Patents by Inventor Qiaoyun Fan
Qiaoyun Fan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8068673Abstract: The disclosure relates to a rapid and high precision centroiding method for spots image comprising the following steps. First, the method requires convoluting the gray value of a pixel with a Gaussian filter and judging whether the result thereof exceeds a predetermined threshold. If the value exceeds the predetermined threshold, the method requires marking the current pixel with a flag to identify which spot it belongs to, and then accumulating the product of the gray value and a coordinate value of the same spot; and at the same time, accumulating the gray value of the same spot; and saving the results of the accumulation respectively. If the gray value of the pixel does not exceed the predetermined threshold, the method requires marking the current pixel as a background flag.Type: GrantFiled: March 16, 2007Date of Patent: November 29, 2011Assignee: Beihang UniversityInventors: Guangjun Zhang, Jie Jiang, Qiaoyun Fan, Xuetao Hao
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Patent number: 7822572Abstract: A method for calibration of a digital celestial sensor is disclosed. First, an integrated mathematic model for imaging of a celestial sensor is established according to external and internal parameters of the calibration system of the celestial sensor. Second, by rotating two axes of a rotator by different angles, calibration points data are acquired and sent to a processing computer through an interface circuit. Finally, a two-step calibration program is implemented to calculate the calibration parameters by substituting calibration points' data to the integrated mathematic model. An application device of the calibration method is also provided. The device may include a celestial simulator to provide simulated sunlight or starlight, a two-axis rotator to acquire different calibration points' data, and a processing computer to record the calibration points' data and calculate the calibration parameters.Type: GrantFiled: February 25, 2008Date of Patent: October 26, 2010Assignee: Beihang UniversityInventors: Guangjun Zhang, Xinguo Wei, Qiaoyun Fan, Jie Jiang
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Patent number: 7615728Abstract: The disclosure relates to a signal processing method for multi aperture sun sensor comprising the following steps: reading the information of sunspots in a row from a centroid coordinate memory, judging the absence of sunspots in that row, identifying the row and column index of the sunspots in the complete row, selecting the corresponding calibration parameter based on the row and column index, calculating attitude with the attitude calculation module the corresponding to identified sunspots, averaging the accumulated attitude of all sunspots and outputting the final attitude. At the same time, a signal processing device for multi aperture sun sensor is also presented. It is comprised of a sunspot absence judgment and an identification module and an attitude calculation module. The disclosure implements the integration of sun sensors without additional image processor or attitude processor, reduces field programmable gate array resource and improves the reliability of sun sensors.Type: GrantFiled: December 31, 2007Date of Patent: November 10, 2009Assignee: Beihang UniversityInventors: Guangjun Zhang, Jie Jiang, Qiaoyun Fan
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Patent number: 7552026Abstract: The disclosure relates to an APS based integrated sun sensor comprising: a diaphragm unit, a detection unit, a processing electronics unit and an interface unit. The diaphragm unit is operatively connected with the detection unit for forming a sunspots image. The detection unit is configured for outputting a gray value of each pixel. The processing electronics unit is operatively connected with the detector unit and the interface unit respectively, for evaluating an attitude angle on the basis of the gray value and coordinate of each pixel. The interface unit is operatively connected with a host computer, for transferring the attitude angle to the host computer. This disclosure has such merits as high accuracy, wide FOV (Field of View), low power consumption, low weight, small size and high update rate.Type: GrantFiled: March 16, 2007Date of Patent: June 23, 2009Assignee: Beihang UniversityInventors: Guangjun Zhang, Jie Jiang, Qiaoyun Fan
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Publication number: 20090012734Abstract: A method for calibration of a digital celestial sensor is disclosed. The method comprises the following steps: firstly, an integrated mathematic model for imaging of a celestial sensor is established according to external and internal parameters of the calibration system of the celestial sensor. Secondly, by rotating two axes of a rotator by different angles, calibration points data are acquired and sent to a processing computer through an interface circuit. Finally, a two-step calibration program is implemented to calculate the calibration parameters by substituting calibration points' data to the integrated mathematic model. The disclosure also relates to an application device of the calibration method, wherein the device comprises: a celestial simulator to provide simulated sunlight or starlight, a two-axis rotator to acquire different the calibration points' data, a processing computer to record the calibration points' data and calculate the calibration parameters.Type: ApplicationFiled: February 25, 2008Publication date: January 8, 2009Inventors: Guangjun Zhang, Xinguo Wei, Qiaoyun Fan, Jie Jiang
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Publication number: 20090012731Abstract: A method for calibration of a digital sun sensor is disclosed. The method comprises following steps. First, an integrated mathematic model for imaging of a sun sensor is established according to the external and internal parameters of the calibration system of the sun sensor. Next, the two axis of the rotator are rotated by different angles. Then, calibration points' data are acquired and sent to a processing computer through an interface circuit. Finally, a two-step calibration program is implemented to calculate the calibration parameters by substituting the calibration points' data to the integrated mathematic model. The disclosure also relates to an application device of the calibration method. The device comprises: a sun simulator to provide the incident sunlight, a two-axis rotator to acquire different the calibration points' data, and a processing computer to record the calibration points' data and calculate the calibration parameters.Type: ApplicationFiled: January 24, 2008Publication date: January 8, 2009Inventors: Guangjun Zhang, Xinguo Wei, Qiaoyun Fan, Jie Jiang
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Publication number: 20080317283Abstract: The disclosure relates to a signal processing method for multi aperture sun sensor comprising the following steps: reading the information of sunspots in a row from a centroid coordinate memory, judging the absence of sunspots in that row, identifying the row and column index of the sunspots in the complete row, selecting the corresponding calibration parameter based on the row and column index, calculating attitude with the attitude calculation module the corresponding to identified sunspots, averaging the accumulated attitude of all sunspots and outputting the final attitude. At the same time, a signal processing device for multi aperture sun sensor is also presented. It is comprised of a sunspot absence judgment and an identification module and an attitude calculation module. The disclosure implements the integration of sun sensors without additional image processor or attitude processor, reduces field programmable gate array resource and improves the reliability of sun sensors.Type: ApplicationFiled: December 31, 2007Publication date: December 25, 2008Inventors: Guangjun Zhang, Jie Jiang, Qiaoyun Fan
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Publication number: 20080131002Abstract: The disclosure relates to a rapid and high precision centroiding method for spots image comprising the following steps. First, the method requires convoluting the gray value of a pixel with a Gaussian filter and judging whether the result thereof exceeds a predetermined threshold. If the value exceeds the predetermined threshold, the method requires marking the current pixel with a flag to identify which spot it belongs to, and then accumulating the product of the gray value and a coordinate value of the same spot; and at the same time, accumulating the gray value of the same spot; and saving the results of the accumulation respectively. If the gray value of the pixel does not exceed the predetermined threshold, the method requires marking the current pixel as a background flag.Type: ApplicationFiled: March 16, 2007Publication date: June 5, 2008Inventors: Guangjun Zhang, Jie Jiang, Qiaoyun Fan, Xuetao Hao
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Publication number: 20080029652Abstract: The disclosure relates to an APS based integrated sun sensor comprising: a diaphragm unit, a detection unit, a processing electronics unit and an interface unit. The diaphragm unit is operatively connected with the detection unit for forming a sunspots image. The detection unit is configured for outputting a gray value of each pixel. The processing electronics unit is operatively connected with the detector unit and the interface unit respectively, for evaluating an attitude angle on the basis of the gray value and coordinate of each pixel. The interface unit is operatively connected with a host computer, for transferring the attitude angle to the host computer. This disclosure has such merits as high accuracy, wide FOV (Field of View), low power consumption, low weight, small size and high update rate.Type: ApplicationFiled: March 16, 2007Publication date: February 7, 2008Inventors: Guangjun Zhang, Jie Jiang, Qiaoyun Fan