test.py

"""Example simulation using a pre-built paraglider model."""

# https://pfheatwole.github.io/glidersim/usage.html#running-simulations

import pfh.glidersim as gsim
import scipy.interpolate

from mescal_6 import skywalk_mescal_6

# Component models: use a pre-built wing and add a suitable harness
wing = skywalk_mescal_6(size='XS', verbose=True)
harness = gsim.paraglider_harness.Spherical(
    mass=75,
    z_riser=0.5,
    S=0.55,
    CD=0.8,
    kappa_w=0.1,
)

# The system dynamics model provides the physical accelerations
paraglider = gsim.paraglider.ParagliderSystemDynamics6a(wing, harness)

# Build a control input sequence for right brake using linear interpolation:
# the input is 0 until t=3, increases to 1 over t=3..5, holds at 1 until t=22,
# decreases to zero over t=22..23, and holds at 0 indefinitely.
delta_br = scipy.interpolate.interp1d(
    [0, 3, 5, 22, 23],  # times
    [0, 0, 1, 1, 0],  # percentages
    fill_value=0,
    bounds_error=False,
)

# Inputs to the state dynamics are either constants or functions of time `t`
sim_parameters = {
    "delta_a": 0.0,
    "delta_bl": 0.0,
    "delta_br": delta_br,
    "delta_w": 0.0,
    "rho_air": 1.225,
    "v_W2e": (0, 0, 0),  # Uniform global wind velocity
}

input('Waiting for user input ...')

# The state dynamics model provides the state derivatives
model = gsim.simulator.ParagliderStateDynamics6a(paraglider, **sim_parameters)

# Setup and run the simulation
state0 = model.starting_equilibrium()  # Start the simulation at equilibrium
dt = 0.5  # Record the state every 0.5 seconds
T = 25  # Run for 25 seconds
times, states = gsim.simulator.simulate(model, state0, dt=dt, T=T)

# 3D plot: position over time
points = gsim.extras.simulation.sample_paraglider_positions(model, states, times)
gsim.extras.plots.plot_3d_simulation_path(**points)