Quote:
Originally Posted by cjl2625
I have an idea for the code if you rearranged the layout to something like this:
You could do regular 4 wheel swerve calculations, and then end up with an (x, y) vector for back left, back right, front left, and front right. For each of those corners, take the x value and send it to the horizontal wheel, and take the y value and send it to the vertical wheel.
Might be better ways of doing it, but that's my idea.
Edit: I'm starting to realize that all 8 wheels might not be independent. In that case, my idea probably won't work. |
Actually that's probably a better idea than my current one, even with each wheel not being controlled independently, because both of the wheels on each side would end up being the same speed no matter what, because the robot can only move in a straight line and rotate. It's an interesting idea, and the layout makes more sense than my current idea.
Quote:
Originally Posted by Chris is me
The reason H drive has more forward traction than mecanum or omni is because more of the robot's weight is supported on the wheels pointing forwards than the wheels pointing sideways. In this configuration having more sideways wheels cancels out that effect.
With some specific exceptions, simply increasing the number of wheels on the ground does not significantly increase traction. So this drive is going to perform exactly as well as a holonomic 4 omni drive in terms of traction or manuverability.
In addition, once you put more than 4 wheels on the ground you run into problems with maintaining wheels contact. Unless your frame is perfectly rigid with every wheel at exactly the same height (and a perfectly rigid drive doesn't exist) you'll have some wheels supporting far more weight than others, this disproportionately influencing the direction of travel.
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From the sides or the front, where most robots would end up pushing, the robot would be able to push back without any problems, because of the direction of the wheels themselves, with a reconfiguration to cjl2625's idea. Also my team made a west coast drive without the dropped center (robot was wider than it was long) work last year. I don't think the maintaining contact thing will be an issue. As for the weight issue, I see what you're saying. That could be an issue.
As for something I've seen in a few posts in this thead: This would probably use four motors to avoid the weight issue with 8 motors. We'd have to check in offseason testing, though, since we don't have much to do to prepare for our offseason competition.
Anyways, if I can't convince my team anyway, we'd probably end up testing a butterfly drive or the like.