Omron NJ501-1300, User Manual

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9-55
9 Motion Control Functions
NJ-series CPU Unit Motion Control User’s Manual (W507)
9-
7 Co
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Fun
ctio
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9
9-7-3
Jer
k
f
o
r Multi-ax
es Coo
rdinated Cont
rol
You can read Axes Group Variables in the user program to monitor interpolation acceleration and inter-
polation deceleration rates.
Jerk for multi-axes coordinated control is used to reduce shock on the machine by smoothing the inter-
polation acceleration/deceleration rate along the interpolation path into an S-curve. The unit is the
same as for single axes, command units/s
3
.
The jerk used in an actual interpolation is specified by the Jerk input variable to the motion control
instruction.
The acceleration/deceleration rate will change at a constant rate over the range where jerk is specified.
The command interpolation velocity will form a smooth S-curve. A fixed interpolation acceleration rate is
used in areas where the jerk is set to 0. This command interpolation velocity will form a straight line.
Monitoring Interpolation Acceleration and Interpolation Deceleration
Rates
Variable name Data type Meaning Function
_MC_GRP[0-31].Cmd.AccDec LREAL Command Interpo-
lation Accelera-
tion/Deceleration This is the current value of the com-
mand interpolation accelera-
tion/deceleration rate. A plus sign is
added for acceleration, and a minus
sign is added for deceleration.
9-7-3 Jerk for Multi-axes Coordinated Control
Specifying Jerk for Axes Group Motion
Jerk Example (Setting Other than 0)
Vt: Specified interpolation velocity, At: Specified acceleration rate, Dt: Specified deceleration rate, Jt: Specified jerk
Jt
-Jt
Vt
Time
Time
Time
Jerk
Deceleration
rate
Acceleration
rate
Interpolation
velocity
At
-Dt