83 results about "Rotational transformation" patented technology

The invention discloses a 3D printing path planning method based on electric arc additive anisotropy and a stress field, and the method comprises the steps: constructing a CAD three-dimensional model of a part, and obtaining the stress field of the part through finite element simulation; determining a slice plane; mapping the stress field to a slice plane to form a force flow line; according to the obtained force flow line, rotation transformation regeneration is carried out according to the anisotropy of the used electric arc additive, and a reference trajectory considering the anisotropy of the material is obtained; under the principle of alternate arc starting and extinguishing, the corresponding printing sequence in the layers and between the layers is further planned, and the reference trajectory lines are connected end to end to be planned into a continuous path; and generating a code file, and printing according to the printing sequence. The comprehensive mechanical property of a printed piece is improved.

The invention provides a robot action redirection method, a storage medium, electronic equipment and a product, and relates to the field of robot control. The method comprises the steps that motion data of a to-be-simulated object and pre-configured joint offset parameters are obtained, wherein the joint offset parameters are used for describing rotation transformation data from a joint coordinate system of the to-be-simulated object to a joint coordinate system of a robot; based on the joint offset parameters, joint offset mapping from the to-be-simulated object to the robot is established; and based on the joint offset mapping, converting the motion data of the to-be-simulated object into motion data of the robot so as to drive the robot to execute corresponding actions. According to the method, the difference between the to-be-simulated object and the robot in joint coordinate system rotation transformation can be effectively eliminated, the physical feasibility and motion naturalness of robot actions are ensured, and the interaction requirements in a complex interaction scene are met.

The invention belongs to the field of four-wheel-foot robots, and provides a track optimization and motion generation method, controller and system for a four-wheel-foot robot. The method comprises the steps that a trajectory optimization objective function is constructed based on a motion dynamics model of the four-wheel-foot robot, and the whole-body optimal trajectory of the four-wheel-foot robot in a motion period is solved under the condition that set constraint conditions of the four-wheel-foot robot are met; introducing a virtual joint angle, enabling the world coordinate system to be always aligned with the contact coordinate system through rotation transformation, and constructing a single-wheel-leg kinematics model containing a wheel-ground contact point; and performing inverse kinematics calculation on the single-wheel-leg kinematics model containing the wheel-ground contact points to obtain position information of the wheel legs and the body, and performing motion control on the four-wheel-leg robot in combination with expected foot end contact force.

A graphics processing system that provides a micromap defining property values for sub-regions of a primitive of a scene to be rendered; and generates a first tree representation of the micromap; and applies a first barycentric rotational transform to the micromap and for the first barycentric rotational transform generates a second tree representation of the micromap; and selects one of the first or second tree representations for processing as the selected tree representation. The selected tree representation of a micromap is used when it is desired to determine whether and / or how a ray interacts with a sub-region of a primitive, the tree representation of the micromap is traversed to determine a property value for the sub-region of the primitive.

The present invention discloses a method and system for identifying and controlling extreme horizontal wind shear for a wind turbine, including: obtaining blade root bending moments in two directions of the blade root, namely, the blade root flapping bending moment and the blade root shimmy bending moment; obtaining the blade root out-of-plane bending moment through rotational transformation based on the current measured pitch angle; obtaining the current blade azimuth angle, performing coordinate transformation on the blade root out-of-plane bending moment, and calculating the rotor shimmy bending moment; calculating the horizontal wind shear coefficient based on the rotor shimmy bending moment and the current average wind speed; identifying the current wind condition as extreme horizontal wind shear when the horizontal wind shear coefficient exceeds a preset threshold; and when the current wind condition is identified as extreme horizontal wind shear, calculating and outputting an additional independent pitch control command, which is superimposed on the pitch control command output by the pitch controller, so that the additional bending moment generated on the rotor counteracts the rotor shimmy bending moment. The present invention identifies whether the current condition is extreme horizontal wind shear based on the measured blade root load and reduces the load by providing the additional independent pitch control command.

The invention discloses a traction type device of a concrete spreader and a construction method thereof, the device comprises an XYZ three-dimensional force sensor, a set of spherical hinge traction device and a buffer damping structure, the device can filter part of interference force generated at the tail end of a mechanical arm due to concrete pumping, and traction force applied by workers within a certain height can be accurately measured. According to the rotation transformation matrix, obtaining the representation of the traction force under the base coordinate, and carrying out self-adaptive admittance control according with the actual construction, so as to realize the transformation from force to displacement; closed-loop feedback control is combined to realize traction construction operation; the construction method based on the traction type device is suitable for two construction working conditions, a worker pulls a traction rod of an execution part according to the construction working conditions, the tail end of a concrete hose of the concrete spreader is adjusted to the position above a pouring position in real time, and pouring operation is achieved. According to the pull-type device of the concrete spreader and the construction method of the pull-type device, the construction efficiency of pouring concrete by using the spreader can be greatly improved, the construction safety is ensured, and the construction intensity of workers is reduced.

The present application belongs to the field of permanent magnet synchronous motor control technology, and relates to a kind of permanent magnet synchronous motor torque ripple compensation control method, comprising: acquisition stator phase current and cross axis given current, generate cross axis and straight shaft feedback current by coordinate rotation transformation;Extract cross axis and straight shaft harmonic current;According to the period difference of cross axis current feedback residual error, calculate cross axis time delay distortion coefficient;The coefficient is in situ input coordinate rotation transformation correction rotor electric angle, and combine electric angle change rate to calculate phase angle advance compensation angle;Using the angle to calibrate harmonic current space phase to synthesize offset current instruction and superimposed output, the present application eliminates control loop timing response lag, makes compensation current maintain spatial orthogonal state with rotor harmonic magnetic field under variable speed condition, avoid positive feedback excitation, guarantee the steady convergence and stability of closed loop.

This application discloses a positioning method for a motion mechanism. The method includes: on a control side used for controlling the motion mechanism, acquiring a transformation relationship, wherein the transformation relationship characterizes the translational and rotational transformations between the motion mechanism in a first state and the motion mechanism in a second state; using the transformation relationship, determining the spatial position information of the point to be positioned in the motion mechanism in the second state based on the spatial position information of the point to be positioned in the motion mechanism in the first state, wherein the second state is a running state. This application is compatible with various two-dimensional positioning application scenarios, has higher portability and versatility, and possesses better geometric interpretation than planar point operations, thus improving the development efficiency of intelligent control of motion mechanisms.

The invention discloses a cylindrical permanent magnet linear motor thrust characteristic optimization method based on a matrix algorithm, and the method comprises the steps: carrying out the grouping of a stator tooth part height, a stator tooth part width, a groove part height, a groove part width, an air gap width, a magnetic pole width, and a magnetic pole height parameter through an SEM measurement model, and constructing two dynamic measurement models; and performing data quantization on the SEM measurement model to respectively obtain a TPMLM average thrust value and a TPMLM thrust fluctuation value. The method comprises the following steps: establishing sub-Hankel matrixes based on a G-L fractional derivative algorithm, rotationally converting two sub-Hankel matrixes into a Hankel matrix bundle, and solving a determinant value of the Hankel matrix bundle as an optimization coefficient of motor thrust and thrust fluctuation values. Compared with the prior art, the SEM measurement model, the matrix algorithm and the G-L fractional derivative algorithm are adopted to carry out optimization design on the motor, the thrust of the cylindrical permanent magnet linear motor is improved, the thrust fluctuation of the motor is reduced, the performance of the motor is improved, and the cost of a permanent magnet material is reduced.

The invention discloses a vibration reduction periodic structure for guiding directional transmission of vibration energy and a design method, and the vibration reduction periodic structure is formed by combining two basic unit cells with symmetrical structures to form the vibration reduction periodic structure in array arrangement; two basic unit cells are arranged on the two sides of a transmission path used for guiding directional transmission of vibration energy in the vibration reduction periodic structure respectively. Each basic unit cell is formed by original unit cells through rotation transformation; the original unit cell is of a hollow hexagonal embedded fan blade structure and comprises a hollow regular hexagonal frame and a plurality of fan blades evenly distributed on the inner side of the hollow regular hexagonal frame. The two basic unit cells in the vibration reduction periodic structure are obtained by rotating the fan blades in the original unit cells by the same angle in the forward direction and the reverse direction respectively. The problems that the implementation difficulty is increased and the vibration reduction effect is not ideal under the trend that a vibration structure system develops towards the direction of complexity, large scale and function diversification in an existing mode for reducing or avoiding harmful vibration are solved.

The present invention relates to a method, device, equipment and storage medium for detecting a geometric model structure. The method comprises: receiving an input geometric model; after confirming that the number of vertices of two geometric surfaces to be detected in the geometric model is the same, and confirming that the vertices of the geometric surfaces are associated with arc edges, calculating a periodic surface rotation transformation matrix according to the arc edges; after confirming that there is a one-to-one correspondence between the boundary points of the two geometric surfaces according to the periodic surface rotation transformation matrix, confirming that the two geometric surfaces are a pair of rotational periodic surfaces. The solution provided by the present invention can quickly determine whether the two geometric surfaces to be detected in the geometric model are a pair of rotational periodic surfaces, which is conducive to improving the efficiency of mesh generation and improving the calculation efficiency and accuracy of numerical simulation.

This invention discloses an IPMSM position estimation method and system based on rotating high-frequency injection, comprising: (1) injecting a high-frequency voltage signal into the stationary α-β coordinate axis of the motor; (2) sampling the three-phase current and obtaining the two-phase stationary coordinate system through Clark transformation; (3) obtaining the fundamental current through a notch filter; (4) obtaining the high-frequency response current of the stationary α-β coordinate axis; (5) rotating the transformation and obtaining the high-frequency response negative sequence current through low-pass filtering; (6) designing and modulating the compensation phase; (7) cross-multiplying the compensation phase vector with the modulated compensation phase vector to obtain the estimated angular velocity and rotor position of the motor. This invention uses a notch filter to process the signal, eliminating the band-stop filter in the d-axis and q-axis current feedback loop in the control loop, thus simplifying the system complexity; by compensating for the rotor position lag angle, it increases the system stability and improves the rotor position identification accuracy.

This application discloses a positioning control method, system, equipment, and medium for aerospace forgings, relating to the field of intelligent manufacturing technology for aerospace forgings. The method includes the following steps: acquiring a theoretical digital model of the target forging and a three-dimensional digital model of the target mold to obtain the theoretical placement pose of the target forging; acquiring a three-dimensional scanning digital model of the target forging after the manipulator grips it to obtain a rotation matrix R and a translation vector T; wherein the rotation matrix R represents the rotational transformation from the actual pose of the target forging to the theoretical placement pose, and the translation vector T represents the spatial offset of the target forging; and inputting the rotation matrix R and translation vector T into a preset trajectory planning model to generate the optimal motion trajectory for the manipulator to transport the target forging to the target mold. This application has the advantages of improving the placement positioning accuracy and efficiency, and improving the performance of the final product.

The invention relates to a method for predicting concentricity of first and second fulcrums of an aero-engine fan casing. Comprising the following steps: measuring mounting side column jump and end jump data of each stage of receiver and a first and second fulcrum bearing seat; defining a global coordinate system of the assembly body, and determining a machining error matrix and a high-low point position matrix according to end jump and column jump measurement data of the mounting side of each stage of rotor; determining an installation phase matrix of each stage of cartridge receiver; determining a positioning error matrix caused by coordinate translation transformation and a directional error matrix caused by coordinate rotation transformation after all the fan casings and the first and second fulcrum bearing seats are assembled; then determining a mounting seam allowance matching error matrix caused by deformation of the mounting edge; secondly, determining global positioning and orientation matrixes of the casings and the bearing seats at all levels after translation, rotation and high-low point corresponding deformation transformation; and finally, determining the global positioning and orientation matrix of the assembly, and determining the concentricity of the first and second fulcrums of the fan casing. According to the method, the false assembly workload is reduced, and the assembly efficiency of the fan unit body is improved.

This invention provides a seamless trapezoidal correction method, a projection device, and a storage medium. The method includes the following steps: obtaining the attitude angle of the projection device; obtaining a first rectangular reference area based on a preset rotation transformation relationship, the attitude angle, and the original rectangular projection area; mapping the first rectangular reference area to a first plane based on the projection transformation relationship to obtain a second trapezoidal reference area; obtaining a second rectangular reference area with a preset aspect ratio within the second trapezoidal reference area; mapping the second rectangular reference area to the first rectangular reference area according to the inverse transformation relationship of the projection transformation relationship to obtain a third trapezoidal reference area; obtaining a fourth trapezoidal reference area according to the inverse transformation relationship of the rotation transformation relationship; and adjusting the projection area based on the fourth trapezoidal reference area. Using this method and the projection device and storage medium carrying this method, seamless correction is achieved, improving the user experience.

The present invention discloses a calculation method and system for reducing the storage overhead of the rotation transformation in FFT. The method includes: Step 1, calculating n2 discrete Fourier transforms of length n1, where the on-chip cache of the processor can store at most the data required for calculating m discrete Fourier transforms of length n1, and m = on-chip cache of the processor / cache required for calculating the discrete Fourier transform of length n1; Step 2, calculating the rotation factor, performing the rotation transformation, and calculating n1 discrete Fourier transforms of length n2, where the on-chip cache of the processor can store at most the data required for calculating t discrete Fourier transforms of length n2. While maintaining a relatively low computational amount, the present invention effectively reduces the cache overhead required for calculating the rotation factor.

An image encoding / decoding method, a bit stream transmission method, and a computer-readable recording medium for storing a bit stream are provided. An image decoding method according to the present disclosure relates to an image decoding method performed by an image decoding device, and may comprise the steps of: reconstructing a picture from a bitstream; and transforming the reconstructed picture based on one of the at least one candidate transformation, where the at least one candidate transformation corresponds to a rotational transformation or a symmetric transformation for the picture.

The application discloses a point cloud 3D object detection method not influenced by rotation transformation, comprising the following steps: (1) regarding the network weight of the first layer of the neural network as a vector set distributed in a feature space with the same dimension as the point cloud feature; (2) performing seed point sampling and neighborhood aggregation on the input point cloud data to obtain the local point cloud around each seed point; (3) performing principal component analysis on the network weight and the local point cloud; (4) aligning the weights of the network weight and the local point cloud to obtain a feature with rotation invariance; (5) inputting the local point cloud feature of step (4) into the neural network for feedforward transmission, detecting the prediction of the head output 3D object frame of the network; (6) training the neural network through gradient back propagation; and (7) after the training is completed, performing a 3D object detection task on the point cloud. According to the application, the classification accuracy of the point cloud under arbitrary rotation transformation can be greatly improved, and thus the accuracy of the 3D object detection task can be improved.

The application discloses a polar coordinate decoupling-based image mirroring and rotating unified transformation method, which comprises the following steps: S10, inputting parameters: an original image, a transformation center point coordinate, a mirroring direction parameter and a rotating angle; S20, traversing each pixel position of an output image; S30, unified mirroring and rotating transformation mapping; S40, interpolation sampling; S50, assigning to the output image; S60, traversing all pixels until completion; and S70, outputting the image. The application abandons the traditional linear algebra idea of firstly constructing a mirroring matrix and then multiplying the mirroring matrix with a rotating matrix, and instead reconsiders the combined operation of mirroring and rotating from the perspective of polar coordinate transformation. In a local polar coordinate system around an arbitrary specified center point, the mirroring operation can be regarded as a sign operation or a shift operation on a polar angle, and the rotating is an addition operation on the polar angle. The two can be combined into a simple expression in the polar angle domain.

The present invention relates to a learning method for temporal knowledge graph representation based on quaternion rotation, comprising: S1, given a quaternion (h, r, t, τ), wherein h represents a head entity, r represents a relationship, t represents a tail entity, and τ represents a timestamp, the entity and time information are integrated and rotated in the quaternion space to complete the construction of the model; S2, in order to measure the effectiveness of the quaternion and measure the similarity between vectors based on the angle between the vectors, a scoring function is set to score the sample, and a loss function, parameter regularization and time smoothing constraints are set to obtain an objective function; S3, the performance of the model is evaluated by link prediction performance on the temporal knowledge graph. The present invention models the dynamic evolution characteristics of entities over time as a rotation transformation in the quaternion space, can effectively express the complex relationship model in the temporal knowledge graph, and can effectively improve the performance of the original model by adding parameter regularization terms and temporal smoothing constraints.

The embodiment of the application discloses a rotor position detection method and detection circuit of a three-phase permanent magnet motor, acquires two-phase back electromotive force; performs coordinate transformation on the two-phase back electromotive force to obtain a rotating transformation component, and adjusts an estimated angular velocity according to a real-time value of the rotating transformation component, so that the real-time position of the motor rotor can be obtained, and the accuracy of the position of the motor rotor is ensured.

In one example, a method includes determining a feature displacement gradient (DG) tensor characterizing a deformation feature. The method includes, in an iterative routine, calculating an objective function value associated with a trial DG tensor, the calculating based at least in part on pixel values within an automatically determined ZOC, where the ZOC is based at least in part on the trial DG tensor. In another example, a method includes determining one or more rotational transformation components corresponding to a test image, and determining a feature DG tensor based at least in part on the rotational transformation components. In another example, a system includes an electro-optical assembly, a detector assembly, and a controller programmed to determine a feature DG tensor. In another example, a non-transitory computer-readable medium stores instructions that, when executed by a computer, cause the computer to perform a method of determining a deformation characteristic.

The invention discloses a robot servo motor load rate detection method and device and a medium, and the method comprises the following steps: dividing robot parts according to motion joints, and measuring the quality information of each part; joint coordinates of all parts and a rotation matrix are established according to the rotation joints of the robot, and the rotation matrix comprises the rotation angle of the current axis of the robot; establishing a rod length matrix of each part of the robot according to the robot joint coordinates, and establishing a rod length matrix of each part of the robot after rotation transformation by combining the joint rotation matrix; carrying out translation and rotation transformation on the rotational inertia of the coordinate axis by the robot component to obtain the inertia of each joint of the robot after translation and rotation transformation; and calculating a joint motor load rate according to the speed reducer acceleration and deceleration capability and the motor overload capability. The method has the advantage that the load rate of each shaft joint motor of the robot in any posture can be obtained.

The invention discloses a chiral metasurface construction method based on rotation transformation, a metasurface device comprises a substrate and a chiral metasurface located on the substrate, and the chiral metasurface is a rectangular nanorod array arranged periodically. The metasurface unit is composed of rotating rectangular silicon nanorods, and selective regulation and control of spin angular momentum of incident light are achieved by introducing in-plane mirror symmetry of a geometric rotation destroying structure. Simulation results show that the metasurface shows remarkable circular dichroism at the resonant wavelength of 633 nm, the transmissivity of the metasurface to left-hand circularly polarized light reaches up to 73%, and meanwhile the transmissivity of right-hand circularly polarized light is restrained to 2%. The device has the advantages of compact structure, easiness in integration and the like, and is expected to provide an effective solution for chiral biosensing application.

The invention discloses a control method and system for a bulldozer working device, and relates to the technical field of engineering machinery control, and the method comprises the steps: building a base coordinate system {O}, a lifting coordinate system {A}, a pitching coordinate system {B} and a scraper knife tail end tooth tip coordinate system {C} of the bulldozer working device based on a D-H coordinate system; the Z-Y-Z Euler theorem is used for conducting rotation transformation on the base coordinate system {O}, the lifting coordinate system {A}, the pitching coordinate system {B} and the scraper knife tail end tooth top coordinate system {C}, and a forward kinematics solution of the bulldozer working device is obtained; performing formula transformation on the forward kinematics solution to obtain an inverse kinematics solution of the bulldozer working device; and based on the inverse kinematics solution, the lifting angle and the pitching angle of the bulldozer working device to be controlled are obtained by combining the position of the working target surface of the bulldozer. The lifting and pitching angles of the working device can be determined, the kinematics analysis result is more accurate, and precise control over the working device of the bulldozer is achieved.

The present invention belongs to the technical field of 3D printing, and discloses a 3D printing rotation surface slicing method, system, device and storage medium. The method obtains basic data of a workpiece and a rotation surface, and performs a first translation and then a rotation transformation on the rotation surface and the workpiece, respectively, to obtain a transformed rotation surface and a transformed workpiece; obtains a first rotation contour line, rotates, extends the head and tail, and offsets to obtain an offset contour line; then performs axial discretization and circumferential discretization to obtain multiple rows of discrete point clouds, divides them into blocks, adds boundary points, reduces sampling and reconstructs face patches, obtains screened face patches, and obtains a sliced ​​surface after rotation and translation transformation. The method is mainly aimed at a solid of revolution model or workpiece, and can set the precision in both the axial and circumferential directions to achieve controllable precision, avoid self-intersection problems, and has a fast calculation speed and a good surface generation effect.

The present invention relates to a method for generating a controllable parametric model of a three-dimensional braided composite material. By using the kinematic analysis of the four-step three-dimensional braiding process, a trajectory model of the three-dimensional braided preform is generated. Based on the parametric modeling of the trajectory, the geometric reconstruction of the yarn cross-section is implemented. Then, multi-scale pore primitives are generated by randomizing the geometric parameters of the ellipsoid, and randomly placed after random rotation transformation using Euler angles to enhance the spatial heterogeneity characteristics of the pore morphology. Subsequently, using the model dynamic compaction algorithm, a physical accurate simulation of the densification behavior of the yarn and pores during the compaction process is achieved. Finally, using the three-dimensional crack random generation algorithm, the crack characteristics inside the yarn during the compaction process of the three-dimensional braided composite material are accurately simulated, and a three-dimensional braided parametric random model can be obtained. The present invention accurately reproduces the topological structure of the yarns, the initial pore distribution, and the initial damage characteristics inside the three-dimensional braided composite material specimen.

The invention discloses a method and device for improving rotation robustness of an aortic valve CTA image classifier, and the method comprises the steps: obtaining aortic valve CTA image data, and carrying out the preprocessing of the data, and forming a training sample set; extracting aortic valve features of the training sample set; designing an axial rotation attack algorithm according to the extracted features, and performing axial rotation transformation on the training sample set to generate an adversarial sample set with different rotation angles; adding the confrontation sample set into the training sample set to form a rotating pool; and adversarial training is performed on the aortic valve CTA image classifier through the rotation pool, so that the rotation robustness of the classifier can be improved. According to the method, the adversarial training technology is utilized, the rotation robustness of the aortic valve CTA image classifier is remarkably improved, the complexity of system development and the deployment cost are low, and the method can be directly applied to an existing aortic valve CTA image classifier system and has good universality and applicability.

In an example, a method includes determining a characteristic displacement gradient (DG) tensor that characterizes a deformation characteristic. The method includes, in an iterative routine, calculating an objective function value associated with a trial DG tensor based, at least in part, on pixel values within a zone of consideration (ZOC) that is determined automatically based at least in part on the trial DG tensor. In another example, a method includes determining one or more rotational transformation components corresponding to a test image and determining a characteristic DG tensor based at least in part on the rotational transformation component(s). In another example, a system includes an electron optics assembly, a detector assembly, and a controller programmed to determine a characteristic DG tensor. In another example, a non-transitory computer readable medium stores instructions which, when executed by a computer, cause the computer to perform a method of determining a deformation characteristic.

The invention relates to a spiral bevel gear actually-measured tooth surface geodesic curvature calculation method, which comprises the following steps: acquiring tooth surface actually-measured coordinates and a tooth thickness angle of a gear pair by means of gear measurement equipment, and determining a relative position relation of two actually-measured tooth surfaces through rotation transformation. The method comprises the following steps of: forming a pairing dot matrix by actual measurement point coordinates of a large gear and a small gear according to a geometric position system when gear teeth work, calculating a meshing rotation angle of the large gear and the small gear and a spatial distance between pairing points under the condition that normal vectors are equal, and calculating a tooth surface contact path by taking a tooth surface parameter and the meshing rotation angle corresponding to a point pair with the minimum spatial distance as initial values of actual measurement tooth surface contact analysis. And determining the position of a design reference point through a transmission ratio condition or an iteration method, and projecting all contact points to a tangent plane of the design reference point. The projection points are fitted into a plane curve, the geodesic curvature at the design reference point is calculated, the gear meshing performance is judged through the geodesic curvature, the solving process has high precision, and complexity brought by direct use of a space curve NURBS curve for fitting is avoided.