Research On The Fault Diagnosis Technology Of The Multi-cylinder Diesel Engine Based On The Instantaneous Speed

Intelligent engine is the most important features of the development on diesel in the new century. The online diagnosis is the method, while the safety operation is the target, so the on-line diesel malfunction diagnosis, the automatic protection and the intelligent alarming are the significant research topics in the intelligent engine. The instantaneous speed of diesel contains a lot of information related to the status of the combustion and the mechanical movement of the diesel. The type of non-contact tachometer sensor has the characteristic of simply installment, using suitable, conveniently reliable, and long life cycle. The online supervision of the engine status, which related to the combustion and the affected cylinder that the pressure is changed, and the malfunction diagnosis by using the instantaneous speed, has been developed into the most practical and valuable technology and tended to mature in the diesel engine malfunction diagnosis technology in recent years.However, concerning to diesel engine, because the cylinder number is more, the mutually affects is bigger, the change of the instantaneous speed is much more undulation. As a result, it is difficult to obtain the instantaneous speed profile, which is consistent with the cylinder number directly. Moreover, the original malfunction diagnosis method is not very reliable. Therefore, the diagnosis technology based on instantaneous speed also needs further study and the consummation in the application of the multi-cylinder machine.In view of the characteristic of the multi-cylinder machine, the article has conducted the research and analysis the key technology on the status inspection and the malfunction diagnosis of the diesel engine, which based on the instantaneous speed, and advanced the corresponding technological project and validated it through the experiment. The paper has mainly completed the following work:(1)It has analyzed the measure and processes of the instantaneous speed signal, and the digital filter design;(2) It has proposed the practical application of the analysis single overtone phase analytic method on multi-cylinders diesel engine by using the principle of the single overtone phase analytic method;(3) It has related the hardware design and software design of the malfunction diagnosis gathering system based on the FPGA technology in detail;(4) It has carried on the experimental confirmation on multi-cylinders diesel engine by using the malfunction diagnosis gathering system. It concluded that the method of the malfunction diagnosis by using of the principle of the single overtone phase analytic method, has good effect on multi-cylinders diesel engineThis dissertation is supported financial by the tackle key project "The system research on the On-line inspection and Fault diagnosis technology of the multi-cylinder ternal Combustion Engine based on the instantaneous speed" in science and technology of HuBei Province. (Number: 2004AA101C28)...