A Study On A PID Control Based On Multi Objective Evolutionary Algorithm And Its Application

Evolutionary algorithm is in the process of natural biological evolution as a template,using the computer simulation technology to complete the evolution,using the global search mechanism to complete a modern optimization algorithm for optimal solution.The algorithm for group search,to avoid the phenomenon of concentration of optimal solution;numerical method shows the global optimization ability and strong robustness of the system,especially for solving the multi-objective optimization problem is particularly prominent.This article launches in Northern Fujian tobacco greenhouse shed PID controller parameters optimal combination problem,comprehensive research and analysis of the multi-objective evolutionary algorithm.And the non dominated sorting genetic algorithm NSGA-II as the optimization algorithm of the system,complete the tobacco seedling shed PID controller and the control system of the overall design.Through the course of development of evolutionary algorithms show the multi-objective optimization technology in the development process,through four kinds of popular evolutionary algorithms,optimization step explanation and final test,the distribution of each kind of algorithm in convergence and comparison,stability and running efficiency on the length of the final selection system the theory and data support optimization algorithm,so as to ensure the successful completion of the optimization design of control system of tobacco seedling shed.As the control field of classical PID control technology,three control factor Kp,Ki,Kd tuning is particularly important for the optimal system.The influence of conventional three parameter tuning technology through long-term development,has a certain point,but with the complexity of industrial control,the conventional setting shows many but the disadvantages of intelligent multiobjective optimization technology with its excellent performance by the common people.This paper is to optimize the cognition of the classical multi-objective optimization algorithm NSGA-II PID parameters,and use simulation technology to simulate the optimization results prove the optimization results fully meet and meet the design requirements.Just to prove the thoughts and methods of theoretical research and practical application is the key.The tobacco seedling in greenhouse as the research object,through careful analysis of characteristics of seedling in greenhouse small environment,regulation and conventional environmental factors in greenhouse,get necessary modeling conditions.Finally the quality to complete the established dynamic mathematical greenhouse greenhouse model of equilibrium principle,and then using the simulation technology of the mathematic model of early verification,confirmation of mathematical modeling accuracy and stability.The final completion of tobacco greenhouse freenhouse PID controller structure design,optimization and complete the PID tuning parameters,complete the verification of greenhouse freenhouse intelligent control system by using Matlab/Sinmlink technique,the result shows that in greenhouse studio PID controller has good effect,meet the design requirements.