Strategies to prevent overcurrent/breaker trip

[kmcclary]

Please describe in this thread your team's method of preventing motor overcurrent/overload (and subsequent breaker tripping) with an optimized drivetrain.

What are the different methods to prevent breaker trips, and what are the pros and cons of each? How did you implement it with a multimotor gearbox? Can your method adapt and still protect the breakers in case of sudden huge load changes like ramp inclines, goal towing under all load conditions, your robot being pinned, or tug-of-wars?

Suggestions I've seen so far, each with their own strengths and weaknesses:

1) Design the drivetrain to simply tire slip at any torque greater than 30A will provide. (Paul Copioli, Thunderchickens)

2) Software limiting PWM at "full stick" unless a "turbo" button is hit (Al Skierkiewicz, 111)

3) Current sense and throttle back (various teams), including Tim Skloss' "Brown Toast Breaker" method (team 930): Current sense & integrate, modeling the breaker's heating curve. Throttle back whenever the "toast starts to get brown"...

Current sensing is "currently" being discussed at: http://www.chiefdelphi.com/forums/sh...?threadid=2205

Has anyone implemented any of the following?
- Breakaway/autoslip clutch of some kind
- Automatic transmissions (NOT operator controlled)
- *TORQUE* sensor feedback to the RC (i.e. strain gauge)
- How to throttle back multimotor drives CORRECTLY to prevent backdriving any of the motors
- Automatic load shedding / load prioritizing
If so, please describe the system.

Anyone have another system??

<edit>
If you've already discussed your system in another thread, please just cite the thread (add a link) and summarize it here. I'd love to see this thread become a nice summary / collection of all the methods in one place! Thanks!
</edit>

- Keith