442 results about "Terminal sliding mode" patented technology

The invention relates to an aircraft limited time adaptive attitude control method based on the enhanced index approaching law, aims to solve an aircraft attitude stabilization problem having concentration uncertainty, utilizes a sliding mode control method based on the enhanced index approaching law and is integrated with adaptive control. A terminal sliding mode surface is designed for guaranteeing limited time convergence of a system, a problem of buffeting is reduced in an actual control system through the enhanced index approaching law, moreover, adaptive control is for adjusting a self characteristic feedback control system according to environment change in an intelligent mode to make the system operates in the optimal state according to certain setting standards. The method is advantaged in that the problem of buffeting of the sliding mode surface and control torque can be reduced, on the condition that the system has uncertainty and interference, limited time consistent boundary control of the system is finally realized.

The invention discloses a direct torque control system of a permanent magnet synchronous motor based on a terminal sliding mode, which belongs to the field of motor control. The system comprises a main circuit, a signal detection circuit, a rotational-speed outer-ring controller for the terminal sliding mode, a torque linkage inner-ring controller for an adaptive fuzzy sliding mode, a stator-linkage electromagnetic torque estimation module, an SVPWM module, a 3/2 coordinate transform module, and a rotor position/speed estimation module; the design on the rotational-speed outer-ring controller is realized by using a terminal sliding mode control method based on the adaptive estimation of load disturbance, and the rotational-speed outer-ring controller outputs direct-torque controlled demand signals; and the design on the torque linkage inner-ring controller is realized by using an adaptive fuzzy sliding mode control method, and the torque linkage inner-ring controller outputs two-phase alternating voltages in a two-phase stationary coordinate system; and through carrying out SVPWM transformation on the two-phase alternating voltages, a power switching element acted on an inverter of the main circuit implements the direct torque control of the permanent magnet synchronous motor. The direct torque control system in the invention has the advantages of quick torque response speed, good robustness, small tracking error, and capability of improving the reliability and static/dynamic characteristics of the system.

An aerial vehicle finite-time adaptive attitude control method based on an improved power reaching law aims at a problem of aerial vehicle attitude stabilization with concentrated uncertainty. A sliding mode control method based on the improved power reaching law is utilized, and furthermore through adaptive controlling, the aerial vehicle finite-time adaptive attitude control method based on the improved power reaching law is designed. A terminal sliding mode surface is designed for ensuring definite-time convergence of a system. Furthermore through the improved power reaching law, a buffeting problem is reduced in an actual control system. Furthermore the adaptive controlling is used for a feedback control system which intelligently adjusts a self characteristic according to the environment change so that the system can operate in an optimal state according to some preset standards. The invention provides the control method which can reduce the buffeting problem of the sliding mode surface and a control torque and furthermore realizes uniform ultimate boundedness of finite time of the system on the condition that uncertainty and interference exist in the system.

The invention relates to the technical field of remote operating robot synchronous control, specifically discloses a remote operating robot fixed time control method based on a rapid terminal sliding mode. The method includes: selecting a master robot and a slave robot to form a remote operating system, measuring system parameters of the master robot and the slave robot respectively, measuring position information of the master robot and the slave robot on line, obtaining speed information of the master robot and the slave robot, designing a rapid terminal sliding mode surface, based on the designed rapid terminal sliding mode surface, using the system parameters of the main robot and the slave robot to design a self-adaptive fixed time controller, and using a Lyapunov equation to provide a relational expression between a parameter self-adaptive law, controller parameters, sliding mode surface parameters and system convergence time, thereby determining the controller parameters and the sliding mode surface parameters according to requirements of practical application for system convergence time and a relational expression between the system parameters and the system convergence time. The remote operating robot fixed time control method based on the rapid terminal sliding mode makes up for the defects in control speed and control accuracy of an existing remote operating robot system control method.

The invention provides a motor servo system jitter-free sliding mode position control method based on disturbance compensation. According to the method, the nonlinear friction characteristic, external disturbance and other modeling uncertainty of a system are considered, continuous and smooth friction compensation is made for nonlinear friction, and the low-speed servo performance of the motor position servo system is further improved; uncertainty such as non-modeling disturbance is estimated through an extended state observer, feedforward compensation is made when a controller is designed, and the robustness of the actual motor position servo system to external disturbance is improved; jitter and singularity will not be caused to voltage output of the designed terminal sliding mode controller, the controller can guarantee that the state of the system tends to be balanced in a limited time, and the tracking performance of the system is greatly improved; the designed terminal sliding mode controller is simple, has certain robustness to system parameter variation and is more favorable for being applied to engineering practice.

The invention discloses a mechanical arm trajectory tracking control method based on a high-order sliding-mode observer. The method comprises the following steps of 1, establishing a dynamical model of an n-degree-of-freedom rotary joint rigid mechanical arm system; 2, acquiring measurement information of joint angles q of a mechanical arm by utilizing a photoelectric encoder, and calculating a mechanical arm trajectory tracking error e = q - qd according to a set expected joint angle qd; 3, establishing a global integral fast terminal sliding mode surface according to e; 4, determining control torque tau of joint driving motors of the mechanical arm according to the sliding mode surface and establishing a control gain self-adaptive rate capable of being dynamically adjusted; and 5, establishing the output feedback high-order sliding mode observer according to the control torque tau and the joint angles q of the mechanical arm, and estimating current angular velocity of joints and lumped disturbance. According to the method, under the situation that nonlinear uncertain items such as system parameter perturbation, external torque interference and damping friction exist in the mechanical arm system, the trajectory tracking control of the mechanical arm is realized only based on the measurement information of all the joint angles, and robustness of whole control process is ensured.

The invention relates to a method of taking over and controlling attitude after a space tethered robot captures a flexible target satellite. Taking regard of nondeterminacy of inertia, the coupling effect, external interference and other factors, the method of taking over and controlling attitude after space tethered robot captures flexible target satellite establishes a complex attitude and orbit coupling kinetic equation, designs inner and outer ring terminal sliding mode controllers, and gives consideration on the saturation characteristics of a thruster and a tether so as to stably control the attitude and angular velocity of the complex. The method of taking over and controlling attitude after a space tethered robot captures a flexible target satellite includes the following steps: establishing an attitude kinetic equation of a complex after a space tethered robot captures a target satellite; designing inner and outer ring terminal sliding mode controllers and the corresponding adaptive law; taking the inner ring control law and the outer ring control law as the input of a control system to take over and control the attitude after the flexible target satellite is captured; and proving Lyapunov stability. The method of taking over and controlling attitude after a space tethered robot captures a flexible target satellite can solve the problem that the flexible complex parameters are not determined and the self-supplied thruster of the space tethered robot is saturated.

A limit time cooperative control method of a mechanical arm servo system includes: building the dynamic model of the mechanical arm servo system, and initiating the system state, sampling time and related control parameters; approximating the nonlinear input dead zone linearity in the system into a simple time-varying system according to the differential mean value theorem, and deriving a mechanical arm servo system model with an unknown dead zone; calculating the tracking error, the non-singular terminal sliding mode surface and the first derivative of a control system; selecting a neural network approximation unknown function on the basis of the mechanical arm servo system model with the unknown dead zone, designing a neural network limit time cooperative controller according to the system tracking error and the non-singular terminal sliding mode surface, and updating a neural network weight matrix. By the method, additional inverted compensation of a nonlinear dead zone can be avoided, sliding model high-frequency buffeting is reduced, and limit time fast tracking of the mechanical arm servo system is achieved.

The invention provides an uncertain mechanical arm fixed time track following control method with input saturation, which can overcome influences of mechanical arm control input saturation effect anduncertainty, and improves robustness of a system. The method comprises the following steps: establishing a kinetic equation of an n-freedom rotary joint rigid mechanical arm system with a viscous friction item; according to the established kinetic equation and a mechanical arm track error following signal, establishing a following error kinetic equation which takes parameter uncertainty into consideration; establishing a state space model of mechanical arm track following errors; establishing a fixed time disturbance observer according to the established space model; establishing a fixed timenon-singular terminal sliding mode surface according to the mechanical arm track following error signal; preliminarily determining each joint drive motor control moment instruction of a mechanical arm, and integrating a moment output range of a performer, thereby obtaining each joint control moment of the mechanical arm. The invention relates to the field of mechanical arm control.

The present invention provides an accurate track tracking control method based on a finite time expansion state observer. The method comprises the following steps of: establishing a mathematical modeland a kinematic equation representing current unmanned ship motion features, designing a combined nonsingular rapid terminal sliding-mode control law according to the unmanned surface ship motion tracking errors and a nonsingular rapid terminal sliding-mode surface, designing a finite time expansion state observer according to the unmanned ship motion features, and designing an accurate track tracking control law according to the combined nonsingular rapid terminal sliding-mode control law and the finite time expansion state observer. Through design of the finite time expansion state observer, the lump interference comprising external interference and a complex nonlinear term can be observed by the finite time to a small enough range to avoid the limitation of the approximation observation. Through the designed combined nonsingular rapid terminal sliding-mode control law and the nonsingular rapid terminal sliding-mode unmanned ship track tracking controller, the accurate track tracking control method achieves the accurate track tracking control performance in a complex external interference.

The invention discloses an aircraft attitude control method based on a self-adaptive sliding mode. The method includes the following steps that firstly, a translational motion equation of the center of mass of an aircraft is built; secondly, the influence of earth rotation on attitude control is taken into consideration, and a corresponding rotation around center of pass equation is obtained according to the translational motion equation of the center of mass of the aircraft, wherein the rotation around center of pass equation determines the rotating angle around the center of mass of the aircraft and the angular rate of the aircraft and is mainly used for achieving attitude control of the aircraft; thirdly, a referenced aerodynamic model is given; fourthly, a self-adaptive controller based on a Terminal sliding mode is designed, wherein a slow loop controller and a quick loop controller are designed.

A rotary-table servo system neural network control method comprises (1) building a mechanical dynamic model of a permanent magnet synchronous motor rotary-table servo system, and initializing the system state, sampling time and relative control parameters; (2) according to the differential mean value theorem, enabling a non-linear input dead zone in the system to linearly approximate to a simple time-varying system, avoiding complex calculation of dead-zone inverse compensation, and finally inferring a rotary-table servo system model provided with an unknown dead zone; (3) at each sampling moment, calculating and controlling a system tracking error, a fast terminal sliding mode surface and a first-order derivative of the system; (4) based on the rotary-table servo system model provided with the unknown dead zone, selecting a neural network approaching unknown trend, designing an adaptive robust finite-time neural network controller according to the system tracking error, the fast terminal sliding mode surface and the first-order derivative of the system, and updating a neural network weight matrix; and (5) entering the next sampling moment, and repetitively executing the steps from (3) to (5).

The invention discloses an adaptive terminal sliding-mode controller based mechanical arm trajectory tracking control method. The method includes the following steps: 1, establishing a rigid mechanical arm system dynamics model having n degrees of freedom rotating joints; 2, obtaining the measuring information of each joint angle q and angular velocity which is shown in the description of a mechanical arm through a photoelectric encoder, setting the expected angle q<d> and expected angular velocity which is shown in the description tracked by each joint, and calculating mechanical arm trajectory tracking errors [epsilon]1 = q - q<d> and the first derivative shown in the description of trajectory tracking error versus time; 3, establishing a novel non-singular terminal sliding-mode surface s according to the [epsilon]1 and [epsilon]2; and 4, designing the controlling moment tau of the driving motor of each joint of the mechanical arm according to the sliding-mode surface s, and establishing an adaptive rate which can adjust control gain to dynamically estimate system lumped disturbance upper bound. Under the circumstance that internal and external interference such as parameter perturbation and torque disturbance existing in the mechanical arm system, the method can perform real-time feedback so as to realize the accurate controlling of mechanical arm trajectory tracking based on the measuring information of each joint angle and angular velocity, and the controlling on the robustness of the whole course can be guaranteed.

The invention relates to a voltage-current double closed-loop terminal sliding mode control method of a Buck converter. The voltage-current double closed-loop terminal sliding mode control method of the Buck converter aims to solve the problems that the traditional linear sliding mode control method is slow in response speed and low in stability precision, and includes the following steps: 1 mathematics model building of the Buck converter; 2 load observer design according to output voltage VC of the Buck converter and the loaded current iL; 3 voltage terminal sliding mode controller design: a voltage controller outputs an inductive current demand signal iL* according to a demand input direct-current voltage tracking error ev; 4 current linear sliding mode controller design: a current controller outputs a control signal mu of a controllable switch tube V of the Buck converter according to the inductive current demand signal iL*. The voltage-current double closed-loop terminal sliding mode control method is applied to the electricity field.

The invention discloses a wheel type moving robot track tracking method based on a fast terminal sliding mode. The wheel type moving robot track tracking method comprises steps of (1) establishing a kinematic model of the wheel type moving robot and an expectation track model and establishing an error model according to the kinematic model and the expectation track model, (2) introducing an appropriate sliding mode surfaces s1, s2, designing a virtual feedback amount according to the error model <~ > theta e<->, (3) obtaining a linear speed deviation signal <~ > Upsilon and a angular velocity deviation signal <~ >Omega, (4) constructing the wheel type moving robot kinematic model and substituting the linear speed deviation signal <~ > Upsilon and the angular velocity deviation signal <~ >Omega into the kinematic model, and designing a left-and-right-wheel torque controller Tau, an unknown parameter estimator <^>Phi and an external interference disturbance estimator. The wheel type moving robot track tracking method based on a fast terminal sliding mode can track the expectation track in the limited time under the disturbance complicated working condition of the unknown parameters and the external disturbance, has a good tracking effect and has a strong robustness for the unknown parameters and the external disturbance.

The invention provides a four-rotor aircraft sliding mode control method based on a nonlinear disturbance observer. The influence of system uncertainty and external disturbance of the four-rotor aircraft is considered, the method comprises the following steps: firstly, establishing a four-rotor dynamical model considering external disturbance and providing a nonlinear disturbance observer to estimate the actual value of the external disturbance; the invention aims to ensure the stability of a four-rotor aircraft, four-rotor dynamics is decomposed into an attitude subsystem and a position subsystem according to the design thought of double rings, controllers are designed for the two subsystems respectively, the nonsingular fast terminal sliding mode controller designed for the inner ring can ensure fast convergence of the attitude, backstepping and the nonsingular fast terminal sliding mode are combined and applied to an outer ring, the tracking performance is guaranteed, and the methodhas good tracking performance and high robustness for the four-rotor aircraft with system uncertainty and external disturbance.

The invention relates to a method for designing a Terminal sliding mode controller of a hypersonic vehicle. The Terminal sliding mode control has an advantage that a system on a sliding mode surface can be converged within limited time. In order to keep the nonlinearity of a model and to facilitate the design of a control system, an input-output linearization method is used for processing the model in the paper, after that, state variables are reselected according to the design requirements of the Terminal sliding mode control, and a nonlinear sliding mode surface is designed; a sliding mode control law is designed for the designed Terminal nonlinear sliding mode surface, to ensure that the system can reach the sliding mode surface, and to prove the stability of the system; finally, the given control law is subjected to simulation verification, and the results show that the designed sliding mode controller can realize the effective control of the hypersonic vehicle.

The invention provides an unmanned vehicle-side longitudinal coupling tracking control method based on a rapid terminal sliding mode principle. The method comprises the following steps: 1) selecting an input parameter and an output parameter of an unmanned vehicle-side longitudinal coupling tracking controller; 2) defining a tracking control error and a state equation; 3) using the tracking control error as a state variable and establishing a rapid terminal sliding mode; 4) taking a rapid terminal tendency rate as a sliding mode tendency rate of the tracking control; 5) according to a vehicle dynamics model and the above content, deriving a coupling relation between an expected driving force or a braking force and an expected side force; 6) calculating an expected front-wheel turning angle; 7) according to positive or negative of obtained reverse longitudinal force model output, determining whether an expected throttle percentage or an expected braking torque should be calculated currently; 8) calculating the expected throttle percentage or the braking torque. From a simulation result, by using the method in the invention, error precision of position tracking control is increased and good error precision of speed tracking control is possessed.

The invention discloses a higher-order non-singularity Terminal sliding-mode control method of a high supersonic speed aircraft. A nonlinear model of the high supersonic speed aircraft is processed ina feedback linear method, and modeling errors and outside disturbance of a system are compensated via an RBF neural network control strategy. On the basis of the linearized vertical model, a novel neural network sliding-mode controller is in a nominal cruse flight condition based on a sliding mode surface of a regression structure, and an instruction signal and elevator deflection signal set by an engine throttle valve of the high supersonic speed aircraft are controlled to control the speed and height of the aircraft. The controller is highly robust for uncertainty of aerodynamic nonlinearity, pneumatic interference and system parameters. According to a simulation result, the instruction signal can be tracked effectively, and the response speed is higher.

The invention relates to an adaptive second-order terminal sliding-mode control system and method. On the basis of comparison of a given speed signal and a feedback speed signal of a servo system of a permanent magnet linear synchronous motor, an error amount is obtained; a terminal sliding mode surface is designed based on the error amount and a super-coiling algorithm controlled by the second-order sliding mode is used for realizing the input of a speed controller; and an adaptive control way is introduced to carry out dynamic adjustment on a control gain of the super-coiling algorithm. Therefore, the rapid response of the system is realized; and the system robustness is improved. With the control method, the system can have the high robustness and the system buffeting can be weakened effectively.

The invention relates to a nonlinear control method for a small unmanned helicopter, especially to an attitude control method for the small unmanned helicopter based on a second-order self-adaptive terminal sliding mode controller, and realizes rapid attitude error convergence and maintains relatively accurate attitude tracking control effect and relatively high system robustness under the condition that external interference of the small unmanned helicopter exists. According to the technical scheme of the invention, a second-order self-adaptive terminal sliding-mode method is applied to attitude system control of the small unmanned helicopter under the condition that the small unmanned helicopter has external interference. The method comprises the following steps that 1) an attitude dynamics model of the small unmanned helicopter is determined; 2) an attitude angle tracking error is defined, and a dynamics error model is arranged; 3) a control law is designed; and 4) self-adaptive control gain is designed. The method of the invention is mainly used for nonlinear control of the helicopter.

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

The invention relates to a hypersonic aerocraft tracking control method with an interference observer. The problem that the fact that the observer is bounded in the interference process of an observing system cannot be proved in the prior art is solved. The method provided by the invention comprises the steps that 1 a second-order system model with system interference is established according to the longitudinal input and output linearization model of a hypersonic aerocraft; 2 according to the second-order system model with system interference in the step 1, a finite time terminal sliding mode controller is designed based on a sliding mode control theory; and 3 system stability proving is carried out on the finite time terminal sliding mode controller designed in the Step 2. According to the method provided by the invention, the finite time of the sliding surface of the system is stable, and the system state is asymptotically convergent. The method provided by the invention is applied to the field of hypersonic aerocraft control.

The invention provides a quadrotor unmanned aerial vehicle attitude fault-tolerant control method based on an adaptive terminal sliding mode. The method comprises the steps that a quadrotor unmanned aerial vehicle is divided into a position subsystem and an attitude subsystem, and a corresponding mathematical model is established; the error function of the position subsystem is defined, and enabled to fly along a desired trajectory; then, in the case of the time-varying failure of the pitch angle theta of the attitude subsystem, a control law is designed by using the control method based on the adaptive terminal sliding mode; and the attitude angle error of the unmanned aerial vehicle is stabilized to zero to achieve adaptive fault tolerance. The quadrotor unmanned aerial vehicle fault-tolerant control method based on the adaptive terminal sliding mode, which is provided by the invention, can effectively solve the problem of time-varying fault in limited time, reduces the influence ofnoise, and is used in reconnaissance, rescue, cruise and other tasks.