Sunday, August 22, 2010

ADAPTIVE CRUISE CONTROL.......

Autonomous cruise control is an optional cruise control system appearing on some more upscale vehicles. The system goes under many different trade names according to the manufacturer. These systems use either a radar or laser setup allowing the vehicle to slow when approaching another vehicle and accelerate again to the preset speed when traffic allows. ACC technology is widely regarded as a key component of any future generations of intelligent cars.

TYPES OF CRUISE :

                            Laser-based systems are significantly lower in cost than radar-based systems; however, laser-based ACC systems do not detect and track vehicles well in adverse weather conditions nor do they track extremely dirty (non-reflective) vehicles very well. Laser-based sensors must be exposed, the sensor (a fairly-large black box) is typically found in the lower grille offset to one side of the vehicle.




 CRUISE CONTROL STEERING DIAGRAM:
 



AVAILABILITY

Mitsubishi was the first automaker to offer a laser-based ACC system in 1995 on the Japanese Diamante. Marketed as "Preview Distance Control", this early system did not apply the brakes and only controlled speed through throttle control and downshifting Mercedes introduced Distronic in late 1998 on the S-class.[9] For 2006, Mercedes-Benz refined the Distronic system to completely halt the car if necessary (now called 'Distronic Plus' and offered on their E-Class and S-Class range of luxury sedans), a feature now also offered by Bosch as 'ACC plus' and available in the Audi Q7, the Audi Q5, 2009 Audi A6 and the new 2010 Audi A8. The Audi A4 is available with an older version of the ACC that does not stop the car completely. In an episode of Top Gear, Jeremy Clarkson demonstrated the effectiveness of the cruise control system in the S-class by coming to a complete halt from motorway speeds to a round-about and getting out, all without touching the pedals.

Jaguar began offering a system in 1999; BMW's Active Cruise Control system went on sale in 2000[citation needed] on the 7-series and later in 2007, added a system called Stop-and-Go system to the 5-series.[10] Volkswagen and Audi introduced their own systems in 2002[citation needed] through the radar manufacturer Autocruise.

In the United States, Acura first introduced Adaptive Cruise Control (ACC) integrated with a Collision Mitigation Braking System (CMBS) in the late calendar year 2005 in the model year 2006 Acura RL as an optional feature.[11] ACC and CMBS also became available as optional features in the model year the 2010 Acura MDX[12] Mid Model Change (MMC) and the newly introduced model year 2010 Acura ZDX.

                    NOW CAN VISIT THE CAR FOR CRUISE CONTROL:
 2005 Acura RL, MDX, ZDX




Audi A4 (see a demonstration on YouTube), A5, Q5, A6, A8 (with GPS and front camera input)[14], Q7


BMW 7 Series, 5 series, 6 series, 3 series (Active Cruise Control)


2004 Cadillac XLR, 2005 STS, 2006 DTS


2007 Chrysler 300C


2006 Ford Mondeo, S-Max, Galaxy, 2010 Taurus [15]


2003 Honda Inspire, Legend


Hyundai Genesis (Smart Cruise Control, delayed)


Infiniti M, Q45, QX56, G35, FX35/45/50 and G37


1999 Jaguar XK-R, S-Type, XJ, XF


2000 Lexus LS430/460 (laser and radar), RX (laser and radar), GS, IS, ES 350, and LX 570


Lincoln MKS, MKT


1998 Nissan Cima, Nissan Primera T-Spec Models (Intelligent Cruise Control)


1998 Mercedes-Benz S-Class, E-Class, CLS-Class, SL-Class, CL-Class, M-Class, GL-Class, CLK-Class


2010 Porsche Panamera, 2011 Porsche Cayenne


Range Rover Sport


Renault Vel Satis


Subaru Legacy & Outback Japan-spec called SI-Cruise


1997 Toyota Celsior, Sienna (XLE Limited Edition), Avalon, Sequoia (Platinum Edition), Avensis, 2009 Corolla (Japan) [16], 2010 Prius


Volkswagen Passat, 2003 Phaeton, Touareg, 2009 Golf


Volvo S80, V70, XC70, XC60, S60


In August 1997, Toyota began to offer a "radar cruise control" system on the Celsior.[4][5] Toyota further refined their system by adding "brake control" in 2000 and "low-speed tracking mode" in 2004. The low-speed speed tracking mode was a second mode that would warn the driver if the car ahead stopped and provide braking; it could stop the car but then deactivated.[6] In 2006, Toyota introduced its "all-speed tracking function" for the Lexus LS 460. This system maintains continuous control from speeds of 0 km/h to 100 km/h and is designed to work under repeated starting and stopping situations such as highway traffic congestion.[7] The Lexus division was the first to bring adaptive cruise control to the US market in 2000 with the LS 430's Dynamic Laser Cruise Control system.




Radar-based sensors can be hidden behind plastic fascias; however, the fascias may look different from a vehicle without the feature. For example, Mercedes packages the radar behind the upper grille in the center; however, the Mercedes grille on such applications contains a solid plastic panel in front of the radar with painted slats to simulate the slats on the rest of the grille.

WORKING: 
             
                 In car steering it consist of four buttons.......................
                    "ON" Button- it is used to ON the cruise control of the car
                    "OFF" Button-it is used to OFF the cruise control of the car
                    "UP arrow"button-it is used to increase the speed of the vehicle when it is engaged
                    "DOWN arrow" button-it is used to decrease the speed of the vehicle when it engaged

            
DETAILED FLOW DIAGRAM:

Tuesday, August 17, 2010

TWO STROKE COFIGURATION................

FOUR STROKE CONFIGURATION............................................

Operation:


Four-stroke cycle (or Otto cycle)
1. Intake

2. Compression

3. Power

4. ExhaustAs their name implies, operation of four stroke internal combustion engines have four basic steps that repeat with every two revolutions of the engine:



Intake

Combustible mixtures are emplaced in the combustion chamber

Compression

The mixtures are placed under pressure

Power

The mixture is burnt, almost invariably a deflagration, although a few systems involve detonation. The hot mixture is expanded, pressing on and moving parts of the engine and performing useful work.

Exhaust

The cooled combustion products are exhausted into the atmosphere

Many engines overlap these steps in time; jet engines do all steps simultaneously at different parts of the engines.


Combustion:

All internal combustion engines depend on the exothermic chemical process of combustion: the reaction of a fuel, typically with oxygen from the air (though it is possible to inject nitrous oxide in order to do more of the same thing and gain a power boost). The combustion process typically results in the production of a great quantity of heat, as well as the production of steam and carbon dioxide and other chemicals at very high temperature; the temperature reached is determined by the chemical make up of the fuel and oxidisers (see stoichiometry).



The most common modern fuels are made up of hydrocarbons and are derived mostly from fossil fuels (petroleum). Fossil fuels include diesel fuel, gasoline and petroleum gas, and the rarer use of propane. Except for the fuel delivery components, most internal combustion engines that are designed for gasoline use can run on natural gas or liquefied petroleum gases without major modifications. Large diesels can run with air mixed with gases and a pilot diesel fuel ignition injection. Liquid and gaseous biofuels, such as ethanol and biodiesel (a form of diesel fuel that is produced from crops that yield triglycerides such as soybean oil), can also be used. Some engines with appropriate modifications can also run on hydrogen gas.



Internal combustion engines require ignition of the mixture, either by spark ignition (SI) or compression ignition (CI). Before the invention of reliable electrical methods, hot tube and flame methods were used.



Gasoline Ignition Process:

Gasoline engine ignition systems generally rely on a combination of a lead-acid battery and an induction coil to provide a high-voltage electrical spark to ignite the air-fuel mix in the engine's cylinders. This battery is recharged during operation using an electricity-generating device such as an alternator or generator driven by the engine. Gasoline engines take in a mixture of air and gasoline and compress it to not more than 12.8 bar (1.28 MPa), then use a spark plug to ignite the mixture when it is compressed by the piston head in each cylinder.



Diesel Ignition Process :

Diesel engines and HCCI (Homogeneous charge compression ignition) engines, rely solely on heat and pressure created by the engine in its compression process for ignition. The compression level that occurs is usually twice or more than a gasoline engine. Diesel engines will take in air only, and shortly before peak compression, a small quantity of diesel fuel is sprayed into the cylinder via a fuel injector that allows the fuel to instantly ignite. HCCI type engines will take in both air and fuel but continue to rely on an unaided auto-combustion process, due to higher pressures and heat. This is also why diesel and HCCI engines are more susceptible to cold-starting issues, although they will run just as well in cold weather once started. Light duty diesel engines with indirect injection in automobiles and light trucks employ glowplugs that pre-heat the combustion chamber just before starting to reduce no-start conditions in cold weather. Most diesels also have a battery and charging system; nevertheless, this system is secondary and is added by manufacturers as a luxury for the ease of starting, turning fuel on and off (which can also be done via a switch or mechanical apparatus), and for running auxiliary electrical components and accessories. Most new engines rely on electrical and electronic control system that also control the combustion process to increase efficiency and reduce emissions.

INTERNAL COMBUSTION ENGINE...........

The internal combustion engine is an engine in which the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber. In an internal combustion engine the expansion of the high temperature and pressure gases, which are produced by the combustion, directly applies force to component of the engine, such as the pistons or turbine blades or a nozzle, and by moving it over a distance, generates useful mechanical energy.

The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the Wankel rotary engine. A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.
The internal combustion engine (or ICE) is quite different from external combustion engines, such as steam or Stirling engines, in which the energy is delivered to a working fluid not consisting of, mixed with, or contaminated by combustion products. Working fluids can be air, hot water, pressurized water or even liquid sodium, heated in some kind of boiler.

A large number of different designs for ICEs have been developed and built, with a variety of different strengths and weaknesses. Powered by an energy-dense fuel (which is very frequently petrol, a liquid derived from fossil fuels), the ICE delivers an excellent power-to-weight ratio with few disadvantages. While there have been and still are many stationary applications, the real strength of internal combustion engines is in mobile applications and they dominate as a power supply for cars, aircraft, and boats, from the smallest to the largest. Only for hand-held power tools do they share part of the market with battery powered devices.

INTERNAL COMBUSTION ENGINE

The internal combustion engine is an engine in which the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber. In an internal combustion engine the expansion of the high temperature and pressure gases, which are produced by the combustion, directly applies force to component of the engine, such as the pistons or turbine blades or a nozzle, and by moving it over a distance, generates useful mechanical energy.



The term internal combustion engine usually refers to an engine in which combustion is intermittent, such as the more familiar four-stroke and two-stroke piston engines, along with variants, such as the Wankel rotary engine. A second class of internal combustion engines use continuous combustion: gas turbines, jet engines and most rocket engines, each of which are internal combustion engines on the same principle as previously described.


The internal combustion engine (or ICE) is quite different from external combustion engines, such as steam or Stirling engines, in which the energy is delivered to a working fluid not consisting of, mixed with, or contaminated by combustion products. Working fluids can be air, hot water, pressurized water or even liquid sodium, heated in some kind of boiler.



A large number of different designs for ICEs have been developed and built, with a variety of different strengths and weaknesses. Powered by an energy-dense fuel (which is very frequently petrol, a liquid derived from fossil fuels), the ICE delivers an excellent power-to-weight ratio with few disadvantages. While there have been and still are many stationary applications, the real strength of internal combustion engines is in mobile applications and they dominate as a power supply for cars, aircraft, and boats, from the smallest to the largest. Only for hand-held power tools do they share part of the market with battery powered devices.