蓝牙室内测距模型研究与精度分析

Research and precision analysis of indoor ranging model based on Bluetooth

针对低功耗蓝牙进行室内定位过程中,蓝牙信号在室内传播过程中受到多路径、反射、非视距等误差的影响,导致蓝牙信号值存在波动性、奇异值等问题,进一步导致测距误差较大。为了验证环境对信号传播的影响,本文验证了3种主要影响因素对信号值的影响,并提出3种滤波方法对采集的初始值进行预处理;根据实际环境利用最小二乘法分段拟合测距模型;根据拟合的测距模型与处理后的RSSI值,得到准确的测距信息。实验表明,利用分段拟合的测距模型和混合滤波方法处理后的强度值,测距精度得到了明显的提高。

Aiming at the problem that the Bluetooth signal value existed fluctuation and singular value due to the influence of multipath,signal reflection and NLOS,et al.in the process of indoor positioning,therefore,Bluetooth ranging error was large.In order to verify the influence of environmental factors on Bluetooth signal propagation,three experiments with different environmental influence factors were designed.Firstly,three filtering methods were proposed to preprocess the initial values of Bluetooth signals.Then,least square method was used to fit the ranging model in different segment according to the actual environment.Finally,accurate ranging information was obtained according to the fitted ranging model and the processed RSSI value.The final experiments showed that using the segmented-fitting ranging model and the intensity value processed by the hybrid filtering method,the ranging accuracy had been significantly improved.