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A Novel Prediction Algorithm for Heavy Vehicles System Rollover Risk Based on Failure Probability Analysis and SVM Empirical Model

China Automotive Technology and Reseach Center Co.,Ltd-Zhenfeng Wang, Fei Li, Xinyu Wang
Harbin Institute of Technology-Zheng Wang
  • Technical Paper
  • 2020-01-0701
To be published on 2020-04-14 by SAE International in United States
The study of heavy vehicles rollover prediction, especially in algorithm-based heavy vehicles active safety control for improving road handling, is a challenging task for the heavy vehicle industry. Due to the high fatality rate caused by vehicle rollover, how to precisely and effectively predict the rollover of heavy vehicles became a hot topic in both academia and industry. Because of the strong non-linear characteristics of Human-Vehicle-Road interaction and the uncertainty of modeling, the traditional deterministic method cannot predict the rollover hazard of heavy vehicles accurately. To deal with the above issues, this paper applies a probability method of uncertainty to the design of a dynamic rollover prediction algorithm for heavy vehicles and proposes a novel algorithm for predicting the rollover hazard based on the combined empirical model of reliability index and failure probability. Moreover, the paper establishes a classification model of heavy vehicles based on the support vector machine (SVM) and uses the Monte Carlo method to calculate the failure probability of rollover limit state of heavy vehicles. The fishhook, double lane change, and slalom…
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Model-Based Calibration of an Automotive Climate Control System

BMW AG-Gerrit Lassahn, Kang Qiu
TU Munich-Patrick Jahn
  • Technical Paper
  • 2020-01-1253
To be published on 2020-04-14 by SAE International in United States
This paper describes a novel approach for modeling an automotive HVAC unit. The model consists of black-box models trained with experimental data from a self-developed measurement setup. It is capable of predicting the temperature and mass flow of the air entering the vehicle cabin at the various air vents. A combination of temperature and velocity sensors is the basis of the measurement setup. A measurement fault analysis is conducted to validate the accuracy of the measurement system. As the data collection is done under fluctuating ambient conditions, a review of the impact of various ambient conditions on the HVAC unit is performed. Correction models that account for the different ambient conditions incorporate these results. Numerous types of black-box models are compared to identify the best-suited type for this approach. Moreover, the accuracy of the model is validated using test drive data. This validation demonstrates the accuracy of the model of 2 K for temperature predictions. Further studies are recommended to quantify the impact of the model inaccuracies on the model-based calibration process.
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Evaluation Methodologies in the Development of Dynamically Reconfigurable Systems in the Automotive Industry

BMW Group-Florian Oszwald, Ruben Bertelo
Karlsruhe Institute Of Technology-Juergen Becker
  • Technical Paper
  • 2020-01-1363
To be published on 2020-04-14 by SAE International in United States
Classical decentralized architectures based on large networks of microprocessor-based Electronic Control Units (ECU), namely those used in self-driving cars and other highly-automated applications used in the automotive industry, are becoming more and more complex. These new, high computational power demand applications are constrained by limits on energy consumption, weight, and size of the embedded components. The adoption of new embedded centralized electrical/electronic (E/E) architectures based on dynamically reconfigurable hardware represents a new possibility to tackle these challenges. However, they also raise concerns and questions about their safety. Hence, an appropriate evaluation must be performed to guarantee that safety requirements resulting from an Automotive Safety Integrity Level (ASIL) according to the standard ISO 26262 are met.In this paper, a methodology for the evaluation of dynamically reconfigurable systems based on centralized architectures is presented. The aim is to evaluate the reliability and probability of failure while exploring the design space without compromise the overall system performance.The methodology is divided into three stages. In the first stage, the system is decomposed, and its sub-systems are isolated before applying…
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Engine mount design & failure analysis in commercial vehicle and a correlation between virtual & physical validation.

VE Commercial Vehicles Ltd.-Mahendra Parwal
VE Commercial Vehicles, Ltd.-Arushi Dev
  • Technical Paper
  • 2020-01-0491
To be published on 2020-04-14 by SAE International in United States
Vehicle life and performance is affected by many factors when in use. The most influential being the vibrations generated especially when the vehicle is in motion. These vibrations are directly experienced by the driver, whose performance goes down, if under continuous influence of these vibrations. This increases the fatigue and greatly reduces the return on investment done by the customer. There are two major sources of vibrations, the engine and the road on which the vehicle moves. To prevent such issues engine mounts are used in vehicles, which may seem simple but perform a critical role, of providing comfort to the driver. Therefore it becomes important that thoroughly designed and examined mounts are being used in the vehicle. This paper focuses on the parameters and methodology to be followed for design and validation of an engine mount used in heavy duty vehicles. Case study has been presented to show the failure cases in an engine mount, especially the separation of rubber and metal bonding. Importance of surface pre-treatments to have better bonding has been discussed…
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A Methodology for Automotive Steel Wheel Life Assessment

Fraunhofer ITWM-Manfred Baecker, Axel Gallrein
MW Italia-Davide Rovarino, Luca Actis Comino
  • Technical Paper
  • 2020-01-1240
To be published on 2020-04-14 by SAE International in United States
A methodology for an efficient failure prediction of automotive steel wheels during fatigue experimental tests is proposed. The strategy joins the CDTire simulative package effectiveness to a specific wheel finite element model in order to deeply monitor the stress distribution among the component to predict damage. The numerical model acts as a Software-in-the-loop and it is calibrated with experimental data. The developed tool, called VirtualWheel, can be applied for the optimisation of design reducing prototyping and experimental test costs in the development phase. In the first section, the failure criterion is selected. In the second one, the conversion of hardware test-rig into virtual model is described in detail by focusing on critical aspects of finite element modelling. In conclusion, failure prediction is compared with experimental test results.
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An Analytical Model for Predicting the Fatigue Behavior of Tubular Weldments Subjected to Compressive Loading

American Axle & Manufacturing, Inc.-Anoop Vasu, Shizhu Xing, Jifa Mei, William Webster, Scott Jacob, Jerry Chung, Ravi Desai
  • Technical Paper
  • 2020-01-0185
To be published on 2020-04-14 by SAE International in United States
It has been well-documented in academic literature that, when subjected to compressive cyclic loading (R = -∞), weldments can experience fatigue failure. However, unlike non-welded components, it has been shown that mean stress has a negligible impact on the fatigue life of welds (Gurney, 1979). Currently, most analytical weld prediction methods neglect the influence of mean stress and instead focus only on the relationship between the stress (or strain) amplitude and the respective number of cycles to failure. To better understand the influence of compressive mean stress on tubular weldment fatigue life, three case studies were performed under varying loading conditions: 1) Welds were subjected to compressive pre-stress using pretensioned bolts and then subjected to various cyclic loading conditions via three-point bending, 2) Welds without pre-stress were subjected to various cyclic loading conditions intended to generate compressive mean stress in the welds via three-point bending, 3) Welds without pre-stress were subjected to various cyclic loading conditions intended to generate a stress state of pure tension or pure compression in the welds via four-point bending. It…
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A Robust Failure Proof Driver Drowsiness Detection System Estimating Blink and Yawn

Kettering University-Yogesh Tony Jesudoss, Jungme Park
  • Technical Paper
  • 2020-01-1030
To be published on 2020-04-14 by SAE International in United States
The fatal automobile accidents can be attributed to fatigued and distracted driving by drivers. Driver Monitoring Systems alert the distracted drivers by raising alarms. Most of the image based driver drowsiness detection systems face the challenge of failure proof performance in real time applications. Failure in face detection and other important part (eyes, nose and mouth) detections in real time cause the system to skip detections of blinking and yawning in few frames. In this paper, a real time robust and failure proof driver drowsiness detection system is proposed. The proposed system deploys a set of detection systems to detect face, blinking and yawning sequentially. A robust Multi-Task Convolutional Neural Network (MTCNN) with the capability of face alignment is used for face detection. This system attained 97% recall in the real time driving dataset collected. The detected face is passed on to ensemble of regression trees to detect the 68 facial landmarks. The eye and mouth landmarks are isolated to detect the blink and yawning by identifying the open/closed state by calculating their aspect ratios.…
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Fault-Tolerant Control of Regenerative Braking System on In-Wheel Motors Driven Electric Vehicles

Xiaohui Hou
Tsinghua University-Yuan Ji, Junzhi Zhang, Weilong Liu
  • Technical Paper
  • 2020-01-0994
To be published on 2020-04-14 by SAE International in United States
A novel fault tolerant brake strategy for In-wheel motor driven electric vehicles based on integral sliding mode control and optimal online allocation is proposed in this paper. The braking force distribution and redistribution, which is achieved in online control allocation segment, aim at maximizing energy efficiency of the vehicle and isolating faulty actuators simultaneously. The In-wheel motor can generate both driving torque and braking torque according to different vehicle dynamic demands. In braking procedure, In-wheel motors generate electric braking torque to achieve energy regeneration. The strategy is designed to make sure that the stability of vehicle can be guaranteed which means vehicle can follow desired trajectory even if one of the driven motor has functional failure. Considering longitudinal velocity and yaw rate control, Electric vehicle with four independent In-wheel driven motor is a typical over-actuated control system whose control inputs outnumbers the state variables. Therefore, typical nonlinear controller design methods based on Lyapunov theory cannot be applied directly. In this paper, the problem is settled down by transferring the input matrix whose dimension is larger…
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Frequency Domain Analysis of 2-Wheeler Systems

CAEfatigue Ltd.-Neil Bishop, Harsha Kolar
Hero MotoCorp Ltd.-Mohit Sethi
  • Technical Paper
  • 2020-01-0476
To be published on 2020-04-14 by SAE International in United States
Most automotive companies validate their vehicle designs by running vehicle on the durability proving grounds. Part fractures and collisions between two components are common failures observed during proven ground testing. Laboratory testing and FEA simulation are used to validate designs in the concept stage as it consumes less time and cost as compared to proven ground testing. The lab testing and simulation process both have their own limitations. It is difficult to incorporate effect of multi-direction input loading (x, y, z) with single direction loading in laboratory testing due to restrictions with electrodynamic shaker testing. However, in simulation, multi direction input can be easily incorporated but often actual vehicle measured test track data is not available in the early design stage.In the present work, Modern methodologies have been employed [ref 1, 2] in frequency domain to validate design in FEA simulation. First, relative random response calculation is performed for calculating the probability of collision between parts of motorcycle rear cowl. Second, multi-channel loading (x, y, z) on the front cowl is used to derive a…
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Estimation of the Mechanism to Suppress Water Degradation of 1K Heat-Curing Epoxy Adhesive with High Durability

Aisin Chemical Co., Ltd.-Kazumasa Sakaguchi
  • Technical Paper
  • 2020-01-0227
To be published on 2020-04-14 by SAE International in United States
In recent years, structural adhesives have been used to improve the rigidity, shock resistance, etc. of joints, and the requirements for these characteristics are expected to expand further. However, heat, loads, water, etc. can become deterioration factors for adhesives, and the consequent loss of strength is known to occur. In this study, the author has focused on water absorption deterioration, considered as one of the largest deterioration factors for adhesives, and has succeeded in providing high-water resistance to a one-component(1K) heat-curing epoxy adhesive through the addition of appropriate additives. This adhesive exhibited no hydrolysis during the 14-day 70 °C, 100% RH deterioration acceleration test, and strength retention and cohesive failure rates of 100% have been confirmed. In this study, the factors that provide high durability to the adhesive are identified, and the mechanism of how these factors suppress water absorption deterioration has been estimated.