PID parameter setting method based on step response characteristic data of controlled object

Abstract

The invention discloses a PID parameter setting method based on step response characteristic data of a controlled object. The method comprises the following steps: performing a step response test on aself-balancing controlled object to obtain a step response curve; after sampling and calculating according to a sampling period, determining a unit step response sequence of the controlled object; setting a PID parameter optimization interval, an optimization parameter and a fitness function, and randomly generating an initial PID parameter; simulating a PID closed-loop control system set value disturbance test, and according to a control quantity increment formula and a controlled quantity change quantity prediction formula, obtaining a predicted value of the controlled quantity change quantity at each sampling moment in a PID tuning time domain and a deviation value between the set value and the controlled quantity; and calculating fitness functions corresponding to each group of PID parameters, and optimizing the PID parameters according to a genetic algorithm principle to obtain an optimal PID control parameter meeting a fitness criterion. Model identification does not need to becarried out on the controlled object, and the optimal PID control parameter is determined directly based on the step test characteristic data of the controlled object by using the optimization algorithm.

Description

technical field [0001] The invention belongs to the technical field of automatic control, and more specifically relates to a PID parameter setting method based on step response characteristic data of a controlled object in an automatic control system. Background technique [0002] Proportion-integral-derivative (PID) controllers have many advantages such as simple structure, easy implementation, and good robustness, and are widely used in industrial process automation systems. In engineering applications, if the PID parameters are unreasonable, not only the dynamic performance of the automation system is poor, but also may require frequent intervention by the operator, and even cause the automation system to exit the automatic control state. The PID controller has only three adjustable parameters, but it is not easy to obtain the best combination of parameters. At present, technicians mainly use experience or theoretical methods to adjust the PID parameters. [0003] Experi...

AI Technical Summary

Problems solved by technology

However, whether it is object model identification or PID parameter optimization, technicians are required to have relatively high professional theoretical knowledge and engineering practice experience; After that, it takes a lot of time for offline model identification, and it is impossible to tune PID parameters online

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