Basics

Overview

What is process control ?
Automatic control of a process in which a computer is used to regulate usually continuous operations.

This includes areas such as;

Factors that may be monitored include;

[Timber mill control]

The problems of a human controlling a Process control situation include;

If you were asked to sit in a booth for 8 hours a day, and control a set of traffic lights, what problems might you encounter?

Store transactions, and process as a group.

Examples

Mars Pathfinder mission
Store instructions which the are recalled at a later stage.
Eg. A robot trained to spray paint a chair, car, etc.
Airplanes have their route coordinates stored into their on-board computer to enable autopilot. (The Mt. Erabus crash was caused by incorrect co-ordinates).

missile0.gif (24827 bytes)

Real time - as it happens (parallelism)

Examples

Real time (Interactive, on-line) - within an allowable tolerance.

Examples

In glasshouse control, if a shower of rain comes over, the vents 'may' not need to be instantly closed.
Traffic lights

Problems could include; boredom, hunger, comfort stops, experimenting, applying personal values (want to hold up a particular person at the lights!), distractions, uneven delays, etc.