针对工业现场自动导引运输车(AGV)定位方式灵活性差的问题,应用DW1000射频(RF)芯片,设计实现了一种超宽带(UWB)室内定位系统。首先,提出了高效的多基站测距和多标签调度机制,解决标签冲突和组网问题。其次,针对三角形质心算法实际应用中测距极大误差引起的定位精度低、稳定差的问题,引入可信度概念,提出了内三角形质心算法,通过可信度算子削弱测距极大误差的影响,提高算法性能。最后,将该系统应用于工业车间,当系统容纳20个标签时,单个标签的坐标平均更新频率达到24 Hz,标准差为3 Hz;静态平均定位误差为11.7 cm,标准差为2.5 cm;动态最大误差小于30 cm。实验结果表明,该系统具有高实时性、高精度和高稳定性的特点。
Aiming at the poor flexibility of Automated Guided Vehicle (AGV) localization method in industrial working field, an Ultra WideBand (UWB) indoor localization system by using DW1000 Radio Frequency (RF) chip was designed and implemented. Firstly, to solve the problem of conflicts and networking of tags, the efficient mechanisms for multi-station ranging and multi-tag scheduling were proposed. Secondly, concerning the low accuracy and poor stability of the triangle centroid localization algorithm caused by maximal ranging errors, a concept of credibility was introduced and the inner triangle centroid algorithm was proposed, which could weaken the influence of maximal ranging errors through credibility coefficient to improve the algorithm performance. Finally, the proposed system was applied to the industrial workshop with 20 tags. For a single tag, the average frequency of coordinate updating reached 24 Hz and its standard deviation was 3 Hz; the static average localization error was 11.7 cm and its standard deviation was 2.5 cm; the dynamic maximum error was within 30 cm. The experimental results show that the proposed localization system has the characteristics of high real-time performance, high precision and high stability.