26-12-2012, 02:12 PM
Introduction to Control Systems
[attachment=45288]
INTRODUCTION
Control engineering is based on the foundations of feedback theory and
linear system analysis, and it generates the concepts of network theory and
communication theory. Accordingly, control engineering is not limited to any
engineering discipline but is applicable to aeronautical, chemical, mechanical,
environmental, civil, and electrical engineering.
A control system is an interconnection of components forming a system
configuration that will provide a desired system response. The basis for analysis
of a system is the foundation provided by linear system, which assumes a causeeffect
relationship for the components of a system. A component or process to be
controlled can be represented by a block as shown in Figure 1.
TEMPERATURE CONTROL SYSTEMS
Figure 4 shows a diagram of temperature control of an electric furnace. The
temperature in the electric furnace is measured by a thermometer, which is an
analog device. The analog temperature is converted to a digital temperature by an
A/D converter. The digital temperature is fed to a controller through an interface.
This digital temperature is compared with the programmed input temperature,
and if there is any error, the controller sends out a signal to the heater, through an
interface, amplifier, and relay, to bring the furnace temperature to a desired value.
DESIGN EXAMPLE: DISK DRIVE READ SYSTEM
A hard disk uses round, flat disks called platters, coated on both sides with a
special media material designed to store information in the form of magnetic
patterns. The platters are mounted by cutting a hole in the center and stacking
them onto a spindle. The platters rotate at high speed, driven by a special spindle
motor connected to the spindle. Special electromagnetic read/write devices called
heads are mounted onto sliders and used to either record information onto the
disk or read information from it. The sliders are mounted onto arms, all of which
are mechanically connected into a single assembly and positioned over the
surface of the disk by a device called an actuator. A logic board controls the
activity of the other components and communicates with the rest of the computer.
For details see Figure 8 and Figure 9.
[attachment=45288]
INTRODUCTION
Control engineering is based on the foundations of feedback theory and
linear system analysis, and it generates the concepts of network theory and
communication theory. Accordingly, control engineering is not limited to any
engineering discipline but is applicable to aeronautical, chemical, mechanical,
environmental, civil, and electrical engineering.
A control system is an interconnection of components forming a system
configuration that will provide a desired system response. The basis for analysis
of a system is the foundation provided by linear system, which assumes a causeeffect
relationship for the components of a system. A component or process to be
controlled can be represented by a block as shown in Figure 1.
TEMPERATURE CONTROL SYSTEMS
Figure 4 shows a diagram of temperature control of an electric furnace. The
temperature in the electric furnace is measured by a thermometer, which is an
analog device. The analog temperature is converted to a digital temperature by an
A/D converter. The digital temperature is fed to a controller through an interface.
This digital temperature is compared with the programmed input temperature,
and if there is any error, the controller sends out a signal to the heater, through an
interface, amplifier, and relay, to bring the furnace temperature to a desired value.
DESIGN EXAMPLE: DISK DRIVE READ SYSTEM
A hard disk uses round, flat disks called platters, coated on both sides with a
special media material designed to store information in the form of magnetic
patterns. The platters are mounted by cutting a hole in the center and stacking
them onto a spindle. The platters rotate at high speed, driven by a special spindle
motor connected to the spindle. Special electromagnetic read/write devices called
heads are mounted onto sliders and used to either record information onto the
disk or read information from it. The sliders are mounted onto arms, all of which
are mechanically connected into a single assembly and positioned over the
surface of the disk by a device called an actuator. A logic board controls the
activity of the other components and communicates with the rest of the computer.
For details see Figure 8 and Figure 9.