基于PIC18F4680单片机的动态小压力微弱信号检测

采用泥浆压力传输开关信号,是石油钻井探测过程中地面与几千米井下少有的信号传输方式之一,但井下由于压力产生信号变动为毫伏级微小信号,再结合井下高达150℃高温及高震动、强干扰的恶劣环境,这使得有用信号的可靠稳定采集成为难题.针对该问题,以PIC 18 F4680单片机为平台,采用硬件滤波初步排除强干扰信号和软件卡尔曼滤波进一步精确提取有用信号相结合的方式实现井下钻井小压力信号的检测.给出了硬件平台及硬件滤波的详细设计方法,描述了软件卡尔曼滤波应用于压力小信号处理的实现方法,并通过仿真及现场验证证明其可靠性,而且性能超过国外同类技术.

Weak Signal Detection of Dynamic Small Pressure Based on PIC18F4680 Microcontroller

The mud pressure transmitting switch signal is one of the rare signal transmission ways in oil drilling process in the course of detecting signal on the ground and thousands of meters underground.However,due to the tiny pressure signal in the pit,further,combined with the high temperature and high vibration,strong interference environment underground,making reliable and stable acquisition of useful signal become an aporia.To solve this problem,the PIC18F4680 microcontroller is used as the platform,the detection of small pressure signal in underground drilling is initially realized,namely,the interference is ruled out by hardware filtering mode and the useful signal is further extracted by software Kalman filtering.The detailed design method of hardware platform and hardware filtering is given,in addition,the realization method applying Kalman filtering software to tiny pressure signal processing is described,and the results of simulation and field test show that this platform is credible and its performance is better than other similar foreign technologies.