Mecanum Drive Technique

[Dan Petrovic]

Can anyone help me understand the technique behind making a mecanum drive system?

I know there are mecanum wheels that are reversed, and all that, but how would they be set up and driven to drive sideways and diagonally and all that fancy stuff?

Thanks

[Stephen Kowski]

mmmm kinematics.....try reading this paper to start with, it should get you on your way....http://www.chiefdelphi.com/media/papers/1836

[EricS-Team180]

Can anyone help me understand the technique behind making a mecanum drive system?


Here are a couple of links on how you'd go about programming the stick...

holo-drive math (http://www.chiefdelphi.com/forums/showthread.php?p=421092#post421092)

...and more (http://www.chiefdelphi.com/forums/showthread.php?p=354984#post354984)

...and there's more out there, too....just search on holonomic and omni-wheel ;)

Eric

[Tytus Gerrish]

mecanum works the same way as an Omni-directional Holonomic drive. its just that the rolers are at 45° instead of the whole wheel. simple as that.

[Dan Petrovic]

Thank you all so much.

This will definately help.

[Madison]

mecanum works the same way as an Omni-directional Holonomic drive. its just that the rolers are at 45° instead of the whole wheel. simple as that.

The programming required to achieve the same motion varies pretty significantly, however, between holonomic and mecanum drivetrains. The principles by which they operate are similar, but the implementation is different.

[Lil' Lavery]

mecanum works the same way as an Omni-directional Holonomic drive. its just that the rolers are at 45° instead of the whole wheel. simple as that.
As Madison said, Holonomic and Mecanum drives can actually be quite different. For instance, the rollers don't even have to be at 45º (different angles will alter the amount of energy that is used when going different directions. A 45º angle results in the movement in both the X and Y axis being equal, but any other angle they would not be).
Basically, a mecanum drive's angled rollers directs some of the energy of motion sideways, and depending on the direction and speed (the vector) of each wheel, you can move your robot in any direction.

[Alan Anderson]

The programming required to achieve the same motion varies pretty significantly, however, between holonomic and mecanum drivetrains.
Not so. Program-wise, a standard omniwheel mounted at 45 degrees works exactly like a mecanum wheel with its rollers at 45 degrees.

[Madison]

Not so. Program-wise, a standard omniwheel mounted at 45 degrees works exactly like a mecanum wheel with its rollers at 45 degrees.

Yes, that's correct. The programming only differs if you consider 'forward' to be a direction parallel to one pair of omniwheels in a holonomic platform. Thanks for pointing out my oversight.

[Tytus Gerrish]

As Madison said, Holonomic and Mecanum drives can actually be quite different. For instance, the rollers don't even have to be at 45º (different angles will alter the amount of energy that is used when going different directions. A 45º angle results in the movement in both the X and Y axis being equal, but any other angle they would not be).
Basically, a mecanum drive's angled rollers directs some of the energy of motion sideways, and depending on the direction and speed (the vector) of each wheel, you can move your robot in any direction.

45º is simply a rule of thumb you can do it at whatever angle you would like you could even actuate the angle to get some diffrent properties out of the preformance.