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Unread 14-03-2014, 08:58
gpetilli gpetilli is offline
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Re: URGENT: wheel grinding noise

Quote:
Originally Posted by xXhunter47Xx View Post
It was a code issue. It was grinding because the wheel was getting an input from something (still haven't figured it out), and it would twitch back and forth, making a grinding noise.
Priority 1 is always safety.

It sounds like you do (did?) have encoders with a PID loop (running on CAN Jaguars) on the wheels that is marginally stable due to slack in the mechanical system. Removing the slack (tighten the chain) will help. Closed loop systems have trouble with non-linear delays. This is one reason many Mecanum systems are direct drive. We also square our joystick inputs [ joy * abs(joy) to preserve sign] to improve drive-ability and reduce the sensitivity to the joystick returning to center.

So one mechanical tweak and one software tweak. Closed loop systems are fantastic when they work and adapt to changing environments well but tend not to fail gracefully. Keep pushing your bot (and your team) to higher levels of performance. It does show on the field.
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