Dynamic torsional modeling and analysis of a fluid mixer

Mixers and agitators are used in a variety of processing industries. Each application has its own uniqueness requiring a high degree of customization in process design and mechanical design. Many of the processing and mechanical performance characteristics of mixers are derived from torque cell and tachometer measurements usually located between the motor and speed reducer. This thesis deals with the development of a dynamic modeling and analysis procedure to simulate the torsional response of mixers. This procedure will allow for the characterization of the torsional response at any point within the system, as well as relate the response as observed at the measurement location on full scale tests to any point of interest within the system. Various modeling options were developed for each of the mixing subsystems and compared to determine which configurations more accurately describe the system torsional dynamics. The developed modeling options were simulated using Simulink and MATLAB. For torsional frequency verification of the simulation model, a finite element model was constructed, analyzed, and compared to the simulation model. Also, the results of a full scale test were obtained and compared to the simulation model. Recommendations for usage, further study, and model development are also discussed

STUDY OF STRATEGIES FOR AN OPTIMAL ENERGY MANAGEMENT ON ELECTRIC AND HYBRID VEHICLES

Questa tesi di dottorato è focalizzata sull’identificazione di strategie di gestione dell’energia a bordo di veicoli elettrici e ibridi, con l’obiettivo di ottimizzare la gestione dell’energia e, quindi, consentire un risparmio di risorse. Infatti, l’ottimizzazione della fase d’uso del veicolo, attraverso una più efficiente gestione dell’energia, consente di dimensionare in modo ridotto i principali componenti, come il pacco batterie. Innanzitutto, viene presentato un tool di simulazione denominato TEST (Target-speed EV Simulation Tool). Questo strumento consente di effettuare simulazioni di dinamica longitudinale per veicoli completamente elettrici o ibridi e, quindi, di monitorare tutti i dati rilevanti necessari per effettuare un corretto dimensionamento del gruppo propulsore, inclusi il/i motore/i elettrico/i ed il pacco batterie. Inoltre, è possibile testare anche diversi layout di propulsori, compresi quelli che utilizzano celle a combustibile, le cosiddette “fuel cell”. Viene poi presentata una strategia di frenata rigenerativa, adatta per veicoli FWD, RWD e AWD. L’obiettivo principale è quello di recuperare la massima energia frenante possibile, mantenendo il veicolo stabile, con buone prestazioni in frenata. La strategia è stata testata sia attraverso un consolidato software di simulazione della dinamica del veicolo (VI-CarRealTime), sia attraverso simulazioni “driver-in-the-loop” utilizzando un simulatore di guida. Inoltre, la strategia proposta è stata integrata nel tool TEST per valutarne l’influenza sull’autonomia e sui consumi del veicolo. Gli strumenti sopra menzionati sono stati utilizzati per studiare uno scenario di casi reali, per valutare la fattibilità dell’utilizzo di una flotta alimentata a fuel cell a metano per svolgere attività di raccolta rifiuti porta a porta. I risultati mostrano un’elevata fattibilità in termini di autonomia del veicolo rispetto alle missioni standard di raccolta dei rifiuti, a condizione che i componenti siano adeguatamente dimensionati. Il dimensionamento dei componenti è stato effettuato attraverso iterazioni, utilizzando diversi componenti nelle stesse missioni. Infine, è stata riportata un’analisi approfondita degli studi LCA (Life Cycle Assessment) relativi ai veicoli elettrici, con particolare attenzione al pacco batterie, evidenziando alcune criticità ambientali. Questo studio sull’LCA sottolinea quindi l’importanza di una corretta gestione dell’energia per ridurre al minimo l’impatto ambientale associato al consumo stesso di energia.This PhD thesis is focused on identifying energy management strategies on board electric and hybrid vehicles, to optimize energy management and thus allow for resource savings. In fact, vehicle’s operational phase optimisation through a more efficient energy management allows main components downsizing, such as battery pack. First of all, a simulation tool called TEST (Target-speed EV Simulation Tool), is presented. This tool allows to carry out longitudinal dynamics simulations on pure electric or hybrid-electric vehicles, and therefore monitoring all the relevant data needed to carry out a proper powertrain sizing, including the electric motor(s) and the battery pack. Furthermore, several powertrain layouts can be also tested, including those using fuel cells. Then a regenerative braking strategy, suitable for FWD, RWD and AWD vehicles, is presented. Its main target is to recover the maximum possible braking energy, while keeping the vehicle stable with good braking performance. The strategy has been tested both through a state-of-art vehicle dynamics simulation software (VI-CarRealTime) and through driver-in-the-loop simulations using a driving simulator. Furthermore, the proposed strategy has been integrated into TEST to evaluate its influence on vehicle range and consumptions. The above-mentioned tools have been used to evaluate a real-world case scenario to assess the feasibility of using a methane fuel cell powered fleet to carry out door to door waste collection activities. Results show high feasibility in terms of vehicle range compared to standard waste collection missions, provided that components are properly sized. Components sizing has been done through iterations using different components on the same missions. Finally, an in-depth analysis of the LCA (Life Cycle Assessment) studies related to electric vehicles has been reported, with particular focus to the battery pack, highlighting some environmental critical issues. This LCA study therefore emphasizes the importance of a correct energy management to minimize the environmental impact associated with energy consumption

DESIGN AND CONTROL OF AN ACTIVE HUMANOID LEG FOR TESTING LOWER-LIMB PROSTHESES

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Design and Development of An Ultra-capacitor based Peak Power Management System for Electrified Metro Transit Powertrains

Hybridization of the metro traction systems has been the research focus during the last few years. Research has been done on various technologies that combine, in addition to its main energy source (DC rail), reversible energy storage devices like fly-wheels, ultra-capacitors, and batteries. Among these technologies, ultra-capacitors are promising because of their high power density and the fact that their lifespan is about ten years longer than that of batteries. The idea is to store the regenerative braking energy in an ultra-capacitor module. This energy will be used during the acceleration. As such, the grid will be protected from the over-currents related to start-up of the metro car. Moreover, the traction system efficiency will increase since the braking energy which is dissipated in resistors in the current system, will be recovered. In this thesis the Montreal Metro Traction system is studied. The main energy source (MES) is the DC rail in Metro. The metro system is first analysed and model. Ultra-capacitor sizing is done for the system. For the purpose of simulation, the initial system is scaled down. A 2 Hp machine is used as the traction motor. A bidirectional buck-boost DC/DC converter is designed to drive the motor. The ultra-capacitor interfaced bidirectional DC/DC converter and the ultra-capacitor bank are modeled and simulated. A unidirectional boost DC/DC converter is designed and simulated along with PI controllers, to control the flow of power from the DC rail (MES). Moreover, two efficient supervisory control strategies are developed for two possible ultra-capacitor bank sizes of the Montreal metro system. The novel control strategies enables superior regulation capability and ease of control

New trends in electrical vehicle powertrains

The electric vehicle and plug-in hybrid electric vehicle play a fundamental role in the forthcoming new paradigms of mobility and energy models. The electrification of the transport sector would lead to advantages in terms of energy efficiency and reduction of greenhouse gas emissions, but would also be a great opportunity for the introduction of renewable sources in the electricity sector. The chapters in this book show a diversity of current and new developments in the electrification of the transport sector seen from the electric vehicle point of view: first, the related technologies with design, control and supervision, second, the powertrain electric motor efficiency and reliability and, third, the deployment issues regarding renewable sources integration and charging facilities. This is precisely the purpose of this book, that is, to contribute to the literature about current research and development activities related to new trends in electric vehicle power trains.Peer ReviewedPostprint (author's final draft

Battery, Hybrid and Fuel-Cell Propulsion Systems

The main purpose of the Research is theoretical and experimental evaluation of electric propulsion systems: pure electric ones, fed exclusively by electrochemical energy storage, hybrid electric, in which the power for propulsion comes from different sources, and fuel cell-based vehicles. These studies were carried on through an extended modelling and experimental activity, related to: • Modelling and experimental activities on electrochemical storage systems and super-capacitors, to evaluate their performance and to better individuate the optimal sizing for usage on-board electric and hybrid vehicles. • Design and realisation of a Fuel-Cell based vehicle, starting from the design of the propulsion system, for which dedicated models in Matlab-Simulink® environment were specifically realised, coming to an extended laboratory test activity for all the components, specially for the Fuel-Cell System. • Design of a complete line of electric and hybrid buses, based on the modelling of the propulsion system in collaboration with the manufacturer, through the usage of new object-oriented modelling techniques realised in Dymola-Modelica® environment. After evaluating different energy management strategies, an exhaustive comparison with conventional and electric pure versions has been carried on. The PhD Thesis, after an introduction about innovative propulsion systems, describes in detail all the activities presented, trying to summarise general techniques of design and management for hybrid vehicles

Additive Manufacturing Powder Removal

Metal powder-bed fusion is an additive manufacturing process which enables the creation of unique shapes in metal parts that would otherwise be difficult, expensive, or impossible to machine. Metallic powder is melted and fused together by either a laser or electron beam to produce parts quickly. The excess powder covers newly printed parts and can be difficult to remove from small internal features. The scope of this project is to design a device that effectively removes the powder from newly printed parts safely, while reclaiming as much powder as possible for reuse. The solution for this project must be able to remove powder safely, accommodate the properties of different parts, and reclaim most of the powder removed. The chosen design solution is a device that would suspend and vibrate the part to remove powder. There are two axes of rotation of this system, allowing the part to be rotated to any optimal orientation to remove powder from the internal cavities of the part. A vibration motor housed in the device will shake the part, loosening the powder and sifting it down to the drain holes and ultimately out of the part. This design is called the Vibration Induced Powder Evacuator and Reclaimer(VIPER).Since the system has been constructed, tests have started to be done to determine the effectiveness of the removal method and the orientation method.As of June 2018, the bulk of testing still needs to be performed to quantify the effectiveness of vibration as a primary removal technique. This document captures the results of the design process, including background research and benchmarking, the project’s scope, requirements, comparative analysis of potential designs, the iterative design solutions, cost analysis, potential risks with the design solution, manufacturing/assembly plans, completed design verification, future testing plans,lessons learned, and the recommended next steps for the project

Design and Test of an Automotive Clutch Actuation

This thesis builds on the analysis of a automatic system for automotive automatic clutches. In this field of study there are some constraint to take into account and through them it is possible to find the best technological solution. The system under consideration is characterized as electromechanical, with an electric motor brush DC and reduction system very complex. The system was modeled using the Bond-Graph technique which allowed the drafting of the dynamical system equations, in state space form. In fact the system itself is quite complex due to the fact that multiple dynamic domains were taken into account. The result is a unique model where all the dynamics are represented, with constitutive equations. Three alternative solutions have been proposed to improve performance and reduce power consumption and system complexity. The prototypes were built and tested. The evaluation of the results were followed by a model parameter identificatio

Power transmission systems: from traditional to magnetic gearboxes

L'abstract è presente nell'allegato / the abstract is in the attachmen

Control algorithm implementation for a redundant degree of freedom manipulator

This project's purpose is to develop and implement control algorithms for a kinematically redundant robotic manipulator. The manipulator is being developed concurrently by Odetics Inc., under internal research and development funding. This SBIR contract supports algorithm conception, development, and simulation, as well as software implementation and integration with the manipulator hardware. The Odetics Dexterous Manipulator is a lightweight, high strength, modular manipulator being developed for space and commercial applications. It has seven fully active degrees of freedom, is electrically powered, and is fully operational in 1 G. The manipulator consists of five self-contained modules. These modules join via simple quick-disconnect couplings and self-mating connectors which allow rapid assembly/disassembly for reconfiguration, transport, or servicing. Each joint incorporates a unique drive train design which provides zero backlash operation, is insensitive to wear, and is single fault tolerant to motor or servo amplifier failure. The sensing system is also designed to be single fault tolerant. Although the initial prototype is not space qualified, the design is well-suited to meeting space qualification requirements. The control algorithm design approach is to develop a hierarchical system with well defined access and interfaces at each level. The high level endpoint/configuration control algorithm transforms manipulator endpoint position/orientation commands to joint angle commands, providing task space motion. At the same time, the kinematic redundancy is resolved by controlling the configuration (pose) of the manipulator, using several different optimizing criteria. The center level of the hierarchy servos the joints to their commanded trajectories using both linear feedback and model-based nonlinear control techniques. The lowest control level uses sensed joint torque to close torque servo loops, with the goal of improving the manipulator dynamic behavior. The control algorithms are subjected to a dynamic simulation before implementation