413 results about "Linear matrix inequality" patented technology

The invention belongs to the field of spacecraft control and relates to a fuzzy singular perturbation modeling and robust attitude control method for complex flexible spacecraft, namely a robust combined control method for fusing static output feedback control and output integration. The method comprises the following steps of: establishing an uncertain continuous fuzzy singular perturbation model and a standard discrete fuzzy singular perturbation model according to a dynamic model and a kinematic model of the spacecraft in combination with fuzzy logic and singular perturbation technology; and designing a robust controller combined by a static output feedback controller and an output integrator by a spectral norm and linear matrix inequality (LMI) method and resolving a group of LMIs which are unrelated to a perturbation parameter so as to obtain a controller parameter and solve an ill-conditioned problem caused by the perturbation parameter and the problem of difficulty in selection of an initial value in an LMI resolving static output feedback controller gain method. Through the method, flexible vibration and external interference can be overcome effectively, and control effects such as high response speed, high attitude control accuracy, high anti-jamming capability and high robust performance are achieved.

The invention relates to a WAMS (wide area measurement system) based low-frequency oscillation coordinated damping control method for a power system, and belongs to the technical field of low-frequency oscillation analysis and control of power systems. The method includes adopting a hierarchical clustering technology to perform primary region division according to power angle curves or angular velocity curves obtained after preprocessing, performing low-frequency oscillation mode identification on the system on the basis of a Prony identification algorithm, adopting a PSS (power system stabilizer) to inhibit regional oscillation modes for strong correlation generators with generated low-frequency oscillation modes belonging to regional oscillation modes, introducing wide-area signals of other regions for generators with generated low-frequency oscillation modes belonging to inter-region oscillation modes, designing a controller for a reduced mathematic model of an identification system, and solving parameters of the controller by an LMI (linear matrix inequality). By the low-frequency oscillation controller design method, in a regional and hierarchical control mode, coordinated damping control of the power system is realized.

The invention provides a security control method of an event-driven network control system under a multi-network attack. Considering the network transmission security problem, a random network spoofing attack, a replay attack and a DoS attack are sequentially introduced, and a system closed-loop model under the multi-network attack is established. Further considering the constraint of the limitednetwork bandwidth, an event trigger mechanism is introduced to screen and release sampling data meeting a preset event trigger condition to the network for transmission, thereby establishing a new switching system model on the basis of the system closed-loop model. Based on a switching system model, a Lyapunov stability theory is utilized to obtain a sufficiency condition for enabling the system to meet the stability of a mean square index, and a group of linear matrix inequalities is solved to obtain the gain of the state feedback controller. Compared with an existing controller design method, safe and stable operation of the network control system under the influence of multi-network attacks is guaranteed, meanwhile, the data transmission frequency is reduced, and limited network bandwidth resources are saved.

The invention provides a wind energy converting system sliding mode control method and device based on a T-S fuzzy model. To solve the problem of the fault of an actuator in a wind energy converting system, the T-S fuzzy model is utilized for describing a nonlinear wind energy converting system with uncertain actuator fault information, the approximation accuracy of a controlled object is improved, and a good model foundation is established for sliding mode control. Meanwhile, by means of a sliding mode controller designed based on the linear matrix inequality technology, the stability of the wind energy converting system is guaranteed, and the robustness and fault tolerance of the wind energy converting system are improved. The precise tracking of the rotating speed of a power generator and the electromagnetic torque can be achieved when the uncertain actuator fault exists in the wind energy converting system, and the maximum wind energy capturing of the wind speed below the rated value is achieved, and a valuable reference scheme is provided for efficient and stable running of the wind converting system.

The invention belongs to the control field and provides a design method of a robustness fault detection filter of a linear uncertain system. A Lyapunov function method on which a homogeneous polynomial parameter depend is introduced into robustness fault detection of a linear time invariant system with convex polyhedron nondeterminacy. Firstly, existence of an HPPDL function used for designing an RFDF can be verified through feasibility of a linear matrix inequality; secondly, maximal fault sensitivity is obtained through solving a generalized eigenvalue problem, and an optimal RFDF is obtained. With increase of polynomial time, quantity of the linear matrix inequality and a free variable are increased, and conservation of verification is reduced substantially. The design method comprises two phases: (1) designing an optimal RFDF for a residual error generator with certain interference attenuation and largest fault sensitivity; (2) carrying out threshold design for a residual error generated by estimation. Compared with a previous analogy method, the design method in the invention has generality.

The invention discloses an improved method for improving the stability property of a communication system, belonging to the technical field of communication. The improved method comprises the steps of: determining a parameter, a determining an optimization program, simplifying the optimization problem, introducing a slack variable, transforming a half-infinite limit condition into a linear matrix inequality, obtaining a final form of the optimization problem, proving that the solution is an optimal solution, solving an optimal sending power popt, and outputting the optimal sending power popt. According to the improved method, on the premise of considering that the channel state information of a wiretap channel is not completely known, an optimal scheme is re-designed, therefore, the stability property of secret communication is improved. Under the condition of realizing that the state information of the wiretap channel is not completely known, a manual noise covariance matrix and a transmission beam forming vector are combined for optimization design, thus the stability of the secret communication is improved. Compared with the condition of known channel state information, the improved method has remarkable advantages on the stability of the whole system.

The invention discloses a 2D controller design method for interval time lag in the injection modeling process. The method comprises the steps that A, a state space model is established according to a control requirement of parametric variables in the injection modeling process; B, according to the repeated operation characteristic of the injection modeling process, the established state space model is converted to be a 2D error augmentation model by a 2D-FM model design method; C, a controller meeting a control law r (tk) is designed according to the 2D error augmentation model; D, a linear matrix inequation mode is used for solve the gain K of the controller. The 2D controller design method directs at the time lag phenomenon existing in the injection modeling process to establish the state space model based on a two-dimensional system theory, a 2D-FM model is used for designing the controller, the system can be quickly stabled in the injection modeling process, tracking can be conducted quickly, and the system can be still kept in good control performance even though the system is influenced by time lag. The 2D controller design method for interval time lag in the injection modeling process can be widely applied to the technical field of injection modeling.

The invention relates to a robust fuzzy predictive fault-tolerant control method for an interval time-varying-delaying system. The robust fuzzy predictive fault-tolerant control method includes the following steps that firstly, a T-S fuzzy model of a nonlinear system is constructed; secondly, the constructed T-S fuzzy model is converted into an expanded T-S fuzzy model; thirdly, according to the constructed expanded T-S fuzzy model, a fault-tolerant controller that satisfies a control law is designed; and fourthly, a gain of the fault-tolerant controller is solved in a form of linear matrix inequality and the robust fuzzy predictive fault-tolerant control law is calculated. According to the robust fuzzy predictive fault-tolerant control method for the interval time-varying-delaying system,the robust fuzzy predictive fault-tolerant control method with time-delay dependence is provided according to the fact that a type of the industrial process has the characteristics such as nonlinearity, uncertainty, unknown disturbance, interval time-varying-delaying and partial actuator failure, thus the industrial process operates more smoothly and efficiently, the performance of a system is improved, and the fault tolerance of the system is increased.

The invention discloses a fault-tolerant control method for a networked control system with time-varying delay. In view of conditions of parameter perturbation, time-varying delay, external disturbance and random failure happening to an actuator, a discrete time closed-loop nonlinear networked control system model is firstly built, a Lyapunov-Krasovskii function with the delay information is then built, a Lyapunov stability theory and a linear matrix inequality analysis method are used, sufficient condition for asymptotic stability of the nonlinear networked control system and existence of an H-infinity fault-tolerant controller are obtained, a Matlab LMI toolbox is used for solution, and a gain matrix for a non-fragile fault-tolerant controller is: K=K<->P; and conditions for optimizing the minimum disturbance rejection rate gamma is given, and the controller gain matrix K<*> optimized under the minimum disturbance rejection rate gammamin= square root of e is acquired. The condition of time-varying delay existing in the system is considered, the time-varying delay is analyzed and processed based on a free-weighting matrix method, and the conservation is reduced.

A gait generating device 32 includes a desired particular-site motion velocity value determining unit 45 that uses a quadratic evaluation function having a particular-site motion velocity vector ↑Vb as a variable and a linear matrix inequality having ↑Vb as a variable to sequentially determine, as a desired value ↑Vb_cmd2 of ↑Vb, a value of ↑Vb that can minimize the value of the evaluation function within a range in which a restriction condition that the linear matrix inequality holds is satisfied, by arithmetic processing according to a solution method for a quadratic programming problem. The device then integrates ↑Vb_cmd2 to sequentially determine desired values of the position and posture of the particular site (the body) 2 of the robot 1. The linear matrix inequality is set to satisfy a condition restricting the operations of the joints between the particular site 2 and the distal portion of each leg link 3.

The invention aims at an intermittent process with uncertainty, and proposes a constrained 2D tracking control method for the uncertainty intermittent process. The constrained 2D tracking control method comprises the steps of: firstly, designing an iterative learning control law for a given system dynamic model; secondly, converting the original system dynamic model into a 2D-FM closed-loop systemmodel expressed in the form of a predictive value according to a 2D system theory and the designed iterative learning control law through introducing state errors and output errors; and finally, giving a sufficient condition expressed in the form of a linear matrix inequality (LMI) for ensuring robust asymptotic stability of a closed-loop system and an expression form of the optimal control law according to a designed infinite time domain performance index and a Lyapunov stability theory. According to the constrained 2D tracking control method, numerical values of tracking errors under the control of the constrained 2D tracking control method are smaller, and the convergence is faster; more importantly, the control input does not drastically fluctuate and only require slight adjustment, thereby being conducive to resource conservation and reducing troubles caused by frequent operations.

The invention relates to a state feedback based vehicle path tracking H-infinity control method, which comprises the steps of firstly acquiring horizontal and vertical coordinates of a reference path, solving a reference course angle, finding a corresponding reference point on the reference path according to the current position of a vehicle, and calculating the position deviation and the course angle deviation between the reference point and a current point of the vehicle; then improving a single-track traditional vehicle dynamic model into a position deviation and course angle deviation based dynamic model, and acquiring a state equation of the system; then taking major influence factors for transverse motion control of the vehicle in the model as bounded disturbance of the system by referring to the yaw rate, and designing a static state feedback controller according to a state feedback H-infinity control law; and finally, converting into a convex optimization problem with linear matrix inequality constraints and a linear objective function, solving a coefficient matrix of the controller by using a linear matrix inequality toolbox, acquiring controller output, namely, a tire rotation angle, and thus realizing path tracking control for the vehicle. The method provided by the invention is applicable to vehicle path tracking control in complex traffic scenes.

The invention discloses a nonlinear multi-time-scale delay system modeling and control method and belongs to the technical field of controlling of complex systems. The method is based on the UDTTDFSPM and combined with a spectral norm and linear matrix inequality method, a robust combination controller is designed for controlled NMTSTDSs, and high-precision and stable control of the NMTSTDSs is achieved. According to a dynamic model of the NMTSTDSs, an uncertainty continuous time delay obscurity singular perturbation model of the NMTSTDSs is set up, a proper sampling period is selected, a zero-order holder method is adopted to perform discretization on the obtained continuous model, and the UDTTDFSPM of the NMTSTDSs is obtained. The robust combination controller is designed on the basis and is composed of an obscurity slow state feedback controller and an output integrator. The nonlinear multi-time-scale delay system modeling and control method has the advantage of solving the problem of steady-state errors which are caused by system external disturbance and the fast modality of the NMTSTDSs and cannot be solved by an existing modeling and control method, and the control performance of the NMTSTDSs is greatly improved. The nonlinear multi-time-scale delay system modeling and control method is used for controlling the simulation result of postures of a CE150 helicopter, and validity of the method can be shown.

The invention discloses an aircraft tracking control direct method with input saturation to solve the technical problem that input saturation tracking control is difficult to realize if an aircraft has uncertain parameters and external disturbance exists. The method includes the steps: firstly, establishing an aircraft model with a time-varying uncertain parameter and external disturbance, and converting a non-linear system into a linear parameter varying error system through linearization along a time-varying path; then, obtaining a convex polyhedron description form of the error system through a tensor product model transform method, and directly describing a saturation effect of a control quantity also through a convex polyhedron structure if the state of the system is restricted within some local scope; and finally, on the basis of the robustness H-infinite theory, obtaining an input saturation controller by solving linear matrix inequations with limited number, the controller accurately tracking instructions and effectively inhibiting disturbance within the system state local range. In particular, if state constraint matrixes are made to be equal to control matrixes, saturation of the controller can be prevented.

The invention provides an event triggering-based control method for a T-S fuzzy network system. Stability and H<infinity> performance analysis is conducted on nonlinear NCSs based on an event triggering mechanism. A system model is built through a T-S fuzzy model; a transmission strategy of the event triggering mechanism (ETM) is provided by adopting a relative error threshold idea on the basis ofthe system model; a corresponding state feedback controller is designed by introducing a parallel distribution compensation (PDC) technology; and by constructing an appropriate Lyapunov-Krasovskii function method and combining a linear matrix inequality (LMI) idea, a sufficient condition for ensuring the mean square stability of the system and an index for ensuring the system to meet the certainH<infinity> performance are obtained.

The present invention belongs to the technical field of power system, and relates to a method of time-delay stability criterion. The method adopts the idea of Lyapunov stability criterion; an appropriate Lyapunov functional is selected at first, and is transformed into a group of linear matrix inequalities (LMI) for solution through the Leibniz-Newton formula, relaxation and other means; simultaneously, the redundant items which are generated in the deduction process is eliminated so as to acquire the stability criterion. In the method, the items to be calculated are greatly reduced, and the operating efficiency is correspondingly improved. Moreover, because the time-delay stage widely occurs in various systems, the method is suitable for various environments with the time delay.

The invention relates to a method for estimating the state of a networked control system with random uncertainty and delay of distributed sensors, particularly to a method for estimating the state of random uncertainty and delay of distributed sensors. The method solves the problem that the existing method for state estimation can not treat the random uncertainty and the delay of distributed sensors at the same time, so the performance of state estimation is influenced. According to the method of the invention, the influence of random uncertainty and delay of distributed sensors on the performance of state estimation is considered at the same time, and a Lyapunov function is used to fully consider the effective information of the delay. Compared with the existing method for estimating the state of a nonlinear complex dynamic system, the method for state estimation of the invention can be used to treat random uncertainty, delay of distributed sensors and bounded time-varying delay at the same time so as to obtain a method for state estimation on the basis of the solution of a linear matrix inequality; therefore, the purpose of resisting nonlinear perturbation can be achieved. The method is suitable for estimating the state of the nonlinear complex dynamic system.

The invention, which belongs to the technical field of networked multi-agent systems, provides a packet consistent method for heterogeneous networked multi-agent systems with time-varying delays. A discrete time dynamic model of a heterogeneous networked multi-agent system with the time-varying delay is established; a state observer is constructed and state prediction is performed; a packet consistency control protocol is designed; on the basis of the designed packet consistency control protocol, compact expression forms of a packet state error equation and an estimation error equation are obtained; a state feedback matrix is obtained based on a linear matrix inequation; and then the obtained state feedback matrix is substituted into the designed packet consistency protocol to realize packet consistency of the heterogeneous networked multi-agent system with time-varying delay. Therefore, a problem that the system convergence speed is affected by using the outdated information to realize the system consistency in the existing heterogeneous networked multi-agent systems with the time-varying delay is solved. The method is suitable for the packet consistency design of the high-order heterogeneous system.

The invention discloses a fault tolerant control method of a four-rotor-wing aircraft based on an optimal sliding mode. The optimal fault tolerant control method is provided by considering time lag caused by wireless network transmission, aiming at actuator faults of the four-rotor-wing aircraft and combining optimal control and sliding mode control. According to the fault tolerant control method, a sliding mode surface with time lag compensation is designed, and sufficient conditions of asymptotical stability of an ideal sliding mode is given by utilizing a linear matrix inequality principle; an optimal control concept is introduced, and quadratic form optimal performance indexes are adopted; and the sliding model control is combined to finally form a complete fault tolerant controller. According to the method disclosed by the invention, the sliding mode surface with the time lag compensation is configured and influences caused by the time lag can be eliminated; the quadratic form optimal performance indexes are designed so that a control rule of a nominal system can be optimized; and the control precision of the four-rotor-wing aircraft is effectively improved, and design evidences of the fault tolerant controller are provided for a complicated four-rotor-wing aircraft with the actuator faults. The fault tolerant control method is used for carrying out passive fault tolerant control on the four-rotor-wing aircraft with the time invariant time lag.

The invention discloses a combined navigation method which is based on robust dissipative filtering, and relates to a combined navigation systematic method of strapdown inertia, satellite and astronomy. Firstly, the combined navigation method uses a strapdown inertia navigation system, a GPS receiver and an astronomical navigation system for forming a combined internal navigation system; secondly, according to the dissipative control idea of the modern control theory, the combined navigation method uses a linear matrix inequality (abbreviated as LMI) algorithm for designing a robust dissipative filter so as to implement the fusion of high-precision GPS position and the posture measurement information of speed and the astronomical navigation system; the combined navigation method completely exerts high reliability and usability of traditional navigation means, as well as high precision of satellite and astronomy navigation, and finally achieves the high-reliability and high-precision combined navigation that is based on multiple sensors.

The invention introduces a design method and control method of a robust pitch controller above the rated wind speed of a wind power generator. The pitch controller design method first establishes the blade load model, performs vector transformation to achieve decoupling, and linearizes the decoupling model in the vertex set of the scheduling parameter convex set; secondly, converts the model into an LPV system, and uses H The ∞ theory standardizes the model as a standardized augmented control object containing performance indicators, uses the linear matrix inequality method to design the controllers on the vertex set of the convex set of scheduling parameters, and uses the gain scheduling principle to obtain the global pitch controller, and finally uses the vector The inverse of the transform yields the actual control signal.

The invention discloses a design method of an auto disturbance rejection controller with an anti-integral compensation function. The method includes the following steps that: a nonlinear system modelis established; a linear auto disturbance rejection controller with an anti-integral compensation function is designed for the nonlinear system model, wherein the linear auto disturbance rejection controller is composed of an extended state observer and linear feedback; and the parameters of the anti-integral compensation auto disturbance rejection controller are determined by solving a linear matrix inequality. According to the design method of the invention, the anti-integral compensation function is applied to the design of the auto disturbance rejection controller, and therefore, the performance degradation of the control system caused by actuator saturation can be offset, and the stability of a closed loop system using auto disturbance rejection control can be ensured.

The invention discloses a nonlinear networked control system non-fragile H-infinity fault tolerance control method. Firstly a closed-loop nonlinear networked control system model is established for considering the situation of parameter perturbation, time delay and packet loss of the nonlinear networked control system and random fault of an actuator, and then a Lyapunov function including packet loss information is constructed. The sufficient conditions of nonlinear networked control system stochastic stability and existence of an H-infinity fault tolerance controller are obtained by using the theory of Lyapunov stability and a linear matrix inequality analysis method. Solving is performed by using a Matlab LMI tool box, a non-fragile fault tolerance controller gain matrix K=YP<-1><011> is given, the conditions for optimization of the minimum disturbance suppression ratio gamma are given, and the optimized controller gain matrix K* under the minimum disturbance suppression ratio gamma<min> (the square root of e) is acquired. The situation of the random fault of the actuator is considered, and the probability of the random fault meets BerRoulli distribution so as to have more practical meaning.

The present invention discloses a non-fragile dissipative filtering method of a nonlinear networked control system. The method comprises the steps of firstly establishing a nonlinear networked filtering error system model on the conditions of considering the time delay and the packet loss of the nonlinear networked control system and the perturbation of the filter parameters, then constructing a Lyapunov function, and then utilizing a Lyapunov stability theory and a linear matrix inequality analysis method to obtain the sufficient conditions of the mean square exponential stability of a nonlinear networked filtering error system and the existence of a non-fragile dissipative filter, utilizing a Matlab LMI tool kit to solve, and definding a non-fragile dissipative filter parameter matrix. The method of the present invention considers the random time delay and the pocket loss situations between the sensors and the filters, is suitable for the general dissipative filtering including the H-infinite filtering, and enables the conservatism of the non-fragile dissipative filter design to be reduced. Moreover, a non-modeling state of the system is considered when a full-order filter is designed, thereby being able to reduce the calculation burdens and the design cost.

The present invention discloses a self-adaptive sliding-mode control method for a liquid level control system based on a Delta operator. In process control systems such as liquid control, uncertainty and time delay existing in the control systems may influence stability of the system, thus a sliding-mode control method based on a delta operator in combination with self-adaptive control is provided. A non-linear sliding mode surface is designed, a sufficient condition for asymptotic stability of a time-delay uncertain system is given in the form of linear matrix inequality, input disturbance is taken in consideration, and an upper bound is estimated through a self-adaptive boundary estimation method, so that a complete self-adaptive sliding-mode controller is formed. According to the self-adaptive sliding-mode control method of the present invention, a special non-linear sliding mode surface is designed, thus motion quality of the system is improved; by combining the advantages of self-adaptive control with the advantages of sliding-mode control, the designed control law can have a good control effect when the system has time delay and uncertainty. The self-adaptive sliding-mode control method is used for a liquid level control system with time-varying delay and system modeling uncertainty.

A quantization-based wide-area power system output feedback control method comprises the following steps that: 1) the information acquisition is finished through a PMU in a wide area measurement system, the PMU measures a power system state quantity at a fixed sampling period, and establishes a closed loop power system discretized state space model by taking T as the sampling period; 2) all states of the system are difficult to be measured in a real system; 3) and the obtained power system model is subjected to stability analysis by adopting a Lyapunov stability theory and a linear matrix inequality method, so that an inequality (15) is satisfied, and controller gains are designed for analysis validation. The quantization-based wide-area power system output feedback control method can ensure the stability of the power system with a quantizer, effectively alleviates the communication network congestion, reduces the construction costs of a communication network, saves storage space of a data storage center, is conducive to the expansion of the system, and increases the economic benefit.

The present invention belongs to the field of automation technology advanced control, and especially relates to a batch process 2D constraint fault-tolerance control method through infinite time domain optimization. An iteration learning control law is designed for a constraint fault control system model with interference, state errors and output errors are introduced, a Roesser model is employedto convert a dynamic model of an original system to a closed-loop system model expressed by a prediction mode, and the designed iteration learning control law is converted to a determined constraint update law; and according to the designed infinite optimization performance index and a 2D system Lyapunov stability theory, giving an update law real-time online design which can ensure the asymptotically stable closed loop system robustness in a linear matrix inequality (LMI) mode. The problem is solved that the control performance cannot be improved with the batch progressive increasing and theproblem of initial value indetermination batch process is solved, and finally, energy saving and consumption reduction are achieved, the cost is reduced, and the generation probability of accidents being harmful for personal safety.

A method for controlling the position and speed of a vehicle having steered wheels includes, determining an overall path comprising a plurality of points and defining the course of the vehicle between a starting point and an endpoint; determining the current position of the vehicle; if the current position does not correspond to a point on the overall path, generating a local path connecting the current position of the vehicle to a point on the overall path; and generating control signals in order to steer the steered wheels and control the speed of the vehicle so that the vehicle moves along the local path. The control signals are generated by convex optimisation of linear matrix inequalities.

The invention provides a quaternion theory-based convex relaxation global optimization algorithm-based robot hand-eye calibration method which is used for solving a problem that a non-linear optimization-based hand-eye calibration algorithm cannot ensure that an object function converges to a global minimum value when deviations are found in robot kinematics forward solutions and camera external parameter calibration. Based on consideration of effects exerted on calibration equation solution precision by included angles formed between relative movement rotation shafts on a tail end of a mechanical hand, a random sample and consensus algorithm is used for pre-screening the included angles formed between the rotation shafts in calibration data, a quaternion parameterized rotation matrix is used for building a polynomial geometry error object function and constraints, and a linear matrix inequality convex relaxation global optimization algorithm is used for solving a global optimal hand-eye transformation matrix.

The invention provides an electric power system wide-area output feedback control method considering WAMS (Wide Area Measurement System) signal time delay. The method comprises the following steps of: firstly, building a closed-loop wide-area electric power system general model considering feedback signal time lag on the basis of a networked control system theory; then introducing an improved free-weighting matrix approach to obtain a theorem and a deduction for time lag stability analysis of a wide-area electric power system networked control system; meanwhile, converting a non-linear matrix inequality (NLMI) into a linear matrix inequality (LMI) which is convenient to resolve by adopting an improved cone compensation algorithm, and obtaining the maximum time lag boundary of a wide-area electric power system networked controller with lower conservative property and a corresponding state feedback controller via a non-linear iterative optimization algorithm; and finally, realizing time lag output feedback control of an electric power system in combination with a mature state observer theory. The electric power system wide-area output feedback control method has the advantages of simple calculating process, higher running speed, capability of obtaining the maximum time lag upper bound of a wide-area electric power system rapidly, and easiness in implementing on the aspect of engineering.