Fractional order PID (proportion integration differentiation) control method of single input single output time lag system

Abstract

The invention discloses a fractional order PID (proportion integration differentiation) control method of a single input single output time lag system. The method comprises the following steps: 1) carrying out automatic relay feedback identification on a controlled object by utilizing an industrial control system to obtain a transfer function model of the controlled object; 2) appropriately selecting integration order Lambda and differentiation order Mu for parameters of a controller, wherein Lambda is more than 0 and less than 2, and Mu is more than 0 and less than 2; 3) traversing a control parameter and calculating stable region border lines of another two control parameters in a two-dimensional plane based on the give Lambda and Mu; 4) judging the side of the border line having less unstable poles to determine a stable region of the control parameters from the regions split by the border lines; and 5) creating a fractional order PID controller monitoring module, selecting control parameters by mouse click in a control parameter stable region on a graphical interface, and ensuring the control parameters to accord with preset performance index values. The invention is applicable to a single input single output system with any transfer function model.

Description

technical field [0001] The invention relates to a method used in the technical field of industrial process control, in particular to a fractional-order PID control method for a single-input and single-output time-delay system. Background technique [0002] PID controller is widely used in actual industrial process control systems such as papermaking, metallurgy, chemical industry and machinery because of its simple structure, strong versatility and easy operation. The actual operation experience and theoretical analysis have fully proved that the PID controller can obtain satisfactory control effects on the spot when controlling many industrial objects. The derivative and integral terms of conventional PID controllers are of integer order, and the controlled objects are also of integer order. However, many systems in reality belong to fractional order. Using integer order models to describe such systems will cause large errors between the mathematical model and the actual s...

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Problems solved by technology

For fractional PI λ D. μ There are still few studies on the stability of controllers. The existing research methods are to give the stable domain of control parameters in the form of diagrams, and it is impossible to realize the parameterization of the controller in an analytical way. The integral order and differential order of the controller The relationship with the control domain boundary is ambiguous; for the existing fractional PI λ D. μ In the controller design method, only one performance index can be considered in the design process, and it is impossible to intuitively analyze the design

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