Design Of Transmission Gear Stress Multi-point Dynamic Monitoring System

Since modern times,with the rapid development of shipbuilding industry,the requirements of speed,accuracy,load and reliability of transmission gearbox are higher and higher.Especially in order to reduce the radiated noise of ships,more and more attention is paid to the vibration problem caused by the uneven stress of gears.In this paper,a set of multi-point dynamic monitoring system is designed for the problem of stress balance of transmission gear.The system is divided into two subsystems: telemetry subsystem and self-contained subsystem.The telemetry subsystem realizes the real-time dynamic monitoring of gear stress,and the self-contained subsystem realizes the large capacity and high-speed acquisition of gear stress data.The two subsystems complement each other to complete the task of signal acquisition and monitoring of gear root stress.According to the particularity of transmission gear working environment and the installation position of the two subsystems,the installation structure of the two subsystems is designed,and the installation position of the hardware circuit on the structural parts is given.According to the installation space and system index requirements,the hardware circuit design of the system is given,including multiple functional units.The signal conditioning unit uses Wheatstone bridge and bridge amplifier to convert the stress information into electrical signal and amplify it.the analog-to-digital conversion unit uses AD7768 as the analog-to-digital conversion chip,which can set different channel number,sampling rate and power consumption according to the indicators of the two subsystems,and has anti-aliasing filtering function.the data storage and upload unit adopts FPGA+STM32 MCU as the processing core,the FPGA selects EP1C3T100I7 N with small size,which is responsible for integrating A/D acquisition data and sending the data to STM32 MCU.STM32 MCU selects STM32L4R9VIT6 with ultra-low power consumption,which is responsible for receiving the data sent by FPGA and storing or uploading the data.The self-contained subsystem stores the data in SD card,which can read out the data through USB card reader chip.The telemetry subsystem uploads the data to the upper computer through WIFI module.the command sending and receiving unit is responsible for sending file information to the upper computer and receiving commands.in the system power supply unit design,the telemetry subsystem uses wireless power supply mode,and the self-contained subsystem uses lithium battery pack to supply power.Then,on the basis of hardware circuit,the software program of the system is designed.FPGA program realizes A/D acquisition function and SPI transmission function;STM32 MCU program realizes the functions of data buffer,data storage and command receiving,and realizes the signal generator function of wireless power supply unit.At last,the function units of the system are tested and analyzed in detail,and the whole system is tested.The test results show that each functional unit can meet the requirements of the system index.The telemetry subsystem realizes wireless power supply and 320KB/s Wi Fi transmission rate.The self-contained subsystem realizes 20 channel,16 bit,40KHz synchronous acquisition.Both subsystems can run stably for a long time.