https://github.com/ua-kxie/pid-ctrl

Flexible pid controller with time delta as argument
https://github.com/ua-kxie/pid-ctrl

embedded pid-controller rust

Last synced: about 1 month ago
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Flexible pid controller with time delta as argument

• Host: GitHub
• URL: https://github.com/ua-kxie/pid-ctrl
• Owner: ua-kxie
• License: apache-2.0
• Created: 2022-08-11T08:54:26.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2023-04-04T02:57:02.000Z (almost 2 years ago)
• Last Synced: 2025-01-02T01:24:35.680Z (about 2 months ago)
• Topics: embedded, pid-controller, rust
• Language: Rust
• Homepage:
• Size: 18.6 KB
• Stars: 5
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE-APACHE

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• awesome-rust-list - ua-kxie/pid-ctrl - kxie/pid-ctrl?style=social"/> : Flexible pid controller with time delta as argument. (Motion Control)

README

        
## Overview

A proportional-integral-derivative (PID) controller.

Inspired by [pid-rs](https://github.com/braincore/pid-rs) 

With cleaner API and assumptions (constant time delta and symmetrical limits) dropped.

## Features

* Discrete time PID controller

* Defined for generic float types

* Attempts to conform to rust [API Guidelines](https://rust-lang.github.io/api-guidelines/about.html)

* ```#![no_std]```

* Limits for each of p, i, d terms and output

* Calculates derivative term using measurement over error (no derivative kick on new setpoint)

* Clamps time interval to between ```Float::epsilon()``` and ```Float::infinity()```

## Installation

```cargo add pid-ctrl```

## Examples

```rust

use pid_ctrl;

use num_traits;

fn main() {

    let mut pid = pid_ctrl::PidCtrl::new_with_pid(3.0, 2.0, 1.0);

    let setpoint = 5.0;

    let prev_measurement = 0.0;

    // calling init optional. Setpoint and prev_measurement set to 0.0 by default.

    // Recommended to avoid derivative kick on startup

    pid.init(setpoint, prev_measurement);

    let measurement = 0.0;

    let time_delta = 1.0;

    assert_eq!(

        pid.step(pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(15.0, 10.0, 0.0, 25.0)

    );

    // changing pid constants

    pid.kp.set_scale(4.0);

    assert_eq!(

        pid.step(pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(20.0, 20.0, 0.0, 40.0)

    );

    // setting symmetrical limits around zero

    pid.kp.limits.set_limit(10.0);

    assert_eq!(

        pid.step(pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(10.0, 30.0, 0.0, 40.0)

    );

    let time_delta = 0.5;

    assert_eq!(

        pid.step(pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(10.0, 35.0, 0.0, 45.0)

    );

    // setting upper limits returns error if new value conflicts with lower limit

    pid.ki.limits.try_set_upper(28.0).unwrap();  

    assert_eq!(

        pid.step(pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(10.0, 28.0, 0.0, 38.0)

    );

    // time_delta gets clamped to Float::epsilon() - Float::infinity()

    let measurement = 1.0;

    let time_delta = -7.0;

    pid.kd.set_scale(num_traits::Float::epsilon());

    assert_eq!(pid.step(

        pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(10.0, 28.0, -1.0, 37.0)

    );

    // configure setpoint directly

    pid.setpoint = 1.0;

    assert_eq!(pid.step(

        pid_ctrl::PidIn::new(measurement, time_delta)), 

        pid_ctrl::PidOut::new(0.0, 28.0, 0.0, 28.0)

    );

}

```

## Contribute

Feel free to raise issues. 

Would like to make ```#![no_std]``` optional so types can impl Display trait.