Safer Car Controls

The sight of a shiny new car suggests streamlined high-tech devices. But appearances are deceptive. Under the hood, all is confusion. Around 100 microprocessors control auxiliary functions such as ABS, ESP or the headlight that can shine around corners. Almost as many control units send their commands to fuel injection systems, airbags and other functional modules.

Components from numerous manufacturers are scattered throughout the car body. Vehicle development engineers attempting to unite all the different systems into a working entity face a truly Herculean task, for each control unit carries its own software. Experts expect the volume of software in new cars to continue to increase by as much as 300 percent in the next four years.

The Fraunhofer Institute for Software and Systems Engineering ISST in Berlin has joined the international development initiative AUTOSAR (Automotive Open System Architecture) on behalf of the BMW Group. All the well-known car manufacturers and suppliers are members of the partnership. The goal of AUTOSAR is to pare down the ballast of in-car software and make it easier to handle.

The idea behind it is that vehicle functions will first be defined and linked together independently of their specific platforms. Only at the next stage are these functions to be assigned to the vehicle’s existing control units. After this the infrastructural software, likewise standardized, needs to be “fine-tuned”. However, the actual information processing takes place at a higher level, on the AUTOSAR Virtual Functional Bus. This approach simplifies matters tremendously and reveals a way of structuring the growing confusion of software.

“At long last, AUTOSAR gives software integrators in the automotive industry something that developers in other sectors, in the form of standardized development libraries, have had at their fingertips for decades,” says Markus Hardt, head of the department for reliable technical systems at the ISST. But before AUTOSAR can take to the road in tomorrow’s cars, it has to be tested to ensure it functions in a stable manner.

To enable this, Markus Hardt and his colleagues are developing the “aXBench”, a test platform that simulates the AUTOSAR architecture’s mode of operation and suggests an optimal distribution of functions. The “aXBench” enables the scientists to imitate and evaluate the correct functioning of control units, the swift transmission of data between the middleware and the receiver, and even true-to-life details such as hardware and software response times.