Servo Motor for Positioning Accuracy

Servo motor is motor that can perform the rotation with high accuracy where the servo has a feedback sensor (encoder) for correction of mechanical rotation.

SMARTSTEP servo motor by Omron

Servo motor is very different from the induction motor. Induction motor is controlled simply by a magnetic contactor to disconnect the power supply, while the servo motor is controlled with a special driver that regulates rotation so that the mechanical movement, speed, acceleration, decceleration and other parameters can be controlled entirely accurately.
There are a lot of servomotor maker used on automation such as Siemans, Omron, Allan Bradley, Mitsubishi, Fuji and so on. Each has its own character so that for each brand between the motor and servo driver must be matched with their own brand. For example Omron servo can not be paired with Mitsubishi servo driver. As an important note, of course, quite different from the servo motor with induction motor in which all the induction motor can be paired with all brands of inverter.
Back to the discussion of servo motor. To be running a servo driver and motor must be controlled by pulse train generator, or often called positioning unit. Positioning unit will issued a pulse wave, which is parameter number of pulse and speed (frequency) will determine how much rotation, direction and rotation speed. The larger the pulse the more rotation. Likewise for the speed parameter.
The following image is an example application of the arrangement of the connection between servo motor and positioning unit. From the figure shows that the positioning unit issued a pulse which controls servo driver.

Example of connection of
servo motor and positioning unit by Omron

In the application, servo motor is widely used as rotation motion or converted into linear motion. One of common application is of linear linear motion on robot which has high accuracy and smooth motion.The following image is an example of servo motors in robot Yamaha. Rotation of motor is converted into forward-return through the screw.

Robot F14H by Yamaha