Testing for Motor Modifications

Amen! That would eliminate a lot of the problems and it would look cool!:smiley:

All,
I’d like to respond to some of the technical comments made in this thread. 100% of teams had motors tested as part of the normal inspection process at the VEX Robotics Competition World Championship.

The test run at inspection has four distinct stages:
**1. ** Motors are powered through an inspector’s test rig and set to run full power in one direction. These motors are loaded (manually stalled by hand) and the results observed. The inspector will watch for how long until the PTC cuts current to the motor.
If this never occurs, the inspector will flag the motor for closer analysis.
If this occurs, but it takes a long time, the inspector will flag the motor for closer analysis.

If a motor cuts out, the inspector will repeat the test. The inspector will watch the recovery time. If it seems that the motor is recovering quicker than normal, the inspector will flag the motor for closer analysis.

2. If any motors were flagged for analysis, the inspector will ask the team to step aside to a separate area. The team will be asked by a secondary inspector to remove the motor from the robot. At this point test 1 will be repeated, and will typically be done using a clamp-on multi-meter so the current draw behavior of the motor can be closely observed. Motors displaying the characteristics described in step 1 above will be flagged for additional analysis.

**3. ** If at this point the two independent inspectors agree the motor is suspect, additional motors on the robot will be tested in the manner described by point 1 and 2 above.

**4. ** All motors identified by the 3 steps above will be disassembled and analyzed by IFI / VEX engineers.

It should be noted that the modifications to 100% of the motors flagged as illegal were identified by our engineering team. There were no false positives. If the inspection team said a motor was illegal, it was 100% illegal and based on our findings there is very little room for argument or ambiguity. I will not go into specifics here.

During the competition, the VEX Worlds Senior Field Techs were instructed to randomly test teams in their divisions for additional modifications. In addition they were asked to test any robot which displayed behavior inconsistent with their expectations for normal performance. Some teams were flagged for additional scrutiny in the interest of ensuring fair play.

In addition, 100% of teams who advanced past the divisional Quarter Finals were tested before their semi-final matches.

Teams were randomly tested after matches only to provide time for motor cool down.

Based on our in-house testing and discussions with the PTC manufacturer: the PTCs in the motor will return to high levels (95%) of performance within 15-20 minutes of being tested. They will be “as good as new” within 1 hour after a test. Our inspectors and field techs did everything they could to ensure that this test did not influence on field performance, and to ensure that any influence was “fair” (i.e. before the semi-finals ALL teams were tested.)

This is not true. Teams who exhibited anomalous behavior were flagged and tested.

This is untrue, as I described in the detailed outline above. A “high performing” motor would not fail the tests we performed at Worlds. If for some reason it did fail in step 1, 2, or 3 – it would be opened and verified during step 4 as legal. I am confident that no “legal” motors were ruled “illegal” during our inspections at VEX Worlds.

All teams were checked between the quarter finals and the semi finals of division play. All teams were subjected equally to this inspection. As I describe above, PTCs will recover 95% of their performance within 20 minutes of being tested. Our Senior Field Techs tested teams during the elimination tournament in such a way that almost all teams had 20 minutes of cool down time between the test and their time to play. In addition the Senior Field Techs did what they could to minimize the impact on the robots during this time.

This is not true. The range of quality was accounted for in our testing, and our step 4 analysis verified that motors flagged as illegal were in fact illegal. The test performed at VEX World Championship was 100% conclusive.

These teams were not penalized. DC motors vary by +/- 10%. This variance would not cause a failure in the test. We opened up every single failed motor and verified that the motor was illegal.

As described above, the motors will suffer no long-term damage from the test.

Andy,
Based on all our testing of the PTCs and discussions with the manufacturer, we have no reason to believe that this is true. As described above, the motors suffer short-term impact from the testing, but over time they are as good as new.

As discussed above, no off-the-shelf motors would fail all 4 parts of our test. The variance was taken into account and does not affect the outcome of the test. I am confident there were no false positives.

Thank you for clearing up all of the rumors.:slight_smile:

Didn’t want to quote the above post because of itssize.

A lot of teams really appreciated the tests performed by the inspectors and the field tech. I had never heard of teams being accused of cheating and DQed without actually having cheated. The teams that were tested multiple times seemed to take it as a compliment and their only fear was motors not cooling down in time.

The few inspectors I asked were not willing to comment on specific teams or even on specific numbers but were willing to admit the amount of teams caught for this was less than 100 but definitely greater than 5.

For this kind of benefit we should all give a round of applause to the work the vex engineers did to ensure our competition was fair.

Thanks. This definitely clears up a lot. Now I know why we had to watch two guys sing for 20 minutes after quarterfinals. I guess I just have a few more questions.

How many teams were found with modified motors? I’m fairly certain it wasn’t just 9090C. What was the usual punishment for teams that had modified motors, since only one team was disqualified? And what was the extent of modification teams had to go to get disqualified?

Thank you JVN for the info about the process. It definitely is very informative.

Thanks to all the VEX/IFI Engineers and the Field Techs.

Would it ever be possible to do these sorts of tests at local competitions?

During the course of the 2013-2014 season we discovered teams who were violating the spirit and ethos of the competition to gain an advantage over their fellow competitors. Teams were intentionally modifying their VEX motors by bypassing the internal PTC in an effort to increase and improve performance. When this type of cheating occurs, our entire community is affected. The entire Game Design Committee was shocked, appalled, and disappointed that this was taking place in a community that has become known for good sportsmanship and ethical competition.

The greatest impact from these type of illegal actions is not felt by those who suffer on the field, but by those who contemplate, “Do I need to also try to gain this advantage to stay competitive with the team next to me? Do I need to violate a rule to be able to succeed?”

Throughout our many discussions, one thing has been universal: we don’t want anyone to feel this way. In the name of fair play for everyone – this needs to stop immediately. Thus it was decided to test motors from every single team at the World Championship. John V-Neun, VP of VEX Engineering, has provided a detailed insights into the entire testing process used in Anaheim.

The tests caught numerous teams who flagrantly had violated our rules in an intentional manner. Because of the serious nature of these offenses, the Game Design Committee was forced to hand out serious punishments. Teams who were caught during the inspection process, prior to playing any matches, were issued two automatic losses in the standings. Teams who were caught after the inspection process, during the random post-match tests, were disqualified from the entire tournament.

These were not easy decisions to make for our committee. All of us at VEX Robotics and the REC Foundation are here because we have a passion for competition robotics. We truly believe that these programs can change our culture, and have seen this in action. We would not be the people we are today if it wasn’t for the impact of these programs, and seeing people violate the ethos of the competition was heartbreaking. Our hope is that the testing process that took place in Anaheim ensured that all teams ended up competing on a level playing field, and made sure no teams had to feel like they needed to violate our rules to keep up with their opponents.

Despite what we saw take place by a small minority of teams in Anaheim, we need to remember that it was exactly that, a small minority. The majority of our VEX Robotics Competition teams have and will always compete ethically and with class. We were overwhelmed by the thousands of instances of sportsmanship we saw throughout the Championship. Those heartwarming acts will be what we all take away from the event, easily outweighing these few acts of negativity.

We want to thank all our teams for exhibiting great degrees of patience while undergoing these tests. We know the process wasn’t ideal, but at the end of the day we wanted to ensure fair play for all teams, a result that we both hope and feel we achieved.

Yes, what are the consequences. And also why would people want to cheat!! :confused: The idea behind a composition is that everyone gets a fair chance!!! If you want a metal that bad buy one at the dollar store. We need people helping the community not hurting it.

Karthik just posted the punishments for offending teams above.

It’s sad that it happens in a competition like this, but I feel as though it’s the right one.

Could this explain why some middle school teams were no-shows at their matches? :confused:

While our team was very happy that motors were tested and to hear that cheaters were penalized, we were also freaked out when one of our alliances did not show up. This alliance told us that their robot was broken and my kids even offered to help them fix it, but instead of seeing the no-show team work hard to fix whatever was wrong, we saw the no-show team sit in their pits playing video games. The no-show team, which was ranked very low, later got pulled up in alliance selection for the finals. :confused:

Sounds like gaming the system. Rank low, nobody will choose you. Set yourself up to purposefully fail and get selected by a close alliance and you get yourself an ideal alliance

Would you mind publishing some high level statistics on percent failed?

I have no idea how pervasive the problem was. Rumors always abounded but I did not know people actually did it versus re-engineer their robot to be within the rules.

FullMetalMentor has a point though. Is a two match penalty too lenient if they are only to be picked in the elimination rounds? Yes scouting is good, but isn’t egregious cheating not to be tolerated at all? They went all the way to worlds and paid to get there, but…

I liken it to penalties for steroid use in professional sports. Is it (current) baseball level of bans for 100+ games or football level of bans for a few games for the first infraction?

All very tough decisions! But I’m glad you clamped down on it to level the playing field. (Just like overcharged with batteries last year)

I think the punishment should have been more strict. In divisions some teams that were 8-2 were able to be alliance captains so it would be possible for the team to still be a captain. I think it sould have been a 4+ automatic loss with a removal from elimination.

All teams who were punished with the automatic two loss penalty had those losses assigned at random. Thus they did not know which two matches they would be disqualified from, making attempts to game the system more difficult.

One other note, all teams who received the two match penalty for motor modifications caught during inspections were regularly reinspected with increased scrutiny to ensure they had not reverted back to any illegal motors.

Okay. Thanks for clearing that up. Apparently our no-show alliance was just another case of video game addiction in action and nothing else. :smiley:

Thank you to all who have contributed to this thread. The spirit of honest competition is strong within the VEX community, but we have some bad seeds out there. We have mentors, team members or both who are cheating, but in the end they are responsible for each other’s actions. When it comes to the electronics of the robot, I am with a few on this post that there should be a zero tolerance rule. No exceptions. Slaps do not get results, ultimatums do.

Thank you to the VEX engineers who crafted a way to comprehensively test motors at Worlds, and explain it clearly in this thread. I will bring up again, how do we perform tests like this at regional and national tournaments? Can the process at worlds be trained to volunteers and create a new local tournament position for testing? If so I am an advocate of maybe special marking of the motors so a retest is not necessary, just look for the special mark of that tournament on the body of the motor. Another option is to have VEX sell the motors sealed with pre-set gear ratios. Maybe we are not the norm, but once we change a motor’s ratio, we never change it back. For School labs and clubs, the motors we use today are fine, but I am talking about “competition” motors. Just an idea, don’t’ shoot me.

What is important in all of this is that suspicion has been confirmed and the process of weeding out dishonesty in competition has started.

I got a response from the mentor of that team tonight and he told me that the motor had not passed the original inspection test because the inspector could not adequately reach the motor shaft to stall it. Apparently they were trying to stall it by grabbing hold of the chain it was driving, but the chain would break loose before the motor stalled. So the mentor was freaking out when I had talked to him. Later, they took enough of the robot apart for the inspector to get to the shaft itself, and then the motor finally passed the test.

Good to know it was just user error, that’s one of the flaws with in system testing. I saw one robot with a 15:1 arm/lift mechanism, the only way to stall the motor was by holding the arm, there was the potential for damage. In normal operation when I build this type of mechanism, software prevents excess mechanical stress by limiting current and also keeping motors in sync with each other. A stall test on one of perhaps four arm system motors is not an ideal way of testing, not that I have any better practical solutions.

That’s interesting. How can you limit current in software? by using encoders?

Yes, or in some circumstances potentiometers. Several months of work by Chris Seigert (vamfun) and myself resulted in the “SmartMotor” library for ROBOTC (now at V1.04, stop downloading the old version everyone ! ). You can read about some of the work here.
https://vexforum.com/showpost.php?p=318273&postcount=1