摘要：This paper addresses the gas path component and sensor fault diagnosis and isolation(FDI) for the auxiliary power unit(APU). A nonlinear dynamic model and a distributed state estimator are combined for the distributed control system. The distributed extended kalman filter(DEKF)is served as a state estimator,which is utilized to estimate the gas path components’ flow capacity. The DEKF includes one main filter and five sub-filter groups related to five sensors of APU and each sub-filter yields local state flow capacity. The main filter collects and fuses the local state information,and then the state estimations are feedback to the sub-filters. The packet loss model is introduced in the DEKF algorithm in the APU distributed control architecture. FDI strategy with a performance index named weight sum of squared residuals(WSSR) is designed and used to identify the APU sensor fault by removing one sub-filter each time. The very sensor fault occurs as its performance index WSSR is different from the remaining sub-filter combinations. And the estimated value of the soft redundancy replaces the fault sensor measurement to isolate the fault measurement. It is worth noting that the proposed approach serves for not only the sensor failure but also the hybrid fault issue of APU gas path components and sensors. The simulation and comparison are systematically carried out by using the APU test data,and the superiority of the proposed methodology is verified.

摘要：This paper deals with the research of the GPS/INS integrated navigation system applying Extended kalman filter, which involves integrated principles, scheme and technology of combining with real INS and GPS receiver data. Emphases are placed on the modeling of system errors and implementation of the integrated system. Both loose and tightly coupled GPS/INS integrated in schemes are analyzed. On the basis of our experience accumulated in the research of GPS/INS for many years, the GPS/INS integrated navigation developing system is developed. It can be put into efficient and economic use in the study and design of integrated navigation system. It plays an important role in the aeronautical and astronautical fields in China. This system is not only a computer aided design software but also a semi physical simulation system by obtaining real INS and GPS receiver data. So the key software unit of the developing system could be conveniently transferred into practical engineering software in actual hardware integrated system. The application of this system shows that the design ideas and integrated scheme of this development system are successful, and can achieve good navigation result.

摘要：In the performance based navigation（PBN）,the flight technical error（FTE）and the navigation system error（NSE）are two main parts of total system error（TSE）.The implementation of PBN requires pre-flight prediction and en-route short-term dynamical prediction of *** the sum of predicted FTE and NSE is greater than the specified PBN value,PBN cannot ***,it requires accurate modeling and thorough analysis of the two main ***-input multiple-output（MIMO）longitudinal flight control system of ARIC model is designed using the linear quadratic Gaussian and loop transfer recovery（LQG/LTR）method,and FTE in symmetrical plane of aircraft is analyzed during the turbulence disturbed *** error estimation mapping function of FTE in symmetrical plane and its bound estimation model are proposed based on the singular value *** model provides an approach based on the forming mechanism of FTE,rather than the costly flight test and the data ***-data based simulation validates the theoretical analysis of FTE in symmetrical *** also shows that FTE is partially caused by the turbulence fluctuation disturbance when the automatic flight control system（AFCS）is engaged and increases with escalating the environmental turbulence intensity.

摘要：The orchards usually have rough terrain,dense tree canopy and *** is hard to use GNSS for autonomous navigation in orchard due to signal occlusion,multipath effect,and radio frequency *** achieve autonomous navigation in orchard,a visual navigation method based on multiple images at different shooting angles is proposed in this paper.A dynamic image capturing device is designed for camera installation and multiple images can be shot at different ***,the obtained orchard images are classified into sky and soil detection *** image is transformed to HSV space and initially segmented into sky,canopy and soil regions by median filtering and morphological ***,the sky and soil regions are extracted by the maximum connected region algorithm,and the region edges are detected and filtered by the Canny ***,the navigation line in the current frame is extracted by fitting the region coordinate *** the dynamic weighted filtering algorithm is used to extract the navigation line for the soil and sky detection stage,respectively,and the navigation line for the sky detection stage is mirrored to the soil ***,the kalman filter algorithm is used to fuse and extract the final navigation *** test results on 200 images show that the accuracy of visual navigation path fitting is 95.5%,and single frame image processing costs 60 ms,which meets the real-time and robustness requirements of *** visual navigation experiments in Camellia oleifera orchard show that when the driving speed is 0.6 m/s,the maximum tracking offset of visual navigation in weed-free and weedy environments is 0.14 m and 0.24 m,respectively,and the RMSE is 30 mm and 55 mm,respectively.