Dears.

Until now, I have been using CNC libraries with Codesys 3.5SP11. I was using SMC_Polynomial_AbsMaxLocs function, from CNC library, to calculate the axis jerks, interpolating splines, to limit it.

Now I have passed to SP20, and the functions which calculates the zeros and the maximum-minimum and zeros of polynomials has been disapeared.

Questions:

-Exist any FB wich can limit the jerk of individual axis in CNC?
-Exist any other functions which can calculate max-min and zeros of polynomials?

Thanks

Dear josepmariarams,

this (internal) function has been removed with SoftMotion 4.17.0.0. We do not have public functions to compute the extrema of a polynomial.

On which polynomials exactly did you call SMC_Polynomial_AbsMaxLocs? (Maybe if I understand better how you limit the jerk I can come up with an alternative.)

There is no functionality to limit the jerk of individual axes in the CNC. With SMC_LimitDynamics, you can limit the velocity and acceleration of cartesian (X/Y/Z) and additional (P/Q/U/V/W/A/B/C) axes, but not the jerk. And with a quadratic ramp type you can limit the jerk on the path.

Best regards,

Georg

I am using both functions for:

I override SMC_LimitDynamics o calculate the individual axis jerk on polynomial movements. LimitDynamics only controls acceleration and velocity, it's not enought to create smooth movements.

To solve the problem when smothing path create loops. It seems that polynomial passes two times by the same point and smc_smooth path chooses incorrect one.

Interesting. In the SMC_LimitDynamics case, do you reduce the maximum velocity of the SMC_GeoInfo based on the third derivative of the spline?