In the world of modern industry, accuracy and precision are key to production efficiencyServo Motor thus becomes the core of high-precision automated systems, with the ability to control position, speed, and torque accurately.
What is a Servo Motor?
A Servo Motor is a special motor that can control movement with high precision, whether it's position, speed, or rotation angle. It relies on feedback control as the key mechanism, unlike regular motors which simply spin when powered. However, servo motors can continuously monitor and adjust their own operation, making Servo Motor a crucial component in high-precision automated systems.
The special feature of servo motors lies in their ability to control three main aspects:
- Position Control - Can precisely set the servo motor to rotate and stop at a specific degree or position.
- Speed Control - Adjusts the rotation speed of the Servo Motor as needed.
- Torque Control - Precisely sets the torque for the servo motor's rotation.
How a Servo Motor Works
A servo motor operates on a basic principle similar to that of a three-phase synchronous motor. When electrical current is supplied to the stator windings, a rotating magnetic field is generated at a constant speed. The rotor, which is a permanent magnet, is pulled along with this rotation. However, what makes a Servo Motor special compared to regular motors is its feedback and control system orhow servo motors work.
A servo motor consists of four main components:
- DC Motor (Direct Current Motor) - responsible for the rotational movement
- Gear System - helps adjust the speed and torque of the servo motor
- Encoder - responsible for detecting and sending signals about the position of the Servo Motor. Learn more about Encoder
- Control Electronics - processes data and adjusts the operation of the servo motor to meet requirements
When we command a servo motor to operate, the control circuit receives the command and calculates how the motor should rotate to achieve the desired position. While the Servo Motor is rotating, the encoder continuously monitors its position and sends data back to the control circuit in real-time, allowing the Controller Servo to immediately fine-tune its operation. If the servo motor rotates too fast or too slow, the circuit will adjust the power accordingly.
Types of Servo Motors
In the world of industry, we can categorize Servo Motors into the following main types:
1. By Power Supply Type
- DC Servo Motor - Suitable for applications requiring quick response and was popular in older machinery.
- AC Servo Motor - Suitable for high-power applications, currently gaining popularity due to advancements in transistor technology.
2. By Construction Type
- Brush-type Servo Motor - Has a permanent magnet stator and uses brushes with commutators to supply current to the windings.
- Brushless Servo Motor - The rotor is a permanent magnet, without brushes, making it more durable and requiring less maintenance.
3. By Angle of Rotation
- 180 Degree Servo Motor - Rotates up to 180 degrees (some models may rotate up to approximately 200 degrees), suitable for applications requiring precise angle control.
- 360 Degree Servo Motor - Rotates continuously, often modified to rotate in both directions. Used in applications requiring continuous rotation such as wheels.
Components for Using Servo Motors
To use a Servo Motor efficiently, it is necessary to have all three main components:
1. Controller (Controller Servo)
The controller acts as the brain of the servo motor system, receiving commands from the user regarding how the Servo Motor should operate, whether it's setting speed, position, or torque. It then sends these commands to the servo driver. Selecting an appropriate Controller Servo will help ensure that the system operates efficiently.
2. Servo Driver
The servo driver acts as a mediator between the controller and the servo motor, receiving commands from the Controller Servo and converting them into appropriate signals to control the Servo Motor. It also adjusts various settings such as speed, torque, and position to suit the required work, ensuring that the servo motor operates accurately and efficiently.
3. Servo Motor
The servo motor drives various equipment according to commands received from the servo driver. During operation, the Servo Motor has an encoder that detects position and speed and sends this information back to the Controller Servo via the driver, allowing the system to fine-tune the performance of the servo motor accurately and in real-time.
Servo Motor Control
PWM Signal Control
General Servo Motors receive PWM (Pulse Width Modulation) control signals at a frequency of 50Hz, with three wires:
- Signal Wire - Orange or white color, used to receive control signals for the servo motor
- VCC (Power Supply) - Red color, used to supply 5V power to the Servo Motor
- GND (Ground) - Brown or black color, used for grounding the servo motor
The angle of rotation of a Servo Motor can be controlled by adjusting the width of positive pulses:
- At 0 degrees - Use a positive pulse width of approximately 0.5-1 milliseconds
- At 90 degrees - Use a positive pulse width of approximately 1.5 milliseconds
- At 180 degrees - Use a positive pulse width of approximately 2-2.5 milliseconds
For 360-degree Servo Motors, control is done by setting speed and direction:
- 90 degrees - The servo motor stops
- 0-89 degrees - Servo Motor rotates clockwise (the closer to 0, the faster it rotates)
- 91-180 degrees - The servo motor rotates counterclockwise (the closer to 180, the faster it rotates)
Usage with Arduino
For Arduino developers, controlling servo motors is easy using the Servo.h library, which is a software-based Controller Servo with functions that help in conveniently controlling Servo Motors:
- attach() - Specify the signal pin to which the servo motor is connected to the board
- write() - Control the degree position of the Servo Motor
- writeMicroseconds() - Control by directly setting pulse width
- read() - Read the latest degree value sent to the servo motor
- attached() - Check if the Servo Motor is connected or not
- detach() - Disconnect the servo motor
Selecting the Right Servo Motor
When choosing a suitable Servo Motor for your work, consider the following factors:
Torque (Torque)
Torque indicates the power of the servo motor. The higher the value, the more powerful the Servo Motor is, making it suitable for lifting or moving heavy objects. Selecting a servo motor with appropriate torque will help your system work efficiently.
Rotation Speed (Speed)
This indicates how quickly the Servo Motor can change position. If the job requires quick response, choose a servo motor with high speed. The performance of the Controller Servo will be more efficient when selecting a Servo Motor that has an appropriate speed for the work.
Shaft Material
There are plastic and metal options. For heavy-duty jobs requiring continuous use over long periods, choose a servo motor with a metal shaft which is more durable. In some cases where heat resistance is required, you may need to consider using Immersion Heater as well.
Shaft Size
Each model of Servo Motor has a different shaft size. Choose one that fits the equipment you will be using it with. Selecting an appropriate shaft size will help the servo motor work efficiently and have a longer lifespan.
Power Supply
Servo Motors consume relatively high electrical current, especially for larger models with high torque. Therefore, prepare an adequate power supply such as a 5V adapter or switching 5V power supply. An appropriate power supply will help the Controller Servo work at full efficiency.
Usage of Servo Motors in Industries
Servo motors are used across various industries that require high precision, such as:
- Aerospace Industry - Used in automatic flight control systems and satellite antenna control systems.
- Navigational Systems - Used in the automatic navigation systems of ships, aircrafts, and weapon control systems.
- Electronic Equipment - Used in cameras to adjust lens focus and hard disks for data head positioning.
- Robots - Used to control the movement of robots both in industrial and service applications.
- Automated Machinery - Used in high-precision production systems.
Comprehensive Servo Motor Services from SCMA
SCMA Company Limited is a leading provider of measurement tools and automation solutions in the industry. With over 40 years of experience, we do more than just sell servo motors; we are your full-service partners for Servo Motor systems and automatic control solutions. You can find out more at Our Services:
Custom Installation and Tuning of Servo Motor Systems
We have a team of expert engineers ready to consult, design, and install the right servo motors for your business needs. Whether it's basic systems or highly complex ones, we can customize Controller Servos to fit specific applications perfectly.
Analysis and Efficiency Improvement of Existing Systems
For businesses with existing systems, we can analyze them and help improve their efficiency by applying modern servo motor technology. This reduces costs and increases productivity. Upgrading Controller Servos to the latest models will enhance system performance.
After-Sales Support and Maintenance Services
Our support team is available 24/7 for troubleshooting servo motor issues, preventive maintenance, and keeping systems up-to-date. This ensures your servo motor system runs continuously at peak efficiency.
In-Depth Technical Training for Your Team
We have a seminar room of 600 sqm available to provide in-depth training on the use and maintenance of Servo Motors for your team. We offer both free and In-house Training sessions tailored to specific groups, so you can fully utilize servo motors and Controller Servos.
Summary
Servo motors are crucial components in industrial automation systems that require high precision. With the ability to control position, speed, and torque with great detail, the operation of a Servo Motor relies on both the Servo Controller and the servo driver. The selection of an appropriate servo motor depends on several factors including torque, speed, and material of the rotating shaft. SCMA Company Limited is ready to be your partner in helping your business fully leverage servo motor technology with comprehensive services that truly meet your needs.
Frequently Asked Questions
What does a Servo Motor do?
A servo motor precisely controls position and rotation angle, consisting of a motor, gear reduction set, and control circuit in one unit. It is connected through three wires: signal (Signal), power supply (VCC), and ground (GND). This allows for precise positioning, making it suitable for applications requiring high precision control.
How do Inverters differ from Servos?
Servo drivers respond quickly within a few milliseconds and are ideal for tasks that require rapid changes and highly accurate control. On the other hand, inverters have slower response rates and are suitable for applications that do not require high precision such as general motor speed control.
How does a Servo Motor differ from a DC Motor?
A servo motor integrates a DC Motor with a control circuit and position sensor. The main difference is that a servo motor can detect its own position and accurately change to the specified angle, while a standard DC Motor only controls direction and speed of rotation. Therefore, servo motors are commonly used in applications requiring precise angular control such as rudder control on model boats.
