I am currently trying to create a lawn mowing robot which also uses Object Detection. Does the following patent prohibit me from doing this? http://www.freepatentsonline.com/9563204.html
The claims seem pretty broad but patents do not cover a result, rather a particular manner of achieving a result. You might study this patent, and many others in the same field and see a good way to address the problem that does not fall under anyone's claims. You can start by looking at earlier patents cited in this patent and subsequent patents that cite this patent as well as doing a more comprehensive search.
Another search element could be to look at other patent by the same inventor. Put inventor:(Mikael Willgert) into google patents to see a few titles that seem relevant like - Boundary definition system for a robotic vehicle - US9497901B2
You not only need to avoid patents specific to automated lawnmowers but patents that might be broader. The particular way you might combine radar and lidar data (to make up an example), might be patented outside the application area you are interested in. An extreme example is that there are patents are tire tread patterns.