Mecanum wheel programming in labview


#1

:eek: I need help programming mecanum wheels in teleport… Our programmers all left for college and I am left to learn… I have basic programming knowledge but not implementing mecanum drive… I went to implementing mecanum drive instructions but got lost in step4 implementing rotation case structures… it jumps from one set of structure logic to another… pretty vague … can anyone help?
Daleolgren


#2

Here’s an example:
http://www.team358.org/files/programming/ControlSystem2015-2019/labview/index.php#MecanumDrive


#3

Mecanum drive is actually pretty simple once you understand it. I’m willing to offer any help I can, but first I’d like to know how you plan to drive the robot. We’re personally using an Xbox controller, with the left thumbstick mapped to forward/backward/strafe left/strafe right and the triggers mapped to left/right rotation, but you can do this however you want. In order to help, however, I need to know what you guys want to do.


#4

The WPI Robotics libraries provide pretty straight forward VIs for implementing Mecanum. You shouldn’t even need to write the logic.


#5

You don’t even need to program the mecanum if you are using teleport. Just beam the entire robot to the desired location.

sorry, Star Trek fan, couldn’t resist


#6

I am trying to get z axis ( rotation ) to work … I am using Xbox controller and victor sp drive controllers… tried using team 353 implementing mecanum wheels in labview but got got a little confused in step 4 with the use of case structures in those examples… and also please excuse the auto type mistake in my original post regarding teleport vs teleop
Thanks
Daleolgren
Mentor team 4375


#7

Also we are using left joystick to control motion … but we wire the z (rotation) to axis 2 … by doing this you need to push axis 2 to drive and it is full power and no throttle


#8

replied to your other post, but make sure your using the right axis for your triggers.

Open up the driver station, go to the controllers tab and pull the triggers you should see what you need to reference to get proportional control.

You’ll have to negate one of them, but thats easy.


#9

Thanks I’ll try that…


#10

How can I wire a button to cut power in half with mecanum drive?


#11

Thanks for your help… the z axis is working… but I copied the code to another project so I could try different things with the code and I deployed the code under the different project before changing anything… when I enable on the driver station the wheels start running and I have no control with the joystick??? Any ideas… I’ve cross checked the code and it appears to be the same


#12

Divide the axis value by 2

Are you testing in teleop or autonomous? Make sure you have teleop selected on the DS.


#13

Why do you want to do that? What is the problem you’re trying to solve? If you don’t give details like that you may receive bad advice.


#14

Trying to have a little finesse with drive when backing in to the lift… in panic mode… our driver hasn’t been able to practice with all the programming issues we’ve had… and now won’t be able to until competition … and we need some programming options


#15

You should just be able to use the joystick to proportionally control, but if not, you could put a case structure in line with your axis, with a button controlling it.

Inside the true case you would multiply it by .5 or whatever scaling factor you want, inside the false case just wire it straight through.


#16

Does this look right?

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#17

her is a shot in false

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capture 2.JPG


#18

In the True case, I would take the value from the joystick axis, multiply it by the 0.5 you already have in the case structure and then send it out to the holonomic drive block. This way the driver still has control over the robot if they want to go slower or reverse, but they can only go up to half speed.

Your False case looks correct.

You may want to consider doing the same with the rest of the axes.

Eric


#19

exactly.


#20

Hello

We were a rookie team last year upgrading to mecanum and you post or send your code to us