I want to down sample my vehicle speed.

Hello, I am working on calculations of tractive force using vehicle longitudinal model. I want to down sample my vehicle speed which has steps in it. I am using diff(Vehicle_Speed) / diff(time) in order to calculate acceleration. The acceleration is too noisy which in turn gives me noisy tractive curve. Please let me know how to down sample my data to 10 Hz.

[Chunru]

doc resample

[Walter Roberson]

diff(Vehicle_Speed) / diff(time) in order to calculate acceleration

See instead gradient

Answer 1

[TITTU GEORGE]

Filtering the differnce equation to get acceleration can be considered..This will help in removing the noise

[Riddhesh]

I tried filtering the difference equation, its not working. Is there a way I can use downsample() and reduce it to desired frequency, say 10 Hz ?

[Walter Roberson]

@Riddhesh

You can only use downsample() for that purpose if the ratio of the original frequency to 10 Hz happens to be an integer. Otherwise you should use resample

... I don't think you will be satisfied with the results, but you will need to try it and see.

[TITTU GEORGE]

A simple first order filter with a suitable time constant will do the trick in this case