This document establishes minimum performance criteria at GCWR and calculation methodology to determine tow-vehicle TWR for passenger cars, multipurpose passenger vehicles and trucks. This includes all vehicles up to 14000 lb GVWR.

Tow Vehicle Trailer Rating Committee

Speedometer and Odometer Systems for On-Highway Vehicles

J2976_201602 (Historical)

2/3/2016

This recommended practice is intended to provide industry technical personnel with an overview of vehicle speedometer system accuracy and offset requirements and odometer system accuracy requirements. Speedometer and odometer systems covered by this document are integrated into a vehicle's electrical and electronics system, assembled directly into the vehicle by the OEM, and use rotational data from at least one vehicle wheel that is appropriately converted into longitudinal vehicle speed and distance traveled information. This standard is limited to radial ply tires on new (as manufactured) cars, light trucks, and medium duty trucks. Other methods for measuring vehicle speed and distance traveled may be used provided they meet the performance recommendations herein. Any local market regulatory requirements must be met and shall supersede this document. Service parts are beyond the scope of this recommended practice.

Odometer and Speedometer Standards

Aerodynamic Optimization of Trailer Add-On Devices Fully- and Partially-Skirted Trailer Configurations

2015-01-28859/29/2015

As part of the United States Department of Energy's SuperTruck program, Volvo Trucks and its partners were tasked with demonstrating 50% improvement in overall freight efficiency for a tractor-trailer, relative to a best in class 2009 model year truck. This necessitated that significant gains be made in reducing aerodynamic drag of the tractor-trailer system, so trailer side-skirts and a trailer boat-tail were employed. A Lattice-Boltzmann based simulation method was used in conjunction with a Kriging Response Surface optimization process in order to efficiently describe a design space of seven independent parameters relating to boat-tail and side-skirt dimensions, and to find an optimal configuration. Part 1 concerns a fully-skirted tractor-trailer system, and consists of an initial phase of optimization, followed by a mid-project re-evaluation of constraints, and an additional period of optimization. The most influential parameters are identified in achieving significant aerodynamic drag reduction relative to a base configuration. Part 2 uses a similar set of optimization parameters, but finds a fundamentally different drag response to one critical factor, due to a different set of trailer operational constraints using only partial skirting. Results from both portions are supported by physical testing.

Schaut, Nicholas, Sengupta, Raja

Heavy-Duty Vehicle Fuel Saving Technology Analysis to Support Phase 2 Regulations

2015-01-27759/29/2015

This paper presents the fuel consumption results of engine and vehicle simulation modeling for a wide variety of individual technologies and technology packages applied to a long haul heavy duty vehicle. Based on the simulation modeling, up to 11% in fuel savings is possible using commercially available and emerging technologies applied to a 15L DD15 engine alone. The predicted fuel savings are up to 17% in a Kenworth T700 tractor-trailer unit equipped with a range of vehicle technologies, but using the baseline DD15 diesel engine. A combination of the most aggressive engine and vehicle technologies can provide savings of up to 29%, averaged over a range of drive cycles. Over 30% fuel savings were found with the most aggressive combination on a simulated long haul duty cycle. Note that not all of these technologies may prove to be cost-effective. The fuel savings benefits for individual technologies vary widely depending on the drive cycles and payload.

Badain, Nicholas, Reinhart, Thomas, Cooper, Coralie, MacIsaac, James, Whitefoot, John

Analysis Process for Truck Fuel Efficiency Study

2015-01-27789/29/2015

Medium- and Heavy Duty Truck fuel consumption and the resulting greenhouse gas (GHG) emissions are significant contributors to overall U.S. GHG emissions. Forecasts of medium- and heavy-duty vehicle activity and fuel use predict increased use of freight transport will result in greatly increased GHG emissions in the coming decades. As a result, the National Highway Traffic Administration (NHTSA) and the United States Environmental Protection Agency (EPA) finalized a regulation requiring reductions in medium and heavy truck fuel consumption and GHGs beginning in 2014. The agencies are now proposing new regulations that will extend into the next decade, requiring additional fuel consumption and GHG emissions reductions. To support the development of future regulations, a research project was sponsored by NHTSA to look at technologies that could be used for compliance with future regulations. Data presented in this paper detail how engine and vehicle simulation models were developed for current medium and heavy duty vehicles and then validated against available test results. In addition, the paper describes how potential future engine and vehicle technologies were added to the baseline models to simulate future improvements in medium and heavy duty vehicle fuel consumption and GHG emissions. Wherever possible, experimental data was used as inputs to the models or to validate the simulation results. The effect of drive cycle on engine efficiency is also explored.

Reinhart, Thomas, Cooper, Coralie, Whitefoot, John, MacIsaac, James

Accelerated Durability Tests of Commercial Vehicles Powertrains Performed on Road by a Towing Trailer with an Electromagnetic Brake

2015-36-03069/22/2015

Durability tests of commercial vehicles are performed on road running uphill and downhill as well as on flat roads; these tests take very long time and have high costs. To lower test time and costs, it is proposed to accelerate the durability tests of commercial vehicles power trains by using a Towing Trailer with an electromagnetic (EM) brake, developed in Brazil, simulating uphill. This Trailer was already presented [1], [2] for cooling test simulation at 20 km/h on commercial vehicles up to 250 HP. In the cabin (cab) of the vehicle under test, there are the braking level control and a laptop, which receives wireless and registers the operational parameters of the Towing Trailer. The GPS in the truck cabin (cab) supply information such as time, speed, latitude and longitude allowing the control of the route. Strain gauges glued on the traction rod measure the traction and compression forces between truck and Towing Trailer, capturing the effect of EM braking forces, acceleration and deceleration of the convoy, gear changes and the geographical road influence. Measurements were performed with powerful trucks (420 HP and 360 HP), higher than the foreseen Trailer EM brake capacity, to evaluate the limits of the testing system on flat ground, at 20 km/h (normally used for cooling tests) and on roads with varied slopes, at speeds up to 80 km/h. By the variation of the EM forces through the current, it is possible to evaluate the contribution of the EM braking forces for the durability tests.

Rehder, Haraldo, Rehder, Gustavo P.

Diagnostic Connector

J1962_201509 (Historical)9/11/2015

Vehicle E E System Diagnostic Standards Committee

Model Architecture and Interfaces Recommended Practice for Ground Vehicle System and Subsystem Dynamical Simulation

J3049_201508 (Current)

8/27/2015

The “Model Architecture and Interfaces Recommended Practice for Ground Vehicle System and Subsystem Dynamical Simulation” defines the architectural structure of a ground vehicle system dynamical model by partitioning it into subsystem models and by defining subsystem interfaces required to enable plug-and-play operation of a dynamical simulation models. All types of ground vehicle were considered in the development of the architecture, such as, passenger cars, light and medium duty trucks, heavy duty tractor trailer trucks, and vehicles/equipment for military, farming, construction, and mining. Versatility of this architectural partitioning is demonstrated by showing how it can be applied to different vehicle configurations. Application examples of architecture are provided for a large number of the publicly known ground vehicle configurations in production, testing, or development. This recommended practice encompasses standards to enable seamless plug-and-play reusability of dynamical models for simulating the functional behavior of a ground vehicle system and its subsystems. A single ground vehicle system is the system of interest. The architecture and interfaces support vehicle models that describe vehicle motion in one dimension (longitudinal), two dimensions (longitudinal and lateral or longitudinal and vertical), and three dimensions (longitudinal, lateral, and vertical). The scope includes defining recommended practices for: 1 Model architectural structure, and interfaces that enable the plug-and-play development of: (1) a top-level ground vehicle system model from subsystem models, and (2) subsystem models from other subsystem models; and 2 Model architecture and interfaces for all hardware and controller interfaces; however, the internal structure of control algorithms and software will not be included in this recommended practice. Since, other groups (such as, AUTOSAR) are addressing architecture and interfaces of models for control applications and software; they are not included in the scope of the recommended practice. However, in the future, the internal structure of control algorithms and software should be addressed for special issues of dynamical modeling and simulation of ground vehicle systems that are not covered by other standards groups.

Dynamical Modeling and Simulation Committee