7 results about "Generalized coordinates" patented technology

This invention relates to the field of multibody system dynamics, specifically a dynamic modeling method for simulating the flight motion of a morphing aircraft with an arbitrary number of rotating components. The method first abstracts the morphing aircraft as a tree-like multibody system containing virtual rigid bodies and virtual hinges. Rigid bodies and hinges are uniformly numbered using a depth-first traversal search, with the relative rotation angles between rigid bodies used as generalized coordinates. Then, a path matrix is ​​used to describe the system topology, and the center-of-mass velocity, center-of-mass acceleration, angular velocity, and angular acceleration of each rigid body are derived using the generalized coordinates. Next, based on the above kinematic parameters, the deflection velocity, deflection angular velocity, generalized active force, and generalized inertial force are calculated and substituted into the Kane equations to establish the multibody system dynamic equations. Finally, the dynamic equations are solved, and the motion state is updated according to a set time step, repeating the process until the simulation of the set duration is completed. This invention has strong versatility and good scalability, and is applicable to the flight motion simulation of morphing aircraft with an arbitrary number of rotating components.

This invention discloses a method for predicting the pose error of a machine tool slide and the force on the slider, specifically for a double-guide-rail, four-slider linear motion system. First, a unified geometric and mechanical model of the system is established. The guide rail is abstracted as a continuous, smooth curve in space, and the interface between the guide rail and the slider is assumed to be continuous, uniform, and linearly elastic, with constant stiffness coefficients per unit length in both directions. The slide and guide rail are considered rigid bodies. Then, based on the model, the system is decoupled between the horizontal and vertical planes, using the position and attitude errors of the slide as generalized coordinates. Based on deformation compatibility conditions and the principle of minimum potential energy, a balance equation is established between the slide pose error caused by the guide rail contour error and the force on the slider. Solving this equation yields the slide pose error, which is then substituted into the slider force expression to obtain the force and torque distribution of each slider. This method enables the prediction of the multi-degree-of-freedom pose error of the slide and the force state of each slider throughout its entire stroke.

A method for determining the hinge reaction torque in the event of a holding-moment hinge deployment impact includes: establishing the system dynamic equations; setting the current values ​​(HoldMarker_H5, HoldMarker_H6) of the holding hinge flags for hinges H5 and H6, and the updated values ​​(HoldMarker_H5_update, HoldMarker_H6_update) of the holding hinge flags for hinges H5 and H6; updating the system generalized coordinate matrix q, the generalized coordinate first-order derivative matrix with respect to time, and obtaining the system generalized coordinate q at the next moment. i The constraint reaction force of each hinge is compared with the structural strength of the hinge. This invention solves the problem of high safety design and testing costs of the entire satellite hinge caused by the large impact torque during satellite antenna deployment.

The application provides a character recognition method and system based on a Hamiltonian shape conservation network, a medium and equipment, belonging to the technical field of character recognition based on deep learning. The system comprises an input module, a feature extraction module, an initial feature generation module, an energy conversion network ETN, a Hamiltonian dynamics evolution network HDNN and a Transformer decoder. The input module acquires an optical character recognition (OCR) image and performs preprocessing; the feature extraction module performs feature extraction on the preprocessed OCR image to obtain a spatial feature map F; the initial feature generation module performs serialization processing and semantic conversion on the spatial feature map F based on Mamba technology to obtain initial generalized coordinates and initial generalized momentum of a Hamiltonian system; the Hamiltonian dynamics evolution network HDNN performs Hamiltonian dynamics evolution according to and according to the Hamiltonian energy conservation, and outputs an evolution result; and the Transformer decoder obtains a character recognition result through decoding, thereby improving the character recognition accuracy in a complex writing scenario.

This invention discloses a theoretical model for spiral self-feeding straightening of pipes, including, under the assumption that the rotation axis of the pipe coincides with the bending plane and axial roll of the pipe is ignored, establishing the total kinetic energy of the pipe based on the thin-wall assumption. T The theoretical formula is derived; neglecting the plastic dissipation of the pipe, a simplified potential energy model for the pipe is established based on the unified curvature theorem of reciprocating bending and the bidirectional effect. V The theoretical formula is used to model the motion trajectory of the pipe based on the Lagrange equation, thereby obtaining a set of motion trajectory equations. These equations include the circumferential bending angle of the pipe, the helical azimuth angle of the pipe, and the axial self-feed displacement. s The coupling relationship between them; where the Lagrange equation is, Q q For the generalized forces acting on the pipe, L For Lagrange units, q For a generalized coordinate system, , for q The first derivative.

The application discloses a knowledge graph entity field conflict detection method based on semantic processing and relates to the technical field of natural language processing, and comprises the following steps: S1, generating a static semantic feature vector by encoding entity attribute features through semantics; S2, calculating the vector from a semantic particle to a category clustering center as field gravity; S3, iteratively solving the change rate of the generalized coordinates and the generalized momentum of the semantic particle through a Hamilton equation; S4, calculating the tangent space Jacobian matrix of the dynamic state sequence and the local Lyapunov index of the semantic particle; S5, performing reverse time integration on the Hamilton equation; S6, generating a semantic dissipation coefficient by using a Langevin equation parameter; and S7, correcting the entity attribute features. The application overcomes the limitations of traditional methods, such as the ignorance of the dynamic evolution mechanism, the difficulty in detecting implicit conflicts and the non-optimization of the correction strategy, and provides an efficient solution for the dynamic consistency maintenance of a knowledge graph.

The application discloses a centering tracking control method and device based on FTESO and PNTSMC; the method comprises the following steps: a dynamic model of a centering platform is established, vertical displacement, pitch angle and roll angle of the centering platform are taken as generalized coordinates, and external disturbance and unmodeled dynamics are modeled as lumped disturbance; based on a finite time extended state observer, velocity states of the generalized coordinates and the lumped disturbance are estimated in real time; based on a pre-defined time nonsingular terminal sliding mode control strategy, a control law is designed; the control law controls driving force of a hydraulic cylinder based on disturbance estimation value provided by the finite time extended state observer, so that the centering platform can track an expected trajectory within a preset time. The application can realize fast, accurate and robust tracking of a pose of the centering platform, and allows a user to preset a convergence time, thereby significantly improving performance and reliability of an automatic centering process.