Automatic control technology is one of the fastest growing and most influential technologies in the 20th century and one of the most important high technologies in the 21st century.
Today, technology, production, military, management, and life are all inseparable from automatic control technology.
By definition, automatic control technology is the technical implementation of cybernetics.
It is through an automatic control system with certain control functions to complete certain control tasks, to ensure that a certain process is performed as expected, or to achieve a certain target.
From the perspective of control, the automatic control system has two types which are closed loop and open loop.
Closed loop control is also (negative) feedback control.
The principle is similar to the purpose of human and animal behavior.
The system consists of a sensor (equivalent to the senses), a control device (equivalent to the brain and nerves), and an actuator (equivalent to the hands and legs and muscles).
The sensor detects the state information (output) of the controlled object and converts it into a physical (electrical) signal to the control device.
The control device compares the deviation of the current state (output amount) of the controlled object with the desired state (a given amount), generates a control signal, and drives the controlled object to move by the actuator to make the motion state close to the desired state.
In practice, closed-loop (feedback) control methods are diverse and applied to different fields and aspects.
Currently widely used and rapidly developed are:
- Best control
- Adaptive Control
- Expert control (ie establishing control rules and procedures based on expert knowledge base)
- Fuzzy control
- Fault tolerant control
- Intelligent control
Open loop control
Open loop control is also called program control.
This is to send signals to control objects in turn according to a predetermined procedure.
According to the conditions generated by the signal, open loop control include time limit control, sequence control, condition control.
Since the 1980s, programmable controllers produced using microelectronics have been widely used in industrial control (elevators, multi-step machine tools, waterworks).
Of course, some complex systems or processes often use multiple control types and multiple types of control programs.
With the development of electronic computer technology and other high technologies, the level of automatic control technology is getting higher and higher, the application is more and more extensive, and the role is becoming more and more important.
Especially in the fields of automation of production processes, factory automation, robotics, integrated management engineering, aerospace engineering, military technology, etc., automatic control technology plays a key role.