87 results about "Rigid body model" patented technology

The present invention models dynamic behavior of flight vehicles for simulation, analysis, and design. The present invention allows a user to define the complexity of a flight vehicle model, and such models may be simple rigid body models, models of medium complexity, or very complex models including high order dynamics comprising hundreds of structural flexibility modes and variables related to aero-elasticity, fuel sloshing, various types of effectors, tail-wags-dog dynamics, complex actuator models, load-torque feedback, wind gusts, and other parameters impacting flight vehicles. The present invention accommodates and analyzes multiple vehicle and actuator concepts and configurations as defined in flight vehicle input data, which specifies flight vehicle parameters at a steady-state condition for modeling flight vehicle response to dynamic forces and flight control commands with respect to steady state operation.

The invention discloses a parametric modeling method of a rigid-flexible coupled model. The method includes the steps of 1, establishing a rigid component model, 2, establishing an APDL macro file of a flexible body model, 3, establishing a rigid-flexible coupled system parametric graphical user interface, 4, inputting flexible body parameters in the interface and reading, altering and updating the APDL macro file, 5, executing the updated APDL macro file to build the flexible body model, 6, inputting rigid body model parameters, reconstructing a rigid body model, importing a flexible body modal neutral file and generating a command file containing a rigid-flexible coupled dynamics simulation model, 7, importing the command file, loading a virtual prototype model, conducting dynamics simulation analysis and outputting a simulation result and 8, outputting the optimum simulation data and storing a data file according to the simulation result. According to the rigid-flexible coupled model parametric modeling method, automatic creation of the parametric modeling of a flexible body and the rigid-flexible coupled model can be achieved, manual intervention is not needed in the whole process, the problem that it is difficult to parameterize the flexible body in the engineering practice is solved, the modeling efficiency is improved, and the method has very good engineering application value.

The invention provides a three-dimensional non-rigid body reconstruction method based on multiple depth maps. The method comprises the following steps: performing multi-depth map photographing on a non-rigid body according to different angles and different postures so as to obtain multiple depth maps; converting each depth map into a group of three-dimensional point clouds, and acquiring multiple matching dotted pairs among the multiple groups of three-dimensional point clouds; performing position change on each matching point, and solving a conversion parameter corresponding to each matching point of which the position is changed; splicing all conversion parameters, and constructing an energy function according to the splicing result; and solving the energy function so as to reconstruct a three-dimensional non-rigid body model according to the solution result. According to the method, the required input information is simple and is easily acquired, and a high-precision complete three-dimensional model can be obtained. The method is accurate and robust in solution, the influence brought by the accumulating is eliminated, and the method is high in operating speed and has wide application prospect. The invention also provides a three-dimensional non-rigid body reconstruction system based on multiple depth maps.

The invention mainly relates to a dynamical joint simulation analysis method of a door system of a rail transit vehicle, and the method mainly comprises the steps as follows: (1) a system is subjected to three-dimensional modeling and a three-dimensional model is converted to a neutral file in a SolidWorks environment to be imported into ADAMS (automatic dynamic analysis of mechanical systems); (2) the modal analysis of a flexible body component is conducted in Ansys, and converted to a neutral file to be imported into the ADAMS to replace a corresponding rigid body model; (3) a simulation model is preprocessed; (4) a system control model is built in Matlab, the door system is subjected to simulation control by an ADAMS / Control module to accomplish the kinematic and dynamical simulations of the whole system; (5) an experimental test platform is constructed, and a motion experimental test of the system is conducted; (6) a simulation result is compared with an experimental result, and the model is modified continuously; and (7) motion simulations of opening and closing a door and simulating a practical operating condition are conducted to search an optimal door control system mode.

A motor control system (200) includes a motor (1) connected to a load (2) through a connecting shaft (3), an electric power converter (4) for driving the motor, and a motor controller (100) for controlling the electric power converter according to a target command value and a motor current that flows in the motor; the motor controller has an auto tuner (11) that receives a motor torque value and motor rotational speed of the motor as input signals and automatically adjusts control parameters used in the control; the auto tuner handles a machine system including the motor, connecting shaft, and load as a rigid-body model and a resonant model that are connected in series, the auto tuner having a parameter identifying means for separately identifying parameters constituting the rigid-body model and parameters constituting the resonant model. Both rigid-body characteristics and resonant characteristics of a controlled target can thereby be identified online with a small amount of calculation.

The invention discloses a nuclear power plant breakwater overtopping impact simulation method based on a mixed model. The method includes the following steps that at first, a three-dimensional entity finite element model of a fine structure of a breakwater is established; secondly, a breakwater structure rigid body model and a neighboring environment entity model are established; thirdly, initial stress is added to the established three-dimensional mixing finite element model of the nuclear power plant breakwater to simulate the initial operating condition to obtain the initial state of the nuclear power plant breakwater under the action of gravity and seawater pressure; finally, after distribution of initial stress of the nuclear power plant breakwater is obtained, the impact state and the overtopping state of the nuclear power plant breakwater under the action of waves are obtained, and integral simulation of the breakwater is achieved. According to the method, simulation analysis of numerical simulation of the super-large-scale nuclear power plant breakwater is achieved, response rules of an overall model can be contained, meanwhile local structures can be finely analyzed, local dangerous positions are obtained, and reference bases are provided for engineering design of the nuclear power plant breakwater.

The embodiment according to the invention discloses a method for establishing a rigid body model based on a three-dimensional model in digital home entertainment, comprising the following steps: a rigid body model in a three-dimensional game engine is set in a three-dimensional Cartesian coordinate system; the rigid body model is simplified based on centroid coordinates and a quality value; a collision detection bounding box is created based on the rigid body model; an intersection test is performed on the created rigid body model based on a physical simulation system to determine whether collision exists among graphic elements; a collision detection of the rigid body model is performed based on a three dimensional game system; and response results of the collision detection of the rigid body model are obtained based on the three dimensional game system. The embodiment in the invention adopts a capsule as a geometric model of the rigid body in the three-dimensional game engine, the model being conductive to the realization of a collision detection algorithm, and being liable to meet the requirement of small calculation amount. Further, appropriate physical quantities are selected to establish a simplified physical model according to needs, and a geometric model and a physical model of the rigid body are combined to establish the rigid body model in the three-dimensional game engine.

The invention discloses a three-dimensional static modeling method of a rope-driven continuous mechanical arm. The method comprises the following steps: (S1) three-dimensional force balance equationsof each equivalent torsion spring are built according to a three-joint false rigid body model to obtain deflection angles of each torsion spring when the rope-driven continuous mechanical arm is suffered from preset rope tension, external force and gravity; (S2) resultant force and resultant torque expressions of the rope tension, external force and gravity to each branch section terminal are built according to the deflection angles of each torsion spring; and (S3) the resultant force and resultant torque expressions of the rope tension, external force and gravity to each branch section terminal are substituted into the three-dimensional force balance equations of each torsion spring to obtain three-dimensional static balance equations of the rope-driven continuous mechanical arm. A two-dimensional plane false rigid body equivalent method is developed into three-dimensional space; and the operation efficiency is greatly improved.

The invention discloses a control method and device for bionic jumping action of a quadruped robot, electronic equipment and a computer readable medium. The control method comprises the steps that thequadruped robot is simplified into a rigid body model; according to the simplified rigid body model, the actual state of a mass center of a body is calculated through gyroscope data in combination with the foot end state and the joint angles of four legs; in the preparation, take-off and landing stages of the quadruped robot, the expected acceleration and angular acceleration are given, the position and posture of the body of the quadruped robot are planned respectively, the feed-forward virtual force and virtual moment are calculated according to the given acceleration and angular acceleration, and according to the error between the expected state and the actual state, the total virtual force and virtual moment required by the mass center is calculated by combining the proportional-differential control law and the feed-forward quantity; the moment of each joint of the supporting leg is obtained according to the obtained mass center virtual force and virtual moment; and the moment ofeach joint of the supporting leg is executed by a motor to jump.

The invention discloses a three-dimensional model search method based on topology and visual feature. The method comprises the following steps of: inputting a three-dimensional model to be searched; carrying out standardization preprocessing on the input three-dimensional model, that is to say, transforming the three-dimensional model to a uniform coordinate system through translation transformation, scaling transformation and rotated transformation; constructing a topology structure for the transformed three-dimensional model by a multilayer Reeb picture method; rendering an image of each key topology point of the topology structure; extracting the visual feature of the rendered three-dimensional model; computing similarity according to the extracted visual feature point and the three-dimensional model in a model feature library; and returning the searched result to the user according to the similarity size. According to the three-dimensional model search method provided by the invention, a rigid body model and a non-rigid body model are searched quickly and accurately.

The invention relates to a three-dimensional virtual human body movement generation method based on key frames and spatiotemporal restrictions, belonging to the technical field of computer three-dimensional animations. The method comprises the steps of using a multi-rigid-body model with a skeleton structure as a geometrical model for three-dimensional virtual human body movement control, wherein vectors formed by all determined angle parameters indicating freedom in the geometrical model are taken as parameters for virtual human body static posture formal description; making human body static postures at two key frame moment, i.e. a minimum movement span and a maximum movement span; conducting equal or non-equal time sampling to the time sequence of movement, determining the angle offset of each time sampling point and obtaining the angle parameters of time sampling points in a movement process to be generated; and then generating virtual human body static postures at the moment, determining position parameters and generating the full movement process of a virtual human body in a three-dimensional space. By adopting the method, special video capture equipment is not required, the simplicity in making three-dimensional human body animations is improved and the method has the characteristics of convenience, high efficiency and high flexibility.

An optimizing method for the colliding accident of car-human based on the three-dimensional multi-steel model. The process: (1) make the three-dimensional multi-steel mathematical model of the car, the human and the environment; (2) determine the centroid position coordinate of the car stopping and the coordinate of the human buttocks; (3) determine the optimizing design variable, the limiting condition and the optimizing object function; (4) resolve the giving object function by the optimizing arithmetic; (5) determine the astringency of the function after computing. The invention has decreases the reappearance time, the error and the indeterminacy by man-made interference.

The invention relates to a fire-fighting robot arm double-coupling simulation method, which is characterized by comprising the steps of hydraulic loop design, a Pro / e rigid body modeling, an ANSYS flexible body modeling, a kinematics and dynamics simulation, a machine and hydraulic coupling simulation, rigid and flexible coupling simulation and double-coupling analysis, wherein the rigid and flexible coupling simulation is that an ANSYS flexible body model of a large arm and an ANSYS flexible body model of a small arm respectively replace rigid body models of the large arm and the small arm in a rigid body assembling body, thereby obtaining the rigid and flexible coupling model to carry out the rigid and flexible coupling simulation; and the double-coupling analysis is that the combined simulation of the machine and hydraulic simulation and the rigid and flexible simulation. The method is mainly used for the dynamic simulation and experiment of the fire-fighting robot arm, is convenient for integrally mastering the change rules of stress, strain and hydraulic pressure system parameters, saves the simulation time, improves the simulation efficiency, and shortens the design cycle ofthe robot arm.

The invention discloses an evaluation method for measurement uncertainty introduced by mechanism errors of a three-coordinate measuring machine. The three-coordinate measuring machine has a complex mechanical structure and multiple error sources, and the errors of the mechanical structure have the greatest influence on the uncertainty of space points and are difficult to be quantified. The measurement error model of the space points is obtained under the quasi-rigid body model of the three-coordinate measuring machine. 21 error information caused by the mechanical structure of the three-coordinate measuring machine is obtained through a calibration experiment or a calibration certificate, the distribution type is determined, and then the measurement uncertainty introduced by the mechanism errors of the three-coordinate measuring machine is evaluated through combination of the mechanism error model of the space points by utilizing a monte carlo random sampling method. The measurement uncertainty of the space points evaluated by the evaluation method for the measurement uncertainty has the characteristics of repeatability, reproducibility and stability so that the influence of 21 mechanism errors of the three-coordinate measuring machine on the measurement result is objectively reflected.

The invention discloses a method and a device for controlling bionic jumping action of a quadruped robot. The method comprises the following steps: simplifying the quadruped robot into a rigid body model; according to the simplified rigid body model, obtaining the actual state of the mass center of the body through calculation by combining gyroscope data with the foot end state; considering the closed loop of the actual state and the expected state, and calculating the virtual force and moment required by the mass center; obtaining the moment of each joint of the supporting leg according to the obtained virtual force and moment required by the centroid; and executing the moment of each joint of the supporting leg by a motor to jump. According to the technical scheme, the leg power generation mode of the robot is optimized, that is, the leg power generation mode is divided into three stages, the mode that the front leg and the rear leg respectively exert force according to stages is adopted, the torque output capacity of a leg control motor of the robot is almost utilized to the limit, the retention time of the robot in the air is more reasonably utilized, the jumping distance and the obstacle clearing height which are obviously superior to those of Pronk actions are obtained, and the crossing distance reaches about 1.5 m.

The invention discloses a quick simulation analysis method for a radar antenna servo system. The quick simulation analysis method includes the steps that (1) parametric modeling of a bond graph is carried out, components in the system are simplified according to the modeling sequence of a drive motor, a transmission mechanism and a reflecting surface body and accordingly a bond graph model of the antenna servo system is built; (2) virtual prototype multi-rigid-body modeling is carried out, part rigid-body models in all links are sequentially built on the basis of the modeling theory that each solid body in the system corresponds to one rigid body in a multi-rigid-body model, the corresponding rigid bodies are combined according to a parametric model of the bond graph and accordingly a system design model is obtained; (3) a parameter synchronization mechanism is introduced, and design model parameters are transferred to the bond graph model synchronously by means of a design model information file; (4) a system mathematic model is deducted according to the system bond graph model. Mathematical modeling simulation, multi-rigid-body modeling simulation and bond graph modeling simulation methods are well combined, advantages are made use of and defects are avoided.

The invention provides a composite material flexible part assembling deviation analysis method. The method comprises the steps of: 1, collecting data and obtaining initial manufacture deviations of composite material flexible parts; 2, extracting corresponding super-element rigidity matrixes by using finite element software; 3, establishing a part rigidity matrix model based on fiber reinforced composite material lay-up angle deviations and defining super-element rigidity matrixes; 4, performing determinative location on the flexible parts based on rigid body models; 5, adding an over-location clamp; 6, clamping assembling connecting points of the composite material flexible parts to nominal positions via assembling pressing force; 7, forming an assembling body when the composite material flexible parts arrive at the nominal assembling positions by the action of the assembling pressing force; 8, determining a rebound deviation; 9, finally releasing the over-location clamp to obtain a rebound deformation deviation, and obtaining the final rebound deviation of the assembling body. The method can determine the influence of composite material lay-up angle deviations on flexible assembling body deviations and thus improve the engineering application scientificity.

The invention discloses a longitudinally arranged power assembling suspension system matching method and system. The longitudinally arranged power assembling suspension system matching method comprises steps of arranging suspension points according to a four-pint suspension system; increasing two auxiliary suspension points with a target of enabling the static bending moment of the rear end surface of a flywheel casing to be equal to zero when the static bending moment of the four points is larger than the maximum bending moment; matching to obtain a rigid body model of a six-point suspension system, if the rigid body model does not satisfy an NVH (Noise Vibration and Harshness) design requirement and matching and acquiring the six-point suspension system within a setting range of a static compression amount under constraint conditions of enabling the static bending moment to be smaller than the maximum static bending moment, the vertical static rigidity of the middle suspension of the six-point suspension to be smaller than that of the rear suspension of the four-point suspension and the rigid body model to satisfy a requirement for the frequency difference in the NVH and with the decoupling rate of Z2 and RX direction being served as a maximum optimization target. The longitudinally arranged power assembling suspension system matching method can guide a designer to achieve matching of the six-point suspension system, reduces requirements for the designer, shortens the development period of the suspension system and saves the testing costs.

The invention discloses a quasi-flexible body discrete suspension modeling method based on a bushing, which relates to the technical field of automobile suspension. By establishing a rigid body component model of the suspension, the model needing to be flexible is divided into several rigid blocks with centralized mass. The rigid blocks are connected by bushings, and the model stiffness to be flexible is approximately replaced by bushing stiffness, which is used as the bearing element. Input rigid body model parameters; The suspension dynamics simulation analysis is carried out and the simulation results are output. Compared with the modal synthesis method, the flexible body modeling method has stronger parametric modeling ability and simplicity. Compared with the flexible body discretization method, the simulation accuracy of thin plate parts is higher, and because the degrees of freedom of the bushing do not affect each other, so the shear locking can be effectively avoided when therigid parts are discretized by the flexible body discretization. In addition, by setting the liner stiffness, the expected simulation optimization results are obtained, which plays a guiding role in the optimization design of the model.

The invention discloses a snailflower citric acid transporter gene VuMATE, which has a nucleotide sequence represented by SEQ ID No.1. The invention also discloses a method for breeding an aluminum-tolerance transgenic crop, which comprises the following steps: 1) selecting the snailflower citric acid transporter gene VuMATE having the nucleotide sequence represented by SEQ ID No.1; 2) constructing a constitutive type expression transgenic vector; and 3) and breeding the transgenic crop, namely infecting leaf disc of tomatoes Micro-Tom with Agrobacterium rhizogenes EHA105 into which the pseudo-rigid-body model (pRBM) vector is transferred, co-culturing the transgenic plant, selecting, differentiating and rooting to obtain transgenic tomatoes MATE-2. The snailflower citric acid transporter gene VuMATE disclosed by the invention can be used for plant transgenosis for improving the aluminum tolerance of the crop.

A machine model estimating device of an electric motor control apparatus having an electric motor for driving a load machine, a rotation detector for detecting a rotating angle of the electric motor, and a servo control device for controlling the electric motor. The machine has a calculating device for outputting an operation command signal for operating the electric motor to the servo control device, and frequency characteristic equations for a rigid body model and an N-inertia model, N being an integer which is equal to or greater than 2, which are previously input to the calculating device. The calculating device includes a frequency characteristic measuring section, a frequency characteristic peak detecting section, an attenuation estimation value analyzing section, a frequency characteristic error calculating section, and a machine model deciding section.

In a magnetic resonance (MR) navigator-based method and apparatus, MR data are acquired from a large joint of a patient, which is not modelable as a whole based on a single rigid body model. The field of view which the MR data are acquired is divided in a processor into multiple sub-sections, with each sub-section being modelable based on a rigid body model. MR navigator signals are acquired from each of the sub-sections, and these navigator signals are used in a motion tracking algorithm that is based on a rigid body model in order to generate a modeling result that tracks the movement of the overall joint within the field of view. The modeling result can be used for prospective or retrospective motion correction of the MR data.

The present invention discloses a parachutist falling motion simulation method based on a multi rigid body model. Based on the human body multi rigid body model, deplaning falling motion simulation of a parachutist in a non-rigid body model is achieved for the first time. During a falling motion process, the parachutist can adjust positions and attitudes of the head and arms and legs relative to the trunk according to the need, and furthermore the whole body falling track and attitude can be changed. The method is already used in a parachutist parachute training simulation system, and compared with a traditional simulation method, simulation of parachutist falling motion tracks and complex attitudes is really achieved.

The invention relates to a double-shaft balancing design method of a V8 type diesel engine. The double-shaft balancing design method comprises theoretical design, multi-rigid-body dynamics simulation and rigid-flexible coupling vibration simulation; the theoretical design comprises the steps of selection of air cylinder included angles and crank modes, fitting of an upsetting moment and analysis of harmonic waves and determination of balancing shaft spatial layout modes, phase angles, mass distribution, cross section shapes and parameters; a V8 type diesel engine multi-rigid-body model is built by dynamics simulation, and a double-shaft balancing effect determined by the theoretical design is verified; rigid-flexible coupling vibration simulation aims at the V8 diesel engine which is additionally provided with the double-shaft balancing design to build a diesel engine rigid-flexible coupling model, and stimulation is conducted on the vibration condition of the diesel engine which is additionally provided with a balancing device, and the balancing effect of a double-shaft balancing scheme is verified on the other hand. The double-shaft balancing design method of the V8 type diesel engine has the advantages that the method which combines the theoretical design with the dynamics simulation together is adopted, results in the stages are verified mutually, the correctness of the design scheme is ensured, and the reasonability of the design scheme and the good balancing effect can further be ensured.

The invention discloses a pseudo-rigid-body model of a flexible slider-crank mechanism, which comprises a crank and a flexible rod, wherein the crank can rotate in a complete circle; one end of the flexible pole is hinged with a free end of the crank, and the other end thereof is hinged with a sliding block through a featured joint; and a torsional spring is arranged in the featured joint. According to the invention, in consideration of motion of the flexible rod, the optimal design of the flexible slider-crank mechanism is discussed on basis of the probability hypothesis method of random variable affecting fatigue strength. Based on the pseudo-rigid-body model of the flexible mechanism, in combination with probability, fatigue, structure of mechanism and the like, and in consideration of dynamic effect influence of the mechanism motion, the invention provides an optimal design method of the flexible slider-crank mechanism.

The invention discloses a dynamics modeling method for a multiple-input-multiple-output gear transmission system. The dynamics modeling method comprises the following steps of S1, dividing the multiple-input-multiple-output gear transmission system into a plurality of sub transmission systems; S2, performing rigid body modeling on components in each sub-transmission system, and assembling the components to form a sub-system model; S3, simplifying the coupling into a multi-degree-of-freedom spring with rigidity and damping, and connecting the subsystem models through the coupling to form an overall model of the multi-input multi-output gear transmission system; s4, performing multi-body dynamics simulation analysis on the overall model to obtain discrete data of wave power and fluctuation torque at the multi-degree-of-freedom spring; s5, performing numerical fitting on the discrete data to obtain a time-varying fluctuation function; and S6, establishing a centralized mass dynamic modelof each subsystem, and adding the wave function into a degree-of-freedom equation of a node corresponding to the centralized mass dynamic model to obtain a decoupled subsystem dynamic model. The method is simple in modeling and high in solving speed.

The invention provides a method and a system for tracing cascade rigid motion. The method for tracing cascade rigid motion includes steps of measuring attitude data of each cascade rigid body, establishing rotation matrix corresponding to the rigid bodies according to the attitude data, building a cascade point set consisting of cascade points and two end points of the cascade rigid bodies, selecting one point in the cascade point set as a known point by utilizing the cascade point set as a processed object, multiplying the coordinates of the known point with the rotation matrix of the corresponding rigid body so as to acquire the coordinates of another cascade point of the rigid body, and sending data of the coordinates of the cascade point set to a motion tracing center so that the motion tracing center can drive the corresponding portion of a model of the cascade rigid body to move by utilizing data of the coordinates and show the motion process virtually. The invention further provides a method and a system for tracing walking processes. By the aid of the method and system for tracing cascade rigid motion and walking processes, motion tracing is simple and convenient, limit factors are fewer and data are accurate.

A linear element with two stable points, it can be used as trust element allows for change in length. It can transform structure from one shape to another thus allowing for morphable configuration. A new model is presented herein for a linear bi-stable compliant mechanism and design guidelines for its use. The mechanism is based on the crank-slider mechanism. This model takes into account the first mode of buckling and post-buckling behavior of a compliant segment to describe the mechanism's bi-stable behavior. The kinetic and kinematic equations, derived from the Pseudo-Rigid-Body Model, were solved numerically and are represented in plots. This representation allows the generation of step-by-step design guidelines. Because different applications may have different input requirements, two different design approaches are described herein with different parameters subsets as inputs.

The invention provides a hypersonic flight vehicle preset performance control method and device based on disturbance estimation. The method comprises steps of carrying out the control of the preset performance of a hypersonic flight vehicle based on a motion rigid body model of the hypersonic flight vehicle according to a finite time convergence preset performance function and a corresponding system error function; respectively determining conversion errors of a speed subsystem and a height subsystem in the model; and controlling the speed and height of the hypersonic aircraft according to the unknown interference item estimated value obtained by the interference observer and each conversion error so that a tracking error of the hypersonic aircraft meets preset transient and steady-state performance. According to the method, a convergence time value can be set according to system tracking performance requirements through a designed performance function, so the tracking error is converged to a steady-state value within a preset finite time, the convergence speed and precision are improved, a virtual instruction derivative item and a disturbance item are combined to be regarded as a total disturbance item, observation compensation is carried out, the design process of the controller is simplified, and complexity is reduced.