- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Chengdu, China (2019.5.21-2019.5.24)] 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia) - Designs and Applications for the Controller Parameters of the Photovoltaic System
摘要： Many economically important minerals have absorption features in the short-wave infrared (SWIR; 2000–2500 nm). Sensors which measure this part of the spectrum cannot detect the wavelength minimum of a feature at ～900 nm (F900), indicative of ferric iron mineralogy. A method based on Gaussian processes (GPs) was developed and compared with multiple linear regression (MLR) to estimate the wavelength position of F900 from SWIR data (1002–1355 nm). SWIR data with different signal-to-noise ratios were acquired from crushed rock samples by a nonimaging spectrometer and an imaging spectrometer. GP estimates of wavelength position were converted to the proportion of goethite using coefficients from a regression of the proportion of goethite determined from X-ray diffraction (XRD) on wavelength position measured directly from spectra. GP-estimated wavelength positions were within the 2-nm and ～4-nm root-mean-square error of measurements made directly from spectra for nonimaging and imaging spectrometer data, respectively. Proportions of goethite derived from these estimates were respectively within 4% and 6% of the values measured by XRD. MLR performed poorly compared to GPs when applied to data with no added noise and failed when applied to data with added noise or to imaging spectrometer data. These findings indicate that the wavelength position of F900—an indicator of ferric iron mineralogy—can be estimated from data acquired at SWIR wavelengths (1002–1355 nm). This opens up possibilities for using a single (SWIR) sensor to acquire information on ferric iron mineralogy (using F900) and other minerals with diagnostic absorptions between 1000 and 2500 nm.
关键词： geology,infrared spectroscopy,iron,image sensors,remote sensing,Gaussian processes (GPs),mining industry,Electromagnetic radiation,spectral analysis,signal processing
更新于2025-09-19 17:13:59
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The Influence of Selected Selective Laser Sintering Technology Process Parameters on Stress Relaxation, Mass of Models, and Their Surface Texture Quality
摘要： The article presents the results of research on the impact of basic process parameters of selective laser sintering technology on the mass of the produced models (density of the sintered material—polyamide PA 2200), stress relaxation during compression determined in accordance with the ISO 3384 standard, and geometric surface structure parameters (SGPs). During the tests, the influence of process parameters such as the location of the models on the virtual construction platform (printing direction), the density of the energy supplied to the sintered layer of powder, and the layer thickness of the manufactured material layer was taken into account. The test results confirmed that the process parameters have a significant impact on the density of the model material (in the sintered state), the mechanical properties (stress relaxation during compression), and the quality of the surface texture (SGPs). The most favorable positioning variants of the models on the construction platform were determined. The most favorable thickness variants of the combined layers and the density value of the energy supplied to the sintered powder layer were selected, depending on the expected mass, strength, and SGP quality. In addition, it has been shown that it is possible to build models with reduced mass (>20%), while maintaining satisfactory mechanical and qualitative properties of the surface texture.
关键词： additive manufacturing technologies,GPS,rapid prototyping,SLS,3D printing,stress relaxation
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Wing Integrated Solar Array Performance Study Using Photoluminescence
摘要： Recent investigations have revealed the susceptibility of phasor measurement units (PMUs) to the time synchronization attack by spoofing its global positioning system (GPS). This paper proposes a cross-layer detection mechanism to fight against simultaneous attacks toward multiple PMUs. In the physical layer, we propose a GPS carrier-to-noise ratio (C/No) based spoofing detection technique. We apply the patch-monopole hybrid antenna to two GPS receivers and compute the difference between the standard deviation of each receiver’s C/No. The priori probability of spoofing is calculated from the distributions of the difference. A counter is embedded in the physical layer to identify the most suspicious PMU. In the upper layer, the spoofing attack is considered similarly to the bad data injection toward the power system. A trustworthiness evaluation, which is based on both the physical layer information and power grid measurements, is applied to identify the PMU being attacked. An experiment has been carried to validate the proposed algorithm.
关键词： multiple attacks detection,Cross-layer mechanism,global positioning system (GPS) spoofing,phasor measurement units (PMU)
更新于2025-09-19 17:13:59
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[IEEE 2019 Big Data, Knowledge and Control Systems Engineering (BdKCSE) - Sofia, Bulgaria (2019.11.21-2019.11.22)] 2019 Big Data, Knowledge and Control Systems Engineering (BdKCSE) - Thermoelectric Cooling Driver for Laser Projection Systems
摘要： Recent investigations have revealed the susceptibility of phasor measurement units (PMUs) to the time synchronization attack by spoofing its global positioning system (GPS). This paper proposes a cross-layer detection mechanism to fight against simultaneous attacks toward multiple PMUs. In the physical layer, we propose a GPS carrier-to-noise ratio (C/No) based spoofing detection technique. We apply the patch-monopole hybrid antenna to two GPS receivers and compute the difference between the standard deviation of each receiver’s C/No. The priori probability of spoofing is calculated from the distributions of the difference. A counter is embedded in the physical layer to identify the most suspicious PMU. In the upper layer, the spoofing attack is considered similarly to the bad data injection toward the power system. A trustworthiness evaluation, which is based on both the physical layer information and power grid measurements, is applied to identify the PMU being attacked. An experiment has been carried to validate the proposed algorithm.
关键词： Cross-layer mechanism,multiple attacks detection,phasor measurement units (PMU),global positioning system (GPS) spoofing
更新于2025-09-16 10:30:52
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[American Society of Agricultural and Biological Engineers 2019 Boston, Massachusetts July 7- July 10, 2019 - ()] 2019 Boston, Massachusetts July 7- July 10, 2019 - <i>Laser detection of the boundary of UAV spray operation</i>
摘要： The agricultural plant protection UAV is beneficial to reducing pesticide, improving utilization rate, reducing harm to human beings and animals. The boundary detection and identification of the drone spray operation is an important aspect of the UAV spraying. The two-dimensional laser scanning range finder has the function of measuring object reflection characteristics. In order to obtain the detailed field information in the sampling interval, the laser detection system constructed not only measures the distance from the UAV to the rice and ridge, but also measures the reflection value of the rice and ridge. The distance between the rice and ridge is used as the threshold to identify the boundary. The signal division point appears near 1m with a variance of 0.27m. In the process of segmentation, there are many misjudgment points on the left side of the laser emission origin. Accurate identification of boundaries can provide a basis for path planning, especially the UAV spraying.
关键词： Boundary identification,UAV,2D Laser Range finder,Height measurement,GPS
更新于2025-09-11 14:15:04
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A new 3D laser-scanning and GPS combined measurement system
摘要： Terrestrial laser scanning (TLS) is widely used because of its ability to quickly acquire high-density and high-precision 3D image and topographic data. However, it can only acquire independent coordinate system points, which restricts its application in large-scale deformation monitoring. In this study, we constructed a measurement system to acquire global coordinate point cloud data by combining TLS and GPS (Global Positioning System). The coordinate values of retro-re?ective targets could be acquired in different coordinate systems, the GPS coordinate and the TLS station coordinate, synchronously. Our experiments showed that, after registration with the homonymy points acquired by 30-min short-baseline differential GPS using the ICP algorithm, the positional accuracy of the TLS retro-re?ective target center in the global coordinate was better than 10 mm. This high precision meets, for instance, the requirements of coal mining subsidence monitoring. We used our new combined measurement system to acquire and process the point cloud data of a frame structure. The measurements demonstrated the practicability and robustness of the new measurement system.
关键词： ICP,Differential GPS,Data fusion,Terrestrial laser scanning
更新于2025-09-11 14:15:04
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Evaluation of a Survey-Grade, Long-Range Uas Lidar System: a Case Study in South Texas, USA
摘要： Over recent years, light detection and ranging (lidar) sensor technology has rapidly evolved and miniaturized. The reduced sensor size and weight have opened more doors for lidar sensors to be carried onboard unmanned aircraft systems (UASs). Compared with traditional airborne lidar mapping, UAS platforms offer more flexibility in terms of flight design and data collection, rapid response capabilities, and potentially cost at local mapping scales. UAS-based lidar studies have primarily been focused on monitoring vegetation structure, simultaneous localization and mapping (SLAM) and so forth. A comparison between UAS and terrestrial laser scanning (TLS)-derived plant height for crop monitoring was made in [2]. Descriptive statistics derived from polygon grids were analyzed and a correlation R2 = 0.91 was found in plant height derived from both methods. In [3], a lidar-based perception and guidance system was built on a helicopter to perform obstacle detection and avoidance, terrain following, and close-range inspection, and a high success rate was claimed by the authors. Structure-from-Motion (SfM) / Multi-View stereo (MVS) photogrammetry represents an alternative to airborne lidar to derive 3-D point cloud data. It relies on adequate image overlap to extract key point correspondence and collinearity to reconstruct the 3-D scene. This single return solution is sometimes susceptible to false parallax induced from moving vegetation between overlapping images (for instance due to wind) and to poor feature correspondence in areas where the image texture is highly uniform [4], [5]. One advantage of using lidar is it uses pulsed ranging technique and many lidar systems provide multiple return detection capability. This multi-return capability has enabled lidar to be widely applied to forestry inventory surveys among other applications because it allows for canopy and below canopy measurement. A mini-UAS-borne lidar system was built in [6], and its applicability for fine-scale mapping was validated in terms of tree height estimation, pole detection, road extraction, and digital terrain model refinement. A more recent study in [7] developed a lidar-hyperspectral image fusion method in treated and controlled forests with varying tree density and canopy cover to classify vegetation and measure 3D structure. It was claimed that the fusion method performed better than either data type alone at the study site in the southwestern USA. In this paper, initial results on the testing and evaluation of a single-rotary UAS integrated with a long-range, multi-return lidar sensor is presented. Testing was performed at an airfield in South Texas, USA. The study primarily focuses on: 1) description of the platform and enabling technology (i.e., lidar/IMU/GPS) of the fully integrated UAS solution, 2) sensor calibration and initialization (e.g., boresight calibration and IMU initialization), and 3) description of the geospatial surveying, data processing and analysis.
关键词： geospatial,lidar,UAS,IMU,surveying,GPS
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Analysis of CYGNSS Data for Soil Moisture Applications
摘要： An analysis of CYGNSS data is presented, with the objective of assessing the potentials of these data for land applications. The GPS-Reflections over land acquired by the CYGNSS observatories are exploited to detect properties of the land soil moisture. A land reflectivity observable, derived from CYGNSS Delay/Doppler Maps, is computed using a calibration approach suitable for land reflections. The sensitivity of the reflectivity observable to the soil moisture parameter is investigated through a comparison with soil moisture data from the SMAP satellite. Some preliminary results on the correlation between the CYGNSS reflectivity and the SMAP soil moisture are presented. This work is being conducted within the framework of the European Space Agency Project “Potential of Spaceborne GNSS-R for Land Applications”.
关键词： Delay-Doppler Map,soil moisture,GPS-Reflectometry
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Measure of the Absolute Phase Angle of a Power Frequency Sinewave with Respect to UTC
摘要： This paper presents a method to measure the absolute phase angle of a power frequency sinewave with respect to the passage of the UTC second. The need for such a technic arises during the calibration or adjustment of PMUs or SAMUs. The accuracy of these instruments depends on their ability to measure the absolute phase. The principle of the method is based on a phase comparison between a sine wave and the fundamental component of a square wave of identical frequency. The absolute phase angle of the square wave is first established against the PPS signal of an atomic clock.
关键词： Pulse Per Second (PPS),low pass filter,Global Positioning System (GPS),Absolute phase measurement,Phasor Measurement Unit (PMU),Coordinated Universal Time (UTC),Stand Alone Merging Unit (SAMU)
更新于2025-09-10 09:29:36
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[IEEE 2018 IEEE International Conference on Vehicular Electronics and Safety (ICVES) - Madrid, Spain (2018.9.12-2018.9.14)] 2018 IEEE International Conference on Vehicular Electronics and Safety (ICVES) - Development of Robust Validation Method through Driverless Test for Vision-based Oncoming Vehicle Collision Avoidance System
摘要： This paper presents a robust validation test method to prove and improve the oncoming vehicle collision avoidance systems. This system is developed to reduce traffic accidents while a driver's vehicle crashes into an oncoming vehicle out of its lane. It consists of a front camera on the windshield to detect the vehicle on the other side and an electric power steering to control the host vehicle to prevent head-on collision. It requires high performance for planning and controlling accurate avoidance path at close distance at the right time. Thus, safe and accurate validation vehicle test method is essential to develop the high quality system and determine the performance. The proposed validation test method includes robust vehicle test scenarios with test specification, vehicle test equipment based on automated robots and detailed analysis method for system performance. The robust test scenarios with test specification are developed to prove robustness of the system and seek weakness points from diverse conditions on the road and test specifications. The vehicle robots based on GPS/INS are utilized to conduct validation tests safely, repeatedly and accurately as the designed the test scenarios. Overall, the suggested analysis method determines the reliability of robot tests by the error distribution of the dynamics and avoidance performance of the system through estimating internal errors of the components which cause errors of the avoidance system. The vehicles tests using presented robust test scenarios and driverless tests based on vehicle robots are conducted repeatedly to prove the robustness of the system thoroughly. The results of vehicle tests show the proposed method is powerful to validate the system and present proper value of design parameters applied to optimal avoidance path to improve the performance under the robust environment.
关键词： brake robot,analysis method,Oncoming vehicle collision avoidance system,steering robot,GPS/INS,validation method,acceleration robot
更新于2025-09-10 09:29:36