non linearity of sensor

hello there

i am investigating the effect that nonlinearity will have on my inertial sensors and i am having some problems constructing a code to show the effects, basically i am trying to generate a random non-linear sine wave which i then want to plot on top of my linear actual sine wave signal.

[Daniel M]

What do you mean by random non-linear sine wave?

A*sin(2*pi*B + C) + D
% A = amplitude (vertical elongation)
% B = frequency (horizontal elongation)
% C = phase shift (horizontal transformation)
% D = baseline (vertical transformation)

Which of A, B, C and/or D do you want to be random and nonlinear?

If you're not sure, perhaps a drawing would help.

Answer 1

[Daniel M]

In the figure I don't see a different value for B. I see a phase shift (C is close to but less than pi/4) and decreased amplitude (A ~ 0.8). If you are interested in a changing frequency , then I suggest you look into the chirp function.

https://www.mathworks.com/help/signal/ref/chirp.html

Edit: sorry, I only saw part a. If you want something like part b, it looks like there is coupling of some higher frequency behaviour with the phase of the original signal. That is, when the signal is at a peak or trough, there is some jitter/noise. It's not straightforward how to represent this, but you could try adding another signal composed of various noise (rand or randn) and step functions.