Oct 20, 2011

Understanding the Servo & Motion Basics

Servo systems are used widely to control the position and velocity or torque of the load.Accurate and Precise motion of machines is achieved with the help of servo systems. We have already discussed about the Servo Fundamentals in our earlier post. Today we will try to understand the fundamentals of Servo and Motion control for the beginners. First of all we should understand that what do we mean by a Servo System? What a Servo System consists of and What functionality it gives , these will be the questions which we will be discussing in this post.

Basic Fundamental of Servo Control and Motion :-
A Servo system consists of a Servo drive and Servo Motor. These systems are used where precise positional move is required,where there is frequent starting and stopping and also where there is very frequent change in direction of motion. Servo Motion has gained the attention from all over the world because of its frequent precise movement capabilities.Servo Control is a closed loop system , where there is feedback form the load side to the controller about the present condition.
A servo responds to the feedback signal in few milliseconds and the desired correction is done. Servo Control generally used for Velocity and Position control. But in majority of applications both the control are needed. There are applications where it is desired that the positional move should occur within a time frame for increased productivity , so in all such applications both velocity and position control are needed. Industries demanding such application include textile, medical and packaging.

Servo Control Terminology and Parts of Servo Motion System :-
Servo Motor - It is the section of servo control which drives the load or it provides motion to load. Servo Motor may be connected via Gearbox with load. The Servo Motor have very fast response and usually low inertia.

Servo Control - It is the part of system which controls the amount of voltage and current given to motor i.e it controls the amount of power supplied to the motor. The amount of power supplied to motor decides the motion i.e if more voltage given then motor moves fast and so on. The servo control moves the motor to a specific position with desired speed and continuously monitors the feedback signal to monitor that desired motion is achieved or not , if not then it changes the signal to correct it and all these things happen in a matter of milliseconds.

Feedback - A feedback device (encoder, resolver)is located inside the motor and gives signal to servo control about the current position speed etc .

Power Supply - It is used to convert the AC Supply to DC Supply.

Motion Controller for Accurate Positioning :-
The servo Drive only controls the speed or velocity of motor. SO we need a controller which issue the command for the movement , so a controller is needed and this controller is programmable and we can program it according to our application requirement. See the Below block diagram for a better understanding.

A Motion controller is the heart of the system , i.e it monitors the position and issue accurate commands for the desired motion to take place. User can program it according to application demand and moreover we can have multiple servo control with the single controller. User interface can be a PC or HMI.
We hope that after reading this article you must be familiar with the servo basics and in further articles we will discuss more about the Servo and Motion , till then you can subscribe to get all latest updates.
If you have any doubts then you can contact us through the comment section.
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1 comment:

  1. Welcome Engineers ..

    Hope u all understand Servo Basics after reading this Article.

    Learn--->> Share --->> Innovate


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