172results about How to "Small distortion" patented technology

The embodiment of the invention discloses a midpoint potential control method based on a diode clamping type three-level grid-connected inverter and a related device. The method comprises the following steps: generating an initial three-phase modulation wave through a current loop closed-loop control method according to a collected three-phase current value and a three-phase voltage value of a power grid side of the diode-clamped three-level grid-connected inverter; according to an initial modulation waveform generated by the initial three-phase modulation wave, a three-phase current value and an acquired voltage value of a voltage dividing capacitor at the direct current side of the diode clamping type three-level grid-connected inverter, calculating a zero-sequence component required by neutral-point potential balance; superposing a zero-sequence component required by neutral-point potential balance with the initial modulation waveform to obtain a final modulation wave; and generating a driving signal matched with each phase of bridge arm in the diode clamping type three-level grid-connected inverter according to the final modulation wave. By adopting the invention, the neutral-point voltage can be balanced, the distortion of the output waveform at the alternating current side is reduced, the voltage stress of the device is reduced, and the service life of the power device is prolonged.

The invention provides a projection lens, which comprises six lenses in total, and sequentially comprises a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from a projection surface to an image source surface, the surface of the projection side of the second lens is a convex surface, and the surface of the image source side of the second lens is a concave surface; the surface of the projection side of the third lens is a concave surface, and the surface of the image source side of the third lens is a convex surface; the surface of the projection side of the fourth lens is a concave surface; the surface of the image source side of the fifth lens is a convex surface; the surface of the projection side and the surface of the image source side of the sixth lens are convex surfaces; wherein the surface curvature radius R11 of the projection side of the sixth lens and the surface curvature radius R12 of the image source side of the sixth lens meet the following conditions:-0.8 lt; (R11 + R12) / (R11-R12) lt; and 0.1. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

The invention relates to the technical field of audio noise reduction, in particular to an audio noise reduction method and system based on deep learning. The method comprises the following steps: acquiring original audio and sound production equipment operation data associated with the original audio; invalid audio elimination is carried out on the original audio, so that effective audio is generated; carrying out audio time alignment on the effective audio so as to generate a preprocessed standard audio; performing audio output mode detection on the preprocessed standard audio and the sound production equipment associated with the original audio to generate single-equipment output audio and multi-equipment output audio; audio period regular segmentation is carried out on single-device output audio, and single-device short-period output spectrum data and single-device long-period output spectrum data are generated. According to the invention, through invalid audio elimination, time alignment, layered noise extraction and abnormal noise identification, the accuracy and real-time performance of the noise reduction effect are improved.

The invention relates to a medium-focus large-aperture long-flange video lens with a focal length of 50mm. The medium-focus large-aperture long-flange video lens comprises a first lens group, an iris diaphragm and a second lens group which are sequentially arranged along a light incidence direction of a light path, wherein the first lens group serves as an immovable fixed group, the focal power is positive, and the first lens group is composed of lenses L11-L17 which are sequentially arranged in the light incidence direction of a light path and comprises two groups of doublet lenses and a group of triplet lenses; the second lens group serves as a movable focusing group, the focal power is positive, and the second lens group is composed of lenses L21-L27 which are sequentially arranged in the light incidence direction of the light path and comprises two groups of doublet lenses and a glass aspheric lens; the focal length value f1 of the first lens group and the focal length value f2 of the second lens group satisfy 0.47 lt; f2 / f1lt; and 0.56% of the total weight. The lens achieves a large clear aperture, high MTF resolution, small distortion and reduced achromatism, is short in total optical length, and meets a camera module matched with a long flange back focus.

The invention discloses an optical lens and imaging equipment, the optical lens sequentially comprises a first lens, a second lens with focal power, a third lens, a fourth lens with focal power, a fifth lens with focal power and a sixth lens with focal power from a first side to a second side along an optical axis, the first lens has negative focal power, the second lens has focal power, the third lens has focal power, the fourth lens has focal power, the fifth lens has focal power, and the sixth lens has focal power. The first side surface and the second side surface are concave surfaces; the third lens has positive focal power, and the first side surface of the third lens is a convex surface.

The invention provides a projection lens, which comprises seven lenses from a projection surface to an image source surface along an optical axis: a first lens with negative focal power, a second lens with negative focal power, a third lens with negative focal power, a fourth lens with negative focal power and a fifth lens with negative focal power, the surface of the projection side of the second lens is a concave surface, and the surface of the image source side of the second lens is a convex surface; the surface of the projection side of the third lens is a convex surface, and the surface of the image source side of the third lens is a concave surface; the surface of the projection side of the fourth lens is a convex surface, and the surface of the image source side of the fourth lens is a concave surface; the surface of the image source side of the fifth lens is a concave surface; the surface of the projection side and the surface of the image source side of the sixth lens are convex surfaces; and the seventh lens has positive focal power, and the image source side surface of the seventh lens is a convex surface. According to the projection lens provided by the invention, the projection quality of the projection lens is improved through the reasonable configuration of the surface types of the lenses and the reasonable matching of the focal power.

The invention provides an optical system of a laser radar transmitting lens. The optical system comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, an optical filter, protective glass and an image surface which are arranged in a direction from an object side to an image side. According to the invention, by reasonably using the lenses with specific shapes and structures and limiting the focal power of each lens, the field angle of the optical system is increased to 150 degrees and the relative illumination is greater than 90%, the radar detection field of view is wider and clearer, the F-theta distortion is less than 1%, the CRA is less than 1 degree, the detection distance and precision are improved, and the detection cost is reduced. According to the utility model, more accurate distance measurement data and farther detection distance can be provided, TTL is 29 mm, the size is small, miniaturization can be realized, the camera can be arranged in a vehicle, the matching of 2G3P glass and plastic enables the whole optical system to optimize high and low temperature excursion compensation, it is ensured that the lens does not have virtual focus at high and low temperatures, the cost is more advantageous, and the cost performance is higher.

The invention discloses an automatic focusing and distortion optimization method based on a large-target-surface industrial lens, relates to the technical field of lens distortion optimization, and aims to accurately identify different distortion types and provide accurate data for subsequent optimization and adjustment by comprehensively analyzing the distortion of the lens from multiple dimensions (radial, tangential and comet distortion). Through calculation of a comet distortion coefficient HJ obtained by calculating a detailed radial distortion coefficient # imgabs0 #, a first tangential distortion coefficient # imgabs1 # on an x axis and a second tangential distortion coefficient # imgabs2 # on a y axis in combination with S44, various distortion conditions (radial, tangential and comet distortion) of the lens can be quantified, and the total distortion rate D is calculated; the distance between the front focusing group A and the rear fixed lens group B of the lens is evaluated and corrected, and the imaging quality of the lens is improved through step-by-step correction (including focal length, distortion, brightness attenuation and the like) in each step from S2-S5.

The invention belongs to the technical field of chaos secret communication, and particularly relates to a microwave communication system and method based on chaos carrier hybrid overlay encryption, and the system comprises a chaos feedback loop at a transmitting end, an aliasing device of an optical signal of information to be encrypted and a chaos optical signal, and a chaos feedback open-loop link at a receiving end. The aliasing device is a balance detector; the receiving end further comprises a power divider, a photoelectric detector and an electric subtractor, the power divider divides received electric signals into two paths to be output, one path enters the input end of the chaotic feedback open-loop link, the other path enters one input end of the electric subtractor, the output end of the chaotic feedback open-loop link is connected with the input end of the photoelectric detector, and the output end of the photoelectric detector is connected with the output end of the electric subtractor. The communication method is based on linear aliasing of input chaotic carrier waves and encrypted information power by the balance detector, and has the advantages of being simple in structure, high in safety and small in transmission distortion.

The invention relates to the technical field of cable circulation current monitoring, in particular to a time-sharing self-powered cable circulation current monitoring device, which comprises a CT (Current Transformer) energy taking module comprising a current transformer and a rectifying circuit; the energy storage module comprises an energy storage capacitor and a charging comparator; the current signal processing module is used for dividing the voltage of the output end of the rectifying circuit and weakening the error amount of the pulsating direct current signal by outputting a first current value and a second current value; a 4G module; and the main controller is used for determining the current measurement value of the cable, adjusting the current monitoring frequency of the current transformer according to the fluctuation value of the current measurement value, and determining whether to adjust the transmission power of the current measurement value transmitted from the 4G module to the background or adjust the amplification gain of the pulsating direct current signal according to the number of abrupt change points in the current change image. According to the invention, the monitoring precision and the monitoring range are increased.

The invention relates to the technical field of image generation, and discloses an arc-shaped screen multi-view 3D image generation method and device, and the method comprises the steps: collecting a view parameter set of an arc-shaped screen, and carrying out the residual feature processing of an original image sequence, and obtaining a multi-dimensional space feature map; performing tensor product operation on the multi-dimensional spatial feature map and the view angle parameter set to obtain view angle conversion delay data; performing graph convolution operation to obtain space-time dependence features; performing multi-head self-attention calculation on the space-time dependency features to obtain delay compensation features, and performing comparative learning on the view angle features based on the delay compensation features to obtain view angle mapping parameters; the view angle mapping parameters, the delay compensation features and the original image sequence are input into a U-Net network for 3D image reconstruction, and a 3D image sequence with continuous view angles is output, the feature consistency in the view angle conversion process is improved, image distortion during view angle switching is reduced, and therefore the visual quality of 3D images is improved.

The invention discloses a method and a system for splicing infrared images of an ultra-long string-disc-shaped suspension type porcelain insulator. The method comprises the following steps: acquiring segmented infrared images of the ultra-long string-disc-shaped suspension type porcelain insulator; the obtained segmented infrared images are preprocessed; dividing an overlapping region of the preprocessed segmented infrared image into a plurality of sub-block pairs; obtaining matching feature points of the sub-block pairs; a confidence coefficient is calculated by screening reliable matching feature points through an optimization sub-block algorithm, and a sub-block pair with the highest confidence coefficient is obtained as an optimal sub-block pair by comparing the confidence coefficients of the matching feature points between different sub-block pairs; performing conversion on the preprocessed segmented infrared images corresponding to the optimal sub-blocks to realize alignment and splicing of the preprocessed segmented infrared images; according to the invention, through the designed optimization sub-block algorithm, the reliability of the screened matching feature points is higher, the distortion of the spliced image is less, and the condition of wrong splicing of the infrared image of the insulator is obviously reduced.

The invention belongs to the technical field of inverters, and mainly provides a three-phase inverter midpoint potential control method and device based on a feed-forward neural network, in the embodiment of the invention, real-time characteristic parameters of a three-phase inverter are obtained, and the real-time characteristic parameters are input into a target feed-forward neural network model obtained through pre-training, so that the midpoint potential of the three-phase inverter is controlled. The method comprises the following steps: firstly, obtaining a midpoint potential offset predicted value output by a target feedforward neural network model, then adjusting a modulation parameter of SVPWM modulation according to the midpoint potential offset predicted value, and finally, outputting a PWM signal for controlling an inverter switching device based on the adjusted modulation parameter to drive a three-phase inverter. The active balance of the neutral-point potential of the three-phase inverter bus based on the feedforward neural network and combined with SVPWM modulation is realized, and the technical problems that the neutral-point potential of the three-phase inverter bus is unbalanced and easy to deviate are solved.

The invention relates to the technical field of building engineering, in particular to a vibration test system of a prefabricated building component and a control method.The vibration test system comprises a portal frame, a fixing device, a vertical loading device, a horizontal loading device and a control center, and the fixing device is used for fixing a test piece; the vertical loading device can apply a static load to the upper end of the test piece; the horizontal loading device is used for applying a dynamic load to one side of the test piece; the control center acquires deformation generated by the test piece through the data acquisition unit and simulates seismic waves to apply loads. The horizontal loading device is provided with a first hydraulic cylinder and a second hydraulic cylinder, and through coordination and cooperation of the two hydraulic cylinders, a loading push plate arranged at the tail end of the horizontal loading device can adjust the posture of the loading push plate according to deformation of the test piece, so that the loading push plate can be always kept parallel to the surface of the test piece. The testing accuracy can be improved, distortion generated in the load conveying process is reduced, and the stability of the system is improved.

Disclosed are a target recognition device, a training device and method of a target recognition model. The technical field relates to image processing technology, and the target recognition device comprises a processor configured to: acquire a to-be-detected image, the to-be-detected image comprising a target object; process the to-be-detected image based on a target recognition model to obtain first confidence of each category of the target object and second confidence of each occlusion degree of the target object; and determine a target category of the target object based on the first confidence of each category and the second confidence of each occlusion degree. The embodiment of the disclosure can accurately recognize the target object in the occlusion condition, improve the target object recognition accuracy in the occlusion scene, and reduce the safety risk caused by the recognition error.

This application discloses an optical lens. The optical lens, along its optical axis from the object side to the image side, sequentially comprises: a first lens with negative optical power, its object side being convex and its image side being concave; a second lens with negative optical power, its object side being convex and its image side being concave; a third lens with negative optical power, its object side being concave and its image side being concave; a fourth lens with positive optical power, its object side being convex and its image side being concave; a fifth lens with positive optical power, its object side being convex and its image side being convex; a sixth lens with negative optical power, its image side being concave; a seventh lens with positive optical power, its object side being convex and its image side being convex; and an eighth lens with positive optical power, its object side being convex. The effective focal length F1 of the first lens and the effective focal length F of the optical lens satisfy: -8.8 ≤ F1 / F ≤ -7.7.

This invention discloses a high-definition lens, comprising a first lens, a first cemented lens group, an aperture stop, a fourth lens, and a fifth lens arranged sequentially from the object plane to the image plane; wherein the first lens and the fourth lens have negative optical power; the first cemented lens group and the fifth lens have positive optical power, and the fifth lens has a biconvex structure; the focal length of the lens is f, and the focal length of the first cemented lens group is f. U1 f U1 The following relationship exists between f and f: 0.35 < |f U1 / f|<0.90. The lens formed by this invention is not only compact and economical, but also ensures high imaging resolution, small aperture and low distortion, which can meet the needs of industrial applications and has great market prospects and economic value.

The application discloses a camera module distortion determination method, a distortion correction method and a depth measurement device. The scheme establishes a mapping relationship between a distortion value of a module and a field angle based on a grating equation. Based on the established mapping relationship, the distortion value of the module can be quickly obtained only by knowing the field angle of the module, so that further design is made according to the distortion value of the module, the distortion value of a receiving module and the distortion value of a projecting module are offset to each other, distortion correction is realized, and the distortion of the whole depth measurement device can be reduced, and the influence of the distortion on the depth measurement precision can be effectively avoided.

The application discloses a protection and distortion control method and system during sound operation, and relates to the technical field of audio processing. An audio signal and a reference signal are acquired; the reference signal is preprocessed to obtain a trigger signal of a level effective value; a trigger threshold is acquired according to the trigger signal of the level effective value; the trigger threshold is adjusted to obtain a preset trigger threshold; the preset trigger threshold is dynamically adjusted according to a voltage value corresponding to a frequency of the audio signal to obtain a voltage value corresponding to the preset trigger threshold; and the audio frequency corresponding to the voltage value corresponding to the preset trigger threshold is a protected and distortion-controlled audio signal. The application realizes dynamic change of a high-frequency cutoff frequency of an audio high-frequency unit while maintaining the loudness of a sound field restoration of a sound system, and improves the protection and distortion control accuracy of the sound in a limit operation state of high power and long time.

The utility model relates to a magnification display device, belongs to the technical field of optical imaging, and particularly relates to a desktop optical imaging magnification display device which comprises a support, a storage barrel and a limiting sliding barrel are fixedly mounted on the surface of the support, a threaded rod is slidably mounted in the storage barrel, a mounting block is fixedly mounted at the end of the threaded rod, and the limiting sliding barrel is fixedly mounted in the mounting block. An imaging assembly is also included; according to the utility model, the effect of obtaining a non-deformation and high-definition magnified picture by using the two lenses easy to process is achieved, and the problems that although a magnified imaging effect can be achieved in the prior art, the height of the imaging device cannot be adjusted, the height of the imaging device cannot be effectively adjusted for users with different body types and heights, and the imaging effect is poor are solved. And the use effect is poor.

The application belongs to the technical field of information security, and discloses an attribute correlation-based differential privacy anonymous method. First, the correlation between attributes is analyzed through data distribution analysis of a data set, the number of each equivalent group of each attribute group is calculated by using permutation and combination, all minimum attribute combinations are found, if the number of each equivalent group of the attribute combination is greater than or equal to 30, and there is an equivalent group with a number less than 30 in each equivalent group when any attribute is added, the attribute combination is a minimum equivalent group. Then, the set condition of each attribute is obtained by performing intersection on all minimum attribute groups, the number of each attribute under the intersection is calculated, then the priority of the attributes with intersection is divided, the intersection number is used as the privacy protection priority of the attribute, privacy budget is allocated through the privacy protection priority of each attribute, and finally, the attributes with intersection are protected by differential privacy.

This invention provides a projection lens. The projection lens includes a lens group comprising at least eight lenses, which, from a first side to a second side, are sequentially: a first lens with negative optical power, a second lens with negative optical power, a third lens with positive optical power, a fourth lens with negative optical power, a fifth lens with positive optical power, a sixth lens with optical power, a seventh lens with optical power, and an eighth lens with optical power. At least one group of lenses from the fourth to the eighth lens is cemented together to form a cemented doublet lens or a cemented triplet lens. The ratio between the combined focal length of the cemented doublet lens and the focal length of the second lens group is greater than or equal to 1 and less than or equal to 8; or, the ratio between the focal length of the cemented triplet lens and the focal length of the second lens group is greater than or equal to 0 and less than or equal to 14. This invention solves the problem in existing projection lenses where it is difficult to simultaneously achieve both high-quality projection and miniaturization.

The utility model relates to a fluorescence camera shooting bayonet and an endoscope system. The fluorescence camera shooting bayonet is sequentially provided with a front protection sheet, an optical lens group and a band elimination optical filter in the direction from the object side to the image side. The plane where the band-stop optical filter is located intersects with the plane where the front protection sheet is located. According to the three-dimensional endoscope, the distortion is small, an MTF modulation function tends to the diffraction limit, the maximum radiuses of imaging confusion spots in different view fields are all within the Airy spot radius range, the three-dimensional endoscope can achieve clear imaging within the wide waveband range, ghost images of the endoscope are eliminated, and observation and operation convenience of a user is improved; a prism model is further added, and endoscope visible light imaging and endoscope ICG (indocyanine green) fluorescence imaging can be simultaneously carried out by using a fluorescence camera shooting bayonet.

This application relates to a high-precision visual inspection system and method for product sides, belonging to the technical field of visual inspection. It includes a worktable, a light source, a vision camera, and reflectors. The worktable has an inspection area for placing the product. The light source illuminates the side of the product within the inspection area. The vision camera is positioned above the inspection area. Several reflectors are obliquely arranged on the worktable, each corresponding to a side of the product within the inspection area. The reflectors are located to the side of the corresponding side of the product. When the light source illuminates the side of the product, the light reflected from the side is reflected by the reflectors to the central area of ​​the vision camera. This application achieves high-precision inspection of all sides of a product under single-vision camera conditions, reducing equipment cost and size.

The invention provides a low-light multispectral imaging device under low illumination at night, which is used for solving the problem that spectral characteristic information of a target cannot be acquired by adopting a low-light detection system in a low-illumination environment at night at present. And a visible near-infrared spectrum imager cannot be used for imaging or cannot be used for acquiring a high-contrast image for target detection and identification. According to the low-light-level multispectral imaging device, the electric filter wheel is arranged between the low-light-level imaging lens and the low-light-level detector, hardware external synchronization is arranged between the electric filter wheel and the low-light-level detector, switching of one narrow-band optical filter is completed every time the rotating structure rotates once, switching of one spectral band channel is achieved, and switching of the low-light-level imaging lens and the low-light-level detector is achieved. At the moment, through hardware external synchronization between the electric filter wheel and the low-light detector, the low-light detector synchronously exposes once; according to the invention, through coupling of a low-light imaging technology and a light splitting technology of a plurality of narrow-band optical filters, information of a plurality of spectrum band channels of a detected target is obtained, and efficient detection under low illumination at night is realized.

The embodiment of the application discloses a high-definition zoom lens applied to micro-nano high-precision 3D printing, comprising: coaxially arranged lens groups with positive light angles, a diaphragm, a light splitting device, a galvanometer, a protective glass and an imaging surface, wherein the lens groups comprise coaxially arranged first group lenses and second group lenses in sequence, and the diaphragm is located between the first group lenses and the second group lenses. Through the high-definition zoom lens, the printing pixel size can be continuously changed, the lens distortion is small, the relative luminance is high, the light efficiency is high, and the use requirements are met.

The present application relates to the technical field of partial discharge detection, and discloses a multi-band signal filtering method and system for partial discharge monitoring equipment. First, a corresponding first filter channel is set according to the first analog instruction obtained, and the first analog impedance and the first analog capacitive reactance are matched and configured accordingly, and then the corresponding first analog signal received by the detection terminal is controlled to be filtered, and the first filtered signal is output. Then, after obtaining the second analog instruction, the first filter channel is closed, and the discharge is continuously preset for a first time length, and then it is configured as a second filter channel corresponding to the second analog instruction. When configuring, the second analog impedance and the second analog capacitive reactance are first matched, and then the configuration is completed accordingly, and finally the second filter channel is controlled to filter the corresponding second analog signal received by the detection terminal, and the second filtered signal is output. The filtering processing of multi-band signals is realized in this way. The present application can use software for dynamic control to achieve dynamic filtering.

The aerospace-level near-field rendezvous and docking TOF optical system comprises an object side surface lens group, a diaphragm, an image side surface lens group and a photosensitive imaging surface which are sequentially arranged from an object side surface to an image side surface, the object side surface lens group contracts the aperture of the incident light; the diaphragm is used for adjusting the luminous flux by adjusting the size of an aperture formed in the diaphragm; the image side surface lens group further focuses the light, corrects aberration, and then projects the light onto a photosensitive imaging surface to form a final image; the object side surface lens group comprises a first negative meniscus lens, a second negative meniscus lens, a first biconvex lens and a first positive meniscus lens which are sequentially arranged from the object side surface to the image side surface; and the image side surface lens group comprises a first optical filter, a third negative meniscus lens, a second positive meniscus lens, a second biconvex lens, a first plano-convex lens and a first plano-concave lens which are sequentially arranged from the object side surface to the image side surface. The optical system provided by the invention can realize high-precision imaging of a near-field target, and has a guiding effect on improvement of imaging precision in rendezvous and docking.

The invention relates to the field of atomic interference measurement, in particular to an atomic Raman interferometer based on a flat-topped beam. Comprising two Raman interference subsystems arranged in parallel, each of the two Raman interference subsystems comprises an ultrahigh vacuum cavity and a light path system, and the light path system comprises a flat-topped beam shaping module located on one side of the high vacuum cavity and a Raman light Doppler sensitive configuration module located on the other side of the high vacuum cavity; in the flat-topped beam shaping module, the holographic algorithm principle is adopted, the actual size of atoms in an interference area is combined to determine the size of a target flat-topped beam, the initial complex amplitude is precisely constrained, and a final diffraction phase is obtained through iterative optimization. After the Raman light passes through the diffraction phase, the Raman light is shaped into a flat-topped light beam with a target size and uniform intensity distribution at the ultrahigh vacuum cavity, so that the coherence efficiency under the same interference time is remarkably improved.

Embodiments of the present application provide a projection lens and a projection device. The projection lens comprises, in order from the magnification side to the demagnification side: a first lens group with negative focal power, a second lens group with positive focal power, a diaphragm, a third lens group with negative focal power, and a fourth lens group with positive focal power. The projection lens only comprises one aspherical lens, the aspherical lens is located in the first lens group, and the materials of the lenses comprised in the projection lens are all glass materials.