Struct Controller

pub struct Controller { /* private fields */ }

PID controller

The target param sets the value we want to reach. The proportional_gain, integral_gain and derivative_gain parameters are all tuning parameters.

Examples

use pid_lite::Controller;
use std::thread;
use std::time::Duration;

let target = 80.0;
let mut controller = Controller::new(target, 0.5, 0.1, 0.2);

loop {
    let correction = controller.update(measure());
    apply_correction(correction);
    thread::sleep(Duration::from_secs(1));
}

Implementations

impl Controller

pub const fn new( target: f64, proportional_gain: f64, integral_gain: f64, derivative_gain: f64, ) -> Self

Create a new instance of Controller.

Examples

use pid_lite::Controller;

let target = 80.0;
let mut controller = Controller::new(target, 0.20, 0.02, 0.04);

pub const fn target(&self) -> f64

Get the target.

Examples

use pid_lite::Controller;

let target = 80.0;
let mut controller = Controller::new(target, 0.20, 0.02, 0.04);
assert_eq!(controller.target(), 80.0);

pub fn set_target(&mut self, target: f64)

Set the target.

Examples

use pid_lite::Controller;

let target = 80.0;
let mut controller = Controller::new(target, 0.20, 0.02, 0.04);
controller.set_target(60.0);
assert_eq!(controller.target(), 60.0);

pub fn set_proportional_gain(&mut self, proportional_gain: f64)

Set the proportional gain

pub fn set_integral_gain(&mut self, integral_gain: f64)

Set the integral gain

pub fn set_derivative_gain(&mut self, derivative_gain: f64)

Set the derivative gain

pub fn update(&mut self, current_value: f64) -> f64

Push an entry into the controller.

Examples

use pid_lite::Controller;

let target = 80.0;
let mut controller = Controller::new(target, 0.0, 0.0, 0.0);
assert_eq!(controller.update(60.0), 0.0);

Panics

This function may panic if the time_delta in millis no longer fits in an f64. This limit can be encountered when the PID controller is updated on the scale of hours, rather than on the scale of minutes to milliseconds.

pub fn update_elapsed(&mut self, current_value: f64, elapsed: Duration) -> f64

Push an entry into the controller with a time delta since the last update.

The time_delta value will be rounded down to the closest millisecond with a minimum of 1 millisecond.

Examples

use pid_lite::Controller;
use std::time::Duration;

let target = 80.0;
let mut controller = Controller::new(target, 0.5, 0.1, 0.2);
let dur = Duration::from_millis(2);
assert_eq!(controller.update_elapsed(60.0, dur), 16.0);

Panics

This function may panic if the time_delta in millis no longer fits in an f64. This limit can be encountered when the PID controller is updated on the scale of hours, rather than on the scale of minutes to milliseconds.

pub fn reset(&mut self)

Reset the internal state.

Examples

use pid_lite::Controller;
use std::time::Duration;

let target = 80.0;
let mut controller = Controller::new(target, 0.0, 0.0, 0.0);
let dur = Duration::from_secs(2);
let correction = controller.update_elapsed(60.0, dur);

controller.reset();

Trait Implementations

impl Debug for Controller

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.