The angle/range-based integrated navigation system is a favorable navigation solution for deep space explorers.However,the statistical characteristics of the measurement noise are time-varying,leading to inaccuracies ...The angle/range-based integrated navigation system is a favorable navigation solution for deep space explorers.However,the statistical characteristics of the measurement noise are time-varying,leading to inaccuracies in the derived measurement covariance even causing filter divergence.To reduce the gap between theoretical and actual covariances,some adaptive methods use empirically determined and unchanged forgetting factors to scale innovations within the sliding window.However,the constant weighting sequence cannot accurately adapt to the time-varying measurement noise in dynamic processes.Therefore,this paper proposes an Adaptive Robust Unscented Kalman Filter with Time-varying forgetting factors(TFF-ARUKF)for the angle/range integrated navigation system.Firstly,based on a statistically linear regression model approximating the nonlinear measurement model,the M-estimator is adopted to suppress the interference of outliers.Secondly,the covariance matching method is combined with the Huber linear regression problem to adaptively adjust the measurement noise covariance used in the M-estimation.Thirdly,to capture the time-varying characteristics of the measurement noise in each estimation,a new timevarying forgetting factors selection strategy is designed to dynamically adjust the adaptive matrix used in the covariance matching method.Simulations and experimental analysis compared with EKF,AMUKF,ARUKF,and Student's t-based methods have validated the effectiveness and robustness of the proposed algorithm.展开更多
Smart contact lens has drawn extensive research interests due to the noninvasive real-time detection of the human body to provide biomedical information for health management.However,it has been difficult to accuratel...Smart contact lens has drawn extensive research interests due to the noninvasive real-time detection of the human body to provide biomedical information for health management.However,it has been difficult to accurately measure the physiological signals in tears,and the use of external power source has also hindered the future applications.Here,we demonstrated an organic electrochemical transistor based multiplexed sensors self-powered by the organic solar cells(OSCs).The integrated device was fabricated via simple process including solution blade-coating and thermal evaporation.OSCs were optimized to provide optimal operation voltage for the sensors that exhibit semilog-linear response to the glucose and calcium ions in tear fluids without any peripheral circuits.The sensing signals can be transmitted to the laptop wirelessly through a near filed communication unit.This integrated self-powered multiplexed sensing device will provide real-time monitoring of the biomarkers in tears,prospected to be installed on the smart contact lens for the early detection and diagnosis of diabetes.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA0350400)。
文摘The angle/range-based integrated navigation system is a favorable navigation solution for deep space explorers.However,the statistical characteristics of the measurement noise are time-varying,leading to inaccuracies in the derived measurement covariance even causing filter divergence.To reduce the gap between theoretical and actual covariances,some adaptive methods use empirically determined and unchanged forgetting factors to scale innovations within the sliding window.However,the constant weighting sequence cannot accurately adapt to the time-varying measurement noise in dynamic processes.Therefore,this paper proposes an Adaptive Robust Unscented Kalman Filter with Time-varying forgetting factors(TFF-ARUKF)for the angle/range integrated navigation system.Firstly,based on a statistically linear regression model approximating the nonlinear measurement model,the M-estimator is adopted to suppress the interference of outliers.Secondly,the covariance matching method is combined with the Huber linear regression problem to adaptively adjust the measurement noise covariance used in the M-estimation.Thirdly,to capture the time-varying characteristics of the measurement noise in each estimation,a new timevarying forgetting factors selection strategy is designed to dynamically adjust the adaptive matrix used in the covariance matching method.Simulations and experimental analysis compared with EKF,AMUKF,ARUKF,and Student's t-based methods have validated the effectiveness and robustness of the proposed algorithm.
基金support from National Natural Science Foundation of China (21704082,21875182)Key Scientific and Technological Innovation Team Project of Shaanxi Province (2020TD-002)+1 种基金111 project 2.0 (BP2018008)X-ray data was acquired at beamlines 7.3.3 at the Advanced Light Source,which is supported by the Director,Office of Science,Office of Basic Energy Sciences,of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘Smart contact lens has drawn extensive research interests due to the noninvasive real-time detection of the human body to provide biomedical information for health management.However,it has been difficult to accurately measure the physiological signals in tears,and the use of external power source has also hindered the future applications.Here,we demonstrated an organic electrochemical transistor based multiplexed sensors self-powered by the organic solar cells(OSCs).The integrated device was fabricated via simple process including solution blade-coating and thermal evaporation.OSCs were optimized to provide optimal operation voltage for the sensors that exhibit semilog-linear response to the glucose and calcium ions in tear fluids without any peripheral circuits.The sensing signals can be transmitted to the laptop wirelessly through a near filed communication unit.This integrated self-powered multiplexed sensing device will provide real-time monitoring of the biomarkers in tears,prospected to be installed on the smart contact lens for the early detection and diagnosis of diabetes.
