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A low-dimensional test problem with a known solution is used to verify various computer implementations of F.C. Schweppe's likelihood detector (1965). In this case a closed-form solution is provided for a Schweppe likelihood detector in terms of an intermediate Kalman filter, as utilized in its implementation, for detecting the presence of a two-state signal model in Gaussian white noise. The associated error probabilities are also evaluated following a procedure that utilizes optimized Chernoff-like bounds for a tight approximation. A methodology is demonstrated for appropriately setting the decision threshold for this example as a tradeoff against allowable observation time. By using this or similar examples, certain qualitative and quantitative aspects of the software implementation can be checked for conformance to anticipated behavior as an intermediate benchmark, prior to modular replacement of the various high-order matrices appropriate to the particular application 相似文献
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GPS/INS uses low-cost MEMS IMU 总被引:3,自引:0,他引:3
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This paper describes one alternative to rehosting TPS software to newer computer platforms. It describes the solution that Southwest Research Institute (SwRI) used to solve a problem with re-engineering legacy software into a modern object-oriented language. The advantages gained by this method are more advanced instruction to the operator (such as pictures and movies), flexible reporting scheme to diagnose system problems, and ease of software maintenance. This solution uses commercially available products including National Instruments/spl trade/ TestStand/spl trade/ and LabVIEW/spl trade/ and Microsoft/spl reg/ Visual Basic/spl reg/. The system is a four-tiered architecture to drive all test execution. The user interface is written in Visual Basic and allows the user to interact with the test execution when needed. This user interface in turn calls tests that are written in TestStand, and finally the individual tests call driver functions written in LabVIEW. A database serves as a repository for all test results, displays, and test limits. The use of this database allows for easy querying of measurement data to analyze trends in failures that help diagnose specific problems. By using this database, all test limits and test displays are contained in one central location that enables engineers to change these displays and limits on the fly without needing to change or even understand any test code. One other benefit of this data containment is that all Government classified data is separated out of the code and stored as one file, instead of in various locations as it was in the original source code. 相似文献
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《Aerospace Science and Technology》2000,4(6):415-422
In this paper, an approach to detect and isolate the aircraft sensor/actuator faults affecting the mean of the Kalman filter innovation sequence is presented. The effects of the sensor and actuator faults in the innovation process of the channels are investigated, and a decision approach to isolate the sensor and actuator faults is proposed. When a Kalman filter is used, the decision statistics change regardless of whether the fault is in the sensors or in the actuators, whilst when a Robust Kalman Filter (RKF) is used, it is easy to distinguish the sensor and actuator faults. A novel feature of this diagnostic method is that the innovation sequence based fault isolation algorithm has been presented and hence, the sensor/actuator fault detection and isolation problem has been solved. The categories (or classes) of the likely faults are not demanded. The statistical characteristics of the system are not required to be known after the fault has occurred. In the simulations, the longitudinal dynamics of an aircraft control system are considered, and the detection and isolation of pitch rate gyro faults and actuator faults affecting the mean of the innovation sequence are examined. 相似文献
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Kalman filtering with state equality constraints 总被引:5,自引:0,他引:5
Kalman filters are commonly used to estimate the states of a dynamic system. However, in the application of Kalman filters there is often known model or signal information that is either ignored or dealt with heuristically. For instance, constraints on state values (which may be based on physical considerations) are often neglected because they do not fit easily into the structure of the Kalman filter. A rigorous analytic method of incorporating state equality constraints in the Kalman filter is developed. The constraints may be time varying. At each time step the unconstrained Kalman filter solution is projected onto the state constraint surface. This significantly improves the prediction accuracy of the filter. The use of this algorithm is demonstrated on a simple nonlinear vehicle tracking problem 相似文献
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研究了在某型现役机载雷达系统中, 采用广义Kalman 滤波器方法来预估目标机的俯仰角和方位角,产生跟踪目标用的雷达天线驱动信号, 替代传统的速率陀螺测量元件来补偿本机机动所造成的扰动的方法,同时对探测信号本身所具有的延迟起到了补偿作用。对目标的运动采用直角坐标系中的Singer 模型描述, 而对测量信号则是应用极坐标系中的描述, 采用广义Kalman 滤波器来完成估计, 即在每一步的估计和控制中对计算测量方程进行线性化结果, 实现两种坐标系的转换。通过应用Matlab/ Simulink 软件对整个系统的建模、设计及仿真研究, 得到了满意的结果。 相似文献
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航空发动机双重传感器故障诊断逻辑研究 总被引:2,自引:1,他引:1
针对航空发动机控制系统的双重传感器故障,提出了一种采用双路容错设计的卡尔曼滤波器故障检测隔离系统.故障检测隔离系统由一系列卡尔曼滤波器组成,每个滤波器都假定2路传感器故障,而以故障支路外的测量值作为输入量.当双重传感器故障发生时,只有不包含故障传感器信息的滤波器保持较低的估计残差,其他滤波器都会产生较大的估计残差,如此双重传感器故障便可以被隔离.利用滤波器组估计残差的特征,进一步设计合理的运算逻辑,系统就可以同时对传感器单一故障进行检测和隔离.为了验证故障诊断系统的有效性,在发动机慢车状态分别对传感器发生双重故障和单一故障的情况进行仿真.仿真结果表明:故障诊断系统能够准确有效地对传感器双重故障和单一故障进行检测和隔离. 相似文献
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基于BP人工神经网络的GPS/SINS组合导航算法 总被引:1,自引:0,他引:1
基于扩展Kalman滤波的GPS/SINS组合导航算法,需要对原始的非线性连续系统模型进行线性化和离散化处理,要求系统噪声和测量噪声为零均值的高斯白噪声,且易于出现滤波器发散。BP人工神经网络毋需对所求解的问题建模,能够很好地逼近系统非线性特性,获得较高精度的导航定位信息;还具有计算过程稳定,不涉及矩阵求逆,不需要迭代逼近,以及容易实现并行处理等优点。本文设计适用于GPS/SINS组合导航系统的BP网络模型,并在标准的BP算法基础上,采用共轭梯度法改进网络训练速度及精度。最后,通过仿真算例说明BP网络方法用于GPS/SINS组合导航计算的可行性。 相似文献
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Adaptive Two-Stage Extended Kalman Filter for a Fault-Tolerant INS-GPS Loosely Coupled System 总被引:5,自引:0,他引:5
Kim Kwang Hoon Lee Jang Gyu Park Chan Gook 《IEEE transactions on aerospace and electronic systems》2009,45(1):125-137
The well-known conventional Kalman filter requires an accurate system model and exact stochastic information. But in a number of situations, the system model has an unknown bias, which may degrade the performance of the Kalman filter or may cause the filter to diverge. The effect of the unknown bias may be more pronounced on the extended Kalman filter (EKF), which is a nonlinear filter. The two-stage extended Kalman filter (TEKF) with respect to this problem has been receiving considerable attention for a long time. Recently, the optimal two-stage Kalman filter (TKF) for linear stochastic systems with a constant bias or a random bias has been proposed by several researchers. A TEKF can also be similarly derived as the optimal TKF. In the case of a random bias, the TEKF assumes that the information of a random bi?s is known. But the information of a random bias is unknown or partially known in general. To solve this problem, this paper proposes an adaptive two-stage extended Kalman filter (ATEKF) using an adaptive fading EKF. To verify the performance of the proposed ATEKF, the ATEKF is applied to the INS-GPS (inertial navigation system-Global Positioning System) loosely coupled system with an unknown fault bias. The proposed ATEKF tracked/estimated the unknown bias effectively although the information about the random bias was unknown. 相似文献
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《中国航空学报》2021,34(5):601-616
Unmanned Aerial Vehicles (UAVs) and Unmanned Ground Vehicles (UGVs) have been used in research and development community due to their strong potential in high-risk missions. One of the most important civilian implementations of UAV/UGV cooperative path planning is delivering medical or emergency supplies during disasters such as wildfires, the focus of this paper. However, wildfires themselves pose risk to the UAVs/UGVs and their paths should be planned to avert the risk as well as complete the mission. In this paper, wildfire growth is simulated using a coupled Partial Differential Equation (PDE) model, widely used in literature for modeling wildfires, in a grid environment with added process and measurement noise. Using principles of Proper Orthogonal Decomposition (POD), and with an appropriate choice of decomposition modes, a low-dimensional equivalent fire growth model is obtained for the deployment of the space–time Kalman Filtering (KF) paradigm for estimation of wildfires using simulated data. The KF paradigm is then used to estimate and predict the propagation of wildfire based on local data obtained from a camera mounted on the UAV. This information is then used to obtain a safe path for the UGV that needs to travel from an initial location to the final position while the UAV’s path is planned to gather information on wildfire. Path planning of both UAV and UGV is carried out using a PDE based method that allows incorporation of threats due to wildfire and other obstacles in the form of risk function. The results from numerical simulation are presented to validate the proposed estimation and path planning methods. 相似文献
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直接根据性能指标进行航空发动机LQG/LTR控制器设计 总被引:3,自引:1,他引:2
本文提出了一种根据性能指标要求设计航空发动机LQG/LTR控制器的方法。采用这种方法,可根据发动机模型及性能指标要求直接获得卡尔曼滤波器增益,而无需求解Riccati方程。随后的仿真结果表明,所设计的控制系统具有较好的稳定鲁棒性及较好的动态性能。 相似文献
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研究分析了目前企业信息化管理存在的问题,结合实际应用中的需求,采用组件化和智能化的设计思想,利用面向对象和中间件技术,构建了软件多层结构体系,对信息化一站式管理进行了设计与实现,实现了现代化信息技术与先进的管理理念相融合。系统在西北工业大学后勤产业集团得到了实际应用,结果表明,系统具有安全可靠、信息多样、界面友好、操作简便,到达了需求目标,取得了良好的效果。 相似文献
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一种基于可观测度分析的SINS/GPS自适应-反馈校正滤波新方法 总被引:2,自引:0,他引:2
针对机载捷联惯导系统(SINS)/全球定位系统(GPS)组合导航系统不完全可观测导致滤波器精度下降甚至发散的问题,提出了一种基于系统状态可观测度分析的自适应反馈校正滤波新方法。该滤波方法改进了系统可观测度的归一化处理方法,将归一化处理后的系统状态可观测度作为反馈因子,对SINS系统进行自适应反馈校正。最后,将该方法应用于机载合成孔径雷达(SAR)运动补偿用SINS/GPS组合导航系统中,飞行试验结果表明该方法在系统不完全可观测的情况下有效地提高了导航精度。 相似文献