Given fairly widespread reports of firmware 1.1.3 dramatically impacting robots, especially autons, is there any official guidance from RECF or Vex about whether robots competing this weekend are required to use it? I understand that the default position of RECF, according to the inspection sheet, is that the ONLY valid firmware version is whatever the most recently published version is.
@Mentor_355U As with all questions similar to this one, please appropriately post this to the Official VRC 2023-2024 VRC Q&A to receive an official answer.
We can’t and will not provide an official answer here.
I would personally appreciate any community help with compiling any & all reports of issues caused by updating VEXos to 1.1.3
Details, pictures, videos, code, etc. are all appreciated if possible.
I posted official Q&A … but seriously uncool in championship weekend to have new firmware released eve of these important events - could it not have waited a couple of weeks?
R14.b clear, Teams MUST run 1.1.3 as it is an official firmware release.
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That is fair; I’ve posted what is probably a duplicate of @lacsap . That said, I have more faith in getting a timely response on VF that RobotEvents.
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What are the reports ? There have been no reports here and there’s nothing that should have had any negative impact on teams in 1.1.3.
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Release notes mention:
Fixed current limit calculation when using a mixture of 11w and 5.5w motors
Which seems to imply that the current delivered to robots using a mix of 11w and 5.5w motors will be different under 1.1.3 than before. From the short release notes, there is certainly concern that this might impact autons. Or is that a misunderstanding?
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On the SCORE Livestream, when match 88’s score is shown, the MC makes mention of problems with 1.1.3 and advises against upgrading firmware
I would be surprised. If you had 16 x 5.5W motors you might under some circumstances (near stalled) see a slight change in as much as the current cap in that situation is going to be higher. But for teams with a mixture of 11W and 5.5W motors that are not running anywhere near stalled, there really is no perceptible difference.
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That could be anything, perhaps a team had a bad USB cable or something and had issues.
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Can you explain how exactly the current cap calculations have changed? Is a 5.5w motor just essentially treated as “half” of a 11w motor (as opposed to being treated the same as a 11w motor previously) or is there more to it than that?
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No, that’s it, half a 11W motor, testing showed it was close enough to simplify to that.
current limit looks ok, not sure about your power assumption. Torque will be higher because current is higher, but max power for these motors does not happen at max current so (without trying to do the math) I don’t think you can say power increases by that much. Practically teams don’t run motors near the current limit most of the time so gains are there but minimal.
To be honest I don’t really know why no one asked about this over the last few months. The reduction in current cap over 8 motors is a well known fact. The change in the current cap calculation was always on the cards and implemented last summer, many other factors have delayed releasing a vexos update until now.
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It was not a bad USB cable. I don’t know what happened at SCORE, but I know the head refs made the decision not to ask teams to update because of how the update affects Team’s program’s because of motor power changes. Also because of a firmware update being made on a Friday, is VERY difficult and frustrating for teams and EPs to implement.
I have heard from multiple EP’s that there is issues with teams interacting with TM on the new firmware. Personally, as an EP hosting an event tomorrow, I haven’t yet seen these issues, but my team’s autonomous functions have had to be retuned, and the functions of several teams coming to our event have also needed to be retuned.
I haven’t touched a V5 brain today on a robot. I am only passing along the messages that I have recieved and the complaints of the teams coming to my event. But as an EP, a 10 year Vex competitor, and someone that mentors multiple teams, I beg you (and all those that work at Vex) that in the future, PLEASE don’t push a firmware update on any days but Monday, and ideally not during championship season. I’ve called so many people trying to figure out if we can ignore the update, and am VERY frustrated with the support we have recieved.
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Is this affecting only those teams using 5.5Watt motors? Is current limit calculation changed for 11Watt motors? I know the “proper” answer is to upgrade the OS and test all code but it’s frustrating and difficult to meet and make changes few days before our States when teams will battle hard for the few spots to Worlds. Not to mention inspection next week will be a complete massacre of schedule and people running around with cables and laptops and confused faces.
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Simple answer is yes, if you do not have 5.5W motors nothing has changed.
We have always limited the maximum motor current if you have more than 8 motors on a robot. In previous years this only impacted VexU as VRC motor limit was 8 x 11W motors. The reason for the limit is to limit maximum battery current.
This years rule change to allow 5.5W motors meant that some teams would have a legal robot with more than 8 motors even though the total limit of (theoretical) motor power remained at 88W.
For example, if you had a 6 x 11W motor drive and then used 4 x 5.5W motors elsewhere, the motor current limit for all 10 motors would be set to 2.29A rather than the default 2.5A. This was the situation with vexos 1.1.2, it didn’t understand that 5.5W motors draw less current from the battery and could be treated differently from the 11W motor.
1.1.3 now revises the calculation of the current limit by treating a 5.5W motor as “half” an 11W motor.
Just because the current limit for a motor is now a little higher, it does not necessarily mean that the motors will perform significantly differently. The limit is only reached when the motor is under excessive load or stalled. Maximum torque with 1.1.3 will be higher, in the above example there will be perhaps be10% more torque available, but maximum motor power by my back of the envelope calculation is only increased by perhaps 1.5%. Using theoretical numbers again, under 1.1.2 the 11W motor may have only been producing 10.9W rather than 11W with the 6x11 + 4x5.5 example above.
In addition to all this theoretical math, the motors actually have a bit more power than 11W, you will notice that our published dyno data has max power above 12W. you will also see motor to motor differences, some will be slightly more or less powerful than the average. That’s one reason the motors have the internal PID control to try and control speed to that set by the user and also some battery voltage compensation to try and normalize operation as if the battery was always the ideal 12V.
but again, if the robot is just using 8 x 11W motors nothing has changed.
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Agree, it is the most important factor, when you consider long term power output and thermal dissipation capacity of the motor. Like how much total power it could deliver over the period of entire match without triggering thermal protection.
However, for the short term consideration of individual autonomous command, which could last just the fraction of the second, this must be having larger influence:
For example, if user program commands V5 motor to spin up to certain velocity or position, then, if V5 firmware PID could utilize 10% more torque in the transition, this could affect a lot of physical behaviors, like compression of the rubber rollers and floor tiles, momentary slipping of the wheels, a tiny bit of flexing of the robot frame, etc… Which could all amplify the error in the precisely tuned autonomous routine.
Of course, if the team utilizes full feedback loop of odometry for estimating robot velocity and position and custom PID that carries integral value(s) over multiple steps, then effects of the firmware change could be somewhat compensated.
But for teams who rely only on V5 builtin PID for each individual step, I could totally see how their autonomous could be affected.
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