Acceptance of automatic braking and crash-avoidance technology should become more prevalent in the coming years, thanks to the development of Delphi's Forewarn Active Cruise Control (ACC) system.
According to Dr Richard Lind, director of advanced engineering at Delphi Electronics & Safety, says "the new technology increases the precision of ACC at highway speeds and provides an innovative new Stop and Go function that extends the convenience of ACC to congested roads. The new system, which also includes a forward collision warning function, will be introduced during 2006 on two premium-sector European vehicles."
Delphi's new system uses forward-looking radar to help the driver maintain a driver selected time gap behind the vehicle ahead. At highway speeds, if the lane ahead is clear, the system will maintain the cruising speed set by the driver. When slower traffic is detected in front of the vehicle, the system will automatically maintain the driver-selected headway (adjustable between 1.0 and 2.2 seconds) using throttle control and limited braking.
Though the system will bring the vehicle to a stop in normal traffic situations, it may not be able to if "the gap is closing sufficiently quickly," in which case it will provide "audible and visual warnings" to alert the driver that manual intervention is required. Whether it's stopped by the ACC system or the driver, the vehicle won't move forward again until the driver presses the gas pedal.
Lind says the fourth generation Forewarn system is "thought to be the first production ACC to successfully overcome the many challenges of extending this functionality to city speeds."
This is apparently extremely hard for a computer, says Michele Daniels, a senior algorithm design engineer at Delphi's engineering laboratory in Malibu, California. "At city speeds," she explains, "it becomes difficult to discern driver intent. Road clutter, such as manhole covers and traffic calming devices (bollards, road humps, etc), also become much more difficult to differentiate from potentially hazardous objects. Our solution is based on a new type of object discrimination system that uses statistical modelling to test objects against a range of pre-defined criteria."
Daniels says particular attention was paid to delivering accurate information about the edges of objects. "If we know how wide the object is, for example, we have a good idea if it is a pole or a car. This tells the system which other tests to apply to confirm this assumption and to add more context."
To provide the data required for accurate scene analysis at all speeds, Delphi has specified a 76GHz narrow-beam radar system that provides improved angular accuracy and target discrimination compared with rival multi-beam fixed-sensor systems.
"The wide-angle of view (up to 15 degrees) provides early warning of vehicles entering the lane ahead and superior tracking in tight curves," Daniels explains. "It also allows an automatic alignment feature to compensate for installation tolerances and for changes in sensor alignment during the vehicle's life, reducing fitting costs for the vehicle manufacturer and increasing system reliability."
The radar system is integrated with a yaw sensor in an easily packaged housing that can be mounted in the nose of the vehicle or in the grille behind a polymer body panel.
"A separate Electronic Control Unit processes the radar data to calculate the range (distance), rate (closing speed) and azimuth (lateral deviation) of targets up to 150 meters ahead," says Daniels, "and delivers appropriate control signals to the engine and brake control systems via the vehicle's CAN bus."
However it works, Delphi's system will add a new level of safety to the vehicles it's on, and that's extremely welcome.
According to Dr Richard Lind, director of advanced engineering at Delphi Electronics & Safety, says "the new technology increases the precision of ACC at highway speeds and provides an innovative new Stop and Go function that extends the convenience of ACC to congested roads. The new system, which also includes a forward collision warning function, will be introduced during 2006 on two premium-sector European vehicles."
Delphi's new system uses forward-looking radar to help the driver maintain a driver selected time gap behind the vehicle ahead. At highway speeds, if the lane ahead is clear, the system will maintain the cruising speed set by the driver. When slower traffic is detected in front of the vehicle, the system will automatically maintain the driver-selected headway (adjustable between 1.0 and 2.2 seconds) using throttle control and limited braking.
Though the system will bring the vehicle to a stop in normal traffic situations, it may not be able to if "the gap is closing sufficiently quickly," in which case it will provide "audible and visual warnings" to alert the driver that manual intervention is required. Whether it's stopped by the ACC system or the driver, the vehicle won't move forward again until the driver presses the gas pedal.
Lind says the fourth generation Forewarn system is "thought to be the first production ACC to successfully overcome the many challenges of extending this functionality to city speeds."
This is apparently extremely hard for a computer, says Michele Daniels, a senior algorithm design engineer at Delphi's engineering laboratory in Malibu, California. "At city speeds," she explains, "it becomes difficult to discern driver intent. Road clutter, such as manhole covers and traffic calming devices (bollards, road humps, etc), also become much more difficult to differentiate from potentially hazardous objects. Our solution is based on a new type of object discrimination system that uses statistical modelling to test objects against a range of pre-defined criteria."
Daniels says particular attention was paid to delivering accurate information about the edges of objects. "If we know how wide the object is, for example, we have a good idea if it is a pole or a car. This tells the system which other tests to apply to confirm this assumption and to add more context."
To provide the data required for accurate scene analysis at all speeds, Delphi has specified a 76GHz narrow-beam radar system that provides improved angular accuracy and target discrimination compared with rival multi-beam fixed-sensor systems.
"The wide-angle of view (up to 15 degrees) provides early warning of vehicles entering the lane ahead and superior tracking in tight curves," Daniels explains. "It also allows an automatic alignment feature to compensate for installation tolerances and for changes in sensor alignment during the vehicle's life, reducing fitting costs for the vehicle manufacturer and increasing system reliability."
The radar system is integrated with a yaw sensor in an easily packaged housing that can be mounted in the nose of the vehicle or in the grille behind a polymer body panel.
"A separate Electronic Control Unit processes the radar data to calculate the range (distance), rate (closing speed) and azimuth (lateral deviation) of targets up to 150 meters ahead," says Daniels, "and delivers appropriate control signals to the engine and brake control systems via the vehicle's CAN bus."
However it works, Delphi's system will add a new level of safety to the vehicles it's on, and that's extremely welcome.