15 results about "Stability theorem" patented technology

The invention discloses a cascaded auto-disturbance rejection rotating speed stability control method with a quasi-resonance link based on propeller load, and the method comprises the following steps: S1, building a speed ring mathematical equation containing disturbance according to the basic structure and working principle of a surface-mounted permanent magnet synchronous motor; s2, according to aerodynamic characteristics of the propeller, establishing a mathematical model of tension and load torque of the propeller; s3, establishing a quasi-resonance cascade active-disturbance-rejection speed controller containing disturbance compensation according to the S1 and the S2, and performing stability analysis on a cascade expansion observer equation according to a Lyapunov stability theorem; and S4, a cascade active disturbance rejection control method with a quasi-resonance link is used to realize suppression of periodic and non-periodic disturbance of the rotating speed so as to realize high-performance speed control. According to the method, the motor and the propeller are integrally modeled, the influence of periodic disturbance and non-periodic disturbance on the rotating speed is considered at the same time, and the method has better dynamic performance and steady-state performance.

The invention belongs to the technical field of intelligent control, and discloses a speed tracking self-adaptive iterative learning control method for an extrusion rod of an extruding machine, which comprises the following steps of: determining a dynamic model of the extrusion rod and a control target according to the physical property and the motion mode of the extrusion rod; based on an approximation theory, establishing a neural network model for an uncertain part in the extrusion rod motion model, and determining a speed tracking error system of the extrusion rod; designing virtual control input and actual control input based on a self-adaptive iterative learning control theory; based on the Lyapunov stability theorem, the stability of the controller is analyzed and designed. According to the speed tracking self-adaptive iterative learning control method for the extrusion rod of the extruding machine, limited time speed tracking of the extrusion rod can be effectively controlled, accurate motion control over the extrusion rod is achieved, and the size precision, the surface quality and the production efficiency of products are ensured.

The invention discloses a high-order multi-agent system control method with unknown input time lag and quantization, which comprises the following steps: S1) under the condition of unknown time-varying time lag and input quantization, carrying out system description on an uncertain high-order multi-agent system and introducing a lag uniform quantizer; s2) converting an uncertain high-order multi-agent system tracking control problem with unknown time-varying time-lag and input quantization into a bounded problem of a differential equation solution with time-lag; s3) constructing a dominant expression of the system and feasibility conditions for realizing bounded tracking according to the bounded problem of the time delay differential equation; and S4) performing control design according to a dominant expression of the system and bounded tracking feasibility conditions. The invention designs an adaptive finite time dynamic surface control scheme for a high-order multi-agent system with unknown input delay. Meanwhile, the finite time stability theorem is utilized to prove that all signals in the closed-loop system are semi-globally practical and stable in finite time.

The invention relates to the technical field of super networks, and provides an improved super network rumor propagation model establishment method which comprises the following steps: step 1, establishing an SEIAR super network rumor propagation model with an opposite state according to a classical SEIR model; 2, according to a rumor propagation rule, a differential dynamics equation set is established; 3, according to the differential dynamics equation set, a rumor-free balance point of the model is calculated; 4, calculating a basic regeneration number; step 5, solving local and global asymptotic stability conditions of the balance point by using a Routh-Hurwitz criterion and a Lyapunov stability theorem; 6, a control strategy is adopted according to the rumor spreading condition. The behavior of the rumor refuter in the social network can be well described, and the dynamic influence of the rumor refuter on the rumor spreading process is disclosed.

The application discloses a state-restricted high-order nonlinear information physical system security control method and device, and relates to the technical field of information security. The method comprises the following steps: a state-restricted high-order nonlinear information physical system with external disturbance under malicious attack is established to obtain a control-oriented dynamic model; an ideal virtual controller and an adaptive law are designed based on the dynamic model; a fixed-time adaptive fuzzy controller is designed based on the dynamic model, the ideal virtual controller, the adaptive law and Lyapunov stability theorem, so as to realize security control of the information physical system suffering from malicious attack. The application can ensure that the system output accurately tracks the ideal output in a fixed time, and the rest of the system states can also track the ideal virtual control signal, and meanwhile, all the system states satisfy the respective state constraint conditions in the whole control process.

The present invention discloses an adaptive exponential sliding mode control method for an optoelectronic pod based on a disturbance observer. The method comprises the following steps: first, establishing a mathematical model of the optoelectronic pod system based on the principle of the optoelectronic pod. Then, based on the mathematical model of the optoelectronic pod system, designing an adaptive exponential sliding mode controller based on a disturbance observer. The disturbance observer observes external disturbances and parameter uncertainties to obtain a control input that offsets the aggregated disturbance. An adaptive law is designed to online estimate the switching gain in the sliding mode controller to avoid chattering caused by excessive switching gain. Finally, Lyapunov's stability theorem is used to prove that the optoelectronic pod system has asymptotic stability in a closed-loop state, so that the actual attitude of the optoelectronic pod ultimately converges to the desired attitude.

This invention discloses a dual non-fragile control method for non-cooperative spacecraft based on electromagnetic capture, comprising: S1, establishing a dynamic model of the relative motion of the non-cooperative spacecraft under electromagnetic capture based on the T-H equations; S2, considering comprehensive disturbances and rewriting the dynamic model into state-space form; S3, designing a dual non-fragile observer / controller to address the coexistence of additive / multiplicative gain perturbations in the observer and controller; S4, substituting the dual non-fragile observer / controller into the state-space equations in step S2 to establish a state-space model of the closed-loop electromagnetic capture system; S5, deriving sufficient conditions for the system to be uniformly eventually bounded based on the LMI method and Lyapunov stability theorem, and solving for the observer / controller parameters in step S3. This invention fully considers the complex situation of coexistence of additive / multiplicative gain perturbations in the observer and controller, and can solve the electromagnetic capture control problem of non-cooperative spacecraft under multi-source disturbances such as external interference, elliptical orbit eccentricity, and unknown mass.

The invention discloses a wide and thick plate hot working furnace temperature guarantee performance control method based on an electric furnace power supply switching device. The method comprises the following steps: firstly, establishing a partial differential equation mathematical model and corresponding performance indexes of the wide and thick plate hot working system of the electric furnace power supply switching device; and then, designing a furnace temperature state feedback controller of the wide and thick plate hot working system of the electric furnace power supply switching device. And then, a closed-loop control system is constructed according to the wide and thick plate hot working mathematical model of the electric furnace power supply switching device and a furnace temperature state feedback controller. And the Lyapunov stability theorem, the Poincare inequality and the linear matrix inequality theory are utilized to obtain sufficient conditions for the existence of the hot working guaranteed performance control of the wide and thick plate of the electric furnace power supply switching device. A state feedback controller and a switching rule are designed, so that the temperature stability of the wide and thick plate hot working system of the electric furnace power supply switching device can be ensured, and the performance index of the wide and thick plate hot working system of the switching device can meet a certain requirement. According to the method, the influence of the Laplace operator coefficient in the electric furnace power switching device wide and thick plate hot working mathematical model on the system is fully considered, and the design is more scientific and reasonable. The method has the advantages that feedback control is carried out on the furnace temperature state of wide and thick plate hot working through the furnace temperature power supply cut-off device, engineering implementation is easy, and the purposes that the wide and thick plate hot working furnace temperature is stable and certain performance indexes are met under switching and external nonlinear disturbance of an electric furnace power supply switching control system can be achieved.

The invention provides a predefined time preset performance tracking control method under input saturation of a mechanical arm, and belongs to the technical field of robot control. The method comprises the steps that a mechanical arm dynamic model is established, and a tracking error is defined; designing a finite time performance function for constraining the dynamic behavior of the tracking error; the design auxiliary system is used for generating a modification signal when the input is saturated; dynamically adjusting the finite time performance function by using the modification signal to obtain a self-correction flexible finite time performance function, and converting the tracking error based on the finite time performance function; and based on the predefined time stability theorem and the conversion error, a predefined time preset performance sliding mode controller is designed, and trajectory tracking of the mechanical arm under the input saturation and model uncertainty conditions is achieved. The method solves the problem that the control precision of the mechanical arm is low.

The present invention belongs to the technical field of intelligent control, and discloses a speed tracking adaptive iterative learning control method for the extrusion rod of an extruder, which includes the following steps: determining the dynamic model of the extrusion rod and the control objective according to the physical properties of the extrusion rod and the movement mode of the extrusion rod; establishing a neural network model for the uncertain part in the movement model of the extrusion rod based on the approximation theory, and determining the speed tracking error system of the extrusion rod; designing a virtual control input and an actual control input based on the adaptive iterative learning control theory; and analyzing the stability of the designed controller based on the Lyapunov stability theorem. By adopting the above-mentioned speed tracking adaptive iterative learning control method for the extrusion rod of an extruder, the present invention can effectively control the finite-time speed tracking of the extrusion rod, realize the precise movement control of the extrusion rod, and ensure the dimensional accuracy, surface quality and production efficiency of the product.

The application discloses a grid-connected converter large-signal stability analysis method and device and a storage medium, wherein the method comprises the following steps: based on a system space model of the grid-connected converter, a system state space equation of the grid-connected converter is established; based on T-S fuzzy theory, a state space model of the grid-connected converter is established according to the system state space equation of the grid-connected converter; based on a stability theorem of the T-S fuzzy theory, a Lyapunov function of the grid-connected converter is constructed according to the state space model, each dimension of the Lyapunov function is projected to a two-dimensional state space plane, and a stable attractor domain of the Lyapunov large signal is obtained; an affine angle of the stable attractor domain is calculated, when the affine angle meets a preset condition, the stability strength of the grid-connected converter is calculated according to the affine angle, and a large-signal stability analysis result of the grid-connected converter is obtained according to the stability strength. The application can effectively improve the accuracy and reliability of the large-signal stability analysis of the grid-connected converter.

A preset performance control method for an intelligent vehicle steering system is proposed, which studies the preset performance tracking control problem of an intelligent vehicle steering system with model nonlinearity and parameter uncertainty. First, a radial basis function neural network is used to online approximate the nonlinearities in the steering system that are difficult to model, including friction torque and return torque. Then, the barrier Lyapunov function technology is combined to design a preset performance controller for the intelligent vehicle's wire-controlled steering system. In the controller design, dynamic gain technology is used to compensate for the influence of unknown control gain on the system control performance. Finally, combined with the Lyapunov stability theorem analysis, it is verified that the designed controller can achieve the tracking error of the front wheel angle of the intelligent vehicle steering system to converge to the preset neighborhood of the origin within a preset time. Compared with the existing control methods, the present invention greatly shortens the time of the controllable process and improves work efficiency.

The invention provides a robust beam forming method for spaceflight measurement and control, which comprises the following steps of: 1, acquiring statistical channel state information of ground communication users by a satellite, performing eigenvalue decomposition on a channel autocorrelation matrix of each user, and extracting an eigenvector corresponding to a maximum eigenvalue; 2, grouping the users in the service range, and serving one group of users in one time slot; 3, aiming at a non-convex problem, reconstructing a control stability constraint through a Lyapunov class stability theorem; 4, aiming at each user group, establishing an optimization problem taking traversal and rate maximization as targets; 5, the Jensen inequality and the Mullet's inequality are utilized, the auxiliary variable is introduced to process the target function, the Bernstein inequality and the continuous convex approximation method are combined to solve the optimization problem, and the beam forming weight vector and the transmitting power of each group of users are obtained.According to the method, the satellite resource utilization efficiency is improved through communication and control collaborative design.

The invention discloses a four-rotor unmanned aerial vehicle obstacle avoidance system new criterion based on affine formation control. According to the method, an interference observer is designed to estimate an unknown interference true value of the quad-rotor unmanned aerial vehicle, and a corresponding anti-interference controller is provided. Besides, in order to avoid obstacles during formation flight, leader-follower affine formation control is realized by using an affine transformation method, and the leader decides the required collective formation. Finally, by means of the Lyapunov stability theorem, several sufficient criteria are established to ensure that the leaders are consistent and finally bounded at the zero speed, the constant speed and the time-varying speed, and then formation control is achieved.

The application discloses a cost performance-based dynamic optimization control method for a switched Chua circuit system. The method constructs a cost function of the switched Chua circuit system, gives a corresponding Hamiltonian equation, and solves the optimization control input corresponding to the equation through a Critic neural network. In addition, based on the Lyapunov stability theorem, the consistent ultimate bounded condition of the switched Chua circuit system is ensured.