Chief Delphi

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)
-   Control System (http://www.chiefdelphi.com/forums/forumdisplay.php?f=177)
-   -   Steering for mecanum? (http://www.chiefdelphi.com/forums/showthread.php?t=61112)

eyekantspel 08-01-2008 20:36

Steering for mecanum?
 
For teams who have used a mecanum drive before or plan to use one this year, what are you planning to use as a controller to steer the robot? I had in mind a joystick, where the driver could twist the joy stick to spin the robot, push to the side to strafe, and any other combinations of movement.

qwertyuiop[]\ 08-01-2008 20:44

Re: Steering for mecanum?
 
i think that my team is considering a joystick with 2 buttons for spinning.

alicen 08-01-2008 20:50

Re: Steering for mecanum?
 
joystick with 3 axis. twist the joystick = rotate the robot.

Alan Anderson 08-01-2008 21:21

Re: Steering for mecanum?
 
The TechnoKats built a simple Mecanum prototype a couple of years ago. Control is done with two joysticks and tank-style steering, but pushing sideways on the joysticks results in the 'bot "strafing" sideways.

It takes a lot of practice to control well, since there's no wheel speed feedback to keep the robot going in the desired direction without constant adjustment by the operator. With appropriate sensors and software, I think it would be very natural and easy to drive.

GBilletdeaux930 08-01-2008 21:42

Re: Steering for mecanum?
 
We used a 3-axis joystick for it. Rotation was used for turning like the post above. It was worked really well and we were able to use the full functions of the mecanum wheels nicely

MrForbes 08-01-2008 22:02

Re: Steering for mecanum?
 
We have a mecanum promobot with a vex controller, and it uses a vex transmitter to control it...left joystick is direction control (left, forward, right, back, all relative to a driver "sitting on the robot"), right joystick controls rotation, left to rotate counterclockwise, right to rotate clockwise, with proportional control so you can rotate slowly, or quickly as needed.

Seems to be pretty easy to drive, could be improved upon?

Bryan Herbst 09-01-2008 20:41

Re: Steering for mecanum?
 
Our team last year used two joysticks- one joystick was tank drive, the other joystick used only the x axis and was for strafing only.This setup worked quite well, and we will probably be using the same setup this year.

talltree357 09-01-2008 21:19

Re: Steering for mecanum?
 
We have always used one joystick for steering mecanum drive. 2005 and 2006 were single joystick with the trigger used to engage translational drive. 2007 we used a 3 axis joystick, both work fairly well.

Bryan Herbst 09-01-2008 21:50

Re: Steering for mecanum?
 
Quote:

Originally Posted by talltree357 (Post 673884)
We have always used one joystick for steering mecanum drive. 2005 and 2006 were single joystick with the trigger used to engage translational drive. 2007 we used a 3 axis joystick, both work fairly well.

We've been considering this, and so far we've come to the following conclusion-
One joystick, trigger to activate strafe results in a smaller control board, less joysticks to worry about, and more open ports for other things, but...
Two joystick (or three axis joysticks) allow for strafing while using tank drive, making it much more maneuverable.

So far, it looks like 2 joysticks will make a comeback for us, as it gives you more maneuverability, which really is one of the major reasons why we went to mechanum in the first place.

Elgin Clock 09-01-2008 21:58

Re: Steering for mecanum?
 
I think Mecanum is pretty cool myself, and just want to know some more details about it even if it's not for this year.

That kind of drive concept intrigues me coming from a team who's only done tank or 4-6 wheel drives in the past.

I can't wait to see how teams do with the Mecanum drives a lot of them are talking about this year.

Does anyone have any sample code they used with a quick rundown of how it worked, or a list of hardware (both mechanically based and electrically based) needed for those interested in Mecanum drive?

This sounds like teams who have used this in the past could share a lot of insider knowledge this year, which is a cool concept in our world of sharing knowledge, and mentoring here in FIRST.


All times are GMT -5. The time now is 20:39.

Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi