Functions

on_autopilot(ssc::SystemStateControl)

Command the system to start automated power production (ssPowerProduction state). Precondition: the kite must be parked at a sufficiently high elevation angle.

on_parking(ssc::SystemStateControl, tether_length=nothing)

Command the system to transition to the ssParking state. Optionally pass the current tether_length [m] to allow a controlled approach.

on_reelin(ssc::SystemStateControl)

Command the system to reel in the tether (ssReelIn state).

on_stop(ssc::SystemStateControl)

Stop all automation and switch to ssManualOperation.

on_winchcontrol(ssc::SystemStateControl)

Switch to ssWinchControl state: winch is controlled automatically, steering is performed manually.

on_new_systate(ssc::SystemStateControl, sys_state)

Feed the current SysState (from the kite model or measurement) into the SystemStateControl. Must be called once per simulation time step before calling calc_v_set and calc_steering.

calc_v_set(ssc::SystemStateControl)

Compute and return the winch speed set-point [m/s] for the current time step. Returns nothing if no system state has been provided yet via on_new_systate.

get_depower(_ssc::SystemStateControl)

Return the current depower set-point (0..1) computed by the flight path planner.

read_project() -> String

Read the active project filename from data/gui.yaml. If the file does not exist it is created from gui.yaml.default.

get_use_turbulence(project::String) -> Union{Float64, Nothing}

Read use_turbulence from <data_path>/<project>. If no overwrite block is present, return get_default_turbulence().

start(fpp::FlightPathPlanner, v_wind)

Start automated power production.

Transitions the flight path planner from the parking or manual-operation state into the power-production phase (state POWER) and updates the ground-level wind speed used by the flight path calculator.

Precondition: the kite must be parked at a high elevation angle (system state ssManualOperation or ssParking). If the system is in any other state this call has no effect on the flight phase, though the wind speed is still updated.

Arguments

• fpp: the FlightPathPlanner instance.
• v_wind: current ground-level wind speed in m/s.

is_active(fpp::FlightPathPlanner)

Return true if the flight path planner has left its initial state, i.e. start has been called and the planner is actively managing the flight phase.

get_state(fpp::FlightPathPlanner)

Return the current flight phase of the planner as an Int, suitable for logging. The integer corresponds to the underlying @enum value (e.g. INITIAL, POWER, …).

on_new_systate(fpp::FlightPathPlanner, phi, beta, heading, course, v_a, u_d)

Forward the current estimated kite system state to the FlightPathController by calling on_est_sysstate. Sign conventions are applied before forwarding: azimuth and heading angles are negated to match the controller's coordinate frame.

Arguments

• fpp: the FlightPathPlanner instance.
• phi: azimuth angle of the kite in radians (positive to the left).
• beta: elevation angle of the kite in radians.
• heading: kite heading angle ψ in radians, in the range 0 .. 2π.
• course: kite course angle χ in radians, in the range 0 .. 2π.
• v_a: apparent wind speed in m/s.
• u_d: relative depower setting of the kite, in the range 0.0 .. 1.0.

on_new_data(fpp::FlightPathPlanner, depower, length, heading, height, _=0.0)

Evaluate the current kite state and trigger a flight-phase transition via _switch when the transition conditions defined in Tables 5.3–5.6 of the PhD thesis are satisfied.

Arguments

• fpp: the FlightPathPlanner instance.
• depower: relative depower setting of the kite, in the range 0.0 .. 1.0.
• length: tether length in metres.
• heading: kite heading angle ψ in radians, in the range 0 .. 2π.
• height: kite height above ground in metres.

State read from fpp.fpca

• _phi: kite azimuth angle in degrees.
• _beta: kite elevation angle in degrees.
• _omega: kite angular speed in degrees per second.

on_control_command(fpc, attractor=nothing, psi_dot_set=nothing, radius=nothing, intermediate = true)

Input: Either the attractor point (MVector of azimuth and elevation in radian), or psi_dot, the set value for the turn rate in degrees per second.

on_est_sysstate(fpc, phi, beta, psi, chi, omega, v_a; u_d=nothing, u_d_prime=nothing)

Parameters:

• phi: azimuth angle of the kite position in radian
• beta: elevation angle of the kite position in radian
• psi: heading of the kite in radian
• chi: course of the kite in radian
• omega: angular velocity of the kite on the unit sphere in degrees/s ???
• u_d: depower settings [0..1]
• u_d_prime normalized depower settings [0..1]

Either u_d or u_d_prime must be provided.

function calc_steering(fpc, parking)

Calculate the steering output u_s and the turn rate error err, but also the signals Kpsi_out, Ku_out and int_in.

Implements the simulink block diagram, shown in: 01_doc/flight_path_controller_I.png

If the parameter parking is true, only the heading is controlled, not the course.

calc_v_set(ssc::SystemStateControl)

Compute and return the winch speed set-point [m/s] for the current time step. Returns nothing if no system state has been provided yet via on_new_systate.

observe!(ob::KiteObserver, log::SysLog, elev_nom=26)

Process a SysLog and populate the KiteObserver with per-half-cycle elevation measurements and correction values for the flight path planner.