Study On Speed Control Algorithm Of Diesel Engine Based On Auto Disturbance Rejection Controller

The controller is the core of the diesel engine.It is the main technology to improve the speed performance of diesel engine set.It controls the injection volume of fuel injection pump by controlling the rack position of electromagnetic actuator,so as to control the speed of diesel engine.At present,most of the speed control strategies are based on double closed loop control scheme of position loop and speed loop.A common strategy in engineering application is double loop control using conventional PID control.This method is simple and effective,but it also has its defects.Because the diesel engine is nonlinear and time-varying,And the ordinary PID can't automatically adjust the parameters.Therefore,we need to carry forward the essence of PID control technology and draw on modern control theory knowledge on the basis of traditional PID,and propose a new control algorithm to get better control effect.The ADRC algorithm improves the performance of the traditional PID controller by introducing the "arranging the transition process" and "extracting differential signals" reasonably on the basis of the traditional PID framework,and adopting the nonlinear combination way of the error signals.ADRC is constructed by tracking differentiator(TD),extended state observer(ESO)and nonlinear state error feedback(NLSEF).It is more suitable for the characteristics of the nonlinear strength of the diesel engine.In order to better verify the superiority of the algorithm,we use tracking differentiator(TD)to improve the conventional PID,and verify the three algorithms of conventional PID,improved PID and ADRC respectively.In order to verify that the ADRC can be combined with other advanced algorithms,the auto disturbance rejection controller(ADRC)and the sliding mode controller are combined to verify.In this paper,the research object is selected as D6114 type diesel generator set,the mathematical modeling is carried out in Simulink,and the modeling method adopts the average value scheme.In the way of Matlab-function programming,the custom module is combined with the original Simulink module to build the controller model.The controller model under five different control algorithms is set up respectively.First,off-line simulation verification is carried out to verify the feasibility of the algorithm.Then the semi physical simulation is completed step by step,and the controller model under the five control algorithms is introduced into the dSPACE,respectively.The diesel engine body is modeled by D6114 average value and added disturbance to the model.The actuator is in real object,and the reliability of ADRC is further verified by semi physical simulation debugging.In this paper,the DS1103 single board computer of dSPACE company is used as the controller to complete the experimental verification.The experimental verification of the traditional PID,the improved PID and the auto disturbance rejection controller is completed respectively in the starting,stable operation and the dynamic running stage of the load and subtraction.The results show that the steady-state and transient speed control effects of the controller have been greatly improved by using the differential tracker(TD)to improve the PID.The control effect of the self disturbance rejection controller based on the improved PID is better,and it can meet the control precision requirements of the second level power station.Verify the combination of auto disturbance rejection and sliding mode controller.It is found that the combination of ADRC and sliding mode controller can effectively reduce chattering and improve the transient speed regulation effect.