PING Tracking

I'm working on this arm that tracks object movement with the PING Ultrasonic Sensor.

I kinda need some ideas on how to get it to track people. I've already got this mode set up. When you turn the arm on, a servo rotates the ping around to capture distances. It stores them in variables. Then from that it goes into a scanning mode where it takes a measurement in the same area. If the measurement is different, then it starts it's tracking. If not it continues taking and comparing measurements.

One of my ideas for tracking was that when it finds that the surrounding is different, it turns left and right really fast and takes measurements. If one of the measurements are different, it turns the way were it had the different measurement. But I thought it would be way to slow because people can run. 

If you have any ideas just tell me. :)

The only real way to improve

The only real way to improve the tracking ability is to add one (or more) additional sensors - that way the arm can track in the correct direction immediately without having to sweep back and forth.

I was aiming to just use one

I was aiming to just use one sensor, because I thought if I used more than one, I’d have to go through more code and spend more money.

** "I thought if I used more**

  "I thought if I used more than one, I’d have to go through more code and spend more money."

Thats usually how it goes…

If you only have one sensor

If you only have one sensor then sweeping back and forth is your only real option, apart from just scanning around and around, which isn’t really tracking at all.