Research On Marine Diesel Engine Speed Control Based On Neural Network Self-tuning PID

As the earliest developed control strategy, PID (PID-Proportion Integration Differentiation) control algorithm is still widely used in practical engineering applications today. PID control has great advantages of simple design process, high reliability, good stability, zero steady-state error, clear physical meaning of each parameter and easy to be implemented in engineering. However, for controlled object which is nonlinear and time-varying, the system performance and robustness is poor. In order to improve the control effect, the PID parameters must be re-adjusted.Along with the progress of society, the development of science and technology and the improvement of engineering technical level, the controlled object and production process are more complex than ever before. For control systems in engineering, the system parameters will change with system run-time accumulation and changes of operation condition. For the conventional PID controller, it’s the only way to adjust PID parameters frequently to meet the needs of the engineering. Therefore, the PID controller which is designed aim at time-varying system with features of nonlinearity. Satisfying performance of system is hard to be obtained. It is necessary to explore an intelligent control method which can adjust the controller parameters automatically, and excellent control effect can remain be achieved when the parameters and operation conditions of system change.At present, mechanical governor and electronic governor equipped with conventional PID controller are mainly used in diesel engine speed regulation system. The former has high reliability, but the regulation accuracy is low; the latter has better adaptability, but considering the nonlinearity of diesel engine, and variation of model parameters because of rotational speed, system load and working time accumulate, it’s hard for electronic governor keep satisfactory control effect.Based on current neural network research, combined with PID control strategy, an intelligent PID controller is presented in this thesis and applied in diesel engine speed control. The simulation results show that:Compared with the conventional PID controller, the intelligent PID controller designed in this paper can achieve better control effect when operation condition of the diesel engine change, which verities the controller has good adaptability.