This document will provide recommendations to vehicle manufacturers and component suppliers in securing the SAE J1939-13 connector interface from the cybersecurity risks posed by the existence of this connector.
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
This document outlines general requirements for the use of Computational Fluid Dynamics (CFD) methods for aerodynamic simulation of mass-produced cars and light-duty trucks. The document provides guidance for aerodynamic simulation with CFD methods to support current vehicle characterization, vehicle development, vehicle concept development and vehicle component development. The guidelines presented in the document include Navier-Stokes and Lattice-Boltzmann based solvers.
Dramatic changes in transportation are coming. Cities and states looking to be at the forefront and reap the benefits, need an engaged and informed citizenry. Hear how the SAE Demo Day in Tampa supported Florida's AV initiatives and can benefit states nationwide.
In May 2018, SAE International in partnership with THEA and leading AV technology companies gave citizens in Tampa a chance to test ride the future. The event included a pre- and post-ride survey, a ride in an automated vehicle, interactive displays and engagement with industry experts. See highlights of the event and feedback from participants.
This RP applies to on-highway vehicles over 4536 kg (10000 lb) GVWR. This RP is intended to characterize the squeal propensity and behavior of the friction couple, without the influence of the complete wheel-end or vehicle.
Synthetic diesel fuel can be made from a variety of feedstocks, including coal, natural gas and biomass. Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics. Moreover, synthetic diesel fuels may also be economically competitive with California diesel fuel if produced in large volumes. Previous engine laboratory and field tests using a heavy-duty chassis dynamometer indicate that synthetic diesel fuel made using the Fischer-Tropsch (F-T) catalytic conversion process is a promising alternative fuel because it can be used in unmodified diesel engines, and can reduce exhaust emissions substantially. The objective of this study was a preliminary assessment of the emissions from older model transit operated on Mossgas synthetic diesel fuel. The study compared emissions from transit buses operating on Federal no. 2 Diesel fuel, Mossgas synthetic diesel (MGSD), and a 50/50 blend of the two fuels.
This communication examines three strategies of predictive lubricant monitoring and replacement, used for farm tractors or similar vehicles. These strategies optimise the draining periodicity. They are the off-line follow-up, the sensors follow-up and the analytical model follow-up. The implementation of the suggested analytical model will be discussed, on the basis of field collected data (on a series of tractors, either customer's or on loan). Regular oil samples, and significant ones carried out at the end of the study, were taken and analysed in order to predict the evolution of the lubricant characteristics. Extensions to the experimental study were carried out at the end of this work. They are discussed in the paper (FZG gear scuffing, 4 ball wear and EP…).
1 Since 1997 the ELF group has been working on a new fuel designed in priority for use with urban services (buses, lorries). Basically, it is a diesel/water emulsion stabilised by a series of new additives. A lot of testing programmes on engine and vehicles test benches was carried out. They have clearly shown that with this new fuel there is a reduction of nitrogen oxide emissions by up to 30% and black smoke by up to 80%, without any technological modifications being necessary as against EN 590 diesel fuel marketed normally. The water content is, however, the cause of a certain loss in engine performances. Nevertheless, hydrocarbon consumption is reduced by up to 4%. The use of an oxidation catalyst is compatible with a water-diesel emulsified fuel and results in larger emission benefits. Furthermore, a 50 ppm sulphur emulsion with a continuously regenerating particle filter give a particle reduction of 90%.
Testing cycles for heavy-duty vehicles are an important topic for authorities, manufacturers, fleet owners, etc. in order to assess exhaust gas emissions and fuel consumption. A new methodology was developed to derive representative testing cycles from velocity versus time driving information. During the development, the work was focussed on city-buses, but the methodology can be applied to heavy-duty vehicles in general. The testing cycles are ‘distance-based’, meaning they impose goal speeds at each location. This implies that during acceleration phases, the accelerator-pedal - and gear lever in case of manual transmission - can be operated in a realistic way. The techniques for deriving this kind of testing cycle are proposed. Results of on-board emission and fuel consumption measurements employing these testing cycles are presented for two 19 tons, 160kW city buses, equipped with respectively a diesel and a CNG (stoechiometric) engine, and a 10 tons 112 kW diesel delivery truck.
The current popularity of the Sport Utility Vehicle (SUV) market has led to new developments aiming to increase product performance. Such vehicles pose a significant challenge as they must perform to a high standard over a large variety of road conditions. Previously, emphasis has been placed on off-road ability. However, SUVs are now seen as an alternative to conventional luxury cars, and hence are expected to perform similarly, but without significantly degrading off-road performance. The introduction of a roll control system can achieve body roll levels lower than a conventional sports saloon, whilst improving off-road ability by removing the compromises associated with conventional anti-roll bars. This paper investigates the characteristics of such a system by developing a computer simulation of the vehicle and the associated roll control scheme.
This paper discusses the needs for utilizing pure simulation based studies in the algorithm development process for cost reduction in today's competitive business environment. Continuous improvement to any algorithm is essential for sustained existence and any modification to the logic needs to be verified to work for every scenario from feasibility and robustness viewpoints. A Pareto analysis performed on the development cycle of an ABS algorithm identifies these high cycles clearly. In this paper, it is proposed that significant cycle time reduction can be achieved with the aid of pure desktop simulations during the development phases. Additionally, the feasibility of using such simulations is demonstrated through the ABS algorithm simulation model that is developed at AlliedSignal Truck Brake Systems.
Partially filled tanker trucks are susceptible to rollover instabilities due to fluid sloshing. Due to the catastrophic nature of accidents involving the rollover of tanker trucks, several investigations have been conducted on the parameters affecting stability of partially filled heavy-duty tankers. Since stability of heavy-duty tankers undergoing on-road maneuvers such as braking, and/or lane changing has been an issue that concerned many researchers for a long time, a literature review has been conducted which underlines the most important contributions in this field. This review covers work done in the field of fluid-structure interaction, yaw and roll stability of heavy-vehicles, and fluid-vehicle dynamic interaction. In addition, vehicle stability issues are addressed such as jack-knifing, side slipping, vehicle geometry and container geometry among others.
The development of advanced ABS, EBS, and vehicle dynamics control systems requires significant resources and testing. Even in the most controlled environment, on-track vehicle tests are not repeatable. A heavy vehicle model combined with pneumatic brake hardware connected to actual brake system controllers creates a powerful engineering tool. This tool is useful for control system development, electro-mechanical actuator development, and brake system development. An existing heavy vehicle model is modified to interact with the realtime simulation hardware and the pneumatic brake system hardware. Data from several hardware in the loop simulations are presented.
The accuracy of existing rotational wheel dynamics models has been found to be insufficient for heavy vehicle Antilock Braking System (ABS) and Electropneumatic Braking System (EBS) simulation, specifically when wheelspeeds are at or near zero but the vehicle speed is not. Control strategies specific to ABS and EBS, the low frequency response of pneumatic actuation, and the practice of using fewer modulators than braked wheels require that a vehicle model be able to handle lockedwheel scenarios accurately. Commercially available models have been found unsatisfactory in this regard, and technical literature has not been found to address this issue.