Your Selections

Logistics
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

Series

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Automated Driving System Safety: Miles for 95% Confidence in “Vision Zero”

Driving Safety Consulting LLC-Richard Allen Young
  • Technical Paper
  • 2020-01-1205
To be published on 2020-04-14 by SAE International in United States
Engineering reliability models from RAND, MobilEye, and Volvo concluded that billions of miles of on-road data were required to validate that the real-world fatality rate of an “Automated Driving System-equipped vehicle” (AV) fleet for an improvement over human-driven conventional vehicles (CV). RAND said 5 billion miles for 20%, MobileEye 30 billion for 99.9%, and Volvo 5 billion for 50% improvement. All these models used the Gaussian distribution, which is inaccurate for low crash numbers. The current study proposes a new epidemiologic method and criterion to validate real-world AV data with 95% confidence for zero to ten fatal crashes. The upper confidence limit (UL) of the AV fatal crash rate has to be lower than the CV fatal crash rate with 95% confidence. That criterion is met if the UL of the AV fatal crash incidence rate ratio estimate is below one. That UL was estimated using the mid-P exact method for calculating confidence limits for a dual Poisson process, using a one-tailed 95% confidence level. The required AV mileage was adjusted by trial and error…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Tightening Reliability of Bolted Joints in Calibrated Wrench Method (Improvement of Initial Clamping Force Distribution and Optimum Tightening Torque by Elliptical Confidence Limit)

Tokyo Metropolitan University-Soichi Hareyama, Ken-ichi Manabe, Satoshi Kobayashi
  • Technical Paper
  • 2020-01-0218
To be published on 2020-04-14 by SAE International in United States
On tightening bolted joints, the calibrated wrench method is used in manufacturing industries for a large amount of tightening work. It is important to give high initial clamping force in respect of tightening reliability, prevention of self-loosening, the prevention from fatigue breakage, and so on. In this method the clamping force of bolted joints is controlled by grasping the wrench torque. However, since the clamping force is indirectly applied by wrench, it varies greatly in lot of tightening in factory, etc. Therefore, the calibrated wrench method is not so accurate from the viewpoint of clamping force control. It is thought that distribution of this kind is conventionally varied in a rhombus. When tightening torque and clamping force are considered to be two independent random variables, the clamping force is distributed within an elliptical confidence limit. We also show that the distribution of equivalent stress is obtained in an elliptical confidence limit. Considering the permitted limit for working load stress on a bolted joint, elliptical distribution has big margin to yield point than the shape of…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Cooling Fan Model and Heat Exchange Model of Condenser to Predict the Cooling and the Heat Resistance Performance of Vehicle

Honda R&D Co., Ltd.-Yuichi Fukuchi, Kunihiko Yoshitake, Kazutaka Yokota
  • Technical Paper
  • 2020-01-0157
To be published on 2020-04-14 by SAE International in United States
The cooling performance and the heat resistance performance of commercial vehicle are balanced with aerodynamic performance, output power of power train, styling, the location of sensors, cost and many other parameters. Therefore, it is desired to predict the cooling performance and the heat resistance performance with high accuracy at the early stage of development. Three forms of heat transfer consist of conduction, convection and radiation. Among of these components, it is sometimes difficult to solve the thermal conduction accurately, because to prepare accurate shape and properties needs lots of time and efforts at the early stage of development. Therefore, the cooling performance of heat exchangers and the air temperature distribution in the engine compartment are predicted to access the cooling and the heat resistance performance of vehicle at the preliminary design stage. The air temperature distribution is dominated by the distribution of heat radiation on heat exchangers, the flow distribution which is produced by fans and thermal convection at the surface of parts in the engine compartment. For the case of middle or high vehicle…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of a New High Orientation Paint System to Achieve Outstanding Real Metallic Designs

Toyota Motor Corporation-Takao Tsukimori
  • Technical Paper
  • 2020-01-0899
To be published on 2020-04-14 by SAE International in United States
High metallic silver colors using thin, smooth aluminum flake pigments are typically adopted for the luxury grades by each car manufacturer. Regarding the paint formulation for these types of colors, low non-volatile(N.V.) content and high aluminum flake pigment content are generally known to be necessary to achieve high metallic appearance designs. However, poor distribution of the aluminum flake pigments can cause mottling. In addition, a high concentration of aluminum flake pigments can result in a weak coating. Therefore, current paint systems are limited in the degree of high metallic appearance design that is possible. As a countermeasure to those problems, we investigated whether cellulose nanofiber (CNF) dispersion liquid can function as both the coating binder and rheology control agent in a new type of waterborne paint system. CNF is an effective rheology control agent because it forms strong hydrogen bonds with other fiber surfaces when it is dispersed for waterborne paint. For example, viscosity versus shear rate testing of an aqueous solution of 0.4wt% CNF and less than N.V. 5wt% showed a response curve similar…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Robust Methodology for Predicting the Fatigue Life of an Automotive Closures System Subjected to Hinge and Check Link Load

Ford India Pvt., Ltd.-Nirmal Puthuvayil, Sivasankari S
RLE India Pvt., Ltd.-Thoheer Zaman
  • Technical Paper
  • 2020-01-0599
To be published on 2020-04-14 by SAE International in United States
Quality in the automotive industry symbolizes the development and the manufacturing of vehicles whose specifications meet customer requirements. Among the quality issues, opening and closing effort of any closures in a vehicle is a characteristic that strongly affects the customer first opinion about vehicle design. The closure opening and closing effort is affected by different uncertainties like opening angle, load to the check-link, hinge stoppage, materials and manufacturing process. A check stop & hinge stop load durability cycle occurs when a customer opens the closures beyond the closure detent position with a force applied on the check link or hinge check stops. Due to few uncertainties like abuse opening, manufacturing imperfections, weak mounting locations, the closures will be subjected to fatigue failure. The present study is aimed to introduce a probabilistic frame-work for fatigue life reliability analysis that addresses the uncertainties associated with door opening-closing effort due to check-hinge loads, door closure opening angles and hinge stop tolerance. A fatigue life probabilistic model of various closure systems was developed using Monte-Carlo simulation, where the stress…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

The Review of Vehicle Purchase Restriction in China

Tsinghua University-Feiqi Liu, Han Hao, Fuquan Zhao, Zongwei Liu
  • Technical Paper
  • 2020-01-0972
To be published on 2020-04-14 by SAE International in United States
In the past two decades, rapidly expanding economy in China led to burst in travel demand and pursuit of quality of life. It further promoted the rapid growth of China's passenger car market. China had already become the largest vehicle sales country, exceeding the U.S. in 2010. By the end of 2018, there had been over 240 million cars in China, with over 200 million passenger cars. The surge of car ownership has also brought a series of problems, like traffic congestion, long commuting time, insufficient parking space, etc. Therefore, some local governments in China introduced vehicle purchase restriction policies to control the growth and gross of vehicle stock. Different cities issued different rules. Lottery and auction mechanisms both exist. There are also differences in classification and licensing of electric vehicles. While, With the recent slowdown of economic development, China's car sales began to decline in 2018, and the trend of 2019 is also not optimistic. As a result, the central government issued document, indicating that it is strictly forbidden to introduce new restrictions on…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Impact of plasma length on flame kernel development under flow condition

University of Windsor-Hua Zhu, Qingyuan Tan, Xiao Yu, Zhenyi Yang, Li Liang, Ming Zheng, Graham Reader
Zhuzhou Torch Spark Plug Co., Ltd.-Jin Qian
  • Technical Paper
  • 2020-01-1114
To be published on 2020-04-14 by SAE International in United States
Advanced ignition systems with enhanced discharge current level have been extensively investigated in research, since they are highly regarded to have potentials to overcome challenges arisen when spark-ignition engines are running under lean or EGR diluted conditions. Local flow field is also of particularly importance to improve the ignitability of the ignition system as spark plasma channel is stretched under flow conditions, leading to more thermal spark energy distribution to the air-fuel mixture in the vicinity of the spark plug. Research results have shown that a constantly high discharge current is considered to be effective to maintain stable discharge with less restrikes and longer plasma holding period. However, with the further increase of the discharge current, plasma channel becomes thicker, and the stretched plasma length becomes shorter under certain flow speed, which may suppress the advantages of the presence of air flow. In this work, the interaction between discharge current level and plasma length under flow conditions is investigated. Whether a thick but short plasma or a thin but stretched long plasma are more effective…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Characterization of Seat Lateral Support as a Mechanical Behavior

General Motors LLC-Bonita Thomas
OBannon Technologies-Terry O'Bannon
  • Technical Paper
  • 2020-01-0870
To be published on 2020-04-14 by SAE International in United States
Seat lateral support is often talked about as a design parameter, but usually in terms of psychological perception. There are many difficulties in quantifying lateral support mechanically to the engineering teams: Anthropometric variation causes different people to interact with the seat in different places and at different angles, BPD studies are usually planar and don’t distinguish between horizontal support and vertical resistance to sinking in, most mechanical test systems are typically single-DOF and can’t apply vertical and horizontal loads concurrently, and there is scant literature describing the actual lateral loads occupants. In this study, we characterize the actual lateral loading on example seating (both driver and passenger, as passenger experience will become more important as autonomous vehicles evolve) from various sized/ shaped occupants according to dynamic pressure distribution. From this information, a six-DOF load and position control test robot (KUKA OccuBot) is used to replicate that pressure distribution. The effect of various sizes and shapes of indenters is explored. In the spirit of the appendix of SAE standard J2896, we suggest some standard mechanical test…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Analysis of Various Vehicle Dynamic Simulations Software Packages Using Design of Experiments (DOE)

Engineering Systems Inc.-R. Matthew Brach, Emmanuel Jay Manuel, Robert Bailey, Joshua Rogers, Shawn P. Capser
  • Technical Paper
  • 2020-01-0639
To be published on 2020-04-14 by SAE International in United States
A previous paper on this topic presented the use of design of experiments (DOE) to evaluate the sensitivity of vehicle dynamics simulation of the postimpact motion of a vehicle that included high initial rotational rates. That investigation involved only one software package and thus was confined to one simulation model for the purposes of developing and refining the analysis method rather than including a variety of simulation models for broader application. This paper expands the application of the method to investigate the comparative behavior and sensitivity of several other vehicle dynamic simulation models commonly used in the field of crash reconstruction. The software packages included in the studies presented in this paper are HVE (Simon and EDSMAC4), PC-Crash and VCRware. This paper will present the results of the study, conducted using DOE, using these models. The eleven factors selected for the study presented here were chosen based largely on the results of the prior study. The experimental design was expanded from 16 trials to 32 trials to provide additional insight into the interactions between the…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Development of Quantitative Fuel Film Distribution Measurement by LIEF Technique and Application to Gasoline Spray

Toyota Motor Corporation-Sachio Mori, Hiroyuki Sakai, Shinichiro Nogawa, Koichiro Nakatani
  • Technical Paper
  • 2020-01-1159
To be published on 2020-04-14 by SAE International in United States
From the point of global and local environment, internal combustion engine is facing the significant improvement of exhaust emission. Especially, the reduction of unburned HC (hydrocarbon) from fuel film on liner under cold condition is important. In this study, at first, quantitative fuel film measurement technique by using LIEF (Laser Induced Exciplex Fluorescence) was developed. For the light source, 4th harmonic pulse YAG laser (266nm) was used. For the tracer, the combination of DMA(N,N-Dimethylaniline) and naphthalene was used and proper concentration for quantitative measurement was decided by calibration test. In LIEF, by the measurement of fluorescence only from the liquid phase, it becomes possible to obtain the distribution of fuel film. In order to evaluate the effect of fuel film to exhaust HC emission from engine, the film distribution was measured with glass liner. For the injector, prototype 6 hole gasoline injector was used. For the evaluation of total amount of fuel film on liner that was made by side mounted 6 hole injector, the film distribution image was take from both of exhaust and…