hello
see my suggestion below
clc
clearvars
data = csvread('data.csv',1); % time & Acceleration data
t = data(:,1);
acc = data(:,2);
acc = detrend(acc,'linear');
N = length(t);
dt = mean(diff(t)); % Average dt
fs = 1/dt; % Frequency [Hz] or sampling rate
% some additionnal high pass filtering
N = 4;
fc = 0.05; % Hz
[B,A] = butter(N,2*fc/fs,'high');
acc2 = filter(B,A,acc);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
velocity = cumtrapz(dt,acc2);
velocity = detrend(velocity,'linear');
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
disp = cumtrapz(dt,velocity);
%
figure(1)
subplot(311),plot(t,acc);
subplot(312),plot(t,velocity);
subplot(313),plot(t,disp);
