Momentum Tuner

A set of wrappers and utility classes for storing PID values in a .ini file, while also listening for updates to these values over the network tables.

The goal of this project is to improve the user experience of tuning PID controllers on the robot, no matter if the controller runs on the RIO or on a motor controller. Using the PIDTuner class to configure any given PID controller provides several benefits:

• PID constants are collected in one unified location, allowing them to be easily backed up
• PID constants are saved to disk as soon as they are updated, and they are automatically loaded back into the PID controller at startup
• PID constants can be adjusted via the NetworkTables using any NetworkTables client, including the ShuffleBoard or Glass
• Process state variables from the PID controller are published to the NetworkTables, where they can be graphed using Glass, much improving the process of tuning the constants

Notes

There are two basic types of values handled by this tuner class: PID properties and state values.

A property is some value you set to configure the PID controller, also known as a PID constant or gain. Examples include kP, kI, and kD.

A state value is some value that describes the current state of the PID system. It is not a value you set, but a value you are interested in measuring to characterize the current behavior of the feedback loop. Examples include the setpoint and the current measurement of the controller.

The PIDTuner class can handle any number of floating-point properties and state values. One simply needs to pass in a key and a consumer or supplier (consumer for properties, supplier for state values) to the constructor. However, it is often easier to use the PIDTunerBuilder class, which provides helper functions for common properties and state values.

One function of note on the PIDTunerBuilder is the safeBuild() method. This will attempt to build the PIDTuner, but if any exceptions occur it will catch them and report them to the driver station.

Example

PIDController drivePid = new PIDController(kP, kI, kD);
PIDTuner tuner = PIDTuner.builder("DrivePID")
        .withP(drivePid::setP)
        .withI(drivePid::setI)
        .withD(drivePid::setD)
        .withSetpoint(() -> lastSetpoint)
        .withMeasurement(() -> lastMeasurement)
        .safeBuild();