Haven't found that software glitch, Toyota? Keep trying

Hi Folks,

I just noticed this article on the Los Angeles Times web site:

Haven't found that software glitch, Toyota? Keep trying - latimes.com

"An electronics problem isn't to blame for the sudden acceleration, say the carmaker's engineers. That's nearly impossible to conclusively determine through laboratory tests."

Written by an embedded system engineer who worked on the Mars Pathfinder project.

I think the takeaway here is that any system who's malfunction can endanger life and property needs to have a failsafe mechanism. This failsafe needs to be completely independent from the main control logic/system. For example, in the fly-by-wire Prius, you can't rely on any input that is controlled by the computers to cancel unexpected operation. The computers monitor the shift knob, the on/off switch and even the brake pedal. If the computers fail in the mode commanding acceleration, they may also fail to monitor the "reset" buttons. What is needed is a separate system that has it's own sensor inputs, a second brake pedal actuation switch, a current monitor on the traction motor feed, and an ICE manifold vacuum sensor, for example. When these independent sensors detect power going to the wheels when the brake pedal is depressed, will cut power to the ICE ignition system and open a relay cutting power to the traction motor. You get the idea.

Also, I just heard on the news that the fellow in San Diego who had the runaway Prius experience filed for bankruptcy, has been accused of a real estate scam, and was five-month behind on his Prius payments. The Highway Patrol isn't saying the incident didn't happen as reported, but you have to wonder. (heard on a Fox News broadcast) I think we're going to see an increase in runaway Toyotas.