Bifalgorithm post

You've definitely heard of PID. It's the control loop holding this robot upright. But what do the three letters actually do? Let's turn them on one at a time. The robot has one job. Keep this angle at zero. Every instant, it measures how far it's tipped, which is called the error. Now here's the equation that turns that error into a motor command. Yeah, it looks scary. But look closer. It's just three pieces added together. One for each level. P is proportional. The further it tips, the harder it pushes back. Tip a little, push a little. Tip a lot, push a lot. On its own, P reacts fast, but it never quite settles. It drifts and leans. I is integral. It adds up that leftover error over time, so a small lean that won't go away keeps building correction until it's gone. I kills the steady offset P leaves behind. D is derivative. It watches how fast the error is changing and pushes against the motion, like a shock absorber. D is what stops the overshoot and damps the wobble. Put all three together and the whole equation lights up at once. And the robot just stands there. Proportional reacts, integral cleans up, derivative smooths. That's PID. And it's the same loop balancing drones, arms, and every robot that has to hold itself steady.

You've definitely heard of PID. It's the control loop holding this robot upright. But what do the three letters actually do? Let's turn them on one at a time.…