Yazdan Batmani

• PhD
• Professor (Associate) at University of Kurdistan

The tuning of the state-dependent Riccati equation (SDRE) is achieved by selecting/adjusting weighting matrices for states, \({\textbf {Q(x)}}\), and inputs, \({\textbf {R(x)}}\). The tuning results in a trade-off between the performance of the control system and energy consumption. An increase in \({\textbf {Q(x)}}\) or a decrease in \({\textbf {R...

Distributed cooperative control strategies for DC microgrids have been rapidly evolving in recent years. However, introducing a cyber layer to enhance robustness, scalability, and reliability also exposes the system to potential cyber‐attacks. The damage inflicted by such attacks on the system performance can be catastrophic, reaching a point where...

This paper proposes an observer-based event-driven approach to decrease the overuse of communication networks. The suggested approach aims to estimate the required data for sharing between units in line with as much communication reduction as possible. In other words, the proposed approach effectively determines which state variables should be shar...

In an autonomous droop-based microgrid, the system voltage and frequency (VaF) are subject to deviations as load changes. Despite the existence of various control methods aimed at correcting system frequency deviations at the secondary control level without any communication network, the challenges associated with these methods and their abilities...

In an AC microgrid, the active/reactive power is usually shared among its distributed generators (DGs) based on the frequency‐active power (F−P$F-P$) droop and the voltage‐reactive power (V−Q$V-Q$) droop. By increasing the resistant/inductance ratio (R/X$R/X$) of feeder lines; however, adverse effects of interactions between these two control loops...

The negative impedance characteristic of constant power loads (CPLs) can cause DC bus voltage fluctuations or even DC microgrid instability. In this paper, a nonlinear synergetic control method is used to guarantee the DC bus voltage stability of DC microgrids with CPLs. First, to regulate the capacitor voltage to its desired value, a macro-variabl...

The management of distributed and heterogeneous modern power networks necessitates the deployment of communication links, often characterized by limited bandwidth. This paper presents an event detection mechanism that significantly reduces the volume of data transmission to perform necessary control actions, using a scalable scheme that enhances th...

Cable robots are an important class of both parallel and serial robots. Since this kind of robot inherits nonlinear dynamics, designing a nonlinear suboptimal controller such that the robot tracks time-varying trajectories in complex missions to achieve optimal performance is of great importance. In this paper, a nonlinear suboptimal controller is...

The Muskingum model is one of the most widely used hydrological methods in flood routing, and calibrating its parameters is an ongoing research challenge. We optimized Muskingum model parameters to accurately simulate hourly output hydrographs of three flood-prone rivers in the Karun watershed, Iran. We evaluated model performance using the correla...

In this paper, a multi-input multi-output (MIMO) robust proportional-integral (PI) controller is designed for zero-level control of AC microgrids. The study system is a voltage-sourced converter connected to the rest of the microgrid through a distribution line and an AC output filter. The design procedure of the proposed high-gain PI controller is...

This paper proposes a zero‐sum dynamic game (ZSDG) design to mitigate frequency deviations in the secondary control layer of islanded AC microgrids. By defining a min‐max optimization problem, where the control input minimizes the frequency deviations while the external disturbances maximizes the cost function, a robust control law is designed. The...

In this paper, a new bi-objective control technique is proposed for the load frequency control in microgrids. The first objective is to set the system frequency to its desired value despite uncertainties in the system inertia and damping caused mainly by the penetration of renewable energy sources. The employed strategy to address this objective is...

In this paper, an event-triggered dynamic surface control technique is proposed for strict-feedback uncertain nonlinear networked systems in the presence of network-induced time delays. First, an event-based dynamic surface control law is designed. Then, by rewriting the control law as a communication-delay-distribution-dependent model, the closed-...

Due to the nonlinear dynamics of direct current (DC) microgrids, the existence of input constraints, and their multi-input multi-output (MIMO) nature, classical linear controllers cannot provide an appropriate performance in a wide range of operations. In this paper, to address these issues, nonlinear suboptimal controllers are systematically devel...

In this article, an event-triggered technique is proposed to implement state feedback controllers for continuous-time linear systems. Toward this end, the closed-loop dynamic is decomposed into the fast and slow subsystems. Then, two individualized event-triggered mechanisms (ETMs) are designed to compute two sequences of updates. The first ETM det...

The optimal design of a microgrid’s primary control’s inner loops is a severe challenge in high-bandwidth (BW) applications. Mostly, nonoptimal controllers are given as a sublevel design for the current and voltage inner loops. Unlike conventional methods, such as proportional resonant, proportional-integral, and finite-set model predictive control...

In this paper, the nonlinear optimal control of 3-degrees of freedom (DOF) articulated robot is investigated, both numerically and experimentally. The dynamical equations of the robot are extracted using the Newton–Euler formulation. The control objective is to design a nonlinear controller such that the end-effector tracks time-varying trajectorie...

In this paper, an event-triggered dynamic surface controller is proposed for strict-feedback nonlinear networked systems with mismatched uncertainties. Towards this aim and first of all, an event-based dynamic surface control law is designed. Then, the closed-loop error dynamics is derived and rewritten as a linear dynamics with nonlinear perturbat...

This article proposes a data-driven passive fault-tolerant tracking controller for single-input single-output (SISO) discrete-time linear systems with slowly-varying unknown parameters in the presence of actuator faults. Initially, a parameterized controller is considered. Using the internal model principle, the controller structure is determined s...

In this article, a decentralized event-triggered technique is developed to effectively implement the state-feedback controllers for a class of linear systems. Toward this end, the system dynamics is represented in its Jordan canonical form, and the system states are sorted based on their time constants. Then, for any Jordan block, an event-triggere...

Voltage regulation and proper load-sharing are two main control objectives of DC microgrids which the consensus-based secondary control can be regarded as a feasible approach to achieve them. Using this approach, in addition to the stable voltage regulation, the load is shared according to the nominal potential of the distributed generation units....

Increasing penetration of renewable energy sources based on power electronic interfaces in traditional power systems reduces the inertia constant and damping coefficient. It also increases uncertainty and the sensitivity of the system to disturbances. The concept of the virtual synchronous generator (VSG) is used to emulate the inertia constant and...

Like other multi-input multi-output (MIMO) systems, adverse effects of interactions among control loops on the system performance is one of the most challenging issues in the control of microgrids (MGs). In this paper, a robust MIMO controller is proposed for the MGs to solve the problem of power sharing among its distributed generators systematica...

In this paper, an individualized intelligent multiple-model technique is proposed to design automatic artificial pancreas (AP) systems for the glycemic regulation of type 1 diabetic patients. At first, using the multiple-model concept, the insulin-glucose regulatory system is mathematically identified by constructing some local models. In this step...

An attempt is made to design a fault-tolerant control system using a nonlinear technique, called the state-dependent Riccati equation (SDRE) method. The proposed mechanism consists of a master controller, an observer-based fault detection and isolation system, and three emergency controllers, designed using the SDRE methods. The master controller,...

The fully-distributed secondary control can be regarded as a viable solution to achieve acceptable voltage regulation and proper load-sharing of DC microgrids. Using this secondary controller, in addition to acceptable voltage regulation, the load is shared according to the nominal capacity of the distributed generation units. This manner is tradit...

The fully-distributed secondary control can be regarded as a viable solution to achieve acceptable voltage regulation and proper load-sharing of DC microgrids. Using this secondary controller, in addition to acceptable voltage regulation, the load is shared according to the nominal capacity of the distributed generation units. This manner is tradit...

As an inevitable issue, voltage unbalancing can have some adverse effects on the power systems equipment. This paper investigates a double synchronous reference frame-based control method to compensate unbalanced voltage, helping to properly active and reactive power-sharing. This approach controls the positive and negative components of the voltag...

Abstract: In this paper, a new observer is proposed for a class of nonlinear systems which is based on an output-dependent Riccati equation. Necessary conditions for convergence of the state estimation to the system state are investigated through a theorem. Then, based on the proposed observer, two techniques are developed to solve nonlinear stabil...

One of the major challenges in the real-time control of structures is the uncertainty in identifying the mechanical properties of the system, including mass, stiffness, and damping. However, the presence of uncertainty in time-varying systems (under severe environmental factors, the dynamic characteristics of the system change due to damage) is mor...

In this paper, a novel event-triggered observer is proposed to decrease the information exchange in continuous-time linear networked systems. The structure of the proposed observer consists of two main parts. The first one, called the event-triggered mechanism (ETM)), is placed by the system and is used to determine when the measured output of the...

In this study, a multiple-model strategy is evaluated as an alternative closed-loop method for subcutaneous insulin delivery in type 1 diabetes. Non-linearities of the glucose-insulin regulatory system are considered by modelling the system around five different operating points. After conducting some identification experiments in the UVA/Padova me...

This paper focuses on designing an adaptive Back-stepping controller for the nonlinear structure of Synchronverters used for emulating the virtual inertia in AC microgrids. Syn-chronverter control technique for the inverter-based generation units is a well-known method within the virtual inertia generating approaches, which is introduced briefly. I...

Artificial pancreas (AP) systems perform automated insulin delivery to subjects with type 1 diabetes mellitus (T1DM). In this paper, a nonlinear suboptimal controller is designed to make a trade-off between the elimination of hypoglycemia events and the limitation of postprandial hyperglycemia. All the in silico simulations are performed using the...

In this paper, using a novel event-triggered method, a robust H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> depth tracking controller is designed for a remotely operated underwater vehicle (ROV). It is assumed that the desired trajectory of the ROV is determined by an operator outside of th...

In this paper, an online adaptive optimal controller is firstly designed to optimize the performance of an automatic voltage regulator (AVR). Towards this end, an optimal quadratic tracking problem is defined based on the error between the synchronous generator’s terminal voltage and its desired value. Then, this optimal control problem is solved u...

In this paper, a multiobjective fault‐tolerant fixed‐order output feedback controller design technique is proposed for multivariable discrete‐time linear systems with unmeasured disturbances. Initially, a multiobjective fixed‐order controller is designed for the system by transforming the problem of tuning the parameters of the controller into a st...

In this paper, the problems of chaos control and chaos synchronization are solved using the state-dependent Riccati equation methods. In the former problem, a nonlinear suboptimal control law is found, which leads to a stable closed-loop system. In the latter, an optimal infinite-time horizon tracking problem is defined and solved using the state-d...

In this paper, a suboptimal controller is proposed for a DC microgrid interfaced with constant power loads (CPLs). Towards this end, a nonlinear model of the DC microgrid is utilized to define an optimal tracking control problem based on a discounted quadratic infinite-horizon cost function. The problem is solved using a State-Dependent Riccati Equ...

In this paper, two suboptimal event-triggered control techniques are proposed for both the regulation and the tracking problems in a broad class of nonlinear networked control systems. The proposed techniques are based on the state-dependent Riccati equation (SDRE) methodology. In the case of the regulation problem, the asymptotic stability of the...

In this paper, a new technique is proposed to solve the H ∞ tracking problem for a broad class of nonlinear systems. Towards this end, based on a discounted cost function, a nonlinear two-player zero-sum differential (NTPZSD) game is defined. Then, the problem is converted to another NTPZSD game without any discount factor in its corresponding cost...

In this study, a closed-loop treatment strategy is proposed for the control of blood glucose levels in type 1 diabetic patients. Toward this end, a non-linear technique for designing suboptimal tracking controllers, called the state-dependent Riccati equation tracker, is used based on a mathematical model of the glucose-insulin regulatory system. S...

In this paper, using the state-dependent Riccati equation (SDRE) approach, an event-triggered technique is proposed to solve the tracking problem for a broad class of nonlinear discrete-time networked control systems. It is shown that the proposed tracking controller leads to an asymptotically stable system while the information exchange between th...

This study proposes H 2 and H ∞ robust controllers to be applied to a DC-DC boost converter operates in the continuous conduction mode (CCM) in a DC microgrid system. Towards this end, the DC-DC boost converter is modelled based on the state-space averaging method with possible uncertainty in its parameters and also considerable variation in the in...

In this paper, an islanded microgrid is modelled as a linear multivariable dynamic system. Then, the multivariable analysis tools are employed. The generalized Nyquist diagram and the relative gain array are used respectively for the stability assessment and solving the paring problem among the inputs and outputs. Droop control dependency on the X/...

In this brief, a new technique for solving a suboptimal tracking problem for a class of nonlinear dynamical systems is presented. Toward this end, an optimal tracking problem using a discounted cost function is defined and a control law with a feedback-feedforward structure is designed. A state-dependent Riccati equation (SDRE) framework is used in...

The state-dependent Riccati equation (SDRE) technique can be used to solve optimal control problems for a wide class of nonlinear dynamical systems. In this method, instead of solving a complicated Hamilton-Jacobi-Bellman (HJB) equation, a state-dependent Riccati equation is solved which leads to a suboptimal control law. However, a priori model of...

Fractional-order systems, which involve integration and derivation of non-integer order, are increasingly being used in the fields of control systems. In this paper based on an extension of the well-known state-dependent Riccati equation (SDRE) techniques, a new method is proposed to design state feedback controllers in a wide class of nonlinear fr...

In this paper, we analyze stability of the equilibrium points in the Mayer model in case of having delay. It is shown that some of those points were overlooked in the analysis done by Buric et al. and Yu et al. However, the existence of such points in the validation of Mayer model is so essential in accordance with the realities in the immunology s...

This paper proposes a new method to design suboptimal sliding manifolds for a class of nonlinear uncertain systems with state and input delays. A switching control law is obtained based on the designed suboptimal sliding manifold. It is proved that the proposed method is able to guarantee the stability of the closed-loop system in the presence of u...

This paper suggests a new method to design observers in a class of nonlinear time-delay systems with delays in system states. The method is based on an extension of the well-known state-dependent Riccati equation (SDRE) technique. The conditions for locally asymptotic stability of the proposed observer are investigated. Some numerical simulations a...

Mathematical modelling and methods from control theory can be employed to find appropriate drug regimens in human immunodeficiency virus (HIV) treatment. In this study, using a non-linear time-delay model, the authors design some suboptimal highly active antiretroviral therapy (HAART) [http://www.en.wikipedia.org/wiki/Protease_inhibitor_%28pharmaco...

In this paper, based on two mathematical models, a set of optimal anticancer drug regimens is designed. Two important difficulties in treating cancers with chemotherapy are drug resistance and toxicity. They were considered in our treatment design; a compartmental model was extended to appropriately describe drug resistance and two constraints were...

In this work, we design a nonlinear state feedback controller based on the State Dependent Riccati Equation (SDRE) technique to eliminate the tumor. One of the most interesting advantages of the SDRE is that it is possible to consider the specific conditions of patients by defining appropriate weights in the cost function and by limiting the admini...

A method for solving the optimal control problems in linear systems with equal state and input delays has been recently presented by Basin and R-Gonzalez (2005, Automatica, 41, 915–920). In this note, based on a counterexample, it is shown that the method does not find the optimal solution.

Mathematical modeling and methods from control theory are employed to optimize drug regimens in cancer chemotherapy. In this paper, we utilized a PK-PD model to describe the effects of drugs on the tumor cells. In chemotherapy, it is essential to prescribe the drug dosages in a way that the number of cancer cells decreases while the least side effe...