
B-65150E/04 3. α SERIES PARAMETER ADJUSTMENT
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3.4 ADJUSTING PARAMETERS FOR HIGH SPEED AND HIGH
PRECISION
3.4.1 Level-up HRV Control Adjustment Procedure
(1) Overview
With standard systems of the i Series CNC (Series 15i, 16i, and 18i),
the current control period can be changed from the conventional value
250 µs to 125 µs by employment of a high-speed DSP for servo control.
(This function is optional with Series 21i.) With a reduced current
control period, the response of the current loop increases. As the result,
a high velocity loop gain and high position loop gain can be set stably.
With higher velocity loop
and position loop gains, the
response and rigidity of a
servo system can be
improved. This capability
enables cutting figure error
reduction and higher-speed
positioning with machine
tools. Moreover, this
capability simplifies servo
adjustment. Thus, level-up
HRV control can improve
overall servo performance.
Fig. 3.4.1 (a) Achievements of level-up HRV control
After servo system adjustment with level-up HRV control, the
parameters for advanced preview control, AI contour control, and
high-precision contour control on the CNC side need to be adjusted.
For information about adjustment of these parameters, see Subsec.
3.4.3, "Servo Parameter Adjustment Procedure for Achieving High
Speed and High Precision."
Employment of high-speed servo DSP
Current loop response improvement
Higher velocity loop gain
Cutting figure
improvement
High-speed positioning
Simplified servo
adjustment