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