铁道标准设计
鐵道標準設計
철도표준설계
RAILWAY STANDARD DESIGN
2014年
12期
125-129,130
,共6页
城市有轨电车%GPS/RFID组合定位%BP神经网络%定位精度
城市有軌電車%GPS/RFID組閤定位%BP神經網絡%定位精度
성시유궤전차%GPS/RFID조합정위%BP신경망락%정위정도
City trams%GPS/RFID integrated positioning%BP neural network%Positioning accuracy
在城市有轨电车定位系统中,单一的GPS定位方式已很难满足电车连续精确定位的要求。采用GPS和RFID组合定位的方法,可实现在弱信号环境下的连续精确定位。针对GPS/RFID组合定位时,因加入RFID观测值带来的较高计算复杂度而引起定位时间延长,以及对系统定位误差影响不确定性等问题,建立基于BP神经网络的城市有轨电车GPS/RFID组合定位模型。仿真结果表明,采用BP神经网络进行分析时,将GPS和RFID观测值归一化后输入到训练好的网络中,可以在较短的时间内得到可靠的网络输出。经训练后的网络输出较未经训练的输出更接近于期望值,且更为稳定,证明在GPS信号受遮挡条件下城市有轨电车定位系统的定位精度和定位时长得到了有效改善。
在城市有軌電車定位繫統中,單一的GPS定位方式已很難滿足電車連續精確定位的要求。採用GPS和RFID組閤定位的方法,可實現在弱信號環境下的連續精確定位。針對GPS/RFID組閤定位時,因加入RFID觀測值帶來的較高計算複雜度而引起定位時間延長,以及對繫統定位誤差影響不確定性等問題,建立基于BP神經網絡的城市有軌電車GPS/RFID組閤定位模型。倣真結果錶明,採用BP神經網絡進行分析時,將GPS和RFID觀測值歸一化後輸入到訓練好的網絡中,可以在較短的時間內得到可靠的網絡輸齣。經訓練後的網絡輸齣較未經訓練的輸齣更接近于期望值,且更為穩定,證明在GPS信號受遮擋條件下城市有軌電車定位繫統的定位精度和定位時長得到瞭有效改善。
재성시유궤전차정위계통중,단일적GPS정위방식이흔난만족전차련속정학정위적요구。채용GPS화RFID조합정위적방법,가실현재약신호배경하적련속정학정위。침대GPS/RFID조합정위시,인가입RFID관측치대래적교고계산복잡도이인기정위시간연장,이급대계통정위오차영향불학정성등문제,건립기우BP신경망락적성시유궤전차GPS/RFID조합정위모형。방진결과표명,채용BP신경망락진행분석시,장GPS화RFID관측치귀일화후수입도훈련호적망락중,가이재교단적시간내득도가고적망락수출。경훈련후적망락수출교미경훈련적수출경접근우기망치,차경위은정,증명재GPS신호수차당조건하성시유궤전차정위계통적정위정도화정위시장득도료유효개선。
It is difficult to realize the continuous and precise positioning in the positioning system of city trams only by GPS, while it can be performed with the integration of GPS and RFID in the environments with weak signals. A model of GPS/RFID integrated positioning of city trams with the application of BP neural network is established to solve the problems of prolonged positioning caused by high computation complexity and the uncertainties of the impact on the system positioning errors with the introduction of RFID observations in GPS/RFID integrated positioning. The analysis indicates that the reliable network output values are to be obtained in a short period of time after the input of the normalized GPS and RFID observations into the trained network in positioning analysis with the application of BP neural network. The output values of the trained network, which are more stable and closer to the expectations than the ones of the untrained network, demonstrate the improvement of positioning accuracy and the shortening of positioning time in the positioning system of city trams under the condition of blocked GPS signals.