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Unread 05-04-2016, 13:01
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Re: Searching For Swerve / Holonomic Drive Idea

Quote:
Originally Posted by Ari423 View Post
I would have imagined that if you only get a sideways force from the back two wheels, you would rotate rather than strafe (the same way you would turn if your horizontal wheel in an H-drive was all the way at the back), but I could be wrong.
I don't know why you would imagine that. The pair of drive balls doesn't simply apply a fixed-orientation thrust. Each of them moves at a specific speed in a specific direction. When strafing directly to the side, that velocity is exactly sideways. There is no forward or backward motion of either ball. Unless they slip on the carpet, the robot simply does not rotate. Since the omniwheels are also not turning during a pure sideways strafe, they too act to keep the robot direction constant.

I think you're failing to recognize that the balls are completely controlled in both x and y directions. Unlike omniwheels or Killough cagewheels or Mecanum wheels, there is no direction in which they "slip".
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