What does a servo control system generally consist of?

The servo control system is a high-precision, high-response speed automatic control system, which is widely used in industrial automation, robotics, aerospace and other fields. This article will introduce the composition of the servo control system in detail, including servo motors, drivers, controllers, sensors, actuators and other parts, as well as their interrelationships and functions.

1. Servo Motor

The servo motor is the core component of the servo control system. It is a high-precision, high-response speed motor that can achieve precise control of the rotor position, speed and acceleration. The working principle of the servo motor is to convert the input electrical signal into mechanical motion and drive the load to move through the motor's rotor.

There are many types of servo motors, such as DC servo motors, AC servo motors, stepper motors, etc. Among them, DC servo motors have the advantages of simple structure, convenient control, and fast response speed, but they have disadvantages such as brush wear and high maintenance cost. AC servo motors have the advantages of high efficiency, high power density, and low maintenance cost, but the control is relatively complex. Stepper motors have the advantages of simple structure, low cost, and convenient control, but their accuracy and response speed are relatively low.

1. Drive

The driver is a key component in the servo control system. It is responsible for receiving the command signal from the controller, converting electrical energy into mechanical energy, and driving the servo motor to move. There are many types of drivers, such as pulse drivers, analog drivers, digital drivers, etc.

Pulse drive is the most common type of drive, which controls the speed and direction of the motor by receiving pulse signals. The advantages of pulse drive are simple control and low cost, but the accuracy and response speed are relatively low.

Analog drives control the speed and direction of the motor by receiving analog signals. They have high accuracy and response speed, but are relatively expensive.

Digital drivers use digital signal processing technology and have the advantages of high precision, high response speed, and high reliability, but they are more expensive.

1. Controller

The controller is the brain of the servo control system. It is responsible for receiving feedback signals from sensors, generating control instructions based on the system's control algorithm, and controlling the movement of the servo motor through the driver. There are many types of controllers, such as PLC, single-chip microcomputer, industrial computer, etc.

PLC (Programmable Logic Controller) is a controller widely used in the field of industrial automation. It has the advantages of simple programming, high reliability and good scalability.

The microcontroller is a small, low-cost, powerful microcontroller suitable for simple servo control systems.

Industrial computer is a high-performance, high-reliability controller suitable for complex servo control systems.

1. sensor

The sensor is the sensing organ of the servo control system. It is responsible for detecting the motion state of the system and feeding back the detected information to the controller. There are many types of sensors, such as encoders, photoelectric sensors, Hall sensors, etc.

An encoder is a high-precision position sensor that can detect the rotor position and speed of a motor. There are many types of encoders, such as incremental encoders, absolute encoders, etc.

The incremental encoder calculates the position and speed of the rotor by detecting the rotation direction and number of steps of the motor rotor. The advantages of the incremental encoder are simple structure and low cost, but there is a cumulative error.

The absolute encoder detects the absolute position of the motor rotor and calculates the rotor position and speed. The advantages of the absolute encoder are high accuracy and no cumulative error, but the cost is relatively high.

Other types of sensors, such as photoelectric sensors and Hall sensors, can be used to detect other states of the system, such as load force, temperature, etc.

1. Actuator

The actuator is the executive component of the servo control system, which is responsible for converting the movement of the motor into actual mechanical movement to achieve load control. There are many types of actuators, such as screws, gears, hydraulic cylinders, etc.

The lead screw is a common actuator that drives the lead screw to rotate through a motor to achieve linear motion of the load. The lead screw has the advantages of simple structure and high precision, but it has disadvantages such as wear and low efficiency.

Gear is a common transmission mechanism, which realizes the rotational motion of the load by driving the gear to rotate through the motor. The advantages of gear are simple structure and high efficiency, but there are disadvantages such as noise and wear.

The hydraulic cylinder is a common actuator that drives the hydraulic pump through a motor to achieve linear or rotary motion of the load. The advantages of the hydraulic cylinder are large torque and fast response speed, but there are disadvantages such as leakage and high maintenance cost.

1. System Software

System software is an important part of the servo control system, which is responsible for implementing the system's control algorithm, data processing, human-computer interaction and other functions. There are many types of system software, such as embedded software, PC software, etc.

Embedded software is a type of software that runs on a controller and has the advantages of high real-time performance, high reliability, and low cost. The development of embedded software needs to consider the limitations of hardware resources and use specific programming languages ​​and development tools.

PC software is a kind of software running on industrial computers, which has the advantages of powerful functions, easy development, and easy expansion. The development of PC software needs to consider the compatibility of the operating system and use common programming languages ​​and development tools.

1. System debugging and maintenance

The debugging and maintenance of the servo control system is an important part of ensuring the normal operation of the system. Debugging includes parameter setting, performance testing, fault diagnosis, etc., which need to be adjusted according to the actual situation of the system.