Ultrasonic water meter flow metering method, system and device based on depth sampling

The invention discloses an ultrasonic water meter flow metering method, system and device based on depth sampling and belongs to the technical field of metering instruments. Sampling sequences in the downstream direction and the countercurrent direction are obtained through a front-end sampling system, the absolute flight time and the relative flight time of ultrasonic waves are obtained through secondary interpolation and cosine interpolation calculation, ultrasonic water meter flow metering is achieved, and therefore the zero drift characteristic caused by the temperature influence of an ultrasonic transducer is effectively reduced; higher metering precision and lower starting flow are ensured so that reliability of fluid flow measurement is improved; besides, the irrelevant ultrasonic speed is applied to the calculation model, a problem that consistency of batch production is influenced by the difference of temperature sensor devices can be avoided, production efficiency is improved, and error consistency