Mecanum Question about strafing.

[TheBassett]

How are you guys driving your robot? We used tank drive when we had mecanum wheels(both Vex Pro and Andymark) and had no problem strafing with it, even before we put any regulating code on it. We haven't really tried anything but tank when we were using mecanum so maybe that's the difference?

Also, if you are using Andymark wheels try making sure each roller spins freely, occasionally those rods got bent on ours and it would stop or slow down one of the rollers from spinning and also make the robot do strange things.

[SeafordVikingR]

At the moment, we have the controls on one joystick, but we may move onto tank drive too. Though, I read what hunter said about the gyro and maybe that's it? We have a gyro, but I wasn't sure if we needed to use it.

[orangemoore]

Originally Posted by SeafordVikingR

At the moment, we have the controls on one joystick, but we may move onto tank drive too. Though, I read what hunter said about the gyro and maybe that's it? We have a gyro, but I wasn't sure if we needed to use it.

Are you using encoders at all? If not it is hard to control you robot really well.

[Tyler2517]

I would be that your frame is either to ridged and all 4 wheels are not getting the same amount of traction, or your weigh is not distributed correctly leaving uneven traction.

Depending on how your algorithms (i am not a programmer all i know is that we wright our own C++ code for it) work can you manually compensate (ie try turning when you rotate). Or implement PID on each of the wheels we have has success with both methods and depending on the driver we have enabled our PID or disabled it.

[lcoreyl]

I can say in general in my experience you don't need gyro, encoders, or precision weight distribution to get a good strafe.

posting a quick video showing these things below will greatly increase your chances of getting some help, because we are all making a lot of assumptions in trying to guess your problem.

1) show your best and worst spinning rollers
2) show wheel rotations during strafe (as magnets mentioned). you can also put the bot on blocks to show this.
3) a clear shot to show the path the robot goes in when commanded to strafe


Also, the "O" vs "X" configuration wouldn't affect your ability to strafe, it would just go in the opposite direction. a worm's eye view X configuration would make it hard to rotate the bot.

[xXhunter47Xx]

That's how we sort of solved our problem. It still does the curve thing but a lot less, it only curves at slow turtle speeds. We're currently implementing PID with Encoders so we can make it do that even less.