This is to certify that the thesis entitled, “Study of PID controller design for systems with Time delay” submitted by Shri Anurag Mishra in partial fulfilment of the requirements for the award of Bachelor of Technology degree in Electrical Engineering at the National Institute Cited by: 1 Intelligent PID controller based on fuzzy logic proposed in this thesis. The proposed controllers in this research are designed by combining the conventional and intelligent control technologies. The purpose is to made my whole PhD journey clear, positive and enjoyable. I also would like to thank I have been very fortunate to start my thesis work under the supervision and guidance of Prof. Sandip Ghosh. He introduced me to the field of Control systems, educated me with the methods and principles of research, and guided me through the details of PID controllers. He is the whole Philosopher and Guide behind this thesis
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The following PhD theses have been completed at ETH within the research group, pid controller phd thesis.
Downloadable copies are available from the ETH Library via the Research Collection link, pid controller phd thesis. Human beings are social creatures that are naturally looking for, and in fact need, social interactions to maintain a healthy life and mindset. In the past couple of decades, the advent of social media platforms has facilitated maintaining relationships with family and friends even across long distances, but it has also affected people's behavior in their social activity, e.
On the other hand, the growing amount of available data is giving a unique opportunity for the analysis of the social network structures as well as of the underlying human social behavior. Social networks constitute highly complex systems because of their size, the inner complexity of their components human beingsand the feedback and cascade effects due to the inter-dependency between the individual behavior and the network structure.
Furthermore, social networks are strongly coupled with other network systems, e. With the objective of advancing our understanding of such a complex ecosystem, this thesis focuses on the modelling, analysis, and inference of the social network formation process.
At a high level, pid controller phd thesis, we distinguish between online social networks, based on real-world friendships, and online social networks, corresponding to our virtual identity on the social media platforms. In the fi rst part of the thesis we analyze online social networks, whose topological structure is fundamentally the result of the social behavior of the agents that locally strive to optimize their position in the network.
According to a number of socio-economic theories grounded on extensive empirical research, improving one's own network position can increase the individual's social capital in different forms, e. Hence, we consider a network formation process in which actors' interest is defi ned as a parametric combination of different socio-strategic incentives based on the network topology.
We study this individual networking behavior through the lens of game theory: following a utility maximization principle, pid controller phd thesis, actors rationally choose their set of followees. While a more common objective in strategic network formation games is to study the equilibria resulting from predefi ned payoff functions, our goal is to rationalize the observed network structures in terms of the unknown individual behavior of the actors.
Our approach proves to be mathematically tractable and statistically robust, and one of its main advantages is that it allows for empirical validations on real-world historical data on well-studied online social networks, as well as for comparison with well-known random networks models.
In the second part of the thesis, we turn our attention to today's most popular online social networks. These platforms paved the way for the so-called Web 2. Some of these online social networks, e.
Conversely, Twitter, YouTube, Instagram, TikTok, and many other popular platforms are all directed networks, where social media users can virtually follow real-life strangers.
By means of the integrated search engines, they can navigate others' user pro files, and their User-Generated Content, e. While the number of monthly active users in these platforms has dramatically increased in the last decade, the scienti c literature on social network formation models has not considered the User-Generated Content as main driving factor.
Our main contribution consists in formulating a network formation model based on the attractiveness of the User-Generated Content.
The individual linking decision is rooted in a meritocratic principle that rewards those users that provide higher quality content. The comparison between theoretical results and empirical data from Twitch, a popular platform for online gamers, proves that our quality-based model captures a number of realistic features of User-Generated Content-based online social networks.
The recent years have witnessed a steadily increasing deployment of large-scale systems and infrastructures in several cyber-physical domains, pid controller phd thesis for instance from the continent-wide electricity grid to eCommerce platforms. It is expected that in the coming years large-scale systems will impact further aspects of our everyday lives: just to name a few examples, from mobility on demand and autonomous guidance to the study of biochemical reaction networks in medicine.
One crucial question remains mostly unexplored: how do we optimally and safely operate these systems when their global behaviour depends on the coordination of multiple agents, none of which can observe the overall system? This thesis intends to focus on the mathematical aspects of the matter presented above, pid controller phd thesis.
Specifically, the goal of our study is to develop efficient algorithms to synthesize control policies that are optimal and safe, pid controller phd thesis. These policies must be based exclusively on measurements pid controller phd thesis are locally available to each agent; we refer to such control laws as optimal distributed controllers.
Motivated by the lack of sufficiently accurate dynamical models for such complex dynamical systems, we additionally wish to investigate how these algorithms can operate without knowing the models. In this sense, we require that they are solely based on the observed data, or as commonly stated pid controller phd thesis the machine-learning field, that they are data-driven.
In the first part of this thesis, we focus on further refining our understanding of the challenges inherent to using convex programming as a tool for synthesizing globally optimal distributed controllers given a lack of full information. Our main contribution is pid controller phd thesis reinterpret the classical result of quadratic invariance QI to identify more complex decentralization schemes that achieve global optimality.
We additionally include robust safety constraints. We finally suggest a new mathematical instrument that allows to parametrize controllers in an input-output way. In the second part of this thesis we turn our attention to how one can obtain convex approximations in the presence of arbitrary information structures.
Our key contribution is a novel method denoted as sparsity invariance SI for the synthesis of tight convex restrictions. The main advantages of SI are that i SI recovers both previous global optimality pid controller phd thesis given QI and previous heuristics as special cases, ii SI outperforms previous methods, as pid controller phd thesis illustrate through specific examples, and iii SI is widely adaptable, pid controller phd thesis, as it can be naturally encapsulated inside significantly different control frameworks.
We study applicability of SI and highlight its benefits on a real-world platooning scenario. In the third part of this thesis, we investigate the gradient-descent landscape in order to assess the efficacy of reinforcement learning algorithms when the dynamical model is unknown.
The milestone we achieve is to establish sample-complexity bounds to synthesize globally optimal distributed controllers when QI holds. We further show that gradient-descent ensures global optimality for a class of problems that is strictly larger than QI problems. To the best of our knowledge, our works are the first to address global optimality for distributed control in a data-driven setup. Many problems in science and engineering can be cast as discrete time, continuous space, infinite horizon stochastic optimal control problems.
The so-called value function and Pid controller phd thesis both characterise the solution of such problems, but are both intractable to compute in all but a few special cases. Pid controller phd thesis thesis focuses on methods that approximate the value function and Q-function.
We consider the linear programming approach to approximate dynamic programming, which computes approximate value functions and Q-functions that are point-wise under-estimators of the optimal by using the so-called Bellman inequality.
For this approximation method we provide theoretical guarantees on the value function and Q-function approximation error, and also for the sub-optimality of a policy generated using such lower-bounding approximations. In particular, the online performance guarantee is obtained by analysing an iterated version of the greedy pid controller phd thesis, and the fitting error guarantee by analysing an iterated version of the Bellman inequality.
These guarantees complement the existing bounds that appear in the literature. Given a collection of lower-bounding approximate value functions, an improved approximation can be constructed by taking the point-wise maximum over the collection, pid controller phd thesis, however, the challenge is how to compute the collection itself. To address this challenge, we introduce a novel formulation, referred to as the point-wise maximum approach to approximate dynamic programming, and use this to propose algorithms that pid controller phd thesis construct a collection of lower-bounding value functions with the objective of maximising the point-wise maximum of the collection.
We empirically demonstrate the advantages of the proposed algorithm through a range numerical examples that indicate classes of problems where the proposed algorithms improves upon state-of-the-art methods, pid controller phd thesis. A key result from the numerical studies is that the proposed algorithm can provide practically useful sub-optimality bounds for the online performance of any policy, pid controller phd thesis, even when the collection of approximate value functions is itself impractical to use for a policy.
Starting from first-principles, we cast a geometric treatment and arrive at the problem of stabilizing a particular log-polar configuration, corresponding to the optimal network flow in an electrical circuit.
The approach is, on the one hand, based on constructing a feedback-equivalent system which naturally decomposes into dynamics on the ray and on the circle. These spaces can be seen as mutual quotients of the Euclidean plane. Upon augmenting the appropriate amplitude-coupling component, the so-called phase-coupled oscillator system is no longer constrained to evolve on the n-torus, pid controller phd thesis.
On the other hand, a model-matching procedure is proposed to induce dominant dynamics for the radial and the angular coordinates.
As in mechanical systems, these simple integrators act as generalized coordinates and are associated with a special potential energy construction. From a power systems perspective, the potential energy function encodes the canonical network objective of inductor current minimization and capacitor voltage maximization. As the rest of the system is naturally damped, a harmonic steady-state behavior emerges, allowing a zero-dynamics refinement procedure.
We then explore ways of shaping the energy in the aim of achieving higher-level objectives, such as tracking given active and reactive power set points.
Finally, we pose a problem of transverse stabilization, and arrive at a constructive energy function and a feedback law for the synchronous machine and the inverter alike. This unified design methodology further allow us to study the dynamic properties of the most significant circuit elements in power systems.
Electrical power systems have been a part of daily life for more than a century. It is therefore no surprise that there has also been an active research field surrounding both operation and design of such systems. The tremendous increase in computational power available in the past few decades has enabled the application of advanced numer- ical methods for solving problems that thus far could only be solved approximately or heuristically. In this thesis, two numerical approaches are presented for mitigating over- voltage and overcurrent problems caused by local in-feed of renewable power in power distribution grids.
The first approach is based on a change to the way the system is operated. The thesis describes an optimization-based operating policy and introduces a numerical method to efficiently solve the optimization problems involved. The presented method can be warm- started more efficiently than other existing methods and is shown to be computationally advantageous in simulation settings.
The second approach is based on making upgrades to the power system hardware. A numerical approach for power system upgrade pid controller phd thesis is developed that is compu- tationally reasonable while allowing for the integration of practical system operating policies in the algorithm, pid controller phd thesis.
More specifically, pid controller phd thesis, the problem is addressed of which lines in a power distribution network should be strengthened in order to increase resilience to the aforementioned operating constraint violations.
The approach strives to make as few approximations as possible, incorporating a computationally demanding but rather accurate non-linear model of the equations pid controller phd thesis the steady state of the power flows and voltages.
Past research in area of hardware upgrade planning has made various approximations to arrive at computationally attractive algorithms, albeit at the cost of the results not having many guarantees regarding the non-approximated original prob- lem. In contrast, by the addition of knowledge of the way a system operator will control the system once deployed to the formulation, both the computational tractability of the method presented in this thesis and the practical relevance of the optimization results are increased.
The presented algorithm and extensions act as a unifying framework for such power system planning problems, being able to incorporate advances in convex relaxations as well as heuristic methods naturally. In order to demonstrate the effectiveness of the method, a subset of a real power system is studied in various experiments throughout the thesis, pid controller phd thesis.
Press Enter to activate screen reader mode. Homepage Navigation Search Content Footer Contact Sitemap. PhD theses Main content. publications of Modeling, Analysis, and Inference in Social Network Formation. DOI: Optimality in Distributed Control from Convex Programming to Reinforcement Learning. Region of Attraction Analysis of Uncertain Equilibrium Points and Limit Cycles - with Application to Airborne Wind Energy Systems.
On the theory and applications of mechanism design and coalitional games in electricity markets. Economic Model Predictive Control of Energy Storage.
Optimization Algorithms as Feedback Controllers for Power System Operations. Approximate Dynamic Programming: theoretical guarantees and practical algorithms for a continuous space setting, pid controller phd thesis.
Transverse feedback passivation in control of multi-machine and multi-converter power networks. Algorithms for Policy-based Power System Planning. System Design and Power Flow of Stationary Energy Storage Systems.
PID Control Basics in 10 Minutes
, time: 14:21PhD theses – Automatic Control Laboratory | ETH Zurich
Apr 13, · Thesis statement of the prince and thesis on pid controller The editor can then use it; such simple acts as a verb; use it as a. Whereas one may apply to casual conversations, english speakers may disagree with it, which is the language errors at sentence level the words they describe. the dissertation or master s thesis Apr 5, fractional blogger.com pid controller gives superior performance of fractional calculus applying in this thesis. A thesis. ahmad, cosmopolitan, fractional pid pay someone fractional order pid thesis. Experimental study. Nov 6, phd thesis physics homework pal singh3 1 Evaluation and Tuning of Robust PID Controllers Birgitta Kristiansson, Bengt Lennartson November 3, Abstract A general controller evaluation method is introduced, based on four performance and robustness criteria including both low-, mid- and high-frequency properties. Ac-cording to this method, optimal PI and PID controllers are blogger.comg: phd
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