MODERN TRENDS IN AUTOMOBILE.docx (Size: 763.5 KB / Downloads: 391)
The rapid development of electronic systems in automotive vehicles has been driven for decades
by constantly growing requirements of legislation for environmental protection, as well as rising
demands of the end-user to improve fuel economy, safety, driving comfort and driving
excitement. The manufacturers of mobile work machines also see themselves increasingly
confronted with these requirements. Can Robert Bosch GmbH use the technical experiences
from automobiles also in this area to efficiently develop high-quality electronic systems.
The word automobile is made up of two words I,e.auto and mobile. Auto is self propelled and mobile is vechicles and meaning of these two words is “self propelled vechile”.
Now a days the Indian automobile market in world is in second rank.
First the technology gap are being briged not only between India and world but also the present and future. Almost every player is introducing new engines which are smaller but powerful,lighyer but efficient.
1. AUTOMOBILES, FUEL AND CO2 IN A LONGER TERM PERSPECTIVE
Energy used and travel for transport purpose in wealthy countries is dominated by automobiles.while fuel economy improvement and some slowing of the risein ownership and use of automobile has lower the growth fuel use , these vehicles are account roufly for 9% of total energy used in oecd countries. Their share in total energy use in developing countries is smaller, but rising rapidly (2). Since most all fuel is from oil products or natural gas, automobiles also account for a significant amount of global release of carbon dioxide, the main greenhouse gas associated
with climate change. Hence the automobile and its energy use is a central focus of energy and environmental authorities in almost every country.
This paper focuses on automobile fuel economy, defined as fuel use per traveled of automobiles and household light trucks. By paying some attention to car ownership and use, as well as new vehicle characteristics like weight, power, and fuel, policy makers gain of understanding of what is causing total fuel use to rise, and what components of that rise might be changing towards restraint of fuel use.
This work updates a series of papers by Schipper and co-workers. Schipper et al. (3,4) set out some of the difficulties facing development of data and subsequent analysis of the components of automobile fuel use, particularly in countries like the United States, where actual fuel use is not surveyed and vehicle usage only inferred from infrequent travel surveys.
2. ON ROAD FUEL ECONOMY - APPROACH
We have updated the figures for on-road fuel economy from previous work. While the national data sources are similar those used previously (see Appendix), those from France, UK, and Japan have more details and expanded coverage than previously. As we shall argue, understanding on-road fuel economy (and consequent CO2 emissions) is critical for both interpreting how changing fuel prices and other conditions have changed vehicle use and vehicle purchases, and for estimating the impacts of future policies and technologies Whatever the tested or hoped-for fuel economy and emissions were, the atmosphere sees the real emissions.
National authorities have three approaches to estimating fuel economy and vehicle usage. The most accurate fields surveys of thousands of drivers to record annual fuel use and annual vehicles (Australia, Canada, France, Netherlands until 1998, the US in the early 1980s). Some countries survey partsof this couplet, Sweden for vehicle use for example. As a variant, it is possible to derive annual vehicle use from national travel surveys if these represent all seasons and days of the week. It is also possible to estimate fuel use from household budget surveys if respondents also supply average prices of fuel they paid. These approaches are bottom-up.
3. RESULTS FOR ON ROAD FUEL ECONOMY
Figure 1 shows on-road fuel economy for six countries: US, Japan, UK, France, Germany, and Italy, with Germany representing “western” Germany before 1995 and all Germany from 1991, leaving four overlapping years. Diesel and LPG are included at gasoline equivalents defined above.
4. NEW CAR FUEL ECONOMY
New car fuel economy, as measured by tests and weighted by sales, is an important indicator of how on-road fuel economy will behave as the fleet is renewed. But a cautionary note is important. Ref. (5) and references therein have emphasized the enormous uncertainties in interpreting sales-weighted test values of vehicles. While such indicators are extremely important in determining the overall impact of technology and
consumer choice, they are very difficult to translate into on-road values that can be matched derived from bottom –up surveys or top-down analysis applied to the entire stock. Ref. (18) and other US
EPA sources make some estimates of the approximate translation of CAFÉ test values of each model year EPA sources make some estimates of the approximate translation of CAFÉ test values of each model year into on-road that are remarkably realistic. For the 1996-2005 period, for example, (18) estimated on road MPG of the combined new car and light truck sales at 21.3+-0.2 MPG, remarkably close to the estimate that as not fluctuated very much. Were the “real values” for these cars that would be measured by
surveys much different, the on road estimates would not have been so flat.
FIGURE 2 New vehicle sales-weighted fuel economy gasoline equivalents for each year shown, using each country/region’s testing procedures, from each country’s official publications.
With this in mind, Figure 2 shows US, Japan, and a number of European Country averages for new vehicle fuel economy. For the US, the EPA light truck average is counted with cars, using 80% of the light truck sales as indicative of how many should be averaged with cars sold to give a combined value. Japanese values are chained from the 15-mode (and earlier 10mode) tests reported by ( 21). European values are given as weighted averages provided by EU (22) and before then the European Automakers Association (ACEA) as tabulated by the European Council of Ministers of Transport (S. Perkins, ECMT/OECD, priv., comm. Figure 3 then shows these values indexed to their 1995 values, the year from which EU authorities tabulated figures to gauge the progress of their voluntary agreement on lower CO2 emissions/fuel economy. Indexing eliminates misleading comparisons of countries with different test procedures. As noted above
diesel is counted at its energy equivalent, which gives somewhat different values for France, Italy .
FIGURE 3 Long term trends in new car sales-weighted fuel economy indexed to 1995. Source: Official national sources, EU
What is clear from either portrayal is that there have been three periods—the 1970s and early 1980s which saw a dramatic decline in new vehicle fuel intensity in the US and (from 1975/6, when data are available), more modest but still substantial declines in Japan and EU. In the mid 1980s to mid 1990s, EU new vehicle fuel intensities were stagnant while those in Japan and the US rose as SUVs in the US and larger cars in Japan became increasingly more important. After 1995, values in Japan and EU headed down again presumably as voluntary agreements came under discussion, while the US average fluctuated. While the E values through 2005, approximately 165 gm/km of CO2 in absolute terms, fall short of a path to the ultimate goal (140 gm/km) the improvements are still in stark contrast to developments in the US, where, ironically, the relative changes in fuel prices from higher crude prices have been much larger because so little of the price is taxation.
5. IMPACT OF DIESELS – AMBIGUOUS
Shifting from gasoline to diesel should save fuel and reduce CO2 emissions as well, goes the Brussels. In theory diesels are much more efficient, as matched pair analysis in Schipper et al 2002 showed.
But the same analysis questioned the ultimate role of shifting to diesel if the goal is less fuel use or carbon emissions than otherwise.
The analysis of data in the 2002 study was reviewed briefly and the same important surprises still hold. Recall that when account is taken of the greater energy density of diesel and the greater CO2 released per unit of energy in diesel fuel, diesel fuel economy values have to be increased by 12% in energy terms or
18% in CO2 terms before they can be compared with gasoline. This step cuts the apparent advantage
6. THE RACE FOR WEIGHT, POWER, AND SPEED
Throughout this report we have avoided using the term “efficiency” for the indicators we have presented. The reason is clear – real fuel efficiency, if expressed as energy required to move a given mass a given distanceor the energy required to provide a given level of power to an engine, or to extract a given amount of power from a given volume has risen markedly in the US and Europe. In simple terms, these efficiency improvements have more or less countered increased weight and power (as well as extras) in overwhelmed them in one period in Japan, but only taken back part of the improvements in true efficiency in Europe.
FIGURE 5 New car engine power (diesel and gasoline averaged).
Figure 4 shows new vehicle weight, Figure 5 power in the US and selected European countries over time (7,17). The European countries bracket the averages for years where all countries’ data are available. Swedes buy the largest cars, Italians the smallest in Europe. These figures have been creeping up in both the US and Europe. In Japan, however, an indicator of a possible trend break trend is the percentage of mini-cars in overall new car purchases, up from the teens in the 1980s, the 20s in the 1990s, and the 30s after 2000
(21). This represents a break in trends, motivated as much by the lack of space for parking and narrow streets .
FIGURE 7 Fuel consumption to power ratio for new cars
When we divide fuel economy by weight or by power, we obtain indicators of “efficiency” in the narrow sense (Figs 6 and 7). The first reveals a big drop in fuel use required to move a vehicle. Since power to weight ratios increases in the US and Europe, this means acceleration and top speed have both increased. That is, the lower fuel-use to weight ratio signals greater efficiency, not declining performance, power/weight is up in all countries. The lower fuel use to power ratio says the engine itself is more efficient, providing potentially more power for a given average fuel consumption. In short efficiency has fed power .
7. DRIVING FORCES
The foregoing suggests that short of a low-carbon fuel that can be produce at a level of 20 million barrels per day for IEA countries, serious oil saving or reduction in GHG emissions – say bringing automobiles back to their 1990 levels of emissions or fuel use --- cannot occur without both reductions in vehicle use and an end to the upward spiral of weight and power. What could drive this change?
8. CHANGING THE TRENDS?
Johansson and Schipper’s (8) findings suggest economic forces – fuel prices – are a important determinant fuel use for cars. In the US, at least, the reaction to higher prices has been small (26,20). Yet comparing both new vehicle fuel economy and changes in the stock among the US, EU and Japan since 2000 show that improvements in the later two but not in the first. This occurred even though the relative price changes in the US were larger since the price of crude and refining represents a much larger share to consumers than US were larger since the price of crude and refining represents a much larger share to consumers than Japan and Europe, where taxes are 2-3 times higher. From this comparison it is difficult not to conclude that the Voluntary agreements in both regions affected new vehicle fuel economy.
The issue remains: what will change the car buying preferences of Americans? In 2005 and 2006 the share of SUVs in the total number of light duty vehicles sold fell slightly, but average weight, engine size and horsepower of the combined fleet still increased and the stalemate of technology and car remained. In the EU, by contrast, efficiency factors improved more than car power or weight (EU 2006 leading to a real improvement in both new vehicle and fleet, on-road fuel intensity. In Japan the arrest increased car power and size and technology together led to fuel economy improvements.
TRENDS IN AC DRIVE APPLICATIONS
AC drives were traditionally first applied in process industries, such as cement, plastic, textile,etc. With development of various vector control methods, AC drives started also to replace DC drives in industries requiring high precision of speed control and good dynamic performance, such as machine tools, robotics, metal rollin g, paper mill finishing lines, etc. These are all applications which must have adjustable speed, by Induction motors are predominantly used, although at power below 10 KW, PM motors have been preferred in servo applications. That application has had spectacular growth over the last 20 years. For example, over
that period, one manufacturer has approximately halved the time period for sale of each subsequent However, because AC drive penetration into these applications is almost 100%, (adjustable speed drives are provided to all applications where the
speed has to be regulated), the future growth in this application segment is expected to essentially.
Fuel cell drive for bus
Improve engine efficiency
The modern gasoline engine is nearing its peak efficiency, only small gains can be made by enhanced combustion and variable camshaft timing.
The diesel cycle engine may once again take over as the engine of choice.
A small turbodiesel / electric hybrid with a CVT and regenerative braking provides the most benefit, 40% to 80% gain.
Changing to tall and thin tires for reduced rolling resistance can add another 2 to 4% gain.
Mounted to Carbonfiber and magnesium wheels for low weight, another 2% gain.
Reducing vehicle load
The passive use of electronics provide multiple benefits:
o Flat body panels can be constructed of photovoltaic materials to recharge the batteries and provide electricity to load devices.
o This can provide up to 5 to 10% gain.
Electronics can also be used for:
o Temperature control (heat pump)
Engine support (coolant circulation
• Choose the appropriate vehicle for the task.
• One passenger in a large sedan for a short commute is inefficient.
• 5 passengers in a small sedan for a long commute is also inefficient.
• The smaller vehicle will work harder to maintain road speeds and traffic conditions.
• Case: 1997 Chevy Malibu with 5 occupants, Austin to Dallas, 16 mpg loaded, 30 mpg with driver only
• Case: 1999 Ford Crown Victoria with 5 occupants, Austin to Dallas, 17 mpg loaded, 19 mpg with driver only.
• What about the 100 mpg car?
• To obtain 100 mpg in a modern auto, we need the following improvements:
• Improve aerodynamics (wind resistance increases to the square of the speed)
• Reduce weight
• Improve engine efficiency
• Reduce rolling resistance
• Dramatically increase the use of vehicle electronics
On-road fuel economy is improving in Japan and Europe, but hardly at all in the US, at least through 2006. Fuel economy (miles/gallon) is higher in Europe and to some extent Japan than in the U.S. In 2005, on-road fuel economy in the U.S. was slightly above 11 l/100 km (above 21mpg. Japan’s average was 10.5 km/100 km (22 mpg), while Germany, the U.K. and France were 8 (29), 7.7 (31) and 7.5 (32) respectively. These real world” on-road figures include diesel and other fuels. For the US, the figure includes the portion of light trucks that are household vehicles, such as SUVs, all of which are far less significant in countries.
1. IEA, 2004. After 30 Years. Oil and Energy in IEA Countries. Paris, International Energy Agency.
2. WBCSD 2003. Sustainable Mobility 2030. Report of the Sustainable Mobilty Project. Geneva- World
Business Council for Sustainable Development
3. Schipper, L.J. M.J. Figueroa, L. Price, and M. Espey, 1993a, Mind the Gap: The Vicious Circle of
Measuring Automobile Fuel Use, Energy Policy 21. (12)1173-1190.
4. Schipper, L., Steiner, R., Figueroa, M., Dolan, K., 1993b, Fuel Prices and Economy: Factors Effecting
Land Travel, Transport Policy 1 (1) 6-20. LBL-32699.
5. Schipper, L.J. and W. Tax. 1994. New Car Test and Actual Fuel Economy: Yet Another Gap?