Modern Control System Theory and Design, 2nd Edition

1.5.  MODERN CONTROL-SYSTEM APPLICATIONS WITH A PREVIEW OF THE FUTURE

Feedback control systems are to be found in almost every aspect of our daily environment. In the home, the refrigerator utilizes a temperature-control system. The desired temperature is set and a thermostat measures the actual temperature and the error. A compressor motor is utilized for power amplification. Other applications of control in the home are the hot-water heater (see Problem 1.3), the central heating system, and the oven, which all work on a similar principle. We also encounter feedback control systems when driving our automobile. Automatic control systems are used for maintaining constant speed (cruise control), constant temperature (climate control) steering, suspension, engine control, and to control skidding (antiskid system) [3–5].

In industry the term automation is very common. Modern industrial plants utilize robots for obtaining temperature controls, pressure controls, speed controls, position controls, etc. The chemical process control field is an area where automation has played an important role [6]. Here, the control engineer is interested in controlling temperature, pressure, humidity, thickness, volume, quality, and many other variables. Areas of additional interest include automatic warehousing [7] and inventory control [8] and automation of farming [9].

In this section, I present the state of the control-system field by illustrating its application in the following important aspects ...