Siemens SINUMERIK 840D sl Function Manual

Also see for SINUMERIK 828D Turning: Diagnostic manual Function manual Equipment manual Programming manual Operating manual

4.4 Dynamic adaptations4.4.1 Smoothing of the path velocityIntroductionThe velocity control function utilizes the specified axial dynamic response. If the programmedfeedrate cannot be achieved, the path velocity is brought to the parameterized axial limit valuesand the limit values of the path (velocity, acceleration, jerk). This can lead to repeated brakingand acceleration on the path.If a short acceleration takes place during a machining function with high path velocity, and isthus followed almost immediately by braking, the reduction in the machining time is onlyminimal. Acceleration of this kind can, however, have undesirable effects if, for example, itresults in machine resonance.In some applications in mold making, especially in the case of high-speed cutting, it is desirableto achieve a constant path velocity. In these cases, it can therefore be reasonable to sacrificetransient acceleration processes in favor of a smoother tool path velocity.FunctionIf the "smoothing the path velocity" function is active, a smoothing factor, which determinesthe maximum permissible productivity loss, takes effect with a view to achieving smoother pathvelocity control: Acceleration processes which contribute less than this factor to a shorterprogram runtime are not performed. Account is only taken of acceleration processes whosefrequencies lie above the configurable limit frequencies of of the axes involved.Benefits:● Avoidance of excitations of possible machine resonance due to continuous, transientbraking and acceleration processes (in the area of less IPO cycles).● Avoidance of constantly varying cutting rates due to acceleration which brings no significantshortening of the program running time.NoteThe smoothing of the path velocity does not lead to contour errors.Variations in axis velocity due to curvatures in the contour at constant path velocity maycontinue to occur and are not reduced with this function.Variations in path velocity due to the input of a new feedrate are not changed either. Thisremains the responsibility of the programmer of the subprogram.B1: Continuous-path mode, Exact stop, Look Ahead4.4 Dynamic adaptationsBasic Functions210 Function Manual, 01/2015, 6FC5397-0BP40-5BA2