Comment by TrackerFF

This is one of the problems where I think a simple camera or two would suffice.

Years ago I worked as a consultant on a projects which is quite similar to this, but larger scale and involving moving machinery. The task was basically to come up with sensors that would register when and which machines would be at what place in a structure. In the end we came up with a solution which only involved cameras and object detection...this was before AlexNet etc., so fun times with classical machine learning.