44results about How to "Eliminate static errors" patented technology

The invention discloses a linear servo motor control method for numerically-controlled machine tool driving. According to the method, a sine wave linear motor is controlled through a feedback signal detection module, a position control ring, a speed control ring and a current control ring, and the feedback signal detection module comprises a position detection module, a speed detection module and a current detection module, wherein the position control ring adopts a composite control method combining PI (proportional-integral) feedback control and neural network given compensation control, the speed control ring adopts a fuzzy controller with a disturbance observer, and the current control ring adopts a space vector PWM (pulse-width modulation) technology with a PI regulator. The linear servo motor control method has the advantages that the neural network compensation PI control technology, the fuzzy control and the alternating current motor vector control are combined, and the anti-jamming capability, the dynamic response capability and the system stable state precision of a linear servo motor are improved.

The invention relates to a road surface self-adaptive driving anti-skid control method and system of a distributed driving electric automobile and belongs to the technical field of vehicle control. According to the road surface self-adaptive driving anti-skid control method of the distributed driving electric automobile, by estimating a current road surface peak adhesion coefficient in real time,a current road surface optimal slip rate is obtained according to a corresponding linear relation between the current road surface peak adhesion coefficient and the current road surface optimal slip rate; by combining a current wheel center speed, a current wheel reference wheel speed is determined; a difference between an actual wheel speed and the reference wheel speed is calculated; according to the wheel speed difference, the moment of a wheel, which slips in a driving state, is controlled by using a sliding mode variable structure controller; and therefore, it is guaranteed that the wheelslip rate is controlled to the current road surface optimal slip rate. According to the road surface self-adaptive driving anti-skid control method of the distributed driving electric automobile, thewheel slip rate is controlled to the current road surface optimal slip rate to realize self-adaptive control of anti-skid driving of the wheel.

The invention relates to a control method of a grid-connected inverter of a large-scale grid-connected photovoltaic power station. The control method is characterized by comprising the following steps: establishing a grid-connected inverter model under a d-q coordinate system; realizing active and passive power decoupling control by adopting a state feedback exact linearization nonlinearity control strategy; and eliminating static control errors generated by inaccurate system parameter estimation by utilizing cascaded PI (Proportion Integration) adjustment. By utilizing the method of the invention, modeling and grid-connected dynamic analysis are carried out on the grid-connected inverter of the large-scale grid-connected photovoltaic power station to fully reflect the validity of the control method under the conditions of considering different power factors, intensities of illumination, faults, and the like. Compared with a traditional control method, the control method disclosed by the invention is scientific, simple to adjust parameters, can eliminate static errors and has the advantages of favorable dynamic characteristics, stronger robustness, strong suitability, high practical application values, and the like.

The invention discloses a temperature control method of a proton exchange membrane fuel cell. The method comprises the following steps: step 1, establishing a temperature model of a proton exchange membrane fuel cell according to physical properties of each device in the proton exchange membrane fuel cell; step 2, arranging an incremental fuzzy controller according to the established temperature model and a control experience rule, and establishing a temperature closed-loop control algorithm of the proton exchange membrane fuel cell by utilizing the incremental fuzzy controller; step 3, controlling the temperature of the proton exchange membrane fuel cell in real time by utilizing the incremental fuzzy controller according to the temperature closed-loop control algorithm. The incremental fuzzy controller is used for performing the fuzzy control and is set according to the control experience rule, no precision mathematic model is needed, the temperature control method has the advantages of high robustness, simplicity in operation, rapidness in response, easiness in modification and the like, a PEMFC (proton exchange membrane fuel cell) galvanic pile is maintained at a fixed temperature, and electrochemical reaction inside the PEMFC can be safely and efficiently carried out.

The invention relates to a control method capable of improving the stability during power exchange of a VSC (voltage source converter) and a weak AC network. The control method comprises a nonlinear control law of outer loop control in double closed-loop control, an integral control law for eliminating a static error increase in the nonlinear control law, and outer loop control of the double closed-loop control formed through the nonlinear control law and the integral control law. According to the control method provided by the invention, the stability of a whole system formed by the voltage source converter and the weak AC network when the power is transmitted to the weak AC network by using the voltage source converter or the weak AC network outputs the power outwards by using the voltage source converter is improved, the possibility of a potential instability failure is reduced and the utilization efficiency of the voltage source converter is improved, thereby reducing the cost.

The invention discloses an improved integral separation type PID control method, belonging to the field of the PID control. Because the upper limit value umax and the lower limit value umin of the theoretical output value are set, too large or small control amount can be avoided. Even if the integral saturation phenomenon occurs, the overshoot can exit quickly due to less integral accumulation, and hereby the response speed of the overshoot is increased and the overshoot is reduced. In addition, the increment delta P of the theoretical output value and the difference delta U of the theoretical output value and the set threshold value are calculated, and the increment delta P is compared with the difference delta U: the smaller one of the increment delta P and the difference delta U is compared with xi if the overshoot phenomenon is possible to occur, wherein, the integral coefficient ki is easy to be neglected at the moment and the occurrence of overshoot is prevented hereby, and the smaller one of the increment delta P and the difference delta U is compared with the xi if the static errors of the system are likely difficult to be eliminated, wherein the integral coefficient Ki is easy to be considered at the moment and the static errors of the system are easy to be eliminated hereby. The improved integral separation type PID control method can also realize the positive and negative adjustment, thus the adjustment precision of the system can be improved.

The invention relates to a ramp-error compensation circuit for a peak current controlled BUCK converter, belongs to the technical field of switching power supplies and solves the problem that the output current of the peak current control BUCK converter has a static error after ramp compensation in the prior art. The ramp-error compensation circuit disclosed by the present invention comprises a ramp compensation sub-circuit, an error compensation sub-circuit and a conditioning amplifier sub-circuit, wherein the error compensation sub-circuit comprises a ramp compensation sub-circuit, an errorcompensation sub-circuit and a conditioning amplifier sub-circuit. The input signal of the error compensation sub-circuit is taken from the output voltage of the BUCK converter, and the error compensation value is proportional to the output voltage of the BUCK converter and equal to the static error of the output current of the ramp compensation sub-circuit. Therefore, the BUCK converter with anyduty cycle can achieve error compensation and eliminate the static error caused by ramp compensation.

The invention discloses a denitration and ammonia spraying control system for a W-flame boiler and a method thereof. The system comprises an SCR inlet NOx concentration module, an SCR outlet NOx concentration setting module, an SCR outlet NOx concentration module, a boiler real-time flue gas flow calculation module, an ammonia gas flow module, a boiler combustion state variable module, an NOx quantity module theoretically needing to be removed, a combustion state estimation controller, a static deviation controller, a theoretical ammonia-nitrogen molar ratio module, an arithmetic operator module, an ammonia flow controller, and an ammonia flow regulating valve. A control strategy of a feedforward loop, an estimation loop, and a feedback loop is set, and a state estimation controller, an NOx quantity module theoretically needing to be removed and a static deviation controller are correspondingly arranged. According to the control method, denitration optimization control and precise ammonia spraying of the W-flame boiler can be achieved in any DCS and any external system configuration of the DCS, and partition dynamic precise ammonia spraying optimization can be achieved in cooperation with SCR partition.

The invention discloses a control method and a device of network transmission speed. According to the embodiment of the invention, when it is detected that difference exists between actual speed and a speed threshold value of the current network data transmission, deviation reduction processing is performed on the difference. A proportional constant Kp is capable of rapidly eliminating a difference value between actual speed and the speed threshold, so when the proportional constant is bigger, the response speed of the difference value adjustment is faster, so the transmission speed of the network data can be quickly adjusted, the adjustment efficiency of the network data transmission speed can be increased and a problem of low adjustment efficiency of the current network transmission speed control method can be solved.

The invention provides a power transmission line and power transmission equipment inspection system. The system comprises a power transmission line monitoring terminal and a power transmission line detection device which is in communication connection with the power transmission line monitoring terminal and used for inspecting power transmission lines and power transmission equipment; a terminal acquisition module acquires inspection data information, transmitted by the transmission line detection device, of the transmission lines and transmission equipment. The transmission line detection device can perform targeted inspection on the transmission lines and transmission equipment, acquire video information or image information of the transmission lines and transmission equipment, and perform fixed-point inspection on the transmission lines or inspect the entire tower. Visual detection of the inspected transmission lines is realized, and the problem that the transmission lines can be seen is solved.

The embodiment of the invention provides a display synchronization method and a video display terminal. The method comprises the following steps: receiving first frequency identification information;calculating a difference value between the first frequency identification information and second frequency identification information; determining a corresponding target difference value according tothe calculated difference value; judging whether an absolute value of the determined target difference value is greater than a first set threshold; if yes, calibrating the own determined target difference value by using a proportional differential PD algorithm; if no, calibrating the determined target difference value by using a proportional integral differential PID algorithm; determining a corresponding target voltage according to the calibrated target difference value; and adjusting the own actual output frequency according to the determined target voltage. By adoption of the scheme, the clock frequency of video display terminals can be quickly adjusted to be consistent with that of a main video display terminal, and the adjustment accuracy is well ensured as well.

The invention discloses a brushless DC motor position tracking controller based on fuzzy control, comprising a fuzzy position regulator, a speed regulator, a gain regulator, a DC brushless motor and position sensors, wherein three position sensors are installed in the motor, with a difference of 120 DEG between every two adjacent sensors; the fuzzy position regulator, the speed regulator, the gain regulator, the DC brushless motor and the position sensors are in connection in an electric loop mode to form a brushless DC motor controller based on fuzzy control. The brushless DC motor position tracking controller has the characteristics of simple circuit, low cost, interference resistance and good dynamic/static state servo characteristic, and effectively solves the problem of low tracking precision of a traditional control algorithm by realizing a fuzzy control algorithm in a DSP.

The invention provides a self-adaptive fault-tolerant unmanned aerial vehicle tracking and cruising system and method. The system comprises an unmanned aerial vehicle flight parameter acquisition module, a self-adaptive alignment calculation module, an early warning and obstacle avoidance control module and a wireless power supply module. The self-adaptive alignment calculation module comprises an upper-layer control module and a bottom-layer control module, and the bottom-layer control module comprises a position control module, a tension and posture distribution module, a posture control module and an accelerator control module; the tension and posture distribution module controls the position control module, the posture control module and the accelerator control module to achieve the purpose of reaching the expected cruise route with the minimum inclination angle and power. The three-dimensional attitude speed, the position coordinates and the three-dimensional stress condition of the unmanned aerial vehicle in the flight process can be monitored in real time, the random forest method is adopted to optimize iteration, deviation generated in the calculation process is avoided, active fault-tolerant control is carried out through the early warning obstacle avoidance control module, it is guaranteed that deviation of the unmanned aerial vehicle from the flight route can be corrected in real time, and the unmanned aerial vehicle flight safety is improved. And cruising in the predetermined target cruising route.

The invention provides an AC-DC converter based on a constant power load and a control method thereof, and the method comprises the steps: obtaining a power observation value PCPL* of the constant power load based on an output current iodc and a DC side voltage vdc of a switch unit in the AC-DC converter; calculating a predicted value iod1* of the output active current of the AC-DC converter based on the power observed value PCPL*; performing nonlinear proportional-integral adjustment based on the output direct-current voltage vdc and the reference voltage vdc* to obtain a reference current correction value delta(iod*); obtaining a reference active component iod* of the AC output current based on the reference current correction value delta(iod*) and the predicted value iod1*; based on the reference active component iod* of the alternating current output current, the active component iod of the alternating current side line current, the reactive component ioq of the alternating current side line current and the reference reactive component ioq* of the alternating current output current, obtaining the active component vood and the reactive component voq of the output line voltage of the alternating current-direct current converter; and controlling a switch unit of the AC-DC converter based on the active component vod and the reactive component voq.

The invention discloses a method for correcting signal transmission error among DCS (Decentralized Control System) hardware. In the process of signal transmission among the DCS hardware, an analog quantity signal is output through a system and then is input by the other system hardware, thus the precision of the hardware must bring a channel error for the signal transmission; and the economical performance of the system is directly influenced by an important analog quantity control signal. The invention provides the method for correcting signal transmission error among DCS hardware, which is characterized in that signal source data before correcting are directly taken as output data to be output; when correcting, deviation obtained by reducing communication feedback data from the output data before correcting passes through a step delay loop as hardware error, and then the signal source data are superposed with the hardware error to obtain the output data after correcting. The application of the method for correcting signal transmission error among DCS hardware can make the signal transmission error among the DCS hardware and realize the effects of completely removing static error and obviously reducing dynamic error, thereby improving the accuracy of the DCS.