344 results about "Pressure response" patented technology

The invention relates to the technical field of monitoring and early warning, in particular to a fire hydrant monitoring intelligent early warning system based on an anomaly analysis technology, which comprises a flow velocity anomaly identification module, a node collaborative pressure difference detection module, a pressure difference trend independence judgment module, a node degradation feature extraction module and a risk level generation module. According to the method, through correlation judgment of flow velocity deviation and control signals, no-signal recognition of abnormal water taking behaviors and a cooperative analysis mechanism of pressure change of adjacent nodes, a hydraulic disturbance area under non-manual control can be accurately recognized, and through analysis of spatial independence of a pressure response trend, a water flow disturbance area under non-manual control can be accurately recognized. The function degradation level of the device is extracted according to historical data of on-off time delay and response performance, the quantitative evaluation capability of the node function state is enhanced, the capability of finely dividing the risk level is achieved when risk early warning is given out, the risk identification accuracy is improved, and the active discovery capability of early fault hidden dangers is enhanced.

The invention relates to the technical field of precise injection molding control, and discloses an injection molding process parameter self-adaptive compensation system which comprises a multi-source sensing module used for collecting mold cavity pressure, melt temperature and screw displacement information in the injection molding process in real time; the data fusion module is used for performing time sequence synchronization, space registration and noise suppression on the multi-source sensing data; the dynamic modeling module is used for constructing a dynamic model of an injection molding process state based on the fused process data and outputting a state estimation value; and the stability analysis module is used for carrying out system stability analysis based on the dynamic model and generating a control compensation strategy. Cooperative control of precise positioning and high-pressure response is realized through a composite driving framework and a dynamic disturbance compensation technology; an incremental learning algorithm and a multi-dimensional quality evaluation system are combined, a process parameter self-evolution mechanism is constructed, material characteristic drift and complex working condition disturbance are effectively dealt with, and closed-loop optimization from process control to quality feedback is formed.

The invention relates to the technical field of high-precision pressure sensing, and discloses a pressure response data calibration method and device and computer equipment, and the method comprises the steps: collecting the output response data of a pressure sensor array, and constructing a spatial feature matrix, a time feature matrix and an environment feature matrix based on the output response data; performing trilinear least square separation to obtain dynamic response data and time characteristic data; performing symmetric geometric mode decomposition to obtain linear response component data, periodic fluctuation component data and nonlinear characteristic component data; inputting a multi-branch gating circulation unit network model to carry out dynamic calibration strategy prediction to obtain a first dynamic calibration strategy; performing particle swarm iterative optimization to obtain a second dynamic calibration strategy, and generating a progressive calibration parameter set; static and dynamic pressure sensing calibration is performed on the pressure sensor array to obtain a comprehensive pressure sensing calibration result, so that the accuracy of pressure sensing calibration is improved.

The invention relates to the technical field of food processing, in particular to a cooking and processing system for fermented glutinous rice cake chilies based on temperature feedback. In the hot pepper cooking treatment process, the temperature distribution of the temperature control points with different heights in the cavity is obtained and the layered gradient difference value sequence is constructed, so that the space difference of the temperature change in the cavity can be effectively identified, and further the advance or lag state of the heat response is periodically judged; on the basis, time sequence structure data are constructed according to the top and bottom temperature and pressure change sequences, and the upper and lower layer pressure response relevance is identified in a trend matching mode, so that the hot-pressing state prediction is closer to the real change process, and the accuracy of hot-pressing state prediction is improved. Finally, the opening and closing frequency and direction of a hot air circulation channel are rhythmically scheduled based on a prediction result, balance and smoothness of internal hot air circulation are ensured, and the thermal control precision and the hot-pressure adjusting capacity in the cooking process are enhanced in the whole process.

The invention relates to the technical field of data processing, and provides an automatic control system and method for a hollow plate extrusion production line, and the method comprises the steps: collecting a real-time temperature data sequence, a speed change data sequence and a pressure response data sequence in a hollow plate extrusion process, and carrying out the multi-dimensional feature extraction and response collaborative analysis; obtaining a traction speed correction instruction sequence and a screw rotation speed adjustment instruction sequence; and performing linkage control on the hollow plate extrusion production line according to the traction speed correction instruction sequence and the screw rotation speed adjustment instruction sequence. Through multi-dimensional feature extraction and response collaborative analysis, accurate monitoring and adjustment of multiple key parameters such as temperature, speed and pressure are achieved, the production efficiency and the stability of product quality are improved, a hollow plate extrusion production line can operate efficiently and stably in a complex and changeable production environment, and the production efficiency is improved. The problems that an existing control method is low in reaction speed and insufficient in adjusting precision in the face of complex production working conditions are solved.

The invention relates to the technical field of response time testing of electro-hydraulic proportional valves, and discloses a response time testing method and system of an electro-hydraulic proportional valve, and the method comprises the steps: collecting multi-point pressure, step response, pipeline length and medium parameters, and unifying the time reference to obtain an original pressure sequence; constructing an inverse filter spectrum to remove damping interference so as to recover a sharp peak value; lagging offset is calculated according to pipeline and medium parameters, time delay compensation is carried out, and an alignment sequence is obtained; intercepting a non-stationary segment to eliminate residual delay deviation; constructing a response dynamic data set, extracting harmonic frequency domain representation, and reconstructing a pressure sequence through inverse transformation and superposition of compensation factors; and calculating a deviation integral quantity, adjusting a dynamic compensation parameter, performing weighted correction, and outputting an optimized reconstruction response sequence. According to the method, accurate reconstruction of the real pressure response of the proportional valve can be realized, so that the accuracy and the reliability of response time testing are improved.

The invention discloses an abnormity monitoring method and system for a digital pressure transmitter, and relates to the technical field of transmitter monitoring, and the method comprises the following steps: obtaining an original pressure response sequence in a high-frequency pressure pulsation environment, and synchronously recording a sampling clock pulse sequence in an acquisition process, establishing double-track mapping based on the original pressure response sequence and the sampling clock pulse sequence, and forming an input condition with a unified time baseline; and performing instantaneous phase difference extraction on the double-track mapping on the unified time base line. Through double-track mapping, phase difference extraction and nonlinear cross spectrum reconstruction, the stroboscopic aliasing risk is quantified and recognition in advance is realized, and the sensitivity and accuracy of abnormal monitoring of the digital pressure transmitter are improved; meanwhile, the multi-scale risk amplification and reversible time-frequency rearrangement technology is combined, covered high-frequency components are separated and recovered, a real pressure pulsation curve is output after dynamic correction, continuous and stable monitoring is guaranteed, and pressure measurement reliability and operation safety are improved.

The invention discloses an efficient preparation and construction optimization system and method for a cold patch asphalt mixture, and belongs to the technical field of construction optimization. Environmental parameters of a construction site are collected, including altitude, an air pressure correction coefficient and a light volatile factor, and a multi-scale mixture model coupled with air pressure response is constructed; analyzing the volatilization path, the structural stability and the initial bonding strength of the mixture in combination with discrete elements and fluid mechanics simulation, and further extracting a structural retention threshold value and reversely deducing the proportion adjustment amount of medium-high boiling point solvent components; meanwhile, a microcapsule controlled release technology is adopted to delay release of light components, adaptive construction parameters are output based on a simulation platform and a machine learning model, the paving temperature and the compaction frequency are dynamically optimized, and efficient cooperation and intelligent regulation and control of the cold patch material performance and the site construction technology are achieved.

The invention discloses an electrochemical pressure sensor based on polyelectrolyte gel and a preparation method thereof, and belongs to the technical field of pressure-sensitive elements and pressure sensors. The electrochemical pressure sensor comprises a polyelectrolyte gel pressure sensitive layer, a positive electrode and a negative electrode, wherein the surface of the polyelectrolyte gel pressure sensitive layer is provided with a bowl-shaped groove array structure; the positive electrode is positioned on the upper surface of the pressure sensitive layer; the negative electrode is positioned on the lower surface of the pressure sensitive layer; the polyelectrolyte gel pressure sensitive layer comprises PVA, LiCl and PSS. The surface bowl-shaped groove array structure prepared by using the nucleation effect has excellent pressure-sensitive performance: on one hand, the sensitivity of contact between polyelectrolyte gel and an electrode to pressure is improved, so that the sensor realizes excellent pressure response characteristic; and on the other hand, the surface microstructure gel electrolyte preparation method with less damage to the mold and wider applicability is realized. The electrochemical pressure sensor provided by the invention has the characteristics of high response rate and high output power, and has important value for development of high-performance self-energized pressure sensors.

The invention relates to the technical field of abnormity monitoring, in particular to a composite insulation board production process abnormity monitoring system based on a sensor, which comprises a pressure data acquisition module, a local pressure abnormity detection module, a stress lag analysis module, a pressure accumulation evaluation module and an abnormal area classification module. According to the method, the abnormal pressure accumulation diffusion area in the production process of the composite insulation board is accurately recognized by calculating the pressure change rate and the deviation thereof, the area with obvious delay in pressure response is screened through the rate change lag value, abnormal stress caused by uneven pressure transmission can be recognized, the pressure accumulation ratio of the adjacent areas is compared, and the abnormal pressure accumulation diffusion area in the production process of the composite insulation board is recognized. According to the method, the pressure characteristics of the abnormal area are comprehensively evaluated by combining pressure lag and accumulated trend analysis, and short-time, lag and long-term pressure anomalies are distinguished, so that the accuracy of anomaly recognition can be improved, anomaly early warning stays at a problem discovery level, and more effective data support is provided for optimizing process adjustment.

The invention is suitable for the technical field of medical instruments, and provides a pneumatic global self-adaptive ankle-foot artificial limb which comprises a rear sole and a front sole which are connected through a front and rear foot connecting piece. The pressure response assemblies are located at the bottoms of the rear sole and the front sole, and pressure changes after bearing; and the ankle self-adaption assembly is connected with the pressure response assembly through a valve communication assembly and drives the ankle to do eversion, centering and introversion motions based on pressure changes. According to the embodiment of the invention, an ankle joint inward and outward turning automatic adjusting mechanism directly driven by plantar pressure change can enable the artificial limb to adapt to complex terrains such as uneven road surfaces and lateral slopes in real time, an inward and outward turning motion mode of a physiological ankle joint in the walking process is simulated, and the gait of a user is smoother and more natural; the pure pneumatic control structure is relatively simple and light, and an external power supply pressure driving pump or a complex sensor is not needed.

The invention relates to a pressure control method and system and a storage medium. The method comprises the steps that the monitored current angle of a butterfly valve and the monitored current pressure of a process cavity are obtained; determining the current air inflow of the process chamber according to the current angle and the current pressure of the butterfly valve; determining the predicted pressure of the process chamber at the next moment according to the current angle of the butterfly valve and the current air inflow; according to the set target pressure, the predicted pressure at the next moment and the current air inflow, the target angle of the butterfly valve is determined; and the operation path of the butterfly valve reaching the target angle of the butterfly valve in the shortest time is planned, and the butterfly valve is controlled according to the operation path so that pressure control over the process cavity can be achieved. The real-time air inflow is automatically estimated, the future pressure is accurately predicted, pressure overshoot is reduced, and the stabilization time is shortened; and the opening switching speed of the butterfly valve is maximized, the target angle is reached as soon as possible within the hardware bearing range, and then the pressure response speed is increased.

The invention discloses an aquifer energy storage dynamic pressure regulation and control system and method based on multi-parameter feedback, and relates to the field of pressure regulation and control. Data normalization is ensured through a standardized parameter type set, and high-quality input is provided for a subsequent model; a pressure mapping model trained based on historical data can accurately predict pressure response under an injection-production strategy, and deviation caused by experience dependence is avoided; through partition clustering and mean value calculation, the aquifer with high heterogeneity is converted into a regulation and control unit with uniform characteristics, and the pertinence of an injection-production strategy is remarkably improved; through dynamic adjustment of a pressure interval, the energy storage efficiency reduction caused by an overpressure risk or underpressure is effectively prevented; an introduced physical intervention mechanism breaks through the limitation of pure data optimization, and the hydrogeological condition is directly improved when model adjustment is invalid; the three purposes of stabilizing the pressure of the aquifer, improving the energy storage efficiency and preventing and controlling geological risks are achieved, and scientific support is provided for long-term sustainable energy storage operation.

The invention provides a low-coupling flexible self-powered multi-mode sensor and a preparation method and application thereof, and belongs to the technical field of flexible electronic materials. Comprising a temperature sensing layer, a pressure sensing layer and a humidity sensing layer which are stacked in sequence. The temperature sensing layer is made of a PEDOT: PSS / MWCNT composite material and outputs a temperature response signal through resistance change; the pressure sensing layer is formed by combining a PDMS layer with a micro-nano structure and a PET layer, and outputs a pressure response voltage signal based on a triboelectric effect; the humidity sensing layer is composed of PVA / CA composite matrix and EGaIn liquid metal, and humidity response signals are output through hygroscopicity induced resistance change. The sensor realizes simultaneous detection of three physical quantities of temperature, pressure and humidity, has low coupling degree among the sensing units, and can be applied to the fields of robot interaction, wearable health monitoring and environment monitoring.

The invention belongs to the technical field of biological sewage treatment, and relates to a bacteria-algae particle preparation method and system for promoting bacteria-algae system granulation based on pressure response. The preparation method comprises the following steps: co-culturing the mixed microalgae cultured to a logarithmic phase and aerobic activated sludge in a photobioreactor, in the culture process, jointly regulating and controlling aeration, a carbon source and inlet and outlet water to promote granulation of a bacteria-algae system according to the principle of'pressure-induced stress response ', and controlling dissolved oxygen levels in different periods according to the principle of'unbalanced air supply' during aeration regulation and control; the carbon source regulation follows the principle of unbalanced nutrition to control the COD concentration in different time periods; the water inlet and outlet regulation follows the principle of reducing the settling time, and the water change settling time is gradually shortened in the culture period. The bacteria-algae granular sludge which is good in settling performance, high in dirt-removing power and compact in structure is prepared, the prepared bacteria-algae granular sludge is used for treating sewage and wastewater, pollution of carbon, nitrogen, phosphorus and the like can be efficiently solved, the effluent quality is effectively improved, and carbon emission reduction in the sewage treatment field is promoted.

The invention relates to the technical field of drilling parameter optimization control, and provides a petroleum drilling parameter optimization method and system and a storage medium. Comprising the steps that torque fluctuation amplitude and bit pressure response delay data are collected in real time, an original data sequence is constructed, and parameter trend data are obtained; analyzing the parameter trend data to identify a stratum change mode, extracting trend feature information, and when the trend feature information meets a preset condition, determining a corresponding abnormal mode identifier; generating a parameter adjustment direction of drilling control according to the abnormal mode identifier, and optimizing the parameter adjustment direction in combination with parameter weight analysis and a real-time feedback mechanism to obtain final optimization guidance data for guiding drilling operation; and mapping the final optimization guidance data to a control interface, and generating a dynamic adjustment instruction for drilling operation. The problems that in the existing petroleum drilling process, parameter adjustment lags behind, and stratum changes are difficult to adapt are solved, and intelligent optimization and dynamic control over drilling parameters are achieved.

The invention relates to the field of homogenizer intelligence, and discloses a homogenizer intelligent pressure increasing and reducing control system based on servo synchronous transmission, which comprises the following steps: extracting the operation inertia difference of each plunger mechanism under a multi-pump parallel structure, generating a synchronous offset vector map, and calculating the pressure increasing and reducing of the homogenizer based on the synchronous offset vector map. Calling a slip registration algorithm and an inertia field decoupling network, extracting reconstructed plunger stroke and pressure response mapping data, constructing a three-dimensional flow-path-stress tensor model, judging whether fluctuation-wear coupling sensitive points exist or not, activating a frequency conversion regulation and control strategy set of a servo driving layer based on a disturbance window and the coupling sensitive points, and carrying out the control of the servo driving layer. And judging whether structural thermal drift feedback unbalance exists or not, dynamically adjusting servo redundancy and a buffer response strategy in combination with a preset life curve and an abnormal response backtracking channel, and outputting a synchronous regulation and control instruction set. The method has the advantage of improving the long-term operation reliability of the homogenizer.

The invention provides a regulation and control method, system and device for a relay valve overrun test and a medium, and belongs to the technical field of air braking systems. The method comprises the steps that pressure response characteristics of a relay valve pipeline system under different opening degrees of a proportional pressure regulating valve are tested, a finite set representing pipeline dynamic response is constructed based on pressure data in a sampling period, and a dynamic matrix model is generated to describe the relation between future pressure output and control quantity; pipeline pressure output at the future moment is predicted based on the dynamic matrix model, an optimized target function is established in combination with the target boosting rate, and the optimal control quantity is solved to adjust the opening degree of the proportional pressure regulating valve in real time; comparing a predicted pressure value with an actual measurement value to obtain an error, dynamically correcting a predicted model parameter by using a weighted error sequence, and adjusting a subsequent control quantity to compensate system hysteresis and external interference; and circularly executing the processes until the pipeline pressure and the regulation and control time reach corresponding target values, and cutting off the gas source.

The invention provides an anti-freezing and anti-crystallization hydraulic breather valve and a control method thereof, and belongs to the technical field of breather valves, the anti-freezing and anti-crystallization hydraulic breather valve comprises a valve body and an upper valve box, the valve body is internally provided with a main valve cavity, the main valve cavity is internally provided with an inner valve body, the inner valve body is internally provided with a negative pressure valve assembly, and the negative pressure valve assembly comprises a negative pressure valve seat, a negative pressure diaphragm, a negative pressure valve disc and a negative pressure valve rod; an upper diaphragm is arranged between the upper valve box and the valve body, a valve seat part is arranged at the upper end of the valve body, an anti-freezing solution is arranged in the upper valve box, and the upper diaphragm and the valve seat part are sealed under the gravity of the anti-freezing solution; through the synergistic effect of anti-freezing solution gravity sealing and hydraulic self-balancing design, compared with a traditional breather valve which depends on elastic elements such as a spring to maintain sealing pressure, the technical problems of sealing failure, complex mechanical structure, dynamic response lag and the like in a low-temperature environment are solved; high reliability, long service life and rapid pressure response of the breather valve are achieved, and the breather valve is particularly suitable for the extremely low-temperature working condition.

The invention relates to the technical field of automatic control of drilling parameters, in particular to a coal bed gas underground drilling construction parameter optimization method and system.The method comprises the following steps that sound wave response signals are obtained, propagation characteristics are calculated, bit pressure data are aligned, abnormal fluctuation is recognized, pumping pressure information is extracted, and the change trend is analyzed; and comparing the consistency of the regulation and control points and organizing regulation and control actions to finally form a coal-bed gas well drilling parameter optimization control flow. According to the method, accurate calibration of an abnormal state is achieved by constructing a sound wave propagation delay sequence and synchronizing bit pressure response, key regulation and control fragments are recognized in combination with a pumping pressure change trend, a time sequence coupling relation between bit pressure and pumping pressure is established, regulation and control action combinations meeting response consistency are extracted, and sequential organization is conducted; a control instruction set with continuity and pertinence is formed, collaborative recognition and linkage regulation and control of multi-parameter change trends are achieved, and stability and response coordination in the construction process are improved.

The invention belongs to the technical field of transducer matching layers, and particularly relates to a high-frequency underwater acoustic transducer matching layer structure for deep sea detection, which comprises an integrated gradient functional material layer, the acoustic impedance of the gradient functional material layer is in gradient change along the sound wave propagation direction, and a pressure self-adaptive microstructure is embedded in the material layer. In the invention, aiming at the problem that a pressure-resistant structure is not designed in a contrast patent, acoustic performance drift caused by deformation under the high pressure of 60MPa is prevented, the negative Poisson's ratio honeycomb substrate expands but does not shrink under the hydrostatic pressure of 60MPa and resists compression deformation, and the pressure response type silicone oil filled in the microsphere system has the advantages that the density is increased along with the increase of the pressure, and the sound velocity change is automatically compensated; and the acoustic impedance fluctuation is relatively small, so that 6000-meter deep-sea long-term operation is supported, the problem of performance degradation of the existing transducer in deep sea is solved, and meanwhile, the micron-sized displacement risk of a filling cone in a contrast patent is avoided.

The invention relates to an organic artificial synaptic transistor pressure sensor based on a suspension structure and an array, a preparation method and application thereof, and belongs to the technical field of semiconductor devices and sensing. The pressure sensor is composed of a substrate, source and drain electrodes, a supporting layer and a suspension structure based on an organic semiconductor layer, a dielectric passivation layer, a polyelectrolyte dielectric layer and a flexible grid electrode, and current change is caused through contact change between the organic semiconductor layer and the source and drain electrodes so as to achieve pressure response. The pressure sensor has the advantages of low power consumption, fast response, high sensitivity, wide detection range and the like, and can simulate a biological synapse function to realize a pressure synapse characteristic which is crucial to complex signal processing. In addition, the integrated array of the pressure sensors can be combined with an algorithm to realize high-accuracy touch recognition of braille characters. The results provide a new opportunity for the potential application of the method in bionic electronic skin, touch imaging, electrical equipment monitoring, sensing, storing and computing intelligent terminals and man-machine interaction systems.

The invention provides a wafer loading table and a system and method for online adjusting wafer loading pressure, and belongs to the technical field of semiconductor chemical mechanical polishing, the wafer loading table comprises a carrying table body and a plurality of pressure actuator sets, the carrying table body is used for bearing wafers, and the bearing surface of the carrying table body is provided with a plurality of pressure response areas; and the plurality of pressure actuator groups are arranged in the plurality of pressure response areas in a one-to-one correspondence manner, and the pressure actuator groups are used for providing upward supporting force for the wafer. According to the wafer loading table, the carrying table body is divided into the multiple pressure response areas, and the pressure actuator sets are arranged in the pressure response areas, so that the carrying table body can dynamically respond and adjust the supporting force on the wafer in real time, and pressure nonuniformity generated when a polishing head presses downwards is actively counteracted; the problem of microcracks or fragmentation caused by local stress concentration when the wafer is loaded is avoided, and the loading yield of the wafer is greatly improved.

The invention relates to the technical field of water supply control, and discloses an intelligent quality-based pressure-superposed non-negative pressure water supply control system and method, and the system comprises a data collection control module, a volume identification module, a water age observation module, a mixing decision module, and an impedance verification module. The effective volume parameters of the steady flow compensation tank are inversed through the pressure response characteristics of the variable frequency booster pump set in the starting stage; dynamically calculating the hydraulic retention time in the tank based on the system flow and the effective volume; when the residence time exceeds a safety threshold value, a forced mixing strategy is generated, and municipal inlet water is driven to be mixed with residence water by adjusting the opening degree of a bypass electric adjusting valve and controlling a pump set to operate; and meanwhile, verifying the effectiveness of the mechanical action of the valve according to the deviation between the real-time power and the theoretical reference power of the pump set after the regulation instruction is issued. Volume parameters can be corrected in real time, aged water is actively replaced under the low-flow working condition, closed-loop verification is carried out on faults of an executing mechanism, and the water supply quality and the system reliability are guaranteed.

The utility model provides an automobile part bending resistance detection device which comprises a bottom plate, the top of the bottom plate is fixedly provided with a supporting frame, the top of the supporting frame is fixedly provided with a hydraulic cylinder, the bottom of the hydraulic cylinder is fixedly provided with a lower pressing plate, the bottom of the lower pressing plate is provided with a pressure induction lower pressing block, and the pressure induction lower pressing block is provided with a pressure sensor. A vertical plate is fixedly installed at the top of the supporting frame, a pressure display panel is fixedly installed on the front side of the vertical plate, a clamping mechanism is arranged on the surface of the bottom plate, and the clamping mechanism comprises a motor and a lead screw. And the situation that the position of the pressure induction lower pressing block deviates due to contact between the pressure induction lower pressing block and the automobile part when the pressure induction lower pressing block carries out bending test on the automobile part downwards, and consequently the accuracy of bending resistance detection on the automobile part is affected is avoided, and an operator can use the device conveniently.

The invention relates to the field of intelligent water affairs, and discloses a precise flow control system for intelligent water affairs, which comprises the steps of collecting local water flow change data in real time, extracting flow velocity disturbance characteristics and pipe network transient pressure response, and judging whether unexpected disturbance trigger exists or not; constructing a local disturbance label library based on disturbance trigger source features and a historical operation model, and identifying disturbance sources and flow direction tendentiousness by using fuzzy discrimination and variable weight filtering algorithms; according to the pipe section hydraulic characteristics corresponding to the mismatching behavior, the flow of the target pipe section is corrected through a high-resolution electric proportional valve set and a two-way feedback control unit; constructing a cross-section response chain through the intelligent edge control node, and generating a multivariable adjustment gradient according to the multi-period callback simulation data; flow state data and peripheral environment variables before and after the current round of regulation and control intervention are collected, and system model parameters are dynamically corrected through the integrated evolutionary prediction network. The stability of the intelligent water affair system is improved.

The invention discloses a control method of a proportional electromagnetic valve for a hydraulic retarder. The control method mainly solves the technical problems that an existing control method is long in pressure response time, large in overshoot, poor in following performance and the like. The control method comprises the steps that feedback pressure of a working cavity of the hydraulic retarder and input signals of a proportional electromagnetic valve are periodically collected; the current target pressure request state is judged, and the current target current of the proportional electromagnetic valve is calculated in a corresponding mode according to the judgment result; calculating to obtain the current duty ratio of the proportional electromagnetic valve; and finally, the flutter is superposed, and the final duty ratio is output, so that the control of the proportional electromagnetic valve for the hydraulic retarder is realized. According to the control method, accurate control over the proportional electromagnetic valve can be achieved, and the control method has the advantages of being short in response time, small in overshoot and good in following performance.

The invention provides a flexible pressure sensor array for measuring the airspeed of an unmanned aerial vehicle and a preparation method of the flexible pressure sensor array. The sensor array comprises a net-shaped structure and a plurality of flexible pressure sensors arranged at nodes of the net-shaped structure. The sensor is of a sandwich structure, a sensitive layer is arranged in the middle, a flexible substrate layer and an electrode layer are symmetrically arranged up and down, the sensitive layer is composite conductive foam with a conductive elastomer filling framework, and the composite conductive foam is obtained by dipping foam in a conductive material solution for multiple times. The sensitive layer framework is obtained by forming through holes in composite conductive foam in a laser array mode and filling conductive elastomers with the through holes. According to the sensor array, heterogeneous network porous foam with good conductivity and multi-layer pressure response characteristics is used as a sensitive layer, and the sensor array has a wide pressure response range; the conductive elastomer framework improves the problem that the foam structure is easy to collapse due to compression deformation, and the service life is prolonged; by utilizing the internet design, the Young modulus of the whole structure is reduced, and the device can be closely attached to the curved surface of the leading edge of the wing in a conformal manner.

The invention provides a hydraulic cooler double-bypass-valve pressure self-adaptive adjusting method and system, and relates to the technical field of hydraulic systems.The method comprises the steps that a fluctuation trend characteristic value is calculated by reading pressure data, characteristic matching is carried out to generate an adjusting instruction, temperature and flow data are collected in real time in a monitoring period, and oil viscosity and Reynolds number are calculated; and when a flow state transition control mode is entered, calculating an optimal flow velocity based on a pressure gradient, converting the optimal flow velocity into a double-bypass valve target opening degree combination, and establishing a mapping relation between an opening degree value and a pressure response by utilizing a steady-state working condition database. Accurate pressure control of the hydraulic system is achieved, and the stability of the system is improved.

A method for determining fluid friction pressure losses in a well into which fluid is being pumped includes measuring fluid pressure in the well while pumping at a first flow rate. The first rate is changed to a second rate and measuring the fluid pressure continues for a selected time. A pressure response of the well using a selected value of a parameter related to pipe friction factor / is modeled. The modeled pressure response is compared to the measured pressure. A value of the parameter related to / is adjusted and the modeling and comparing are repeated until the modeled pressure response substantially matches the measured pressure. The first flow rate is chanted and the measuring, modeling, comparing, adjusting the parameter related to / and repeating modeling and comparing are repeated to determine a relationship between the value of the parameter related to / and the first flow rate.