Filter löschen
Filter löschen

Road profile, car model, suspension model

26 Ansichten (letzte 30 Tage)
Mattia Abrate
Mattia Abrate am 10 Mär. 2022
Beantwortet: Divyanshu am 4 Mär. 2024
Hi everyone I made this MATLAB code in order to generate random road profiles starting from the corresponding PSD value:
psi0=1;
plot1=1;
L=100;
L1=0; %start length of the road
L2=L1+L; %end of the road (m)
psi0=psi0*10^-6;
omega1=.01; %low cutoff wavenumber for PSD
omega2=100; %high cutoff wavenumber
delta=omega1; %step size
N=((omega2-omega1)/delta)+2; %number of points in PSD plot
omega=linspace(omega1,omega2,N); %psd plot wavenumber range
psi=zeros(1,N); %initialize PSD
Ns=100; %number of samples in one meter of road profile
s=L1:1/Ns:(L2-1/Ns); %road profile range
z=zeros(1,Ns*L2); %initialize road
a=zeros(1,N); %initialize amplitude
phi=rand(1,N)*2*pi; %random angles
W=2; %waviness
psi(1:N)=psi0*(omega(1:N).^(-W)); %Calculate PSD
a(1:N)=(2*psi(1:N)*(delta)).^(1/2); %Calculate amplitude
for i=1:Ns*L2
for j=1:N
z(i)=(a(j)*sin((omega(j)*s(i))-phi(j)))+z(i);
end
end
z(1:Ns*L2)=z(1:Ns*L2)-z(1); %fix initial conditions to 0
if plot1==1
figure
subplot(2,1,1);
loglog(omega,psi)
title('PSD of road profile');
xlabel('wavenumber (rad/m)');
ylabel('PSD m^2/(rad/m)');
subplot(2,1,2);
plot(s,z*100);
title('road profile');
xlabel('road longitudinal axis (m)');
ylabel('road vertical ondulations (cm)');
set(gcf,'color','w');
end
The code works pretty nicely and here is an example of an obtained plot:
Now, I'm trying to use it as an input for the suspension simulink model, I used the blocks: MATLAB function and interpreted MATLAB functions, in both the cases, the solving time is really high and the plot I obtained has the following form:
It looks as Simulink is not able to interprete the for cycle and it recalculates the whole profile for each time step, also if I run the model again I obtain always the same output, while in MATLAB I obtain a different profile every time I run the code.
Can someone help me to solve this??
Thanks,
Mattia

Antworten (1)

Divyanshu
Divyanshu am 4 Mär. 2024
Hi Mattia,
I created a dummy model, with only MATLAB Function Block and placed the above code inside the block.
On Simulation, I was able to get multiple different profiles correctly as expected. Therefore, the Simulation with MATLAB Function block is working as desired and probably the other parts/blocks of the Suspension model are affecting the final plot.

Kategorien

Mehr zu General Applications finden Sie in Help Center und File Exchange

Produkte


Version

R2021b

Community Treasure Hunt

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

Start Hunting!

Translated by