排序方式: 共有67条查询结果,搜索用时 15 毫秒
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Unscented粒子滤波在静基座捷联惯导系统大方位失准角初始对准中的应用研究 总被引:7,自引:0,他引:7
静基座大方位失准角的捷联惯导系统误差方程是非线性的,Unscented粒子滤波从非线性系统状态向量概率分布出发,结合Unscented卡尔曼滤波和粒子滤波的特点,无需对非线性系统模型进行处理而能达到较高的滤波精度。本文对Unscented粒子滤波进行了研究,并结合重采样算法,运用于捷联惯导系统静基座大方位失准角初始对准中,计算结果验证了该方法的有效性与优越性。 相似文献
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为满足运载体长航时、高精度的导航需求,解决系统可观测性弱导致的航向角易发散的问题,提出了一种基于MEMS非线性组合导航系统的用于提高航向角估计精度的算法。通过采用单天线GNSS航向角作为量测量进行航向约束,解决了MEMS-SINS/GNSS姿态估计中航向角可观测性弱、估计值收敛差的问题;通过转弯判断规则和常规无迹卡尔曼滤波改进算法,抑制了偏流角对系统估计精度的影响。仿真结果表明,该算法有效地抑制了航向角估计精度差的问题,水平姿态精度达到0.01°,航向角精度达到0.1°,提高了系统的导航精度及可靠性。 相似文献
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基于Unscented卡尔曼滤波器的卫星自主天文导航研究 总被引:13,自引:1,他引:13
针对星光折射间接敏感地平的卫星自主天文导航方法,建立了带摄动项的状态方程和以星光视高度为观测量的量测方程。由于该状态方程和量测方程都是严重非线性的,利用推广的卡尔曼滤波器进行导航时精度较低。Unscented卡尔曼滤波是一种针对非线性系统的估计新方法。本文提出将Unscented卡尔曼滤波用于自主天文导航。计算机仿真结果显示Unscented卡尔曼滤波的估计精度远优于推广的卡尔曼滤波。 相似文献
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针对目前应用于SINS/GPS组合导航系统中的扩展卡尔曼滤波(Extended Kalman
Filter, EKF)存在精度低、实时性差的缺点,提出一种基于模型误差预测(Model Error
Prediction, MEP)的Unscented 卡尔曼滤波(Unscented Kalman Filter,
UKF)。MEP-UKF滤波算法将惯性器件测量误差作为模型误差使用MEP进行实时预测的同时,采 用UKF估计载体的姿态、速度及位置等误差信息,并反馈给SINS系统来校正导航参数。MEP-U KF不仅克服了UKF必须假设惯性器件误差为高斯白噪声的局限性,而且降低了SINS/GPS组合 导航系统状态变量的维数,大大缩短了导航解算的时间。仿真结果表明,MEP-UKF的收敛速 度和滤波精度均明显优于EKF,更好地满足了工程应用中对导航精度和实时性的要求。 相似文献
Filter, EKF)存在精度低、实时性差的缺点,提出一种基于模型误差预测(Model Error
Prediction, MEP)的Unscented 卡尔曼滤波(Unscented Kalman Filter,
UKF)。MEP-UKF滤波算法将惯性器件测量误差作为模型误差使用MEP进行实时预测的同时,采 用UKF估计载体的姿态、速度及位置等误差信息,并反馈给SINS系统来校正导航参数。MEP-U KF不仅克服了UKF必须假设惯性器件误差为高斯白噪声的局限性,而且降低了SINS/GPS组合 导航系统状态变量的维数,大大缩短了导航解算的时间。仿真结果表明,MEP-UKF的收敛速 度和滤波精度均明显优于EKF,更好地满足了工程应用中对导航精度和实时性的要求。 相似文献
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Xiuqiang Jiang Shuang Li Xiangyu Huang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(5):1342-1358
Supposing future orbiting and landing collaborative exploration mission as the potential project background, this paper addresses the issue of Mars entry integrated navigation using radio beacon, flush air data sensing system (FADS), and inertial measurement unit (IMU). The range and Doppler information sensed from an orbiting radio beacon, the dynamic pressure and heating data sensed from flush air data sensing system, and acceleration and attitude angular rate outputs from an inertial measurement unit are integrated in an unscented Kalman filter to perform state estimation and suppress the system and measurement noise. Computer simulations show that the proposed integrated navigation scheme can enhance the navigation accuracy, which enables precise entry guidance for the given Mars orbiting and landing collaborative exploration mission. 相似文献
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In this paper, a modified unscented Kalman filter (UKF) for nonlinear stochastic systems is proposed, and it is applied to autonomous orbit determination for Earth satellites. Based on some standard results about the boundedness of stochastic processes and a new formulation of the unscented transformation (UT), it is demonstrated that the design of the noise covariance matrix plays an important role in enhancing the filter stability. Furthermore, a particular design of the noise covariance matrix is proposed as a modification of the UKF. The modified UKF is less sensitive to the initial error than the usual one. High performance of the modified UKF is illustrated in comparison with the usual one by using the real data obtained from an Earth sensor. 相似文献
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Reliability analysis based on a novel density estimation method for structures with correlations 总被引:1,自引:0,他引:1
Estimating the Probability Density Function (PDF) of the performance function is a direct way for structural reliability analysis,and the failure probability can be easily obtained by integration in the failure domain.However,efficiently estimating the PDF is still an urgent problem to be solved.The existing fractional moment based maximum entropy has provided a very advanced method for the PDF estimation,whereas the main shortcoming is that it limits the application of the reliability analysis method only to structures with independent inputs.While in fact,structures with correlated inputs always exist in engineering,thus this paper improves the maximum entropy method,and applies the Unscented Transformation (UT) technique to compute the frac tional moments of the performance function for structures with correlations,which is a very efficient moment estimation method for models with any inputs.The proposed method can precisely estimate the probability distributions of performance functions for structures with correlations.Besides,the number of function evaluations of the proposed method in reliability analysis,which is determined by UT,is really small.Several examples are employed to illustrate the accuracy and advantages of the proposed method. 相似文献
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基于四元数非线性误差模型的快速传递对准(英文) 总被引:1,自引:0,他引:1
基于小角度假设的常规线性误差模型不能适用于大失准角时的初始对准,针对这一问题研究了一种没有小失准角假设,以速度误差和姿态四元数误差作为量测的非线性快速传递对准误差模型,并证明当误差变为小角度时,该非线性误差模型可以简化为常规线性误差模型。使用 Unscented 卡尔曼滤波代替通常采用的扩展卡尔曼滤波来处理非线性数据融合问题。为了评估和分析该非线性误差模型,设计了一个传递对准仿真系统,仿真结果表明,当初始失准角为小角度时,该新模型和线性模型有着相当的对准性能,但是当初始失准角为大角度时,本文提出的非线性误差模型仍然能够精确完成对准过程,而基于线性误差模型的对准滤波器却发散了。 相似文献