12 results about "Dual quaternion" patented technology

The invention discloses a gait recognition method based on a Pluecker straight line, and belongs to the technical field of computer vision and biological feature recognition. The core of the method is to provide a double-layer gait feature modeling framework. The method comprises the following steps: firstly, modeling human skeletons into spatial straight lines by utilizing Pluecker coordinates, and calculating absolute rigid body motion characteristics of each skeleton between adjacent frames through dual quaternions; furthermore, by combining the absolute motion characteristics of adjacent bones, the relative motion characteristics of the joints, which can better reflect the physiological characteristics of individuals, are calculated. And finally, aggregating the two complementary features to construct a gait feature sequence, and completing identity recognition by using a time sequence deep learning model. According to the method, the overall motion information and the local joint motion information are separated and fused, so that the defects that an existing method is incomplete in feature representation and is greatly interfered by the overall motion are effectively overcome, and the accuracy, the discrimination capability and the robustness of gait recognition are remarkably improved.

This invention relates to a method for solving the inverse kinematics of a six-DOF offset serial manipulator based on dual quaternions, belonging to the field of manipulator design technology. The method is as follows: Six-DOF offset serial manipulators are classified into Type I and Type II. A reference coordinate system and an end-effector coordinate system are established for each type. The link lengths, position coordinates, unit direction vectors, and line spacings of each joint are defined, thus obtaining the Plück coordinates of each joint. Inverse kinematics analysis and solutions are performed for both Type I and Type II manipulators. The solution method is then validated. This invention achieves efficient inverse kinematics solving, meeting the real-time requirements for inverse kinematics solving speed in industrial scenarios and improving the control performance and application efficiency of manipulators in high-precision operation scenarios.

The invention discloses an inverse kinematics solving method for a six-degree-of-freedom bias type series mechanical arm based on dual quaternions, and belongs to the technical field of mechanical arm design. The method comprises the following steps that the six-degree-of-freedom offset type series mechanical arms are classified, and the six-degree-of-freedom offset type series mechanical arms comprise the I-type six-degree-of-freedom offset type series mechanical arms and the II-type six-degree-of-freedom offset type series mechanical arms; respectively establishing a reference coordinate system and a tail end coordinate system, and defining the connecting rod length of each joint of the mechanical arm, the position coordinate of each joint, the unit direction vector of each joint and the line distance of each joint to obtain the Pluecker coordinate of each joint; the I-class six-degree-of-freedom bias type series mechanical arm and the II-class six-degree-of-freedom bias type series mechanical arm are respectively subjected to inverse kinematics analysis and solution; and verifying the solving method. According to the method, efficient solving of inverse kinematics is achieved, the real-time requirement for the inverse kinematics solving speed in an industrial scene is met, and the control performance and application efficiency of the mechanical arm in a high-precision operation scene are improved.

This invention relates to a safe obstacle avoidance control method for greenhouse inspection drones. Addressing the camera blind spot avoidance and obstacle collision avoidance constraints in the drone's strategy for monitoring diseased and pest-infested crop areas and inspecting tomato maturity and yield, this invention constructs a geometric relationship between the flight path evolution trajectory and the line-of-sight cone based on dual quaternions. A pose-integrated safe tracking and control scheme based on a geometric control obstacle function is proposed. This includes modeling safe collision avoidance constraints and line-of-sight occlusion avoidance constraints; constructing a geometric control obstacle function based on the motion derivation trajectory using the geometric relationship between the obstacle occlusion line-of-sight cone and the drone's motion state, based on a unified description of dual quaternions; and embedding the safety constraints of the control obstacle function into a quadratic programming solver. This achieves safe collision avoidance while ensuring the camera's line of sight can always monitor the local diseased area, mitigating the risk of obstacle occlusion during flight path monitoring.

This invention discloses a method and application for identifying position-related geometric errors based on multi-dimensional measurement data fusion. The method includes: constructing an actual motion model of the machine tool rotary axis B-axis under the influence of geometric errors based on dual quaternions, and obtaining the first actual position of the tool end target ball in the machine tool coordinate system; determining the second actual position of the tool end target ball in the machine tool coordinate system based on dual quaternions, and obtaining coordinate value expressions of the X, Y, and Z directions of the measurement points of the rotary axis B-axis in the machine tool coordinate system related to position-related geometric errors and position-independent geometric errors; obtaining the coordinates of the measurement points in the built-in coordinate system of the laser tracker using a laser tracker; constructing a least-squares model of geometric errors and the actual distance between the measurement points of the rotary axis B-axis, and solving it using the Powell algorithm; this invention significantly improves the measurement efficiency of the rotary axis.

This invention discloses a pose-coupled path planning method for unmanned aerial vehicles (UAVs) based on dual quaternions. The method uses dual quaternions to uniformly represent the spatial position and three-dimensional attitude of the UAV, achieving pose-coupled modeling. The flight path is discretized into a series of path nodes, and the pose parameter of each node is parameterized as a motion vector. A dual quaternion optimization model is constructed. Through predefined motion operators and unit dual quaternion operators, a mapping is established between the dual quaternion space and the motion vector space, thereby transforming the dual quaternion optimization model into a motion optimization model in the motion vector space. The motion optimization model is iteratively solved in the motion vector space, updating the path node sequence to obtain the optimal path that satisfies all constraints. The optimized path nodes are then smoothed to generate the flight trajectory. This invention significantly improves path planning efficiency and path quality.

The invention discloses a human body lower limb kinematics modeling method based on dual quaternion, and relates to the technical field of biomechanical measurement and motion analysis, and the method comprises the following steps: building a lower limb Pluecker linear model by using binocular vision calibration data; on the basis of real-time visual data, dual quaternions of joint movement are constructed through point cloud registration and relative transformation calculation, and the poses of the limb segments are updated through chain multiplication of the dual quaternions; and performing differential operation on the dual quaternion time sequence to directly solve the dual velocity spinor so as to obtain accurate angular velocity and linear velocity. According to the method, binocular vision data and a unified mathematical framework are combined, the problems that a traditional method is not unified in model and complex in speed solution are solved, efficient and accurate conversion from three-dimensional coordinates to motion parameters is achieved, and the method is suitable for the fields of gait analysis, rehabilitation engineering, robot control and the like.

This invention belongs to the field of spacecraft control technology, specifically relating to a spacecraft formation attitude-orbit coupling predetermined time control method based on dual quaternions. First, a spacecraft relative motion attitude-orbit coupling control system is established. Then, a predetermined time attitude-orbit coupling controller for the spacecraft formation is designed. Finally, based on the coupled dynamics model, the attitude-orbit dual quaternion and dual velocity of each spacecraft are output. These are fed back to the input of the coupling control system, and the differences between these errors and the given desired attitude-orbit dual quaternion and desired velocity are calculated to obtain the dual quaternion error and dual velocity error. Based on these two error states, the predetermined time controller for the spacecraft formation attitude-orbit coupling is calculated, and the predetermined time result of the spacecraft formation attitude-orbit coupling is output. This invention considers model uncertainties and external disturbances by constructing an extended state observer and a predetermined time attitude-orbit coupling controller to achieve predetermined time stability of the spacecraft formation system.

The invention discloses a dual quaternion-based SSRMS configuration mechanical arm inverse kinematics solving method, and belongs to the technical field of mechanical arm design. The method comprises the following steps that a reference coordinate system and a tail end coordinate system are established, the connecting rod length of each joint of the mechanical arm, the position coordinate of each joint, the unit direction vector of each joint and the line distance of each joint are defined, and then the Pluecker coordinate of each joint is obtained; the pose of the tail end coordinate system relative to the reference coordinate system when the mechanical arm rotates is calculated through the dual quaternion; inverse kinematics derivation is conducted when the first joint, the second joint, the sixth joint and the seventh joint are fixed; and verifying the solving method. According to the method, the constraint relation between the rotation angle values is established, the technical bottleneck that multi-configuration optimization and real-time performance are difficult to consider in traditional inverse kinematics solution is broken through, and the inverse kinematics solution speed is remarkably increased while the solution precision is guaranteed.

The application discloses a UAV path planning method based on dual quaternion and block coordinate descent ant colony optimization, the method uniformly represents the position and attitude of the UAV through dual quaternion, constructs a comprehensive cost function containing path length, terrain threat and path smoothness, and utilizes the block coordinate descent ant colony optimization algorithm to perform optimized search on path nodes, thereby improving the convergence efficiency of path planning. Finally, the planned path is subjected to smoothing processing, and the optimal flight trajectory of the UAV satisfying the flight safety constraint is obtained. The method can effectively coordinate the position and attitude planning of the UAV, and improve the solving efficiency and path quality of the path planning in a complex three-dimensional environment.

The SSRMS configuration mechanical arm inverse kinematics solving method based on dual quaternion belongs to the technical field of mechanical arm design. The method is as follows: a reference coordinate system and an end coordinate system are established, the lengths of the connecting rods of each joint of the mechanical arm are defined, the position coordinates of each joint are defined, the unit direction vectors of each joint are defined, the linear distances of each joint are defined, then the Plucker coordinates of each joint are obtained; the dual quaternion is used to calculate the pose of the end coordinate system relative to the reference coordinate system when the mechanical arm rotates; the inverse kinematics derivation of the first joint, the second joint, the sixth joint and the seventh joint is carried out respectively; the solving method is verified. The constraint relationship between the rotation angle values is established, the technical bottleneck that the real-time performance is difficult to consider in the traditional inverse kinematics solving is broken through, and the solving speed of the inverse kinematics is significantly improved while the solving accuracy is ensured.