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Unread 14-01-2011, 09:51
Greg McKaskle Greg McKaskle is offline
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Re: Omni-directional drive

The general answer to these questions is determined by drawing an arrow at each wheel position, appropriate for the type of wheel. For example, an omni has a two headed arrow parallel to the roller pins, indicating how the wheel can enact a force on the robot. Mecanum wheels would have a two headed arrow at ~45 degrees, parallel to the roller pin, etc.

The wheel speed direction determine the vector lengths, and once you have these, you combine the vectors to determine the robot direction. In many cases, the vectors are in a single heading, so they simply sum to produce an overall robot force vector. If the vectors are in at different angles, pay attention to the moment from a common point such as the center of the robot. For a qualitative evaluation, you will soon be able to do this in your head, and it will be "common sense", but it is good to be able to analyze new systems you have never seen, and when you want to start predicting numbers, the vectors will do that as well.

Greg McKaskle