Allowable Error Range For Circular Interpolation - Mitsubishi Electric A173UHCPU Programming Manual

4. PARAMETERS FOR POSITIONING CONTROL
4.4.3

Allowable error range for circular interpolation

As shown below, the S curve ratio setting serves to select the part of the sine curve
to be used as the acceleration and deceleration curve.
A
B
B/2 B/2
Sine curve
S curve ratio = B/A 100%
In control with the center point designated, the locus of the arc calculated from the
start point address and center point address may not coincide with the set end
point address.
The allowable error range for circular interpolation sets the allowable range for the
error between the locus of the arc determined by calculation and the end point
address.
If the error is within the allowable range, circular interpolation to the set end point
address is executed while also executing error compensation by means of spiral
interpolation.
If the setting range is exceeded, an error occurs and positioning does not start.
When such an error occurs, the relevant axis is set in the minor error code area.
Locus determined by spiral
interpolation
Start point address
Fig. 4.3 Spiral Interpolation
V
(Example)
Positioning
speed
When the S curve ratio is 100%
V
Positioning
speed
Error
End address determined
by calculation
Center point address
4 − 25
A
B
B/A=1.0
B
B/A=0.7
A
When the S curve ratio is 70%
Set end address
t
t