Research On Model Based Development For High-power Diesel Engine Electronic Control System

The high-power diesel engine control system development is more difficult since the electronic degree of high-power diesel engine is improving and the increasing number of control modules.Now the diesel engine control system development is using Model-Based Design(MBD)as the empirical design has been unable to meet the control quality and functional safety requirements of the control system.So the simulation design and test verification development of the high-power diesel engine control system are carried out based on the MBD principle.Firstly,the model parameters are obtained according to the experimental generally for the control-oriented diesel modelling,but the coupling between the sub-models will decrease the accuracy of the model.So using the parameter identification alone cannot guarantee the accuracy of the overall diesel engine model.Secondly,the PID algorithm has large overshoot and adjustment hysteresis for the idle control.In the experiment,author finds that the overshoot event would lead to a period of zero fuel injection during the adjustment phase,which probability make the high-power diesel engine can’t start normally and enter into the idle operating.Finally,when the diesel engine control strategy application layer is deployed to the controller,the application layer model often generates code and integrates with the basic software layer code in the external compiler.This method has better flexibility but increases the workload and Error-prone.For the requirements of high precision and real-time performance of the control-oriented diesel engine model,a mean value high-power diesel engine model is established.The sub-model parameters fitting methods are given according to the steady state experiment.All the model parameters are solved by the least squares method.For the purpose to ensure the accuracy of the whole diesel engine model,this paper proposes the sub-model outputs are used to replace the experiment inputs of the series sub-model to calibrate the identification parameters of the series sub-model.The model verification result shows that the calibrated diesel engine model has high precision and real-time performance,which can reflect the dynamic characteristics of the diesel engine.The paper designs high-power diesel engine management system based on torque control.The PID algorithm for idle control has problems of adjustment hysteresis,large overshoot and long adjustment time.So this paper proposes a friction torque model-based linear active disturbance rejection control(FTM-LADRC)for idle control,which adding the friction torque model into the linear expansion state observer to improve the disturbance estimation speed and accuracy,using the real-time disturbance compensation and proportional control law to control idle speed.The algorithm is verified by off-line simulation and hardware-in-the-loop experiments.The results show that the FTM-LADRC can reduce overshoot and oscillation and has strong anti-interference ability.This paper studies the integration method of the diesel electronic control software development platform.The integration method includes hardware driver configuration module,hardware driver interface module and hardware driver code.The diesel engine software layer is integrated into Simulink by this integration method,and the hardware channels can be managed in Simulink.Then this paper integrates the traditional hand-written look-up table functions and memory management functions into Simulink in order to meet the requirements of offline data programme and online calibration.