Design Of The Fault Diagnosis Instrument For I.C.Engine Based On AVR Controlled And Signal Of Crankshaft Angular Vibration

Development of the testing and diagnostic equipment of I.C. Engine, monitoring working conditions of the I.C. Engine, to ensure the safe operation, reasonable maintenance, reduce costs is essential. Presently the crank angular oscillation test and diagnostic instrument for I.C.Engine is unable the long-term run to monitor the I.C.Engine,and can not satisfy the non-professinal's operation requirement as a result of its specialization. To sove the problem of the current diagnosis system,the text based on the analysis of characteristics of the current and international diagnosis instrument of I.C. Engine and the testing methods, successfully develop a cylinder deactivation instrument. The system integrates data acquisition, data analysis, and liquid crystal displays, it can operate simple and independently from the computer. It can been not only manual operatied but also can been made the built-in instrument for long-term monitor the I.C.Engine.Major study contents and conclusions are as follows:1.According to the detection system requirements and functional requirements, the strategy based on sensor technology and the single-chip microcomputer control technology has been proposed, and determined the instrument's design project. Elaborated realized the method of exploitation and the development step of the crank angular oscillation diagnostic equipment using AVR monolithic integrated circuit ATmegal28L,selectivly analysis and study the principle of the angular oscillation signal measurement using the AVR monolithic integrated circuit and application of the signal failure diagnosis technology based on the I.C. Engine crank angular oscillation,and study the influence of the number of teeth to the profile analytic method.2.The instrument hardware development and design has been completed based on the modular design concept. The instrument as the core of ATmega128L,and it is made up of signal acquisition, signal conditioning, signal processing and liquid crystal display, data communications, and other functions module.It introduced the design proposal of the major function module,and has given the main part electric circuit schematic diagram when hardware design. It analysis the characteristics and the role of the main chip and the working principle of circuit modules. The hardware design follows the observation system reliable principle, propose the specific measures of the system reliable design, guarantee the system movement reliability.3.The software routine uses the modulation design concept.It has been completed, including the main program, data collection procedures and communication procedures, and other functional modules design with the compiler of AVR-GCC.It gives the software flow and the program method.4. In order to confirm instrument's accuracy, the reliability and the precision, this article has conducted the experimental study.The experiment has been carried on the experiment contrast the instrument with the demarcation angular oscillation survey analysis system(PTVM). The experimental results show that measurement analysis of the vibration signal and fault diagnosis is accurate and reliable and it has a certain value in the measurement and fault diagnosis of I.C. Engine.