There’s That Mustang

Vehicles of virtually every type and make have been steadily growing over the past ten years. “Entry level” cars by companies like BMW are almost the same size nowadays as a mid-size car from a decade ago. One of the consequences of vehicle sizes expanding is that parking now is harder than ever.

Nowhere is this gigantism more visible than in the pickup truck segment, where even previously ’small’ trucks like the Dodge Dakota have inflated until they now dwarf their predecessors. In turn, full-size trucks have fought their own battle of the bulge, getting heavier, wider and taller. Toyota has not been immune to these market forces. The first generation Toyota Tundra was a mid-size pickup marketed to the full-size crowd, and when Toyota realized that they could cram more buyers into a larger vehicle, the 2007 Tundra re-design greatly increased the capacity of 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?

The system works using a set of “eyes”, or special sensors, mounted in the vehicle’s bumpers. The sensors regularly transmit highly focused sound waves from the bumpers, which are reflected back towards the sensor whenever they hit a solid object. Since sound travels at a fairly constant speed through air, a computer can calculate the distance between the bumper and object based on the amount of time it takes for the signal to return to the bumper. Submarines using active sonar underwater employ the same basic principle, although water transmits sound better than air, which results in better range for the submarine sensors.

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!