21 results about "Great circle" patented technology

This invention relates to a microscopic visual measurement method for machine tool trajectories, and more specifically, a microscopic visual measurement method for machine tool trajectories based on small circle codes scattered within a large circle. The method includes the following steps: S1, a measuring head is fixedly attached to the first moving end of the machine tool, and a measuring target is fixedly attached to the second moving end of the machine tool; the measuring head is connected to a host computer; S2, the field of view of the measuring head is adjusted to the center of the scale range of the measuring target; S3, the image from the host computer is observed to complete the focusing operation, and the coded pattern within the field of view of the measuring head on the measuring target is acquired to determine whether the optical axis of the measuring head is orthogonal to the target plane; S4, the second moving end is moved, with the movement range not exceeding the effective measurement range of the target, to measure the actual movement trajectory of the spindle relative to the worktable. This non-contact microscopic visual measurement method improves the accuracy, efficiency, and safety of positioning.

The application discloses a kind of aircraft off-line trajectory planning methods based on spherical Anya, comprising the following steps: step 1: the mathematical modeling of aircraft flyable area and threat area is carried out, and the Web Mercator coordinate of flyable area and the Web Mercator coordinate of threat area are obtained;Step 2: the mathematical modeling of any two points great circle route, and the mathematical modeling of great circle route and the intersection coordinates of certain meridian or parallel;Step 3: spherical Anya algorithm heuristic value f is designed using great circle route and the intersection coordinates of great circle route and certain meridian or parallel;Step 4: initialize map, input the Web Mercator coordinate of starting point and terminal point, and the Web Mercator coordinate of flyable area and the Web Mercator coordinate of threat area between starting point and terminal point, obtain the optimal path of spherical Anya using spherical Anya algorithm heuristic value f.

A method and an apparatus for constructing a three-dimensional channel, and a non-transitory computer-readable recording medium are provided. In the method, a depth image corresponding to a first panoramic image is generated. Then, channel object detection is performed on the first panoramic image to obtain channel object boxes in the first panoramic image. Each of the channel object boxes is four annularly interconnected arc-shaped sides, and each of the arc-shaped sides is a circular arc of a great circle. Then, a three-dimensional point cloud of a channel object in the first panoramic image is generated based on the first panoramic image, the channel object boxes and the depth image.

The invention discloses a centroid-offset-resistant multi-circle special-shaped target and a binocular vision positioning method thereof, and belongs to the technical field of industrial vision measurement and precise positioning, the target comprises a white background substrate and seven symmetrically distributed black circles, a large circle is arranged in the center, standard perfect circle small circles are arranged right above and right below respectively, and a large circle is arranged in the middle of the black circles. The four corners are respectively provided with special small circles which are designed according to a cylindrical surface nonlinear projection formula. The positioning method comprises the steps that a binocular camera collects a target image, and two-dimensional circle center coordinates are extracted; calculating a three-dimensional point cloud through stereo matching; extracting a cylindrical space axial vector and constructing a normal plane, and orthogonally projecting the three-dimensional feature points to the normal plane for two-dimensional circle fitting; and calculating the reference point coordinates of the internal anchoring column center and the surface highest axis through inverse coordinate transformation. According to the method, positioning errors caused by curvature deformation, space inclination and rotation around the axis of the cylinder are effectively overcome, and positioning robustness and universality under complex working conditions are remarkably improved.

The invention discloses a negative poisson ratio structure metal mesh compounded by a circle and a curved-edge concave quadrangle, and relates to the technical field of negative poisson ratio materials. The metal mesh with the negative Poisson's ratio structure is composed of a plurality of periodically arranged units, each unit is composed of a central circle and a peripheral curved edge concave quadrilateral, and the central circle and the peripheral curved edge concave quadrilateral synergistically generate a remarkable negative Poisson's ratio effect. The adjacent units share a curved-edge concave quadrangle to form a stable structure. And a pattern of sleeving a small circle with a large circle is formed by the circular ring and the four curved-edge concave quadrilateral arc edges, so that the elimination of a high-order diffraction effect is facilitated, the concentrated distribution of stray light is homogenized, and the optical performance is improved. By adjusting the radius of the circle and the arc angle of the curved quadrangle, different optical requirements can be flexibly met, and efficient light wave regulation and control are achieved.

A method for estimating the rotational motion of a camera in an indoor scene based on the Manhattan structure assumption, belonging to the field of computer vision. In this invention, (1) a new method is adopted for plane fitting. Three points are randomly selected from the three-dimensional point cloud data of the indoor environment depth image to generate a plane model. Through sequential probability ratio testing and LO-RANSAC optimization of the model, an accurate dominant plane is obtained; (2) lines are detected from the RGB image, and the lines are projected onto the Gaussian sphere to obtain the projected great circle and the normal vector of the great circle. At the same time, the dominant plane is also projected onto the Gaussian sphere in the form of a normal vector and cross-multiplied with the normal vector of the line projection to determine the structure of the Manhattan coordinate system; (3) a cost function is proposed to optimize the structure of the Manhattan coordinate system to obtain a more stable and accurate result; (4) the rotational motion of the camera is indirectly calculated through the rotation matrix between the Manhattan coordinate system and the camera coordinate system.

The application discloses a kind of earth magnetic field horizontal component representation methods of removing pole singularity, comprising: based on adolf schmidt semi-normalized spherical harmonic theory, the spherical harmonic representation of geomagnetic field magnetic potential function is obtained by spherical harmonic polynomial expansion calculation method;With south pole or north pole as center, mirror center symmetry extension is carried out to great circle on sphere, so that each point on sphere has a mirror point, so that the mirror extension function of geomagnetic field magnetic potential function is obtained;Two-dimensional Fourier expansion is carried out to mirror extension function using double Fourier series, and double coverage function expansion is obtained;Based on double coverage function expansion, the horizontal component of geomagnetic field is calculated, i.e. the spherical gradient of spherical magnetic potential function is calculated.The realization is based on the existing IGRF model magnetic potential expansion coefficient, the magnetic field tangent vector representation is obtained without being polluted by pole problem, and a new modeling idea and calculation method of spherical tangent vector field are provided.

The present invention provides a method for judging the instability of a rock slope, comprising obtaining the direction α0 and the inclination θ0 of the slope, the direction α i and the inclination angle θ i and the rock mass structural friction angle ψ; the strike of the rock layer structural surface α i Subtract the slope strike α0 to obtain the relative strike β of the rock formation surface i ; Draw a reference plane circle with radius R, and define the center coordinates of the reference plane circle as x=0, y=0; draw a friction circle inside the reference plane circle, the friction circle is concentric with the reference plane circle, and the radius of the friction circle is R f =Rcosψ; draw a slope projection circle in the reference plane circle, the coordinates of its center O0 can be obtained according to x=Rtanθ0*cosα0, y=Rtanθ0*sinα0, and its radius r0 can be obtained according to r0=R / cosθ0; draw multiple rock layer structural surface circles in the reference plane circle, the center O i The coordinates can be obtained according to x = Rtanθ i *cosβ i , y=Rtanθ i *sinβ i We get the radius r i According to r i =R / cosθ i According to θ0≥θ i Using the principle of ≥ψ, the intersection of the slope's projected great circle and the friction circle is considered a possible sliding zone. When i > 1, if the intersection of any two great circles of rock stratum structural surfaces falls within the possible sliding zone, the slope is considered potentially unstable. This procedure allows for the development of a program to implement automated intelligent identification software, resolving the existing challenges of difficult-to-understand, complex analysis, and significant workload associated with rock slope stability assessment.

A cricket ball is disclosed. The cricket ball includes an at least substantially spherical body and multiple spaced apart bumps about a great circle of the spherical body. Each bump has a height in a range of 1.0mm – 3.0mm. A method for making the cricket ball is also disclosed.

The invention relates to a self-adaptive great circle route guidance and control method based on great circle correction, which belongs to the field of ship track tracking and comprises the following steps of: establishing a ship motion nonlinear mathematical model; determining the course of the large circle based on the correction of the large circle; determining the self-adaptive foresight distance of the ship; based on the great circle course and the self-adaptive foresight distance, designing a guidance strategy of the great circle course, and obtaining an expected course of the ship sailing along the great circle course; based on the ship motion nonlinear mathematical model, a final controller is designed through a third-order closed-loop gain forming algorithm and used for controlling the ship to track the expected course, and the ship is made to sail along the large circle route. Through simulation verification, the ship can be effectively controlled to sail in a large arc line, and the sailing efficiency is improved.

The invention discloses an extraterrestrial celestial body Moho surface depth calculation method and a related device, and relates to the technical field of deep space exploration data processing, and the method comprises the steps: obtaining a seismic event with position information of a target extraterrestrial celestial body, and picking up the observation travel time difference Tobs of a plurality of seismic phases of a seismic body wave relative to a first arrival P wave; constructing a plurality of seismological structure models, calculating the theoretical travel time and the theoretical P wave first arrival time of each seismic phase, and obtaining the theoretical travel time difference Tcal of the seismic phase relative to the first arrival P wave; and according to the theoretical travel time difference Tcal and the observation travel time difference Tobs, calculating a travel time residual error Tres of each seismological structure model so as to determine the average Moho surface depth of the event-station great circle path of the target extraterrestrial celestial body. According to the method, Moho surface depth distribution in a larger area range can be obtained, and the geologic structure, the formation process and the evolution mechanism of extraterrestrial celestial bodies can be understood.

A method and associated systems for implementing blur effects in 360-degree spherical space is disclosed. The method operates by identifying a pair of great circles 106 in a spherical view 100 which intersect orthogonally at a pixel (θ0,φ0) to which the blur effect is to be applied. The great circles are mapped to a two-dimensional representation 102 of the image data and used as orthogonal axes to define a blur area. In some examples a series of points (θi,φi) along each great circle 106 are extracted and used to form one-dimensional sampling arrays which are swept across the two-dimensional image data in two orthogonal directions.

The application discloses a multi-class circle special-shaped target resisting heart drift and a binocular vision positioning method thereof, and belongs to the technical field of industrial vision measurement and precision positioning. The target comprises a white background substrate and seven symmetrical black circles, wherein a large circle is arranged at the center, a standard normal small circle is arranged above and below the large circle respectively, and four specially-made class circles are arranged at four corners respectively. The specially-made class circles are designed according to a cylindrical surface nonlinear projection formula. The positioning method comprises the following steps: a binocular camera collects a target image and extracts two-dimensional circle center coordinates; three-dimensional point clouds are solved through stereo matching; a cylindrical space axial vector is extracted and a normal plane is constructed, and three-dimensional feature points are orthogonally projected to the normal plane for two-dimensional circle fitting; and the coordinates of an internal anchor cylinder center and a surface highest axial reference point are solved through coordinate inverse transformation. The application effectively overcomes positioning errors caused by cylindrical curvature deformation, space inclination and rotation around an axis, and significantly improves the positioning robustness and universality under complex working conditions.

The application is a Mercator chart-based great circle route guidance and control method, belonging to the ship track tracking field, comprising the following steps: establishing a ship motion nonlinear mathematical model; designing a great circle route guidance strategy, so that the ship sails along the great circle route according to the expected heading; based on the ship motion nonlinear mathematical model, a third-order closed-loop gain shaping algorithm is used to design a final controller for controlling the ship to track the expected heading; the plan of the great circle route in the ship running process is converted to the Mercator projection chart to obtain the ship sailing trajectory along the great circle route under the Mercator projection. Through simulation verification, the application can effectively control the ship to sail along the great circle arc line, reduce the track error and improve the sailing efficiency.

The invention describes a table tennis ball (2) on the spherical ball surface (6) of which a marking (8) is applied which makes the ball spin detectable with measuring technology. The marking (8) comprises a number of marking points (P i ) which are distributed on the ball surface (6) in such a way that the standard deviation of the lengths (Z i,j ) of the great circle lines (20) between each marking point (P i ) and its three nearest neighbours (14, 16, 18) is at least 12% of the average value (μ) of these lengths (Z i,j ) and the minimum length of the great circle lines (20) between each marking point (P i ) and its three nearest neighbours (14, 16, 18) is at least 40% of the average value (μ) of these lengths (Z i,j ).

The invention provides a method for calculating longitude and latitude of an aircraft route passing point by using a vector, and belongs to the technical field of drawing of a large circle route of an aircraft, and the method specifically comprises the following steps: setting the earth as a regular sphere, establishing a spherical coordinate system by taking the center of the sphere as a coordinate origin, and calculating coordinates of a starting point A and a target point B in the spherical coordinate system; the method comprises the following steps: obtaining coordinates of a starting point A and a target point B in a space rectangular coordinate system, equally dividing a space vector of the starting point A pointing to the target point B according to the number m of required passing points to obtain a plurality of intermediate points, and calculating coordinates of each passing point in the space rectangular coordinate system; converting the coordinate of each passing point in the space rectangular coordinate system into the coordinate in a spherical coordinate system; the coordinates of the passing points in the spherical coordinate system are converted into radian values of the longitude and latitude, and the longitude and latitude of the passing points are obtained according to the radian values of the longitude and latitude of the passing points. According to the processing scheme, the complexity of latitude and longitude calculation of the passing points of the aircraft route is reduced.

The invention relates to a major circle route guidance and control method based on a Mercator chart, which belongs to the field of ship track tracking and comprises the following steps of: establishing a ship motion nonlinear mathematical model; designing a guidance strategy of a great circle route, and enabling the ship to sail along the great circle route according to an expected course; based on the ship motion nonlinear mathematical model, a final controller is designed by adopting a third-order closed-loop gain shaping algorithm and is used for controlling the ship to track an expected course; and converting the plane graph of the great circle route in the ship driving process into a Mercator projection chart to obtain the navigation track of the ship along the great circle route under Mercator projection. Through simulation verification, the ship can be effectively controlled to sail in a large arc line, the track error is reduced, and the sailing efficiency is improved.

The present application provides a calculation method for a Mohorovičić discontinuity (Moho) depth of an extraterrestrial celestial body and a related apparatus. The method includes: obtaining a seismic event with location information from a target extraterrestrial celestial body, and picking up observed travel time differences Tobs of a plurality of seismic phases of seismic body waves relative to a first-arriving P-wave; establishing a plurality of seismological structural models, and calculating a theoretical travel time and a theoretical P-wave first-arrival time for each seismic phase to obtain a theoretical travel time difference Tcal of the seismic phase relative to the first-arriving P-wave; and calculating a travel time residual Tres of each seismological structural model based on the theoretical travel time difference Tcal and the observed travel time differences Tobs so as to determine an average Moho depth of an event-station great circle path of the target extraterrestrial celestial body.

The invention provides a navigation precision assessment data processing method, which comprises the following steps of: 1, determining a transmitting point and a navigation point according to track parameters, and converting from a Chinese geodetic coordinate system to a geocentric large earth coordinate system; 2, according to the basic theorem of a spherical triangle, solving a large circle route between a launching point and a navigation point; 3, according to the sine and cosine theorem of the spherical triangle, the deviation distance between the actual track of the target and the large circle route is determined in the spherical right triangle, and the deviation distance represents the actual navigation precision; and performing navigation precision assessment according to the deviation distance. According to the method, a target navigation precision problem is converted into a target actual track and large circle route distance problem through coordinate conversion by utilizing a large circle route method and a spherical triangle theorem, so that a problem processing thought is simplified, the operation is simple and clear, the result precision is high, and data processing personnel can conveniently carry out processing work.

The invention provides a method for judging instability of a rock slope. The method comprises the steps that the trend alpha 0 and the inclination angle theta 0 of the slope, the trend alpha i and the inclination angle theta i of a rock stratum structural plane and the friction angle psi of a rock mass structure are obtained; subtracting the trend alpha0 of the side slope from the trend alphai of the rock stratum structural plane to obtain a relative trend betai of the rock stratum structural plane; drawing a reference plane circle through the radius R, and defining the circle center coordinates of the reference plane circle as x = 0 and y = 0; a friction circle is drawn in the reference plane circle, the friction circle and the reference plane circle are concentric, and the radius Rf of the friction circle is equal to Rcospsi; a slope projection large circle is drawn in the reference plane circle, the coordinate of the circle center O0 of the slope projection large circle can be obtained according to x = Rtan theta 0 * cos alpha 0 and y = Rtan theta 0 * sin alpha 0, and the radius r0 of the slope projection large circle can be obtained according to r0 = R / cos theta 0; a plurality of rock stratum structural plane large circles are drawn in the reference plane circle, the coordinates of the circle center Oi of the large circles can be obtained according to x = Rtan theta i * cos beta i and y = Rtan theta i * sin beta i, and the radius ri of the large circles can be obtained according to ri = R / cos theta i; according to the principle that theta0 > = thetai > = psi, the intersection area of the slope projection large circle and the friction circle is judged as a possible sliding area; when i is larger than 1, if the intersection point of the large circles of any two rock stratum structural planes falls in the possible sliding area, it is judged that the slope is likely to be unstable. Programs can be written through the steps, automatic intelligent judgment software is achieved, and the problems that in the prior art, a rock slope stability judgment method is not easy to understand, the analysis process is complex, and the workload is huge are solved.