Siemens SINUMERIK 840D sl Programming Manual page 34

Description
1.8 Measurement principle
The deceleration path to be considered is calculated as follows:
s
b
v
t
a
Δs
Δs = v / Kv
Kv
Example of calculation:
● v = 6 m/min = 0.1 m/s measuring velocity
● a = 1 m/s
● t = 16 ms signal delay
● Kv = 1 in (m/min)/mm
Intermediate steps:
Δs = v / Kv
Δs
2
Δs
1
Overall result:
s = Δs
b
The deflection of the probe = braking distance to zero speed of the axis is 12.6 mm.
34
Braking distance
Measuring velocity
Delay signal
Deceleration
Following error
Servo gain
deceleration
2
= 6[m/min] / 1[(m/min)/mm] = 6 mm
= v²/2a = 0,1 [m/s]² / 2 · 1 [m/s²]
= v · t = 0,1 [m/s] · 0,016 [s]
+ Δs + Δs = 6 mm + 5 mm + 1,6 mm = 12,6 mm Braking distance
1 2
in mm
in m/s
in s
in m/s
2
in mm
v here in m/min
in (m/min)/mm
Following error
= 5 mm Axis-specific component
= 1,6 mm Percentage due to signal delay
Programming Manual, 02/2011, 6FC5398-4BP40-0BA0
Measuring cycles