
A-78640E
Sheet
Title
Draw
No.
04 Feb.08.’03 Part of (4) is added or modified. Addition of 2.16.5
03 Jul.02.’02 A. Fukumoto Part of (3) is added or modified. T.Endo
02 May.13.’02 A. Fukumoto Addition of Tool Radius control for 5-axis machining etc T.Endo
Ed. Date Design Description
Date Jan.25.’02 Desig. A.Fukumoto Apprv. T.Endo
FANUC Series 16i /18i -TB
Specifications of AI High-Precision Contour Control /
I Nano High-Precision Contour control
18/190
2.13 Smooth Interpolation
2.13.1 Outline
Either of two types of machining can be selected, depending on the program
command.
(1) For those portions where the accuracy of the figure is critical, such as at
corners, machining is performed exactly as specified by the program
command.
(2) For those portions having a large radius of curvature where a smooth figure
must be created, points along the machining path are interpolated with a
smooth curve, calculated from the polygonal lines specified with the
program command (smooth interpolation).
This function can use only in the AI HPCC / AI NANO HPCC mode.
This function is an additional option.
2.13.2 Format
G05 P10000 ; : Starting of AI HPCC / AI NANO HPCC mode
G01 ; : Linear interpolation mode
G05.1 Q2 X0 Y0 Z0 ; : Starting of smooth interpolation mode
…
G05.1 Q0 ; : Ending of smooth interpolation mode
G05 P0 ; : Ending of AI HPCC / AI NANO HPCC mode
2.13.3 Explanations
To machine a part having sculptured surfaces a part program usually
approximates the sculptured surfaces with minute line segments. As shown in
the following figure, a sculptured curve is normally approximated using line
segments with a tolerance of about 10µm.
10µm
Enlarged
:Specified point
Fig. 2.13.3(a) Approximation with Line Segments
When a program approximates a sculptured curve with line segments, the length
of each segment differs between those portions that have mainly a small radius
of curvature and those that have mainly a large radius of curvature. The length
of the line segments is short in those portions having a small radius of curvature,
while it is long in those portions having a large radius of curvature. The AI
HPCC / AI NANO HPCC moves the tool along a programmed path thus enabling
highly precise machining. This means that the tool movement precisely follows
the line segments used to approximate a sculptured curve. This may result in a
non-–smooth machined curve if control is applied to machining a curve where
the radius of curvature is large and changes only gradually. Although this effect
is caused by high-precision machining, which precisely follows a pre–
programmed path, the uneven corners that result will be judged unsatisfactory
when smooth surfaces are required.