Hannover, April 2, 1995
Daimler-Benz Research's latest automotive study focused on an aspect that is becoming increasingly important to car buyers: versatility. The Vario Research Car (VRC) is a flexible companion for all areas of living, making individual mobility even more many-faceted and appealing. With this research car, Mercedes-Benz hopes to both provide a stimulus for future automotive development and test the public's reaction to the concept of the "intelligent" Vario.Research is about shaping the future. Today's researchers are forging tomorrow's world. They not only have visions, they evaluate what chance of success such visions have. They not only have ideas, they test these ideas for technological feasibility - both in the laboratory and in real-life situations.
Developing the car of tomorrow poses a challenge of a special sort. Setting the right course entails not only careful analysis of the latest technological developments, but above all also keeping abreast of social trends and developing a feel for future customer needs.
To this end, Daimler-Benz's scientists and engineers worked closely with their colleagues at the Mercedes Advanced-Design department in the development of their newest automotive study. The Vario Research Car has been conceived as both a standard bearer of new technology and a blueprint for further research. On the one hand, it functions as a sort of rolling research laboratory for testing future vehicle systems, while on the other hand, it serves as a study for a completely new automotive concept. It is planned to further develop this new concept, which is being presented to the public by experts for the first time, by entering into a dialog with customers. Mercedes-Benz is thus asking drivers for their opinions. The public response will show whether the Vario concept will be accepted, thus determining whether the research car will one day make it to series production.
One car - four concepts
The two-door compact car presented to the public by Daimler-Benz at the Hannover Trade Fair is a true quick-change artist. A few adjustments suffice to radically transform its appearance: the one-part body superstructure, consisting of roof, sidewalls and rear assembly, can be lifted off and exchanged at will for a different one. At the owner's whim, the station wagon becomes a convertible or the sedan becomes a pickup, according to the transportation needs of the moment.
The research vehicle has a range of four possible body designs:
The sedan is notable for its sporty, elegant body, marked by a rear assembly resembling a coupe. This option provides a four-seat interior, offering more freedom of movement than the average car of this size. Both rear seat backs can be folded down completely for maximum loading capacity.
The station wagon is marked by its large windows, which form a panel of glass running from the hatch door around to the car's side walls. The hatch door opens onto a spacious luggage compartment, which can be expanded by folding down the rear seats. In this way a flat loading surface extending from the rear of the car up to the back of the front seats is created. The station wagon is also outfitted with roof rails for transporting surfboards, snowboards and bicycles.
The attractively designed pickup body superstructure transforms the compact car into a small truck with two seats. After folding down the rear seats, the superstructure can be placed on the lower body section, closing off the interior at a point behind the front seats. The loading area can accommodate all kinds of bulky items - from small pieces of furniture to house plants, from a bicycle to a rubber boot. The tailgate can be opened to make loading easier.
The convertible option of the Vario Research Car offers room for four passengers. The folding top can be operated manually and disappears almost entirely into a compartment at the rear of the vehicle. Power control of the convertible top is available as an option.
A transformation in just minutes
The car's transformation from station wagon to convertible or from pickup to sedan takes only a few minutes and is almost as simple as putting the hard top on an SL roadster. The upper body structure attaches securely at eight points. Specially designed locking mechanisms and powerful electromagnets ensure a solid connection between the upper and lower body sections. Unfastening the body module is child's play. All the driver needs to do is to actuate levers on the door posts and on the top of the windshield frame: six servo motors take care of the rest. These unbolt the locks and lift the superstructure up slightly so that it can be easily removed.
Lightweight construction with high-tech materials
Changing body types on the Vario Research Car takes service technicians only a few minutes. And because the upper body modules are made of high-tech carbon fiber-reinforced plastic - a material already enjoying great success in airplane and racing car construction - muscle power is not required for the job. This plastic is not only 25% lighter than aluminum, another popular lightweight construction material, it also exhibits high strength. Thus, despite weighing only 30 to 50 kilograms, the upper body units offer a high degree of stability and crash safety.
Rental stations for the superstructure variations
Mercedes-Benz has developed an equally remarkable sales concept to accompany this vision of the variable automobile. In order for car owners to take full advantage of the flexibility of their vehicle, they should be able to exchange the different upper body types whenever they wish. Special service stations, in which a large number of different upper body units are always in stock, could permit this. While the owner waits over a cup of coffee, technicians change the body superstructure, preparing the "new" car in a just few minutes. It is entirely up to the customer how long the particular body variation is to be used. The rental system should be just as flexible as the research car itself. Fans of the convertible could go "topless" the entire summer, or the driver could have the station wagon assembly mounted on the car just for a big weekend shopping trip, exchanging it for a different option the following Monday.
Cars for leisure time - the up-and-coming generation
The Vario Research Car concept is of course more than just a vision. In developing this project, the engineers at Daimler-Benz were guided by the results of customer surveys and the projections of social scientists. In these visions of the future, the automobile continues to play an important role, but its tasks and functions change as society becomes increasingly oriented towards leisure time. While today private cars are used predominantly for transportation to and from work, and for shopping, in the future recreational use will increase markedly, especially among young people (and the young at heart). In concrete terms: while today recreation accounts for about thirty percent of private car use, this figure will more than double in the years to come.
Pleasure trips and sporting activities will dominate future recreational activities involving the car:
While today, about one in six car owners drives out to the country on weekends, in just a few years about thirty percent of drivers will regularly make these weekend excursions.
Today about ten percent of all sports fans use their own cars for transportation to sporting events; soon this figure will more than double.
These social tendencies are influencing automobile development. More than ever, flexibility and versatility are in demand to meet diverse transportation needs and the customer's desire for mobility. This is how the idea of the Vario Research Car came into being. Whereas conventional cars offer only a limited spectrum of uses, depending on their body type, the research car is multi-talented. It is as much a recreational car as a small truck, and is equally suited for use as a family sedan or as a vacation car.
And there's one other little point worth mentioning. As well as being extremely versatile, the Vario Research Car is a lot of fun to drive - a feature whose value is appreciated by leisure-oriented consumers.
Each variation has its own personality
The whole technology of the research car is housed under the lower body section, from which the ready-to-use individual car is created through combinations with one of the four available upper body types. Considerable thought has been given to the construction of these superstructures: not only do they fit seamlessly onto the lower part of the vehicle, but the dividing line between the two body sections is also cleverly concealed. This was a particular challenge for the experts at Mercedes-Benz AG's Advanced-Design department, who dream up the shape of tomorrow's cars. The design of the side sections shows clearly how the research engineers and designers worked together to solve this difficult problem. For the upper and lower body sections, they developed special connection elements, tailored to permit an exact fit during installation. Via internal guides, the superstructure shell slides precisely onto the low inside edge of the lower section, which is a structural element running from the headlights back to the taillights. In this way the two body sections form a visual unit.
The side windows also form a flush fit with the doors without the use of B-pillars, continuing the flow of the body's line toward the rear, and thus strengthening the impression that the body is made of a single piece. Thanks to this intelligent structural concept, each body type has its own personality. Whether in the guise of convertible, pickup, sedan or station wagon, the research car never betrays its true identity as a "modular car."
Central power outlet at the back
So that the two body parts form not just a unified visual entity, but also a technological one, the researchers developed a central power outlet, providing the necessary connection to the car's electrical network. It is built into each upper body attachment, fitting into a special socket in the rear of the research car. After both body sections have been linked via cables, the car's electronics automatically recognize which superstructure type has been installed and make the appropriate connections. This electronic identification process is necessary because each superstructure type has its own electrical requirements. The station wagon, for example, requires power for the rear washer/wiper, while the sedan needs 12-volt power for the rear window heater and luggage compartment light; the convertible needs power for the electric motors that raise and lower the folding top.
The research car's body not only looks good, it also exhibits excellent technical characteristics. Aerodynamics is a key word here: the drag coefficient (Cd value) of a road-ready Vario Research Car is a low 0.28. The streamlined body is one of the most important factors in achieving optimal fuel consumption and low emissions figures.
Developing the interior in the ergonomics laboratory
The Vario Research Car's interior was developed by Daimler-Benz engineers in collaboration with designers in the ergonomics laboratory. Here they made use of a new measurement process that represents the movements of the vehicle's occupants in three-dimensional images: stereo videometry. Different sized drivers served as test subjects, sitting behind the wheel of a model of the research car for about twenty minutes at a time. Video cameras showed the freedom of movement that each test driver had with his or her respective seat adjustment, and whether the driver could comfortably reach the dashboard controls. Another important factor was the analysis of the drivers' movements in getting into and out of the car. This gave the designers important data for determining the angle of incline of the windshield and the opening angle of the doors.
Based on these video observations, the engineers also developed a particularly comfortable folding mechanism for the front seats, making getting into and out of the two-door car much easier for passengers riding in the back. Strenuous manual effort is no longer required. A nudge on the shoulder of the seat back is enough to engage electric motors that slide the seat forward and fold it.
As roomy as the C-series
As far as the design of the interior specifications was concerned, the experts also concentrated on developing solutions oriented towards the future. Their work was thus guided by predictions of the overall increase in average height of the population, which has been following an upward curve for several years. As a measure, the so-called "ninety-five percent man," whose height is exceeded by only five percent of all men, was used. In 1975, the ninety-five percent man stood 1.86 meters tall (6' 1"); by 2005 he will have reached a towering 1.93 meters (6' 4"). This giant fellow will be comfortable in the front and in the back of the Vario Research Car, for its interior has been designed in strict accordance with the dimensions of the future ninety-five percent man. There is thus no question that smaller drivers will enjoy an optimum level of comfort and freedom of movement in the research car. The distance between the passengers in the front and those in the rear is 80 centimeters, about the same as in a C series sedan.
The interior of a modern automobile must, however, not only be roomy and comfortable - it must also be visually attractive. The designers have met this requirement through, among other features, an attractive organization of form and color. Sapphire blue, mint green and eucalyptus are the three hues they have chosen for the interior. The colors harmonize well, creating a bright, friendly atmosphere that fits an elegant, sporty car like the Vario Research Car.
Cockpit with color display
For the dashboard of the Vario Research Car, the engineers developed a new operating and display concept that utilizes modern microelectronics to ease the driver's burden. All important indications appear in the form of symbols and textual instructions on two color displays located in the cockpit and the upper part of the center console.
On the primary display in the cockpit, the on-board electronics display all the information needed by the driver during the trip. Using a special rotary switch on the center console, the driver can select particular indications from the menu at the side of the screen. These include not only engine r.p.m., on-board computer, and trip odometer, but also the routes recommended by the on-board navigation system. A noteworthy feature is the safety display. It shows a green circle as long as the driver maintains the prescribed speed limit and a safe distance from the car in front. If the driver is going too fast or gets too close to the next car, the shape and color of the symbol change: from a green circle to a yellow ellipse or a red triangle, depending on the speed or the distance to the next car. To "feed" this symbol-based display, which contains all important data at a glance, the car's electronics system continuously evaluates data provided by the distance radar, traction monitoring and other vehicle safety systems. Also, the microprocessor uses a video camera to look at roadside traffic signs to see whether there is a posted speed limit, a restriction on passing, or some other traffic regulation in force. These road signs can also be called up on the display at will, so that the driver can have them constantly in view. Malfunction and warning notices, which also appear on the primary display, always appear with a concrete recommendation for action. Thus, for example, the driver is not merely told that the coolant is overheating, but is at the same time given directions for first aid: "Stop the vehicle. Raise the hood. Turn on the heat."
The information on the secondary display can be called up by the driver and the passenger by using the rotary switch in the center console. This switch has an unusual feature: during the trip, access to additional functions is disabled for the driver, while the passenger has unrestricted access to all secondary information. In this way the engineers hope to prevent the driver's attention from being drawn away from the traffic situation. The user recognition involved here is touch-sensitive: the computer "feels" whether the switch in the center console is being grasped with the left hand (the passenger's hand) or with the right (the driver). The secondary display shows the time of day, along with operating indications and settings for the climate control and navigation systems. Operating instructions for the various vehicle systems can also be called up. When stopping at a service station, the display informs the driver whether the tire air pressure and the levels of oil, coolant fluid, and wiper fluid are okay, and whether the lighting system is functioning properly.
Prototype development via computer
In developing the intelligent operating and display concepts, the research engineers and psychologists at Daimler-Benz broke new ground. Instead of producing a large number of laboratory models and prototypes, the displays, menus and operation were conceived entirely on a computer in a process called "virtual prototyping." In the future, with the help of powerful mainframe computers it will be possible to develop complex vehicle systems almost entirely in the laboratory. The data collected there will be used to create a first model for practical testing, which is indispensable for the confirmation of the results achieved in the laboratory. However, while in the past it often took days or weeks to implement changes in a prototype so that tests could be continued, on a computer these modifications can be made in a few hours. The benefits of the new process are obvious: fewer expensive prototypes and significantly shorter development times.
The display and operating concepts of the Vario Research Car were not only developed on the computer by the Stuttgart experts, but were also tested there. Dozens of drivers tried out the new type of menu control on the computer screen and gave the engineers advice on optimizing the display system. Practical tests, to be carried out in coming months, will show how reliable the results of virtual prototype development are.
A rolling research laboratory
As far as the research scientists and engineers at Daimler-Benz are concerned, the Vario Research Car is much more than "just" an innovative body design. In their eyes, the car also has a vital role to play as a testing ground for the automobile systems of tomorrow and beyond. Here the developing and testing spectrum extends from adaptive running gear and new types of steering systems to distance warning indicators and electronic traffic guidance systems.
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© 1995 Daimler-Benz