dmytro-dovg/pid-combinator

PID Combinator is a mod for the game Factorio that adds a new type of combinator, a device Factorio players use to build in-game logic circuits. This combinator runs a PID controller, which is a standard feedback algorithm used to hold a measured value steady at a chosen target. In Factorio, the most common use is keeping a space platform flying at a set speed rather than letting it speed up or slow down unpredictably. To use it, you wire the space platform's reported speed into the combinator as the value you want to control, wire in a constant signal as the target speed, and wire the combinator's output to a pump that supplies fuel. You then open the combinator's interface, match up the input and output signals on the Variables tab, and start tuning gain values called Kp, Ki, and Kd on the Tuning tab. Because a basic setup only turns the pump fully on or fully off, the mod also explains how to add pulse width modulation, a technique that switches the pump on and off in short bursts so fuel delivery becomes proportional rather than all or nothing, which keeps the platform's speed much steadier. A further section describes an even more responsive two-pump setup that can both add and remove fuel from the thruster's buffer. For players who do not want to tune the three gain values by hand, the combinator includes an auto-tune feature. You let the platform settle near a target speed, choose a tuning rule such as Astrom-Hagglund AMIGO PID or Ziegler-Nichols No overshoot, and press Auto-tune, and the mod measures the platform's response and fills in Kp, Ki, and Kd automatically. The README also includes a detailed manual tuning guide, explaining what to look for on the combinator's live speed graph as you adjust each gain in turn.