also, the mechanistic approach of water splitting and the way that a chemical reaction occurs with the cPTFE film during the contact electrification that have been proved by UV-spectroscopy, FT-IR, and XRD analyses were investigated in this manuscript. The contact-angle measurements revealed that the surface-hydrophobicity values of the films were decreased after the CS-FluTENG and LS-FluTENG experiments due to a roughness increment, and the fibril distance from the nodes was increased. The triboelectric-power density values reached up to 2.15mW/m<SUP>2</SUP> for the CS-FluTENG and 0.8mW/m<SUP>2</SUP> for the LS-FluTENG, respectively. Moreover, the instantaneous power reached up to 2.4 µW for the CS-FluTENG and 1.85 µW for the LS-FluTENG, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel fluid based TENG(FluTENF) using DI water and cPTFE film is proposed. </LI> <LI> Lateral sliding and contact separation type FluTENG is compared and analyzed by FE-SEM analysis. </LI> <LI> The triboelectric power density is achieved upto 2.15mW/m<SUP>2</SUP> for CS-FluTENG and 0.8mW/m<SUP>2</SUP> for LS-FluTENG. </LI> <LI> The energy loss in CS-FluTENG is significantly higher than LS-FluTENG. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P> <B>Scheme1</B>. Schematic illustration of a fluid triboelectric nanogenerator.</P> <P>[DISPLAY OMISSION]</P>
A psycho-biological controller for electro-hydraulic actuator position controlling
S. A. Nahian(시아부나히안),D. Q. Truong(딩광청),K. K. Ahn(안경관) 유공압건설기계학회 2013 유공압건설기계학회 학술대회논문집 Vol.2013 No.10
Modern research have been relying on electro-hydraulic actuators owing to its high nonlinearity and uncertainty. Therefore, to solve the control problem like trajectory control, researchers proposed many control idea in different ways. One of the very recent innovations named Brain Emotional Based Intelligent Controller (BELBIC) is becoming a well known model free adaptive controller which has effective capabilities to handle nonlinearities and uncertainties. This paper proposed a modified version of BELBIC where fuzzy inference system tunes the reward function parameter of it for the trajectory control of EHA system. Results implied that proposed controller has the ability to follow different reference trajectory with minimal position error which bear out strongly the aptitude of the proposed control method.
Real-time sensor fault tolerant control for an Electro-hydraulic actuator
Syed Abu Nahian,Phi Luan Nguyen,Hyung Gyu Park,Kyoung Kwan Ahn 유공압건설기계학회 2015 유공압건설기계학회 학술대회논문집 Vol.2015 No.10
Electro-hydraulic actuators (EHAs) become more and more important in the modern industry due to their advantages over electrical drives. Although EHAs have been applied to various applications for precise pressure, force, or position control tasks, operating EHA systems under faults, especially from sensors could lead the economic losses and catastrophic failure to overall system, or even put human life in danger. Thus, retaining the stability of these systems under sensor failures is one of the critical issues in developing EHAs. In this paper, a study on an advanced sensor fault tolerant control of a typical EHA with tracking control tasks under sensor-fault conditions has been carried out. Here, an extended Kalman-Bucy unknown input observer (EKBUIO) composed with a density threshold-based fault detection (DTFD) is proposed in designing the real-time sensor fault tolerant control (SFTC) of EHA system. The effectiveness of the proposed SFTC architecture has been investigated by experimenting on a test bed using an EHA in sensor failure conditions.
Modeling and Fault Tolerant Control of an Electro- Hydraulic Actuator
Syed Abu Nahian,Dinh Quang Truong,Puja Chowdhury,Debdatta Das,안경관 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.10
In the modern industry, electro-hydraulic actuators (EHAs) have been applied to various applications for precise position pressure/ force control tasks. However, operating EHAs under sensor faults is one of the critical challenges for the control engineers. For its enormous nonlinear characteristics, sensor fault could lead the catastrophic failure to the overall system or even put human life in danger. Thus in this paper, a study on mathematical modeling and fault tolerant control (FTC) of a typical EHA for tracking control under sensor-fault conditions has been carried out. In the proposed FTC system, the extended Kalman-Bucy unknown input observer (EKBUIO) -based robust sensor fault detection and identification (FDI) module estimates the system states and the time domain fault information. Once a fault is detected, the controller feedback is switched from the faulty sensor to the estimated output from the EKBUIO owing to mask the sensor fault swiftly and retains the system stability. Additionally, considering the tracking accuracy of the EHA system, an efficient brain emotional learning based intelligent controller (BELBIC) is suggested as the main control unit. Effectiveness of the proposed FTC architecture has been investigated by experimenting on a test bed using an EHA in sensor failure conditions.
A Study on Energy Saving of IMV Circuit using Pressure Feedback
Park, Hyoung Gyu,Nahian, Syed Abu,Anh, Kyoung Kwan The Korean Society for Fluid Power and Constructio 2016 드라이브·컨트롤 Vol.13 No.4
In recent hydraulic actuation systems, conventional hydraulic spool valves with pressure compensators are becoming less popular, after the introduction of the independent metering concept for valves. Within this concept, four valves are needed for actuating a single cylinder. Subsequently, this increases the freedom of controlling both chamber pressures of the cylinder, and it then provides for electronically-controlled pressure compensation facilities. Additionally, this has the potential to save valuable energy. The primary focus of this paper is to develop a new generation of hydraulic circuits using the independent metering valve (IMV). This configuration can function well as a conventional IMV circuit while providing better pressure control. We first describe the working principles of five distinct modes of the proposed IMV system. Then, mathematical models for each working mode are presented. Finally, we present numerical simulations that have been carried out to evaluate the system performance, in comparison with that of the conventional IMV configuration. The simulation results demonstrate that the performance of the new IMV configuration is superior to the conventional IMV system in terms of energy savings.
Organ Rupture Detection Algorithm of Surgical Robot
Ju Seok Kang,Nahian Rahman,Sung Min Yoon,Gm Gang Cha,Min Cheol Lee 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10
Reaction force estimation is the major challenge of surgical robotic procedures. In previous research, sliding mode control with sliding perturbation observer (SMCSPO) is used to estimate the reaction force in the sensor-less system. Moreover, a fuzzy-SPO method is also proposed to separate actual reaction force in presence of dynamic disturbances. However, in both those research, some physical constraints determined the SMCSPO parameters, which play a vital role in the force estimation sensitivity. The force sensitivity of the algorithm is equally important because extra force can cause organ impairment, rupture during surgery. Therefore, in this study, the force resolutions of the SPO and fuzzy-SPO for a robotic model have studied by Matlab simulation and it has seen that fuzzy-SPO performs better than classical SPO.