KiteControllers

Discrete controllers for kite power systems.

This package is part of Julia Kite Power Tools, which consists of the following packages:

mkdir myproject
cd myproject
julia --project="."

using Pkg
pkg"add KiteControllers"

using Pkg
pkg"test KiteControllers"

git clone https://github.com/aenarete/KiteControllers.jl.git
cd KiteControllers.jl
git checkout v0.2.9

cd bin
./create_sys_image --update
cd ..

You can now start Julia with ./bin/run_julia and execute the autopilot or any other of the examples with:

include("example/autopilot.jl")

saturate(value, min_, max_)

Calculate a saturated value, that stays within the given limits.

wrap2pi(angle)

Convert an angle, given in radians in an infinite range to the range from -pi to pi

This package contains some generic control components that are documented here.

CalcVSetIn              # component that calculates the set speed using soft switching
SpeedController         # controller for normal operation
LowerForceController    # controller when force near lower limit
UpperForceController    # controller when force near upper limit
WinchController         # winch controller, combining the three controllers above
WCSettings              # settings of the winch controller
WinchModel              # simplified model for unit testing

FlightPathController    # represents the flight path controller
FPCSettings             # settings of the flight path controller
FlightPathCalculator    # calculate the planned flight path
FlightPathPlanner       # execute the planned flight path
FPPSettings             # settings of the flight path planner
KiteModel               # simplified model for unit testing

SystemStateControl      # high level state machine, receives commands from the GUI
                        # and calls FlightPathPlanner and WinchController

FlightPathController as specified in chapter six of the PhD thesis of Uwe Fechner.

FlightPathController
FPCSettings
on_control_command(fpc, attractor=nothing, psi_dot_set=nothing, radius=nothing, intermediate = true)
on_est_sysstate(fpc, phi, beta, psi, chi, omega, v_a; u_d=nothing, u_d_prime=nothing)
on_timer(fpc)
calc_steering(fpc, parking)

The control commands are usually received from the FlightPathPlanner, the output of the model or the system state estimator must call on_est_systate() each time step.

Flight path control of kite power systems in a turbulent wind environment

For a kite power system, the reel-out speed of the winch must be controlled such that the maximal tether force is never exceeded, while the reel-out speed should be optimized for maximal power over the full cycle at wind speeds below rated wind speed. To keep the kite controllable, also a minimal tether force limit has to be kept. Depending on the mode of operation, one of the following three controllers is used:

The WinchController combines the three controllers, mentioned above. It can be operated in two modes of operation:

• position control
• power production

In position control mode it requires a set speed as input. Upper and lower force limits are respected. In power production mode it does not require any input but the measured tether force. Output is the set speed of the asynchronous motor.

For a usage example look at the script test_winchcontroller.jl .

The FPCA is a stateless component that calculates the coordinates of the attractor points and turn points that determine the flight path. In addition, it calculates the desired turn radius of the turns.

The Flight Path Planner executes the planned flight path using a state machine.

While the Flight Path Planner is in charge of calculating the flight path during automated power production, this component handles other system states, like fully manual operation, automated winch control combined with manual steering, parking etc.

If you want to modify this package, create a fork on github and checkout the fork using Git. Then create a system image of all the packages, used by Kitecontrollers itself and the examples by running the script bin/create_sysimage --update. If you are on Windows make sure you have git-bash installed because this is a bash script. You can then launch Julia with the command bin/run_julia which is fast. Try to run the test scripts from the folder test to understand what they are doing. Now you can modify the source code according to your needs, restart Julia, run the relevant test script again and see the effect. If you are happy, commit your changes and create a pull request. If you have any questions, please ask them at https://discourse.julialang.org/ .

This project is licensed under the MIT License. Please see the below WAIVER in association with the license.

Technische Universiteit Delft hereby disclaims all copyright interest in the package “KiteController.jl” (controllers for airborne wind energy systems) written by the Author(s).

Prof.dr. H.G.C. (Henri) Werij, Dean of Aerospace Engineering

A Methodology for the Design of Kite-Power Control Systems

If you like this software, please consider donating to https://gofund.me/508e041b .

• Research Fechner for the scientific background of this code
• The meta package KiteSimulators which contains all packages from Julia Kite Power Tools.
• the packages KiteModels and WinchModels and AtmosphericModels
• the packages KiteViewers and KiteUtils