필터 지우기
필터 지우기

Create local coordinate system and update throughout flight

조회 수: 1 (최근 30일)
hologramkazaam
hologramkazaam 2021년 8월 30일
답변: darova 2021년 9월 5일
I am trying to monitor the position of a rocket throughout its trajectory by creating a local coordinate system. I would like it to update throughout the flight. My vector calculus is a bit rusty, so I'm having trouble getting the right angles to get the new axes. Right now, I'm trying to plot the new axes in a crude way, but I would appreciate any help in figuring this out or advice for a better way to do this.
close;
clear;
clc;
t = 0:pi/16:pi;
x = sin(t);
y = cos(t);
z = t;
[m,n] = size(t);
radius = zeros(1,n);
theta = zeros(1,n); % angle from +z axis to vector (zenith)
phi = zeros(1,n); % angle from +x axis to vector projection on xy-plane (azimuth)
rocket_angle = zeros(1,n);
lsm = 0.25; % line size modifier
for i=1:length(x)
plot3(x(i),y(i),z(i),'*r');
%plot3(x(i),y(i),0,'*b'); % vector projection
hold on;
pause(0.01);
radius(i) = sqrt(x(i)^2 + y(i)^2 + z(i)^2);
theta(i) = acosd(z(i)/radius(i)); % global coordinate system
phi(i) = atand(y(i)/x(i)); % global coordinate system
if i > 1
rocket_angle(i) = atand((y(i)-y(i-1))/(x(i)-x(i-1)));
% show rocket x-axis
line([x(i)-lsm*sind(rocket_angle(i)) x(i)+lsm*sind(rocket_angle(i))], [y(i)+lsm*sind(rocket_angle(i)) y(i)-lsm*sind(rocket_angle(i))], [z(i)-lsm*sind(rocket_angle(i)) z(i)+lsm*sind(rocket_angle(i))]);
% show rocket y-axis
% show rocket z-axis (cross product of x and y)
end
end
xlabel('X');
ylabel('Y');
zlabel('Z');
grid on;

답변 (1개)

darova
darova 2021년 9월 5일
Just find tangent of a trajectory
x = 0:.1:pi;
y = sin(x);
u0 = diff(x); % component of a tangent
v0 = diff(y); % component of a tangent
u1 = u0./hypot(u0,v0); % normalization
v1 = v0./hypot(u0,v0);
line(x,y)
h = line(0,0,'color', 'r');
axis equal
for i = 1:length(x)-1
set(h,'xdata',x(i)+[u1(i) 0 -v1(i)]/2); % tangent and normal
set(h,'ydata',y(i)+[v1(i) 0 u1(i)]/2); % tangent and normal
pause(0.5)
end

카테고리

Help CenterFile Exchange에서 Programming에 대해 자세히 알아보기

제품


릴리스

R2019a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by