Structure self-adaptive fractional order proportional integral or proportional differential controller design method

Abstract

The invention discloses a structure self-adaptive fractional order proportional integral or proportional differential controller design method. The method comprises the following steps: firstly, through inputting a sinusoidal signal and a capture output signal to a controlled object, acquiring an amplitude value and a phase of an open-loop system of the controlled object in appointed grain crossover frequency; through inputting another sinusoidal signal and the capture output signal to the controlled object, acquiring a phase frequency curve slope of the controlled object; substituting three obtained experimental data into a constructed relational expression between an amplitude value, a phase and a phase slope of a controlled object transfer function and three parameters of a fractional order controller, resolving to obtain the three parameters of the fractional order controller, wherein the three parameters comprise a proportionality coefficient, a time constant and a calculus order,and the calculus order determines whether the fractional order controller is a proportional integral or proportional differential structure. The method is not dependent of a mathematic model of the controlled object, and capable of, through a self-adjusting process of the controller parameters, automatically calculating the controller parameters, and determining the controller structure.

Description

technical field [0001] The invention relates to the field of automation, in particular to a design method of a structure-adaptive fractional-order proportional-integral or proportional-derivative controller. Background technique [0002] In closed-loop controllers in industrial processes, the simple proportional-integral (PI) control or proportional-derivative (PD) control methods are widely used. As industrial processes have higher and higher requirements for control performance, the traditional integer-order PI or PD control has been difficult to meet the requirements. It forces engineers and technicians to look for a control method with superior performance, but also to ensure that the control method is simple and easy to use, which is convenient for engineering implementation. [0003] The theory of fractional calculus has a history of more than 300 years. After people's continuous improvement of its theory and great progress of science and technology in recent years, ...

AI Technical Summary

Problems solved by technology

In practical applications, especially some large-scale industrial processes with subsystem interaction, their structures and operating mechanisms are complex, and it is usually difficult to obtain their accurate dynamic characteristics and prior knowledge, and it is impossible to determine whether to use PI control or PD control, and the controller The parameters are also difficult to determine, and a large number of experiments are required for trial and error, which brings great difficulties to the structural design of the controller and increases the complexity of the controller design.

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