トンネル施工現場における無線LAN位置推定のための精度改善手法の提案

摘要

本稿では，トンネル施工現場に無線LAN 位置推定技術を適用する際に生じる課題について述べ，その解決策を提案する．トンネル施工現場に無線LAN 位置推定を適用した場合，計測時刻の差によって発生する受信信号強度の変化が精度を低下させるという問題がある．この問題を解決するために受信信号強度の時刻変化を補正する手法を述べ，無線LAN によるシーン解析法と多辺測量法に適用する．また実験を行い，実際のトンネル環境での提案手法による補正の効果を評価する．結果から，シーン解析法の正答率は5.4％，平均誤差は28％改善し，多辺測量法では平均誤差が37％改善することを確認した．%In this paper, we present a serious degradation problem with positioning accuracy that occurs when applying wireless LAN-based positioning systems to a tunnel construction site and propose a correction method to solve the problem. The degradation is due to considerable time variation in the received signal strength. In order to mitigate the impact of the time variation, the proposed method corrects the measured signal strength. It is designed for two localization methods: i.e., location fingerprinting and multi-lateration. Furthermore, we evaluate the effectiveness of the proposed method by experiments at an actual tunnel construction site. From the results, we confirm that location fingerprinting with the proposed correction can improve the successful ratio by 5.4% and the average error by 28%, as compared to that without the correction. Moreover, as for multi-lateration with the correction, the average error is reduced by 37%.