Research And Design Of The Crane's Status Analysis System

Status analysis of the crane is a commonly used mean to prevent crane accidents,which can determine the current status of the crane and estimate its lifespan.At present,the crane industry usually hands over the crane to relevant departments for status analysis on a regular basis.But this approach is not only operating troublesome but also cannot guarantee that there will be no failure during the two inspections.A system has been designed in the thesis to solve the problems above,setting the gantry crane as an example,and used a fault diagnosis method based on the input/output and signal processing.The system could be installed on the crane to monitor and analyze its status more easily.The system's design focuses on both vibration and stress,using a multi-factor joint analysis to judge the crane's status more accurately.The system was divided into three parts: the collection,the transmission and the analysis.The collection part was responsible for collecting the multi-point vibration and stress signals of the crane and transforming them into electrical signals(one of the points has been taken as an example in the thesis),two kinds of light and cheap chip sensor was used in this part to get the signal through a close contact with the target point,the electrical signals from the sensors were converted to digital signals by high-speed A/D chips(AD9235).In order to avoid interference and ensure that the information source was pure,the electrical signals were transmitted through the V/I circuit into the form of current,and then converted to voltage signals what A/D chips could accept through the conditioning circuit.The AD9235 chip has a maximum acquisition rate of 40 MSPS,which is possible to ensure that it can convert the analog signal into the corresponding discrete digital signal at maximum rate without distortion.The transmission department used an FPGA chip(EP3C16F484)to control the operation of each part,including the AD chip conversion process,the data in the DDR2 chip access process and communication with the host computer process.In order to ensure the transmission of large amounts of data collected from the crane,I have used a USB interface chip(CYUSB3014)in the thesis to extend a USB3.0 high-speed interface for the FPGA,which can upload data to the host computer at ultra-high speed(can be 5Gbps in theory).On the host computer,I discussed and used the Db3 wavelet basis function to realize the wavelet packet analysis of the vibration signal,analyzed the stress signal with the S-N curve life estimation method,and finally the results of the two analysis were combined to give a more accurate judgment to the current status of the crane.The collaboration of the three major components ensured the high efficiency of the monitoring system.Finally,I used the proportional strength of the experimental device as the object of the test system for a failure test.After comparing the waveform characteristics of vibration and stress in some given cases,the reliability of the system is confirmed and the idea of this paper is verified.