Displacements and velocity from acceleration integration (accelerometer data)

Hi, i have a matrix with acceleration values. I would like to find velocity and displacements with integration. I wrote a code with Newmark method but i'm not sure about results. The accelerometers registered data from 0 to 600 sec, i have 200 m displacements in the end! I have DT=0.005 from each istant of time.

i think because it is a cumulative integration.

Is there another method/code to find displacements and velocity? Thank you very much

Answer 1

[Benjamin Thompson]

Integration naturally has some error when integrating a sampled signal because the integration algorithm has to make assumptions about the values of the signal between sample points. You can reduce errors by reducing step size, using a higher order method like Runge Kutta 4, or having a variable step size when the dynamics are changing more rapidly.

[loiacono.giuseppe97]

Thank you for the reply! I can't reduce step size, because i have sampling frequency 200. So, step size = 1/f = 0.005 sec. Runge Kutta 4 working also ? I don't believe i could have variable step size

I used these ones: Newmark-beta method - Wikipedia

[Benjamin Thompson]

It sounds like you are able to research numerical integration methods on the Internet, so try some different ones and choose one that gives you the best results.

[loiacono.giuseppe97]

thank you very much, i'll try to use Runge Kutta 4. Do you know other method or is there a code about Runge Kutta ? Thanks

[Benjamin Thompson]

Simulink supports a wide variety of integration algorithms. Go to Model Settings, Solver, and see the types available. The one for Runge Kutta 4 is called ode4.

[loiacono.giuseppe97]

I don't know how to use simulink. I have only matrix accelerations.. i have not the model

Answer 2

[Benjamin Thompson]

The Simulink Onramp training course is a good place to start:

https://www.mathworks.com/learn/tutorials/simulink-onramp.html?s_tid=srchtitle_simulink%20onramp_1