High-density electrode switching access method and system based on FPGA and analog switch

Abstract

The invention belongs to the technical field of high-density resistivity measurement, and discloses a high-density electrode switching access method and system based on an FPGA and an analog switch, wherein the system comprises a signal channel N and other four-channel resistivity measurement buses, and the connection and disconnection of the analog switch are controlled through an I / O port of theFPGA. The signal channel N and the signal channel P are connected with an A / D analog-to-digital converter to realize analog-to-digital conversion of voltage signals between the electrodes; the current channel A and the like are connected with a controllable constant current source circuit controlled by a D / A digital-to-analog converter to realize power supply between the electrodes; An ARM processor realizes program control of electrode switching access, and is connected with the A / D analog-to-digital converter and the D / A digital-to-analog converter through GPIO ports to realize voltage signal acquisition between the electrodes and electrode power supply current control of the current channel A and the current channel B. According to the analog switch switching access method, the problems of high power consumption, relay contact use frequency limitation and the like of a traditional relay method are solved, and electrode switching access of any combination can be achieved based on FPGA analog switch control.

Description

technical field [0001] The invention belongs to the technical field of high-density resistivity measurement, and in particular relates to a high-density electrode switching access method and system based on FPGA and analog switch. Background technique [0002] At present, the closest existing technology: high-density electrical prospecting is a geophysical prospecting method developed in recent years. The essence of high-density electrical prospecting is still electrical prospecting. The difference is the physical basis and precondition. The high-density DC prospecting instrument is a measuring instrument used to observe the two parameters of the potential difference ΔU between the measuring electrodes M and N and the current intensity I in the circuit of the power supply electrodes A and B. According to the different arrangements and polar distances of the power supply electrodes A, B, and the measuring electrodes M, N, it is divided into a variety of measuring arrangement...

AI Technical Summary

Problems solved by technology

[0005] To sum up, the distributed electrode switching access method is a common design scheme for high-density direct current exploration instruments. The advantage of this method is that it has a large measurement range and fewer connecting cables. Flexible and arbitrary electrode combination measurement requirements are not commonly used in probe-rod high-density resistivity measurement systems

The centralized electrode switching access method is currently a common method for probe-rod high-density resistivity measurement systems, but limited by the influence of contact resistance, the current electrode switching access method usually used is a contact relay, a contact relay It has the disadvantages of limited service life of contacts, slow switching speed, and high power consumption

[0006] Aiming at the centralized control requirements of the electrode switching access of the probe-type high-density resistivity measurement system and the problem of the existing contact relay switching access control, the present invention proposes a high-density electrode switching interface based on FPGA and analog switches. entry method and system

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