Looking to buy and program drone for warehouse inventory conciliation

I am currently looking to implement Aerial Drones to perform inventory reconciliation with my company WMS.

The drone would have to perform an indoor fly route; or to be controlled by a computer or application performing a fly path and taking pictures in specific points.
The case scenario would be to perform photos of rack positions to be later processed by independent image software. Ideally the dron would need to know its orientation in relation to the racks in order to avoid crashes.

I have been researching drone indoor technologies.
http://www.andfestival.org.uk/projectdaedalus/tracking-your-drone/

Has anyone seen an actual implementation of the Visual Positioning System or maybe a triangulation like?
http://www.novadem.com/Technologie-en.html

Would it be possible for example to program the drone to make an XZ route like this example for four racks via some SDK or interface?

The flight plan would be the following.
Stop in the asteriks and take a picture.

-----*-----*-----*-----*-----*-----*-----
|
-----*-----*-----*-----*-----*-----*-----
|
-----*-----*-----*-----*-----*-----*-----
|
-----*-----*-----*-----*-----*-----*-----

or
*------* *-----* *-----*
| | | | | |
* * * * * *
| | | | | |
* * * * * *
| | | | | |
* *-----* *-----* *
In addition it would have to avoid the racks NOTmoving in the Y axes. Maybe y can stay in place by the visual positioning system?



Thanks in Advance