Hab 2 Jump Speed


#1

My team has discussed using the Hab 1 ramp to jump to Hab 2, but we are unsure if we can do it with our mecanum drive and ~120lb robot.

How fast would a robot have to go to complete the jump, and could ours do it?


#2

I think it depends on lot of factors, and the best thing to do is get out there and test it. The process of a Dukes of Hazzard climb is pretty interesting - the robot will tip back as it goes up the ramp, and you have a little bit of time to get your front and center wheels onto the platform before you tip forward again. We’ve found that you need to increase your robot’s moment of inertia for the best results - typically this means taking the elevator up. Robots with 8WD’s will generally perform better than those with 6WD’s. Watch out for G12, though - you need to keep your robot below 78" from the carpet as you climb. In general, faster is better because it means you take less time to get from the ramp to the platform, meaning there’s a lower chance you’ll rock back forward and beach yourself.


#3

I’m unsure what type of damage you would sustain with a mecanum drive if the robot lands awkwardly when attempting to jump, which would be my only concern. The weight of your robot should be okay as long as you can move the robot fast enough to get enough ground clearance to leap onto level 2, and honestly the best way to test it is to do it and be prepared for the consequences (wheel or bumper damage) if something goes awry.


#4

I have seen plenty of teams do it with 6 traction or a 2+4 but not one with 4 wheels/mecanum yet. I think you’ll have a large problem with beaching if you try.


#5

The faster the better. Just watch 2337.

And send it.


#6

The speed is something you’ll have to determine on your own, some other key factors you may want to know are; Is it top heavy or is all the weight focused on the centermost part of the robot at the bottom, how easy is it to tip, what is your maximum drivetrain speed, weight, torque? General things you’ll want to understand if you don’t pass the first or second question it would be best that you didn’t. However if you do what our team did instead driving off of a ramp and you do it successfully then you already know the answer yes you could do it, it’s just a matter of what speed to use. I would keep in mind that you may want to have a way to stop the robot or tie it down so it doesn’t fall and damage a part


#7

I do not believe that a 4 wheel robot is capable of doing this jump, mecanum or not as the ramp is too short for a drive base spread out that much.
You can watch in this video that it is clearly the center drive wheel that is vaulting the robot up into the air. Also 5458 found that you have to balance your speed very closely. Too fast and your vertical velocity doesn’t change enough to clear the edge by the time you arrive. Too slow and you don’t get enough height by the time you reach the edge as well. You have to be going at the RIGHT speed, which will depend on your drivetrain, CG, weight, and your robot’s rotational inertia.