def compute_next_flight_point(self, flight_points: List[FlightPoint],
time_step: float) -> FlightPoint:
"""
Computes time, altitude, speed, mass and ground distance of next flight point.
:param flight_points: previous flight points
:param time_step: time step for computing next point
:return: the computed next flight point
"""
start = flight_points[0]
previous = flight_points[-1]
next_point = FlightPoint()
next_point.mass = previous.mass - self.propulsion.get_consumed_mass(
previous, time_step)
next_point.time = previous.time + time_step
next_point.ground_distance = (
previous.ground_distance +
previous.true_airspeed * time_step * np.cos(previous.slope_angle))
self._compute_next_altitude(next_point, previous)
if self.target.true_airspeed == self.CONSTANT_VALUE:
next_point.true_airspeed = previous.true_airspeed
elif self.target.equivalent_airspeed == self.CONSTANT_VALUE:
next_point.equivalent_airspeed = start.equivalent_airspeed
elif self.target.mach == self.CONSTANT_VALUE:
next_point.mach = start.mach
else:
next_point.true_airspeed = previous.true_airspeed + time_step * previous.acceleration
# The naming is not done in complete_flight_point for not naming the start point
next_point.name = self.name
return next_point
def compute_from(self, start: FlightPoint) -> pd.DataFrame:
self.complete_flight_point(
start) # needed to ensure all speed values are computed.
if self.target.altitude is not None:
if isinstance(self.target.altitude, str):
# Target altitude will be modified along the process, so we keep track
# of the original order in target CL, that is not used otherwise.
self.target.CL = self.target.altitude # pylint: disable=invalid-name
# let's put a numerical, negative value in self.target.altitude to
# ensure there will be no problem in self._get_distance_to_target()
self.target.altitude = -1000.0
self.interrupt_if_getting_further_from_target = False
else:
# Target altitude is fixed, back to original settings (in case
# this instance is used more than once)
self.target.CL = None
self.interrupt_if_getting_further_from_target = True
atm = AtmosphereSI(start.altitude)
if self.target.equivalent_airspeed == self.CONSTANT_VALUE:
atm.equivalent_airspeed = start.equivalent_airspeed
start.true_airspeed = atm.true_airspeed
elif self.target.mach == self.CONSTANT_VALUE:
atm.mach = start.mach
start.true_airspeed = atm.true_airspeed
return super().compute_from(start)
def _complete_speed_values(flight_point: FlightPoint):
"""
Computes consistent values between TAS, EAS and Mach, assuming one of them is defined.
"""
atm = AtmosphereSI(flight_point.altitude)
if flight_point.true_airspeed is None:
if flight_point.mach is not None:
atm.mach = flight_point.mach
elif flight_point.equivalent_airspeed is not None:
atm.equivalent_airspeed = flight_point.equivalent_airspeed
else:
raise FastFlightSegmentIncompleteFlightPoint(
"Flight point should be defined for true_airspeed, "
"equivalent_airspeed, or mach.")
flight_point.true_airspeed = atm.true_airspeed
else:
atm.true_airspeed = flight_point.true_airspeed
flight_point.mach = atm.mach
flight_point.equivalent_airspeed = atm.equivalent_airspeed
