Studies Of Controlling System Of Automobile Rear Bridge On-line Detect Based On PLC

The Rear Bridge is one of the key parts of the automobile, according as statistic,20% accidents result from Rear Bridge. So it is necessary to inspect it strictly before Rear Bridge leave factory. And design of this Controlling System of Truck Rear Bridge on-line detect is of major practical significance.In this system vibration and yawp diagnosis method is adopted to realize the quality inspection of the Rear Bridge. The vibration feature of the rear bridge was analyzed and measure position was ascertained according to the actual operation mode and the surveying result. Then using on-line system which I designed completed the vibration and yawp signal sampling and processing.Changchun FAW of liberation plant determines if the vibration value of the rear bridge is more than 0.5 g and noise is more than 86 db in accordance with the experience of workers, if so, the rear bridge is considered as failure. Therefore, this system put 0.5 g, 86 db as the alarm level, the on-line measurement system does the series detection under the automatic mode at first and then the real-time detection of the rear axle vibration and noise value, if not over the alarm level, that the rear axle qualified; if over the alarm level, we'll make use of the online system of manual functions, do the step-by-step test to find out the fault, and then repair it.Whether the feature parameter which can right reflect the running condition of the Rear Bridge can be extracted is most important in product inspection , and can affect the reliability and validity of the inspection results. The system model is very well, so the signal is very right. In this system control part is designed by PLC, so the system working is credibility and stabilization.To perfect the function of the system , improve the advances, and guarantee the liability, CAN bus is adopted. The front processor is to sample signals , and then send them to the upper computer. Finished processing received data, the upper computer displays the results.The design idea, the total scheme and the correlative basic knowledge of the hardware and software of the Rear Bridge on-line detection System, and some key sections are analyzed in detail.