This paper deals with the synchronization of chaotic systems with structure or parameters difference. Nonlinear differential geometry theory was applied to transform the chaotic discrepancy system into canonical form....This paper deals with the synchronization of chaotic systems with structure or parameters difference. Nonlinear differential geometry theory was applied to transform the chaotic discrepancy system into canonical form. A feedback control for synchronizing two chaotic systems is proposed based on sliding mode control design. To make this controller physically realizable, an extended state observer is used to estimate the error between the transmitter and receiver. Two illustrative examples were carried out: (1) The Chua oscillator was used to show that synchronization was achieved and the message signal was recovered in spite of parametric variations; (2) Two second-order driven oscillators were presented to show that the synchronization can be achieved and that the message can be recovered in spite of the strictly different model.展开更多
Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations ...Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations by taking advantage of automatic observations with self compensation of tilt of the tube.We here propose In-situ Lunar Orientation Measurement(ILOM) to study lunar rotational dynamics by direct observations of the lunar rotation from the lunar surface by using a small telescope like PZT with an accuracy of 1 milli-seconds of arc(1 mas) in the post-SELENE mission.Our second application is to obtain local gravity field on the Earth by combining deflection of the vertical measured by PZT and the position measured by Global Positioning System(GPS) or Global Navigation Satellite System(GNSS).The accuracy required for this purpose is not as strict as ILOM.We have already developed a Bread Board Model(BBM) of the telescope for ILOM and made some experiments in order to know the performance of the driving mechanism under a similar condition to the lunar environment showing high vacuum,large temperature change and dusty condition.We have also shown that it is possible to correct the effects of uniform temperature change upon the optical system by using a simple model with an accuracy of better than 1 mas.This model has the potential to attain the accuracy of 1 mas,based on the results of the experiments and the simulations.展开更多
基金Project (No. 20040146) supported by Zhejiang Provincial Edu-cation Department Foundation, China
文摘This paper deals with the synchronization of chaotic systems with structure or parameters difference. Nonlinear differential geometry theory was applied to transform the chaotic discrepancy system into canonical form. A feedback control for synchronizing two chaotic systems is proposed based on sliding mode control design. To make this controller physically realizable, an extended state observer is used to estimate the error between the transmitter and receiver. Two illustrative examples were carried out: (1) The Chua oscillator was used to show that synchronization was achieved and the message signal was recovered in spite of parametric variations; (2) Two second-order driven oscillators were presented to show that the synchronization can be achieved and that the message can be recovered in spite of the strictly different model.
基金supported by the Advanced Technology Center (Grant No. 2009-101)supported by the National Natural Science Foundation of China (Grant No. 10973031)+1 种基金Chinese National High-Tech Project (Grant No. 2009AA122206)the Grant-in-Aid for Scientific Research (B) (Grant No. 22340128)
文摘Like other optical astrometric techniques,the Photographic Zenith Tube(PZT) has played a key role in the past observations of the Earth rotation,and it also has a potential to be applied to several other observations by taking advantage of automatic observations with self compensation of tilt of the tube.We here propose In-situ Lunar Orientation Measurement(ILOM) to study lunar rotational dynamics by direct observations of the lunar rotation from the lunar surface by using a small telescope like PZT with an accuracy of 1 milli-seconds of arc(1 mas) in the post-SELENE mission.Our second application is to obtain local gravity field on the Earth by combining deflection of the vertical measured by PZT and the position measured by Global Positioning System(GPS) or Global Navigation Satellite System(GNSS).The accuracy required for this purpose is not as strict as ILOM.We have already developed a Bread Board Model(BBM) of the telescope for ILOM and made some experiments in order to know the performance of the driving mechanism under a similar condition to the lunar environment showing high vacuum,large temperature change and dusty condition.We have also shown that it is possible to correct the effects of uniform temperature change upon the optical system by using a simple model with an accuracy of better than 1 mas.This model has the potential to attain the accuracy of 1 mas,based on the results of the experiments and the simulations.
