Research On Multipoint Synchronous Monitoring System Of Dynamic Load And Deformation Of Shaft

Rotation shaft plays an essential role in the industrial production and our daily life.From the truck drive shaft to the ship shaft,different types of shaft have been widely used.The dynamic parameters of the shaft like speed,torque,power and torsional deformation are the key information which indicates the operating state of mechanical equipments.The accurate measurement of these parameters can provide valuable data for the design of mechanical equipment,and help verify whether the power output meets the design requirements.And at the same time,it also can help carry out the necessary monitoring and fault reminding on the working conditions of the equipments.The testing of shaft dynamic parameters has become an indispensable part in the design,quality inspection,condition monitoring and fault diagnosis of all kinds of rotating machines.Therefore,developing an accurate and reliable set of shaft dynamic parameter test system has great value in the fields of mechanical design and industrial control.In this paper,based on the comparison of existing test techniques,a new method of torque measurement based on the principle of phase difference was proposed.The method can effectively recognize the zero point of the signal phase difference and realize the zero correction which is difficult under static conditions by using pulse signals.As for the shaft power,the principle of measuring the speed by pulse counting was introduced.After acquiring the dynamic load and the shaft speed,the method of calculating the power was also proposed.In order to detect the dynamic load of the shaft due to power adjustment,load abrupt change and mechanical impact,the technical scheme based on multi-point strain synchronous detection and negative delay storage is designed and realized,and the complete process before and after the dynamic load can be obtained.Based on the cooperation mechanism between ARM and FPGA,a universal test system was designed which includes information acquisition and conditioning module,control module,data acquisition module,storage module,communication module and processing software.The main control module with ARM uses UCOSII as its operating system which can realize the scheduling and management of multiple tasks such as parameter setting,status monitoring and data transmission.The data acquisition and storage subsystem with FPGA achieved pseudo-synchronous acquisition of multi-channel signals through the cooperation of AD module and high-speed analog switch,which can solve the synchronization problem of multi-point test.By adopting the loop storage mode and managing the trigger signal and test time,the storage ability of negative delay time was realized.While realizing the high-speed data transmission with WIFI module,the application of UWB and Zigbee communication was theoretically studied considering the practical need of data transmission security and low power consumption.PC software is responsible for the tasks of the test system control,data processing and displaying.In order to verify the performance of the test system,a simulation experiment platform was set up in the laboratory environment.A variety of test experiments were proposed for channel switching,data storage function,the strain and speed measurement.Finally,the verification test of torsional deformation of the test system was carried out in the national defense high torque measuring station.Experimental results show that the system can achieve the accuracy and is competent for the measurement of the dynamic load and multi-point strain.