Este trabalho está voltado para a avaliação de alternativas de instalação propulsora para o empurrador de comboios fluviais. Estes comboios devem atender o objetivo da Petrobras / Transpetro de transportar álcool e derivados de petróleo pela hidrovia Tietê-Paraná. São apresentados como elementos de subsídio para o trabalho um estudo da demanda de álcool combustível em âmbito mundial e os argumentos para seu uso, bem como da oferta brasileira do produto. Além disso, apresentam-se, de forma sucinta, as principais restrições da hidrovia Tietê-Paraná, que devem servir de base para o projeto do comboio, e as características dos comboios em operação na hidrovia, que transportam outras cargas. São apresentados os critérios estabelecidos para construção de comboios fluviais adaptados ao transporte de álcool e derivados de petróleo, segundo as exigências da Norman e das sociedades classificadoras. O trabalho apresenta também uma investigação sobre novas concepções de instalação propulsora para emprego no empurrador. Assim, para seleção da instalação propulsora do empurrador são consideradas três alternativas: a instalação Diesel, que é concepção empregada em todos os comboios da hidrovia, e duas instalações dieselelétrica, uma convencional e outra com sistema Azipod. São empregados como critérios de avaliação o custo operacional do comboio, o impacto ambiental produzido pela emissão de gases e a segurança de navegação do comboio. Como método de avaliação multi-criterial foi utilizado o método de análise hierárquica. Os resultados da avaliação indicaram uma preferência pela instalação propulsora Diesel. / This work focuses on the evaluation of alternatives of main propulsion plants for towboats of fluvial convoys. These convoys must attend the objectives of Petrobras/Transpetro of transporting ethanol and oil derivatives through Tiete-Parana waterway. A study of the demand for ethanol worldwide and the arguments for its use are presented as supporting elements for the work, as well as the Brazilian supply of the product. Moreover, the main restrictions of the Tiete-Parana waterway, which must be the basis for the project of the convoy, and the characteristics of the convoys in operation in the waterway, which transport other loads, are succinctly presented. Complying with Norman 02 requirements and classifying societies, the criteria established for the construction of fluvial convoys adapted to the transport of ethanol and oil derivatives are also presented here. The work also presents an investigation about new concepts of propulsive installation for the use in the towboat. Therefore, for the selection of the propulsion system of the towboat, three alternatives are considered: the Diesel plant, which is the concept used in all convoys of the waterway, and two Diesel-electric propulsion systems, a conventional one and another with an Azipod system. The operational cost of the convoy, the environmental impact produced by the emission of gases and the safety of navigation of the convoy are used as criteria for evaluation. The method of hierarchical analysis was used as method of evaluation. The results of the evaluation indicated a preference for the Diesel propulsion plant.

Este trabalho está voltado para a avaliação de alternativas de instalação propulsora para o empurrador de comboios fluviais. Estes comboios devem atender o objetivo da Petrobras / Transpetro de transportar álcool e derivados de petróleo pela hidrovia Tietê-Paraná. São apresentados como elementos de subsídio para o trabalho um estudo da demanda de álcool combustível em âmbito mundial e os argumentos para seu uso, bem como da oferta brasileira do produto. Além disso, apresentam-se, de forma sucinta, as principais restrições da hidrovia Tietê-Paraná, que devem servir de base para o projeto do comboio, e as características dos comboios em operação na hidrovia, que transportam outras cargas. São apresentados os critérios estabelecidos para construção de comboios fluviais adaptados ao transporte de álcool e derivados de petróleo, segundo as exigências da Norman e das sociedades classificadoras. O trabalho apresenta também uma investigação sobre novas concepções de instalação propulsora para emprego no empurrador. Assim, para seleção da instalação propulsora do empurrador são consideradas três alternativas: a instalação Diesel, que é concepção empregada em todos os comboios da hidrovia, e duas instalações dieselelétrica, uma convencional e outra com sistema Azipod. São empregados como critérios de avaliação o custo operacional do comboio, o impacto ambiental produzido pela emissão de gases e a segurança de navegação do comboio. Como método de avaliação multi-criterial foi utilizado o método de análise hierárquica. Os resultados da avaliação indicaram uma preferência pela instalação propulsora Diesel. / This work focuses on the evaluation of alternatives of main propulsion plants for towboats of fluvial convoys. These convoys must attend the objectives of Petrobras/Transpetro of transporting ethanol and oil derivatives through Tiete-Parana waterway. A study of the demand for ethanol worldwide and the arguments for its use are presented as supporting elements for the work, as well as the Brazilian supply of the product. Moreover, the main restrictions of the Tiete-Parana waterway, which must be the basis for the project of the convoy, and the characteristics of the convoys in operation in the waterway, which transport other loads, are succinctly presented. Complying with Norman 02 requirements and classifying societies, the criteria established for the construction of fluvial convoys adapted to the transport of ethanol and oil derivatives are also presented here. The work also presents an investigation about new concepts of propulsive installation for the use in the towboat. Therefore, for the selection of the propulsion system of the towboat, three alternatives are considered: the Diesel plant, which is the concept used in all convoys of the waterway, and two Diesel-electric propulsion systems, a conventional one and another with an Azipod system. The operational cost of the convoy, the environmental impact produced by the emission of gases and the safety of navigation of the convoy are used as criteria for evaluation. The method of hierarchical analysis was used as method of evaluation. The results of the evaluation indicated a preference for the Diesel propulsion plant.

Critical automated maneuvers for ships typically require a redundant set of thrusters. The motion control system hierarchy is commonly separated into several layers using a high-level motion controller and a thruster allocation (TA) algorithm. This allows for a modular design of the software where the high-level controller can be designed without comprehensive information on the thrusters, while detailed issues such as input saturation and rate limits are handled by the TA. However, for a certain set of thruster configurations this decoupling may result in poor control performance due to the limited knowledge in the high-level controller about the physical limitations of the ship and the behavior of the TA. This thesis investigates different approaches of improving the control performance, using nonlinear Model Predictive Control (MPC) as a foundation for the developed motion controllers due to its optimized solution and capability of satisfying constraints. First, a decoupled system is implemented and results are provided for two simple motion tasks showing problems related to the decoupling. Thereafter, two different approaches are taken to remedy the observed drawbacks. A nonlinear MPC controller is developed combining the motion controller and thruster allocation resulting in a more robust control system. Then, in order to keep the control system modularized, an investigation of possible ways to augment the decoupled system so as to achieve similar performance as the combined system is carried out. One proposed solution is a nonlinear MPC controller with time-varying constraints accounting for the current limitations of the thruster system. However, this did not always improve the control performance since the behavior of the TA still is unknown to the MPC controller.

One method to increase efficiency, robustness and accuracy of automatic control, is to introduce mathematical models of the system in question to increase performance. With these models, it is possible to predict the behavior of the system, which enables control according to the predictions. The problem here is that if these models do not describe the dynamics of the system well enough, this method could fail to increase performance. To address this problem, one idea is to estimate the dynamics of the system during operation, using methods for system identification, signal processing and sensor fusion. In this thesis, the possibilities of estimating a ship's dynamics during operation have been investigated. The mathematical model describing the dynamics of the ship is a graybox model, which is based on the physical and mechanical relations. This model's properties are therefore described by physical quantities such as mass and moment of inertia, all of which are unknown. This means that, when estimating the model, these physical properties will be estimated. For a systematic approach, first a simulation environment with a 4-degrees-of-freedom ship model has been developed. This environment has been used for validation of system identification methods. A model of a podded propulsion system has also been derived and validated. The methods for estimating the properties of the ship have been analyzed using the data collected from the simulations. For system identification and estimation of ship properties, the influence of measurement noise and potential of detecting a change in dynamics has been analyzed. This has been done through Monte Carlo simulations of the estimation method with different noise realizations in the simulations, to analyze how the measurement noise affects the variance and bias for the estimates. The results show that variance and bias vary a lot between the parameters and that even a small change in dynamics is visible in some parameter estimates when only ten minutes of data have been used. A method based on cumulative summation (CUSUM) has been proposed and validated to analyze if such a method could yield fast and effective detection of system deviations. The results show that the method is rather effective a with robust detection of changes in the dynamics after about four minutes of data collection. Finally, the methods have been validated on data collected on a real ship to analyze the potential of the methods under actual circumstances. The results show that the particular data is not appropriate for this kind of application along with some additional problems that can yield impaired results. / Genom att inkludera matematiska modeller som beskriver ett systems dynamik i styrningsalgoritmer, kan man åstadkomma en automatisk styrning med förbättrad effektivitet, robusthet och noggrannhet. Med dessa modeller går det att förutsäga beteendet hos systemet och därmed öppnas också möjligheten att använda sig av detta i styrningen. Problemet är att om dessa modeller inte beskriver systemets dynamik tillräckligt bra kan prestandan istället sänkas genom dessa metoder. Den här sortens problem kan man lösa genom att aktivt skatta systemets dynamik under körning, med hjälp av metoder för systemidentifiering, signalbehandling och sensorfusion. I denna exjobbsrapport har möjligheterna att skatta ett skepps girdynamik undersökts. Den matematiska modell som beskriver skeppets dynamik är en grålådemodell som baserar sig på fysikaliska och mekaniska samband. Denna modells egenskaper beskrivs därför av fysikaliska storheter så som massa, tröghetsmoment och tyngdpunkt, vilka alla är okända. Detta innebär att vid modellskattning skattas dessa fysikaliska storheter, vilka kan vara av stort intresse. En simuleringsmiljö med en skeppsmodell med fyra frihetsgrader har skapats och använts för att validera metoder för systemidentifiering. En modell av ett roterbart framdrivningssystem har också härletts och inkluderats i simuleringsmodellen. Vid systemidentifiering och skattning av skeppets egenskaper har dels inverkan av mätbrus analyserats samt även möjligheter till att detektera skillnader i dynamik. Detta har gjorts med Monte Carlo-simuleringar av skattningsmetoden med olika brusrealiseringar för att analysera hur mätbrus påverkar variansen och metodfelet hos skattningarna. Resultaten visar att vissa parametrar skattas med större noggrannhet och hos dessa kan därmed en förändring i dynamik identifieras när endast tio minuter av data har använts. En metod baserad på kumulativ summering av residualer har formulerats och validerats, detta för att undersöka om en sådan metod kan ge snabb och effektiv detektion av systemförändringar. Resultat visar på robusthet i att detektera skillnader i dynamik efter ungefär fyra minuter av datainsamling. Slutligen har metoderna validerats på data insamlad på ett riktigt skepp för att undersöka potentialen under verkliga omständigheter. Resultaten visar att just denna data inte är lämplig för denna applikation samt några problem som kan leda till försämrade resultat.