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1.
基于多传感器观测信息抗差估计的自适应融合导航   总被引:7,自引:0,他引:7  
首先利用抗差估计原理构造了基于观测信息的融合导航解,再利用动力学模型信息进行自适应融合,最后利用模拟算例进行多种方案的计算与比较。  相似文献   

2.
基于方差分量估计的自适应融合导航   总被引:23,自引:4,他引:23  
多源传感器观测信息的精度一般不一致,利用方差分量估计理论可以合理地顾及各传感器观测信息在融合导航解中的权比.首先给出基于多源观测信息的融合导航解算模式,进而基于方差分量估计讨论了各传感器观测信息在融合导航解中的合理平衡问题,然后应用自适应因子顾及动力学模型预报信息的贡献,给出了计算过程,并利用模拟数据进行了试算与比较.  相似文献   

3.
针对车载全球导航卫星系统/惯性导航系统(global navigation satellite system/inertial navigation system,GNSS/INS)组合导航中卫星信号中断,惯性导航系统单独导航误差积累较大的问题,提出了附加载体运动条件约束的卡尔曼(Kalman)滤波解算方法。通过利用载体固有的运动约束,包括近似高程约束、近似速度约束和近似姿态约束,减少载体自由度和模型参数;通过引入新的观测类型,增加观测冗余,可以加强Kalman滤波解,提高在GNSS信号中断时组合导航系统的定位精度,实现无缝导航。  相似文献   

4.
一种基于Bancroft算法的GPS动态抗差自适应滤波   总被引:3,自引:0,他引:3  
基于抗差自适应滤波的思想,结合非线性Bancroft算法的特点,提出了一种基于Bancroft算法的GPS动态抗差自适应滤波。计算表明,该算法不仅在一定程度上减弱了由于线性化忽略高次项对导航解的影响,而且再次证实抗差自适应滤波在控制扰动异常的有效性和合理性。  相似文献   

5.
In urban canyons, buildings and other structures often block the line of sight of visible Global Navigation Satellite System (GNSS) satellites, which makes it difficult to obtain four or more satellites to provide a three-dimensional navigation solution. Previous studies on this operational environment have been conducted based on the assumption that GNSS is not available. However, a limited number of satellites can be used with other sensor measurements, although the number is insufficient to derive a navigation solution. The limited number of GNSS measurements can be integrated with vision-based navigation to correct navigation errors. We propose an integrated navigation system that improves the performance of vision-based navigation by integrating the limited GNSS measurements. An integrated model was designed to apply the GNSS range and range rate to vision-based navigation. The possibility of improved navigation performance was evaluated during an observability analysis based on available satellites. According to the observability analysis, each additional satellite decreased the number of unobservable states by one, while vision-based navigation always has three unobservable states. A computer simulation was conducted to verify the improvement in the navigation performance by analyzing the estimated position, which depended on the number of available satellites; additionally, an experimental test was conducted. The results showed that limited GNSS measurements can improve the positioning performance. Thus, our proposed method is expected to improve the positioning performance in urban canyons.  相似文献   

6.
多源传感器融合导航有多种算法,但不同算法之间存在理论和计算方面的差异。本文试图从理论上探讨联邦滤波融合法、动静态滤波融合法、基于观测信息的融合法以及基于各传感器几何导航解融合法的基本原理,分析各种方法的优劣,为多传感器融合导航的应用打下基础。  相似文献   

7.
自适应联邦滤波器在GPS-INS-Odometer组合导航的应用   总被引:1,自引:0,他引:1  
针对多传感器观测信息较多、计算效率较低、对动力学模型误差稳键性不佳的问题,提出了一种自适应联邦滤波器并应用于GPS-INS-Odometer组合导航。首先介绍GPS-INS-Odometer组合导航的动力学模型和观测模型,比较分析了信息分配因子和自适应因子的共同特性,论证了联邦滤波器和自适应滤波器的等价性及其等价成立条件,提出了自适应联邦滤波器的信息分配因子构造方法。最后利用实测数据验证了算法的有效性。结果表明,相比于基于GPS和Odometer(里程计)初始方差构造信息分配因子的联邦滤波器,本文提出的自适应联邦滤波器兼容了联邦滤波器高效计算效率,且具有较好的抵抗动力学模型误差效果,能够有效削弱多传感器动力学模型误差对于导航解算的影响,对直接可测参数和间接可测参数的精度提高均起到了积极的作用。  相似文献   

8.
简要介绍了GPS/INS松组合导航系统状态方程和观测方程。针对标准Kalman滤波算法存在的状态方程截断误差、噪声统计特性的不确定性以及状态扰动异常的影响,给出了一种应用于GPS/INS组合导航系统的迭代滤波算法。该算法采用迭代策略,不断利用观测信息实时修正状态预报值。实测数据计算结果表明,通过对状态预报值的实时修正,该算法能够很好地抑制状态预报信息的不确定性和扰动异常等对导航解的影响。其滤波解精度明显优于标准Kalman滤波。  相似文献   

9.
基于Kalman滤波的动力学模型误差估计算法   总被引:1,自引:1,他引:0  
本文分析介绍了模型误差对滤波解和预报残差影响的表达式.随后,针对GPS/INS松组合导航系统观测信息无冗余的情况,给出了基于Kalman滤波的动力学模型误差估计算法.最后利用一个车载实测数据证明了算法的有效性.  相似文献   

10.
神经网络辅助的GPS/INS组合导航故障检测算法   总被引:2,自引:0,他引:2  
针对GPS/INS松组合导航系统观测信息无冗余,而且观测信息可能存在故障的情形,提出一种神经网络辅助的组合导航故障检测算法。该算法克服了基于模型的故障检测算法受模型误差影响的局限性;能够自动地对观测信息进行故障的检测、定位和剔除;能够基于故障检测后可靠的观测信息进一步调整动力学模型信息对导航解的贡献;能够在GPS失锁时,较好地进行导航预报。最后利用车载实测数据进行验证,结果表明该算法能够很好地从模型误差中分离出观测信息含有的故障信息,降低了故障检测算法存在的虚警率,避免故障信息对导航解的影响;且GPS失锁时,神经网络的预报输出在一定程度上能够进一步提高导航解的精度。  相似文献   

11.
多源传感器动、静态滤波融合导航   总被引:12,自引:2,他引:12  
首先给出联邦滤波各局部输出量之间的相关协方差矩阵,进而给出了基于各传感器独立观测信息的动、静态滤波解法,这种解法避免了重复使用载体状态方程信息的问题,保证了多传感器数据融合的最优性,而且很容易扩展到抗差滤波和自适应滤波融合。  相似文献   

12.
Adaptive fitting of systematic errors in navigation   总被引:4,自引:0,他引:4  
To use Kalman filtering for kinematic positioning and navigation, we have to deal with both observational and kinematic models. Both of the functional models may contain global or local systematic errors. The influence functions of the systematic errors on the estimates of kinematic states are derived. An adaptive fitting method for systematic errors of the observations and kinematic model errors is presented. The systematic errors are fitted with a mean or a weighted mean by using the residuals of observations and residuals of predicted states within a chosen time window. The covariance matrices of the modified observations and the predicted states are estimated within the same window. The estimation formulae and calculation strategy, as well as a real example, are given. It is shown by theory and calculations that Kalman filtering based on the adaptive fittings of the systematic errors and covariance matrices can, to some degree, resist the influences of systematic errors on the estimated states of navigation.  相似文献   

13.
Due to their complementary features of GPS and INS, the GPS/INS integrated navigation system is increasingly being used for a variety of commercial and military applications. An attitude determination GPS (ADGPS) receiver, with multiple antennas, can be more effectively integrated with a low-cost IMU since the receiver gives not only position and velocity data but also attitude data. This paper proposes a low-cost attitude determination GPS/INS integrated navigation system. The proposed navigation system comprises an ADGPS receiver, a navigation computer unit (NCU), and a low-cost commercial MEMS IMU. The navigation software includes a fault detection and isolation (FDI) algorithm for integrity. In order to evaluate the performance of the proposed navigation system, two flight tests have been performed using a small aircraft. The first flight test confirmed the fundamental operation of the proposed navigation system and the effectiveness of the FDI algorithm. The second flight test evaluated the performance of the proposed navigation system and demonstrated the benefit of GPS attitude information in a high dynamic environment. The flight test results show that the proposed ADGPS/INS integrated navigation unit gives reliable navigation performance even when anomalous GPS data is provided and gives better navigation performance than a conventional GPS/INS unit.  相似文献   

14.
Although the integrated system of a differential global positioning system (DGPS) and an inertial navigation system (INS) had been widely used in many geodetic navigation applications, it has sometimes a major limitation. This limitation is associated with the frequent occurrence of DGPS outages caused by GPS signal blockages in certain situations (urban areas, high trees, tunnels, etc.). In the standard mechanization of INS/DGPS navigation, the DGPS is used for positioning while the INS is used for attitude determination. In case of GPS signal blockages, positioning is provided using the INS instead of the GPS until satellite signals are obtained again with sufficient accuracy. Since the INS has a very short-time accuracy, the accuracy of the provided INS navigation parameters during these periods decreases with time. However, the obtained accuracy in these cases is totally dependent on the INS error model and on the quality of the INS sensor data. Therefore, enhanced navigation parameters could be obtained during DGPS outages if better inertial error models are implemented and better quality inertial measurements are used. In this paper, it will be shown that better INS error models are obtained using autoregressive processes for modeling inertial sensor errors instead of Gauss–Markov processes that are implemented in most of the current inertial systems and, on the other hand, that the quality of inertial data is improved using wavelet multi-resolution techniques. The above two methods are discussed and then a combined algorithm of both techniques is applied. The performance of each method as well as of the combined algorithm is analyzed using land-vehicle INS/DGPS data with induced DGPS outage periods. In addition to the considerable navigation accuracy improvement obtained from each single method, the results showed that the combined algorithm is better than both methods by more than 30%.  相似文献   

15.
Due to their low cost and low power consumption, single-frequency GPS receivers are considered suitable for low-cost space applications such as small satellite missions. Recently, requirements have emerged for real-time accurate orbit determination at sub-meter level in order to carry out onboard geocoding of high-resolution imagery, open-loop operation of altimeters and radio occultation. This study proposes an improved real-time kinematic positioning method for LEO satellites using single-frequency receivers. The C/A code and L1 phase are combined to eliminate ionospheric effects. The epoch-differenced carrier phase measurements are utilized to acquire receiver position changes which are further used to smooth the absolute positions. A kinematic Kalman filter is developed to implement kinematic orbit determination. Actual flight data from China’s small satellite SJ-9A are used to test the navigation performance. Results show that the proposed method outperforms traditional kinematic positioning method in terms of accuracy. A 3D position accuracy of 0.72 and 0.79 m has been achieved using the predicted portion of IGS ultra-rapid products and broadcast ephemerides, respectively.  相似文献   

16.
GPS单点测速的误差分析及精度评价   总被引:6,自引:0,他引:6  
首先从理论和实测数据模拟两方面分析了SA取消后各类误差源对GPS测速的影响,推导并计算了GPS单点测速可能达到的精度水平。然后用静态数据模拟动态测速试验和实测动态数据测速与同步高精度惯导测速的动态试验进行验证。结果表明,采用载波相位导出的多普勒观测值使用静态数据模拟动态测速,其精度可以达到mm/s级;用接收机输出的多普勒观测值进行测速时,其精度为cm/s级。在动态测速试验中,GPS单点测速方法(即多普勒观测值测速与导出多普勒观测值测速)间的符合精度达到cm/s级,与高精度的惯导测速结果的符合精度为dm/s级,而且和运动载体的动态条件(如加速度和加速度变化率的大小)具有很强的相关性。  相似文献   

17.
本文利用Kalman滤波方法对动态测量进行数据处理,由于高动态的GPS测量,不易确定系统动态噪声和观测噪声.同时标准的Kalman滤波在应用过程中由于状态模型确定的误差存在,滤波效果不佳.因此本文结合动态导航的实时性和高动态性,建立了动态导航系统中滤波状态方程和观测方程,采用改进的Sage-Husa自适应滤波对来进行实时定位数据处理,利用已有测量数据进行了实例分析.改进的Sage-Husa自适应滤波在计算过程中计算量小,结果稳定,有较强的自适应性.  相似文献   

18.
针对低动态高抖动环境下,影响GPS/INS紧组合精度的重要因素——惯性测量单元(IMU)数据中的噪声,该文提出利用小波降噪方法分离IMU数据中的噪声和有用信号以提高GPS/INS紧组合的精度。首先对IMU数据进行小波分解后得到的高频系数进行阈值量化处理,然后将GPS观测数据与降噪后的IMU数据进行GPS/INS紧组合解算,最终得到载体的导航信息。实例结果表明,该方法可以大幅提升GPS/INS紧组合的精度和稳定可靠性。  相似文献   

19.
The method of integrated data processing for GPS and INS(inertial navigation system) field test over the Rocky Mountains using the adaptive Kalman filtering technique is presented. On the basis of the known GPS outputs and the offset of GPS and INS, state equations and observations are designed to perform the calculation and improve the navigation accuracy. An example shows that with the method the reliable navigation parameters have been obtained.  相似文献   

20.
IntroductionGPS/INS integrated system exploited the INSand differential GPS pseudo-range and carrierphase technique to promote the accuracy of thedynamic platform navigation and positioning,and increase the reliability and stabilization.Incalculation, Kal…  相似文献   

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