Automatic control (principle) refers to the use of an additional device (called a control device or controller) to make a machine, device or a certain working state or the parameters (ie, the amount being controlled) of a production process (collectively referred to as the controlled object) automatically operate according to a predetermined rule.
Automatic control theory is the technical science to study the common law of automatic control.
In its early development, it was based on the feedback theory and was mainly used for industrial control.
During the World War II, in order to design and manufacture aircraft and marine autopilots, artillery positioning systems, radar tracking systems and other military equipment based on feedback principles, the development of automatic control theory was further promoted and improved.
After the war, a complete automatic control theory system has been formed.
This is the classical control theory based on the transfer function.
It mainly studies the analysis and design of linear constant constant systems with single input and single output.
In the early 1960s, with the introduction of new modern applied mathematics and the application of electronic computers, in order to adapt to the development of aerospace technology, the automatic control theory has entered a new stage – modern control theory.
It mainly studies the optimal control problem of multivariable parameters with high performance and high precision.
The main method used is the state-based state space method.
At present, the theory of automatic control continues to develop.
The theory of intelligent control based on cybernetics, information theory and bionics is going deeper.
Automatic Control System
In order to realize various complicated control tasks, the controlled object and the control device are first connected in a certain way to form an organic whole.
This is an automatic control system.
In the automatic control system, the output of the controlled object, that is, the controlled quantity is a physical quantity that requires strict control.
It can be required to remain at a constant value such as temperature, pressure or flight path.
The control device is the entirety of the relevant mechanism that exerts control on the controlled object.
It can control the controlled object by different principles and methods, but the most basic one is the feedback control system based on the feedback control principle.
Feedback control system
In the feedback control system, the control action exerted by the control device on the controlled device is feedback information taken from the controlled amount, which is used to continuously correct the deviation between the controlled amount and the control amount to realize the control of the controlled amount.
This is the principle of feedback control.