160results about How to "Eliminate Steady State Error" patented technology

The invention relates to a modified fuzzy sliding mode controlling method of a monopole three-phase photovoltaic grid-connected system, belonging to the control technical application field of a photovoltaic grid-connected system; the method has the advantages of strong robustness, good stability and rapid dynamic response speed; the method comprises the following steps particularly: firstly, feedforward compensation is led in to rapidly compensate the coupling part of d, q shaft current id and iq which are output by an inverter, thereby realizing rapid dynamic decoupling between id and iq; secondly, by controlling reaching law of lead-in index of an integral sliding mode controller, the dynamic performance of a sliding mode controlling system is improved, the response speed of the system at the initial starting stage is accelerated, and a system state trajectory is ensured to rapidly and smoothly enter in a sliding mode surface to move, wherein the sliding mode surface has good robustness to system interference; finally, a fuzzy control is led in to weaken the buffeting of common sliding mode control in the sliding mode surface, the output of the sliding mode controller is softened, and the stability of the system is improved.

The invention discloses an air conditioner control method, an air conditioner control device and an air conditioner. The control method includes the steps that the indoor environment temperature and the outdoor environment temperature are detected; the difference value delta T between the indoor temperature and the temperature set by a user is computed; the operating time of the air conditioner is detected; when the operating time is smaller than a preset time, the fuzzy control coefficient of a compressor is computed according to the difference value delta T, the outdoor environment temperature and a preset fuzzy control rule, and the operating frequency of the compressor is computed according to the fuzzy control coefficient; and when the operating time is larger than or equal to the preset time, the operating frequency correction value of the compressor is computed according to the difference value delta T and a preset PI control model, and the operating frequency correction value is added to the operating frequency to control the compressor to operate according to the corrected operating frequency. According to the control method, fuzzy control and PI control are combined to control the compressor so that the compressor can achieve a better control effect; and the precision of steady control is guaranteed and the steady state error is eliminated while the higher response speed is achieved.

The invention discloses an automatic navigation path tracking method for an aquaculture workboat. The method comprises the following steps: 1, collecting the position information of corners reflecting the contour of a work region, and obtaining the target navigation lien and speed of the workboat through track planning; 2, collecting the real-time position, navigation and speed of the workboat, setting the navigation speed of the workboat, and judging whether a target path needs to be switched or not; 3, calculating a tracking target point of the workboat through employing a method of real-time point insertion; 4, enabling the attitude and movement state data of the workboat to be compared with a tracking target point and a target path, obtaining the navigation direction and speed deviation, obtaining the navigation direction and speed control amount through employing the PD and PI algorithms, and finally obtaining the control amounts of left and right paddle wheels; 5, carrying out the real-time navigation control of the workboat according to the final control amounts. The method can remarkably improve the effect of automatic navigation path tracking, and provides guarantee for the high-efficiency completion of aquatic plant cleaning and uniform bait casting.

The invention discloses an improved droop control method based on a communication network for a distributed power source in a parallel connection operation mode in a micro power grid system. The defect of a traditional droop control method is overcome, the performance of the distributed power source in the parallel connection operation mode is improved, the stability of the system is improved, and the improved droop control method is suitable for control over the parallel connection operation mode in the micro power grid system which integrates with new energy resource distributed power generation. According to the improved droop control method, a communication network is used as the basis, a central controller in the micro power grid system and controllers of all inverter units form an entire control system, the active power and the reactive power of public loads are calculated, and the droop control scheme of each distributed power source is corrected. The scheme is used, a better power flow equalizing effect can be achieved, smaller deviation of busbar voltage frequency and amplitude is achieved, and a good application prospect is achieved.

The invention provides an underwater robot three-dimensional path tracking control method based on a second-order filter. Underwater robot three-dimensional path tracking control is carried out by means of a filtering back-stepping method, the second-order filter established on the basis of two underwater robot three-dimensional path tracking kinematics error models is brought in to obtain virtual controlling quantity of postures, virtual controlling quantity of speed and virtual controlling quantity of angular speed and derivatives of the postures, derivatives of the speed and derivatives of the angular speed, then an underwater robot kinetic model is combined, control input of a path tracking controller is obtained and acts on a robot propeller and a steering engine, and therefore tracking of a three-dimensional path is achieved; according to the Lyapunov energy function, filtering feedback compensation items are designed for location and posture control loops, an integration element is led in a speed control loop, a system error compensation loop is constituted, and precision of a tracking system is promoted.

The invention discloses a current compensation based power decoupling method of a virtual synchronous power generator. The power decoupling method comprises the following steps of 1) acquiring a dq component of an output current of a virtual synchronous motor through sampling, acquiring power angle information by a mechanical property simulation part, and further calculating reactive power-power angle decoupling current compensation instruction; 2) acquiring transient state variable quantity of a virtual excitation electromotive force, and calculating active power-voltage decoupling current compensation instruction by combining the dq component, obtained in the step 1), of the output current; and 3) correcting the reactive power-power angle decoupling current compensation instruction obtained in the step 1) and the active power-voltage decoupling current compensation instruction obtained in the step 2) to obtain a new current instruction, and obtaining a switching signal through a current ring to drive a switching network. The invention proposes the power decoupling method applicable to the virtual synchronous motor, and the influence of a power angle on droop control can be eliminated; and compared with the prior art, the power decoupling method has the advantages that dynamic power oscillation and a steady-state error brought by power coupling can be eliminated.

The related control system for crystal equal-diameter growth comprises: a crystal growing furnace, a crystal diameter detection part, a control part for crucible temperature, a control part for crystal tension speed to real-time gather crystal tension speed signal and feedback to regulate the speed by algorithm of Fuzzy control and PID control, and a common controller to receive all former signal. this invention improves control precision greatly as well as the one-draw yield.

The invention discloses a nonlinear multi-time-scale delay system modeling and control method and belongs to the technical field of controlling of complex systems. The method is based on the UDTTDFSPM and combined with a spectral norm and linear matrix inequality method, a robust combination controller is designed for controlled NMTSTDSs, and high-precision and stable control of the NMTSTDSs is achieved. According to a dynamic model of the NMTSTDSs, an uncertainty continuous time delay obscurity singular perturbation model of the NMTSTDSs is set up, a proper sampling period is selected, a zero-order holder method is adopted to perform discretization on the obtained continuous model, and the UDTTDFSPM of the NMTSTDSs is obtained. The robust combination controller is designed on the basis and is composed of an obscurity slow state feedback controller and an output integrator. The nonlinear multi-time-scale delay system modeling and control method has the advantage of solving the problem of steady-state errors which are caused by system external disturbance and the fast modality of the NMTSTDSs and cannot be solved by an existing modeling and control method, and the control performance of the NMTSTDSs is greatly improved. The nonlinear multi-time-scale delay system modeling and control method is used for controlling the simulation result of postures of a CE150 helicopter, and validity of the method can be shown.

The invention discloses a parallel robot motion control method with fast response and robust performance, which belongs to the field of electromechanical control. The method comprises steps: an ideal displacement instruction for each driving shaft is obtained through inverse solution according to a parallel robot expected trajectory; and a fractional order PDmu controller is used to ensure a control system to be stable and have a quick response ability through selecting an ideal cutoff frequency, a phase margin and a robust design criterion. During the motion process, a grating ruler is used for feeding back the actual motion state of each driving shaft, the PDmu controller gives the motion control amount according to the ideal displacement instruction and the feedback state, and the motion control amount is sent to a motor driver to drive the motor to rotate. In addition, a dynamic model for the parallel robot is built, a driving torque command is obtained according to the model, the driving torque command sends a compensation signal to a driver through a dynamic feedforward compensation controller, disturbance torque of the parallel robot during a linkage process is compensated, system robustness is enhanced, and the parallel robot can be ensured to complete planning motion.

The present invention provides a circulation power theory-based distributed parallel control method applied to a miniature power grid system island mode. The method is characterized in that a distributed power generation and energy storage unit in a miniature power grid system is connected with an AC bus via an inverter and operates in a parallel mode in the island mode, and by taking a communication network as the basis in a parallel operation mode, the controllers of the inverter units in the miniature power grid system form a whole control system. According to the method of the present invention, the circulation active power and the circulation reactive power of an inverter parallel system in the parallel operation mode of the miniature power grid system can be restrained effectively, the situation that the parallel system has the optimal dynamic performance and transient response capability is guaranteed, the reliability of the system is improved, at the same time, the steady-state errors of the frequencies and the amplitudes of the output voltages of the inverter units are eliminated, and the inverter units share the public load power evenly according to the occupied proportions of the respective power capacities of the inverter units in the parallel system, so that the method has a very strong practicality.

The invention relates to a vehicle stability control system based on an active intervention steering system, which is characterized by at least comprising: an electronic assistance steering module used for receiving a torque request instruction from an electronic brake control module and outputting torque for intervening with the positions of a turning wheel and a steering wheel by torque; the electronic brake control module configured to determine the running state of a vehicle according to the hydraulic pressure applied by the driver through the brake pedal, the wheel working state input through wheel speed sensors, and the vehicle actual acceleration and yaw rate signals input by vehicle inertia sensors and calculate the stability deviation of the current vehicle control state from theideal control state and the turning wheel rotating angle required to compensate for the stability deviation according to the brake back pressure applied by the driver, and obtain the assist torque value to be provided for achieving the target turning wheel rotating angle and send the same to the electronic assistance steering module.

The invention discloses a Buck-Boost converter variable damping passive control method based on a port controlled dissipation Hamiltonian model. The method comprises the following steps of 1, according to the system state averaging model and the state variables of a Buck-Boost converter, converting the system state averaging model of the Buck-Boost converter into a port controlled dissipation Hamiltonian model form, and verifying the passivity of the port controlled dissipation Hamiltonian model form; 2, according to the port controlled dissipation Hamiltonian model of the Buck-Boost converterand an interconnection and damping distribution passive control method, giving an expected interconnection and damping matrix and carrying out passive controller design; 3, designing a second-order differential tracker according to the influence of the damping coefficient change of the given damping matrix on the system performance, and realizing the real-time change of the injection damping; 4,designing a variable-damping passive controller according to the passive controller and the second-order differential tracker, and controlling the output voltage of the Buck-Boost converter. Accordingto the invention, by means of the control method, the output voltage of the Buck-Boost converter can be quickly converged to the expected output voltage. The steady-state error of the output voltageis reduced, and the overall performance of the system is improved.

The invention relates to an inverter control method based on fuzzy PCI (Proportional Complex Integral) and PR (Proportional Resonance) parallel composite control. The inverter control method comprises the steps of S1, acquiring a current three-phase grid-connected current under a three-phase static coordinate system in real time; S2, acquiring a grid-connected current instruction under the three-phase static coordinate system to obtain an AC error signal under the three-phase static coordinate system; S3, acquiring a first current value under the three-phase static coordinate system after the AC error signal passes through a PR controller; S4, acquiring a second current value under the three-phase static coordinate system after the AC error signal passes through a PCI controller; and S5, acquiring a composite control current value under the three-phase static coordinate system after the first current value is added to the second current value, and inputting the composite control current value to a PWM (Pulse Width Modulation) module. Compared with the prior art, the inverter control method has the advantages that a coordinate conversion link can be omitted, the inverter control method can be directly applied to the three-phase static abc coordinate system, the control stability of a system is ensured, and the waveform quality, the tracking precision and the power factor of the grid-connected current are improved.

The invention discloses a compound control method of a photovoltaic grid-connected inverter. The compound control method comprises the steps of performing 3s / 2r transformation on input current and establishing a grid-connected inverter model under a d-q coordinate system; and utilizing a compound controller to control output current to eliminate even harmonic component disturbance in the output current, wherein the compound controller comprises a proportional plus integral (PI) controller and a repetitive controller which are connected in parallel. By means of the technical scheme that the 3s / 2r transformation is performed on the input current, and the compound controller composed of the PI controller and the repetitive controller which are connected in parallel is utilized to eliminate the even harmonic component disturbance in the output current, dynamic response of a system is increased, accuracy and stability are high, harmonic component disturbance can be controlled well, steady-state errors can be eliminated, and the grid-connected current control effect is good.

The invention relates to a control analysis method for inverters in a grid-connected test power supply, and belongs to the technical field of electronic power. The control analysis method for the inverters in the grid-connected test power supply comprises the following steps that (1) the topological structure of the inverters in the grid-connected test power supply is determined; (2) the model of an inversion circuit is constructed; (3) the control strategy of the inversion circuit is determined; (4) quasi PR control analysis is performed; (5) the transfer function of a quasi PR controller is discretized, modeling of the discretized PR controller is performed through Simulink and then various control parameters of the inverters are calculated; and (6) a 30KW hardware-in-the-loop grid-connected test power supply dual-core control experiment platform is established based on dSPACE and the correctness of the control model is verified. According to the method, PR control is adopted, and the specific frequency can be accurately tracked by PR control in comparison with PI control so that the gain of the frequency is increased and the steady state error of PI control is eliminated.

The invention relates to a method for controlling harmonic currents in a synchronous rotating reference frame by several times. Compensated harmonic currents at a certain time are converted to the synchronous rotating reference frame with the same times of rotating speeds and directions, harmonic instruction current information of an SFR is fully utilized, AC disturbance quantity brought by other nonsynchronous current components in the SFR is removed through a simple algorithm, so that the DC quantity corresponding to the compensated currents at the time in the SFR is extracted, and PI static-error-free decoupling control is achieved. The stability margin and the dynamic response speed of a control system can be effectively improved, and the steady state errors of the system are removed.

The invention provides a composite adaptive model prediction control method of a Boost converter. The method includes: establishing a continuous model according to an equivalent circuit of the Boost converter in different switching states, performing discretization on the continuous model, and obtaining a discrete model of the Boost converter; designing a Luenberger observer by regarding a circuitoutput voltage and an inductive current as quantities of state based on the discrete model of the Boost converter, and obtaining observed values of an inductive resistance and a load resistance; establishing a controller of the Boost converter, and regarding a PI controller and a feedforward compensator based on the discrete model as an outer loop; regarding model prediction control as an inner loop; forming a value function based on the square of the difference between an inductive current reference value generated by the outer loop and an inductive current predicted value of the inner loop;and selecting an optimal switching state through minimization of the value function. According to the method, prediction results of different switching states are compared through the value functionto obtain the optimal switching state and realize tracking control of current and voltage so that stabilization can be rapidly recovered from disturbance.

The invention discloses a power feed-forward compensation based isolated operation direct current micro grid energy storage voltage stabilizing control method. An isolated direct current micro grid system platform comprises a plurality of circuit modules which are connected through a direct current bus and the direct current bus is served as an energy exchange intermediary agent of the direct current micro grid system, keeps the voltage of the direct bus to be consistent and is significant meaningful in the energy exchange and the stable operation of the system. According to the power feed-forward compensation based isolated operation direct current micro grid energy storage voltage stabilizing control method, direct current bus voltage fluctuation caused by renewable energy source fluctuation and load fluctuation in the direct current micro grid is restrained and eliminated through a power feed-forward compensation voltage stabilizing control method, the system operation stability is improved, the equipment working reliability is improved, the equipment maintenance costs are reduced, and the equipment service life is prolonged.

The invention discloses an automatic medical butt-joint cart. According to the automatic medical butt-joint cart disclosed by the invention, a controller is connected with a central processing module to control an automatic lifting device so as to drive the ascending and descending of a guide rail; in the ascending and descending process, two connection carts or infrared sensors between two connection carts or between the connection carts and a hospital bed are mutually induced to carry out bidirectional communication so as to transport sampling data, and the central processing module can preciously process the received data by adopting a fuzzy control algorithm and a PID (Proportion Integration Differentiation) algorithm, thus the automatic lifting device can be preciously controlled so as to drive a guide rail rack to ascend or descend to the height suitable for the other connection cart or the hospital bed; and then, the two connection carts or the connection cart and the hospital bed are locked by an electro-magnetic induction lock of the connection cart. The process does not need people to adjust the heights of the two connection carts, and the two connection carts are automatically locked after being connected in a butt joint way, thus the connection time is saved, and the work intensity and workload of nursing staff are greatly reduced.

The invention discloses a control system for suppressing torque ripples of a brushless direct current motor and a torque ripple suppression method for the control system and belongs to the filed of motor control technology. The problem that existing brushless direct current motors generally have torque ripples is solved. The control system comprises a Sepic converter, a voltage inverter and a direct current voltage sampling module; the Sepic converter is used for converting a direct current source Us voltage with a constant amplitude into a direct current voltage with a variable amplitude; the voltage inverter is used for converting the direct current voltage with the variable amplitude output by the Sepic converter into an alternating current and driving the controlled brushless direct current motor; the direct current voltage sampling module is used for collecting the direct current voltage output by the Sepic converter and sending a collected direct current voltage signal to a motor controller; a Hall signal of the controlled brushless direct current motor is collected and sent to the motor controller, and the motor controller controls the work state of the Sepic converter and the voltage inverter according to the collected voltage signal and Hall signal. The control system and the method are mainly used for controlling motor torque ripples.

This invention is controlling method of a kind of power factor correction circuit. The method concludes: the rectifier bridge transforms the inputting alternating current voltage to unipolar output voltage and provides to the said BOOST circuit. The said voltage detecting circuit and current detecting circuit provide kinds of needed input to the controller. Based on acquired input, the said controller calculates the switch tube on-and-off driving pulse of the said BOOST circuit. The switch tube of the said BOOST circuit accepts driving wave from the said controller. It makes the shape of inducted currents follow the shape of the input voltage provides by the rectifier bridge. Thus, the power factor correction is completed and the steady direct-current bus voltage output is provided. This invention decreases the system cost. It increases the stability and dynamic capability of circuit. It decreases the inductance ripple wave, radiation and inductance cubage. The efficiency is increased.

The invention discloses a variable-rotating-speed hydraulic power source flow control system and method. The system comprises a controller, a servo driver, a permanent magnetic motor, a gear pump, an oil tank, a motor and a flow sensor for detecting flow information in an oil outlet of the gear pump, wherein the output end of the servo driver is connected with the control end of the permanent magnetic motor; an output shaft of the permanent magnetic motor is connected with a driving shaft of the gear pump; an oil outlet of the oil tank is communicated with an oil inlet of the gear pump; an oil outlet of the gear pump is communicated with an oil inlet of the motor; an oil outlet of the motor is communicated with an oil inlet of the oil tank; the output end of the flow sensor is connected with the input end of the controller; and the output end of the controller is connected with the input end of the servo driver. The system and the method can quickly control the variable-rotating-speed hydraulic power source flow in real time with high precision.

The invention discloses a heating furnace temperature controller design method based on an improved Dahlin algorithm.For the nonlinear characteristic of a heating furnace, according to the heating furnace temperature controller design method, different temperature set value jump intervals are set according to the size differences of temperature difference jump values of set target temperature and initial temperature, and different expected closed loop transfer functions are set in all the intervals to design a temperature controller.When heating furnace temperature controller design is conducted, the problems that for a traditional Dahlin algorithm temperature controller, the adjusting time is long, and steady state error elimination is slow are considered, the Dahlin algorithm is combined with integral control, special processing is conducted on control quantity limitation, the steady state error is further eliminated, the adjusting time is further shortened, and control over the heating furnace temperature can be achieved more rapidly and accurately.

The invention discloses an electric heating furnace temperature control method, which employs a single circuit heating furnace as a controlled object, and according to the strong-nonlinearity and pure lag characteristics of the controlled object, employs a piecewise linearization processing method to design a least-beat algorithm controller, allowing the controlled object to possess a unique corresponding largest ascending velocity at any effective starting temperature and any effective temperature outburst value, and effectively solving poor control effects caused by incomplete matching between model parameters and real objects. The invention also employs an improved least-beat control algorithm with an attenuation factor, realizes control amount flexibility, allows a system to rapidly and stably enter a stable state process from a dynamic state process, and effectively reduces the overshoot of a heating furnace temperature control system. An integrating link is provided based on the improved least-beat algorithm, thereby eliminating system stable state errors, and finally realizing heating furnace temperature rapid and accurate control.

The invention discloses a four-rotor aircraft attitude control method and controller. For the disadvantage that a four-rotor aircraft system is difficult to establish a precise physical model, the nonlinear dynamic characteristic of the system is described by establishing a RBF-ARX model, which is locally linear and globally nonlinear, by adopting a system identification method; for the characteristic of the model and to satisfy quick response characteristic and relatively high control performance requirements of the system, the model is converted into a non-minimum state space model having anintegration link at first; then, a prediction controller is designed; furthermore, input is parameterized by using a laguerre function; therefore, predictive control of the online optimization variable of the system is reduced; furthermore, a given reference signal can be precisely tracked; and, for the numerical stability problem due to increasing of a prediction time domain, an exponential decay weight is introduced into a target function, so that a closed-loop system has the specified stability. The scheme has the characteristics of being short in online optimization time and steady in numerical value in a relatively large prediction time domain condition, and has relatively high practical value and application prospect.

The invention discloses a control system and method for a laser radar galvanometer servo motor. The system comprises an upper computer, a drive control digital module, a three-loop control analog module, a high-frequency pulse laser front end and a scanning galvanometer, and the drive control digital module comprises a main control ARM unit and an FPGA unit, which are connected with each other. The method comprises the following steps: after the galvanometer servo motor starts to work smoothly, judging whether the system performs scanning in a working mode with the highest performance, judgingthe mode according to a set threshold, and adopting two index improvement methods: in a smooth speed running mode, importing an interpolation module to improve the resolution of a control signal so as to achieve the purpose of high-precision scanning; and in a high-speed scanning mode, importing a repeated tracking accumulated error control unit to perform error collection and correction for multiple cycles so as to achieve the purpose of improving the precision. The control system disclosed by the invention ensures stable and efficient operation of a high-precision three-dimensional imagingscanning system in a high speed state.

The invention discloses a method for improving control accuracy of a coil current driver of a magnetic suspension planar motor. The method comprises the following steps of calculating a real-time resistance value of a planar motor coil according to a temperature distribution model of each ring of a moving-iron magnetic suspension planar motor during the working process; and calculating a parameter variable of a proportional integral (PI) controller according to the real-time resistance value of the coil so as to control the output of the PI controller. By the method, the limitation of the moving-iron magnetic suspension planar motor is overcome, a method for controlling real-time adjustment of parameters is provided for the coil current driver of the moving-iron magnetic suspension planar motor according to the temperature distribution model of the moving-iron magnetic suspension planar motor during the working process, and the control performance of a coil current driving ring is improved.

The invention belonging to the field of artificial intelligence particularly relates to a PID control method, apparatus and system based on a network optimization algorithm. The method comprises: a target quantity and an actual output of a controlled object are obtained, wherein an error is obtained by subtracting the target quantity by the actual output; on the basis of a neural network optimization algorithm, calculation is carried out to obtain membership degrees of input variables, wherein the input variables of the neural network optimization algorithm are the error and an error changing rate; according to the membership degrees of the error and the error changing rate, calculation is carried out by using a fuzzy control algorithm by using the error and an error changing rate as the input variables so as to obtain a PID control parameter; on the basis of the error and the PID control parameter, calculation is carried out to obtain a control parameter of the controlled object; and then the control parameter is inputted into the controlled object. The method, apparatus and system are suitable for a non-linear controlled object; and the robustness to the uncertain interference during the control process is high.

The invention discloses a magnetic suspension ball position prediction control method based on an RBF-ARX model and a Laguerre function. Through the adoption of historical input and output data of a magnetic suspension ball system, according to a system identification principle, the RBF-ARX model of the system is established to describe nonlinear dynamic characteristics of the input voltage of anelectromagnetic winding and the position of a steel ball. In order to meet the requirements of the system for fast response characteristics and high control performance, the local linear and global nonlinear RBF-ARX model is converted into a non-minimum state space model with integral links, on this basis, a prediction controller based on input parametrization of the Laguerre function is designed,a prediction control system can solve a quadratic programming problem with constraints online at a short sampling interval, and a given reference signal can be accurately tracked. By means of the method, a solution is provided for prediction control over the fast response nonlinear system, and the method has high application and popularization value.

The invention provides a tension system control device and method of a sheet extruding unit. The device comprises a cold aid roll control system, a pinch roll control system with a tension roll and a tension detector, and a winding roll control system with a winding system tension roll and a winding system tension detector, which are connected with a control chip and sequentially arranged along the winding direction of sheets. The method comprises a control method of the cold aid roll control system, a control method of the pinch roll control system and a control method of the winding roll control system, which are sequentially executed and adopt adaptive fuzzy PID (proportion integration differentiation) control algorithms, wherein the control methods of the cold aid roll control system and the pinch roll control system adopt speed control modes to perform control, and the control method of the winding roll control system adopts a torque mode of a winding serve motor to perform control. The tension system control device is mainly applied to a high-precision tension closed-loop control system of the sheet extruding unit, and aims to improve the operation stability of the system, the tension control precision and the sheet quality.