High-frequency digital signal processing system of Coriolis mass flow meter

Abstract

The invention relates to a high-frequency digital signal processing system of a Coriolis mass flow meter. The high-frequency digital signal processing system comprises a signal conditioning and ADC (analog-to-digital conversion) module, a DSP (digital signal processing) chip, peripheral device FRAM (ferroelectric random access memory) chip, a UART (universal asynchronous receiver / transmitter) chip, a liquid crystal display controller, a DDS (direct digital synthesis) chip and a current output chip. The signal conditioning and ADC module comprises a first signal conditioning module, a second signal conditioning module, a first ADC module and a second ADC module; the DSP chip is a TMS320C6726 chip; the peripheral device FRAM chip, the UART chip, the liquid crystal display controller, the DDS chip and the current output chip have identical interface forms, are connected with one another in a bus form and control corresponding peripheral devices via respective chip select signals. The high-frequency digital signal processing system of the Coriolis mass flow meter has the advantages that signals of high-frequency Coriolis mass flow sensors can be pertinently processed, the TMS320C6726 chip with high computing power and processing speed is used as a core processor, the high-frequency digital signal processing system is implemented on the basis of a zero-cross detection algorithm and a DTFT (discrete time Fourier transform) algorithm, and the problem that the timeliness of algorithms cannot be guaranteed after high-frequency sensor signal sampling frequencies are increased can be pertinently solved.

Description

technical field [0001] The invention relates to the field of flow detection, in particular to a digital signal processing system of a high-frequency Coriolis mass flowmeter. Background technique [0002] Coriolis mass flowmeter (hereinafter referred to as Coriolis mass flowmeter) is the most researched and most promising direct mass flow measuring instrument. The Coriolis mass flowmeter consists of a primary instrument and a secondary instrument. The primary instrument includes a detection tube (or flow tube), a magnetoelectric speed sensor (or a photoelectric displacement sensor), an exciter and a temperature sensor; It is called a transmitter, which mainly includes a driving circuit, a signal conditioning circuit and a signal processing unit, and is mainly responsible for driving the primary instrument, calculating parameters such as flow rate and density, and human-computer interaction. According to the shape of the detection tube, Coriolis flowmeters can be roughly divi...

AI Technical Summary

Problems solved by technology

At present, the relatively mature elbow type Coriolis flowmeter has a low natural frequency, generally 70-150Hz, and the phase difference generated when the detection tube vibrates is relatively large, the signal processing is relatively easy, and the measurement accuracy is high (U-type Coriolis mass flowmeter The measurement accuracy can reach more than 0.1%); but the weight and size of the flowmeter of this shape are large, and it cannot be installed in some occasions, and its use is limited

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