Development Of Virtual Lab For Internal Combustion Engine

The virtual lab of internal combustion engine is a comprehensive teaching experiment platform for internal combustion engine,it integrates software program and hardware control.In this platform,two main functions are provided: engine design and virtual experiment.In the design part,the user can freely set the design parameters of the internal combustion engine according to the specified procedure to build a controllable virtual engine that can be used for virtual experiment.In the virtual experimental part,the user can use the external controller and the function buttons provided on the software interface to manipulate the designed virtual engine,complete the experiment and record the experimental data.During the development of the virtual lab of the internal combustion engine,two different types of development models,software development of computer programs and hardware development of virtual engine controllers,were applied.In the software development section,the C++ high-level programming language was used.The programming and debugging environment of the program code was based on the Visual Studio software and the Qt plug-in.In the hardware development section,the hardware circuit board based on ATmega8 A microcontroller was designed and printed.Atmel Studio software was used to write,debug and program the ATmega8 A microcontroller program.The main tasks of the development of a virtual lab for internal combustion engine are as follows:(1)The numerical calculation method of internal combustion engine cylinder working process is the basic algorithm of virtual engine design.In the development process,firstly established the mathematical model of internal combustion engine cylinder working process.According to the relevant formula of engine principle,the calculation formula of engine dynamics,the empirical and semi-empirical formulas,etc.,combined with numerical algorithms,finally establish the functional relationship between the engine operating conditions of engine and the engine performance parameters.(2)The concept of simulation model is used in the virtual engine design process.The virtual engine simulation model can be used for quickly calculation of the performance parameters of each operating condition.The design of the program realizes the reading and writing function of the virtual engine model file.This function separates the design and application of the virtual engine model,correspond with the reality that once designed engine can be used repeatedly.(3)Through hardware schematics such as circuit schematic drawing,PCB design,and production experiment controller,a virtual internal combustion engine controller based on ATmega8 A microcontroller was developed.The controller can be in encrypted communication with a virtual engine lab program in the computer and can control the virtual engine model loaded in the laboratory.(4)In the laboratory program,the functions of the virtual engine model and the virtual engine controller were integrated,and the virtual engine control program was designed based on the reality.The function of recording experimental parameters was implemented in the program.In the experiment,the virtual engine's timely status can be recorded into the virtual experimental results.The program can visually display the recorded data and plot the load characteristics and speed characteristics of the virtual engine based on the virtual engine model and the recorded data.