Kuby

Crash your Kerbals using Ruby!

Kuby is a Ruby wrapper for the game Kerbal Space Program. This gem exposes a simple DSL with which you can control your rockets.

Installation

Install the gem:

$ gem install kuby

Make sure you have a recent version of KSP and also install the Telemachus plugin.

Usage

Basic example

Create a ruby file with the following contents (simple_launch.rb for example):

require 'rubygems'
require 'kuby'

# Optional parameters :host, :port, otherwise defaults will be used (127.0.0.1:8085)
link = Kuby::Link.new

# Connect to KSP
link.connect!

# Initiate first stage
link.stage!

# Set to full throttle
link.throttle_full

# Activate SAS
link.toggle_sas

Now create a new rocket in KSP or load an existing one. Be sure to add one of the Telemachus antennas to it, otherwise your rocket won't be able to communicate. Now go to the launchpad and when the ship is loaded and you are ready for launch, execute the following command in a terminal:

$ ruby simple_launch.rb

Kuby will connect to your rocket and issue the commands in the order you specified in the file, your rocket will activate the first stage, go to full throttle and enable SAS. After that, the script ends but your rocket will keep flying.

Advanced example

This example will fly your rocket to ± 150 meters and then keeps it floating there by changing the throttle using an implementation of a PID controller

require 'rubygems'
require 'kuby'

# Optional parameters :host, :port, otherwise defaults will be used (127.0.0.1:8085)
link = Kuby::Link.new

# Connect to KSP
link.connect!

# Initiate first stage
link.stage!

# Set to full throttle
link.throttle_full

# Activate SAS
link.toggle_sas

# Wait untill we're at 150 meters
while link.altitude < 150 do
    sleep 0.2
end

target = 0.0
previous = 0.0
error = 0.0
integral = 0.0
derivative = 0.0
time = link.mission_time

loop do
    dt = link.mission_time - time
    time = link.mission_time
    error = target - link.vertical_speed
    integral = integral + error * dt
    derivative = (error - previous)/dt

    new_throttle = (error/10 + integral/15 + derivative/30)

    if new_throttle > 1.0
        new_throttle = 1.0
    elsif new_throttle < 0.0
        new_throttle = 0.0
    end

    link.set_throttle new_throttle

    previous = error

    sleep 0.2
end

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request