25
4.0 C om m is s io nin g
Time [s]
0,0
–100
–200
100
200
300
0,0
–0,5
–1
0,5
1
1,5
0,0
0,5
1,0
1,5
2,0
2,5
3,0
Example: Low risk of generating over speed or tracking error
faults
Actual speed is the same as speed setpoint (1)
Speed [mm/s]
Motor current/10 and Tracking error [mm]
Tracking error (2)
Tracking error (2)
Speed setpoint [mm/s]
Actual speed [mm/s][mm/s]
Tracking error [mm][mm/s]
Motor current/10 [A][mm/s]
0,0
–100
–200
100
200
300
0,0
–0,5
–1
0,5
1
1,5
0,0
0,5
1,0
1,5
2,0
2,5
3,0
Example: High risk to generate overspeed or tracking error
faults
Speed [mm/s]
Motor current/10 and Tracking error [mm]
Speed overshot (1)
Tracking error (2)
Time [s]
Speed setpoint [mm/s]
Actual speed [mm/s][mm/s]
Tracking error [mm][mm/s]
Motor current/10 [A][mm/s]
1. In this example, there is no difference between the
speed setpoint and the actual speed. If a level triggering
overspeed fault is established at 230 mm/s, for example,
and if this graph stays identical on several for-
ward-backward movements, then the risk of generating
an overspeed fault is very low.
2. The value of tracking error is low (max ~40 µm). If the
level triggering a tracking error fault is established at 0,7
mm, for example, and if this graph stays identical on
several forward backward moves, then the risk to gener-
ate a tracking error fault is very low.
1. In this example, there is a big difference between the
speed setpoint and the actual speed, which causes a
speed overshoot phenomena (max speed near 230
mm/s) necessary to decrease tracking error. If the level
triggering overspeed fault is established at 230 mm/s,
for example, then the risk to generate an overspeed fault
is very high.
2. The value of tracking error is significant (max ~0,6 mm).
If the level triggering a tracking error is established at 0,7
mm, for example, then the risk to generate a tracking er-
ror fault is very high.
Summary of Contents for SLSA Series
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