How Does It Work? – Axel Catton
Mercedes-Benz Safety Assistance Systems – The Whys and Hows
Throughout the history of the Mercedes-Benz company, automotive development has been driven by innovation to make driving safer. While American manufacturers offered automatic transmissions, air-conditioning systems and power seats decades before the Stuttgart brand, it was Mercedes that pioneered crumple zones, anti-lock braking systems and airbags.
With the advent of vehicle electronics, the focus has shifted largely to electronic safety and assistance systems, geared to support drivers in everyday tasks while keeping them in control. One of the earliest examples is anti-lock braking systems (ABS), introduced in the late 1970s, followed by electronic stability programs (ESP) in the ’90s and a wider range of driver-assisistance systems in the last decade. With the launch of the 2017 Mercedes E-Class at the Detroit Auto Show in January, Mercedes set another benchmark in automotive safety. Earlier last year, we had the chance to test many of those features in the S550e Plug-In Hybrid. We take a close look at the range of new assistance systems and explain them in detail.
Active Brake Assist
What is it? This system detects objects in your way and warns before an impending crash, provides assistance when the driver initiates an emergency-braking situation – even applying the brakes automatically.
How does it work? A 360-degree camera detects slower-moving or stationary traffic in your path and will initially warn you of objects that are in your way. We unintentionally tested this feature while distracted for “just one second” (don’t we all say that?) when the system detected a car stopping in front of us to turn right. The emergency warning tone chimed just as I looked up; I was able to slow the car and avoid a collision. Had I delayed just one more blink of an eye without paying attention, the car would have been able to step in and bring me to a stop or at least minimize the force of impact.
Active Blindspot Assist
What is it? This is more than the annoying beep when a car approaches your blind spot. This system can actively steer you out of the path of the vehicle.
How does it work? A camera constantly monitors the approaching traffic behind you in either lane to your right and left. If you intentionally or unintentionally steer into the path of a vehicle overtaking you on either side, the system first emits a warning sound with a triangle flashing in the mirror (a feature I gladly switch off in any test car). If this fails, the system will apply the brakes on one side of the car and bring you out of the collision path.
Active Lane Keeping Assist
What is it? A very descriptive name for a system that deals with the possibly of wandering out of your lane because for a fraction of a second, you weren’t paying attention to driving. The capability is also a part of the Mercedes Semi-autonomous driving functions, allowing you to relax while in rush-hour traffic.
How does it work? Again, cameras do the trick here. At speeds between 37 and 125 mph, they can detect the lane markings ahead, monitor your steering input, and assess whether the lane-change/turn indicator has been switched on, which temporarily cancels the system. If the car veers out of its lane, Active Lane Keeping Assist corrects the path by targeted brake application at individual wheels.
Adaptive Highbeam Assist
What is it? Instead of a conventional and rigid low- and high-beam setup, this system adjusts the headlamp range automatically.
How does it work? When driving at night, light sensors in the front detect the light beam of an oncoming car and automatically adjust the lights so as to not blind others. When the other car has passed, the system automatically switches to the best possible light output, making night driving safer.
Attention Assist
What is it? This often-overlooked system has been present in Mercedes-Benz cars for some time. Using intricate algorithms, it detects when driving behavior indicates tiredness and sends an audible and visible warning signal suggesting a break.
How does it work? Depending on how you look at it, this might sound simplistic or a slightly bit creepy, but Attention Assist is actually a very intricate and clever function. Within 15 minutes of the beginning of every journey, the on-board computer creates an individual driver profile using no less than 70 different measurables such as speed and acceleration, as well as using indicators and other control functions. A high-resolution sensor records steering input: Research has shown that drowsy drivers overcorrect minor steering errors abruptly. If the system now detects a stronger deviation from the original profile, it emits a warning sign and suggests a break.
Brake Assist System Plus
What is it? BAS Plus helps overcome one of the most frequent causes of avoidable accidents – lack of adequate brake force.
How does it work? Many accidents could be avoided if the driver in an emergency situation applied all the brake force possible and used the braking capacity of modern high-performance brakes. A stereo camera and a system of long-, medium- and short-range radar sensors monitor traffic and surroundings – now also in cross-traffic situations. The data from the camera and radar system are processed and the system analyzes whether crossing traffic poses a risk. If the driver applies the brakes, BAS Plus can ensure that optimum brake pressure is applied.
Car-to-X Communication
What is it? Another step toward communication between cars, this system warns of obstacles farther ahead in the car’s path.
How does it work? This mobile-phone-supported exchange feeds information about obstacles detected by other cars’ monitoring systems into a central database, which sends the data to cars traveling immediately behind. This effectively allows cars to “see” around bends, gaining valuable time to slow and potentially avoid a collision.
Collision Prevention Assist Plus
What is it? Another clever system that does what skilled drivers should be doing on their own – keeping a safe distance from the car in front of them.
How does it work? Using the stereo camera and radar, Collision Prevention Assist Plus monitors the distance to the car traveling directly ahead and displays a warning signal in the instrument cluster if the distance in relation to speed becomes too short. If that gap is closing too fast, there will be an additional intermittent tone. And if that gap gets close to critical range and the driver has switched the system on, brakes will be applied to prevent a rear-end collision.
Digital Car Key
What is it? This effectively replaces the car key with the driver’s smartphone.
How does it work? Using near-field technology, the driver’s smartphone pairs with the car using a unique code so it can be used like like a car key. This increases safety and provides added convenience.
Distronic Plus with Steering Assist
What is it? Basically, it’s an adaptive cruise control that keeps your car at the desired speed or below in relation to traffic in front of you. Steering Assist now ensures the car stays in its lane.
How does it work? When Distronic Plus is activated, the car’s radar system monitors traffic ahead and keeps a preset distance from slower cars in front. The newly added Steering Assist now monitors lane markings with help from the stereo camera to keep the car in the center of the lane. At slower speeds, the car can base its path to the car ahead, even if lane markings are barely visible or non-existent. The sensors are so sensitive, they can register whether drivers’ hands are on the wheel. We tested this feature in the S550e; it worked formidably. The semi-autonomous system provides steering input to prevent the car from leaving the road in a curve, even with the hands off the wheel. With the hands off the wheel for more than 15 seconds, the steering input subsides and a warning sound rings.