16results about How to "Eliminate Steady State Error" patented technology

The invention discloses an electric energy metering method and device based on harmonic self-adaptive observation and zero point tracking type SOGI-FLL. The electric energy metering method comprises the following steps: step 1, carrying out ADC sampling on voltage and current signals of a power grid; 2, performing frequency rapid estimation on the voltage signal based on a zero point tracking frequency-locked loop, and obtaining a fundamental wave angular frequency of a power grid in real time; step 3, constructing adaptive observers of voltage and current by using the fundamental wave angular frequency, and estimating parameters of fundamental waves, harmonic waves and direct current components in voltage and current signals in real time through an adaptive law based on Lyapunov stability; 4, according to the parameter estimation value, the amplitude and phase of the voltage and current are calculated; and step 5, calculating active power and reactive power of each harmonic based on the voltage and current amplitudes and phases obtained in the step 4, and summing to obtain total active power and total reactive power so as to realize metering of active electric energy and reactive electric energy. According to the invention, rapid and accurate metering of fundamental wave and harmonic wave electric energy under complex working conditions is realized.

The application relates to the technical field of heat exchange device control, in particular to an energy-saving control method and device for an industrial low-temperature air conditioner, which comprises the following steps: analyzing the correlation between an equivalent refrigeration load and the temperature on the air outlet side of an evaporator, combining the difference between the instantaneous temperature and the average temperature of the application area of the low-temperature air conditioner, constructing a first self-adaptive compensation factor, and correcting the proportional gain of a PID controller; analyzing the difference between the equivalent refrigeration loads at all adjacent moments to construct a second self-adaptive compensation factor and correct the integral gain of the PID controller; and generating a control instruction of the low-temperature air conditioner based on the corrected proportional gain and integral gain to dynamically regulate and control the temperature of the low-temperature air conditioner. The application dynamically corrects the PID parameters based on the load and temperature response characteristics, solves the problems of frosting, overshooting and high energy consumption caused by traditional control, and improves the energy-saving control effect and operation stability of the industrial low-temperature air conditioner.

The application discloses a communication-restricted multi-agent tracking control method for trains, which comprises the following steps: S1, for a high-speed train dynamics model, a train formation dynamics model is designed; S2, a non-singular sliding mode surface is designed, which is brought into a dynamics equation, an equivalent control law and a total control law are designed; S3, a fixed threshold strategy is designed based on a control input signal error, and an event trigger condition is constructed; S4, through information interaction of adjacent vehicles, unmeasured states are estimated by using local measurable states, full-state feedback is provided for a controller, and a distributed observer is designed; the application has the beneficial effects that an improved terminal sliding mode surface is designed by using a non-singular terminal sliding mode surface, wherein the non-singular terminal sliding mode surface is a coprime odd number, fraction exponent irreducibility is ensured, periodic oscillation is avoided, and the singularity problem of traditional sliding mode control in time is eliminated by the fraction exponent term.

The invention discloses an optimal control method for improving the power tracking precision of a hybrid synchronous converter, and belongs to the field of power electronic technology and power system control. The invention provides an improved control strategy based on a series high-pass filter in order to solve the problem of low active power tracking precision caused by steady-state coupling of a voltage synchronization loop in existing hybrid synchronization control. According to the invention, the high-pass filter is connected in series in the voltage synchronization loop, continuous interference of a steady-state power angle to the frequency is blocked by utilizing the direct current blocking and alternating current alternating current characteristics of the high-pass filter, and the power synchronization loop independently dominates the steady-state frequency, so that the steady-state power error is thoroughly eliminated, and zero-static-error tracking is realized. And meanwhile, the response capability of the voltage synchronization loop to transient high-frequency disturbance is reserved, so that the excellent transient damping characteristic of the hybrid synchronization control strategy still exists. In addition, the method is simple in structure, does not need to depend on complex system parameter identification, and has high robustness and engineering adaptability.

The invention discloses a direct-current voltage improvement method of an ice melting device, which belongs to the technical field of electrical engineering and comprises the following steps of: setting a direct-current reference value, and generating an initial modulation direct-current voltage through a direct-current control loop; adjusting the initial modulation direct-current voltage to enable the initial modulation direct-current voltage to be matched with the integral multiple of the rated capacitor voltage of the sub-modules of the ice melting device, and obtaining the adjusted modulation direct-current voltage for eliminating the fluctuation of the input number of the sub-modules of the ice melting device caused by the non-integral multiple voltage; correcting a direct current reference value by adopting a dual-mode control strategy; real-time direct current is monitored, and when the real-time direct current exceeds the deviation range of the preset target value, correction is conducted again through the dual-mode control strategy. By introducing the dual-mode control strategy, namely using the starting mode and the steady-state mode, the ice melting current is gradually increased to the preset target value in the system starting stage, and sudden change of the current is avoided.

The invention relates to the technical field of equipment control, and provides a control method, system and device of a single-channel electromagnetic valve and related equipment. The method comprises the steps that in the process of controlling the pressure of controlled gas, a target pressure value of the pressure of the controlled gas is obtained, and a feedback pressure value collected by a pressure sensor is obtained; determining a pressure deviation value between the target pressure value and the feedback pressure value; determining a target control state from a plurality of predefined control states based on the pressure deviation value; calling a control strategy corresponding to the target control state, and generating a driving control signal; wherein in the pressurization state and the decompression state, the driving control signal is generated based on the invalid interval control quantity, and the invalid interval control quantity is obtained by calibrating the dead zone characteristic of the electromagnetic valve according to the initialization stage; and driving the single-channel electromagnetic valve according to the driving control signal so as to adjust the pressure of the controlled gas.

This invention belongs to the technical field of robotic arm motion planning and discloses a robotic arm motion planning method and system based on an error-driven adaptive gradient model. The method includes: S1 establishing the joint velocity at two adjacent moments with respect to the adaptive coefficient λ based on a Lyapunov function. n The gradient relationship is obtained; S2. The joint velocity at time n+1 is calculated using the gradient relationship, and the error between the calculated joint velocity at time n+1 and the adaptive coefficient is updated using the central finite difference method; S3. n = n+1; return to step S2 until the joint velocities at all times are obtained; S4. The joint position is calculated using the relationship between the joint velocity and position; the velocity of the end effector is calculated using the robotic arm motion planning model and the joint velocities at each time, thereby realizing the motion planning of the robotic arm. This invention solves the problem of low computational efficiency in robotic arm motion planning.

The application discloses a wide-range multi-level converter control method based on improved integral sliding mode control, which comprises the following steps: establishing a fractional-order multi-modal unified state space model of a multi-level converter control system, and constructing a distributed collaborative predictive control architecture; adopting a composite nonlinear integral sliding mode controller as an execution layer of the distributed collaborative predictive control architecture; adopting a radial basis function neural network to provide an accurate feedforward compensation signal for the multi-level converter control system; based on stability analysis, proposing an adaptive online setting rule of an effective integral coefficient of a composite nonlinear integral sliding mode surface S of the composite nonlinear integral sliding mode controller, and realizing parameter self-healing of the multi-level converter control system through a parameter identification module. The wide-range multi-level converter control method has the advantages of being capable of eliminating steady-state error, significantly improving output voltage precision and response speed, dynamically optimizing robustness and dynamic performance of the multi-level converter control system and the like.

This application provides a vehicle tire blowout control method, system, program product, medium, and device. The method includes the following steps: acquiring information about the blown tire wheel, the current target steering wheel angle, and the current yaw rate; calculating the target yaw rate based on a vehicle model using the blown tire wheel information and the current target steering wheel angle; calculating the steering wheel angle adjustment amount using feedforward control and feedback control of the yaw rate based on the current yaw rate and the target yaw rate; and controlling the vehicle to perform a steering angle equal to the steering wheel angle adjustment amount. The blown tire wheel information includes the wheel dynamics information of the blown tire wheel. This method improves the response speed and control accuracy of tire blowout control, and can comprehensively improve the driving stability and safety of the vehicle under tire blowout conditions.

The invention belongs to a mass spectrometry technology, and particularly provides a gas pressure control method and system for an electrospray ion source, and the method comprises the steps: A1, setting algorithm parameters, and randomly generating the position of a whale population; a2, decoding the positions of the individuals into M groups of PID parameters, applying the M groups of PID parameters to a PID controller, calculating the fitness value of each channel, and updating the optimal individual; a3, according to surrounding predation, bubble net attack or random search behaviors of the improved whale optimization algorithm; a4, the step A2 is repeated, inferior individuals are recognized according to the fitness values of all the channels, and the optimal individuals are updated; a5, repeating the steps A2-A4 until the maximum number of iterations is reached or a preset convergence condition is met; a6, decoding a plurality of groups of PID parameters from the position of the optimal individual, and outputting the PID parameters; and A7, loading the final optimized PID control parameters into a PID controller to realize closed-loop control of the gas pressure of each channel. The method has the advantages of accurate control and the like.

This invention provides a method and system for harmonic mitigation in islanded microgrids. The method includes modeling an average model of the inverters in an islanded microgrid system with multiple inverters connected in parallel and containing nonlinear loads using the state-space averaging method; optimizing the inverter control using a low-frequency voltage compensation controller and a high-frequency disturbance compensation controller optimized based on the gradient descent method based on the average model of the inverters; estimating the state variables and harmonic disturbances of the islanded microgrid system using a second-order linear state observer designed based on the bandwidth tuning method; and mitigating the microgrid voltage harmonics caused by nonlinear loads using a linearized active disturbance rejection control method based on second-order sliding mode based on the estimated state variables and harmonic disturbances of the islanded microgrid system. This invention significantly improves the dynamic performance and robustness of harmonic compensation in microgrids.

This invention relates to the field of intelligent manufacturing and industrial quality management technology, and in particular to a management system for die-cast housings of new energy vehicles. The system includes a data acquisition module for periodically collecting production data, quality data, and production equipment data of the die-cast housings; a data analysis module for determining the defect type of the die-cast housings within a single cycle based on the average defect density and defect clustering index of the die-cast housings within that cycle; a traceability module for determining different traceability methods based on the defect type of the die-cast housings within a single cycle; and an adjustment module for adjusting the judgment parameters for the defect type of the die-cast housings within a single cycle based on the defect traceability accuracy. This invention, through automatic and accurate defect classification and differentiated traceability, quickly locates the root cause of problems, greatly shortens the problem response time, and reduces the generation of defective products.

The invention discloses a hydrogen doping ratio control method of a pipeline natural gas hydrogen doping device, and belongs to the technical field of process control, the method is applied to an ejector device with an adjustable throat nozzle, and the method comprises the following steps: setting a target hydrogen doping ratio; collecting natural gas inlet pressure, ejector throat pressure and hydrogen source pressure in real time; based on the target hydrogen doping ratio and the real-time pressure, the target throat diameter is calculated through the established fluid dynamic model; the target diameter is converted into the displacement amount of the driving ring block according to the geometrical relationship; the driving assembly is controlled to drive the ring block to move to adjust the throat diameter; and finally, the actual hydrogen doping ratio is calculated based on the adjusted parameters, feedback verification and iterative adjustment are carried out, and closed-loop control is formed. According to the invention, automatic, accurate and stable adjustment of the hydrogen doping ratio is realized, through combination of model feedforward and feedback correction, the response is rapid, the anti-interference capability is strong, a safety monitoring and fault processing mechanism is integrated, and the safety and reliability of system operation are guaranteed.

The application discloses a single-winding bearingless flux switching motor's suspension magnetic chain repeat control method, which establishes a suspension magnetic chain model of a rotor dynamic eccentricity according to a magnetic suspension rotor system of a single-winding bearingless flux switching motor; a model compensation repeat controller with an integral element, a model compensator and a same-frequency phase shift notch filter is arranged in the magnetic suspension rotor system; the integral element is used for eliminating a steady-state error, the model compensator is used for obtaining an inverse system output signal so as to obtain an accurate displacement control signal, and the notch filter is used for reducing a same-frequency pulsation of the rotor radial displacement; a desired suspension magnetic chain is calculated and obtained through the model compensation repeat controller, a magnetic chain error is obtained by comparing the desired suspension magnetic chain with an actual magnetic chain obtained by a magnetic chain observer, a desired voltage is calculated through the magnetic chain error, and thus inverter switch signals are obtained. The application effectively handles the rotor radial displacement pulsation under a steady-state condition and the displacement sudden change phenomenon under a dynamic condition, and good control is realized.

The invention provides a transmission system PID control stability optimization method based on a characteristic root locus, and relates to the technical field of transmission system torsional vibration control, and the method comprises the steps: obtaining a physical structure of a transmission system, enabling the physical structure to be equivalent to a two-inertia torsional vibration model, calculating the current zero pole distribution, and judging the system stability according to the current zero pole distribution. The method comprises the following steps: selecting a dominant pole, analyzing the damping ratio of the dominant pole, judging the damping ratio of the related dominant pole, adjusting an integral coefficient and a proportionality coefficient according to a judgment result, carrying out a closed-loop performance test on the adjusted PID controller, and realizing optimization based on a test result. The method breaks through the empirical limitation of a traditional cut-and-try method, achieves the precise quantification of the parameters on the vibration characteristics, can evaluate the system stability in advance, greatly improves the debugging efficiency, solves the problem of local optimization caused by parameter coupling through a proposed optimization strategy system, and improves the reliability of the system. And the transmission system has the comprehensive performance of quick response, high stability and accurate control at the same time.

The invention discloses an image code rate control device and method based on a feedback mechanism, and belongs to the technical field of image compression. The device comprises an encoding module, a decoding module, a controller unit and a code rate counter. The encoding module compresses and encodes an input image and outputs a code stream. And the code rate counter calculates the bit number of the code stream in real time and feeds back the bit number to the controller. And the controller compares the real-time code rate with a preset target value, dynamically calculates a scale factor parameter through a proportion-integral-differential algorithm, and feeds back the scale factor parameter to the quantization stage of the coding module in real time so as to dynamically adjust the quantization step length, thereby controlling the output code rate. And the decoding module synchronously receives the code stream and the adjustment parameter, and reversely recovers the quantization table which is completely consistent with the coding end by using the parameter for decoding. According to the invention, accurate and stable closed-loop control of the output code rate is realized, parameter synchronization of a coding end and a decoding end is ensured, distortion is avoided, and code rate fluctuation is effectively controlled on the premise of maintaining high image quality.