Maths help - exponential throttle curve formula required

grumpybeard · 28 Oct 2013 at 11:38

Hi,

My maths ability is quite rusty and thus I turn to GD for some help.

Currently working on a robotics rover project, have the gamepad control up and running but looking to smooth out the throttle acceleration and heading.

For example I have a throttle input of 0-100, with 0=no throttle, 100=max throttle. I would like to calculate a more smoothed exponential curve on the controlling Arduino before sending motor value to the motor controller, so that the throttle value is quite low until say the gamepad input is at 70, i.e. the throttle curve is quite flat until about 70% gamepad input.

Most grateful for some maths help on this.

Cheers

rubberduck · 28 Oct 2013 at 11:53

If T=throttle and I=input... try something like:

T=100*(I/100)^3.3219

Just change the value of the exponential to get different fits. The one I chose had an input of 70% equivalent to a throttle of 30%

The Dread Pirate · 28 Oct 2013 at 11:57

Do your own homework :mad:

grumpybeard · 28 Oct 2013 at 12:44

rubberduck said:
If T=throttle and I=input... try something like:

T=100*(I/100)^3.3219

Just change the value of the exponential to get different fits. The one I chose had an input of 70% equivalent to a throttle of 30%

Thanks matey, that helps, just playing with the expo now, cheers!

grumpybeard · 28 Oct 2013 at 12:45

The Dread Pirate said:
Do your own homework

I tried, failed miserably when googling, rubberduck to the rescue!