Can An Engineer Prevent the Unknown?
Charles Murray, Senior Technical Editor, Electronics & Test
1/9/2014
"....As automakers roll out autonomous driving features at the Consumer Electronics Show and the Detroit Auto Show this week and next, there's an unspoken question nagging at the fringes of the technology: Will future engineers have to find ways to prove these self-driving features don't cause accidents?
The question is especially relevant now in the wake of the recently settled Toyota unintended acceleration case. A jury found Toyota responsible after a 76-year-old woman sped out of control in her 2005 Toyota Camry as she was exiting an Oklahoma highway. The crash injured the woman and killed her passenger. A jury found in favor of the driver, awarding $1.5 million to her and $1.5 million to the family of the passenger.
The disturbing issue at the heart of the case is that we still don't know what caused the accident. Toyota claimed pedal misapplication -- the driver stepped on the accelerator when she thought she was stepping on the brake. The plaintiff's lawyers targeted the electronic throttle, citingtestimony from an expert who said that the car's software code was faulty. But with no smoking gun-type evidence, Toyota was left with the unenviable task of proving that its questionable software didn't cause the accident.
If you think about it, that's a tough task. Virtually all software-based products have some issues. And powertrain controllers contain hundreds of thousands of lines of software code, all of which can interact with vehicle subsystems in billions of ways -- maybe trillions. To prove something didn’t happen, engineers essentially would have to say, "We know exactly how many possibilities exist. We've tried all 16 trillion of them, and we know it can't happen."..."