GPS systems are a great way to find your way – when they work. For those times that GPS doesn’t live up to its moniker, North Carolina State University is developing the shoe radar.
One way to deal with the problems encountered when GPS units go offline – typically due to satellite connection issues caused by tall buildings or cave roofs, is to use what are known as inertial measurement units (IMU)s. These little things measure acceleration and deceleration forces to determine how far and how fast an individual or object is moving.
In theory, one could lose their GPS signal, walk forty steps in a random direction at an unknown speed, and an IMU would let them retrace their steps to a viable GPS position. The trouble is that IMUs themselves are prone to error. Even minor computation errors lead to problems, and these errors tend to compound as time goes on.
If an IMU is recording that you’re not moving when you actually are, your “original position” will soon be lost and you may never find that strong-signal GPS haven again.
Taking up the IMU challenge, researchers at NCSU have created a new type of “shoe radar” that will help to limit these errors.
The radar would do this with the aid of a small navigation computer used to measure the distance between your heel and the ground – and nothing else – and then relay thisinformation to the IMU. If your heel doesn’t come off of the ground, the computer and the IMU know that you’re not moving, and as soon as you take a stride, the computer can tell the IMU to start recording.
With a reasonable time threshold for how long a foot will stay motionless between steps and incorporating distance, IMU and last known GPS data, NCSU scientists hope that this Get Smart-esque footwear will help ensure that fewer people get lost in our increasingly wireless world.
Sadly, phone calls are not yet available – we’re sure Apple is working on that one. iShoe anyone?
Source: North Carolina State University