214 results about "Finite time control" patented technology

The invention discloses a reentry aircraft finite time control method based on a disturbance observer and relates to the reentry aircraft finite time control method. The reentry aircraft finite time control method belongs to the field of aircraft control technology. The reentry aircraft finite time control method comprises the following steps: a first step, establishing a reentry aircraft dynamic model, presenting a finite time gesture tracking task; a second step, performing feedback linear processing on a model which is established in the first step; a third step, providing a finite time control law; a fourth step, providing a finite time disturbance observer for estimating system uncertainty and outer disturbance; and a fifth step, providing a finite time global sliding mode control method based on the disturbance observer, and effectively improving tracking precision of a gesture control system through substituting an estimated disturbance value into the control law. The reentry aircraft finite time control method has functions of improving system error convergence speed, preventing a singular problem and improving uncertainty of the controlled system to the parameter, global robustness of outer disturbance and tracking precision.

The invention discloses a method for controlling postures of an aircraft converged at a fixed time, relates to an aircraft posture control method, and belongs to the technical field of aircraft control. The method comprises the following steps of (1) establishing a reentry aircraft dynamic model and offering a limited time posture tracking task; (2) performing feedback linearization treatment on a model established in the step (1); and (3) giving out a limited time control law, starting the state of a system from an optional initial value and consulting a trace on tracking within a set time. The method can be used for implementing system error fixed time convergence when part of initial value information is unknown. Moreover, the method has high robustness under the conditions that system parameters are uncertain and external interferences exist.

A finite time fault-tolerant control method for approaching and tracking a space non-cooperative target belongs to the field of orbit control and attitude control, and aims to solve the problem of low tracking supervision precision caused by big tracking control error of an existing tracking spacecraft which performs line-of-sight tracking for a non-cooperative target. The finite time fault-tolerant control method is characterized in that dynamical and kinematical equations are established under a line-of-sight coordinate system, the situations such as nondeterminacy of a system, partially unknown motion parameters of the non-cooperative target, control input saturation and dead zone are taken into consideration, self-adaptive estimation and compensation can be performed through adoption of an RBF neural network, and a back-stepping thought is adopted to design a controller so that the tracking spacecraft can converge to an expected attitude and orbit within finite time and can keep the attitude and the orbit. The finite time fault-tolerant control method of the present invention has the advantages of quick control convergence, good robustness and high tracking control precision.

The invention provides a finite time oriented team forming air vehicle cooperative control method and control system. The cooperative control method includes that a navigator and n followers form a team forming system and a dynamical model of the team forming system is established; measuring states of the team forming members; designing an ESO (Expansion State Observer) and an output value; basedon output of the ESO and the states of adjacent team forming members, calculating an integral type sliding mode variable structure of an i team forming member; based on the integral type sliding mode variable structure, designing a control protocol of the i team forming member so as to realize finite time coordination of the team forming state. According to the technical scheme provided bythe invention, aiming at influences due to constraints such as non-linear items, non-matching uncertainty, directional communication and the like in a practical team forming system, based on distributive control and a finite time control theory, based on the states of the adjacent team forming members, the ESO and the sliding mode control protocol are designed separately so as to ensure that theteam forming member state converges to the neighborhood of the navigator state in finite time.

The invention discloses a multi-intelligent-agent system collaborative fault-tolerant control method based on finite time control. The method comprises the steps of firstly, selecting an intelligent agent as a leader node in all the intelligent agents, constructing a multi-intelligent-agent system communication topology and expressing by an undirected graph through communication links among the multiple intelligent agents, calculating a weighted adjacent matrix, establishing a finite time controller based on the state error based on a finite time theory for the established multi-intelligent-agent system with the leader nodes, establishing different finite time controllers for each intelligent agent, and obtaining a global dynamic equation of the multi-intelligent-agent system, so that thesystem can achieve cooperative fault-tolerant control within a specified time from the time a fault occurs. The defects of a non-finite-time closed-loop control system are overcome, and the robustnessand the disturbance resistance of a multi-intelligent-agent system are improved.

The invention discloses a bridge crane finite time trajectory tracking controller and a design method thereof. Firstly, a non-singular terminal sliding mode surface is introduced, and the advantages of a first-order sliding mode control method and a second-order sliding mode control method can be integrated together to obtain an absolutely continuous control input. Secondly, inspired by the static torque calculation method, a finite time controller is proposed. Through introducing the Lyapunov candidate function, the stability of a closed-loop system is analyzed, and the limited convergence time T is obtained. Through comparing the above controller, an LQR controller, an enhanced coupling nonlinear controller and a motion planning-based self-adaptive controller, the correctness and the effectiveness of the control method can be proved.

The invention discloses an input saturation considered asynchronous motor command filter finite time fuzzy control method. Aiming at nonlinear problems of a motor driving and control system, a fuzzy logic system is adopted for approximation to a nonlinear function in the system, a command filter technique is introduced into a traditional backstepping design method, errors generated in filtering are reduced through introduction of a compensation mechanism, the problem of computation explosion caused by continuous derivation in traditional backstepping control is successfully solved, and control precision is improved. Small system stable tracking errors and short dynamic responding time under finite time control are realized, system convergence rate is increased, and interference rejection capability is improved. Under the condition of consideration of input saturation, bounded parameters of a closed-loop system can be guaranteed, and convergence of tracking errors of the system into a sufficiently small origin neighborhood in finite time can be guaranteed as well.

The invention discloses a relative orbit attitude finite time control method for a non-cooperative target spacecraft, and relates to the field of aerospace. The method solves the problems in present relative orbit attitude joint control of non-cooperative target spacecrafts. The relative orbit attitude finite time control method for the non-cooperative target spacecraft comprises the following steps: 1, projecting a relative orbit dynamics model expressed by an inertial system to a sight system, and describing the relative orbit dynamics model of the spacecraft by adopting the sight system; 2, establishing an attitude dynamics model and an attitude kinematics model; 3, performing state space representation on the relative orbit dynamics model, the attitude dynamics model and the attitude kinematics model to obtain a relative orbit attitude dynamics model; and 4, obtaining a finite time continuous controller according to the relative orbit attitude dynamics model and the finite time control theory. The method is suitable for relative orbit attitude joint control of non-cooperative target spacecrafts.

The invention discloses a finite time consistency-based distributed cooperative control method for a DC micro-grid. The method comprises the steps of (10) carrying out primary control, automatically maintaining power balance of a DC micro-grid system; and (20) carrying out secondary control, achieving voltage regulation and load power distribution. The control method is a distributed control method; the requirements of a central controller and a complicated communication topology are removed; a multi-agent system is controlled through finite time; current proportion distribution is achieved in a distributed manner; meanwhile, average output current of a distributed power supply is obtained; and cooperative regulation of the voltage of the DC micro-grid and proportional distribution of the load power can be quickly and accurately achieved.

The invention discloses a method and system for controlling anti-sway of a terminal sliding mode for an underactuated crane system based on a disturbance observer, and uses a finite time interferenceobserver to estimate external interference. A finite-time control law was designed by transforming the system into a chain system, combining the disturbance observer and introducing the proper slidingsurface. The analysis shows that when external disturbance is present, the designed controller can adjust the trolley to reach the predetermined trajectory within a limited time, thereby realizing the precise positioning of the trolley and the suppression of the load swing angle. The simulation results show the effective control effect of the proposed control method in the realization of trolleypositioning and anti-sway.

The invention discloses an advanced control method for direct-current boost converter system, applicable to high precision control of the direct-current boost converter system. The method adopts a current tracking mode based on extended state observers and a limit time control technology, and specifically includes the steps of: firstly, respectively observing disturbance of voltage change and resistive load by designing two extended state observers, based on the above, designing the limit time controller, and thereby obtaining a composite controller to control the direct-current boost converter system such that the direct-current boost converter system can quickly track target voltage with high precision under the presence of voltage change and resistive load disturbance. The method is simple to implement and relatively less in parameter adjustment, not only can improve the tracking speed of the direct-current boost converter system for reference signals, but also can effectively reduce steady-state wave motion of the power electronic direct-current boost converter and meet the application of high-performance power electronic direct-current boost converter systems.

The invention provides an active disturbance rejection control method for cluster spacecraft electromagnetic traction, complexity of a cluster spacecraft system and model uncertainty are fully considered, an electromagnetic force/torque model and a relative motion dynamics equation are established, so that the active disturbance rejection control method formed by a most speed tracking differentiator, a non-linear extension observer and a non-linear feedback control law has good working performance, a coupled problem of a dynamic model is effectively solved, high precise electromagnetic traction control can be realized, and the effectiveness and the Lyapunov asymptotic stability of the method are verified; compared with the control performance of a finite time control method, the control method has better rapidity, vibration resistance ability and disturbance rejection, and the control method is simple in design and has engineering realizability.

The invention provides a finite time track tracking control method for a rotorcraft, which comprises the following steps: establishing a mathematical model of the rotorcraft; using a layered control scheme to divide the rotorcraft into a height channel, a translation system and an attitude system, and separately designing a controller for each channel; for the height channel, designing a finite time controller to generate required lift for flight, and introducing an auxiliary system to compensate for input saturation action; for the translation system, designing a finite time controller to produce a desired roll angle and a desired angle of pitch; for the attitude system, designing a linear active disturbance rejection controller to generate torque required for flight. The control strategyprovided by the invention can not only improve the convergence speed, the tracking accuracy and anti-disturbance capability of the rotorcraft but also effectively compensate for the influence of input saturation on the control performance. The control strategy provided by the invention is simple in design, small in calculation amount, and easy to implement, and has a high practical application value.

The invention discloses a single-phase inverter finite time control method based on a disturbance observer. The method comprises steps: a disturbed state space average model for the single-phase inverter is built; with the tracking error value between the voltage actually outputted by the inverter and reference voltage as a state variable, influences of lumped disturbance are also considered, an error dynamic model for the single-phase inverter is built, and a finite time disturbance observer is designed; output of the observer serves as feedforward compensation and is combined with an output feedback control method, a finite time anti-disturbance controller based on the finite time disturbance observer is designed; and according to the finite time anti-disturbance controller, control on the output voltage of the single-phase inverter is realized. thus, quick and accurate tracking on the reference output voltage of the single-phase inverter in a finite time and accurate compensation suppression on multisource disturbance and uncertainty can be realized, the anti-disturbance ability of the system is improved, the system cost is reduced, and the fault-tolerance performance of the system is improved.

The invention discloses a command filter limited time fuzzy control method of a permanent magnet synchronous motor. The control method is capable of, in allusion to the existent nonlinear problem in a motor drive and control system, introducing a command filter technology into the traditional backstopping design method, and successfully overcoming the problem of 'computation explosion' in the traditional backstopping control caused by the continuous derivation. A fuzzy logic system is used for approaching the nonlinear function in the system, and the command filter backstopping technology is combined with a fuzzy self-adaption method to construct a fuzzy self-adaptive controller; the limited time method has the anti-interference performance and the robustness to the signals, such as the external load interference; and under the limited time control, the system stability tracking error is small, the dynamic response time is short, and the convergence rate and the interference rejection capability of the system are improved. Compared with the prior art, the control method has the faster response speed, the stronger anti-interference performance and the better tracking effect.

The invention relates to a quaternion description based rapid convergence control method of a quardrotor, and belongs to the technical field of flight control. A quardrotor control system model is established, a quardrotor control system is divided into a position subsystem and an attitude subsystem, a finite-time position controller of the quardrotor is designed, a finite-time attitude controllerof the quardrotor is designed, a motor rotating speed controller of the quardrotor is obtained, and flight of the quardrotor is controlled according to the motor rotating speed controller thereof. Afinite-time control technology is used to improve the convergence speed of a closed-loop system, so that the system can be converged to an expected value more rapidly within finite time; and comparedwith a traditional PID control method, the rapid convergence control method of the quardrotor is higher in anti-interference performance and robustness, and influence of different external interference on the quardrotor in practical flight is reduced effectively.

The invention discloses a multi-actuator underwater robot robust adaptive motion control device and method. The control device comprises a second-order sliding mode controller. The second-order sliding mode controller has a control gain adaptive device. The second-order sliding mode controller is connected with a control allocation module. The control allocation module controls and establishes anactuator nonlinear model. The actuator nonlinear model controls and establishes an underwater robot kinematics and dynamics module. The underwater robot kinematics and dynamics module and an expectation module jointly control the second-order sliding mode controller. The device and method overcome external disturbance of underwater complex environment and uncertainty of an underwater robot in theworking process; a multivariable second-order sliding mode motion control law is provided; by designing the adaptive law for control gain of a second-order sliding mode, finite-time control can be realized, chattering phenomena caused by a conventional method is prevented; and for a condition where multiple actuators work together, optimal control allocation is finished based on a quadratic form function.

The present invention discloses an image transmission method and system based on memristor chaotic system finite time synchronization, the method and system adopts chaotic signals to encrypt and transmit an image, uses bitwise OR logical calculation to encrypt and decrypt the image, in the same time, through a finite time control strategy, releases finite time synchronization of two memristor chaotic systems of a driving terminal and a response terminal, and uses a discrete chaotic sequence obtained by synchronous sampling and coding as an encryption sequence and a decryption sequence to successfully complete the encryption and decryption of the image without transmitting a key through a channel. Compared with a progressive synchronization strategy applied in the memristor chaotic system in the past, the finite time synchronization strategy has a faster convergence speed and better anti-interference performance, thereby avoiding a risk of the key being intercepted in the channel.

The invention discloses an impedance control method for a multi-joint mechanical arm based on finite time command filter and belongs to the technical field of robot control. Based on a backstepping method, force/position control of the mechanical arm is achieved by means of an impedance control technique. An unknown friction quantity in a multi-joint mechanical arm system is approached by adoptinga fuzzy adaptive technique and a command filter technique is introduced to solve the computing complexity problem in a conventional backstepping controller design, and meanwhile, an error compensating mechanism is introduced to eliminate influence of filter errors. A force/position tracking signal of the mechanical arm is converged within a finite time by means of finite time control, so that itis ensured that the force/position tracking error of the mechanical arm can be converged in a small enough field of an origin within the finite time. In a word, according to the control method provided by the invention, a force/position track at the tail end of the mechanical arm can track an expected trajectory quickly and effectively.

The invention provides a multiagent network finite time containment control method and apparatus. The method comprises the following steps: obtaining a minimum geometric space formed by a navigation agent by detecting the position of a barrier; determining an expected position and speed of a following agent during operation in the space according to a multiagent network topology and the position and speed information of the navigation agent; obtaining a relative position and speed between the following agent and the adjacent agent according to the topological connection situation between the following agents, and designing a finite time control protocol of the following agent according to the relative position and speed; and controlling the following agent to enter the minimum secure areaaccording to the finite time control protocol, and causing the following agent to move according to the expected position and speed. According to the multiagent network finite time containment controlmethod and apparatus, the coordinated security control of the multiagent network is guaranteed by few navigation agents provided with sensors; and second-order linear control based on the positions and speeds of the agents is adopted to effectively improve the fastness and stability of the nonlinear agent group coordinated control.

The invention discloses a finite time control method for a teleoperation system with the consideration to a triangular structure, and the method comprises the steps: establishing a teleoperation system model under an n-dimensional triangular structure, and defining a position synchronization error variable among a main robot I, a main robot II and a slave robot under the network communication time-varying delay; designing an auxiliary intermediate variable which does not depend on the time-varying delay precise information based on the position synchronization error variable among the main robots and the slave robot; designing a non-smooth finite time control method based on the designed auxiliary intermediate variable; establishing the precise relation between system convergence time andcontrol parameters through using the backstep recursion, dynamic surface control and Lyapunov methods. A time-varying weight variable is introduced during the consideration of the triangular structure, and the method greatly improves the flexibility between an operator I, an operator II and the slave robot. The design of the non-smooth finite time control method can provide a better synchronization precision while improving the system convergence speed. The conservative property of the system is reduced, and the actual application range of the system is enlarged.

The invention discloses a continuous finite time control method for a teleoperation system under time-varying delay, and the contents of the method are that the method comprises the steps: introducinga new intermediate variable to split the teleoperation system into two subsystems, and designing a finite time control strategy based on a power integration method for the first subsystem to ensure that the synchronization error of the first subsystem tends to a zero point in the finite time; performing the strict proving of the finite time stability and finite time synchronization performance ofthe first subsystem based on the Lyapunov theory, and building the relationship between control parameters and system convergence time; designing a finite time controller for the second subsystem with delay information; building the relation between the infinite time convergence of the second subsystem and the controller parameters and time delay derivative upper bound based on the weak finite time input-to-state stability, weak finite time input-to-output stability and finite time small gain theorem. Compared with the general P+d, PD+d and direct force feedback methods, the method has fasterconvergence speed and higher convergence precision.

The invention relates to a dead zone characteristics considered servo system finite-time control method, and the method comprises the steps: a servo system model is established, system state and controller parameters are initialized; approximate compensation is performed on dead zone part; a non-linear extended state observer is designed, parameters of the observer is determined by adopting a pole assignment method; a full-order sliding mode controller is designed. The extended state observer is designed to estimate the system state and uncertain items including system friction and external disturbance, gain parameters of the observer is determined by adopting the pole assignment method; and the full-order sliding mode controller is designed to ensure the system tracking error to be quick, stable and converge to zero, the chattering problem is reduced, and quick and stable control of the servo system is realized. According to the invention, the method solves problems of unmeasured external disturbance state such as system friction, influence of non-linear dead zone part existed in system is compensated, problems of chattering problem and long convergence time existed in common sliding mode method are improved, anti-interference capacity of the system is improved, and the system can quickly and stably track a wanted signal.

The invention discloses a method for controlling the finite time of a discrete networked multi-agent system having a communication delay, and relates to a method for controlling the finite time of a discrete multi-agent system. The method solves the problem that the current method for controlling the finite time of the discrete networked multi-agent system cannot actively compensate the network communication delay and affect the control performance of the finite time. The method comprises: establishing a networked prediction model based on a dynamic model of the established discrete networkedmulti-agent system; obtaining a prediction state of the neighboring agent according to a networked prediction model, and designing a distributed protocol to obtain a closed loop system; obtaining an observer gain L and a state feedback gain K based on a bounded sufficient condition of the finite time of the discrete networked multi-agent system having a communication delay, and respectively substituting into the networked prediction model and the distributed protocol to control the finite time of the discrete networked multi-agent system having the communication delay. The method for controlling the finite time of the discrete networked multi-agent system having the communication delay is suitable for controlling the finite time of the discrete networked multi-agent system.