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

Abstract

The invention discloses a PID parameter setting method based on the step response characteristic data of the controlled object. The invention conducts a step response test on the self-balancing controlled object to obtain a step response curve; after sampling and calculating according to the sampling period, the unit step response sequence of the controlled object is determined; the PID parameter optimization interval, optimization parameters and The fitness function, and randomly generate the initial PID parameters; simulate the PID closed-loop control system set value disturbance test, according to the control variable increment formula and the controlled variable change prediction formula, the controlled variable change at each sampling time in the PID tuning time domain is obtained The deviation between the predicted value and set value of the quantity and the controlled quantity; calculate the fitness function corresponding to each group of PID parameters, optimize the PID parameters according to the principle of genetic algorithm, and obtain the best PID control parameters that meet the fitness criterion. The invention does not need to perform model identification on the controlled object, and directly determines the best PID control parameters based on the step test characteristic data of the controlled object by using an 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

Images