“fourbarpos” Function Group 13

% This is a function that is used in the main code that plots the behavior of our fourbar mechanism.

function [theta_3, theta_4] = fourbarpos(l,theta_1,theta_2,delta)

% define bar lengths

a = l(2);

b = l(3);

c = l(4);

d = l(1);

% theta_1_r = deg2rad(theta_1);

% theta_2_r = deg2rad(theta_2);

% define K values

K1 = d/a;

K2 = d/c;

K3 = ((a^2)-(b^2)+(c^2)+(d^2))/(2*a*c);

% calculate A B C

A = cosd(theta_2) - K1 - (K2*cosd(theta_2)) + K3;

B = (-2)*sind(theta_2);

C = K1 - ((K2+1)*cosd(theta_2)) + K3;

% calculate theta_4

theta_4 = 2*atand((-B+(delta*sqrt((B^2)-(4*A*C))))/(2*A));

% calculate theta_3

theta_3 = asind(((c*sind(theta_4))-(a*sind(theta_2)))/b);

% display angle values

% fprintf("Angle 3 = %.3f\n", theta_3);

% fprintf("Angle 4 = %.3f\n", theta_4);