Design And Implementation Of Signal Simulation Device For Internal Combustion Engine

As an important power mechanical device,internal combustion engine is widely used in automobiles.With the progress of electronic technology,the level of electronic control technology of internal combustion engines has been improved continuously,and the characteristics of engine efficiency,fuel economy,emission,and so on have been greatly improved.Usually in the research and development of EFI control of internal combustion engine,a large number of control algorithm verification experiments and performance test experiments need to be done on site.In order to make thing convenient for verification tests and reduce the cost of experimental,this paper proposes the research and development of a simulation device capable of simulating the signals of various operating conditions of an internal combustion engine,for use in the engine electrical control system for simulation verification experiments.This thesis firstly introduces the basic principles of the internal combustion engine and its electronic control system,and analyzes the sensor signals of various functions of the engine,especially the crankshaft and cam position sensor signals which are important for the ignition and cylinder signals of the internal combustion engine.Due to using different kinds of engine crankshafts and camshaft sensors(hall and electromagnetic)and the number of engine cylinders is different,there is some differences between the crankshaft signal and camshaft signal,the synchronization correspondence between the crankshaft signal and the camshaft signal is analyzed,thereby the overall structure of the engine working condition signal simulator is proposed.The MC9S08DZ60 microprocessor chip of NXP company is selected as the main control core,and designs the system peripheral circuit modules around the main control chip according to the function requirements.The device analog signals are divided according to the importance and the type of the engine electronic control signals,which includes the crankshaft position sensor signal,the cam position sensor signal,the analog quantity signals,and the ignition switch signal.Based on the Code Warrior software editing environment,the control software for the MC9S08DZ60 microprocessor is developed.Two different forms of crankshaft camshaft position sensor signals for different cylinder numbers are produced by simulation particularly.The engine speed change can be controlled by the main control chip.speed change of the engine can be realized by the main control chip collecting a knob potentiometer that specifically controls the speed signal,the various analog signals can be adjusted through upper computer calibration interface.In addition,In order to facilitate the user to monitor the signal in real time,the upper computer display interface is designed,and the CAN communication interface for the information interconnection between the signal simulator and the engine electronic control unit ECU is designed.Finally,various functional tests were performed on the designed engine signal simulation device.Firstly,the output test of the crankshaft camshaft signal of different cylinder number engines under different speeds is made.Next,the communication test between the signal simulation device and the host computer is carried out to verify the adjustment output function of the analog signal.The output of each analog signal is calibrated,and the error between the feedback detection result and the calibration value satisfies the technical requirements;finally,the communication test between the simulation device and the engine ECU is completed.The test results of the system show that the designed engine signal simulation device can generate the expected engine state signal,and the communication function is also verified.The system provides convenience for the development and development of the internal combustion engine EFI control system.