23 results about "Singularity avoidance" patented technology

The invention provides an unmanned surface vessel recursive terminal sliding mode control method based on a novel disturbance observer, and relates to the technical field of unmanned surface vessels. The method comprises the following steps: firstly, designing a fixed time disturbance observer (FTDO) to suppress model uncertainty and adverse effects of external disturbance; and then an adaptive fixed time disturbance observer (AFTDO) is developed, and the adaptive law does not need lumped disturbance priori knowledge. Different from an existing fast non-singular terminal sliding mode surface (FNTSMs) which adopts a linear sliding mode (LSM) to avoid singularity, the method innovatively constructs a recursive terminal sliding mode surface (RTSM), thoroughly avoids singularity through a recursive structure, and remarkably improves convergence precision and speed near a balance point at the same time. A fixed-time recursive terminal sliding mode controller (FTRTSMC) is designed based on a lumped disturbance estimated value of the AFTDO, and it is strictly ensured that a trajectory tracking error converges to zero within fixed time (convergence time is irrelevant to an initial state).

The invention discloses a singularity-avoiding trajectory planning method for a free floating space mechanical arm, and belongs to the technical field of robot trajectory planning. The method comprises the steps that the expected whole-course tail end position track and posture track of the mechanical arm are obtained; setting a control period and circularly executing; at each control moment, a generalized Jacobian matrix and system singularity measurement are calculated, and whether the system is close to singularity or not is judged; traversing all the possible values of the base postures if the base postures are close to singularity, calculating joint angle states and corresponding singularity measurement which do not change the tail end postures, and searching a system configuration corresponding to the maximum singularity measurement; then, the state of the mechanical arm is reconstructed, and the mechanical arm is made to move to the maximum singularity measurement configuration to be separated from singularity; and calculating the inverse of the generalized Jacobian matrix to obtain velocity inverse kinematics, and further calculating the joint angular velocity and the joint angle at the next moment. According to the method, an accurate trajectory planning effect without introducing any theoretical error is realized while the singularity avoidance capability is ensured.

The invention discloses a singular avoidance control method and device for a six-axis mechanical arm based on virtual seven degrees of freedom. The tail end of the mechanical arm is provided with a virtual rotating shaft which coincides with the original point of a tail end coordinate system and is perpendicular to a rotating shaft of the tail end coordinate system. The control method comprises the steps that position information and angle information of all joints of the mechanical arm and the actual pose and expected pose of the tail end in the current detection period are obtained; based on the position information and the angle information of all the joints, the weight value of the virtual rotating shaft is correspondingly adjusted by combining the state that the mechanical arm approaches the shoulder singular point and / or the wrist singular point, a quadratic programming problem used for avoiding the singular points is reconstructed, and a to-be-executed joint angle increment vector is solved; and on the basis of the to-be-executed joint angle increment vector, the angle value of each joint of the mechanical arm in the next detection period is calculated, and the mechanical arm is controlled to move on the basis of the angle value of each joint so as to avoid shoulder singular points and / or wrist singular points of the mechanical arm.

The invention relates to a universal swing-up stabilization control method for a vertical multi-link mechanical arm with a single passive joint, which belongs to the technical field of robot control and comprises the following steps: S1, establishing a mechanical arm dynamic model with a single passive joint configuration by adopting a Lagrangian method; s2, designing a system track based on initial and target states of the system; s3, designing a switching condition through a track error threshold value and a parameter coupling relation; s4, performing off-line optimization on the trajectory parameters by adopting an ant colony optimization algorithm; s5, designing a sliding mode tracking controller for avoiding singular values; and S6, designing a stabilizer.

The invention discloses a redundancy allocation and rigidity enhancement method and system based on task space stochastic optimization, and is applied to the technical field of robot intelligent manufacturing and trajectory planning. The method comprises the following steps: performing task space redundancy parameterization on a given discrete path point sequence, and constructing a tail end attitude family meeting tail end position constraint; the multiple candidate redundant sequences are disturbed through zero-mean-value Gaussian, the weight of each candidate sequence is calculated, the weighted expectation of disturbance is solved, and iterative updating optimization is carried out; calculating a multi-target composite cost based on the joint configuration corresponding to each path point; s curve time parameterization is carried out, smooth interpolation of the tail end position and the posture is carried out at each interpolation time point, and finally a joint track sequence is obtained through inverse kinematics solving. According to the method, on the premise of strict path tracking, redundant parameters are globally and continuously optimized, rigidity maximization and singularity avoidance are both considered, seamless coupling with S curve time parameterization is achieved, and a high-implementability track capable of being directly issued is output.

This invention is an attitude control method for asymmetric spacecraft, comprising three steps: First, quantifying the disturbance torque of the asymmetric structure and establishing a multi-rigid-body dynamics model including a pyramid-configured control moment gyroscope group and the asymmetric spacecraft; second, designing the control law of the control moment gyroscope group, adjusting the rotation angle and angular velocity of the four frames to output control torque while avoiding singularities, for controlling the attitude of the asymmetric spacecraft; finally, designing the control law for the spacecraft base attitude, updating the inertial torque in real time by feeding back the current attitude error, and simultaneously providing nonlinear torque and compensation torque. The three torques are combined and provided as the desired control torque to the control law of the control moment gyroscope group.

The invention relates to the technical field of robot motion control, and discloses a robot control method and system combining singular point avoidance and obstacle function control. The robot control method is applied to robot control equipment and specifically comprises the following steps that S101, a robot control request is received, a position coordinate system in a Cartesian space is established at the tail end of a mechanical arm, and a tail end position vector x = [x, y, z] T and a virtual wall center coordinate C are defined, the radial distance r = x-c from the tail end to the center of the virtual wall and a radial unit vector are calculated, boundary parameters are set, a virtual wall area is defined by an outer boundary radius rmax and an inner boundary radius rmin, and a safe motion range is formed; s102, decomposing the expected velocity vdes in the Cartesian space into a radial component and a tangential component; the limitation that a traditional potential field method is prone to oscillation and a speed truncation method is discontinuous is broken through by fusing a control obstacle function and a singular point evasion strategy, and strict mathematical constraints established by the control obstacle function ensure that the tail end does not break through a virtual wall boundary absolutely.

The invention discloses an acceleration level continuous quaternion trajectory planning method, system and device and a medium, relates to the technical field of mechanical arm control, and solves the technical problem that acceleration level planning cannot be performed on the tail end posture of a robot. A vector transformation rule is utilized to determine a quaternion attitude rotation direction, and quaternion ambiguity is eliminated; according to the method, quaternion decoupling is achieved through the transformation relation between descriptors, interpolation is conducted on the decoupled pose in an acceleration level continuous mode, it is guaranteed that the smoothness of the mechanical arm in the movement process is achieved, meanwhile, singularity is avoided, and error calculation is simplified. While robot end posture acceleration level planning is achieved, universal joint locking existing in the movement process is avoided, and complexity in the mechanical arm planning process is reduced.

The application discloses a free floating space mechanical arm singular trajectory planning method and belongs to the technical field of robot trajectory planning. The method comprises the following steps: acquiring a desired whole-range end position trajectory and an attitude trajectory of a mechanical arm; setting a control period and cyclically executing; at each control time, calculating a generalized Jacobian matrix and a system singularity measure, judging whether the system is close to singularity; if the system is close to singularity, traversing all base attitude possible values, calculating joint angle states without changing the end position and corresponding singularity measures, searching for a system configuration corresponding to the maximum singularity measure; subsequently, reconstructing the mechanical arm state to make it move to the maximum singularity measure configuration to get rid of singularity; calculating the inverse of the generalized Jacobian matrix to obtain velocity inverse kinematics, and then calculating joint angular velocity and joint angle at the next time. The application realizes the accurate trajectory planning effect of guaranteeing the singularity avoidance capability while not introducing any theoretical error.

The application discloses a kind of adaptive fast sliding mode guidance methods of air-to-air missile in simulation environment, comprising: establishing missile target relative motion model under line-of-sight coordinate system, and establishing missile three-dimensional guidance model according to missile target relative motion model;Based on the three-dimensional guidance model of missile, the line-of-sight normal pitch guidance law and the line-of-sight normal yaw guidance law are designed respectively;The first radial basis function RBF neural network trained in advance is used to estimate the parameters to be estimated in line-of-sight normal pitch guidance law, and the first estimated value obtained is substituted into line-of-sight normal pitch guidance law, and the second radial basis function RBF neural network is used to estimate the parameters to be estimated in line-of-sight normal yaw guidance law, and the second estimated value obtained is substituted into line-of-sight normal yaw guidance law, to obtain angle-constrained fixed-time nonsingular fast terminal sliding mode guidance law.The application avoids singularity while improving the convergence speed of the system, and the convergence time upper bound of the system can be set.

The invention discloses a performance constraint control method and system for multi-robot collaborative carrying of large workpieces. The method comprises the steps that firstly, a unit quaternion is adopted to establish a coupling dynamic model containing closed-chain constraint under a task reference coordinate system; secondly, designing a completely distributed finite time observer, and performing consistency estimation on a global reference trajectory only through neighborhood communication; secondly, designing a consistency indicator function based on the estimated value, gradually activating a performance constraint function only after an observation error is converged so as to apply transient and steady-state performance boundaries, and generating an expected motion state of each robot; and finally, designing a distributed robust adaptive controller to realize trajectory tracking. According to the method, singularity is avoided through quaternion modeling, controller design of a task reference coordinate system is achieved through rigid body transformation, dependence on a centroid coordinate system is avoided, the requirement for a priori track is eliminated through a distributed observer, constraint conflicts are avoided through a strategy of'feasibility first and then constraint ', and the robustness of the system is improved. And the safety, the precision and the robustness of collaborative carrying are effectively improved.

The application discloses a kind of redundant manipulator trajectory tracking methods based on hierarchical geometric model predictive control.It includes: in task space, the dynamic model and tracking error model of redundant manipulator based on Lie group SE (3) are established;Linearization processing is carried out to pose error dynamics based on Lie group theory, and the global consistent, singular augmented linear state space model is obtained;Design double-layer geometric model predictive controller, the first optimal control input sequence is obtained by solving the upper controller with the primary goal of minimizing task space tracking error;Under the premise of constraining the deviation of its solution and the optimal solution of upper layer, the redundant degree of freedom is optimized in advance, to realize configuration stable, singularity avoidance and other secondary objectives.The application avoids inverse kinematics solution, solves the problem of attitude singularity, ensures the absolute priority of main task through hierarchical optimization mechanism, realizes high-precision, high-robustness trajectory tracking and systematical redundant degree of freedom utilization.

The invention discloses a large component robot smooth grinding and polishing surface quality control method and system. The method comprises the steps that a grinding and polishing initial track is generated based on a large component design model or actual measurement point cloud; based on the compliant grinding and polishing removal model, with the target removal amount and the surface roughness as core optimization targets, optimal process parameters are decided through a PB-MOPSO multi-target optimization algorithm; on the basis of the optimal parameters, the contact deformation and the removal profile in smooth grinding and polishing are fused to generate a uniform removal grinding and polishing track; the redundant machining configuration is optimized in combination with joint performance, singularity avoidance and anti-collision indexes; and after the contact force is adaptively controlled through the compliant device to implement grinding and polishing, process parameters of a defect area are secondarily optimized, and the track and the configuration are corrected according to a detection result. According to the method, the grinding and polishing removal uniformity and the surface quality consistency of the large component are remarkably improved, and closed-loop self-adaptive operation and high-quality grinding and polishing are achieved.

The application discloses a sliding mode control method based on fixed time control theory, comprising the following steps: obtaining a strict feedback system expression of a motor servo system, designing a fixed time non-singular terminal sliding mode surface based on an auxiliary switching function, recursively deriving a sliding mode controller based on the strict feedback system expression and the fixed time non-singular terminal sliding mode surface, and finally converging the tracking error time of the motor servo system to a preset range according to the obtained sliding mode controller. The application designs a novel fixed time non-singular terminal sliding mode surface, so that the recursively derived sliding mode controller can converge the tracking error of the motor servo system to the preset range, effectively improves the convergence speed, effectively avoids the singularity phenomenon, and guarantees the convergence precision.

The invention discloses a mechanical arm singular point avoiding method, system and device and a storage medium, and the technical scheme is characterized in that the pose and the joint angle of a mechanical arm are obtained; judging whether a singular area and a singular type are entered or not according to the pose and the joint angle; and when the singular type is a wrist singular type, carrying out first-stage processing, when the singular type is a shoulder singular type, carrying out second-stage processing, and when the singular type is an elbow singular type, carrying out third-stage processing. According to the invention, the obstacle avoidance efficiency can be improved, the motion stability is ensured and the calculation complexity is reduced.

The application discloses a mechanical arm singular point avoidance method, system, device and storage medium, and technical scheme points thereof are as follows: acquiring a pose and a joint angle of a mechanical arm; judging whether to enter a singular region and a singular type according to the pose and the joint angle; performing first-level processing in the case of a wrist singular type, performing second-level processing in the case of a shoulder singular type, and performing third-level processing in the case of an elbow singular type. The application can improve obstacle avoidance efficiency, ensure motion stability and reduce calculation complexity.

The application relates to the technical field of logistics automation, and discloses a through method for singular point areas of a shoulder and a wrist of a spherical-wrist 6R industrial robot, which comprises the following steps: firstly, off-line loading of geometric parameters of the robot and presetting of three types of singular judgment thresholds; continuously collecting and buffering joint angles in a servo cycle; solving end poses by means of homogeneous transformation and synchronously calculating a Jacobian matrix; and parallelly completing three types of singular state detection of the shoulder, the elbow and the wrist. The scheme distinguishes two types of operation branches, i.e. singular and non-singular, closes damping in the non-singular state, adopts a standard Jacobian pseudo-inverse to output a motion instruction, starts adaptive damping correction only when the robot approaches a singular boundary, and solves joint speeds by adapting three types of mainstream control modes. The scheme can completely identify all singular configurations of the robot, avoids singular missed judgment to cause equipment out of control, continuously and real-timely identifies dangerous areas, and avoids the problem of large rotation of multiple axes caused by small end displacement.

The invention discloses a spacecraft agile maneuvering control method using a three-orthogonal configuration double-frame control moment gyro system. The method comprises the following steps: firstly, establishing a spacecraft attitude dynamic model of the double-frame control moment gyro system, and constructing an attitude error criterion in combination with an expected attitude of task planning and current attitude information acquired by an attitude sensor; secondly, if the attitude angle error does not reach the control precision, a nonlinear model predictive control method is adopted, and the optimal control input torque is solved under the constraint condition; and finally, generating a frame angular velocity instruction of the double-frame control moment gyro system based on the singular robust control law, and outputting a control moment to drive the spacecraft to flexibly maneuver. And in the control process, attitude kinematics and dynamics equations are updated in real time until the attitude angle error meets the task requirement. The method can effectively avoid singular point influence while keeping singular robustness, realizes rapid and accurate attitude maneuver control of the spacecraft, and has high engineering application value.

This invention discloses a method, system, device, and medium for avoiding singularities in a robotic arm under different operational requirements. The method includes: determining the transformation matrix between the joint coordinate system and the Cartesian coordinate system based on the kinematic model of the robotic arm; marking all operational areas on the Cartesian motion trajectory of the robotic arm; identifying all singularities from all operational areas based on several motion information associated with several interpolation points in each operational area and the transformation matrix; and assigning corresponding singularity avoidance strategies to all singularities based on a singularity avoidance evaluation parameter library associated with all operational areas. This invention can accelerate the singularity detection speed by automatically adjusting the detection step size, and corrects the trajectory of all singularities within different operational areas by assigning singularity avoidance strategies to different operational areas containing singularities, thereby reducing the damage caused by the singularity of the robotic arm while better completing the task.

The application discloses a double-arm cooperative motion planning method and system for closed-chain singularity avoidance, and comprises the following steps: acquiring a starting point and an ending point of a carried object; determining joint paths and Jacobians of a closed-chain system according to the starting point and the ending point of the carried object; determining a singular region part of the joint paths of the closed-chain system according to the Jacobians of the closed-chain system; determining a master arm and a slave arm of the closed-chain system for the singular region part, determining joint speeds of the master arm based on a damped least square pseudo-inverse method of Jacobians; determining joint speeds of the slave arm according to the joint speeds of the master arm; integrating the joint speeds of each arm to obtain joint angle change values of each arm; and replacing the singular region part in the joint paths by the joint angle change values of each arm to obtain a planning path of the closed-chain system without singularity. The singularity of the closed-chain system is avoided, and the certainty of the joint solution of the closed-chain system at the singularity and the solution of the carried object in the task space are ensured.

The invention relates to the technical field of robot motion track planning, and particularly discloses a carbon fiber automatic laying track planning method of a robot and the robot, the SAC algorithm is deeply combined with redundant degree of freedom robot track planning, and offline training is performed through a deep reinforcement learning framework based on the SAC algorithm; the calculation burden of online optimization in the prior art is avoided, and compared with an online optimization mode in the prior art, the planning time can be greatly shortened, and the calculation efficiency is remarkably improved; meanwhile, the decision-making capability of the SAC algorithm is extended to the redundant degree of freedom of the redundant degree of freedom robot by using a null space optimization method, so that the redundant degree of freedom robot can autonomously perform secondary tasks such as obstacle avoidance, singular point avoidance, configuration optimization and the like by using null space motion while completing a main paving task, and the task efficiency is improved. Therefore, the flexibility and the potential of the redundant degree-of-freedom robot are brought into full play, and the overall laying performance is improved.

The application discloses a permanent magnet synchronous motor sliding mode speed control method and belongs to the technical field of control. The method comprises the following steps: a permanent magnet synchronous motor mathematical model containing disturbance is established based on a stator voltage equation, an electromagnetic torque equation and a mechanical motion equation of the permanent magnet synchronous motor; a non-singular fast integral terminal sliding mode surface is designed to avoid singularity and reduce the chattering phenomenon; a variable function gain term and a sliding mode surface power term are introduced on the basis of a traditional exponential reaching law to improve the reaching law; a permanent magnet synchronous motor sliding mode speed controller is designed based on the improved reaching law and the sliding mode surface; and an improved non-singular fast terminal sliding mode disturbance observer is designed, and the improved reaching law is introduced into the non-singular fast terminal sliding mode disturbance observer. The technical scheme improves the response speed of the permanent magnet synchronous motor speed control, simultaneously suppresses the chattering of the system and enhances the robustness of the system.