(Transmitter\Receiver) pairs

Wireless & IoT
1

Hello Guys ! I hope u can help me with this :slight_smile:

I’m building a robot , one of its main function is to do the following :

Go to a predefined destinations.I don’t want to Use path-follower because it clashes with another main function( avoiding obstacles ) . So i figured , one way to do this , is to get several (Transmitter\Receiver) pairs with different frequency for each pair.I’ll place Transmitter1 in destination1 , Tarnsmitter2 in destination2 etc. and place all the receivers in the robot.So when Receiver1 is activated the robot will go toward Transmitter1 (destination1) and so on .

My questions :smiley: :

does it make sense - is it possible ? if no what is the alternative ?

if Yes

which Transmitter/Receiver pair should i use ( long rang , reliable … etc )? , can i get one with built-in circuit ?

can i get different pairs working together (different frequencies) ?

Thanks a lot in advanced

2

How will the robot navigate to a transmitter?

Leon

3

leon_heller:
How will the robot navigate to a transmitter?

Leon

I guess the receiver will be able to locate the transmitter . and base on the data given by the receiver the microcontroller will direct the robot toward the transmitter . But it all depends on the features of the the pair , hence my questions :slight_smile:

4

You would need some sort of positioning system at that point (read: GPS).

Unless you can come up with a method of using an orientable directional antenna to determine which direction the transmitter is in. I’m not sure how well this would work, things like reflection and shielding and ghosting and general noise come to mind). Granted, I’m not very familiar with these ideas…

5

To do that accurately requires two transmitters, like the LORAN system:

http://en.wikipedia.org/wiki/LORAN

Leon

6

According to the wikipedia paged linked from yours (http://en.wikipedia.org/wiki/Multilateration), he/she could perform the inverse, and simply have three receivers.

Thanks for that link, I never knew it was a formalized system. Neat!

7

thanks a lot guys , but how do i implement Multilateration or LORAN ??

8

RF direction finding is not an easy subject. You might want to consider infrared, which could be implemented this way:

  1. Infrared transmitter stations are placed at the predefined locations. Each IR station has an associated RF receiver.

  2. When the robot wants to go to a particular location, it sends a CODED RF transmission to turn on that location’s IR transmitter. Only that particular IR station’s RF receiver responds to the transmission and turns on its IR transmitter. The IR tranmission is also coded, to distinguish it from the IR transmitters of other locations.

  3. The robot rotates its narrow field IR receiver to locate the coded IR transmission. Once the transmitter is located, it can proceed towards it.

Hope this helps.

Satz

9

Ultrasonics is another technique that is often used, with a rotating scanner to find the direction to a transmitter. Rotating the robot will also work.

Leon