Environment for Green Vehicles, Efficient is better

Transcription

1 Copyright 2002 Society of Automotive Engineers, Inc Environment for Green Vehicles, Efficient is better Peter T. Peterson United States Steel, LLC ABSTRACT This paper concerns itself with the environmental aspects of personal automotive transport. It must be said at the outset that improvement in environmental performance of personal automotive transport cannot be achieved at the expense of either the vehicle s safety or its affordability. INTRODUCTION The ULSAB-Advanced Vehicle Concepts (AVC) Program focused on development of steel applications for vehicles for the year 2004 and beyond. In its execution, concepts were developed for the popular European C-Class, or so-called Golf Class, and the North American Midsize Class (see Figure 1), which is the target for the PNGV program, hereafter referred to as PNGV-Class vehicle. Therefore, the vehicle body structures employ the unique advantages of advanced steel grades, which provide heightened strength with excellent part forming. ULSAB-AVC vehicle body structure uses 100 percent high-strength steel grades, of which over 80 percent are advanced high-strength steels. These steels are combined with the most advanced manufacturing and joining technologies to achieve the structurally efficient designs and safety features found in ULSAB-AVC concepts. The resulting Midsize Class vehicle concept has a mass of less than a 1000 kg and has the capability of achieving a five-star safety rating. It also approaches the PNGV target mileage by achieving 60 miles per gallon on the highway, 47 miles per gallon in the city and 52 miles per gallon in the combined U.S. Driving Cycle. With high-volume manufacturing of 225,000 units per year, the AVC concept would not cost more to manufacture than comparable family sedans. Benchmarking data indicate that the Midsize Class ULSAB-AVC concept vehicle selling price would be below the selling price of current vehicles in the same class. The ULSAB-AVC is the most recent addition to the global steel industry s series of initiatives offering steel solutions to the challenges facing automakers around the world today. It succeeds ULSAB [1, 2], ULSAC [3] and ULSAS [4]. The ULSAB-AVC concepts revolutionize the kinds of steels normally applied to vehicle architectures, as well as demonstrating cutting edge steel vehicle design. In addition to extensive use of advanced steels, ULSAB-AVC features a full spectrum of the latest steel technologies, including tailor welded blanks, tailored tubes, advanced joining techniques and tube and sheet hydroforming. Figure 1 ULSAB-AVC Midsize or PNGV-Class Vehicle Key to reaching the program objectives was meeting anticipated 2004 crash requirements with steel, achieving the delicate balance of mass efficiency without compromise to safety. Table 1 This project was envisioned by the collaborative efforts of 33 international steel producers forming the ULSAB-

2 AVC Consortium. This concept, engineered by Porsche Engineering Services, Inc., Troy, Michigan, USA, brings the potential for safe, affordable, fuel efficient vehicles, which are environmentally responsible, to near-term reality. This paper presents ULSAB-AVC engineering results on the Environmental Performance of the complete vehicle. Detailed information on ULSAB-AVC can be found in reference [5, 6]. ENVIRONMENTAL CONTEXT In August of 2000, at an automotive management seminar in Traverse City, Michigan, Teruyuki Minoura, President and CEO of Toyota Motor Manufacturing North America told his audience that the biggest challenge facing the automotive industry in the ensuing decade would be to reduce the environmental footprint of the automobile. Although Minoura San s audience was largely from developed nations, he was speaking globally. Even in India for instance, where the cost of fitting a personal vehicle with a catalytic converter exceeds the average annual income of the person owning the vehicle, the human health problems are causing almost draconian environmental regulations to be enacted. Despite the cost, standards equivalent to Europe s 1993 Euro I standards, requiring the use of three-way catalysts, were adopted in India in 1999 for noncommercial four-wheeled vehicles operating on diesel or gasoline. More advanced Euro II standards took effect in April 2000, with proposals to adopt Euro III standards in 2004, and Euro IV standards in 2007, a short two years behind their implementation in Europe itself. Surprisingly, these environmental initiatives have come not from the legislative or executive branches of government, but from the Supreme Court, under a constitutional provision that ensures a certain quality of life to residents of India. In January of 1998 the Indian Environment Pollution Authority was created with a mission to reduce pollution in and around Delhi. It immediately proposed the following strategies, which were approved by the Supreme Court: Augment public transport Reduce vehicle emissions by setting standards for fuels and auto emissions Establish inspection and maintenance of in-use vehicles Use clean alternative fuels In July of 1998 the Supreme Court handed down a number of directives relating to public transport and fuel use. One directed that all pre-1990 taxis and autorickshaws (including those owned by individuals) must be replaced with new vehicles running on clean fuels by March 31, All pre-1990 taxis and autorickshaws were successfully removed from the road by the deadline. Other directives handed down at the same time were not as successful, but a great deal of progress is being made. [7] In its August 2001 issue, Automotive Engineering International discusses the results of an extensive survey by the Automotive Industry Technology & Strategy Study Group of the Society of Automotive Engineers of Japan. [8] The study projected the top ten automotive customer needs in the year 2025, the first four of which were environmental; i.e.: 1. Protection of global environment and effective energy use. 2. Development of alternative energy sources. 3. Air pollution control. 4. Promotion of recycling. Apropos of the cost and safety requirements noted at the beginning of this paper, number 5 on the list was Traffic Safety. [9] Whether it is concern for human health, as it is in India, or concern for the future viability of personal automotive transportation, one thing is clear: Reducing the environmental footprint of the automobile is the biggest challenge facing the automotive industry. STRUCTURAL EFFICIENCY Improving the structural efficiency of a vehicle through holistic design is first and foremost an exercise in systems engineering. The ULSAB-AVC body structure was treated as a total system rather than a collection of individually optimized components. This enabled the design team to optimize the entire structure, adding mass where it made sense, enabling more mass reduction elsewhere. It also encouraged the use of more advanced high strength steels, taking advantage of their unique combination of high ultimate tensile strength, in-process work hardening to increase in-part strength and superior formability. The result was a significant reduction in body structure mass without sacrifice of structural or safety related performance. SOURCE REDUCTION - It is interesting to note that in the examples of environmental concern and action cited above, both the Indians and the Japanese focused on the use phase of the vehicle and, in the case of the Japanese, the end-of-life (EOL) recycling issue. The initial environmental opportunity having to do with the

3 manufacture of the vehicle itself, should also be addressed. The concept of Life Cycle Assessment (LCA) is based upon evaluating the environmental inputs and outputs that are required for and result from the production of a functional unit, in this case a PNGV class automobile. The resources required to construct competing functional units of equivalent utility often differ. In the case of ULSAB-AVC the resources required to construct the vehicle were considerably less than what is typically required to construct a PNGV Class vehicle. Vehicle Benchmark Fleet 263 ULSAB-AVC 218 Table 2 Body Structure Mass (Kg.) It should be noted that the benchmark fleet, being current production, in general does not meet the significantly more stringent 2004 safety standards with which ULSAV-AVC fully complies. The addition of the 40% offset frontal and side-pole impact requirements will add significant mass to most if not all of the benchmark fleet, and certainly not uniformly. Despite the fact that the comparison suffers, the example is worthwhile. In the data provided in Table 2, ULSAB-AVC s body structure is 45 Kg. or about 100 lbs. lighter than the current benchmark average. Taken together with the accompanying engineered scrap this represents a source reduction opportunity of between 140 lbs. and 150 lbs. of steel per vehicle. Taken as an average mass reduction opportunity given the vehicle class involved, and extended across current North American production of all vehicles, it could mean over 1 million fewer tons of steel required to satisfy present market requirements. A not insubstantial environmental achievement, USE PHASE - As discussed in a seminal automotive environmental study described in SAE Paper , Life cycle Inventory of a Generic U.S. Family Sedan [10] the use phase dominates the energy consumption profile. For this reason, means of reducing fuel consumption will continue to be the primary focus of reducing the environmental impact of automotive transport. Improving the structural efficiency of the vehicle, with the consequent reduction in curb weight, is one means of improving fuel economy. Further, it is one in which the global steel industry has an interest, and the ability to provide solutions, which do not exacerbate other design and manufacturing problems in the process. In addition to conserving the fuel itself, improved miles per gallon performance reduces exhaust emissions, improving air quality in the process. PNGV - the Partnership for a New Generation of Vehicles was formed in September of It is a cooperative research and development (R&D) program between the federal government and the United States Council for Automotive Research (USCAR), whose members are DaimlerChrysler, Ford and General Motors. The objective of the PNGV program is to develop technologies for a new generation of vehicles that can achieve fuel economies up to three times (80 miles per gallon of gasoline) those of today s comparable midsize sedans, while maintaining performance, size, utility, and cost of ownership and operation and meeting or exceeding federal safety and emissions requirements. ULSAB-AVC in its North American version was conceived and designed to meet the targets set forth in Goal 3 of the PNGV program. Insofar as the steel industry s interest and technical expertise was focused on the vehicle s structure and related cost and performance, no attempt was made to develop alternative powertrains. The prototype vehicles developed by DaimlerChrysler, Ford, and General Motors included powertrain development activities. ULSAB-AVC focused primarily on developing a steelbased structural platform that could demonstrate the structural efficiency and low mass which, when coupled with advanced powertrain technologies, would be capable of achieving the PNGV Goal 3 objectives. Comparison of the ULSAB-AVC, pre-production prototype PNGV vehicles and the benchmark fleet of current PNGV class vehicles is provided in Table 3, below. Following are notes and comments on that comparison: Safety ULSAB-AVC began the design exercise with the understanding that safety was non-negotiable. Further, since the consortium had neither the time nor the finances to update a design for future changes in safety requirements it was necessary to anticipate those changes. We had the advantage of starting considerably later than PNGV with the result that ULSAB-AVC is capable of meeting all anticipated 2004 safety standards. The PNGV vehicles as well as the benchmark fleet meet current requirements, but would have to be re-designed in order to comply with anticipated 2004 safety standards. There are both mass and cost implications to be considered in that re-design process. Affordability PNGV objectives were quite clear with regard to cost of ownership and operation. It should be noted that the cost estimates provided by DaimlerChrysler, Ford and General Motors involve considerable uncertainty, in part related to the advanced powertrain technologies, but also related to the use of higher cost structural materials (i.e., aluminum and

4 carbon fiber reinforced composites). A more meaningful comparison can be made between ULSAB-AVC and the PNGV Class Average benchmark fleet. Please note that the ULSAB-AVC numbers are manufacturing cost while the others are selling prices. Fuel Efficiency The miles per gallon of gasoline values for ULSAB-AVC were actually generated through computer modeling of the U.S. combined driving cycle. Values of 47 mpg City and 60 mpg Highway were estimated from the 52 mpg combined driving cycle total. While the 52 mile-per gallon achievement doubles the current PNGV average benchmark fleet performance, it is still far from the 80 mile per gallon goal. This level of fuel efficiency, it must be pointed out, has been achieved with a current-technology reciprocating internal combustion engine. It has, therefore, not benefited from the significant developmental work embodied in the drivetrains of the PNGV prototype vehicles. Clearly, the ULSAB-AVC receives considerable benefit from its 2200 Lb. (1000 Kg.) curb weight. ULSAB AVC PNGV Gasoline Fuel Economy 52 (mpg) Vehicle Mass 2200 (lbs) Manufacturing Cost/Selling 9,500 price ($) Crash > 2004 Requirements PNGV Comparison ULSAB AVC PNGV Diesel ,200 > 2004 GM Precept * 90/ > 50,000 Ford Prodigy * 78/ > 50,000 DCX ESX3 * 80/ ,000 PNGV- Class Avg ,000 * PNGV concept vehicles are equipped with a diesel/hybrid powertrain; first fuel economy number reflects that while the second is based on a gasoline-equivalent formula Table 3 Environmental Responsibility is a concept developed by the ULSAB-AVC consortium which expresses the ability to show improvements in environmental performance while at the same time maintaining or improving performance in all other attributes and requirements (e.g., cost, manufacturability, safety, structural performance). The basic premise is that it is possible to improve the environmental performance of a vehicle without compromising its affordability or its performance. And, conversely, it is not environmentally responsible to propose improvements in environmental performance at the expense of other attributes and characteristics. The key is using low cost structural materials in a way that improves the structural efficiency. Further, the new steels being used to achieve these environmental improvements are completely recyclable and do themselves contain approximately 1/3 postindustrial and post-consumer scrap. Steel s inexpensive and simple recyclability has made the automobile the most recycled consumer product in North America, with a recycling rate approaching 100%. CONCLUSION By working to improve the structural efficiency of a PNGV Class (mid-size) sedan, ULSAB-AVC has achieved a source reduction amounting to 140 to 150 lbs. per vehicle. The resultant doubling of fuel efficiency on the U.S. Combined Driving Cycle can provide substantial reduction in fuel consumption, while at the same time improving air quality. These results have been achieved together with improvements in safety that will enable ULSAB-AVC to meet or exceed the anticipated 2004 federal safety standards, and significant improvements in structural performance (i.e., torsional and bending rigidity and first body mode). Manufacturing and ownership costs have not been increased, nor recyclability impaired. ACKNOWLEDGMENTS The ULSAB Advanced Vehicle Concepts project discussed in this paper is based on the results of research intended to optimize the use of advanced steels in automotive applications, sponsored by the UltraLight Steel Auto Body - Advanced Vehicle Concepts Consortium, a consortium funded by most of the World s producers of flat-rolled steel. Porsche Engineering Services, Inc conducted the project. The American Iron and Steel Institute (AISI) is participating in the project on behalf of the North American consortium members. For further information on ULSAB AVC please log on to or The author wishes to thank the Communication Contractors of the ULSAB AVC-project who prepared the deliverables that were the basis for this paper. Special thanks are made to Kathy Hickey from Icon, Ed Opbroek, ULSAB AVC Program Director, and Jon Harrington, AISI. REFERENCES 1. UltraLight Steel Auto Body Final Report, Porsche Engineering Services, Inc. March UltraLight Steel Auto Body Electronic Report, American Iron and Steel Institute, May UltraLight Steel Auto Closures Final Report, Porsche Engineering Services, Inc. May UltraLight Steel Auto Suspension Final Report, Lotus Engineering Services, Inc. January ULSAB-Advanced Vehicle Concepts Final Report, Porsche Engineering Services, Inc. June ULSAB-Advanced Vehicle Concepts Virtual Exhibit, ULSAB-AVC Consortium, January Transportation in Developing Countries, Greenhouse Gas Scenarios for Delhi, India, Ranjan

5 Bose - Tata Energy Research Institute and Daniel Sperling - Institute of Transportation Studies, University of California, Davis, Pew Center on Global Climate Change May 2001` 8. Automotive Engineering International August, 2001 Global Viewpoints: Japan Plans for the Future 9. ibid. pp SAE Paper Sullivan et. al. Life Cycle Inventory of a Generic U.S. Family Sedan Overview of Results Graz Austria 1998 CONTACT Peter T. Peterson Director-Marketing, Automotive U. S. Steel Group, a unit of USX Corp. Automotive Flat Rolled Products 600 Grant Street Pittsburgh, PA ptpeterson@uss.com ADDITIONAL SOURCES SAE Paper , ULSAB-Advanced Vehicle Concepts -- Materials. Jody Shaw, US Steel, et al. 6. SAE Paper , Achieving an Affordable Low Emission Steel Vehicle; An Economic Assessment of the ULSAB AVC Program Designs. Jody Shaw, US Steel, Richard Roth, Massachusetts Institute Of Technology. 7. SAE Paper , ULSAB-Advanced Vehicle Concepts -- Safety/Crash Management. Blake Zuidema, National Steel Corp. 8. SAE Paper , ULSAB-Advanced Vehicle Concepts Manufacturing and Processes, Paul G. Schurter, Dofasco Inc. 9. SAE Paper , ULSAB-Advanced Vehicle Concepts Chassis and Suspension, Marcel van Schaik, American Iron and Steel Institute 10. SAE Paper (number unknown), ULSAB-Advanced Vehicle Concepts Powertrain, Ron Hughes, Rouge Steel. 11. IBEC (SAE) Paper , Advanced High- Strength Steels and Hydroforming Reduces Mass and Improves Dent Resistance of Light Weight Doors, Marcel van Schaik, American Iron and Steel Institute SAE Paper , ULSAB-Advanced Vehicle Concepts -- Overview and Design. Mike Thorpe, Stelco, and Henrik Adam, Thyssen Krupp Stahl.