Better Gas Mileage

Almost every kind of vehicle has experienced a growth in size over the past decade. An “entry-level” car by a company such as BMW nowadays might be near the size and weight of a mid-size car ten years ago. As vehicles have gotten bigger, parking has become harder and harder.

The vehicle growth spurt is most visible in the pickup truck segment, where even such “small” trucks as the Dodge Dakota are now so big that they dwarf earlier models. Full-size trucks too have grown, getting heavier, wider and taller. Toyota vehicles have followed this market trend. When it was first introduced, the Toyota Tundra was a mid-size pickup aimed at the full-size crowd. But when Toyota realized they could fit more buyers in a larger vehicle, the 2007 Tundra redesign ballooned the truck in almost every dimension.

Size may have its benefits, but it has its downfalls as well. The biggest problem with bigger vehicles is that parking has become a lot harder. Sitting behind the wheel of a new Toyota Tundra, it might be hard to gauge just where the truck begins and ends. To make things easier, vehicle designers have introduced “parking assist” as an aid to drivers struggling with parking their new vehicles.

On most vehicles, “parking assist” is a system of sensors in the front and/or rear bumper that create an audible “beep” when your vehicle gets close to an obstacle. Depending on the system, the beeps will begin when you’re about 6 feet away, and then increase in frequency until you get about 6 inches away, when the beeps will become a continuous tone. This is a great feature - it can really help with parallel parking, as well as warning you if something small (i.e. a fence post, a mailbox, or even a small child) is near your vehicle. But how does it work?

Basically, a set of eyes are mounted in the vehicle’s bumpers. These “eyes”, or special sensors, transmit highly focused sound waves at regular intervals from the bumper. When these sound waves come into contact with a solid object, they reflect back towards the sensor. Since the speed of sound is fairly constant through air, a computer uses the time it took for the reflection to be returned in order to calculate the distance between the bumper and the object. This is exactly the same principle employed by submarines using active sonar underwater, except that water transmits the sound waves much better than air, allowing for better range.

Although the sensors can effectively detect stationary objects such as parked vehicles and garage doors, they’re not sensitive enough for smaller mobile objects, such as animals or children. These objects might not generate a warning beep, or at least not consistently. Therefore, drivers still need to use caution and be aware of their vehicle’s surroundings when parking. Parking assist, also called parking sonar, is definitely a useful tool, but is not a replacement for a careful driver.

High-end luxury cars have started to move on to the next generation of parking assist systems, which use a video camera and complex computer program alongside the sound sensor system. The result is more accurate input to the vehicle, which instead of merely warning drivers close to an object, will actually steer and park the vehicle for them. This is very useful with parallel parking - you just have to let the car control the steering, gas and brake. What interesting and amazing technology we have these days!

If you're new here, you may want to subscribe to my RSS feed. Thanks for visiting!