Guided wave radar level meter echo signal processing system and method based on first-order derivative

Abstract

The invention relates to a guided wave radar level meter echo signal processing system based on first-order derivative. The system comprises a single-chip microcomputer for controlling transmitting and receiving of pulse signals, a pulse transmitting circuit, a guided wave rod, an echo signal receiving circuit and a equivalent time sampling circuit. A signal conditioning circuit, a single-chip microcomputer system for processing echo signals, a liquid crystal display and software are further provided. The echo signals processed by the equivalent time sampling circuit are sent back to the signal conditioning circuit, subjected to voltage dividing, biasing and impedance conversion and sent to the single-chip microcomputer system to be sampled. Echo signal processing includes that the echo signals are subjected to 9-point moving average filtering preprocessing, filtered signals are subjected to first-order derivative calculation to detect echo, material level echo is judged through multi-parameter organic combination, a material level location point and a reference starting point are determined to calculate time difference, then the time difference is substituted into a function relational expression of the material level determined by calibration and the time difference to calculate the material level.

Description

technical field [0001] The invention relates to the field of material level detection, and is a guided wave radar level gauge, in particular to a single-chip microcomputer-based system and method for processing echo signals of a guided wave radar level gauge based on first-order derivatives. Background technique [0002] The material level is divided into material level, material level and phase interface position. The height or surface position of liquid stored in tanks, towers, tanks and other containers during the production process, as well as natural rivers and reservoirs is defined as the material level. The accumulation height or surface position of solid blocks, granules, powder, etc. stored in hoppers, tanks, yards, warehouses, etc. is defined as the material level. The liquid-liquid and liquid-solid interface positions are defined as the phase interface positions. Level is one of the four measurands in the process industry. For example, in the centralized transp...

AI Technical Summary

Problems solved by technology

[0007] Butterworth low-pass filtering is a frequency-domain filtering method, which is applied to the echo signal processing of guided wave radar level gauges with inconspicuous frequency-domain characteristics, and the effect is not obvious; the construction of the reference curve needs to construct the empty tank condition first, and needs to be updated , otherwise it cannot follow the subsequent interference changes; the subtraction of the echo signal from the reference curve may cause the nonlinear movement of the echo positioning point and affect the accuracy

Images