Your article does not explain what a choke or inductor
have a look at this:-http://en.wikipedia.org/wiki/Inductor
It is simply a coil of wire on a ferrite core.
I can't find anything specific to robotics
There is nothing specific about the application to a robot than anything else.
When you say "supply decoupling lines" you mean the power supply lines to my sensor board
Anything that supplies power to anything. To be effective decoupling should be applied as close to the chip as possible.
Kinda like a mini faraday cage
That is only effective if the interference is radiated, it has no effect on conducted interference.
One thing to try is to power your arduino and sensors from a completely independent supply like some batteries. Don't join the grounds together. If you still get the problems then it is likely you have a radiated problem. Then you can look towards screening and suppressing the causes of interference which in your case is likely to be the motor.