Design Of Electronic Control System For Optically Accessible CAI Engine

Since the beginning of the twenty-first century，the rapid growth of the vehiclepopulation make the world’s energy and environmental issues become more and moreserious. Automobile engines have consumed a lot of oil resources and polluted the urban airseverely. In this case, a new combustion mode which named Controlled Auto Ignition hasappeared on the field of internal combustion engine research. This combustion modeobtained the researchers widely favored because of good fuel economy and low emissions.But this combustion mode could only be achieved in the laboratory now, This is mainlybecause of we don’t clear the CAI combustion’s cylinder mixed gas concentration andtemperature distribution, and we can’t use spark plug to control the combustion time, SoCAI combustion engine’s key problem such as low scope of work can be resolved hardly.So people begin to consider how to adjust the cylinder gas and temperature distribution tocontrol CAI combustion. But the engine combustion is closed; it is very difficult to get thecylinder combustion information. Then people remind of the optically accessible engine, ithas a visible optical path, so researchers can use optical diagnostic technique to measure theCAI combustion engine parameters such as the concentration and temperature distributionThis paper has designed a set of electronic control system for optically accessible CAIengine, through this system to realize the optically accessible engine of CAI combustion,and provide the foundation for the optical diagnostic tests. First, we selected the sensor thatthe system required. Choice the fuel injection and ignition device，researched of the controlprocess of fuel injection quantity and ignition timing., used an electro-hydraulic cam-lessvalve train in order to realize optical engine of CAI combustion. Design the systemhardware circuit of the system based80C196KC microprocessor. And divided the hardwareinto microprocessor and the expansion circuit, power supply circuit, signal input/outputcircuit and so on. We used the assembly language to develop control software. At the sametime, took a series of measures to improve the system’s ability of anti-interference.According to the requirements of engine controlled auto ignition, the system has added aset of on-line monitoring system.After the design is completed, undertook the preliminary test on the opticallyaccessible engine bench which refitted from ZS1105diesel engine to verify the feasibility of the system. The preliminary experimental results show: The sensors, actuators of thisdesign have good linearity; they can realize the acquire of accurate measurement control,And the response delay time of electro-hydraulic cam-less valve train drive the valves toopen and close can also meet the basic requirements. And through the online system off thespark plug drive signal, control engine late closing of exhaust valve can realize the opticallyaccessible engine controlled auto ignition.