What Is Autonomous Cruise Control System?
An Autonomous Cruise Control system, also called Adaptive Cruise Control (ACC) or Intelligent Cruise Control (ICC) is a speed control system founded on modern vehicles. This system uses radar or laser sensors to measure the distance and slows down or increases the vehicle speed to a preset speed in order to maintain a safe distance to the vehicle ahead.
Ford's Adaptive Cruise Control
In 1995, the world’s first autonomous cruise control system integrated on a production vehicle was introduced by Mitsubishi called "Preview Distance Control" and offered on the Mitsubishi Diamante. The system maintains the distance to other vehicle by means of throttle control and downshifting, but that early system was not able to completely stop the car in an emergency situation.
In 1998, Mercedes introduced its first ACC system called “Distronic” on the S-class models. In 2001, Lexus introduced the DLCC (Dynamic Laser Cruise Control), which was first offered on the LS 430 and the RX series. Other manufacturers also followed, including Volkswagen which developed a system called Autocruise.
In 2006, Mercedes-Benz has improved the "Distronic" system featuring the ability to completely stop the vehicle in an emergency situation. The system was renamed to “'Distronic Plus” and offered on the Mercedes E-Class and S-Class range of luxury sedans. Bosch did the same for its system which now called “ACC plus” and offered on the Audi Q7, the Audi Q5, 2009 Audi A6 and the new 2010 Audi A8.
Currently, there are two types of autonomous cruise control: laser-based and radar-based systems.
In laser-based ACC system, a small laser sensor works as a transmitter and since laser-based sensors must be exposed, it is usually mounted behind the front grille. The main advantage is it’s a low-cost system which seems affordable for middle class vehicles, but the main drawback is it works poorly in bad weather conditions or when the car is dirty, especially when the front grille covered in dust.
In contrast, radar-based sensor is much less affected by these problems and therefore it can be hidden behind plastic fascias.
To prevent the car slowdown from any stationary object (such as a lamppost or a vehicle parked on the side of the road), the ACC system does not detect stationary objects / vehicles to make traffic flow as good as possible.
In the first generation radar-based ACC system, the radar sensor had a range of about 150 m and the angle of the detection field was limited to 8°. With the second generation, these values were increased to 180 m and 16° respectively. In the third generation the radar range was extended to 200 m.
Since 2002, for German car manufactures, Audi and Volkswagen started to offer the ACC system for their upper class models such as the A8 and the Phaeton. Since then, several revised versions have been made to the ACC system:
- ACC first-generation (activated from 30 to 180 km/h): from 2002, offered on the A8 and Phaeton.
- Second generation (activated from 30 to 200 km/h) from 2004, offered on the Audi A6 and the Audi C6.
- Third generation (activated from 30 to 210 km/h) from 2005, offered on the VW Passat B6.
- Fourth generation (activated from 0 to 200 km/h): from 2006, offered on the Audi Q7 and VW Touareg, and since 2007 this system is offered on the VW Phaeton, the new Audi A4 B8 (for the Audi A4 B8, the system has a speed range of 30 to 200 km/h), the new VW Passat CC, the Bentley Continental GT, the Flying Spur and also as an optional feature on GTC. An ACC system was also announced for the Golf VI, but for unknown reasons, the project was discontinued.
- Fifth and latest generation (activated from 0 to 250 km/h): Starting in 2010 and offered on the Audi A8.
From the fourth generation, the speed range was modified to include the range from 0 to 30 km/h. This is especially useful in case of stop and go traffic situations such as slow-moving or traffic jams.
Audi and Volkswagen refer to the ACC system as Adaptive Cruise Control. BMW, however, calls it as Active Cruise Control. The first BMW’s ACC system was launched in 2000 on the BMW 7-series (E38) with 3 radar beams made by Bosch with the angle of the detection field was 8° and maximum distance of 150 m. The second BMW’s ACC system was introduced in 2004 and offered on the 6-series (E63/E64) featuring four enhanced radar beams also made by Bosch with angle of detection field of 16°. For the current BMW 3-series, the system is also offered on middle class models for the first time. In March 2007, in addition to ACC system, BMW also offeres Stop & Go function for its 5-series (E60/E61). In this version, the system can be automatically activated from 0 to 180km. In traffic jam situations, depends on the traffic flow, it can slow down or even completely stop the car. After 3 seconds or after confirmed by the driver, the vehicle can move again. Also on the 5-series, BMW for the first time offeres another safety feature called iBrake (intelligent brake).
For U.S manufactures, since 2005, Cadillac offers the ACC system on its STS model under the name of Adaptive Cruise Control, followed by Chrysler in 2007 with the 300C featuring an ACC system (only available for the SRT8 6.1 engine version). Ford also introduces the ACC on the S-MAX and Galaxy since June 2006, the Mondeo in 2007 and the Focus since April 2011.
For Japanese manufactures, since autumn 2006, the ACC was offered on the Honda Legend, Honda Accord, and since 2007, the new Honda CR-V.
Jaguar offers the ACC system on the XF, XJ and XK models. Land Rover offers ACC system for the Range Rover Sport.
In North America, a laser-based adaptive cruise control system was offered on Lexus LS since 2000. A radar-based ACC system for the LS in Europe was available since August 2004.
List of vehicles currently support full adaptive cruise control (can completely stop the car if necessary):
- BMW 7 Series, 5 series, 6 series Active Cruise Control with "Stop & Go" option, 2007+ models (radar)
- Mercedes-Benz Models equipped with "Distronic Plus" ACC with "Presafe Brake" option (radar)
- Volvo S60 equipped with "Technology Package" (Adaptive Cruise Control (ACC) with Queue Assist and Distance Alert), 2011+ models (radar)
- Audi A8 and Audi A6 equipped with "Adaptive Cruise Control with Stop and Go function", 2011+ models (radar)
- 2010 Porsche Panamera, 2011 Porsche Cayenne
List of vehicles currently support partial cruise control (cuts off below a set minimum speed, requiring driver intervention):
- 2005 Acura RL, MDX, ZDX
- Audi A4 (see a demonstration on YouTube), A5, Q5, A6, A8 (uses also data from navigation and front camera sensors),Q7
- BMW 7 Series, 5 series, 6 series, 3 series (only as an option together with big engines, Stop & Go Variant available on 5, 6 and 7 models) (Active Cruise Control)
- 2004 Cadillac XLR, 2005 STS, 2006 DTS (shuts off below 25 mph)
- 2007 Chrysler 300C (laser, for a limited time, now uses a Bosch radar-based system)
- 2011 Dodge Charger (radar, by Bosch)
- 2011 Dodge Durango (radar, by Bosch)
- 2006 Ford Mondeo, S-Max, Galaxy, 2010 Taurus, 2011 Edge (radar)
- 2003 Honda Inspire, Legend, 2007 Honda CR-V series III - Adaptive Cruise Control and Collision Mitigating Braking System
- Hyundai Genesis (Smart Cruise Control, delayed)
- Infiniti M, Q45, QX56, G35, FX35/45/50 and G37 (shuts off below 3 mph)
- 1999 Jaguar XK-R, S-Type, XJ, XF
- 2011 Jeep Grand Cherokee (radar, by Bosch)
- 2000 Lexus LS430/460 (laser and radar), RX (laser and radar), GS, IS, ES 350, and LX 570 (shuts off below 30 mph)
- 2009 Lincoln MKS, 2010 MKT, 2011 MKX
- 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, 2012 C-Class
- Range Rover Sport
- Subaru Legacy & Outback Japan-spec called SI-Cruise
- 1997 Toyota Celsior, 2009 Sienna (XLE Limited Edition), Avalon, Sequoia (Platinum Edition), Avensis, 2009 Corolla (Japan), 2010 Prius
- Volkswagen Passat, Phaeton all generations, Touareg
- Volvo S80, V70, XC70, XC60, V60
at 11/3/2012 3:35:31 PM