CPA method in chemical process with viscosity of actuated valve

Abstract

The invention discloses a CPA (Control Performance Assessment) method in the chemical process with viscosity of an actuated valve. The method comprises the steps as follows: 1, collecting output observed values from the moment t-1 to the moment t-p in a control loop of which the performance is to be assessed to obtain a sequence y(t), and collecting the output observed value yt at the moment t; 2,adopting an RBF (Radial Basis Function) neural network to perform nonlinear time sequence modeling on the y(t) to obtain an initial predicted value; 3, building the sequence, performing Gaussian / linear test, calculating the network evaluation index EHT and outputting the predicted value till the EHT reaches the set value; 4, circulating the operation steps 2 and 3, and outputting the optimal value of Spread and the optimal output predicted value; and 5, building the sequence, modeling and solving to obtain a minimum variance performance lower limit of the control loop to be assessed, and utilizing the minimum variance performance lower limit to assess performance of the control loop. The CPA method is suitable for control loops with the viscosity of the actuated valve, and can accurately assess the control performance reference in the chemical process.

Description

technical field [0001] The invention relates to the field of control performance evaluation of industrial control systems such as petrochemical industry, in particular to a control performance evaluation method of a chemical process with a viscous characteristic of an actuator valve. Background technique [0002] Industrial sites usually contain many control loops, and inspection and maintenance of these control loops is a tricky and arduous task in the operation of the production process. According to the survey, there are performance degradation problems in more than 60% of industrial controllers. How to use the daily operation data to measure the performance of the control loop, so as to optimize its settings to obtain more economic benefits, has become a hot spot for many scholars. In recent years, the research on performance monitoring and evaluation of control loops has become a topic of widespread concern in the field of industrial control. [0003] Control performa...

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Problems solved by technology

[0010] The performance evaluation method established based on the above two ideas has limitations in application: First, the method based on the spline smoothing function cannot completely remove the nonlinearity of the process output due to the interpolation function, resulting in performance evaluation results that are greater than the real value, and The error of the sticking characteristic of the actuator valve increases further; secondly, the method of searching for the equilibrium state of the actuator valve is more suitable for the control loop with a long enough stagnation stage of the actuator valve, and this control loop is the most important in practical industrial applications. hard to guarantee

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