393results about How to "Improve anti-disturbance ability" patented technology

The invention pertains to the technical field permanent magnet motors, and relates to a permanent magnet motor sliding mode control strategy. The permanent magnet motor is controlled by adopting double-closed speed current. The permanent magnet motor sliding mode control strategy is characterized in that a sliding mode speed controller and an extended sliding mode observer are adopted in the control strategy, the sliding mode speed controller adopts an exponential approach law containing the speed error and the sliding mode surface information, the deviation between a given rotating speed and a feedback rotating speed is taken as the input quantity, and a q-axis current given value is outputted through the sliding mode control quantity; the extended sliding mode observer is used to estimate the rotor position, the rotating speed and the load torque on a real-time basis, the rotating speed and the rotor position are used to provide the information of speed closed-loop control and coordinate transformation, and the load torque is compensated to the sliding mode speed controller, so that the high-accuracy vector control of the permanent magnet motor can be realized. The control strategy of the invention can be used to make the system fast track a given speed in the dynamic state, reduce the speed overshoot and the current fluctuation, and improve the disturbance resistance performance of the system.

The invention discloses a method and a device for controlling speed of a permanent-magnet synchronous motor. The method includes that an active-disturbance-rejection control technology is adopted for a speed ring, speed setting and a speed detection value are taken as input of a first-order active-disturbance-rejection controller, a tracking differentiator reasonably arranges a transition process, an extended state observer observes an actual value of rotating speed of the motor, estimates total disturbance of a system and acquires output of the speed ring through a nonlinear state error feedback control ratio, a load torque observer is designed through detection values of a current and the speed, and observed load torque through output of a feedforward controller and the active-disturbance-rejection controller is taken as reference input of a quadrature-axis current. The method carries forward characteristics of overshoot freeness, high disturbance rejection capacity, good robustness and the like of the permanent-magnet synchronous motor in speed control in the active-disturbance-rejection control technology, and compensation is performed on the problem of load disturbance, so that the problem of fluctuation of the rotating speed under the circumstance of load disturbance is improved.

The invention discloses a neural-network self-correcting control method of a permanent magnet synchronous motor speed loop. The method is characterized by: taking a current loop and a motor as generalized objects; firstly, collecting information, such as a rotating speed, a current and the like; using an adaptive linear time-delay neural network to carry out off-line parameter identification to the motor; then, taking a weight obtained through off-line learning as an initial value of on-line learning; finally, carrying out on-line parameter identification to the system, calculating a load torque of the motor according to the identified parameter; designing a neural-network self-correcting control law according to the obtained parameter value and a load disturbance value, adjusting the network weight on line according to an error between a controlled object and an identification model, and then setting the parameter of the neural-network self-correcting controller on line so as to realize online adjustment of the controller parameter. Uncertainty of the system and influence brought by the external disturbance can be eliminated. Dynamic performance and an anti-disturbance ability of a servo system can be improved.

The invention discloses a system and method for controlling the current of a permanent magnet synchronous motor for an electric vehicle. The system comprises a rotating speed/position detection module used for detecting the rotating speed value omega and the position angle theta of the permanent magnet synchronous motor, a current sensor, a first coordinate transformation module, a second coordinate transformation module, a PI speed ring controller used for conducting PI operation on the motor rotating speed value omega obtained through the rotating speed/position detection module and a given motor rotating speed value omega r to obtain a q-axis current reference value, a current ring prediction control module, a sliding formwork disturbance observation module, a third coordinate transformation module and a space vector pulse width duration modulation module, wherein the space vector pulse width duration modulation module is used for calculating u alpha and u beta to obtain six-path PWM signal output, PWM signals are used for controlling an inverter, and thus three-phase output voltage is obtained to drive the motor to operate. An advanced continuous time generalized prediction control method is adopted for the tracking and controlling of the current of the permanent magnet synchronous motor for the electric vehicle, and the system and method have the advantages of being small in calculated amount, good in control effect and the like.

The invention relates to a method for predicting the thermal error of a machine tool spindle based on a genetic algorithm wavelet neural network, which belongs to the field of numerical control machine tool processing technology. A temperature sensor is reasonably arranged on a numerical control machine tool, and the temperature of a key temperature measuring point of the machine tool and the temperature data of a proces environment are measured by the temperature sensor, and the thermal error data of a machine tool spindle is obtained by a displacement sensor; the thermal error prediction model of machine tool spindle based on wavelet neural network is established after data processing, combining the advantages of genetic algorithm and wavelet neural network, the thermal error predictionmodel has the advantages of simple calculation, high precision, strong anti-disturbance ability and robustness, and has strong approximation ability and fast network convergence speed. The thermal error of the spindle of the CNC machine tool is effectively reduced, and the machining accuracy of the machine tool is improved.

The invention provides an all working condition standard emission control method for a thermal power unit denitration system. The method comprises the steps that a main ring PID controller, a sub-ringPID controller and a feedforward controller are arranged in a denitration control system; the main ring PID controller calculates an ammonia injection control signal according to an outlet NOx concentration set value and an outlet NOx concentration feedback signal; the feedforward controller calculates an ammonia injection feedforward control signal according to the purge correction NOx concentration, the NOx estimated concentration, the inlet NOx concentration and the flue gas flow; and the sub-ring PID controller controls the opening of an ammonia injection valve according to the ammonia injection control signal, the ammonia injection feedforward control signal and an ammonia flow feedback signal. According to the invention, a gain scheduling model and an hour mean model are added intoa main ring to realize automatic control of the variable working condition of the denitration system; an inlet concentration purge correction model is introduced into a sub-ring to realize dynamic ammonia injection correction; the ammonia injection is accurately controlled; and a technical support is provided for whole process robustness and all working condition standard emission.

The invention provides a method for controlling a servo system of an active disturbance rejection control technology, and aims to provide a method which has a simple algorithm, wide parameter adaptability and small servo system tracking dynamic error, and keeps the disturbance rejection capability of an automatic disturbance rejection controller (ADRC) control system. The method is realized through the following technical scheme that: firstly, a command differentiator ComD is substituted for a tracking differentiator TD which is arranged for a transition process of a standard active disturbance rejection control algorithm, and extracts a new location command value w1, a new speed command value w2 and a new acceleration command value w3; an extended state observer ESO in the standard active disturbance rejection control algorithm is continuously adopted, and calculates a system location observation value z1, a speed observation value z2 and an acceleration observation value z3; and w1 and z1 form a location error e1, w2 and z2 form a speed error e2, e1 and e2 are sent to a nonlinear state error feedback regulator (NLSEF), w3 and the output u0 of the NLSEF are added, w3 is taken as a feedback value, so the servo system of the improved active disturbance rejection control technology is formed.

The invention relates to a control method for a photovoltaic grid-connected inverter on the basis of back-stepping sliding-mode control. The control method is technically characterized in that direct current voltage Udc of a photovoltaic side bus is collected, a mathematical model of a photovoltaic grid-connected single-phase voltage full-bridge inverter is set up, a tracking error of a control variable uac is set, a back-stepping sliding-mode control model of the photovoltaic grid-connected single-phase voltage full-bridge inverter is set up, and the single-phase photovoltaic grid-connected inverter is controlled according to the mathematical model and the back-stepping sliding-mode control model of the photovoltaic grid-connected single-phase voltage full-bridge inverter. The control method is reasonable in design, a back-stepping method and a sliding-mode control method are combined, the stable state and the dynamic property are good, and the control method is suitable for linear and non-linear loads and adapts to engineering application reality, provides a new thought for the inverter control system design and has the good engineering application prospect.

The invention discloses a second-order sliding mode control of three-level DC-DC buck converter and a finite state machine realization method of control. The method comprises the steps that S1) a mathematical model of the three-level DC-DC buck converter is established, the difference between the output amount and the reference value of the DC-DC buck converter is defined as a sliding mode amount, and a sliding mode dynamic equation is established and analyzed; S2)Thus, the the working mode of the converter is divided into four states, on the premise that the switching efficiency is highest and there is no output overshoot, a critical switching coefficient betamin is obtained via calculation; and S3) is implemented according to the critical switching coefficient betamin; and S3) a finite state machine controller of the second-order sliding mode control method is established, the obtained critical switching coefficient betamin is substituted into the finite state machine controller, and the tracking reference value of the output voltage of the three-level DC-DC buck converter is adjusted. Thus, advantages of the three-level DC-DC buck converter can be played.

The invention discloses a permanent magnet synchronous motor control method based on a second-order terminal slip form. The method comprises the following steps that: S1: under a rotator coordinate system, obtaining dq shaft current id and iq; S2: obtaining a q shaft current given value iq'; S3: obtaining a load torque observation value; S4: after compensation, obtaining a q haft current given value iq<*>; S5: obtaining input voltage u[Alpha] and u[Beta] under an [Alpha] [Beta] coordinate system; and S6: adopting a space voltage vector pulse width modulation technology to convert the u[Alpha]and the u[Beta] obtained in S5 into an on-off signal used for controlling a three-phase inverter power device, and finally, driving the permanent magnet synchronous motor to operate. By use of the method, a current loop controller adopts a dead-beat controller, a speed loop adopts a two-order terminal slip form controller to realize the high-accuracy control of the permanent magnet synchronous motor, and therefore, the problem that the speed change range of the permanent magnet synchronous motor with small rotational inertia is large during load mutation or given revolving speed mutation can be solved.

The embodiment of the invention provides a method and a system for realizing composite entire optical fiber localizable perimeter alarm. An auxiliary optical fiber micro vibration sensor is arranged on a monitor optical cable provided with a precise positioning sensor; whether a disturbance signal exists is judged by the precise positioning sensor and the auxiliary optical fiber micro vibration sensor together, namely, whether people invade is judged; if the judgment is confirmed, an alarming signal is sent out, thus effectively improving the anti-interference capacity of the system, lowering effect caused by outside environmental factors like temperature and stress, and the like, reducing false alert rate and missing report rate, and improving the alarming precision of the monitoring system.

The invention provides a novel modular multi-level solid-state transformer and an internal model control method thereof. The solid-state transformer comprises a modular multi-level converter, a DC-DC isolator and a DC-AC inverter, wherein the alternating current side of the modular multi-level converter is connected to a high-voltage AC network and the direct current side of the modular multi-level converter is connected to the input end of the DC-DC isolator; the direct current side of the DC-AC inverter is connected to the output end of the DC-DC isolator and the alternating current side of the DC-AC inverter is connected to a low-voltage AC network or load; through changing the number of power sub-modules connected to each bridge arm of the modular multi-level solid-state transformer in series, the voltage application range of the solid-state transformer is flexibly adjusted, and a problem of application of the solid-state transformer in middle-high voltage occasions is effectively solved. According to the characteristics of internal model control, an internal model current inner loop is combined with a PI voltage outer loop, and a new double closed loop control structure is constructed, so that the modular multi-level converter and the DC-AC inverter are controlled; and through the control method, the current has a quicker response speed and stronger anti-disturbance capability.

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 relates to an unmanned boat target tracking method based on visual feedback in order to solve the problems that existing methods are complicated, the response speed is low, the operationprecision is low and the anti-disturbance capability is poor. The method includes the steps that 1, a KCF tracking algorithm is used for detecting and tracking a tracking target, and a position coordinate of the tracking target is determined; 2, a correspondence relationship, between a pixel coordinate system and a world coordinate system, of the tracking target is established, and a coordinate of the tracking target in the world coordinate system is obtained; 3, an unmanned boat processor calculates the deviation between the position of the tracking target and the position of the unmanned boat processor, sends a command to a motion control unit for conducting control and adjusts the rudder angle of an unmanned boat steering gear and the rotation speed of a propulsion motor to keep the tracking target at the center of a view field of a camera and to keep an unmanned boat and the tracking target within a set distance range, and that is to say that an unmanned boat motion control systemachieves tracking navigation on the target. The unmanned boat target tracking method based on visual feedback is used in the field of unmanned boat navigation.

The invention discloses a PWM rectifier control method based on model prediction and voltage square control. The square of the output direct-current side voltage is controlled to serve as the given inner ring active current, the quick response of a controller is ensured through the linear relation between the square of the voltage and the active current, and the anti-disturbance capacity of a rectifier is further enhanced through the model prediction control of the inner ring current. The cost function of model prediction is quickly obtained through the finite set on-off state so that the control method can be easily achieved on a digital controller. The dynamic response and the anti-disturbance capacity of the whole controller can be enhanced through the selection of the weighting coefficient in the cost function and the coordination with the pre-charging soft start strategy. By means of the double-closed-loop control method, the quick response and the high anti-disturbance capacity for load disturbance are achieved while it is ensured that the alternating-current side of the rectifier reaches the unit power factor and the current total harmonic distortion rate reaches the national standard requirement. By means of the double-closed-loop control method combined with the voltage square model prediction control, the control over the unit power factor and the disturbance resistance of the three-phase voltage type PWM rectifier is achieved, and great reference value is provided for engineering.

The invention discloses a four-rotor UAV flight control method based on a fractional order power switching law. A whole controller is of a backstepping control structure, a second-order nonlinear system of a quadrotor UAV is split into two subsystems, control laws that satisfy Lyapunov's stability theory are constructed, and the two subsystems are in series connection through a virtual intermediate control variable to form the complete controller, so that the controller can well adapt to the nonlinearity of the system and have good integrity. At the same time, in order to enhance the anti-disturbance capability and robustness of the controller, in the second backstepping design, the controlled variable is subjected to the sliding mode control design, which introduces the high disturbance resistance and high robustness of the sliding mode control. .

The invention discloses a second-order sliding mode controller and flying capacitor voltage balance method of a three-level DC-DC buck converter. The method is characterized by including the following steps: S1, establishing a second-order sliding mode control method limit state machine controller, and substituting a critical switching coefficient [beta]min obtained by calculation to a second-order sliding mode controller; and S2, the second-order sliding mode controller performing balance control over flying capacitor voltages, and solving the range of load currents without increases of switch loss of switch tubes. The invention brings forward a novel limit state machine controller structure of a second-order sliding mode control method. The controller can adjust output voltage tracking reference values, balance flying capacitor voltages to be half of input voltage values, bring the advantages of the three-level DC-DC buck converter into full play relative to a conventional buck converter. As for the second-order sliding mode control method adopted by the invention, current detection is not needed, and the method has the characteristics of non-overshoot during a starting process, quick dynamic response speed and high disturbance resistance.

The invention relates to a ship-based net collision recovery unmanned aerial vehicle, comprising an airframe, an airfoil, ailerons, a horizontal tail, an elevating rudder, vertical tails, rudders, an engine and a propeller, wherein the airfoil is mounted on the airframe and adopts an upper single-airfoil layout; the left side and the right side of the airfoil are respectively provided with one aileron; the horizontal tail is mounted at the upper end of the tail part of the airframe and adopts double vertical fin layout; the left and right vertical tails are connected with the wing ends of the horizontal tail respectively; the horizontal tail has a 1.5-degree mounting angle; the front edge of the horizontal tail is higher than the rear edge of the horizontal tail; the elevating rudder is arranged on the rear edge of the horizontal tail; the rudders are arranged on the rear edges of the vertical tails; the engine is mounted at the tail end of the airframe and is used for driving the propeller to rotate. The unmanned aerial vehicle has the characteristics that the endurance time is long, so a flight mission with high requirement on endurance is convenient to carry out during navigation; the wind-resistant ability is strong and the stability is high, so the unmanned aerial vehicle is applicable to the flight emission under a complicated sea condition; catapult-assisted take-off and high-precision net collision zero-distance recovery are adopted, so the unmanned aerial vehicle is applicable to emission and recovery on a narrow space on naval vessels; the whole machine adopts modular design, so containerized transportation is facilitated and the occupied space on the naval vessel is reduced.

The invention relates to a quad-rotor unmanned aerial vehicle integral sliding mode control method based on an expansion state observer. On the basis of a dynamics model and a propeller model of a quad-rotor unmanned aerial vehicle, the integral sliding mode control rate is obtained through integral sliding mode control; and by adopting the expansion state observer, external interference on a system is estimated according to an input and an output of the quad-rotor unmanned aerial vehicle system to obtain an estimated value of the interference on the system, and then the integral sliding modecontrol rate is compensated. The method ensures the precision of tracking expected input of the quad-rotor unmanned aerial vehicle, and has a strong anti-interference capability.

The invention relates to an in-plane-control-based active vibration control method for a wrinkled film. On the basis of the analysis on the influence on dynamic characteristics of a film structure bya wrinkle form, a dynamic model of a wrinkled film is established; according to a modal superposition method, a space vector based on a natural mode of vibration is obtained and dynamic models of thewrinkled film under different loads are established; condensation polymerization is carried out on the dynamic models according to contributions to system vibration deformation by all orders of modes,so that a control-oriented film structural dynamic model is established; and with a model reference adaptive controller, a PID-MRAC control method based on in-plane-control multi-model switching is proposed. According to the method provided by the invention, no actuator needs to be pasted on the surface of the film; the out-of-plane vibration of the film is suppressed effectively; the characteristics of the film are not affected; the high stability of the film structure is ensured; and compared with the conventional PID control method, the in-plane-control-based active vibration control method enables the vibration time to be shortened by about 39.7%.

The invention discloses a permanent magnet synchronous motor speed control system and method for an electric vehicle. The method comprises the steps of obtaining a q-axis desired current according to a designed fuzzy adaptive sliding-mode speed controller, and setting the d-axis reference current as 0; according to a disturbance value feedback compensation observed by a designed disturbance extended state observer, using the q-axis current output from the fuzzy adaptive sliding-mode speed controller as the q-axis input of a dq-axis internal mode current controller; using the difference of a d-axis feedback current value and the given d-axis current value 0 as the d-axis input of the dq-axis internal mode current controller; obtaining ud and uq after the processing by the dq-axis internal mode current controller, and finally outputting the driving voltage currently operated by the permanent magnet synchronous motor through the vector-controlled inverse park conversion, the SVPWM and an inverter. The method increases the response speed and the anti-disturbance performance of the permanent magnet synchronous motor for the electric vehicle, avoids an overshoot phenomenon, reduces system buffeting, and enhances system robustness.

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 provides an azimuth control system and method for a suspension platform system, and the system and method provided by the invention are suitable for carrying out azimuth control on a suspension platform loaded with load which is high in azimuth maneuverability and larger in rotational inertia. Aiming at the problem of lower data update frequency of an azimuth position sensor, a platform azimuth speed control ring which utilizes a sampling signal of an angle rate gyroscope as feedback is additionally arranged in a suspension platform azimuth position control loop. The specific implementation method is as follows: firstly measuring frequency characteristics from the input signal of a power amplification device to the output signal of the gyroscope and designing a control algorithm according to the frequency characteristics; and after completing speed closed loop, designing an azimuth position controller according to the frequency characteristics of the system subjected to speed closed loop. The angle rate gyroscope is higher in data update rate, and the bandwidth of the angle speed control ring is generally greater than that of an angle position control ring, thus according to the invention, the response speed and servo rigidity of a suspension platform azimuth position control ring can be improved, and the antijamming capability of the azimuth control system can be improved.