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2004-10-26
Technical Paper
2004-01-2668
Hannes Hick, Klaus Denkmayr, Michael Aschaber
The AVL Load Matrix is a systematic approach to optimize durability and reliability test programs. It is based on component-specific test acceleration factors and uses damage models as well as statistics. Using the Load Matrix approach helps to achieve complete test programs while avoiding unrealistic over-testing. The paper describes the Load Matrix concept and structure as well as the process of setting up the Load Matrix for a system or component. Examples are provided on damage models, and the procedure to estimate the acceleration factors is discussed.
1999-09-13
Technical Paper
1999-01-2861
Paul Erich Robinson, O. Geoffrey Okogbaa
This paper presents a proposed new statistical distribution which models product reliability in those situations where obsolescence is built in. Typically products in this class are designed so that very few failures occur prior to a predetermined point, after which the majority of units fail within a short timespan. From the reliability point of view automobiles are manufactured for a life span of five years, after which purchase of a new vehicle or a costly major overhaul is required. Examples are discussed which show that the Post-Warranty Distribution is the best fit for this situation.
2016-09-27
Technical Paper
2016-01-8132
Sanket Pawar
Abstract Reliability engineering methods are used to assess risk and eliminate hazards by estimation, elimination, and management of risks of failures. The ISO 26262 functional safety standard gives detailed guidance on reliability engineering methods like Failure Mode and Effect Analysis (FMEA) [7], Fault Tree Analysis (FTA) [8] [2], and etc. While, there are many methods available for reliability engineering; no single method is foolproof for securing safety by eliminating hazards completely. Out of these methods, FMEA is widely being used as an integral part of the product development life cycle [10]. In this method, failure modes of individual components are analyzed considering one failure at a time. FMEA is an efficient method for analyzing failures in simple systems. For complex systems, FMEA becomes impractical. It is also difficult to consider variables in FMEA.
1929-01-01
Technical Paper
290086
E. D. SIRRINE
1955-01-01
Technical Paper
550052
FRANK SKIDMORE
1953-01-01
Technical Paper
530194
L. E. KASSEBAUM
1949-01-01
Technical Paper
490192
W. H. FOLAND
2008-10-07
Technical Paper
2008-01-2709
Tom Erkkinen, Mirko Conrad
Model-Based Design with automatic code generation has long been employed for rapid prototyping and is increasing being used for mass production deployment. With the focus on production usage, comes the need to implement a comprehensive V&V strategy involving models and resulting code. A main principal of Model-Based Design is that generated code should behave like the simulation model. It should also be possible to verify that the model or design was fully implemented in the code. As a result, the transformation of models into generated code must be done in a way that facilitates traceability between the model and code. Also automated tests should be performed to determine that the code executes properly in its final software and hardware environments. For example in a typical commercial vehicle application, the control algorithm and plant model are simulated together in a system simulation environment.
2008-10-07
Technical Paper
2008-01-2708
Kerry Drew, Sebastian A. B. van Nooten, Roger Bortolin, Jeff Gervais, James R. Hrycay
The Electronic Control Modules (ECM) installed on heavy truck engines record data during normal operation. While their primary purpose is to control the mechanical and electrical systems on the engine, they monitor other vehicle systems as well. Stored data from the ECM can be downloaded into reports that are useful for tracking fleet performance, scheduling maintenance or troubleshooting engine problems. Many of the current production heavy trucks also record event information that may be useful when analyzing or reconstructing accidents. It is not uncommon for a vehicle involved in a frontal accident to experience sudden decelerations and/or sustain damage to the coolant system or rupture the oil pan. Sustained data outside normal operating parameters from sensors on the engine will typically trigger the ECM to generate a fault code. On a Caterpillar ECM, a short event record called a Diagnostic Snapshot may also be generated with a fault code.
2008-10-07
Technical Paper
2008-01-2711
Larry Long, Gardell Gefke, Brian McKay
Hardware-in-the-loop (HIL) testing has become an essential verification step in the development of vehicle electronics and software systems. New system concepts continue to drive the requirements for HIL systems. The use of an open architecture for HIL testing provides many benefits to meet these requirements quickly and cost effectively. In this paper we will discuss the development of an open architecture HIL system for a J1939 bandwidth study. We will show how this HIL system was used to test and validate that a heavily loaded networks can operate without compromising the performance of safety critical systems
2008-10-07
Technical Paper
2008-01-2710
Nabil Hammad
The DC power supply is ingredient part in the automotive industries as it has been used as a DC power supplies for a wide range of loads. Meanwhile, it is mandatory for battery charging. These types however, causes many problems such as poor power factor, high input current harmonics distortion and uncontrolled DC voltage. In this paper, an improved input power factor correction that uses a combined control system consists of two nested loops with a feedback of the DC voltage and input current as long as a feed forward from the output power. The system has been analyzed, modeled, simulated and experimentally verified. The novel feature of the proposed control scheme resides in fact that it is not only achieve nearly unity power factor with minimum input current total harmonics distortion only but it also introduce superior performance in DC voltage transient conditions.
2008-10-07
Technical Paper
2008-01-2630
Nagwa Abd-elhalim, Nabil Hammed, Magdy Abdel-hady, Shawki Abouel-Seoud, Eid S. Mohamed
Dynamic modeling of the gear vibration is a useful tool to study the vibration response of a geared system under various gear parameters and operating conditions. An improved understanding of vibration signal is required for early detection of incipient gear failure to achieve high reliability. However, the aim of this work is to make use of a 6-degree-of-freedom gear dynamic model including localized tooth defect for early detection of gear failure. The model consists of a gear pair, two shafts, two inertias representing load and prime mover and bearings. The model incorporates the effects of time-varying mesh stiffness and damping, backlash, excitation due to gear errors and modifications. The results indicate that the simulated signal shows that as the defect size increases the amplitude of the acceleration signal increases. The crest factor and kurtosis values of the simulated signal increase as the fault increases.
2008-10-07
Technical Paper
2008-01-2622
E. Tolga Duran, A. Çağri Sever
The crankshaft is the component which transmits dynamical loading from cylinder pressure and inertial loads in engine operating conditions. Because of the crucial importance of its function, crankshaft fatigue life is desired to be higher than the predicted engine operating life. In this study, Puma I5 crankshaft dynamic simulation is performed with multi body dynamics technique. Fatigue safety factors are calculated with the dynamical loadings of engine operating conditions. The effects of single mass and dual mass flywheel on endurance limit are analyzed in this study.
2008-10-07
Technical Paper
2008-01-2621
Tímea Fülep, Michael Herges, Laszlo Palkovics
The road transport is becoming more and more problematic in the countries of the European Union. Some predictions show an increase of 80–100% of the current volume of goods and passengers will be transported in the EU within the next decade, and most of this increase – despite of the efforts made in promoting the rail and waterway transport – will be added to the already overloaded roads. It seems, the only feasible solution to fulfill this transportation demand is to increase the vehicle overall length and weight at the lowest complexity, providing the maximum utilization of the existing vehicle units only with smaller modifications and higher reliability.
2008-10-07
Technical Paper
2008-01-2712
Will Cooper, James Lenz, Anant Mishra
The history of off-road equipment manufacturing has been based on proven designs and long times between model updates. In sharp contrast with this strategy is the electronic manufacturing services (EMS) industry. The EMS industry is driven by the larger consumer product industry's continuing pressure for lower costs. Because of this, EMS tools, processes, and practices have evolved to support rapid technology and component changes. However the increasing consumer demand for features like better user-interfaces, more efficient fuel consumption, and the desire for increased operational controls in equipment have forced the off-road industry to increase the frequency of product updates to meet customers' needs. Equipment manufacturers make running changes leading to a “Learning-by-doing” development and manufacturing process. But rapid changes sometimes have an unpredictable impact on the reliability of the final product.
2008-10-07
Technical Paper
2008-01-2713
Koos Zwaanenburg
Hardware-in-the-loop (HIL) testing of automotive control systems is a very mature methodology. Yet there are a number of reasons why it has not yet seen wide proliferation in the commercial vehicle industry. First, until recently, hardware-in-the-loop testing required the use of expensive special-purpose hardware solutions to achieve the needed real-time performance. Second, the development of highly accurate real-time-capable models of diesel engines, transmissions and complete vehicles was prohibitively labor-intensive. Third, the development of test cases required special programming skills. Fourth, the test cases were not portable from one controller program to the next, which limited their re-use. In recent years the performance and user-friendliness of commercial-of-the-shelf (COTS) hardware and software products have changed to the point that they can now be used in very complex and sophisticated HIL test systems for automobiles and commercial vehicles.
2005-11-01
Technical Paper
2005-01-3565
Ragnar Ledesma, Leonard Jenaway, Yenkai Wang, Shan Shih
In this paper, we describe the development of multi-axis, accelerated durability tests for commercial vehicle suspension systems. The objective of the exercise is to design accelerated durability tests that have well-defined correlation with customer usage. The procedure starts with a definition of the vehicle's duty cycle based on the expected operational parameters, namely: road profile, vehicle speed, and warranty life. The second step is determining the durability proving ground test schedule such that the accumulated pseudo-damage (based on spindle loads) is representative of the vehicle's duty cycle. The third step in the process is developing a multi-axis laboratory rig test for the suspension system, such that the accumulated damage in the proving ground is replicated in a compressed time frame.
2006-10-31
Technical Paper
2006-01-3498
Grant A. Malmedahl, Nicholas Dembski, Giorgio Rizzoni, Ahmed Soliman, Lorenzo Disarò
Highway and roadway surface measurement is a practice that has been ongoing for decades now. This sort of measurement is intended to ensure a safe level of road perturbances. The measurement may be conducted by a slow moving apparatus directly measuring the elevation of the road, at varying distance intervals, to obtain a road profile, with varying degrees of resolution. An alternate means is to measure the surface roughness at highway speeds using accelerometers coupled with high speed distance measurements, such as laser sensors. Vehicles out rigged with such a system are termed inertial profilers. This type of inertial measurement provides a sort of filtered roadway profile. Much research has been conducted on the analysis of highway roughness, and the associated metrics involved. In many instances, it is desirable to maintain an off-road course such that the course will provide sufficient challenges to a vehicle during durability testing.
1992-11-01
Technical Paper
922501
D. C. Doskocil
As power trains become more electronically complex, the process of vehicle requirements definition and electronics integration requires greater structure. Elements of the necessary structured process may be evolved from aerospace systems engineering processes, while specifically avoiding some of the inefficiencies associated with military development. The advantage of the structured process is that it facilitates needed decision making with regard to vehicle parameters which ultimately drive the bottom line transportation cost. Such a structured process is discussed, as well as the more classic integration functions such as standards, specifications, interface control, and integration and test.
1990-10-01
Technical Paper
902279
Rudolf Seufert
Flange Bearing Units increasingly become interesting as wheel bearings of truck front axles, as wheel bearings of trailer axles, as final drive pinion bearings. These Bearing Units integrate the functions of 2 pre-adjusted single bearings the seal package the lubrication system the attachment flanges the pulse ring, if ABS is applied. Dependent on the dimensions, 2 designs of Flange Bearing Units have been developed for trucks, the Fully Integrated Unit and the Insert Unit. This paper itemizes the advantages to the user of these Flange Bearing Units, advantages concerning the assembly line, the service life, the maintenance of the component or of the vehicle.
1992-04-01
Technical Paper
920909
Jan Leuridan, Willy Bakkers
“Noise and vibration are not invented here!”. Undesirable structural dynamic behaviour is normally experienced on final assemblies, by which time the underlying cause of the problem is difficult to solve intuitively. Solving the problems classically involves the partial breakdown of assemblies and the application of various structural dynamics testing and analysis procedures. Preferably, noise and vibration problems should be avoided by designing the product right the first time, by the use of various integrated analysis and testing disciplines, from the component level to the final assembly. Such an approach is referred to, in a broader sense, by trendy themes as concurrent engineering, forward engineering, simultaneous engineering.... This paper analyzes trends in analytical and experimental structural dynamics toward better integration of the various discipline oriented techniques that are currently used.
1994-11-01
Technical Paper
942281
Gary P. Hansen, Virender Jain
An electronic refrigerant management system has been developed which increases the reliability and performance of heavy duty vehicle air conditioning systems. The entire system is packaged in a single module which contains the sensors, electronics, and refrigerant flow control device. The system includes an SAE J1708 serial link and SAE/TMC J1587 documented fault codes for easy troubleshooting and system maintenance.
1994-11-01
Technical Paper
942312
Dominick A. Vermet, Christopher W. Ferrone
For over a decade engine manufacturers have been pursuing alternative fuel strategies for vehicle powertrains. First came the discussion of fuel selection. Next, whether or not these alternative fuels can provide the utility offered by traditional diesel. Finally, the footrace of technology and hardware to provide utility, reliability and maintainability with the use of alternative fuels. Now the day has come where many alternative fuels are a practical reality. The body of this paper will discuss the utilization of natural gas as an alternative fuel. This paper targets the fleet operator in an effort to provide a single source of information in a concise format. A discussion of emission standards, engine operational strategies, component technology, fuel characteristics and the utility of using natural gas as a fuel will be addressed. The understanding of present and future engine development is of great importance to a successful fleet operation.
1994-11-01
Technical Paper
942291
Bo Fransson, Per Olov Fryk, Rolf Nilsson
Abstract For commercial vehicles the availability of the truck has become increasingly important to the owner. Unexpected stops and visits to workshops are expensive nuisances not least if caused by some minor faults. The cab comfort and the vehicle response are fundamental to the driver. The accessibility and fault localizing are principal to the mechanic. The safety and the environmental impact are scrutinized by the authorities. The adaptability are vital to the dealers. The climate capability is needed to global presence and to long distance transports. Light weight structural solution permits heavy pay-loads. Low total usage cost is a must to be competitive. Advanced technology is implemented into the truck at increasing rate to satisfy all the aspects above. Quality has become the key issue to reach for the high standard demanded.
1994-11-01
Technical Paper
942288
Larry Goill
: To meet the demands of the future with the competitive environment that Fleet Managers are faced with, a more comprehensive and global strategy for the Utility Fleet Industry will be needed. Not only will Fleet Managers have to standardize the vehicles they have in their own individual fleets to gain an upper hand on soaring costs but they will also need to pool their ideas and develop vehicle chassis and equipment standards that can be used on a global basis. Only then will each Fleet Manager be able to reap the benefits of lower vehicle costs possible from industry wide standardization.
1994-09-01
Technical Paper
941790
Dale A. Ashcroft, Edward H. Priepke, William J. Sauber
Ford New Holland invested in a project to provide a skid steer loader product line to be competitive over the long term in the growing skid steer loader market. They designed and developed a new generation family of skid steer loaders which are customer-driven to be highly-reliable, and competitive in features and performance, while meeting company goals for cost-effective manufacturing. Primary areas addressed in design and development were reliability, durability, serviceability, customer features and performance, complexity reduction and manufacturability.
1989-11-01
Technical Paper
892473
James V. Shannon
This paper describes how the needs of the truck end-user have changed under the pressures of deregulation and competition, and how the truck supply community has responded. It observes that traditional management and hardware responses are yielding diminishing improvements. Significant further improvement is postulated based on application of electronic technology to functional control of a “truck system”. This is defined as a technological discontinuity where a new perspective, “thinking systems” will be needed. The post-1995 truck system is described; and what “thinking systems” entails and “how to create a system” are discussed. It is further postulated that this change in technology will have major impacts on the structure of the truck manufacturing industry, and the capabilities required of its management and technical communities.
1989-09-01
Technical Paper
891890
L. F. Ross
Benefits of adapting electronic controls to off-highway equipment are improved performance and productivity. Such improvements may be realized in several ways; for example, reduced fuel consumption, less time required to complete a task, more accurate results in work performed, and reduced operator fatigue by automating functions. It is obvious that the controller must be reliable, and that the reliability of the system is dependent upon the ability of critical components to operate as intended under environmental stresses normally present in the application. Off-highway equipment can be subjected to harsh environmental stresses produced by various climatic, mechanical and electrical conditions. An understanding of these conditions, the detrimental effects they may produce, and protection against such effects are important considerations for the design of reliable electronic control systems.
1989-09-01
Technical Paper
891889
Scott A. Herbst
In an effort to improve the reliability of electronic control modules used to automate operation of trucks, a database was conceived to aid in the proper selection of electronic components. An accompanying application program provided a means of information exchange between the user and the database, while controlling (accessing, updating, and navigating through) the database.
1989-09-01
Technical Paper
891888
Stephen H. Craney
In calendar year 1988, data was kept on the build of over one million electronic boards and assemblies. The results of this data gives strong evidence on where to receive optimal value for the dollars spent in the various areas of the electronic assembly process. Failure rates given should give good reference points for expected future programs and enable users to make decisions on process controls and vendor screening.
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