This paper proposes a practical and improved position estimation method for real-industry application in localizing a mobile robot that is designed to move along a pre-defined path. The proposed method replaces the use of proximity sensors with much more economical UHF passive RFID tags to perform localization tasks. Considering that there is already a wide dissemination of RFID tags in various industries, the proposed method allows efficient and effective estimation of the position of a target mobile robot by using the already-present matrix of RFID tags as a reference point for localization. Particularly, the proposed method makes use of two readers with identical emission configurations attached to a mobile robot to identify a reference RFID tag. By utilizing the RSSI obtained by the readers from the reference RFID tag, the precise position of the moving robot can be obtained. The experiments prove the effectiveness achieved by the proposed method in improving the accuracy of robot position estimation.