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

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Consolidated composite adsorbent containing graphite flake for sorption cooling systems

Date created: 
2017-07-06
Abstract: 

Heat-driven sorption technology, as a sustainable and clean solution for thermal management and heat storage, has drawn a significant interest in academic and industrial research community. This interest has been intensified in the last decade as environmental and climate changes issues are becoming major global challenges. Numerous studies aim to improve materials sorption performances, as it is at the core of sorption cooling or storage systems. Due to the nature of the sorption process, heat and transport properties, e.g., thermal diffusivity and thermal conductivity of the adsorbent material play an important role in their performance. Higher thermal diffusivity can enhance the heat transfer rate and lead to faster sorption/desorption cycles and more efficient (more compact) heat-driven sorption chillers. A key part of the sorption chillers design is developing adsorbent materials (or composites) with superior hydrophilicity, high water uptake capacity, low regeneration temperature (60-150°C), and high thermal diffusivity. The focus of this research is to design tailored consolidated composite adsorbent containing graphite flakes with improved heat and mass transfer properties for sorption cooling systems. The presented Ph.D. dissertation is divided into three main parts: (i) composite adsorbent fabrication and characterization; (ii) consolidated composite characterization; and (iii) thermal properties modeling of consolidated composite adsorbent. Fabricated loose grain and consolidated composite were characterized in Dr. Bahrami’s Laboratory for Alternative Energy Conversion (LAEC) and SFU 4D LABS.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Majid Bahrami
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) Ph.D.

Plate Heat Exchangers Using Natural Graphite Sheets

Author: 
Date created: 
2017-07-31
Abstract: 

Graphite heat exchangers (G-HEX) are good alternatives to metallic heat exchangers due to their excellent thermal properties, low cost, light weight, and high resistivity to corrosion. In this study, the potential of fabrication of natural flake graphite-based plate heat exchanger is being investigated. A new layered G-HEX and a graphite plate heat exchanger are fabricated and their thermal and hydraulic performance are compared with an off-the-shelf chevron-type plate heat exchanger using a custom-made experimental setup. An optimization study is then conducted to further improve the graphite plate heat exchanger performance. To understand the potential of utilization of G-HEX in corrosive environments, a corrosion test is then performed on natural flake graphite sheets.

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

Electrical impedance and diffuse optical spectroscopy for early breast cancer diagnosis

Author: 
Date created: 
2017-08-16
Abstract: 

In this thesis, we apply sensor-based tools for investigating breast tissue characteristics to identify anomalies, including cancer. The non-invasive technologies utilized are based on the Electrical Impedance Spectroscopy (EIS) and Diffuse Optical Imaging (DOI). As the accuracy of Clinical Breast Examination (CBE) depends on the physician’s experience, these technologies enhance the diagnostic capabilities by providing additional information. We tested twenty patients utilizing these technologies, in a clinical trial, with around 100% success rate in identifying the location of cancerous tumors.The correlation between healthy and cancerous tissue electrical properties is defined by extracting the electrical features of tissues based on Cole-Cole model. Also, by processing the raw data of the DOI-probe, we have been able to create the cross-sectional optical images of the breast in different wavelengths from 690nm to 850nm. This study suggests that EIS and DOI are useful technologies for early detection of breast cancers.

Document type: 
Thesis
Senior supervisor: 
Dr. Farid Golnaraghi
dr. Carolyn Sparrey
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Modelling the stability and maneuverability of a manual wheelchair with adjustable seating

Date created: 
2017-08-17
Abstract: 

Manual wheelchairs are generally designed with a fixed frame, which is not optimal for every situation. Spontaneous changes in seating configuration can ease transfers, increase participation in social activities, and extend reaching capabilities. These changes also shift the centre of gravity of the system, altering wheelchair dynamics. In this study, rigid body models of an adjustable manual wheelchair and test dummy were created to characterize changes to wheelchair stability and maneuverability for variations in backrest angle, seat angle, rear wheel position, user position, and user mass. Static stability was evaluated by the tip angle of the wheelchair on an adjustable slope, with maneuverability indicated by the ratio of weight on the rear wheels. Dynamic stability was assessed for the wheelchair rolling down an incline with a small bump. Both static and dynamic simulations were validated experimentally using motion capture of real wheelchair tips and falls. Overall, rear wheel position was the most influential wheelchair configuration parameter. Adjustments to the seat and backrest also had a significant impact on both static and dynamic stability. For wheelchairs with a more maneuverable (or 'tippy') initial configuration, dynamic seating changes could be used to increase stability as required.

Document type: 
Thesis
File(s): 
Example comparison of experimental and simulation dynamic stability trials
Senior supervisor: 
Carolyn Sparrey
Jaimie Borisoff
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Energy Management Strategies and Evaluation for Plug-in Electric Vehicles - On and Off the Road

Author: 
Date created: 
2017-08-28
Abstract: 

Electric vehicle (EV) industries are driven by new technologies in batteries and powertrains. This thesis studies the cutting-edge Formula E racing vehicles with vehicle simulation and optimization for energy efficiency. On the consumer side, a new challenge EVs introduce is the need for large-scale charging infrastructure with minimum grid impact. This thesis studies EV charging management on the daily basis, featuring practical smart charging solutions at public locations and bi-directional (dis)charging at workplace and residence. Techniques that support smart charging are also studied. A data-mining based load disaggregation approach is developed to evaluate the general energy usage in the residential context. A machine-learning based load forecasting model is proposed to predict short-term residential loads in ultra-small scales. Overall, this thesis anticipates every aspect of EVs' daily activities, whether it is on or off the road, and suggests solutions to maximizing EV utilization for both drivers and the smart grid.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Gary Wang
Hassan Farhangi, Ali Palizban
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) M.A.Sc.

Modeling and Control of the Fuel Supply System in a Polymer Electrolyte Membrane Fuel Cell

Date created: 
2017-05-30
Abstract: 

Prolonging membrane longevity as well as improving fuel economy are essential steps toward utilization of fuel cells in industrial applications. Focusing on polymer electrolyte membrane (PEM) fuel cells, the present work elucidates a systematic approach to deal with cell durability issues, inflicted by membrane pinholes. This includes the model-based control of fuel overpressure, which is defined as the pressure difference between the anode and cathode compartments, at the inlet side of the fuel cell stack. Moreover, to enhance fuel savings, this work proposes a novel model-based technique for estimation of hydrogen concentration, which is used as the basis of fuel purging control. Employing a Ballard 3kW test station equipped with a 9-cell Mk1100 PEM fuel cell, the entire system is modeled using pneumatic variables. The developed model is experimentally validated. Depending on the underlying objective, a relevant system configuration for the PEM fuel cell anode is adopted. These include a flow-through anode, dead-ended anode, and anode with recirculation structures. A model predictive controller (MPC) is deployed to achieve the controller objectives, which include the improvement in control of the system transient response during the load change, reduction of hydrogen emission, and retaining the cell voltage level of a defective cell, by maintaining the fuel overpressure in the desired region. Furthermore, the controller performance is verified experimentally. Using the pressure drop across the fuel cell stack anode, the hydrogen concentration on the anode side is estimated in a hydrogen-nitrogen gas mixture. This pressure drop is correlated to the dynamic viscosity of a gas mixture. The estimation model which is verified experimentally for various scenarios provides a reliable and cost-effective method that can eliminate the use of the hydrogen sensor. This model is then utilized as the basis for controlling the fuel purging. Deploying an MPC based multivariable control strategy, both fuel overpressure and hydrogen concentration are controlled.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Farid Golnaraghi
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) Ph.D.

A Fully 3D-printed Integrated Electrochemical Sensor System

Author: 
Date created: 
2017-08-30
Abstract: 

This thesis investigates the design, fabrication, and characterization of a 3D printed electrochemical sensor as well as compact potentiostat circuits on Printed Circuit Board (PCB) for portable electrochemical sensing applications. Conductive 3D printing technologies are investigated as well as the advances in sensors and electronics applications. An optimized Directly Ink Writing (DIW) technique is adapted to a novel 3D-PCB fabrication platform using silver nanoparticle ink for electronics applications. An electrochemical device called potentiostat is designed based on an open source system. Its prototype is 3D printed on FR4 substrate. Using the same 3D platform, a lactate sensor which is composed of a 3-electrode is printed on the flexible substrate. Together, the 3D printed system demonstrates the electrochemistry test including cyclic voltammetry (CV) and amperometry. Results of this research demonstrate that 3D-PCB technology can significantly accelerate the fabrication process of conventional electronic, and merge its capability into electrochemical applications.

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

Integrated sensing from multiple wearable devices for activity recognition and dead reckoning

Date created: 
2016-03-09
Abstract: 

Wearable devices are increasingly prevalent in our everyday lives. This thesis examines the potential of combining multiple wearable devices worn on different body locations for fitness activity recognition and inertial dead-reckoning. First, a novel method is presented to classify fitness activities using head-worn sensors, with comparisons to other common worn locations on the body. Using multiclass Support Vector Machine (SVM) on head-worn sensors, high degree of accuracy was obtained for classifying standing, walking, running, ascending/descending stairs and cycling. Next, a complete inertial dead-reckoning system for walking and running using smartwatch and smartglasses is proposed. Head-turn motion can derail the position propagation on a head-worn dead-reckoning system. Using the relative angle rate-of-change between arm swing direction and head yaw, head-turn motion can be detected. The experimental results show that using the proposed head-turn detection algorithm, head-worn dead-reckoning performance can be greatly improved.

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

Wearable sensor system for human localization and motion capture

Date created: 
2017-04-27
Abstract: 

Recent advances in MEMS wearable inertial/magnetic sensors and mobile computing have fostered a dramatic growth of interest for ambulatory human motion capture (MoCap). Compared to traditional optical MoCap systems such as the optical systems, inertial (i.e. accelerometer and gyroscope) and magnetic sensors do not require external fixtures such as cameras. Hence, they do not have in-the-lab measurement limitations and thus are ideal for ambulatory applications. However, due to the manufacturing process of MEMS sensors, existing wearable MoCap systems suffer from drift error and accuracy degradation over time caused by time-varying bias. The goal of this research is to develop algorithms based on multi-sensor fusion and machine learning techniques for precise tracking of human motion and location using wearable inertial sensors integrated with absolute localization technologies. The main focus of this research is on true ambulatory applications in active sports (e.g., skiing) and entertainment (e.g., gaming and filmmaking), and health-status monitoring. For active sports and entertainment applications, a novel sensor fusion algorithm is developed to fuse inertial data with magnetic field information and provide drift-free estimation of human body segment orientation. This concept is further extended to provide ubiquitous indoor/outdoor localization by fusing wearable inertial/magnetic sensors with global navigation satellite system (GNSS), barometric pressure sensor and ultra-wideband (UWB) localization technology. For health applications, this research is focused on longitudinal tracking of walking speed as a fundamental indicator of human well-being. A regression model is developed to map inertial information from a single waist or ankle-worn sensor to walking speed. This approach is further developed to estimate walking speed using a wrist-worn device (e.g., a smartwatch) by extracting the arm swing motion intensity and frequency by combining sensor fusion and principal component analysis.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Edward Park
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) Ph.D.

Design of a hybrid spherical manipulator for lower limb exoskeleton applications

Author: 
Date created: 
2017-03-06
Abstract: 

An estimated (7.1%) of North American residents suffered from an ambulatory disability and mobility disablements in 2013. These disabilities cost an estimated annual equivalent of $375 billion in family caregiver support. One emergent technology that aims to address this health problem and improve the quality of life for sufferers is a lower-body exoskeleton which is a wearable robotic system that completely or partially supports users weight and provide controlled guidance of legs movements, thereby allowing them to stand and walk. One major shortcoming of current exoskeleton technologies is their limited range of motion about the hip joint. Such joints are capable of three rotational degrees of-freedom (DOFs). Current technologies only provide a single DOF hip-centered movements. The other two DOFs are either fully constrained or only available with passive motion. This design scheme generally results in a serial joint structure within the exoskeleton device, which has an inherently lower payload to-weight ratio than a parallel structure counterpart. Therefore, this characteristic leads to bulkier than necessary devices. The objective of this thesis is studying the feasibility and later on design compact three DOF robotic joints to replace the single DOF of the hip actuator of the commercially available exoskeletons. In this thesis a three degree-of-freedom (DOF) hip exoskeleton system that is capable of providing decoupled or combined 3-DOF rotational motion to a separate and passive target joint (i.e. the hip joint) is proposed.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Siamak Arzanpour
Department: 
Applied Sciences: School of Mechatronic Systems Engineering
Thesis type: 
(Thesis) Ph.D.