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This is an extension of simple fuel consumption modeling toward HEV. Previous work showed that in urban driving the overhead of running an ICEV engine can use as much fuel as the traction work. The bidirectional character and high efficiency of electric motors enables HEVs to run as a BEV at negative and low traction powers, with no net input from the small battery. The ICE provides the net work at higher traction powers where it is most efficient. Whereas the network reduction is the total negative work times the system round-trip efficiency, the reduction in engine running time requires knowledge of the distribution of traction power levels. The traction power histogram, and the work histogram derived from it, provide the required drive cycle description. The traction power is normalized by vehicle mass, so that the drive trace component becomes invariant, and the road load component nearly invariant to vehicle mass.

Lithium-ion batteries (LIBs) have been used as the main power source for Electric vehicles (EVs) in recent years. The mechanical behavior of LIBs subject to crush loading is crucial in assessing and improving the impact safety of battery systems and EVs. In this work, a detailed 3D finite element model for a commercial vehicle battery was built, in order to better understand battery failure behavior under various loading conditions. The model included the major components of a prismatic battery jellyroll, i.e., cathodes, anodes, and separators. The models for these components were validated against the corresponding material coupon tests (e.g., tension and compression). Then the components were integrated into the cell level model for simulation of jellyroll loading and damage behavior under three types of compressive indenter loading: (1) Flat-end punch, (2) Hemispherical punch and (3) Round-edge wedge. The comparisons showed reasonable agreement between modeling and experiments.

This study focused on occupant responses in very large pickup trucks in rollovers and was conducted in three phases. Phase 1 - Field data analysis: In a prior study [9], 1998 to 2020 FARS data were analyzed; Pickup truck drivers with fatality were 7.4 kg heavier and 4.6 cm taller than passenger car drivers. Most pickup truck drivers were males. Phase 1 extended the study by focusing on the drivers of very large pickup trucks. The size of 1999-2016 Ford F-250 and F-350 drivers involved in fatal crashes was analyzed by age and sex. More than 90% of drivers were males. The average male driver was 179.5 ± 7.5 cm tall and weighed 89.6 ± 18.4 kg. Phase 2 – Surrogate study: Twenty-nine male surrogates were selected to represent the average size of male drivers of F-250 and F-350s involved in fatal crashes. On average, the volunteers weighed 88.6 ± 5.2 kg and were 180.0 ± 3.2 cm tall with a 95.2 ± 2.2 cm seated height.

The brake pedal is the brake system component that the driver fundamentally has contact and through its action wait the response of the whole system. Each OEM defines during vehicle conceptualization the behavior of brake pedal that characterizes the pedal feel that in general reflects not only the characteristic from that vehicle but also from the entire brand. Technically, the term known as Pedal Feel means the relation between the force applied on the pedal, the pedal travel and the deceleration achieved by the vehicle. Such relation curves are also analyzed in conjunction with objective analysis sheets where the vehicle brake behavior is analyzed in test track considering different deceleration conditions, force and pedal travel. On technical literature, it is possible to find some data and studies considering the hydraulic brakes behavior.

Analysis of road accidents has shown that an important portion of fatal crashes involving Commercial Vehicles are caused by rollovers. ESC systems in Commercial Vehicles can reduce rollovers, severe understeer or oversteer conditions and minimize occurrences of jackknifing events. Several studies have estimated that this positive effect of ESC on road safety is substantial. In Europe, Electronic Stability Control (ESC) is expected to prevent by far the most fatalities and injuries: about 3,000 fatalities (-14%), and about 50,000 injuries (-6%) per year. In Europe, Electronic Stability Control Systems is mandatory for all vehicles (since Nov. 1st, 2011 for new types of vehicle and Nov. 1st, 2014 for all new vehicles), including Commercial Vehicles, Buses, Trucks and Trailers.

The brake pedal is the brake system component that the driver fundamentally has contact and through its action wait the response of the whole system. Each OEM defines during vehicle conceptualization the behavior of brake pedal that characterizes the pedal feel that in general reflects not only the characteristic from that vehicle but also from the entire brand. Technically, the term known as Pedal Feel means the relation between the force applied on the pedal, the pedal travel and the deceleration achieved by the vehicle. Such relation curves are also analyzed in conjunction with objective analysis sheets where the vehicle brake behavior is analyzed in test track considering different deceleration conditions, force and pedal travel. On technical literature, it is possible to find some data and studies considering the hydraulic brakes behavior.

In order to optimize the development of bolted joints used to components attachments in the Sidemember of commercial vehicles, the joints development has become relevant to better definition of the fasteners size, eliminating overweight and avoiding under or super-sized. This paper presents a development sequential approach of bolted joints applied on commercial vehicles ensuring the correct specifications usage of the fasteners and the joint to keep their clamp force. The evaluations were conducted based on theoretical and practical aspects applied on products and in the definition of all elements contained in a joint. The calculation methodology was developed based on standardized bolts and forces generated through the reactions of the components required for each vehicle family.

Considering that the most part of commercial vehicles are equipped with air brakes it is very important assure specific technical requirements for air brake system and its components. In addition, the effects of brake system failure are more critical for commercial vehicles which require more attention on their requirements details. Historically, the development of air brakes technology started on North America and Europe and consequently two strong and distinct resolutions were structured: FMVSS 121 and ECE R.13, respectively. For passenger cars were developed the ECER.13H to harmonize North American and European resolutions. However, for commercial vehicles regional applications, culture and implementation time must be considered. These commercial vehicles peculiarities must be understood and their specific requirements harmonized to attend the global marketing growth.

S-cam brakes concept are largely used by commercial vehicles around the world due to its low cost, easy maintenance and robustness. An important component of s-cam brakes is the slack adjuster, that is responsible for amplify brake chamber forces and assure correct lining and drum clearance. Therefore usually slack adjuster mechanism characteristics are defined only by empiric method considering trial and error tentative. This paper aims to demonstrate a methodology created to develop new air s-cam brakes slack adjuster definition taken in consideration its interface with other brake components. During this study was identified design specification for each component and its influence on adjustment process. It was verified the intrinsic characteristics of slack adjuster mechanism and developed a calculation tool to predict its actuation on the brake. The interface of slack adjuster with other foundation brake components and drum compliance were also studied.

This paper will discuss a compliance demonstration methodology for UN38.3, an international regulation which includes a series of tests that, when successfully met, ensure that lithium metal and lithium ion batteries can be safely transported. Many battery safety regulations, such as FMVSS and ECE, include post-crash criteria that are clearly defined. UN38.3 is unique in that the severity of the tests drove changes to battery design and function. Another unique aspect of UN38.3 is that the regulatory language can lead to different interpretations on how to run the tests and apply pass/fail criteria; there is enough ambiguity that the tests could be run very differently yet all meet the actual wording of the regulation. A process was created detailing exactly how to run the tests to improve consistency among test engineers. As part of this exercise, several tools were created which assist in generating a test plan that complies with the UN38.3 regulation.

The air suspension development and its applications have becoming increasingly relevant for commercial vehicles to provide dynamic ride comfort to driver and reduce the load impact onto driver and or cargo. This paper shows the analysis and application of an air suspension system for commercial tractor vehicles and its dynamic influence. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension´s stiffness under different conditions of usage, laden and unladed. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions.

The air suspension development and application has becoming increasingly applied also in commercial vehicles, offering to the driver more dynamic comfort as well as contributing to the reduction of impact loads on highways. Through this project pursuit show the analysis and application of an air suspension system for commercial tractor vehicles application. A special focus was given to pneumatic actuation system, responsible for leveling and control of suspension′s stiffness under different conditions of usage, laden and unladen. The project was conducted starting with the vehicle dynamic performance analysis, evaluating the pneumatic suspension circuit modifications in order to obtain the vehicle dynamic behavior improvement, ensuring directional stability under different maneuvering conditions. For entire development were also used quality tools, considering the possible failure modes and effects as well as virtual simulation tools (Adams) and bench validations.

It is very important and unquestionable that we need to have a clear technical requirement for Air Brake Systems and its components, since it is one of most important regarding safety. Looking to heavy commercial vehicles and possible air brake system failures, everything becomes clearly to pay total attention for these normative and regulatory requirements. Historically, the development of Brakes technology has started on EUA and Europe and consequently two strong and distinct requirements were structured: FMVSS 121 and ECE-R13. From decades people are trying to harmonize these requirements and for passenger cars, the evolution was faster. However, for commercial vehicles there are more peculiarities considering regional applications and some of them cultural and implementation time. As globally market is growing so fast as well new markets around the world, become fundamental the clearly understanding of these similarities, variants, peculiarities and correlated requirements.

The objective for this study was to revisit some of the known factors that affect legibility including font characteristics, as well as, contrast polarity, luminance contrast, and color contrast under high ambient conditions as specified in SAE J1757. The study focused on older drivers due to their increased visual needs and limitations. The study was conducted in 2 phases: 1) a study of font characteristics; character height, character width, and stroke width using a central composite design. Subjects read a group of letters and numerals displayed on a laptop display using occlusion goggles. The reading time (Total Shutter Open Time or TSOT), reading errors, and a subjective Readability Rating (using a 4 point scale "Very Easy," "Easy," "Difficult," "Very Difficult") were recorded. Licensed drivers in three age groups, 25 to 44 yrs, 45 to 59 yrs, and 61 to 91 yrs participated. The response surfaces were generated and compared to the character sizes recommended in ISO 15008.

Regulatory authorities are actively revising and updating the rules for on board diagnostics of diesel powertrains. Diesel oxidation catalysts are among the parts that will have to be monitored. This paper discusses some of the issues related to the feasibility of monitoring these catalysts. We concentrate on the effect of real world noise factors on the ability to distinguish marginal from threshold catalysts and demonstrate that with current sensor and catalyst technology the separation between the two is poor.

The growing competition of the automotive market makes more and more necessary the reduction of development time and consequently, the increase of the capacity to quickly respond to the launching of the competitors. One of the most costly phases on the vehicle development process is the field durability test, both in function of the number of prototypes employed and the time needed to its execution. More and more diffused, the fatigue life prediction methods have played an important part in the durability analysis via CAE. Nevertheless, in order they can be reliable and really being able to reduce the development time and cost, they need to be provided with load cases that can accurately represent the field durability tests. This work presents a CAE approach used for light trucks in order to get a reasonable understanding of component durability behavior due to payload increase. In general, road load data is not available for a new payload condition.

The driver judges his vehicle based on subjective aspects. Vehicle dynamics characteristics including ride and handling have a major impact on this evaluation. For this reason, vehicle manufactures have grown investments in order to improve vehicle dynamics behavior. Subjective evaluation and customer satisfaction research show which dynamic characteristics need to be improved. CAE models, after being validated based on experimental measures, give a good insight on vehicle dynamic behavior and guide change proposals. At end, new subjective evaluations and measures are carried out in order to check the real improvement of CAE proposals. This work shows the use of the described methodology for a pickup vehicle dynamics evaluation. One of the major complains of pickup drives is related to ride quality. Thinking of that feature the evaluation process considers several phenomena, such as abruptness, front topping, front bottoming, head toss and rear aftershake.

This paper is divided into two parts: Part 1 - Systems engineering fundamentals Part 2 - Engine cooling design from a systems engineering perspective In Part 1, we explain how the task of designing a complex system can be made easier by the application of Systems Engineering principles. (This part is self contained and may be of general interest to those who have no special interest in engine cooling). Systems Engineering provides three key benefits: It facilitates communication: Requirements define the problem, they allow team members to see their own work in context Key information is standardized and made easier to visualize and verify. An “audit trail” is maintained ensuring that important information is documented, and human memory is no longer relied on for important decisions. Translates requirements into design.

Do older light trucks, often with second (and subsequent) owners, present a higher risk to either their own occupants or to other road users? And is the safety record for newer trucks better or worse than the record for their older counterparts? To answer these questions, fatalities in crashes involving at least one light truck were examined using the Fatal Analysis Reporting System (FARS). Fatality rates for both occupants of the light truck and for other road users (occupants of other motor vehicles, pedestrians, etc.) in these crashes were computed, based both on the number of registered vehicles and on the vehicle miles of travel. Two trends in these fatality rates are observed. First, as light trucks age, a consistent decline is found in risk both to their own occupants and to other road users. Second, a distinct decrease is found in road user risk for newer light trucks compared to older light trucks when they were new, both for their own occupants and for other road users.

Ford's continued effort to improve fuel economy in automotive applications has emphasized the need for lightweight components that retain all the toughness associated with Ford truck vehicle characteristics. The application of an impact extrusion process to wheel design and manufacture, for Ford Aerostar, provides strength, performance and style more efficiently than other traditional processes. It results in a valuable 33% weight saving over comparable HSLA steel wheels, and provides the customer with uncompromised value. The Ford Aerostar Impact Extruded Aluminum Wheel was designed to be of one-piece construction, manufactured from a less than 1″ thick aluminum wafer-shaped blank. The process permits manufacture in half the steps of a conventional stamped steel wheel, and eliminates extensive machining required with forged or cast aluminum wheels.