Lenze 931M-931W - Manual (Page 80)

Parameter setting
Position controller (position control function)
Overview
7

80 KHB 13.0003-EN 2.0
7.6 Position controller (position control function)
7.6.1 Overview
This chapter describes all parameters that are required for the position controller. The
position setpoint (position_demand_value) of the driving profile generator is assigned to
thepositioncontrollerinput.In addition,the actual position value(position_actual_value)
is sent by the phase-angle encoder (resolver, incremental encoder, etc.). The behaviour of
the position controller can be influenced by parameters.
The following subfunctions are defined in this chapter:
1. Following error (Following_Error)
A following error is the difference between the actual position value
(position_actual_value) and the position setpoint (position_demand_value). If the
following error is for a certain time higher than the value indicated in the following error
window (following_error_window), bit 13 following_error is set in the status word object.
Fig. 10 shows the definition of the window function for the ”Following error” message.
Symmetrically around the setpoint position (position_demand_value) x
i
, the range
between x
i
-x
0
and x
i
+x
0
is defined. The positions x
t2
and x
t3
are, for instance, not within
the window (following_error_window). If the drive leaves the window, bit 13
following_error is set in the status word.
x - x
i 0
x + x
i 0
position x
x
i
x
t2
x
t3
931e_417
Fig. 10 Following error
2. Position reached (Position Reached)
This function is used to define a position window around the target position
(target_position). When the target position of the drive is reached - the drive is within the
tolerance window - bit 10 target_reached is set in the status word.
Fig. 11 shows the definition of the window function for the ”Position reached” message.
Symmetrically around the target position (target_position) x
i
, the position range between
x
i
-x
0
and x
i
+x
0
is defined. The positions x
t0
and x
t1
are, for instance, within the position
window (position_window). When the drive is within this window, bit 10 target_reached
is set in the status word. As soon as the drive leaves the permissible range, bit 10 is reset
to zero.