声表面波室内定位系统与算法研究

鉴于声表面波技术的无源优势,搭建了由声表面波标签和阅读器构成的室内定位系统,在测量标签回波信号强度时,可有效减小多径效应的影响。设计了以三边定位为基础的定位算法,包括测距、选星、位置估计3个阶段,分析了3个定位圆之间位置关系可能出现的全部情况,并有针对性地进行自适应修正。仿真测试结果验证了定位算法的定位误差小于根心法和加权质心法。系统测试结果表明,定位系统可实现2 m×2 m的定位,平均定位误差为31.84 cm。室内定位系统和算法以较少的锚节点实现了较小的室内定位误差。

Research on Surface Acoustic Wave Indoor Positioning System and Algorithm

In view of the passive advantages of surface acoustic wave(SAW) technology, an indoor positioning system composed of SAW tag and reader is set up, which can effectively reduce the influence of multipath effects when measuring the echo signal strength of the SAW tag. A positioning algorithm based on trilateral positioning is designed, including three stages of ranging, satellite selection, and position estimation. All possible situations of the positional relationship among the three positioning circles are analyzed and the adaptive corrections are carried out accordingly. The simulation test results verify that the positioning error of the positioning algorithm is smaller than that of the radical center method and the weighted centroid method. The system test results show that the positioning system can realize positioning range of 2 m×2 m with an average positioning error of 31.84 cm. The indoor positioning system and algorithm achieve smaller indoor positioning errors with fewer anchor nodes.