27 results about "Central projection" patented technology

The present invention discloses an automatic calculation and adjustment method for the central projection parameters of a CT system, and relates to the technical field of industrial CT. The light cone of the CT light-emitting base point is adjusted to irradiate into the detector sensing plate; the CT light-emitting base point is turned on, and the displacement of the Z and X of the first positioning platform is adjusted, and the displacement of the X and Y of the third positioning platform is adjusted, and the projection of the detection plate is adjusted to be displayed in the detector sensing plate; the point position of the detection ball projected onto the detector sensing plate is recorded; the offset detector sensing plate records and combines the four-point data on the multiple offset detector sensing plate, calculates four straight lines, and uses the four straight lines to calculate the central coordinates of the CT light-emitting base point; the center of the CT light-emitting base point is adjusted to be on the same axis as the center point of the detector sensing plate. The tedious operation of accurately calculating the four-point model used for correction is reduced, and the requirements can be met by manual processing only by using a simple four-point model with low precision requirements.

The invention relates to a positioning method and device, computer equipment and a storage medium. The method comprises the following steps: determining feature point global coordinates of region surface feature points of a monocular photography region in a global coordinate system, and fitting a ground curved surface elevation model according to the feature point global coordinates; obtaining a calibration plate image collected by the monocular camera, and determining feature point image point coordinates of the region surface feature points in the image space coordinate system based on the calibration plate image; resection is carried out on the image point coordinates of the feature points and the global coordinates of the feature points, and exterior orientation elements are determined; determining a height distance between the monocular camera and the ground, and determining a target point estimated coordinate of the to-be-positioned target point in a global coordinate system by using a central projection conformation equation according to the exterior orientation elements and the height distance between the monocular camera and the ground; and determining a three-dimensional global coordinate of the target point to be positioned according to the ground surface elevation model and the estimated coordinate of the target point. According to the scheme, the positioning accuracy of the to-be-positioned target point is improved.

The invention provides an antenna and electronic equipment, and belongs to the technical field of antennas. The antenna comprises a dielectric substrate, and a first conductive layer and a second conductive layer which are arranged on the two sides of the dielectric substrate in the thickness direction of the dielectric substrate; each of the first conductive layer and the second conductive layer comprises a feeder line, a first radiation structure and a second radiation structure which are arranged at two opposite ends in the extension direction of the feeder line, and a third radiation structure and a fourth radiation structure which are respectively arranged at two sides in the extension direction of the feeder line; the first radiation structure and the second radiation structure are symmetrically arranged by taking the midperpendicular of the feeder line as a symmetry axis, and are electrically connected with the feeder line through a switch structure respectively; the third radiation structure and the fourth radiation structure are rotationally symmetrical by taking the midpoint of the feeder line as a rotation center, and are electrically connected with the feeder line through a connecting structure respectively; the extension directions of the feeder line of the first conductive layer and the feeder line of the second conductive layer intersect, and orthographic projections of the centers of the two layers on the dielectric substrate coincide.

The application provides a broadband folded transmission array antenna generating an OAM beam and a design method, and relates to the electromagnetic technical field.The array antenna comprises a first super atom array, a second super atom array and an open waveguide feed source;the first super atom array is composed of a plurality of first super atom arrays, and the second super atom array is composed of a plurality of second super atom arrays;the first super atom array is arranged above the second super atom array and the central projections of the two along the vertical direction coincide;the preset second super atom at the center of the second super atom array is removed to place the open waveguide feed source, and the design of the array antenna is completed;phase compensation is provided through the first super atom array, and finally, the OAM beam is generated.The antenna profile of the broadband folded transmission array antenna is further reduced, the bandwidth is significantly improved, the efficiency is higher and more stable.

The invention relates to a hand-held power tool device (48a), in particular a hand-held grinding machine device, for a hand-held power tool (50a), in particular a grinding machine, preferably an eccentric grinding device or a vibratory grinding device, having a housing unit (16a), which has at least one handle housing (52a) and a drive housing (54a), which is coupled to the handle housing (52a). According to the invention, the driver housing (54a) has, on a surface (56a) of an upper side (58a) of the driver housing (54a), a central projection (60a) which is heightened relative to the surface (56a), in particular above which an end (62a) of the handle housing (52a) is arranged, the central projection (60a) falls onto the surface (56a) in two directions starting from a main extension plane (64a) of the handle housing (52a) and extending perpendicularly to the main extension plane (64a) of the handle housing (52a).

Examples of golf club heads and methods to manufacture golf club heads are generally described herein. In one example, a body portion of a golf club head may include a front portion. A face portion may be located at the front portion and may include a central projection located at or proximate a geometric center of the face portion and a plurality of outer projections disposed at different distances from the central projection. For each and every combination of any two outer projections of the plurality of outer projections, a lesser volume is associated with whichever one of the two outer projections is located closest to the central projection and a greater volume is associated with whichever one of the two outer projections is located farthest from the central projection. Other examples may be described and claimed.

The application relates to a central projection type pipeline intersecting line marking device which effectively solves the problems of poor universality, inconvenience in use and unsuitability for large-diameter pipelines of the intersecting line marking equipment; the technical solution comprises a head and a supporting rod, the head comprises a hollow shell, a light-transmitting cover is fixed to the right end of the shell, the light-transmitting cover is made of reversible color-changing material, a first point light source is arranged in the shell, a horizontal mounting rod is arranged on the concave side of the light-transmitting cover and is provided with a parallel light beam projection unit, the parallel light beam projection unit can project parallel light beams on the light-transmitting cover, and the color or light transmittance of the light-transmitting cover in the projection area of the parallel light beams will change; the application uses the equal-ratio amplification principle of the central projection of the first point light source to simulate the equal-ratio amplification projection of the intersecting line on the target pipeline for display and identification, the purpose of representing the intersecting line of the large-diameter pipeline by the small device is achieved, the stability is good, the device is convenient to use, and the intersecting line can be completely displayed.

The invention relates to a method for automatically identifying and measuring a gap in a narrow space in building construction, which comprises the following steps of: 1, starting a double-line laser, enabling the double-line laser to emit two parallel line lasers, capturing an image of the line lasers on a target plane through a monocular camera, extracting an accurate position of a central point of the two line lasers, and calibrating a light plane; 2, according to the central projection relation, the image processing unit calculates a conversion matrix of a light plane and an image plane; 3, capturing the image of the line laser on the target plane through the monocular camera again, and extracting the pixel coordinates of the central point of the line laser; secondly, the pixel coordinates are converted into camera coordinates through the conversion matrix in the second step; 4, after the camera coordinates of the line laser on the target plane are obtained, the attitude calculation unit performs post-processing on the extracted center point of the line laser to filter out abnormal points so as to ensure the accuracy of follow-up plane equation fitting; and finally, fitting an object plane equation so as to obtain attitude information of a target plane.

This invention relates to the field of cross-section borehole positioning technology, specifically disclosing a cross-section borehole positioning method based on central projection. By acquiring the 3D point cloud reconstruction mesh model of the cross-section and its projection pose parameters, the ray intersections and topological constraints are simultaneously calculated within a preset projection domain. An initial intersection set with occlusion determination and distortion ratio form a complete spatial mapping chain. An adaptive correction loop is constructed to relax the mesh protrusion occlusion and borehole spacing distortion in a linked manner, deriving the individualized optimal 3D borehole position distribution in reverse. This method breaks through the rigid limitations of traditional 2D templates, achieving accurate projection based on the true geometric shape of the cross-section, and providing a new high-fidelity pre-distortion guidance path for complex curved surface blasting operations.

An intervertebral prosthesis for insertion between adjacent vertebrae includes an upper plate, a lower plate and a core. The core is retained between the upper and lower plates by a retention feature in the form of central projections on the plates and a corresponding opening in the core. The retention feature is designed to allow the plates to slide over the upper and lower surfaces of the core in the anterior / posterior direction and in the lateral direction and to allow the plates to rotate with respect to each other and the core. The retention feature is also designed to prevent contact between the first and second plates during sliding movement of the plates over the core. Each central projection has a diameter that is smaller than a smallest diameter of a central opening of the core.

The utility model belongs to the technical field of compressors, and discloses an air cylinder structure, a compressor pump body and a compressor. A cylinder cavity is formed in the center of the cylinder body; an air suction opening is formed in the air cylinder wall of the air cylinder body and penetrates through the air cylinder wall of the air cylinder body in the radial direction. The air cylinder body is further provided with a flow expanding hole, and the central projection of the flow expanding hole is located on the central axis of the air suction port. One end of the flow expanding hole is communicated with the air suction port, and the other end of the flow expanding hole is communicated with the axial end face of the air cylinder body. The flow expanding hole is communicated with the air suction port, flow expanding is achieved when air flows through the flow expanding hole by expanding the airflow channel, the effect of effectively reducing airflow resistance and flow velocity is achieved, the purpose of noise reduction is achieved, and the stability and reliability of the air cylinder are improved.

The invention belongs to the technical field of compressors, and discloses an air cylinder structure, a compressor pump body and a compressor. A cylinder cavity is formed in the center of the cylinder body; an air suction opening is formed in the air cylinder wall of the air cylinder body and penetrates through the air cylinder wall of the air cylinder body in the radial direction. The air cylinder body is further provided with a flow expanding hole, and the central projection of the flow expanding hole is located on the central axis of the air suction port. One end of the flow expanding hole is communicated with the air suction port, and the other end of the flow expanding hole is communicated with the axial end face of the air cylinder body. The flow expanding hole is communicated with the air suction port, flow expanding is achieved when air flows through the flow expanding hole by expanding the airflow channel, the effect of effectively reducing airflow resistance and flow velocity is achieved, the purpose of noise reduction is achieved, and the stability and reliability of the air cylinder are improved.

This invention discloses a three-dimensional measurement method based on tilted fringe coding in a trinocular system. First, the distance from the phase plane to the optical axis coordinates is calculated based on a linear imaging model. Then, the vector expression passing through the optical center within the phase plane is obtained through the principle of vector superposition. This expression is then cross-multiplied with the phase line vector to obtain the phase plane normal vector. Next, the plane equation of the phase plane is established based on the phase value. Then, new constraint equations are established based on the relationship between the three-dimensional coordinate points and the phase plane. Finally, the three-dimensional coordinates of the object are calculated by combining the two constraint equations of the pinhole camera imaging model. This invention first derives the constraint equations between the three-dimensional coordinates and the phase plane based on a linear abstract model, and then solves for the three-dimensional coordinates through the constraint conditions of the pinhole camera imaging model. This significantly improves the measurement accuracy of the system when the camera's viewing angle, the central projection optical path, and the baseline direction are not the same in a trinocular system.

The utility model relates to the production of furniture, in particular to the design of a sectional, collapsible cabinet, and can be used in construction and installation work and renovation of premises for the placement and storage of various items and tools.The cabinet-constructor contains two open-type sections connected to each other, located one above the other, each of which is formed by horizontal shelves with sides and two sidewalls connected to each other, wherein in each shelf mounting holes are made for connecting the shelves with the sidewalls, wherein in the lower shelf of the first section two holes are made, and in the lower shelf of the second section - four, in addition, each sidewall of each section is a locking element made of internal, middle and external panels of different sizes, connected to each other with an overlap, wherein on the lower edge of the inner panel a central projection is made for connecting the sidewall with the holes of the lower shelf of the first section, and on the upper edge of the panel two side projections are made, created with the possibility of embracing the central projection of the inner panel and connecting the sidewall with the holes of the lower shelf of the second section, and the outer panel of the locking element is the outer side of the sidewall for each section.The technical result achieved by the claimed utility model is a reduction in labor intensity during assembly. 6 clauses, 7 figs.

To provide a plate material molding method capable of increasing plate thickness of an annular projection in a wide range at a simple manufacturing step while preventing unintended deformation of a material by relative push-in.SOLUTION: A plate material molding method has: a step which molds a central projection composed of a central plate part and a side wall part on an outer peripheral side in a plate-like part of a plate material; a step for molding an outer peripheral curved part on the outer periphery of the side wall part; and a step for deforming at least the outer peripheral curved part and molding an annular projection where plate thickness is selectively increased. In the step for molding the annular projection part, a pressing force is given to the central projection in the direction opposite the projection direction while the outer peripheral curved part is supported by a support member relatively movable in a projection direction of the central projection, and at least a part of what composes the side wall part on a support surface of the support member is moved while compression stress in the projection direction of the side wall part is generated, so that the annular projection whose plate thickness selectively increases is molded.SELECTED DRAWING: Figure 3

The invention relates to a manifold and infinite singular point-based wind power grid-connected system stability evaluation method, which comprises the following steps of: analyzing active power and reactive power characteristics of a fan before and after a fault, enabling the active power and reactive power characteristics to be equivalent to a negative impedance model, merging the fan into a power system to obtain a wind power grid-connected system, and establishing a system motion equation; depicting a system local stability domain boundary BSD in a two-dimensional plane, mapping a two-dimensional local BSD to a three-dimensional unit spherical surface through central projection transformation, and depicting a global BSD of the wind power grid-connected system in combination with an infinite singular point SAIs; determining the position of the SAIs in the projection space by analyzing the SAIs, and establishing a relationship between the SAIs and system parameters; a singular point invariance criterion SIC method is provided according to the relation between the SAIs and system parameters in combination with system BSD changes, and the system parameters are optimized and adjusted in combination with stability constraints; the transient stability control problem of the power system under the current large-scale new energy grid-connected background is solved, and safe and stable operation of the high-proportion new energy grid-connected system is guaranteed.

The present application relates to a kind of based on manifold and far singularity wind power grid-connected system stability evaluation method, comprising: the active power and reactive power characteristics of wind turbine before and after fault are analyzed, which is equivalent to negative impedance model, wind turbine is incorporated into power system to obtain wind power grid-connected system, system motion equation is established;The local stability domain boundary BSD of system is described in two-dimensional plane, and two-dimensional local BSD is mapped to three-dimensional unit sphere by central projection transformation, and the global BSD of wind power grid-connected system is described in combination with far singularity SAI;By analyzing SAI, the position of SAI in projection space is determined, and its relationship with system parameters is established;According to the relationship between SAI and system parameters, and in combination with system BSD change, singularity invariance criterion SIC method is proposed, and in combination with stability constraint, system parameters are optimized and adjusted;The transient stability control problem that current large-scale new energy grid-connected background power system faces is solved, and the safe and stable operation of high proportion new energy grid-connected system is guaranteed.

Optical detection and mechanical light path system and its signal processing system, including shell, at least three light transmission windows are arranged on the shell, the central projection opaque light shielding column is arranged in the geometric center of the area surrounded by the light transmission window, the light shielding column is arranged along the shell axis and is located in the center of the four detection channels, the bottom of the light shielding column is arranged on the main plate, the photosensitive diode is arranged on the main plate, and the photosensitive diode is arranged correspondingly with the light transmission window.The present application has the following beneficial effects: the system can measure four-way light signals with high linearity and high resolution in a wide range of light intensity, and calculate the relative direction deviation of the light source according to the difference of the four-way signals, output the correction amount to drive the actuator to realize closed-loop alignment; at the same time, the system can also be used for other light source, light signal intensity and offset measurement application in the response wave band range.

The invention discloses an automatic calculation and adjustment method for central projection parameters of a CT system, and relates to the technical field of industrial CT. The light cone of the CT light-emitting base point is adjusted to irradiate into the detector induction plate; starting a CT light-emitting base point, and adjusting the displacement of a third positioning platform X and Y by adjusting the displacement of a first positioning platform Z and X, so as to adjust the projection of the detection plate to be displayed in a detector induction plate; recording the point position of the detection ball projected to the detector induction plate; the offset detector induction plate records and combines data of four points on the offset detector induction plate for multiple times, four straight lines are calculated, and the four straight lines are used for calculating the center coordinates of the CT light-emitting base points; and the center of the CT light-emitting base point is adjusted to be on the same axis with the center point of the detector induction plate. The tedious operation of accurate calculation of the four-point model used for correction is reduced, and the requirement can be met only through manual machining by adopting the simple four-point model with the low precision requirement.

The present application relates to a friction stir welding device and a control method thereof, which has a welding table with a material placement plane and a first installation groove. A plate can be placed on the material placement plane and fixed by a surrounding clamping mechanism. A first heating unit is placed in the first installation groove, and its heating surface can be lifted and lowered to fit the side of the plate facing the material placement plane. The distance between the central projection and the weld projection is a first target distance, and the temperature is regulated by a controller to a first target temperature determined according to the performance, thickness and welding temperature of the plate. This friction stir welding device effectively solves the problems of deformation and quality caused by insufficient heat by enhancing the heat input at the bottom of the weld during the friction stir welding process, and realizes a more uniform temperature gradient, welding stability and a significant improvement in joint quality.

The application provides a display panel and a preparation method thereof and a display device, and relates to the technical field of display. The display panel can improve light output rate and normal viewing angle light emission. The display panel comprises: a substrate and a base arranged oppositely; a plurality of light emitting units arranged in an array, the light emitting units being arranged between the substrate and the base; a plurality of scattering structures arranged in an array; the scattering structures are arranged on a light emitting side of the light emitting units and comprise at least one scattering unit, the scattering unit comprises a matrix and a plurality of scattering particles arranged on one side of the matrix, the particle diameter of the scattering particles and the distance between the normal projection of the scattering particles on the substrate and the central projection satisfy a positive correlation relationship, and the central projection is the normal projection of the center of the light emitting unit on the substrate.

The present invention relates to the technical field of information interaction. Disclosed are a virtual reality display method and device for a wide field of view. The virtual reality display method for a wide field of view specifically comprises the following steps: acquiring an included angle between a central axis of the eyes of a target object and a horizontal line; on the basis of the included angle between the central axis of the eyes of the target object and the horizontal line, adjusting an included angle between a flexible display screen that is bent into a semi-cylindrical shape and a visual center of the eyes of the target object; and acquiring motion parameters of the target object that are collected by means of an attitude sensor, and projecting picture information to the flexible display screen on the basis of the motion parameters of the target object and by means of a cylindrical central projection method, so as to realize picture display. Therefore, the computational load during the display of VR helmet pictures of a small animal is reduced, thereby improving the smoothness of the pictures.

The invention relates to a pneumatic vehicle tyre having a profiled tread, the tread having at least one circumferential groove (1) which extends in a planar view, in particular straightly in a circumferential direction, and which has a groove base (3) and two groove flanks (4), wherein projections (5) are formed on the groove base (3), arranged in a distributed manner over the circumference of the tread and functioning as a muffler, each projection (5) having a first plane of symmetry (E1) extending in plan view in the direction of extension of the circumferential groove (1) and a second plane of symmetry (E2) extending in plan view perpendicular to the first plane of symmetry (E1), and wherein each projection (5) consists of a central projection portion (6) formed centrally in the circumferential groove (1) and two lateral projection portions (7) facing the groove flanks (4). The central projection (6) has the shape of an oval extending in an elongated manner in the direction of extension of the first plane of symmetry (E1), in particular in the shape of an ellipsoid extending in an elongated manner in the direction of extension of the first plane of symmetry (E1), as viewed in a plan view. According to the invention, the central projection (6) is designed in the form of an oval, in particular an ellipsoid, which is centrally flat in the radial direction, and the side projections (7) each have a smaller volume than the central projection (6), are designed in the form of a nose, and have a nose bridge which descends from the central projection (6).

The application relates to a positioning method and device, computer equipment and a storage medium. The method comprises the following steps: determining feature point global coordinates of regional surface feature points in a monocular photography region in a global coordinate system, and fitting a ground surface elevation model according to the feature point global coordinates; acquiring a calibration board image collected by a monocular camera, and determining feature point image point coordinates of the regional surface feature points in an image coordinate system based on the calibration board image; performing resection on the feature point image point coordinates and the feature point global coordinates, and determining exterior orientation elements; determining a height distance between the monocular camera and the ground, and determining target point estimated coordinates of a target point to be positioned in the global coordinate system according to the exterior orientation elements and the height distance between the monocular camera and the ground by using a central projection conformation equation; and determining three-dimensional global coordinates of the target point to be positioned according to the ground surface elevation model and the target point estimated coordinates. The above scheme improves the positioning accuracy of the target point to be positioned.

Modular cutting tool (10), comprising: a cutting head (12), comprising: a cutting section (18) which is rotatable about a central longitudinal axis (15); and a cylindrical skirt (20) extending axially from the cutting section (18) and terminating at a contact surface (22) arranged perpendicular to the longitudinal axis (15), the skirt (20) having a number of curved inner surfaces (32) which generally define a bore (34) arranged about the longitudinal axis (15); and a shaft (14), comprising: a cylindrical section (14A) with a first diameter arranged around the longitudinal axis (15); and a central projection (40) arranged in the bore (34) of the cutting section (18), the central projection (40) having a second diameter smaller than the first diameter and extending longitudinally from a contact surface (42) arranged perpendicular to the longitudinal axis (15) at a front end of the cylindrical section (14A); and a mechanism (60) that assists in mounting and locks the cutting head (12) onto the shaft (14), the mechanism (60) comprises: a first locking drive stone (100); a second locking drive stone (200); and a differential screw element (66) arranged within the transverse bore (48) and comprising a first threaded section (68) arranged at or around a first end (66A) and a second threaded section (70) arranged at or around a second end (66B) opposite the first end (66A), wherein the first threaded section (68) includes a first plurality of threads arranged in a first direction, and the second threaded section (70) includes a second plurality of threads arranged in a second direction, opposite to the first direction. wherein the first locking drive stone (100) and the second locking drive stone (200) each comprise: a main body section (102, 202) which generally fits into a corresponding first niche (44) or second niche (46), wherein the main body section (102, 202) has: an interior surface (104, 204) that points towards the longitudinal axis (15); an outer surface (106, 206) which is arranged opposite the inner surface (104, 204); a front side surface (108, 208) extending between the inner surface (104, 204) and the outer surface (106, 206) on a front face of the main body section (102, 202) when the shaft (14) is rotated about the longitudinal axis (15) in a cutting direction; and a rear side surface (110, 210) extending between the inner surface (104, 204) and the outer surface (106, 206) on a rear side of the main body section (102, 202) when the shaft (14) is rotated about the longitudinal axis (15) in the cutting direction; a central projection (112, 212) extending radially inwards from the inner surface (104, 204) of the main body section (102, 202) to the longitudinal axis (15); and a lateral projection (114, 214) which generally extends tangentially with respect to a reference circle centered on the longitudinal axis (15) from the rear side surface (110, 210) of the main body section (102, 202) or on an upper section (102A, 202A) of the main body section (102, 202), wherein the upper section (102A, 202A) of each main body section (102, 202) of each locking drive stone (100, 200) is arranged in one of the respective cutout areas (36) of the skirt (20) of the cutting tool (10), wherein the lateral projection (114, 214) of each locking driver stone (100, 200) is arranged in an axially overlapping position with respect to the longitudinal axis (15) with respect to the section (38) of the skirt (20), wherein the first locking driver stone (100) further includes a threaded opening (116) defined by the main body section (102) and the central projection (112) thereof, which engages in threaded engagement with the first threaded section (68) of the differential screw element (66), wherein the second locking drive stone (200) further includes a threaded opening (216) defined by the main body section (202) and the central projection (212) thereof, which engages in threaded engagement with the second threaded section (70) of the differential screw element (66), and wherein the differential screw element (66) further includes a feature (72) formed in one or both of the first end (66A) or the second end (66B) thereof, which is structured to engage with a suitably designed tool for rotating the differential screw element (66) about a central longitudinal axis (15) thereof.