Update README.md

Author: ufechner7

README.md

@@ -57,4 +57,76 @@ cd WinchControllers.jl
 git checkout v0.1.0
 ```
 For the checkout command, use the tag of the latest version.
-</details>
+</details>
+
+## This package provides
+### Utility functions
+```
+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
+
+### Generic control components
+This package contains some generic control components that are documented [here](./docs/components.md).
+
+### Types that are not generic
+```julia
+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
+```
+
+## Winch controller
+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:
+### Speed Controller
+<p align="center"><img src="./docs/speed_controller.png" width="500" /></p>
+
+### Lower Force Controller
+<p align="center"><img src="./docs/lower_force_controller.png" width="500" /></p>
+
+### Upper Force Controller
+<p align="center"><img src="./docs/upper_force_controller.png" width="500" /></p>
+
+### WinchController - Usage -
+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](./test/test_winchcontroller.jl) .
+
+## Licence
+This project is licensed under the MIT License. Please see the below WAIVER in association with the license.
+
+## WAIVER
+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
+
+## Scientific background
+[A Methodology for the Design of Kite-Power Control Systems](https://research.tudelft.nl/en/publications/a-methodology-for-the-design-of-kite-power-control-systems)
+
+## Donations
+If you like this software, please consider donating to https://gofund.me/508e041b .
+
+## Related
+- [Research Fechner](https://research.tudelft.nl/en/publications/?search=wind+Fechner&pageSize=50&ordering=rating&descending=true) for the scientific background of this code
+- The meta package [KiteSimulators](https://github.com/aenarete/KiteSimulators.jl) which contains all packages from Julia Kite Power Tools.
+- the packages [KiteModels](https://github.com/ufechner7/KiteModels.jl) and [WinchModels](https://github.com/aenarete/WinchModels.jl) and [AtmosphericModels](https://github.com/aenarete/AtmosphericModels.jl)
+- the packages [KiteViewers](https://github.com/aenarete/KiteViewers.jl) and [KiteUtils](https://github.com/ufechner7/KiteUtils.jl)