From Wikipedia, the free encyclopedia
An automobile (also motor car or simply car) is a wheeled passenger vehicle that carries its own motor. Most definitions of the term specify that automobiles are designed to run primarily on roads, to have seating for one to eight people, to typically have four wheels, and to be constructed principally for the transport of people rather than goods.[1] However, the term is far from precise.
As of 2002, there were 590 million passenger cars worldwide (roughly one car for every eleven people).[2]
History
Some sources suggest Ferdinand Verbiest, whilst a member of a Jesuit mission in China, may have built the first steam powered car around 1672.[3][4] François Isaac de Rivaz, a Swiss inventor, designed the first internal combustion engine which was fuelled by a mixture of hydrogen and oxygen and used it to develop the world's first vehicle to run on such an engine. The design was not very successful, as was the case with Samuel Brown, Samuel Morey, and Etienne Lenoir who each produced vehicles powered by clumsy internal combustion engines.[5]
An automobile powered by an Otto gasoline engine was built in Germany by Karl Benz in 1885 and granted a patent in the following year. Although several other engineers (including Gottlieb Daimler, Wilhelm Maybach and Siegfried Marcus) were working on the problem at about the same time, Benz is generally credited with the invention of the modern automobile.[5]
Approximately 25 of Benz's vehicles were built before 1893, when his first four-wheeler was introduced. They were powered with four-stroke engines of his own design. Emile Roger of France, already producing Benz engines under license, now added the Benz automobile to his line of products. Because France was more open to the early automobiles, more were built and sold in France through Roger than Benz sold in Germany. From 1890 to 1895 about 30 vehicles were built by Daimler and his assistant, Maybach, either at the Daimler works or in the Hotel Hermann, where they set up shop after falling out with their backers. Benz and Daimler seem to have been unaware of each other's early work and worked independently.
In 1890, Emile Levassor and Armand Peugeot of France began producing vehicles with Daimler engines, and so laid the foundation of the motor industry in France. The first American car with a gasoline internal combustion engine supposedly was designed in 1877 by George Selden of Rochester, New York, who applied for a patent on an automobile in 1879. In Britain there had been several attempts to build steam cars with varying degrees of success with Thomas Rickett even attempting a production run in 1860.[6] Santler from Malvern is recognized by the Veteran Car Club of Great Britain as having made the first petrol-powered car in the country in 1894[7] followed by Frederick William Lanchester in 1895 but these were both one-offs.[7] The first production vehicles came from the Daimler Motor Company, founded by Harry J. Lawson in 1896, and making their first cars in 1897.[7]
In 1892, Rudolf Diesel got a patent for a "New Rational Combustion Engine". In 1897 he built the first Diesel Engine.[5] In 1895, Selden was granted a United States patent(U.S. Patent 549,160) for a two-stroke automobile engine, which hinderd more than encouraged development of autos in the United States. Steam, electric, and gasoline powered autos competed for decades, with gasoline internal combustion engines achieving dominance in the 1910s.
The large-scale, production-line manufacturing of affordable automobiles was debuted by Ransom Olds at his Oldsmobile factory in 1902. This assembly line concept was then greatly expanded by Henry Ford in the 1910s. Development of automotive technology was rapid, due in part to the hundreds of small manufacturers competing to gain the world's attention. Key developments included electric ignition and the electric self-starter (both by Charles Kettering, for the Cadillac Motor Company in 1910-1911), independent suspension, and four-wheel brakes.
Although various pistonless rotary engine designs have attempted to compete with the conventional piston and crankshaft design, only Mazda's version of the Wankel engine has had more than very limited success.
Since the 1920s, nearly all cars have been mass-produced to meet market needs, so marketing plans have often heavily influenced automobile design. It was Alfred P. Sloan who established the idea of different makes of cars produced by one company, so buyers could "move up" as their fortunes improved. The makes shared parts with one another so larger production volume resulted in lower costs for each price range. For example, in the 1950s, Chevrolet shared hood, doors, roof, and windows with Pontiac; the LaSalle of the 1930s, sold by Cadillac, used cheaper mechanical parts made by the Oldsmobile division.
Design
The design of modern cars is typically handled by a large team of designers and engineers from many different disciplines. As part of the product development effort the team of designers will work closely with teams of design engineers responsible for all aspects of the vehicle. These engineering teams include: chassis, body and trim, powertrain, electrical and production. The design team under the leadership of the design director will typically comprise of an exterior designer, an interior designer (usually referred to as stylists), and a color and materials designer. A few other designers will be involved in detail design of both exterior and interior. For example, a designer might be tasked with designing the rear light clusters or the steering wheel. The color and materials designer will work closely with the exterior and interior designers in developing exterior color paints, interior colors, fabrics, leathers, carpet, wood trim, and so on.
In 1924 the American national automobile market began reaching saturation. To maintain unit sales, General Motors instituted annual model-year design changes (also credited to Alfred Sloan) in order to convince car owners they needed a replacement each year. Since 1935 automotive form has been driven more by consumer expectations than engineering improvement.
There have been many efforts to innovate automobile design funded by the NHTSA, including the work of the NavLab group at Carnegie Mellon University.[8] Recent efforts include the highly publicized DARPA Grand Challenge race.[9]
Acceleration, braking, and measures of turning or agility vary widely between different makes and models of automobile. The automotive publication industry has developed around these performance measures as a way to quantify and qualify the characteristics of a particular vehicle. See quarter mile and 0 to 60 mph.
Fuel and propulsion technologies
- See also: Alternative fuel vehicle
Most automobiles in use today are propelled by gasoline (also known as petrol) or diesel internal combustion engines, which are known to cause air pollution and are also blamed for contributing to climate change and global warming.[10] Increasing costs of oil-based fuels and tightening environmental laws and restrictions on greenhouse gas emissions are propelling work on alternative power systems for automobiles. Efforts to improve or replace these technologies include hybrid vehicles, electric vehicles and hydrogen vehicles.
Diesel
Diesel engined cars have long been popular in Europe with the first models being introduced in the 1930s by Mercedes Benz and Citroen. The main benefit of Diesels are a 50% fuel burn efficiency compared with 27%[11] in the best gasoline engines. A down side of the diesel is the presence in the exhaust gases of fine soot particulates and manufacturers are now starting to fit filters to remove these. Many diesel powered cars can also run with little or no modifications on 100% biodiesel.
Gasoline
Gasoline engines have the advantage over diesel in being lighter and able to work at higher rotational speeds and they are the usual choice for fitting in high performance sports cars. Continuous development of gasoline engines for over a hundred years has produced improvements in efficiency and reduced pollution. The carburetor was used on nearly all road car engines until the 1980s but it was long realised better control of the fuel/air mixture could be achieved with fuel injection. Indirect fuel injection was first used in aircraft engines from 1909, in racing car engines from the 1930s, and road cars from the late 1950s.[11] Gasoline Direct Injection (GDI) is now starting to appear in production vehicles such as the 2007 BMW MINI. Exhaust gases are also cleaned up by fitting a catalytic converter into the exhaust system. Clean air legislation in many of the car industries most important markets has made both catalysts and fuel injection virtually universal fittings. Most modern gasoline engines are also capable of running with up to 15% ethanol mixed into the gasoline - older vehicles may have seals and hoses that can be harmed by ethanol. With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85%. 100% ethanol is used in some parts of the world (such as Brazil), but vehicles must be started on pure gasoline and switched over to ethanol once the engine is running. Most gasoline engined cars can also run on LPG with the addition of an LPG tank for fuel storage and carburetion modifications to add an LPG mixer. LPG produces fewer toxic emissions and is a popular fuel for fork lift trucks that have to operate inside buildings.
Electric
The first electric cars were built in the late 1800s, but the building of battery powered vehicles that could rival internal combustion models had to wait for the introduction of modern semiconductor controls. Because they can deliver a high torque at low revolutions electric cars do not require such a complex drive train and transmission as internal combustion powered cars. Some are able to accelerate from 0-60 mph (96 km/hour) in 4.0 seconds with a top speed around 130 mph (210 km/h). They have a range of 250 miles (400 km) on the EPA highway cycle requiring 3-1/2 hours to completely charge. Equivalent fuel efficiency to internal combustion is not well defined but some press reports give it at around 135 mpg.
Steam
Steam power, usually using an oil or gas heated boiler, was also in use until the 1930s but had the major disadvantage of being unable to power the car until boiler pressure was available. It has the advantage of being able to produce very low emissions as the combustion process can be carefully controlled. Its disadvantages include poor heat efficiency and extensive requirements for electric auxiliaries.[12]
Gas turbine
In the 1950s there was a brief interest in using gas turbine (jet) engines and several makers including Rover produced prototypes. In spite of the power units being very compact, high fuel consumption, severe delay in throttle response, and lack of engine braking meant no cars reached production.
Rotary (Wankel) engines
Rotary Wankel engines were introduced into road cars by NSU with the Ro 80 and later were seen in several Mazda models. In spite of their impressive smoothness, poor reliability and fuel economy led to them largely disappearing. Mazda, however, has continued research on these engines and overcame most of the earlier problems.
Future developments
Much current research and development is centered on hybrid vehicles that use both electric power and internal combustion. Research into alternative forms of power also focus on developing fuel cells, Homogeneous Charge Compression Ignition (HCCI), stirling engines[13] and even using the stored energy of compressed air or liquid nitrogen.
Safety
Road traffic injuries represent about 25% of worldwide injury-related deaths (the leading cause) with an estimated 1.2 million deaths (2004) each year.[14]
Automobile accidents are almost as old as automobiles themselves. Early examples include Mary Ward, who became one of the first document automobile fatalities in 1869 in Parsonstown, Ireland,[15] and Henry Bliss, one of the United State's first pedestrian automobile casualties in 1899 in New York.[16]
Cars have many basic safety problems - for example, they have human drivers who make mistakes, wheels that lose traction when the braking or turning forces are too high. Some vehicles have a high center of gravity and therefore an increased tendency to roll over. When driven at high speeds, collisions can have serious or even fatal consequence.
Early safety research focused on increasing the reliability of brakes and reducing the flammability of fuel systems. For example, modern engine compartments are open at the bottom so that fuel vapors, which are heavier than air, vent to the open air. Brakes are hydraulic and dual circuit so that failures are slow leaks, rather than abrupt cable breaks. Systematic research on crash safety started[citation needed] in 1958 at Ford Motor Company. Since then, most research has focused on absorbing external crash energy with crushable panels and reducing the motion of human bodies in the passenger compartment. This is reflected in most cars produced today.
Significant reductions in death and injury have come from the addition of Safety belts and laws in many countries to require vehicle occupants to wear them. Airbags and specialised child restraint systems have improved on that. Structural changes such as side-impact protection bars in the doors and side panels of the car mitigate the effect of impacts to the side of the vehicle. Many cars now include radar or sonar detectors mounted to the rear of the car to warn the driver if he or she is about to reverse into an obstacle or a pedestrian. Some vehicle manufacturers are producing cars with devices that also measure the proximity to obstacles and other vehicles in front of the car and are using these to apply the brakes when a collision is inevitable. There have also been limited efforts to use heads up displays and thermal imaging technologies similar to those used in military aircraft to provide the driver with a better view of the road at night.
There are standard tests for safety in new automobiles, like the EuroNCAP and the US NCAP tests.[17] There are also tests run by organizations such as IIHS and backed by the insurance industry.[18]
Despite technological advances, there is still significant loss of life from car accidents: About 40,000 people die every year in the United States, with similar figures in European nations. This figure increases annually in step with rising population and increasing travel if no measures are taken, but the rate per capita and per mile traveled decreases steadily. The death toll is expected to nearly double worldwide by 2020. A much higher number of accidents result in injury or permanent disability. The highest accident figures are reported in China and India. The European Union has a rigid program to cut the death toll in half by 2010, and member states have started implementing measures.
Automated control has been seriously proposed and successfully prototyped. Shoulder-belted passengers could tolerate a 32 g emergency stop (reducing the safe inter-vehicle gap 64-fold) if high-speed roads incorporated a steel rail for emergency braking. Both safety modifications of the roadway are thought to be too expensive by most funding authorities, although these modifications could dramatically increase the number of vehicles able to safely use a high-speed highway. This makes clear the often-ignored fact road design and traffic control also play a part in car wrecks; unclear traffic signs, inadequate signal light placing, and poor planning (curved bridge approaches which become icy in winter, for example), also contribute.
Economics and Impacts
Cost and benefits of ownership
The costs of automobile ownership, which may include the cost of: acquiring the vehicle, repairs, maintenance, fuel, depreciation, parking fees, tire replacement, taxes and insurance,[19] are weighed against the cost of the alternatives, and the value of the benefits - perceived and real - of vehicle ownership. The benefits may include personal freedom, mobility, independence and convenience.[20]
Cost and benefits to society
Similarly the costs to society of encompassing automobile use, which may include those of: maintaining roads, pollution, public health, health care, and of disposing of the vehicle at the end of its life, can be balanced against the value of the benefits to society that automobile use generates. The societal benefits may include: economy benefits, such as job and wealth creation, of automobile production and maintenance, transportation provision, society wellbeing derived from leisure and travel opportunities, and revenue generation from the tax opportunities. The ability for humans to move rapidly from place to place has far reaching implications for the nature of our society. People can now live far from their workplaces, the design of our cities is determined as much by the need to get vehicles into and out of the city as the nature of the buildings and public spaces within the city.[21]
Impacts on society
Transportation is a major contributor to air pollution in the United States, according to the Surface Transportation Policy Project, and nearly half of all Americans are breathing unhealthy air. Their study showed air quality in dozens of metropolitan areas has got worse over the last decade.[22] In the United States the average passenger car emits 11,450 lbs (5 tonnes) of carbon dioxide, along with smaller amounts of carbon monoxide, hydrocarbons, and nitrogen.[23] Residents of low-density, residential-only sprawling communities are also more likely to die in car collisions, which kill 1.2 million people worldwide each year, and injure about forty times this number.[24] Sprawl is more broadly a factor in inactivity and obesity, which in turn can lead to increased risk of a variety of diseases.[25]
Improving the positive and reducing the negative impacts
Fuel taxes may act as an incentive for the production of more efficient, hence less polluting, car designs (e.g. hybrid vehicles) and the development of alternative fuels. High fuel taxes may provide a strong incentive for consumers to purchase lighter, smaller, more fuel-efficient cars, or to not drive. On average, today's automobiles are about 75 percent recyclable, and using recycled steel helps reduce energy use and pollution.[26] In the United States Congress, federally mandated fuel efficiency standards have been debated regularly, passenger car standards have not risen above the 27.5 miles per gallon standard set in 1985. Light truck standards have changed more frequently, and were set at 22.2 miles per gallon in 2007.[27] Alternative fuel vehicles are another option that is less polluting than conventional petroleum powered vehicles.
Future car technologies
Automobile propulsion technologies under development include hybrid cars, battery electric vehicles, hydrogen cars, and various alternative fuels. New materials which may replace steel car bodies include duraluminum, fiberglass, carbon fiber, and carbon nanotubes.
Alternatives to the automobile
Established alternatives for some aspects of automobile use include public transit (buses, trolleybuses, trains, subways, monorails, tramways), cycling, walking, rollerblading and skateboarding. Car-share arrangements are also increasingly popular – the U.S. market leader has experienced double-digit growth in revenue and membership growth between 2006 and 2007, offering a service that enables urban residents to "share" a vehicle rather than own a car in already congested neighborhoods.[28] Bike-share systems have been tried in some European cities, including Copenhagen and Amsterdam. Similar programs have been experimented with in a number of U.S. Cities.[29] Additional individual modes of transport, such as personal rapid transit could serve as an alternative to automobiles if they prove to be socially accepted.[30]
Further reading
References
- ^ (1976) Pocket Oxford Dictionary. London: Oxford University Press. ISBN 0-19-861113-7.
- ^ WorldMapper - passenger cars.
- ^ SA MOTORING HISTORY - TIMELINE. Government of South Australia.
- ^ Setright, L. J. K. (2004). Drive On!: A Social History of the Motor Car. Granta Books. ISBN 1-86207-698-7.
- ^ a b c Ralph Stein (1967). The Automobile Book. Paul Hamlyn Ltd.
- ^ Burgess Wise, D. (1970). Veteran and Vintage Cars. London: Hamlyn. ISBN 0-600-00283-7.
- ^ a b c Georgano, N. (2000). Beaulieu Encyclopedia of the Automobile. London: HMSO. ISBN 1-57958-293-1.
- ^ Past projects, NavLab.
- ^ DARPA Urban Challenge.
- ^ Global Climate Change. U.S. Department of Energy. Retrieved on 2007-03-03.
- ^ a b Norbye, Jan (1988). Automotive fuel injection Systems. Haynes Publishing. ISBN 0-85429-755-3.
- ^ Setright, L.J.K. "Steam: The Romantic Illusion", in Ward, Ian, ed., World of Automobiles (London: Orbis Publishing, 1974), pp.2168-2173.)
- ^ www.werbos.com/E/WhoKilledElecPJW.htm. Retrieved on 2007-04-10.
- ^ World report on road traffic injury prevention.
- ^ www.universityscience.ie/pages/scientists/sci_mary_ward.php. Retrieved on 2007-04-10.
- ^ CityStreets - Bliss plaque.
- ^ SaferCar.gov - NHTSA.
- ^ Insurance Institute for Highway Safety.
- ^ car operating costs. my car. RACV.
- ^ Setright, L. J. K. (2004). Drive On!: A Social History of the Motor Car. Granta Books. ISBN 1-86207-698-7.
- ^ John A. Jakle, Keith A. Sculle. (2004). Lots of Parking: Land Use in a Car Culture. ISBN 0813922666.
- ^ Clearing the Air. The Surface Transportation Policy Project (2003-08-19). Retrieved on [[2007-04-26]].
- ^ Emission Facts. United States Environmental Protection Agency.
- ^ World report on road traffic injury prevention. World Health Organization.
- ^ Our Ailing Communities. Metropolis Magazine.
- ^ Automobiles and the Environment. Greenercars.com.
- ^ CAFE Overview - Frequently Asked Questions. National Highway Traffic Safety Administration.
- ^ Flexcar Expands to Philadelphia. Green Car Congress (2007-04-02).
- ^ About Bike Share Programs. Tech Bikes MIT.
- ^ Jane Holtz Kay (1998). Asphalt Nation: how the automobile took over America, and how we can take it back. ISBN 0520216202.
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