P-Pi Control Automatic Switch - Sanyo SUPER BL P5 Manual

11. SPECIAL SERVO FUNCTION

11.6 P-PI Control Automatic Switch

The function that automatically switches between velocity loop proportional control and proportional
integrate control according to the Motor speed is available. This function can shorten positioning time in
position control.
11.6.1 Parameter setting
(1) P-PI automatic switch function (Func6 bit1: Mode2 page7)
Setting
Func6 bit = "0"
Func6 bit = "1"
(2) Low speed setting (LTG: Mode1 page5)
In case that P-PI control automatic switching is valid:
• When Motor speed is low speed setting value (LTG) or lower, turning into the velocity loop
proportional integrate control.
• When Motor speed is over low speed setting value (LTG), turning into the velocity loop proportional
control.
There is an effect that positioning time will be shorter when setting the lower LTG. However, in case
that there is a slight speed fluctuation even at Motor stoppage due to backlash or so on, too low LTG
may result in counter effect. Normally set between 10 to 200rpm. Also, the low speed setting value
(LTG) should differ enough from the fixed Motor speed. The speed will be unstable if switching P-PI
control when fixed speed rotation.
11.6.2 The operation when P-PI control automatic switch function is valid
Velocity loop integrate process will be changed based upon the Motor speed.
(1) When Motor accelerates and beyond the low speed setting value, the current command (torque
command) generated by velocity loop integrate formula will be "0". Operation of proportional control
is the same as that when velocity loop integrate time constant is invalid (1000Hz setting).
(2) When Motor decelerates to or below low speed setting value, velocity loop integrate time constant
will be valid.
(3) When Motor rotates at fixed speed over low speed setting value in position control, position deviation
will be wider (if position command pulse frequency is the same, there is no motor speed difference by
proportional control and proportional integrate control).
(4) When inputting the command over the low speed setting value in velocity control, Motor rotates at the
speed with deviation against the command.
11.6.3 Notificaiton
In the position control, there is an effect that positioning time will be shortened. Depending upon device
structure however, P-PI control switching will result in counter effects. Sufficient evaluation is required for
the devices of which belt driver has low rigidity, etc.
When the motor speed exceeds LTG by vibration or disturbance during motor stoppage, P control is
activated. Since the integral is cleared, motor output torque becomes smaller. Superficially, the operation
looks as if the holding torque became smaller. When there is vibration or disturbance, adjust LTG.
In the P-PI control switching, general-use input (CN1-35pin, 36pin) can be also used. Validate general-use
input PCON at Func3 bit3, 2, 1 and 0 (Mode2 page4). For general-use input PCON, P-PI control will switch
within 12msec. after input signal change.
Contents
P-PI control automatic switch function is invalid
P-PI control automatic switch function is valid
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