36 results about "Filter theory" patented technology

The invention discloses a synthetic aperture radar automatic target recognition method which belongs to the target recognition field and mainly solves the problem that the space complexity of the existing synthetic aperture radar automatic target recognition technology is higher and single classifier has low recognition rate. The method comprises the following recognition steps: preprocessing, extracting characteristics, training classifiers and identifying target, wherein the step of extracting characteristics is to extract PCA characteristics of the synthetic aperture radar image, elliptic Fourier descriptor and two-dimensional Fourier transform; the step of training classifiers is based on the extracted three characteristics to separately use K-nearest neighbor method, support vector machine and MINACE filter theory to train three classifiers; and the step of identifying target is to input the extracted synthetic aperture radar image to be identified in the trained three classifiers for classification and finally adopting the Dempster-Shafer evidence theory to fuse the recognition results of the three classifiers. The method has the advantages of high recognition rate and low space complexity and can be used in the target tracking of the military or civilian field.

The invention discloses a distributed passive radar target detection method under a direct wave-free condition, and belongs to the technical field of distributed passive radar target detection. A conventional passive radar target detection method is based on the classical matched filtering theory, and approximately optimal detection properties can be achieved on premise that a direct wave with a relatively high signal-to-noise ratio can be acquired in real time and an emitted signal can be estimated with high quality by using a direct wave signal received by a reference channel. To solve the problem of detecting a target which cannot receive the direct wave signal in practical, the invention discloses the distributed passive radar target detection method under a direct wave-free condition, and a concentrated target detector under the direct wave-free condition is established, so that target detection can be implemented when the signal-to-noise ratio of the direct wave signal is relatively low or the direct wave signal cannot be received in a multiple-input multiple-output geometric structure, and meanwhile the target matching problem which is very hard to solve among different receiving stations of a distributed passive radar is indirectly avoided.

The invention discloses a permanent magnetic synchronous motor rotor speed estimation method. The method includes establishing a permanent magnetic synchronous motor mathematical model, and performing vector transformation to decouple; performing order reduction on a system model, and establishing a simplifying filter model estimating the rotor speed and position only; adding stator parameters into the system model, and acquiring an augmented system model containing the generator electromechanical state and rotor parameters; finally, according to the established augmented model, acquiring an estimation value of the permanent magnetic synchronous motor rotor speed and stator parameters by the H8 filter theory. By the aid of the method, the rotor speed and stator parameters can be estimated accurately, the calculation amount is reduced, and the system robustness against parameter uncertainty is improved effectively.

The present invention provides a low-illuminance image / video enhancement method based on adaptive multi-scale filtering. The present invention is based on the atmospheric light scattering model, adaptive filtering based on regional characteristics, and adaptive brightness restoration theory, in the field of low-illuminance video and image enhancement , the adaptive multi-scale filtering theory and method proposed can improve the brightness of the processed image, and at the same time improve the contrast and sharpness of the image or video, with the classic mean filter, low computational complexity; adaptively Calculation of internal parameters has a wide range of adaptation, and can be applied to color images or grayscale images, and has good versatility.

The invention discloses a horizontal array motion aperture synthesis positioning method and a device therefore. The horizontal array motion aperture synthesis positioning method comprises: decomposing the underwater acoustic data collected by the array elements of a horizontal array into a plurality of time units; evaluating the phases of each narrowband time unit laminated spatially between the array elements, to obtain a phase evaluation factor, processing time delay sampling and phase compensation on the array element time units; processing aperture synthesis for the time sequence obtainedby different array elements in one narrow band, to form a large aperture virtual horizontal array; according to zero point control full normal mode filter theory, processing zero point control mode filtration on the large aperture virtual horizontal array, to obtain target mode information; using the target mode information to obtain three-dimension positioning result of the target according to maximum likelihood method. The method and device can obtain high positioning accuracy, with simple and practical process. The invention can realize real-time application without much additional computing resource.