The Study On Engine Air-fuel Ratio Measuring Instrument

In traditional design research and development of a new type engine, researchers need to use the engine air-fuel ratio measuring instrument to analyze engine air-fuel ratio value of engine combustion characteristic, important influence of emission characteristics and economic characteristics, visible engine air-fuel ratio measuring instrument in the traditional engine plays important role in the process of design research and development, this paper is introduced a can satisfy the requirement of a certain measurement range and accuracy of simple type of air-fuel ratio measurement instrument development process, the main research content is as follows:(1)Air-fuel ratio measuring instrument general electric scheme design:according to the domestic market the air-fuel ratio measuring instrument of existing product and consulting a large number of domestic and foreign literature and research, at this stage of the existing conditions, the comprehensive comparative analysis and design of the overall electrical scheme of air-fuel ratio measuring instrument.(2)The working principle of oxygen sensor the wide domain analysis:wide domain oxygen sensor is important in the process of air-fuel ratio in the engine combustion parameters into electrical signal device, to master its features, working principle and control method, the accuracy of the collected signal and subsequent signal processing is very important.(3)Air-fuel ratio measuring instrument hardware design:the air-fuel ratio measuring instrument hardware needed to calculate, research and selection, insure the accuracy and the stability of the working process of the various modules, and use DXP Altium Designer PCB design software, carry on the reasonable layout and PCB production and debugging of hardware system.(4)Air-fuel ratio measuring instrument software design:use rapid prototyping platform Mototron and function of Simulink of state machine, heating control algorithm design verification wide domain of oxygen sensor. Use of Matlab data Processing function and function of Simulink and convenient modular programming, to deal with the experimental data and algorithm formula of the writing of the program. Finally, on the basis of the above work is completed, the use of Simulink RTW directly to the above application into C code.(5)Air-fuel ratio measuring instrument of building and system commissioning test on engine test bench:choosing of the construction of the engine test bench, first of all, is to carry out experiment, to obtain experimental data; Second, it is late to the air-fuel ratio meter integrated system test, debug and validation.