Oct 24 2014
An increasing number of assistance systems are being designed to facilitate driving. Things are heading towards automated driving. What role does the person behind the steering wheel play? Scientists at TU Darmstadt have presented “pieDrive”, an interactive operating concept for vehicles of the future.
pieDrive is based on the “Conduct-by-Wire” project that has been under development since 2008 as part of a German Research Society project at TU Darmstadt.h The idea behind this is similar to the way people drive a car. Driving a car is seen as a series of “maneuvers”: “straight ahead”, “turn right ahead”, “change lanes and pass”. The large number of individual steps that, for example, lane-changing involves – looking in the mirror, blinking, accelerating, looking over your shoulder, turning the car to the left, leaving your own lane, moving into the other lane – is carried out automatically by experienced drivers. In highly automated driving, this is performed by the car and its assistance systems. They provide support to drivers in steering the vehicle safely.
Recently, TU Darmstadt and its research partner Continental presented a partially functional prototype of a comprehensive driver assistance / automatic maneuvering concept in a real vehicle.
But researchers at TU Darmstadt examined another side of automatic, maneuver-based driving, in which even complex driving situations were studied extensively in a driving simulator. The pieDrive project at the Institute of Industrial Engineering of the Department of Mechanical Engineering at TU Darmstadt was concerned with the question of how the commands of the driver can be transferred as simply and intuitively as possible to the car during maneuver-based driving. “How do you design an interactive user interface so that drivers can handle it well and have the feeling that they are in control?” summarizes Dr. Benjamin Franz, who developed pieDrive together with his colleague Dr. Michaela Kauer.
Michaela Kauer and Benjamin Franz opted for a two-part system, consisting of a heads-up display and an input device in the form of a touchpad on the center console. The driving maneuvers that are possible in a certain situation are projected onto the windshield so unobtrusively but clearly that it looks like they are part of the scenery behind the windshield. By swiping their finger on the touchpad, drivers can then select the maneuver their car should perform. Their view remains on the road. Changes in speed or lane positions can also be controlled. The semicircular arrangement in the heads-up display looks like a pie chart, giving the whole system its name: pieDrive. However, the specific design is still variable and can be adapted to the needs of automakers. For example, operation of the system using rotary pushbuttons is also conceivable.
For the driver, pieDrive is primarily an operating system. But it does more in the background, clustering a wide variety of assistance systems. “Drivers don’t care which assistance system is currently operating – they just want to use the functions”, explains Benjamin Franz. Because pieDrive combines the tasks of several assistance systems, it can also prevent overloads when several systems compete for the driver’s attention by issuing warning sounds or performing actions at the same time. If several driving assistants were to warn loudly of a lane change, pieDrive simply does not offer the option of a lane change. Nevertheless, drivers can “overrule” the system at any time and assume full control with conventional controls (steering wheel and pedals). If you want, however, you can largely leave the driving to pieDrive. The current test version detects not only complex intersections in the city and in the country, but also, for example, speed limits; it also brakes before pedestrian crossways and for rowdies who rudely take the right of way from the simulator vehicle.
Fast learning, high degree of acceptance
Engineer Franz and psychologist Kauer worked hand-in-hand in the development of pieDrive so that the new system would not only function, but could also tailor its services to people. Two rounds of tests in the simulator followed, with nearly 100 test subjects, each of which steered their simulator car for several hours. “The subjects learned extremely quickly how to operate pieDrive”, says Michaela Kauer. “They usually missed the first intersection, but there weren’t many mistakes 50 meters later.” Even older subjects, who were initially somewhat more restrained, quickly adjusted to the system and accepted it very positively. The most advantageous driving style for automatic driving was also discovered during the tests. “The system is designed to drive like a chauffeur – generally calm, relaxed and defensive”, explains Kauer. This is how most of the subjects wanted to be driven – “even those that describe their own driving style as sporty and aggressive”. Subjects imagined that they could relax for a change and leave the work to pieDrive and the assistance systems especially on drives they make every day, on long monotonous drives or in heavy traffic.
pieDrive has brought the theoretical and technical concept of automated driving, even in complex road conditions, a lot closer. The TU Darmstadt has registered for a patent for the system, and developers Kauer und Franz have founded Custom Interactions, a company that works on the design and evaluation of interfaces. Whether pieDrive reaches series production is now up to the automotive industry, which must spur on the development and marketing of automated vehicles. Thereafter, legal experts will also have to deal with any unanswered legal issues involving insurance that are associated with the introduction to market of automated vehicles. One question that has already been answered is the original question of the research team, one which many potential drivers will ask themselves: “How do I drive a vehicle like this?” Thanks to pieDrive: by pointing a finger.