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Improving electric vehicles’ overall thermal management strategy can directly or indirectly improve battery efficiency and vehicle range [1]. In this study, the effect of the coolant type used in BTMS (battery thermal management system) units used for heating batteries in cold weather conditions was investigated in electric buses. In this investigation, tests were performed with two types of antifreeze, which have different characteristics. The study evaluated the impact of coolant flow, BTMS circulation pump performance, and battery heating using these two types of antifreeze in the BTMS coolant line. In addition to carrying out tests, 1D computational fluid dynamics models’ simulations were carried out for both types of antifreeze, and the results were validated with experimental findings. In this study, a 12-m EV Citivolt vehicle of Anadolu Isuzu was used for tests. As a result, it was observed that differences in the properties of the antifreeze that is used in BTMS coolant line
Çetir, ÖzgürBirgül, Çağrı Emre
This document was prepared by the SAE AS-1A2 Committee to establish techniques for validating the Network Terminal (NT) complies with the NT requirements specified in AS5653, Revision B. Note that this verification document only verifies the specific requirements from AS5653 and does not verify all the requirements invoked by documents that are referenced by AS5653. The procuring authority may require further testing to verify the requirements not explicitly defined in AS5653 and in this verification document.
AS-1A Avionic Networks Committee
This document establishes test plans/procedures for the AS5643 Standard that by itself defines guidelines for the use of IEEE-1394b as a data bus network in military and aerospace vehicles. This test specification defines procedures and criteria for testing device compliance with the AS5643 Standard.
AS-1A Avionic Networks Committee
This document was prepared by the SAE AS-1A2 Committee to establish techniques for verifying that Network Controllers (NCs), Network Terminals (NTs), switches, cables, and connectors comply with the physical layer requirements specified in AS5653B. Note that this verification document only verifies the specific requirements from AS5653B and does not verify all of the requirements invoked by documents that are referenced by AS5653B. The procuring authority may require further testing to verify the requirements not explicitly defined in AS5653B and in this verification document.
AS-1A Avionic Networks Committee
Dedicated lanes provide a simpler operating environment for ADS-equipped vehicles than those shared with other roadway users including human drivers, pedestrians, and bicycles. This final report in the Automation and Infrastructure series discusses how and when various types of lanes whether general purpose, managed, or specialty lanes might be temporarily or permanently reserved for ADS-equipped vehicles. Though simulations and economic analysis suggest that widespread use of dedicated lanes will not be warranted until market penetration is much higher, some US states and cities are developing such dedicated lanes now for limited use cases and other countries are planning more extensive deployment of dedicated lanes. Automated Vehicles and Infrastructure: Dedicated Lanes includes a review of practices across the US as well as case studies from the EU and UK, the Near East, Japan, Singapore, and Canada. Click here to access the full SAE EDGETM Research Report portfolio.
Coyner, KelleyBittner, Jason
Recent advances are reducing the cost of space launch, high specific power solar cells, and the production of satellite systems. Modular architectures with no moving parts and distributed power systems would minimize assembly and maintenance costs. Together, this may enable space-based solar power to provide decarbonized dispatchable power at a lower cost than equivalent technologies such as nuclear power stations. Space-based Solar Power for Instantaneously Dispatchable Renewable Power on Earth discusses the advances in emerging technologies, like thin film solar cells, reusable launch vehicles, and mass-produced modular satellite systems that would make economic space power feasible. Click here to access the full SAE EDGETM Research Report portfolio.
Muelaner, Jody Emlyn
Abstract With the development of intelligent transportation systems and the increasing demand for transportation, traffic congestion on highways has become more prominent. So accurate short-term traffic flow prediction on these highways is exceedingly crucial. However, because of the complexity, nonlinearity, and randomness of highway traffic flows, short-term prediction of its flows can be difficult to achieve the desired accuracy and robustness. This article presents a novel architectural model that harmoniously fuses bidirectional long–short-term memory (BiLSTM), bidirectional gated recurrent unit (BiGRU), and multi-head attention (MHA) components. Bayesian optimization (BO) is also used to determine the optimal set of hyperparameters. Based on the PeMS04 dataset from California, USA, we evaluated the performance of the proposed model across various prediction intervals and found that it performs best within a 5-min prediction interval. In addition, we have conducted comparison and
Chen, PengWang, TaoMa, ChangxiChen, Jun
Abstract Traffic flow prediction is very important in traffic-related fields, and increasing prediction accuracy is the primary goal of traffic prediction research. This study proposes a new traffic flow prediction method, which uses the CNN–BiLSTM model to extract features from traffic data, further models these features through GBRT, and uses Optuna to tune important hyperparameters of the overall model. The main contribution of this study is to propose a new combination model with better performance. The model integrates two deep learning models that are widely used in this field and creatively uses GBRT to process the output features of the front-end model. On this basis, the optimal hyperparameters and the robustness of the model are deeply explored, providing an effective and feasible solution to the difficult problems in traffic flow prediction. This model is experimentally studied using three different data transformation methods (original data, wavelet transform, Fourier
Ma, ChangxiJin, Renzhe
Abstract Aiming at the problem of insufficient cross-scene detection performance of current traffic target detection and recognition algorithms in automatic driving, we proposed an improved cross-scene traffic target detection and recognition algorithm based on YOLOv5s. First, the loss function CIoU of insufficient penalty term in the YOLOv5s algorithm is adjusted to the more effective EIoU. Then, the context enhancement module (CAM) replaces the original SPPF module to improve feature detection and extraction. Finally, the global attention mechanism GCB is integrated with the traditional C3 module to become a new C3GCB module, which works cooperatively with the CAM module. The improved YOLOv5s algorithm was verified in KITTI, BDD100K, and self-built datasets. The results show that the average accuracy of mAP@0.5 is divided into 95.1%, 72.2%, and 97.5%, respectively, which are 0.6%, 2.1%, and 0.6% higher than that of YOLOv5s. Therefore, it shows that the improved algorithm has better
Ning, QianjiaZhang, HuanhuanCheng, Kehan
Wind noise is an important indicator for evaluating cabin comfort, and it is essential to accurately predict the wind noise inside the vehicle. In the early stage of automotive design, since the geometry and properties of the sealing strip are often unknown, the contribution of the sealing strip to the wind noise is often directly ignored, which makes the wind noise obtained through simulation in the pre-design stage to be lower than the real value. To investigate the effect of each seal on wind noise, an SUV model was used to simulate the cases of not adding body seals, adding window seals, and further adding door seals, respectively. The contribution of each seal to wind noise was obtained and verified by comparing it with the test results. The influence of the cavity formed at the door seal was also addressed. In the simulations, a CFD solver based on the lattice Boltzmann method (LBM) was used to solve the external flow field, and the noise transmitted into the interior of the
Zhang, YingchaoHe, TengshengWang, YuqiNiu, JiqiangZhang, ZheShen, ChunZhang, Chengchun
In this article we examine the behavior of oil in the lubrication channel between the main bearing and the connecting rod bearing in the crankshaft of an internal combustion engine. The requirement for high service life and proper operation of these bearings, while minimizing input power of the lubrication system, lead to the need to understand the function of these structural parts in detail. To simulate and visualize this process, an experimental device was created. The device allows the experimenters to change individual parameters such as rotation speed, oil pressure, oil temperature, and aeration, while simultaneously visualizing the process with the help of a special rotating camera. These parameters are then obtained by image processing. In this way, the following influences are investigated here: at oil temperatures of 30, 50, and 80°C, relative oil pressures of 1, 2, 3, and 4 bar, at undissolved air in the oil of 5 and 10 vol% and crankshaft station speeds from 0 to 6000 1/min
Rychtar, Vaclav
The SAE Aerospace Information Report AIR5315 – Generic Open Architecture (GOA) defines “a framework to identify interface classes for applying open systems to the design of a specific hardware/software system.” [sae] JAUS Service (Interface) Definition Language defines an XML schema for the interface definition of services at the Class 4L, or Application Layer, and Class 3L, or System Services Layer, of the Generic Open Architecture stack (see Figure 1). The specification of JAUS services shall be defined according to the JAUS Service (Interface) Definition Language document.
AS-4JAUS Joint Architecture for Unmanned Systems Committee
This document defines a set of standard application layer interfaces called JAUS Unmanned Ground Vehicle Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The Unmanned Ground Vehicle Services represent the platform-specific capabilities commonly found in UGVs, and augment the Mobilty Service Set [AS6009] which is platform-agnostic. At present ten (10) services are defined in this document. These services are categorized as:
AS-4JAUS Joint Architecture for Unmanned Systems Committee
This document defines a set of standard application layer interfaces called JAUS Autonomous Capabilities Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The Autonomous Behaviors Services represent the platform-independent capabilities commonly found in platforms across domains, including air, maritime, and ground. At present five (5) services are defined in this document. These services are: Comms Lost Policy Manager: Detect and recover from loss of communications with a control station Retrotraverse: Return along a path previously traveled Self-Righting: Attempt to recover from a tip over condition Cost Map 2D: Provides information about the current operating environment of the platform Path Reporter: Provides information about the previous or future planned path of the platform
AS-4JAUS Joint Architecture for Unmanned Systems Committee
This document defines a set of standard application layer interfaces called JAUS Manipulator Services. JAUS Services provide the means for software entities in an unmanned system or system of unmanned systems to communicate and coordinate their activities. The Manipulator Services represent platform-independent capabilities commonly found across domains and types of unmanned systems. At present, twenty-five (25) services are defined in this document. These services are categorized as: Low Level Manipulator Control Services – The one service in this category allows for low-level command of the manipulator joint actuation efforts. This is an open-loop command that could be used in a simple tele-operation scenario. The service in this category is listed as follows: Primitive Manipulator Service Manipulator Sensor Services – These services, when queried, return instantaneous sensor data. Three services are defined that return respectively joint positions, joint velocities, and joint
AS-4JAUS Joint Architecture for Unmanned Systems Committee