669 results about "Inverse kinematics" patented technology

A suitable waypoint is selected using a goal score, a section from a start point to a goal point through the waypoint is divided into a plurality of sections based on the waypoint with a solution of inverse kinematics, and trees are simultaneously expanded in the sections using a Best First Search & Rapidly Random Tree (BF-RRT) algorithm so as to generate a path. By this configuration, a probability of local minima occurring is decreased compared with the case where the waypoint is randomly selected. In addition, since the trees are simultaneously expanded in the sections each having the waypoint with a solution of inverse kinematics, the solution may be rapidly obtained. A time consumed to search for an optimal motion path may be shortened and path plan performance may be improved.

A robotic system for steering a flexible needle during insertion into soft-tissue using imaging to determine the needle position. The control system calculates a needle tip trajectory that hits the desired target while avoiding potentially dangerous obstacles en route. Using an inverse kinematics algorithm, the maneuvers required of the needle base to cause the tip to follow this trajectory are calculated, such that the robot can perform controlled needle insertion. The insertion of a flexible needle into a deformable tissue is modeled as a linear beam supported by virtual springs, where the stiffness coefficients of the springs varies along the needle. The forward and inverse kinematics of the needle are solved analytically, enabling both path planning and correction in real-time. The needle shape is detected by image processing performed on fluoroscopic images. The stiffness properties of the tissue are calculated from the measured shape of the needle.

The invention provides a redundant manipulator motion planning method which comprises the following steps that: (1) an upper computer analyzes the inverse kinematics of a manipulator on a velocity layer through quadratic optimization, the designed minimum performance index can be velocity norm, repetitive motion or kinetic energy and is bound by a velocity jacobian equation, an inequation and a joint angular velocity limit, and the angular velocity limit changes with a joint angle; (2) the quadratic optimization of step (1) is optimized into a quadratic programming problem; (3) the quadratic programming problem in step (2) is calculated by a linear variational inequation primal-dual neural network solver or a numerical method; and (4) the calculation result in step (3) is transmitted to a lower computer controller to drive the manipulator to move. The redundant manipulator motion planning method is based on the primal-dual neural network of the linear variational inequation, has global exponential convergence, does not involve matrix inversion and other complicated operations, greatly improves the calculation efficiency, and simultaneously has strong real-time performance, and can adapt to the changes to the joint angular velocity limit.

The invention relates to a genetic-algorithm-based trajectory planning optimization method for a mobile mechanical arm. According to the technical scheme, the method comprises the following steps of first establishing a forward kinematic model and an inverse kinematic model of a multi-degree-of-freedom mobile mechanical arm; then fitting a joint trajectory by adopting a composite curve of a quartic polynomial mathematical model and a quintic polynomial mathematical model, and calculating solutions of the corresponding mathematical models according to a linear constraint equation; next selecting a trajectory optimization target according to the principles of shortest motion time, minimum spatial motion distance and less than or equal to maximum set joint torque of the mobile mechanical arm; and finally globally optimizing the optimization target by utilizing a genetic algorithm to obtain an optimal trajectory curve of an end actuator of the mechanical arm. According to the method, the trajectory planning efficiency and the tracking accuracy of the mechanical arm are improved, and the problems of real-time trajectory planning of the mobile mechanical arm and trajectory planning optimization and control of the mechanical arm in an uncertain environment are also solved; and the trajectory planning optimization method for the mobile mechanical arm is effective.

The invention discloses a gait planning method for walking of a biped robot along a slope, and belongs to the technical field of robots. The method contains two core theories, namely, non-orthogonal decomposition and synthesis of a three-dimensional linear inverted pendulum and gait planning based on a biped long linear inverted pendulum. The method comprises the steps of gait parameter configuration, non-orthogonal decomposition of a three-dimensional linear inverted pendulum, foot trajectory planning based on three times of spline interpolation, centroid trajectory planning of a sagittal plane and a coronal plane based on a biped long linear inverted pendulum, non-orthogonal synthesis of the centroid trajectories of the sagittal plane and the coronal plane, and solving of joint trajectories of a robot based on inverse kinematics. By adopting the method of the invention, stable walking of a biped robot along all directions of a slope can be effectively achieved. The method is universal, simple in algorithm and high in practicality.

A robotic system for flexible needle steering under ultrasound imaging. A robot is used to steer the needle along a predetermined curved trajectory by maneuvering the needle base. The needle tip position is detected by an ultrasound sensor and the tracking error of the needle tip from a predetermined needle path is input to a controller which solves the inverse kinematic based on the needle position, and the needle and tissue properties. The control algorithm uses a novel method to detect the elastic properties of the tissue by analyzing tissue motion at the region in front of the needle tip. The inverse kinematic solution may be performed on a model of the needle as a flexible beam having laterally connected virtual springs to simulate lateral forces exerted by the tissue elasticity. The system is able to direct the needle to a target within the tissue while circumventing forbidden regions.

The invention discloses a control method, equipment, a system, and construction machinery for a multi-joint mechanical arm support. The control method mainly comprises the steps that a moving track path of the tail end of the mechanical arm support is divided into a plurality of sub track paths; aiming at each sub track path, the length value that the tail end of the mechanical arm support can move within a set duration, and current position information of each joint of the mechanical arm support is collected to calculate the required moving angle information of each joint of the mechanical arm support under the position information of subgoals capable of being reached by the tail end of the mechanical arm support; the obtained angle information of each joint in converted into control instructions, so that each joint of the mechanical arm support is controlled to move; the track path of the tail end of the mechanical arm support is subjected to discrete programming; and aiming at the sub track paths after programming, the moving angle information of each other joint of the mechanical arm support are determined according to the inverse kinematic principle. Therefore, the operation stability of the tail end of the arm support is guaranteed sufficiently, and the control precision for the tail end of the multi-joint mechanical arm support is improved.

The invention discloses a method for quick solution of six-degree-of-freedom humanoid dexterous arm inverse kinematics. The method includes: firstly, setting up a six-degree-of-freedom human arm simulated joint structural model, solving an elbow joint angle and two joint angles of the shoulder joint according to a planar relation formed by the shoulder center, the elbow center, the wrist center and the neck center of the dexterous arm and the tail end position of the dexterous arm, and further solving three joint angles of the wrist joint by the aid of the dexterous arm tail-end posture relation; and calculating position error of a dexterous arm target link to prove effectiveness of the solution of the inverse kinematics by means of a positive kinematic model. Compared with a numerical solving method for robot inverse kinematics, the method for quick solution of six-degree-of-freedom humanoid dexterous arm inverse kinematics is high in precision and quick in speed, and can be used for humanoid dexterous arm operational tasks having high requirements on precision and instantaneity.

The invention provides a hot-line work robot control system based on dual mechanical arms and an auxiliary arm. The first mechanical arm, the second mechanical arm and the auxiliary mechanical arm each carry a binocular camera; the binocular cameras are used for acquiring operation scene images of the mechanical arms and sending the operation scene images to a data process and control system; the data process and control system plans a mechanical arm spatial path according to the operation scene images; according to a specific method, the tail end positions of the mechanical arms and an operation target position are converted into a same reference coordinate system, and the coordinate difference between the tail end positions of the mechanical arms and the operation target position under the same reference coordinate system is acquired; and according to the coordinate difference, the angle expected value of each joint of the mechanical arms is solved out through an inverse kinematic computing method. According to the hot-line work robot control system based on the dual mechanical arms and the auxiliary arm, based on a method in which binocular vision is combined with coordinate conversion, the mechanical arms are autonomously controlled to complete the hot-line work target of a distribution line, the labor intensity of operation personnel is relieved, and safety is improved.

A method of controlling a redundant manipulator for assigning one or more redundant joints from a plurality of joints and obtaining the solution to an inverse kinematics problem at high-speed. The joints are arbitrarily classified into redundant joints and non-redundant joints, and an initial value is set for the joint angle of the classified redundant joint as a parameter. Then based on an evaluating function or a constraint condition defined by the joint angle of the redundant joint provided as a parameter and the joint angle of the non-redundant joint, which is determined by the inverse kinematics calculation according to the change of the parameter, an optimum solution of a set of joint angles is determined, and until the optimum solution covers the target range of the hand position, the procedure to determine the optimum solution is repeated with relaxing the constraint conditions.

The invention relates to an industrial robot positioning precision calibration method used for improving robot absolute positioning precision. The method comprises the steps that: a robot kinetics model is established; a rotary joint equation is established by using a circumferential method; joint torsion angle parameter values are calculated; the actual pose of a robot end is measured accurately by utilizing a laser tracker; D-H algorithm inversion kinetics equation is improved to obtain geometrical structural parameters; calibration of joint distance parameter values and calibration of joint offset are realized, and thereby first calibration is completed. Error correction is carried out on D-H parameters based on first calibration results, and if positioning precision can not meet requirements, second calibration can be carried out by substituting parameter correction values, instead of theoretical parameter values, into the kinetics equation. Absolute positioning precision of the robot is improved with the calibration method, which is proved in experiments. According to the invention, the calibration method is advantaged in that the method is simple and practical and introduces small external errors.

The present invention is typically embodied to exert active control of two same-shipboard cranes performing joint lifting of a payload. Sensory signals indicative of ship motion, and of luff angle and hoist line length of both cranes, are transmitted to a computer. The sensory signals are processed by the computer using a ship motion cancellation algorithm, which solves for values of the respective luff angles and hoist line lengths of both cranes, such values achieving static equilibrium (e.g., zero motion horizontally, vertically, and rotationally in the same vertical geometric plane) of the suspended payload. Inverse kinematic control signals in accordance with the mathematical (e.g., minimum norm) solutions are transmitted by the computer to respective luff angle actuators and hoist line length actuators of both cranes so that the suspended payload tends toward steadiness. Inventive control thus acts on a continual basis to significantly reduce pendulation during the two-crane lifting operation.

The invention discloses a method for uniquely solving the inverse kinematics numerical value of the joint type mechanical arm, belongs to the technical field of modern intelligent manufacturing, relates to the technical field of industrial robots, relates to a method for uniquely solving the inverse kinematics numerical value of a joint type six-degree-of-freedom mechanical arm with shoulder joints facing forward. According to the method, a mechanical arm joint coordinate system is built according to an improved DH parameter method, four structural geometrical parameters between adjacent joints of the mechanical arm are determined, a homogeneous coordinate transformation matrix of two adjacent coordinate systems is calculated. For a given pose matrix of a tail end coordinate system O6, animproved newton iteration method, namely a Levenberg marquardt iterative algorithm is adopted, the inverse kinematics solution of the joint coordinate system is calculated by using a jacobian matrix J, and the six joint rotation angle values theta i which correspond to the pose matrix and meet the precision requirement are obtained. The method overcomes the requirement that a traditional newton iteration method needs to fully rank the jacobian matrix j, the modeling method is simple, clear and effective, the method has the characteristics of being high in solving precision, high in solving speed and simple and feasible in solving process.

The invention discloses a redundancy dual-mechanical-arm multi-index coordinate exercise planning method. The method includes the steps that (1) based on a target problem, quadric form prioritization schemes are adopted for an upper computer to conduct inverse kinematics analysis on double mechanical arms on the speed layer, designed performance indexes are formed by the weighted array of three indexes including a minimum velocity two-norm, repeating motion and a minimum velocity infinite norm, and the performance indexes are limited to the kinematical equations, the joint angle extremities and the joint angle velocity extremities of the double mechanical arms correspondingly; (2) the quadric form prioritization schemes of the double mechanical arms in the step (1) are converted into standard quadratic programming problems; (3) the quadratic programming problems of the double mechanical arms in the step (2) are unified into one quadratic programming problem; (4) the unified quadratic programming problem in the step (3) is solved with a simplified original dual neural network solver based on the linear variational inequality; and (5) a solving result in the step (4) is transmitted to a lower computer controller to drive the double mechanical arms to move.

The present invention provides an animation creation program whereby the posture of a structure comprising a plurality of links can be determined by means of a simpler and easer operation. In accordance with the movement of one link in the structure comprising a plurality of links, the animation creation program of the present invention automatically determines the spatial positions of the other links of the structure so that the structure retains a posture that is as natural as possible. The animation creation program of the present invention uses, for example, inverse kinematics computation that is a computation method for controlling a human-type robot (humanoid) and is based on a matrix known as a Jacobian and the inverse matrix thereof which is known as the Singularity-Robust Inverse (SR-Inverse). By using this computation method in an animation creation program, in the creation of an animation of a structure comprising a plurality of links, it is possible, when moving one link of a structure displayed on a screen, to automatically determine the positions of the other links of the structure so that the posture of the structure as a whole does not become unnatural, and to create an animation of the structure comprising a plurality of links by means of a simpler and easer operation.

The invention provides an inverse-kinematics universal solving method of a robot with multi-degree of freedom. The common space theory is used for setting a universal kinematical equation of an nR robot, the weighted space vector projection method is used for analyzing the relationship between space vector projection values and revolute joint angles of a space robot, projection weighted values of joint vectors on robot tail end vectors are used as the basis for regulating the tail end pose of the robot, and projection weighted values of joint vectors are determined to achieve half-analytic solution of the inverse kinematics. The method achieves kinematical salvation of the nR robot and also finishes the space obstacle avoidance task. The method can be widely applied to series type space nR robots, has the advantages of being high in calculation speed and high in solving precision, provides control input parameters for series type robots, and meets the requirement for robot kinematics solving operation on industrial sites.