Research On Hardware-in-loop Technology For Feedback Control Of Marine Engines Based On In-Cylinder Pressure

With the development of cylinder pressure sensor technology,the reduction of cost and the demand for high efficiency,reliability and low emission,the application of feedback control technology based on in-cylinder pressure is begun to explore on marine diesel engines.However,feedback control technology based on in-cylinder pressure on marine engines is still in the stage of research and development,and a large number of experiments and scientific exploration are needed.The rapid prototyping and hardware in the loop simulation platform can provide development platform and test environment for the research of feedback control system based on in-cylinder pressure,and it can reduce the cost and risk in experiments as well.Taking the 6L16/24-CR marine diesel engine as the research object,a feedback controller rapid prototyping based on in-cylinder pressure with independent intellectual property rights is developed;A hardware in the loop simulation platform is built to verify the hardware and software of rapid prototyping.The in-cylinder feedback control rapid prototyping for marine engines is developed based on NI cRIO-9082 and LabVIEW software.Taking IMEP and CA50 as feedback variables,injection pulse width and timing as control variables,a cylinder pressure feedback control strategy is designed,which is composed of a piston location management module and a cylinder pressure signal acquisition and processing module developed specially to extract feedback variables.The hardware in the loop simulation platform is mainly composed of virtual engine,LabCAR system hardware and rapid prototyping.Virtual engine is an engine model built by simulation modeling and can simulate the running state of the engine in real time.It is an important part of hardware in the loop simulation platform.Refined fuel injection,combustion,turbocharger module,the 6L16/24-CR diesel engine simulation model severed as feedback control is established with cyclic fluctuation simulation function and verified on the AVL Cruise M software platform.The results show that the real-time and accuracy requirements of hardware in the loop platform are met.A software in the loop simulation platform is developed by the verification engine real-time model in-cylinder feedback variables,control strategy and injection control variables.According to the actual situation of the diesel engine,then a program is developed and implemented based on this platform.The results show that the starting time,stable time,steady and transient speed regulation under start,idle speed,load ascent and reduction conditions meet the requirements of the classification society.At the same time,the coefficient of variation of CA50 and IMEP were reduced about 99%,it can significantly improve the cylinder uniformity.The signal connections between a virtual engine and cylinder pressure feedback control rapid prototyping are built based on ETAS software and hardware system,and real-time monitoring interfaces of PC are achieved at the end of this platform development.The hardware function and software control logic of the rapid prototyping is tested at this platform.The results show that the cylinder pressure feedback control strategy is feasible,function of each module is normal,and the maximum torque ripple can be reduced by 1.08%.This research is carried out on the rapid prototyping design and feedback controller development based on cylinder pressure,real-time simulation engine modeling,development and test of software in the loop simulation platform and test hardware in the loop simulation platform in this paper.The research results can provide a basic platform for pressure feedback control strategy validation,and It also can be used to debug and calibrate marine engine control system.