23 results about "Multibody system" patented technology

The invention discloses a multi-body system dynamics intelligent modeling calculation system and method based on a natural language, and belongs to the field of overall design of spacecrafts. The problems that in the prior art, when the simulation requirement related to extreme working conditions and strong nonlinear coupling is met, the period is long, manual experience is relied on, and the maintenance cost is high are solved. The system comprises a text segmentation embedding unit used for carrying out text segmentation embedding processing on a multi-body dynamics knowledge base and constructing a vectorized dynamics knowledge context; the large language model unit is used for receiving natural language task description input by a user, performing semantic understanding through LLM (Logistics Language Model) and generating a task analysis result according to dynamic knowledge context learning; and the task processing unit is used for classifying the tasks into inquiry tasks, command and control tasks or construction tasks according to the task analysis result, and calling corresponding modules according to LLM and MCP technologies. The method is used in the field of multi-body system dynamics modeling of spacecrafts.

The application provides a kind of aircraft dynamics modeling method containing multi-degree-of-freedom actuator, the modeling method returns general mechanics and advanced theory and thought of mechanics basic disciplines, aircraft is regarded as multi-rigid body system, based on virtual power principle and multi-body system topological configuration recursive modeling method, the deformation multi-body system dynamics model suitable for aircraft containing multi-actuator is established, and the motion characteristics of multi-degree-of-freedom, strong coupling between the motion characteristics of aircraft external body attitude motion and internal component relative motion are accurately described.

The invention relates to a contact collision dynamics modeling method for a spacecraft flexible multi-body system, which is used for simulating collision force generated by mutual contact collision of flexible collision bodies of a service satellite and a target satellite. Establishing a spacecraft flexible multi-body system kinetic equation containing the flexible collision body; calculating and considering a relative motion relation of the flexible collision body Tf relative to the flexible collision body Se and geometric deformation of all contact points on the two flexible collision bodies; calculating a normal collision force FNp and a tangential friction force Ftp of each contact point p; according to the normal collision force FNp and the tangential friction force Ftp of the position of each contact point p, and calculating the concentrated collision force acting on the distributed collision force rigid body of the vibration of the flexible component of the service satellite where the flexible collision body Se is located and the concentrated collision force acting on the movement of the flexible component of the service satellite where the flexible collision body Se is located and acting on the distributed collision force rigid body of the vibration of the flexible component of the target satellite where the flexible collision body Tf is located and the concentrated collision force acting on the movement of the flexible component.

The embodiment of the invention provides a multi-body system processing method and device, a multi-body system and a medium. The method comprises the following steps: determining an integral step length corresponding to each subsystem model according to at least two subsystem models corresponding to the multi-body system at the current moment; and predicting the prediction state of the multi-body system at the next moment based on the integral step length corresponding to each subsystem model and the corresponding current state of the multi-body system at the current moment. And based on the prediction state, determining a target control instruction from the plurality of control instructions through the at least two subsystem models. And at the next moment, executing the target control instruction to control the multi-body system. Wherein the dynamic components corresponding to different subsystem models have different time scale characteristics, and the faster the time scale characteristics are, the smaller the integral step corresponding to the subsystem model is. The method is used for achieving the effects of improving calculation efficiency and saving calculation resources.

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 modeling the plastic hinge dynamics of a train coupler device, relating to the field of rail transit vehicle collision safety technology. The method includes: establishing a structural discretization criterion; identifying failure modes of the coupler device under different collision conditions, extracting key mechanical parameters, generating a master list of plastic hinges, and obtaining benchmark simulation data for model verification; based on the discretization criterion and the master list of plastic hinges, discretizing the coupler device into a multi-body system topology consisting of several rigid bodies connected by kinematic pairs; simulating plastic deformation and fracture behavior based on the multi-body system topology; assembling and solving the system dynamic equations to obtain the dynamic response of the coupler device during the collision process and determining the simulation results; and verifying the accuracy of the multi-body dynamics model and evaluating computational efficiency by comparing the simulation results with the benchmark simulation data. This invention significantly improves the depth of collision safety assessment.

The embodiment of the invention discloses a method, a device, a medium and equipment for analyzing the attitude of a rake arm of a trailing suction dredger, and the method comprises the following steps: taking a hull and the rake arm of the trailing suction dredger as rigid bodies, and taking a wave compensator of the trailing suction dredger as a flexible body; a multi-body system block matrix coupling equation of the trailing suction hopper dredger is constructed with the fluid-solid action additional mass of the dredger body and the trailing arm as the rigid body additional mass; acquiring an external load vector acting on the trailing suction dredger; and solving the multi-body system block matrix coupling equation of the trailing suction dredger based on the external load vector to obtain the rake arm posture of the trailing suction dredger. According to the embodiment of the invention, the analysis precision of analyzing the attitude of the rake arm can be improved.

This invention discloses a multi-level mapping method for characterizing machine tool accuracy degradation and optimizing its key parameters, belonging to the field of machine tool accuracy retention technology. This method constructs a complete technical framework of forward modeling and prediction followed by reverse parameter optimization, achieving quantitative prediction and proactive control of machine tool accuracy retention throughout its entire lifecycle through four-level mapping. First, based on the small displacement screw method and multibody system theory, a whole-machine spatial accuracy model considering geometric errors at large assembly interfaces is constructed. Second, combining numerical simulation, the Arcard wear model, and the superposition method, a time-varying degradation model of guideway straightness under multi-physics coupling is established. Third, by integrating the straightness and perpendicularity degradation laws, a time-varying equation for whole-machine spatial accuracy is derived, clarifying the mapping relationship of multi-level time-varying factors. Finally, using the accuracy degradation rate as an evaluation index, the machining and assembly process parameters are optimized through reverse derivation, forming a closed-loop optimization system. This invention is of great significance for improving the accuracy retention of high-end CNC machine tools.

The embodiment of the invention provides a multi-body system control method, equipment and a medium. The method comprises the steps that a pre-trained generalized force estimation model is called, the predicted generalized force of the multi-body system is obtained according to the system state of the multi-body system at the current moment, and the generalized force estimation model is a model which is trained based on a physical information neural network in advance and predicts the generalized force borne by the system according to the system state; adopting a variational integrator to calculate the system state at the next moment according to the system state and the predicted generalized force; and outputting the system state at the next moment to an actuator of the multi-body system. The method is used for achieving the effects of improving the stability of a simulation process and the precision of a simulation result in a complex multi-body system dynamics analysis scene, and further improving the stability and the precision of multi-body system control.

The invention discloses a suspension dynamics system and a construction method, and the method comprises the steps: carrying out the recursion of a multi-body model and a neural network model, carrying out the equivalent transformation through introducing an auxiliary rigid body and a corresponding kinematic pair, and simplifying the kinematic pair in an actual vehicle multi-body system; cutting a preset position of the vehicle multi-body system to convert a closed-loop topological structure of the vehicle multi-body system into an open-loop structure comprising a plurality of branch chains, and adding a constraint equation to realize the equivalence of the open-loop structure and the original closed-loop topological structure; the recursive multi-body model is a multi-body dynamic system described in an ordinary differential equation form, and the neural network model is used for obtaining C characteristic parameters of the suspension according to tire force. According to the method, the dynamic model of the vehicle multi-body system and the K / C multi-direction coupling characteristics of the suspension system are integrated, the data-driven vehicle multi-body system model, namely the suspension dynamic system, is obtained, and the calculation efficiency and the solving precision can be effectively improved.

The present invention relates to a system and method for evaluating vibrations in flexible multibody systems (100) comprising a base structure (10) which is a rigid surface (12) horizontally placed on the structure (10) that allows the coupling of various components; a power supply and energy regulation that provides electrical power to a motor (20) that is coupled to the base structure (10) by means of a motor support (21) that receives operating signals from a controller (30) that has the ability to generate functions with periodic, non-periodic or random behaviors at variable frequencies;wherein said motor (20) drives a vibration mechanism (40) whose elements allow the transformation of rotational motion into reciprocating linear motion by means of a modified yoke (45) that allows the coupling of an amplitude modulator (2), which has the function of modulating the amplitude of the final oscillatory motion, which is transferred to an oscillating platform (48); a clamp (50) coupled and attached to the upper face of the oscillating platform (48) which serves to delicately and firmly hold a test specimen (1) that simulates feather art, paintings, or other flexible multibody systems; a high-speed video recording device (70) that records the oscillatory motion of the test specimen (1) at a determined amplitude and frequency, with the contrast surface (60) as a background; and, a computer (80) that receives and analyzes the information obtained by the video recording device (70) by means of machine vision.

A method (500) and a multi-body system (100) comprising two body segments (101, 102, 103, 104) assembled via joints (105, 106, 107), wherein one of the body segments (104) comprises a camera (110) movable between a first position (P1) and a second position (P2). The method (500) comprises: detecting (501) a reference object (200a, 200b, 200c, 200d) with the camera (110) positioned at the first position (P1); determining (502) a reference value of the reference object (200a, 200b, 200c, 200d); requesting (503) movement of the camera (110) from the first position (P1) to the second position (P2); initiating (504) movement of the camera (110) from the first position (P1) to the second position (P2) while iteratively sampling images of the reference object (200a, 200b, 200c, 200d); determining a current object value of the reference object (200a, 200b, 200c, 200d) based on the sampled images; matching the reference value with the current object value; and determining (505) success of the camera movement based on the matching.

The invention provides a geometric-gravity error integrated calibration method of a large gantry machine tool. The method comprises the steps that a geometric error model of the gantry machine tool is established based on the multi-body system kinematics theory and rigid body kinematics analysis, and the geometric error model is used for describing geometric error sources of all motion axes and the transmission relation of the geometric error sources; establishing a gravity deformation error model of the gantry machine tool based on mechanical analysis and a potential energy method; coupling the geometric error model with the gravity deformation error model to obtain a rigid-flexible coupled integrated geometric-gravity error model; measuring static error parameters of each motion axis of the machine tool, and substituting the static error parameters into the integrated geometry-gravity error model to obtain geometric error parameters without influence of gravity error factors; and on the basis of the integrated geometry-gravity error model and the geometric error parameters with the influence of the gravity error factor eliminated, the error compensation amount of each movement position point of the gantry machine tool is calculated, and the gantry machine tool is calibrated on the basis of the error compensation amount of each movement position point.

The invention discloses a joint driving torque determination method of a six-axis mechanical arm, and relates to the technical field of multi-body system dynamics, and the joint driving torque determination method comprises the following steps: determining a connecting rod mass center linear velocity jacobian matrix and a joint rotation axis angular velocity propagation matrix so as to determine a rigid body part mass matrix; determining a Jacobian matrix of the motor rotor centroid linear velocity; determining a motor rotor mass matrix based on the motor rotor mass center linear velocity Jacobian matrix so as to determine a system mass matrix, and further obtaining a joint inertia moment item; determining a gravity compensation torque item based on the connecting rod centroid linear velocity Jacobian matrix, the connecting rod mass, the motor rotor centroid linear velocity Jacobian matrix and the motor rotor mass of all the mechanical arms; determining a non-linear velocity torque item based on the system mass matrix, the joint angle vector and the joint angular velocity vector; a joint driving force is determined based on the joint inertia moment term, the gravity compensation moment term, and the non-linear velocity moment term. According to the method, the determination precision of the joint driving torque of the six-axis mechanical arm is improved.

The invention discloses a method for analyzing the machining precision of a machine tool by bolt performance degradation in consideration of hole position errors, which considers the influence of manufacturing hole position errors on the rigidity of a bolted part for the first time. The method comprises the following steps: firstly, extracting normal and tangential contact rigidities of a joint surface under the conditions of different hole position errors, fractal parameters and pre-tightening forces by utilizing an abaqus finite element method to obtain a data set; and then, taking the hole position error, the fractal parameter and the pre-tightening force as input vectors, taking the joint surface rigidity as an output vector, and training data by utilizing a BP neural network to complete rigidity prediction. And finally, establishing a dynamic model of the gantry machine tool based on a multi-body system transfer matrix method so as to explore the influence of performance degradation of the bolts on the machining precision of the machine tool, and providing technical guidance for optimization of the bolt joint surfaces in engineering.

The application discloses a kind of shipboard aircraft dynamics fast calculation method.Method includes following process: establishing shipboard aircraft catapult take-off multi-flexible body system dynamics model, establishes shipboard aircraft catapult take-off multi-flexible body system topology, utilize finite element method to establish main tire refinement finite element model, then tire flexible body dynamics characteristic parameter is exported and deduces the dynamics equation of tire flexible element, based on multi-body system transfer matrix method (MSTMM) and finite element modal synthesis method deduce shipboard aircraft catapult take-off multi-flexible body system total transfer equation and total transfer matrix, solve the inherent frequency of shipboard aircraft multi-flexible body system considering inflatable flexible tire and the dynamic response of catapult take-off;The method proposed in the application overcomes the defects of high matrix order and large amount of calculation of traditional methods when dealing with complex coupling system of shipboard aircraft containing inflatable flexible tire, has the advantages of fast calculation speed, high degree of programming and strong universality, provides an efficient calculation method for the dynamic analysis of complex shipboard aircraft multi-flexible body system.

A comprehensive error modeling and adaptive compensation method for a multi-axis linkage turning-milling compound machine tool taking into account all working conditions belongs to the field of machine tool precision improvement. The present invention first analyzes the topological structure of the nine-axis machine tool, and based on the homogeneous coordinate transformation method of the multi-body system theory, establishes a comprehensive error model taking into account all working conditions; secondly, the Jacobian matrix is ​​used to solve the comprehensive error compensation amount of each motion axis; finally, an adaptive compensation method based on the tool and axis motion information of the CNC system is proposed. The present invention improves the accuracy of modeling by establishing a comprehensive error model taking into account all working conditions and establishing different comprehensive error models for different working conditions; an adaptive compensation method is introduced to perform comprehensive error compensation on the processing chain under different working conditions, so that the compensation result is more accurate and more efficient. The method pointed out by the present invention provides a theoretical basis and research ideas for the structural analysis, error modeling and error compensation of complex machine tools with multiple workpiece chains and multiple tool chains.

The invention discloses a worm grinding wheel gear grinding machine multi-body dynamics performance analytical calculation method considering rolling contact interface abrasion, and belongs to the technical field of machine tool dynamics. According to the method, firstly, grinding force is measured through experiments, and working loads and normal contact force of key joint parts such as a guide rail pair, a lead screw pair and a bearing pair are solved through a space force system balance equation; secondly, identifying fractal parameters of contact interface morphology by adopting a structure function method, and calculating initial contact stiffness by combining a Hertz theory; then, the abrasion depth of the rolling contact interface is predicted according to the kinematic characteristics and the Archard abrasion theory, the interface morphology and fractal parameters are updated accordingly, and the contact rigidity after abrasion is calculated; and finally, establishing a complete machine dynamic model based on a multi-body system transfer matrix method, solving and comparing the inherent frequency and the vibration mode of the system by substituting the contact stiffness parameters before and after abrasion, and quantifying the influence of interface abrasion on the dynamic performance of the complete machine.

The invention provides a steel wire rope dynamics modeling method based on multi-body dynamics in order to solve the problems that an existing steel wire rope dynamics modeling method is time-consuming in calculation, difficult to simulate the bending wave propagation effect of a steel wire rope in a high-energy impact scene and difficult to meet the requirement for high-precision and high-efficiency solving of stress characteristics of the steel wire rope under complex working conditions. Firstly, a global coordinate system is established, and enough cylindrical rigid body units and local coordinate systems fixedly connected to the centroids of the cylindrical rigid body units are established to describe the whole steel wire rope; secondly, a motion equation of a steel wire rope rigid body unit multi-body system is given; then establishing a flexible connection equation between adjacent rigid body units; and finally, establishing a three-dimensional contact force equation of the rigid body unit and other objects so as to establish a dynamic model of the steel wire rope under the high-energy impact. The dynamic model can effectively simulate the propagation process of bending waves in the steel wire rope under high-energy impact, and the dynamic response of the steel wire rope is accurately solved.

The application provides a method for integrated control of multi-body coupled motion of an aircraft and components thereof, which comprises: establishing a full-state dynamic model of the multi-body coupled motion aircraft, and deriving a scalar differential equation capable of explicitly showing a control input and a controlled variable; designing a basic control structure of feedback linearization without considering modeling errors, parameter errors and external disturbances; designing a control structure considering external disturbances and modeling errors, and designing a model compensation extended state observer to online estimate the external disturbances and the modeling errors, and then compensating the output of the control structure to ensure the closed-loop control effect, and finally generating the control structure compensated for the external disturbances and the modeling errors. The method can solve the problems of control structure design difficulty and poor control effect of the dynamic model of the multi-body coupled motion aircraft, and achieve the purpose of high-precision and strong-robust integrated control of the aircraft components and attitude.

The invention discloses an in-tunnel TBM precise and safe disassembling method based on model driving, and belongs to the technical field of engineering equipment disassembling. Aiming at the problems of large separation impact, high space interference risk, non-optimal disassembly sequence, difficulty in attitude control and the like in the traditional disassembly process, a'digital twinning 'framework comprising four technical modules is constructed: a main drive controllable separation model based on structural dynamics realizes low-impact flexible separation; a cutter head safe disassembly window model based on space analytic geometry ensures the space safety in the lifting process; generating a global optimal sequence on the basis of a graph theory topological sorting and multi-target evaluation disassembly sequence optimization model; a screw conveyor collaborative hoisting model based on multi-body system mechanics realizes accurate attitude control. According to the method, experience judgment is replaced by mathematical model driving, so that the safety, efficiency and adaptability of disassembly are remarkably improved.

The embodiment of the application discloses a draghead posture analysis method, device, medium and equipment for a trailing suction dredger, which comprises the following steps: regarding the ship body and the draghead of the trailing suction dredger as rigid bodies, regarding the wave compensator of the trailing suction dredger as a flexible body, regarding the fluid-structure interaction added mass of the ship body and the draghead as the rigid body added mass, and constructing the multi-body system block matrix coupling equation of the trailing suction dredger; obtaining an external load vector acting on the trailing suction dredger; and solving the multi-body system block matrix coupling equation of the trailing suction dredger based on the external load vector to obtain the draghead posture of the trailing suction dredger. The embodiment of the application can improve the analysis accuracy when the draghead posture is analyzed.

The invention belongs to the technical field of vibration table simulation analysis, and discloses a vibration table rigid-flexible coupling multi-body system dynamics modeling method and a related device, and the method comprises the steps: building a vibration table three-dimensional geometric model; generating a vibration table rigid body model based on the vibration table three-dimensional geometric model; selecting a preset key component in the three-dimensional geometric model of the vibration table, and establishing a flexible modal neutral file of the preset key component; based on a flexible modal neutral file of a preset key component, replacing a predetermined rigid member in the rigid body model of the vibration table with a flexible body member, and obtaining a rigid-flexible coupling model of the vibration table; performing dynamic simulation analysis on the vibration table rigid-flexible coupling model to obtain a dynamic modeling result of the vibration table rigid-flexible coupling multi-body system; according to the method, the pre-determined rigid component in the rigid body model is replaced with the flexible body component, so that the flexibility characteristic of the key component in the vibration table system can be fully considered, the mechanical behavior in the system can be described more accurately, and the simulation precision is effectively improved.