CHANGELOG.md

KiteModels v0.11.6 2026-03-21

Added

• the functions copy_examples_3d() and install_examples_3d()
• add the functions states(kps) to determine the number of states of a model
• add parameter -y --yes to install script

Changed

• add parameter --update to install script and remove it from create_sys_image script

Fixed

• the create_sys_image2 script now includes KiteViewers only if needed for the 3d examples

KiteModels v0.11.5 2026-03-17

Fixed

• fixed citation metadata in CITATION.cff

KiteModels v0.11.4 2026-03-11

Changed

• all files in src and all files in the examples now free of warnings
• the install script now keeps the currently active Julia version
• fixed all JETLS warnings in the src folder and the examples

Added

• the script bin/jetls which checks the syntax of the src files
• the script bin/jetls_examples which checks the syntax in the examples

KiteModels v0.11.3 2026-03-04

Changed

• bumped KiteUtils to 0.11.3
• add parameter dtmax to the solver settings to improve stability

KiteModels v0.11.2 2026-03-03

Changed

• fixed most JETLS warnings, only two left
• fixed many warnings in the examples
• suppressed some more warnings in .JETLSConfig.toml.default
• the install script now copies .JETLSConfig.toml.default to .JETLSConfig.toml if it does not exist yet
• deleted unused code
• moved the initialization functions from init.jl to KPS4.jl and renamed init.jl to utils.jl

KiteModels v0.11.1 2026-03-02

Changed

• first version with good support for MacOS
• the install script now installs qtagg for MacOS
• bumped ControlPlots to 0.2.13 for MacOS support. Plots are blocking now.
• bumped KiteViewers to 0.5.1 for MacOS support. Different text positions, new font.
• updated many other dependencies
• when a plot is closed, the main app gets activated (MacOS)
• when the KiteViewer is displayed, it is brought into the foreground (MacOS)
• updated all examples for MacOS support
• the install script is more robust now and reports warnings at the end (if needed)
• examples_3d is a workspaces now
• improved create_sys_image and install scripts

Fixed

• examples_3d/parking_4p.jl is working now
• examples_3d/show_kite.jl is working now

Added

• example auto_parking.jl
• example parking_wind_dir.jl

KiteModels v0.11.0 2026-02-20

Changed

• remove SymbolicAWEModels
• fix warnings and spelling errors
• improve find_steady_state!, print warning if the solver fails
• test-steady-state-kps4.jl is now a separate test file
• all test files can be executed separately
• test files have been renamed, now all start with test-
• use workspaces for the test, examples, and docs folder
• all markdown files are now checked with markdownlint
• no more global variables in the main test scripts

Fixed

• all examples and tests that call find_steady_state! succeed now without warning
• other fixes of examples
• dead or wrong links in README.md and the documentation
• many JETLS warnings, only two left

Added

• configuration files from BestieTemplate.jl
• installer script bin/install
• a warning if find_steady_state! does not succeed

KiteModels v0.10.0 2026-02-06

Changed

• Support Julia 1.12
• Bump KitePodModels to 0.4.0
• Bump KiteUtils to 0.11.1
• Breaking: rename c_spring to axial_stiffness and damping to `axial_damping
• Breaking: rename force to winch_force when SysState is referred to
• Make tests more robust by deleting unused files from the temporary directory and by increasing tolerances

Added

• the configuration file .JETLSConfig.toml
• the script reuse_lint to check the licenses

KiteModels v0.9.0 2025-07-14

Changed

• BREAKING: rename init_sim! to init!
• removed the parameter upwind_dir! from init!; use set.upwind_dir instead. Careful: This is in degrees.
• the function init! accepts (and ignores) the parameters delta and stiffness_factor if applied to a SymbolicAWEModel
• bump KiteUtils.jl to v0.10.15
• bump AtmosphericModels to v0.3.0, the first version that supports turbulent wind fields

Added

• add the test script test_interface.jl
• add the field integrator to KPS4 and KPS3 structs

KiteModels v0.8.1 2025-06-20

Changed

• renamed POWER to POWER_LINE and STEERING to STEERING_LINE
• improved documentation, fixed example

KiteModels v0.8.0 2025-06-19

Added

• add a tutorial for custom system structures
• add documentation for SystemStructure components #229
• add the Transform struct which defines initial orientation of the SystemStructure #214
• add a custom amount of kites to the SystemStructure #208
• make model initialization faster #222
• implement missing methods for the SymbolicAWEModel #198

Changed

• fixed the performance regression when using the KPS4 model with a winch model of type AsyncMachine
• improved the script create_sys_image; it is now also available if you install the package without using git
• make model initialization faster #222
• make next_step! return nothing #213
• Change the names of RamAirKite to SymbolicAWESystem and PointMassSystem to SystemStructure #208

KiteModels v0.7.4 2025-06-08

Added

• added licenses to each file, the command pipx run reuse lint succeeds now
• add the command above to the CI scripts
• the script create_xz_file
• the option to linearize the SymbolicAWEModel system using ModelingToolkit
• a simplified ram air kite model for faster development and testing
• the example lin_ram_model.jl to show how to linearize a model
• add the page Examples SymbolicAWEModel do the documentation

Changed

• the example ram_air_kite.jl can now be run like this SIMPLE=true; include("examples/ram_air_kite.jl")
• the package Rotations is no longer re-exported
• improved documentation

Fixed

• small fixes of the SymbolicAWEModel model

KiteModels v0.7.3 2025-05-05

Fixed

• fix function update_sys_state!()

KiteModels v0.7.2 2025-05-05

Changed

• bump KiteUtils to v0.10.5, which provides much more fields for in the SysState

KiteModels v0.7.1 2025-04-28

Changed

• fixed or documented issues found by Aqua.jl
• made DSP a test dependency
• remove package OrdinaryDiffEqSDIRK
• improve documentation for SymbolicAWEModel

Added

• the examples calc_spectrum.jl and plot_spectrum.jl to the menu
• the quality insurance package Aqua.jl
• added the script update_default_manifest
• calculate side_slip angle in radian

KiteModels v0.7.0 2025-04-20

Fixed

• fixed broken installation by freezing NLSolversBase to ~7.8.3 in Project.toml

Added

• added mwe_26.jl for debugging the initial state solver
• the example ram_air_kite.jl
• the struct SystemStructure for easy definition of the kite power system

Changed

• BREAKING: the model KPS_3L was renamed to SymbolicAWEModel
• the SymbolicAWEModel model is using the VortexStepMethod with a deforming wing now
• bump KiteUtils to v0.10
• bump ModellingToolkit to 9.72
• bump VortexStepMethod to 1.2.5
• the file CONTRIBUTING.md was updated

KiteModels v0.6.17 2025-02-11

Changed

• always use the brake if the set_speed is zero; this fixes the example steering_test_4p.jl

KiteModels v0.6.16 2025-02-06

Changed

• initial_reel_out_4p.jl shows a simulation that starts with an initial reel-out speed > 0
• initial_reel_out_4p_torque_control runs a simulation with a torque controlled winch and an initial reel-out speed > 0

Fixed

• initial reel-out speed handled correctly

KiteModels v0.6.15 2025-02-03

• log kcu_steering in SysState (output of KCU without applying corrections)
• fix tests for Julia 1.11.3
• cleanup run_julia
• add function calculate_rotational_inertia!()
• add example calculate_rotational_inertia.jl and add it to the menu

KiteModels v0.6.14 2025-01-16

Fixed

• crash due to a new version of DierckX_jll

Changed

• bump versions in Project.toml
• add upwind_dir to settings.yaml file, remove v_wind_ref vector
• add p_speed, i_speed and max_acc to winch settings
• replaced autodiff=false with autodiff=AutoFiniteDiff() to fix warnings
• added package ADTypes to provide AutoFiniteDiff()
• cleanup code

KiteModels v0.6.13 2024-12-06

Changed

• update the fields set_steering, bearing and attractor of the SysState struct in the function update_sys_state!
• add the parameters bearing and attractor to the function next_step! for logging

Fixed

• fix #88: the function init_sim!() has the new parameter upwind_dir to define the initial wind direction

KiteModels v0.6.12 2024-12-01

Changed

• update the fields set_torque, set_force, set_speed, alpha3, alpha4, roll, pitch, yaw of the SysState struct in the function update_sys_state!
• add the parameter set_force to the function next_step! for logging
• the four point kite model KPS4 was extended to include aerodynamic damping of pitch oscillations; for this purpose, the parameters cmq and cord_length must be defined in settings.yaml
• the four point kite model KPS4 was extended to include the impact of the deformation of the kite on the turn rate; for this, the parameter smc must be defined in settings.yaml
• improve examples
• add the packages JLD2 and Colors to the system image

Added

• add examples calc_spectrum.jl and plot_spectrum to plot the eigenfrequencies of the system
• the script calculate_rotational_inertia.jl for calculating the inertia matrix of the kite
• function menu2() which displays a menu with scripts for model verification

KiteModels v0.6.11 2024-11-09

Fixed

• fixed bug in spring_forces(), it used 4000N hardcoded max force

Changed

• bump KiteUtils to 0.9.0
• the fields AoA, CL2, CD2 and the vectors v_wind_gnd, v_wind_200m and v_wind_kite are now updated when converting KPS3 or KPS4 to SysState

Added

• add example test_steady_state.jl

KiteModels v0.6.10 2024-11-01

• fixed the installation of the examples
• updated the documentation
• the package Rotations is now re-exported by KiteModels
• reduce number of dependencies of the examples

KiteModels v0.6.9 2024-11-01

• added tests for calc_azimuth(s::AKM), the azimuth in wind reference frame
• re-enable logging of the angles of attack of the three plates
• steering_test_4p.jl now calculates both c1 and c2 of the turn-rate law
• the environment variable NO_MTK disables the pre-compilation of the SymbolicAWEModel model to save time during development
• the script menu2.jl for model verification was added

KiteModels v0.6.8 - 2024-10-23

Changed

• the sign of the steering signal was changed. Now, a positive steering signal causes a positive turn rate. The turn rate is the derivative of the heading angle.
• all orientation tests pass now (calculation of roll, pitch, yaw, azimuth_north, elevation, heading)
• add example steering_test_1p.jl
• improve steering_test_4p.jl, use fully powered kite now
• the logged steering signal is now divided by set.cs_4p, because the new version of KitePodModels.jl multiplies the steering value with this constant
• update documentation regarding steering and heading

KiteModels v0.6.7 - 2024-10-20

Changed

• renamed test_init.jl to test_init_4p.jl
• by default, azimuth in wind reference frame is now used
• the orientation is now represented in NED reference frame
• the method calc_heading has two new, optional parameters: neg_azimuth=false, one_point=false
• the definition of heading and azimuth has changed, which will require adaptions in the controller

Added

• example plot_side_cl.jl
• example plot_cl_cd_plate.jl
• example steering_test.jl
• example test_init_1p.jl
• the test script test_orientation.jl was contributed by Daan van Wolffelaar; currently, some of these tests are still broken (error of about 2%)

Fixed

• many of the examples; all examples of menu.jl now work

KiteModels v0.6.6 - 2024-09-03

Changed

• the method next_step! uses now upwind_dir as parameter and not longer wind_dir
• install matplotlib if it is not already installed after user confirmation in a Julia specific environment
• replaced OrdinaryDiffEq with the three packages OrdinaryDiffEqCore, OrdinaryDiffEqBDF and OrdinaryDiffEqSDIRK. This should help to reduce the pre-compilation time.
• set the parameter delta in the examples
• always specify the system.yaml file to use in the examples, always use load_settings instead of se. This ensures that the settings are always freshly loaded from the file when the script is launched, so any changes to the settings become immediately effective.
• the SymbolicAWEModel model was replaced by the pure ModelingToolkit (MTK) based version. This allows not only a much faster simulation, but the results are also much more accurate.

KiteModels v0.6.5 - 2024-08-12

Changed

• bump KiteUtils to 0.7.7
• add new examples to menu
• major change to the function that finds the initial equilibrium; the function init_sim! has the new parameter delta which should be in the range of 0.01 to 0.03.
• better error message if init_sim!, but no exception any more. I just returns nothing.
• remove dependency StatProfilerHTML

Added

• add KCU drag, based on kcu_diameter and cd_kcu
• add function bridle_length (not exported)
• unit tests for the KPS3_3L model, based on ModelingToolkit
• script examples/plot_cl_cd.jl
• script examples/plot_cl_cd_plate.jl
• script torque_controlled_mtk.jl

Fixed

• correct tether drag based on l_bridle; if the kite has more than 7 bridle lines l_bridle must be larger than bridle_length(se)

KiteModels v0.6.4 - 2024-08-12

Added

• a new kite model, KPS3_3L was contributed by Bart van de Lint. It uses three lines to the ground and three winches for steering a ram-air foil kite.
• caching for the initial equilibrium
• function KiteModels.install_examples() that copies the examples, the data folder and installs the required extra packages
• log alpha2, alpha3, alpha4; they must never become negative

Fixed

• the calculation of the call-backs per time step was fixed in all examples and the tests

KiteModels v0.6.3 - 2024-08-06

Changed

• the function copy_examples() copies now all examples
• updated the documentation
• improved the scripts in the bin folder, not relevant for most users

KiteModels v0.6.2 - 2024-08-06

Changed

• renamed the example simulate.jl to simulate_simple.jl
• renamed the example simulate_ii.jl to simulate_steering.jl
• add the script menu.jl that provides a menu with all the examples
• bump ControlPlots to 0.1.4
• bump KiteUtils to 0.7.4

KiteModels v0.6.1 - 2024-07-25

Changed

• bump WinchModels to 0.3.2
• bump KitePodModels to 0.3.3
• fix example reel_out_4p_torque_control.jl

KiteModels v0.6.0 - 2024-07-25

Changed

• use a new version of WinchModels.jl which provides an additional, torque-controlled winch
• add many new winch parameters to settings.jl
• BREAKING change: rename v_ro to set_speed in function step()

KiteModels v0.5.16 - 2024-06-25

Changed

• bump KiteUtils to version 0.6.16
• bump ControlPlots to version 0.0.12

KiteModels v0.5.15 - 2024-06-18

Changed

• bump KiteUtils to version 0.6.12
• drop support for Julia 1.9

KiteModels v0.5.14 - 2024-05-05

Changed

• replace Plots with ControlPlots in the examples

KiteModels v0.5.13 - 2024-04-14

Changed

• use rel_compr_stiffness and rel_damping from settings.yaml

KiteModels v0.5.12 - 2024-04-14

Changed

• update KiteUtils to v0.6.7
• update Documenter to v1.0

Added

• add type SymbolicAWEModel, which is now only a copy of KPS4, but shall implement a kite with the steering lines going to the ground

KiteModels v0.5.11 - 2024-04-04

Added

• document the support for the DImplicitEuler solver, which is not very accurate, but because it is well known it can serve as a reference
• support changing max_order for the DFBDF
• further reduced the memory usage

KiteModels v0.5.10 - 2024-04-03

Added

• it is now possible (and suggested) to use the DAE solver DFBDF.

This requires adding the following line to the settings.yaml file:

solver: "DFBDF"

The new solver is much faster (4x average, 1.8x worst case), has a lot less memory allocations (~ 50%) and is also much more stable in highly dynamic situations.

KiteModels v0.5.8 - 2024-04-01

Added

• new, non-allocating function update_sys_state!(ss::SysState, s::AKM, zoom=1.0)

KiteModels v0.5.7 - 2024-04-01

Changed

• improved performance by 10% by implementing custom norm() function for 3D vectors

KiteModels v0.5.6 - 2024-03-30

Fixed

• fix the method clear!(s::KPS4) which failed for models with less than 6 tether segments

Simulations should work fine now for one to about 28 tether segments (no hard upper limit, but things become slow and the visualization ugly if you have too many segments).