Research And Implementation Of Low Power Single Channel Cable-free Seismic Data Acquisition System

With the rapid development of society and economy and the continuous improvement of China's comprehensive national power,the demand for mineral resources is increasing day by day,and the depletion of shallow mineral resources is the main factor that restricts the development of national economy.To solve the outstanding contradiction between economic development and limited resources,deep earth exploration has become the main trend of future mineral resources exploration.Geophysical exploration mainly includes five categories of methods namely,gravity,magnetic,electrical,seismic methods and radioactive methods.As an important method of geophysical exploration,the seismic method has been playing an irreplaceable role.The seismograph is the core instrument in the seismic exploration system and provides technical support for seismic exploration operations.In recent years,with the rapid development of cable-free seismograph at home and abroad,the characteristics of cable-free seismograph for a long-time field work and a variety of working conditions makes its power requirements getting higher and higher.The current domestic prototype system suffers from bulky and high power problems,which directly restricts the development of deep exploration.In order to meet the needs of long-term field work of cable-free seismic exploration equipment,this paper focuses on the low power design of single-channel cable-free seismic data acquisition system.First,analyzes the power distribution of each functional module in the cable-free seismograph;On this basis,according to the main control unit,synchronous timing unit and power supply unit optimized design,completed the design of the main control unit with Cortex-M4 processor as the core,low power GPS timing module(u-blox MAX7 Series)combined with temperaturecompensated crystal oscillator(TCXO)a time synchronization unit and high efficiency DC/DC power supply unit.Based on the low power design of the system hardware,the power of the system is further optimized.According to the working mode and working condition,based on the dynamic power management and dynamic frequency modulation technology,operation frequency of dynamic adjustment of main control unit and related modules,to further reduce the average power consumption of the system.Built eclipse softwareon the STM32 platform,the Free RTOS operating system and LWIP protocol stack,based on the completion of the main control software design of driver software and system,realize the basic functions of seismic data acquisition,time synchronization,storage and data recovery etc.Finally,the system prototype is built and the power consumption is tested.The test results show that the power consumption of the prototype system designed by this method has been significantly improved,and the average power consumption of the prototype is reduced to 250 m W,compared with cable-free seismic data acquisition system and Jilin University National Geophysical Instrument Engineering Technology Research Center of independent research and development of GEIWSR cable-free stored seismic data acquisition system,effectively reduce the power consumption of the system,meet the design requirements.