Car Engine Monitoring And Control Teaching System Based On Labview Design And Development

This paper based on Volkswagen Santana 2000 AJR EFI engines, under the premise of not affecting all kinds of electronic controlled engine performances, has completed to rebuild its electronic control system, and increased multimedia signal acquisition system. at last designed a set of the experimental which can experiment,teach,research and engine failure detection.Through the signal display and measuring panel, signal simulating bench, faults setting bench, and the software platform which is based on the virtual instrumental technology, this system can realize the display and check of the signals from the electronic controlled engine, the simulation of master signals, the settlement of some usual faults, the display, analysisand reappearance of the waveform and parameter of the signals, the comparison with the standard waveform and the analytical functions of the data stream. And hence, it offers a diagnosing function on the faults. The main contents are:1.This thesis expounds the structure of electronic controlled engine, the methodand classification of failure diagnosis of electronic control system, and the principle and processes of fault self-diagnosis of electronic controlled engine.2. It designs and develops a set of experimental bench of setting-failure,simply rebuilded to its electronic control system. The bench can continuously produce different failures of sensors, actuators, electronic controlled unit and circuits. And it can provide convenient inspect port and intuitionistic dynamic display panel.making use of the switch and the regulation of the potentiometer, it can simulate 2 master signals; designing the modular circuit of the settlement of faults and using AT89C51 SCM,74LS 154 and 74LS249 chip to scan the state of the keystroke of the settlement of faults, it can control the relay of terminal operation, so realizes the settlement of 30 usual faults;3.Based on AJR engine electronic control units and fault set, Design of software which is based on the virtual instrumental technology.Selecting appropriate computer and data acquisition card according to the testing requirement and choosing LabVIEW in reference to the features of the platform of software development, it designs the login module, simulation testing, real-time test software modules to realize the system's landing, the signal simulation, acquisition, display and other functions.4. In this test platform, we make many experiment of the original machine, signal simulation, and failure to set tests, adopt some appropriate fault diagnosis methods, watch the change of engine, record relative data, and according to data analyze affection which the failure causes engine, and the engine control system to take control strategy. The paper emphasizes to analyze these experimental results, such as the oxygen sensor test; crankshaft position sensor test, throttle sensor test, air flow sensor test, the ignition signal experiments, and the results analyzed in detail.