Software jungle challenges auto engineers
By Christoph Hammerschmidt
EE Times
October 1, 2003 (1:21 p.m. ET)
ArchivesBADEN-BADEN, Germany — Quality software alone isn't enough to tame the exponentially increasing complexity of auto electronics. Instead, experts at a conference here this week demanded implementation of data and interface standards along with specs for manufacturing processes.
Electronics represents up to 90 percent of innovations expected to be made in automotive engineering in the coming years. Increasingly, auto electronics are synonymous with software. Experts estimate that by 2010 software complexity in cars, expressed in the number of lines of code, will increase 100-fold.
Alberto Sangiovanni Vincentelli, professor of electrical engineering and computer science at the University of California, Berkeley, told the Motor Vehicle Electronics conference he is concerned about escalating complexity. In the system software of one vehicle OEM, for example, he counted 500 calibration parameters. “This is nothing to be proud of,” Vincentelli said. “It's a sign of illness.”
Software complexity springs from several sources. For instance, the number of electronic control devices grows constantly. But space constraints, power needs, communication networks and weight all place limits on the expansion of control devices.
Additional functions, according to experts at the conference, must be implemented within the existing control devices. Doing so, however, will force designers to both drop the link between control-device hardware and its function as well as accept a further increase in complexity.
Burdening an existing control device with additional tasks could become a problem for the timing between systems. While most operate in real time, the complexity problem cannot be overcome by simply generating more code.
Vincentelli added that it remains difficult to efficiently partition software, — including application code, communications links, drivers and operating systems. Hence, car makers are increasingly becoming systems integrators.
This emerging role has fueled demands modularization and standardization as a way to get development and manufacturing processes under control.
Play, or pray?
Auto makers remain perplexed. “Some of them can do it, and some can't,” said senior developer at Audi. But Vincentelli offered another explanation: “Embedded software is not really software. Embedded software is a union of hardware and software,” he said. The challenge of modularizing software for embedded systems would therefore far exceed the strict definition of an interface," he continued. Thus, "one cannot really speak of plug-and-play when it comes to embedded software systems — at best it is “plug-and-pray.”
Andreas Eppinger, director of IBM's Global Automotive Software Business, also said plug-and-play often does not work. Frequently, systems don't work even though during troubleshooting each component appears to be error-free. “The diagnosis 'no trouble found' is a huge problem,” said Eppinger. “Obviously, something is wrong with the way that the components work together.”
With auto hardware well under control, according to Eppinger, problems are usually blamed on software. This fuels the belief that problems can be solved merely through high-quality code generation. The problem is deeper, Eppinger said. "This problem is not a question of software quality, it is a question of systems engineering."
Along with modularization, auto engineers have focused on reusable software as one way to handle complexity. The idea has yet to catch on with suppliers, however. “This requirement makes the suppliers afraid that they will become interchangeable,” said Wolfgang Runge of ZF Friedrichshafen AG, a supplier of driveline and chassis technology. Reusable software is "a must if you want more and better electronics in vehicles.”
Another problem worrying designers is the multitude of suppliers and software versions. Volkswagon's Fabian Wolf said a linking process is needed to integrate software from various suppliers.
Even at the process-management level, too many software versions is a problem for designers. According to Eppinger, the key to managing proliferating software for individual control devices is to use a deployment manager. Here, too, software reuse plays a role.
Hence, important policy decisions must be made by the industry. “Either each OEM needs to develop it for itself, or there will be an open, shared infrastructure,” said Eppinger. IBM has already established a strategic partnership with BMW to explore standardization. One goal is to create a standardized data model.
