matlab_code

Matlab codes:

close all
clear all
%Load CSV
   tic %start timer
   fprintf('%4.2f seconds - Time to Load Data\n',toc)
   Z_acc = csvread('ottobot z acc - Sheet1.csv',0,1); %array of data for acc z
   Z_acc= Z_acc./9.81;  % normalising acc. data
   Z_acc= Z_acc + 1;
   Z_acc= Z_acc.';
   [N,L]= size(Z_acc)
   %Determine variables and Display size
%plot data of acc and time  
t = 0:124892;
%t=t.';
plot(t,Z_acc)
figure
title('z_acc with time');
xlabel('time(s)');
ylabel('acc z(g)');
grid on;
Fs=500;  % sampling frequency
Y= fft(Z_acc);  % fast fourier transform, to find frequency at maximum vibration
P2=abs(Y/L);
P1=P2(1:L/2+1);
P1(2:end-1) = 2*P1(2:end-1); % to remove symmtric curve
f=Fs*(0:(L/2))/L;  % frequency vector
%plot(f,10.^(log(P1)))
%figure
%title('FFT spectrum of x(t)')
%xlabel('f(hz)')
%ylabel('|P1(f)|')
% ploting Acceleration density curve(or PSD)
P1 = ( L/Fs) .* abs(P1).^2
area = trapz(flip(P1),flip(f));
disp(area);
GRMS= sqrt(area) %Grms is square root of area
plot(f,P1)
title('PSD curve with GRMS value', GRMS);
xlabel('f (Hz)');
ylabel('G^2/Hz');
grid on;