# IR positioning camera

#### kate90

##### New Member
hello,
I've been trying to work with the DFRobot IR positioning camera but I have no idea what it does.
can anyone help me understand what it reads?
(does the camera read distance? is the output of the camera in pixels?...)
(Basically, I have 4 IR transmitters placed on a platform and the IR camera is fixed on a robot. I have to measure the distance from the camera to the transmitters so I can position the robot perfectly on the platform.)

Last edited:

#### alec_t

##### Well-Known Member
can anyone help me understand what it reads?
The camera calculates the [x,y] co-ordinates of up to four IR sources. Download the two documents listed on the supplier's website to find out more.

#### kate90

##### New Member
The camera calculates the [x,y] co-ordinates of up to four IR sources. Download the two documents listed on the supplier's website to find out more.
Do you have any idea how can I find out the coordinates of the camera itself?

#### DrG

##### Active Member
Do you have any idea how can I find out the coordinates of the camera itself?
I was just looking at the linked info of the camera.... "The horizontal angle of camera is 33 degrees while the vertical angle is 23 degrees. It returns up to four points at a time describing" where, in the field, the object appears.

Think about the viewing field of the camera as described. It does not read distance and it does not return pixels, per se say. I looks like is reading the location of IR "objects" within the viewing field and identifying their position(s) using a coordinate system.

(Basically, I have 4 IR transmitters placed on a platform and the IR camera is fixed on a robot. I have to measure the distance from the camera to the transmitters so I can position the robot perfectly on the platform.)
There might be some way to approximate distance by centering the robot first, measuring the distance by hand and getting the coordinates. That would be, for lack of a better term, the calibrated distance. If the camera, and its placement on the robot and the ir transmitters were all at fixed locations. Then, you could systematically move the robot to return to the place that gives those exact coordinates.

There is probably some method of moving the robot a known distance (some scaling that you have determined, e.g., one wheel revolution=xx inches) and derive distance from the change in coordinates - is that the assignment? If so, maybe starting here would help.

Last edited:

#### kate90

##### New Member
I was just looking at the linked info of the camera.... "The horizontal angle of camera is 33 degrees while the vertical angle is 23 degrees. It returns up to four points at a time describing" where, in the field, the object appears.

Think about the viewing field of the camera as described. It does not read distance and it does not return pixels, per say. I looks like is reading the location of IR "objects" within the viewing field and identifying their position(s) using a coordinate system.

There might be some way to approximate distance by centering the robot first, measuring the distance by hand and getting the coordinates. That would be, for lack of a better term, the calibrated distance. If the camera, and its placement on the robot and the ir transmitters were all at fixed locations. Then, you could systematically move the robot to return to the place that gives those exact coordinates.

There is probably some method of moving the robot a known distance (some scaling that you have determined, e.g., one wheel revolution=xx inches) and derive distance from the change in coordinates - is that the assignment? If so, maybe starting here would help.
Thank you!

#### DrG

##### Active Member
Thank you!
You're welcome. Is it starting to make a little more sense to you?