I am very thrilled to see how accurate I was able to get the wheels with the Optical Quad Encoders. Below is a simple test but it is much more difficult than it appears to perform the back and forth motion with such accuracy.
- YouTube (the actual trial begins at 2:30)
Can you adjust the PID function parameters so that it works without overshoot?
I’m new to vex robotics, so I don’t really know what PID is xd
The way it works is the OpticalQuadEncoders need to be within a certain range of the desired destination before the wheel stops(I think its two-three pulses, I’d have to check the code again). I could try to fine tune it to minimize this range, but it is very tricky to get a stable reading on the optical quad encoders so having accurate down to even 1 pulse would be quite tricky.
It would be possible though, to have the module preffer undershooting rather than overshooting - but the idea is that it doesn’t really matter if it overshoots or undershoots as its programmed to compensated for in the next cycle or so.
I just ran this test over a much longer distance and it maintained its accuracy. I will upload a video of it maybe tonight.
Post your code and maybe someone can provide some ideas.
Reading up on PID might help. I think the idea is to slow the motors down as you approach the desired count, not just stop immediately when you get to the count.
I am slowing the motors. However, the OpticalQuadEncoders are reading in a rather unstable matter. Its also hard to slow the motors without significantly lowering the torque. I fine-tuned the bumping speed to the min torque needed to move the wheel.