Research On Real-time Simulation Of Diesel Technology Engine Combustion Closed-Loop Control

Due to the characteristics of high combustion efficiency,low fuel consumption,and excellent power performance,diesel engines occupy a large market in the marine engine field.However,in traditional diesel engine control method,the engine speed and torque are usually used as closed-loop feedback quantities,which is difficult to solve the problems such as cyclic fluctuations and non-uniformity between cylinders during the operation of the diesel engine.In order to solve this problem,a real-time simulation system for the closed-loop control of diesel combustion is designed in this paper.Setting the combustion status of the diesel engine as the starting point,Intermediate point of combustion CA50,speed and rail pressure are used as feedback for the control system.Under the closed-loop combustion control,it can effectively compensate the deficiency under combustion open-loop control.First,according to the actual working process of a diesel engine,a mathematical theoretical model of a 6K high-pressure common rail diesel engine is established.On the base of the idea of modular modeling,the mathematical model is divided into a high-pressure common rail fuel injection system,a intake and exhaust system,a cylinder,a rotor dynamic system,and a Weber combustion model.In the Weber combustion model,the calculation theory of typical combustion closed-loop feedback parameters is analyzed,and corresponding solutions are given.In view of the requirements of the diesel combustion closed-loop control strategy.Then based on the MATLAB / Simulink real-time simulation platform,according to the calculated mathematical model of the diesel engine,a 6K high-pressure common rail real-time simulation model is established,and the model accuracy was verified.Then,according to the idea of control variate method,the influence of controllable boundary parameters(speed,rail pressure,fuel injection timing,and load)of diesel engines on the combustion closed-loop control feedback parameters(CA5,CA50,IMEP,Pmax)is studied in this paper.The qualitative change regularities between boundary parameters and closed-loop feedback parameters are obtained.Furthermore,a four-factor and four-level Taguchi test is designed to quantify the above regularities.After three repeated tests and normalization,the signal-to-noise ratio,P value,and correlation coefficient of the closed-loop feedback parameters are used to evaluate the influence of the diesel engine boundary parameter on combustion closed-loop control feedback At last,this paper calculates a quantitative index is calculated to describe the degree of influence of the closed-loop feedback parameters of the combustion on each boundary parameterFinally,in the light of the ETAS Lab Car real-time simulation platform,a system between the the real-time simulation model of the diesel engine and the signal interaction interface of the combustion closed-loop control is established,including the real-time monitoring interface.Then followbility between the calculation of CA50 and the target CA50 under combustion closed-loop control is analyzed in the real-time simulation system.Finally,the control effect of combustion closed-loop control is verified.Under the given conditions,CA50 is used as the combustion feedback amount,and the calculated value of 6-cylinder CA50 and IMEP is used as the evaluation data,which significantly reduces the cycle variation and inter-cylinder non-uniformity of the diesel engine.At the same time,the circulating fuel injection volume of the diesel engine is reduced,which improves the economy of the diesel engine.