The Future is Safer
DaimlerChrysler previews enhanced safety technologies.
Deborah Whistler
Editor
What driver wouldn't want an early warning of a sharp bend ahead, an intelligent steering system, a 360-degree field of vision and assistance systems that make parking or maneuvering easier and safer?
Safety technologies that accomplish this will become a reality within a matter of years. If fact, they're already being tested and were recently demonstrated to journalists at DaimlerChrysler's state-of-the-art Papenburg, Germany, test facility.
Here are some of the safety technologies we saw:
Emergency Braking
The emergency braking system uses three radar beams to detect moving obstacles in the lane ahead of the truck and continuously calculates the difference in speed between the two vehicles. If the traffic situation does not change and an accident appears possible, the driver first receives a visual warning – a red triangle symbol lights up – followed by an audible warning. If the risk of a collision increases, partial braking (30 percent of braking power) is initiated to give the driver a further warning. If the driver does not react, the system automatically applies full braking power. This form of emergency braking system will be introduced as an option for the Mercedes-Benz Actros heavy-duty trucks in 2006.
An enhanced version of the emergency braking system featuring auxiliary functions is already undergoing testing. A microphone in the wheel area records the tire noise and passes this information on to a computer that, in turn, determines the level of road grip. The fact that tire noise, road speed and the measured distance to vehicles in front are taken into account enables the emergency braking system to respond more precisely to the situation at hand.
The enhanced system can distinguish between five levels of road grip, from dry surfaces to wet surfaces and from snow to black ice. In addition, the enhanced system works as the vehicle approaches stationary obstacles. Thanks to a wide road scanning angle of 15 degrees, this version also can be effective on bends in the road, as long as there is a clear view ahead.
Lane Assistant
Already successfully introduced as an option, the Lane Assistant is based on a camera system that detects the limit lines on the road and warns drivers if they are coming close to leaving their lane. In an enhanced version, the steering system intervenes, making it an active system rather than a passive one. This technology is called Road Departure Avoidance.
If the truck starts to approach the side lane markings, the driver will feel an aligning torque tugging on the steering wheel, allowing him to intuitively steer back into the lane before the system's warning signal sounds. The torque felt on the steering wheel increases gradually as the truck gets closer to the edge of the lane.
After emitting a warning signal, this active safety system guides the truck back into its lane by applying precise braking pressure at one of the truck wheels.The driver remains in ultimate control of the situation, since the system is deactivated automatically whenever the driver applies the brakes or turns the steering wheel.
Predictive Curve Assistant
Predictive Curve Assistant can help when a driver underestimates the radius of turn at an offramp, cannot see all of the bend in the highway with the naked eye or misjudges the dynamics of a laden trailer.
Using navigation system data, the Predictive Curve Assistant computer constructs a model of the road ahead of the truck. The computer can then define an uncritical maximum speed for the vehicle and continuously compare it with the actual road speed, the shape of the bend and the truck's side tilt. If the actual speed of the vehicle starts to approach the critical level before a bend, the driver receives two warnings well in advance of the danger zone.
Truck Parking System
Precise maneuvering of a heavy truck when space is tight is an art in itself, requiring a great deal of feel and experience on the part of the driver. And repairing minor fender damage is one of the largest costs for truck fleets.
A Truck Parking System with ultrasonic sensors at the front and rear makes maneuvering easier and helps prevent costly minor damage. Yellow warning lights progressively warn the driver of the distance to obstacles immediately in front of or behind the truck. If the obstacles get too close, red warning lights come on and a warning signal sounds to alert the driver of an imminent crunch. It is also possible to mount ultrasonic sensors at the rear of a semitrailer to ensure smoother docking.
Reversing Assistant
Precise reversing of truck and trailer combinations involves a high risk of jack-knifing and accidents, especially if the driver is inexperienced.
Designed to help drivers of tractor-trailer combinations, the Reversing Assistant consists of a camera at the rear of the trailer, which sends an image to a monitor in the driver's cab. With the Reversing Assistant activated, the driver can guide the vehicle using a sidestick mounted on the armrest of the driver's seat rather than by turning the steering wheel. An electric motor is used to send the commands to the steering system.
Sensors detect the steering angle while an electronic brain converts the steering commands into the predicted vehicle movement, which is highlighted on the monitor. Typical tasks, such as maneuvering on ramps, reversing around corners and aligning the vehicle precisely when swapping bodies, are made much easier. In addition to helping prevent accidents when maneuvering, the Reversing Assistant also saves drivers of tractor-trailer combinations valuable time.
Night View Assist
Night View Assist enhances driver range of vision considerably to reduce the risk of accidents when it's dark. The system is based on infrared light, which is invisible to the human eye so doesn't blind oncoming drivers.
In addition to the existing headlamps, two infrared headlamps illuminate the road ahead and extend the truck driver's range of vision – even in the rain or fog and when oncoming vehicles have their headlamps on. Night View Assist allows the driver to see pedestrians, cyclists, parking cars, other obstacles and practically everything that is happening on the road much earlier. An infrared camera on the inside of the windshield records the reflected image of the road and projects it onto a black-and-white display on the dashboard.
Remote Hitching
With the exception of the statutory safety checks, the driver can leave hitching and unhitching of the semitrailer to the automatic fifth-wheel coupling system. When the semitrailer is being hitched up, the fifth-wheel coupling is locked automatically and secured in the same movement.
A green indicator light in the cab informs the driver that the semitrailer has been hitched up successfully, while a red signal light comes on in the event of any errors.
A single push of a button is all that is required to unlock and release the fifth-wheel coupling. The automatically extending and retracting semitrailer supports are also linked to the clutch. For safety reasons, they can only be lowered when the parking brake is applied. An additional mechanical lock prevents the semitrailer supports from being extended or retracted unintentionally.
If an automatic fifth-wheel coupling is specified, the semitrailer supply lines are guided by the kingpin and the fifth-wheel coupling. They are connected by means of a plug system, which is opened or closed automatically when hitching and unhitching the semitrailer.
Besides enhanced safety and convenience and the great amount of time the driver saves, the system also prevents damage due to the vehicle hitting the supply lines.
MDAS-II Warns Tired Drivers
If the driver is unable to keep the truck in the middle of its lane, this often indicates the onset of fatigue. Using a complex active assistance system, MDAS-II (Mitsubishi Driver's Attention Monitoring System) warns the truck driver if concentration levels start to dip. At the heart of the system is a combination featuring the Lane Assistant, a camera system and radar-based proximity control. The driver receives a warning when there is a risk of the vehicle crossing over the lane limit lines or if there is not enough distance between the truck and the vehicle in front. The warnings increase as the situation becomes more critical.
Semi-Self-Propelled Unimog
One of the most dangerous tasks that road maintenance crews have to perform is driving a safety vehicle when working on steep banks or when erecting marker pylons. In order to protect the driver of the safety vehicle against accidents, Mercedes-Benz is developing a semi-self-propelled Unimog. Thanks to remote control, the safety vehicle can be controlled from a safe distance. Instead of having to use the accelerator and brake pedal, the driver operates a sidestick that controls the forward movement of the Unimog up to a brisk walking pace.
An automatic steering system based on the Lane Assistant ensures that the Unimog always moves along the limit lines at the right edge of the road, even if there is no driver on board. To prevent danger due to uncontrolled movements of the vehicle or operator errors, the semi-self-propelled Unimog is equipped with several emergency-stop switches, including one on the remote control unit.
As well as allowing remote control from outside of the vehicle, the technology at the heart of the semi-self-propelled Unimog also enables the vehicle to be operated from the co-driver's seat using the sidestick, making jobs such as mowing work at the side of the road much easier. In addition, the remote control allows precise control of the vehicle when coupling and uncoupling add-on units, because the operator can see what is going on outside the vehicle.
Forward-Looking Cruise Control
Conventional cruise control systems maintain a pre-programmed road speed. However, because they are passive systems, they cannot react to external influences – they cannot "see" or automatically respond to the changing situation on the road.
Freightliner is working on an advanced cruise control system called Predictive Cruise Control. PCC reacts to information that is stored on a three-dimensional road map and uses this data to create a predictive driving strategy. It sets the speed selected by the driver, taking into account fuel consumption and driving time. Thanks to its GPS receiver, PCC always knows the precise location of the truck. PCC accounts for the weight of the vehicle, detects dangerous downhill stretches at an early stage, and decelerates in good time before less-steep descents in order to save fuel. The result is a tangible fuel saving and less potential for danger, while the driving time remains the same. Vehicles with PCC are already undergoing tests. During the Papenburg demonstration, PCC was showcased in a Freightliner Century Class. The system could be in production by the year 2010.
Equipment Focus continued...
