How can a car use sonar to park?

Scott Benjamin

For some drivers, sonar systems can take a lot of the anxiety out of parallel parking. (AP Photo/Carolyn Kaster)

I know that I'm not announcing any breaking news here or anything like that, but sonar parking systems for cars and trucks have suddenly become much more common than they once were. Some are simple systems that use a few LEDs in the rear view mirror (or elsewhere in the driver's line of sight) and an audible warning that reinforces the visual display. Others systems are extremely advanced (more about that in a moment), but either way, the intent is the same: To prevent you from hitting anything with your car as you try to squeeze into a tight parking space or even your own garage.

I'm just guessing, but I'd say that there's a good chance that you've seen the Lexus Advanced Parking Guidance System in action. That's the one that made the media buzz a few years ago because at a certain point, the driver could simply hand over the controls to the car's on-board computer system and the car would parallel park itself. And now, Ford Motor Company offers a similar Active Park Assist system on its new 2010 Lincoln MKT model. Nice features, yes, but you've got to admit that the price tag attached to a new Lincoln or Lexus is a little out of reach for a lot of new car buyers.

That's why I was a little surprised today when I learned that a fairly advanced version of a sonar parking system is now available on the 2010 Toyota Prius. If you can spare about three minutes of your time, I really think you'll be interested in watching this short video clip that shows the Intelligent Parking Assist system in action:

More related stuff: How Light Emitting Diodes Work How the Toyota Prius Works How Ford Works HowStuffWorks Videos - "Assignment Discovery: Bat Sonar"