def update_orientations(segment):
""" Updates the orientation of the vehicle throughout the mission for each relevant axis
Assumptions:
This assumes the vehicle has 3 frames: inertial, body, and wind. There also contains bits for stability axis which are not used. Creates tensors and solves for alpha and beta.
Inputs:
segment.state.conditions:
frames.inertial.velocity_vector [meters/second]
frames.body.inertial_rotations [Radians]
segment.analyses.planet.features.mean_radius [meters]
state.numerics.time.integrate [float]
Outputs:
segment.state.conditions:
aerodynamics.angle_of_attack [Radians]
aerodynamics.side_slip_angle [Radians]
aerodynamics.roll_angle [Radians]
frames.body.transform_to_inertial [Radians]
frames.wind.body_rotations [Radians]
frames.wind.transform_to_inertial [Radians]
Properties Used:
N/A
"""
# unpack
conditions = segment.state.conditions
V_inertial = conditions.frames.inertial.velocity_vector
body_inertial_rotations = conditions.frames.body.inertial_rotations
# ------------------------------------------------------------------
# Body Frame
# ------------------------------------------------------------------
# body frame rotations
phi = body_inertial_rotations[:, 0, None]
theta = body_inertial_rotations[:, 1, None]
psi = body_inertial_rotations[:, 2, None]
# body frame tranformation matrices
T_inertial2body = angles_to_dcms(body_inertial_rotations, (2, 1, 0))
T_body2inertial = orientation_transpose(T_inertial2body)
# transform inertial velocity to body frame
V_body = orientation_product(T_inertial2body, V_inertial)
# project inertial velocity into body x-z plane
V_stability = V_body * 1.
V_stability[:, 1] = 0
V_stability_magnitude = np.sqrt(np.sum(V_stability**2, axis=1))[:, None]
# calculate angle of attack
alpha = np.arctan2(V_stability[:, 2], V_stability[:, 0])[:, None]
# calculate side slip
beta = np.arctan2(V_body[:, 1], V_stability_magnitude[:, 0])[:, None]
# pack aerodynamics angles
conditions.aerodynamics.angle_of_attack[:, 0] = alpha[:, 0]
conditions.aerodynamics.side_slip_angle[:, 0] = -beta[:, 0]
conditions.aerodynamics.roll_angle[:, 0] = phi[:, 0]
# pack transformation tensor
conditions.frames.body.transform_to_inertial = T_body2inertial
# ------------------------------------------------------------------
# Wind Frame
# ------------------------------------------------------------------
# back calculate wind frame rotations
wind_body_rotations = body_inertial_rotations * 0.
wind_body_rotations[:, 0] = 0 # no roll in wind frame
wind_body_rotations[:, 1] = alpha[:, 0] # theta is angle of attack
wind_body_rotations[:, 2] = beta[:, 0] # psi is side slip angle
# wind frame tranformation matricies
T_wind2body = angles_to_dcms(wind_body_rotations, (2, 1, 0))
T_body2wind = orientation_transpose(T_wind2body)
T_wind2inertial = orientation_product(T_wind2body, T_body2inertial)
# pack wind rotations
conditions.frames.wind.body_rotations = wind_body_rotations
# pack transformation tensor
conditions.frames.wind.transform_to_inertial = T_wind2inertial
return
def update_orientations(segment,state):
# unpack
conditions = state.conditions
V_inertial = conditions.frames.inertial.velocity_vector
body_inertial_rotations = conditions.frames.body.inertial_rotations
# ------------------------------------------------------------------
# Body Frame
# ------------------------------------------------------------------
# body frame rotations
phi = body_inertial_rotations[:,0,None]
theta = body_inertial_rotations[:,1,None]
psi = body_inertial_rotations[:,2,None]
# body frame tranformation matrices
T_inertial2body = angles_to_dcms(body_inertial_rotations,(2,1,0))
T_body2inertial = orientation_transpose(T_inertial2body)
# transform inertial velocity to body frame
V_body = orientation_product(T_inertial2body,V_inertial)
# project inertial velocity into body x-z plane
V_stability = V_body
V_stability[:,1] = 0
V_stability_magnitude = np.sqrt( np.sum(V_stability**2,axis=1) )[:,None]
#V_stability_direction = V_stability / V_stability_magnitude
# calculate angle of attack
alpha = np.arctan2(V_stability[:,2],V_stability[:,0])[:,None]
# calculate side slip
beta = np.arctan2(V_body[:,1],V_stability_magnitude[:,0])[:,None]
# pack aerodynamics angles
conditions.aerodynamics.angle_of_attack[:,0] = alpha[:,0]
conditions.aerodynamics.side_slip_angle[:,0] = beta[:,0]
conditions.aerodynamics.roll_angle[:,0] = phi[:,0]
# pack transformation tensor
conditions.frames.body.transform_to_inertial = T_body2inertial
# ------------------------------------------------------------------
# Wind Frame
# ------------------------------------------------------------------
# back calculate wind frame rotations
wind_body_rotations = body_inertial_rotations * 0.
wind_body_rotations[:,0] = 0 # no roll in wind frame
wind_body_rotations[:,1] = alpha[:,0] # theta is angle of attack
wind_body_rotations[:,2] = beta[:,0] # psi is side slip angle
# wind frame tranformation matricies
T_wind2body = angles_to_dcms(wind_body_rotations,(2,1,0))
T_body2wind = orientation_transpose(T_wind2body)
T_wind2inertial = orientation_product(T_wind2body,T_body2inertial)
# pack wind rotations
conditions.frames.wind.body_rotations = wind_body_rotations
# pack transformation tensor
conditions.frames.wind.transform_to_inertial = T_wind2inertial
return
def update_orientations(segment, state):
# unpack
conditions = state.conditions
V_inertial = conditions.frames.inertial.velocity_vector
body_inertial_rotations = conditions.frames.body.inertial_rotations
# ------------------------------------------------------------------
# Body Frame
# ------------------------------------------------------------------
# body frame rotations
phi = body_inertial_rotations[:, 0, None]
theta = body_inertial_rotations[:, 1, None]
psi = body_inertial_rotations[:, 2, None]
# body frame tranformation matrices
T_inertial2body = angles_to_dcms(body_inertial_rotations, (2, 1, 0))
T_body2inertial = orientation_transpose(T_inertial2body)
# transform inertial velocity to body frame
V_body = orientation_product(T_inertial2body, V_inertial)
# project inertial velocity into body x-z plane
V_stability = V_body
V_stability[:, 1] = 0
V_stability_magnitude = np.sqrt(np.sum(V_stability**2, axis=1))[:, None]
#V_stability_direction = V_stability / V_stability_magnitude
# calculate angle of attack
alpha = np.arctan2(V_stability[:, 2], V_stability[:, 0])[:, None]
# calculate side slip
beta = np.arctan2(V_body[:, 1], V_stability_magnitude[:, 0])[:, None]
# pack aerodynamics angles
conditions.aerodynamics.angle_of_attack[:, 0] = alpha[:, 0]
conditions.aerodynamics.side_slip_angle[:, 0] = beta[:, 0]
conditions.aerodynamics.roll_angle[:, 0] = phi[:, 0]
# pack transformation tensor
conditions.frames.body.transform_to_inertial = T_body2inertial
# ------------------------------------------------------------------
# Wind Frame
# ------------------------------------------------------------------
# back calculate wind frame rotations
wind_body_rotations = body_inertial_rotations * 0.
wind_body_rotations[:, 0] = 0 # no roll in wind frame
wind_body_rotations[:, 1] = alpha[:, 0] # theta is angle of attack
wind_body_rotations[:, 2] = beta[:, 0] # psi is side slip angle
# wind frame tranformation matricies
T_wind2body = angles_to_dcms(wind_body_rotations, (2, 1, 0))
T_body2wind = orientation_transpose(T_wind2body)
T_wind2inertial = orientation_product(T_wind2body, T_body2inertial)
# pack wind rotations
conditions.frames.wind.body_rotations = wind_body_rotations
# pack transformation tensor
conditions.frames.wind.transform_to_inertial = T_wind2inertial
return
def update_orientations(segment,state):
""" Updates the orientation of the vehicle throughout the mission for each relevant axis
Assumptions:
This assumes the vehicle has 3 frames: inertial, body, and wind. There also contains bits for stability axis which are not used. Creates tensors and solves for alpha and beta.
Inputs:
state.conditions:
frames.inertial.velocity_vector [meters/second]
frames.body.inertial_rotations [Radians]
segment.analyses.planet.features.mean_radius [meters]
state.numerics.time.integrate [float]
Outputs:
state.conditions:
aerodynamics.angle_of_attack [Radians]
aerodynamics.side_slip_angle [Radians]
aerodynamics.roll_angle [Radians]
frames.body.transform_to_inertial [Radians]
frames.wind.body_rotations [Radians]
frames.wind.transform_to_inertial [Radians]
Properties Used:
N/A
"""
# unpack
conditions = state.conditions
V_inertial = conditions.frames.inertial.velocity_vector
body_inertial_rotations = conditions.frames.body.inertial_rotations
# ------------------------------------------------------------------
# Body Frame
# ------------------------------------------------------------------
# body frame rotations
phi = body_inertial_rotations[:,0,None]
theta = body_inertial_rotations[:,1,None]
psi = body_inertial_rotations[:,2,None]
# body frame tranformation matrices
T_inertial2body = angles_to_dcms(body_inertial_rotations,(2,1,0))
T_body2inertial = orientation_transpose(T_inertial2body)
# transform inertial velocity to body frame
V_body = orientation_product(T_inertial2body,V_inertial)
# project inertial velocity into body x-z plane
V_stability = V_body
V_stability[:,1] = 0
V_stability_magnitude = np.sqrt( np.sum(V_stability**2,axis=1) )[:,None]
#V_stability_direction = V_stability / V_stability_magnitude
# calculate angle of attack
alpha = np.arctan2(V_stability[:,2],V_stability[:,0])[:,None]
# calculate side slip
beta = np.arctan2(V_body[:,1],V_stability_magnitude[:,0])[:,None]
# pack aerodynamics angles
conditions.aerodynamics.angle_of_attack[:,0] = alpha[:,0]
conditions.aerodynamics.side_slip_angle[:,0] = beta[:,0]
conditions.aerodynamics.roll_angle[:,0] = phi[:,0]
# pack transformation tensor
conditions.frames.body.transform_to_inertial = T_body2inertial
# ------------------------------------------------------------------
# Wind Frame
# ------------------------------------------------------------------
# back calculate wind frame rotations
wind_body_rotations = body_inertial_rotations * 0.
wind_body_rotations[:,0] = 0 # no roll in wind frame
wind_body_rotations[:,1] = alpha[:,0] # theta is angle of attack
wind_body_rotations[:,2] = beta[:,0] # psi is side slip angle
# wind frame tranformation matricies
T_wind2body = angles_to_dcms(wind_body_rotations,(2,1,0))
T_body2wind = orientation_transpose(T_wind2body)
T_wind2inertial = orientation_product(T_wind2body,T_body2inertial)
# pack wind rotations
conditions.frames.wind.body_rotations = wind_body_rotations
# pack transformation tensor
conditions.frames.wind.transform_to_inertial = T_wind2inertial
return