Research On Magnetostrictive Water Level Sensor And Water Level Flow Collecting System In Irrigated Area

With the development of industry and agriculture in the world,the shortage of water resources is a global problem.Agricultural irrigation water in China occupies more than 60% of the total water consumption in the country,but the utilization coefficient is less than 0.5,so it is very important to measure water consumption and scientific water for the irrigation area.Traditional measuring tools have not been able to meet the needs of real-time irrigation,so the automatic measurement of water regime has become a trend.Based on the analysis of the development and research status of water level flow measurement technology in Irrigation District,this paper designs and develops a high precision and low cost magnetostrictive water level sensor based on the characteristics of the current irrigation area,and studies the water level flow collection system of the irrigation canal by the magnetostrictive water level sensor.The main research contents are as follows:(1)Development of magnetostrictive water level sensor.According to the requirement of water level measurement in irrigation area,the mechanical mechanism of sensor head shell,metal probe rod shape,movable floater form and size,coil skeleton and so on are designed.Through the analysis of the excitation pulse parameters,the selection of the square wave monopulse and the amplitude and width of the pulse are determined,and finally the excitation amplifier circuit is composed of a single chip computer pin simulating the excitation pulse,a charge pump boost circuit and a field-effect tube circuit.In allusion to the faint echo signal,through the analysis of the loop structure and the echo signal,the AD8420 amplifier and the comparison shaping circuit are used to make the echo signal processing circuit,and the echo signal is modulated into a square wave signal with a amplitude of 5V.Based on the requirement of the precision of water level measurement in irrigation area,the timing circuit is composed of D flip-flop,non gate and single chip computer,and the time interval between excitation pulse and echo signal is modulated into PWM waveform,which is convenient for accurate timing.At last,the peripheral circuit of single-chip microcomputer is designed.After completing the hardware circuit of each module,we use C language to write the sensor program to realize the water level measurement.The sensor has the characteristics of high precision,low power consumption and stable and reliable.(2)Water level flow collection system in irrigation area.Using the trapezoidal channel as the typical channel of this research,utilizing the self-developed magnetostrictive water level sensor as the channel water level collection sensor of the irrigation area,the water level information is sent to the remote Cloud service by GPRS wireless transmission Equipment WG-8010 GPRS DTU.In the remote cloud server,the corresponding flow value is calculated according to the fitted water level-flow formula,the data is saved to the My SQL data of the cloud service,and the data acquisition device is designed to store the local SD card.In order to facilitate the management staff to log on to view the water regime trends and download historical data,the design based on Linux Cloud Server irrigation Channel level flow collection system site.In this paper,the sensor technology,GPRS wireless transmission technology,My SQL technology and cloud server technology are synthetically applied,and a set of system is designed and developed to monitor the water level flow in the irrigation area remotely.The whole test proves that the system is stable,reliable,high measuring precision and low cost,and can be applied to the measurement of canal water level in irrigation district,and has higher application value.