Overview

Task

NC programs describe tool motions using linear blocks and arcs. Smoothing methods are required to enable these contours to be traversed without stopping. Depending on the application and hardware, various options are available, each with suitable generators for feed rate profiles. In addition, axis command values can be filtered symmetrically [FCT-C37] and FIR filter.

Parts of these functionalities are additional options that require a license.

Possible applications

• Contour mode methods which smooth each corner are ideal for programs with long motion blocks. This is often referred to as polynomial contouring.
• HSC methods are suitable for free-form surfaces that contain several short blocks since they machine the entire contour. The surface option represents an excellent, robust method.
• The B spline method places fewer requirements on the hardware and is suitable for programs with uniform linear blocks.

Parameterisation

• With all smoothing methods, the deviation between a smoothed and a programmed contour is limited by the parameter PATH_DEV. TRACK_DEV can also be specified for tracking axes.
• The higher HSC methods are expansions that require a license and can be enabled at controller start-up [P-CHAN-00605].
• The CIR_MODE option and the channel parameter P-CHAN-00239 are required to smooth transitions with arcs. If a kinematic is used, it may be useful to activate the automatic segmentation of NC programs.

Programming

Smoothing methods can be configured and selected using the following commands:

• #CONTOUR MODE [PATH_DEV=.. ], select with G261 and deselect with G260
• #HSC ON [SURFACE PATH_DEV= ] and #HSC OFF
• #SLOPE [TYPE= TRAPEZ, STEP or HSC]

References

• [PROG] G functions \ Path conditions and
• [PROG] Additional options \ Jerk-limiting slope and Surface