Design Of Weak Signal Acquisition Circuit Drive And Adaptive Filter Processing

Data acquisition technology is widely used in military,aerospace,industrial measurement and control fields.With the development of science and technology,various fields have put forward higher demands for accuracy.High-precision acquisition of weak signals such as weak voltage,weak light,and weak magnetism has gradually become an important development direction.Based on the design requirements,this paper completed the design of transmission and processing of microvolt level,100 KHZ wideband weak signals(DC signal accuracy 0.002%,AC signal accuracy 0.02%)by dividing the hardware system modules.For weak voltage signal of wide band,this paper designed a frequency measurement algorithm based on a hardware LRC adjustable narrow-band filter and adaptive filtering technology.The real-time control of the LRC adjustable narrow-band filter completed the frequency-selective filtering process of the wide-band signal.The paper realized weak signal acquisition based on adaptive filter control algorithm.This paper first described the development of data acquisition technology,and then divided the data acquisition system into modules according to the design requirements of the system.The paper decoupled the hardware acquisition circuit and transmission processing circuit,and designed a detailed scheme of the hardware and software of drive module,and designed the application of the computer by dividing into modules.The main work is as follows:(1)Hardware and software design of the drive module.The paper designed the drive module with USB as the communication interface,SRAM as the intermediate cache,and ARM as the control core.The paper realized the data and instruction interaction of the acquisition module with FPGA as the control core,and completed the communication program design with the computer.The paper realized AD Transport stream of sampling data to the computer.(2)Software design of computer.The paper layered sub-module d,and completed the software design of USB driver module,interaction module,system management module,and data processing module.(3)Design of adaptive filtering processing.The paper completed the adaptive filter processing design for the wideband signal,and called this model based on hardware narrowband adaptive filtering,and completed the adaptive frequency search algorithm and adaptive adjustment steps.The paper achieved the narrow-band filtering of the input signal by driving the implementation of the hardware LRC adjustable narrowband bandpass filter and improved the acquisition accuracy.(4)Finally,the paper called the debugging process and debugging results of the drive module,and verified the functions modules of the host computer software and the results after data processing.The paper verified the feasibility of the design.