Re: 2010 Lesson Learned: The Negative
 

Exactly. We saw that as a danger from day one, and knew that a 'push bot' would have that vulnurability -- and thus elected not to build a push bot!

Re: 2010 Lesson Learned: The Negative
 

While I don't think that the goal design is GDC oversight, virtually any drivetrain can get stuck in the goal in the manner 2041 did. Only swerves can easily get out.

Re: 2010 Lesson Learned: The Negative
 

This is true. We were shoved into a goal during our second qualification match and couldn't get out. After the match I looked at the goal lip and how it caught on the wheels and saw that the only way a team could've prevented this from happening was to either build a robot too talk to go into the goal, or by giving your chassis about .5" of ground clearance.

Re: 2010 Lesson Learned: The Negative
 

You know 1501? They had a quarter inch of ground clearance if I remember correctly and it didn't stop them from encountering a similar problem. 2791 got stuck twice (we had weird programming glitches that would make part of the drive move when the kicker was being recharged).

I wonder why they didn't make the foam flush with the lip of the ramp?

Re: 2010 Lesson Learned: The Negative
 

1501 is a bit different though. They really didn't have the traction or power to get themselves out. (Or even a wheel in the correct direction, or touching the floor IIRC)

I think the non-flushness of the goal had something to do with keeping the balls in, but I'm not sure. Who knows, maybe those brilliant minds at the GDC made the goals like this just to laugh at us when our robots get stuck? :D

Re: 2010 Lesson Learned: The Negative
 

My biggest complaint: bumpers.

When rules on bumpers get close to the same length as the robot rules... you have a problem.

1. If they have to be mandatory, then at least let teams choose their own colors and only ban red and blue. Allow teams to show their own team colors. Red and blue mandatory bumpers this year took away from many teams image.

2. Make bumpers optional. If I want to risk my 6 weeks of hard work then so be it. I don't like being told that I have to protect something I worked on. Current bumper rules take away from many frame options. Take the rule back to 2006, where teams could opt to use them and there was the added weight bonus if you chose to.

3. If you keep them mandatory, supply the noodles in the kop. It isn't fair to teams in cold weather states to have to pay a premium compared to teams in warm areas.

Re: 2010 Lesson Learned: The Negative
 

Not really, low ground clearance would just mean your frame gets stuck. It was really a tough spot to be in, as you had little room to move forward and back to wiggle out.

Re: 2010 Lesson Learned: The Negative
 

The price we have to pay during the winter for pool noodles is outrageous. It was almost cheaper for us to buy online than to purchase from a local shop/store.

Re: 2010 Lesson Learned: The Negative
 

We borrowed router because the routers from Israel are not useable because of the settings change and the router was not working well. Just after we replaced the router with another one in thespare parts and set the settings manually there were not field issues to my team.

Re: 2010 Lesson Learned: The Negative
 

Thursday Matches in Atlanta: As much as we all liked having extra qualification matches, I did not like what it did to the "intensity" of Thursday. Too short of time to practice and make final repairs on the robots, too short of time for inspections, team members trying to get pits organized while competing, pit scouting, match scouting, giving conference presentations and trying to attend the conferences. Our team also organizes the All Rookie Meet and Greet and we had invitations to deliver. Even with a detailed team schedule, our team members all ended up trying to do several things at once which was very stressful!

I am not a fan of the red and blue bumpers, but I have to admit that they win out over the flags! But my team really missed it's red camo bumpers. Or even the choice of putting red camo numbers on the bumpers. We would have made sure they were visible from 300 feet, so I still don't understand why we were limited to a solitary color.

The changing dimensions in the game manual. We build a whole field and also make a game test for our students. The manual said the tower was this tall, the drawing said it was this tall. The manual said the target was this diameter, the drawings said it was this diameter. We were convinced that the bump height changed multiple times until it finally settled down to one dimension in the manual and +/- 1/4 inch in the team update. We rebuilt field elements and revised the team test more than once. In the end we all had to go with eh, its close enough.

Not allowing teams to measure field elements at competition! Our robot hanger lifted the robot to the same dimension every time - guaranteed to be at least an inch above the platform - according to the drawings. At our second regional, it wasn't tall enough. We asked to measure the field so we could make a spacer for the robot hanger and were denied.

Little things - not showing the Chairman's videos at each regional. We are zero for two for the past two years at different regionals. And the list of WFFA nominees should be shown as part of the WFFA presentation.

Re: 2010 Lesson Learned: The Negative
 

During Build, we can't find them at any price. We had to steal them from last year's robot this year.

Re: 2010 Lesson Learned: The Negative
 

Do what we do and buy them in the summer and store them. problem solved.

I'm hoping we can use the same ones we built this year again::safety::

Re: 2010 Lesson Learned: The Negative
 

Seems like we're a rare breed. A mentor for our rookie mentee found some at a dollar store. We ended up with enough to build all 4 sets of bumpers (2 for each team).

Re: 2010 Lesson Learned: The Negative
 

We usually don't meet during the off-season, and almost didn't have enough money for a team this season. But that's a good suggestion, and hopefully we can pick up enough this summer to last us for years!

Re: 2010 Lesson Learned: The Negative
 

I go to the "Dollar Tree" store during the summer and by a case of 40 for a dollar a piece. I did that two years ago and we still have some left over. The funny thing is, we store them in a high school engineering class room and for some strange reason, they seem to grow legs and walk away.

Re: 2010 Lesson Learned: The Negative
 

Last year I found noodles at a pool supply store here in Wisconsin in the middle of winter. I found them this year at Walmart.
I REALY LIKE THE BUMPER COLORS MATCHING THE ALLINCE COLOR. Yes, I was yelling. I think it is the best thing I have seen to help teams and spectators identify the alliance partners. Hope we keep doing it. I don't mind the idea of being able to customize the middle third.

I think the control system stinks. Way to complicated and buggy.

Bruce

Re: 2010 Lesson Learned: The Negative
 

This definitely isn't the first time I've heard complaints about this. I understand that there are only so many judges, and there are so many teams to visit, but I would definitely be upset if we didn't get to say hello to the nice people in the blue and green shirts. Even if a lot can be said about a team by their actions (which is a good thing), not being able to explain your team organization and history, or even being able to hand over a business plan is a huge loss and a huge disappointment.

Re: 2010 Lesson Learned: The Negative
 

Blue shirts, yes I would be upset
Green shirts, not so much. I would actually rather not talk to them.


About the complaints on the control system:
1. The system is two years old. There are bugs. We don't like them, but they are still there and haven't been worked out yet.

Scenarios that are true: About half an hour before "ship" (bag), we begin to do some drive practice in the basement on the practice field and the arm (that arm with 650ft-lbs of torque at stall) suddenly goes out of control, slams into the chassis control bar, and then pushes that into the tower (and is disabled). Having no idea what is going on and wanting to not fix it then (drive practice is more important), we disconnect the motor wires and continue. We didn't see it, but the kicker is also acting funny (but its hidden by the hood). A few days later, we opened the bag for a two hour unbag time before our week 1 district. We power on the robot, but do not enable it, and probe the voltage of the arm potentiometer (and chassis string pot) using a multimeter. Both are about where they should be. In software, we then see that the voltage is actually returning 0. We can't figure out what is wrong. A PWM cable did not come disconnected, because the sensors have power. Could it be a loose connection between the Analog Bumper and the Analog Module, could it be a bad Analog Bumper, could it be a bad Analog Module, etc. We send a runner to grab a spare analog module and bumper from the practice bot upstairs. We look at this one, and see that the analog module has actually come out of the cRio. We have checks in software to see if the sensor is out of range (like shorted to ground or +5), but when the module ejected the Get Avg Voltage returned the last good voltage, which was legitimate. We re-inserted the analog module, glued it in with silicone, rebooted, and were fine. Kinda annoying thing to happen.

Numerous practice occurrences: We find that, suddenly, all of our Victors and Spikes loose comm with the cRio. We are enabled, but something is wrong. What could it bee? A loose power connection to the Digital Sidecar? A loose DB37 cable (two possible loose connections)? A loose digital module? It turned out to be metal shavings in the DIO side had shorted out the +5 line (which left the disable circuit unpowered).

Michigan State Championship: During inspection, we find that there is a short between ground and the frame. Pulling the cRio connection we find that it is the cRio (we guessed cRio first). After removing the cRio, verifying that the plastic sleeve on the bolt is intact, we begun pulling modules until we discovered it was on the digital sidecar's line. We looked for possible shorts on the digital sidecar, removing each PWM, Relay, and DIO until none were it. We then saw that one of the bolts securing the digital sidecar was touching a screw for the DB37 cable. If we wiggled the connection, we would loose the continuity between the frame and ground. After finding this and covering the bolt with electrical tape, were now left with a robot that had all of its digital IO disconnected and its cRio in pieces.

More MSC: While re-assembling it, we broke something on the Analog Bumper or Analog Module (we don't know which). We looked at the kicker and the arm, and both were oscilating. Graphing all of the used analog inputs we found that all of the analog inputs were oscilating, by around .4 volts. We replaced the analog module and bumper with our only spares, which we got from our practice bot that was in Jim's truck.

Kettering: We found that Kitty's kat box had no input at all. It simply wasn't being found by the Classmate. Apparently there is a bug in the Cypress driver that will cause it to crash under the right conditions, and it's more likely to happen when connected to the FMS. The solution is to reboot the classmate twice, but full Windows reboots take more than the 5 minutes allowed for team-caused field delays (However, the FTA at Kettering was nice and let us reboot the classmate if it happened). We implemented a check for loss of Kitty's box (pull DIO 8 high and check if it goes low), but we then found that if it has the Cypress board and looses it it will continue to send the last good data, and that check will fail (however, it the Classmate boot without getting any data at all, it will send blank data and this check will pass). We then transfer the major functions (kick, deploy claw, flip robot) to buttons on Matt's gamepad.


33 control system failures this year:
Analog module fell out of cRio (friction locks are not good enough)
DSC poorly designed so mounting bolt can touch DB37 screw and create ground short which is almost impossible to track down
Analog module or bumper broke for no apparent reason
Radio spontaneously reboots going over the bump (poor reliability of radio, mounting orientation helps this)
Radio power cable loosens going over the bump (poor power connection design, a friction based solution will NEVER work in FIRST, except Lunacy where stresses were really really low)
Cypress board/driver has issues, causing loss of Kitty's Kat Box when booting (Greg McKaskle says its around 1 in 10 times)
No App switch often has to be pressed to download code (lack of any hint of optimization in WPI code)
Builds take more time then a match (LV-RT design flaw causing it to re-compile entire library every build)
FMS Lock (design oversight; in past systems a FMS lock would have been reset when the FMS cable was unplugged because the DS would reboot on power loss, now its very obvious that it exists and is hard to get rid of)


Lack of blame: If you call/email NI for support, they can redirect you to WPI if it could be a software problem (who could likewise redirect you to NI if its a software problem), or any number of other sources. It's hard to blame the fault on a single company, so it's hard for any one company to give you support on products that aren't entirely theirs.

Re: 2010 Lesson Learned: The Negative
 

I couldn't agree more...black numbers (however wide) on blue bumpers Just Doesn't Work. But what I don't understand about that is that R15 is quite clear -- "...in a contrasting color....". Now, I guess there can be some interpretation of that, but the point of the rule is clear -- people need to see the numbers -- so I really can't understand why black on blue was acceptable. While inspecting in the St. Louis regional, we made teams renumber their bumpers in contrasting colors. Meaning white. One coach asked if he was expected to go out & buy white paint -- we told him yes, if that was what it'd take. Unsurprisingly, when the announcement went out "anyone have white paint?" the answer was "yes".

The simple answer to this problem is as someone else suggested in the thread -- make R15 say "white numbers on all bumpers". Done.

Re: 2010 Lesson Learned: The Negative
 

Ball manipulation devices often touched and not receiving a penalty for this is the CORRECT call.

Incidental contact penalties do not exist.

G37...
http://www.usfirst.org/uploadedFiles...0Game-RevG.pdf

Re: 2010 Lesson Learned: The Negative
 

Add me to the list of people that want to see the Chairmans Videos and the WFFA and Deans List nominees. Or publish their names in the official event program. Or better yet, do both. Those people work hard, a few moments of fame!

Bumpers: I like the bumpers and after 6 years we now have bumper design and assembly down to a science. They are the same size, they mount / dismount in < 2 mins, etc. (We are thinking of having a three day class in Bermuda to teach these valuable skills, contact me off list if you want to go :rolleyes: ) We buy pool noodles during the summer and stock them up. After three years it's a good bet we will need them next year.

We luck out because our school colors are blue/gold so we do gold numbers on the blue bumpers and it looks fine for our demo bots. But I feel for the teams that have massive color schemes like 1511 Red/Black camo and Moe's "Moe Green" not being able to have the bumpers match.

For VRC we have these little license plates that go on the robot. In FRC we could get 8 12" long (4 red, 4 blue) iron on fabric strips in the correct "FIRST Red and FIRST blue" colors with the team numbers in "approved contrasting colors" of the "required height and brush stroke" in the KoP. Make bumpers with your custom colors / design, iron on the numbers and you are good to go.

After this many years we should have bumpers down to a science. And there are more "mature" teams than rookies so we should be able to share the knowledge.

Bumpers save robot lives, but also I'm happier doing a demo in our sponsors space knowing I'm unlikely to leave huge gouges in their office walls.

Re: 2010 Lesson Learned: The Negative
 

Well, I can tell you that teams got on more than they were alloted. Like, even if we assume that there were twenty hours of practice time slots. Then three teams on per division, and hour long slots were fitted into four, 15 minute slots. So that's 20 * 4 * 3 = 240. So that's 240 slots with each team getting roughly 3?

Well, the practice fields aren't the smoothest run operations. For some reason, the coordinators are more worried about having all of the robots on the fields and running the fields in a "match" format rather than a practice field format.

Regardless, I think everyone can agree that the practice fields are hard to get. And I don't know what exactly FIRST can do, but something might be better than nothing.


Another thing that I noticed was that no matter how much we yelled "ROBOT", people would not move. One time, we were walking toward a mass of people, Yelling "Robot", and they would not move. It wasn't until I was almost right at them that they jumped back with surprise. I'm not going for the safety award, I'm just trying to get my robot from the pit to the field without hurting anyone.

- Sunny

Re: 2010 Lesson Learned: The Negative
 

I used the wrong language there. G37c says that incidental contact will not be penalized, but that in general contact out the bumper zone is not acceptable, and will be penalized -- red carded if egregious. It never was.

Re: 2010 Lesson Learned: The Negative
 

Dean's List. I agree with everyone about Dean's List. Dean couldn't possibly wonder why he didn't receive as many submissions as he had expected if he announced his idea a week before the deadline was set for the nominations.

Safety Award. It's quite hard to try and explain to pit scouters what exactly your robot does when every other minute you hear, "ROBOT COMING THROUGH!" yes, that call is helpful if there are people clearly in the way, but a simple "excuse me, robot coming through!" would suffice if someone was in the way. So the Safety Award should be judged differently in my opinion, as certain behaviors are certainly not safe.

The DOGMA System. Oh my oh my, this caused such a panic when one of our balls hadn't been returned in our second match in the finals at the New Jersey Regional. We received something like 72 penalty points for not returning a ball to the field, when it had just fallen off the ball return before passing through the photogate. That definitely jeopardized our chances of winning, as each alliance had won one match each, but we managed to be more careful in the third and final match :rolleyes:

Camera Operators. I noticed there were a lot of zoom shots and close-ups, but I prefer a nice view of the entire field rather than seeing the focus on one or two robots at a time.

Re: 2010 Lesson Learned: The Negative
 

I felt like the DOGMA system caused more faulty penalties than legitimate penalties. Not only was it the cause of some 80+ point penalties, but the Alliance cannot do anything about it. It is even possible that an Alliance could be doomed before Autonomous even finishes, just because someone put the ball onto the field rather than giving it back to the human player. I would suggest that next time, they make it impossible for the ball to fall off before the photogate, or even have an override to avoid it.

Re: 2010 Lesson Learned: The Negative
 

Did anybody else have zero volts reading on the classmate before the match, but when the match started, the robot worked just fine?

Re: 2010 Lesson Learned: The Negative
 

I must say that what I've heard about the Israeli regional is simply pathetic. Towers there weren't built per the legal dimensions - making functional hangers dysfunctional - bumps weren't the right size - semis were decided by a coin flip :facepalm: - etc. The soccer balls used there weren't even the specified soccer ball (http://www.chiefdelphi.com/media/img...40212523_l.jpg) - they were Nike soccer balls donated by a team (at least that's what I heard). Here's a thread, written by an Israeli team mentor, that details just some of the many problems there: http://www.chiefdelphi.com/forums/sh...ad.php?t=84605.

My personal complaint is that FIRST personnel seem not to abide by 'Gracious Professionalism' when it comes to possible mistakes on their part; their motto for such occasions seems to be "It has never been FIRST's fault, it is not FIRST's fault, and it cannot be FIRST's fault. End of story." I don't mean to come across so harsh, but...

At the New York regional - during an elimination match, but I'm not sure which - the field system had to be rebooted. Prior to doing so, we were instructed to close the lid on our Classmate. However, as many people discovered throughout the season, letting your Classmate start sleeping whilst the Cypress is connected leads to the Classmate not recognizing the connection to the Cypress, and consequently a person not being able to use any switches wired through the Cypress - in other words, letting your Classmate sleep while it's connected to the OI has the potential to kill everything on your OI that is not a joystick/controller. When the referees instructed us to close the lid, we immediately pointed out this glitch, and they didn't retract the instruction; we were, however, allowed to leave our Classmate open.

One of our batteries had also been wired improperly - the terminals had been reversed, inverting the current - and this (probably) caused us to fry our analog breakout. We quickly replaced it, and when we found an opportunity to, we talked to the NI representative about it. Much to our dismay, we found out that a third-party manufacturer is licensed to produce the analog breakout, and consequently, we were unable to definitively determine the root of the problem in our fried breakout (although reviewing the circuit map of the breakout, we did find that the most probable cause was the frying of the 5v power supply on it, since that had visible internal damage). It wasn't a problem of much importance, but it would have been nice if there was someone that we could actually talk to about what the problem and its cause was.

At the Hartford regionals, we had field connection issues - I only found out during quarters, since I was in the pits the majority of the time - and it turned out that one of the driver stations on our half of the field had been inconsistent for a while, and that totally messed up our play. We ended up holding our own for a few matches in the quarters, with just one or two active robots (an alliance member's bridge connection had come loose) - and if not for bad ref calls, in conjunction with the field problems, we definitely would have made it to semis.

At Nationals, we lost communication during one match because a volunteer insisted on untethering our robot from the practice field and we didn't check to make sure that he plugged the radio (wireless bridge) back into the cRIO properly. We came out of that match panicking, and then we see the loose wire. I mean, honestly.

Re: 2010 Lesson Learned: The Negative
 

I did not actually realize this was a problem. Admittedly, I'm not much of an electronics person and I'm always scared to death to touch that thing because it's so costly, but I know that we killed one at SVR (:ahh: $5000 we don't have anymore) and got it replaced before our next match... I'll talk to our programmer about that because we just got it out, got a replacement in, and kept playing.

Re: 2010 Lesson Learned: The Negative
 

There were a number of teams at Championship that saw 0.00V battery readings, yet had their robots function. The primary causes were: not having the Analog Module installed in slot #1 of the cRIO, not having the appropriate jumper installed on the analog breakout board, or a bad connection between the analog breakout board and the PDU. In all cases, the lack of a correct battery voltage reading did not affect the robot performance.

Even though its an inspection item, the battery voltage reading is just a diagnostic tool. Some teams having robot issues on the field were informed by the FTA (or FTAA) after a match that their battery voltage was dropping to very low values (<8V). Bad batteries can cause radio or cRIO resets, which result in loss of communications on the field. Not a good thing...

Re: 2010 Lesson Learned: The Negative
 

Perhaps it's the frequency in which so many teams were yelling "ROBOT!" when there was no one even close by, that caused everyone else to become annoyed and ignorant of teams actually trying to clear their way through. For next year, howabout we have everyone try leaving their pit area a little earlier, and taking their time to walk with everyone else, instead of trying to blast through/past them all.

Re: 2010 Lesson Learned: The Negative
 

Re: 2010 Lesson Learned: The Negative
 

Really? If this is true, you really need to look harder at the resources available to you.

NI is RMAing cRIO's free of charge. Purchasing a new cRIO costs $750 for the first one per year, and $1500 afterwards.

Re: 2010 Lesson Learned: The Negative
 

Tyler,
Are you talking about the robot 12 volt display on the Classmate or the voltage on the Classmate battery?

The 12 volts from Module 1 is used by the Crio to determine if the robot battery level is getting too low. The Crio power supply on the PD drops out at 4.5 volts. So knowing this fact, the designers added a safety margin of 1 volt to the Crio firmware. The Crio disables all output when the battery falls to 5.5 volts. Without the voltage monitor, it is possible for odd behavior from your robot during these low battery conditions.

Re: 2010 Lesson Learned: The Negative
 

LOL. I should have known not to use categorical language on a forum full of engineers and aspiring engineers.

By "never" in this case I mean "never at FLR", as that was the only Overdrive event we attended. :P

Re: 2010 Lesson Learned: The Negative
 

Does anybody else wonder why after three or four years, the field still cannot accurately count scoring devices without being overloaded?

Re: 2010 Lesson Learned: The Negative
 

In the last 2 seasons we've replaced our cRio 4 times and have never done it in less than an hour. Each time the cRio that was on the robot was replaced with a unit from spare parts that was completely clean of any code so it required a timely re-imagining process in addition to new user code.

I have seen some teams replace cRios in between elimination matches, but I believe these units had the appropriate code on them already.

Next season I'm going to pursue investing the $700 or so into a spare cRio that we can bring with us to events that will be an exact copy of whatever cRio is on the competition bot so that swapping one out is just a matter of the physical swap.

Re: 2010 Lesson Learned: The Negative
 

I would simply suggest that FIRST warn manufacturers that come January 9th there may or may not be a swarm of 14-18 year old children demanding to buy this product. Who said stores can't have a Black Saturday as well?

Re: 2010 Lesson Learned: The Negative
 

We've been reccomending that to FIRST for several years that they warn the vendors so there is a stock. It would be win win for the vendor and the teams but FIRST has yet to do so, hence the comment. In 2009 they supposedly went with something that would be readily available, but FIRST's order interferred with Walmart getting their order and Walmart cancelled so we could no longer buy them easily.

Re: 2010 Lesson Learned: The Negative
 

Even I started becoming somewhat unaware of the "ROBOT COMING THROUGH!" shouts in the pits (though I'm guilty of saying it myself). The problem, at least at Buckeye this year, was that the pit walkways were blocked way too often. You couldn't flow with the traffic, because there was no traffic to flow with. I remember our aisle being congested constantly due to two teams apart from each other having so many visitors constantly that they would overflow into the walkway. The backs from one group almost touched the backs of another.

Unfortunately, that "ROBOT!" chant wasn't enough to even break through sometimes. I'd stand there for what seemed like ages, shouting at the top of my lungs before they'd even realize I was right behind them. I think we'd eliminate a lot of the shouts if the pits were actually passable at all times.

That was a mess, especially because an orbit ball wasn't exactly a household item that you could find anywhere. Neither were the rings in 2007, if I recall correctly.

This is a pretty big deal that could be solved easily by more communication with FIRST. I assume they're worried that details about the gamepiece/game being leaked early, but I'm sure most companies wouldn't mind keeping a secret for a few weeks or months in exchange for an influx in orders from teams around the country. ;)

Re: 2010 Lesson Learned: The Negative
 

Not the ones at philly at least. Our alliance partner had their cRIO blow out and it took 2 timeouts to reformat and re-upload to the new one

Re: 2010 Lesson Learned: The Negative
 

I know of at least 3 teams that have about that much ground clearance.... Us, 254, and 968. :D To be able to go over the bumps we had to countersink all of the holes to mount our electronics and place all the screws from the bottom up. The bottom of the robot was literally SMOOTH. And we never got stuck!

And I know that all the holes are countersunk because I was the one who was in charge of drilling all of them....

Re: 2010 Lesson Learned: The Negative
 

Us, too... Unfortunately, we engineered things too closely, and while we could climb our practice hump, and the humps at FLR, we could not climb the humps at Championship.

My students learned a bit of a lesson about design tolerance this year!

Re: 2010 Lesson Learned: The Negative
 

I teach preschool, and it's so interesting to me how similar 4 year olds and high schoolers are to each other. ;)

Have you ever had someone yell in your face about something? Do you actually hear their words, or do you hear OBNOXIOUSLY LOUD NOISES?! Combine that with being in the Pit Area, which is already an obnoxiously loud area, and you don't register any loud noise because it's blending in with the rest of the loud noises that you've blocked out.

Now, have you ever had someone whisper something to you? Maybe you didn't quite understand what they said right away, but you heard the whisper, and it intrigued you enough to pay attention.

Instead of yelling "ROBOT" and push through, perhaps we could all walk with the crowd, and then when it gets congested, gently tap the person who is in the way, say, "Excuse me, we need to get through for our match" in a polite tone, with a smile on our faces.

I tell my four year olds, "Use your gentle words". Most of the time it works for high schoolers too. ;)