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A novel high precision Doppler frequency estimation method based on the third-order phase-locked loop 被引量:1
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作者 Tao Deng Mao-Li Ma +1 位作者 Qing-Hui Liu Ya-Jun Wu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第9期83-90,共8页
In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points... In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points of the third-order phase-locked loop(PLL)and find a new Doppler measurement strategy.Based on this finding,a Doppler frequency measurement algorithm with significantly higher measurement accuracy is obtained.In the actual data processing,compared with the existing engineering software,the accuracy of frequency of 1 second integration is about 5.5 times higher when using the new algorithm.The improved algorithm is simple and easy to implement.This improvement can be easily combined with other improvement methods of PLL,so that the performance of PLL can be further improved. 展开更多
关键词 Doppler frequency measurement:deep space exploration:carrier tracking:phase locked loop:high precision
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Dual-assisted high-precision tracking technique for wideband multiplexed signals in new generation GNSS
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作者 Yunhan Qi Zheng Yao Mingquan Lu 《Satellite Navigation》 SCIE EI CSCD 2024年第1期52-73,共22页
With the evolution of Global Navigation Satellite System(GNSS),new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques,which jointly modulate multiple signals located on multiple... With the evolution of Global Navigation Satellite System(GNSS),new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques,which jointly modulate multiple signals located on multiple sub-frequencies into a Wideband Multiplexed Signal(WMS).Although WMSs were proposed initially to reduce the complexity of satellite transmitters and improve the transmission efficiency of signals,their multi-component structures and wide root mean square bandwidths introduced by high-frequency subcarriers also provide the possibility to improve the GNSS ranging precision.Therefore,this paper proposes a Dual-assisted Multi-component Tracking(DMT)technique,which can not only fully use high-frequency subcarriers in WMSs,but also effectively track carrier,subcarrier,and code by jointly utilizing all components in WMS.In this paper,the tracking and ranging performances of DMT are comprehensively analyzed theoretically and by simulation and real experiments.The results show that compared with existing WMS tracking methods,DMT can achieve tracking results with lower tracking jitters and ranging results with higher precision,providing a highly advantageous solution for new generation GNSS signal processing. 展开更多
关键词 Wideband multiplexed signal Dual-assisted MULTI-COMPONENT High precision tracking
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Modeling and Tracking Control for Piezoelectric Actuator Based on a New Asymmetric Hysteresis Model 被引量:5
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作者 Geng Wang Guoqiang Chen +1 位作者 Hong Zhou Fuzhong Bai 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第4期782-791,共10页
This paper presents a new asymmetric hysteresis model and its application in the tracking control of piezoelectric actuators. The proposed model is based on a coupled-play operator which can avoid the conventional Pra... This paper presents a new asymmetric hysteresis model and its application in the tracking control of piezoelectric actuators. The proposed model is based on a coupled-play operator which can avoid the conventional Prandtl-Ishlinskii(CPI)model's defects, i.e., the symmetric property. The high accuracy for modeling asymmetric hysteresis is validated by comparing simulation results with experimental measurements. In order to further evaluate the performance of the proposed model in closed-loop tracking application, two different hybrid control methods which experimentally demonstrate their performance under the same operating conditions, are compared to validate that the hybrid control strategy with proposed hysteresis model can mitigate the hysteresis more effectively and achieve better tracking precision. The experimental results demonstrate that the proposed modeling and tracking control strategy can realize efficient control of piezoelectric actuator. 展开更多
关键词 Asymmetric hysteresis model motion control piezoelectric actuator precise tracking
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Precise Decoupling Tracking of Airspeed and Altitude for UAV Based on Causal Solution of Stable Inversion
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作者 张建宏 张平 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2009年第3期307-315,共9页
Use stable inversion to accomplish precise decoupling tracking of airspeed and altitude for conventional takeoff and landing of unmanned aerial vehicles (UAVs) is in essence a non-minimum phase output tracking problem... Use stable inversion to accomplish precise decoupling tracking of airspeed and altitude for conventional takeoff and landing of unmanned aerial vehicles (UAVs) is in essence a non-minimum phase output tracking problem. The main contribution of this article is that a new method to calculate the causal solution of stable inversion is proposed by introducing a well defined perturbed signal to the system’s unstable internal dynamics. It is helpful to overcome the pitfalls resulting from non-causality in existin... 展开更多
关键词 precise decoupling tracking causal solution stable inversion non-minimum phase unmanned aerial vehicles
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A precise approach to tracking dim-small targets using spectral fingerprint features 被引量:1
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作者 Hao SHENG Chao LI +1 位作者 Yuanxin OUYANG Zhang XIONG 《Frontiers of Computer Science》 SCIE EI CSCD 2012年第5期527-536,共10页
A precise method for accurately tracking dim- small targets, based on spectral fingerprint is proposed where traditional full color tracking seems impossible. A fingerprint model is presented to adequately extract spe... A precise method for accurately tracking dim- small targets, based on spectral fingerprint is proposed where traditional full color tracking seems impossible. A fingerprint model is presented to adequately extract spectral features. By creating a multidimensional feature space and extending the limited RGB information to the hyperspectral information, the improved precise tracking model based on a nonparamet- ric kernel density estimator is built using the probability his- togram of spectral features. A layered particle filter algorithm for spectral tracking is presented to avoid the object jumping abruptly. Finally, experiments are conducted that show that the tracking algorithm with spectral fingerprint features is ac- curate, fast, and robust. It meets the needs of dim-small target tracking adequately. 展开更多
关键词 dim-small target precise tracking spectral fingerprint features LPF algorithm for spectral tracking
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