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Alleviating the Magnetic Effects on Magnetometers using Vehicle Kinematics for Yaw Estimation for Autonomous Ground Vehicles

Michigan Technological University-Ahammad Basha Dudekula, Jeffrey D. Naber
  • Technical Paper
  • 2020-01-1025
To be published on 2020-04-14 by SAE International in United States
Autonomous vehicle operation is dependent upon accurate position estimation and thus a major concern of implementing the autonomous navigation is obtaining robust and accurate data from sensors. This is especially true, in case of Inertial Measurement Unit (IMU) sensor data. The IMU consists of a 3-axis gyro, 3-axis accelerometer, and 3-axis magnetometer. The IMU provides vehicle orientation in 3D space in terms of yaw, roll and pitch. Out of which, yaw is a major parameter to control the ground vehicle’s lateral position during navigation. The accelerometer is responsible for attitude (roll-pitch) estimates and magnetometer is responsible for yaw estimates. However, the magnetometer is prone to environmental magnetic disturbances which induce errors in the measurement. The present work focuses on alleviating magnetic disturbances for ground vehicles by fusing the vehicle kinematics information with IMU senor in an Extended Kalman filter (EKF) with the vehicle orientation represented using Quaternions. In addition, the error in rate measurements from gyro sensor gets accumulated as the time progress which results in drift in rate measurements and thus affecting the vehicle…
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Rolling Element Bearings - Advanced Modeling for Multibody Simulations

Ghent University - Soete-Dieter Fauconnier
Siemens DI Software NV-Pavel Jiranek
  • Technical Paper
  • 2020-01-0508
To be published on 2020-04-14 by SAE International in United States
The electrification of vehicles, together with the ever-increasing need for more lightweight and durable designs, is putting the NVH performances of the transmission in the spotlight since the generated noises are not masked by the internal combustion engine. To correctly estimate the performances of the transmission while still in the design-phase, predictive models for the main components of the gearbox are of paramount importance. This paper focuses on the modeling of rolling element bearings, a key component that is responsible of transmitting the vibrations from the gear pairs to the surrounding structure while introducing additional excitation frequencies. The modeling techniques use the relative displacement of the rings to compute the corresponding reaction forces by calculating the equilibrium of each rolling element. To do so, the interaction between the rolling elements and the raceways can be modeled employing two different contact models depending on the level of accuracy required. The contact models are, respectively, a Hertz-Based approach that allows for fast computations, and an EHL (Elasto-Hydrodynamic Lubricated) contact model which accounts for the effects of lubrication.…
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Capabilities and Limitations Related to Vehicle Dynamics and Operator Kinematics of Electric Scooter Micro-Mobility Modes

Exponent Inc.-Christina MR Garman, Steven G. Como, Ian C. Campbell, Jeffrey Wishart, Kevin O'Brien, Scott McLean
  • Technical Paper
  • 2020-01-0935
To be published on 2020-04-14 by SAE International in United States
Micro-mobility is a fast-growing trend in the transportation industry with stand-up electric scooters (e-scooters) becoming increasingly popular in the United States. To date, there are over 350 ride-share e-scooter programs in the United States. As this popularity increases, so does the need to understand the performance capabilities of these vehicles and the associated operator kinematics. Scooter tip-over stability is characterized by the scooter geometry and controls and is maintained through operator inputs such as body position, interaction with the handlebars, and foot placement. In this study, testing was conducted using operators of varying sizes to document the capabilities and limitations of these e-scooters being introduced into the traffic ecosystem. A test course was designed to simulate an urban environment including sidewalk and on-road sections requiring common maneuvers (e.g., turning, stopping points, etc.) for repeatable, controlled data collection. A commercially available e-scooter was instrumented to measure acceleration and velocity, steering angle, roll angle, and GPS position. Operators ranging from the 15th percentile to the 85th percentile were instrumented with wearable sensors to gain insight into the…
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Finite Element Analysis Technique To Roll Crimp Solenoid’s Can

BorgWarner Inc.-Chandreshwar Rao
  • Technical Paper
  • 2020-01-0749
To be published on 2020-04-14 by SAE International in United States
Roll forming assemblies are generally neat and robust, but there are structural integrity risks involved too if the forming procedures and design features do not complement each other. Specifically, in solenoid valves, an imprecised roller crimping (or forming) adversely affect the desired magnetic performance of the valves. Furthermore, in-depth evaluations of the formed shape using hardware and lab testing are extremely challenging cost wise and time consuming as well. However, utilizing simulation technique such as finite element analysis (FEA) to understand the in-sights of roller formed assemblies of a solenoid valve (or other products) could be an effective way to minimize overall cost and time involved in the product development. Therefore, a three-dimensional non-linear FEA model of roller crimping simulation was established in ANSYS Workbench Mechanical, and the predicted results were correlated with real hardware data to prove the technique & process adopted. Then the design was improved computationally to eliminate the magnetic Core's flux-bridge distortion issue of a solenoid valve, and finally the design was validated through hardware testing.
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Facility for Complete Characterization of Suspension Kinematic and Compliance Properties of Wheeled Military Vehicles

SEA, Ltd.-Dale Andreatta, Gary Heydinger, Anmol Sidhu, Scott Zagorski
  • Technical Paper
  • 2020-01-0175
To be published on 2020-04-14 by SAE International in United States
As part of their ongoing efforts to model and predict vehicle dynamics behavior, the US Army’s Ground Vehicle Systems Center procured a facility in two phases. The facility is called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and has a capacity covering all of the military’s wheeled vehicles, with vehicle weights up to 100,000 lbs (45,400 kg), up to 150 inches wide, with any number of axles. The initial phase had the ability to measure bounce and roll kinematic and compliance properties. The SPIdER is the companion machine to the Vehicle Inertia Parameter Measuring Device (VIPER) which measures the inertia properties of vehicles of similar size. In 2015, the final phase of the SPIdER was completed. This phase includes ground plane wheel pad motion so that lateral, longitudinal, and aligning moment compliance and kinematic properties can be measured. These capabilities greatly enhance the SPIdER’s features, giving it the ability for making complete suspension and steering system kinematic and compliance measurements. Horizontal forces and aligning moments can be applied up to the limits of tire…
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The Effect of Obesity on Rollover Ejection and Injury Risks

Exponent Inc.-Chantal Parenteau, Janine Smedley, Michael Carhart, Alan Dibb
  • Technical Paper
  • 2020-01-1219
To be published on 2020-04-14 by SAE International in United States
Obesity rates are increasing among the general population. This study investigates the effect of obesity on ejection and injury risk in rollover crashes through analysis of field accident data contained in the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) database. The study involved front outboard occupants of age 15+ years in 1994+ model year vehicle rollover crashes. Complete and partial ejection risks were first assessed seating location relative to roll direction and belt use. The risk of serious-to-fatal injuries (MAIS 3+F) in non-ejected occupants were then evaluated. Occupants were sorted into two BMI groups, normal (18.5 kg/m2 ≤ BMI <25.0 kg/m2) and obese (BMI ≥30 kg/m2). The overall risk for complete ejection was 2.10% ± 0.43% when near-sided and 2.65% ± 0.63% when far-sided, with a similar risk for both the normal and obese BMI groups. Complete ejection was uncommon for belted occupants with a risk of 0.2% or less for all groups. The risk of partial ejection was greater for obese compared to normal BMI occupants. For near-side occupants, the overall risk of partial…
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SUV Kinematics during a Steer-Induced Rollover Resolved Using Consumer-Grade Video, Laser Scans and Match-Moving Techniques

MEA Forensic Engineers & Scientists-Cole R. Young, David J. King, Gunter P. Siegmund
  • Technical Paper
  • 2020-01-0642
To be published on 2020-04-14 by SAE International in United States
Rollover crashes are complex events that generate motions in all six degrees of freedom (6DOF). Directly quantifying the angular rotations from video can be difficult and vehicle orientation as a function of time is often not reported for staged rollover crashes. Our goal was to evaluate the ability of using a match-moving technique and consumer-grade video cameras to quantify the roll, pitch and yaw angles and angular velocities of a rollover crash. We staged a steer-induced rollover of an SUV at 106 km/h. The vehicle was fitted with tri-axial accelerometers and angular rate sensors, and five consumer-grade video cameras (2 on tripods, 2 on drones, 1 handheld, ~30 fps) captured the event. Roll, pitch and yaw angles were determined from the video using specialized software. We then compared the vehicle orientation angles from the video data to the integrated angular rate data measured by onboard sensors, and also compared the angular rates from the differentiated video data to the angular rates measured directly by the sensors. We found that both methods of measuring the 3D…

Magnetorheological Semi-Active Anti-Roll Bar for Automobiles

SAE International Journal of Passenger Cars - Electronic and Electrical Systems

Hefei University of Technology, China-Chao Tang, Xianxu Bai, Shi-Xu Xu
  • Journal Article
  • 07-12-02-0007
Published 2020-03-11 by SAE International in United States
Aiming at improving safety (anti-roll performance) with consideration of ride comfort of vehicles during cornering and over road irregularities, magnetorheological (MR) fluid-based semi-active anti-roll bar is investigated in this article. The vehicle roll model with both roll stiffness and roll damping of the vehicle body influenced by the MR anti-roll bar is established to analyze the impact of the torsional stiffness and torsional damping. Combining with the Pareto front of the lateral load transfer ratio (LTR) of the front axle, the optimal roll stiffness and roll damping of a vehicle are determined, and correspondingly the torsional stiffness and torsional damping of the anti-roll bar are determined. And then the mathematical model and multibody dynamic model of the anti-roll bar are established, and the simulation of the MR semi-active anti-roll bar model is carried out via MATLAB/Simscape Multibody. CarSim vehicle model equipped with the MR anti-roll bar is built and a fuzzy controller is designed according to the roll angle and roll rate. Co-simulation based on CarSim and MATLAB/Simulink is conducted to analyze the impact of…
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Design of Elevons for a Hybrid VTOL-Blended Wing Body Unmanned Aerial Vehicle

Delhi Technological University-Amit Bainsla, Vikas Rastogi, Pranav Bahl
  • Technical Paper
  • 2020-01-0047
Published 2020-03-10 by SAE International in United States
The two primary requirements for a safe flight of a UAV are its stability and manoeuvrability. The purpose of this study is to design and validate elevons for a UAV having Blended Wing Body configuration which requires knowledge of various domains applied in a complex combination. Elevons are the unconventional control surfaces for the flying wings which will cause a pitching moment when moved in same direction and will cause a rolling moment when moved differentially and their preliminary design is affected by the function which is dominant. A MATLAB© code was written to decide the position, shape and size of elevons and later on accurately evaluated using high fidelity Computational Fluid Dynamics simulations. The MATLAB© code calculates the required roll time rate taking into consideration the longitudinal and lateral control requirements. Using this coupled approach of MATLAB© code and Computational Fluid Dynamics simulations significant optimization is achieved in designing the elevons.

Pinpointing Consumption “Sweet Spot” Makes Formation Flight More Fuel-Efficient

  • Magazine Article
  • TBMG-35825
Published 2020-01-01 by Tech Briefs Media Group in United States

Formation flying — when one aircraft flies behind another — reduces drag and results in improved fuel consumption in the trailing vehicle; however, no sensor currently exists that directly measures drag. Instead, pilots rely on fuel flow measurements or induced aircraft moments — roll, pitch, and yaw — to estimate the best location within a leading vehicle's wave vortex. Fuel flow alone is a lagging drag estimate, which leads to inaccurate estimates. Aircraft moments alone also do not sufficiently indicate the best location for the trailing aircraft.