Software · Controls

PID Tuning Lab

Tune a simulated FRC mechanism. The faded ghost is the goal you set, the solid part is where the mechanism really is, and the graph records both over time.

Feedforward

What these do

Feedforward doesn't wait for error. kG holds the mechanism up against gravity. kS overcomes friction in the direction of the error. On our robots that is kS in the gain slot with StaticFeedforwardSign = UseClosedLoopSign, like the 2026 shooter hood. kV supplies the voltage a moving setpoint needs, so on the arm and elevator it only matters with the motion profile on. Feed Forward Control explains each term.

Feedback (PID)

Advanced: kI and kD

With good feedforward, many FRC mechanisms only need kP. kI can remove a small leftover error, but it builds up during long moves and causes overshoot. kD damps overshoot when kP alone rings.

Copying gains to the robot

Conditions

Trapezoid motion profile
Moves the setpoint smoothly toward the goal with a speed and acceleration limit, like calling setTargetPositionMotionProfile(...) instead of setTargetPosition(...) on an MW-Lib mechanism.

Sensor noiseoff

Simulated plant constants

Single-jointed arm

Click or drag to move the goal

Goal–

Actual–

Error–

Position vs time

Goal Measured position

Motor output

Applied voltage±12 V battery limit

Last step response

Since the goal last changed

Rise time 10–90%: –
Overshoot: –
Settling time ±2%: –
Error now: –
Bump recovery: –

The controller runs every 20 ms like a roboRIO loop. The physics runs every 1 ms.

PID Tuning Lab

Tuning walkthrough

Single-jointed arm

Position vs time

Motor output

Last step response

Things to try