Pizazz Over Safety = Disaster
Courtesy of Karl Denninger at The Market Ticker
Here we go again on the Toyota issue:
Feb. 3 (Bloomberg) — Electronic throttle systems are under review by U.S. safety officials as a possible cause of sudden acceleration in Toyota Motor Corp. vehicles, as alleged in at least seven lawsuits.
I wrote on this the other day in which I opined:
But not all cars can "run away" in this fashion, and it can be argued that none should. Indeed, it can be argued that that any vehicle with a drive-by-wire system MUST have a means of intuitively overriding an "un-commanded" acceleration in order to be considered reasonably safe and thus able to be certified for sale.
Now I happen to think that all drive-by-wire throttles should be interlocked with the brake pedal. Put a means to install an override on it if you want (rally drivers will complain if they can’t get one) but for ordinary street use this is something that just plain old-fashioned ought to be there.
If I stomp the brakes the throttle should be returned to idle. Period.
In my VW Jetta Wagon it is.
That won’t cover the case where the computer goes insane, however.
That is only covered by a mechanical ignition switch that interrupts power to the ignition circuit, and that too should be mandatory.
To use electronic "start buttons" for reason of vanity is outrageous. And let’s not kid ourselves- that’s exactly what those switches are.
Second, I’ve been around a lot of dangerous gear in my life with a lot of "emergency stop" buttons all over the wall (or on the machine.) You don’t have to hold them in for three seconds to stop the machine, you just hit them and that’s it – power’s off!
I have a lathe in my shop. It has a big fat RED emergency stop button front and center on the control panel where I can get to it FAST if I need to. It does exactly what you think it should do too – it cuts the power. If I need that machine to stop in an emergency I need it to stop NOW, not three or five seconds later.
Try holding in your "start" button on these newfangled cars for three seconds continually while attempting to avoid playing bumper cars with all the other vehicles that are going half as fast as you are because your vehicle’s throttle is locked wide open!
Vanity sounds great until people start dying as a consequence.
We both can and must demand better.
We must insist that all vehicles sold in the United States be fitted with an actual mechanical ignition switch that interrupts powers to the ignition circuit when turned off with a key that is easily reached from the operator’s position – not an electronic signal "asking" that the computer turn off power but an actual physical opening of the circuit that supplies the power necessary for the ignition to work.
Way back when (20ish years ago) I used to design and implement computer-based control circuitry to precisely position very big and heavy pieces of equipment. The "business end" weighed many tons and was driven by high-horsepower motors through reduction gearing, with drive systems capable of generating more than enough force to easily rip a man into little pieces (or go right through the side of a building.)
These controllers used optical encoders with differential signals to "know" where the machine was. There were lots of "failsafe" checks in the code, such that if the encoder wasn’t returning both differential signals of opposite polarity as expected, if the unit was moving faster or slower than it should be or there were any of a half-dozen other things "not quite right" the unit would shut down and sound an alarm – just like "drive by wire" throttles have a "limp" mode they allegedly go into if they detect some sort of problem.
But in each of these installations I demanded that in addition there were physical limit switches that opened the power circuit DIRECTLY to the motor. That is, if for any reason (such as the computer going insane due to a software or hardware failure) the machine was driven to the limit of its safe travel power would absolutely be interrupted to the motor and it would thus stop before it killed someone or did severe property damage.
To the best of my knowledge none of these controllers or drive systems ever failed in a fashion that actually hit the limit switches, but they were part of what I insisted be present in the design and installation – just in case.
It costs little or nothing to do this. In the present case, with ignition switches, the reason to omit them is vanity – to appear "high tech" or "cool" – not for any particular functional purpose.
That vanity has removed from the driver a capability that he has had for the last fifty years of automobile operation – the ability to absolutely, positively stop a runaway engine in less than one second by turning off the ignition key.
Tell me again which is more important here – safety or vanity?
