https://github.com/gabetax/pid_controller

Ruby implementation of a PID Controller
https://github.com/gabetax/pid_controller

control-theory pid-controller ruby

Last synced: about 1 year ago
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Ruby implementation of a PID Controller

• Host: GitHub
• URL: https://github.com/gabetax/pid_controller
• Owner: gabetax
• License: apache-2.0
• Created: 2017-11-27T01:22:30.000Z (over 8 years ago)
• Default Branch: main
• Last Pushed: 2020-06-24T01:33:42.000Z (almost 6 years ago)
• Last Synced: 2025-02-28T00:51:22.520Z (about 1 year ago)
• Topics: control-theory, pid-controller, ruby
• Language: Ruby
• Homepage:
• Size: 29.3 KB
• Stars: 14
• Watchers: 1
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# PidController

[![Gem Version](https://badge.fury.io/rb/pid_controller.svg)](https://badge.fury.io/rb/pid_controller)

[![Build Status](https://travis-ci.org/gabetax/pid_controller.svg?branch=master)](https://travis-ci.org/gabetax/pid_controller)

This is a Ruby implementation of a [PID Controller](https://en.wikipedia.org/wiki/PID_controller). A PID controller is a feedback system that is configured with a target setpoint, can read measurements of the system to see how close we are to the setpoint, and will omit an output. Every day examples include:

- Cruise control

- Thermostats

- Quadcopters (appearently, because they predominate search results)

- Database load (yay! This is why the purpose I'm actually writing this for).

## Recommended reading

- [PID without a PhD](https://www.wescottdesign.com/articles/pid/pidWithoutAPhd.pdf)

- [Throttling Utilities in the IBM DB2 Universal Database Server](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.660.9095&rep=rep1&type=pdf)

## Usage

I mentioned databases, so here's an example of how we can prevent a low priority task (e.g. bulk deletion) from contending with customer traffic:

```ruby

sensor = MySQLSensor.new # Use your imagination

controller = PIDController.new(

  setpoint: 60.0,

  kp: 5.0,

  ki: 1.0,

  kd: 0.1,

  output_max: 0.0,

  integral_max: 0.0

  )

Event.where(account_id: account_id).in_batches do |relation|

  relation.delete_all

  backoff = -1 * controller << sensor.cpu_utilization

  sleep backoff if backoff > 0

end

```

## Development

After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.

## Contributing

Bug reports and pull requests are welcome on GitHub at