基于PVDF压电传感器的水滴冲击力检测系统

Detection System of Droplet Impact Force Based on PVDF Sensor

水滴冲击力是衡量喷头性能的重要技术指标。水滴撞击土壤表面产生的冲击会冲蚀土壤,引起板结,影响入渗,损伤作物。设计一种水滴冲击力自动检测系统和水滴自动发生试验装置,实现对水滴冲击力的自动测量。系统选用PVDF压电传感器作为力检测元件,采用USB7333高速数据采集卡,利用Lab Windows/CVI编写数据采集与处理程序,获取水滴冲击力检测数据。试验实现了在水滴频率、大小稳定控制试验条件下,对不同水滴大小冲击力的动态测量。结果表明:PVDF压电传感器对水滴冲击力检测具有良好的动态响应特性;水滴冲击力与传感器输出电压具有良好的线性关系,拟合程度达0.936,系统测量误差小于10%。利用该系统测定水滴冲击力,解决了传统人工测量的不稳定问题。

The water droplets impact of irrigation equipment is an important technical indicator for measuring nozzle performance. The impact force of water droplets hit the surface of the soil would erode the soil,causing soil compaction,resulting in runoff affect the infiltration effect,while water droplets impact would cause foliar damage,which affects crop growth. This paper developed a droplet impact automatic detection system to measure the water droplets impact force. The PVDF piezoelectric sensor was chosen as the sensing element,and the water droplets automatically generating device was designed by a stepping motor drive and system was controlled by a microcontroller. The USB7333 high-speed data acquisition card was used and the program was written in Lab Windows / CVI-based computer data acquisition and process procedures to detect the water impact force. As the result,in the frequency of water droplets,the size of the stability control experimental conditions,the detection system could achieve the dynamic measurement of different droplets size to show that the PVDF piezoelectric sensor for detecting water droplet impact with good dynamic response. The result proved that the water droplets micro force sensor output voltage had a good linear relationship,and the trend line with the actual data fitting degree of 0. 936,the system measurement error less than 10%. This droplet impact force detection system solves the traditional manual measurement method of water droplets instability problems and has great practical application value.