摘要
群体农业机器人是农业机器人研究的前沿,为了研究大田WI-FI信号的传播特性,进而为大田群体农业机器人的无线通信等工作提供技术依据,研究了小麦成熟期麦田中2.4 GHz WI-FI无线信号在不同传输距离时的信号强度和信号传输率等特性。首先,实地测试了麦田每隔1.5m处的信号百分比强度和信号传输率;其次,对试验数据进行了回归分析和建模;最后,将测得的信号强度数据与平坦空地测试数据、自由空间损耗模型数据进行了对比分析。研究表明:2.4GHZWI-FI无线信号的百分比强度衰减符合三次多项式衰减模型,相关系数为0.948 6,均方根误差为4.98%;2.4GHz WI-FI无线信号对数传输率符合三次多项式模型,相关系数为0.943 2,均方根误差为1.589 dbt。结果表明:所构建的信号百分比强度模型和信号传输率模型能较好地预测麦田各接收点的信号强度和数据传输率;小麦反射和散射作用对WI-FI信号强度产生较大的衰减,大于平坦地面的衰减作用,且表现为近距离快速衰减和稳定衰减两个阶段。
For agricultural multi-robots are the forefront of agricultural robotics research, to understand the WI-FI signal propagation characteristics and then provide the technical basis for agricultural robots communicating with each other in farmland fields, this paper studied the signal attenuation and transmission rate of 2.4 GHz WI-FI radio channel in ripe wheat fields at different distances. Firstly, the percentage signal strength and signal transmission rate of wheat field were tested at intervals of 1.5m. Secondly, a regression analysis of experimental data was conducted. At last the measured signal strength was compared with flat open ground test data and free space loss model data. Test data analysis showed that 2.4GHz WI-FI wireless percentage signal strength attenuation conform to cubic polynomial decay model, the correla- tion coefficient is 0. 948 6, root mean square error is 4.98%. The signal logarithmic transmission rate is also consistent with cubic polynomial model, the correlation coefficient is 0. 943 2, root mean square error is 1. 589dbt. The results showed that the constructed percentage signal strength model and signal transmission rate model was effective in predicting signal strength and data transfer rate of each wheat receiving point and that reflection and scattering of wheat makes WI- FI signal strength greater attenuation, which much larger than the attenuation of flat ground, and it showed close fast de- cay and stable attenuation of two stages.
出处
《农机化研究》
北大核心
2015年第2期155-160,共6页
Journal of Agricultural Mechanization Research
基金
"十二五"国家科技支撑计划项目(2012BAH29B04)
