Page 502 - Sensors and Control Systems in Manufacturing

FIGURE 9.16 Method of automating a drilling machine. Communications 455

ends of the traveled distance. Today, DC motors, which provide infi-
nite and simple adjustments for all axes and for the main drive, are
widely used.
Two different methods are used to describe the course of a tool or
machine slide: incrementally and absolutely. Accordingly, the subcon-
trol task, movement of a machine slide, is solved differently for each.
The two types of incremental control systems are illustrated in
Fig. 9.17. In an incremental control system with an incremental dis-
placement encoder, the processor counts the pulses supplied by the
linear displacement sensor. A pulse corresponds to the smallest mea-
surable unit of displacement. The distance to be traveled and the
direction of travel are passed on to the processor as reference values.
From these data, the processor forms a control signal for the final