Modeling and Control of Complex Physical Systems:The port-hamiltonian approach

Well structured reference book presenting the new paradigm of Port Hamiltionian Systems which has a large potential to be successful in tackling some of the big challenges in modern control theory and engineeringThe potential reference for many new developments taking place in modeling and controlExtend the readers knowledge and understanding of advanced modeling, analysis and control methods using the Port-Hamiltonian Systems paradigmProvides systematic methods for analysis and control, closely linked to the physics of the system. The power of these methods is demonstrated in various physical domain

Exergetic Port-Hamiltonian Systems Modeling Language

Mathematical modeling of real-world physical systems requires the consistent combination of a multitude of physical laws and phenomenological models. This challenging task can be greatly simplified by hierarchically decomposing systems. Moreover, the use of diagrams for expressing such decompositions helps make the process more intuitive and facilitates communication, even with non-experts. As an important requirement, models have to respect fundamental physical laws such as the first and the second law of thermodynamics. While some existing modeling frameworks can make such guarantees based on structural properties of their models, they lack a formal graphical syntax. We present a compositional and thermodynamically consistent modeling language with a graphical syntax. As its semantics, port-Hamiltonian systems are endowed with further structural properties and a fixed physical interpretation such that thermodynamic consistency is ensured in a way that is closely related to the GENERIC framework. While port-Hamiltonian systems are inspired by graphical modeling with bond graphs, neither the link between the two, nor bond graphs themselves, can be easily formalized. In contrast, our syntax is based on a refinement of the well-studied operad of undirected wiring diagrams. The language effectively decouples the construction of complex models via the graphical syntax from physical concerns, which are dealt with only at the level of primitive subsystems that represent elementary physical behaviors. As a consequence, reuse of models and substitution of their parts becomes possible. Finally, by construction, systems interact by exchanging exergy, i.e. energy that is available for doing work, so the language is particularly well suited for thermodynamic analysis and optimization

Impedance Transformers

Non

System- and Data-Driven Methods and Algorithms

An increasing complexity of models used to predict real-world systems leads to the need for algorithms to replace complex models with far simpler ones, while preserving the accuracy of the predictions. This two-volume handbook covers methods as well as applications. This first volume focuses on real-time control theory, data assimilation, real-time visualization, high-dimensional state spaces and interaction of different reduction techniques

Measurement of Electromagnetic Noise Coupling and Signal Mode Conversion in Data Cabling

Nonuniformity in transmission lines is known to be one of the causes of electromagnetic compatibility (EMC) and signal integrity (SI) issues, especially at high frequencies. This may include unpredictability in the manufacturing process, design constraints, tolerances in the values of terminal components, pigtail effects, etc., that can generate, common mode currents – with resultant degradation of signal performance of transmission lines with respect to ground. All these phenomena are capable of converting the desired differential mode (DM) signal into the unwanted common mode (CM) signal and vice versa. This study looks at cable nonuniformity resulting from irregular cable twists in twisted pair cabling, using the Category 6 UTP as an example, and considers this phenomenon responsible for signal mode conversion. Although twisted pair cables are generally often regarded as balanced transmission lines, the study shows that signal mode conversion is capable of twisted pair cables, and that makes twisted pair cabling a non-ideal balanced transmission line. However, it is difficult to analyse nonuniformity using differential equations because of the changing per-unit-length (p.u.l) parameters throughout an entire line length. Because of this, experimental measurements based on mixed-mode s-parameters analysis are designed and used to show that twisted pair cables can convert a differential mode signal to common mode signal and thus cause radiated emissions to the circuit environment. A vital contribution of this study is in the measurement techniques used. Similarly, a common mode signal (represented by an externally generated noise signal) can couple onto the transmission line, and because of the physical structure of the line, the line could become susceptible to external noise. These phenomena are not associated with ideal balanced transmission lines. In either case, if the mode conversion is not minimized, it has the potential to affect the performance of the twisted pair transmission line in terms of bit error rate. Bit error rate, BER, is basically the average rate at which transmitted errors occur in a communication system due to noise and is defined as the number of bits in error divided by the total number of bits transmitted. Therefore, reducing mode conversion in a transmission line helps to reduce the bit error rate and indeed minimise crosstalk in the communication channel. The experiments were conducted using a 4-Port Vector Network Analyser. The significance of using the 4-port VNA is that it has a general application in cable parameter measurement in the absence of specialized/customized measuring instruments. Nonetheless, with some transmission line assumptions based on the Telegrapher’s equation and applying the concept of modal decomposition, the mechanisms of signal mode conversion could be recognised. Consequently, an approximate first step symbolic solution to identifying EM radiation and hence DM-to-CM conversion and vice versa in data cable were proposed.Tertiary Education Trust Fund (Nigeria

Modeling EMI Resulting from a Signal Via Transition Through Power/Ground Layers

Signal transitioning through layers on vias are very common in multi-layer printed circuit board (PCB) design. For a signal via transitioning through the internal power and ground planes, the return current must switch from one reference plane to another reference plane. The discontinuity of the return current at the via excites the power and ground planes, and results in noise on the power bus that can lead to signal integrity, as well as EMI problems. Numerical methods, such as the finite-difference time-domain (FDTD), Moment of Methods (MoM), and partial element equivalent circuit (PEEC) method, were employed herein to study this problem. The modeled results are supported by measurements. In addition, a common EMI mitigation approach of adding a decoupling capacitor was investigated with the FDTD method

Fault tolerant electromechanical actuators for aircraft

This thesis reviews the developments in commercial aviation resulting from More Electric Aircraft initiatives. The present level of electromechanical actuation is considered with discussion of the factors affecting more widespread use. Two rather different electromechanical actuators are presented for commercial aircraft; DEAWS electrical flap actuation and ELGEAR nose wheel steering. Both projects are industrially driven with specifications based on existing medium-sized commercial aircraft. Methods comparing fault tolerant electric drive topologies for electrical actuators are presented, showing two different categories of electric drive and comparing each category in a variety of operating conditions to assess size and component count. The safety-driven design process for electromechanical actuators is discussed with reliability calculations presented for both proposed actuators, showing where fault tolerant design is required to meet safety requirements. The selection of an optimum fault tolerant electric drive for each actuator is discussed and fault tolerant control schemes are presented. The development of the electric flap and nose wheel steering systems is described, with the focus on the work performed by the author, primarily on the power electronic converters and control software. A comprehensive range of laboratory and industrial results are given for both actuators, showing demonstrations of fault tolerance at power converter and actuator levels. Following testing, further analysis is given on various issues arising prior and during testing of both converters, with design considerations for future electromechanical actuators. From design testing and analysis, the two projects can be compared to attempt to determine the optimal electromechanical actuator topology and to consider the challenges in evolving the two actuators to aerospace products.EThOS - Electronic Theses Online ServiceEPSRC : DTIGBUnited Kingdo