Ms. Xue-fen Wan Profile

Xue-fen Wan

at North China Institute of Science & Technology

SPIE Involvement:

Author

Publications (5)

Proceedings Article | 27 November 2023 Poster + Paper

Research on fruit picking recognition based on deep learning

Yijing Wu, Xuefen Wan, Jie Zhang, Yi Yang

Proceedings Volume 12767, 127670V (2023) https://doi.org/10.1117/12.2685765

KEYWORDS: Target detection, Detection and tracking algorithms, Agriculture, Deep learning, Target recognition, Video, Video processing

Read Abstract +

Proceedings Article | 12 January 2018 Paper

Smartphone based hemispherical photography for canopy structure measurement

Xuefen Wan, Jian Cui, Xueqin Jiang, Jingwen Zhang, Yi Yang, Tao Zheng

Proceedings Volume 10621, 106210Q (2018) https://doi.org/10.1117/12.2285911

KEYWORDS: Photography, Agriculture, Forestry, Cameras, Image acquisition, Image processing, Radiation effects, Lens design, Image quality

Read Abstract +

Proceedings Article | 24 October 2017 Paper

Distributed solar radiation fast dynamic measurement for PV cells

Xuefen Wan, Yi Yang, Jian Cui, Xingjing Du, Tao Zheng, Muhammad Sohail Sardar

Proceedings Volume 10460, 104600M (2017) https://doi.org/10.1117/12.2283431

KEYWORDS: Solar radiation, Solar cells

Read Abstract +

To study the operating characteristics about PV cells, attention must be given to the dynamic behavior of the solar radiation. The dynamic behaviors of annual, monthly, daily and hourly averages of solar radiation have been studied in detail. But faster dynamic behaviors of solar radiation need more researches. The solar radiation random fluctuations in minute-long or second-long range, which lead to alternating radiation and cool down/warm up PV cell frequently, decrease conversion efficiency. Fast dynamic processes of solar radiation are mainly relevant to stochastic moving of clouds. Even in clear sky condition, the solar irradiations show a certain degree of fast variation. To evaluate operating characteristics of PV cells under fast dynamic irradiation, a solar radiation measuring array (SRMA) based on large active area photodiode, LoRa spread spectrum communication and nanoWatt MCU is proposed. This cross photodiodes structure tracks fast stochastic moving of clouds. To compensate response time of pyranometer and reduce system cost, the terminal nodes with low-cost fast-responded large active area photodiode are placed besides positions of tested PV cells. A central node, consists with pyranometer, large active area photodiode, wind detector and host computer, is placed in the center of the central topologies coordinate to scale temporal envelope of solar irradiation and get calibration information between pyranometer and large active area photodiodes. In our SRMA system, the terminal nodes are designed based on Microchip’s nanoWatt XLP PIC16F1947. FDS-100 is adopted for large active area photodiode in terminal nodes and host computer. The output current and voltage of each PV cell are monitored by I/V measurement. AS62-T27/SX1278 LoRa communication modules are used for communicating between terminal nodes and host computer. Because the LoRa LPWAN (Low Power Wide Area Network) specification provides seamless interoperability among Smart Things without the need of complex local installations, configuring of our SRMA system is very easy. Lora also provides SRMA a means to overcome the short communication distance and weather signal propagation decline such as in ZigBee and WiFi. The host computer in SRMA system uses the low power single-board PC EMB-3870 which was produced by NORCO. Wind direction sensor SM5386B and wind-force sensor SM5387B are installed to host computer through RS-485 bus for wind reference data collection. And Davis 6450 solar radiation sensor, which is a precision instrument that detects radiation at wavelengths of 300 to 1100 nanometers, allow host computer to follow real-time solar radiation. A LoRa polling scheme is adopt for the communication between host computer and terminal nodes in SRMA. An experimental SRMA has been established. This system was tested in Ganyu, Jiangshu province from May to August, 2016. In the test, the distances between the nodes and the host computer were between 100m and 1900m. At work, SRMA system showed higher reliability. Terminal nodes could follow the instructions from host computer and collect solar radiation data of distributed PV cells effectively. And the host computer managed the SRAM and achieves reference parameters well. Communications between the host computer and terminal nodes were almost unaffected by the weather. In conclusion, the testing results show that SRMA could be a capable method for fast dynamic measuring about solar radiation and related PV cell operating characteristics.

Proceedings Article | 14 November 2016 Paper

Remote canopy hemispherical image collection system

Xuefen Wan, Bingyu Liu, Yi Yang, Fang Han, Jian Cui

Proceedings Volume 10025, 100251N (2016) https://doi.org/10.1117/12.2248710

KEYWORDS: Image acquisition, Super resolution, Calibration, Cameras, Image sensors, Image quality, Solar radiation, Image processing, Sensors, Photosynthesis

Read Abstract +

Canopies are major part of plant photosynthesis and have distinct architectural elements such as tree crowns, whorls, branches, shoots, etc. By measuring canopy structural parameters, the solar radiation interception, photosynthesis effects and the spatio-temporal distribution of solar radiation under the canopy can be evaluated. Among canopy structure parameters, Leaf Area Index (LAI) is the key one. Leaf area index is a crucial variable in agronomic and environmental studies, because of its importance for estimating the amount of radiation intercepted by the canopy and the crop water requirements. The LAI can be achieved by hemispheric images which are obtained below the canopy with high accuracy and effectiveness. But existing hemispheric images canopy-LAI measurement technique is based on digital SLR camera with a fisheye lens. Users need to collect hemispheric image manually. The SLR camera with fisheye lens is not suit for long-term canopy-LAI outdoor measurement too. And the high cost of SLR limits its capacity. In recent years, with the development of embedded system and image processing technology, low cost remote canopy hemispheric image acquisition technology is becoming possible.

In this paper, we present a remote hemispheric canopy image acquisition system with in-field/host configuration. In-field node based on imbed platform, low cost image sensor and fisheye lens is designed to achieve hemispherical image of plant canopy at distance with low cost. Solar radiation and temperature/humidity data, which are important for evaluating image data validation, are obtained for invalid hemispherical image elimination and node maintenance too. Host computer interacts with in-field node by 3G network. The hemispherical image calibration and super resolution are used to improve image quality in host computer. Results show that the remote canopy image collection system can make low cost remote canopy image acquisition for LAI effectively. It will be a potential technology candidate for low-cost remote canopy hemispherical image collection to measure canopy LAI.

Proceedings Article | 26 November 2012 Paper

Radiation distribution measurement for forest plant canopies tracing

Xuefen Wan, Jian Cui, Yi Yang, Hui Liu

Proceedings Volume 8557, 85571F (2012) https://doi.org/10.1117/12.999521

KEYWORDS: Gyroscopes, Solar radiation, Sensors, Monte Carlo methods, Climatology, Solar radiation models, Laser beam diagnostics, Humidity, Fermium, Astronomical engineering

Read Abstract +

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years