Amir Abolfazl Suratgar

• Ph.D.
• Professor (Associate) at Amirkabir University of Technology

In this paper, a novel data-driven distributed optimal control (DDOC) scheme via neighbourhood optimization is proposed for affine nonlinear interconnected systems with unknown dynamics. In this scheme, each subsystem merely broadcasts its local information to its neighbours, and receives information only from them. The proposed distributed method...

Oil and gas wells frequently encounter the issue of drilling fluid loss circulation as drilling progresses, leading to significant complications and expenses. Effective prediction of mud loss during drilling is crucial for optimizing the selection of loss circulation materials (LCMs), improving drilling efficiency, and reducing costs and risks. Thi...

This study delves into the distributed optimal coordination (DOC) problem, where a network comprises agents with different relative degrees. Each agent is equipped with a private cost function. The goal is to steer these agents towards minimizing the global cost function, which aggregates their individual costs. Existing literature often leans on k...

In this study, a new approach for modification of membership functions of a fuzzy inference system (FIS) is demonstrated, in order to serve as a pattern recognition tool for classification of patients diagnosed with multiple sclerosis (MS) from healthy controls (HC) using their visually evoked potential (VEP) recordings. The new approach utilizes K...

Pollutants and particles have a dynamic character, are highly volatile, and exhibit a high degree of temporal and spatial fluctuation, making it challenging to forecast air quality accurately. On the other hand, the ability to model, forecast, and monitor air quality is becoming more critical, particularly in metropolitan areas. This is because air...

Objective. Voxel-wise visual encoding models based on convolutional neural networks (CNNs) have emerged as one of the prominent predictive tools of human brain activity via functional magnetic resonance imaging signals. While CNN-based models imitate the hierarchical structure of the human visual cortex to generate explainable features in response...

The synchronization of two chaotic electrostatic and electromechanical transducers is addressed via a continuous terminal sliding-mode control (SMC) strategy. Recently, fixed-time convergence has received increased attention among scholars. The convergence time with this type of controller has an upper bound independent of the initial conditions. I...

There is an infinite number of objects in outer space, and these objects and asteroids might be harmful. Hence, it is wise to know what is surrounding us and what can harm us amongst those. Therefore, in this article, with the hyperparameters tuning of Extra Tree, Random Forest, Light Gradient Boosting Machine, Gradient Boosting, and Ada Boost, the...

Brain Computer Interface (BCI) offers a promising approach to restoring hand functionality for people with cervical spinal cord injury (SCI). A reliable classification of brain activities based on appropriate flexibility in feature extraction could enhance BCI systems performance. In the present study, based on convolutional layers with temporal-sp...

It is essential to have accurate projections of the quantity of solar energy that will be generated in the future to improve the competitiveness of solar power plants in the energy market and reduce the dependence of both the economy and society on fossil fuels. This can be accomplished by having a better understanding of the amount of solar energy...

This paper proposes a distributed gradient dynamics approach for solving Multi-Objective AC Optimal Power Flow (MO-ACOPF) problem. The fuel cost, environmental pollution, and network loss are considered as objective functions. The non-convex MO-ACOPF problem is reformulated as a gradient dynamical system. We derive condition under which the equilib...

Voxel-wise encoding models based on convolutional neural networks (CNNs) have emerged as state-of-the-art predictive models of brain activity evoked by natural movies. Despite the superior predictive performance of CNN-based models, the huge number of parameters in these models have made them difficult to interpret for domain experts. Here, we inve...

In this paper, a continuous terminal sliding mode control (SMC) design is used to address the problem of synchronizing two chaotic electrostatic and electromechanical transducers. Recently, fixed-time convergence has received increased attention among scholars. The convergence time with this type of controller has an upper bound independent of the...

The open-loop drive of the MEMS tunable capacitor does not guarantee accurate output voltage in an AC voltage reference source (VRS). For a precise regulation, the capacitor movable plate should track the pull-in point trajectory harmlessly and should be kept at a certain distance from the fixed plate. Achievement of this objective is a highly chal...

Inverted pendulum and its variants, including two connected inverted pendulum on carts (TCIPC), are suitable benchmarks to study various control methods of underactuated systems. This work will use an adaptive fuzzy terminal sliding mode controller (AFTSMC) to investigate the stabilization problem of the TCIPC system. First, two finite-time sliding...

Images captured through the glass often consist of undesirable specular reflections. These reflections detected in front of the glass remarkably reduce the quality and visibility of the scenes behind it. The process of reflection removal from images through the glass has many important applications in computer vision projects. Recently deep learnin...

Microgrids have become one of the most challenging areas of power systems in recent years. Microgrid control methods often require a complete model of the system. In this paper, state-space model of DGs, network, and loads as components of microgrids is studied. Nominal set points of the output voltage are used as input for the secondary voltage co...

Today, decoding electroencephalography (EEG) data is an important and efficient achievement in neuroscience and Brain-Computer Interface (BCI) systems. So that improving the performance of BCI systems can be effective in helping spinal cord injury (SCI) patients to perform daily tasks and rehabilitation work. In contrast, some of the challenges tha...

Soft robots are utilized in various operations such as rehabilitation, manipulation, and locomotion. These robots are sometimes excited by means of rubber based bending actuators, which are highly nonlinear and hyperelastic. In addition, in contrast to robots with rigid links and common actuators, continuous deformation of soft bending actuators in...

In this paper, a new distributed optimal control strategy for continuous-time nonaffine nonlinear systems with unknown dynamics is presented. We exploit a paradigm based on an Extended Adaptive Dynamic Programming (EADP), which will be fully stated in the paper, to provide a distributed optimal control strategy in the presence of subsystem interact...

This paper deals with robust fault detection (FD) of continuous time Lipschitz nonlinear switched systems based on observer method. A switched observer with average dwell time (ADT) approach is designed using projection lemma wherein the Lipschitz constant is maximized and simultaneously the effect of disturbances is attenuated effectively. Lipschi...

This study presents a conventional Ziegler-Nichols (ZN) Proportional Integral Derivative (PID) controller, having reviewed the mathematical modeling of the Micro Electro Mechanical Systems (MEMS) Tunable Capacitors (TCs), and also proposes a fuzzy PID controller which demonstrates a better tracking performance in the presence of measurement noise,...

This article proposes a distributed nonconvex optimization algorithm for energy efficiency (EE) in mobile ad hoc networks (MANETs). The proposed model for EE in MANETs can be classified into the category of nonconvex optimization problems. There are various distributed algorithms for solving nonconvex optimization problems. But, they are associated...

In this paper, a feedforward factional order PID (FFOPID) control strategy for load frequency control of a microgrid is presented. In the proposed scheme, a feedforward controller is applied in control of the microgrid in islanded operation. In order to use the feedforward controller, the disturbance signal, which is defined as the difference betwe...

In this study, an adaptive neuro-observer-based optimal control (ANOPC) policy is introduced for unknown nonaffine nonlinear systems with control input constraints. Hamilton–Jacobi–Bellman (HJB) framework is employed to minimize a non-quadratic cost function corresponding to the constrained control input. ANOPC consists of both analytical and algeb...

MEMS Tunable Capacitors (TC) are major elements in AC Voltage Reference Sources (VRS). Physical parametric uncertainties, external electrostatic disturbance, and measurement noise malfunction their operation and ruin the preciseness of the VRS output voltage. Our objective problem is the design of a controller to cope with the mentioned parametric...

A novel Nonlinear Consequent Part Recurrent Type-2 Fuzzy System (NCPRT2FS) is presented for the modeling of renewable energy systems. Not only does this paper present a new architecture of the type-2 fuzzy system (T2FS) for identification and behavior prognostication of an experimental solar cell set and a wind turbine, but also, it introduces an e...

Tunable micro-electro-mechanical systems (MEMS) capacitors as the fundamental parts are embedded in MEMS AC voltage reference sources (VRS). Being concerned with the accuracy of the output voltage in the reference sources, it gets important to address uncertainties in the physical parameters of the MEMS capacitor. The uncertainties have the great i...

Not only does this paper present a novel type-2 fuzzy system for identification and behavior prognostication of an experimental solar cell set and a wind turbine, but also it brings forward an exquisite technique to acquire an optimal number of membership functions and the corresponding rules. It proposes a seven-layered NCPRT2FS. For fuzzification...

As the reservoir pressure declines, production decreases and there is no way just using artificial lift methods such as the gas lift to make the production economical. Gas lift optimal control is one of the dominant problems in gas lift operation. There are various methods for this purpose in literature, but all of them use a primary control method...

The focus of this paper is to address a novel control technique for stability and transparency analysis of bilateral telerobotic systems in the presence of data loss and time delay in the communication channel. Different control strategies have been reported to compensate the effects of time delay in the communication channel; however, most of them...

Uncertainty in parameters of a tunable Micro Electro Mechanical System (MEMS) capacitor, as the main component of AC Voltage Reference Source (VRS), is significant to obtain a precise output voltage unaffected by disturbance and noise. Although attempts are done to craft the capacitor with desired physical specification and improve accuracy of para...

Uncertain parameters in a MEMS tunable capacitor, as one of the fundamental elements in a MEMS AC voltage reference source (VRS) structure, is an important issue for acquisition of a rigorous voltage in the VRS output. The output is mostly supposed to be destroyed by harmful disturbance and noise. Even though the manufacturers make attempts to buil...

This paper presents a new state estimation scheme using the second-level adaptation technique and Multiple High-Gain Observers (MHGO) for improving the transient response and attenuating undesired peaks of High-Gain Observers (HGOs). The proposed method considers state estimation as a convex combination of provided information by multiple high-gain...

In this paper, the problem of position tracking in the teleoperation systems subject to external forces is considered. An adaptive control algorithm and adaptive laws are proposed based on nonlinear disturbance observer in order to address the tracking error caused by external forces in the presence of constant communication time delays. First, we...

In this paper, a legless capsule robot (capsubot) comprised of a sealed external body, an internal body, and a rotational actuator is proposed. The aim of this robot is to move in a two-dimensional viscous environment. After the robot is designed and modeled, a four-stage angular velocity profile is proposed to move the robot in one direction. In a...

In the gas lift, gas injection rate has an optimum value and increasing or decreasing its amount decreases the oil production rate. This optimum point changes in production time and creates an optimum trajectory. There has previously been much research in this area, but none have used a powerful tool in a dynamic model to find a good optimal path f...

In this paper, distributed optimization in heterogeneous dynamical networks that consist of both single- and double-integrator agents are studied. This paper is divided into two main parts. In the first part, all agents shall reach a consensus point that minimizes the sum of local convex objective functions. In the proposed solution, it is assumed...

This article introduces a new algorithm for nonlinear state estimation based on deterministic sigma point and EKF linearized framework for priori mean and covariance respectively. This method reduces the computation cost of UKF about 50% and has better accuracy compared to EKF due to propagating mean and Covariance of state to 3rd order Taylor seri...

You can find the pre-print version on: https://arxiv.org/ftp/arxiv/papers/1907/1907.03109.pdf

Uncertainty in physical parameters of a tunable MEMS capacitor, as the main element of MEMS AC voltage reference (VRS), is a significant matter to be regarded in order to obtain a precise output voltage which could be ruined by disturbance and noise. Even though many attempts are done to make MEMS tunable capacitor with desired precise physical cha...

This paper presents two well-known designs of model reference adaptive control (MRAC) based on state and output feedback, to control microelectromechanical system AC voltage reference source (MEMS AC VRS). The best performance of AC voltage reference is achieved when the movable plate of MEMS capacitor is located and stayed under the pull-in point....

This paper deals with the design of a model-based rapid fault detection and isolation strategy using sliding mode observers. To address this problem, a new scheme is proposed by adaptively combining the information provided by a bank of observers. In this regard, a new structure for sliding mode observers is considered. Then, the well-known recursi...

In this paper a comprehensive simulator for a 2 × 25 kV AC autotransformer electrified traction system with MTL arrangement is developed. The main goal of this simulator is to complete performance analysis of a traction system consisting of some moving trains controlled by a virtual driver or ATO system under natural constraints and traction power...

In this paper, a contributive just schematic design of a 3-DOF MEMS (Micro Electro Mechanical System) vibratory gyroscope is presented. Not only does the conceptual design have the advantage of being manipulated by balanced force actuation mechanism, but also it benefits providing a differential capacitive one. The three sets operate along drive an...

Intraoperative brain shift decreases the accuracy of neuronavigation systems based on preoperative images. In this paper, this problem is addressed by calculating an estimation of brain shift which can be employed to update the preoperative brain images. Therefore, the precision of navigation can be improved. In this regard, a brain shift estimatio...

In this paper, an optimal consensus problem with local inequality constraints is studied for a network of single-integrator agents. The goal is that a group of single-integrator a gents rendezvous at the optimal point of the sum of local convex objective functions. The local objective functions are only available to the corresponding agents that on...

In this paper, an optimal consensus problem with local inequality constraints is studied for a network of single-integrator agents. The goal is that a group of single-integrator a gents rendezvous at the optimal point of the sum of local convex objective functions. The local objective functions are only available to the corresponding agents that on...

Magnetic resonance images (MRI) play an important role in supporting and substituting clinical information in the diagnosis of multiple sclerosis (MS) disease by presenting lesion in brain MR images. In this paper, an algorithm for MS lesion segmentation from Brain MR Images has been presented. We revisit the modification of properties of fuzzy-c m...

MR images can support and substitute clinical information in the diagnosis of multiple sclerosis (MS) by presenting lesion. In this paper, we present an algorithm for MS lesion segmentation. We revisit the modification of properties of fuzzy c means algorithms and the canny edge detection. Using reformulated fuzzy c means algorithms, apply canny co...

The paper contributes a special design of a 2-DOF MEMS (Micro Electro Mechanical System) vibratory gyroscope in a mere schematic way which has benefit of being manipulated by balanced force actuation mechanism and a differential capacitive sensing one as well. These two embedded mechanisms function along drive and sense axes because the controltask...

This paper fully studies distributed optimal consensus problem in non-directed dynamical networks. We consider a group of networked agents that are supposed to rendezvous at the optimal point of a collective convex objective function. Each agent has no knowledge about the global objective function and only has access to its own local objective func...

This paper fully studies distributed optimal consensus problem in non-directed dynamical networks. We consider a group of networked agents that are supposed to rendezvous at the optimal point of a collective convex objective function. Each agent has no knowledge about the global objective function and only has access to its own local objective func...

This paper presents a novel approach for stability and transparency analysis for bilateral teleoperation in the presence of data loss in communication media. A new model for data loss is proposed based on a set of periodic continuous pulses and its finite series representation. The passivity of the overall system is shown using wave variable approa...

The accuracy of physical parameters of a tunable MEMS capacitor, as the major part of MEMS AC voltage reference, is of great importance to achieve an accurate output voltage free of the malfunctioning noise and disturbance. Even though strenuous endeavors are made to fabricate MEMS tunable capacitors with desiderated accurate physical characteristi...

In this paper, distributed convex optimization problem over non-directed dynamical networks is studied. Here, networked agents with single-integrator dynamics are supposed to rendezvous at a point that is the solution of a global convex optimization problem with some local inequality constraints. To this end, all agents shall cooperate with their n...

In this paper, an attempt is made to tune the controllers of a doubly fed induction generator (DFIG)–based wind energy conversion system (WECS). The procedure is optimized to improve the performance of the WECS under both normal and transient operating conditions. It is shown that under normal operating conditions, the outer control loop of the rot...

Till now, various models of the motion of nanobots have been submitted; the pioneer models, in spite of being exact in mathematics, had their own kind of problems. The most recent challenge is to describe a model whose attitude can be practical so that these motions can be estimated. Considering the massive uses of nanobots, the kinds of motions an...

This paper presents a new self-evolving recurrent Type-2 Fuzzy Radial Basis Function Network (T2FRBFN) in which the weights are considered Gaussian type-2 fuzzy sets and uncertain mean in each RBF neuron. The capability of the proposed T2FRBFN for function approximation and dynamical system identification perform better than the conventional RBFN....

This paper presents a sufficient condition for stability of a class of multiple input multiple output recurrent type-2 TSK fuzzy systems using spectrum analysis. In this class of type-2 TSK fuzzy systems, the antecedent part is interval Gaussian type-2 fuzzy sets and the consequent part is a linear combination of inputs with crisp coefficients. In...

One of the rudimental and practical systems for guidance and stabilization of the vehicles is the Electric Power steering (EPS) system. EPS and SBW (Steer by Wire) are utilized in advanced vehicle control systems. The convenience and safety of the driver, over car steering at high and low speeds are essential parameters in the determination of qual...

This paper introduces a new adaptive output feedback control scheme to synchronize two Hindmarsh-Rose neurons while all of the parameters of neural model are considered to be unknown. The controller signal will be only applied to the membrane potential of neuron and it is possible to measure this mentioned potential as the other states are not phys...

Predictive quantitative structure-activity relationship was performed on the novel4-oxo-1,4-dihydroquinoline and 4-oxo-4H-pyrido[1,2-a]pyrimidine derivatives to explore relationship between the structure of synthesized compounds and their anti-HIV-1 activities. In this way, the suitable set of the molecular descriptors was calculated and the import...

This paper presents a novel adaptive neuro fuzzy inference system that uses interval Gaussian type-2 fuzzy sets in the antecedent part and Gaussian type-1 fuzzy sets as coefficients of linear combination of input variables in the consequent part. The capability of the proposed ANFIS2 for function approximation and dynamical system identification is...

In this paper, the stability and tracking control problem of a task space nonlinear bilateral teleoperation system is addressed interacting with a unknown environment. The controllers consist of adaptive controller and nonlinear disturbance observer to deal with uncertain dynamic model of manipulators, environmental and operators forces, respective...

A necessary condition for stability of a class of recurrent type-2 TSK fuzzy systems is presented. In this system, the antecedent part is indeed represented by interval Gaussian type-2 fuzzy set, and the consequent part is an ordinary nonlinear function of the system’s inputs. In the proposed method, at first a type-2 fuzzy model is established, an...

This paper focuses on the optimal structural design of a hybrid permanent-magnet-electro-magnetic suspension system (PEMS) for a magnetic levitation (Maglev) transportation system in order to decrease the suspension power loss. First, the nonlinear magnetic force expression of a PEMS system is obtained by developing the magnetic equivalent circuit...

This paper presents a new dynamic model, motion mechanism, and control for an underwater fish-like micro mobile robot. The micro mobile robot is actuated by two Lead Zirconate Titanate (PZT), each of which operates independently; this means that the robot has 2 Degrees of Freedom (DOF). PZT actuators are considered linear models without dynamics. D...

In this study, the problem of estimation of brain shift is addressed by which the accuracy of neuronavigation systems can be improved. To this end, the actual brain shift is considered as a Gaussian random vector with a known mean and an unknown covariance. Then, brain surface imaging is employed together with solutions of linear elastic model and...

In this paper, the problem of stability and tracking performance of FRVF (Forbidden Region Virtual Fixture) for bilateral nonlinear teleoperation systems is studied in presence of varying time delay. It is proved that PD-like controllers can stabilize the teleoperation systems with FRVF in slave side and variable time delay in communication channel...