
B-63943EN-1/02 1.AXIS CONTROL
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1.3.7 Gradient Compensation
Overview
By compensating for those errors in tools such as feed screws that
depend on the position of the machine system in detection units,
machining precision can be improved and mechanical life can be
prolonged. Compensation is performed along an approximate straight
line formed with a parameter-specified compensation point and a
compensation amount related to it.
Explanation
Three approximate straight lines are formed with four
parameter-specified compensation points and compensation amounts
related to the respective compensation points. Gradient compensation
is carried out along these approximate straight lines at pitch error
compensation intervals. The gradient compensation amount is added
to the pitch error compensation amount.
. . . . . .
0 1 2 3 60 61 126 127
<1>
<2> <3> <4>
. .
. .
a
b
c
d
α
ε
To perform gradient compensation, stored pitch error compensation
must be set for the axis subject to compensation.
(1) Number of the most distant pitch error compensation point on the
- side (parameter No.3621)
(2) Pitch error compensation point interval (parameter No. 3624)
(3) Number of the pitch error compensation point of the reference
position (parameter No. 3620)
(4) Number of the most distant pitch error compensation point on the
- side (parameter No. 3622)
Gradient compensation parameters must be set.
a,b,c,d : Compensation point numbers. (Pitch error compensation
point numbers are used. Parameters Nos. 5861 to 5864)
α,β,γ,ε : Compensation amounts at compensation points a, b, c, and d
(parameters Nos. 5871 to 5874)
In above figure, a, b, c, and d are 1, 3, 60, and 126, respectively.
Unlike stored pitch error compensation, whose amount is set up for an
individual compensation point, an amount of gradient compensation is
calculated for individual compensation points by setting up four
typical points and compensation amounts for them.
Example: