压电式谷物质量流量传感器设计及试验

Design and test of a novel piezoelectric grain mass flow sensor

设计了一种新型压电式谷物质量流量传感器,以实现实时动态测量田间谷物产量.应用LS-DYNA显式动力学软件仿真研究了谷粒冲击力敏元件的过程,对力敏元件的材料进行筛选,根据计算结果确定传感器力敏元件的材料为铝合金;建立了压电式谷物质量流量传感器的三维有限元模型,应用ANSYS软件对压电式谷物质量流量传感器进行模态分析,使传感器固有振动频率避开了联合收割机的固有振动频率;用ARM9开发板作为开发工具,在WINCE平台上开发了数据采集和处理的EVC程序;对传感器进行了标定试验,传感器的线性相关系数达到0.999 4;对压电式谷物质量流量传感器分别进行了室内试验和田间试验,结果均表明该型传感器有较高的精度.

To acquire the grain yield information real time,a novel piezoelectric grain mass flow sensor was invented.Processes of single grain impacts on different sensitive elements of sensors which were made of aluminum alloy,steel No.45,ceramic and PVC were simulated respectively in LS-DYNA plat-form to select right force sensitive element material.Based on the simulation result,aluminum alloy was selected as force sensitive element material.Meanwhile,this sensor′s natural vibration frequency was computed based on the finite element model.From the computing result it′s concluded that this sensor′s natural vibration frequency is different from the combine′s.Furthermore,the program of data acquisition and processing was developed in WINCE platform applying C＋＋ programming language.This sensor′s calibration test shows that its linear relative coefficient is up to 0.999 4.Both indoor and farm test results indicate that this sensor is of high precision and prospect for applications.