New level of safety: Intelligent assistance systems with a keener eye

Feb 8, 2013
What started with the PRE-SAFE® system some ten years ago and continued with DISTRONIC PLUS has resulted in a new dimension of motoring at Mercedes-Benz: comfort and safety are merged into one, opening up all sorts of new prospects for motorists and car developers alike. Mercedes-Benz refers to this as "intelligent drive". Optionally, the E-Class features a whole host of new or optimised systems on board which help to make motoring more comfortable and safer. 
In the main markets, the Saloon and Estate models are fitted as standard with COLLISION PREVENTION ASSIST, a radar-based collision warning system with brake assist systems. It helps to significantly reduce the risk of a rear-end collision. Also forming part of the standard equipment is ATTENTION ASSIST, which is now able to warn of inattentiveness and drowsiness across a wider speed range, and also inform the driver about his level of fatigue and the amount of driving time which has elapsed since the last break. It also offers an adjustable sensitivity level. 
"The intelligent assistance systems of the future will be able to analyse complex situations and recognise potential dangers out on the road with the aid of improved environment sensor systems even more accurately than today," explains Prof. Dr Thomas Weber, Member of the Daimler Board of Management responsible for Group Research and Head of Mercedes-Benz Cars Development. "Figuratively speaking, the new E-Class doesn't just have eyes at the front, it has 360-degree all-round vision."  
Of crucial importance in this respect is the networking of all systems, or "sensor fusion" as the safety experts call it. Mercedes-Benz is continually enhancing the performance capabilities of its assistance systems with the aim of ensuring comprehensive protection, not just for the occupants of a Mercedes-Benz, but for all other road users too. 
The new systems hold tremendous potential for either preventing accidents or mitigating their consequences according to Dr Weber: "Take, for instance, the new BAS PLUS assistance system with Junction Assist. The results of our accident research based on the data from the GIDAS (German In-Depth Accident Study) indicate that it could reduce or prevent 27 percent of all accidents at road junctions resulting in personal injury. That equates to some 20,000 accidents a year in Germany alone." 
New sensors, new senses, new intelligence  
The basis for the innovative functions comes courtesy of highly modern sensors and appropriately networked algorithms. Mercedes-Benz is making a major leap forward with the introduction of the Stereo Multi-Purpose Camera (SMPC), or stereo camera for short. Just like the Multi-Purpose Camera (MPC) fitted previously, it is positioned behind the windscreen in the vicinity of the rear-view mirror. It has an aperture angle of 45 degrees and is capable of spatial detection of objects moving crossways ahead and also pedestrians, and calculating their path. The camera's two "eyes" provide it with a three-dimensional view of the area up to approx. 50 metres in front of the vehicle, and it is able to monitor the overall situation ahead for a range of up to 500 metres. In this way, the new camera is able to provide data for processing by various systems.  
Intelligent algorithms evaluate this information in order to detect and carry out spatial classification of both vehicles that are driving ahead, oncoming or crossing, as well as pedestrians and a variety of traffic signs within a large field of vision.  
Whereas the stereo camera's lenses act as the car's eyes, the radar sensors are its ears, so to speak, and provide additional data. The system of radar sensors comprises two short-range radar sensors in the front bumper with a range of 30 metres and a beam angle of 80 degrees, which are complemented by a long-range radar (200 metres, 18 degrees) including medium-range detection (60 metres, 60 degrees). The data from the camera and radars is amalgamated in a control unit in order to provide the system-specific data for the various functions. 
Comfort-enhancing assistance with lateral lane guidance: DISTRONIC PLUS with Steering Assist 
The DISTRONIC PLUS proximity control system is a driver aid designed to keep the vehicle at the desired distance from another vehicle in front that is travelling slower than the selected cruising speed. This basic radar-based function has now been enhanced by the addition of Steering Assist, which helps drivers to stay centred in their lane by generating the appropriate steering torque when travelling on a straight road and even on gentle bends.  
The stereo camera recognises lane markings as well as vehicles driving ahead together with their spatial positioning, and relays this information to the electric steering assistance system. When driving at slow speeds, e.g. in congested traffic, the Steering Assist can use the vehicle ahead as a means of orientation, enabling semi-autonomous tailback tracking even when there are no clear lane markings visible. As a result, the system is able to further boost driving comfort and substantially ease the driver's workload in many traffic situations.  
The new Steering Assist sub-function integrated into the DISTRONIC PLUS system is predominantly based on the new stereo camera. At the same time, the area in front of the vehicle continues to be monitored by two short-range radar sensors and a long-range radar sensor with medium-range detection. The system fuses the data gleaned from both technologies, calculates any reactions required, and then regulates the vehicle's linear speed as requirements dictate by controlling engine power, transmission and brakes, as well as actuating the electric steering for lateral vehicle guidance. 
The DISTRONIC PLUS with Steering Assist can be activated as before with a selector lever on the steering wheel in a speed range from 0 - 200 km/h. Any speed between 30 km/h and 200 km/h can be selected as the desired cruising speed. A green steering wheel symbol appears in the instrument cluster to indicate when the Steering Assist is operating while DISTRONIC PLUS is activated. Meanwhile, linear controlling actions (cruise control function) continue to be visualised in the speed display by means of circular segments and the speedometer needle. 
Drivers must keep their hands on the steering wheel at all times even when Steering Assist is activated, as the function only works in bends above a certain, speed-dependent radius. Legal considerations also mean there are no plans to introduce hands-free driving. The system's design is so refined that the sensors can detect whether the driver's hands are actually on the steering wheel. If they are not, a visual warning is issued first. Should the driver fail to react to this, a warning signal sounds and lateral lane guidance is deactivated. This does not affect the cruise control function, however, which continues to be operative.  
Needless to say, the driver is able to override the Steering Assist at any time. If the driver signals to change lane, for instance, the lateral guidance function will switch into passive mode for the duration of the lane change. 
The performance capabilities of the basic DISTRONIC PLUS function have been increased once again. Now, the system is able to brake at a rate of up to 5 m/s² without any intervention from the driver. If the "S" drive mode button is pressed, the rate of acceleration increases, too. Vehicle acceleration is also far more dynamic if the driver signals a wish to overtake by switching on the indicators, assuming the road is clear.  
By combining the radar and camera data, DISTRONIC PLUS is also able to detect both vehicles cutting in and vehicles ahead in adjacent lanes and take any necessary action promptly. This can prevent illegal undertaking on motorways and similar multi-lane highways, for example, by adapting the speed to that of vehicles in the outside lanes.  
Braking assistance for cross traffic too: BAS PLUS with Junction Assist  
Apart from material damage, accidents at junctions often result in serious personal injuries, too. The new Brake Assist BAS PLUS with Cross-Traffic Assist from Mercedes-Benz is therefore capable of more than just helping the driver to avoid collisions with vehicles ahead or lessen their consequences in a purely linear direction: the new Junction Assist function can also come to the driver's aid when there is a risk of a collision with cross traffic at junctions.  
If this anticipatory system detects a hazardous situation of this type, it prompts the driver to start emergency braking by activating visual and acoustic warnings. If the driver presses the brake pedal too tentatively, BAS PLUS will step in by automatically boosting brake pressure for effective emergency braking, even applying the brakes at full power if necessary. Applying just the right amount of braking power for the situation at hand maximises the available braking distance for traffic behind. 
The Junction Assist function is operative at speeds up to around 72 km/h, while BAS PLUS is able to aid the driver in linear situations at any speed. 
BAS PLUS with Junction Assist is potentially able to either prevent or lessen the severity of around 27 percent of all accidents at road junctions resulting in personal injury. This equates to some 20,000 accidents a year in Germany alone (source: investigations carried out by the GIDAS – German In-‑Depth Accident Study – and Mercedes-Benz Accident Research). 
With pedestrian detection and city brake function: BAS PLUS and PRE-SAFE® Brake  
Pedestrian detection has been added to the BAS PLUS and PRE-SAFE® Brake functions, while autonomous braking for vehicles in front has undergone a major enhancement too. 
Thanks to the combination of stereo camera and radar sensors, it is now possible to detect pedestrians in front of the vehicle. Visual and acoustic warnings are triggered when a hazard is spotted. If the driver then reacts by braking, the braking power will be boosted by BAS PLUS as the situation requires, right up to a full brake application. Should the driver fail to react, PRE-‑SAFE® Brake triggers autonomous vehicle braking. The PRE-SAFE® Brake with pedestrian detection is active up to approx. 72 km/h, and is able to prevent collisions with pedestrians autonomously from an initial speed of up to 50 km/h.  
Evaluations of GIDAS accident data indicate that this new technology could avoid six percent of pedestrian accidents and reduce the severity of a further 41 percent. The operating range of the autonomous braking function for stationary vehicles has been optimised so that rear-end collisions can likewise be avoided at speeds of up to 50 km/h.  
BAS PLUS with Junction Assist and the PRE-SAFE® Brake with pedestrian detection rely on the same sensors employed for the adaptive proximity control system DISTRONIC PLUS with Steering Assist: the new stereo camera plus the multistage radar sensor system.
Reacts to broken lines too: Active Lane Keeping Assist 
The new improved version of the Active Lane Keeping Assist is now also able to intervene should the driver inadvertently cross a broken line when the neighbouring lane is not clear and this could result in the risk of a collision when changing lane. The system can determine if this is the case using the information from the stereo camera and the radar system. The latter has been supplemented by a sensor at the rear, which works in unison with the other sensors in the front and rear bumpers.
The Active Lane Keeping Assist is not only capable of recognising critical situations such as overtaking vehicles, vehicles to be overtaken and parallel traffic, it can also respond effectively to oncoming traffic. If the system detects the vehicle crossing the lane markings when the adjacent lane is not clear, not only does it cause the steering wheel to vibrate in pulses as a tactile warning for the driver, it guides the vehicle back into lane by applying a corrective braking force on one side via the ESP®. It thereby forms the ideal complement to the Active Blind Spot Assist, and for the first time also enables the often fatal collisions with oncoming traffic to be avoided. 
The Active Lane Keeping Assist is active at speeds between 60 and 200 km/h. If driver activity in the form of e.g. active steering, braking or acceleration is detected or when the indicators are switched on, both the warning and the corrective brake actuation are suppressed. 
Now also identifies no-overtaking zones and no-entry signs: Traffic Sign Assist 
A new Traffic Sign Assist which builds on the capabilities of the previous Speed Limit Assist represents yet another contribution to accident prevention from Mercedes-Benz. The system is now also able to recognise no-overtaking zones and alert drivers to no-entry restrictions. 
The camera on the inside of the windscreen continues to pick up speed limit signs, including those on overhead gantries and in roadworks, for example. The camera's data is cross-referenced against the information in the navigation system and can be displayed in both the instrument cluster and the map view. If the camera fails to spot any road signs showing a speed limit or a speed limit is lifted, the legal speed limits based on the navigation data are shown instead, such as a maximum speed of 100 km/h on country roads in Germany or 50 km/h in built-up areas. 
No-overtaking zones and the signs signalling their end are also registered and displayed, while in the case of signs imposing access restrictions, an acoustic warning is additionally emitted together with a visual warning in the instrument cluster – making an effective contribution towards helping to prevent serious accidents caused by wrong-way drivers.
Visualising drowsiness: ATTENTION ASSIST 
A quarter of all motorway accidents in Germany are put down to drowsiness, making it one of the most frequent causes of accidents, most of which are of a serious nature. In 2009, Mercedes-Benz presented ATTENTION ASSIST, which is able to detect tell-tale signs of inattentiveness and increasing drowsiness based on changes in steering behaviour and a host of other factors.  
The system has been subject to on-going development, and the latest version has the ability to detect drowsiness and inattentiveness across a far greater speed range from 60 - 200 km/h. Furthermore, the system's sensitivity can be adjusted, e.g. for drivers who already feel tired when they get behind the wheel. 
A new menu in the instrument cluster display also makes the system more tangible and transparent for the driver by visualising the current attention level and the driving time since the last break. What's more, it is also possible to see whether the system is active in the current driving situation.  
The system can be deactivated by making the appropriate selection in the instrument cluster menu. However, it will always be automatically reactivated with the sensitivity setting last selected the next time the vehicle is started. 
Automatic manoeuvring into and out of parallel and end-on parking spaces: Active Parking Assist 
The Active Parking Assist enables automated parking with active steering and brake control in both parallel and end-on spaces. It is an advanced version of the PARKTRONIC system with Parking Guidance offered previously. What's more, the system is now also able to manoeuvre out of parallel parking spaces again all by itself with automatic steering and brake control, assuming the vehicle was parked there automatically previously. 
When travelling at speeds below 30 km/h, ultrasonic sensors with an extended range in the bumpers' side sections survey the nearside of the road for suitable parallel and end-on parking spaces. The same procedure is carried out for the far side of the road if the driver indicates accordingly. A symbol in the instrument cluster shows that the system is in the process of measuring. If a suitable parking spot is identified, an arrow appears alongside the symbol indicating that the system is ready for automatic parking. All the driver now has to do to activate the system is engage reverse gear and confirm by pressing the OK button on the steering wheel.  
The Active Parking Assist steers and brakes the vehicle automatically as well as indicating the required driver actions in the display in each case, such as the transmission position to be selected. The driver moves the vehicle by lightly pressing the accelerator or releasing the brake.  
Permanent high beam with no dazzling: Adaptive Highbeam Assist Plus 
Around 20 percent of all road journeys in Germany are undertaken at night. But this is when some 40 percent of all accidents occur. A main cause for this is poor visibility. According to a study by the University of Michigan, high-beam headlamps can only be used during eight percent of driving time - which is nowhere near enough. Based on this, it can be assumed that the time during which high-beam headlamps can be used in Germany is likely to be even lower given the denser amounts of road traffic compared with the USA. 
For the first time, the Adaptive Highbeam Assist Plus allows the high-beam headlamps to be kept on permanently while driving by masking out any other road user detected in the beams' cone of light. If the camera-based system registers either oncoming traffic or vehicles ahead, it will adapt the light distribution according to the specific situation when the high beam is switched on. Consequently, the driver can simply leave the high-beam headlamps on at all times and use their full range without irritating or even endangering other road users. There is no need to switch them on and off manually, resulting in a significant increase in the overall driving time with high beam. 
The Adaptive Highbeam Assist Plus likewise makes use of the new stereo camera also employed by other assistance systems. If its image recognition algorithm picks up a vehicle that is oncoming or driving ahead, it actuates a mechanism in the headlamp module. This then masks the portion of the LED headlamp's high-beam cone of light where there are other vehicles to prevent their drivers from being dazzled. If road users are detected outside the area that can be masked – for instance when cornering with multiple vehicles in the headlamps' beams – the system will switch to the familiar system of headlamp range control using the low-beam headlamps. 
Possible backglare caused by increased use of the high beam and highly reflective signs at the side of the road is also detected and eliminated by dimming the headlamps accordingly.
The Adaptive Highbeam Assist Plus builds on the Adaptive Highbeam Assist system first introduced by Mercedes-Benz in 2009. If this system detects oncoming traffic or traffic driving ahead with the help of a camera, it dips the headlamps and automatically adapts the low beam's range according to the situation. In this way, it allows the road to be illuminated for a long way ahead without dazzling other drivers. In addition to this, adaptive control of the low-beam headlamp range with smooth transitions results in gentler lighting changes that the eyes can quickly adjust to. 
At a glance
The main new functions of Mercedes-Benz assistance systems
Comfort-oriented assistance
DISTRONIC PLUS with Steer Assist
helps with keeping the vehicle in its lane
and tracks traffic in tailbacks
Safety - longitudinal guidance
BAS PLUS
can also detect crossing traffic and boost
the braking power applied by the driver can detect pedestrians and boost the braking power applied by the driver
PRE-SAFE® Brake
can detect pedestrians, avoid collisions
with pedestrians or stationary traffic at up to 50 km/h by means of autonomous braking and reduce the consequences of a collision at up to 72 km/h
Safety - towards the rear
PRE-SAFE® PLUS
can detect imminent rear-end collisions,
trigger PRE-SAFE® occupant protection measures in an imminent rear-end collision, firmly apply the brakes of the stationary vehicle in a rear-end collision to reduce the forces to which occupants are subjected and to avoid secondary collisions
Safety - lateral guidance
Active Lane Keeping Assist
can detect oncoming traffic and if the
adjacent lane is occupied, and prevent the vehicle from leaving its lane unintentionally by applying the brakes on one side
Safety - at night
Adaptive Highbeam Assist Plus
allows the high-beam headlamps to be kept
on permanently without dazzling traffic by masking out other vehicles in the beams' cone of light
Safety - when parking
Active Parking Assist
enables automated parking in both parallel
and end-on spaces with automatic steering and brake control enables automatic manoeuvring out of parallel parking spaces
Driver's level of attention and condition
ATTENTION ASSIST
can warn of lack of attention and
drowsiness in an extended speed range of 60 to 200 km/h. can provide the driver with information on his level of fatigue and the amount of driving time which has elapsed since the last break provides an adjustable sensitivity level
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