[MCC] Minimum Competitive Concept 2012
 

Each year I am amazed by what teams come up with to compete in FRC. Teams have a ton of wonderful ideas and some even see good execution of those ideas.
I would like this thread to focus on the "Minimum Competitive Concept" for a robot for 2012. It is often easy to identify all the possible tasks you could have a robot do. Prioritizing those tasks, and realizing it in the form of a competitive robot is in my opinion much more impressive.

If you haven't read the Simbotics Strategy Presentation, please do before responding to this thread. Especially review the "Golden Rules 1&2".

Assumptions are that one of the priamry goals of the MCC is to play in elims (not necessarily win on Einstein), and you team has mid-pack to lower fabrication resources.
Please list your assumptions, strategy to seed high, estimate of a winning score, and what robot design elements would achieve this score.

I will throw my $0.02 in later.

Re: [MCC] Minimum Competitive Concept 2012
 

My match strategy priorities would be sorted by highest (estimated) points-per-second value, in that each discreet objective takes X time and nets N points. It doesn't take repetition within a single match into account, but does assume consistency between matches.

I'll also add that every team should lay out ALL stretch objectives, how to meet ALL objectives and then decide how much they can accomplish in a given season. Teams often grossly underestimate how much time it takes to build something, which is the root cause of why their robots do not work properly on the field.

Strategy to seed high: Autonomous points + Coopertition points. If at least 8 points can be achieved consistently in autonomous and Coopertition points achieved in most matches, then the rules of the ranking system put the achieving team higher than those who do only one or the other (given the same win/loss/tie record).

Minimum Objectives to meed the High-Seed Strategy

• Minimum objectives to net autonomous points: 2 balls go into a basket.
• Minimum objectives to net coopertition points: Bot gets onto the coopertition bridge via driving.
• Robot can also minimize opponents' teleop points by blocking the inbounder lane as best as possible (realized at first competition)

If achieved each match, average contributing score is 8-12 points + 2 coopertition points. In hindsight, that wasn't enough for a win in an average match (depending on which week is played) yet that WAS enough for a seed higher than 8 at most Regionals, given an equal win/loss ratio. These are particularly true of Regionals in which there were relatively few teams (30-50) in the first few weeks.

Stretch Objectives for higher effectiveness, in order of highest to lowest priority:

1. Robot lowers the coopertition bridge
2. Robot drives onto coopertition bridge after it is lowered
3. Robot gets 2 balls in autonomous into at least the middle basket. Driving straight may be required, depending on the mechanism.
4. Robot is able to collect balls and deliver them to the mechanisms that scored the 2 autonomous points, in order to potentially score some teleop points
5. Given #1 and #4 in this list, traversal of the field and active delivery of balls also becomes a realized strategy
6. Given #4 in this list, the robot may also reverse the intake to feed another robot in autonomous also becomes a realized strategy

Assumptions
From here we will assume that the robot will perform stretch objectives 1-3, given only a drill press, band saw, hand tools, the KOP, no automated machining support and a ~$1000 budget. We'll assume moderate quality with the hand tools (i.e. the students actually do measure twice/cut once). We'll also assume no CAD on the robot :ahh: .

There may be some extra cost/time associated with individual mechanisms for each team, yet I reduce that down to each team's knowledge about materials and their own capabilities. This is how I would estimate it given the assumptions above, what I personally know about materials, and what I know about time for 3-4 students on my team to prototype & build the mechanisms.

Drive Train
2-CIMs through CIMple Box transmissions, default gear ratio. Configuration is a 4WD wide-drive with default KOP wheels. Victors/Jags are in 'brake' mode.
Satisfies: Stretch Objective #2.
Cost: $0.00
Time to Build: 6 hours. Could be done by the end of Day 2 depending on how much strategy happens, and it's only done so early so that there is something to mount other things to right away.

Bridge Lowering Mechanism
2 arms that are linked together in the middle via a cross bar. At the ends, the arms have a passive angled inverse-ramp. Powered by 2 KOP window motors via 2 Spikes. Mounted via the Igus rods/bearings. The leverage on the rotating provides the majority of the downward force in most situations,
Satisfies: Stretch Objective #1
Cost: ~$150 for 2 spikes, some 3/4" plywood, some sandpaper, a small 1/16" Teflon sheet, some glue, 2 #35 48T sprockets, 2 12T #35 sprockets. There should also be some left over for 2-4 limit switches.
Time to Build: 24 hours (1-2 weeks depending on how often a team is allowed to meet)

Autonomous Scoring Mechanism
A single-sided shooter wheel utilizing the remaining KOP wheels, 1 CIM motor, and a $15 AM CIM hub. Wheel is positioned relative to the front of the robot such that it allows room for the bridge lowering device, and is positioned at roughly the maximum allowed height. If its gravity fed, the wheels are on the top, putting a forward spin on the ball. If the feeding mechanism is used, the wheel is on the bottom putting a backspin on the ball. For manufacturing, the wheels are spun on a drill, and using a chisel the nubs of the tread are cut off such that the wheel becomes ~5.5" diameter and has a smooth tread finish. Assume a 45-degree fixed launch angle. Using the $30 Banebots voucher, 1 RS-550 is affixed to the rotating shaft such that its back EMF current can be utilized as a speed sensor on an analog port. The max amount of Banebot RS-550's is purchased on the vouchers since they might also be used in future years.
Satisfies: Stretch Objective #3 & #5.
Cost: ~$350 for wiring, Jags/Victors, 1 CIM motor, framing, mounting structure, nuts/bolts, shaft & adapter for the BB550. May be offset via FIRST Choice.
Time to Build: 20-30 hours (1-3 weeks, depending on how often the team meets)

Ball Gathering Mechanism
Premise: A single conveyor feeds directly from the ground to the spinning wheel. The conveyor is single-sided and has guide rails, with ~1" compression.
Materials: Hollow round Urethane belts from McMaster, some 1.5-2" PVC pipe, strips of rubber (keeps the belts inline), glue (keeps the rubber on), steel axles from Lowes (or wherever), 1 CIM motor, 2 AM hubs as shaft adapters (from CIM to the steel axles), some 1" Aluminum tubing and some plywood for framing & structure (also from Lowes... or wherever), 1 Victor/Jag, some wiring, 4 pillow blocks that allow for misaligment
Satisfies: Stretch Objective #4, #5, & #6.
Cost: ~$350 -- may be offset somewhat via FIRST Choice
Time to Build: ~20 hours (1-2 weeks, depending on how often the team meets)

Programming:
The programmers would need diligence and a methodical approach to calibrating autonomous. We were able to sit on a corner of the key and get >90% accuracy after calibration at championships, so it's definitely possible. They'd also need to calibrate the conveyor speed.

Re: [MCC] Minimum Competitive Concept 2012
 

While reading the OP, I immediately thought of team 2781 (we played with and against them at Midwest). They weren't able to do much, but what they could do, they did really well.

Here is what they would do pretty much every match:
1) During autonomous, they drive forward to the fender and drop both of their balls into the bottom basket. 8 points guaranteed every match.
2) Play defense. They weren't able to pick up basketballs from the ground, but that didn't stop them from helping out their alliance during tele-op. They played solid defense.
3) Bridge balance. This, again, is something they could do very well. They co-op balanced in 8 of their 11 matches.

They ended up 6-5 with a qualification score of 28. This was enough to put them in the 7 spot, guaranteeing them a spot in eliminations. After all was said and done, they ended up as the 4th alliance captain, and picked us and 2709.

We ended up winning in the quarterfinals, 45-15, and 36-14. Though, we ended up losing to 16, 148, and 2022 in the semifinals (gave them a couple of good matches).

Long story short, you don't have to do everything to be competitive in FRC. As long as you can do 1 or 2 things very well, you can be fairly competitive.

Re: [MCC] Minimum Competitive Concept 2012
 

I think the following is the simplest way to seed in the top 8 (not necessarily in the top 4). If it wants to do well in eliminations or be picked by another alliance, it will have to add at least one more capability.

Capabilities:

Bridge balancing
• Tip the bridge down for yourself
• Tip the bridge down to let another robot onto a bridge from the same side
• Tip the bridge up to let another robot onto the bridge from the opposite side, or to dislodge balls under a bridge.
• Push another robot with a weak drive up the bridge
Use PG71 Gearmotor, some AndyMark parts, and an arm to push the bridge. Gear motor with 4:1 reduction pushes the bridge down easily. Our first arm was simple to make and worked well.

In addition to the 2 CP these abilities can net you, they also make it possible to assist alliance partners onto the bridge for 10 or 20 balancing points. This was an underutilized strategy, in my opinion. Lots of robots lacked a good bridge manipulator but had a good enough drive to climb and balance.

Barrier traversal
Use the simplest drive that can get over the barrier. I’m thinking long 8WD using 8” wheels and angled skids on the front end.
This capability significantly improves the odds of bridge success. It provides Plan B in case balls get stuck under bridges or a robot tips on one side of a bridge. It also allows you to pop over the barrier and help the opponent onto the Co-op bridge if their bridge manipulator is failing to get the job done. Also, it allows the robot to cross to the other side to sit underneath a bridge to stabilize it while a robot or two balances to speed up the process.

Gathering
None.

Scoring
• Dump 2 balls into low goal in hybrid mode.
Device consists of a space to preload two balls plus an actuator to let them roll out into the low goal.
In Hybrid, the robot would need to drive forward, stop, and dump. Ideally the programmers would have also write a more complex autonomous mode where the robot lines up in the corner of the key.

Autonomous scoring: 8 pts

Match Strategy
1) Score 8 points in Hybrid.
2) Help allies double balance by any means necessary.
3) Balance on co-op bridge.
Strategy changes if an ally has a weak drive that is unable to climb, and the other ally can’t push them up. One possibility: let the better of the allies do co-op bridge and push the weak ally onto alliance bridge to balance (possibly having other ally under bridge for stabilizing). If an ally is a good scorer, the strategy might also change away from double balancing, but that’s okay if it results in a higher expected score.

The goal is to get 28 points as often as possible from Hybrid + balancing. That wins quite a bit of the time, especially at average to weak events. Combined with consistent coopertition balancing, that will result in good seeding if pulled off consistently.

Overall
Everything on this robot is setup for balancing. The lack of a tall shooter makes it easier to keep the center of gravity low, even if 8” wheels make it harder. The drive would be geared quite slow. Maybe 6 FPS. Example: use 12.76:1 Toughboxes with a 26:12 reduction. It is important to have nice fine control for balancing, and it is important to have torque for climbing and pushing while climbing. Speed is not important for this robot.

Upgrades
If a team built this robot and finished early, looking into a collector that can grab basketballs (even one at a time) and dump them over the barrier could make it an attractive second pick. Adding a brake for 1 CP on unbalanced co-op bridge is also a good upgrade.

This might be on the edge of MCC, and that was my goal. Removing gathering and shooting takes out a LOT of complexity, and the bridge is more important than shooting in qualifier matches at an average Rebound Rumble competition.

Re: [MCC] Minimum Competitive Concept 2012
 

IMO, The design of the MCC should focus more on being a viable second or even first round pick than seeding high. I think seeding high relies on too many variables. Therefore, i think it should have:
A wide frame to make yourself a more favorable second pick. I noticed that there was a huge demand for wide bots as second picks at the events I attended.
A one point dump auto because 8 pts per match guaranteed looks good and helps seeding.
A bridge manipulator on the back because the bots with coop autons were in even higher demand than the wide bots. Even if the auto was 'Feed and drive back to bridge', you would almost be insured a slot playing Saturday afternoon.

I think this design would be a very valuable second (or even first) pick at most events.
If possible, I would add:
Collector to feed the shooters on your alliance
Bump crossing to get to the side you will be defending faster
2 point dump capibilities because 12 pts per match is better than 8.
Brakes for easier balancing and 1 cp almost guaranteed
In that order.

Strategy would be to get your auto points however possible, play defense either at the fender or the spot where the inbounder is bouncing balls across the bump, and then head to the bridge (preferably coop).

Re: [MCC] Minimum Competitive Concept 2012
 

I have a question for all of you "low goal dump in auto" guys. Which is simpler to build & program for autonomous: a robot that sits in place and launches 2 balls at the basket via a single control loop, or a robot that moves towards the basket (presumably in a straight line ... oh wait) and then dumps?

Now the same question, without knowing about the ball inconsistencies?

Now the same question, with a team who will do what it takes to tweak, hone-in, and otherwise calibrate to mitigate the ball inconsistencies?

Re: [MCC] Minimum Competitive Concept 2012
 

I agree with you that it is easier to program a bot to just sit there and shoot than to drive up to the fender and shoot. However, it takes a much more powerful shooter as well as a more precise shot. IMO, it is easier overall to drive up and shoot.

Re: [MCC] Minimum Competitive Concept 2012
 

In my opinion, the following were this year's essential tasks:

• Floor pickup / reverse
• Cross bridges by self (i.e. can lower bridge and drive on)
• Score in a goal at the fender. (2 point goal?)

1 point or 2 point - In my opinion / observation, it is not that much harder to score in the 2 point goal than it is to score in the 1 point goal. So while I am not sure if it is essential, I would suggest a team go for it as I don't think there is much of any opportunity cost. The autonomous gain of shooting for the higher goal isn't that much (25% more points) but in teleop it's twice as many points per ball which is too big of a margin to ignore unless it is significantly harder to achieve. Which I don't think it is.

Then again, a 20 point contribution to the match alone (low goal in auto + 2 balls on bridge + single balance) is probably significant enough to be competitive at many events this year. Maybe the 2 point goal isn't so important...

In auton, a drive forward and shoot routine is pretty doable. Driving 12 feet straight(ish) is not unfathomable, and the fender itself helps the drive base square up. The 10 points here are somewhat easy to get, if you design for it in particular rather than a more general shooter.

I don't think crossing the bump is mandatory, and I think the other criteria cover most of the other roles the robot could play at higher roles. Having floor pickup and reversal allows for feeding a higher power auton, playing ball starvation defensive strategies, etc. in a match where the robot is the least good scorer. Being able to lower the bridge is important for those easy 10 points and also allows the robot full field mobility.

Scoring 20+ points a match and being able to co-op bridge is probably plenty to seed high at many events. I haven't run the numbers though.

I didn't include anything about orientation, but I think building a robot longer than 28 inches with such simple goals would only limit the robot rather than help it.

In my mind, 4334 is the epitome of the minimum competitive concept. I don't know how reliable their auton is, but they did an awesome job doing the mandatory parts of the game well, and proved themselves as an Einstein worthy asset to an alliance.

Re: [MCC] Minimum Competitive Concept 2012
 

I'm not sure how effectively they did it in competition, but at champs i saw 4334 running a low goal auto on the practice field very consistently.

Re: [MCC] Minimum Competitive Concept 2012
 

Team 61 comes to mind this year when it comes to an extremely basic yet effective robot. Pretty much it was a tank drive robot with a low goal dumper and a good bridge mechanism. While I don't have the scouting data for each match we did play with them once at GSR and then again this past weekend at Battlecry. In auton they would drive forward and dump their two into the low goal (8pts). They actually preferred not to score in teleop because they viewed their 1points shots better served doing defense/feeding over the bump then focusing on a double balance or co-op. Overall they were extremely successful and in our match with them at GSR between our two autonomous modes we pretty much had the match won once they hopped up onto the bridge in the first few seconds (51pts when the round ended!). They finished GSR with a record of 7-3!

My minimum competitive concept is very similar. It would essentially be a basic 4wd wide robot with a dumper, basic off the floor pickup, human fed (elevator from the pickup goes straight up to a roller that can also be loaded from a slanted hopper), and a bridge mechanism.

Basic strategy would be to drive to the fender and dump the two balls in auto (8pts) or A-bomb to another robot, knock the balls of the co-op & alliance bridge once teleop begins, cross the bridge, play defense, pickup balls from the floor to return over the bump, load balls from inbounder and return over the bump, and then balance on the co-op or double balance with an alliance member (20pts).

Overall you are only scoring 8pts-20pts a match but you offer so much to an alliance in eliminations between a triple balance, feeding, and autonomous.

EDIT: As to dumping vs shooting in auto they are both challenging. Shooting from the key would require a shooter of some sort which would need to take into account ball in consistency as well as accuracy. Dumping on the other hand entails a smaller mechanical challenge with a programming challenge. Assuming your robot drives relatively straight it wouldn't be too hard to make a program that drives straight to the fender before dumping the two balls. Or you utilize the kinect and let your human player practice lining it up.

Re: [MCC] Minimum Competitive Concept 2012
 

This is great discussion, and I really appreciate folks calling out specific examples of teams that executed a solid plan and had strong performance to back it up.

My MCC for 2012 was more simple than most here. In fact it is simple enough I can CAD it right here:
|\_
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O O

This little robot is a wide 4WD with large enough wheels and high enough bumpers to plow over the barrier and would likely use about 8" pneumatic tires. The sides are plywood, and the first half of the side profile is flat and att approximately 10" height. The second half is at 45 degrees incline. On the flat section would be a couple of small depressions to set 2 balls during hybrid just to get them off the bridge.

While initially this appears to just be a BOW (box on wheels), it is a very tactical box on wheels. Assuming 0 offensive capability in the alliance, the MCC would cross the barrier and tilt the alliance bridge towards its home side to clear the balls and prep it for the 2 partners to climb the bridge. Once they are on, you back up until just the flat will engage the bridge and have your partners drive forward until it catches them. At 10" you get it very nearly level, close enough for your teammates to make minor tweaks, and the support keeps the robots from Charlie-Browning. 20 pts. 20 pts. was higher than the average score at most events (only a couple of teh 50+ regionals averaged higher than 20 pts./alliance). The average (this includes winning scores as well), thus you would be able to win a majority (though not all) matches this way.
The MCC would then prep the CoOp bridge and hopefully Co-Op almost every match.
How do I know this would work? Not only does the math look good, but at Kettering there was a software issue with the speed control on our shooter which rendered it all but useless for most matches. And we executed this exact strategy. While our robot was far from an MCC, it had the same features built into it, and those were the features we used with a great deal of success in qualifying at that event.

Initially I wasn't thrilled with this concept as I believed it required a partner to do the bridge. Later I learned by watching very similar robots to this concept that you could tilt the bridge and catch it on the rebound if you timed it just right.

This is not a design that would likely win Einstein, but it is one that had a lot of potential to do well at District and regional events. Because it isn't trying to do too much, it would get very good at what it does.

Other roles that it can play when there is good offense on its alliance:
Inbounder alley blocking (between bridges)
Fender Defense
Opponent scavenger blocking (between bridges)
Middle bot for the 40 pt. triple balance in elims.

Re: [MCC] Minimum Competitive Concept 2012
 

I agree with much of this. If I was going for the most attractive 2nd pick, I'd simplify a bit. Brakes are unnecessary since you aren't trying to seed well. Autonomous shooting and dumping are unnecessary since you aren't trying to seed well. Those functions are unnecessary for success in eliminations as a defender / gatherer robot / balancing robot. In fact, it is to your disadvantage to seed too high and become an alliance captain if you are trying to be the ideal second pick. Instead of shooting ability, simply make sure the gatherer can reverse and feed two balls to a shooting robot during Hybrid.

As has been stated, 4334 was smart enough to pull this off, and the proof is in the pudding. Kudos to that team for a really smart strategy for the year.

I think it's fascinating to try to figure out how to be the elusive 2nd pick of the #1 or #2 alliance. It's tricky and requires some luck, but I think this was a better year to try it than most.

Re: [MCC] Minimum Competitive Concept 2012
 

I won't use the word "mandatory," but crossing the barrier is a low cost / high benefit capability for a robot that is banking on bridge success as the cornerstone of its strategy. I think deleting that capability would reduce the percentage success rate of alliance and co-op bridge balancing below the threshold of "competitive."

Re: [MCC] Minimum Competitive Concept 2012
 

Ike, how would this robot seed high? It would be (at best) middle-of-the-pack when it came to autonomous score, thus not be near the top of the rank of robots with identical coopertition/win points. There are several instances where teams had 'lucky' schedules this year, yet when making design decisions in Build Week 1 a team doesn't know that schedule. So I think that this robot would compete and be luckily competitive rather than competitive no matter what.

Re: [MCC] Minimum Competitive Concept 2012
 

I can show you several with this basic strategy that seeded quite high. Focusing effort on a low effort high return scoring element like balancing tended to have higher average scoring capability than running around picking up balls and randomly throwing them at the back board. This gets you above average wins which will/should get you well into the top 20 of a 40 team event. Teams that put extra focus on the Co-Op this year were more successful with the Co-Op plain and simple. Many teams early in the season waited until the last 20 seconds to Co-Op and failed. Many good teams in Michigan gave it a full 60 to 45 seconds, and had a dramatically higher success ratio. This was true of later events elsewhere. By not having the distraction of doing anything with the balls, it this concept will get very good at the things it does well.
Yes, you will have a lower than average HP score which is the second criteria, but you will have above average Wins, and well above average Co-Op points.

The key to this strategy is the assumption that others will not follow Simbots Golden Rule #2. That one says basically it is better to be really good at 3 things than it is to be mediocre or worse at 5 or 6 things.
The other key to this strategy is that allow you will "finish" early, you will use the extra time to develop your drivers. Most teams give their drivers less than an hour or two of drive time before their first competition. Many have never driven the robot as it is still being put together and code being added. If your drivers have an extra week of driving and concentrated practice, they will be better than half the field.

In theory if a high enough percentage of teams listen to this advice, then it would no longer become good advice and teams would need to add features. It has been my experience that many teams will appluad the concept of MCC. Give it as advice to others, and then do the opposite (my own team included on most occasions). Some will do better with a more complicated concept. Most will not.

Re: [MCC] Minimum Competitive Concept 2012
 

Funnily enough, we were almost 95% accurate in GTR regional (When we did autonomous), and through some unfortunate mistakes in programming, electrical, placement and of course, chance, we did not do very well in Archimedes. It was luck that brought us in an alliance with 1114 and 2056, two perfectly capable autonomous robots (Who we fed balls to).

Re: [MCC] Minimum Competitive Concept 2012
 

I agree that the brakes are not strictly necessarily, that's why they were the last item on the 'if possible' list. My reasoning for adding them at all was i felt that they were a low cost item that could easily help with defense as well as balancing. I saw autonomous as necessary because many teams didn't (or couldn't) have a feedable autonomous, so without an auto, your alliance would be left with a max of 6 pts. out of your 2 auto balls, as apposed to the 8 pts (or worse, they would end up on the bridge). you could get from you scoring them in auto. I think that the primary purpose of the bot is to play in elims, and seeding higher can only increase your chances of doing that.

Re: [MCC] Minimum Competitive Concept 2012
 

From looking at this years game, I think team 16 nailed the minimum competitive concept. What they executed in the finals of Galileo didn't require all the complexities their robot had, but the strategy was perfect as a 2nd pick.

Their robot:
-Consistently made both autonomous shots for 12 points
-Was much quicker than 80% or more of the rest of the robots on the field
-Could grab balls off the ground like nobody's business, and quickly release them.
-was small, and could get across the field and up the bridge.

Re: [MCC] Minimum Competitive Concept 2012
 

While I agree that 16 was a great robot they were the complete opposite of minimum. From their swerve drive, catapult, and full width pickup it was an extremely effective yet complex robot. Minimum competitive robots are ones that are extremely basic/simple and any team with limited resources, tools, and budget can produce in the 6 weeks.

Re: [MCC] Minimum Competitive Concept 2012
 

I think the drive that we built this year was very simple and could climb the barrier pretty easily. It uses mostly stock kit parts with the addition of some 1/8" angle aluminum. It uses 36 teeth sprockets on the wheels to slow it down a bit from the standard KoP configuration.



This drive worked really well for us.

Re: [MCC] Minimum Competitive Concept 2012
 

I posted about their strategy, not their implementation.

A minimum competitive robot could do the exact same things that team did, without all the complexity.

Swap swerve drive with some AM mecanum and you've reduced the complexity to something any team could do, while still maintaining mobility.
Even skid steering would suffice, as long as the driver has enough practice with the robot and it's geared appropriately.

Remove their catapult feeding mechanism, replace their one reloadable catapult with two non-reloadable. I'm fairly certain a team with limited resources could tune two catapults to be very consistant. The point here is that you need to make your two shots in autonomous, and if you don't aim high you won't get picked.

A full width feeding mechanism shouldn't be too difficult to implement, it doesn't even have to be that. It has to be quick, and able to reverse to spit balls out on the other side of the field. A bonus implementation is if it can be extended outside the frame perimeter.

As far as what goes into that robot, four jags, three/four spikes (two for the catapults, one for the feeder, and possible one for a compressor), an extra controller for a feeder that needs to extend outside the frame perimeter (maybe another spike?).
Four AM mecanum wheels, four gearboxes. Two catapults, a feeder, maybe a compressor. Slap it all on a kitbot frame that isn't full sized, and you've got a minimum competive robot.

Re: [MCC] Minimum Competitive Concept 2012
 

Wide/square orientation 6WD or 8WD would be even better. Done correctly, it would still be able to cross the barrier without any issues.

All else considered equal, having a wide robot was the easiest way to move up pick lists in 2012.

Re: [MCC] Minimum Competitive Concept 2012
 

So for minimums here. They can be adapted to work with any game

First read & understand the rules. Understand what your robot can do to play the game. Make sure your drive team understands the game, can communicate with & work with its alliance partners. This is one thing that can be done even with minimum physical resources.

Second make a robot that can move reliably. It needs to be able to cross the bump or pull down the bridge & cross it. If it moves reliably it can be the second robot on a balance. along with understanding the rules, it can play defense.

Third it needs to be able to score something in hybrid. Points lost there it can never get back.

Do these three & you have a good chance of a second pick. If your are an alliance captain then you are already doing more the minimum

Re: [MCC] Minimum Competitive Concept 2012
 

This is not true. If a team hits two low baskets 100% of the time they are more valuable than my robot that always hits one ball in the top and occasionally the second. Several teams including 2168 decided to aim for the middle hoop in hybrid because their accuracy in the middle hoop was much greater than the top hoop and only worth 2 less points. Another strategy for aiming low is that you don't interfere with your partner. At GSR in elims we were on an alliance with two other robots who all claimed to have gone 2 for 2 in the past several matches. We all setup for the start of our match and only 12 points were scored for our alliance because our shots hit each other. A nice feature of going low is that you are out of the way of everyone else. 16 had a great catapult but it was never 100% accurate. I think a lot of people including myself have underestimated exactly how hard it is to reach the top basket. If you are building a minimum competitive robot that just shoots in autonomous you are better off aiming low with high accuracy. I would always pick the consistent hybrid robot that isn't in my way.

Re: [MCC] Minimum Competitive Concept 2012
 

The reason FRC2168 aimed for the second goal often in elims was to avoid interference with our partners, our accuracy for the top goal was actually higher than the mid goals. You'll notice that in the offseason we stuck with just shooting for the high.

Re: [MCC] Minimum Competitive Concept 2012
 

I basically agree. I focused my first suggestion purely on seeding high while ignoring factors that would help a team get picked. In my response to you, I focused on getting picked and ignored seeding. In both cases I was trying to suggest the minimum for a particular goal. In a real season it certainly makes sense to consider both. This season was tricky since the eliminations weren't quite the same game as qualifiers, so teams had to decide what to focus on.

Agreed.

The concept I described was long because it's less tippy, which should increase balancing success rate and improve seeding. I was going for seeding high at the expense of being a more attractive pick. Long is probably unnecessary in that concept since it doesn't need to be tall.

Re: [MCC] Minimum Competitive Concept 2012
 

Having watched them perform at the IRI, I tend to agree. While their concept is not particular good at seeding high, they picked a very valuable attribute to excel at and thus nearly garuanteed being picked.

Re: [MCC] Minimum Competitive Concept 2012
 

Simplicity & Golden Rules from Simbotics 1114 Presentation
Golden Rule #1: Always build within your team’s limits. Evaluate your abilities and resources honestly and realistically .Limits are defined by manpower, budget, experience . Avoid building unnecessarily complex functions
Golden Rule #2: If a team has 30 units of robot and functions have maximum of 10 units, better to have 3 functions at 10/10 instead of 5 at 6/10
Please list your assumptions, strategy to seed high, estimate of a winning score, and what robot design elements would achieve this score
Background Information for Sophomore FRC Team 3548 - Team consists of 1 sophomore coach, one electrical engineer with Labview programming and robotics experience on teams 47 (2 years) and team 1 (2 years) and 8 students, only 4 of which will be involved in the robot build . High School coach has access to woodshop but no metal cutting tools (lathe or mill) on site. Engineer has new access to water jet at work location 30 miles from office location due to GM sponsorship.
Assumptions: 1) Minimal parental involvement, 2) no time to prototype shooter concepts, 3) Shooter designs will have to access water jet limitations (2 dimensional) and be designed and mostly built by engineer and Andy Mark parts , 4) Robot build will consume all time available, 5) drive team practice before first event less than one hour, 6) Budget limits encourage strong use of KOP components, 7) Additional funds estimated to be $1000 from school, 8) Team resources prevent building of single wheel, hooded ball shooter design.

Midpack robot design goals: 1) Robot drivetrain must never fail – no one wants to pick a sophomore team whose robot fails on the field!, 2) Shoot 2 balls during autonomous and 6 during hybrid period, 3) Must be able to lower bridge in order to score cooperation points, 4) Be able to shoot balls from opponents side into team side to assist in team point scoring, 5) Will not typically go over middle barrier, 6) Part of elimination field of 24 robots in both Michigan District events, 7) Will not attend Michigan State Competition due to budgetary constraints but choose instead to go to third Michigan District event ($500), 8) Take maximum advantage of other FRC team's learnings in first two weeks to help with design direction and order and read FRC book on robot design that featured shooting mechanism's from previous FRC competition (2006?).

Robot Design Elements: 1) 6WD chassis. Read Simbotics presentation on “gold standard”. Will use 6 inch KOP wheels. First time team using 6WD configuration. Will use robot long design configuration for ease of building for students and because of limited number of balls being picked up.
2) Ball collector – used Chief Delphi and Youtube to help design. Team 245, Roch Adams, recommended using ¼ id tubing with barb inserts from McMaster-Carr for belt design. Will use 550 motors with Bane Bot transmissions (new for us). Team 1 recommendation of 64:1 transmission ration accepted. Read instructions for breaking in transmission on Chief Delphi. Stretch factor of 5% on Chief Delphi initially used and found to be too tight. Motors smoked. Reduced friction in rollers. Reduced friction in system. Belt tension reduced to make system operational (thanks Paul C. - Thunderchickens).
3) Bridge Arm – Chief Delphi thread indicated that 20 lbs at given distance required. KOP PG-71 gearmotor sufficient with 3:1 ratio. Chain driven system used with purchased Andy Mark Hubs and sprockets. Only Bridge Arm testing was to lift robot in shop – no measurements made. Bridge arm very successful in Waterford District event.
4) Ball Shooter Design – using information gathered from Chief Delphi, design 4 wheel, dual axle, 6 inch past KOP wheel, direct driven by incorporating Andy Mark SimCIM product on both drive axles. Control backspin by varying motor speed ratio (Chief Delphi). Gravity feed ball between wheels via ramp. Use water jet capability to fashion two end plates that will marry the shooter system.

Michigan District Results. Waterford -There is no measurement scale at school so we arrived and weighed in at 125 lbs (first time over weight due to all robot features) . FRC Waterford Captains Team instrumental in helping us lose 5 lbs in about 2 hours . Missed first match due software issues. Ball collector mechanism design still under development. Very successful in lowering bridge and gaining co-opertition points. Ended event at 8th alliance position. Never dreamed we would be in a position to select other teams . Consulted with Team 1 to arrive at pick list. Team alliance not strong – eliminated quickly from afternoon fun.
Michigan District Results. Troy – This is the toughest Michigan District Event. For some team’s it is their third or fourth event having gone outside of Michigan to compete in the Midwest events. Now our robot could shoot and score consistently (50%) in both hybrid and operator controlled. Robot is fully operational. It’s fun not to have to be building your robot but enjoying the venue. End up being ranked around 24 but not selected for the afternoon. Next year let’s skip Troy and go to Livonia where the competition is reported to be easier!

So, Ike, how did you have us ranked? Were we a Midpack robot or a MCC? BTW, thanks for starting the thread. It gave me a chance to rethink about what happened this season.

Some lessons learned:
1) Need to recruit some varsity athletes for the team (see Simbotics presentation)
2) Need more adult support.
3) Chief Delphi support from FRC teams is invaluable for Mid-pack competitive robotics team.
4) FRC teams are willing to share and help your team build a competitive robot!.
5) Familiarize yourself with the Andy Mark website! Order parts early if possible to beat the rush (FP-0673 motors).

Re: [MCC] Minimum Competitive Concept 2012
 

Here's a snapshot of our ball shooter design prior to robot installation

http://www.chiefdelphi.com/forums/sh...d.php?t=102704

Re: [MCC] Minimum Competitive Concept 2012
 

First thing's first: a reliable, strong drivetrain and somewhat trained drivers (reliable comes before strong)

Then you'll want good ball pickup capability. Again, with a little driver practice, picking up balls is relatively easy.

Shooting will need to be very accurate. I'd go with a mid shooter that makes the shot 90% of the time instead of a high shooter that makes the shot 50% of the time. In order to really be competitive, low basket scoring won't be seen much. Mainly middle or high, whichever one they're more accurate on.

A bridge lowering-mechanism. The need to get on a bridge to balance is crucial, and the need to cross over to the other side is also helpful, so a wedge-like bridge mechanism will make the robot much more useful.

Other things: A wide robot would increase chances of getting picked. A decent autonomous would also help. A smart strategy also is a nice thing.


Finally, my MCC: A wide bot with a relatively large intake (about 21 inches wide) that can accurately score balls in at least the middle hoop, with a wedge bridge-manipulator that allows them to go to the other side of the field and get on the bridge.

Re: [MCC] Minimum Competitive Concept 2012
 

I fully agree with the drive train part, but we must remember that the first M in MCC stands for minimum. Something designed with goal 1 being 'get picked'. For this reason, I don't think a shooter should even be considered. MCC, for me at least, is something potentially simpler than 4334 was (they we're simple, but I think MCC could be simpler). IMO, the best thing you could do is design a robot that will never be on your side of the field. It should be easier to sell a good defensive not than mediocre offensive one as a second pick to an alliance captain.

Re: [MCC] Minimum Competitive Concept 2012
 

I'm in love with minimum competitive concepts now and after giving it some thought heres what I came up with. For the record I'm not assuming the team is a rookie but instead has at least some experience and a knowledge of the teams potential/resources and is aware that they're relatively low. Think 3rd year team wanting to play in eliminations for the first time.

Assuming the goal is to play in eliminations the odds of being picked are significantly higher then that of seeding high enough to be a picking robot. But to improve all chances of playing in eliminations I wont write off attempting to seed high still.

Game analysis: Comparing difficulty to reward it shows that balancing on a bridge is relatively easier then scoring balls to obtain a similar number of points. The difficulty to reward ration is increased during eliminations with the 40 point bonus. Thus we'll rely on the bridge as a primary scoring method.

Since we are relying on the bridge to score the majority of our points our robot should be designed to balance 2 robots easily as well as facilitate triple balancing. A wide, 6 wheel, tank drive robot provides the easiest method of accomplishing this strategy. A basic upgrade is to use two super shifters with the 4:1 spread, as the transmissions with 2 cims each. Using reasonable gearing the robot can have an average "high" gear, and an absolutely crawling "low" gear. This low gear provides two advantages. 1. the robot is now very capable of pushing 2 other robots up the bridge relatively easily. A problem a fair number of triple balancing alliances suffered from. 2. The low gear enters the range where internal system friction can be enough to act as a break on an unbalanced bridge. Finally to lower the bridge a simple arm with a wheel on the end (like 61's robot linked earlier in the thread) powered by 2 window motors.

Now for more assumptions. In general robots that shoot well are long. Long robots have more difficulty triple balancing. Not saying that it is impossible but that if a team has the forethought and resources to build a high ball scoring robot that can triple balance easily as well, then the MCC is simply out classed and should just hope to be picked by them. However in general this is a reach and an alliance of good shooting long bots will have difficulty triple balancing. Since shooting requires balls, we will attempt to stop these robots at their source.

Build a diagonal wall across the robot up to the hight limit. It can be netting and PVC to keep it light, sturdy, and cheap. Stuff your starting balls behind the wall to prevent the other team from getting them. After the match starts immediately move into the opposing teams lane and park against the inbounders corner.

Match Situation 1: If your alliance partners can score then this prevents the inbounders from skipping balls across the field to their high scoring robots to keep them replenished. If your inbounders hold the maximum number of balls as well as your team then balls begin to run out quickly. If your teammates can continue to score then inbounders will be forced to inbound balls bouncing them off of your robot and deflecting them toward the key where your scoring teammates can in theory easily pick them up and continue the cycle. Until the last 30 seconds this strategy is effective then the inbounders begin to throw over the wall. Now you drive cross field and hopefully have a partner or two waiting to balance with or else you can leave a bit early and lower the bridge and have someone follow you up instead.
Qualification Score: ~35 with a double balance
Elimination Score: ~70 with a triple balance

Match Situation 2: You begin the match the same. The opposing alliance sends over a robot to deal with you and give you a penalty for being in their lane and/or force you to move. After they cross the goal becomes to keep them on your side. Assuming robots capable of crossing the barrier or bridge quickly are above average and by keeping them away from their side you are preventing them from scoring. The goal is to use your low gear to push the opposing robot into the opposite corner and keep them there. If they stay in the lane at least your denying the opposition of a robot that is playing defense on your team and from scoring. Wait until the last 30 seconds and then go balance.
Qualification Score: ~30 with a double balance
Elimination Score: ~65 with a triple balance

Match situation 3: Your team cannot score baskets. Use the bridge lowering device to cross a bridge and play defense. Push, pin, box in, and possibly use the net wall to block shots if your lucky. Avoid penalties as best as absolutely possible but don't get too down because this is basically the worst case scenario.
Qualification Score: 10 with single balance
Elimination Score: 40 with a triple balance

TL;DR: wide bot, shifters with high torque low gear, diagonal wall to block balls.

Marketable skills:
1. Engine for a triple balance
2. Very low gear for defence
3. Deflector wall

Additional features for improved performance(ranked by difficulty and reward):
1. Wide roller to intake extra balls/spit them out into a shooting robot.
2. Larger (possibly pneumatic) wheels for crossing the bump.
3. Shift weight forward off of the back set of wheels to allow robot to overhang and increase triple balancing capabilities
4. Pneumatic stinger. (2056 style)

Re: [MCC] Minimum Competitive Concept 2012
 

[quote=mikemat;1171048]If possible, I would add:
Collector to feed the shooters on your alliance
Bump crossing to get to the side you will be defending faster
2 point dump capibilities because 12 pts per match is better than 8.
Brakes for easier balancing and 1 cp almost guaranteed
In that order.

What concept did you use for Brakes?