Re: interpolator

["Les Watts" <leswatts-at-alltel.net>]

Great Till! That would be a potentially good student project.

The only problem might be implementing it in EMC. I have
noted in cubic.h that many of the cubic interpolation functions
are declared as EXTERN scope. So they are used all over the place.
It might be a major rework to change it... so it could be too big
a project to contemplate.

For example:
----------------------------------------------------------------------------
------------------
extern int cubicInit(CUBIC_STRUCT *ci);
extern int cubicSetSegmentTime(CUBIC_STRUCT *ci, double time);
extern double cubicGetSegmentTime(CUBIC_STRUCT *ci);
extern int cubicSetInterpolationRate(CUBIC_STRUCT *ci, int rate);
extern int cubicGetInterpolationRate(CUBIC_STRUCT *ci);
extern int cubicAddPoint(CUBIC_STRUCT *ci, double point);
extern int cubicOffset(CUBIC_STRUCT *ci, double offset);
extern double cubicGetInterpolationIncrement(CUBIC_STRUCT *ci);
extern CUBIC_COEFF cubicGetCubicCoeff(CUBIC_STRUCT *ci);
extern int cubicFilled(CUBIC_STRUCT *ci);
extern double cubicInterpolate(CUBIC_STRUCT *ci,
                               double *x, /* same as return val */
                               double *v, /* velocity */
                               double *a, /* accel */
                               double *j); /* jerk */
extern int cubicNeedNextPoint(CUBIC_STRUCT *ci);
extern int cubicDrain(CUBIC_STRUCT *ci);
----------------------------------------------------------------------------
------------

But most are perhaps ok as an interpolator spits out waypoints independent
of the interpolation scheme. Also most are just rates, segment lengths, etc
that could be used as is with a higher order engine.

I note that while only cubic the function cubicInterpolate() has position,
velocity,
acceleration , and jerk as inputs already so it is well set up for higher
order.

Les

Leslie Watts
L M Watts Furniture
Tiger, Georgia USA
http://www.alltel.net/~leswatts/wattsfurniturewp.html
engineering page:
http://www.alltel.net/~leswatts/shop.html

----- Original Message -----
From: "Till Franitza" <xfa-at-isw.uni-stuttgart.de>
To: "Multiple recipients of list" <emc-at-nist.gov>
Sent: Thursday, September 12, 2002 2:14 AM
Subject: AW: interpolator


>
> Hi Les!
> You are right. The next thing to do in the interpolator is the quintic
> interpolation. So it would be possible to have a limited jerk. Let me see
if
> i find a student that wants to work on this.
> till