In order to stabilize the video module to build digital image stabilization image sequence, a method of using inertial measurement system is proposed. Through applying real-time attitude in- formation of the camera th...In order to stabilize the video module to build digital image stabilization image sequence, a method of using inertial measurement system is proposed. Through applying real-time attitude in- formation of the camera that obtained by high-precision attitude sensor to estimate the image motion vector and then to compensate for image, the purpose of stabilizing the image sequence can be a- chieved. Experiments demonstrate that this method has a high image stabilization precision, and the up to 16 frame/s video output rate completely meets the real-time requirements.展开更多
A new digital image stabilization method is proposed for real-time application based on image contour. The image intensities are projected to several gray levels by thresholding before extracting contour points. Match...A new digital image stabilization method is proposed for real-time application based on image contour. The image intensities are projected to several gray levels by thresholding before extracting contour points. Matching position could be found using these contour points. All pixels are still used for refined matching near the matching position. This algorithm is more robust against changes in illumination and noise affection. The adaptive global motion judgement can remove the affection of intruding object. All those are realized on normally available PC.展开更多
Purpose The high energy photon source(HEPS)is the fourth-generation synchrotron photon source.Compared with the third-generation synchrotron photon source,the brightness is 100-1000 times higher,and the electron emitt...Purpose The high energy photon source(HEPS)is the fourth-generation synchrotron photon source.Compared with the third-generation synchrotron photon source,the brightness is 100-1000 times higher,and the electron emittance of the storage ring is low to the diffraction limit of light.Through physical calculations,it is required that the stability of the storage ring quadrupole magnet power supply be better than 10 ppm,and the accuracy of output current be better than 80 ppm.This high demand for technical parameter poses a challenge to the development of high precision and stability power supplies.Methods The main circuit topology of the power supply adopts a phase-shifted full bridge soft switching scheme,which avoids interference caused by switching noise and improves power stability and efficiency.The high-precision digital power supply controller based on FPGA improves the sampling speed and control accuracy of the power supply,and the constant temperature control circuit ensures that the output current of the power supply meets the requirements of HEPS for power supply performance.Results In the batch testing section,a testing facility was built to test the stability,accuracy,repeatability,voltage ripple,and other parameter of high precision and stability power supplies.After a year and a half of testing,the performance tests of 1066 power supplies,including linear accelerators power supplies,booster power supplies,storage rings power supplies,dipole and quadrupole combined power supplies,dipole and quadrupole power supplies,were completed.The results all met and exceeded the design specifications.Conclusions The HEPS high precision and stability power supply meets the design requirements in terms of current stability,accuracy,repeatability,voltage ripple,and other aspects.The batch test results show that the power supply performance using the full bridge phase shifting soft switching technology combined with high-precision digital controller scheme is excellent,and the power supply consistency is good,providing a guarantee for the successful operation of HEPS in the future.展开更多
Purpose The high-energy photon source(HEPS)is the first fourth-generation synchrotron photon source in China(Jiang et al.in Sci Sin Phys Mech Astron 44:1075-1094,2014).The strip electrode and its power supply provide ...Purpose The high-energy photon source(HEPS)is the first fourth-generation synchrotron photon source in China(Jiang et al.in Sci Sin Phys Mech Astron 44:1075-1094,2014).The strip electrode and its power supply provide necessary hardware support for correcting the magnetic field of the wiggler as reported by Zhao and Yin(Particle accelerator technology,Higher Education Press,Beijing,2006).The design of the conventional power supply for accelerators,with a large output current and high output voltage,making it easy to achieve high stability of the output current.The strip electrode power supply poses difficulties in achieving high stability due to its small output current and voltage.Because of size limitations,as well as the requirements of the power architecture,there are currently no commercial products for this type of power supply.Methods Designed and developed 32 strip electrode power supplies.Considering the large number of power supplies and limited space,a rack structure design was adopted,placing all power supplies in one rack.The main circuit of the power supply adopts a full bridge transformation structure(Chao et al.in Radiat Detect Technol Methods 6:470-478,2022),and the control scheme adopts full digital control based on FPGA(Long and Cheng in At Energy Sci Technol 43:780-784,2009).The power supply has two control modes:local operation and remote operation as reported by Lu(Particle accelerator technology,Hunan University,Changsha,2010).Results The test shows that all power supplies meet the indicator requirements,with a stability of less than 100 ppm.Conclusions The strip electrode power supply can effectively correct the multipole integral field error and improve the integral field performance of the wiggler.展开更多
文摘In order to stabilize the video module to build digital image stabilization image sequence, a method of using inertial measurement system is proposed. Through applying real-time attitude in- formation of the camera that obtained by high-precision attitude sensor to estimate the image motion vector and then to compensate for image, the purpose of stabilizing the image sequence can be a- chieved. Experiments demonstrate that this method has a high image stabilization precision, and the up to 16 frame/s video output rate completely meets the real-time requirements.
文摘A new digital image stabilization method is proposed for real-time application based on image contour. The image intensities are projected to several gray levels by thresholding before extracting contour points. Matching position could be found using these contour points. All pixels are still used for refined matching near the matching position. This algorithm is more robust against changes in illumination and noise affection. The adaptive global motion judgement can remove the affection of intruding object. All those are realized on normally available PC.
文摘Purpose The high energy photon source(HEPS)is the fourth-generation synchrotron photon source.Compared with the third-generation synchrotron photon source,the brightness is 100-1000 times higher,and the electron emittance of the storage ring is low to the diffraction limit of light.Through physical calculations,it is required that the stability of the storage ring quadrupole magnet power supply be better than 10 ppm,and the accuracy of output current be better than 80 ppm.This high demand for technical parameter poses a challenge to the development of high precision and stability power supplies.Methods The main circuit topology of the power supply adopts a phase-shifted full bridge soft switching scheme,which avoids interference caused by switching noise and improves power stability and efficiency.The high-precision digital power supply controller based on FPGA improves the sampling speed and control accuracy of the power supply,and the constant temperature control circuit ensures that the output current of the power supply meets the requirements of HEPS for power supply performance.Results In the batch testing section,a testing facility was built to test the stability,accuracy,repeatability,voltage ripple,and other parameter of high precision and stability power supplies.After a year and a half of testing,the performance tests of 1066 power supplies,including linear accelerators power supplies,booster power supplies,storage rings power supplies,dipole and quadrupole combined power supplies,dipole and quadrupole power supplies,were completed.The results all met and exceeded the design specifications.Conclusions The HEPS high precision and stability power supply meets the design requirements in terms of current stability,accuracy,repeatability,voltage ripple,and other aspects.The batch test results show that the power supply performance using the full bridge phase shifting soft switching technology combined with high-precision digital controller scheme is excellent,and the power supply consistency is good,providing a guarantee for the successful operation of HEPS in the future.
文摘Purpose The high-energy photon source(HEPS)is the first fourth-generation synchrotron photon source in China(Jiang et al.in Sci Sin Phys Mech Astron 44:1075-1094,2014).The strip electrode and its power supply provide necessary hardware support for correcting the magnetic field of the wiggler as reported by Zhao and Yin(Particle accelerator technology,Higher Education Press,Beijing,2006).The design of the conventional power supply for accelerators,with a large output current and high output voltage,making it easy to achieve high stability of the output current.The strip electrode power supply poses difficulties in achieving high stability due to its small output current and voltage.Because of size limitations,as well as the requirements of the power architecture,there are currently no commercial products for this type of power supply.Methods Designed and developed 32 strip electrode power supplies.Considering the large number of power supplies and limited space,a rack structure design was adopted,placing all power supplies in one rack.The main circuit of the power supply adopts a full bridge transformation structure(Chao et al.in Radiat Detect Technol Methods 6:470-478,2022),and the control scheme adopts full digital control based on FPGA(Long and Cheng in At Energy Sci Technol 43:780-784,2009).The power supply has two control modes:local operation and remote operation as reported by Lu(Particle accelerator technology,Hunan University,Changsha,2010).Results The test shows that all power supplies meet the indicator requirements,with a stability of less than 100 ppm.Conclusions The strip electrode power supply can effectively correct the multipole integral field error and improve the integral field performance of the wiggler.
