Closing the Loop—Examples

Finally, the control routine is written, using display screen graphics and a keyboard, and the loop is closed. A simple example of such a routine is illustrated in Fig. 10.7. In 

To implement Ml image process control, an IR line scanner is placed at the oven exit, scaiming across each blank as it leaves the oven. The forward movement of the part, combined with the fast response of the line scanner, provides the Ml thermal map to the computer. A Ml statistical control chart is software-generated, based on mean temperature and standard deviation over the entire surface. The oven heater is zoned and the computer interfaced to a relay control board with one relay managing a set-point controller for each zone. The statistics for each control zone are calculated based on the corresponding section on the part, and a closed-loop statistical process control algorithm is implemented. The result is seen on the 3D strip map presentation shown in Fig. 10.8(b). The color hues indicate temperatures in accordance with the scale at the left. The control level temperature is about 300°F. 

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