50 results about "Spherical coordinate system" patented technology

The invention belongs to the technical field of computer vision and digital media, and discloses a dome-screen film production method and system based on a high-altitude aerial image. Projecting the multi-view aerial video sequence to a unified spherical coordinate system, and constructing a panoramic space with an overlapping region; performing non-rigid geometric deformation processing on the overlapping region of the panoramic space to generate an intermediate image with aligned pixels; calculating the fusion cost of each pixel point in the overlapping region in the intermediate image, and performing path search based on the fusion cost of each pixel point to generate a dynamic suture line; generating an image mask based on the dynamic suture line, performing multi-scale frequency domain adaptive fusion on the intermediate image by using the image mask to generate a fused panoramic image, and remapping the fused panoramic image into a projection format adaptive to dome screen playing to output; and the real reducibility and the manufacturing quality of the dome film are greatly improved.

The invention provides a laser SLAM (Simultaneous Localization and Mapping) navigation method for point cloud processing and pose optimization bidirectional closed-loop regulation, which comprises the following steps: screening a current frame point cloud under a spherical coordinate system by using a previous frame pose uncertainty scalar and a previous frame loop importance scalar and adopting a point cloud screening method to obtain a current frame reserved point cloud; judging whether the current frame is a key frame or not based on the reserved point cloud of the current frame, storing the current frame to a key frame set only when the current frame is the key frame, and obtaining a current optimal pose and a pose uncertainty scalar of the current frame by adopting a pose optimization method based on the key frame set; the current optimal pose is used as a current positioning result of the navigation system.

The invention discloses a transcranial magnetic stimulation head target point pose determination method and device and a medium. Relates to the field of magnetic stimulation treatment equipment, and solves the problems that a mechanical arm is not reachable, the posture is not stable or the mechanical arm interferes with the surrounding environment due to the fact that only a unique target posture is determined in the transcranial magnetic stimulation treatment process. The method comprises the following steps: firstly, establishing a head three-dimensional model, determining a three-dimensional coordinate and a unit normal vector of a target spot, converting the head three-dimensional model into a spherical model, establishing a spherical coordinate system, and simultaneously dividing into a plurality of non-overlapping space partitions; calling a corresponding rotation angle mapping strategy to generate a plurality of candidate rotation angles based on a space partition to which a target point belongs, constructing a target pose matrix for each candidate rotation angle, solving a joint angle solution through inverse kinematics, then carrying out constraint condition screening, finally determining an executable pose, and carrying out pose adjustment only by using a rotation freedom degree of a treatment beat around a normal direction. A plurality of pose selection spaces are provided for the mechanical arm, and the execution rate of poses is greatly improved.

The application provides an earth-ionospheric waveguide three-dimensional electromagnetic field prediction method based on a U-Net architecture and a spherical coordinate system physical law and application, and comprises the following steps: constructing a physical information neural network of the U-Net architecture; obtaining multiple groups of ionospheric parameters, generating a three-dimensional electromagnetic field as a label for each group of ionospheric parameters based on simulation simulation to obtain a training sample set; iteratively training the physical information neural network with the training sample set, and in the iterative training process, taking the spherical coordinate system physical law, the ground impedance boundary condition and the ionospheric impedance boundary condition as constraints; stopping iteration and saving the optimal parameters of the physical information neural network when the loss function meets the preset condition to complete training. The scheme takes the spherical coordinate system physical law, the ground impedance boundary condition and the ionospheric impedance boundary condition as constraints to ensure the prediction accuracy of the physical information neural network at the ground boundary and the ionospheric boundary.

This invention discloses an angle positioning method and device based on the geomagnetic field, belonging to the field of engineering surveying and quality control. The angle positioning method includes the following steps: S1: Establish a global coordinate system; S2: Establish a local spherical coordinate system for the construction site using magnetic and gravitational fields; S3: Perform zero-point correction on the local spherical coordinate system of the construction site; S4: Calculate the relationship between the global coordinate system and the local spherical coordinate system; S5: Numerically correct the actual measured angle of the local spherical coordinate system. The positioning device of this invention allows workers to hold a handle for close-range direction indication, or the handle can be fixed to a specific location at the site using a fixing claw. In this case, a laser can be emitted from a second laser emitter to indicate the direction, or a thin line can be tied to the second laser emitter on the handle and pulled taut to indicate the direction. This not only makes operation convenient, reduces the workload of measurement, and is not limited by the site during measurement, but also improves measurement accuracy by using laser and a taut thin line to indicate the direction.

The application relates to the technical field of mobile communication, in particular to a reference signal received power testing method and a testing device. The reference signal received power testing method of an embodiment of the application comprises the following steps: signals are sent to user equipment from each test point of a spherical coordinate system in sequence. Corresponding reference signal received powers at each test point from the user equipment are acquired. The omnidirectional reference signal received power of the spherical coordinate system is calculated according to the corresponding reference signal received powers at each test point. The application can measure the signal receiving performance of the user equipment based on the reference signal received power.

This invention relates to the field of pressure testing technology and discloses an omnidirectional pressure measurement system and method. The omnidirectional pressure measurement system includes a spherical piezoelectric sensor array module, a signal conditioning module, a signal storage and transmission module, and a host computer. The spherical piezoelectric sensor array module collects pressure signals in space, processes them through the signal conditioning module, and transmits them to the host computer via the storage and transmission module. The host computer calculates the pressure field intensity and pressure source location at each point and reconstructs the pressure field using the data. This invention employs a spherical array design with a dodecahedral vertex topology, enabling the system to achieve multi-angle information acquisition and depth perception, eliminating detection blind spots. This invention constructs a weighting function in a spherical coordinate system, calculates the pressure intensity at each point in space using a weighted average, estimates the initial position of the pressure source by squaring the measured value, and combines iterative algorithms for precise positioning. This invention not only improves measurement accuracy and efficiency but also enables the reconstruction of dynamic pressure fields.

The invention discloses a satellite alignment method for a terminal. The method comprises the steps that a built-in ephemeris of a terminal, calibration initial time of the terminal and a satellite and a target moment when the terminal is connected to the satellite are acquired, and the built-in ephemeris comprises operation state parameters used for representing that the satellite is in a satellite orbit; determining a first coordinate of the satellite in an orbital coordinate system according to the operation state parameter, the calibration initial time and the target moment; the first coordinate of the satellite in the orbital coordinate system is converted into a second coordinate in a station center sphere coordinate system, and the sphere center in the station center sphere coordinate system is a terminal; and determining relative position information between the terminal and the satellite according to the second coordinate, and adjusting the terminal according to the relative position information. According to the method and the device, the technical problems of long connection time and low efficiency caused by blind search when the handheld terminal initially accesses the satellite are solved.

The application provides a simplified attitude distribution cooperative control method for a directed communication leader-follower spacecraft formation, which comprises the following steps: firstly, describing the simplified attitude motion of the spacecraft in a unit celestial coordinate system, and converting the simplified attitude motion into a translation of the terminal point of a pointing vector on a unit celestial sphere; secondly, designing a distributed cooperative virtual control quantity under a directed communication topology according to the consistency theory, so as to ensure that the pointing vector of the follower spacecraft converges to a fixed pointing direction in the inertial space determined by the pointing vector of the leader spacecraft, and then calculating an ideal angular velocity vector of the follower spacecraft according to the virtual control quantity; thirdly, taking the difference between the angular velocity vector of the follower spacecraft and the ideal angular velocity vector as a sliding mode variable, and designing a sliding mode surface; and finally, designing a distributed cooperative control law for the follower spacecraft based on a super-twisting second-order sliding mode control method. The application can ensure that the pointing vector of the follower spacecraft in the directed communication formation converges to the pointing vector of the leader spacecraft fixed in the inertial space under a disturbance environment, and reduces the communication amount of the formation.

A method and apparatus for moving a virtual object, an electronic device, and a storage medium are provided. The method includes: displaying a computer-generated three-dimensional environment; detecting position data of an interactor and determining a first movement vector of the interactor in a world rectangular coordinate system; determining, based on the first movement vector, a second movement vector of the interactor in a local rectangular coordinate system with a user's own position as an origin; determining, based on the second movement vector, a third movement vector of the interactor in a local spherical coordinate system with the user's own position as an origin; determining, based on the third movement vector, a fourth movement vector of a target virtual object in the local spherical coordinate system; and obtaining second coordinates of the target virtual object based on first coordinates of the target virtual object and the fourth movement vector.

This invention provides a multi-scale fusion-based method for target recognition and localization using lidar point clouds, belonging to the field of lidar data processing technology. This method employs a cascaded architecture of "macro-meta-micro." At the macro level, topological dimensionality reduction is performed, including constructing a dynamic secure envelope, rapidly stripping massive background point clouds using the surround number method, and clustering foreground targets by introducing radial compensation coefficients. At the meso level, probability peak finding is performed, including transforming the point cloud to a spherical coordinate system, constructing a probability density function of radial distance, and finding the peak to accurately pinpoint the target depth layer. At the micro level, complex plane optimization is performed, including constructing a multi-index joint optimization loss function mapped to the complex plane to achieve high-fidelity extraction and verification of target geometric features. This invention significantly reduces computational overhead and improves the accuracy and robustness of target recognition and localization in long-range and noisy environments.

The application belongs to the technical field of aircraft planning, and provides an aircraft online trajectory re-planning method based on meta-learning hot start sequence convex optimization, which comprises the following steps: step one: establishing an aircraft dynamics model and an offline trajectory library; a three-degree-of-freedom high-speed aircraft dynamics model under a spherical coordinate system is established, and an offline trajectory library is constructed; step two: establishing a model-independent meta-learning training framework fused with nearest neighbor residuals; data features in the offline trajectory library are learned by fusing the nearest neighbor residuals, and optimal common initial parameters are trained and obtained, so that MAML can quickly adapt to a new environment; step three: establishing an online trajectory re-planning framework based on MAML hot start sequence convex optimization; the hot start initial value of the sequence convex optimization is used to guide the sequence convex optimization iteration to reach convergence, and an obstacle avoidance trajectory is generated under the premise of meeting the aircraft dynamics constraints. The application realizes the dual improvement of computational efficiency and control smoothness while ensuring the avoidance of threat areas.

The invention discloses a low-altitude continuous coverage performance test method and method based on a communication base station, and the method comprises the steps: collecting radiation characteristic data through an unmanned aerial vehicle, recording the position information and pose of the unmanned aerial vehicle, and correcting the position information of the unmanned aerial vehicle; constructing a covariance matrix with noise according to the corrected position of the unmanned aerial vehicle, reconstructing a low-altitude coverage map of the communication base station in combination with the collected radiation characteristic data, and evaluating the low-altitude airspace radiation coverage capability of the communication base station; calculating the relative transmitting antenna gain of the unmanned aerial vehicle according to the corrected unmanned aerial vehicle position, the position of the communication base station and the receiving antenna gain of the unmanned aerial vehicle; mapping the corrected position of the unmanned aerial vehicle to a spherical coordinate system with the communication base station as the center, and mapping the relative transmitting antenna gain of the unmanned aerial vehicle to the corresponding position of the spherical coordinate system; and reconstructing a three-dimensional radiation pattern of the communication base station according to the relative transmitting antenna gain of the unmanned aerial vehicle under the spherical coordinate system, and evaluating the low-altitude direction radiation coverage capability of the communication base station.

A photovoltaic power generation module may include a ball lens that receives a medium from the outside or outputs a medium to the outside, receives sunlight that proceeds thereto from the outside when a medium is introduced thereto, and focuses the medium on one focal point, a solar cell that is disposed at a point at which sunlight is focused by the ball lens and produces electric energy from the sunlight, a support part supporting the ball lens and the solar cell and that being rotatable in a preset direction, a first motor that moves the solar cell in a direction in which the solar cell becomes distant from or close to the ball lens, a second motor that rotates the solar cell in a direction θ on a spherical coordinate system, and a third motor that rotates the support part in a direction φ on the spherical coordinate system.

The application relates to a variable-speed motion target adaptive active following method based on spherical coordinates, a spherical coordinate system is established with the optical center of a PTZ camera as the origin, a perception module and a control module are respectively established, the perception module realizes acquisition of position, category and id information of a target by using a yolov5 target detection algorithm, after the target is locked, a target re-identification algorithm is used to improve the target locking effect and acquire target historical information; the locked target pixel coordinates are converted into spherical coordinates to acquire longitude, latitude and angular velocity of the target; the control module comprises a speed control equation which is established by comprehensively considering system start-up delay, target motion angular velocity and distance deviation between the target center and the image center, and the PTZ camera is controlled by using an incremental PID control algorithm to complete active following of the target. Beneficial effects: the variable-speed motion target adaptive active following method based on spherical coordinates can improve the active following target performance of the PTZ camera, and effectively improves the active tracking target precision and stability of the PTZ camera.

An image synthesis device includes a memory storing a virtual viewpoint image synthesis program, and a processor configured to execute the program. The program receives images of multiple viewpoints obtained by filming around a user, position information on the user, and information on a direction in which scene is viewed, estimates color and density by inputting the position information of the user and the direction in which the object is viewed to a neural radiance field model constructed by using the images of the multiple viewpoints, and synthesizes images of a virtual viewpoint by performing volume rendering by using estimated color and density, the neural network radiance field model is constructed based on a quasi-uniform spherical coordinate system, and the quasi-uniform spherical coordinate system includes a sum of a Yin grid and a Yang grid and has a grid structure that increases exponentially in a radial direction.

Techniques for mapping a user input motion includes detecting an input motion by a user, determining an origin for an input motion in a user-centric spherical coordinate system, determining an arc length for the input motion based on the determined origin, mapping the arc length of the input motion to a 2D plane of a user input component, and presenting a movement of a user input component on the 2D plane in accordance with the mapping.

This invention provides a projection-based method and system for compressing and transmitting LiDAR point clouds, belonging to the field of LiDAR data processing technology. The method includes: receiving and initializing raw 3D point cloud data from a LiDAR system; mapping the point cloud data in a spherical coordinate system to 2D image pixel coordinates; generating a dual-output depth image and a pseudo-color visualization image; filling in void regions using a distance-weighted interpolation algorithm; and compressing the pseudo-color image using JPEG and pushing it via the RTSP protocol. This invention, through spherical projection dimensionality reduction, a dual-output mechanism, and distance-weighted interpolation with horizontal surround characteristics, reduces the transmission bandwidth from 5.22MB / s to 39KB / s while ensuring the integrity of spatial information, achieving low-latency, high-compression-ratio, and cross-platform compatible real-time transmission of LiDAR point clouds.

A method of assessing the ability to remove powder from an additively manufacturable article includes performing the following for each of a plurality of discrete starting points distributed within a sampling volume: calculating the starting point directional trajectory lengths of a plurality of trajectories of a particle starting from the starting point and moving in an initial direction respectively along a plurality of combinations of a polar angle φ and an azimuthal angle θ of a spherical coordinate system about the starting point, and calculating an average of the starting point directional trajectory lengths to give a starting point average trajectory length for the starting point. The method also includes calculating an average of the starting point average trajectory lengths respectively of the plurality of starting points to give a global average trajectory length for the article.

This invention proposes a laser SLAM navigation method based on bidirectional closed-loop adjustment of point cloud processing and pose optimization, comprising: using the pose uncertainty scalar of the previous frame and the loop closure importance scalar of the previous frame, a point cloud filtering method is used to filter the current frame point cloud in spherical coordinates to obtain the point cloud of the current frame that is retained; based on the point cloud of the current frame that is retained, it is determined whether the current frame is a key frame; only when the current frame is a key frame is the current frame saved to a key frame set, and based on the key frame set, a pose optimization method is used to obtain the current optimal pose and the pose uncertainty scalar of the current frame; the current optimal pose is used as the current positioning result of the navigation system.

Embodiments of the present disclosure provide a solution for point cloud coding. A method for point cloud coding is proposed. In the method, for a conversion between a current point cloud (PC) sample of a point cloud sequence and a bitstream of the point cloud sequence, a plurality of reference PC samples are determined. In response to an attribute inter prediction being enabled, in a spherical coordinate system, spherical coordinates of the plurality of reference PC samples and the current PC sample are updated based on an offset value. The conversion is performed based on the updated spherical coordinates.

The application provides a gait emotion joint recognition method based on heterogeneous space neural architecture search, comprising the following steps: extracting three-dimensional human posture joints in different emotion video data; performing space conversion, and converting into a rectangular coordinate system and a spherical coordinate system respectively; performing position information space mapping and angle information space mapping on the joints in different coordinate systems based on a similarity minimization strategy; constructing a neural architecture search space and a joint search strategy in different spaces, searching for optimal backbone networks respectively, and training the optimal backbone networks respectively; extracting human time sequence gait emotion features in different spaces by using the trained optimal backbone networks, inputting the features into a Softmax classifier, and obtaining scores of different emotions; and performing joint scoring to complete the gait emotion joint recognition based on the heterogeneous space neural architecture search.

The application provides a ship trajectory prediction method based on Bayesian optimization of directional inertia correction, comprising: acquiring a historical trajectory sequence of a ship containing time-sequentially arranged latitude and longitude coordinate points; calculating an instantaneous speed vector containing a latitude component and a longitude component based on the historical trajectory sequence of the ship; multiplying the latitude component of the instantaneous speed vector by the i-th power of an inertia attenuation factor to obtain a latitude direction correction speed for the i-th prediction step; multiplying the longitude component of the instantaneous speed vector by the product of the i-th power of the inertia attenuation factor and a directional inertia factor to obtain a longitude direction correction speed; wherein the inertia attenuation factor represents the exponential attenuation characteristic of the inertia of the ship movement with the prediction step, and the directional inertia factor represents the scale anisotropy of the longitude direction and the latitude direction in the earth spherical coordinate system; and sequentially calculating the predicted positions of a plurality of future prediction steps based on the latitude direction correction speed and the longitude direction correction speed to obtain a future trajectory sequence of the ship.

The invention provides a dynamic vehicle detection method and device, camera equipment and a storage medium, and the method comprises the steps: carrying out the detection of a vehicle target based on video information collected by the camera equipment, and obtaining the vehicle target in the video information; coordinate system conversion is carried out based on pixel coordinate information of the vehicle target in the video information and set external parameters corresponding to the camera equipment, and spherical coordinate information, corresponding to the vehicle target in the video information, in a spherical coordinate system is obtained; and determining whether the vehicle target in the video information is a dynamic vehicle based on the change of the spherical coordinate information of the vehicle target in the video information. According to the scheme, the actual position information of the vehicle target can be determined through conversion of the coordinate system, so that interference of dynamic background factors is removed, whether the vehicle target is a dynamic vehicle or not is accurately judged, and the reliability of dynamic vehicle detection under the dynamic background is improved.

The invention discloses an SINS / LBL tightly integrated navigation method and device based on double equidistant transformation groups SE2 (3), and relates to the technical field of autonomous navigation of underwater vehicles. Comprising the following steps: acquiring navigation parameters of an inertial navigation system, and converting inertial navigation mechanical arrangement under an earth coordinate system through auxiliary gravity and auxiliary speed to obtain converted earth coordinate system mechanical arrangement; taking navigation parameters as group elements of SE2 (3), and defining an invariant error state; error modeling is carried out on the SE2 (3) through logarithm mapping; deriving a system matrix and a noise distribution matrix to obtain an invariant error state space model; deducing a conversion relation between the measurement information and an invariant error state to obtain an SINS / LBL tight combination measurement model; generating a sampling point in the error Lie algebra so as to map the sampling point to an SE2 (3) group and execute nonlinear measurement updating to obtain an updated error state; and feeding back to a navigation calculation result of the inertial navigation system to obtain a parameter estimation result. The starting efficiency and the navigation calculation precision of the integrated navigation system are improved.

This invention discloses a method for calculating the steady-state seepage field of a foundation pit in a low-permeability soil layer, comprising: S1: simplifying the target foundation pit into a circular foundation pit using the principle of area equivalence; S2: establishing a three-dimensional seepage model of the foundation pit in a homogeneous soil layer based on the circular foundation pit; S3: determining the boundary conditions based on the three-dimensional seepage model of the foundation pit in the homogeneous soil layer; S4: obtaining the homogeneous differential equation of seepage continuity in spherical coordinates based on Hansberg's seepage law considering nonlinear seepage characteristics and the seepage continuity equation under the boundary conditions; S5: separating the variables of the homogeneous differential equation of seepage continuity to obtain the homogeneous differential equation after variable separation; S6: obtaining the pore water pressure and the water inflow at the bottom of the foundation pit at each point in the steady-state seepage field outside the foundation pit based on the homogeneous differential equation after variable separation and the boundary conditions. This invention can solve the problem of low permeability coefficient caused by the failure to consider nonlinear seepage factors in existing seepage field calculations.

This invention provides a semi-analytical method for calculating the residual amount of water droplets after evaporation in high-temperature flue gas. The method includes: acquiring and preprocessing ambient temperature data and initial parameter data of water droplets in high-temperature flue gas; constructing a radial unsteady-state partial differential equation for heat conduction based on spherical coordinates; transforming the preprocessed data to the Laplace domain using a Laplace transform to obtain an analytical formula for the temperature field; applying the Stehfest numerical inverse transform algorithm to reconstruct the analytical solution in the Laplace domain into a time-domain solution; calculating the spatiotemporal evolution matrix of the temperature field based on the analytical formula to obtain the spatiotemporal evolution data of the temperature field inside the water droplet; setting an evaporation threshold temperature; searching for and locating the evaporation front based on the temperature field evolution data; calculating its precise radius through interpolation to obtain the instantaneous residual diameter of the water droplet; and generating a time-residual diameter evolution curve. This invention eliminates the need for complex mesh generation and high-risk physical experiments, achieving rapid and accurate calculation of the dynamic evolution of the radial temperature field inside the water droplet and the residual water content.

This invention belongs to the field of electromagnetic numerical methods, specifically providing a domain decomposition equivalent source-high frequency coupling solution method for electromagnetic radiation problems on an open-field university platform. First, in the modeling stage, the complex multi-scale model is modeled separately. A virtual equivalent sphere is constructed for the antenna array, and the electromagnetic field on the sphere is calculated using a domain decomposition algorithm. A near-field equivalent source file containing three-dimensional field components in spherical coordinates is exported, and a spherical near-field equivalent source reflecting the mutual coupling characteristics of the array is constructed based on the equivalence principle. Then, the equivalent source file is imported into the physical optics simulation area of ​​the open-field university platform, and the near-field incident electromagnetic field generated on the platform surface is calculated. The induced current on the platform surface is then quickly solved using physical optics. Finally, the direct radiation field of the equivalent source and the secondary radiation field of the induced current on the platform are superimposed in the far-field vector, ultimately achieving a fast and high-precision electromagnetic simulation of the radiation characteristics of the antenna array on the open-field university platform.

Embodiments of the present disclosure disclose a track filtering method and device based on measurement noise variance in a spherical coordinate system. A specific embodiment of the method comprises: determining a mass center dynamic model of an aircraft in a speed coordinate system; determining a state vector for the aircraft according to the mass center dynamic model; constructing a measurement equation corresponding to the measurement data and the state vector; and performing track filtering and characteristic parameter identification on track data according to an extended Kalman filter in a sliding window manner. The embodiment improves the estimation accuracy of the position, speed and acceleration of the aircraft.

The invention provides a texture rendering method and device of a stereoscopic model, electronic equipment, a computer readable storage medium and a computer program product. The method comprises the steps that a first three-dimensional model is converted into a second three-dimensional model under a spherical coordinate system, and the coordinate system used by the first three-dimensional model is different from the spherical coordinate system; segmenting the second three-dimensional model into a plurality of sub-models; voxelization is carried out on the multiple sub-models, multiple voxel data sets are obtained, and one sub-model corresponds to one voxel data set; combining a plurality of voxel data sets into a voxel data set of a third stereoscopic model; and rendering the texture of the third stereoscopic model based on the voxel data in the surface area of the third stereoscopic model in the voxel data set of the third stereoscopic model. According to the invention, the efficiency and flexibility of model texture rendering can be improved.