Servo motor

A servo motor is a closed-loop system that enables precise control of mechanical movement in automatic control systems. These motors allow for angular or linear position, speed, and acceleration control, maintaining the target position with high accuracy thanks to a feedback mechanism. They are widely used in industrial robots, RC (radio-controlled) vehicles, CNC machines, and automation systems.

Servo Motor Internal Structure (Created with Artificial Intelligence)

History

The foundation of servo motors dates back to hydraulic systems in the 19th century. The first electric servo motor was developed in the 1920s by John C. Stevens. During World War II, their use expanded in artillery systems and radar antennas. With the advancement of microprocessor technology in the 1970s, modern servo motors became standard in industrial production lines.

Components

Motor

Feedback Sensor

Control Circuit

Gearbox

Working Principle

Servo motors are controlled via PWM (Pulse Width Modulation) signals. The control signal consists of electrical pulses repeated at specific intervals. The pulse width determines the motor's target position:

Example PWM Values

The motor processes the incoming signal every 20 ms. The feedback sensor continuously measures the shaft's position. The control circuit moves the motor until the difference (error signal) between the target and current position is minimized. This closed-loop system ensures precision and stability.

Types of Servo Motors

Positional Rotation Servo

Continuous Rotation Servo

Linear Servo

AC and DC Servo Motors

Applications

• Robotics: Controlling joint movements in robotic arms.
• Aviation: Flap and landing gear control in UAVs (drones).
• Automation: Packaging machines, 3D printers, and CNC machines.
• Consumer Electronics: Camera autofocus systems and solar panel sun tracking.

Advantages and Disadvantages