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A Novel Kind of Proportional Electromagnetic Dynamic Vibration Absorber

South China University of Technology-Tao FU
Published 2019-06-05 by SAE International in United States
A new proportional electromagnetic dynamic vibration absorber (EDVA) is proposed for control of engine vibration during idling. The device consists of an electromagnetic actuator attached to the primary structure through elastic element, where the driving force pair is implemented between the reaction-mass and the primary structure. The design of the proportional electromagnetic actuator is realized considering the geometric parameters of the core to achieve nearly constant magnetic force over a broad range of its dynamic displacement but proportional to square of the current. A methodology is proposed to achieve magnetic force proportional to square of current and consistent with the disturbance frequency. The proportional EDVA is subsequently applied to a single-degree-of-freedom primary system with an acceleration feedback control algorithm for attenuation of primary system vibration in a frequency band around the typical idling vibration frequencies. The effectiveness of the hybrid proportional EDVA is evaluated through simulations and laboratory experiments under harmonic excitations in the 20-30 Hz frequency range. Both the simulation and measurements show that the hybrid proportional EDVA can yield effective attenuation of periodic…
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Noise and Vibration Prediction and Validation for Off-Highway Vehicle Cab Using Hybrid FE-SEA Methodology

John Deere C&F-Joseph Sullivan, Jinghao Liu, Sanghoon Suh
John Deere India Pvt., Ltd.-Parag Chaudhari
Published 2019-06-05 by SAE International in United States
Operator noise is an important aspect for noise and vibration of off-highway vehicles and a quieter cab is critical for the operator comfort. The noise level inside the cab is influenced by structural and acoustic transfer paths. In this paper, we used hybrid FE-SEA approach to consider both structural and acoustic transfer path as FEM and SEA methods individually face limitations in high and low frequencies respectively. A hybrid FE-SEA cab model was built to predict the structural and acoustic transfer functions. The analysis model was built with the systematic approach validated at each step with the laboratory test results. For the structural transfer function, structural excitations were applied at four cab mount locations and accelerations at various locations on the cab were validated. For the acoustic transfer function, the cab was excited with the volume velocity source inside the cab and sound power output of various panels were calculated and compared to the test results. Good agreement was observed between the simulation and the test results for both structural transfer path and acoustic transfer…
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Vulnerability of FlexRay and Countermeasures

SAE International Journal of Transportation Cybersecurity and Privacy

Panasonic Corporation, Japan-Takeshi Kishikawa, Ryo Hirano, Yoshihiro Ujiie, Tomoyuki Haga, Hideki Matsushima, Kazuya Fujimura, Jun Anzai
  • Journal Article
  • 11-02-01-0002
Published 2019-05-23 by SAE International in United States
The importance of in-vehicle network security has increased with an increase in automated and connected vehicles. Hence, many attacks and countermeasures have been proposed to secure the controller area network (CAN), which is an existent in-vehicle network protocol. At the same time, new protocols-such as FlexRay and Ethernet-which are faster and more reliable than CAN have also been proposed. European OEMs have adopted FlexRay as a control network that can perform the fundamental functions of a vehicle. However, there are few studies regarding FlexRay security. In particular, studies on attacks against FlexRay are limited to theoretical studies or simulation-based experiments. Hence, the vulnerability of FlexRay is unclear. Understanding this vulnerability is necessary for the application of countermeasures and improving the security of future vehicles. In this article, we highlight the vulnerability of FlexRay found in the experiments conducted on a real FlexRay network. Consequently, we clarify the conditions under which attackers masquerade as legitimate electronic control units (ECUs) and transmit spoofed FlexRay frames. We also confirm that a consumer vehicle’s functions such as steering, braking,…
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Why JLR is reviving the inline-six

Automotive Engineering: May 2019

Stuart Birch
  • Magazine Article
  • 19AUTP05_11
Published 2019-05-01 by SAE International in United States

The market may have been surprised by Jaguar Land Rover's decision to offer the latest Range Rover with an I-6 gasoline engine, but it's been on the company's development list since the Ingenium engine series was conceived more than eight years ago. With refinement a salient Range Rover selling point, it was determined the I-6 had sufficient advantages over a V6 (including manufacture) to tip the balance in its favor.

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Landing Response Analysis on High-Performance Aircraft* Using Estimated Touchdown States

Aeronautical Development Agency, India-P.S. Suresh, Niranjan Kumar Sura
Indian Institute of Technology Madras, India-K. Shankar
  • Journal Article
  • 01-12-01-0001
Published 2019-04-08 by SAE International in United States
A novel use of state estimation methods as initial input for a landing response analysis is proposed in this work. Six degrees of freedom (DOF) non-linear landing response model is conceived by considering longitudinal dynamics of aircraft as a rigid body with heave-and-pitch motions coupled onto a bicycle landing gear† arrangement. The DOF for each landing gear consist of vertical and longitudinal motions of un-sprung mass, considering strut bending flexibility. The measurement data for state estimation is obtained for three landing cases using non-linear flight mechanics model interfaced with pilot-in-loop simulation. State estimation methods such as Upper Diagonal Adaptive Extended Kalman Filter (UD-AEKF) with fuzzy-based adaptive tuning and Un-scented Kalman Filter (UKF) were adapted for landing maneuver problem. On the basis of estimation error metrics, aircraft state from UKF is considered during onset of touchdown. These estimated states are used as an initial condition for the six DOF non-linear landing response model, numerically solved in Matlab environment. The dynamic responses such as displacement, velocity, and acceleration for the aircraft and the loads on landing gears…
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Driver’s Response Prediction Using Naturalistic Data Set

Ohio State University-Venkata Raghava Ravi Lanka, Dennis Guenther
SEA, Ltd.-Gary Heydinger
Published 2019-04-02 by SAE International in United States
Evaluating the safety of Autonomous Vehicles (AV) is a challenging problem, especially in traffic conditions involving dynamic interactions. A thorough evaluation of the vehicle’s decisions at all possible critical scenarios is necessary for estimating and validating its safety. However, predicting the response of the vehicle to dynamic traffic conditions can be the first step in the complex problem of understanding vehicle’s behavior. This predicted response of the vehicle can be used in validating vehicle’s safety.In this paper, models based on Machine Learning were explored for predicting and classifying driver’s response. The Naturalistic Driving Study dataset (NDS), which is part of the Strategic Highway Research Program-2 (SHRP2) was used for training and validating these Machine Learning models. Various popular Machine Learning Algorithms were used for classifying and predicting driver’s response, such as Extremely Randomized Trees and Gaussian Mixture Model based Hidden Markov Model, which are widely used in multiple domains.For classifying driver’s response, longitudinal acceleration vs lateral acceleration plot (Ax-Ay plot) was divided into nine different classes and selected Machine Learning models were trained for predicting…
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Accuracy and Sensitivity of Yaw Speed Analysis to Available Data

MEA Forensic Engineers & Scientists-Bradley Heinrichs, Janice Lee, Cole Young
Published 2019-04-02 by SAE International in United States
Accident reconstructionists rarely have complete data with which to determine vehicle speed, and so the true value must be bracketed within a range. Previous work has shown the effect of friction uncertainty in determining speed from tire marks left by a vehicle in yaw. The goal of the current study was to assess improvements in the accuracy of vehicle speed estimated from yaw marks using progressively more scene and vehicle information. Data for this analysis came from staged S-turn maneuvers that in some cases led to rollover of sport utility vehicles. Initial speeds were first calculated using the critical curve speed (CCS) formula on the yaw marks from the first portion of the S-maneuver. Then computer simulations were performed with progressively more input data: i) the complete tire marks from the whole S-maneuver, ii) measured vehicle mass, iii) measured suspension stiffness and damping, and iv) measured steering history. Simulations based on the complete tire marks reduced the average error compared with the CCS equation if measured accelerations were also matched. Adding the remaining input data…
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Lateral and Tangential Accelerations of Left Turning Vehicles from Naturalistic Observations

Kineticorp LLC-Neal Carter, Steven Beier, Rheana Cordero
Published 2019-04-02 by SAE International in United States
When reconstructing collisions involving left turning vehicles at intersections, accident reconstructionists are often required to determine the relative timing and spacing between two vehicles involved in such a collision. This time-space analysis frequently involves determining or prescribing a path and acceleration profile for the left turning vehicle. Although numerous studies have examined the straight-line acceleration of vehicles, only two studies have presented the tangential and lateral acceleration of left turning vehicles. This paper expands on the results of those limited studies and presents a methodology to automatically detect and track vehicles in a video file. The authors made observations of left turning vehicles at three intersections. Each intersection incorporated permissive green turn phases for left turning vehicles. The authors recorded video of left turning vehicles at each intersection from a small unmanned aerial system (sUAS), and that video was analyzed with a convolutional neural network designed to detect vehicles. The detected vehicles were then tracked over time and the results were analyzed. A total of 86 left turning vehicles were analyzed. In 23 of the…
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Research on Key Factors for Range and Energy Consumption of Electric Vehicles

Chongqing Changan New Energy Auto Co.Ltd.-Chen Zhao, Guan Gong, Cheng Yu, Ying Liu, Shu Zhong, Yanxing Song, Chenghao Deng, Anjian Zhou, Honglu Ye
Published 2019-04-02 by SAE International in United States
Investigations were conducted to examine the potential to optimize the energy consumption and drive range of Electric Vehicles (EV). Theoretically, the energy consumption is strongly influenced by: 1) system efficiency, 2) coasting resistance, 3) energy recovery technology. These three factors are studied in detail through both simulation tool and experimental test. Research was performed on a Changan EV sedan to explore the influence of each factor on energy consumption and drive range. The most paramount factor is vehicle coasting resistance, followed by drivetrain system efficiency. To reduce coasting resistance, tires with low resistance coefficient, low friction brake clamps, and the modification of vehicle styling can all be applied. Drivetrain efficiency includes motor efficiency, inverter efficiency, and gearbox efficiency. Interestingly, the impact of energy recovery technology is sensitive to driving conditions. I-pedal technology which can supply deceleration up to 0.2g has little influence over NEDC (New European Drive Cycle) but can extend the range over real-world driving by up to 10%. This is because the regenerating potential is higher in real world driving (higher acceleration and…
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Distributed Drive Electric Vehicle Longitudinal Velocity Estimation with Adaptive Kalman Filter: Theory and Experiment

China Automotive Engineering Research Institute Co., Ltd.-Yaming Zhang
Tongji University-Bo Leng, Lu Xiong, Zhuoping Yu, Dequan Zeng
Published 2019-04-02 by SAE International in United States
Velocity is one of the most important inputs of active safety systems such as ABS, TCS, ESC, ACC, AEB et al. In a distributed drive electric vehicle equipped with four in-wheel motors, velocity is hard to obtain due to all-wheel drive, especially in wheel slipping conditions. This paper focus on longitudinal velocity estimation of the distributed drive electric vehicle. Firstly, a basic longitudinal velocity estimation method is built based on a typical Kalman filter, where four wheel speeds obtained by wheel speed sensors constitute an observation variable and the longitudinal acceleration measured by an inertia moment unit is chosen as input variable. In simulations, the typical Kalman filter show good results when no wheel slips; when one or more wheels slip, the typical Kalman filter with constant covariance matrices does not work well. Therefore, a gain matrix adjusting Kalman filter which can detect the wheel slip and cope with that is proposed. Simulations are carried out in different conditions, including no wheel slips, one wheel slips, all wheel slip, passing a bump, and variable acceleration…
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