I am trying to figure out what would be the best way (by best way I mean the cheapest, and simplest effective way) to detect slippage of the wheel. The surface is very low friction, somewhere in the range of 0.05 mu. Here are my ideas: Sense current, watch for spikes/troughs monitor wheel speed with optical encoder and compare to velocity limit acceleration I do have a question about the current draw solution: what would happen to the current draw if the wheel were to lose traction? Would that be an effective indicator at all. If it would work, that would be my preferred option. What else could I use? Which of these would/wouldn't work? Thanks for your help.