Understanding the Holonomic Drive

Programming Support
#1

So, my team is trying to code a Holonomic Drive (Edit: It’s an X-Drive) for this year’s competition and I am just trying to understand how to program the controller for it (like the concepts, not the actual code- although that would be helpful).
Can someone please explain it to me (also I know how to code at an intermediate level, so please go easy-ish on me)?

Thanks in Advance! :slight_smile:

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#2

It’s important to specify what kind of holonomic drive first: X-Drive, meccanum, or H-Drive?

#3

Sorry, it’s an X-Drive.

1 Like
#4

The search bar is your friend, searches for terms like “x-drive programming” returned lots of results with discussion of this topic.

This thread looked particularly useful; it’s got code examples in ROBOTC but shouldn’t be too hard to write equivalent code in whatever V5 programming setup you prefer.

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#5

Thanks for the help!

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#6

So, I made a sample code for our x-drive and it can go forward and backward and it can turn, but it won’t strife left to right or go diagonal. Am I missing something? (I followed the threads and this is what I came up with)

Here is the code (it’s in Vex coding studio):

Screen Shot 2020-07-06 at 1.43.30 PM

#7

What happens when you try to strafe? do the wheels fight each other, does the robot turn?

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#8

At a glance the code looks fine, I’m not really sure what went wrong here.

#10

When the robot tries to strafe, it turns.

#11

You might have to switch around some of the + and - for the strafing inputs

here is my code that I made for a mecanum drive (should work for an x-drive too):

    fwdAmt = Controller1.Axis3.position();
    turnAmt = Controller1.Axis1.position();
    strafeAmt = Controller1.Axis4.position();

    LeftFront.spin(directionType::fwd, fwdAmt + turnAmt - strafeAmt, velocityUnits::pct);
    LeftBack.spin(directionType::fwd, fwdAmt + turnAmt + strafeAmt, velocityUnits::pct);

    RightFront.spin(directionType::fwd, fwdAmt - turnAmt - strafeAmt, velocityUnits::pct);
    RightBack.spin(directionType::fwd, fwdAmt - turnAmt + strafeAmt, velocityUnits::pct);

note: the right side motors are both reversed in the config

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#12

Thank you so much ! :grin:

1 Like