IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.158
Shrinidhi Gomathi Sankar , Victor Daniel Reyes Dreke , Mircea Lazar
{"title":"Hierarchical Model Predictive Control for Modular Multilevel Converters: A Linear Parameter Varying Approach","authors":"Shrinidhi Gomathi Sankar , Victor Daniel Reyes Dreke , Mircea Lazar","doi":"10.1016/j.ifacol.2024.10.158","DOIUrl":"10.1016/j.ifacol.2024.10.158","url":null,"abstract":"<div><div>Modular multilevel converters (MMCs) are novel voltage source converters (VSCs) with the capacity to achieve higher efficiency and lower total harmonics distortion, but more challenging to control. MMCs can be modelled using a hierarchical structure comprising a model predictive controller (MPC) that controls the current in the top layer and sends signals to capacitor voltage modules in the lower layer (which can run in open-loop or closed-loop with a simple local controller). Typically, the prediction model used in the MPC current controller does not take into account the capacitor voltage dynamics in the bottom layer, which reduces the efficiency of the hierarchical control scheme and MMC circuit. Therefore, in this paper, we develop an extended prediction model for current control that includes the capacitor voltage dynamics for the modules in the bottom layer. This results in a nonlinear MPC control problem of higher complexity but with improved performance. To reduce the complexity of the nonlinear MPC problem for MMCs, we make use of a linear parameter varying embedding of the nonlinear prediction model, which allows solving a sequence of quadratic programs online instead of a nonlinear program. The proposed control scheme shows better performance while decreasing the computation load. Furthermore, compared to classical hierarchical control schemes, the proposed scheme reduces the capacitor voltage ripple by 20%.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 21","pages":"Pages 126-131"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.199
Erik I. Verriest , Gunther Dirr , W. Steven Gray
{"title":"Generalized Functions in the Study of Signals and Systems","authors":"Erik I. Verriest , Gunther Dirr , W. Steven Gray","doi":"10.1016/j.ifacol.2024.10.199","DOIUrl":"10.1016/j.ifacol.2024.10.199","url":null,"abstract":"<div><div><span>We collect three instances where the theory of generalized functions may still make contributions to the study of signals and systems. In the first, a purely algebraic approach is presented for LTI-ODE's, in terms of two operators, D and T, respectively the differentiation operator and the multiplication-by-the-independent-variable operator. This formalism adds simplicity, a duality theory, and nicely generalizes to other classes of operator equations and their solutions. In the second part we extend the classical bilateral Laplace transform to include Bohl functions with support in</span> ℝ <span>by invoking Sato's hyperfunctions. Finally, in the third case we use the Colombeau algebra to allow for products of generalized functions. This is important in the study of (smooth) nonlinear systems driven by impulsive inputs, and hybrid system theory.</span></div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 17","pages":"Pages 380-385"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.160
Tsuyoshi Yuno , Shingo Nishinaka , Rin Saeki , Yoshio Ebihara , Victor Magron , Dimitri Peaucelle , Samuele Zoboli , Sophie Tarbouriech
{"title":"Stability Analysis of Feedback Systems with ReLU Nonlinearities via Semialgebraic Set Representation","authors":"Tsuyoshi Yuno , Shingo Nishinaka , Rin Saeki , Yoshio Ebihara , Victor Magron , Dimitri Peaucelle , Samuele Zoboli , Sophie Tarbouriech","doi":"10.1016/j.ifacol.2024.10.160","DOIUrl":"10.1016/j.ifacol.2024.10.160","url":null,"abstract":"<div><div>This paper is concerned with the stability/instability analysis problem of feedback systems with rectified linear unit (ReLU) nonlinearities. Such feedback systems arise when we model dynamical (recurrent) neural networks (NNs) and NN-driven control systems where all the activation functions of NNs are ReLUs. In this study, we focus on the semialgebraic set representation characterizing the input-output properties of ReLUs. This allows us to employ a novel copositive multiplier in the framework of the integral quadratic constraint and, thus, to derive a new linear matrix inequality (LMI) condition for the stability analysis of the feedback systems. However, the infeasibility of this LMI does not allow us to obtain any conclusion on the system's stability due to its conservativeness. This motivates us to consider its dual LMI. By investigating the structure of the dual solution, we derive a rank condition on the dual variable certificating that the system at hand is unstable. In addition, we construct a hierarchy of dual LMIs allowing for improved instability detection. We illustrate the effectiveness of the proposed approach by several numerical examples.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 21","pages":"Pages 138-143"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"State reconstruction for stochastic nonlinear systems with unknown local nonlinearities via output injection","authors":"Neha Aswal , Adrien Mélot , Laurent Mevel , Qinghua Zhang","doi":"10.1016/j.ifacol.2024.10.222","DOIUrl":"10.1016/j.ifacol.2024.10.222","url":null,"abstract":"<div><div>This paper addresses state estimation for dynamical systems involving localized unknown nonlinearities. Direct application of linear state estimation techniques, e.g., the Kalman filter, would yield erroneous state estimates. Existing approaches in the literature either assume or estimate the nonlinearities. Alternatively, the present paper proposes to reject the unknown nonlinearities as if they were unknown disturbances. By applying an existing disturbance rejection technique, the need to know or to estimate the nonlinearities is avoided. The efficiency of the proposed method is demonstrated through numerical simulations on a nonlinear mechanical system.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 21","pages":"Pages 256-261"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.207
Tanathorn Supithak , Koji Tsumura
{"title":"Stability on the Robust Dissipative Coding in Quantum System for Thermal Noise","authors":"Tanathorn Supithak , Koji Tsumura","doi":"10.1016/j.ifacol.2024.10.207","DOIUrl":"10.1016/j.ifacol.2024.10.207","url":null,"abstract":"<div><div>In this paper, we deal with the stability of the improved quantum coding method based on Markovian dissipative dynamics that is robust against thermal noise. This coding method was proposed by Nishino et al. and the suppression of the effect of thermal noise was demonstrated by numerical simulations, however the mathematical proof was not given. In this paper, we analyze the impact of the thermal noise in this method and mathematically prove that the quantum states converge to a neighborhood around the target code words. The bound of the neighborhood set is also given strictly. We also demonstrate numerical simulations, which confirm the theoretical results.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 17","pages":"Pages 427-432"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.193
Patricia Pauli , Dennis Gramlich , Frank Allgöwer
{"title":"State space representations of the Roesser type for convolutional layers","authors":"Patricia Pauli , Dennis Gramlich , Frank Allgöwer","doi":"10.1016/j.ifacol.2024.10.193","DOIUrl":"10.1016/j.ifacol.2024.10.193","url":null,"abstract":"<div><div><span>From the perspective of control theory, convolutional layers (of neural networks) are 2-D (or N-D) linear time-invariant dynamical systems. The usual representation of convolutional layers by the convolution kernel corresponds to the representation of a dynamical system by its impulse response. However, many analysis tools from control theory, e.g., involving linear matrix inequalities, require a state space representation. For this reason, we explicitly provide a state space representation of the Roesser type for 2-D convolutional layers with c</span><sub>in</sub><span>r</span><sub>1</sub> <span>+ c</span><sub>out</sub><span>r</span><sub>2</sub> <span>states, where c</span><sub>in</sub><span>/c</span><sub>out</sub> <span>is the number of input/output channels of the layer and r</span><sub>1</sub><span>/r</span><sub>2</sub> <span>characterizes the width/length of the convolution kernel. This representation is shown to be minimal for c</span><sub>in</sub> <span>= c</span><sub>out</sub><span>. We further construct state space representations for dilated, strided, and N-D convolutions.</span></div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 17","pages":"Pages 344-349"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.198
Yannic Rohde , Eva Zerz
{"title":"Linear Dynamical Systems over Finite Rings","authors":"Yannic Rohde , Eva Zerz","doi":"10.1016/j.ifacol.2024.10.198","DOIUrl":"10.1016/j.ifacol.2024.10.198","url":null,"abstract":"<div><div>We present the theory of linear systems over various kinds of finite commutative rings. Since these systems are finite, the trajectories have to run into repeating cycles eventually. This periodic behavior is the main interest of this topic. Using an approach similar to Fitting's lemma, a bijective-nilpotent decomposition of the system can be achieved, which in some cases even gives a decomposition of the system matrix. In particular, this allows us, to apply results about invertible system matrices, where all trajectories are purely periodic, to the more general setting. Finally, the algorithmic potential of the theory is discussed.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 17","pages":"Pages 374-379"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.018
Nerea Martínez-López , Carlos Vilas , Adrián Pedreira , Míriam R. García
{"title":"Moment Closure for a Birth-Death Model of Antimicrobial Heteroresistance","authors":"Nerea Martínez-López , Carlos Vilas , Adrián Pedreira , Míriam R. García","doi":"10.1016/j.ifacol.2024.10.018","DOIUrl":"10.1016/j.ifacol.2024.10.018","url":null,"abstract":"<div><div>Developing predictive Antimicrobial Resistance (AMR) models supporting optimal treatment design to combat ”superbugs” poses a significant challenge for mathematical biology. Birth-Death (BD) processes constitute an intuitive and flexible approach for modelling biological systems’ stochastic dynamics that is regaining attention due to the advances in computational techniques. This work presents a multivariate BD model of antimicrobial heteroresistance, a phenotype in which a bacterial isolate contains many subpopulations with heterogeneous antimicrobial responses. The model includes Lotka-Volterra competition between subpopulations, leading to an infinite coupled system of equations for the moment dynamics of the BD process. Then, a moment closure is proposed by assuming a log-normal distribution for a univariate BD process approximating the total population behaviour. The results are compared with stochastic simulations of the multivariate BD process during a typical time-kill assay.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 23","pages":"Pages 103-108"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142437990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.002
A. Arboleda-Garcia , M. Stiebritz , Y. Boada , J. Picó , A. Vignoni
{"title":"DBTL bioengineering cycle for part characterization and refactoring","authors":"A. Arboleda-Garcia , M. Stiebritz , Y. Boada , J. Picó , A. Vignoni","doi":"10.1016/j.ifacol.2024.10.002","DOIUrl":"10.1016/j.ifacol.2024.10.002","url":null,"abstract":"<div><div>The Design-Build-Test-Learn (DBTL) cycle is a crucial framework in Synthetic Biology for the development and optimization of biological systems. However, the manual nature of the cycle poses limitations in terms of time and labor. This paper focuses on the application of automation techniques to the DBTL cycle, specifically in the testing and characterization of standard bioparts, which are essential components of genetic circuits. By automating the testing process, throughput, reliability, and reproducibility can be significantly improved. This paper discusses the challenges associated with manual testing methods and explores various automation strategies and technologies that can address these challenges. High-throughput screening methods, laboratory robotics, and data analysis algorithms are key elements in the automation process. As a case study, we utilize the automated DBTL cycle to refactor a biosensor, aiming to enhance its performance. Integrating automation in the DBTL cycle offers numerous advantages, including increased efficiency, standardization, and quality control of bioparts. It also enables the exploration of larger design spaces and rapid prototyping of complex genetic systems. Here, we show the advantages of using the DBTL cycle to refactor a biosensor that presents improved performance and can be readily used in more complex circuits.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 23","pages":"Pages 7-12"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142437995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
IFAC-PapersOnLinePub Date : 2024-01-01DOI: 10.1016/j.ifacol.2024.10.275
Juan D. Gil , José González-Hernández , Fernando Cañadas-Aránega , Igor M.L. Pataro , Ángeles Hoyo , Pablo Otálora , Francisco Rodríguez , J.L. Guzmán , Manuel Berenguel
{"title":"Gamification in control engineering: An ongoing initiative at the University of Almería*","authors":"Juan D. Gil , José González-Hernández , Fernando Cañadas-Aránega , Igor M.L. Pataro , Ángeles Hoyo , Pablo Otálora , Francisco Rodríguez , J.L. Guzmán , Manuel Berenguel","doi":"10.1016/j.ifacol.2024.10.275","DOIUrl":"10.1016/j.ifacol.2024.10.275","url":null,"abstract":"<div><div>Gamification refers to the utilization of gaming methods and tactics in non-traditional areas, like education. In this work, we describe different gamification-based methods for teaching automatic control in engineering studies as an alternative or support to the traditional teaching system. The experiences are being developed within the framework of a teaching innovation project developed at the University of Almería (Spain). The main objective of this project is to analyze the academic feasibility and acceptance of the use of gamified experiences by both professors and students. Specifically, the paper gives an overview of three different types of games. The first is a solitaire-style card game focused on the reinforcement of the theoretical concepts related to open-loop dynamic system analysis and the design of closed-loop control systems. The second is a virtual challenge of tuning Proportional, Integral, and Derivative (PID) controllers. The goal of this game is for students to understand the impacts of proportional, integral, and derivative actions when these controllers operate in closed-loop mode. The third is an escape room with the primary objective of improving students’ comprehension of basic control principles covered in the initial introductory course in engineering studies.</div></div>","PeriodicalId":37894,"journal":{"name":"IFAC-PapersOnLine","volume":"58 26","pages":"Pages 82-87"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}