The Experts below are selected from a list of 30753 Experts worldwide ranked by ideXlab platform
Derek D Lichti - One of the best experts on this subject based on the ideXlab platform.
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Terrestrial Laser Scanner self-calibration: Correlation sources and their mitigation
ISPRS Journal of Photogrammetry and Remote Sensing, 2010Co-Authors: Derek D LichtiAbstract:Instrument calibration is recognised as an important process to assure the quality of data captured with a terrestrial Laser Scanner. While the self-calibration approach can provide optimal estimates of systematic error parameters without the need for specialised equipment or facilities, its success is somewhat hindered by high correlations between model variables. This paper presents the findings of a detailed study into the sources of correlation in terrestrial Laser Scanner self-calibration for a basic additional parameter set. Several pertinent outcomes, resulting from experiments conducted with simulated data, and 12 real calibration datasets captured with a Faro 880 terrestrial Laser Scanner, are presented. First, it is demonstrated that panoramic-type Scanner self-calibration from only two instrument locations is possible so long as the scans have orthogonal orientation in the horizontal plane. Second, the importance of including Scanner tilt angle observations in the adjustment for parameter de-correlation is demonstrated. Third, a new network measure featuring an asymmetric distribution of object points that does not rely upon a priori observation of the instrument position is proposed. It is shown to be an effective means to reduce the correlation between the rangefinder offset and the Scanner position parameters. Fourth, the roles of several other influencing variables on parameter correlation are revealed. The paper concludes with a set of recommended design measures to reduce parameter correlation in terrestrial Laser Scanner self-calibration. © 2009 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).
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terrestrial Laser Scanner self calibration correlation sources and their mitigation
Isprs Journal of Photogrammetry and Remote Sensing, 2010Co-Authors: Derek D LichtiAbstract:Instrument calibration is recognised as an important process to assure the quality of data captured with a terrestrial Laser Scanner. While the self-calibration approach can provide optimal estimates of systematic error parameters without the need for specialised equipment or facilities, its success is somewhat hindered by high correlations between model variables. This paper presents the findings of a detailed study into the sources of correlation in terrestrial Laser Scanner self-calibration for a basic additional parameter set. Several pertinent outcomes, resulting from experiments conducted with simulated data, and 12 real calibration datasets captured with a Faro 880 terrestrial Laser Scanner, are presented. First, it is demonstrated that panoramic-type Scanner self-calibration from only two instrument locations is possible so long as the scans have orthogonal orientation in the horizontal plane. Second, the importance of including Scanner tilt angle observations in the adjustment for parameter de-correlation is demonstrated. Third, a new network measure featuring an asymmetric distribution of object points that does not rely upon a priori observation of the instrument position is proposed. It is shown to be an effective means to reduce the correlation between the rangefinder offset and the Scanner position parameters. Fourth, the roles of several other influencing variables on parameter correlation are revealed. The paper concludes with a set of recommended design measures to reduce parameter correlation in terrestrial Laser Scanner self-calibration.
Wonje Jang - One of the best experts on this subject based on the ideXlab platform.
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TENCON - Object Classification of Laser Scanner by Using Recurrent Neural Network
TENCON 2018 - 2018 IEEE Region 10 Conference, 2018Co-Authors: Jhonghyun An, Wonje JangAbstract:These days, Laser Scanners becomes the primary sensor for advanced driver assistance system (ADAS). The most important theme of ADAS is to distinguish surroundings of egovehicle because notification of situation is the beginning of ADAS such as path planning, mapping and tracking. In this paper, we present approach for object classification by using a Laser Scanner mounted in vehicle. For object classification, we suggest Recurrent Neural Network (RNN) which is widely used in linguistic study or language model. We rearrange Laser Scanner data to equivalent theta intervals and apply recurrent neural network model to identify of class about Laser Scanner point. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments indicate that the proposed method has good performance in real-life situation.
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Object Classification of Laser Scanner by Using Recurrent Neural Network
TENCON 2018 - 2018 IEEE Region 10 Conference, 2018Co-Authors: Jhonghyun An, Wonje JangAbstract:These days, Laser Scanners becomes the primary sensor for advanced driver assistance system (ADAS). The most important theme of ADAS is to distinguish surroundings of egovehicle because notification of situation is the beginning of ADAS such as path planning, mapping and tracking. In this paper, we present approach for object classification by using a Laser Scanner mounted in vehicle. For object classification, we suggest Recurrent Neural Network (RNN) which is widely used in linguistic study or language model. We rearrange Laser Scanner data to equivalent theta intervals and apply recurrent neural network model to identify of class about Laser Scanner point. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments indicate that the proposed method has good performance in real-life situation.
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Histogram-model based road boundary estimation by using Laser Scanner
2016 16th International Conference on Control Automation and Systems (ICCAS), 2016Co-Authors: Jhonghyun An, Wonje JangAbstract:In this paper, we present road boundary estimation based on Laser Scanner by using histogram model. For raw Laser Scanner data, we apply histogram model, which means that the histogram of the number of Laser point is applied from a center of ego-vehicle. After histogram is made, we estimate the boundary point and select point of road boundary. We estimate selected points to clothoid model and update them by using Kalman filter. Experimental results carried out with Laser range data illustrate the robustness of our approach.
Kunsoo Huh - One of the best experts on this subject based on the ideXlab platform.
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Sensor Fusion Algorithm Design in Detecting Vehicles Using Laser Scanner and Stereo Vision
IEEE Transactions on Intelligent Transportation Systems, 2016Co-Authors: Seungki Kim, Hyunkyu Kim, Wonseok Yoo, Kunsoo HuhAbstract:—It is well known that Laser Scanner has better accu-racy than stereo vision in detecting the distance and velocity of the obstacles, whereas stereo vision can distinguish the objects better than the Laser Scanner. These advantages of each sensor can be maximized by sensor fusion approach so that the obstacles in front can be detected accurately. In this paper, high-level sensor fusion for the Laser Scanner and stereo vision is developed for object matching between the sensors. Time synchronization, object age, and reordering algorithms are designed for robust tracking of the objects. A time-delay update algorithm is also developed to deter-mine the process time delay of the Laser Scanner. The expanded Laser Scanner data at every 1 ms is predicted by Kalman filter and is matched with the stereo vision data at every 66 ms. A cost function is formulated to describe the object matching similarity between the sensors, and the best matching candidate is selected for the minimum cost function. The proposed matching algorithms are verified experimentally in field tests of various maneuvering cases.
Xinghu Fu - One of the best experts on this subject based on the ideXlab platform.
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A terrestrial 3D Laser Scanner: accuracy tests
ACM Transactions on Graphics, 2013Co-Authors: Changqing Zou, Jingbin Jianbo Jianzhuang Liu, Xiaoming Li Zhang, Lingli Zhu, Zhengjun Liu, Weihong Bi, Juha Hyyppä, Kun Zhang, Xinghu FuAbstract:Systems of measurement and calculation based on a terrestrial Laser Scanner (called a close-range Laser Scanner) are increasingly being used for surveying, documentation, and solid modeling of three-dimensional monuments, sites, and scenes. One of these systems, the Cyrax 2400, is of great interest because of its rapidity in scanning and creation of 3-D models (1000 points/sec--range 1.5 to 100 m). However, it is important to assess the accuracy of the models obtained with this and similar instruments, especially in the measurement of complex 3-D objects. Some recent measurements with the Cyrax system allowed the authors to perform the tests presented here. The measured object was a historic building (15th century) near the city of Ferrara, Italy. The authors studied the accuracy achieved in the positioning of natural points and targets situated on parts of the building. The 3-D positioning of these points and targets were carried out with different object-Scanner distances (from 5 to 100 m) and with different inclinations of the Laser impulses; the aim was to systematically evaluate the parameters determining the measurement accuracy of the Laser Scanner. To perform these assessments, the targets and natural points were also measured with traditional high-accuracy topographic instrumentation. The results of the Cyrax measurement were then compared with those of topographic measurement.
Abdullah F Al-dwairi - One of the best experts on this subject based on the ideXlab platform.
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2D Laser Scanner selection using fuzzy logic
Expert Systems With Applications, 2011Co-Authors: Tarek Al-hawari, Omar Al-araidah, Samir Khrais, Abdullah F Al-dwairiAbstract:Research highlights? Fuzzy logic is used as a multi-criteria selection tool of 2D Laser Scanners. ? Selection criteria are identified and classified into static and dynamic based on their dependency on the application. ? The ability of fuzzy logic to deal with quantitative as well as qualitative factors is shown. Laser Scanners are widely used today in many fields. This paper presents a multi-criteria decision-making selection process of these sensors for different applications using a fuzzy logic approach. Factors affecting the selection process are divided into dynamic and static ones based on their dependency on the application considered. Fuzzy sets and fuzzy rules are used to translate implicit and vague expert opinions provided in linguistic terminology into assessment ratings for different types of Laser Scanners based on the established factors. The Laser Scanner with the highest overall assessment rating is chosen as the best alternative for an application. Three Laser Scanner models from different manufacturers are compared using this method for a shape detection application and the best alternative is found. Results show that the fuzzy logic approach can easily deal with both qualitative and quantitative data and can identify quantitatively the best Laser Scanner for an application. Fuzzy logic enhances the understanding of the different factors that are the base for any comparison. Moreover, this approach reduces the effect of bias and subjective judgments made by the decision makers.
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2D Laser Scanner selection using fuzzy logic
Expert Systems with Applications, 2011Co-Authors: Tarek Al-hawari, Omar Al-araidah, Samir Khrais, Abdullah F Al-dwairiAbstract:Laser Scanners are widely used today in many fields. This paper presents a multi-criteria decision-making selection process of these sensors for different applications using a fuzzy logic approach. Factors affecting the selection process are divided into dynamic and static ones based on their dependency on the application considered. Fuzzy sets and fuzzy rules are used to translate implicit and vague expert opinions provided in linguistic terminology into assessment ratings for different types of Laser Scanners based on the established factors. The Laser Scanner with the highest overall assessment rating is chosen as the best alternative for an application. Three Laser Scanner models from different manufacturers are compared using this method for a shape detection application and the best alternative is found. Results show that the fuzzy logic approach can easily deal with both qualitative and quantitative data and can identify quantitatively the best Laser Scanner for an application. Fuzzy logic enhances the understanding of the different factors that are the base for any comparison. Moreover, this approach reduces the effect of bias and subjective judgments made by the decision makers. ?? 2010 Elsevier Ltd. All rights reserved.
