基于应变片测力原理研制了一种新型嵌入式土壤压实度传感器和车载行进式农田土壤压实度实时测量系统。该系统将微型压力传感器嵌入到锥体前部,直接测量行进过程中锥头受到的土壤阻力,简化了测量结构,提高了系统的复合度。以超低功耗MSP430单片机作为内核的数据采集器实现了多路模拟信号的测量,2个串口分别用于与上位机的通讯和GPS信号的接收,采用PDA作为数据处理、存储以及显示终端。传感器实验室标定结果表明,嵌入式土壤压实度传感器输出电压与标准载荷具有良好的线性关系。田间试验结果表明,车载行进式农田土壤压实度实时测量系统工作稳定,土壤压实度测量结果与GPS信息融合效果良好,系统能够快速获取农田土壤压实度及其空间变异信息。
A new embedded sensor based on the principle of measuring forces with strain gauges and real-time system for measurement of soil compaction was developed, The soil compaction sensor was embedded in the front of the cone; the tip can directly transmit the pressure from the soil to the sensor, which simplifies the structure of measuring system and increases the systematic synthesized degree, The data acquisition system that uses MSP430 as its core collects signals and accomplishes A/D conversion. Two serial ports complete the communication with PDA and receive the GPS signals, in which PDA is used for processing and saving data. The experimental results showed that the embedded sensor for measuring soil compaction could effectively reflect the compaction variation in the field, the function of the real-time system performed well for long time operation and the agreement of the signals from the integrated sensor and GPS was good.