114 results about "Fractional-order control" patented technology

The invention discloses a method for setting a fractional-order PID (proportion, integration and differentiation) controller for a parameter uncertainty system which is a controlled object. The fractional-order PID controller is applied to the parameter uncertainty system which is the controlled object. The method is used for optimally setting to-be-set parameters of the fractional-order PID controller, and includes firstly determining stability regions of parameters of the system; secondly, determining frequency and parameter variation ranges of the stability regions of the parameters of the system; thirdly, optimally setting the parameters of the controller by a genetic algorithm. The method for setting the parameters of the fractional-order PID controller on the basis of the parameter uncertainty system has the advantages that the parameters of the fractional-order controller can be effectively set when the controlled object is the parameter uncertainty system, the dynamic performance of the system can be optimized, and the fractional-order controller can realize a good control effect and is excellent in dynamic performance.

The invention discloses a fractional-order PID controller parameter optimizing and setting method based on a closed-loop reference model. The method comprises the steps that S1, an ideal closed-loop reference model is selected, and the cut-off frequency omega c and the order alpha of the ideal closed-loop reference model are selected according to the control performance requirements of a system; S2, according to a transfer function expression of the closed-loop system and by combining with the ideal closed-loop system model H(s) and a fractional order PID controller model Gc(s), an ideal control object model (shown in the description) is derived; S3, the frequency domain response characteristics of an unknown controlled object model Gp(s) are obtained, so that the ideal control object model (shown in the description) and Gp(s) are identical in response when omega = 0 and omega = x, and a function relation of kp, kd and mu when omega = omega x is calculated; S4, by optimizing and identifying parameters in the ideal form of an unknown object (shown in the description), so that the unknown object (shown in the description) is close to the actual object Gp(s) in frequency domain response index in a cut-off frequency range, frequency domain response error indexes are established, the error indexes are optimized (shown in the description) when 0 < mu < 2, and finally parameters of a fractional-order controller are obtained. The fractional-order PID controller parameter optimizing and setting method utilizes an identification method of the system to rapidly obtain controller parameters and meanwhile can also ensure best approximation of the ideal reference model.

The invention discloses an RBF dual neural network adaptive sliding mode control method for an active power filter. The method is characterized by comprising the following steps: step (1), establishing a mathematical model of the active power filter; (2) designing an adaptive RBF dual neural network based on a fractional order sliding mode surface, and separately approximating the nonlinear function and the upper bound of interference of the system by using the two RBF neural networks; and step (3) controlling the active power filter according to a fractional order RBF dual neural network sliding mode controller. According to the method disclosed by the invention, the characteristics that the fractional order can get rid of the dependence of system functions and improve the control response of the system are adopted; on this basis, the nonlinear function and the upper bound of interference values of the system can be approximated by adopting the characteristic that the RBF neural networks do not relay on the model of the system; and moreover, the stability of a system controller can be proved by designing the Lyapunov function, the real-time tracking compensation can be performed for the instruction current, and high reliability, high robustness to parameter variation and high stability can be achieved.

The invention relates to a photoelectric sight stabilizing platform control method based on a disturbance observation fractional order controller, and belongs to the field of high-precision tracking control. A two-axis two-frame rate type gyro stabilized platform is selected, a disturbance observation fractional order control system is constructed, which comprises a fractional order control law FOPI with high precision and high flexibility and an extended state observer ESO with disturbance observation capability. According to the invention, the characteristics of high fractional order controlresponse speed and high precision are inherited; the advantage of the anti-interference capability of the disturbance observer is absorbed; the disturbance observer can effectively overcome the influence of external disturbance and uncertain factors of the system on the performance of the photoelectric sight-stabilizing platform, on the basis, the response speed of the system can be increased bycombining the fractional order control rate, the steady-state error of the system is reduced, and the visual axis stabilization precision and disturbance suppression capacity of the photoelectric sight-stabilizing platform are improved.

The invention provides a double-closed-loop control method of a permanent magnet synchronous motor. The double-closed-loop control method includes the steps: A, detecting three-phase current, actual rotating speed and a rotor position angle of the permanent magnet synchronous motor, and transforming the three-phase current to obtain stator current in a d-q axis coordinate system; B, controlling the actual rotating speed of the motor and expectation rotating speed by a rotating speed loop fractional order controller to obtain q axis reference current, controlling d axis current and d axis reference current by a current loop fractional order controller to obtain d axis voltage, and controlling q axis current and q axis reference current by the current loop fractional order controller to obtain q axis voltage; C, performing a series of transformations for d-q axis voltage and the rotor position angle, then outputting three-phase voltage, and controlling the permanent magnet synchronous motor. The invention further provides a double-closed-loop controller of the permanent magnet synchronous motor. The controller overcomes the shortcomings of poor applicability and weak anti-jamming capability when a current loop is controlled by the aid of an integer order, so that the motor has better dynamic rotating speed performance and anti-load jumping capability, and the efficiency of a motor system is improved.

The invention discloses a CO2 supercritical extraction temperature fraction order PID control method. In the method, internal model control and fractional-order control are combined; a disadvantage that there are many controller setting parameters is overcome and performance of a control system is improved. Simultaneously, based on an OPC technology, a WinCC is used as a bridge so that MATLAB/Simulink and S7-200PLC can realize real-time communication. On the Simulink, real-time control can be performed on kettle temperature extraction through using a fraction order PID control algorithm. By using the method in the invention, accurate control of the temperature can be effectively realized so that application of intelligent control in an actual industrial control system is realized.

The invention discloses a linear-motor precision trajectory tracking device. The linear-motor precision trajectory tracking device comprises a fractional-order auto-disturbance rejection controller, a first differencing circuit, a current controller, a power driving amplifier, a current sensor and a displacement sensor. The fractional-order auto-disturbance rejection controller comprises an acceleration feed-forward circuit, a second differencing circuit, a third differencing circuit, a fractional-order controller, a summing circuit and an extended state observer. The invention further discloses a tracking method of the linear-motor precision trajectory tracking device. By means of the linear-motor precision trajectory tracking device and the method, the acceleration feed-forward circuit and the fractional-order controller are introduced on the basis of a common auto-disturbance rejection controller to form the fractional-order auto-disturbance rejection controller; compared with the common auto-disturbance rejection controller, by means of the fractional-order auto-disturbance rejection controller, the influence of non-linear factors of the system and the influence of indetermination interference of the system on the system performance can be effectively inhibited, and the linear-motor precision trajectory tracking control performance is achieved.

The invention discloses a four-rotor unmanned aerial vehicle flight control method based on a fractional-order control algorithm. According to the method, a controller is of a back-stepping control structure on the whole, a second-order nonlinear system of a four-rotor unmanned aerial vehicle is divided into two subsystems, control laws meeting Lyapunov stability theories are built, and the two subsystems are serially connected into a complete controller through virtual intermediate control variables, so that the controller can effectively adapt to nonlinearity of a system and has good integrity. Besides, in order to enhance the anti-disturbance capability and robustness of the controller, sliding mode control design of controlled variables is performed in second back-stepping design, andhigh anti-interference capability and high robustness of sliding mode control are introduced.

The invention discloses a rationalization realization method of a fractional-order PID controller. The rationalization realization method comprises the steps of: S1, acquiring an optimum rational approximation realization criterion according to an optimum approximation principle, and establishing an optimum rational approximation function according to the optimum rational approximation realization criterion; S2, establishing an optimum rational approximation function of a fractional-order integral term and a fractional-order differential item in the fractional-order PID controller, and substituting a transfer function of the fractional-order PID controller, so as to carry out rational design of the fractional-order PID controller. The rationalization realization method can improve the transient-state response and steady-state response features of the fractional-order PID controller, enriches and perfects a fractional-order control theory, and can be effectively applied to the design, analysis and realization of the fractional-order controller.

The invention discloses a linear motor point position control device based on a fractional order controller. The device comprises a fractional order controller, a driving module, a linear motor and a sensing module, wherein the fractional order controller comprises a tracking differentiator, a first differential module, a fractional order proportional differentiator, a second differential module and a state observer. A control method comprises the steps: allowing the sensing module to acquire an actual motion position x of the linear motor, allowing the fractional order controller to receive a target position xd of the linear motor, allowing the fractional order controller to output control quantity u by using the actual motion position x and the target position xd of the linear motor, transmitting the control quantity u to the driving module, and allowing the driving module to control operation of the linear motor. According to the method and the device, based on a fractional order calculus theory, the fractional order proportional differentiator is constructed to form the fractional order controller; the influence of non-linearity factors and uncertain interference of a system on system performance is effectively inhibited; and the precise point position control performance of the linear motor is achieved.

The invention discloses a method for building an artificial fish swarm algorithm fractional order PID controller of an axial mixing magnetic bearing. The method for building the artificial fish swarm algorithm fractional order PID controller of the axial mixing magnetic bearing comprises the steps that (1) comparison is carried out between an axial displacement signal of the axial mixing magnetic bearing and a given displacement reference position signal to obtain a displacement deviation signal, the displacement deviation signal is input into a conventional fractional order PID controller; (2) fish swarm scale, a sight range, a moving step length, a crowding degree factor, a maximum attempt limit and maximum iterations are set; (3) the states of each artificial fish include a proportion coefficient, an integral coefficient, a differential coefficient, a differential degree coefficient and an integral degree coefficient; (4) calculation is carried out on an initial fish swarm, current-moment artificial fish food concentration, a fish swarm visual field and a step length; (5) each artificial fish carries out foraging calculation, gathering calculation, and tailgating calculation to update the position of the artificial fish, and finally outputs an optimal parameter. The method for building the artificial fish swarm algorithm fractional order PID controller of the axial mixing magnetic bearing integrates the advantages of an artificial fish swarm algorithm and the advantages of the fractional order PID controller, real-time optimization is carried out on parameters of the fractional order PID controller according to performance indexes of a system, the system can have better static stability and better dynamic stability, and the self-adaptation capacity of the system is improved.

The invention discloses an adaptive order fractional order fuzzy PI lambda controller method. The method specifically includes the following steps that 1, three control parameters of a fractional order PI lambda controller are determined aiming at controlled object GP; 2, a fuzzy rule and a subordinating degree function are set up based on the fuzzy set theory, and a set-up fuzzy controller is added into the fractional order PI lambda controller and used for correcting the parameters; 3, the fractional order controller corrected by the fuzzy controller is connected into a control system, the fuzzy controller corrects the parameters of the PI lambda controller in real time according to input, and a needed control effect is achieved. The adaptive order fractional order fuzzy PI lambda controller method is high in response speed and small in overshoot, and has good robustness for disturbance.

A digital signal synthesizer for generating a frequency and/or phase modified digital signal output comprises an input buffer, a transform module, a processing module, and an output buffer. The input buffer receives a digital input that is represented in a frequency domain representation. The transform module stores a fractional order control system that models a desired frequency and/or phase response defined by an assembly of at least one filter component. Each filter component is defined by a Laplace function that is modified to include a non-integer control order having a variable fractional scaling exponent. The processing module multiplies or divides the digital input with the fractional order control system stored in the transform module. Moreover, the output buffer stores a synthesized output of the input, which is modified in the frequency domain, the phase domain, or both according to the desired frequency and/or phase response by the processing module.

The invention discloses a parameter tuning method for a fractional-order PID controller, and the method comprises the following steps of calculating an integration order lambda and a differential order mu of a model of the fractional-order PID controller based on a neural network model; and calculating a proportional gain Kp, an integral gain Ki and a differential gain Kd of the model of the fractional-order PID controller by using a horizontal phase criterion based on the obtained integration order lambda and the differential order mu of the model of the fractional-order PID controller. The method provided by the invention first calculates the integration order lambda and the differential order mu of the fractional-order PID controller based on the neural network model, and then calculates the proportional gain Kp, the integral gain Ki and the differential gain Kd of the model of the fractional-order PID controller by using the horizontal phase criterion based on the integration orderlambda and the differential order mu obtained based on the neural network model, which can achieve the best dynamic response performance while ensuring good robustness of the PID controller, and simplify the entire calculation process.

The invention discloses a fractional-order control method for a doubly-fed induction generator grid connection process, and the method comprises the following steps: constructing a motor control modeland a fractional-order operator; for a doubly-fed wind power generation system, using a continuous transfer function method to rationalize the fractional-order operator, i.e., using a rational transfer function is to effectively simulate the fractional-order operator in amplitude-frequency characteristics and phase-frequency characteristics; and establishing a fractional-order PI [lambda] controller to control a motor control model and to control a doubly-fed induction generator no-load grid connection process. The fractional-order PI[lambda] controller can effectively reduce the active powerand reactive power of a starting phase, so that the system enters the steady-state stage smoothly, avoiding the excessive impact on the power grid; The fractional-order PI[lambda] control method canalso be used to reduce the system oscillation under a short-circuit fault condition.

The invention discloses a fixed-wing unmanned aerial vehicle robust discrete fractional order control method considering external wind interference. The method specifically comprises the steps that firstly, a fixed-wing unmanned aerial vehicle longitudinal control system and attitude dynamics system model under external wind interference is established; then, a continuous form unmanned aerial vehicle nonlinear model with wind interference is converted into a discrete form by using an Euler approximation method, and a discrete interference observer is designed to compensate the adverse influence of external wind interference on the flight control performance of the fixed-wing unmanned aerial vehicle; and finally, a discrete fractional order theory and a backstepping method are combined to design a control scheme based on the discrete interference observer so as to solve the problem of unmanned aerial vehicle robust discrete anti-interference tracking control considering external wind interference. According to the invention, the influence of wind interference on the flight control performance of the fixed-wing unmanned aerial vehicle is considered, and the robust discrete fractionalorder control method based on the interference observer is provided, so that flight of the fixed-wing unmanned aerial vehicle can be effectively controlled, and an expected reference trajectory can be tracked.

The invention discloses a mechanical arm position cascade fractional order control method and system based on data driving. The method is characterized in that the same control input signal is used for carrying out two-time excitation experiments on joints of a mechanical arm, preset inner and outer ring reference systems and acquired relevant data are used for calculating a virtual reference signal and a following error signal, an ideal filter is used for carrying out filtering processing on the inner ring signal and the outer ring signal, then a setting criterion taking a position cascaded fractional order controller parameter as an optimization variable is constructed, and finally the optimal design of an optimal position cascade fractional order controller is completed. According to the method and system, the design of the controller is carried out by directly utilizing the actually acquired input and output data, the model identification of a controlled object does not need to becarried out, and therefore the influence of unmodeled dynamics and model errors is avoided, the process data of a repeated test are used, so that the influence of data noise is eliminated, moreover, the internal and external ring fractional order controllers can be optimized and set at the same time, the efficiency of the control algorithm is guaranteed, and the robustness and the control precision of the system are improved.

The invention discloses a highly-efficient inverter fractional order voltage and frequency control method under a microgrid off-grid mode. A mechanism modeling method and abc/dq coordinate transformation are employed to establish a state space model of an inverter in dq coordinates under the microgrid off-grid mode. Droop control, fractional order voltage PI control and fractional order current PI control are employed as voltage and frequency control method. The weighted values of two performance indexes including an integral value of the product of a voltage offset absolute value and time and the integral value of the product frequency offset absolute value and time serve as fitness functions. A colony evolution method based on adaptive variation operation is designed to optimize and set parameters of a fractional order controller, and optimized control signals generated after coordinate transformation are transmitted to a space vector pulse width modulation module, thereby realizing optimized operation of an inverter under the microgrid off-grid mode. Optimized voltage and frequency control effects under complex conditions and the microgrid off-grid mode can be realized.

The invention relates to a parameter setting method for a robust controller of a direct current motor, and belongs to the technical field of automatic fractional order control. The parameter setting method is applied to the direct current motor in a position servo system. The transfer function is that , the transfer function of the FO[PI] controller to be subjected to setting is that , the Bode diagram of the controlled object P(s) is drawn up through a MATLAB, the module value m and the phase angle n at the frequency are obtained; through C(s)P(s)=G(s), the equation about integral order lambda is solved through the MATLAB, through the stability condition, the proportionality coefficient and the differential coefficient are solved, through the obtained lambda, the obtained Kp and Ki are substituted into the formula that . The parameter setting method has the advantages that the calculation amount of the parameter setting of the controller is reduced, and the parameter setting process of the factional order FO[PI] robust controller is simplified.

The invention discloses a structure self-adaptive fractional order proportional integral or proportional differential controller design method. The method comprises the following steps: firstly, through inputting a sinusoidal signal and a capture output signal to a controlled object, acquiring an amplitude value and a phase of an open-loop system of the controlled object in appointed grain crossover frequency; through inputting another sinusoidal signal and the capture output signal to the controlled object, acquiring a phase frequency curve slope of the controlled object; substituting three obtained experimental data into a constructed relational expression between an amplitude value, a phase and a phase slope of a controlled object transfer function and three parameters of a fractional order controller, resolving to obtain the three parameters of the fractional order controller, wherein the three parameters comprise a proportionality coefficient, a time constant and a calculus order,and the calculus order determines whether the fractional order controller is a proportional integral or proportional differential structure. The method is not dependent of a mathematic model of the controlled object, and capable of, through a self-adjusting process of the controller parameters, automatically calculating the controller parameters, and determining the controller structure.

The invention provides a high-accuracy fractional order PID controller for a five-degree-of-freedom robot. The key point of the fractional order PID controller is the setting and selection of five parameters, at first, according to the existing integer-order PID controller, the appropriate fractional order is selected, and according to the needs of an actual system, the other three parameters are determined based on the known parameters, and at the end, the fractional order PID controller is compared with the integer-order PID controller, the accuracy of the fractional order controller is displayed. The fractional order PID controller is reasonable in design and novel in conception, can improve the accuracy of the five-degree-of-freedom robot, guarantees the reliability of the robot, and is particularly applicable to the design of medical and civil robots.

The invention discloses a vibration control method for a rigid-flexible coupling electromechanical servo system. The vibration control method comprises the steps of separately collecting encoder dataon a drive motor and a load motor, acquiring torsion angles of two ends of a flexible shaft rod, computing the torsion angle of a micro unit located at any position of the flexible shaft rod, and computing a frequency domain characteristic equation according to the length, polar moment of inertia, elasticity modulus and rotational inertia of the flexible shaft rod; by using the frequency domain characteristic equation, computing a coupling torque between the flexible shaft rod and a rigid driving flywheel; building a rigid driving flywheel balance equation; putting the coupling torque into thebalance equation to acquire a frictional order transfer function model of the system; and according to the frictional order transfer function model, building a fractional order controller, and controlling the vibration of the system by using the controller. According to the method provided by the invention, the dynamic behaviors of the viscous-elastic material is accurately described via the frictional order model, and the residual vibration of the system is effectively suppressed.

The invention relates to an improved BP setting fractional order PID grid-connected inverter control method. A fractional order PID controller is adopted for inductive current outer loop control, a proportional compensator is adopted for a capacitive current inner loop to control a three-phase LCL grid-connected inverter, and parameter setting is performed on a proportionality coefficient Kp, an integral coefficient Ki, a differential coefficient Kd, an integral order lambda and a differential order mu in the fractional order PID controller by adopting a BP neural network. Multivariable fractional order PID control acts on an inductive current outer loop, so that the system has better robustness, and the THD value of grid-connected current is greatly reduced; and a proportional controller is used as a capacitive current inner loop to realize double-closed control. In order to solve the parameter setting problem caused by introduction of the fractional order PID algorithm, an improved BP neural network algorithm is adopted to identify and optimize parameters, stable control over grid-connected inversion is achieved, and the robustness of the system is improved.

The invention belongs to the related technical field of controller design, and discloses a design method of an FOPD-GESO controller. The design method comprises the following steps: S1, selecting a fractional order PD controller and a generalized extended state observer to control a motor speed loop, and designing the fractional order PD controller and the generalized extended state observer; S2,using the total disturbance estimated by the generalized extended state observer to compensate and simplify a speed loop control object to obtain a compensated speed loop control model, wherein the compensated speed loop control model reflects the characteristics that the tracking performance is only related to a fractional order PD controller and the anti-interference performance is only relatedto the bandwidth omega o of GESO; and S3, respectively solving unknown parameters in the fractional order PD controller and the generalized extended state observer. According to the invention, overshoot-free tracking of the speed of the permanent magnet synchronous motor is realized, and the method has excellent anti-interference performance and resists external load, model change and the like.