基于UWB的室内停车场高精度定位系统设计

将基于TOA测距的 UWB高精度定位技术运用于室内停车场车辆定位系统.选用 DW1000射频收发器设计定位节点硬件,采用时分复用机制实现多标签共享信道.分析测距误差来源,认为信号飞行时间的测量值相对于真实值的误差应该由节点的时钟漂移、本地响应延迟和飞行时间真实值表示,因此,从该角度详细推导并仿真对比4种测距算法受时钟漂移影响的程度,最终选定改进的SDS-TWR算法进行测距.实验发现天线延迟会给测距结果带来相对固定的偏差,针对这一测距误差,提出通过修正天线延迟参数予以校正.基于均方误差最小化方法,采用约束线性最小二乘定位算法估计标签位置.实验结果表明,测距精度小于4 cm,定位精度不超过20 cm,能够满足室内停车场车辆定位系统的厘米级精度要求.

Design of lndoor Parking Areas High-precision Localization System Based on UWB

In the paper,UWB which is a high precision localization technology based on TOA ranging is applied to indoor parking areas localization system.The DW1000 RF transceiver is chosen to design anchors and tags.TDM mechanism is used to achieve that one chan-nel is shared by the multiple tags.The source of the ranging error is analyzed,it is proposed that the error between the measured value and the true value of time of flight of signal should be expressed by the clock drift of the node,the local response delay and the true value of TOF.From this perspective,the ranging error is derived in detail.And ranging errors of four ranging algorithms caused by clock drift are simulated and compared.Finally,the advanced SDS-TWR algorithm is applied.It is found that the antenna delay brings a relatively fixed deviation to the ranging results.To correct this error,it is proposed to adjust the antenna delay parameter.Depending on the mean square error minimization method,the constraint linear least squares localization algorithm is used to estimate the tag position.The result of experiments show that the accuracy of ranging is less than 4 cm,and the accuracy of localization is not more than 20 cm.Therefore, this localization system can meet the requirements of centimeter-level accuracy for indoor parking areas.