48 results about "Dual quaternion" patented technology

A spacecraft attitude-track integrated backstepping tracking control method is provided, and aims to solve the problems that an existing method respectively uses separate control modes to track the spacecraft track and attitude, so the tracking effect is poor; the method comprises the following steps: 1, building a spacecraft attitude-track integrated relative kinematics and dynamics model according to dual quaternions; 2, designing a controller according to a backstepping method and the spacecraft attitude-track integrated relative kinematics and dynamics model built in step 1; 3, designing an anti-saturation method based input bounded controller according to the controller designed in step 2. The method considers the input bound problems on the backstepping controller base, and designs the anti-saturation node based input bounded backstepping controller; the method can track the spacecraft and realize the 6-degree of freedom attitude-track cooperation tracking of the target spacecraft, is suitable for practical in orbit conditions, and applied to the spaceflight field.

The invention relates to a position sensor and a three-dimension laparoscope camera calibration device and method. The method comprises compensating an output error of an electromagnetic position sensor through a high-precision optical positioning system, calculating the position and posture of a three-dimension laparoscope camera through calibrating a reference cube, and analyzing the coordinate relation between the electromagnetic position sensor and the three-dimension laparoscope camera using dual quaternion at last. By adopting the sensor and the three-dimension laparoscope camera calibration device and method, offset defect, generated by deformation of the magnetic field, of output of a present electromagnetic position sensor can be overcome, the calibration is accurate, the instantaneity is good. The calibration device and method are easy to operate, positional relationship between an electromagnetic position sensor and an endoscope camera can be speculated only through the electromagnetic position sensor fixed to the front end of the endoscope camera and calibration grids.

The invention discloses a strapdown inertial navigation method of dual quaternion based on a frequency domain analysis method. The invention is designed aiming at the following problem: various errors of carrier movement can not be fully compensated because of polynomial fitting of the angular velocity and the specific force of the carrier in the traditional time-domain strapdown inertial navigation algorithm. The principle of the invention is as follows: carrying out smooth continuation and discrete Fourier transform on the increment signal output by an inertial navigation device and the navigation information obtained in the solving process by utilizing the frequency domain analysis method, then solving the spectrum signal obtained through transform by utilizing the strapdown inertial navigation algorithm of dual quaternion realized in the frequency domain and finally carrying out inverse Fourier transform on the signal obtained by solving to obtain the navigation solution in the time domain. Compared with the existing time-domain strapdown inertial navigation methods of dual quaternion, the method is characterized by taking full advantage of the information of the signal output by the inertial navigation device in each frequency range and having higher precision under high dynamic environment.

The invention comprises a learned model of human body shape and pose dependent shape variation that is more accurate than previous models and is compatible with existing graphics pipelines. Our Skinned Multi-Person Linear model (SMPL) is a skinned vertex based model that accurately represents a wide variety of body shapes in natural human poses. The parameters of the model are learned from data including the rest pose template, blend weights, pose-dependent blend shapes, identity-dependent blend shapes, and a regressor from vertices to joint locations. Unlike previous models, the pose-dependent blend shapes are a linear function of the elements of the pose rotation matrices. This simple formulation enables training the entire model from a relatively large number of aligned 3D meshes of different people in different poses. The invention quantitatively evaluates variants of SMPL using linear or dual-quaternion blend skinning and show that both are more accurate than a Blend SCAPE model trained on the same data. In a further embodiment, the invention realistically models dynamic soft-tissue deformations. Because it is based on blend skinning SMPL is compatible with existing rendering engines and we make it available for research purposes.

The invention relates to a geometric deformation based skin deformation method for a three-dimensional animated character model. The method comprises the steps that according to the skeleton structure of an initial character model, the initial character model is divided into joint areas and bone areas, and deformation control points among the bone areas are calibrated manually; according to the body zoom parameters set by a user and the calibrated deformation control points, geometric deformation is implemented on the bone areas of the initial character model based on a free deformation technology; after the geometric deformation, influence of joints on apexes is adjusted; and according to the influence of the joints on the apexes of the joint and bone areas, the character model is driven to make translational and rotary movement via a dual-quaternion method to generate vivid and lifelike skin deformation effect. The skin deformation method of the invention can overcome the defects as collapse and shape explosion caused by large moving amplitude of the model, and obtains more real skin deformation while ensuring the instantaneity.

The invention relates to a method for robot hand-eye calibration. A calibration plate provided with a calibration point is fixed at the tail end of a robot. The calibration method comprises the following steps that pose information of a tool center point of the robot in a robot base coordinate system is acquired, and the pose information is converted into a dual quaternion form to obtain hand movement spiral information; image information of the calibration plate is acquired, coordinate information of the calibration point in a camera coordinate system is calculated according to the image information, and the coordinate information is converted into a dual quaternion form to obtain eye movement spiral information; a movement transformation equation between the hand movement spiral information and the eye movement spiral information is established, and matrix factors of the movement transformation equation are extracted; a plurality of matrix factors of the robot in different poses areacquired, a transformation matrix is constructed according to each matrix factor; and each transformation matrix is subject to singular value decomposition to obtain a unit dual quaternion of the robot base coordinate system relative to the camera coordinate system. The method has the advantages of being high in calibration speed and simple in calculation.

The invention discloses a position reversal solution control method of a six-freedom cascade mechanical arm. Characteristics of rotation and translation of a three-dimensional object can be expressed by using a dual quaternion, all rotational joints of the six-freedom cascade mechanical arm are expressed by using the dual quaternion through conversion, a conversion relationship of the rotational joints and the dual quaternion of the six-freedom cascade mechanical arm is determined, and an equation is determined by using links among rotational joints for solving a reversal solution. The position reversal solution control method of the six-freedom cascade mechanical arm has the advantages of better instantaneity and high accuracy.

Techniques for concatenating, interpolating and upsampling pose transforms represented as dual quaternions are described, including: (1) derivation of a complex-valued matrix form of dual quaternions and dual quaternion operations; (2) derivation of a transformation operator on position vectors which obviates an explicit conversion to a classical 4×4 spatial transformation matrix and keeps results in complex-valued matrix space; (3) design for a generic lookup table system for functions to supply logarithm and exponentiations of the dual quaternion in its native format with trigonometry lookup tables to avoid precision issues when denominators tend to zero; and (4) a mechanism for wrapping the complex-exponentiation together with a simple complex arithmetic unit for computing dual quaternion macro-operations in both native dual quaternion space and through simplifications of the equivalent complex-valued matrix to compute dual quaternion operations such as inverses, multiplications, logarithms and exponentials in order to chain the pose transformations encoded within.

The invention discloses a method for generating a dimension balanced jacobian matrix of a general six-axis parallel mechanism based on dual quaternions. Optimum design is carried out to the moving performance of a six-axis vibration isolation platform. Rotation and movement of a tail end executer are expressed by using two quaternions. The standard of a dimension scaling factor is defined as the norm ratio of the two quaternions; the dimension balanced jacobian matrix is exported. The isotropy of partial kinematics is taken as a performance index; and the optimized vibration isolation platform has the minimum movement coupling.

Methods and systems for two-phase skinning of an object undergoing rigid and non-rigid transformations are disclosed. One method of skinning the object may include separating the object's joint transformations into rigid and non-rigid parts by determining if a joint is scale compensating or scale non-compensating, applying non-rigid joint transformations to the mesh, and applying rigid joint transformations to the mesh. Separation of the object's joint transformations into rigid and non-rigid parts may include determining a bind pose based on an initial configuration of the object's joints and determining an intermediate pose based on the configuration of the object's joints after non-rigid joint transformations are applied to the joints.

The invention provides an inertial navigation system transfer alignment modeling method based on dual quaternion. A nominal dual quaternion between a main inertial navigation system and an auxiliary inertial navigation system is constructed, the dual quaternion is calculated to describe an auxiliary inertial navigation system carrier system relative to a main inertial navigation system carrier system, rotation and translation motion of the carrier systems are calculated, and a normal dual quaternion differential equation of transfer alignment is constructed by reasoning spinor expressions of relative rotation and translation motion of the main inertial navigation system and the auxiliary inertial navigation system and calculated; a dual quaternion error equation is obtained in combination with an accelerometer parameter error equation and a gyroscope error differential equation; a systematic observation equation is constructed by using the linear velocity of an accelerometer and the angular velocity of rotation of a gyroscope, an initial calibration parameter of the auxiliary inertial navigation system is calculated through kalman filter iteration, the effects of rotation and translation separation calculation on coning errors and sculling errors are eliminated, and the calculation accuracy and the calculation efficiency are effectively improved.

The invention discloses a dual quaternion solution of six degrees of freedom parallel robot forward kinetics. According to the method, dual quaternions are taken as generalized coordinates of a parallel robot system, a forward kinetic equation set is a quadratic algebraic equation about the dual quaternions, a high-efficiency value algorithm is brought forward for the equation set, and least square solutions of the position and attitude of such a six degrees of freedom parallel robot motion platform can be rapidly calculated. For a parallel robot not including redundancy driving, a least square solution is also an exact solution.

The invention provides a hand motion three-dimensional simulation method based on dual quaternion. The hand motion three-dimensional simulation method comprises the following steps of: (1) inputting a virtual hand grid model for modeling and a motion skeleton model corresponding to the virtual hand grid model; (2) determining an initial position of each vertex in the virtual hand grid model and normal of each vertex; (3) calculating dual quaternion of each joint point in the motion skeleton model; (4) aiming at each vertex in the virtual hand grid model, searching the dual quaternion corresponding to the skeleton which is bound with each vertex and assigning respective weight value, and then calculating the dual quaternion after linear mixture; (5) unitizing the double quaternion after linear mixture; and (6) calculating vertex positions and normals after deformation of all the vertices for hand three-dimensional simulation. The hand motion three-dimensional simulation method recalculates the positions and normals after the deformation of the vertices for hand three-dimensional simulation by calculating and unitizing the double quaternion after the linear mixture so as to enable a virtual hand to have stronger motion and visual reality sense and avoid the phenomena such as wrapping with candy wrappers and collapse.

The invention comprises a learned model of human body shape and pose dependent shape variation that is more accurate than previous models and is compatible with existing graphics pipelines. Our Skinned Multi-Person Linear model (SMPL) is a skinned vertex based model that accurately represents a wide variety of body shapes in natural human poses. The parameters of the model are learned from data including the rest pose template, blend weights, pose-dependent blend shapes, identity-dependent blend shapes, and a regressor from vertices to joint locations. Unlike previous models, the pose-dependent blend shapes are a linear function of the elements of the pose rotation matrices. This simple formulation enables training the entire model from a relatively large number of aligned 3D meshes of different people in different poses. The invention quantitatively evaluates variants of SMPL using linear or dual quaternion blend skinning and show that both are more accurate than a BlendSCAPE model trained on the same data. In a further embodiment, the invention realistically models dynamic soft-tissue deformations. Because it is based on blend skinning, SMPL is compatible with existing rendering engines and we make it available for research purposes.

The invention discloses a method for compressing matrixes through dual quaternions. The method mainly includes the steps that a CPU calculates the matrixes to be transformed, namely calculates vertex data information to be processed and decomposes each matrix into two quaternions after obtaining a matrix list; the solved quaternions are transmitted to a GPU, and new vertex data information (namely new positions of vertexes) are obtained through rotation, translation and shrinkage transformation. By the utilization of the method for compressing the matrixes through the dual quaternions, the defects that in the prior art, the calculation process is complex, occupied internal storage is large and the application range is narrow are overcome, and the method has the advantages that the calculation process is concise, occupied internal storage is small and the application range is wide.

The invention discloses a LiDAR point cloud no-initial-value registration method based on planar feature constraint. According to the invention, expression of plane features in a three-dimensional space is realized by adopting a four-parameter method; parameters of homonymous plane features of the registered adjacent observation stations are equal to serve as constraint conditions, a three-dimensional space similarity transformation objective function based on dual quaternion description under plane feature constraint is constructed according to the least square criterion, and non-initial-value solving of the registration parameters is achieved through extreme value analysis of the objective function. The four-parameter expression of the plane features provides a simpler and more effective mode for the comparison of homonymous features; compared with a vector algebra, the spatial similarity transformation model based on dual quaternion description is simpler in expression form and fewer in additional constraint conditions in the registration process; compared with an iteration method, the algorithm has the advantages that the parameters are directly solved on the premise that the initial values of the parameters of the space similarity transformation model do not need to be determined in advance, the stability of the algorithm is better, and the reliability is higher.

The invention discloses a Mars DEM making and strip aerial triangulation method. According to the method, a mars probe laser-measured height data is used as the basic data source, the basic data source is subjected to conversion between mars geographical coordinates and mars tangent plane coordinates, and then, a high-precision mars DEM is generated by interpolation, and thus, the current blank space of mars DEM in China is solved; strip aerial triangulation is carried out through dual quaterion, the posture and the relative position of a time sequence analog image are uniformly processed by dual quaternion, integral geometric meaning is provided, and the iterative operation process is independent from the initial value, so that orientation elements and encrypted point coordinates of high-precision mars sequence image can be obtained.

The invention provides a motion mapping method of a heterogeneous master and slave system. The method comprises the following steps of S1, acquiring the direction data of each connecting rod of a master arm, and determining the posture of the master arm corresponding to the direction data; S2, based on a unit dual quaternion, adopting the direction data of each connecting rod of the master arm asthe input, and mapping the posture of the master arm as the posture of a slave arm by adopting the forward kinematics FK algorithm and the inverse kinematics IK algorithm. Based on the motion mappingmethod and the motion mapping system of the heterogeneous master and slave system, the unit dual quaternion is combined with the forward kinematics FK and the inverse kinematics IK, and then the posture of the master arm is successfully mapped into the posture of the slave arm. The algorithm is simple and effective, and the method is easy to realize.

The invention relates to a geometric deformation based skin deformation method for a three-dimensional animated character model. The method comprises the steps that according to the skeleton structure of an initial character model, the initial character model is divided into joint areas and bone areas, and deformation control points among the bone areas are calibrated manually; according to the body zoom parameters set by a user and the calibrated deformation control points, geometric deformation is implemented on the bone areas of the initial character model based on a free deformation technology; after the geometric deformation, influence of joints on apexes is adjusted; and according to the influence of the joints on the apexes of the joint and bone areas, the character model is driven to make translational and rotary movement via a dual-quaternion method to generate vivid and lifelike skin deformation effect. The skin deformation method of the invention can overcome the defects as collapse and shape explosion caused by large moving amplitude of the model, and obtains more real skin deformation while ensuring the instantaneity.

The invention discloses a method for identifying position-independent errors of double rotating shafts of a cradle-type five-axis machine tool. The invention discloses a method for detecting the position-independent errors of double rotary tables of the cradle-type five-axis machine tool at any rotating shaft position, and the method is characterized in that a universal double-rotary-table linkage track is designed by utilizing a ball bar instrument aiming at the cradle-type five-axis machine tool with any rotary table axis position structure, a kinematics error model between a workpiece end and a cutter end is established according to a global representation form of unit dual quaternion and the error definition, the problem that the motion of the ball bar instrument and the collection rate are not synchronous is solved through the uniform differentiation processing of a motion track, and the simplified error kinematics model is decoupled based on a least square algorithm in combination with the experimental data of the ball-bar instrument so as to identify the position-independent combination error of the double rotary tables. According to the method, the position-independent geometric error identification is carried out through a single experiment track, the method is suitable for various cradle-type five-axis machine tools with any rotating shaft position structures, and the method is simple and rapid and is good in practicability.

The invention relates to a non-cooperative spacecraft pose integrated estimation and inertial parameter determination method, and provides a non-cooperative spacecraft pose and inertial parameter estimation method based on dual quaternion aiming at the problem of missing of relative angular velocity and relative linear velocity measurement information of a target spacecraft in a visual navigation process. The method comprises the following steps: a space rigid spacecraft six-degree-of-freedom attitude kinematics and dynamics model described by a dual quaternion frame is established for accurately describing an inherent coupling relationship between relative attitude motion and relative position motion; then error amounts of a dual quaternion vector part, a dual angular velocity vector part and a rotational inertia ratio of the target spacecraft are selected as state variables, and a state equation and an observation equation are determined; finally, a state correction method of error dual quaternion is given, a multiplicative extended Kalman filter is designed, the real-time pose and inertial parameters of the target spacecraft are estimated online, and the on-orbit task execution precision is improved.

The invention discloses an inter-satellite relative pose coupling isomorphism integrated dynamic modeling method for flexible spacecraft formation, relates to a dynamics high-precision modeling methodfor spacecraft formation, in particular to an integrated dynamics modeling method which is used for flexible spacecraft formation, considers the relative pose-structure vibration coupling between formation satellites and is described based on the same mathematical tool. The innovation points of the invention are as follows that firstly, the influence of structural vibration on high-precision formation configuration is considered, and an inter-satellite relative position-relative attitude-structural vibration coupling kinetic model is established; secondly, on the basis of a dual quaternion mathematical tool, relative position motion, relative attitude motion and structural vibration among satellites are unified to be under the same mathematical framework, and an isomorphic integrated dynamic model is obtained.

The invention discloses a knowledge graph link prediction method and system based on dual quaternions, and the method comprises the steps: loading data and analyzing the data, and obtaining triple data of a knowledge graph; performing training and parameter adjustment on a preset dual quaternion knowledge graph model according to the triple data of the knowledge graph to obtain a trained dual quaternion knowledge graph model; and predicting the to-be-tested triad according to the trained dual quaternion knowledge graph model to obtain a prediction result. The system comprises a data loading module, a model training module and a link prediction module. By using the method and the device, the problem that a plurality of relations exist between the head entity and the tail entity in the knowledge graph can be effectively solved by effectively utilizing the characteristics of the dual quaternion. The knowledge graph link prediction method and system based on the dual quaternion can be widely applied to the field of knowledge graphs.

The invention discloses a point cloud registration method and system based on a feature extraction module and dual quaternion, and the method comprises the steps: reading 3D point cloud data from a data set, and obtaining the three-dimensional coordinates and category labels of points contained in each sample; randomly sampling points contained in each sample to obtain a template point cloud; translating and rotating the template point cloud to obtain a source point cloud, and dividing the source point cloud and the template point cloud into a training set and a test set according to the category label of the sample; constructing a point cloud registration model based on the feature extraction module and dual quaternion, and constructing a loss function of the point cloud registration model; and training a point cloud registration model by using the divided training set, and performing point cloud registration on the divided test set by using the trained point cloud registration model. According to the method, global and local information in the point cloud is fully mined, and the deficiency of local features in a global feature extraction stage of point cloud registration is effectively made up.

The invention discloses a view registration method, system and equipment based on dual quaternion and a storage medium, and the method comprises the steps of obtaining the multi-frame point cloud data, and selecting a first frame point cloud in the multi-frame point cloud data as a world coordinate system; performing any two adjacent frames of registration by adopting an ICP algorithm to obtain each frame of point cloud data and a registration processing result; obtaining the rigid transformation by adopting a dual quaternion mixing method; obtaining new multi-frame point cloud data; adoptingan ICP algorithm to obtain new multi-frame point cloud data and a registration processing result; and judging whether the registration processing result converges or not until the registration processing result converges. According to the method, the problem of registration failure caused by the fact that data cannot be converged in the registration process only by adopting an ICP algorithm in theprior art is solved; and through fusion of a dual quaternion mixing method and an ICP algorithm, the registration errors generated in a multi-view pairwise registration process are reduced, so that the registration precision is improved.

The invention discloses an overall rigidity modeling method for a six-axis industrial robot hole making system comprising an operation tool, and the method comprises the following steps: obtaining a robot equivalent joint rigidity matrix according to a virtual joint method; a robot body stiffness matrix is obtained according to the dual quaternion; obtaining an operation tool stiffness matrix according to the Euler-Bernoulli beam theory; and obtaining an overall rigidity model of the six-axis industrial robot drilling system comprising the operation tool according to a linear superposition principle. According to the method, the integrity and the accuracy of rigidity modeling of an industrial robot hole making system can be improved, an overall rigidity modeling method including an operation tool is provided for optimizing the hole making rigidity of a six-axis industrial robot, and a new thought is provided for overcoming insufficient rigidity of robots and improving the machining precision and the machining quality in the intelligent manufacturing industry.