Industrial control computer is a kind of computer system specially designed for the field of industrial automation control, which is characterized by high performance, high reliability, real-time and scalability. This paper will introduce the architecture of industrial control computer in detail, including its hardware structure, software structure, communication protocols, control strategies and other aspects.
1.Hardware structure
The hardware structure of industrial control computer mainly includes the following parts:
1.1 Central Processing Unit (CPU)
CPU is the core component of industrial control computer, responsible for executing program instructions and processing data. Industrial control computers usually use high-performance, low-power processors, such as ARM, x86 and other architectures.
1.2 Memory
Memory includes RAM (Random Access Memory) and ROM (Read-Only Memory), RAM is used to store programs and data, and ROM is used to store system firmware and startup programs.
1.3 Input/Output Interface
Input/output interfaces are the interfaces for industrial control computers to communicate with external devices, including digital input/output interfaces, analog input/output interfaces, and communication interfaces. The digital input/output interface is used to receive and send switching signals, the analog input/output interface is used to receive and send analog signals, and the communication interface is used to exchange data with other devices.
1.4 Power supply module
The power supply module provides a stable power supply for the industrial control computer, usually using switching power supply or linear power supply.
1.5 Expansion Module
Industrial control computers usually have expansion modules for expanding their functions, such as motion control modules, image processing modules, etc.
1.6 Thermal System
The heat dissipation system is used to dissipate the heat generated by the industrial control computer to ensure the stable operation of the system.
2. Software structure
The software structure of an industrial control computer consists of the following main parts:
2.1 Operating System
The operating system is the basic software of the industrial control computer, which is responsible for managing hardware resources, scheduling tasks, providing programming interfaces and so on. Common industrial control computer operating systems are Linux, VxWorks, QNX and so on.
2.2 Real-time operating system (RTOS)
Real-time operating system is a special operating system with high real-time, high reliability and other characteristics, applicable to the field of industrial control. Common real-time operating systems are FreeRTOS, RT-Thread and so on.
2.3 Programming Languages
Industrial control computers usually support a variety of programming languages, such as C, C++, Python, etc., to meet the programming needs of different scenarios.
2.4 Driver
Driver is the bridge between operating system and hardware devices, responsible for realizing the control and management of hardware devices.
2.5 Application Software
Application software is the software of industrial control computer to realize specific control tasks, including PLC programming software, motion control software, image processing software and so on.
3. Communication protocols
Industrial control computers need to communicate with other devices for data exchange and control. The common communication protocols are:
3.1 Serial communication protocols
Serial communication protocols include RS-232, RS-485, etc., which are suitable for short distance and low rate communication.
3.2 Fieldbus protocols
Fieldbus protocols include Modbus, Profibus, CAN, etc., which are suitable for communication of devices in industrial sites.
3.3 Ethernet communication protocols
Ethernet communication protocols include TCP/IP, UDP, etc., which are suitable for high-speed and long-distance communication.
3.4 Wireless communication protocols
Wireless communication protocols include Wi-Fi, Bluetooth, ZigBee, etc., applicable to wireless communication scenarios.
4. Control strategy
The control strategy of an industrial control computer consists of the following main aspects:
4.1 Open-loop control
Open-loop control means that the controller directly outputs control signals according to the input signals without feedback of the actual output signals. Open-loop control is simple and low cost, but the control accuracy is low.
4.2 Closed-loop control
Closed-loop control means that the controller adjusts the control signal according to the difference between the input signal and the actual output signal. Closed-loop control has high control accuracy and stability.
4.3 PID Control
PID control is a common closed-loop control strategy, which realizes the control of the system through the three parameters of Proportional (P), Integral (I) and Differential (D).
4.4 Fuzzy control
Fuzzy control is a control strategy based on fuzzy logic for systems with uncertainty and ambiguity.
4.5 Neural Network Control
Neural network control is a control strategy based on artificial neural network, which is characterized by self-learning ability and adaptability.
5.Application Fields
Industrial control computers are widely used in various industrial automation fields such as:
5.1 Manufacturing
Industrial control computers are used in the manufacturing industry to realize automated control of production lines and improve production efficiency and product quality.
5.2 Power Industry
Industrial control computers are used in the electric power industry to realize the monitoring and control of the power grid to ensure the stable operation of the power grid.
5.3 Petrochemical industry
Industrial control computers are used in the petrochemical industry to realize the monitoring and control of the production process, improve production efficiency and safety.
5.4 Transportation industry
Industrial control computers are used in the transportation industry to realize the automatic control of traffic signals, subway and other equipment.