Filter Objects
Filters
provide linkage between motors and axes: motors are mapped to
filters, and filters are mapped to axes. (It is not possible to
map a motor directly to an axis without a filter.) Depending upon
the algorithm employed, filters use such coefficients as gains,
feed forward and torque limits.
Filter
Configuration Attributes
The
Filter Summary window lists Filter attributes in three tab pages:
"Config," "Coeffs," and "SERCOS."
Configuration
Attributes: "Config" Tab Page
"Config"
Filter attributes include configurations for standard and custom
filter features.
- Save
to Flash-- Pre-selects current Filter settings for saving
to flash memory. For more information on using Save to Flash,
see description in the first
part of this chapter.
- View
Sub-objects-- Shows all sub-objects for Filter object.
For more information, see Object Summary
Windows.
- Motor
Map-- Displays the Filter Motor Map Configuration window.
For more information, see Object List
Configuration Dialog Boxes.
- Algorithm
-- Software filter algorithm. There are five types:
None
-- Filter is OFF. No algorithm is applied.
PID
-- Proportional Integral Differential algorithm.
PIV
-- Proportional Integral Velocity.
PIV1
-- Proportional Integral Velocity.
SERCOS
Drive -- SERCOS protocols applied. (See "SERCOS Coefficients"
below.)
User
-- User-defined algorithm defined in firmware. (For more information,
please contact MEI.)
Configuration Attributes: "Coeffs"
Tab Page
The
display of filter coefficients changes according to the Algorithm
chosen (selectable from the Filter / General panel).
The algorithm combo box on the Coeffs tab merely changes how
the coefficients are displayed. It changes the row headers and
displays N/A for coefficients that are not used for the
selected algorithm. If the algorithm of a filter object does
not match the algorithm being displayed, then N/A is
displayed for all coefficients.
Each
set of coefficients is described in separate tables below.
PID
Coefficients
PID
coefficients are defined in the table below.
Filter
Coefficients (PID Algorithm)
Coefficient
|
Description
|
Kp
|
Proportional
gain
|
Ki
|
Integral
gain
|
Kd
|
Derivative
gain
|
Kpff
|
Position
feed forward gain
|
Kvff
|
Velocity
feed forward gain
|
Kaff
|
Acceleration
feed forward gain
|
Kfff
|
Friction
feed forward gain
|
ImaxMoving
|
Position
loop integration maximum (while moving)
|
IMaxRest
|
Position
loop integration maximum (while resting)
|
DRate
|
Derivative
sub-sampling rate
|
Output
Limit
|
Voltage
command output limit
|
Output
Limit High
|
Maximum
command output voltage limit.
|
Output
Limit Low
|
Minimum
command output voltage limit.
|
Output
Offset
|
Offset
added to output.
|
Ka0
|
Fast
Fourier transform (FFT) testing gain (0)
|
Ka1
|
Fast
Fourier transform (FFT) testing gain (1)
|
Ka2
|
Fast
Fourier transform (FFT) testing gain (2)
|
PIV
Coefficients
PIV
coefficients are described in the table below.
Filter
Coefficients (PIV Algorithm)
Coefficient
|
Description
|
Kpp
|
Position
loop proportional gain
|
Kip
|
Position
loop integral gain
|
Kpv
|
Velocity
loop proportional gain
|
Kvff
|
Velocity
feed forward gain
|
Kaff
|
Acceleration
feed forward gain
|
Kfff
|
Friction
feed forward gain
|
ImaxMoving
|
Position
loop integration maximum (while moving)
|
IMaxRest
|
Position
loop integration maximum (while resting)
|
Kdv
|
Velocity
estimate feedback gain
|
Output
Limit
|
Voltage
command output limit
|
Output
Limit High
|
Upper
voltage command output limit.
|
Output
Limit Low
|
Lower
voltage command output limit.
|
Output
Offset
|
Offset
added to output
|
Kiv
|
Velocity
loop integral gain
|
VintMax
|
Velocity
loop integration maximum
|
Ka0
|
Fast
Fourier transform (FFT) testing gain (0)
|
Ka1
|
Fast
Fourier transform (FFT) testing gain (1)
|
SERCOS
Coefficients
SERCOS
coefficients are described in the table below.
Filter
Coefficients (SERCOS Algorithm)
Coefficient
|
Description
|
IDN
Value 0
|
Value
of IDN mapped to this coefficient.
|
.
.
.
|
.
.
.
|
IDN
Value 15
|
Value
of IDN mapped to this coefficient.
|
Kvff
|
Velocity
feed forward gain
|
Kaff
|
Acceleration
feed forward gain
|
Kfff
|
Friction
feed forward gain
|
Ksff
|
Feed
forward scale factor.
|
Configuration
Attributes: "SERCOS" Tab Page
The
SERCOS tab page maps gain values to IDNs. If the map value is
0, then the gain is not mapped to an IDN. If the gain value
is non-zero, then the MPI functions for getting and setting
gain values will automatically read/write the gain values to
the drive via the SERCOS service channel.