共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
为解决弹载环境下两轴陀螺传感器难以实现三轴校正的问题,提出基于地磁辅助的两轴陀螺 传感器校正方法。建立两轴陀螺传感器测量误差模型,由单轴地磁信号解算得到弹丸x轴 角速率,解决了因陀螺传感器量程限制而无法测量低旋弹丸x轴滚转角速率的问题;研究线性最小二乘模型和卡尔曼滤波模型校正两轴陀螺传感器相关参数的方法,数值仿真分析弹丸x轴角速率解算误差和陀螺传感器测量噪声对校正结果的影响;半实物仿真模拟两轴陀螺传感器在工程中的应用,研究基于地磁辅助的两轴陀螺传感器校正方法校正效果。数值仿真结果表明:当弹丸x轴 角速率解算误差在0.261 8 rad/s以内且当陀螺传感器测量噪声在0.001 6 rad/s以内时,经过校正后,弹丸y轴和z轴角速率校正误差在0.01 rad/s以内。半实物仿真结果表明:当弹丸x轴角速率解算误差在0.8 rad/s以内时,两种校正模型均能将陀螺传感器的测量误差从-0.30~-0.05 rad/s范 围减小到-0.02~0.02 rad/s范围内。数值仿真和半实物仿真结果证明:基于地磁辅助的两轴陀螺传感器校正方法具有较好的校正效果。 相似文献
4.
5.
矢量传感器的转向差与信号检测 总被引:2,自引:1,他引:1
三轴磁强计广泛地用于磁信号检测,但由于转向差的存在限制了它对微弱信号的检测。在分析矢量传感器转向差的基础上,提出一种校正转向差的方法,结果显示该方法能显著地降低转向差,从而改善了对微弱信号的检测能力。 相似文献
6.
7.
针对基于磁强计的组合导航研究中,须事先确定滚转角这一不足,提出了一种磁强计和MEMS陀螺组合确定姿态的四元数卡尔曼滤波算法。利用陀螺测量的姿态角速率,结合磁强计输出的地磁分量测量值,运用卡尔曼滤波算法对三个姿态角同时进行最优估计,而不需要先验假设。仿真误差分析表明:姿态角解算结果具有较小的误差,且不随时间积累。 相似文献
8.
推导了磁阻/DR的组合方法,利用加速度计与磁强计测量的载体姿态角适时的对陀螺所测的载体姿态角进行修正,抑制了陀螺所测量载体姿态角误差的迅速扩大.探讨了GPS/SINS组合导航系统中抗差自校正卡尔曼滤波的应用,并对此进行了仿真.最后的仿真结果表明:抗差自校正卡尔曼滤波效果优于标准卡尔曼滤波效果. 相似文献
9.
10.
分析了测试陀螺加速度计的试验中存在的三轴台位置误差,得出引起三轴台位置误差的原因为三轴台的定位误差和动不平衡扰动,研究了两种位置误差对仪表测试结果的影响,提出采用总体最小二乘法补偿三轴台的位置误差.总体最小二乘法为一种具有噪声清除的方法,其应用有效地补偿了测试试验中三轴台的位置误差,提高了陀螺加速度计的测试精度. 相似文献
11.
The stability under illumination of transmission-mode GaAs photocathode sealed in the third generation intensifier is investigated by use of spectral response testing instruments. The variations of spectral response with the illumination times under weak and intense illumination are compared. The variations of photoemission performance parameters are also characterized. The results show that during initial several weak illuminations photocathode behaves no evident decay and a maximum sensitivity is achieved, while under intense illumination the sensitivity of photocathode begin to decrease largely at the first illumination. The calculated performance parameters show that the variation of surface escape probability with illumination times is a direct cause of instability of photocathode. It is also found that under intense illumination peak wavelength is moved towards short-wave and peak response is decreased, which shows that the ability of long-wave response of photocathode is decreased. 相似文献
12.
A Passive Acoustic Radar is presented as a necessary complement to electromagnetic wave radar, which will be expected to be an effective means for detecting cruise missiles. Acoustic characteristics of supersonic flying projectiles with diverse shapes are expounded via experiment. It is pointed out that simulation experiment could be implemented using bullet or shell instead of cruise missile. Based on theoretical analysis and experiment, the ““acoustic fingerprint““ character of cruise missile is illustrated to identify it in a strong noise environment. After establishing a locating mathematical model, the technique of acoustic embattling is utilized to resolve a problem of confirming the time of early-warning, considering the fact that velocity of sound is much slower than that of light. Thereby, a whole system of passive acoustic radar for detecting supersonic cruise missile is formed. 相似文献
13.
The test scheme of static postponing time given in our actual national military test standard on shrapnels used to control riot is a nine-point test scheme on the combined action of three kinds of temperatures and three kinds of pressures,the consumed ammunitions are more excessive. Statistic analysis and tentative checkout about a lot of test data are done,feasibility gists are put forward for optimizing of the test design scheme. The optimizing design and data analysis of test scheme of the item are done by managing uniformity design theory, two scientific and reasonable six-point test schemes are confirmed. The feasibility and reliability of the optimizing design schemes put forward above are proved ulteriorly by test validating. The gained schemes not only have good design uniformity and little ammunition wastage and meet the test demand, but also have better forecast ability for the result data of other points using the mathematic models from the actual test points. 相似文献
14.
A novel image restoration scheme, which is super-resolution image restoration algorithm Poisson-maximum-afterword-probability based on Markvo constraint (MPMAP) combined with evaluating image detail parameter D, has been proposed. The advantage of super-resolution algorithm MPMAP incorporated with parameter D lies in the fact that superresolution algorithm MPMAP model is discrete, which is in accordance with remote-sensing imaging model, and the algorithm MPMAP is proved applicable to linear and non-linear imaging models with a unique solution when noise is not severe. According to simulation experiments for practical images, super-resolution algorithm MPMAP can retain image details better than most of traditional restoration methods; at the same time, the proposed parameter D can help to identify real point spread function (PSF) value of degradation process. Processing result of practical remote-sensing images by MPMAP combined with parameter D are given, it illustrates that MPMAP restoration scheme combined PSF estimation has a better restoration result than that of Photoshop processing, based on the same original images. It is proved that the proposed scheme is helpful to offset the lack of resolution of the original remote-sensing images and has its extensive application foreground. 相似文献
15.
A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law. 相似文献
16.
The design problem of non-fragile estimator is addressed for a class of perturbed linear continuous systems. The perturbations occur on the plant and estimator parameters. The estimator designed should force the error system to achieve the desired decay rate and force the steady error variance less than the specified upper bound irrdevancy of the admissible plant perturbations and estimator perturbations. Consistency problem of the decay rate with the variance upper bound is first considered via linear matrix inequality (LMI) approach. The solution of the estimator parameter under specifications to be consistent is then discussed. The consistency condition of specifications and estimator parameter solution are transformed to feasible or minimum problems subject to a set of LMI respectively. The method is illustrated by a numerical example. 相似文献
17.
The improved scene-based adaptive nonuniformity correction (NUC) algorithms using a neural network (NNT) approach for infrared image sequences are presented and analyzed. The retlna-like neural networks using steepest descent model was the first proposed infrared focal plane arrays (IRFPA) nonuniformity compensation method, which can perform parameter estimation of the sensors over time on a frame by frame basis. To increase the strength and the robustness of the NNT algorithm and to avoid the presence of ghosting artifacts, some optimization techniques, including momentum term, regularization factor and adaptive learning rate, were executed in the parameter learning process. In this paper, the local median filtering result of Xij ( n ) is proposed as an alternative value of desired network output of neuron Xij ( n ), denoted as Tij ( n ), which is the local spatial average of Xij ( n ) in traditional NNT methods. Noticeably, the NUC algorithm is inter-frame adaptive in nature and does not rely on any statistical assumptions on the scene data in the image sequence. Applications of this algorithm to the simulated video sequences and real infrared data taken with PV320 show that the correction results of image sequence are better than that of using original NNT approach, especially for the short-time image sequences (several hundred frames) subjected to the dense impulse noises with a number of dead or saturated pixels. 相似文献
18.
The disadvantages of IR images mostly include high noise, blurry edge and so on. The characteristics make the existent smoothing methods ineffective in preserving edge, To solve this problem, a piecewise moment filter (PMF) is put forward. By using moment and piecewise linear theory, the filter can preserve edge. Based on the statistical model of random noise, a related-coefficient method is presented to estimate the variance of noise. The edge region and model are then detected by the estimated variance. The expectation of first-order derivatives is used in getting the reliable offset of edge. At last, a fast moment filter of double-stair edge model is used to gain the piecewise smoothing results and reduce the calculation. The experimental result shows that the new method has a better capability than other methods in suppressing noise and preserving edge. 相似文献
19.
A best linear unbiased estimation (BLUE) algorithm for bistatic sonar localization is proposed. The Cramer-Rao bound for bistatic Sonar and the geometrical dilution of precision (GDOP) in different conditions are given. The simulation results show that the location accuracy of BLUE algorithm is higher than the weighted least square method. 相似文献
20.
A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal. 相似文献