Hi, our team use optical shaft encoder to calculate the velocity. As we know, the maximum velocity it can detect is 1133 rpm. Our robot launch gear ratio is 1:7, so the output will be like 1680 rpm if we use max power output which means the encoder can no longer detect the velocity. How can we deal with this without changing to IME?
The simple (and easiest) answer to this is to lose a bit of accuracy and move the shaft encoder onto a shaft that is spinning slower, for instance, an intermediary shaft or the motor shaft. Remember that you will have to change your code to adjust for this change.
My team gears the encoder down from the flywheel shaft with low strength chain. We do this so we can keep the accuracy as high as possible while not destroying the sensor.
This is a good idea. Lots of ratios are open with the LS chain and they add very little friction.
Just gear it down from the main axle with a lightly tensioned chain (doesn’t matter what strength, this won’t be resisting or taking much load). I have a 1:35 with a high strength 4:1 ratio using chain from the main axle, and like i thought, its readings are more stable due to the mass of the flywheel smoothing it out. It actually alluded me to a fault in my code causing the IME to be inaccurate (thanks jpearman!) because i had a comparison that was more reliable.