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Training / Education

Photogrammetry and Analysis of Digital Media

2022-09-21
Photographs and video recordings of vehicle crashes and accident sites are more prevalent than ever, with dash mounted cameras, surveillance footage, and personal cell phones now ubiquitous. The information contained in these pictures and video provide critical information to understanding how crashes occurred, and in analyzing physical evidence. This course teaches the theory and techniques for getting the most out of digital media, including correctly processing raw video and photographs, correcting for lens distortion, and using photogrammetric techniques to convert the information in digital media to usable scaled three-dimensional data.
Training / Education

Critical Concepts of Tolerance Stacks ASME Y14.5 1994, 2009, 2018 – Foundational Level

2022-04-04
Using tolerance stacks ensures that parts fit together properly, reducing scrap and rework, thereby increasing value. This 2-day foundational-level course explains how to use tolerance stacks to analyze product designs and how to use geometric tolerances in stacks. You’ll learn the essential methods used for creating 1D part and assembly tolerance stacks, including these six critical concepts: 1. The importance of stacks 2. The two-column stack method using the SAE stack spreadsheet 3. Determining a stack path 4. Creating 1D part and assembly stacks 5. Interpreting GD&T 6.
Technical Paper

Driving Behaviour Analysis Software for Data-Driven Path Planning Functionalities for Automated Vehicles

2022-03-29
2022-01-0218
Autonomous driving is currently one of the most challenging Artificial Intelligence (AI) problems as it requires combination of state-of-the-art solutions in multiple areas including computer vision, sensor fusion, control theory and software engineering. Deep learning has been pivotal to solving some of these problems, especially in computer vision. This enabled some autonomous vehicle companies started leveraging the benefits of deep learning for creating smooth, natural, human-like motion planning systems. In particular, the plethora of driving data captured from modern cars is a key enabler for training data-driven path planning systems. , Developing deep learning-powered systems relies heavily on big and high-quality data required for training of the models, in which the intrinsic statistics of the data that the model is trained on can result in different agent behavior in different scenarios.
Technical Paper

Padded Self-Piercing Riveting (P-SPR) on magnesium high pressure die casting

2022-03-29
2022-01-0249
Padded self-piercing riveting (P-SPR) is a newly developed multi-material joining technology to enable less ductile materials to be joined by self-piercing riveting (SPR) without cracking. A deformable and disposable pad was employed to reduce the stress distribution on the bottom surface by supporting the whole bottom sheet continuously during rivet setting process. To verify the P-SPR process, 2.0mm thick 6061-T6 wrought aluminum was joined with 3.2mm thick coated AM60B magnesium high pressure die casting (HPDC) by using 1.0mm thick dual-phase 600 (DP600) steel as the pad. Regular SPR processes with 2 different die geometries were studied as a comparison. Compared to the regular SPR processes, P-SPR demonstrated advantages on coating protection, crack mitigation and joint strength.
Technical Paper

Modern Product Development Platform for Living Products in Perpetual Systems

2022-03-29
2022-01-0230
In 1930, John Maynard Keynes predicted, that due to software and automation, 15-hour work weeks would be a reality by the end of the century. While that envisioned “utopia” has not been realized, Mr. Keynes did have the radical vision to imagine a pretty radical low code highly automated future - one to which the future of software in mobility arguably depends on. So, what went wrong? Well, its not about as much about what went wrong but about how adoption is taking place and how it needs to change. In any software development, no matter where in history, as soon as software testing became a hot topic, automation tools started springing up and then "selective parts" that were iterative and time-consuming in the software were automated away. This begs several questions. The first and obvious, why automate these parts - and the second - whether software developers are making themselves obsolete by building automation tools.
Technical Paper

A study on editing method of road load spectrum of automobile rubber isolator using time-frequency domain methods

2022-03-29
2022-01-0272
In order to enhance the efficiency of durability testing of automobile parts, a time-frequency domain accelerated editing method of road load time series of rubber mount on powertrain was discussed. Based on Stockwell Transform method and Accumulative Power Spectral Density, a new time-frequency domain accelerated editing method (ST-APSD) was proposed. The accumulative power spectral density was obtained by ST of the load time series signal of automobile powertrain rubber mounting force which is acquired by the real vehicle in the test field. Based on the accumulative power spectral density, the threshold value was proposed to identify and delete the small damage load fragments, and then the acceleration spectrum was obtained.
Technical Paper

Technical Keynote: Durability Validation for Variable Vehicle Usage

2022-03-29
2022-01-0255
Durability engineering for vehicles is about relating real operational loading to the actual strength of the product and its components. In the first part of this presentation, we show how to calculate failure probabilities and safety factors based on the load and strength distributions. We discuss the uncertainty within the estimations, which is considerably large in case of extremely small failure probabilities as required for safety critical components. In the second part, we focus on modelling and simulating the loads based on real vehicle usage, such that the resulting statistics allows to understand and quantify the usage variability. The idea is, to simulate thousands of vehicle life spans of, say, 300.000 km or 15.000 h of operation each. The input data for such simulations typically consists of a combination of geographic data (like road network, topography, road conditions, traffic data, and points of interest) and properly segmented rich data from measurement campaigns.
Technical Paper

A fatigue life prediction method of rubber material for Automobile vibration isolator under road load spectrum

2022-03-29
2022-01-0253
Automobile rubber isolator was subjected to random load cycle for a long time in the service process, and its main rubber material for vibration isolation was prone to fatigue failure. Since the traditional Miner damage theory overlooked the load randomness, it had a prediction error problem. In order to improve the prediction accuracy of rubber fatigue life, the traditional Miner damage theory was modified by random uncertainty theory to predict the rubber fatigue life under random load. Firstly, the rubber dumbbell-shaped test column, which was vulcanized from rubber materials commonly used in vibration isolators, was taken as the research object. The uniaxial fatigue test of rubber under different strain amplitudes and strain mean values was carried out. Then the fatigue characteristic curve of rubber with equivalent strain amplitude as the damage parameter was established.
Technical Paper

Numerical Investigation on the Internal Flow Field of Electronic Expansion Valve as the Throttle Element

2022-03-29
2022-01-0318
As one of the key components of the heat pump system, the electronic expansion valve mainly plays the role of throttling and reducing pressure in the heat pump system. The refrigerant flowing through the orifice will produce complex phase change. It is of great significance to study the internal flow field by means of CFD calculations. Firstly, a three-dimensional fluid model is established and the mesh is divided. Secondly, the phase change model is selected, the material is defined and the boundary conditions are determined. According to the principle of the fluid passing through thin-walled small holes, the flow characteristics of electronic expansion valve are theoretically analyzed. Then the flow characteristics of expansion valve are numerically calculated, and a bench for testing mass flow rate of the expansion valve is built. Then the theoretical value, CFD value and experimental value are compared to verify the correctness of the established three-dimensional fluid model.
Technical Paper

Numerical Assessment of Tribological Performance of Different Llow Viscosity Engine Oils in a 4-Stroke CI Light-Duty ICE

2022-03-29
2022-01-0321
Decreasing fuel consumption in Internal Combustion Engines (ICE) is a key target for engine developers in order to achieve the CO2 emissions limits during a standard cycle. In this context, reduction of engine friction can help meet those targets. The use of Low Viscosity Engine Oils (LVEOs), which is currently one of the avenues to achieve such reductions, is studied in this manuscript through a validated numerical simulation model that predicts the friction of the engine’s piston-cylinder unit, journal bearings and camshaft. These frictional power losses are obtained for four different lubricant formulations which differ in their viscosity grades and design. Results show a maximum friction savings of up to 6% depending on the engine operating condition, where the major reductions come from hydrodynamic-dominated components such as journal bearings, despite an increase in friction in boundary-dominated components such as the piston-ring assembly.
Technical Paper

An experimental approach for exploring electrified sliding wear of EVs powertrain gears in a pin-on-disc tester

2022-03-29
2022-01-0320
In contrast to conventional powertrains from internal combustion engine vehicles (ICEV), the tribological performance of powertrains of electric vehicles (EVs) must be further evaluated by considering new critical operation conditions such as electric environments. The operation of any type of electric motor produces shaft voltages and currents generated during rotation. Furthermore, the common application of inverters to convert DC voltage of the battery into AC voltage in EVs, intensifies this problem. It has been widely reported that the induced shaft voltages and currents can cause premature failure problems in a series of powertrain components such as bearings, seals, pads, and gears due to accelerated wear and/or fatigue. It is ascribed to effects of electric discharge machining (EDM), also named, sparking wear caused by shaft currents and poor dielectric strength of lubricants.
Technical Paper

An Accurate Analysis Method to Calculate Planetary Gear Set Load Sharing under Non-Torque Load

2022-03-29
2022-01-0653
Given their high-power density, large range of speed change, and reputation of being quieter than counter-shaft gear sets, planetary gear sets (PGS) have advantages to be applied in electric vehicle (EV) applications. Typical rear wheel drive automatic transmissions have only PGS in gearbox, and power is transferred by torque. Most electric drive units (EDU) equipped PGS are like a simplified front wheel drive automatic transmission. PGS is coupled with counter-shaft gear sets normally at planet carrier which has two functions: original planet pinion carrying and additional transfer gear mounting. The latter brings in non-torque power in PGS through the carrier. This condition hasn’t obtained enough attention by automotive gear researchers regarding to PGS load sharing calculation. Excluding non-torque load here causes underestimating gear and bearing uneven loads in both magnitude and variation. In extreme conditions, undersized parts would miss demanding durability requirements.
Technical Paper

Managing Trust along the CAN Bus

2022-03-29
2022-01-0119
Multiple approaches have been created to enhance intra-vehicle communications security over the past three decades since the introduction of CAN. The twin pair differential-mode communications bus is tremendously robust in the face of interference, yet physical access to the bus offers a variety of potential attack vectors whereby false messages and/or denial of service are easy to achieve. This paper seeks to evaluate extensions of a common-mode watermark-based authentication technique recently developed to improve authentication on the CAN bus by considering the watermark as a side-channel communications means for high value information. We also describe a variety of higher layer algorithms, with benefits and pitfalls, for employing the watermark as a physical-layer firewall. All of these results are backed by a software-defined radio (SDR) based hardware testbed.
Technical Paper

A DFSS approach to optimize the Hood design parameters to improve durability performance

2022-03-29
2022-01-0771
In the Vehicle front closure development process, it is very important to meet the durability functional attributes such as Fit and finish, slam event and ease of closing effort. Conventionally softer seal & bump-stop stiffness properties are required for better flushness, but a stiffer seal & bump-stop will help to arrest the hood over travel during the slam event. It is always a challenging and iterative process to arrive at an optimum combination of these design parameters to meet both the flushness and slam targets. This paper highlights the six sigma approach to identify the effect of various control factors like Seal & Bump stop stiffness, latch position, bump-stop design clearance to meet the durability functional attributes. This approach suggests optimum design which is less sensitive to noise factors such as build tolerances on the latch position and the bump-stop design clearance.
Technical Paper

Design of Engine mount bracket for impact load requirement

2022-03-29
2022-01-0758
The primary function of a powertrain mounting bracket is to support the powertrain system in all road conditions. Since it is impossible to change the supporting locations and types of support at a later stage of the development after the powertrain is packaged, the mounting brackets must be verified for all kinds of requirements like NVH, crash, durability and impact strength at the early design stage. Generally, all car manufacturers ensure powertrain mount bracket design through CAE against road load data (RLD), corresponding damage for cumulative strain or stress against specified service life requirements. However, it is challenging to simulate the impact load through CAE, which requires highly complex input data. The energy absorption characteristics of the powertrain mounting bracket are mainly influenced by two variables, the material and the design. Though a bracket may be sound in design for durability, there is a chance of failure due to impact loading.
Technical Paper

Visualization of Frequency Response Using Nyquist Plots

2022-03-29
2022-01-0753
Nyquist plots are a classical means to visualize a complex vibration frequency response function. By graphing the real and imaginary parts of the response, the dynamic behavior in the vicinity of resonances is emphasized. This allows insight into how modes are coupling, and also provides a means to separate the modes. Mathematical models such as Nyquist analysis are often embedded in frequency analysis hardware. While this speeds data collection, it also removes this visually intuitive tool from the engineer’s consciousness. The purpose of this paper is to review the fundamentals of Nyquist plots and their application to structural vibration. The behavior of a single degree of freedom system will be shown to be well described by a circle on its Nyquist plot. This observation allows simple visual examination of the response of a continuous system, and the determination of quantities such as uncoupled natural frequencies, modal damping factors, and uncoupled modes shapes.
Technical Paper

Luminance Estimation with Exemplar Digital Camera

2022-03-29
2022-01-0804
Mapping the luminance values of a visual scene is of broad interest to accident reconstructionists, human factors professionals, and lighting experts. Previous work has shown that pixel intensity captured by consumer-grade digital still cameras can be calibrated to estimate luminance. Suway and Suway presented a methodology for estimating luminance from digital images and video of a scene. This method requires the capture of dark images close in time to the capture of the image that will be used to estimate luminance. Additionally, Suway’s method requires the specific camera and lens combination used to be calibrated for luminance estimation. In this paper, the authors present results of estimating luminance with an exemplar camera and taking exemplar dark images. The analysis was completed with the commercially available luminance estimation software, Nitere.
Technical Paper

Design Optimization of Centrifugal Pump Using CFD Simulations, Metamodeling and Bayesian Inference

2022-03-29
2022-01-0787
Computational expenses aside, simulating and optimizing pumps operating at pressures near the liquid’s saturation pressure needs complete modeling of cavitation physics. This becomes critical in high-temperature applications since the saturation pressure increases with temperature and the pumps become more prone to cavitation. In the present work, the performance of a centrifugal pump was improved by delaying the sudden onset of cavitation at higher flow rates through constrained optimization of impeller geometry. The optimized designs generated over 25% higher head at the operating point, and performed better than the baseline design across the range of operation. Constraints were dictated by geometric/ packaging limitations in order to ensure that the optimized impeller can be retrofitted into an existing fluid-power system. A Gaussian Process Regressor (GPR) based metamodel was constructed utilizing a database of designs generated through Latin Hypercube Sampling (LHS).
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