Full Throttle Issues

Technical Technical Discussion
1

Hello, I’m Mike from team 1982.

We finished our electrical work, and attached out mechanum wheels. We used the basic mechanum drive code, and started trying to control the bot. However, when the robot was put to full throttle forward, the jaguars shut off, and we had to cycle the robot to get them to work again.

HOWEVER; We did the same thing, except full throttle backwards, and it worked just fine.

The same happened when we switched from mechanum drive to standard drive.

Being the scientists we are, we programmed the bot to go full throttle forward in autonomous mode. There was not an issue. The robot kicked into full throttle forward without an issue. There for it wasn’t the electrician’s fault we’re assuming. :cool: (We placed the chasis on some wooden blocks, so no danger there. ::safety:: ) We can’t find an issue in the programming, and we came up with a thought; could the controller be the issue?
We haven’t had time to test it because of the snow days in out area. :wink: But any opinions on what might be causing this would be fantastic as this is slowing our build process because our lift, minibot, and programming team all need the robot at the same time it seems.

Any response would be greatly appreciated.
A good luck to all the other teams out there! Hope to see some of you at the Greater Kansas City Regional!
~Mike

2

Do the Jaguars start flashing red/yellow when they fail in the forwards direction?
They have a safety that trips if they pull too many amps, for example with a stalled or slowly moving CIM at full power as it tries to accelerate the mass of the robot.

If the robot was off the ground for the Autonomous test, then the motors were not stressed the way they are on the floor having to pull the weight of the robot. Does the robot behave in teleop when it’s off the floor?

3

Sorry, It was on the wood block for all of the tests. I would have to double check what the lights were doing. Our Program monkey was telling me, but I can’t remember. They were red, but I can’t remember if it was flashing or solid.

4

Check the power LEDs on your Digital Sidecar. Make sure they are all brightly lit, especially the one labeled BAT.

The “full forward breaks, full reverse works” description is consistent with a missing 12 volt power supply on the Digital Sidecar. The sidecar can steal a teeny bit of power from the PWM signals coming from the NI 9403 module and make things sort of work, but the available power is reduced when the signal goes from neutral to forward.

Even if it doesn’t work in Teleop, it might work in Autonomous if you haven’t initialized other motors or if there are other differences in signal loads.