b.e. 3rd year g.h.raisoni,college of engineering,nagpur

1. * PowerPoint Presentation *
Topic :- Servomechanism And Control Systems
By :-
 Omkar Lokhande

2. Content
Introduction to ServoMechanism
Uses of ServoMechanism
 Position Control
 Speed Control
 Other Uses
Some ServoMechanism Devices
Servo Control system

3. Introduction
 ServoMechanism :-
A servomechanism, sometimes shortened to
servo, is an automatic device that uses error-sensing
negative feedback to correct the performance of a
mechanism and is defined by its function. It usually
includes an in built encoder.
The term correctly applies only to systems
where the feedback or error-correction signals help
control mechanical position, speed or other parameters.
For example, an automotive power window control is
not a servomechanism, as there is no automatic feedback
that controls position—the operator does this by
observation. By contrast a car's cruise control uses
closed loop feedback, which classifies it as a
servomechanism.

4. Uses Of ServoMechanism
1. Position control :-
A common type of servo provides position
control. Servos are commonly electrical or partially
electronic in nature, using an electric motor as the primary
means of creating mechanical force. Other types of servos
use hydraulics, pneumatics, or magnetic principles. Servos
operate on the principle of negative feedback, where the
control input is compared to the actual position of the
mechanical system as measured by some sort of transducer
at the output. Any difference between the actual and wanted
values (an "error signal") is amplified (and converted) and
used to drive the system in the direction necessary to reduce
or eliminate the error.

5. 2. Speed control :-
Speed control via a
governor is another type of
servomechanism. The steam engine
uses mechanical governors; another
early application was to govern the
speed of water wheels. Prior to
World War II the constant speed
propeller was developed to control engine
speed for maneuvering aircraft. Fuel controls for
gas turbine engines employ either hydro mechanical
or electronic governing.

6. Other Uses
 Positioning servomechanisms were first used in military
fire control and marine navigation equipment.
 Its also used in automatic machine tools, satellite-
tracking antennas, remote control airplanes, automatic
navigation systems on boats and planes, and antiaircraft-
gun control systems.
 Many autofocus cameras also use a servomechanism to
accurately move the lens, and thus adjust the focus. A
modern hard disk drive has a magnetic servo system with
sub-micro meter positioning accuracy.
 In industrial machines, servos are used to perform
complex motion, in many applications.

7. Some ServoMechanism Devices

8. Servo Control System
A servo control system is none of the most
important and widely used form of control system.
Any machine or piece of equipment that has rotating
parts will contain one or more servo control system.
The job of control system may include:
 Maintaining the speed of motor within certain limits,
even when on the output of motor might vary. This
is called regulation.
 Varying the speed of motor and load according to an
externally set programme of values. This is called
set point (or reference) tracking.

9. Advantages of Servo Control
System
 Intermediate motor and control costs
 Continuous duty
 Reversible.
 Speed is proportional to the applied voltage
 Torque is proportional to the current
 Very efficient
 No power required to hold a static load in
position
 Flat speed-torque curve
 Peak torque available for short periods of time
 Smooth rotation at low speeds
 Good up to 3,000 RPM

10. Future Treads
 Due to increase of Automation and development of
new application of servo system it has a high scope
in future.
 Due to Price reductions there is a beneficial effect
on growth of servo systems in future.
 Due to continuous technology improvement in this
electronics devices system it has a high scope in
future.
 The servo drives sector is benefiting from the
popularity of intelligent drives that combine drive
and controller capabilities, which leading it towards
high growth.

11. Summary
Servo Control System reduces the error of the
system and improves the output mechanism.
Due to blocking of error, the efficiency of the
devices increases.
Its easier to design and implement.
It can operate on both AC or DC.

12. References
 www.uotechnology.edu.iq/dep-cse/.../ce110-
servo%20trainer%2013
 www.toolingu.com/definition-460330-42782-
servo-system
 Introduction to servo system-
By I. A. Getting
 Servo Control System –
By Elke Laubwald
 IEEE Industry Applications Magazine
March/April 1996, pg 74