Why Ford’s side airbags can’t be set off by an errant shopping cart

Ben Wojdyla:

Ford decided to start using pressure wave detection. In this method, the sensor is placed inside the door on the outer skin of the car, it monitors the ambient air pressure in the door cavity and sends a signal to the crash computer. The crash computer interprets the data every few miliseconds, confirming it with what the other sensors scattered around the car tell it. What’s the advantage? Fidelity. The signal coming from the pressure sensor has a much higher resolution than an accelerometer, which means it can tell the difference between a car hitting your door and say a shopping cart loaded with 110 lbs, hitting the door at 10 MPH. But before it can do that, engineers have to calibrate it to be able to tell the difference. This is where the shopping cart test comes in.

1. [rak0ribz]

   You know what else might work, in 99% of shopping-cart crashes?

   Disabling the airbags when the car is turned off.

   (That said, I’m going on record as ALWAYS being in favor of sticking more sensors in your automobiles.)

2. [Doomstalk]

   Rakoribz: Then what happens if you park your car, and some drunk driver slams into it before you get out?

3. [Scuba SM]

   Or, to expand on DOOMSTALK’s point, what happens to the cop running radar on the side of the road, radioing in cars for the motorcycle cops to pick up?

4. [dculberson]

   There are a lot of situations where you want the airbags to work even with the car off. Yes, it might mean an erroneous discharge every now and then, but that is a lot better than them not discharging when they were needed. (assuming the incidence either way is comparable.)

5. [alowishus]

   High-fidelity, technologically advanced, precision-calibrated sensors controlling an explosive gasbag right next to my head. In a Ford. Yes, I am comfortable with that.

6. [rak0ribz]

   OK, to amend my original snarky comment (apologies if this is a repost):

   There are at least passenger-side pressure sensors in the seats of most cars already, if I’m not mistaken; you could safely disable the airbag if driver and passenger seats register as empty. That would diminish the probability of being in a wreck while your engine is off but you’re still in the car from “vanishingly unlikely” to “spontaneous generation.”

   (As far as cops clocking cars: shouldn’t they leave the engine running?)