A Predictive Control Method for Complex Digital Control System

Abstract

The invention discloses a predictive control method for a complex digital control system. The predictive control method includes the following steps: obtaining status switching determining array of all running status in an iterative-computation mode in advance according to dynamic mathematical models and system parameters of the complex digital control system; and then combining a climbing search method and a linear interpolation method, and fast predicting parameter threshold limit value of system operating status switching and precise time points of corresponding control signals generated, and therefore controlled variables of the complex digital control system are enabled to be limited strictly within the range of preset threshold values. Compared with the prior art, the predictive control method for the complex digital control system not only maintains precision of prediction technique based on mathematical model online iterative calculation, but also has fast calculating characteristics based on an interpolation prediction method, and the predictive control method for the complex digital control system is applicable to a complex digital control system which has multiple dynamic change system parameters and is long in time of online iterative calculation.

Description

technical field [0001] The invention belongs to the technical field of digital control, in particular to a predictive control method suitable for complex digital control systems. Background technique [0002] Compared with traditional analog control, modern digital control has the advantages of strong anti-interference ability, large noise tolerance, easy implementation of complex algorithms, and repeatable programming. However, the control signal generation, transmission and execution process in various practical digital control systems inevitably have control signal delay problems, mainly including: A / D sampling conversion delay, control system calculation delay, control signal transmission Delay and execution delay of the controlled system, etc. Due to the existence of various delays, the digital control system cannot control the controlled system in time, which will affect the dynamic characteristics of the controlled system, especially the phase margin of the control l...

AI Technical Summary

Problems solved by technology

In order to achieve high-precision control of the controlled variable, the iterative calculation time required is relatively long, especially in some complex digital control systems with multiple dynamically changing and interrelated system parameters, the online iterative calculation time is different from other system parameters. The sum of the inherent delay time (that is, the total delay time of the system) may exceed the longest freezing coefficient time interval length allowed by the system, or exceed the total running time of the current system operating state, resulting in a decline in the prediction accuracy of the controlled quantity. Especially at the moment before and after the system operation state switching, the existing method cannot accurately determine the time point of the system operation state switching, which will inevitably bring a certain amount of overshoot

Therefore, for this type of complex digital control system, it is difficult to achieve the performance advantages of fast calculation and accurate calculation by using the first method

The second type of method does not require real-time online iterative calculations, and can obtain very fast calculation speeds, but its prediction accuracy is not high, and it is impossible to achieve high-precision control of the controlled quantity

Images