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Sensor to detect direction over a longer range

marjasin

I want to create a camera that can follow a person around ( a football player on a pitch). Both Ultrasonic and IR-sensors would be way to short range since the maximum distance could be as much as 100 meters. Do you have any ideas on what to use for this application?

  • What do you mean with "follow around"; should your camera physically be on the field and follow a player, or do you have a tripod-based camera that should keep someone in view?

    My first idea would be to use image recognition as you already have a camera.....

  • in reply to vsluiter

    Sorry for the bad description.

     

    The camera is mounted on a tripod with a servo that can change the angle. I need to know if I should change the position more to the right och to the left. Maybe image recognition is a good option, I just thought it might be hard since there will be other people on the pitch as well.

  • in reply to marjasin

    To quote Coldplay: "Nobody said it was easy".

    If you have to track one player you won't be able to use one camera, or that player has to wear another color tshirt than other players.

    Have you looked at this article / the research behind it: Tracking Footballs with Magnetic Fields ?

  • Hi Freddy,

    Can the player wear a small radio transmitter about the size of a USB memory stick?

    If so, it could send a ping every second or two and 2 receivers separated by 10 or more meters of cable could figure out the angle from the difference in time of arrival of the ping. The first receiver to get a ping would start a timer that counts until the second receiver gets the same ping. The comparators and timer trigger would be on the cable half way between receivers. Accuracy of the measurement would need to be about 1 nanosecond. (1 GHz clock)

  • in reply to dougw

    Yes, that would be possible and also maybe prefferable. What kind of transmitter/recievers could you recommend?

  • in reply to marjasin

    I would use the cheapest radio modules I could find in the 2.4 GHz band for a couple of dollars each, as long as they claim to transmit far enough. I would likely have the person-mounted transmitter broadcast a continuous square wave at some frequency like 1 KHz and then compare the phase of this signal from the two separated receivers. Note that the phase difference is only going to be nanoseconds, so your phase discriminator will need to be able to measure small phase differences.