Calculating Time to Stabilisation in Vertical Force Data

Hi all,

I am looking to calculate time to stabilisation after landing from a vertical jump.

To do this, I need to find out when the force data returns to body weight (plus/minus 5%) for 1 second. This needs to return a time value.

For a very basic example (ignoring plus/minus 5%), if I had the following values at 0.01 time increments...

1,3,10,2,4,6,6,6,6

and I was looking for the values to stabilse at 6 for 0.04s, then my time to stabilisation value here would be 0.06 (because it would recognise four lots of 6 and return me a value corresponding to the first 6).

I hope this makes sense.

Thank you

Answer 1

[Mathieu NOE]

hello

this would be my suggestion

clc
clearvars
y = [1,3,10,2,4,6,6,6,6];
dt = 0.01;
t = (1:length(y))*dt;

y_end = y(end);
err = abs(1-y./y_end); % abs error 
ind = find(err<0.05); % find error < 5% indexes 
ind_stab = ind(1);
t_stab = t(ind_stab);
y_stab = y(ind_stab);

plot(t,y,t,err,t_stab,y_stab,'dr')
legend('signal','error vs asymptotic value','stabilisation point');

[Mathieu NOE]

hello

problem solved ?