The DC motor is one of the simplest electrical machines used in industry since it is controlled by direct voltages and currents. These configurations have various advantages, allowing the machine to be adapted to the constraints of its specific application. The present chapter analyzes the DC motor with separate excitation without the use of a speed sensor to approximate the rotor speed. An analysis of the stability of the rotor speed estimation is performed. Enhanced control of the direct action is integrated into the adaptive observer to decrease the roundness capability of the model and simplify implementation. Design guidelines for the feedback gain and speed fractional controller whose parameters are automatically adjusted using intelligent fuzzy logic techniques are also provided to ensure system stability throughout the operating region. The results given in this study verify the validity and effectiveness of the proposed control technique. © 2022 Elsevier Inc. All rights reserved.
Adsorption as an Emerging Technology and Its New Advances of Eco-Friendly Characteristics: Isotherm, Kinetic, and Thermodynamic Analysis
Water contamination with paints causes a colour agent to the water that negatively affects the environment, organisms, and humans. Different physicochemical processes are applied for wastewater treatment; however, they have many drawbacks such as high cost, generating toxic waste, and non-effective at low concentrations. Adsorption is considered a promising technique for pollutant removal from polluted wastewater. Commercial activated carbon, nano-materials, and natural biological materials are used as adsorbents in adsorption. This chapter focuses on discussing the adsorption process, the factors affecting the adsorption, different adsorption materials, and the isothermal, kinetic, and thermodynamic models. © 2023 selection and editorial matter, Irene Samy Fahim and Lobna A. Said; individual chapters, the contributors.
Meminductor: Modeling, analysis, and emulators
This chapter introduces the basic definition of meminductor and its mathematical representation of time-invariant system (Ideal, Generic, and Extended) with some examples. The mathematical model of meminductor and its response under different current excitations (step, sinusoidal, and periodic) are discussed with analytical, numerical, and circuit simulations. Different meminductor emulators are introduced with their mathematical modeling and numerical simulation, and verified using PSPICE simulations. © 2015, Springer International Publishing Switzerland.
Memristor mathematical models and emulators
This chapter introduces different generalized mathematical classes of memristors which can be categorized as: continuous symmetrical models (current and voltage controlled emulators), continuous nonsymmetrical model, switched-memristor model, and fractional-order model with some experimental results. Different emulators with experimental results are discussed based on CCII, discrete components, and MOS realizations. Different analytical expressions, numerical analyses, circuit simulations results as well as experimental results are provided for most of the previous models. © 2015, Springer International Publishing Switzerland.
Memristor: Models, types, and applications
This chapter discusses the main properties of the memristor, a comparison between five recent memristor models, mathematical modeling of the HP memristor with analytical expressions for different excitations, mathematical representations of time-invariant memristor (ideal, generic, and extended), different memristor implementation types, and some memristor-based applications in digital and analog circuits. © 2015, Springer International Publishing Switzerland.
Self-excited attractors in jerk systems: Overview and numerical investigation of chaos production
Chaos theory has attracted the interest of the scientific community because of its broad range of applications, such as in secure communications, cryptography or modeling multi-disciplinary phenomena. Continuous flows, which are expressed in terms of ordinary differential equations, can have numerous types of post transient solutions. Reporting when these systems of differential equations exhibit chaos represents a rich research field. A self-excited chaotic attractor can be detected through a numerical method in which a trajectory starting from a point on the unstable manifold in the neighborhood of an unstable equilibrium reaches an attractor and identifies it. Several simple systems based on jerk-equations and different types of nonlinearities were proposed in the literature. Mathematical analyses of equilibrium points and their stability were provided, as well as electrical circuit implementations of the proposed systems. The purpose of this chapter is double-fold. First, a survey of several self-excited dissipative chaotic attractors based on jerk-equations is provided. The main categories of the included systems are explained from the viewpoint of nonlinearity type and their properties are summarized. Second, maximum Lyapunov exponent values are explored versus the different parameters to identify the presence of chaos in some ranges of the parameters. © 2018, Springer International Publishing AG.
Memristor-based relaxation oscillator circuits
This chapter discusses the analysis and design of memristor-based oscillators which is considered one of the nonlinear analog block required for many applications such as chaotic memristor oscillators and artificial neuron network. The realizations of memristor-based oscillators have been discussed via replacing capacitors with memristors to construct relaxation reactance-less oscillators. The advantages of such oscillators are related to low frequency, nanoscale, and simple designs and can be used in neuromorphic systems. Different topologies of memristor-based relaxation oscillators have been discussed and either symmetric or asymmetric types with analytical formulas of oscillation frequency and condition for oscillations are derived. The analyses of these oscillators are introduced with their numerical simulations, and verified using PSPICE circuit simulations showing a great matching. Moreover, many fundamentals are also discussed such as the effect of boundary dynamics, series and parallel connections as well as power analysis in memristor-based circuits. © 2015, Springer International Publishing Switzerland.
A study on coexistence of different types of synchronization between different dimensional fractional chaotic systems
In this study, robust approaches are proposed to investigate the problem of the coexistence of various types of synchronization between different dimensional fractional chaotic systems. Based on stability theory of linear fractional order systems, the co-existence of full state hybrid function projective synchronization (FSHFPS), inverse generalized synchronization (IGS), inverse full state hybrid projective synchronization (IFSHPS) and generalized synchronization (GS) is demonstrated. Using integer-order Lyapunov stability theory and fractional Lyapunov method, the co-existence of FSHFPS, inverse full state hybrid function projective synchronization (IFSHFPS), IGS and GS is also proved. Finally, numerical results are reported, with the aim to illustrate the capabilities of the novel schemes proposed herein. © Springer International Publishing AG 2017. All rights reserved.
Memristor-based multilevel digital systems
This chapter investigates the advantages of memristor-based digital applications using multi-level arithmetic concepts. Recently, there are huge concerns regarding the memristor in digital signal processing (DSP) circuits to enhance the performance and realize very high density, nonvolatile memories in neural networks. This can be achieved by mapping the high/low logic into the memristor high/low resistances. Recently, the potential to divide the memristance levels to build multilevel digital circuits such as the ternary and redundant circuits are discussed. The concepts have been initiated by designing a half ternary adder based on the memristor; then, the concept is generalized for redundant half adder, full adder, and N-bit adder circuits. The advantages of such circuits that the speed is independent on the operand and parallel processing can be handled efficiently. Moreover, a general approach to build digital functions using mixed memristor-transistor circuits are investigated such as multipliers. © 2015, Springer International Publishing Switzerland.
Chaotic properties of various types of hidden attractors in integer and fractional order domains
Nonlinear dynamical systems with chaotic attractors have many engineering applications such as dynamical models or pseudo-random number generators. Discovering systems with hidden attractors has recently received considerable attention because they can lead to unexpected responses to perturbations. In this chapter, several recent examples of hidden attractors, which are classified into several categories from two different viewpoints, are reviewed. From the viewpoint of the equilibrium type, they are classified into systems with no equilibria, with a line of equilibrium points, and with one stable equilibrium. The type of nonlinearity presents another method of categorization. System properties are explored versus the different parameters to identify the values corresponding to the presence of strange attractors. The behavior of the systems is explored for integer order and fractional order derivatives using the suitable numerical techniques. The studied properties include time series, phase portraits, and maximum Lyapunov exponent. © 2018 Elsevier Inc. All rights reserved.