I was wondering if anyone had any experience with forklift style mechanisms in FRC bots. I would be interested in hearing the pros and cons of such a system when compered to a twin joint articulated arm.
Here are some of the pros and cons we’ve come up with while narrowing down are choices of a manipulator mechanism.
Forklift Pros:
-We have experience with it
-Simple to do
-Doesn’t require a lot of machining
Forklift Cons:
-Not very robust (in our experience)
-Requires upkeep during competition
-Can’t change orientation of object (in itself, requires more mechanism to do so)
Articulated Arm Pros:
-Can manipulate object in a variety of fasions
Articulated Arm Cons:
-Power Consumption
-Weight
-Complex
I would suggest looking here: http://thebluealliance.net/ for the 2007 matches. I think doing your research by watching the matches will give you the best idea of what to do. Remember, just because a complicated-looking device works very well from the past, it is no guarantee of what your team can produce. Stay within your capabilities and get the 'bot done early, so you can practice with it!
Good luck!
The biggest con with an arm this year is the 60’ rule!
772 has ahad great advantigase with a fork lift and was one of my first ideas when i first saw the game this year … here is some pictures of the fork lift from 2008 overdrive.
http://photos.sabrerobotics.com/displayimage.php?album=45&pos=0
It was extremely strong and could even pic up it elf by doing chin ups on the bar. but was heavy having hains linked from top to bottom a few times.
dont you meen 60in. not 60 feet please get your units right
Make sure you analyze the degrees of freedom of the gripper/forklift/articulated arm manipulator. What degrees do you NEED to perform the task? What degrees will HELP perform the task? What degrees will be EASILY CONTROLLED? What degrees will be EASILY PROGRAMMED (remember repeatability is very important)? What can be EASILY CREATED & TESTED with your team’s resources? Turn around time is very important to give the programmers time to work out kinks with autonomous and for the drivers to get some practice in. From there you can decide which rotational and/or which translational degree(s) of freedom will best allow your robot/team to complete the task.
Good luck, I hope this helps!
I Mis-shifted lol
I would say a con for the articulated arm is the complexity of the programming compared to the fork lift. Its only a bit trigonometry, but its not awfully complicated. To make it great is really hard
An arm can’t possibly be harder than a fully autonomous robot…
I said COMPARED. anyways I was gonna do a very simple mechanism, like the platforms that are like a giant car jack. IDK what they are called, but they are powered with pneumatic actuators. I thought that since they extend to a known distance, I can easily have 2 levels of height. First for the 2nd level and Second for the top. Yea apparently I can not do full automation this year due to the lack of fund… We used it for the 2nd regional, I thought my mentor said we are only doing 1 and that we had enough funds for all the sensors and stuff, apparently not.
I mean great as in: http://www.youtube.com/watch?v=vu6APoC0IOA or http://www.youtube.com/watch?v=5cORKyFr_7E
Elevator is the way to go!
Better yet, use metric units, 213.4 cm. http://www.chiefdelphi.com/forums/showthread.php?t=88589
good info were between these ideas to
My team is considering using a vacuum to pick up the tubes instead of an arm, does anybody think that is a bad idea?
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I have experience working with a Forklift, as a deal with them on a day to day basis working in a backroom of a grocery store. So, putting a forklift style mechanism ona robot would be easy to machine. However, it only privides a 3-axis movement. Therefore, taking more time needed to do the task.
As, for an articulated arm? I have been looking at the one we have in our shop. it provides a 6-axis movement but the programming it takes to perform the task is very redundant. It does get the task done in a very timely manner though.
Is there a possible way to combine the forklift style with the articulated arm?
I think it’s a clever idea.
Lends itself well to picking up deflated pieces too.
Go back and look at the 2007 and 2010 games for suction related devices. Many teams used suction in 2007 to pick up tubes, as well as last year to hang on to the soccer balls. Obviously 2007 may have some direct correlations, so start there. If I remember correctly Team Voltage had a pretty nice suction system in 2007 (Team 386).
-Brando
After all, the deflated pieces are still in play. But, we need to devise a way to place the cylinder on an axel and raise it so we can angle the hose, and lift it higher to reach the middle and top rows
As a team that has very successfully implemented a vacuum, I would caution you from using a vacuum to pick up these tubes. Instead look back at 2007 and look at the mechanisms that were most effective, particularly in acquiring and retaining the pieces.