Design And Simulation Of HCCI Optical Engine Electronic Control System

Since the successful development of engine, it provides energy and power for humanin many fields. However, on the other hand, exhaust gas has been polluting air and waterseriously, which is the necessity for people’s survival. In response to this problem andchallenges, researchers are exploring different engine combustion strategies and usingdifferent test methods. HCCI combustion mode has integrated the advantages of dieseland gasoline engines, with a high efficiency, low emission characteristics, which is thefuture direction of research for engine. Inside the engine exhaust gas recirculation (EGR)is an important means to achieve engine HCCI combustion, which include the means ofnegative valve overlap, the exhaust valve late off, the exhaust valve double opens and soon. Using optical testing technology to research HCCI combustion engine strategy hasthe great significance for solving the engine exhaust pollution emissions and globalenergy crisis, while electronic engine control system is the key to achieve the study ofdifferent combustion strategies by using optical methods research.Use Matlab/simulink software to build an engine simulation model, study the PIDcontrol strategy and fuzzy PID parameter self-tuning PID control strategy and build thePID controller model and fuzzy PID parameter self-tuning control strategy model, andstudy the speed control strategy. In order to facilitate model simulation and changeparameters in the model, finally build the engine control simulation platform,implementing all parameters of the model in the display interface. Control the formerestablished model by using these two control strategies in the simulation platform, andcompare these two control performance can proved that fuzzy PID parameter self-tuningcontrol strategy output smaller overshoot and adjustment time is short, which have moreobvious advantages.Build optical HCCI engine electronic control system hardware, using Intel80C196microcontroller as the system’s main core chip, Design input circuit of the enginecompression top deadline center, the temperature signal, and the oxygen sensor. At thesame time, the output circuit is also designed to control actuator, such as the solenoidvalves, spark plug, fuel injector, and lasers. Finally, the printed circuit board wasdesigned and soldering components was finished manually. Programming to control theengine to achieve the operation of combustion strategies, following as a negative valveoverlap, the exhaust valve late off, the exhaust valve opens second time. Debugging and testing optical HCCI engine platform. Electric control system designrequired the installation of sensors and actuators. calibrated the system delay time, theengine speed is1200rpm,1ms engine turned7.2°CA, system delay has a very obviouseffect on engine performance, intake and exhaust valves on the system drive system,calibrated the delay time shows that the delay of the intake valve opens is about6ms,intake valve closing delay is about9.5ms, the exhaust valve opening delay is about6.5ms,the exhaust valve closing delay is about9.8ms, the crank angle corresponding to thedelay to open and close the intake valve delay crank angle was43.2°CA and68.4°CA,the exhaust valve open and close delay crank angle was46.8°CA and70.56°CA, theelectronic control system software needed to compensate each delay. Electrical controlsystem can control the engine via a negative valve overlap strategy, and exhaust valveslate closed and exhaust valves secondary open strategy to achieve HCCI combustionmode and fuzzy PID parameter self-tuning policy control engine speed, engine speed toensure stability in1200rpm. Finally, the electronic control system on the7°CA beforeTDC trigger the laser test system to test the original machine phase combustion mode andnegative valve overlap strategy combustion mode, the test results show that under thenegative valve overlap strategies, CO2and H2O were significantly increased, indicatingthat the engine sucked back a lot of gas from the exhaust airway to achieve compressionignition mode.