Chia-Yuan Li

National Cheng Kung University, 臺南市, Taiwan, Taiwan

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Publications (3)4.73 Total impact

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    ABSTRACT: Digital mobile mapping, which integrates digital imaging with direct geo-referencing, has developed rapidly over the past fifteen years. The direct geo-referencing is the determination of time variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose today are satellite positioning by GPS and inertial navigation using an IMU. They are usually integrated in such a way that the GPS receiver is the main position sensor, while the IMU is the main orientation sensor. KF is considered the optimal estimation tool for teal-time INS/GPS integrated kinematic positioning and orientation determination. In post-mission processing, on the other hand, data from the whole mission can be used to estimate the trajectory. When filtering is used in the first step, an optimal smoothing algorithm can be applied to achieve higher accuracy for mobile mapping applications.An intelligent and hybrid scheme consisting of an ANN and KF is proposed to overcome the limitations of KF and to improve the performance of an INS/GPS integrated system from a previous study. However, the accuracy requirements of general mobile mapping applications cannot be achieved easily even by using an ANN–KF scheme. Therefore, this study proposes an ANN embedded RTS backward smoother to enhance the overall accuracy of POS parameters for a tactical grade INS/GPS integrated system in a post-mission mode. Combing the tactical grade INS/GPS integrated system and intelligent POS scheme proposed in this study, a cheap but reasonably accurate POS can be anticipated.
    Applied Soft Computing 03/2011; 11:2633-2644. · 2.68 Impact Factor
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    [Show abstract] [Hide abstract]
    ABSTRACT: Digital mobile mapping, which integrates digital imaging with direct geo-referencing, has developed rapidly over the past fifteen years. Direct geo-referencing is the determination of the time-variable position and orientation parameters for a mobile digital imager. The most common technologies used for this purpose today are satellite positioning using Global Positioning System (GPS) and Inertial Navigation System (INS) using an Inertial Measurement Unit (IMU). They are usually integrated in such a way that the GPS receiver is the main position sensor, while the IMU is the main orientation sensor. The Kalman Filter (KF) is considered as the optimal estimation tool for real-time INS/GPS integrated kinematic position and orientation determination. An intelligent hybrid scheme consisting of an Artificial Neural Network (ANN) and KF has been proposed to overcome the limitations of KF and to improve the performance of the INS/GPS integrated system in previous studies. However, the accuracy requirements of general mobile mapping applications can't be achieved easily, even by the use of the ANN-KF scheme. Therefore, this study proposes an intelligent position and orientation determination scheme that embeds ANN with conventional Rauch-Tung-Striebel (RTS) smoother to improve the overall accuracy of a MEMS INS/GPS integrated system in post-mission mode. By combining the Micro Electro Mechanical Systems (MEMS) INS/GPS integrated system and the intelligent ANN-RTS smoother scheme proposed in this study, a cheaper but still reasonably accurate position and orientation determination scheme can be anticipated.
    Sensors 01/2009; 9(4):2586-610. · 2.05 Impact Factor
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    Chia-Yuan Li, Yun-Wen Huang, Kai-Wei Chiang
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    ABSTRACT: The new generation Positioning and Orientation System (POS) that integrates Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS) has become the core element of next generation spatial information acquisition systems or mobile mapping systems. The higher positioning and attitude estimation accuracy requirements of a modern mobile mapping system that integrates digital mapping camera, LIDAR, and video camera with a geo-referenced platform from geomatics engineering applications further revolutionize the latest development of those technologies adopted by INS/GNSS integrated positioning and navigation system. The accuracy requirement of mobile mapping system is at least ten times higher than that of general navigation applications, it means that geomatics applications dominate the progress of INS/GNSS technologies in terms of accuracy requirements. Therefore, the primary objective of this research is to develop INS/GNSS integrated POS, including hardware and advanced software architecture to meet the demands for engineering solutions as well as possible scientific applications. The advantages of INS/GNSS technologies in this application include high sampling rate of measurement (>50Hz) and full navigation states including positions, velocities, attitudes and accelerations of the movement of 3 axes. This cannot be done by current GPS or accelerometer- based technologies. This research concerns the development of INS/GNSS integrated technologies for monitoring skyscrapers in Taiwan. Currently, we have been granted the permission to set up observation stations on the top of skyscrapers like Taipei 101 (509.2 meters high), the second highest skyscraper in the world, and 85 SKYTOWER (347.5 meters high), an 85-floor skyscraper located in Kaohsiung City, Taiwan. This would be the first try around the globe to adopt precise INS/GNSS integrated POS to monitor high-rise buildings. In the analysis process, a standard FFT and the second generation of Wavelet transformation will be investigated as well. Such systems can be adopted for seismic events monitoring or earthquake early warning system in the future.

Publication Stats

12 Citations
4.73 Total Impact Points

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Institutions

  • 2011
    • National Cheng Kung University
      • Department of Geomatics
      臺南市, Taiwan, Taiwan