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Unread 25-10-2015, 14:39
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Re: pic: Seen at Fall Classic: Side

Quote:
Originally Posted by seg9585 View Post
I'm trying to understand the overall benefit of this configuration vs a standard mecanum setup or even front mecanum back 2 omni. Surely this config is not favorable in traction with only minimal benefit to powered rotation. Weight reduction (3 gearboxes vs 4)?
Quote:
Originally Posted by AdamHeard View Post
Three points of contact is deterministic at least and makes a suspension not needed to handle ramps such as this year properly.
Yes, that's part of it. It also reduces the amount of width and machining that would be needed to mount rotated omni wheels to produce a kiwi. The angles between the forces of adjacent wheels here are 90- 135-135 as opposed to 120-120-120 for kiwi, but it should be close enough to work after some tweaks to the inverse kinematics.

A peculiar thing I just noticed after mentioning kinematics is that the robot can deliver more drive force in the direction transverse to the direction it picks up totes than in the direction parallel to the totes, by a factor of about 1.7 for equal loading on each wheel, more or less as the CoG moves. This means that when you want to cover ground, you'll want to think of the long edges as the front/back, and the open and closed short edges as the sides.

Edit: If this drive style does not yet have a name, I dub it Meckiwi.
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Last edited by GeeTwo : 25-10-2015 at 21:30.
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