水平贯入式土壤压实度测试系统及试验研究

Design and Experiment of Soil Compaction Testing System in Horizontal Penetration

针对土壤压实度检测的需求,本研究应用CFBLS-100型拉压传感器和基于PCMCIA总线的DAQP-12数据采集卡,在LabVIEW环境下设计了一套土壤压实度现场测试系统。该系统能够实时显示传感器输出电压及所对应的压力变化曲线,并将所采集到的数据存储到计算机中,完成对数据的分析。经标定试验证明:该测试系统所拟合的方程为线性,其相关系数较高,线性度较好,灵敏度较高,系统精度等级小于1级,工作时系统稳定可靠。由室内试验知,在不同水平分层处,土壤压实度与不同模拟压力间均表现出3次多项式的函数关系,显著性较强(α<0.05)。且在不同模拟压力下,不同土壤水平分层处的土壤压实度和土壤容重表现出相似的特性,随着模拟压力的增加和土壤分层逐步加深,土壤压实度和土壤容重的增加趋势趋于一致。为研究作物地下组织与土壤之间的根土系统及合理耕层的构建提供理论基础,并为农业机械的研发具有一定的意义。

A site testing system was developed based on CFBLS-100 type pull-press sensor and DAQP-12 data acquisition card according to the needs for detecting methods and devices of soil compaction. The DAQP-12 data acquisition card was built based on the PCMCIA bus. Meanwhile, the testing interface of site testing system was designed using the LabVIEW software. The output voltage of the sensor and the corresponding pressure curve were displayed in this system and these data were stored and analyzed in the computer. The calibration experiment showed that the system worked stably if the fitting equation was linear with high correlation coefficient, linearity, and system sensitivity, and system accuracy less than 1. The results of laboratory test showed that artificial load had significantly cubic polynomial functional relationships with soil compaction and soil bulk density in different soil horizontal stratification （P 〈 0.05）. Under different levels of artificial load, soil bulk density and soil compaction had similar characteristics at different soil horizontal stratification, which indicated that soil compaction and soil bulk density increased with the artificial load and soil depths. The development of this system had significant promoting effects on configuration model between underground crop and soil and the development of reasonable topsoil, and accelerated the design for agricultural machinery.