Investigation of Electrical Component Failures Affecting Vehicle Electronics

This dissertation describes three independent studies related to electrical component failures affecting vehicle electronics. The topics covered are: comparison of the accelerator-pedal-to-engine-control module (AP-to-ECM), the effect of electrical fast transients on multi-layer ceramic (MLC) capacitors, and electrical behavior of MLC capacitors damaged by electrostatic discharge. The first chapter examines the AP-to-ECM interfaces of five vehicles equipped with electronic throttle control systems. All five vehicles employ simple voltage level sensing from two or three sensors in the accelerator pedal assembly. The purpose of the study is to identify any differences in the AP-to-ECM interfaces of vehicles with high reported rates of unintended acceleration compared to vehicles with low reported rates of unintended acceleration. The study does not attempt to identify the root causes of unintended acceleration; however it points out important design issues that suggest a set of best practices for electronic throttle control design. The second chapter investigates the susceptibility of MLC capacitors to high-voltage electrical fast transients (EFTs). X7R and NP0 MLC capacitors with a 50-V voltage rating and 0603 package size were tested. X7R capacitors often failed during a spike in the voltage, but exhibited no obvious degradation in the measured insulation resistance at low voltages immediately after the failure. NP0 capacitors usually failed by suddenly shorting and maintaining the short after the failure. With the application of additional voltage spikes, some X7R capacitors exhibited a full recovery in terms of the measured resistance, returning to their initial state. The resistance of an X7R capacitor damaged by an EFT event is a function of the applied voltage. The terminal impedance can be modeled as two diodes in parallel. The third chapter investigates the electrical behavior of MLC capacitors subjected to electrostatic discharge (ESD). The degradation of MLC capacitors subjected to repeated discharges manifests itself as a non-linear resistance. The leakage current in degraded capacitors increases exponentially with an applied voltage. The I-V characteristics of these capacitors are symmetric with voltage and independent of the polarity of the ESD discharges responsible for the degradation. A model for a degraded capacitor consisting of two parallel diodes with opposite polarities is proposed

Supervisory Controller Validation For A Plug-In Parallel-Through-The-Road Hybrid Electric Vehicle By Software-In-The-Loop Testing

The goal of this research is to develop an operational supervisory controller for Wayne State University Hybrid Warriors\u27 hybrid electric vehicle architecture that can be transitioned easily to a hardware-in-the-loop testing environment for the 2011-2014 EcoCAR2 competition. It serves to demonstrate how model-based design, specifically software-in-the-loop testing, is effective for the initial steps in design, verification, and validation of a supervisory control strategy. Overall, the supervisory controller aims to meet all safety and functional requirements while reducing fuel consumption. The thesis starts by presenting a plug-in parallel-through-the-road architecture and its powertrain hardware components. Next, characteristics and capabilities of all significant powertrain components are explained along with the implementation of the vehicle plant model. Initial stages and preparations for the development of supervisory controller begin with applying the Design Failure Mode and Effects Analysis and identifying the functional vehicle requirements. Control strategies implemented within the supervisory controller are discussed in detail. Finally, results from the software-in-the-loop testing as well as safety critical fault mitigation are shown, to demonstrate the end product of a supervisory controller that has reached a high level of functionality and safety and therefore is ready for hardware-in-the-loop testing. Outlines are provided for extending the current work into next phases of hardware-in-the-loop testing, optimization using vehicle-in-the-loop results, and special applications such as cold-start

Design and Control of a Unique Hydrogen Fuel Cell Plug-In Hybrid Electric Vehicle

The University of Waterloo Alternative Fuels Team (UWAFT) is a student team that designs and builds vehicles with advanced powertrains. UWAFT uses alternatives to fossil fuels because of their lower environmental impacts and the finite nature of oil resources. UWAFT participated in the EcoCAR Advanced Vehicle Technology Competition (AVTC) from 2008 to 2011. The team designed and built a Hydrogen Fuel Cell Plug-In Hybrid Electric Vehicle (FC-PHEV) and placed 3rd out of 16 universities from across North America. UWAFT design projects offer students a unique opportunity to advance and augment their core engineering knowledge with hands-on learning in a project-based environment. The design of thermal management systems for powertrain components is a case study for design engineering which requires solving open ended problems, and is a topic that is of growing importance in undergraduate engineering courses. Students participating in this design project learn to develop strategies to overcome uncertainty and to evaluate and execute designs that are not as straightforward as those in a textbook. Electrical and control system projects require students to introduce considerations for reliability and robustness into their design processes that typically only focus on performance and function, and to make decisions that balance these considerations in an environment where these criteria impact the successful outcome of the project. The consequences of a failure or unreliable design also have serious safety implications, particularly in the implementation of powertrain controls. Students integrate safety into every step of control system design, using tools to identify and link together component failures and vehicle faults, to design detection and mitigation strategies for safety-critical failures, and to validate these strategies in real-time simulations. Student teams have the opportunity to offer a rich learning environment for undergraduate engineering students. The design projects and resources that they provide can significantly advance student knowledge, experience, and skills in a way that complements the technical knowledge gained in the classroom. Finding ways to provide these experiences to more undergraduate students, either outside or within existing core courses, has the potential to enhance the value of program graduates

Model Based Design Framework Development of a Hybrid Supervisory Controller for a P4 Parallel Hybrid Vehicle

The expected rise in the number of ECUs in an automotive based development environment, poses additional efficiency risk on developer time and code complexity. This thesis examines the design and validation of a Hybrid Supervisory Controller, developed for the University of Waterloo Alternative Fuels Team’s (UWAFT) retrofitted P4 parallel Chevrolet Blazer, in the EcoCAR Mobility Challenge competition. The controller, component models and I/O interaction layers are developed in a MathWorks Simulink environment. The framework discussed, is built to incorporate automation via a custom developed -Model-Configurator tool. Component models, and functional sub-systems are converted to masked library blocks within Simulink, that are populated via an object-oriented class in the MATLAB environment. This opens the possibility for custom environment data population, swapping of data for models while retaining underlying physics and setting up for SIL/HIL requirements testing without explicit/contemporary interaction with the Simulink environment. The advantages of this approach are discussed, along with explanation accompanying the software framework. The HSC incorporates interaction models of 9 stock vehicle, and on-board GM ECUs. The model spans full chassis longitudinal, and powertrain components. The functional controller incorporates 4 powertrain control layers - fault detection, vehicle state control, torque strategy and component level execution layers. The test environment switching time is reduced by >50%, and 86 controls requirements are tested over the course of 3 years. The test vehicle is tested at the Canadian Technical Center McLaughlin Advanced Technology Track (CTC MATT) where a non-standard drive cycle is used due to limitations posed by the COVID-19 pandemic. The vehicle robustly sustains a 91-minute city/highway drive, with a 24% improvement in fuel economy compared to stock. The vehicle however is short of its VTS targets which are attributed to the lack of engine start/stop functionality, and a thermally constrained battery pack. Those remain major design shortcomings and immediate powertrain improvements are proposed, and efficacy of a well-organized model are discussed

Development and testing of a high-country electric vehicle.

HiCEV (High-Country Electric Vehicle), is an electric vehicle conversion project which aims to produce a prototype to test the viability of replacing traditional internal combustion engine (ICE) powered farm vehicles with those having an electric drivetrain. Previous work has been performed on a 70- series Land Cruiser, replacing the existing ICE system with an electric motor and power-train. The project was taken over, by the author, as vehicle hardware was largely pre-installed in the vehicle; however, due to the presence of several faults, most significantly, in the electric vehicle control module (EVCM), significant redesign, rewiring, and reprogramming was required to enable vehicle functionality. Modifications were made to the vehicle to facilitate operating without the EVCM, using the built-in motor control within the inverter. This had the secondary effect of reducing the complexity of the systems, by reducing the number of I/O pins available for switching and monitoring several of the vehicle sub-systems. To work around the EVCM, the inverter took input from several peripherals within the vehicle as well as receiving information from the Battery Management System (BMS), through CAN bus communication. Testing on HiCEV was carried out to establish the operation of the vehicle, and how it relates to both theory as well as the project objectives. It became evident early on in testing that due to the cell tap wiring in the BMS, the vehicle was being shut down as a result of high measured internal resistances within cells. To enable further testing on the vehicle, the capacity for the BMS to shut down the vehicle was bypassed. Testing yielded that motor and inverter characteristics largely resembled the expected theoretical outcomes, with the motor accomplishing peak torque outputs of 320 Nm at lower vehicle speeds with the torque output beginning to lower at 3600 rpm. The motor and inverter configuration ended up accomplishing a peak power of 130 kW, noticeably greater than the original 95 kW produced by the previous power systems; considerably, due to the torque availability at lower speeds, producing a noticeably greater acceleration than most ICE vehicles. Further testing on specific cells within the pack did yield that there were early signs of degradation, which may inhibit long term reliability; in most cells, signs of degradation were expected and minimal given the age of the cells in the vehicle, which is close to 10 years

Towards a Common Software/Hardware Methodology for Future Advanced Driver Assistance Systems

The European research project DESERVE (DEvelopment platform for Safe and Efficient dRiVE, 2012-2015) had the aim of designing and developing a platform tool to cope with the continuously increasing complexity and the simultaneous need to reduce cost for future embedded Advanced Driver Assistance Systems (ADAS). For this purpose, the DESERVE platform profits from cross-domain software reuse, standardization of automotive software component interfaces, and easy but safety-compliant integration of heterogeneous modules. This enables the development of a new generation of ADAS applications, which challengingly combine different functions, sensors, actuators, hardware platforms, and Human Machine Interfaces (HMI). This book presents the different results of the DESERVE project concerning the ADAS development platform, test case functions, and validation and evaluation of different approaches. The reader is invited to substantiate the content of this book with the deliverables published during the DESERVE project. Technical topics discussed in this book include:Modern ADAS development platforms;Design space exploration;Driving modelling;Video-based and Radar-based ADAS functions;HMI for ADAS;Vehicle-hardware-in-the-loop validation system

The Psychology of Vehicle Performance: Implications for the Uptake of Electric Vehicles

Road transport accounts for around 16% of global CO2 emissions, and electric vehicles (EVs) represent a potential mitigation route. High performance might offset the disadvantages of higher cost and short range that make their uptake problematic. This research investigated how consumer drivers construe, perceive and value vehicle performance. Research with UK drivers, using the repertory grid method, found that drivers construe vehicle performance as having two independent dimensions, dynamic and cruising performance. A new inter-goal dynamics and feedback control model of driving behaviour was developed to account for differences in the opportunities afforded to perceive vehicle performance in naturalistic driving. This was embedded in a Bayesian model for perception of available vehicle performance. Driving simulation and test track experiments with UK drivers found that: driving behaviour was strongly affected by goal activation; drivers could perceive performance differences in naturalistic driving, but only if they were large; the lowest perceptual difference threshold, for mid-range available vehicle acceleration, was 7.7%; smaller differences could affect driving behaviour (overtaking) through a process of implicit learning. The symbolic value of products is conferred by their symbolic meanings. Two new methods were developed to quantify symbolic meanings, grounded in costly signalling theory, which represents them in terms of personality traits of a typical user. The symbolic meanings of car types, performance attributes and driving styles were all measured. In a randomised controlled trial, UK consumer drivers rated an EV better on dynamic and cruising performance than a conventional ICE control, but this benefit was insufficient to outweigh the disadvantages. The symbolic meaning of an EV was found to be consistent with cruising performance, but inconsistent with dynamic performance. Extended-range EVs would have the dynamic and cruising performance benefits of EVs without the range disadvantages, and may be a desirable option for many once costs reduce

Toyota recalls : revealing the value of secure supply chain

Thesis (S.M. in System Design and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010.Vita. Cataloged from PDF version of thesis.Includes bibliographical references (p. 116-121) and index.Summary: The warning bells are ringing. Once a global auto giant with a gold-plated reputation for safety and reliability, Toyota has stumbled. Its engineering excellence and traditional craftsmanship are being watered down by years of nips and tucks. With a torrent of high-profile recalls at the beginning of the new decade and a series of highly publicized legal charges, Toyota is all over the headlines. Following a business strategy that sacrifices its customer-first focus but in favor of driving shareholder value, Toyota gradually has shifted away from the tenet of lean manufacturing. Seeking cost leadership and market leadership has gone too far, and differentiation through quality, reliability and fuel efficiency becomes blurred. The execution of such business strategy in the past few years has lured Toyota to rush into relationships with suppliers it has not adequately vetted and to apply questionable security measures as it sourced parts from all around the world. In so doing, Toyota has been constantly adding stress to the security of its supply chain. In the end, its risk mitigation capability does not improve and quality standards have lapsed. Globalization and commoditization have forced today's businesses to focus on cost-cutting and growth to achieve profits of struggle to survive. Consequently, offshoring and outsourcing have become common practice. In such a competitive environment, supply chain is the lifeblood of a business and supply chain security is well-recognized as a competitive advantage and even a marketing tool. Security Secure supply chain is critical in product quality assurance and combating counterfeit, for which authoritative product attribute service represents an urgent need. For a long time, product attribute service is considered a Business-to-Business application. Trading partners of a supply chain build and share product information amongst themselves. Consumers are basically excluded from accessing such information. On the other hand, typically, product information provided to the end consumers are maintained by individual retailers. Such an approach is heterogeneous, error-prone, inaccurate, incomplete, and it undermines consumer confidence. There is a gap for authoritative product attribute service (APAS) that can provide uniform, validated, timely and complete product info to the end consumers. With APAS, consumers will play an active role in monitoring and contributing to the security of the supply chain. With a mobile barcode scanner or mobile RFID reader in hand, consumers will become a vibrant force in combating counterfeits, detecting 'bogus' status and reducing illegal trade. Consumers will benefit from such new capability by protecting their rights to buy genuine products with correct status and through legitimate channels. In addition, a spectrum of important mobile commerce applications will be made possible, such as trustful product attributes retrieval, attribute-based product search and comparison, product rating and commenting. With APAS, brand owners and other supply chain partners will see unprecedented possibilities such as direct customer-facing product marketing e.g. product recommendation, individualized coupon promotion, as well as direct user feedback on feature request and defect report. All of this will allow them to build competitive advantages with shorter user interaction cycles, more fragile to user demand variation, targeted and efficient product design, responsive product recall, and more effective in attacking counterfeits. In this thesis, I strive to provide a timely in-depth analysis on the mechanisms behind Toyota's crisis, especially the linkage between business strategy and supply chain security. I will relate secure supply chain to competitive advantage, and authoritative product attribute service to secure supply chain. Based on this, I perform strategic analysis and propose an architectural design for product attribute service. As a proof of concept, I design and implement a prototype of APAS with decent size of APAS repository and support for both mobile and PC clients. To this end, I first formulate the problems and explain the motivations behind secure supply chain and product attribute service. I then give an overview of the journey of Toyota from the synonym of quality to the reminder for product recalls. To provide further more background knowledge, I will examine business strategy and competitive advantage, together with secure supply chain, in the following two chapters. In particular, I will be deliberating on the causality between business strategy and supply chain strategy, and how supply chain vision and strategy can lead to operational executions that are sources of QA crises. In the next section, I provide details on architectural design for Authoritative Product Attribute Service. Afterwards, I describe the prototyping and implementation of APAS that covers the backend product attribute repository, the web backend that powers the APAS, as well as the Android-based mobile frontend. Finally, I summarize with concluding remarks and outline directions for future research.by Xiaoyuan Gu.S.M.in System Design and Managemen

Towards a Common Software/Hardware Methodology for Future Advanced Driver Assistance Systems

The European research project DESERVE (DEvelopment platform for Safe and Efficient dRiVE, 2012-2015) had the aim of designing and developing a platform tool to cope with the continuously increasing complexity and the simultaneous need to reduce cost for future embedded Advanced Driver Assistance Systems (ADAS). For this purpose, the DESERVE platform profits from cross-domain software reuse, standardization of automotive software component interfaces, and easy but safety-compliant integration of heterogeneous modules. This enables the development of a new generation of ADAS applications, which challengingly combine different functions, sensors, actuators, hardware platforms, and Human Machine Interfaces (HMI). This book presents the different results of the DESERVE project concerning the ADAS development platform, test case functions, and validation and evaluation of different approaches. The reader is invited to substantiate the content of this book with the deliverables published during the DESERVE project. Technical topics discussed in this book include:Modern ADAS development platforms;Design space exploration;Driving modelling;Video-based and Radar-based ADAS functions;HMI for ADAS;Vehicle-hardware-in-the-loop validation system

Engineering assessment of current and future vehicle technologies: FMVSS no. 105 hydraulic and electric brake systems, FMVSS no. 135 passenger car brake systems; final report

This report provides a technical assessment of Federal Motor Vehicle Safety Standards (FMVSS) 105, Hydraulic and electric brake systems, and FMVSS 135, Passenger car brake systems. The review of these standards is part of a NHTSA’s Regulatory Review Plan to systematically examine all of the FMVSS. The primary thrust of the document is to address two questions: Do the current standards impede emerging technologies in passenger car and light/medium truck braking systems? Do the current standards require modification to adequately regulate emerging technologies? Emerging technologies are reviewed. Estimates of the extent and timing of their influence are made. It is concluded that the standards will not impede emerging technologies in the foreseeable future but could do so in the long term. The view is expressed that the approach of the current standards to ensuring adequate performance under partial-failure conditions may become ineffective as more, and more complex, automatic functions are added to automotive brake systems. A new approach may be required. Seventy-eight references are included in an annotated bibliography.National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/55414/1/99826.pd