A Lesson in Failure: Reaction Wheel PID Tuning
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- Опубликовано: 16 окт 2024
- In this video I attempt to throw together a simple inverted pendulum reaction wheel balancing bot with the goal of using it to demonstrate PID tuning. However, things backfire when I can't even make the machine balance let alone talk about the PID tuning. So join me for this honest lesson in failure!
Website: iancarey.ie
Patreon: / careyi3
#reactionwheel #pid #pidtuning #robots #balancebot
I feel like it's important to share failures as well as success, we are all human and make mistakes and underestimate problems! This was one such occasion, maybe you guys will get a certain sense of schadenfreude from this! Enjoy
Hi Ian, this is exactly what I was eluding to in the last video when it comes to slow external loops, ie, a fast acting internal pid loop is a lot easier to tune than a slow reacting external one, what you tackled in this video is one of the hardest types of external control loops, namely a tortional loop.
My hat off to you for trying it. As far as the noise, you may be able to reduce that somewhat by placing a 100nf cap accross the output of the mpu6050... Just note that this will make the unit "less sensitive" much like a smoothing algorithm, did you try any form of smoothing or were you running on raw input?
100%, get your point on the loop timing, good observation! On the module itself, a cap on the output wouldn’t help as the module is fully digital and we communicate with it over I2C. However, I tried using a few different types of filters on the data it returned including a complementary filters and also a Kalman filter. These filters work great with this module, but in my experience you can only get +/- 1 degree of reliable accuracy from them when you try and suppress the noise. With this setup, the noise was too much to overcome with the sensitivity of this rig. I have used this module before for my two wheel balancing robot, but that bot was a super top heavy pendulum which responded much slower, and so the noise and lack of precision actually ends up being fine. This very sensitive finely balanced rig was not to be it seems.
I have another machine currently in the works which I am sure will work and I can put out some good content on the turning.
DOH!!! I forgot is a digital output.... Not analog.... 🤣😂 Egg on my face there... That is not an easy loop you chose. But, to those who dare the most, the greater rewards are reserved..... Good luck!