Block Diagram
A control system may consist of a number of components.
In order to show the
functions performed by each component in control
engineering, we commonly use a
diagram called the Block Diagram.
A block diagram of a system is a pictorial
represe

Rotational mechanical system
The rotational motion of a body may be defined as
motion about a fixed axis. The
variables generally used to describe the motion of
rotation are torque, angular
displacement , angular velocity () and angular
acceleration()
The

Linear Systems
A system is called linear if the principle of superposition
applies the principle of
superposition states that the response ( output) produced
by the simultaneous application
of two different inputs is the sum of two individual
responses (

DIFFERENTIAL EQUATIONS OF
PHYSICAL SYSTEMS
The term mechanical translation is used to describe motion
with a single degree of
freedom or motion in a straight line. The basis for all
translational motion analysis is
Newtons second law of motion which state

Block diagram of a closed loop system
The output C(s) is fed back to the summing point, where it
is compared with
reference input R(s). The closed loop nature is indicated in
fig1.3. Any linear system may
be represented by a block diagram consisting of bl

Frequency Domain analysis of
control systems
Introduction :
It was pointed out earlier that the performance of a
feedback control system is more
preferably measured by its time domain response
characteristics. This is in contrast to the
analysis & design

SIGNAL FLOW GRAPH
The block diagram is useful for graphically representing
control systems. For a
complicated system, however the block diagram reduction
process becomes time
consuming . An alternate approach for finding the
relationships among the system

REQUIREMENTS FOR THE
CONTROL SYSTEM
Speed of response, accuracy and stability are the
requirements demanded of every control
system. We shall understand the significance of the above
taking the example of an
elevator.
As noted earlier, a control system pr

MODELING IN FREQUENCY DOMAIN
The two important topics in the study of control systems
are
1. Control system analysis
2. Control system design
By control system analysis we mean the investigation
under specified conditions of the
performance of the system.

CLOSED- LOOP VERSUS OPEN
LOOP CONTROL SYSTEMS
An advantage of the closed loop control system is the
fact that the use of feedback makes
the system response relatively insensitive to external
disturbances and internal variations
in systems parameters. It i