210results about How to "Avoid singularity problems" patented technology

The invention relates to a steering-law singularity avoiding aircraft attitude control system, comprising an attitude task managing unit, an attitude controller, an attitude measuring unit, a gyro group steering-law unit, a frame angle position measuring unit, a control moment gyro group and an aircraft. The gyro group steering-law unit calculates the frame angle rate of the control moment gyro group by cooperating control moment gyro angle momentum table, zero motion algorithm and pseudoinverse steering-law algorithm, and adopts the angle rate value as the set signal of the control moment gyro group to improve the control precision of the aircraft attitude. The steering-law singularity avoiding aircraft attitude control system introduces the steering-law design method that chooses frame angle rate and the initial value of frame angle position based on look-up table, realizes accurate moment output of the control moment gyro group, avoids the singularity problem produced in the process of calculating frame angle rate of the control moment gyro group by the pseudoinverse steering-law algorithm as well as avoids the deadlock problem caused by the control moment gyro steering law when adopting zero motion algorithm and robust pseudoinverse steering-law iterative computations.

The invention discloses an adaptive control method of four-rotor aircraft finite time on the basis of a quick terminal slip form, and is suitable for a four-rotor aircraft system with inertial uncertainty and external disturbance. A linear slipping modal and a quick terminal sliding modal are comprehensively considered, a terminal attractor is introduced into the system sliding modal, so that a system state is converged in the finite time, the quickness of the linear slip form when an equilibrium state is approached is kept so as to quickly converge the system state to the equilibrium state inthe finite time. The invention applies the quick terminal slip form to put forward the adaptive control method of four-rotor aircraft finite time on the basis of the quick terminal slip form, a system singularity problem is avoided, buffeting is effectively inhibited, the method exhibits good robustness for the external disturbance and the uncertainty in a four-rotor aircraft system, and the system can quickly converge in the finite time.

The invention relates to a rational-polynomial-coefficients (RPC)-based method for improving and calibrating the block adjustment of a three-linear array three-dimensional satellite, which comprises the following steps of: (1) determining the mapping relationship between ground points and image points, namely a strict imaging model; (2) solving RPC parameters of each image in three linear arrays according to the strict imaging model, and searching for connection points among the three linear arrays by image matching; (3) listing three affine transformation formulas of fore sight, front sight and back sight of the three-linear array images; (4) establishing an error equation and solving to acquire corrections of affine transformation parameters, and revising the affine transformation formulas by utilizing the corrections; (5) listing the affine transformation formulas of the fore sight and the back sight again by utilizing camera parameters and the revised affine transformation formula of the front sight; and (6) solving the revised affine transformation formulas of the fore sight and the back sight in the step (4) and the listed affine transformation formulas of the fore sight and the back sight in the step (5) simultaneously to acquire the corrections of the camera parameters, and revising the camera parameters to improve and calibrate the block adjustment of the three-linear array three-dimensional satellite.

The invention discloses a multi-missile time cooperative guidance method with collision angle constraint. A new missile and target dynamic equation is built under the reference coordinate system, andon the basis of the optimal control theory, a guidance rule of the tail end collision angle constraint is designed; the error between current remaining flying time of missiles and the expected remaining flying time serves as a sliding mode surface, the remaining flying time of the missiles has tendency to the expected remaining flying time, on the basis of the sliding mode control theory, the timecontrollable guidance rule is designed; the switching strategy of the tail end collision angle controllable guidance rule and the time controllable guidance rule is designed for enabling the missilesto hit the target at the expected time and angle; a multi-missile time cooperative communication network is built, on the basis of a dual-layer cooperative guidance framework, coordinated variable isdesigned to enable the remaining flying time of the missiles to tend to be consistent, the missiles can hit the target at the same time at the expected collision angles, and multi-missile time cooperation in real meaning is achieved.

The invention discloses an industrial robot geometric parameter calibration method based on a position vector method. The industrial robot geometric parameter calibration method based on the positionvector method comprises the steps that a robot position vector model based on a basis coordinate system oxyz is established, and nominal values of a direction vector and a connection vector in a zerostate of a robot are found from a robot manual; groups of joint angles of the robot are randomly set on a demonstrator according to movement ranges of all joints given by the robot manual, and all thejoints of the robot are controlled to move to the groups of joint angle values qij which have been set; a laser tracker is used for detecting a target which is installed at the tail end G of the robot, and a tail end posture and position data of a measured robot are obtained; and an objective function Ej of the geometric parameter calibration of the robot is established, and a genetic algorithm is used for solving the objective function Ej so as to obtain an optimal solution of the direction vector and the connection vector of the measured robot. According to the industrial robot geometric parameter calibration method based on the position vector method, the problem of singularity caused by parallel and vertical adjacent joints is solved, and meanwhile, an industrial robot geometric parameter calibration error optimization objective function is built based on the model.

The invention discloses an improved adaptive droop control-based island alternating current-direct current hybrid microgrid power flow calculation method. The method mainly includes the following steps that: 1) an alternating current-direct current hybrid microgrid control model is established; 2) an alternating current-direct current hybrid microgrid power flow model is established; 3) a trust domain-based LMTR solving algorithm is established; and 4) an alternating iteration method is adopted to calculate the power flow of the island microgrid alternating current-direct current hybrid system, and a convergence criterion refers to an relational expression described in the descriptions of the invention, if power flow calculation converges, then the method goes to the step 5, if the power flow calculation does not converge, iteration continues until the power flow calculation converges; and 5) a power flow calculation result is outputted, and load active power is changed, an improved adaptive droop control strategy is adopted to update a droop control coefficient, and the power flow is re-calculated. With the method of the invention adopted, the stability of frequencies and voltagescan be maintained; when power disturbance occurs in the system, it can be ensured that all distributed power sources are outputted according to a power source capacity ratio, a condition that the output of a single power source exceeds a limit when overload occurs can be avoided, and the safe, stable, reliable and efficient operation of the system can be maintained.

The invention provides an adaptive inversion nonsingular terminal sliding mode control method of a micro gyroscope. An inversion method and a terminal sliding mode are combined, an inversion terminal sliding mode control law is designed according to the Lyapunov stability theory, and therefore, system status can be converged to a balance point within the short limited time. Furthermore, by means of self-adaptive control, angular velocity and other system parameters of the micro gyroscope can be identified. Nonsingular terminal sliding mode control is introduced in consideration of singularity in the existing terminal sliding mode control, whole nonsingular control of the system is achieved, response speed of a controller is completely comparable to the traditional terminal sliding mode, and therefore, the adaptive inversion nonsingular terminal sliding mode control method has important theoretical and practical application value. By means of the adaptive inversion nonsingular terminal sliding mode control method of the micro gyroscope, the rate of convergence and tracking performance are ensured while strong robustness and adaptive ability to external disturbance are achieved.

The invention relates to a disturbance observer based MEMS gyroscope prediction performance non-singular sliding-mode control method. The method comprises the following steps: in view of a gyrodynamics model of parameter perturbation and external time-varying disturbance, designing an adaptive update law of neutral network weight, and correcting the weight coefficient of the neutral network to realize effective estimation of unknown dynamics; introducing a performance function to limit the tracking error, and converting the limited tracking error into unlimited conversion error through errorconversion; designing a sliding-mode controller based on conversion error to realize prediction performance control on MEMS gyroscope; designing a non-singular terminal sliding-mode controller to realize feed-forward compensation of unknown dynamics while avoiding the problem of system singularity; designing a disturbance observer to perform estimation compensation on external disturbance. The method disclosed by the invention solves the problem that external disturbance, system singularity, overshooting and tracking error cannot be designed in advance, and enhances the control precision and further improves the performance of the MEMS gyroscope.

The invention discloses a terminal sliding mode manipulator trajectory tracking method based on fractional order power reaching law. By designing adaptive rate to an upper bound of uncertainty and switching control of fractional order powder reaching, system state may be converged more quickly to a sliding mode surface; through sliding mode characteristics of a nonsingular quick terminal sliding mode surface, the system state is converged more quickly to a balance point within limited time, namely, a tracking error is converged to 0; therefore, tracking an expected joint angular trajectory isachieved.

A four-rotor unmanned plane finite time self-adaptive control method based on a nonsingular terminal sliding mode is provided; the method aims at a four-rotor unmanned plane system with inertia uncertainty factors and external turbulences; according to the four-rotor unmanned plane dynamic system, a nonsingular terminal sliding mode control method is employed, and self-adaptive control is combined, thus designing the four-rotor unmanned plane finite time self-adaptive control method based on the nonsingular terminal sliding mode; the nonsingular terminal sliding mode is designed so as to ensure the system finite time convergence features, thus preventing singularity problems existing in terminal sliding mode control, and effectively weakening jittering problems; in addition, the self-adaptive control is used for processing system inertia uncertainty factors and external turbulences; the method can remove the sliding mode surface singularity problems, and can effectively prevent and compensate the system inertia uncertainty factors and external turbulences, thus ensuring the system finite time convergence features.

A four-rotor unmanned plane finite time self-adaptive control method based on a fast nonsingular terminal sliding mode is provided; the method aims at a four-rotor unmanned plane system with inertia uncertainty factors and external turbulences; according to the four-rotor unmanned plane dynamic system, a fast nonsingular terminal sliding mode control method is employed, and self-adaptive control is combined, thus designing the four-rotor unmanned plane finite time self-adaptive control method based on the fast nonsingular terminal sliding mode; the fast nonsingular terminal sliding mode is designed so as to ensure the system finite time convergence features and fast convergence speed, thus preventing singularity problems existing in terminal sliding mode control, and effectively weakening jittering problems; in addition, the self-adaptive control is used for processing system inertia uncertainty factors and external turbulences; the method can remove the sliding mode surface singularity problems, and can effectively prevent and compensate the system inertia uncertainty factors and external turbulences, thus ensuring the system finite time convergence features.

The invention relates to a distribution network static voltage stability probability assessment method based on a two-point estimating method. The distribution network static voltage stability probability assessment method comprises the following steps that firstly, a random output model of a distributed power source is established, the statistical property of random variables in the model is determined, and the two-point estimating method is adopted to obtain calculation sample values and the weight of samples; secondly, on the basis of all the samples, the continuation power flow method is adopted to obtain corresponding static voltage stability thresholds and critical load margins, and the statistical property values of the voltage stability thresholds and the critical load margins are calculated based on the results and the weight of all the samples; finally the Cornish-Fisher series are introduced to estimate the probability distribution of the corresponding static voltage stability margins. The two-point estimating method is adopted to select sample points for deterministic calculational analysis, so that an un-deterministic problem is converted into a deterministic calculation; the voltage stability thresholds of all the sample points are found by utilizing the continuation power flow method, in this way, the voltage stability condition of a distribution network of a distributed power source including random output is estimated, and estimation accuracy is high.

The invention relates to a realization method for the real-time transmission of satellite lateral motion image, which is characterized in that: a complete satellite adopts four control antennae for transceiver, so that the control antenna beam is in omnidirectional coverage after the satellite being moved laterally; the complete satellite is controlled to move laterally, continuously and rapidly in a large angle by a momentum wheel; the satellite attitude is measured by using a whirligig in the process of lateral motion; and the satellite crab angle can be calculated in real time, simultaneously, the drift angle can be controlled, so the satellite lateral motion is set to a swinging angle scope stably. In the phase of satellite bias flight, a star sensor and the whirligig are adopted for united attitude determination to the satellite; the camera integral time is calculated in real time by a GPS receiver according to the satellite orbit and latitude; the camera will generate exposure and imaging according to the integral time; the imaging data after the lateral motion can be transmitted to the ground by the satellite through an array data transmission antenna. The realization method for the real-time transmission of satellite lateral motion image has the advantages that: the large-angle lateral motion of the satellite can be realized; thereby the camera development difficulty because of camera wabble or swing mirror addition can be lowered; the visual range of the satellite can be expanded; and the revisit cycle of the satellite can be increased.

The invention provides a relative navigation close range tracking method and system for space noncooperative target capturing. According to the relative navigation close range tracking method and system for space noncooperative target capturing, a kinematical equation of a free-floating space robot system is utilized to deduce and obtain a path planning method for a mechanical arm capturing a moving target, the relative speed and relative posture of the tail end of the mechanical arm and the target are taken as input, joint angle commands controlling the mechanical arm to move can be calculated and obtained, so that capturing operations of the mechanical arm on the moving target can be realized. By means of the relative navigation close range tracking method, in the process of close rangerelative navigation of a space robot on the moving noncooperative target, path planning for the relative position and posture of the tail end of the mechanical arm and the target and continuous inverse kinematics solution from Cartesian space to mechanical arm joint space can be independently realized, and especially for redundant mechanical arms, posture undisturbed planning for a base seat relative to inertial space can be realized.

The invention provides an adaptive fault tolerance control method for a vertical take-off and landing reusable launch vehicle. The method comprises the steps of: Step 1: obtaining a guidance command;Step 2: establishing a landing section fault tolerance control model; Step 3: designing a fixed time convergence and expansion state observer; step 4: designing a non-singular fast terminal sliding mode surface; and Step 5: designing an adaptive fault tolerance controller. According to the adaptive fault tolerance control method, this design pattern not only effectively improves the rejection capability of the system to the complex external interference and the adaptive fault tolerance performance under various engine failure modes, but also guarantees the rapid and accurate tracking of the attitude guidance command.

The invention provides a double-arm robot system in plug-in mounting production. The double-arm robot system comprises two industrial cameras, two laser ranging displacement sensors, two arms, binocular vision cameras and two LED plug-in mounting plates. A system control layer is composed of an industrial computer and a high-speed Ethercat bus. The invention further provides an intelligent control method of the double-arm robot system in plug-in mounting production. The method includes the steps of initiating the system and returning to zero, conducting rough positioning through the binocular vision cameras, sending data to a movement controller to be processed to obtain the laser sensor rotating angle and the laser ranging sensor distance so that precise positioning can be achieved, obtaining coordinates of a target workpiece under a laser ranging system through a positioning algorithm, moving a double-arm robot to the target position according to the coordinates, grapping the workpiece through claws at the tail ends, and placing the workpiece into the device to be assembled to be installed. The double-arm robot system is simple in structure, high in work efficiency and capable of being widely applied to plug-in mounting production of precise assembling of LED automobile lamps and automobile motor claw poles.

The invention discloses a method for identifying a cancer molecular subtype based on a spectral clustering algorithm of a sparse similar matrix. The method is characterized in that based on the spectral clustering algorithm of the sparse similar matrix, a cancer molecular subtype prediction model is built by utilizing cancer gene expression profile data as a training set sample; and the prediction model is used for predicting a cancer modular subtype of an independent test set sample, and a cancer sample set is divided into multiple types of molecular subtypes. According to the method, various patients with different prognosis effects are effectively distinguished for high heterogeneity of cancer molecular expression level, and different individual treatment schemes can be made for various cancer patients respectively.

The invention discloses a satellite attitude control method for space cooperation target tracking imaging. Firstly the conditions required to be met by an imaging time window are determined, and the expected attitude quaternion and angular speed are calculated through the given satellite orbit state and target orbit information so that the error amount between the attitude tracking error quaternion and the actual angular speed and the expected angular speed is calculated; then an attitude kinetic model is established; and finally control law parameters are selected, and the flywheel moment control amount is calculated. The method is based on the attitude quaternion representation so that the possible singularity problem caused by using euler angle in large-angle attitude motion can be avoided. Besides, the method is simple in algorithm, low in calculation amount and simple in project realization and has high pointing control accuracy and great pointing stability.

The invention discloses a multi-axis rapid attitude maneuver jet control method, which comprises: the aircraft obtains the deviation quaternion corresponding to the target attitude angle from the current attitude angle; the aircraft combines the PD control method with the deviation quaternion according to the maximum maneuvering angular velocity The number is subjected to limiting processing; the aircraft decomposes the deviation attitude angles of the three channels of roll, pitch, and yaw according to the limited deviation quaternion; the aircraft uses the PD control method to obtain the attitude maneuvering jet control command. The present invention overcomes the singularity brought by the description of Euler angles when the star is maneuvering at a large angle; by limiting the maximum maneuvering angular velocity through equal-proportional limiting of the deviation quaternion and combining with the PD control law, the optimal path can be achieved The multi-axis rapid attitude maneuvering control ensures the safety of maneuvering at the same time.

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.

The invention belongs to the automatic control technology field and relates to an adaptive fault tolerance control method for flexible liquid-filled satellite attitude based on a fault characteristic model. According to the method, when a system in under the condition of liquid shaking, flexible vibration and external interference, a fault tolerance controller based on the fault characteristic model is designed for performer faults. The method comprises steps that (1), the fault characteristic model is established according to a flexible liquid-filled satellite attitude kinetic equation; (2), a parameter estimation algorithm is utilized to identify a coefficient of the fault characteristic model, and a coefficient estimation value of the fault characteristic model is acquired; (3), the adaptive fault tolerance controller is designed according to the coefficient estimation value of the fault characteristic model; and (4), a control torque is acquired through the adaptive fault tolerance controller, and the control torque is applied to the satellite attitude control system to control a satellite attitude angle. Through the method, control precision before and after fault generation is guaranteed to be quite high, and the time for realizing the stable state is short.

The invention relates to a control system and a control method for posture rail coupling under the shifting state of a big barycenter based on engine pre-swinging. The system comprises a barycenter estimation module, a pre-swinging angle calculation module, a procedure angel de-noising and compensation module, a control feedback bias calculation module, an incremental type PID control module and an equivalent servo swinging angle instruction and amplitude limiting module. The system provided by the invention is used for solving the problem of high-precision control on the shifting posture rail coupling of the big barycenter of an on-orbit aircraft. An excellent engineering application effect is achieved.

The invention relates to a mechanical arm error analysis method. On the basis of a mechanical arm motion model, the sensitivity and influence law of all kinematic parameter errors on the precision of a tail-end position of a mechanism arm are analyzed, and a basis is provided for precision distribution during design, machining and assembling of the mechanical arm. The method comprises the analysis steps that (1) an exponential product method is utilized to establish a kinematic model of the mechanical arm; (2) a mechanical arm tail-end position error model is established according to the kinematic model; (3) the sensitivity of all joint errors and initial pose errors on the precision of the tail-end position of the mechanism arm is analyzed; (4) the influence law of changes of all the joint errors along with all joint angles on the precision of the tail-end position of the mechanism arm is analyzed; and (5) precision distribution of the mechanism arm is guided according to the sensitivity and the influence law of all the errors. The mechanical arm error analysis method has the advantages of precise calculation, convenient operation, comprehensive analysis, etc.

The invention discloses a method for eliminating a five-axis singular problem in a route planning stage. The method includes the steps of inputting curved surface information, cutter parameter information and technique information of a part to be machined; generating cutter paths on a curved surface and meanwhile storing local coordinate system information; converting cutter axis vectors of all cutter location points of any path into C space to obtain a direction curve; judging whether the current direction curve intersects with a taper circle, continuing to detect the next path if the current direction curve does not intersect with the taper circle and otherwise horizontally moving the current direction curve to avoid the taper circle; carrying out back calculation on new cutter location points according to a new direction curve and the correspondingly stored local coordinate system information and continuing to detect the next path; carrying out traversal on all paths to ultimately output a non-singularity five-axis cutter path covering the whole curved surface. The five-axis singular problem is taken into account in the route planning stage, the singular problem can be eliminated on the premise that the cutter location points are not increased, meanwhile cutter contact positions on an original path keep unchanged, five-axis machining efficiency and precision are improved.