The Artificial Immune System And Apply To The Control Of Drum Water Lever Of Boiler

Industrial boiler is a severe nonlinear control object with multi-input, multi-output and multi-loop. Drum water level of boiler is an important indicator for safe and reliable operation of industrial boiler. After many years of theory research, many control strategies have been formed. But because the system has the characters of inertial delay, nonlinearity, time-varying, it is difficult to construct its accurate mathematical model. Traditional control theory can't get the good control performance. This dissertation put forward a immune optimization algorithm and a new-style immune PID controller based on adjustive mechanism of immune system,and they are apply to control system of drun water level of boiler to improve the control quality.This dissertation generalize the knowledge of immunology and the resent main immune algorithms,and analyse the mechanism of earliness convergence of genetic algorithm.Then simulating the antigen identify of organism,immune response and other actual immune behavior, a new artificial immune algorithm is put forward. This dissertation prove the gobal astringency of the algorithm from the theory, and two testing functions are used to test the capability of the algorithm, the result of simulation indicate that the algorithm can improve the earliness convergence and advance the global and local searching ability,indicating the validity of the algorithm.Discussing the adjustive rule of the immune system, abstract and predigest the complicated self-adjustive mechanism of the immune system.Based on the immune recuperative model, a new immune controller is formed. But the simulation of the second order objiect indicate this controller exist steady-state error during the adjustive process. So combining the simple PID controller and the immune controller, a parallel connection immune PID controller is put forward. The simulation of the second order objiect indicate this controller has smaller fluctuatation and short transient process time,so the performance of the immune PID controller is better than the immune controller and the simple PID controller.At last,the essential knowledge of industrial boiler is introduced, the dynamic characteristis and control precept of the drum water level of boiler is detailedly analysed and discussed.Based on this,aiming at the drum water level of boiler ,which flux is 670t/h,the simulation is repectively done based on the simple PID controller, the immune controller and the immune PID controller. The result of simulation indicate the control quality of the immune PID controller is better than the simple PID controller and the immune controller.Combing Artificial Immune Control theory and concrete control object, Adopting the MATLAB software as simulation platform, This dissertation studied the immune control algorithm and immune PID controller on drum water level of boiler, provided a way to solve the system with great delay and nonlinearity, so it has some theory value and application value.