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On the base of the research object of the optical system of polarization maintaining interferometric fiber optical gyroscope(IFOG), when the light signal is modulation under +pi/2 square wave signal, an input-output model is established by making use of Jones matrix and coherence matrix. Based on the model mentioned above, theoretic analysis on the polarization noise of the optical system is made,...
The oil/water two-phase flow is a complicated two-component nonlinear system with time-variance, and the dynamic measuring system for water content in crude oil based on method of dielectric coefficient is affected by manufacturing technology of sensor itself and some non-object parameters, such as temperature and salinity content in oil-water mixture. Consequently, the sensor has serious non-linearity...
RLV (reusable launch vehicle) ascent-trajectory optimization is a difficult problem due to the complexity of many physical constraints and optimization cost surfaces. In this paper, a heuristic technique based on a PSO (particle swarm optimization) algorithm is used. The highly constrained nonlinear trajectory planning problem is decomposed into control parameters search problems, The algorithm is...
A new structure actuator for reducing coupling of bank-to-turn (BTT) missiles to is studied. The new structure actuator can roll independently along the longitudinal axis of the missile. Hence, the actuator instead of airframe needs to steer when controlling BTT missile rolling. So the rolling speed of main airframe is reduced, it can reduce coupling of missile introduced by airframe rolling. And...
The line-of-sight (LOS) stabilization control based on gyro stabilized platform is required to isolate LOS from the movement and vibration of carrier and ensure pointing and tracking for target in electro-optical tracking system. In this paper, a fractional-order PI (FOPI) controller is applied in the design of stabilization loop of LOS stabilization system for the first time, based on the analysis...
In this paper, an improved Levenberg-Marquardt learning algorithm based on terminal attractors for feedforward neural networks is proposed. The effectiveness of the proposed algorithm in improving learning speed is shown by the simulation results.
Departure and arrival procedures of an airport will be changed along with the increasing of air traffic flow and the changing of airspace structure. Based on the present departure and arrival procedures of this airport, aimed at optimizing the procedures and decreasing the unwanted conflicts resulting from the present procedures, this paper chooses Xiamen Gaoqi International airport as the research...
Concerning the problems in the process of the spacecraftpsilas autonomous navigation, the square-root unscented Kalman filter(SRUKF) is designed to estimate the relative state between the pursuing spacecraft and the target. C-W equation is discreted to iterate. For the case that all the measuring datas get from radars, the observing equation was deduced. Compared with the conventional extended Kalman...
A new geomagnetic navigation positioning system is proposed in this paper. Unlike those existing algorithms which rely on the anomaly magnetic field, the method presented in this paper selects the main magnetic field as navigation reference, thus is more adaptive. Meanwhile, it has the advantages of fast calculation, high accuracy as well as low storage requirement, which are theoretically verified...
The output signals of gyros and accelerometers on a rocking base are disturbed by the rocking, so it is difficult to implement initial alignment. To address the problem, a new coarse alignment and accurate alignment algorithm is proposed in early research. But those algorithms are just evaluated by simulations. In this paper, several groups of experiments are designed to validate the algorithms in...
The main problem addressed is the attitude tracking control of rigid satellite in the presence of inertia matrix uncertainty and external disturbances. A sliding mode controller with PID sliding surface is presented. A detail stability analysis of the close loop system is include, and while there exists uncertainty in satellite inertia parameters or external disturbance, this control scheme has global...
A target tracking method based on data fusion of infrared and radar is proposed to improve tracking precision. Unscented Kalman filter (UKF) is applied to process data on distributed fusion architectures. The method combines the advantages of UKF and track-to-track algorithms. The cross-covariances of the two sensors are used to estimate overall covariance and states. The overall estimation is obtained...
Optical collimators are very important components in the construction of practical fiber network. But unfortunately, the problem of low-efficiency alignment is always a bottleneck of optical collimators assembly. Currently, most fiber alignment algorithms are only suitable for lateral axes, and for angular alignment, manual coupling is still widely used in product line. In recent years, engineers...
This paper bases on three micro-satellites which formationally fly on a same orbit and perform three dimension solid mapping for terra. The calculating formula of LEO formation-flying satellite inter-satellite links is guided according to the special require of formation-flying micro-satellite inter-satellite links. A new communication project, which changes code rate according to the inter-satellite...
As a hub airport, the aircraft should arrive at more airports, so the passengers will not change another aircraft to their destinations. But due to the limited time in one day, one aircraft only get few flight missions. At present scheduled flights are arranged between two airports as a pair of flights. This paper researched that when it is known the amount of destination airports how to arrange scheduled...
This paper proposes a novel multi-band semi-circle fractal antenna which develops from the multiple ring antenna. The antenna consists of nesting semi-circles with different radii. Simulated on the commercial software CST MICROWAVE STUDIOreg, the multi-band characteristic of the novel antenna can be controlled by modulating the radii of the nesting semi-circles and the nesting number. Summarized from...
In order to accommodate different combat missions, modern vehicles should be capable of covering wide range and accurately striking a target with multi-constraints, such as the common aero vehicle (CAV) et al. This paper set up the adjustable range and precision guided trajectory models, and analyzed multiple processing constraints and terminal constraints in flight. Furthermore, to enhance control...
Adaptive anti-jam processing used by Global Positioning System (GPS) usually works in an environment where interferences exist. The Power-Inversion (PI) algorithm is often applied to suppress interferences in the system. But variance of amplitude and phase which exists among antenna channel takes bad effect on adaptive anti-jam processing and PI algorithm, so we do our best to research the relation...
Kernel Fisher discriminant analysis (KFDA) has been widely used in fault diagnosis. In this paper, a feature vector selection (FVS) scheme based on a geometrical consideration is given to reduce the computational complexity of KFDA when the number of samples becomes large. Experimental results show the effectiveness of our method.
Space-time Adaptive Processing (STAP) is usually applied to adaptive anti-jam system of Global Positioning System (GPS). It is the most effective way to reject the broadband interference. But STAP often dose matrix compute, which has a huge computational complexity. Paper investigates a recursive algorithm-Frost Least-Mean-Square (FLMS) algorithm. FLMS can reduce the workload of array signal processing...
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