Leadshine EL7-EC Series, Руководство пользователя

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User Manual Of EL7-EC** AC Servo
73
Position loop, velocity loop, velocity detection filter, torque command filter eachhave 2 pairs of
gain or time constant (1st
and 2nd).
Pr1.10
Label
Velocity feed forward
gain
Mode PP HM
CS
P
Range 0~1000 Unit 0.10% Default 300 Index 2110h
Activation Immediate
Used for decreasing following error caused by low responsiveness of velocity loop. Might cause
overshoot or increase in noise if set value is too high.
Pr1.11
Label
Velocity feed forward
filter time constant
Mode PP HM
CS
P
Range 0~6400 Unit 0.01ms Default 50 Index 2111h
Activation Immediate
Set velocity feed forward low pass filter to eliminate high or abnormal frequencies in velocity feed
forward command. Often used when position command with low resolution or high electronic gear
ration to smoothen velocity feed forward.
Position deviation under constant velocity can be lowered with higher velocity feed forward gain.
Please to refer to the equation below.
Position deviation[Uint]=
Pr1.12
Label
Torque feed forward
gain
Mode PP PV HM
CS
P CS
V
Range 0~1000 Unit 0.1% Default 0 Index 2112h
Activation Immediate
Before using torque feed forward, please set correct inertia ratio. By increasing torque feed
forward gain, position deviation on constant acceleration/deceleration can be reduced to close
to 0. Under ideal condition and trapezoidal speed profile, position deviation of the whole motion
can be reduced to close to 0. In reality, perturbation torque will always exist, hence position
deviation can never be 0.
Pr1.13
Label
Torque feed forward
filter time constant
Mode PP PV HM
CS
P CS
V
Range 0~6400 Unit 0.01ms Default 0 Index 2113h
Activation Immediate
Low pass filter to eliminate abnormal or high frequencies in torque feed forward command.
Usually used when encoder has lower resolution or precision.
Noise reduces if torque feed forward filter time constant is set higher but position deviation will
increase at acceleration varied points.