31 results about "Affine nonlinear system" patented technology

The invention discloses a non-affine non-linear flight control system robust adaptive fault-tolerant control system used for a non-linear system with parameters in a non-affine mode. An observer has relatively idea robustness on the situation that the parameters change in a large range. Fault information and disturbance information are implied in the observer, and then a fault-tolerant controller is dynamically designed on the basis of the observer. Due to the non-affine non-linear system, the controller is not easy to design, the non-affine non-linear system approximates to an affine non-linear system with time-varying parameters, and the parameters needing to be known are estimated online through a filter. By means of the non-linear flight control system, effectiveness of a method is verified, and robust adaptive fault-tolerant control of the non-affine non-linear flight control system can be achieved. Robust adaptive fault-tolerant control of the non-affine non-linear flight control system is achieved and applied in the flight control system, and a simulation result displays effectiveness of the method.

The invention discloses a spacecraft attitude stability control method by using a biasing tether. The method comprises: a system dynamics model is established; a nonaffine non-linear system model is converted into an affine non-linear system model; speed information is used as a virtual control value and a controller is designed; the designed virtual control value is used a control instruction and a speed / angular speed controlled is designed; and an anti-saturation module is added into the controller and an influence caused by movement limitation of a tether connecting point can be suppressed. According to the invention, on the basis of movement of a biasing tether point, an attitude of a capture mechanism is controlled, thereby substantially reducing fuel consumption of the capture mechanism during the operation task process. In addition, the nonaffine non-linear system model is converted into the affine non-linear system model by means of first-order taylor expansion and that the similarity and error meet the Lipschitz condition is demonstrated; and when the system design is controlled, an adaptive compensation item compensation module error is designed. The method is simple and the practicability is high.

The invention provides a model-free adaptive control method based on control input saturation. Under the condition of considering control input has position and rate saturation, the invention designs an adaptive neural network constraint controller based on observer technology; and in the design process, a dynamic anti-saturation compensator is provided for adjusting reference preset value in real time to ensure control input does not enter a saturation region. The method is characterized by, to begin with, carrying out model transformation on a common affine nonlinear system through a feedback linearization method; and then, designing a neural network observer and a constraint controller for the transformed system, and providing a dynamic anti-saturation algorithm to adjust a reference set value online to enable the input of the controller to be always within a constraint range.

The invention discloses a design method for a nonlinear system controller of an aero-engine. The method is directed at control problems of the affine nonlinear system of the aero-engine within a large deviation range. The method comprises the following steps: linearizing the nonlinear system of the aero-engine based on the theory of exact linearization, adopting the variable structure control in designing a non-linear sliding mode controller, changing a control structure with a purpose by using a linearized state variable to enable the linearized state variable to move based on the designed sliding mode track so as to offset parameter perturbation and exterior interference, finally directed at the key problem of designing non-linear controller parameters, adopting the artificial bee colony algorithm in adjusting the controller parameters, and calculating the optimal parameter to optimize the control effect. According to the invention, the method is directed at the problem of designing complex controller parameters, and obviates the need for tedious manual debugging and repeated verification. By using the bee colony algorithm in designing a reasonable target performance function, the method enables an automatic calculation of the optimal controller parameters and enables the non-linear controlling system of the aero-engine to have a satisfied dynamic performance and robust stability.

The invention provides a non-affine and nonlinear fault-tolerant controller design method for a non-affine and nonlinear system with disturbance and parameter uncertainty. The designed observer can be applied to the nonlinear system with non-affine parameters, and the observer has ideal robustness in the presence of the parameters of large-range variation. Fault information and disturbance information are hidden in the observer. A fault-tolerant controller is dynamically designed based on the observer. Due to the fact that the system is the non-affine and nonlinear system, the design of the controller is not easy. The invention provides the dynamic non-affine and nonlinear approximation method. The non-affine and nonlinear system is approximated into an affine nonlinear system with time-varying parameters. Parameters which need to be known are estimated online through a filter. A non-affine flight control system is used to verify the effectiveness of the provided method. The robust fault-tolerant control of the non-affine and nonlinear system can be realized.

The embodiment of the invention discloses an underactuated mechanical arm layering sliding mode control method based on fuzzy optimization. The method comprises the steps that a plane two-freedom-degree active-passive (AP) underactuated mechanical arm dynamical model is set up, a nonlinear coupling dynamical model is simplified into an affine nonlinear system, and two joint angles are adopted as control targets; then, layering sliding mode controllers are designed, a subsystem is formed by the angle and the angular speed of each joint, the equivalent input of the two subsystems is solved, a sliding mode main switching surface is constructed through a Lyapunov feedback function, and the control rate is obtained; and finally, a fuzzy rule is designed to dynamically optimizing the switching robust item in the sliding mode control rate, and the buffeting problem existing in a previous control system is solved. Compared with other plane two-freedom-degree AP mechanical arm control methods,by means of the technical scheme, the steady-state time of the control process can be reduced, and the control precision can be improved.

An embodiment of the invention provides a greenhouse temperature and humidity decoupling control method and system. The method comprises the following steps: establishing a greenhouse temperature andhumidity prediction model according to energy and matter conservation laws, outdoor climates influencing indoor states comprising outdoor solar radiation, outdoor temperature, outdoor wind speed and outdoor humidity, and indoor control input comprising heating and ventilation opening degree; converting the greenhouse temperature and humidity system prediction model into an affine non-linear system; carrying out accurate linearization on the affine non-linear system through coordinate transformation and nonlinear state feedback to obtain 2 independent integral and time delay systems; and designing a PID (proportional integral derivative) controller based on the equivalent integral and time delay systems, and obtaining opening degree of heating and ventilation two control devices to enable system state to effectively track a set value. The method and system consider strong coupling characteristic of greenhouse temperature and humidity in the control process.

The invention discloses a robust control method of a three-DOF model helicopter with output limits. The method decomposes a three-DOF model helicopter system into a subsystem 1 formed by pitch and roll channels and a subsystem 2 formed by a yaw channel. The method comprises the following steps: 1, transforming control systems of the subsystem 1 and the subsystem 2 into the form of affine non-linear system equations respectively; and 2, designing a robust controller according to the affine non-linear system equation of each of the subsystem 1 and the subsystem 2. The method takes the motions of three axes of the helicopter into consideration, divides the whole system into two subsystems, and designs the controllers corresponding to the subsystem 1 and the subsystem 2 respectively. The controllers enable the helicopter to have good control performance when the system faces uncertainty, unknown external interference and status which cannot be measured directly.

The invention discloses a nonlinear self-healing control method for a multi-sensor fault of a hypersonic flight vehicle, and the method comprises the steps: obtaining a longitudinal affine nonlinear system of the hypersonic flight vehicle through employing an input and output feedback linearization technology for a longitudinal nonlinear model of a cruise stage of the hypersonic flight vehicle; establishing a sliding mode surface for the obtained system, and designing a sliding mode controller under a fault-free condition; and injecting a multi-sensor constant deviation fault into an originalhealth system, and designing a fault estimation scheme. Specifically, a nonlinear adaptive observer is designed for a speed channel; aiming at a height channel, a backstepping sliding mode observer isdesigned to estimate a state quantity and a sensor fault; and after a fault estimation result of the height sensor and the speed sensor is obtained, a fault-tolerant controller is designed to compensate output signals of the height sensor and the speed sensor. The method can solve the problem of fault-tolerant control under the condition that the longitudinal system of the hypersonic aircraft suffers from speed and angle channel multi-sensor faults, and the self-healing capacity of the system is improved.

The invention discloses a fault diagnosability analysis method applicable to an affine nonlinear system. Through mathematical manipulation, a closed loop system considering nonlinear factors such as friction can be converted into a type of affine nonlinear system. By aiming at the type of system, the definition and the criterion of the fault diagnosability (including detectability and isolability) are given on the basis of the differential geometry theory; two kinds of quantitative indexes are respectively designed by aiming at the fault detectability and isolability; according to the indexes, the fault diagnosability analysis of the nonlinear closed loop system is realized through controlling the distribution conditions of output / output quantity and a mathematical model of the system. The fault diagnosability analysis method has the advantages that the fault diagnosis of the nonlinear closed loop control system can be brought forward to the design stage under the condition of not relying on any fault diagnosis algorithm, and in addition, the theoretical basis is provided for the design of the fault diagnosis algorithm.

The invention discloses a water turbine adjustment system based on random probability distribution control. Firstly, a water turbine speed adjustment system is directly modeled via a differential equation based on an affine nonlinear system, and thus a simplified dissipation Hamiltonian model of a water turbine system is built. Then, a control method based on probability distribution is designed by using a technology of acquiring an exact stationary solution of a dissipation non-integrable Hamiltonian system, and thus a preset stability probability density function value output by the water turbine system can be acquired. In addition, stability analysis of the system is to demonstrate that the transition probability density of a controlled system is convergent to the preset stability probability density function value by using a Lyapunov function method, and system simulation indicates that the provided control strategy can achieve an expected control effect.

An adaptive staggered reinforcement learning method of a DT affine nonlinear system based on matching or mismatching uncertainty belongs to the technical field of industrial control, and comprises thefollowing steps: (1) deriving robust stability conditions of the matching and mismatching DT affine nonlinear system based on the problem of optimal control; and (2) searching a consistent final bounded (UUB) stability robust control strategy in combination with an interleaved RL method of neural network approximation. According to the method, the robust controller of the DT affine nonlinear system is solved by establishing a simplified Hamiltonian Jacobian (HJB) equation, and the method is more general in the applicability significance of unknown structure matching uncertainty and non-structure matching uncertainty.

The invention discloses an optimal control method of a single-machine infinite-bus affine nonlinear system. According to the optimal control method of the single-machine affine nonlinear system, based on a single-machine infinite-bus system, nonlinear optimal control design is performed; the equation of motion of the generator rotor of the single-machine infinite-bus system is written in the mode of an SISO (single input single output) affine nonlinear system; through coordinate mapping, a completely controllable and precisely linearized system can be obtained; then according to the design method of a quadric-form optimal control LQR (linear quadratic regulator), the controlled quantity of the precisely linearized system can be solved, accordingly a nonlinear optimal controller of the original system can be obtained, meanwhile, real-time online semi-physical simulation is performed to test the practical feasibility of a scheme. The optimal control method of the single-machine infinite-bus affine nonlinear system achieves precise linearization of the single-machine infinite-bus system and meanwhile takes the condition of non-real-time performance of pure digital offline simulation, thereby verifying the control effects of a controller based on theoretical control in actual real field application through semi-physical simulation experiments. By testing the effects of the designed controller during actual application, the optimal control method of the single-machine infinite-bus affine nonlinear system is beneficial to high truthfulness of the designed algorithms.

The invention discloses a design method for a nonlinear system controller of an aero-engine. The method is directed at control problems of the affine nonlinear system of the aero-engine within a large deviation range. The method comprises the following steps: linearizing the nonlinear system of the aero-engine based on the theory of exact linearization, adopting the variable structure control in designing a non-linear sliding mode controller, changing a control structure with a purpose by using a linearized state variable to enable the linearized state variable to move based on the designed sliding mode track so as to offset parameter perturbation and exterior interference, finally directed at the key problem of designing non-linear controller parameters, adopting the artificial bee colony algorithm in adjusting the controller parameters, and calculating the optimal parameter to optimize the control effect. According to the invention, the method is directed at the problem of designing complex controller parameters, and obviates the need for tedious manual debugging and repeated verification. By using the bee colony algorithm in designing a reasonable target performance function, the method enables an automatic calculation of the optimal controller parameters and enables the non-linear controlling system of the aero-engine to have a satisfied dynamic performance and robust stability.

The invention discloses a voltage regulation method in a PMSM feedback linearization controller. The method comprises the steps of: establishing a state equation of a PMSM in a PMSM two-phase synchronous rotation dq coordinate system; performing affine of a mathematical model in a standard form of a nonlinear system for the state equation; adopting a feedback linearization method to perform linearization for the mathematical model in the standard form to obtain a feedback linearization mathematical model; and adopting the PI feedback regulation modulation ratio method, namely regulating the SVPWM modulation ratio through PI feedback to change the voltage of the motor to achieve PMSM voltage tracking and regulation. The method for controlling PMSM through adoption of input-output accurate feedback linearization and a method for regulating the modulation ratio through PI feedback are adopted to achieve PMSM voltage tracking and regulation, obtain the more accurate and stable speed effectof PMSM, achieve the PMSM global decoupling and the whole linear control and effectively improve the PMSM speed stability and the speed control accuracy.

The invention discloses a nonlinear ship heading control method and control system, which is based on fluid mechanics control equations including continuity equation, momentum equation, and state equation, combined with the motion equation and state of ship heading and rudder angle Equation, using the quadratic polynomial fitting method to establish a high-order nonlinear mathematical model of the ship's rudder angle, and then using the sliding mode variable structure control theory to obtain a suitable switching surface and a stable sliding mode equation of motion, the ship's rudder angle The nonlinear mathematical model of the angle is regarded as a kind of affine nonlinear system, and the sliding mode variable structure controller structure of the nonlinear mathematical model of the ship's course and rudder angle is solved to realize the simultaneous control of the two state variables of the ship's course and rudder angle . The invention can better control the two state variables of the heading angle and the rudder angle at the same time, and has fast response, small overshoot and strong robustness.

The invention discloses a nonlinear ship course control model and a control system. The method comprises: based on fluid mechanics control equations including a continuity equation, a momentum equation and a state equation, and are combined with motion equations and state equations of ship course and rudder angle, establishing a high-order nonlinear mathematical model of a ship heading rudder angle by using a quadratic polynomial fitting method, then solving a proper switching surface and a stable sliding mode motion equation by using a sliding mode variable structure control theory, and taking the nonlinear mathematical model of the ship heading rudder angle as a class of affine nonlinear system, so as to obtain a stable switching surface; and solving a sliding mode variable structure controller structure of the nonlinear mathematical model of the ship course rudder angle so as to realize simultaneous control of two state variables of the ship course and the rudder angle. According to the method, the two state variables of the course angle and the rudder angle can be well controlled at the same time, response is fast, overshoot is small, and robustness is high.

The invention discloses a distributed model-free self-adaptive control technology for indoor heating, ventilation and air conditioning of a building, and belongs to the field of intelligent control. In order to solve the problem of building indoor multi-zone temperature control with complex topological information and external disturbance, the control scheme is as follows: establishing a dynamic model of a multi-zone heating ventilation air conditioner, writing the dynamic model into a matrix form, and discretizing the dynamic model; a single room physical model is expressed as a general non-affine nonlinear system, and a linear data model containing a pseudo gradient is converted through a differential median theorem; based on a linear data model, a distributed model-free adaptive control law is designed in combination with topology information; and designing a parameter estimation index function by combining a linear data model, and estimating an unknown pseudo gradient in the control method. According to the distributed model-free self-adaptive control technology for the indoor heating, ventilation and air conditioning of the building, a data driving method is used, the method does not depend on model information, only online and offline data and related topological information are used, the temperature adjusting performance of the heating, ventilation and air conditioning is improved, and the indoor temperature adjusting requirement of the building is met.

The invention provides a data-based sewage treatment system self-learning trajectory tracking method, which realizes a self-learning optimal tracking control algorithm of a non-affine nonlinear systemby using a DHP structure, and is applied to sewage treatment process control in rainstorm weather. According to the method, a numerical method is adopted to solve stability control corresponding to an expected trajectory, and then a data-driven self-learning method for solving the optimal control law of the non-affine system based on iterative DHP is established. The method is applied to concentration control of dissolved oxygen and nitrate nitrogen so as to achieve a good trajectory tracking effect of a sewage treatment system.

The invention discloses an optimal control method for a single-machine infinite affine nonlinear system. Based on the single-machine infinite system, the nonlinear optimal control design is carried out, and the motion equation of the generator rotor of the single-machine infinite system is written as a single-input and single-output affine nonlinear system. In the form of coordinate mapping, a completely controllable and accurately linearized system is obtained through coordinate mapping, and then the control quantity of the precisely linearized system is solved according to the design method of quadratic optimal control LQR, so as to obtain the nonlinear optimality of the original system controller, and conduct real-time online hardware-in-the-loop simulation to verify the actual feasibility of the scheme. The invention can realize the precise linearization of the single-machine infinite system, and simultaneously considers the non-real-time situation of the pure digital off-line simulation, and verifies the control effect of the controller based on the theory design in the actual real field application through the semi-physical simulation experiment. By checking the effect of the designed controller in practical application, it is helpful for the designed algorithm to be more realistic.

The invention relates to a reentry stage aircraft attitude control method based on an exponential time-varying second order sliding mode, belonging to the technical field of aircraft control. According to the reentry stage aircraft attitude control method, a plane symmetric unpowered aircraft model is taken as an object, feedback linearization is carried out on an affine nonlinear system of an aircraft, and the attitude control problem of the aircraft when reentering into the atmospheric layer is studied. The aircraft provides operating force and operating torque only through a pneumatic control surface. A control surface deflection angle signal [delta e delta a delta r]T is given through the designed control law, so that an attitude instruction omega c=[alpha c beta c mu c]T given by a guidance loop can be effectively tracked, the attitude angle tracking error can be guaranteed to be asymptotically converged, and strong robustness is generated for tremendous environment change, uncertain pneumatic parameters and external disturbance and the like in the reentry process. Meanwhile, the control law in the method only has integral of a switching function, so that the reaching stage of a sliding mode surface is eliminated, the control quantity is enabled to be a continuous signal, the buffeting phenomenon is effectively reduced, and good control accuracy is achieved.

The invention relates to a self-adaptive tracking control method and system for unmanned helicopter yaw channel dynamics. The method comprises the steps that a parameterized model of a discrete non-affine nonlinear system is determined according to a kinetic equation of a target; designing a parameter updating law for the parameterized model, and estimating unknown parameters according to the parameter updating law to obtain estimated parameters; constructing estimation of a future moment signal based on the parameter updating law to obtain an estimated signal; determining an adaptive implicit function equation according to the estimation parameter and the estimation signal; designing an adaptive control law with an iteration form based on the adaptive implicit function equation; the solution of the adaptive control law in the iterative form is a control signal of the discrete non-affine nonlinear system. According to the method, an analytic adaptive control law is constructed, so that adaptive output tracking performance is realized, and bounded closed-loop signal and practical output tracking of a controlled system are ensured.