Master of Science, The Ohio State University, 2024, Mechanical Engineering

The EcoCAR Electric Vehicle (E.V.) Challenge is a four-year competition that challenges 13 college teams across North America to modify a 2023 Cadillac LYRIQ and convert it from rear wheel drive (RWD) to all wheel drive (AWD) while integrating autonomous capabilities. The Ohio State University designed an architecture utilizing two separate Dana drive units. The front drive unit consists of the Dana iS4500e motor paired to a 9.1:1 gear box, with a rear drive unit consisting of the Dana iS4500e motor paired to a 14:1 gear box with an axle disconnect. Integration of this rear drive unit required modification of the stock rear subframe, as well as modification of the gearbox casing and shortening of the axle disconnect tube. Linear static finite element analysis was utilized in the redesign of the stock rear subframe to ensure that the stress before and after modification, as well as stiffness, was in line with both Ohio State and General Motors's standards. This thesis covers the methodology used to design, fabricate, and validate the rear subframe of the Ohio State University team's Cadillac LYRIQ.

Committee: Sandra Metzler (Committee Member); Shawn Midlam-Mohler (Advisor) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2022, Mechanical Engineering

It is not granted that the advantageous architecture of hybrid electric vehicles will result in improved economy and functionality. This is due to the complex nature of the tradeoff between fuel consumption and battery consumption in the vehicle and how it is controlled. Thus, as hybrid electric vehicles become more ubiquitous, it is necessary to conceive quicker and cheaper ways to prototype their controls. One feasible alternative to the immensely expensive prototypes produced by OEMs is to use an existing conventional vehicle platform as a host for a prototype. This method is explored in this paper and involves the installment of electric motors, a high voltage system, and, if desired, an engine swap. The systems' on-board serial communications structure must be commandeered in order to prototype hybrid supervisory controllers which interact with both the stock and added components. To achieve this a single programmable node equipped with a serial gateway can be inserted into the stock serial system. This tool can then be utilized to enable the torque splitting necessary between the two halves of the powertrain. During the development of this method, it was noted that the programmable node and its serial gateway had the power to enable many secondary features such as shift timing algorithms, P0 series charging, start/stop manipulation, and implementation of an ACC controller.

Committee: Giorgio Rizzoni (Committee Member); Shawn Midlam-Mohler (Advisor) Subjects: Automotive Engineering; Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2021, Mechanical Engineering

The EcoCAR Mobility Challenge is a four-year design cycle which tasks teams with designing a hybrid Chevrolet Blazer that serves the commuter market by efficiently providing a Mobility-as-a-Service. In Year 1 of the competition the OSU EcoCAR team selected a series-parallel hybrid architecture and defined vehicle performance goals to be achieved at the end of the development cycle. In Year 2, the stock GM Blazer was modified and hybrid propulsion components – a downsized 2.0L engine, P0 motor and P4 motor – were integrated and rear powertrain modifications were made. A full vehicle model, driver model, and HIL test harness for the EcoCAR hybrid vehicle was set up and the development of a Hybrid Supervisory Controller (HSC) was started. Components were bench tested after integration into the vehicle. In Year 3, the various algorithms necessary to achieve baseline functionality of the EcoCAR vehicle were developed and tested. A V-systems engineering process was followed to design control strategies from defined system requirements and constraints. Engine torque control was achieved by manipulating ACC (Adaptive Cruise Control) CAN messages through an Engine Control Module gateway. A simple REM torque assist strategy and a series charging algorithm utilizing the BAS were developed and implemented in the vehicle. The vehicle completed 200+ miles of VIL testing at the Transportation Research Center (TRC), maintaining SoC between 30-80% and meeting acceleration requests in performance mode. Methods to improve fuel economy with an energy management strategy has also been discussed for refining the HSC in Year 4.

Committee: Shawn Midlam-Mohler (Advisor); Rizzoni Giorgio (Committee Member) Subjects: Automotive Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2020, Mechanical Engineering

The Ohio State EcoCAR team is a student project team at The Ohio State University providing real-world engineering experience and learning opportunities to engineering students. The EcoCAR Mobility Challenge is sponsored by the U.S. Department of Energy, General Motors, and The Mathworks and challenges twelve universities across the United States and Canada to redesign and reengineer a 2019 Chevrolet Blazer into a hybrid-electric vehicle. The goal of the competition is for students to develop and implement technologies to reduce the vehicle's environmental impact while maintaining performance and to enhance the vehicle with connected and automated technologies for a future in the mobility-as-a-service market. The transition from conventional to hybrid vehicle requires the addition of several hybrid powertrain components, including electric motors, power inverters, and a high voltage battery. These new components have thermal cooling requirements and require the integration of a dedicated thermal management system to prevent components from overheating and to maintain optimal operating temperature. This work models the thermal systems of the internal combustion engine and hybrid powertrain components to provide estimates for component temperatures during steady-state operation and predetermined drive cycles. The GT-Suite modeling software package from Gamma Technologies was chosen to model the two thermal systems because of its extensive library of pre-validated automotive grade component models. This library allowed component models to be built quickly and without extensive data collection. The thermal system models were integrated with a full-vehicle model of the OSU EcoCAR team's vehicle in Simulink. This work seeks to provide a reasonable approximation of the integrated thermal systems in the OSU EcoCAR vehicle, with provisions to update and calibrate the model in the future. The model provides both steady-state and drive cycle feedb (open full item for complete abstract)

Committee: Shawn Midlam-Mohler (Advisor); Giorgio Rizzoni (Committee Member) Subjects: Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2020, Mechanical Engineering

The air we breathe is getting dangerously polluted with passenger vehicles and heavy-duty vehicles being one of the major sources of this pollution, producing significant amounts of nitrogen oxides, carbon monoxide, and other harmful gases. The U.S. Environmental Protection Agency (EPA) has laid stringent rules and aggressive policies to curb this pollution. Hybrid Electric Vehicles (HEV) and Electric Vehicles (EV) are a promising option considering their efficient operation and reduced emissions. These technologies are being developed at a rapid pace and can occupy a significant place in the automotive market. Companies are investing heavily to enhance the skills of future generation of engineers to develop these technologies through student competitions and workshops. EcoCAR Mobility Challenge (ECMC), a four-year Advanced Vehicle Technology Competition (AVTC) is one-way companies are pursuing this challenge. ECMC challenges teams to apply advanced propulsion systems, as well as connected and automated vehicle technology to improve the energy efficiency, safety, and consumer appeal of a 2019 Chevrolet Blazer – specifically for the carsharing market. The work described in this thesis focuses on the Model Based design approach adopted for the vehicle plant model and controls development during years one and two of the competition. The process includes the vehicle architecture selection process, component and soft ECU model development and finally describes the framework developed for testing of the control algorithm using an example of a fault scenario.

Committee: Shawn Midlam-Mohler Dr. (Advisor); Giorgio Rizzoni Dr. (Committee Member) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2020, Mechanical Engineering

The EcoCAR Mobility Challenge is the current iteration of the Advanced Vehicle Technology Competitions that challenges twelve universities across North America to re-engineer a 2019 Chevrolet Blazer into a connected and automated vehicle. The competition goal is to design, prototype, test, and validate a SAE Level 2 advance driver assistance system. This work outlines the development process of a SAE Level 2 perception system. The process began by defining system and component level requirements that iniated a sophisticated sensor and hardware selection process. Then to protoype, test, and validate the system, a V-model approach was followed, which included validation and verification of the system in multiple test environments. The role of each test environment in the validation process along with its advantages and shortcomings is discussed in detail, followed by the evolution of the perception system throughout Year 1 and Year 2 of the competition. Next, three case studies outlining the different subsystems in the perception controller: the I/O layer, the fault diagnostics, and sensor calbration are discussed. Each of these sub-algorithms used various modeling environment to increase the realiability and accuracy of the perception system. This work serves as the foundation of the connected and automated vehicle perception system and will be vital in the implementation of advance driver assistance features such as adaptive cruise control, lane centering control, and lane change on demand in future years of this competition.

Committee: Shawn Midlam-Mohler (Advisor); Lisa Fiorentini (Committee Member); Punit Tulpule (Other) Subjects: Automotive Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2020, Mechanical Engineering

The EcoCAR Mobility Challenge is a four-year collegiate design competition that challenges 12 universities to redesign the 2019 Chevrolet Blazer into a semi-autonomous, hybrid electric vehicle. The goal is for the vehicle to have better fuel economy while maintaining or improving the stock performance and drive quality. The Ohio State University EcoCAR team designed a self-sustaining hybrid electric vehicle which features a rear powertrain. The rear powertrain consists of Parker Hannifin electric machine and a BorgWarner eGearDrive single speed transmission. Successfully integrating the rear powertrain into the vehicle required a custom rear subframe. The custom rear subframe design was created by modifying the stock rear subframe. A topology optimization was used early in the design process to guide the design. Linear static finite element analysis was used to ensure the modified rear subframe design was as strong as the stock rear subframe even with the additional weight and torque from the rear powertrain. This thesis covers the methodology used to design, optimize, and validated the final modified rear subframe design.

Committee: Shawn Midlam-Mohler (Advisor); Sheng Dong (Advisor) Subjects: Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2017, Electrical and Computer Engineering

The transportation sector is a great contributor to overall energy consumption and emissions. Stringent regulations have been put in place to curb the emissions and regulate fuel consumption due to dependency on a finite resource, fossil fuels. This has driven OEMs to re-engineer the automotive powertrain which has led to a burst in production of PHEVs, HEVs and EVs. The U.S. D.O.E, General Motors, Argonne National Laboratory (ANL) and other industry sponsors have spearheaded (Advanced Vehicle Technology Competitions) AVTCs with a goal of training the next generation of automotive engineers by challenging collegiate teams to re-engineer stock vehicles to improve fuel consumption, reduce emissions while maintaining consumer acceptability. The latest in this AVTC series is the EcoCAR 3, a 4-year competition which challenges 16 North American university teams to re-engineer a 2016 Chevrolet Camaro into a HEV while maintaining the performance aspects of the iconic American car. The OSU EcoCAR 3 vehicle boasts a Parallel-series post transmission PHEV architecture designed by the team in Year 1 of the competition. To meet the team designed (Vehicle Technical Specification) VTS targets, the architecture includes a motor coupled to the engine, a Belted Alternator Starter (BAS) which performs engine start/stop, series operation, speed matching and torque assist. Due to the versatility of the component in realizing the VTS targets, this thesis sets to outline the design and validation work done with regards to the BAS system. The BAS system consists of the electric machine, the engine, belt transmission, inverter and battery pack. The thesis outlines the design metrics considered in the design of the BAS system ranging from electrical, performance, mechanical and thermal considerations. The BAS chosen is a sponsor donated component that wasn't supplied with an inverter solution. This thesis details the two inverter choices adopted over Years 2 – 3 of the competition an (open full item for complete abstract)

Committee: Giorgio Rizzoni (Advisor); Levent Guvenc (Committee Member); Shawn Midlam-Mohler (Committee Member) Subjects: Electrical Engineering

Master of Science, The Ohio State University, 2016, Mechanical Engineering

The EcoCAR 3 project is a four-year competition sponsored by General Motors and the U.S. Department of Energy challenging 16 university teams to re-engineer a 2016 Chevrolet Camaro to be a performance hybrid electric vehicle. The Ohio State University designed a parallel hybrid electric vehicle with a 0 to 60 mph acceleration goal of 5.6 seconds and a 44 mile all electric range. Before the performance and emissions goals can be met the team must fully mechanically and electrically integrate their hybrid vehicle architecture. Concurrently to the vehicle integration, the controls team developed the basic vehicle controls that would be required to meet the goals for the second year of the competition. The controls development started with fully defining the vehicle controls requirements and then evaluating which requirements would be met in each part of the development process. The controls validation occurred using a team-developed vehicle model in both the Software- and Hardware-in-the-Loop environments. The main focus for this part of the development was defining and implementing the basic controls, such as controller communication and vehicle startup, which are critical to eventually having a fully functional vehicle. With the Year 2 controls validated in the HIL environment, a vehicle implementation plan was developed to be implemented and validated by May of 2016. The full controls development plan that was developed to meet the high level team goals included both performance and efficiency modes that will be implemented and validated in Year 3 and 4 of the EcoCAR 3 project.

Committee: Shawn Midlam-Mohler Dr. (Advisor); Giorgio Rizzoni Dr. (Committee Member) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2015, Mechanical Engineering

Government regulations and consumer desire continue to aggressively push automotive manufacturers to improve the fuel economy and emissions of new vehicle designs. Vehicle weight reduction and the use of hybrid electric powertrains are becoming more commonly used methods for addressing a need for improved fuel economy and reduced vehicle emission. EcoCAR 2 is a three year collegiate design competition that involves 15 teams from universities across North America, competing to develop a vehicle with improved fuel economy and reduced emissions. Each team starts with a 2013 Chevrolet Malibu and replaces the powertrain with the primary objective being the reduction of fuel consumption and emissions. The team from The Ohio State University incorporated a rear electric powertrain featuring an electric machine and single-speed transmission into their vehicle architecture. This resulted in the need for a customized rear cradle to support the addition of a rear electric powertrain. An initial custom cradle design was created by modifying an existing steel rear sub-frame to accommodate the addition of the rear electric powertrain. However, in order to reduce total vehicle weight and thus improve fuel economy and reduce emissions, a reduced mass, aluminum rear cradle was created for Ohio State's final vehicle design. This study covers the methodology surrounding the design, validation, and optimization of that final rear cradle design.

Committee: Giorgio Rizzoni (Advisor); Shawn Midlam-Mohler (Committee Member) Subjects: Automotive Engineering; Design; Engineering

Master of Science, The Ohio State University, 2015, Mechanical Engineering

As part of EcoCAR 3, an Advanced Vehicle Technology Competition, The Ohio State University is among sixteen teams challenged with the task of re-engineering a stock 2016 Chevrolet Camaro into a hybrid electric vehicle. Part of the Ohio State design process entails using model based design to develop a full vehicle model of the hybrid Camaro that can simulate energy consumption for various testing purposes. This thesis describes the design process behind developing the plant and control models, integrating everything together in a full vehicle model, performing fault insertion testing for mitigation development, and constructing the model architecture such that transfer between In-the-Loop platforms is easier than conventional methods. The full vehicle model developed will be refined and used by the Ohio State team throughout the four year EcoCAR 3 competition.

Committee: Shawn Midlam-Mohler (Advisor); Giorgio Rizzoni (Committee Member) Subjects: Automotive Engineering

Master of Science, The Ohio State University, 2014, Mechanical Engineering

Automotive manufacturers spend many years designing, developing, and manufacturing each new model to the best of their ability. The push to shorten the time of a design cycle is motivated by reducing development costs and creating a more competitive advantage. Model based design and computer simulations have an increasing presence in the automotive industry for this reason. In the automotive industry, current ride and handling tuning methods are subjective in nature. There are few, if any, objective evaluations of the vehicle ride and handling performance. EcoCAR 2 is a three year collegiate design competition, in which 15 teams compete to develop a vehicle with lower petroleum consumption and fewer emissions. The teams begin the task with a 2013 Chevrolet Malibu and are challenged with maintaining consumer acceptability. The stock vehicle has been modified greatly by removal of the stock powertrain and battery system. Nearly 900 lbs of batteries and supporting components have been added to the trunk of the car along with an electric motor and single speed transmission. This change in vehicle mass has led to issues with poor ride and handling performance. Model based calibration of the suspension dampers can be seen as a method to recover some of the lost performance. A CarSIM Model of the vehicle was developed after numerous measurements involving a vehicle inertial measurement facility as well as a kinematics and compliance test from a suspension parameter measurement device. The CarSIM model was validated using experimental testing data. The vehicle was subjected to several different tests including a steady state handling test, transient handling test, and a ride test. To understand how different damper curve parameters would affect the performance of the vehicle, a design of experiments was developed using CarSIM to obtain the outputs. The seven objective metrics based on passenger comfort were used to create seven response surface equations based (open full item for complete abstract)

Committee: Giorgio Rizzoni Dr. (Advisor); Shawn Midlam-Mohler Dr. (Committee Member); Jeffrey Chrstos Dr. (Committee Member) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2012, Mechanical Engineering

Increasingly stringent government regulations and the rising price of oil are causing automotive manufactures to develop vehicles capable of obtaining higher fuel economies and lower emissions. To achieve these goals, automotive manufactures have been developing hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV) that use both electricity and petroleum based fuels as their power sources. The additional power the vehicle receives from the high voltage batteries and the electric machines allow automotive manufacturers to downsize the engine inside of the vehicle. Vehicles with smaller engines are able to obtain a higher overall fuel economy because the smaller engine is able to operate at its more efficient high load operating points more frequently. The addition of a high voltage battery pack and at least one electric machine to a vehicle's conventional powertrain significantly increases the complexity of optimizing the operation of the vehicle's powertrain components. In a hybrid vehicle, the driver's power demand from the accelerator pedal can be met by the engine, the electric machines or a combination of the two. Therefore the vehicle needs a sophisticated control strategy that can divide the driver's power demand between the different torque producing powertrain components as efficiently as possible. The process of designing an optimal control strategy for a vehicle can require a significant amount of time, money and in-vehicle testing. Therefore many automotive manufacturers use Software-in-the-Loop (SIL) simulation to both speed up and reduce the cost of developing a vehicle's control strategy. Software-in-the-Loop simulation allows multiple versions of a control strategy to be tested in a virtual environment, in order to find the control strategy version most likely to increase the vehicle's fuel economy. The best version of the control strategy from the SIL simulations can then be tested later on the vehicle. The work described in this (open full item for complete abstract)

Committee: Dr. Giorgio Rizzoni (Advisor); Dr. Shawn Midlam-Mohler (Advisor); Dr. Yann Guezennec (Committee Member) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2011, Electrical and Computer Engineering

The OSU EcoCAR Team is comprised of a diverse group of students ranging from underclassmen to graduate and engineering to business. This diverse team provides both the ability to take on aggressive designs and meet ambitious goals, but also presents a unique set of management and leadership responsibilities. The team management and growth was critical to being successful in meeting timelines and goals amongst diverse experience and levels of involvement. First, this thesis will include elements and details on how this team management and leadership was structured and changed to produce results. Next, the EcoCAR competition vehicle was designed to maximize efficiency and performance while minimizing emissions and petroleum usage. The Ohio State team designed a unique extended-range electric vehicle (E-REV), which uses two electric machines and a battery to power the vehicle for 40-45 miles until an E85 engine turns on and provides the power. The OSU vehicle is unique in its capability to use the front powertrain as an electric drive, auxiliary power unit (APU), or hybrid drive. The design will be explained in this thesis with a specific focus on the benefits of the design and the unique transmission system designed to provide vehicle function. The vehicle design presents a wide variety of controls options and challenges when managing energy, drivability, and performance. This thesis will also dive deeply into controls algorithms and decisions for the vehicle control algorithm design, calibration, and improvements. Topics such as controls hardware and software structure will be explained along with a variety of test results from simulation and vehicle testing. The results show a very comprehensive control system and vehicle design capable of a wide variety of operating conditions and speeds. In all cases, the design provides robust and reliable operation with high efficiency and performance.

Committee: Giorgio Rizzoni (Advisor); Shawn Midlam-Mohler (Committee Member); Yann Guezennec (Committee Member) Subjects: Electrical Engineering; Engineering; Mechanical Engineering

Master of Science, The Ohio State University, 2010, Mechanical Engineering

Increased pressure for fuel economy improvement in combination with rapid development of battery technology has brought focus to new vehicle architectures like: hybrid electric vehicles (HEV), plug-in hybrid vehicles (PHEV), and extended range electric vehicles (EREV). These architectures require different engine characteristics which must be considered during the component selection phase of a vehicle development program. Throughout the development program a variety of different engine simulation techniques can be used to increase the efficiency of the program. Current literature has shown that a wide variety of engine simulation models have been developed and applied to many different engine research problems. These models vary greatly in their fidelity and computational efficiency. The methods which are used to build and calibrate the different models require varying amounts of empirical data and model calibration effort. With a large number of model based resources available, a key question is how to select and implement models which are best targeted for a project's goals. When developing a new engine control strategy, some of the driving issues are cost and resource minimization and quality improvement. This thesis outlines how a model based approach was used to choose an engine and develop an engine control strategy for an EREV. The outlined approach allowed the development team to minimize the required number of experiments and to complete much of the control development and calibration before implementing the control strategy in the vehicle. It will be shown how models of different fidelity, from map-based models, to mean value models, to 1-D gas dynamics models were generated and used to develop the engine control system. The application of real time capable models for Hardware-in-the-Loop testing and the development of an electronic throttle control strategy will also be shown. The application of this work is the EcoCAR advanced vehicle competition. T (open full item for complete abstract)

Committee: Giorgio Rizzoni Professor (Advisor); Yann Guezennec Professor (Committee Member); Shawn Midlam-Mohler PhD (Committee Member) Subjects: Engineering; Mechanical Engineering