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time derivative

Posted: Tue Nov 24, 2015 3:12 am
by brownts
First off, you guys are awesome.

Second, just wanted to add this into the user database, it might be useful to someone at some point. It's a simple time derivative that stores incoming numbers in a queue after a given interval. It then divides the difference of the stored number and current number with respect to the time step. Pretty basic.

Thanks!

Re: time derivative

Posted: Tue Nov 24, 2015 9:44 am
by Spogg
Fascinating!

This apparently gives a greater output when the rate of change of the input is higher (I tested with a simple knob using 0-10000 as the range).
I'm no maths guy but from my college days in the last century I would say it's a differentiator. Am I right?
Now I just need to think of an application for this! Is this part of a larger project and if so what does it do in your project?

Thanks for sharing this

Cheers

Spogg

Re: time derivative

Posted: Tue Nov 24, 2015 10:10 pm
by brownts
Spogg wrote:Fascinating!

This apparently gives a greater output when the rate of change of the input is higher (I tested with a simple knob using 0-10000 as the range).
I'm no maths guy but from my college days in the last century I would say it's a differentiator. Am I right?
Now I just need to think of an application for this! Is this part of a larger project and if so what does it do in your project?

Thanks for sharing this

Cheers

Spogg


Hi Spogg,

You nailed it! I made this for calculating rates of change. So if you feed it position, it will return the speed. If you feed it speed, it will output acceleration. So if your knob represents position, and it changes in relation to the position of your mouse, it will return the speed of your mouse when you move it.

I use it for time steps, (speed/work/power/etc) but I don't think it would be too difficult to set it up to measure two inputs and calculate the rate of change with respect to each other. I haven't had the need to do that, yet, though.

Thanks!
Trent