269 results about "Pid control system" patented technology

The invention relates to a temperature cascade PID (Proportion Integration Differentiation) control system of a high-temperature high-pressure testing device and a control method thereof. A high-temperature autoclave for test is used for simulating the temperature, the pressure and other parameters of a stratum environment and carrying out detection test on performances of an instrument working in an environment similar to the stratum environment. The temperature cascade PID control system comprises a hot air mixed heating module, a heating power supply module, a fan circulating module and a temperature measurement and control module; a heating area of the hot air mixed heating module is divided into three temperature measurement areas, i.e. a target temperature measurement area, a safetytemperature measurement area and a hearth temperature measurement area; the target temperature of which an output signal is transmitted to an inner ring auxiliary control PID control circuit after operated and processed through an outer ring main control PID control circuit is compared with a safety temperature for operation processing, and the output signal is amended by a temperature control coefficient and converted into a simulation control signal which is output to a power adjusting device for adjusting the output power of the heating power supply. Three temperature control areas in the invention realize the accurate control on the test temperature in the autoclave by using a cascade control method according to the requirement of a process curve of raising, preserving and reducing the temperature.

The invention relates to a PID (Proportional Integral Derivative) control method for an elastic integral BP neural network based on RBF (Radial Basis Function) identification, which comprises the following steps: determining the structure of the BP neural network and determining an initial value; determining the structure of an RBF identification network; sampling; positively calculating the BP network and calculating the output of a PID control system; calculating the RBF identification network; revising the parameters of the identification network; and revising the weighting coefficient of the BP netural network. The invention has the advantages that the BP neural network is combined with the traditional PID control to form an intelligent neural network PID control system; no accurate mathematical model is required to be established; the change of the parameters of the controlled course, the parameters of the automatic setting control and the parameters of adapting to the controlled course can be automatically identified; and the method is an effective measure for solving the problems of difficult parameter setting, no real-time parameter adjustment and weak robustness of the traditional PID control system.

The invention discloses a central air conditioning fuzzy PID control system based on load prediction control. The system comprises a load prediction module, a fuzzy PID control module, an executor, acontrolled object and a sensor. The load prediction module is composed of three load prediction units including the medium-term load prediction unit, the short-term load prediction unit and the flow prediction unit. A load prediction controller calculates the required chilled water flow of a current chilled water system according to history operating data and an outdoor temperature, then the required frequency of a chilled water pump is calculated by means of the intelligent fuzzy PID control system, finally, the rotating speed of the water pump is changed through a water pump frequency changer, variable flow control of central air conditioning chilled water is completed, and therefore, the system has the energy-saving benefit. By means of the refrigeration house temperature feedforward-fuzzy control system based on dynamic load variation and the control method, the phenomena that temperature control through a traditional central air conditioning system chilled water control scheme lags, and the control precision is not high are avoided, early response of a flow control system is achieved, and the performance of a central air conditioning system is guaranteed.

The invention provides an apparatus for stably maintaining sludge micro-bulking for saving energy in biological denitrification technique, which is provided with a water inlet tank, a reactor, and a secondary sedimentation tank sequentially, the water inlet end of the reactor is provided with an anaerobic cellular chamber, the anoxia cellular chamber is provided with a stirrer inside, an aerobic cellular chamber or a passage is arranged behind the anoxia cellular chamber, the aerobic lattice chamber or the passage is provided with a dissolved oxygen probe and an aeration head, and each dissolved oxygen probe is connected to a PID control system, each aeration head is connected to an air compressor through an air-flow meter, each control switch is connected to the PID control system. By adopting reasonable regulating technology operation parameters, particularly, the technology is controlled to be carried out under the conditions of proper sludge burden and dissolved oxygen concentration, the invention improves inter-species balance between filamentous fungi and zoogloea bacterium, and controls the sludge bulking within a certain extent and avoids malignant sludge bulking, thereby stably maintaining sludge micro-bulking. The invention solves the technical problem of how to stably maintain sludge micro-bulking in sewage treatment, and saves aeration energy consumption and achieves sewage water high-efficiency treatment purpose while ensuring the process effect.

The invention discloses an intelligent integration method for anti-integral windup and overshoot suppression of a PID (Proportional, Integral and Derivative) control system. The intelligent integration method comprises the following steps: according to a set input valve r(t) and an output value y(t) of the system, calculating an error signal value e(t); judging whether an actually input signal of a controlled object has a measured value v(t) or not: when the actually input signal of the controlled object has the measured value v(t), calculating an executor over-limit signal x(t) according to a control signal u(t) output by a controller and the measured value v(t), and when the actually input signal of the controlled object does not have the measured value v(t), setting an executor limit value; setting an anti-integral windup parameter alpha for an integral error signal to eliminate system oscillation caused by executor over-limit; setting an overshoot suppression parameter beta for the integral error signal to suppress system step response overshoot caused by an integral action. The intelligent integration method for anti-integral windup and overshoot suppression of the PID control system not only can resist windup and suppress overshoot, but also does not change the original system stability, and has the advantages that the parameters are simple to set and the real-time high-accuracy quick control of the control system is easy to realize.

The invention provides a secondary cooling mode control system of a continuous casing slab which can change as the change of the technology and can adjust water flow quantity in time, and has stable casting slab setting process and little temperature fluctuating on the surface, and can get excellent casing slab quality. The invention comprises a mathematical module and an increment-type PID control system, the mathematical module substitutes an in-site technological parameter into a non-stationary setting-heat transferring equation, the equation is established on the basis of a structural parameter of a casting machine, solving and calculating are proceeded by the equation, and the equation determines the effect relationship of the changing of the parameter to the surface temperature of the casting slab, the depth of a liquid core, and the terminal position of the freezing point, which dynamically displays the positions of the casting slab temperature field and the freezing end. The increment-type PID control system adjusts water quantity according to calculating the differential value between the temperature field and a target temperature field, temperature difference ratio, and temperature difference accumulation degree. The invention is applicable to the technology control of secondary cooling section of continuous casting.

The invention belongs to the aircraft fuel system full-mold test field and relates to an adaptive PID control method and control system of an executing mechanism. The objective of the invention is to solve the problems of poor effects and low precision of an existing PID control method. The adaptive PID control system includes an expert PID controller and a fuzzy PID controller which are respectively connected with the executing mechanism, a state information acquisition device used for monitoring the current status information of a system to be controlled in real time, and a processor used for selecting the expert PID controller or the fuzzy PID controller according to the current status information and expected status information to control the executing mechanism. According to the adaptive PID control system of the invention, the expert PID controller or the fuzzy PID controller is selected to perform control, and therefore, the adaptive PID control system has the advantages of high adjustment speed, short rise time, low overshoot and high control precision. With the control system adopted, requirements for high speed of a servo system can be satisfied, and the control quality of the servo system can be improved.

The invention relates to a rapid subsidence thermoforming mold and a thermoforming method of an aluminum alloy section and in particular relates to the thermoforming mold and the thermoforming method of the aluminum alloy section. The invention aims at solving the problems that the heating efficiency of the existing subsidence thermoforming of the aluminum alloy sections is low, the entire production process is low in efficiency and not suitable for mass production due to the fact that local heating of the large aluminum alloy section is difficult. The rapid subsidence thermoforming mold comprises a male mold, a female mold, a contact-type electrode, a contract-type thermocouple, a pulsed power supply, a PID control system and a section blank. The rapid subsidence thermoforming method comprises the following steps of: placing the aluminum alloy section on the mold, carrying out rapid local heating on the section by virtue of pulse current assisted with self-block heating, and carrying out subsidence thermoforming to form a product with a desired shape by virtue of pressure. By utilizing the rapid subsidence thermoforming method, the heating efficiency can be improved by 300%-500%, the thermoforming cycle is shortened to 10-50 seconds, and the energy utilization rate can be improved by 200%-400%. The rapid subsidence thermoforming mold and the rapid subsidence thermoforming method are applied to the aerospace field.

The invention relates to a closed-loop control system for a LLC half-bridge resonance converter and a system-control method thereof. The closed-loop control system comprises an input power of a main circuit, a switch module, a resonant network module, a transformer, a rectification circuit block, a filter circuit module, a load, a control system of PID, and a voltage controlled oscillator (VCO). The closed-loop control method comprises the steps of: starting the control system of PID by an unstable output voltage signal, adjusting the output voltage, and stabilizing the output voltage. According to the closed-loop control system and the system-control method, the output voltage is adjusted by changing the operating frequency of the LLC half-bridge resonance and the closed-loop controls are associated, therefore the voltage of the LLC half-bridge resonance is steady to increase working efficiency when a switching tube works in a reasonably frequency range.

The invention provides a brushless DC motor fuzzy PID control speed regulation system and method. The method comprises steps of according to the fuzzy control theory, establishing a fuzzy PID controller module of a brushless DC motor speed regulation system; establishing a brushless DC motor speed regulation system module; establishing the objective function of fuzzy PID controller parameter optimization of the brushless DC motor speed regulation system; and obtaining the fuzzy relation between the fuzzy PID controller Kp, Ki, Kd and the error e and the error rate of change ec, and according to the values of the error e and the error rate of change ec, and fuzzy control rules, modifying the three parameters Kp, Ki, Kd. The invention also correspondingly provides a fuzzy control device. The method of the invention adopts the fuzzy PID control for the speed regulation in the PID control system, and has the advantages of good dynamic performance, fast rising speed, small overshoot and good robustness.

The invention relates to an airborne evaporation cycle refrigeration comprehensive heat management system and a method and application thereof and belongs to the airborne equipment cooling field. The airborne evaporation cycle refrigeration comprehensive heat management system comprises a high heat flow heating element spraying cooling cycle sub-system and an evaporation refrigeration cycle sub-system; and the airborne evaporation cycle refrigeration comprehensive heat management system further comprises a phase change heat exchanger (7) connected with the high heat flow heating element spraying cooling cycle sub-system and the evaporation refrigeration cycle sub-system, and a fuzzy PID control system (10). According to the system, by means of the fuzzy PID control system, the influences of heat inertia are considered, and the cold energy is fully utilized to perform cold storage for a phase change material; and by means of frequency conversion of a compressor, the purpose that one evaporation cycle refrigeration system is used to provide the cold energy for a refrigeration space and an airborne high heat flow heating element at the same is achieved, the system is integrated, the cold energy of the evaporation cycle refrigeration system is comprehensively managed, the heat load of the refrigeration space and the heat load of the airborne high heat flow element are reasonably matched, the weight of the system is greatly reduced, and the airborne equipment requirement is met.

The invention discloses a novel anti-integral-saturation PID control method. An anti-integral-saturation link is added into a common PID control method. When PID control is saturated, the anti-integral-saturation link computes a current integration item in combination with a proportional item and differential item. The novel anti-integral-saturation PID control method is easy to implement, not provided with any extra parameter, and capable of effectively inhibiting integral saturation, accelerating de-saturation time, decreasing overshoot, and guaranteeing the robustness, the reliability, and the stability of a system, and can be used in PID control systems in various variational forms.

The invention discloses a control method for an SCR denitration system based on sensitive factor analysis, comprising steps of 1) collecting the history parameter sample of the SCR denitration system operation at the fixed time interval, calculating the sensitive coefficients of various operation parameters which affect the denitration reactor inlet NOx at different moments, drawing the sensitivity curves of the various operation parameters and the reactor inlet NOx according to the obtained sensitive coefficient, 2) determining a plurality of main sensitive factors that affect the denitration reactor inlet NOx according to the drawn denitration reactor sensitivity curve of the step 1, 3) calculating the prediction value of the reactor inlet NOX of the denitration reactor inlet NOx according to the plurality of main sensitive factors that affect the denitration reactor inlet NOx, and 4) adopting a cascade PID control system to control the ammonia spray amount of the SCR denitration system according to the obtained prediction value of the denitration reactor inlet NOx to realize the control on the SCR denitration system. The method can perform real time, fast and affective control on the ammonia spray amount in the SCR denitration system.

The present invention relates to a fuzzy control-based differentiation first PID (proportion integration differentiation) control system. The control system comprises a differentiation first link, a fuzzy controller, a proportion link, an integration link and a feedforward controller; speed deviation and speed deviation change rate are adopted as the input of the fuzzy controller, and a control quantity outputted by the fuzzy controller is the proportion coefficient increment of the proportion link; the differentiation first link is arranged on a feedback loop; a speed measurement value and a change rate value thereof are inputted into the proportion link and the integration link as measurement values; the output quantities of the proportion link and the integration link are adopted as the control signals of the PID control system; and only when a speed set value changes, the feedforward controller performs control for a certain period, namely, the feedforward controller suppresses the output quantities and promotes the change of the output quantities. With the system adopted, overshooting can be effectively avoided, and dynamic performance can be improved. The anti-interference ability and robustness of the system can be enhanced.

The invention discloses a fused salt heat exchange experimental device and a control method thereof. The experimental device comprises a high-temperature fused salt circulating circuit, a heat-conducting oil circulating circuit, a cooling water circulating circuit and a control system, wherein the high-temperature fused salt circulating circuit and the heat-conducting oil circulating circuit are separately connected with parallel fused salt heat exchange experimental sections; the heat-conducting oil circulating circuit and the cooling water circulating circuit are separately connected with a heat-conducting oil heat exchanger and a cooling water heat exchanger; the control system is a Fuzzy-PID (Proportion Integration Differentiation) control system, and has the characteristics of rapid response control, high control precision and easiness for realization. According to the fused salt heat exchange experimental device and the control method thereof disclosed by the invention, the project quantity of replacing the experimental sections is reduced; meanwhile, the experimental sections are simultaneously performed by intelligent control, so that the consumption of energy sources is reduced to a great degree, and accurate control over temperature and flow can be realized; meanwhile, aiming at the control over the parallel experimental sections, huge contribution on energy conservation is realized. Experimental operation personnel are away from an experimental table area, and intelligent automation is completely realized, so that the security of the experimental personnel is realized.

The invention provides an adaptive cascade PID control method. In the method, based on conventional cascade PID control, an adaptation module is introduced into a cascade PID control system, and control parameters of a master controller in the cascade PID control are directly generated by an online fuzzy identification method and a recursive least square algorithm according to the historical information of the control system, so that the robustness and adaptive capability of the cascade PID control system are improved; and in the process of online identifying the control parameters of the master controller, the influence of a secondary controller to the control performance of the system is reflected by the output of a main loop of the cascade PID control system, and good control effect can be obtained only by performing online regulation on the control parameters of the master controller in the system.

The invention discloses a PID controller parameter optimal setting method relating to the field of automatic control and based on swarm intelligence optimization searching technology. Integral performance indexes which can comprehensively measure stability, rapidness and accuracy of an automatic control system are adopted as fitness functions. Through utilization of a global optimization function of a differential evolution algorithm, a proportionality coefficient K[p], an integral coefficient K[I] and a differential coefficient K[D] which can realize global minimization of the performance index function values of a PID control system are searched to be regarded as optimal setting parameters of the PID controller. The PID controller parameter optimal setting method based on the differential evolution method is utilized to carry out simulation experiment direct current motor rotating speed closed loop control system. The experiment result shows that a PID control system obtained after undergoing setting by the method has outstanding advantages of a fast adjusting speed and small overshoot compared with control systems set obtained through a common setting method. The PID controller parameter optimal setting method is a PID controller parameter setting method having a popularization value.

The invention provides a fuzzy neural network PID (proportion integration differentiation) control system and a fuzzy neural network PID control method for a fin stabilizer. After quantization, address mapping and CMAC storage are performed on a detected sea wave dip angle signal by a CMAC (cerebellar model articulation controller) neural network feed-forward control unit, by combining online learning of a fin angular displacement signal output by a fuzzy PID controller, CMAC operation is performed on the fin angular displacement signal and the quantized sea wave dip angle signal to obtain a fin stabilizer anti-interference offset angular displacement signal to be input into a fin stabilizer servodrive unit; a PLC (programmable logic controller) control unit is used for receiving signals detected by a velocity log and an angular velocity sensor, and the signals are output to the fuzzy PID controller after being fitted; the fin angular displacement signal processed by the fuzzy PID controller is sent to the fin stabilizer servodrive unit; the fin stabilizer is driven to rotate by the fin stabilizer servodrive unit according to the fin angular displacement signal and the offset angular displacement signal, and moreover, an angular displacement sensor is used for detecting a current fin angular displacement signal of the fin stabilizer, and the current fin angular displacement signal is sent onward to the fuzzy PID controller after the current fin angular displacement signal and the fin angular displacement signal sent by the PLC control unit are subtracted to drive the fin stabilizer to perform adaptive adjustment, and therefore, the adaptability of a control process is improved.

The invention relates to a dynamic wind temperature control-based method for quickly testing the shortest spontaneous combustion period of coal, which relates to a coal test method. The method comprises the following steps: (1) removing a surface layer of newly-collected coal, and then breaking the coal to obtain a test coal sample for later use; (2) adding the coal sample into a reaction container to allow wind flowing through coal bodies to pass through the reaction container uniformly, and opening a PID control system to monitor the temperature variation of the coal bodies and wind currents hourly; (3) opening an oxygen concentration detection system to detect the change rate of the oxygen concentration of each characteristic point in the coal bodies; and (4) substituting characteristic parameters determined in an experiment in the process of coal spontaneous combustion in a demarcated mathematical model of the shortest spontaneous combustion period of the coal to calculate the shortest spontaneous combustion period of the coal. The test method can determine the shortest spontaneous combustion period of the coal quickly, simply and accurately under the adiabatic condition and test the shortest spontaneous combustion period of the coal scientifically and quickly, and is high in confidence level of test results.

The invention discloses a supercritical unit coordinated predictive function control algorithm. It is difficult for a conventional PID control system to consider the rapidity of load and stability of pressure and temperature at the same time, the quality of a coordinated control system needs to be improved. According to the supercritical unit coordinated predictive function control algorithm, predictive function control is applied to a pressure closed loop of a supercritical unit coordinated control system, a main steam pressure predictive function control system is formed. A control valve instruction and a coal quantity instruction are taken as a disturbance signal source of the whole pressure system. The predictive function control is applied to a temperature control loop of the supercritical unit coordinated control system, and an overhigh temperature prediction function control system is formed. A water supply instruction is taken as a disturbance signal source of a whole temperature system. According to the supercritical unit coordinated predictive function control algorithm, the control quality of the supercritical unit coordinated system is improved, and the rapidity of load and stability of pressure and temperature are considered at the same time.

The invention relates to a leakage compensation method for single-loop non-invasive ventilators. The leakage compensation method is characterized in that the leakage compensation method includes the following steps: (1) a two-dimensional curve of the difference between the oxygen pressure at the front of a leaking tooling and the oxygen pressure at the rear of the leaking tooling and average leakage flow velocity is obtained by automatic calibration; (2) when a patient is ventilated in practice, actual leakage flow velocity is calculated; (3) implementation of leakage pressure compensation by the PID (Proportion Integration Differentiation) control algorithm: according to the obtained actual leakage flow velocity, the rotational speed of a turbofan is regulated, moreover, the turbofan and a pressure sensor are utilized to compose a PID control system, and by monitoring the difference between actual airway pressure and set pressure and feeding back and regulating PID parameters, the rotational speed of the turbofan is rapidly controlled until the set pressure value is reached.

The invention discloses an ultrasonic grooved thrust air bearing. The bearing comprises a rotator, a transducer, a piezoelectric ceramic piece, a thrust disc, a rotating disc, a power supply, a PID control system and a displacement sensor, wherein the piezoelectric ceramic piece is provided with a piezoelectric ceramic piece anode and a piezoelectric ceramic piece cathode, the piezoelectric ceramic piece anode is connected with a power supply anode, the piezoelectric ceramic piece cathode is connected with a power supply cathode, the power supply is connected with the PID control system, the PID control system is connected with the displacement sensor, the piezoelectric ceramic piece is adhered to the middle of the lower end surface of the transducer, and the thrust disc and the transducer are connected in a fastened manner through bolts. The bearing provided by the invention has the benefits that the structural advantages of an aerodynamic bearing and an ultrasonic bearing are combined, so that the squeeze effect and the aerodynamic effect are combined to a certain extent, the squeeze effect of the ultrasonic bearing is adjusted in a real-time manner, the elastic force and damping force of a gas film are remarkably enlarged, and the bearing capacity and stability of the bearing are improved.