Autonomous cruise control system

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Schematic of Intelligent Cruise Control. The red car automatically follows the blue car.

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 smart cars.

[edit] Types

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.

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.

Radar-based systems are available on many luxury cars as an option for approx. 1000-3000 USD/euro. Laser-based systems are available on some near luxury and luxury cars as an option for approx. 400-600 USD/euro.

[edit] Cooperating systems

Radar-based ACC often feature a Precrash system, which warns the driver and/or provides brake support if there is a high risk of a collision. Also in certain cars it is incorporated with a lane maintaining system which provides power steering assist to reduce steering input burden in corners when the cruise control system is activated.

[edit] Available systems

Several Japanese manufacturers first offered ACC systems in the Japanese market in the mid-1990s. These early systems did not apply the brakes and only controlled speed through throttle control and downshifting.

In August 1997, Toyota began to offer a "radar cruise control" system on the Celsior.^[1][2] 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 deactived.^[3] 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.^[4] 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.^[5]

Mercedes introduced Distronic in late 1998 on the S-class.^[6] 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, and the new 2010 Audi A8. The Audi A4 and Audi A6 are 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^[7]. 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^[8]. ACC and CMBS also became available as optional features in the model year the 2010 Acura MDX^[9] Mid Model Change (MMC) and the newly introduced model year 2010 Acura ZDX^[10].

[edit] Examples of vehicles with adaptive cruise control

• 2005 Acura RL/Honda Legend, Acura ZDX
• Audi A4 (see a demonstration on YouTube), A5, A6, A8, Q7
• BMW 7 Series, 5 series, 6 series, 3 series (Active Cruise Control)
• 2004 Cadillac DTS, STS, XLR
• 2007 Chrysler 300C
• 2006 Ford Mondeo, Taurus, S-Max, Galaxy
• 2003 Honda Inspire Accord, 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 (Distronic, removed in 2009 from certain US models)
• 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), Prius, Avensis
• Volkswagen Passat, Phaeton, Touareg, 2009 Golf
• Volvo S80, V70, XC70, XC60

[edit] References

[edit] See also

• Intelligent car
• Lane departure warning system
• Precrash system