Research And Design Of Tower Crane Fatigue Monitoring System Based On Strain Measurement

With the continuous development of the country's urbanization,tower cranes are seen everywhere in the engineering sites.The working conditions of the tower crane are complex.And often due to improper operation and overload,accidents often occur in tower cranes.The basis of the monitoring system of tower crane for judging the working state of the tower crane is mainly the monitoring data of the lifting load.While the technology based on the stress monitoring of the tower crane is not mature enough.Combined with comprehensive test technology,signal processing technology and ethernet technology,the fatigue monitoring system of tower crane based on strain measurement is researched and designed in this paper.The purpose is to analyze and judge the metal fatigue damage of the tower crane metal by calculating the stress of the tower..First,the paper studies the monitoring method of tower crane at home and abroad,and uses the stress strain monitoring method to judge the metal fatigue damage of the tower body The advantages and disadvantages of the existing monitoring methods are analyzed in the stress strain monitoring methods,and the data acquisition of stress and strain is carried out by the method of resistance strain measurement.Secondly,the basic theory of resistance strain measurement and the basic theory of fatigue damage calculation are studied.Then,the functional requirements of the system are analyzed,and the hardware design and software development of the system are carried out based on modular thinking.The strain data acquisition and stress spectrum calculation are realized to provide data for the fatigue monitoring system.In the aspect of hardware,the strain signal conditioning circuit,the strain signal acquisition circuit and the WiFi wireless data transmission circuit are designed.In the aspect of WiFi wireless transmission,the size and congestion avoidance mechanism of congestion window and notification window in the LwIP protocol which is used in transmission process are improved,and the wireless transmission rate is improved.In the aspect of software,the communication protocol between hardware and software and the software for fatigue damage calculation based on MATLAB are designed.Finally,the tower crane model is built and the functions of the system are tested.The transmission rate of contrast test before and after the improvement of the LwIP protocol stack,which proves that the improved transmitted rate increased significantly.The static strain test and dynamic strain test proved that the strain acquisition circuit is of high precision.The system is tested by sets of fatigue damage simulation experiments.The results show that the system has achieved the expected effect.At the end of this paper,the research work of the full text is summarized,and the next research content and system improvement plan are put forward.