Linear Interpolation; Overview - Omron CJ1W-C113 - REV 02-2008 Operation Manual

Linear Interpolation

8-6

Linear Interpolation

8-6-1

Overview

Two or more axes can be designated for linear interpolation work. Use the
axis designation in the positioning sequence to designate the axes for linear
interpolation operations. The target speed set in the positioning sequence for
the starting axis will become the interpolation speed.
For details regarding positioning sequence settings, refer to 8-4 Positioning
Sequences.
Y axis
Start point
The speeds of the axes during linear interpolation are determined according
to the following equations. (The same equations can also be applied for 2 or
3-axis operation.)
Example: Linear interpolation for simultaneous 4-axis operation
X-axis speed = Interpolation speed × Movement of X axis ÷ Total movement
Y-axis speed = Interpolation speed × Movement of Y axis ÷ Total movement
Z-axis speed = Interpolation speed × Movement of Z axis ÷ Total movement
U-axis speed = Interpolation speed × Movement of U axis ÷ Total movement
Total movement = (Movement of X axis)
When the interpolation speed is separated in the way shown above, if the
speed for any axis is greater than its maximum speed setting, the interpolation
speed is automatically lowered so that the speed for that axis (or axes) is
equal to the maximum speed setting.
With this PCU, the interpolation speed can be set up to 1,000 pps so as to
allow each axis to move simultaneously at its maximum speed (500 pps)
whilst operating according to linear interpolation. If a value exceeding 1,000
pps is set, a speed error (error codes 1500 to 1599) will be generated.
The maximum distance the can be moved in one linear interpolation operation
(i.e., for one sequence) is 2,147,483,520 (7FFFFFF80 Hex) pulses. If a linear
interpolation operation that exceeds this value is specified, an overflow error
(error code 8601) will be generated. For example, moving from the point (X, Y)
= (–1073741823, 0) to the point (X, Y) = (1073741823, 1) would, using the
above equations, entail moving a total distance of 2,147,483,647 (7FFFFFFF
Hex) pulses. This value exceeds 2,147,483,520 and so if an operation to
move between these 2 points using linear interpolation was specified, an
overflow error (error code 8601) would be generated.
Interpolation end point
X axis
2 2
+ (Movement of Y axis) + (Movement of Z axis)
Section 8-6
v: Interpolation speed
2
+ (Movement of U axis)
217
2