In modern automation and control systems, motor drivers are the core components for achieving motion control. Linear stepper motor actuators, DC motors, and servo motors are the most common types of drivers. This article will compare these three motor drivers and analyze their working principles, control methods, speeds, application scenarios, etc. to help engineers and designers choose the most suitable driver.
1. Working Principle
- Linear Stepper Motor Actuator
The stepper motor is an open-loop control motor that controls the position of each step by changing the successive power-on, and the step angle of each step is equal. Its working principle is to allow the motor to run at each step angle by constantly changing the on-off state in thelinear stepper motor actuator circuit.
- DC Motor
The DC motor uses the interaction between the magnetic lines of force formed by the current in the magnet and the magnetic lines of force generated from the permanent magnet to generate a rotational torque. It is the most common type of motor with functions such as starting, accelerating, reversing, and braking.
- Servo Motor
The servo motor is based on the closed-loop control principle. The sensor continuously measures the position, speed, and torque of the motor, and then compares the measured actual value with the set value and performs feedback control to achieve precise position control effect. It has the characteristics of high speed, high precision, and high responsiveness, and is often used in situations where position and speed requirements are high.
2. Control Method
- Linear Stepper Motor Actuator
The control method of stepper motor can be divided into single-step control and micro-step control. Among them, single-step control is to achieve motor rotation by changing two-phase or three-phase current at the same time; micro-step control uses small changes in current to finely control the displacement of the motor.
- DC motor
The control methods of DC motors mainly include voltage control, current control, and pulse width modulation (PWM) control.
- Servo motor
The servo motor adopts closed-loop control. After the digital command is input, the actual position, speed, acceleration and other information of the output will be collected by the sensor, and the closed-loop control of the motor will be realized through the PID control algorithm.
3. Speed Performance
- Linear Stepper Motor Actuator
The speed range of linear stepper motors is usually low, which is suitable for low-speed applications. Generally speaking, the maximum speed of stepper motors is limited by their stepping frequency, which is usually between hundreds and thousands of revolutions per minute (RPM).
- DC motor
The speed range of DC motors is also relatively wide, usually between a few hundred and a few thousand RPM. Speed control can be achieved by adjusting the voltage.
- Servo motor
Servo motors have a wide speed range and can reach very high speeds, usually exceeding 3000 RPM or even higher, which is suitable for fast dynamic applications.
4. Scope of Application
- Linear Stepper Motor Actuator
Stepper motors are suitable for applications that require precise positioning, such as digital cameras, 3D printers, and precision instruments.
- DC motor
DC motors are suitable for general industrial applications, such as fans, pumps, cutting machines, and conveyor systems.
- Servo motors
Servo motors are suitable for high-precision, high-performance applications, such as intelligent robots, CNC machine tools, and aerospace fields.
Linear Stepper Motor Drives, Servo Motors VS. DC Motors
| Characteristics | Linear stepper motor actuator | Servo motor actuator | DC motor driver |
| Control Accuracy | High precision, suitable for open-loop control | Extremely high precision, closed-loop control | Low precision, suitable for open-loop control |
| Speed Performance | Good low speed performance, poor high speed performance | Excellent high speed performance, stable torque in full speed range | Wide speed range, but average high speed performance |
| Applicable scenarios | Low-speed, high-precision positioning (such as 3D printers, CNC machine tools) | High-precision, high-speed, high-dynamic response (such as robots, automation equipment) | Low-cost, simple speed regulation (such as fans, conveyor belts) |
Summary
Linear stepper motor actuators, servo motors, and DC motors each have unique advantages and disadvantages and are suitable for different application requirements. When choosing a suitable drive, designers should consider these factors comprehensively based on specific application requirements, performance requirements, and budget constraints to ensure the best performance and efficiency of the system.