The robot does not move straight
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If you can answer a few questions we’ll be better able to help:
-What type of drivetrain do you have? Swerve, tank, something else?
–If swerve, it may help to note module type and which swerve library you’re using.
-What type of motors/speed controllers do you have?
-What sensors do you have on the robot that would affect the drivetrain?
A couple of diagnostic/troubleshooting steps:
-Is any section of the drivetrain (module for swerve, side for tank, wheel and gearbox for mecanum) difficult to move by hand with power off?
-Does it work right with the robot up on blocks, or does it still mess up?
-I assume you’ve already checked for loose or reversed wires, but can you do yourself a favor and double-check?
Final note: Your saying that there is no electrical or code problem indicates that you probably do have an electrical or code problem… CS101 Syndrome is defined as “The code works, of course! I wrote it!” and usually ends with someone finding a bug in the code.
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Hope this isn’t too obvious but…have you checked for mechanical problems? I noticed it was conspicuously absent from your list.
Does each wheel appear to be in good condition and reasonably identical to each other? Are any of the wheels or axels wobbly? When the robot is off, does each wheel rotate freely on its axel - are any of them jammed or have more resistance than the others? When you look at each wheel assembly, can you spot anything that doesn’t look identical/symmetrical to the others? Are all the wheels that are supposed to be touching the ground, touching the ground? When you drive the robot reeeeeally slowly, can you see any wheel doing something different from the others (wobbling, not spinning, etc)? If you’re using belts, are they appropriately tensioned, and do they ever skip teeth when the robot’s driving? If chains, are the chains appropriately tensioned?
Whether the problem is ultimately software, electrical or mechanical, a robot veering when you told it to go straight means that one side or wheel is doing something different than the others and that’s what you need to pin down.
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Well we used basic kit parts, tank drive we have no sensors we tried diffiernt tires but nothing worked out we used the same straps too
Can you describe the error that’s occurring? “Robot doesn’t move straight” isn’t something we can help with unless we get a bit more detail, I would go through @EricH ’s list and answer those, once those questions are answered we can help you a lot better. Are you on Java? If not, what language? Can you post your code so someone more knowledgeable than I am can see if there’s any errors in there that could be causing what you’re experiencing? Telling us it’s a tank drive is a good start, what motors are powering the tank drive?
And gearboxes, too. Some gearboxes have an annoying habit of binding if a small detail is missed. Including the KOP gearbox…
Sounds like CIM motors and KOP gearboxes–is that correct?
we use cim
well we have two robots they use the same codes one works properly the other one not
I see you are from team 9545 in Sariyer, it might be worthwhile to reach out and establish a relationship with another local team like 5665 or another team that is close. They would likely be able to lend someone for an afternoon to discuss issues you may have that are more easily solved in person than over the internet.
Good luck!
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It’s most likely either electrical or mechanical, then. There’s a couple “obvious” blunders to be made on the code side, though.
- Please describe your drivetrain more clearly. You have a kit tank drive with CIM motors. What speed controllers drive those motors? How many motors? What gearboxes? ANY detail here will help us help you. Also confirm that the other, working, drive is set up the same way, including the motors.
- Please go through previously described troubleshooting steps. One side may be binding up, and there are a number of places to look for that.
- Shifting to code/electrical for a moment: it may be possible that one or more motor controllers are plugged in (or addressed–secondary question, PWM or CAN?) differently between the robots. It may also be possible that a motors is disconnected.
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