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Technical Paper

Brake Pedal Feeling Comfort Analysis for Trucks with Pneumatic Brake System

2019-09-15
2019-01-2140
The brake pedal is the brake system component that the driver fundamentally has contact and through its action wait the response of whole system. Each OEM define 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 is possible to find some data and studies considering the hydraulic brakes behavior.
Technical Paper

Comparative Analysis between American and European Requirements for Electronic Stability Control (ESC) Focusing on Commercial Vehicles

2019-09-15
2019-01-2141
Analysis of road accident has showed that an important portion of fatal crashes involving commercial vehicles is caused by rollovers. ESC systems in commercial vehicles can reduce rollovers, severe understeer or oversteer conditions and minimize occurences of jackknifing conditions. 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, trucks and trailers.
Technical Paper

Validating Prototype Connected Vehicle-to-Infrastructure Safety Applications in Real- World Settings

2018-04-03
2018-01-0025
This paper summarizes the validation of prototype vehicle-to-infrastructure (V2I) safety applications based on Dedicated Short Range Communications (DSRC) in the United States under a cooperative agreement between the Crash Avoidance Metrics Partners LLC (CAMP) and the Federal Highway Administration (FHWA). After consideration of a number of V2I safety applications, Red Light Violation Warning (RLVW), Curve Speed Warning (CSW) and Reduced Speed Zone Warning with Lane Closure Warning (RSZW/LC) were developed, validated and demonstrated using seven different vehicles (six passenger vehicles and one Class 8 truck) leveraging DSRC-based messages from a Road Side Unit (RSU). The developed V2I safety applications were validated for more than 20 distinct scenarios and over 100 test runs using both light- and heavy-duty vehicles over a period of seven months. Subsequently, additional on-road testing of CSW on public roads and RSZW/LC in live work zones were conducted in Southeast Michigan.
Technical Paper

On the Robustness of Adaptive Nonlinear Model Predictive Cruise Control

2018-04-03
2018-01-1360
In order to improve the vehicle’s fuel economy while in cruise, the Model Predictive Control (MPC) technology has been adopted utilizing the road grade preview information and allowance of the vehicle speed variation. In this paper, a focus is on robustness study of delivered fuel economy benefit of Adaptive Nonlinear Model Predictive Controller (ANLMPC) reported earlier in the literature to several noise factors, e.g. vehicle weight, fuel type etc. Further, the vehicle position is obtained via GPS with finite precision and source of road grade preview might be inaccurate. The effect of inaccurate information of the road grade preview on the fuel economy benefits is studied and a remedy to it is established.
Technical Paper

Virtual Temperature Controlled Seat Performance Test

2018-04-03
2018-01-1317
The demand for seating comfort is growing - in cars as well as trucks and other commercial vehicles. This is expected as the seat is the largest surface area of the vehicle that is in contact with the occupant. While it is predominantly luxury cars that have been equipped with climate controlled seats, there is now a clear trend toward this feature becoming available in mid-range and compact cars. The main purpose of climate controlled seats is to create an agreeable microclimate that keeps the driver comfortable. It also reduces the “stickiness” feeling which is reported by perspiring occupants on leather-covered seats. As part of the seat design process, a physical test is performed to record and evaluate the life cycle and the performance at ambient and extreme temperatures for the climate controlled seats as well as their components. The test calls for occupied and unoccupied seats at several ambient temperatures.
Journal Article

Aerodynamic Investigation of Cooling Drag of a Production Pickup Truck Part 1: Test Results

2018-04-03
2018-01-0740
The airflow that enters the front grille of a ground vehicle for the purpose of component cooling has a significant effect on aerodynamic drag. This drag component is commonly referred to as cooling drag, which denotes the difference in drag measured between open grille and closed grille conditions. When the front grille is closed, the airflow that would have entered the front grille is redirected around the body. This airflow is commonly referred to as cooling interference airflow. Consequently, cooling interference airflow can lead to differences in vehicle component drag; this component of cooling drag is known as cooling interference drag. One mechanism that has been commonly utilized to directly influence the cooling drag, by reducing the engine airflow, is active grille shutters (AGS). For certain driving conditions, the AGS system can restrict airflow from passing through the heat exchangers, which significantly reduces cooling drag.
Technical Paper

Development of a Commercial Truck Parabolic Leaf Spring Using CAE Simulation with Correlated Experimental Stress Analysis Results

2017-11-07
2017-36-0126
The development costs that new design requires are subject to everyday discussions and saving opportunities are mandatory. Using CAE to predict design changes can avoid excessive costs with prototypes parts, considering the high reliability those current mathematical models can provide. This paper presents the methodology used during the development of a parabolic leaf spring for the rear suspension of a commercial truck, considering mainly the parabolic profiles and stress distribution on the leaves, calculated using CAE software (ANSYS) and experimental tests to measure the actual stress on each leaf, certifying the correlation between computational calculations and real stress on the parts during bench and vehicle evaluations.
Technical Paper

Pedestrian Head Impact Time Estimate based on Vehicle Geometric Parameters

2017-03-28
2017-01-1453
Pedestrian protection assessment methods require multiple head impact tests on a vehicle’s hood and other front end parts. Hood surfaces are often lifted up by using pyrotechnic devices to create more deformation space prior to pedestrian head impact. Assessment methods for vehicles equipped with pyrotechnic devices must also validate that the hood deployment occurs prior to head impact event. Estimation of pedestrian head impact time, thus, becomes a critical requirement for performance validation of deployable hood systems. In absence of standardized physical pedestrian models, Euro NCAP recommends a list of virtual pedestrian models that could be used by vehicle manufacturers, with vehicle FEA (Finite Element Analysis) models, to predict the potential head impact time along the vehicle front end profile. FEA simulated contact time is used as target for performance validation of sensor and pyrotechnic deployable systems.
Technical Paper

An Extensive Validation of an Open Source Based Solution for Automobile External Aerodynamics

2017-03-28
2017-01-1524
The number of computational fluid dynamics (CFD) simulations performed during the vehicle aerodynamic development process continues to expand at a rapid rate. One key contributor to this trend is the number of analytically based designed experiments performed to support vehicle aerodynamic shape development. A second contributor is the number of aerodynamic optimization studies performed for vehicle exterior components such as mirrors, underbody shields, spoilers, etc. A third contributor is the increasing number of “what if” exploratory studies performed early in the design process when the design is relatively fluid. Licensing costs for commercial CFD solutions can become a significant constraint as the number of simulations expands.
Technical Paper

Driveable Automotive Electrical & Electronics Test-Board

2017-03-28
2017-01-1681
This paper describes a test system for improving the completeness and representativeness of automotive electrical/electronic (E/E) test benches. This is with the aim to enable more testing and hence increase the usage and effectiveness of these facilities. A proportion of testing for automotive electrical and electronics systems and components is conducted using E/E testing boards (“test-boards”). These are table-like rigs consisting of most or all electrical and electronic parts connected together as per a car/truck/van. A major problem is that the testing is conducted on the equivalent of a static vehicle: test-boards lack basic dynamic elements such as a running engine, vehicle motion, environmental, component and fluid temperatures, etc. This limits the testing that can be carried out on such a test-board.
Technical Paper

Low-Speed Longitudinal Distance Control with Applications to Parking

2017-03-28
2017-01-0036
We introduce a controller designed to stop a vehicle smoothly and accurately at a specified distance target, while being robust to unmeasured disturbances. This controller has a wide range of applications in instances where low speed longitudinal control of a vehicle is desired. Controller design was validated in a simulation using an ideal vehicle model based on first principles. Real world testing and tuning was performed on a full-size pickup truck to demonstrate controller performance.
Technical Paper

Control for Automated Trailer Backup

2017-03-28
2017-01-0040
We propose a steering controller for automated trailer backup, which can be used on tractor-trailer configurations including fifth wheel campers and gooseneck style trailers. The controller steers the trailer based on real-time driver issued trailer curvature commands. We give a stability proof for the hierarchical control system, and demonstrate robustness under a specific set of modeling errors. Simulation results are provided along with experimental data from a full-size pickup truck and 5th wheel trailer.
Technical Paper

Frequency FE-Based Weld Fatigue Life Prediction of Dynamic Systems

2017-03-28
2017-01-0355
In most aspects of mechanical design related to a motor vehicle there are two ways to treat dynamic fatigue problems. These are the time domain and the frequency domain approaches. Time domain approaches are the most common and most widely used especially in the automotive industries and accordingly it is the method of choice for the fatigue calculation of welded structures. In previous papers the frequency approach has been successful applied showing a good correlation with the life and damage estimated using a time based approach; in this paper the same comparative process has been applied but now extended specifically to welded structures. Both the frequency domain approach and time domain approach are used for numerically predicting the fatigue life of the seam welds of a thin sheet powertrain installation bracketry of a commercial truck submitted to variable amplitude loading. Predicted results are then compared with bench tests results, and their accuracy are rated.
Journal Article

Powersplit or Parallel - Selecting the Right Hybrid Architecture

2017-03-28
2017-01-1154
The automotive industry is rapidly expanding its Hybrid, Plug-in Hybrid and Battery Electric Vehicle product offerings in response to meet customer wants and regulatory requirements. One way for electrified vehicles to have an increasing impact on fleet-level CO2 emissions is for their sales volumes to go up. This means that electrified vehicles need to deliver a complete set of vehicle level attributes like performance, Fuel Economy and range that is attractive to a wide customer base at an affordable cost of ownership. As part of “democratizing” the Hybrid and plug-In Hybrid technology, automotive manufacturers aim to deliver these vehicle level attributes with a powertrain architecture at lowest cost and complexity, recognizing that customer wants may vary considerably between different classes of vehicles. For example, a medium duty truck application may have to support good trailer tow whereas a C-sized sedan customer may prefer superior city Fuel Economy.
Journal Article

Technical Analysis of a Proposed Shock Absorber Design Standard

2016-04-05
2016-01-1543
One important part of the vehicle design process is suspension design and tuning. This is typically performed by design engineers, experienced expert evaluators, and assistance from vehicle dynamics engineers and their computer simulation tools. Automotive suspensions have two primary functions: passenger and cargo isolation and vehicle control. Suspension design, kinematics, compliance, and damping, play a key role in those primary functions and impact a vehicles ride, handling, steering, and braking dynamics. The development and tuning of a vehicle kinematics, compliance, and damping characteristic is done by expert evaluators who perform a variety of on road evaluations under different loading configurations and on a variety of road surfaces. This “tuning” is done with a focus on meeting certain target characteristics for ride, handling, and steering One part of this process is the development and tuning of the damping characteristics of the shock absorbers.
Book

The Multi Material Lightweight Vehicle (MMLV) Project

2015-06-05
The desire for greater fuel efficiency and reduced emissions have accelerated a shift from traditional materials to design solutions that more closely match materials and their properties with key applications. The Multi-Material Lightweight Vehicle (MMLV) Project presents cutting edge engineering that meets future challenges in a concept vehicle with weight and life-cycle assessment savings. These results significantly contribute to achieving fuel reduction and to meeting future Corporate Average Fuel Economy (CAFÉ) regulations without compromising vehicle performance or occupant safety.
Technical Paper

Lubricant Oil Service Interval Strategy for PROCONVE P7 Diesel Commercial Vehicles

2014-09-30
2014-36-0166
This paper describes the strategy of lubricant oil service interval for commercial truck based on new engine technology (PROCONVE P7), the fleet owner's needs, vehicle typical application route, operational costs related to oil change, design of oil pan to adequate the oil volume and lubricant oil available technology. In result, this analysis shows the best annual operational cost for customer in terms of oil change.
Journal Article

Fuel Economy and CO2 Emissions of Ethanol-Gasoline Blends in a Turbocharged DI Engine

2013-04-08
2013-01-1321
Engine dynamometer testing was performed comparing E10, E20, and E30 splash-blended fuels in a Ford 3.5L EcoBoost direct injection (DI) turbocharged engine. The engine was tested with compression ratios (CRs) of 10.0:1 (current production) and 11.9:1. In this engine, E20 (96 RON) fuel at 11.9:1 CR gave very similar knock performance to E10 (91 RON) fuel at 10:1 CR. Similarly, E30 (101 RON) fuel at 11.9:1 CR resulted in knock-limited performance equivalent to E20 at 10:1 CR, indicating that E30 could have been run at even higher CR with acceptable knock behavior. The data was used in a vehicle simulation of a 3.5L EcoBoost pickup truck, which showed that the E20 (96 RON) fuel at 11.9:1 CR offers 5% improvement in U.S. EPA Metro-Highway (M/H) and US06 Highway cycle tank-to-wheels CO₂ emissions over the E10 fuel, with comparable volumetric fuel economy (miles per gallon) and range before refueling.
Journal Article

Effect of Biodiesel (B20) on Vehicle-Aged Engine Oil Properties

2010-10-25
2010-01-2103
High concentrations of diesel fuel can accumulate in the engine oil, especially in vehicles equipped with diesel particle filters. Fuel dilution can decrease the viscosity of engine oil, reducing its film thickness. Higher concentrations of fuel are believed to accumulate in oil with biodiesel than with diesel fuel because biodiesel has a higher boiling temperature range, allowing it to persist in the sump. Numerous countries are taking actions to promote the use of biodiesel. The growing interest for biodiesel has been driven by a desire for energy independence (domestically produced), the increasing cost of petroleum-derived fuels, and an interest in reducing greenhouse gas emissions. Biodiesel can affect engine lubrication (through fuel dilution), as its physical and chemical properties are significantly different from those of petrodiesel. Many risks associated with excessive biodiesel dilution have been identified, yet its actual impact has not been well quantified.
Journal Article

Development and Testing of an Innovative Oil Condition Sensor

2009-04-20
2009-01-1466
In order to detect degradation of engine oil lubricant, bench testing along with a number of diesel-powered Ford trucks were instruments and tested. The purpose of the bench testing was primarily to determine performance aspects such as repeatability, hysteresis effects and so on. Vehicle testing was conducted by designing and installing a separate oil reservoir along with a circulation system which was mounted in the vicinity of the oil pan. An innovative oil sensor was directly installed on the reservoir which can measure five (5) independent oil parameters (viscosity, density, permittivity, conductance, temperature). In addition, the concept is capable of detecting the oil level continuously during normal engine operation. The sensing system consists of an ultrasonic transducer for the oil level detection as well as a Tuning Fork mechanical resonator for the oil condition measurement.
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