Hysteresis control method based on two-step method

Abstract

The invention provides a hysteresis control method based on a two-step method. The method is characterized by comprising the steps of: building a valve hysteresis model and an industrial process model in an SIMULINK of an MATLAB (Matrix Laboratory); building a main controller based on the PI (Power Inversion) algorithm and a compensating controller based on the two-step method in an OPTO22; and then connecting the MATLAB with the OPTO22 to perform communication, so as to form a feedforward-feedback control module taking the compensating controller as a feedforward controller. The method has the advantages that the defects of the prior art is overcome, the valve hysteresis in a loop is compensated by adopting the advanced control algorithm, the vibration in the industrial control loop, caused by the valve hysteresis, can be effectively eliminated without production halts, the anti-interference performance is high, the realizing mode is simple, and the control effect is good. The method can be applied to the practical industrial process.

Description

technical field [0001] The invention relates to a hysteresis control method based on a two-step method, which is used for compensating and controlling loop oscillation caused by valve hysteresis in industrial processes, and belongs to the technical field of advanced process control. Background technique [0002] Valve hysteresis is an important cause of industrial system oscillation, and it is also one of the most common and difficult problems in valve control. Honeywell Company analyzed the performance of 26,000 PID control loop systems in continuous industrial processes through 2-year investigation and research, and came to the following conclusion: only 1 / 3 of the control loop systems have good performance, while the performance of other control loop systems needs to be improved . Studies have pointed out that a 1% improvement in control system performance or energy efficiency in an industrial process can bring tens or even hundreds of millions of dollars in profit. [...

AI Technical Summary

Problems solved by technology

There are some defects in this method: the Knocker signal is a series of pulse signals, and the size of its three parameters will affect the quality of the compensation; the Knocker compensation has many control parameters and is difficult to set, and it belongs to static compensation. It cannot be changed, and the weakening of the output fluctuation is at the expense of frequent action of the valve, which is not expected in engineering

[0006] The above valve hysteresis control methods all have their own limitations, and their compensation effects are not satisfactory

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