Single-channel all-digital AC servo drives QS7 Series
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Position Control Flow Diagram
8.3.3 Basic Parameters Adjustment Diagrams
Position resolution (an impulse travel) determines the stroke per turn on the servo motor
and encoder feedback pulses per turn Pt, which can be expressed with the below formulation:
ΔS
Δl=
P
t
Equation,
Δl: A pulse travel
（
mm
）；
ΔS: Servo motor stroke per revolution
（
mm/r
）；
P
t :
Encoder feedback pulses per revolution
（
pulse/r
）。
The system has four multiplier circuit, so P
t
＝
4×C
，
wherein, C refers to the number of
lines per revolution of encoder. In this system, C = 2500 lines / turn, so Pt = 10000 pulses / turn.
A command pulse multiplies electronic gear ratio G and then it can be transferred into
position control pulse, so a command pulse stroke is expressed as follows:
ΔS×G
Δl
*
＝
Pt
Command Pulse Divider numerator
Equation, G
＝
Command Pulse Divider denominator
When the drive is used for numerical control system, the parameters P12 and P13 are
calculated as follows:
P12
Mechanical reduction ratio
x
system pulse equivalent
x
10000
———— = ——————————————————————————
P13
Screw pitch
(mm)
General CNC pulse equivalent: 0.001mm
P10 pulse mode
P12
electric gear numerator;
P13
electric gear denominator
Position feed-forward
P16
position gain
Internal position control
P12
electric gear numerator
P13
electric gear denominator
P50 current loop gain
P51current integral
Current loop control
M
P16
position gain
P18
position smoothing coefficients
