structural2VRP_feat {AvInertia}

Transform feather specific inertial properties to current position

Description

Transform feather specific inertial properties to current position

Usage

structural2VRP_feat(m_f, I_fCG, CG_start, start, end, normal)

Arguments

m_f

a scalar representing the mass of the feather (kg)

I_fCG

a 3x3 matrix representing the moment of inertia tensor with the origin at the feather calamus end and within the feather frame of reference

CG_start

a 1x3 vector representing the center of gravity of the feather with the origin at the feather calamus end and within the feather frame of reference

start

a 1x3 vector representing the location of the feather calamus end with the origin at the VRP and within the full bird frame of reference

end

a 1x3 vector representing the location of the feather tip with the origin at the VRP and within the full bird frame of reference

normal

a 1x3 vector representing the normal to the plane of the feather vanes within the full bird frame of reference

Value

a list that includes:

• Ia 3x3 matrix representing the moment of inertia tensor of a simplified feather with the origin at the VRP and within the full bird frame of reference

• CGa 1x3 vector representing the center of gravity position of a simplified feather with the origin at the VRP and within the full bird frame of reference

• ma double that returns the feather mass

Examples

# refer to the vignette
library(AvInertia)

# load data
data(dat_id_curr, package = "AvInertia")
data(dat_bird_curr, package = "AvInertia")
data(dat_feat_curr, package = "AvInertia")
data(dat_bone_curr, package = "AvInertia")
data(dat_mat, package = "AvInertia")
data(clean_pts, package = "AvInertia")

# 1. Determine the center of gravity of the bird's torso (including the legs)
dat_torsotail_out = massprop_restbody(dat_id_curr, dat_bird_curr)
# 2. Calculate the inertia of the flight feathers about the tip of the calamus
feather_inertia <- compute_feat_inertia(dat_mat, dat_feat_curr, dat_bird_curr)
# 3. Determine the center of gravity of one of the bird's wings
dat_wing_out      = massprop_birdwing(dat_id_curr, dat_bird_curr,
dat_bone_curr, dat_feat_curr, dat_mat, clean_pts,
feather_inertia, plot_var = 0)
# Visualize the center of gravity of each wing component in the x and y axis
dat_wing_out      = massprop_birdwing(dat_id_curr, dat_bird_curr,
dat_bone_curr, dat_feat_curr, dat_mat, clean_pts,
feather_inertia, plot_var = "yx")
# or the y and z axis
dat_wing_out      = massprop_birdwing(dat_id_curr, dat_bird_curr,
dat_bone_curr, dat_feat_curr, dat_mat, clean_pts,
feather_inertia, plot_var = "yz")
# 4. Combine all data and obtain the center of gravity, moment of inertia
# and principal axes of the bird
curr_full_bird      = combine_inertialprop(dat_torsotail_out,dat_wing_out,
dat_wing_out, dat_id_curr, dat_bird_curr, symmetric=TRUE)