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data-interpolation-for-CNC

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deadlykitten

Programmer
Jun 20, 2015
11
RO
Hi guys and girls,
There is a small problem about numerical machines, as lathes or mills.
Their axis are controled by encodes, or other systems, with, for example, 0.001 mm accuracy.
However, if you want to move the machine on a complex shape, you enter a serie of points, with precision as u need : 0.1, 0.01, 0.003, etc.
So the machine will move not on that shape, but on smaller segments.
The problem is that the machine loses time when works like this.
If you want to move it on a line, you don't need to enter a serie of point, you simple use G01.
Same, for a circle, u can use G02 or G03.
This G codes generate also a serie of points that are send to the machine, but the machine moves faster this way. If you enter directly a serie of points, machine moves slower.
For complex shapes, as sPlines, Beziers, etc, machine has no G, so you must enter the points, or, to say, you enter the serie of small segments.
You can find official explanation in the attached image - so, to say, producers know this thing.

G codes, and data points are written in a file, and that file is read by the machine to control the axis.
So. the program that reads this file, is able, when meets a G code, to generate a serie of points and send it fast to the machine.
But, if you enter point in the file, the program needs too much time to read them and send them to the machine.
So, what i need is a solution to increase response time for complex shapes :
- for example, to create a G code able to generate shapes
- or to read al data points as a buffer, without restrictions,

i don't know how the machine works inside, but is like the electronics can not control the axis at their best accuracy.
I can help with mathematics for complex shapes, or, also CAM software can generate points for complex shapes.

For example, for a circle :
- if u use a G code al process takes T time
- if u use a serie of data at 0.1 precision, al process takes 0.95 ... 1.05 T
- at 0.01 precision, proces takes 2 .. 3 T
- at 0.001 precision, proces takes to much, you can get a buffer overload, and so on

Precision that i need is 0.01 .. 0.003
Time increases because machine accelerates and decelerates for every segment, while, in a G code it goes smoothly.

So, this is it :)
 
 http://files.engineering.com/getfile.aspx?folder=f22ef44e-7c29-42a2-aa10-d97c59d38285&file=01.JPG
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