UFO Sightings

Vehicles of almost every sort have been getting bigger and bigger over the past decade. In fact, even the “entry-level” cars offered by companies like BMW are nearly the same size and weight as mid-size cars were just ten years ago. As vehicles keep getting bigger, parking has gotten progressively more difficult.

The most obvious vehicle size increase has been in the pickup truck segment, where “small” trucks like the Dodge Dakota now look like giants beside their early predecessors. Full-size trucks have also been expanding, becoming heavier, wider and taller. Toyota too has participated in this growth trend. The Toyota Tundra was originally a mid-size pickup marketed to full-size buyers. Toyota realized a larger vehicle could fit more customers, and as a result, the 2007 Tundra was much bigger than earlier models in almost every dimension.

While size does matter, all of that increased mass is nowhere near as easy to park as it used to be. For instance, when you ride in a new Toyota Tundra, you’ll probably find it difficult to tell exactly where the truck begins and ends. Vehicle designers, in an effort to make our lives easier, have come up with something called “parking assist” to help overcome this issue.

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.

The next generation of parking assist systems has begun to appear in high-end luxury cars, and it’s really quite amazing. Rather than using just sound sensors - which are somewhat inaccurate - the system uses a video camera and a complex computer program in conjunction with the sound sensors. Instead of just warning the driver when they get close, this next generation of parking assist actually steers and parks your car for you. This is really helpful with parallel parking - just so long as you’re willing to let your car work the steering, gas, and brake. What will they think of next?

Filed under: Vehicles