Research On 3D Positioning Technology Of Wireless Sensor Node In Forestry Internet Of Things

At present,wireless sensor node positioning technology is mostly used in indoor environments or open outdoor environments,and there are few researches on positioning in complex environments such as forests,and most positioning algorithms are for two-dimensional planes,and there is a lack of research on positioning algorithms in three-dimensional space.Taking the forestry wireless sensor network node positioning as the application background,the node positioning method based on the dual-band received signal strength(RSSI)is studied,the propagation characteristics of the dual-band signal in the complex environment of the forest area are analyzed,the environmental loss model is established,and the ranging method Optimize the three-dimensional positioning algorithm based on the ranging method,and study the three-dimensional positioning technology of forest wireless sensor network nodes.According to the basic principles of wireless sensor node positioning,the commonly used node positioning methods based on ranging method and non-ranging method are analyzed.Aiming at the complex environment of the forest area,establish an RSSI ranging and positioning solution based on 2.4GHz and 433MHz dual-band signals,and test the RSSI value of the dual-band signal transmitted in different forest environments through a self-designed dual-band wireless sensor network node,and analyze the signal Transmission characteristics.The test data fitting results show that the signal attenuation index of the dual-band RSSI data and the logarithmic distance loss model is between 2.297～2.853,and the goodness of fit is between 0.907～0.967,indicating that the logarithmic distance loss model is suitable for forest areas Signal loss prediction for the environment.According to the environmental parameters of the verification and experimental forest areas,a signal attenuation model suitable for the forest environment is further established.Based on the RSSI ranging method,a ranging method that integrates dual-band signal information is proposed.Through experiments in different forest environments,the optimal fusion weight parameters are obtained,and the dual-band information is fused.Using the fusion ranging algorithm to carry out the field ranging experiment in the experimental site,the root mean square error of the result is 1.74m,which is 31.3%less than the ranging error of a single frequency band,which proves that the ranging result of the fusion dual-band ranging is necessary Better than the ranging result of a single frequency band.On the basis of obtaining more accurate ranging results,the traditional four-side positioning algorithm based on the ranging method is improved,and an optimized three-dimensional positioning algorithm is designed based on the improved four-side positioning algorithm and the three-dimensional Euclidean positioning algorithm.The four-side positioning algorithm,the improved four-side positioning algorithm,the 3D Euclidean positioning algorithm and the optimized 3D positioning algorithm are simulated and compared through MATLAB software.The root mean square error value of the positioning results of the two optimization algorithms is lower than that of the traditional algorithm,and the four-side positioning algorithm is improved.The RMSE error value is reduced by 30.57%compared with the four-side positioning algorithm,which verifies the advantages of the optimization algorithm in positioning accuracy.It has certain reference significance for the application of forestry wireless sensor network node positioning technology and the research of network deployment.