HELP: Omni Wheels Programming Tricks

[cesaros]

Hi Everyone,

My team Will try using omni wheels next week, and I wanna now if have Any kind of advice to give for me.It will be my first time programming a robot with omni wheels too so, please give me some feedback.

Thank YOU! =P

[AllenGregoryIV]

It really depends on what you mean by "using omni-wheels".

Are you just adding them to a traditional tank drive setup or are you planning on doing some form of holonomic drive? (Andy Mark Omni Wheels)

Or do you mean meccanum wheels which are similar but different than what are normally referred to as omni-wheels.

[Kevin Selavko]

If you have your omni wheels in a configuration like this,
/ \
\ /
or are using mecanum wheels I would probably suggest using a game pad because it already has two joysticks on it so there would be less wires and you have up/down/left/right buttons. You definitely need to have dead zones. I would also suggest having a buttons to make it go strait in any direction so that if you push the up button it will have all the motors go forward at a selected speed, down button all go reverse at one speed, left button two go forward and two go reverse at the same speed, and if the right button is pressed do the reverse.

[iyermihir]

One thing that my team has done in the past is to put a gyro on the robot. You can then use the gyro to make the robot easy to drive by make it move according to the driver's inputs, but in relation to the driver so that pushing the stick forward will always move the robot away from him or her. This makes it easier for the driver because he or she does not have to worry about robot orientation. I'll see if I can get more information about the implementation sometime today.

[Ether]

Originally Posted by iyermihir

I'll see if I can get more information about the implementation sometime today.

The WPILib RobotDrive functions support the use of a gyro for field-centric control.

Or if you want to do it home-brew, you can find pseudo-code here.

[Ekcrbe]

Originally Posted by iyermihir

One thing that my team has done in the past is to put a gyro on the robot. You can then use the gyro to make the robot easy to drive by make it move according to the driver's inputs, but in relation to the driver so that pushing the stick forward will always move the robot away from him or her. This makes it easier for the driver because he or she does not have to worry about robot orientation. I'll see if I can get more information about the implementation sometime today.

As Team 1717 showed, using a gyro in an omnidirectional drivetrain can be helpful, but the gyroscope itself may be less than wonderful, so be cautious and make sure you get a gyro and setup that will limit "drifting".

[efoote868]

When using a gyro, make sure you use the correct output. The 2012 FRC gyro has a rate and temperature output, if you use the wrong output you may scratch your head at the results.