Digitalisation using the next E-Class as an example: Intelligently developed, intelligently produced

"Digital natives" is the term used for people who have grown up in the digital world. The future E-Class, the 213 series, is also a "digital native": from development to sales, digitalisation has made its mark on this series in all phases and areas. Digital solutions such as the networking of safety and assistance systems help to ensure the E-Class is the most intelligent saloon in its segment. Numerous innovations make it possible to drive semi-autonomously on motorways and country roads, and to enter and leave tight parking spaces by remote control using a smartphone app. Car-to-X communication provides early warning of dangers that lie ahead. Sophisticated radio technology turns the smartphone into a vehicle key.
The car is already the most complex IT product. A software comparison shows this: an average smartphone app, for example, consists of around 50,000 lines of programming code. For Google's Android operating system, the figure is around twelve million lines. A Boeing 787 has around 14 million lines. But even today, there are around 100 million lines of code in a Mercedes-Benz E-Class. That equates to 1.8 million A4 pages. The car is a mobile computer centre, with over 100 control units connected to sensors and each other via several kilometres of wiring. The computing power corresponds to that of a dozen modern PCs.
But the fact that there is so much of the digital world in the next E-Class is only one side of the coin. The other is that, as the latest product, digitalisation of the company itself has already had a decisive influence on the E-Class in all its development phases and lifecycles. The following are a few examples:
Design: first test drive on the PowerWall
During the development process for new Mercedes-Benz models, the designers are the first to benefit from the possibilities of the virtual world. They use it to compare and assess different design ideas, and change them with little effort. Mercedes-Benz has put the tools for this in place in the Virtual Reality Centre in Sindelfingen.
The Virtual Reality Centre provides a wide range of projection options. Initial design ideas can be viewed most effectively on the so-called PowerWall. Several beamers project two or three-dimensional computer images from behind onto this large projection surface, which measures around 17 square metres and enables a complete vehicle to be represented in 1:1 scale.
The virtual car can be examined even more intensively and realistically in the "CAVE" (Computer Aided Virtual Environment). Unlike with conventional image projections, the designers and engineers are not just external observers but become part of the virtual surroundings. The "CAVE" opens the door to another reality, so to speak.
The "CAVE" is an open-fronted cube consisting of five semi-transparent projection surfaces whose edges each measure 2.50 metres, onto which five powerful beamers each project a computer-generated image. Once the engineers put on stereo goggles, a fascinating spatial image of the desired object magically appears in the room. The designers are then able to move freely around the projection space and act almost entirely naturally in the 3D environment by using tracking and working aids such as data gloves and virtual tools.
The powerful computers create such a realistic image of the vehicle in the empty space that the designers can view their creations from any angle, and have the impression that they will leave fingerprints on the shining paint finish when they touch it. Every detail can be seen in the "CAVE": Even the surface of the dashboard or of the seat upholstery is so realistic that there is a temptation to run a finger along it to feel the texture.
Development and testing: simulation allows optimisation at an early stage
Mercedes-Benz is currently the leader in almost all vehicle classes where aerodynamics are concerned: the new E-Class is also at the very top of its segment with an outstanding cd value. The aerodynamics were already optimised during an early development phase, using sophisticated computer calculations and airflow simulations. A total of more than 275,000 CPU hours (Central Processing Unit) were needed for the numerical flow simulation. The models and prototypes spent around 1100 hours in the wind tunnel for measurement work.
Extensive crash test simulations were the basis for safety developments in the E-Class. This is a field which has developed at a furious pace. In the early 1990s, Mercedes-Benz conducted around 200 computer crash tests per year. By 2000 the number was already 1500 simulations, and in 2010 it rose to over 50,000. And that is not the only impressive statistic: For the W 124, a predecessor to the E-Class in the late 1980s, the computer model consisted of only 25,000 finite elements. Nowadays the level of detail is much greater – there are around two million elements in the digital image of the coming E-Class (W 213) and the surface mesh of the virtual vehicle structure is now made up of tiny rectangles and triangles with edges measuring three millimetres. This allows a much more precise and detailed deformation analysis than was possible when the elements were much larger at 25 millimetres.
Crash test simulations are also valuable during the development of restraint systems. The next E-Class will be available with a beltbag - an inflatable seat-belt strap that reduces the load on the ribcage in a frontal impact, and is thus able to reduce the risk of injury to passengers in the rear. Mercedes-Benz safety experts developed the beltbag with the help of virtual human models, which provide a clearer picture of what happens to a vehicle's occupants in an accident than crash test dummies.
Numerous simulators are employed as standard practice in the development and testing of new vehicles at Mercedes-Benz. "Digital prototypes" of a vehicle, which are created with the aid of extremely powerful computers, allow comprehensive testing of a new model in many driving situations before the actual vehicle exists in real life. As a result, the actual prototypes attain a higher maturity level more quickly, enabling even more detailed testing.
At the end of 2010, Mercedes-Benz opened the world's most cutting-edge "moving-base" driving simulator in Sindelfingen. With its 360° screen, fast electric drive and twelve-metre rail for transverse or longitudinal movements, the dynamic driving simulator is the most powerful in the entire automotive industry. With this driving simulator, highly dynamic driving manoeuvres such as changing lane can be simulated in a realistic manner, enabling in-depth research into driver and vehicle behaviour on the road.
Numerous other simulators are used in the development and testing of new vehicles. With a ride simulator, it is possible to carry out subjective assessments of the performance of digital prototypes driving on uneven roads, for example. To this end, Mercedes specialists feed the simulator with the surface data of real-life test stretches and the necessary suspension and functional data relating to vehicle models. Driver and front passenger can sit in the two seats on the test rig to carry out purely digital yet realistic test drives, as the vehicle seats mounted on a hexapod with electrical actuators move as specified by the digital prototypes.
Fixed-base simulators do not have a hydraulically or electrically powered motion system and the vehicle cab is fixed to the floor. Thanks to single or multi-channel projection and the sound systems conveying driving noises, the traffic scenario is nevertheless so realistic that the driver becomes immersed in the virtual world and behaves as if in real-life road traffic. This is where the driving assistance systems are tested in different traffic situations. Development work is also carried out on interior noise using measured and synthetic noises and with the aid of expert panels and customer studies.
Production: the smart factory is becoming a reality
When production of the next E-Class commences, numerous elements from the "smart factory" toolbox will already come into use. These include e.g.
  • Augmented reality: Here the actual status is visually overlaid on the design specification on a monitor. Deviations are immediately apparent. This procedure is used
    • for factory planning: The actual construction status of the production shop (e.g. infrastructure such as compressed air lines, but also production equipment etc.) is compared to the virtual image to detect possible deviations and update the virtual image before the concept is finalised. This ensures the virtual data is of a high quality, as it forms an elementary basis for the planning and design of production facilities during reconfiguration;
    • during assembly testing using virtual components: In the early approval and operating phases of production equipment, components are not available for specific optional extras or variants that will not enter series production until later. Using augmented reality, these can nonetheless be included and assessed as virtual test components during the approval and commissioning process. In contrast to purely virtual analysis, real parameters such as product fixtures in production equipment that are subject to tolerances, and the dynamic routing of flexible equipment components (e.g. hoses), and to an extent, also the dynamic, physical behaviour of components under the effects of gravity can be assessed;
    • during the manufacture of equipment components and production facilities: Both at the supplier and post-installation in the plant, the actual facilities are compared to the virtual design data to ensure a high level of production quality and execution. Deviations are thus detected and rectified prior to commissioning;
    • during the commissioning of production facilities: Compared to classic metrology, augmented reality makes deviations in a complex object detectable in a few minutes, so that possible solutions can be discussed within the workgroup. If analysis becomes necessary during the commissioning process, this is possible by overlaying and evaluating individual images taken with an SLR camera. This can be done without interrupting the operation of the equipment.
  • Virtual assembly: The virtual assembly station was used for the first time as part of the interdisciplinary production preparations (IPP) for the forthcoming E-Class (213 series). Just as the movement control of a games console is able to imitate golf or tennis strokes, virtual assembly installs parts in a vehicle with amazing realism. By testing with an avatar, experienced employees can assess how the relevant job might best be carried out, or whether design changes are still necessary. When used for the 213 series, it was found that it was possible to dispense almost completely with vehicle hardware during the first IPP phases - for the first time, the three first IPP assembly procedures were purely virtual (by human interaction with the computer screen). It also facilitated ergonomic optimisation of individual assembly steps (specific installation and bolting situations). These included: bonnet insulation, Frontbass installation, control unit contacts, accessibility of axle wiring, front axle bolted connections, wrench accessibility.The assembly procedure could therefore be planned at a much earlier stage, allowing earlier influence on product/process design with advantages for all those involved. Following this positive experience, Mercedes-Benz will use virtual assembly for all future model series.
  • Digital process chain: The buildability of the vehicle is already verified at an early stage in the product creation process. This is ensured by the use of digital methods to represent a digital production process chain.
    • This begins by verifying buildability of the individual bodyshell components and their tools in the press plant, continues with an assembly simulation in the body shop using mechanical joining techniques (e.g. spot welding, roller hemming) and goes right up to corrosion protection measures in the paint shop.
    • In this way, the demanding specifications for gap tolerances and transitions in the 213 series were met by combining forming simulation in the press plant with assembly simulation in the body shop. This provides important information about the major influences on the dimensional accuracy of assemblies. For the 213 series, this process chain was used to optimise the aluminium add-on parts in the computer, and establish suitable equipment settings. This intelligent linking of numerical calculation methods allows reduced induction and start-up times.
    • In the interests of corrosion protection for the new E-Class, the bodyshell design was optimised at an early stage for the cathodic dip painting process. In close cooperation with the digital product developers, layer thickness simulations were carried out and countless holes, impressions and bonded seams were moved and redesigned. A drier simulation showed at an early stage the best possible drier configuration to achieve the best paint curing conditions for this new body-in-white.
  • 360°networking (body-in-white): The complex network of 87 body-in-white production systems with 252 programmable logic controllers, 2400 robots and 42 technologies (spot welding, bonding, laser welding, mechanical joining etc.) for the 213 series is linked by approx. 50,000 intelligent network participants (IP addresses). Thanks to comprehensive horizontal and vertical networking, the following superordinate information and intervention options are now available:
    • All the safety parameters of the equipment technology are automatically monitored. Time-consuming manual monitoring is no longer required
    • Monitoring the energy consumption of the new production facilities. On the basis of these data, it is possible to ascertain the energy consumption per component/bodyshell. Further improvements in energy consumption are made possible on the road to "green production".
    • All the parameters of the vehicle’s joining processes are captured as "Big Data" for analysis and monitoring purposes. There is an immediate response to deviations from the specified process thanks to intelligent evaluation.
    • Maintenance: A remote support function is integrated into all equipment. This means that systems experts can use the network to provide rapid and efficient support in the event of problems.
    • Component requisitions are made electronically. This means that the lead times and necessary parameters can be adjusted in the system by the logistics personnel at any time. These adjustments are also made remotely, and require no intervention in the equipment technology.
  • 360° networking (assembly): The vehicle production numbers and the movable tools are digitally linked by the Ubisense system in E-Class assembly. The position of the vehicle body on the production lines is precisely registered, and the tagged Wi-Fi power wrenches are automatically activated at the right moment. All-in-all, around 620 antennae were installed to "light up" approx. 400 workstations and control around 180 Wi-Fi power wrenches. This means that scanning-in the vehicle information is no longer necessary, as thanks to the Wi-Fi and locating technology, the worker is able to move freely around the product and work to best effect.
  • Human-Robot cooperation: A lightweight robot on a mobile carriage is used to calibrate the head-up display. It carries the calibration camera on a lightweight GFRP arm and can calibrate both right and left-hand drive vehicles by one-sided access. Previously calibration was carried out by two permanently installed robots behind a protective fence. This innovation reduces the complexity of the system, and elimination of the fence makes it smaller and more flexible. Another advantage is that the new robot quickly takes its reference from the vehicle's dashboard, and no longer from the door aperture.
  • Automated vehicle transport: What began digitally at the design PowerWall will end automatically in future: During the production period of the forthcoming E-Class, the plan is for the finished vehicle to drive automatically from the assembly shop to the loading points for rail and truck transport, or to the Customer Centre. This is a particularly apt example of a fully digital process chain, because the plant will then be using vehicle capabilities that also provide its future owner with additional comfort and safety.
Vehicle use: Intelligent Drive Next Level and connectivity
The networking of all systems – what applies on a grand scale to "Industrie 4.0" is at the same time the philosophy of "Intelligent Drive" broken down to the vehicle level. Modern safety and assistance systems take their reference from networked sensors – in the next E-Class these will include an enhanced multi-purpose stereo camera behind the windscreen and new multi-stage radar sensors with adjustable range and included angle around the vehicle, plus tried-and-tested sensors such as ultrasonic sensors and the lenses of the 360°-camera. The combined use of data from the sensors allows analysis of complex traffic situations, better detection of potential dangers on the road and, therefore, the ability to further enhance the increasing number of functions provided by the safety and assistance systems.
"Intelligent Drive Next Level" will see the new E-Class showcase the next milestone on the road to autonomous driving. On motorways and country roads, the saloon is not only able to keep the car at the correct distance behind vehicles ahead automatically, it can also follow them at a speed of up to 200 km/h. This can make life easier for the driver, who no longer needs to operate the brake or accelerator pedal during normal driving, and receives considerable steering support – even on slight bends.
A wealth of innovations related to connectivity help to ensure that the E-Class is in many respects the most intelligent saloon in its class. These include:
  • Car-to-X communication: In 2013, Mercedes-Benz was the first manufacturer to introduce car-to-car networking in the form of a retrofit solution. This is now to be followed by the logical next step as the world's first fully integral Car-to-X solution goes into series production. Mobile phone-based exchange of information with other vehicles further ahead on the road, for example, can effectively allow the driver to see around corners or through obstacles. This means that the driver is now warned earlier than before in the event of imminent danger, such as a broken down vehicle at the edge of the road.
  • Digital Vehicle Key: This drive authorisation system uses Near Field Communication technology and allows the driver's smartphone to be used as a vehicle key. Simply holding the smartphone at the door handle is all it takes to unlock the vehicle. This also activates the personal comfort options, e.g. seat and mirror positions or the favourite radio station.
  • Remote Parking Pilot: This system allows the vehicle to be moved into and out of parking spaces remotely using a smartphone app for the first time, enabling occupants to get into and out of the car easily, even if space is very tight. The parking scenario is enacted automatically - including steering, braking and direction changes - as long as the driver continues to provide a confirmation gesture on the smartphone.
Launched a year ago, "Mercedes connect me" enables customers throughout Europe to link up with their vehicles from anywhere at any time. Buyers of the next E-Class will of course be able to use the "Mercedes connect me" services as well. The connectivity services include accident recovery and maintenance and breakdown management, as well as the Mercedes-Benz emergency call system and telediagnosis.
Moreover, digitalisation also helps to improve safety in other areas often unnoticed by the driver. Mercedes-Benz is the first automobile manufacturer to provide rescue stickers, so that the emergency services have rapid access to safety-related information at the scene of an accident. Scanning the QR code on the sticker into a smartphone or tablet displays the current rescue card for the vehicle. This enables emergency services to see immediately where the airbags, battery, tanks, electrical wiring, pressure cylinders and other components critical to a rescue operation are located.
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