Servomechanism
Servo Motors
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Servomechanism - Wikipedia, the free encyclopedia
A servomechanism, or servo is an automatic device which uses error-sensing ... Retrieved from "http://en.wikipedia.org
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servomechanism: Definition from Answers.com
servomechanism n. A feedback system that consists of a sensing element, amplifier, and servomotor, used in the automatic control of a mechanical
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servomechanism -- Britannica Online Encyclopedia
The term servomechanism properly applies only to systems in which the feedback and ... system using a servomechanism is the communications-satellite ...
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servomechanism - Wiktionary
servomechanism (plural servomechanisms) (abbreviated as servo) ... Retrieved from "http://en.wiktionary.org
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Servomechanism Summary and Analysis Summary
Servomechanism summary with 5 pages of encyclopedia entries, essays, summaries, research ... A servomechanism is a device that automatically controls an object ...
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SERVOMECHANISM,
The defining characteristic of a servomechanism is that the controlled output of ... The power steering system in an automobile is an example of a servomechanism. ...
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SERVOMECHANISM,
Encyclopedia ... characteristic of a servomechanism is that the controlled ... The power steering system in an automobile is an example of a servomechanism. ...
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servomechanism - Definition from the Merriam-Webster Online Dictionary
Definition of servomechanism from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games.
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SERVOMECHANISM
SERVOMECHANISM. An engineering term for an automatically operating device for the regulation of ... (s) actuated by the difference between the actual and a ...
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image:servo.jpg
2. position feedback potentiometer
3. reduction gear
4. actuator arm
A servomechanism, or servo, is a device used to provide control of a desired operation through the use of feedback. An example of a servomechanism is a home furnace controlled by a thermostat.
A common type of servo provides is 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. Usually, 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 used to drive the system in the direction necessary to reduce or eliminate the error. An entire science known as control theory has been developed on this type of system.
Servos are found in many applications. They operate the throttle of engines that use a cruise control. CNC machines use servos to make the motion axes of a machine tool follow the desired tool path. Fly-by-wire systems in aircraft use servos to actuate the control surfaces that control the aircraft. Radio-controlled models use RC servos for the same purpose. Many autofocus cameras also use a servomechanism to accurately move the lens, and thus adjust the focus.
Typical servos give a rotary (angular) output. Linear types are common as well, using a screw (simple machine) or a linear motor to give linear motion.
Another device commonly referred to as a servo is used in automobiles to amplify the power steering or brake force applied by the driver. In this form this device is not a true servo, but rather a mechanical amplifier.
In industrial machines, servos are used to perform complex motion.
RC servos RC servos are servos typically employed in industrial robotics, automation, and radio-controlled models. They are also used to provide actuation for various mechanical systems such as the steering of a car, the flaps on a plane, or the rudder of a boat.
RC servos are comprised of a DC motor mechanically linked to a potentiometer. Pulse-width modulation (PWM) signals sent to the servo are translated into position commands by electronics inside the servo. When the servo is commanded to rotate, the DC motor is powered until the potentiometer reaches the value corresponding to the commanded position that it's ordered.
Due to their affordability, reliability, and simplicity of control by modern microprocessors, servo motors are often used in small-scale robotics applications.
The servo is controlled by three wires: ground (black/orange), power (red) and control (brown/other colour) and will move based on the pulses sent over the control wire. This wiring sequence is not true for all servos, for example the S03NXF Std. Servo is wired as brown(negative), red (positive) and orange (signal). The pulses sent over the control wire set the angle of the servo horn. The servo expects a pulse every 20 ms in order to gain correct information about the angle. The width of the servo pulse dictates the range of the servo's angular motion.
A servo pulse of 1.5 ms width will set the servo to its "neutral" position, or 90°. For example a servo pulse of 1.25 ms could set the servo to 0° and a pulse of 1.75 ms could set the servo to 180°. The physical limits and timings of the servo hardware varies between brands and models, but a general servo's angular motion will travel somewhere in the range of 180° - 210° and the neutral position is almost always at 1.5ms.
Servo motors are often powered from nickel-cadmium battery packs common to most RC devices. Voltage ratings vary from product to product, but most servos are operated at 4.8 V Direct current or 6.0 V DC (a 4 or 5 cell battery).
See also
- Synchro (transmitter and receiver motors used in servomechanisms)
- Motion control
External links
- Rane Pro Audio Reference definition of "servo-loop"
- Seattle Robotics Society's "What is a Servo?"
- Community-based project for creating a low-cost digital servo
- Servo Tutorial for Robotics
- Tutorial on how to modify a servo for full 360 degree rotation
Servomechanism - Wikipedia, the free encyclopedia
A servomechanism, or servo is an automatic device which uses error-sensing feedback to correct the performance of a mechanism. The term correctly applies only to systems where the ...
Servomechanism definition of Servomechanism in the Free Online ...
servomechanism, automatic device for the control of a large power output by means of a small power input or for maintaining correct operating conditions in a mechanism.
Definition: servomechanism from Online Medical Dictionary
The Online Medical Dictionary is a searchable dictionary of definitions from medicine, science and technology.
servomechanism - Hutchinson encyclopedia article about servomechanism
servomechanism. Automatic control system used in aircraft, motor cars, and other complex machines. A specific input, such as moving a lever or joystick, causes a specific output ...
servomechanism -- Britannica Online Encyclopedia
Britannica online encyclopedia article on servomechanism: automatic device used to correct the performance of a mechanism by means of an error-sensing feedback. The term ...
servomechanism
Automatic control system used in aircraft, motor cars, and other complex machines ... Tiscali Quicklinks. Please visit our Accessibility Page for a list of the Access Keys you can ...
servomechanism - Definition at Your Dictionary
servo·mecha·nism (sʉr′vō mek ′ ə niz′əm)
servomechanism - Wiktionary
Definition from Wiktionary, a free dictionary
Computerised Management Games: the feedback process and servomechanism ...
1993 Jeremy Hall & Benita Cox Page 1 Computerised Management Games: the feedback process and ...
servomechanism - definition of servomechanism by the Free Online ...
ser·vo·mech·a·nism (sûr v-m k-n z m) n. 1. A feedback system that consists of a sensing element, amplifier, and servomotor, used in the automatic control of a mechanical ...