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Journal Article

Yaw Stability Enhancement of Articulated Commercial Vehicles via Gain-Scheduling Optimal Control Approach

In this paper, a gain-scheduling optimal control approach is proposed to enhance yaw stability of articulated commercial vehicles through active braking of the proper wheel(s). For this purpose, an optimal feedback control is used to design a family of yaw moment controllers considering a broad range of vehicle velocities. The yaw moment controller is designed such that the instantaneous tractor yaw rate and articulation angle responses are forced to track the target values at each specific vehicle velocity. A gain scheduling mechanism is subsequently constructed via interpolations among the controllers. Furthermore, yaw moments derived from the proposed controller are realized by braking torque distribution among the appropriate wheels. The effectiveness of the proposed yaw stability control scheme is evaluated through software-in-the-loop (SIL) co-simulations involving Matlab/Simulink and TruckSim under lane change maneuvers.
Training / Education

Wrought Aluminum Metallurgy

There are a wide variety of wrought aluminum alloys, each developed to provide specific properties. Getting the strength you need in an aluminum alloy requires knowledge of the effects of alloy composition, cold-working, and heat treating on aluminum metallurgy and properties. A good understanding of how aluminum alloys behave and what can be done to modify their properties is critical for being more productive and profitable. The course takes about one hour to complete and consists of one module and a final exam. Also, quizzes and problems give you opportunities to apply the concepts taught.
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Wiley SAE MOBILUS® eBook Package

Committed to being the primary source for aerospace and ground vehicle engineering resources, SAE International has added the full compilation of our Wiley eBook collections to the SAE MOBILUS® technical resource platform. Purchasable as an annual subscription and containing the titles from the Wiley Aerospace Collection, the Wiley Automotive Collection, the Wiley Computer Systems Collection, and the Wiley Cyber Security Collection.
SAE MOBILUS Subscription

Wiley Automotive Collection

Purchasable as an annual subscription, the Wiley Automotive Collection contains 20 eBook titles and focuses on a wide range of categories, including engines, transmission, chassis, body, electrical, safety, and manufacturing. Titles covering new and emerging topics such as battery technology and electric and hybrid vehicles are included as well, making the series an essential addition to any institution’s automotive resources.
Technical Paper

Why You Should Use Web Based Learning for CAD Training in Your Organization

Since 1992, Caterpillar has invested millions of dollars to purchase CAD software, and spends nearly $2M per year keeping its engineers up-to-date, via instructor lead training (ILT), as new enhancements are introduced. Periodic upgrades to the software also require huge resource (people, costs) commitments for the planning and execution of the training requirements required for a large global workforce. This paper will examine gaps uncovered in the efficiency and effectiveness of the current training process, and the cultural change required as a result of switching from an instructor led environment to a completely web-based solution, which, once deployed, had promised to change the way Caterpillar approached training for the future. The proposed change promised to improve human resource capability by utilizing new technological capabilities, and resulted in improvements in organizational capabilities as well.
Technical Paper

Weld Durability Analysis by Equilibrium-Equivalent Structural Stress Approach

Welding has been used extensively in automotive components design due to its flexibility to be applied in manufacturing, high structural strength and low cost. To improve fuel economy and reduce material cost, weight reduction by optimized structural design has been a high priority in auto industry. In the majority of heavy duty vehicle's chassis components design, the ability to predict the mechanical performance of welded joints is the key to success of structural optimization. FEA (finite element analysis) has been used in the industry to analyze welded parts. However, mesh sensitivity and material properties have been major issues due to geometry irregularity, metallurgical degradation of the base material, and inherent residual stress associated with welded joints. An approach, equilibrium-equivalent structural stress method, led by Battelle and through several joint industrial projects (JIP), has been developed.
Technical Paper

Wear of Bearing Materials

Wear characteristics of four bearing materials have been investigated under different sliding conditions. The bearing materials used were CDA 954, CDA 863, CDA 932, and CDA 938. Using a Taber Wear Tester, a cylinder on a flat geometry was used as a tribo contact pair. All bearing materials in the form of a thick cylindrical disk were subjected to combined sliding-rolling motion against a rotating flat disk. The flat disk was either an abrasive disk, or a very soft steel disk, or a hardened steel disk with and without lubrication. Wear was measured as weight loss after several thousand cycles of rotation. Maximum wear of the bearing materials occurred when the counter body was a very soft steel disk. These results together with the wear rate of each bearing material sliding against four different counter bodies are presented. These results are found to be of practical importance in the design and application of journal bearings made of materials used in this investigation.
Technical Paper

Virtual Validation of Truck Chassis Using Wheel Force Transducer Data

Lot of CAE (Computer Aided Engineering) based evaluation methods and DVPs (Design Verification Process) are available which are derived from acceleration data, strain data acquired on vehicle over proving ground. Using peak load summary from acceleration inputs generic gravity loads get derived. Use of these loads for CAE analysis are having certain advantages like faster concept level evaluation, broader perspective and confidence on concept design. But there are few limitations of using these methods like it gives only broader perspective of concept design and not able to capture many failure modes and locations as per RWUP (Real World Usage Pattern). This paper explains the advantages of using WFT (Wheel Force Transducer) data for getting more reliable, realistic and co-relating more failure modes on the vehicle. WFT data acquired on all four wheel-ends at wheel center. Each wheel end transducer records 3 translational and 3 rotational forces.
Technical Paper

Virtual Instrumentation of a Soil Bin for Improved Precision

The existing instrumentation of a soil bin was retrofitted with virtual instrumentation techniques to achieve improved repeatability and more precise measurements. Current-loop sensors were added to the prime mover for improved speed control. Soil preparation operations were instrumented to determine penetrometer forces as a function of soil penetration depth, soil surface smoothness, compaction force, and soil surface elevation. Test hitch-points for agricultural implements were instrumented with wheatstone bridge force transducers. Implement depth was found with ratiometric linear transducers. Distance and speed determinations utilized an optical encoder with a resolution of 3.0 × 10-4 m. Temperature measurements were also recorded with solid state current transducers.
Technical Paper

Virtual Engineering and Morphing Technology

As competitive pressures in the automotive industry continue to increase the need for reduction in product development time, OEM's are searching for ways to eliminate non-valued added activities. Today, still too much time is devoted to the laborious process of manipulation of CAD geometry in the advanced stages of a program in order to develop feasibility for emerging design themes, involving the packaging and function of vehicle systems. Technology is being developed that will eliminate much of the tedium currently involved in this design engineering process. As theme iterations or packaging changes occur, CAD models that intelligently link the theme, the packaging, and the engineering “rules” will automatically “morph” into new designs. This Morphing process will execute CAD model changes according to engineering rules that are considered to be industry best practices.
Technical Paper

Virtual Correlation in Fuel Consumption Analysis

Fuel efficiency is an essential matter at commercial vehicle development. High fuel consumption of commercial vehicles has been considered synonymous with inefficiency or absence of available resources and budget to test more driveline configurations in different customer missions. The Brazilian market has a several request of mission profile, trailer configuration, load distribution, average speed, productivity and fuel economy target. Due to the increase of operational cost, customer expectation of profitability and market competition the company need create some different methodology to develop the best line up for each customer without impact on the program milestones and budget.
Technical Paper

Vibro-Acoustic Analysis for Modeling Propeller Shaft Liner Material

In recent truck applications, single-piece large-diameter propshafts, in lieu of two-piece propshafts, have become more prevalent to reduce cost and mass. These large-diameter props, however, amplify driveline radiated noise. The challenge presented is to optimize prop shaft modal tuning to achieve acceptable radiated noise levels. Historically, CAE methods and capabilities have not been able to accurately predict propshaft airborne noise making it impossible to cascade subsystem noise requirements needed to achieve desired vehicle level performance. As a result, late and costly changes can be needed to make a given vehicle commercially acceptable for N&V performance prior to launch. This paper will cover the development of a two-step CAE method to predict modal characteristics and airborne noise sensitivities of large-diameter single piece aluminum propshafts fitted with different liner treatments.
Journal Article

Vehicle System Simulator: Development and Validation

A graphical user interface (GUI) toolbox called Vehicle System Simulator (VSS) is developed in MATLAB to ease the use of this vehicle model and hopefully encourage its widespread application in the future. This toolbox uses the inherent MATLAB discrete-time solvers and is mainly based on Level-2 s-function design. This paper describes its built-in vehicle dynamics model based on multibody dynamics approach and nonlinear tire models, and traction/braking control systems including Cruise Control and Differential Braking systems. The built-in dynamics model is validated against CarSim 8 and the simulation results prove its accuracy. This paper illustrates the application of this new MATLAB toolbox called Vehicle System Simulator and discusses its development process, limitations, and future improvements.
Technical Paper

Vehicle Integration, Gear Material and Heat Treatment Effects on Rear Axle Whining Noise

This paper will focus whining noise on rear axles applied in mid-size trucks. Vehicle integration changes during development affect directly the gear noise perception, in which it may be intensified. Also, gear material and heat treatment choices for the rear axle need to be done carefully, taking into consideration the integration changes and also the driver usage. A lessons learned collection over the diverse aspects of a rear axle whining noise will be the basis of this paper.
Training / Education

Vehicle Frontal Crash Occupant Safety and CAE

Car companies and suppliers continue to develop new technologies that make vehicles safer and regulatory agencies continue to update safety regulations based on new research studies, making vehicle safety design more and more complex. This seminar covers the mechanics of frontal crashes and how vehicle structures, vehicle restraint systems, and vehicle interiors affect occupant safety. It also describes details of how CAE tools work in the simulation of frontal crashes. The goal of the course is to familiarize participants with engineering principles behind vehicle and restraint designs for occupant safety.
Technical Paper

Vacuum Die Casting Technology with True T6 Heat Treating Capability

Outboard Marine Corporation (OMC) developed its own vacuum die casting process to produce true T6 heat treatable aluminum die castings. This process was initiated by OMC Research and developed jointly with OMC Waukegan. The project began 1990 and was put into production in 1992 on the outboard motor lower mount bracket shown in figure 1. OMC is producing vacuum die cast aluminum parts made with 356.0 alloy and T6 heat treated which meet or exceed the strength of similarly alloyed and processed permanent mold or lost foam cast parts. The application of this process is being expanded within the realm of structural outboard motor parts to include other mounting brackets, as well as fuel system components. An automotive die caster is using the technology and equipment provided by OMC to produce leak tight air conditioner compressor housings.
Technical Paper

Using Rapid Prototyping Techniques to Prototype Metal Castings

Several methods have been developed which use rapid prototyping techniques to assist in the creation of prototype metal castings. Methods exist for a number of casting processes such as sand casting, die casting, investment casting, and evaporative pattern casting. In many cases, these methods can reduce both the time and cost required to create prototype castings.
Technical Paper

Using Pro/ENGINEER and ANSYS in Undergraduate Engineering Education

The authors relate their experience in teaching a senior level Computer-Aided Design (CAD) course in Mechanical Engineering using advanced Computer-Aided Engineering software. The course balances the theory and the need for hands-on experience with commercial CAD software in solving practical design problems. Students are given assignments ranging from simple 3D modeling exercises and 2D finite element analyses to an optimization project requiring more advanced 3D modeling and analysis. Where possible, analytical solutions are found and compared to the finite element results. The software allows the students to explore much more complex problems than would have otherwise been possible.
Technical Paper

Using MCAE and Rapid Prototyping for Casting Design

The conceptualization, design, analysis, prototyping, and testing of a steel casting are described. The methods used include 2D CAD, 3D solid modeling, finite element analysis, Solid Ground Curing rapid prototyping, and laboratory prototype testing. The part was successfully delivered to field testing on time. The use of the MCAE techniques provided a more optimal part more quickly than the use of standard CAD techniques would have provided. A minor cost penalty was paid for the prototype pattern versus conventional prototyping.
Technical Paper

User Oriented, Computer Aided Hydraulic System Design

The Computer Aided Analysis and Simulation (CAAS) package is the result of a multiphased program aimed at developing a user oriented, computer aided design technique for the analysis, design and specification of hydraulic power transmission systems. The package is intended to eliminate the need for detailed computer programming on the part of the system designer and allows effective use of the technique by anyone familiar with the CAAS package. This study has included the development of the general system analysis and optimization techniques, the development of the Probelm Oriented Language (POL), modeling of the most commonly used hydraulic components and testing of a selected group of hydraulic system components to verify the models developed. This paper presents the rationale of the CAAS package. The theoretical basis, program structure and application examples are included.