Interpolation Control - Mitsubishi Electric MELSEC-L LD75P User Manual

9.1.6

Interpolation control

(1) Meaning of interpolation control
In "2-axis linear interpolation control", "3-axis linear interpolation control", "4-axis linear interpolation control", "2-
axis fixed-feed control", "3-axis fixed-feed control", "4-axis fixed-feed control", "2-axis speed control", "3-axis
speed control", "4-axis speed control", "2-axis circular interpolation control", and "3-axis helical interpolation
control", control is carried out so that specified paths (linear, arc, and helical paths) are drawn using a motor set in
two to four axis directions. This kind of control is called "interpolation control".
In interpolation control, the axis in which the control system is set is defined as the "reference axis", and the other
axis is defined as the "interpolation axis".
The LD75 controls the "reference axis" following the positioning data set in the "reference axis", and controls the
"interpolation axis" corresponding to the reference axis control so that a linear or arc path is drawn.
The following table shows the reference axis and interpolation axis combinations.
Axis set to interpolation control in "[Da.2] Control
method"
2-axis linear interpolation control, "2-axis fixed-feed control,
2-axis circular interpolation control, 2-axis speed control
3-axis linear interpolation control, "3-axis fixed-feed control,
3-axis speed control
4-axis linear interpolation control, "4-axis fixed-feed control,
4-axis speed control
The available axis combinations in the 3-axis helical interpolation control are the same as the ones in the "3-axis
linear interpolation control", "3-axis fixed-feed control", and "3-axis speed control". However, the circular
interpolation axis can be specified with "[Da.5] Axis to be interpolated" of the reference axis. The following table
lists the combinations of the reference axis, circular interpolation axis, and linear interpolation axis for the 3-axis
helical interpolation control.
Axis set to interpolation control in "[Da.2]
Control method"
3-axis helical interpolation control
*1 Specify with "[Da.5] Axis to be interpolated" of the reference axis.
*2 An axis which is not specified with "[Da.5] Axis to be interpolated" of the reference axis is automatically assigned.
Reference axis
Any of axes 1, 2, 3, and 4
Axis 1
Axis 2
Axis 3
Axis 4
Axis 1
Axis 2
Axis 3
Axis 4
Reference axis
Circular interpolation axis
Axis 2
Axis 1
Axis 3
Axis 3
Axis 2
Axis 4
Axis 4
Axis 3
Axis 1
Axis 1
Axis 4
Axis 2
CHAPTER 9 MAJOR POSITIONING CONTROL
Interpolation axis
"Axes to be interpolated" set in reference axis
Axis 2, Axis 3
Axis 3, Axis 4
Axis 4, Axis 1
Axis 1, Axis 2
Axis 2, Axis 3, Axis 4
Axis 3, Axis 4, Axis 1
Axis 4, Axis 1, Axis 2
Axis 1, Axis 2, Axis 3
*1
Linear interpolation axis
Axis 3
Axis 2
Axis 4
Axis 3
Axis 1
Axis 4
Axis 2
Axis 1
9
*2
359