From Acceleration to Displacement Trapz Function

Hello,

I have the acceleration values as a vector and I need to integrate it to get velocity and displacement via Trapz function. trapz(acc) gives a value for V but how can i reach to the displacement value? Is there any way to integrate 2 times ? When i integrate V value it naturally gives me zero.

Thank you.

Answer 1

[Mahdi]

Consider using the cumtrapz function to find the displacement.

% Defined Acceleration values as Accel, Time is the steps of time
velocity=cumtrapz(Time, Acceleration)
Displacement=cumtrapz(Time, Velocity)

Or you can use the combination of cumtrapz and trapz to fit which solution you want.

[Ali]

Thank you for answering !

I have my values tabulated but i dont have the exact function. They are just random values. First integration with trapz (V=trapz(time,acc)) gives me one single value as result. So it's a constant one value. When I integrate it for the second time (disp=trapz(V)) It results zero.

[Mahdi]

Yeah, that's why I'm suggesting to use the cumtrapz function because it would give you velocities. Have a look at this link.

Answer 2

[Ali]

I did something hope it makes sense.

I have 485 values for each planes.(x,y,z) That one i wrote just for X values.

I seperated the values into 10 values group and got the trapz value for each interval of 10.

I ignored some of the values.(Like i have 485 but worked on 481 values)

Then I got 48 different Vx values.

Same process for the Ux(displacement) values.

This time each interval includes 5 values.

I hope its right.

for t=0:47;

accx=data((10*t+1):(10*t+11),1);
time=(t+1):(11+t);
Vx(t+1)=trapz(time,accx);

end

plot(Vx,'*');

for n=0:8;

Vxx=Vx(1,((5*n+1):(5*n+6)));

time2=(n+1):(6+n);

Ux(n+1)=trapz(time2,Vxx);

end

plot(Ux,'o');