Mechatronics Systems Engineering - Theses, Dissertations, and other Required Graduate Degree Essays

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Electro-thermal Modeling of Lithium-ion Batteries

Date created: 
2015-07-16
Abstract: 

The development and implementation of Lithium-ion (Li-ion) batteries, particularly in applications, requires substantial diagnostic and practical modeling efforts to fully understand the thermal characteristics in the batteries across various operating conditions. Thermal modeling prompts the understanding of the battery thermal behavior beyond what is possible from experiments and it provides a basis for exploring thermal management strategies for batteries in hybrid electric vehicles (HEVs) and electric vehicles (EVs). These models should be sufficiently robust and computationally effective to be favorable for real time applications. The objective of this research is to develop a complete range of modeling approaches, from full numerical to analytical models, as a fast simulation tool for predicting the temperature distribution inside the pouch-type batteries. In the first part of the study, a series of analytical models is proposed to describe distributions of potential and current density in the electrodes along with the temperature field in Li-ion batteries during standard galvanostatic processes. First, a three-dimensional analytical solution is developed for temperature profile inside the Li-ion batteries. The solution is used to describe the special and temporal temperature evolution inside a pouch-type Li-ion cell subjected to the convective cooling at its surfaces. The results are successfully verified with the result of an independent numerical simulation. The solution is also adapted to study the thermal behavior of the prismatic and cylindrical-type nickel metal hydride battery (NiMH) batteries during fast charging processes, which demonstrated the versatility of the model. Afterward, to resolve the interplay of electrical and thermal processes on the heat generation and thermal processes, a closed-form model is developed for the electrical field inside the battery electrodes. The solution is coupled to the transient thermal model through the heat source term (Joulean heat). The results of the proposed multi-physic are validated through comparison with the experimental and numerical studies for standard constant current discharge tests. The model results show that the maximum temperature in the battery arises at the vicinity of the tabs, where the ohmic heat is established as a result of the convergence/divergence of the current streamlines. In the second part of the study, an equivalent circuit model (ECM) is developed to simulate the current-voltage characteristics of the battery during transiently changing load profiles. The ECM that is calibrated by a set of characterization tests collected over a wide range of temperature, then coupled with a numerical electro-thermal model. The validated ECM-based model is capable of predicting the time variation of the surface temperature, voltage, and state of charge (SOC) of the battery during different driving cycles and environmentaltemperatures.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Majid Bahrami
Department: 
Applied Sciences:
Thesis type: 
(Thesis) Ph.D.

Nonlinear Control and Application of Power Electronics Boost Converters

Date created: 
2014-07-21
Abstract: 

In this thesis, we investigate the development of novel control schemes for single and three phase boost converters operated in different modes of conduction. Study is conducted on development of controllers based on the nonlinear dynamic characteristics of the converters and characteristics such as nonminimum phase behavior in boost converters that give rise to control challenges. The control strategies are further applied to certain areas in sustainable energy systems including maximum power point tracking of photovoltaic panels, load current control of power converters, and energy regenerative suspension in vehicular systems. To this end, the analytical behavior of a boost converter is studied and utilized to design nonlinear controllers to control the input resistive behavior of the converter. The performance of proposed controllers are verified through simulations and experiments on single stage converters. Finally, the design of a feedback control system for input resistance control of a three-phase bidirectional converter is studied. A sliding mode controller is utilized in an application involving energy regeneration for a mechanical suspension system. A permanent magnet machine and a linear vibration generator are utilized along with the proposed control strategy to achieve regenerative damping in a proof-of-concept suspension system. The simulation and experimental results verify that the proposed controller can successfully provide desired damping for mechanical vibrations while storing the vibration energy in battery.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Mehrdad Moallem
Department: 
Applied Sciences:
Thesis type: 
(Thesis) Ph.D.

Optimization of a Low-melting Alloy for Fused Filament Fabrication

Date created: 
2015-08-13
Abstract: 

With low-cost Fused Filament Fabrication (FFF) systems proliferating among researchers, developing new filament materials to expand the design capabilities of 3D printed objects has become a focus for research. One material property that has been difficult to achieve though is high conductivity, which would enable the integration of embedded circuitry into functional 3D printed devices. This thesis presents the optimization and integration of low-melting alloys into a FFF system for the production of FFF metal components. The material, extrusion system, and the print parameters were optimized to enable reliable extrusion of the selected non-eutectic alloy. By combining this new material with existing FFF plastics, a 3D printed device with functional electronic circuits will become possible.

Document type: 
Thesis
File(s): 
Video of Sample 1 being printed
Senior supervisor: 
Woo Soo Kim
Department: 
Applied Sciences:
Thesis type: 
(Thesis) M.A.Sc.

Design and development of A novel slurry pump using Transmission Roller

Author: 
Date created: 
2015-08-12
Abstract: 

The oil and gas industry needs a simple and compact pump that could deal with slurry and other highly viscous or erosive fluid. The pump should also be able to fit in limited space of a borehole while maintaining comparable or higher efficiency than the current applications. Inspired by the algebraic screw, a new design of power transmission device, named as Transmission Roller, is introduced in this work and incorporated into a diaphragm pump. This mechanism converts rotary motion into linear motion and shows promises of high efficiency with its compact structure. Similar mechanisms have never been used in a hydraulic application before. A pump prototype utilizing the Transmission Roller is built and tested with water to prove its functionality. The transmission efficiency of the transmission roller prototype is 73.6%. The Transmission Roller efficiency for the final production pump design is expected to be 96.3%, higher than other designs of the same kind.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Siamak Arzanpour
Gary Wang
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Feature extraction and classification of skiing/snowboarding jumps with an integrated head-mounted sensor

Date created: 
2015-08-24
Abstract: 

With advancing technology in miniature MEMS sensors, wearable devices are becoming increasingly popular, facilitating convenient activity detection. One particular application is in sports performance monitoring. This thesis presents novel real-time jump detection and classification algorithms in skiing and snowboarding using a head-mounted MEMS-based inertial measurement unit (MEMS-IMU), which is integrated with a barometric pressure sensor. The key performance variables of the jump are extracted and evaluated for training and/or entertainment purposes. In contrast to the existing jump detection algorithms based on acceleration signals, the proposed algorithm uses vertical velocity and air time in addition to acceleration in the vertical direction. A support vector machine (SVM) is applied to generate a classification model. The jumps are classified into four different groups – Ollie, Standard, Drops, and Step up jumps. The experimental results show that by incorporating the velocity and air time into the detection algorithm, the sensitivity and specificity increase dramatically to 92% and 93%, respectively. In addition, the proposed classification model achieved 80.5% accuracy.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Edward J. Park
Greg Mori
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Roll-to-Roll Transfer Printing of Reduced Graphene Oxide Thin Film

Author: 
Date created: 
2015-08-11
Abstract: 

A novel thin film transfer mechanism has been studied and developed to transfer chemically reduced graphene oxide (r-GO) thin film using a roll-to-roll printing system. We discover that shear stress generated on the silicon rubber stamp surface facilitates delamination of the deposited r-GO thin film efficiently.A roll-to-roll apparatus is assembled to demonstrate the shear-induced transfer printing in a large scale printing system. Shear stress is applied on the stamp surface by rotating the stamp side roller faster than the substrate side roller.The hydrophobic surface is changed to hydrophilic by polydopamine modification for 15 minutes at 60˚C in order for r-GO thin film to be directly deposited on the rubber stamp.Roll-to-roll printing parameters such as evaporation time during deposition of r-GO, vertical deformation of stamp, RPM, and RPM ratio between two rollers are investigated and adjusted for successful transfer of r-GO.With the adjusted roll-to-roll printing parameters, r-GO thin film has been transferred successfully to glass and PET substrates at a printing rate of 5mm/min. The shear stress required to transfer r-GO thin film in our experiment condition with glass substrate is estimated to be 325.43 kPa by experimental data and computation with ANSYS.A flexible transparent capacitive touch sensor is fabricated with printed r-GO thin film after the sheet resistance is significantly improved by thermal annealing process.Both the shear-induced roll-to-roll printing method and the stamp modification process are expected to contribute to large scale manufacturing systems for flexible printed electronics.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Woo Soo Kim
Edward Jung Wook Park
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Optimal Nonlinear Adaptive Observers for State, Parameter and Fault Estimation

Author: 
Date created: 
2015-07-30
Abstract: 

The demand for reliable, fast and robust techniques for detection and estimation of faults in real-world systems is constantly increasing. A nonlinear adaptive observer for state, parameter and fault estimation is developed in this work using an optimal approach. This observer is capable of estimating unknown parameters as well as sensor faults in the system. The proposed observer also accounts for existing noise and disturbance in the system. By defining appropriate cost functions for each problem, the observer is made to satisfy a performance bound. A systematic method of checking existence conditions and calculating observer gains in terms of Linear Matrix Inequalities (LMIs) is presented. Types of nonlinearities considered are fairly general and encompass sector bounded, Lipschitz and dissipative nonlinearities. The observer can identify time-varying unknown parameters, bias and gain sensor faults. Compared with the method of extended Kalman filter, the proposed observer is not computationally intensive and in its relaxed form, does not require online solution to the Ricatti equation. The observer is applied to representative state space models including a wind turbine mechanical power transmission mechanism. The considered system model is highly nonlinear and contains input disturbances as well. The results are compared with the results obtained from extended Kalman filtering and show satisfactory performance in the presence of noise and disturbances.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Krishna Vijayaraghavan
Department: 
Applied Sciences:
Thesis type: 
(Thesis) M.A.Sc.

Estimation of Chemical Oxygen Demand in WasteWater using UV-VIS Spectroscopy

Author: 
Date created: 
2015-05-08
Abstract: 

The aim of this research is to build a portable system to perform real-time analysis ofwaste water samples. Thus, that can significantly improve existing waste water treatmenttechnology. In waste water treatment plant, an important parameter, chemical oxygen demandis needed to be measured. The amount of chemical oxygen demand determinesthe degree of water pollution by organic material. The conventional method for measuringchemical oxygen demand requires sample preparation and pre-treatment using chemicals.These conventional techniques are time consuming and labour intensive. To overcomethese problems, a system is developed in this work that offers significant advantages overconventional methods. The system employs ultraviolet and visible spectrometer in orderto correlate the absorbance of light after it passes through a waste water sample with theconception of the target chemicals. The spectrometer limits the use and disposal of chemicalsfor the measurement of chemical oxygen demand. In addition, a software system isdeveloped to control the spectrometer and to detect the most sensitive spectral region andwavelength for chemical oxygen demand content. Moreover, an algorithm is introducedby performing linear regression analysis on acquired concentration and light absorbancefrom the acquired spectra. The development and validation of this spectroscopic tool andsoftware system are described in this thesis.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Behraad Bahreyni
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Bulk and interfacial thermal transport in microstructural porous materials with application to fuel cells

Date created: 
2015-04-13
Abstract: 

The performance, reliability and durability of fuel cells are strongly influenced by the operating conditions, especially temperature and compression. Adequate thermal and water management of fuel cells requires knowledge of the thermal bulk and interfacial resistances of all involved components. The porous, brittle and anisotropic nature of most fuel cell components, together with the micro/nano-sized structures, has made it challenging to study their transport properties and thermal behavior. The main purpose of this research was to explore, and guide the improvement of, the thermal behavior of fuel cell materials under compression. Thickness-based methods, having the capability of deconvoluting bulk from the contact resistance, were employed to accurately measure the thermal conductivity of several gas diffusion layers (GDLs) with different PTFE loading. The interfacial thermal resistances of these GDLs with adjacent micro porous layer (MPL) and graphite bipolar plate (BPP) were also determined, through both systematic experiments and comprehensive models developed in this work. The thermal conductivity of a coated MPL as a function of compression and that of a Ballard graphite BPP with respect to temperature were also measured and reported in this thesis. Higher values of contact resistance compared to the bulk resistance at low compression and the reduction of GDL thermal conductivity with PTFE loading are among the main findings of this study. The present work also revealed the following novel counter-intuitive facts: (i) contact resistance may decrease with increasing the porosity of the mating porous materials; (ii) the conventional notion that the thermal conductivity of fibrous materials decreases with increasing porosity does not necessarily hold; and (iii) fiber spacing can be as crucial as porosity to the transport properties of fibrous media. The main conclusion is that the equations that are based solely on porosity should be either discarded or used, with caution, over the limited range of conditions under which they have been formulated. Through a series of experiments combined with theoretical analyses, this thesis presents some key data that helps unravel some unexplained trends reported in the literature. It also provides novel insights into the unexplored thermal behavior of fuel cell components and guides the modification of their micro-structures for better heat management of fuel cells.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Majid Bahrami
Ned Djilali
Department: 
Applied Sciences:
Thesis type: 
(Thesis) Ph.D.

Design and Implementation of a Regenerative Shock Absorber

Author: 
Date created: 
2015-04-14
Abstract: 

In this thesis, the development of a novel regenerative shock absorber sized for a passengercar suspension system is studied. In the first phase, DC and AC rotary machines along with charging circuits, to be used in the energy conversion stage of the proposed shock absorber are analyzed. In this analysis, the rotary damping coefficients provided by these systems are obtained following by experimental results.In the second phase, the development of a novel regenerative shock absorber in a proof of concept setting is presented. This system consists of a new linear-to-rotary conversion mechanism called algebraic screw, a gearhead, and a rotary machine. The design and analysis of this system is presented. The linear damping coefficient provided by this shock absorber is obtained. Experimental results are presented that evaluate performance of the proposed system on a small-scale suspension system.In the third phase, the development of a novel regenerative shock absorber sized for a passenger car is presented. The shock absorber includes a simple and highly efficient motion converter stage called ”two-leg mechanism”, a planetary gearhead, and a brushless three-phase rotary machine. The design and analysis of the regenerative shock absorber is presented by considering the linear damping coefficient and efficiency of the electromechanical device. The performance of the regenerative shock absorber is evaluated under sinusoidal excitation inputs for typical amplitudes and frequencies in a vehicular suspensionsystem.In the fourth phase, the effect of nonlinear terms of the shock absorber on linear dampingcoefficient provided by this system is studied. Next, the idea of using a variable externalresistance, provided by the charging circuit, to compensate the nonlinear terms is presented.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Mehrdad Moallem
Department: 
Applied Sciences:
Thesis type: 
(Thesis) Ph.D.