64results about How to "Guaranteed Steady State Performance" patented technology

The invention relates to a parameter identification based multi-motor servo system synchronization and tracking control method. The parameter identification based multi-motor servo system synchronization and tracking control method comprises the steps that 1, a multi-motor driven servo system containing unknown parameters is analyzed, and a mathematic model of the multi-motor driven servo system containing unknown parameters is established according to a motor structure and a physical law; 2, a load model established in the step 1 is analyzed, and unknown parameters in the load are estimated by utilizing a variable-gain self-adaptive parameter identification method; 3, synchronization and tracking control is conducted on the multi-motor driven servo system by utilizing neural network integral sliding-mode control algorithm according to a parameter identification result obtained in the step 2. The control method can ensure the steady-state accuracy of synchronization and tracking, effectively ensure transient-state and steady-state performance of parameter estimation, decrease the complexity and calculated quantity of algorithm design and effectively improves the response speed and robustness of the multi-motor driven servo system.

The invention relates to a vehicle active suspension system vibration control method based on a specified performance function, belonging to the field of vehicle engineering. The method comprises: firstly establishing a dynamics model of a vehicle active suspension according to the automobile dynamics theory and the Newton's second law of motion; then designing a performance function, to make thevertical displacement, the roll angle and the pitch angle to be converged into the boundary of the performance function; equivalently converting the vertical displacement, the roll angle and the pitchangle to conversion errors by applying the inverse function; and finally, designing the control law in the vertical, roll and pitch directions through the conversion errors, and carrying out active vibration control over the entire vehicle suspension. The vehicle active suspension system vibration control method based on the specified performance function is close to the real vehicle condition, the transient-state and steady-state performance of the suspension system is ensured, and the robustness of the system is improved. For the complex nonlinear system of the vehicle suspension system, the control strategy based on the specified performance function avoids complex operations of the system, such as the accurate modeling process and the neural network on-line calculation, the design issimple, and the calculation amount is small.

The invention discloses a control method for grid-connected current of a three-phase grid-connected inverter, improves the defects of the conventional repetitive control through two disturbance factors of suppressing inverter harmonic generation and resisting power network fluctuation, aims at the problems that the conventional repetitive controller cannot process the aperiodic harmonic and is easily affected by the power network frequency fluctuation based on a principle of adopting last periodic quantity to carry out iteration to cause system instability, provides a multi-target repetitive controller and designs from four aspects of a PI parameter, an internal mode coefficient, a repetitive control coefficient and fractional order phase correction, so that the tracking precision of the grid-connected current about a reference signal is enhanced, the ability of a system to resist power network frequency fluctuation is improved and the steady-state performance of the system is guaranteed.

The invention relates to a robot arm system preset performance control method based on a neural network. The robot arm system preset performance control method based on the neural network comprises the following steps of: S1, establishing a mathematical model of a robot arm servo system, and designing a tangential barrier Lyapunov function; S2, designing a preset performance adaptive controller bycombining the tangential barrier Lyapunov function with an inversion method; and S3, carrying out stability analysis. According to the robot arm system preset performance control method based on theneural network, by setting parameter values of a constraint boundary function, steady-state performance and transient-state performance of the system can be ensured. Moreover, the neural network is utilized to approach an uncertain part of the model and a derivative of a virtual control quantity, so that design of the controller is effectively simplified, robustness of the system is improved to acertain degree, and the robot arm servo system can implement accurate and rapid tracking control.

The invention discloses a hypersonic aircraft self-adaptation time-varying preset performance control method based on LS-SVM. The method includes the steps of firstly, designing LS-SVM identifier and a time-varying preset performance function according to the longitudinal model of an air-breathing hypersonic aircraft to obtain an error transformation model; secondly, designing a speed subsystem self-adaptation time-varying preset performance controller according to the error transformation model; thirdly, designing an altitude subsystem self-adaptation time-varying preset performance controller according to the error transformation model; fourthly, performing stabilizing analysis and performance analysis according to the speed subsystem self-adaptation time-varying preset performance controller and the altitude subsystem self-adaptation time-varying preset performance controller. The hypersonic aircraft self-adaptation time-varying preset performance control method has the advantages that the online approximation algorithm complexity of an unknown nonlinear power model is lowered while the saturation constraint conditions of an aircraft actuating mechanism are not violated; the self-adaptation high-precision control of a hypersonic aircraft is achieved while the stability of the control system of the aircraft is guaranteed.

The invention provides an L1 adaptive ship power positioning double-loop control system based on a neural network. The control system comprises a marine ship, an outer ring position tracking loop controller, an L1 adaptive inner loop controller based on a neural network and a path generator. The outer ring position tracking loop controller can track a reference path of the system to obtain a virtual speed instruction; the L1 adaptive inner loop controller based on a neural network comprises an adaptive wavelet neural network approaching device, a state predictor, a parameter adaptive law and an L1 control law; the L1 control law comprises a filter; and the L1 adaptive inner loop controller based on a neural network solves the problem of uncertainty in the system, and approaches a coupling term in the system using a recursive wavelet neural network. The L1 controller introduces a low-pass filter into the feedback loop during feedback, thereby weakening the influence of unknown high-frequency noise in control signals on high-frequency noise. The control system can be applied to control of other ship power positioning systems.

The invention discloses a five-phase permanent magnet embedded fault tolerant linear motor adjacent two-phase open circuit fault tolerant vector control method. Based on the principles that the magnetic motive force of traveling waves remains unchanged before and after a fault occurs and that the non-fault phase current sum stays at zero and taking the equality of the non-adjacent two-phase current amplitude as a constrained condition, the non-fault phase fault tolerant current is obtained to further deduce the generalized Clark transform matrix from the natural coordinate system of the non-fault phase to the two-phase stationary coordinate system. The non-fault opposite potential is observed by the transpose matrix of the transform matrix. A current internal model controller, a first-order inertial feed-forward voltage compensator and a counter-electromotive force observer are used to convert the nonlinear close coupling system of such motor under the condition of an adjacent two-phase open-circuit fault into a first-order inertial system. According to the invention, not only the thrust fluctuation caused by motor failure is restrained, but also more importantly, the dynamic performance and the steady-state performance are consistent with those under a normal condition to realize the fast response to non-overshoot and the stable switching frequency of a voltage source inverter.

The invention discloses a control method for a hysteresis nonlinear robot system, and belongs to the field of robot system control. A hysteresis nonlinear robot with P-I (Prandtl-Ishlinskii) is selected as a research object to measure system parameters of the robot and joint position information and joint velocity information of the robot, a performance function is introduced to convert a constraint tracking control problem of an original robot to an unconstrained stabilization problem, and unknown parameters in the hysteresis nonlinearity are regulated by employing adaptive control to designan adaptive predetermined performance backstepping control strategy. The control method for the hysteresis nonlinear robot system optimizes the transient performance of the system, improves the convergence rate, ensures the steady state performance of the system, and improves the control precision; and moreover, the adaptive parameter regulation law is employed to estimate the unknown parameters in the hysteresis nonlinearity so as to effectively solve the problems of the system oscillating and system instability caused by hysteresis nonlinearity and improve the working performances of the system.

The invention relates to a forcer/position hybrid control method of a multi-arm teleoperation robot based on a performance function. The situation that the force/position coupling of an operation object and mechanical arms in the operation process in the actual operation process is considered, by correspondingly designing controllers of a master terminal and a slave terminal, in the control process of the slave terminal mechanical arm, by pre-designing the performance function of the mechanical arms, a force position hybrid controller of the slave terminal mechanical arm is designed, so that under the condition that a target is disturbed by certain external factors in the operation process, the influence of disturbance can still be reduced through the control of the mechanical arms, and the position, speed and acting force of the robot can be adjusted adaptively at the same time to ensure the stability of system operation, and thus the cooperative operation of multi-arm teleoperation is realized.

The invention discloses a five-phase permanent-magnet embedded fault-tolerant linear-motor non-adjacent two-phase fault-tolerant vector control method. According to principles that magnetomotive forces before and after a two-phase open-circuit fault are invariant and a non-fault-phase current sum is zero, a condition that adjacent two phase current amplitudes are equal is taken as a constraint condition so as to derive and popularize a Clark transformation matrix; matrix transposition is used to estimate a counter potential; and an inner model controller, a first-order inertia feedforward voltage compensator and a counter potential observer are used to change a nonlinear strong coupling system of the motor under a fault state into a first-order inertia system. According to a principle that a synthesized magnetomotive force of a non-fault-phase short circuit compensation current and a short circuit fault phase current is zero, a short circuit compensation voltage is calculated. The voltage is superposed with an output voltage of a vector control device. By using the method of the invention, a motor thrust fluctuation caused by one phase short circuit and one phase open circuit of non-adjacent two phases of the motor is restrained, and dynamic performance and stable state performance are consistent with the performance under a normal state.

The invention relates to a flexible-spacecraft-attitude control method based on event driving. Under the condition that uncertain inertial parameter information exists, an attitude control method based on event driving is provided, and on the basis that the transient state and steady-state performance of an attitude system are guaranteed, low frequency updating of the control law is achieved. Theflexible-spacecraft-attitude control method based on event driving has the advantages that under the condition that inertial parameter information is unknown, transient state protection and steady-state performance control of the flexible-spacecraft-attitude system are achieved; based on event driving controlling, the updating number of times of the control law is greatly decreased, responding ofan actuator in practical engineering is facilitated, and the flexible-spacecraft-attitude control method based on event driving has the high engineering application value.

The invention discloses a tracking control method of a nonlinear pure time delay system independent of an ideal track comprises the following steps of step1, establishing a mathematic model of an uncertain pure feedback system of controlled band time delay; step2, using a parametric linearity combination of a primary function to reconstruct and estimate an unknown ideal track; step3, designing a controller of a controlled non-linear pure time delay system; and step4, taking a controlled quantity u as control input of an actuator of a controlled non-linear system and realizing preset performance tracking of system output to the unknown ideal track. By using the tracking control method of the nonlinear pure time delay system independent of the ideal track, close tracking of the system to the unknown ideal track is realized and simultaneously transient and stable-state performance of the system and stability of a closed loop system are guaranteed.

The invention discloses a finite time fault-tolerant control method used for a remote operation system. The method specifically comprises the steps that for the remote operation system with an executor failure, according to measured parameters of main and slave robots, a nominal system is obtained; on the basis of position and speed information of the main and slave robots in the nominal system, finite time is designed for the main and slave robots, and executor failures of the main and slave robots and system uncertain information are estimated in an online manner; on the basis of the measured joint position and speed information, a terminal sliding mode surface is designed; on the basis of the terminal sliding mode surface, the executor failure and the system uncertain estimation information, the finite time control strategy is designed; and the Lyapunov equation is used for building the system convergence rate and controller parameter relation. Through executor failure and system uncertain finite time online precise estimation, the compensation of the executor failure and the system uncertainty for the system influence can be successfully achieved, and the stable running of theclosed-loop remote operation system is ensured.

The invention discloses a pseudo continuous conduction mode switch converter set follow current duty ratio control method and an apparatus. Through comparing a ripple voltage signal on an output capacitance equivalent series resistor to an error signal generated by an output voltage and a reference voltage which pass through an error amplifier, control to a main switch tube of a pseudo continuous conduction mode switch converter is completed and voltage stabilization of the output voltage is realized. Through carrying out set follow current duty ratio control on a follow current switch tube, dynamic follow current of an inductive current is realized. By using the method and the apparatus of the invention, the pseudo continuous conduction mode switch converter possesses the advantages that control is simple; stability is good; a load scope is wide; a light load output voltage ripple is small; input and a load transient response speed are fast; and full-load efficiency is high and so on.

The invention relates to a fixed-time predetermined performance recurrent neural network mechanical arm control method. The method comprises the steps that (1) a mathematical model of a mechanical armdriven by a direct-current motor is established, and an actuator model with an unknown nonlinear dead zone is established; (2) system reference output is determined, and a performance function, whicha tracking error needs to meet, is designed; (3) a fixed-time predetermined performance recurrent neural network controller, a neural network weight update law and a fixed-time differentiator are designed so that system output can track a reference output trajectory in fixed time, and meanwhile the system tracking error is limited within a performance boundary range designated in advance; and (4)stability analysis is performed on a control system, and controller parameters are determined according to the stability analysis result. Through the method, fixed-time predetermined performance trajectory tracking can be realized, so that tracking time is shortened, control precision is improved, and transient performance and steady performance of the system in the control process are guaranteed.

The invention discloses a self-adaptive dynamic surface controller structure and a design method thereof. An error feedback unit is added on the basis of self-adaptive dynamic surface control, a virtual given signal can be adjusted according to feedback tracking error information, and especially, the virtual given signal can be adjusted quickly to reduce tracking errors when the tracking errors are large, so that the problem of poor transient performance of a control system due to the tracking errors is solved. By introduction of the error feedback unit, saturation of an executor can be avoided effectively, and mechanical damages caused by dithering of control input signals to the executor can be reduced; a neural network is enabled to quickly and smoothly approach uncertainty in a controlled system, and tracking performance of the system is guaranteed without influences on robustness of a controller; the error feedback unit only plays a role in a transient process. By the design method of the controller, system stability can be guaranteed while transient performance of the control system is improved.

The invention provides a robot preset formation control method. The method comprises the steps: (1) building a motion-dynamics model and a virtual navigation-following motion model, and obtaining a relative pose error state equation of a following robot and a virtual navigator; (2) defining a tracking error e (t), designing a performance index function lambda (t) according to a communication range, and designing a preset error performance function S (epsilon) as a hyperbolic tangent function; (3) designing a sliding mode control rate through deformation of S (epsilon); (4) designing a fuzzy control system; (5) adjusting lambda (0) to enable an inverse function of S (epsilon) not to be negative and not to generate singularity, and enabling a convergence rate of the control error to depend on a value of eta in the control rate; and (6) giving relative poses of virtual pilots and the followers so that distances and angles between the following robots and the virtual pilots are kept to complete formation. According to the method, an output range is obtained, the preset error performance function is designed, the sliding mode controller is designed too, a sliding mode control gain is adaptively adjusted by using a fuzzy logic theory, a switching item is converted into a continuous fuzzy quantity, and buffeting is reduced.

The invention discloses an intelligent harvesting robot path control method considering time delay and environmental constraints, and belongs to the technical field of unmanned auxiliary driving in modern agriculture. The method comprises the following steps: establishing a kinetic model, a kinematic model and a harvester-ground stress model of a harvester steering system, constructing a control system model considering input delay and external disturbance, and taking a comprehensive error as a state variable; constraining the state variable based on a preset performance function, and converting a constrained variable into an unconstrained variable through an error conversion function; aiming at two conditions of steady input time delay and time-varying input time delay, respectively constructing saturation compensation variables based on steady time delay and time-varying time delay estimation values, and designing corresponding control input based on a backstepping method and a Lyapunov stability theorem. According to the method, tracking errors can be effectively restrained, the influence of input time delay on a tracking system is compensated, and the automatic driving navigation effect of the harvester is improved.

The invention discloses a method and a system for designing a double-pendulum PI type Terminal sliding mode controller of a bridge crane. The method comprises the steps: defining a double-pendulum model of a bridge crane system; introducing a composite signal; defining a PI type deviation signal as a difference value between the expected track of the trolley and the composite signal; defining a Terminal sliding mode surface according to the PI type deviation signal; defining a nominal model according to the double-pendulum model of the bridge crane system; and according to the Terminal slidingmode surface and the nominal model, obtaining a PI type Terminal sliding mode controller. A double-pendulum model is adopted, a sliding mode surface is converged in finite time, and convergence timecan be predicted; by introducing a composite signal, the coupling relationship among the trolley displacement, the lifting hook swing angle and the load swing angle is enhanced, the steady-state performance of a control system is ensured, the strong coupling of an under-actuated nonlinear system is fully considered, and a better control effect is easily obtained in engineering application; and a nominal model design method is adopted, so that the method has relatively high robustness to external interference, parameter perturbation and an unmodeled state.