Thread: closed-loop torque (current) wheel control for mecanum
View Single Post
  #4   Spotlight this post!  
Unread 07-02-2010, 00:54
eugenebrooks eugenebrooks is offline
Team Role: Engineer
AKA: Dr. Brooks
no team (WRRF)
  
Join Date: Jan 2004
Rookie Year: 2001
Location: Livermore, CA
Posts: 601
eugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond reputeeugenebrooks has a reputation beyond repute
Re: closed-loop torque (current) wheel control for mecanum
The torque is proportional to the current, limit the torque to just below the torque that causes wheel slip, and your wheels never break traction. It was a good patch given the lack of wheel counters (including a free wheel) in that it only required current sensors and some software.

There are rubs:
As the speed of the robot runs up, some of the torque (measured current) is tied up in drive train friction and because of this you lose a portion of the torque that you would like applied to the wheels.
The best performance is obtained with just a little slip and you can best obtain this by using wheel counters (including a free wheel with a counter).

Eugene