Quadrant Error Compensation Using Neural Networks - Only 840D Sl; Fundamentals - Siemens SINUMERIK 840D sl Function Manual

5.6.3

Quadrant error compensation using neural networks - only 840D sl

5.6.3.1

Fundamentals

Principle of QEC
The purpose of quadrant error compensation (QEC) is to reduce contour errors occurring
during reversal as the result of drift, backlash or torsion. Compensation is effected through
prompt injection of an additional speed setpoint.
In conventional QEC, the intensity of the compensation pulse can be set according to a
characteristic as a function of the acceleration. This characteristic must be determined and
parameterized during commissioning using the circularity test. The procedure for this is
relatively complicated and requires some experience.
Figure 5-20
Advantages of QEC with neural network
On the SINUMERIK 840D, the characteristic block that used to be manually parameterized
can now be replaced by a neural network. This has the following advantages:
● Commissioning has been simplified because the compensation characteristic no longer
● The characteristic for a manually parameterized friction compensation is approximated by
● The system permits simple automatic re-optimization on site at any time.
Extended Functions
Function Manual, 09/2009, 6FC5397-1BP20-0BA0
Injection of an additional speed setpoint pulse
needs to be set manually by the commissioning engineer but is determined automatically
during a learning phase.
a polygon with 4 straight lines. For improved precision, the neural network can reproduce
the real curve much better.
The resolution of the characteristic curve can be adapted to the precision requirements
and a directional quality of the compensation amplitude can be considered.
In addition to the compensation amplitude, it is possible to adapt the decay time to the
acceleration in special cases.
5.6 Friction compensation (quadrant error compensation)
K3: Compensation
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