In the last decades, many solutions are being developed, in various forms, in order to contrast the problems correlated to the pollution and the planet temperature increase. On one hand, more and more research interest is being given to alternative means of transportation within the cities, such as the bicycle, in order to decongest the traffic and to improve the quality of the air. On the other hand, it is a matter of fact that the most of the road vehicles are equipped with internal combustion engines (and so they will be for a long time), and many efforts are nowadays addressing the improvement of exhaust after-treatment systems for these vehicles, to avoid the emission of dangerous gases into the atmosphere, such as the carbon monoxide. In this framework, this project was developed in two different lines of research, yet pointing towards the same objective. It was developed in two different universities, the Politecnico di Milano and the Stanford University (USA). The first part of the thesis, written at Politecnico di Milano, concerns the development of a solution for the comfort increase and the optimization of an automatic shifter for bicycles. The problem was tackled using an estimate of the pedaling cadence, obtained through the rear wheel speed, after having automatically learned the transmission ratios; the optimal shifting instant was then computed after having formulated it as the research of the locally minimum acceleration point. The algorithm was then experimentally validated through road tests. The objective of this work is that of solving a comfort problem, in order to contribute to the improvement of the technology solutions and the on-board electronics in bicycles, and to allow the diffusion of the same among a wider range of users. A paper about this part of the project, co-written by the author, has been presented at the CCTA 2020 conference. The complete version of the paper is currently under review for the publication in the peer-reviewer IEEE journal Transactions on Intelligent Transportation Systems. The second part of the thesis, written at Stanford University, concerns the development of a control-oriented model for a three-way-catalyst (TWC), developed starting from a physics-based model of the device, based on partial differential equations, identified starting from experimental data for differently aged TWCs, and different driving cycles. The simplified model was derived through the Galerkin approach, a formal technique for the model order reduction. Two different variants of the approach have been used, the first one based on analytic functions, and the second one based on numerical functions. The model was then validated in order to verify its accuracy compared to the one of the original model, for different driving cycles and TWC aging processes. The primary objective of this work is the development of accurate yet computationally feasible models for TWCs, to allow the development of adequate closed loop control techniques, capable of managing the engine emissions more effectively. A journal paper about this project, co-written by the author, has been already accepted for the publication in the peer-reviewed ASME Journal of Dynamic Systems, Measurement and Control.
Negli ultimi decenni, per fronteggiare i problemi legati all'inquinamento e all'incremento della temperatura del pianeta, numerose soluzioni stanno venendo sviluppate, in varie forme. Da una parte, sempre più interesse di ricerca è rivolto ai mezzi di mobilità alternativa nelle città, come le biciclette, per decongestionare il traffico e migliorare la qualità dell'aria. D'altra parte, resta un dato di fatto che la gran parte dei veicoli circolanti sono dotati di motori a combustione interna (e lo saranno per molto tempo), e numerosi sforzi sono tutt'oggi rivolti al miglioramento dei sistemi di trattamento dell'aria di scarico di questi veicoli, per evitare l'immissione in atmosfera di pericolosi gas, come il monossido di carbonio. In questo contesto, questo progetto è stato sviluppato su due linee di ricerca diverse ma rivolte allo stesso obiettivo, e presso due diversi atenei, il Politecnico di Milano e la Stanford University (USA). La prima parte della tesi, scritta al Politecnico di Milano, riguarda lo sviluppo di una soluzione per migliorare il comfort e ottimizzare un cambio automatico per biciclette. Il problema è stato affrontato utilizzando una stima della cadenza di pedalata, ottenuta dalla velocità della ruota posteriore, dopo aver automaticamente appreso i rapporti di trasmissione; l'istante di cambiata ottima è poi calcolato, formulato come ricerca del punto di minima accelerazione locale. L'algoritmo è stato infine validato sperimentalmente tramite test su strada. Questo lavoro si pone come obiettivo quello di risolvere un problema di comfort, in modo da contribuire al miglioramento delle soluzioni tecnologiche e dell'elettronica di bordo nelle biciclette, e di permettere una maggior penetrazione delle stesse in più fasce di utenti. Un articolo sul progetto, co-scritto dall'autore, è stato da poco presentato al CCTA 2020. L'articolo esteso è attualmente in fase di revisione presso la rivista peer-reviewed di IEEE Transactions on Intelligent Transportation Systems. La seconda parte della tesi, scritta nella Stanford University riguarda invece lo sviluppo di un modello orientato al controllo per un catalizzatore a tre vie (TWC), sviluppato a partire da un modello fisico del dispositivo, basato su equazioni differenziali alle derivate parziali, identificato a partire da dati sperimentali per TWC invecchiati diversamente, e su diversi cicli guida. Il modello semplificato è sviluppato mediante l'approccio di Galerkin, una formale tecnica di riduzione dell'ordine del modello. Due diverse varianti dell'approccio sono state utilizzate, una basata su funzioni analitiche e l'altra basata su funzioni numeriche. Il modello è stato infine validato per verificarne l'accuratezza rispetto al modello originale, per diversi cicli guida e processi di invecchiamento del TWC. Questo lavoro ha come obiettivo primario lo sviluppo di modelli per TWC accurati ma a basso costo computazionale, per permettere lo sviluppo di tecniche di controllo in anello chiuso più adeguate e in grado di gestire con più eficacia le emissioni del motore. Un articolo su questo progetto, co-scritto dall'autore, è stato accettato per la pubblicazione presso la rivista peer-reviewed dell' ASME, Journal of Dynamic Systems, Measurement and Control.
Development of modeling and estimation techniques geared for sustainable transportation solutions
DETTU', FEDERICO
2019/2020
Abstract
In the last decades, many solutions are being developed, in various forms, in order to contrast the problems correlated to the pollution and the planet temperature increase. On one hand, more and more research interest is being given to alternative means of transportation within the cities, such as the bicycle, in order to decongest the traffic and to improve the quality of the air. On the other hand, it is a matter of fact that the most of the road vehicles are equipped with internal combustion engines (and so they will be for a long time), and many efforts are nowadays addressing the improvement of exhaust after-treatment systems for these vehicles, to avoid the emission of dangerous gases into the atmosphere, such as the carbon monoxide. In this framework, this project was developed in two different lines of research, yet pointing towards the same objective. It was developed in two different universities, the Politecnico di Milano and the Stanford University (USA). The first part of the thesis, written at Politecnico di Milano, concerns the development of a solution for the comfort increase and the optimization of an automatic shifter for bicycles. The problem was tackled using an estimate of the pedaling cadence, obtained through the rear wheel speed, after having automatically learned the transmission ratios; the optimal shifting instant was then computed after having formulated it as the research of the locally minimum acceleration point. The algorithm was then experimentally validated through road tests. The objective of this work is that of solving a comfort problem, in order to contribute to the improvement of the technology solutions and the on-board electronics in bicycles, and to allow the diffusion of the same among a wider range of users. A paper about this part of the project, co-written by the author, has been presented at the CCTA 2020 conference. The complete version of the paper is currently under review for the publication in the peer-reviewer IEEE journal Transactions on Intelligent Transportation Systems. The second part of the thesis, written at Stanford University, concerns the development of a control-oriented model for a three-way-catalyst (TWC), developed starting from a physics-based model of the device, based on partial differential equations, identified starting from experimental data for differently aged TWCs, and different driving cycles. The simplified model was derived through the Galerkin approach, a formal technique for the model order reduction. Two different variants of the approach have been used, the first one based on analytic functions, and the second one based on numerical functions. The model was then validated in order to verify its accuracy compared to the one of the original model, for different driving cycles and TWC aging processes. The primary objective of this work is the development of accurate yet computationally feasible models for TWCs, to allow the development of adequate closed loop control techniques, capable of managing the engine emissions more effectively. A journal paper about this project, co-written by the author, has been already accepted for the publication in the peer-reviewed ASME Journal of Dynamic Systems, Measurement and Control.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/166691