Study On The Fault Diagnosis Of Electronic Controlled Gasoline Injection Engine Based On Signal Wavelet Analysis Method

This dissertation expounds the application prospects of the electronic controlled gasoline injection engine, introduces the automobile fault diagnosis technique and the current fault simulation method, analyzes the status and the problems of the automobile repairing industry, introduces the structure and the working principles of the main sensors and actuators, and the fault diagnosis and test methods of the electronic controlled gasoline injection engine.This dissertation designs and develops the experimental rig of fault simulation for the electronic controlled engine, introduces the composition and the working principles of the experimental rig, and the character of the controlled circuit and showing panel of the experimental rig, and its designing and developing process. The advantages of the experimental rig are as follows:it is an integrated experimental rig of the fault simulation, which comprises the fault simulation experimental rig and dynamometer system for engine.it can accomplish not only the fault simulation experiments under idling condition ,but also under different working condition due to the loading function.In the meantime, it can conveniently detect and collect the information as much as possible, and repeatedly simulate various faults of the sensors, the actuators, the electronic unit and the circuitry under different working conditions. The integrated experimental rig is innovated in fault simulation for the electronic controlled engine.Taking advantage of the experimental rig of fault simulation for the electronic controlled engine, this dissertation accomplishes the fault simulation experiments of the Speed Sensor, the air flow sensor, the cooler temperature sensor and the throttle position sensor on the electronic controlled engine, which adopts LH Type electronic controlled system.This dissertation firstly roundly brings forward and achieves the methods of fault simulation on some sensor signals disconnecting or switching, weakening, losing, and so on.This dissertation collects normal and abnormal exported sensor signals by digital...