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713results about How to "High control precision" patented technology

Reversible cold rolling mill flow quantity AGC band thickness control method

The invention discloses a flow AGC strip thickness control method of a reversing cold rolling mill, which comprises detecting steps of strip thickness and speed at the input and output of the rolling mill, detecting and computating steps of stiffness coefficient of the rolling mill and plasticity coefficient of strip, control steps of precontrolling AGC, monitoring AGC and hydraulic pressure APC in the control of the hydraulic pressure AGC. The invention is characterized in that the flow AGC strip thickness control method of a reversing cold rolling mill, comprises a establishing steps of a mathematical model of the flow AGC control, computating steps of strip theoretical thickness difference at the output of the rolling mill, computating steps of gap compensation regulation of the rolling mill; the cap regulation of delta Sh of the flow AGCregulated by a PI regulator ,is used as the thickness control of the rolling mill, that is, steps of thickness closed ring control of gap compensation of the endocyclic hydraulic pressure AGC of the hydraulic pressure AGC. The invention has real-time thickness compensation without a time delay and is suited to being widely popularized in AGC system of strip single stand reversing cold rolling mill.
Owner:中国一重集团有限公司 +1

Advanced coordinated control system for moisture in cut tobacco dryer

InactiveCN102488308AStrong ability to overcome interferenceHigh control precisionTobacco preparationSelf adaptiveRelative humidity
The invention provides an advanced coordinated control system for moisture in a cut tobacco dryer. The system is characterized by comprising a head control system, a middle control system and a tail step control system, wherein the head control system adopts a multi-input single-output model; in the middle control system, the moisture is introduced into the control system and subjected to feedback correction, and during model predictive control, an error between the process actual output and the model output is adopted for feedback to overcome a defect; and the tail step control system establishes a model for the tail process. The advanced coordinated control system has the advantages that: 1, the control process is fully automatic; 2, the capacity of overcoming interference is high, and the control accuracy is high; 3, the system has an adaptive control function; 4, the dried cut tobacco amount at the head and tail is reduced to the greatest degree; 5, the oscillation in the regulating process is avoided; 6, the fragmentation of the cut tobacco in the production process is reduced; 7, jump and non-smoothness caused by piecewise fitting are avoided; and 8, a condition that the relative humidity in a cut tobacco drying cylinder is influenced due to ultrahigh or ultralow moisture exhaust is avoided.
Owner:DONGHUA UNIV

Load-sensitive electric proportional multi-loop valve

The invention relates to a load-sensitive electric proportional multi-loop valve. The load-sensitive electric proportional multi-loop valve aims to enable all loops to work with different loads, save energy and reduce environmental pollution. According to the technical scheme, the load-sensitive electric proportional multi-loop valve comprises a main oil path, a raising loop, an inclined joint, an attachment joint, a logical direction valve, a two-way solenoid valve, a proportional electric overflow valve and a two-way hydraulic control reversing valve, the main oil path is communicated with two gear pumps P1, P2, the raising loop is connected to the main oil path through an electronic proportional pressure compensation flow control valve, the inclined joint and the attachment joint are connected to the main oil path through an electronic proportional pressure compensation flow control valve, the logical direction valve is connected to the main oil path, the two-way solenoid valve and the proportional electric overflow valve are connected to an oil inlet of the logical direction valve, and the two-way hydraulic control reversing valve is used for controlling whether the gear pump P2 supplies oil to the main oil path or not. The load-sensitive electric proportional multi-loop valve is applied to the technical field of hydraulic system control valves of 5-10t forklifts.
Owner:HANGCHA GRP

Driven-by-wire brake system for electric automobile

ActiveCN104071142AHigh control precisionReduced speed and power requirementsBraking action transmissionBraking componentsElectric machineryDrive motor
The invention relates to a driven-by-wire brake system for an electric automobile. The driven-by-wire brake system comprises a motor, a planetary gear train, a thread lead screw pair, a main cylinder, a brake mechanism, a pedal execution and simulation mechanism, an energy accumulator, an oil pot and a controller. The motor, a speed reduction and torque increase mechanism and the thread lead screw pair are used for replacing a vacuum booster of a traditional vacuum servo hydraulic braking system, a piston in the brake main cylinder is pushed to move to generate brake hydraulic pressure, and therefore dependence on the vacuum degree of an engine is eliminated. The high-pressure energy accumulator is arranged, driving pressure compensation is provided for the system in the initial brake process of the motor, the response time of a traditional automobile brake system can be achieved easily, the control precision of the system is improved, and the requirements of the system for the rotating speed and power of the drive motor can be effectively reduced by being matched with the speed reduction function of the planetary gear train. The high-pressure energy accumulator can provide braking two to three times when the system breaks down and is overall powered off, meanwhile, pedal force provided by people can act on braking at the moment at the same time, and therefore the brake safety of the system is improved.
Owner:TSINGHUA UNIV +1

Automatic switching control method for decentralization and centralization of mobile manipulators

The invention relates to an automatic switching control method for decentralization and centralization of mobile manipulators. The method includes: firstly, establishing a world coordinate system and a vehicle-mounted coordinate system for the mobile manipulators, and acquiring current poses of the mobile manipulators; secondly, aiming at different control strategies, establishing kinematic and dynamical models for a system; and thirdly designing an automatic decentralization and centralization control switcher, and finally completing established tasks by means of coordination control of the mobile manipulators and a movable platform. Aiming at different control tasks, a reasonable control scheme is selected as either decentralization or centralization, the tasks are guaranteed to be completed smoothly under coordination control between the movable platform and the manipulators, and further control performance of the mobile manipulators is improved under the influences of uncertain factors such as unknown external disturbance, environment time varying and obstacle avoidance. The method can be widely used for application fields of industrial production, medical assistance and the like, and researches on different objects of underwater robots, flying robots and the like can be extended.
Owner:WUHAN UNIV OF SCI & TECH

Electronic expansion valve control method and device in heat pump air conditioning system

The invention relates to the technical field of air conditioner control, in particular to an electronic expansion valve control method and device in a heat pump air conditioning system. The method comprises the following steps: acquiring pressure at the suction end of an electric compressor and temperature at an outlet of a vehicle interior heat exchanger; calculating an actual superheat degree through the pressure at the suction end of the electric compressor and the temperature at the outlet of the vehicle interior heat exchanger; acquiring a heating or refrigeration state sent by a panel of an air conditioner, and setting a target superheat degree according to the heating or refrigeration state; differencing the actual superheat degree and the target superheat degree to obtain a superheat degree deviation; and determining a current opening degree of an electronic expansion valve according to the superheat degree deviation, and sending the opening degree of the electronic expansion valve to the electronic expansion valve to control work of the electronic expansion valve. Through the electronic expansion valve control method and device, the control accuracy and the stability of the heat pump air conditioning system are improved.
Owner:ANHUI JIANGHUAI AUTOMOBILE GRP CORP LTD

LCL type three-phase grid-connected inverter control method

The invention relates to an LCL type three-phase grid-connected inverter control method. The method includes first obtaining a preliminary PWM modulation signal by a traditional active damping controlmethod, then estimating the current after the resonance peak is suppressed according to the feature that an L-type filter and an LCL filter are consistent in characteristic at the low and medium frequency, obtaining the difference between the current and the actual current to be corrected by a current observer at the low and medium frequency, meanwhile feeding the higher harmonic part of the error current back to a control loop and introducing a network voltage feed forward item to obtain a final modulation signal and further control the access current of a grid-connected inverter. The accesscurrent is controlled in a two-phase rotating coordinate system, and the shortcoming that PI control cannot track an AC signal without static difference is overcome. On the basis of taking into account the advantages of active damping, the access harmonic components are further attenuated, and the grid-connected current quality and the system rapid response capability are improved. The method hasthe advantages of high control precision, high reaction speed and high reliability and is suitable for new energy integration grid-connected power generation systems.
Owner:SHANGHAI UNIVERSITY OF ELECTRIC POWER

Control method and device of electronic expansion valve and air conditioner

The invention discloses a control method and device of an electronic expansion valve and an air conditioner. The method includes the steps of starting a compressor of the air conditioner; controlling the opening degree of the electromagnetic valve of the air conditioner to the first opening degree value, and starting timekeeping; detecting the first running parameter and the first running condition of the compressor, wherein the first running parameter is the running parameter of the compressor when the time obtained through timekeeping is between the first preset time and the second preset time, and the first running condition is the running condition of the compressor when the time obtained through timekeeping is between the first preset time and the second preset time; calculating the second opening degree value according to the first running parameter and the first running condition; controlling the opening degree of the electronic control valve to the second opening degree value. By means of the control method and device of the electronic expansion valve and the air conditioner, the problem that in the prior art, due to the fact that the control accuracy of the electronic expansion valve is low, the speed at which the compressor in an air conditioner system arrives at the stable running state after being started is low is solved.
Owner:GREE ELECTRIC APPLIANCES INC

High-voltage pulse generator

The invention provides a high-voltage pulse generator which comprises three parts such as a power supply cabinet, an operation board and a simulation lightning wave generator, wherein the power supply cabinet is used for controlling the operation of the generator and generating high-voltage pulse; the operation board is used for displaying and inputting a control instruction; the output end of an intelligent thyristor voltage regulating module is sequentially connected with a rectifier filter circuit, an H-bridge module and an LC (Liquid Crystal) resonance circuit; the LC resonance circuit is sequentially and electrically connected with a high-frequency and high-voltage charging transformer, a multiplier and an impulse voltage generator; and the impulse voltage generator is externally connected with an insulated testing system and is respectively and electrically connected with an external oscilloscope through a resistance voltage divider I as well as is electrically connected with an analog quantity input end of a programmable logic controller (PLC) in the cabinet through a resistance voltage divider II. According to the high-voltage pulse generator provided by the invention, the wave-front time can be regulated by regulating and converting a plurality of parameters in a grading way and the single triggering or automatic continuous triggering once each minute is realized; and the high-voltage pulse generator has the advantages of simpleness for operation, high control precision, safety and reliability.
Owner:四川中物海通特种电源有限责任公司

Dewaxing and sintering integrated technique for large product of hard alloy

ActiveCN101343697AEnsure dewaxing efficiencyHigh control precisionCemented carbideParaffin wax
The invention discloses a cemented carbide dewaxing and sintering integrated process, which comprises the following steps: firstly, argon is filled in a furnace, then the argon is replaced by hydrogen, and the pressure in the furnace is controlled with 1.01X10<5> to 1.03X10<5> Pa; the multistep heat rising and preservation is performed on the condition that the hydrogen flow is 240 L/min to 260 L/min, and paraffin forming agent is eliminated; the atmosphere in the furnace is adjusted as a negative pressure during the heat preservation period after the temperature is increased to 450 DEG C, and the residual paraffin forming agent in the furnace is eliminated through adopting the hydrogen pulse pressure to scour; after the paraffin forming agent is eliminated, the temperature is increased to 1300 DEG C to 1350 DEG C to perform the vacuum sintering; the argon is filled in the late period of the vacuum sintering, and the argon protection sintering is performed at the temperature of 1350 DEG C to 1450 DEG C; after the argon protection sintering is completed, the argon is rapidly cooled. The process has the advantages that the multistep heat rising and preservation is performed on the condition of a micro-positive pressure hydrogen atmosphere, the dewaxing efficiency is high, the product has no peeling, the product carbon content control precision is very high, and the alloy cobalt magnetism value reaches 6.8 percent to 7.2 percent after the hold up hammer sintering.
Owner:ZHUZHOU HARD ALLOY GRP CO LTD
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