calc_inertia_ellipse {AvInertia}

Moment of inertia tensor of solid ellipse CG or a half ellipse centered on the base

Description

Reference:https://apps.dtic.mil/sti/pdfs/AD0274936.pdf

Usage

calc_inertia_ellipse(a, b, c, m)

Arguments

a

half the height along the x direction (m)

b

half the width along the y direction (m)

c

half the length along the z direction (m)

m

mass of the ellipse (kg)

Value

a 3x3 matrix representing the moment of inertia tensor of a solid ellipse about its center of gravity with the major axes aligned.

CAUTION

Origin is at the center of gravity for a full ellipse or at the center of the base if modeling a half ellipse.

Author(s)

Christina Harvey

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)