MC-Basic:axis.PositionBacklash

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Adds a position backlash value to the PCMD value. The value will be added to the positive direction of the movement (<axis>.VCMD > 0), while in opposite direction the value multiplied by -1 is used. At a standstill (VCMD = 0), the previous value of the backlash is used.

Differences between positive and negative applied backlash values will be smoothened by a simple alpha-filter: MC-Basic:axis.PositionBacklashAlpha.

According to:

P = P × Alpha + <sign> × PositionBacklash × (1-Alpha)

where <sign> = -1 on VCMD <0 else equals 1.

Picture showing different values of backlash compensation in different movement directions. Note the influence of PositionBacklashAlpha factor (0.9, 0.95, 0.99)
IMPORTANT.svgIMPORTANT
The backlash position value is not compensated in the position feedback. Therefore, applying position backlash to a non-zero value will result the same opposite value in the position error (PE). It will look like PE is never closed.

Short form

None

Syntax

<axis>.PositionBacklash = <double>

Availability

4.5.33 and later

Type

Double

Range

MIND ... MAXD

Units

Position user units

Default

0

Scope

Task, Terminal

Limitations

Modal only

Examples

a1.PositionBacklash = 0.5

See Also