Man page - ilowpass(9)

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Manual

ILOWPASS

NAME
SYNOPSIS
DESCRIPTION
FUNCTIONS
PINS
PARAMETERS
AUTHOR
LICENSE

NAME

ilowpass - Low-pass filter with integer inputs and outputs

SYNOPSIS

loadrt ilowpass [count= N |names= name1 [, name2... ]]

DESCRIPTION

While it may find other applications, this component was written to create smoother motion while jogging with an MPG.

In a machine with high acceleration, a short jog can behave almost like a step function. By putting the ilowpass component between the MPG encoder counts output and the axis jog-counts input, this can be smoothed.

Choose scale conservatively so that during a single session there will never be more than about 2e9/ scale pulses seen on the MPG. Choose gain according to the smoothing level desired. Divide the axis. N .jog-scale values by scale .

FUNCTIONS

ilowpass. N (requires a floating-point thread)

Update the output based on the input and parameters.

PINS

ilowpass. N .in s32 in
ilowpass. N .out s32 out

out tracks in * scale through a low-pass filter of gain per period.

PARAMETERS

ilowpass. N .scale float rw (default: 1024 )

A scale factor applied to the output value of the low-pass filter.

ilowpass. N .gain float rw (default: .5 )

Together with the period, sets the rate at which the output changes. Useful range is between 0 and 1, with higher values causing the input value to be tracked more quickly. For instance, a setting of 0.9 causes the output value to go 90% of the way towards the input value in each period.

AUTHOR

Jeff Epler

LICENSE

GPL