[MrForbes]

The TARGET is described in the ARENA drawings. As far as I can tell, the only way to make sure your MINIBOT will TRIGGER it is to build it and try it--or do a detailed analysis of how the plate will behave when struck by your MINIBOT. The 2N to 4N thing in the ARENA description gives you an idea of what's required, but you still need to look at the design of the TARGET to be able to figure out exactly what's required.

As for the sensors...I guess we just have to guess at how it works, and make sure the plate will move a long ways when the MINIBOT hits it?