# CNC acc/dec look ahead algorithm

1. Sep 4, 2016

### lionliam96

1. The problem statement, all variables and given/known data
Im having some trouble with an acceleration/deceleration look ahead algorithm Im trying to implement in a CNC controller written in C#/F#, specifically the algorithms treatment of time.

2. Relevant equations
The white paper can be found at:
Page 2 describes T as the interpolation periods and Ts as the sample period. T1, T5, max acc/dec and max jerk are prespecified so Im guessing Im supposed to figure out the duration of the other interpolation periods. If thats the case, than what does Ts represent exactly?? Duration of the interpolation periods? Duration of the acc/const/dec regions? The paper doesnt say...

3. The attempt at a solution
I`ve written out all the equations in f#, I just have no idea what Ts is supposed to be?

Code (Text):

// Number of interpolation periods in acceleration region (Na):
let calcNa (Vs : double, Vm : double, Ts : double) : double =
Math.Round(Math.Sqrt(Vm - Vs / (1.0 + K) * J1 * Math.Exp(Ts)) + 1.0)

Thanks,
Liam

Last edited by a moderator: May 8, 2017
2. Sep 8, 2016

### Bystander

"Sample period" is the length of time you're sampling?