NCT Group 99M, 2000M manual Automatic Acceleration/Deceleration

6 The Feed

automatically in the course of program execution.

The maximum jog feed can also be clamped separately by parameters for human response times.

6.3 Automatic Acceleration/Deceleration

In rapid traverse, the control will automatically perform a linear acceleration and linear deceleration when starting and ending a movement. The extent of acceleration is defined by the machine tool builder, in parameter ACCn, depending on the dynamics of the machine.

Fig. 6.3-1

In feed motions the tangential (programmed) feed value will be assumed by the control in linear acceleration, inversely, its value will be decreased by linear deceleration. This technique offers the advantage over traditional (exponential) accelerations that the machine will sooner attain the desired speed (assuming a given time constant adopted in both cases). Thus the times of acceleration and deceleration (i.e., the times of actual slide movements) will be reduced.

Another advantage of linear acceleration over the exponential one is the lower profile distortion (i.e., radius error), compared with exponential acceleration, in a high-speed machining of a circle.

Fig. 6.3-2

Fig. 6.3-3

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