817A V1 Robot Reveal - Inhaling the Wall

VEX V5 General Discussion VEX Robot Showcase
1

So its time for the annual reveal of the robot that my team and I have worked on throughout the summer. Many teams have talked about the inhale the wall (of game objects) as a possibly unbeatable strategy, and my team is hoping that this is correct. :smiley:

The features we built this robot to have:

–Can pick up all 18 game objects in the center of the gateway field
–Can score the game objects in goals of any height
–Can shuffle game objects while driving between goals

Motor and pneumatic distribution:
Four HS motors internally geared for torque - one per wheel
Two motors of the strafe part of the H-drive
Two motors on the lift
Two motors on tank tread
Two double acting pneumatic pistons to tilt the large bucket

Finally the pictures. Click on the thumbnail for more detail: Its a good way to show pictures without making the page take forever to load.

Interesting features:
–Bevel gear system on the front wheels saved a lot of horizontal space and worked surprisingly well under a lot of weight.
–The robot unfolded because of latex pulling on a winch system, which would keep the robot’s chassis unfolded.
–The pneumatic pistons had a TON of elastic helping to lift the bucket. Each time the pneumatics would fire, the game objects would fly into the air. This was how we would funnel game objects to the tank tread system and combining the two systems, we could shuffle objects while we drove between goals or played defense, until we had only objects of our color in the tank-tread.

In the end, we ended up completely disassembling the robot because of its lack of consistency. At times the robot was unbeatable, but often after a lot of use, it would start to fail. My team decided that we needed a more stable robot, with a more robust drivetrain, that would require less work to maintain.

This robot only went to one competition in Connecticut, where it performed well in the qualifications finishing as the second seed. However in the eliminations we lost in the first round when we were disqualified in one match (The robot drove off the square as I was putting match loads in. My fault.) We won the second match, and in the third match, our alliance partner had a bad battery and our robot performed poorly.

Questions and comments are appreciated.

2

do you have pictures of it in the process of “inhaling”?
or videos would be better :slight_smile:

3

Somewhere, but it will take some searching. I don’t have permission to release video of it yet, but I should be able to find a picture.

Edit: We didn’t take many pictures, so this was the best I could do. Sorry its not a great picture. Unfortunately no pics of it full, but in this picture the robot is “in the process.”

4

Hey, interesting bot.
How quickly could it “inhale” the entire wall?

5

Compared to how we would like it… very slow.

We did not have enough time to write an autonomous program before the first competition, so it was probably be done about fifteen seconds into driver control. We don’t know why, but sometimes we could just drive under the pile, and tilt the bucket back about five seconds into driver control, and sometimes we would have to crash the game objects into a wall, which would take a little over fifteen seconds.

It was just version one, and the ease that it could be defended against was also a major factor in us deciding to disassemble it.

6

Congratulations on taking a radical concept and actually doing it! Not a lot of teams are ready to risk taking a robot that may or may not work.

Questions
-How good was it at scoring? Which goals could it do?
-Was your alliance partner inundated with objects in the isolation zone? Could they still drive around?
-Are you going to build a version two of the same concept?
-Did you find it effective in any of the matches to do this and hoard almost all of the game objects from the other team? Were they left stranded with nothing to score?

Again, great job actually building this robot instead of another standard efficiency bot.

7

I’m also interested in the effectiveness of this robot, kudos for building it!

To add to Totally Generic Name’s questions:

Did you find it necessary to add a scoring element to the robot? In other words: if you rebuilt the robot, would you have kept its scoring capabilities?

8

It was very good at scoring on goals of all heights. I’m not sure if you can tell from the pictures, but the 17 inch tall tank treads are mounted on a 17 inch slidebar. This is how we got high enough to score on the high goal. I would say that we had the most trouble scoring on the 11.5 inch goal because the game objects would have to drop the six inch difference unguided. Also, we did not have enough reach to descore the top of the thirty inch goals, but we could usually add above the top of the goal.

In the one tournament this robot went to, we never dumped into the isolation zone. Although it might be a good idea, the concept this robot was built upon was scoring object starvation, so we didn’t have a problem with opening the isolation gate early.

It will be similar, but I’m not allowed to say how. Version one has been completely disassembled, so structurally it will be completely different. I can say that we plan on using the 8 motor mecanum drive train that showed up to QCC on Saturday. But not in the same way.

The short answer is yes. When we played good teams this strategy worked well, however against the poor teams, they hardly noticed and just scored match loads and objects in the isolation zone. We won either way.

Your team may disagree with this, but my team thinks that qualification matches are very important so that we have an option of who picks us. In your region, robots seem more consistently good, while in our region, teams seem to be on two distinct levels, so we can’t depend on our alliance partners to get the win if we are just defensive. Version two, when completed will be able to score.

Basically we have a choice between game object starvation, and game object starvation with goal starvation. If we want just game object starvation, we just hoard and score game objects. If we decide to go for goal starvation too, then after we pick up game objects and dump them into the isolation zone, (@TMS which would limit our partner’s mobility) we would play pressure defense like your (SweetMochi’s) Z team.

9

It looks interesting enough that I wish the description were better.

One of the counter attacks to this type of robot is a spring loaded catapult that knocks down the wall with a preloaded ball at T=+0.5sec.
But that doesn’t seem like it would work as well against the gatebot that swerves around the wall to deny it to opponents.

10

Since I wrote this description, and will probably write descriptions about other versions in the future, how do you (or others) recommend I improve on my description writing?

I can still answer questions if you ask them.

11

I do not believe I fully understand how it is you manage to get the objects from the picked up pyramid into your conveyor belt and sort through which color you wish score.

Another question I have is to how easy (or difficult) it is for teams to mess up your picking-up-of-the-pyramid routine? And in the event of you “inhaling” the pyramid, can other teams easily grab them out of your unprotected basket?

Anyways, I don’t think I understand how this robot works;), but it looks mighty impressive!

12

OK. I see how this was too vague. The entire process is very complex.

  1. The pyramid starts out on the ground in the center of the field.
  2. We pick up the pyramid by extending the pneumatics on the bucket to make it parallel to the mats. The lexan on the bucket is sharpened to a point, and our robot picks up speed and momentum as we approach the pyramid. At the point when the bucket hits the base of the pyramid:
    2A:About half the time, the lexan easily slides under the pyramid.
    2B:About a quarter of the time, the bottom row of barrels accelerates to the same speed as the robot, and all the game objects except the bottom row fall into the bucket. When this happens the bucket is too full to pick up any more.
    2C:About a quarter of the time, the entire stack stays together, but the lexan doesn’t get under it at all. When this happens, we slowly drive into the opposite wall, so that the bucket can get under the pyramid.
    3:Once the game objects are in they bucket, the two pneumatic cylinders fire to bring the bucket up so it makes a 45 degree angle with the floor. This causes the game objects to go to the back of the bucket because they slide down the slope. One of the pneumatic cylinders is pictured below.

The sorting system never got working as well as we would have hoped, but it did work to some extent. The concept is that the pneumatic cylinders (shown above) quickly fire, expanding and contracting. This quick combination along with the huge amount of latex on the bucket would catapult all of the objects into the air, shuffling the objects. When the object of the correct color slid in front of the bottom of the conveyor system, we would pick it up. Through this process, we could isolate only our color game objects to the tank-tread scoring mechanism. Although it worked well, we had to use this sparingly because of the huge amount of stress catapulting eight pounds out of the robot and then catching them put on the robot. After doing this about five times, every screw on the bucket would become visibly loose, and once we even snapped an L shaped aluminum bar. We had drilled a hole in it, but it still took a lot of force to snap.

The picture below shows the angle that the bucket forms when the pneumatics are contracted. This tilts the bucket and causes the game objects to fall towards the tank-tread.

This robot is very hard to defend against. Since we have changed our design, I am allowed to give away most of these secrets.

At the start of the match, we drive straight at the pyramid, so I think it is almost impossible for another team to get there before us. If another robot drove right at the pyramid, they would just help by pushing it into our bucket. However, if (like jgraber suggested) somebody knocked the pyramid with a catapult, or in a sideways direction, we would not be able to pick up everything, but we would still be able to be very effective as a normal scoring robot.

Taking game objects out of our bucket is very hard to do. The bucket starts out jumbled anyways, the bucket tilts at a large angle, and the bucket moves up and down on slide bars over a range of about sixteen inches. Also, the robot itself moves. These things combined to make taking out of the bucket almost impossible.

There were other effective strategies of defending this robot. (You can’t try them since this robot no longer exists :p) When the bucket was full, ramming the robot would usually cause us to drop a few objects from the top of the pyramid. Also, because of our broad chassis and limited reach, we had to approach each goal straight on.

Thank you!

I guess I didn’t really think about how complicated everything was, but now I realize that if I only saw the robot from the views in the pictures I’ve posted so far, I also would not understand everything. I will try to get more pictures posted in the next few days, and I think one of my friends might have a cell phone video.

13

WOW, thats a GREAT robot!
does the cylinder pistons raise the bucket during autonomous?
what if you flip a robot trying to block you? :open_mouth: jks :wink:
if you had kept and keep improving on this design, i bet it would have been a “green eggs” by worlds! :wink:

14

This is really impressive, but I seriously want a vid. This is insane, I need to see it.

15

KillerBee #33 reveal description was very detailed, with full view pictures from multiple angles, and multiple positions (eg arm up, arm down)

Your following description of inhaling the wall, was much better.
My paraphrase:

  • approach the wall broadside fullspeed with the wide sharp bucket to attempt to underscoop it at speed, else press it against far wall.

A similar but alternate method for underscoop might be to gently tip the wall away from you to lift the near bottom edge, so your underscoop can get a grip.

Just from the pictures, I thought you were trying to clamp it from each of the narrow ends.

Alternative inhalation methods:

  • Gatebot deny the wall: drive to opponent’s side of wall-stack, then expand to 5 foot wide.
  • Alt2: approach wall broadside with wide robot, reach over top with vertical clamp.
  • Alt3: approach wall from narrow end and straddle the wall, like HOV zipper machine.
  • Alt4: approach wall with continuous intake and slurp it up from end to end, into a giant basket.
16

Wow, thanks for the very excellent reply! That picture you included of the basket being lifted up really cleared many doubts. Also nice description of how efficient the basket is.

I hope your team doesn’t abandon the pick-up-the-entire-pyramid-in-one-fell-swoop strategy and builds a even better robot. I would really like to see that working efficiently by worlds.

Oh, and you should totally put up that cell phone video!

17

The cylinder pistons were capable of raising the bucket during autonomous, although we never did that because the process of picking up the wall was too unpredictable. I mentioned the percentages in a previous post.

We actually are capable of flipping other robots with this design (in theory :)). Of course the bucket would have to be empty, and we would have to get them with the center of the bucket, where the lexan has a lot of support. The lexan on the side is too flimsy. We could probably flip any robot with a 12 inch square wheel base, that weighs less than ten pounds.

Everyone: Thanks for the compliments. More stuff coming, as soon as I find it.

18

Is there any video yet? I’d like to see this beast in action.

19

Yes. I wouldn’t say its “in action”, but you can see us pushing it around about a week before our competition before we programmed it. Video taken on a bad cell phone by a person with unsteady hands. :o

http://www.youtube.com/watch?v=i9sQtpACou0 In this video, we demonstrate the elastic powered ratchet system that we use to open the chassis. Normally, the front wheels help it to open. You can hear the ratchet clicking in the video. BAM!

http://www.youtube.com/watch?v=EC9G2GEMey8 In this video, we pick up barrels for the first time with the sanded down lexan. In competitions, once the barrels are more than halfway onto the lexan, the pneumatics contract to tilt the bucket.

Unfortunately, that is all the media my team has of this version of the robot. It has probably been disassembled for about two months now. I do realize that my team should have done a better job getting media of the finished product. :frowning: If anything about this version is unclear please ask me a question.

20

No problem, I’ve had my fair share of robots taken apart before you realize you should’ve taken pictures. You’ve been very informative, thank you :smiley: