The structure of industrial automation illustrates the operations at various levels. These include the sensor level, the automation control level (unit, process control), the regulatory level, and the enterprise level. The pyramid structure indicates that as information is aggregated, it disintegrates. This means we will find detailed information about specific variables at the bottom. Industrial automation does not mean that all levels are automated in the same way as enterprise-level automation.
The sensor level, also known as the processing layer, uses sensors and actuators to continuously or periodically acquire values of process variables. These act as the eyes and arms of industrial processes. Some of these instruments include pneumatic instruments, smart instruments, and more.
The automation control layer, or control layer, uses industrial control equipment such as PCs, PLCs, and DCS. This layer uses various embedded processors and PID algorithms to control the process.
The supervisory level or SCADA layer acquires a large amount of channel information and stores the data in the system database. It retrieves data from various control devices and displays it on the HMI (Human-Machine Interface). It also issues alarms to indicate the levels of process and control variables. It uses specialized software to acquire data and communication protocols for interaction with field devices.
Enterprise-level execution tasks such as planning, orders and sales, and product planning.
Types of industrial automation
Based on the flexibility and integration of the manufacturing process, automated systems are divided into four basic types. These are described below:
1. Fixed Automation
This sequence of operations is fixed through equipment configuration. It is used for mass production and specialized equipment. Examples of this automated system are automated assembly lines, distillation processes, and machine conveyor lines.
2. Programmable Automation
Here, the operation sequence can be changed by modifying the program. The operation sequence varies depending on the product configuration. New programs can also be input into the programmable equipment of new products. This type of system is used in mass production, steel rolling mills, industrial robots, etc.
3. Flexible automation
This is an extension of programmable automation. It provides greater flexibility in handling product design differences. If the sequence of processes needs to be changed, the operator can issue commands in the form of code within a computer program. Lower-level equipment receives on-site operating instructions without loss of production time. This type of automation is used in the manufacture of multi-functional CNC machine tools, automated guided vehicles, etc.
4. Integrated Automation
In this type, the entire system is fully automated under computer control. From the design process to scheduling, the entire system is fully automated, even if the equipment is handled by robots. This system is used in computer-integrated manufacturing systems.
Industrial automation equipment
Sensors and actuators
Sensors detect various process variables and convert them into electrical or optical signals. These sensors include temperature, pressure, speed, flow, etc. Actuators convert electrical signals into mechanical means to achieve process control. These include relays, magnets, servo motors, etc. Some sensors and actuators have the ability to communicate with industrial field communication buses under intelligent devices.
Sensors detect various process variables and convert them into electrical or optical signals. These sensors include temperature, pressure, speed, flow, etc. Actuators convert electrical signals into mechanical means to achieve process control. These include relays, magnets, servo motors, etc. Some sensors and actuators have the ability to communicate with industrial field communication buses under intelligent devices.
Industrial computers
A Programmable Logic Controller (PLC), also known as an industrial computer, is a device that can be programmed to perform certain control functions. It consists of a CPU or processor, I/O modules (including analog and digital) for connecting various input/output devices, and relay modules. These modules can be fixed or integrated, based on available input expansion modules.
Like PLCs, traditional PCs are used to control processes either online or by changing the program. PLCs come with dedicated software for developing control strategies.
HMI (Human Machine Interface)
Human-machine interfaces (HMIs) provide functions such as displaying information on computer screens and other monitors, recording results in databases, and issuing alarm signals. They utilize technologies such as SCADA (Supervisory Control and Data Acquisition) and other vision-based technologies.
Communication System
In industry, numerous sensors, actuators, control PCs, and other control devices are geographically distributed and interact through multiple data buses. There are three types of buses used in industrial automation: plant bus, process bus, and fieldbus.
