Quote:
Originally Posted by Bruceb
one other thing
we NEVER lost comms during extreme contact with another robot or flying over defenses. It always happened when just starting to cross the defense and even happened when crossing the low bar once.
I am beginning to think a static discharge may be part of the problem as we noticed a static discharge when crossing defenses on the practice field.
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I believe you are on to something. Static problems can be so elusive because changes in humidity and surface contact materials are so difficult to track.I can relate one situation where static buildup definitely was the culprit and why it may relate to your problems.
We have used dozens of UsDigital MA3 absolute encoders for steering feedback over years so we know their characteristics pretty well. We have also used aluminum AM Performance wheels that contact the carpet even with tread attached. One off season we decided to replace the performance wheels with AM Plaction wheels for a demonstration robot. Within a couple of hours of run time, we had two encoder failures. The outputs would start to jitter and eventually get too bad to use. After realizing the wheels were Polycarbonate and probably isolating the chassis to allow static buildup, I attached a chain to drag the ground and never had another problem.
Many people are running pneumatic wheels this year without problems but most tires have additives that are conductive. Looking at the beach tires, they don't appear to have additives that other tires have. Is it possible that they are insulating enough to allow a charge to build on your robot? We have also had more static problems when running belts. They tend to create static like a Van De Graaff generator.
I'm not sure if a chain is the best idea this year with the defenses but something to reduce the potential between the carpet and the frame might avoid the big discharge when you touch the metal defense. If you can find a static gun some of this can be more scientifically proven.
For those that might say that the control system is immune to static, after working with plastic extrusion for 30+ years I have seen enough electronic equipment affected and destroyed from static buildup to believe that nothing is immune. Some designs are more tolerant but at some point a large enough discharge will cause damage. Also, many devices will continue to operate after being zapped but are degraded and prone to erratic performance and failure until replaced.