Mitsubishi Electronics MDS-D-SPJ3 ユーザーズマニュアル

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This function is used under full-closed loop control.

When a linear scale is used, the machine-end position, such as a table, is directly detected, which may 

render the position loop control unstable.

With this control, however, high-frequency components are eliminated from the machine-end feedback 

signals, which will lead to stable control.

If the torque output during acceleration/deceleration is close to the servo motor's maximum torque, the motor 

cannot accelerate with the commanded time constant when the torque is saturated due to input voltage 

fluctuation, etc. As a result, speed overshoot occurs when a constant speed command is issued, because 

the position droop for the delay is canceled.

With HAS control, however, this overshoot is smoothened so that the machine operation can be stable.

Position loop gain and speed loop gain are switched between non-interpolation mode, which is used during 

speed command, and interpolation mode, which is used during synchronous tapping and C axis control. By 

switching these gains, optimum control for each mode can be realized.

ENC  

SV051 

+

+

+

-

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Position control  

Primary 
delay filter  

High frequency 
FB element  

Position 

command 

Position droop  

Servo  

motor  

Linear scale  

Table  

Speed 
command 

Position FB

Position FB

Low
frequency FB
element

0[r/min]

0[r/min]

0[r/min]

0[r/min]

HAS control will catch up 
the delay of position. 

Speed feedback

1% or less than 
maximum speed

Speed command

Overshoot will occur to 
catch up the delay of position.  

Speed command

Speed feedback

During current limit

During current limit 

HAS control is disabled.

HAS control is enabled.