Hi,
I have made some changes to the code to eliminate the errors you are getting. Do have a look
Also added some comments where the changes were made.
% Initial Commands
clc;
clear;
close all force
diary('off')
fclose('all') ;
% Simulation physics
x0= 0; %Initial position [s]
v0= 0.1; %Initial velocity [m/s]
t0= 0; %Final time [s]
tf=100; % [s]
dt= 0.1; % Time increment [s]
% Physical parameters
global par;
par.p_max= 22080; % maximum power [W]
par.r= 70; % Rider Mass [Kg]
par.bike= 145.4; % Motorcycle Mass [Kg]
par.m_c= par.r + par.bike; % Total Mass [Kg]
par.k_a= 0.65; % Aerodynamic drag factor [kg/m]
par.c_r= 0.02; % Roll resistance factor
par.mu = 1.1; % Friction Coefficient
par.w= -0; % Wing speed [m/s]
pi= 3.141592; %pi
par.teta= 0/180*pi; % Lane slope angle [rad]
par.g=9.81; % Gravity Acc. [m/s^2]
par.p_d= 1.345; % Wheelbase [m]
par.p_cg= 0.63; % Cog from rear wheel With rider h [m]
par.h_cg= 0.58; % CoG height h with rider h [m]
par.h_cp=0.78; % Pressure CoG height
% Vectors
q0= [x0;v0];
% t1 =t0:dt:tf;
% Solution
[t,q] = ode45(@s,[t0,tf],q0) ; % Correct usage of ode function ,
x=q(:,1); % Change in dimensions
v=q(:,2);
%Graphs
plot(t,v*3.6,'k-')
% xlabel('$t\quad[s]$','fontsize',4);
% ylabel('$v\quad[km/h]$','fontsize',4);
function f=s(t,q)
x=q(1,1);
v=q(2,1);
global par; % Global keyword needed
%Rider
alpha=1; % BRAAAAAAAAAAP Acc
beta_t= 0; % Rear Brake
beta_d=0; % Front Brake
% Engine
p_max= par.p_max; % Max. power cte
%Track
teta=par.teta; %Angle
mu=par.mu; %Friction Coefficient
w=par.w; %Wing speed [m/s] % 'w' insteal of 'W'
%Forces
f_grx=-par.m_c*par.g*sin(teta); % x gravity component
f_gry= -par.m_c*par.g*cos(teta); % y gravity component
f_pro= alpha*p_max/v; %
f_aer=-par.k_a*(v-w)^2; % Drag
f_rol= -par.c_r*abs(f_gry); % Roll resistance
% d function
d=(f_pro+f_aer+f_rol+f_grx+beta_t*mu*f_gry+(beta_d-beta_t)*mu/par.p_d*(-f_aer*par.h_cp + -f_grx*par.h_cg+f_gry*par.p_cg))/(par.m_c*(1-(beta_d-beta_t)*mu*par.p_cg/par.p_d));
% Check function d for any mistakes in variable names
% f(1)=v;
% f(2)=d;
f = [v;d]; % f needs to be a column matrix
end
