Acoustic surface wave sensor node structure for measuring soil moisture content and measuring method

Abstract

The present invention discloses an acoustic surface wave sensor node structure for measuring soil moisture content and a measuring method. The acoustic surface wave sensor node structure of the present invention comprises a housing, an antenna, several single-ended resonator-type surface wave devices and several sensitive elements. All acoustic surface wave devices in the acoustic surface wave sensor node are connected in parallel and fixed inside the housing in an equal space along the length direction of the housing. Interdigital transducers of each of the devices are connected to the corresponding sensitive elements through a matching circuit. Different devices have frequency bands which are adjacent to each other, yet without overlapping each other, characterized in that measurement ofthe soil moisture content of a same surface location at different levels of depth can be realized. According to the actual detection environment requirements, the present invention can, by adopting ahandheld mobile reader or a fixed reader, obtain the spatial-temporal distribution and variation laws of the soil moisture content, thus providing a theoretical basis and practical decision of accurate watering and irrigation for an indoor Bonsai, a greenhouse, an outdoor farming area and other scenes.

Description

[0001] Technical field: [0002] The invention relates to a surface acoustic wave sensor node structure and a measurement method for measuring soil water content, belonging to the fields of soil detection and wireless sensing. [0003] Background technique: [0004] Whether it is indoor potted plants, greenhouses or outdoor fields, in order to ensure the normal growth and development of crops, timely and moderate watering and irrigation are indispensable. In order to achieve precise irrigation, it is necessary to monitor the soil water content (humidity) through sensors, and use the actually obtained soil water content information as the basis for decision-making to implement targeted irrigation. Theory and practice show that even at the same position on the soil surface, the soil water content shows heterogeneity in the depth direction of the soil, so the sensor needs to measure the water content of the soil at different depth levels to obtain its temporal and spatial distribu...

AI Technical Summary

Problems solved by technology

[0005] Existing soil moisture sensors are usually active sensors integrated with signal processing modules and wireless communication modules, which are not only complex in structure and expensive, but also have the trouble of regularly replacing the battery and the potential impact of chemical substances in the battery on the soil ecological environment, etc. question

Although some improved structures use multiple sensor nodes to connect to a common wireless communication module through cables to achieve the purpose of reducing costs, this wired connection is not only cumbersome, but also hinders agricultural operations to a certain extent.

In addition, although some sensors have achieved an integrated design with solar photovoltaic panels to solve the energy supply problem of the sensor, the climate and weather conditions will greatly affect the sensor performance, and the cost is higher

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