Programming swerve drive in Labview?

[Ether]

Originally Posted by autox_vette

I have to ask then, what is the difficult part?

Kenton

In your original post, you stated that you wanted to program a swerve drive that is "fully functional (i.e. simultaneous translate and rotate)". How to compute the necessary speed and steering angle of each of the four wheels at each moment in time for any desired vehicle motion (inverse kinematics) is straightforward and has been explained here on CD in papers and posts. The difficult part is what you then do with those computed values to get a vehicle that drives smoothly, safely, responsively, and predictably.

Read the last 2 paragraphs on Page2 of the paper
2011-03-28 Calculate Swerve Wheel Speeds and Steering angles.pdf
located here.

[Gdeaver]

Ether has done the modeling. The problem with true "fully functional (i.e. simultaneous translate and rotate)" As far as we have found is that it would require an algorithm that keeps a short history of previous wheel position and a calculated future set of wheel positions. Not an easy programming task in any language. We have not done this yet. Our 2012 bot drives quite well with out going down this path. For a first year swerve effort, you may want to leave this off the plate.

[jcbc]

I have posted Team 1640's 2011 "Pivot Drive" (swerve) code here:

http://www.chiefdelphi.com/media/papers/2704

Thanks to the team's 2011 head programmer, Ben Rajcan, it is nicely packaged as a LabVIEW library. I hope that it will be useful to teams who want to try out programming a swerve drive.