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

Content Introduction to ServoMechanism Uses of ServoMechanism Position Control Speed Control Other Uses Some ServoMechanism Devices Servo Control system

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.

Uses Of ServoMechanism 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.

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.

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.

Some ServoMechanism Devices

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.

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

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.

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.

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