45 results about "Singularity avoidance" patented technology

The invention relates to an angular momentum management method for a variable-speed control moment gyroscope (VSCMG). A technical scheme is described as follow. An angular momentum management algorithm for the VSCMGs is designed to mainly solve the following problems: mixed mode instruction torque output based on singularity measurement, zero-motion rotor wheel speed balance, zero-motion frame configuration singularity avoidance, frame angular velocity dead-zone nonlinear processing and neglected item compensation, and gives corresponding theoretical analysis. The mixed mode of the VSCMGs gives full scope to the large torque output of the control moment gyroscope and large-angle fast attitude maneuver operation can be achieved by using the steering law. The present invention provides a novel VSCMGs angular momentum management algorithm which is improved significantly in torque output accuracy, angular velocity tracking, and frame singularity avoidance compared with a conventional angular momentum management algorithm, and which has a good engineering value.

A path programming method for a plane redundancy robot to avoid obstacles and avoid singularities relates to the field of robot motion control, and especially relates to a plane redundancy robot to avoid obstacles and avoid singularities. The invention aims to solve problems that risk of hurting working personnel by existing plane redundancy robots exists in a cooperation process and the speed of joints will exceed a robot allowance scope when the end of the robot moves to a singular position. The method of the invention is carried out according to the following steps: the method of the invention relates to threads which are carried out simultaneously: the first thread relates to several steps of path programming to avoid obstacles; and the second thread relates to various steps of path programming to avoid singularities. The method of the invention ca simultaneously complete the path programming method of obstacle avoidance and singularity avoidance, so that in a cooperation process, collaborator avoidance can be completed, and avoiding of singular configuration of the robot can also be realized to reduce risks of man-machine cooperation and raise the assembling quality. The method of the invention can be applied to the field of robot motion control.

The invention discloses a mechanical arm autonomous robust singularity avoidance method for improving path tracking performance. The method comprises the steps that a maneuverable ellipsoid of a mechanical arm is built according to an inverse kinematics model of the mechanical arm and a mechanical arm speed model, wherein the semi-major axis of the maneuverable ellipsoid is in the direction of theU longitudinal row of a unitary matrix, and the length of the semi-major axis corresponds to singular value of a Jacobian matrix; and then the path of an end effector is amended in the mth spindle direction of the maneuverable ellipsoid, and the singularity avoidance path of the mechanical arm is built. The method can be used for planning the autonomous singularity avoidance path of the mechanical arm, can keep the tracking performance of the path, and can also achieve the multi-task singularity avoidance path planning on the basis of task priority based on the method.

The invention provides a teleoperation system fractional order sliding mode synchronous control method based on an event trigger mechanism. The method comprises the steps: building a kinetic model of a teleoperation system through considering external disturbance and parameter uncertainty; selecting master and slave robots, interactively establishing a teleoperation system through a communication network, and determining system parameters of the kinetic model; designing a fractional order nonsingular fast terminal sliding mode surface equation by utilizing the position tracking error and the fractional order calculus; setting trigger event conditions of master and slave robot information interaction, and designing an adaptive fractional order nonsingular fast terminal sliding mode controller based on a sliding mode; and designing a Lyapunov function for stability analysis, and proving the boundness of a closed-loop state signal of the system. According to the teleoperation system fractional order sliding mode synchronous control method, the singular problem can be solved, the degree of freedom of the controller is expanded, the convergence speed is increased, the control precision is improved, the buffeting problem existing in the integer-order sliding mode surface is reduced, the applicability is higher, the occupation of network bandwidth and communication resources is reduced, and the resource utilization rate is increased.

A method is described for avoiding gyroscopic singularities during attitude correction to a system, such as a spacecraft having a CMG array. The method receives a corrective torque vector μ and gimbal angle values δ for each of at least three gimbals within the CMG array. The method generates a Jacobian matrix A as a function of gimbal angle values δ. The method calculates a determinant D of Jacobian matrix A. If the determinant is not equal to zero, it is not singular, and the method calculates a gimbal rate {dot over (δ)} using a pseudo-inverse steering law equation. If the determinant is equal to zero, it is singular, and the method calculates a gimbal rate {dot over (δ)} using a singularity avoidance steering law equation. The gimbal rate {dot over (δ)} is output and can be applied to a CMG array resulting in applied torque to a spacecraft and attitude correction.

The invention discloses a method for confirming the motion mode of a corresponding free node at a singular configuration part of a hinge bar system mechanism. The method comprises the following steps of: carrying out second-order derivation on a coordination function which is dependent from a mechanism to describe the corresponding free node variable quantity, to judge whether the second-order derivative is equal to zero or not at the singular configuration place, if the second-order derivative is equal to zero, the corresponding free node at the singular configuration part can move like a limiting mechanism; and if the second-order derivative is not equal to zero, the corresponding free node can move like a first-order infinite small mechanism. According to the method, the motion mode of the corresponding free node at the singular configuration place of the hinge bar system mechanism can be confirmed, the motion mode of the mechanism at the singular configuration place can be basically confirmed, the method is high in operability, the basis is provided for the singularity avoidance and the structure design of the novel space structure, and the research of the mechanism singularity and the motion bifurcation has an important impelling action, so that the method is wide in application prospect.

Devices, systems, and methods for providing commanded movement of an end effector of a manipulator concurrent with a desired movement of one or more joints of the manipulator according to one or more consolidated null-space objectives. The null-space objectives may include a joint state combination, relative joint states, range of joint states, joint state profile, kinetic energy, clutching movements, collision avoidance movements, singularity avoidance movements, pose or pitch preference, desired manipulator configurations, commanded reconfiguration of the manipulator, and anisotropic emphasis of the joints. Methods include calculating multiple null-space movements according to different null-space objectives, determining an attribute for each and consolidating the null-space movements with a null-space manager using various approaches. The approaches may include applying weighting, scaling, saturation levels, priority, master velocity limiting, saturated limited integration and various combinations thereof.

The invention relates to the field of vehicle rollover prevention, in particular to a vehicle anti-rollover method based on a control moment gyroscope. When a vehicle turns or is under external interference stimulation, a measurement device detects the response of the vehicle, the own suspension mechanism dynamics of the vehicle can be combined to estimate the state of the vehicle through a vehicle rollover model, the control moment gyroscope generates torques of thousands of N.m for keeping the balance of a vehicle body, and therefore, the vehicle is free from rollover under any situation even under a collision situation. A rollover judgment system can accurately estimate the tilt state of the vehicle so as to judge vehicle rollover. Meanwhile, the own mechanism characteristics of the vehicle are fully considered. Through a continuous anti-rollover moment output by the control moment gyroscope, the vehicle is free from rollover under any situation even under the collision situation, and a corresponding control algorithm can guarantee singularity avoidance and accurate moment output.

The invention discloses a general avoidance method and system for a singular point of a mechanical arm, and belongs to the technical field of avoidance of singular points of mechanical arms. The technical problem to be solved is to provide the improvement of the general avoidance method for the singular point of the mechanical arm. According to the technical scheme for solving the technical scheme, the method comprises the following steps that a kinematic model of the mechanical arm is established, a reference joint coordinate system is established, the spinor of each joint is calculated according to the spinor theory, and a Jacobian matrix is solved; a condition number is calculated by using a joint angle value of a tracing point and the Jacobian matrix; the condition number is used for judging whether the mechanical arm is close to the singular point or not, and after it is judged that the mechanical arm is about to approach the singular point, the mechanical arm uses a singularity avoidance algorithm to calculate a singularity avoidance tracing point till the condition number of the Jacobian matrix of the generated tracing point meets the state of being away from the singular point and the tracing point returns to an original Cartesian trajectory again; and after the singularity avoidance trajectory is planned, smoothing processing and trajectory interpolation are conducted on the planned singularity avoidance trajectory, and a final singularity avoidance trajectory is obtained; The invention is applied to the mechanical arm.

The invention provides a two-wheel single-track carrier static balance control system and method. The two-wheel single-track carrier is of a double-SGCMG parallel symmetrical structure, the two-wheel single-track carrier static balance control system is provided with a first frame motor, a second frame, a first control moment gyroscope and a second control moment gyroscope, the first control moment gyroscope and the second control moment gyroscope correspond to the first frame motor and the second frame respectively, and the first frame motor is provided with a first rotor; the second frame has a second rotor; the two-wheeled single-track vehicle static balance control system comprises a frame desaturation and singularity avoidance controller which executes the following calculation and control of calculating a frame angle error; calculating a bias angle for realizing frame desaturation and singularity avoidance based on the frame angle error; a bias angle being added to the input of the angle loop controller.