38 results about "Instability" patented technology

The invention provides an underwater tunnel shield construction excavation face stability evaluation method, system and equipment, and the method comprises the steps: determining an excavation face stability evaluation index based on a shield construction excavation face instability mechanism; dividing the stability of the excavation surface into a plurality of grades, establishing each grade space, and determining the quantitative interval of each evaluation index in each grade; calculating a combined weight of each stability evaluation index by adopting a combined weighting method, and taking the combined weight as a judgment basis of the influence of the evaluation indexes on an evaluation result; and constructing an ideal point evaluation function by adopting an ideal point method so as to represent the membership degree of the to-be-evaluated object to each grade, calculating the grade membership degree of the to-be-evaluated section in each grade of the evaluation system, and determining the stability grade of the excavation surface in the construction process of the evaluation section.

The invention provides a regulation and control method and system for hole wall instability of a horizontal drill hole in a high ground stress environment, and belongs to the technical field of horizontal drilling. The method comprises the steps that a high ground stress hole wall instability model based on elastic-plastic damage mechanics is established, and a high ground stress correction coefficient, a dynamic damage variable and a multi-field coupling equation are introduced into the model; model parameters are corrected in real time based on measurement while drilling data, and the hole wall stability is dynamically predicted; according to the prediction result, the model prediction error can be greatly reduced through the method, the progressive damage process of the rock mass in the high ground stress environment can be accurately described, and the technical problem of inaccurate prediction of a traditional static model is solved. By correcting model parameters in real time and dynamically adjusting a wall protection strategy, the hole wall instability accident rate is reduced, and the drilling operation safety is remarkably improved.

The invention is suitable for the field of automobile energy absorption structures, and provides a quantitative characterization method for the oblique pressure stability of a thin-walled tube, and the method comprises the steps: determining a segmentation n value, and dividing the thin-walled tube into n segments; establishing quantitative characterization of the instability behavior; establishing a critical instability angle data set; and constructing an instability prediction model. According to the method, the oblique pressure instability behavior is accurately judged by adopting a quantitative index and a threshold expression form thereof. On one hand, a correlation mechanism of the structural parameters and the instability behaviors is established, so that the instability condition is accurately predicted when the structural parameters change, and the deformation stability and high energy absorption of the structure are ensured. And on the other hand, customized design based on the specific loading angle working condition can be achieved, under the condition that the critical instability angle is given, global regulation and control are conducted in the design space, optimal configuration of the structure is achieved, and design insufficiency and design redundancy are avoided.

This invention belongs to the field of automotive technology, specifically relating to a method and system for analyzing and pre-stabilizing the random instability of electric vehicle braking. The vehicle's drive motor adjusts the driving torque output to the wheels according to drive torque control parameters. The control method includes random instability analysis and pre-stabilization control. This invention differs from traditional solutions that only identify, respond to, and compensate for braking vibration after it has already occurred. Instead, it performs random instability analysis and pre-stabilization control during braking: it determines whether to trigger random instability analysis and pre-stabilization control based on wheel angular velocity. Random instability analysis uses stochastic dynamics theory to solve for the stability boundary of braking vibration, which is conservatively designed by introducing calibration constants. Then, pre-stabilization control obtains drive torque control parameters from the conservative stability boundary, thereby achieving early control before braking vibration occurs.

The invention discloses a weak surrounding rock tunnel face instability mechanism experiment device and method. A stratum environment simulation system is arranged above a model box system, and a tunnel excavation simulation system is installed in the model box system; in the stratum environment simulation system, a base of a hydraulic jack is fixedly arranged on a force transmission plate, a counter-force beam is fixedly arranged on the model box system, and a telescopic rod of the hydraulic jack is rotationally connected with the counter-force beam. According to the invention, a weak surrounding rock tunnel face instability mechanism reduced scale model test is carried out, a hydraulic jack is used for applying a load acting on a force transmission plate, the force transmission plate is used for transmitting the load to a position above a stratum so as to simulate surrounding rock overlying loads at different burial depths, and gradual unloading is carried out through a displacement control method so as to realize tunnel face instability failure whole process simulation. The stratum deformation evolution rule and the geometrical characteristics of a plastic instability area in the tunnel instability state are researched, and the method can be used for simulating the stability and instability characteristics of tunnel faces with different section forms, excavation forms and using functions.

The application discloses a kind of linear transport anti-instability linear module, anti-instability method and related equipment, the linear module includes linear module main body, sliding table and controller, the linear module main body is used to drive sliding table to move, the sliding table is used to support load, further include anti-instability device, the anti-instability device includes driving device and connecting device, the driving device is installed on the sliding table, one end of the connecting device is connected with the driving device, the other end of connecting device is connected with the sliding table;The controller is used to control the connecting strength between sliding table load according to the operating state of the linear module by the anti-instability device.Control the anti-instability device work using controller by obtaining the operating state of linear module and combining the quality data of load, input to controller, to avoid load to dump, and then to the state dynamic adjustment of load and sliding table, improve safety.

The application provides a model test method for simulating progressive weakening of slope strength, and relates to the technical field of geomechanical model test, which comprises the following steps: curing base material to obtain a sample, wherein the sample is a cylinder; selecting a weakening solution by trial method according to a preset model slope evolution time length; performing a weakening test on the model slope by immersing the model slope in the weakening solution; obtaining evolution process information of the model slope, and determining a critical time corresponding to the occurrence of a sliding surface of the model slope; performing a weakening test on the sample by using the weakening solution, and performing an unconfined compression test on the sample when the test time reaches the critical time, so as to obtain the cohesion of the sample; and calculating the critical cohesion of a prototype slope from the cohesion of the sample. In the case that the shear strength of the slope body is insufficient, the strength parameter of the slope body is gradually reduced, and the whole process of the slope body instability evolution is studied.

The invention relates to the field of aero-engine gap design, and discloses a transition state gap quantitative evaluation method and system. The method comprises the following steps of: extracting a working clearance maximum value of a takeoff state, a working clearance minimum value of a landing state and a working clearance maximum value and a working clearance minimum value of a repeated acceleration and deceleration state from working clearance values of a rotor and stator structure in a transition state process, and endowing the four extreme values with independent weights; the weights of other gap data except the four extreme values are given as reference weights, instability coefficient analysis is carried out, and whether the rotor and stator structure meets the transition state gap requirement or not is evaluated; according to the evaluation method, the influence of the maximum value and the minimum value of the working gap of each transition state interval on the instability coefficient is comprehensively considered, the problem that the rotor and stator gap design is difficult to judge due to different local fluctuations of different areas is solved, and the rotor and stator gap before and after the structure improvement design can be evaluated more quickly and accurately; and support is provided for forward design of the gap.

The application provides a control method and a control system of a steer-by-wire system. The method comprises the following steps: constructing a steering system dynamics equation based on a target front wheel running parameter, a configuration parameter and a target damping coefficient of a magneto-rheological damper in a shimmy instability mode, wherein the product of the target damping coefficient and a front wheel rotation speed is equal to the product of an initial damping coefficient of the magneto-rheological damper and a magneto-rheological damper current; obtaining a characteristic equation and all characteristic value expressions based on the steering system dynamics equation; obtaining real-time values of the target front wheel running parameter, a value of the configuration parameter, a magneto-rheological damper current real-time value and a value of the initial damping coefficient; obtaining real part values of all characteristic values of the characteristic value expressions based on the obtained values; and adjusting the magneto-rheological damper current real-time value until the real part values of all characteristic values are not greater than zero to obtain a value of the target damping coefficient, if there is at least one characteristic value whose real part value is greater than zero. The method according to the application can solve the front wheel shimmy problem.

The invention discloses a dynamic evaluation model attention optimization method for a specific instability mode, and the method comprises the steps: 1) generating a plurality of training samples of different fault types, and extracting the feature information of each bus node after the fault is cleared and the stability label of the sample as original data; 2) collecting unstable mode samples which are difficult to recognize by the model in the training process; 3) identifying key nodes in the sample according to the severity of the influence of the fault on each node in the sample, and marking the key nodes in the sample; 4) according to the training set sample marked with the key nodes, optimizing a TVSA model based on Transform, constructing an attention guidance loss function, and guiding the model to accurately capture key features of an instability mode; and 5) constructing an attention maintenance loss function. According to the method, the evaluation rule of the model is corrected by utilizing the physical information of the key instability node, so that the model fully learns the information related to the stability in the sample and makes correct evaluation.

The invention relates to a method for predicting the instability characteristic of a planet row needle bearing retainer, belongs to the technical field of bearing characteristic analysis, and solves the problems that in the prior art, the research on the instability of a bearing retainer is mostly limited to a self-rotation working condition, and prediction is carried out only through a dynamic modeling or testing method; the prediction method comprises the following steps of: firstly, establishing a coordinate system of a planetary gear set, and constructing an index for describing the instability characteristic of the retainer on the basis of the coordinate system; using the kinetic model to form training data of the proxy model; furthermore, a construction and training method of the proxy model is provided, the instability characteristic of the planet row needle bearing retainer can be rapidly obtained, a large amount of dynamic calculation involved in the bearing optimization design process can be replaced, consumption of calculation resources and time can be reduced, and therefore rapid optimization design of the high-performance planet row needle bearing is supported.

Aspects of the disclosure provide a method of mitigating liquid instability in controlled intra-well cross-flow between two, or more, zones accessed by a well. One or more embodiments define new functionalities necessary for dynamic multiphase flow (MPF) simulation to model, mitigate and control liquid instability observed in a well.

The invention belongs to the technical field of fault evaluation, particularly relates to a method, a system and equipment for evaluating the pressure bearing of a fault in a reservoir, and aims to solve the problem that the pressure bearing limit of the fault in the reservoir cannot be accurately obtained. According to the method, the vertical mechanical stability critical pressure of the fault in the reservoir is generated through the fault shear slip pressure and the fault rock instability pressure, vertical data are provided for evaluating the ultimate pressure bearing capacity of the fault in the reservoir, and evaluation is more comprehensive and accurate. The lateral closing pressure limit pressure of the fault in the reservoir is obtained through the simulation model, and the data of the fault limit pressure bearing is supplemented from the lateral angle, so that the evaluation result better conforms to the actual situation. And finally, the ultimate bearing pressure value of the fault in the reservoir is obtained, key data are provided for safe development and reasonable utilization of the reservoir, and then the safety and stability of the underground reservoir are guaranteed.

The invention discloses a grouting control method based on stratum stability evaluation. Relates to the technical field of shield construction grouting. The method comprises the steps that S1, multi-source information in the stratum and shield construction process is obtained; s2, taking the simulation data as a supplementary training set, and training a time sequence prediction model; s3, according to the static parameter data and the dynamic detection data, predicting a stratum response amount through the trained time sequence prediction model, and calculating a stability index S and a risk probability P based on a predicted value; s4, a grouting strategy rule base is constructed, a grouting strategy is generated, and grouting is conducted according to the grouting strategy; according to the method, the evaluation model of the stability index and the risk probability is constructed, quantification and predictability of the stratum stability are achieved, a scientific basis is provided for construction decision making, meanwhile, the multi-stage grouting strategy rule base is established, corresponding grouting schemes can be rapidly selected under different risk grades, and therefore stratum instability or excessive disturbance is effectively prevented.

The invention discloses a method and system for evaluating the instability possibility of a fixed jacket platform, and the method comprises the steps: configuring scores representing the influence degrees of different factor states and different measure implementation states on the instability possibility for a single factor and a single management and control measure which affect the instability possibility of the platform, and obtaining a score value of a corresponding state of a target platform; classifying each factor of the target platform, respectively taking the factor type and each factor as corresponding evaluation indexes, and analyzing a first relative importance degree of each first evaluation index relative to the instability possibility of the target platform and a second relative importance degree of each second evaluation index relative to each first evaluation index to determine the instability possibility of the target platform. Obtaining a weight value representing the relative importance of each second evaluation index relative to the instability possibility of the target platform; and obtaining the actual instability possibility of the current target platform by using the score value and the weight value. According to the method, the actual instability possibility of the fixed jacket platform can be accurately obtained.

The present application relates to the technical field of wisdom logistics, and discloses an express package automatic warehousing control method based on digital twinning, which comprises the following steps: obtaining multi-dimensional state data of the package, establishing a virtual model and giving an initial equivalent slip coefficient; generating a space-time difference when tracking the real and theoretical position time sequence; taking the space-time difference as an observation variable for closed-loop iteration, calculating the actual equivalent slip coefficient to update the model; determining the kinetic boundary constraint condition according to the state data and the slip coefficient; based on the space-time difference forward deduction, combining the constraint condition to generate a speed curve and executing it for controlling the running track. The present application updates the equivalent slip parameter through closed-loop iteration, and completes the track trial calculation in combination with the kinetic boundary before issuing the instruction, realizes the dynamic identification and predictability compensation of the nonlinear slip state of the package, helps to solve the attitude instability and cascading interference caused by the regulation lag, and is beneficial to maintaining the warehousing stability in the high-density conveying scene.

The application provides a flexible machine arm instability suppression method and system based on SMA driving, comprising the following steps: step 1: analyzing the constitutive property of SMA and the influence of the discontinuous output force characteristic introduced by the SMA on system dynamics; step 2: combining the physical configuration of the flexible machine arm to construct a universal state equation; step 3: introducing trajectory constraint conditions to plan a reference trajectory and output a desired trajectory; step 4: combining the obtained state equation and the desired trajectory to reconstruct an error dynamics equation, designing a sliding mode control surface and a sliding mode reaching law, and giving a sliding mode control amount of a multiple-input multiple-output (MIMO) system, so as to output a MIMO time sequence control amount while meeting the trajectory tracking accuracy requirement. Through the trajectory constraint method, the application can effectively avoid the problems of control algorithm mismatch or model instability caused by system parameter uncertainty, and ensure that the flexible machine arm works in a model-known and controllable region.

The invention discloses an intelligent monitoring method and system for the safety state of an efflux pump, and relates to the technical field of industrial equipment safety, the system collects working condition data of the efflux pump in real time through a sensor group installed on the efflux pump, and pre-processes the working condition data to construct a fluid state data set and a load evolution data set; medium disturbance evaluation is carried out by calculating a medium disturbance leading edge index VPI and a medium disturbance response threshold TH, when shear disturbance is evaluated to be formed, a load evolution analysis instruction is executed, a load lag evolution index LEI is calculated based on structure response data, and then a joint instability risk index UDR is calculated in combination, so that the shear disturbance is evaluated to be formed. And performing comprehensive instability response evaluation with a set first joint instability boundary threshold UA and a set second joint instability boundary threshold UB, and executing a grading safety adjustment strategy according to a comprehensive instability response evaluation result. According to the system, early recognition, dynamic evaluation and closed-loop response of the abnormal state of the outer conveying pump can be achieved, and the safety and stability of operation of the conveying system are improved.

The application discloses a high flexible structure two-degree-of-freedom coupled galloping critical condition prediction method and system based on regular perturbation high-order expansion. The method comprises the following steps: collecting structure physical and aerodynamic parameters; establishing a motion control matrix equation based on modal displacement; using a regular perturbation method to expand eigenvalues and displacement solutions into power series; according to whether initial crosswind and downwind frequencies are the same, explicit analytical solutions of modal frequencies, damping ratios and amplitude ratios are derived respectively; after solving the modal frequencies by iteration, the damping ratio is directly calculated, and the galloping critical wind speed is determined according to the change of the damping ratio from positive to negative. The application only needs to iterate the modal frequencies, and has high calculation efficiency; the total damping can be decomposed into linear superposition of structure, non-coupling and coupling components, and the instability mechanism is clearly revealed; and the application is suitable for various working conditions such as the same or different frequencies, and has high prediction accuracy, thereby providing a reliable basis for high flexible structure wind resistance design.

The application discloses a kind of leading instability machine group automatic marking method, system, device and medium, belong to electric power technical field.The method includes: obtaining input sample, judge whether input sample is transient instability sample, if yes, leading instability machine group is marked;For transient instability sample, obtain the power angle curve set of all generators {δ i (t)}, according to power angle curve set {δ i (t)} Similarity matrix ρ is obtained;Based on similarity matrix ρ, after AP clustering, get the homology machine group clustering result set G AP ={G1,G2,…,G K};According to homology machine group clustering result set G AP Marking result is obtained.The application is dynamically obtained after each generator fault, and clustering mode is automatically carried out generator homology grouping, and the most leading machine group is regarded as leading instability machine group, and leading instability machine group of mass sample can be marked spontaneously and in batches, to provide fine-grained generator level stability index for data-driven stability evaluation model.

The invention discloses a compression system structure and a method for controlling the instability form of a gas compressor in an experiment through the compression system structure, and the compression system does not need to replace a pipeline and a cavity structure in the test process by introducing a blocking section structure with an adjustable through-flow area. Therefore, flexible control of the instability form (rotation stall or surge) can be realized under different compressor models, the design complexity and the trial and error cost of the test bench are effectively reduced, and the experiment adaptability and repeatability are improved. And moreover, it is ensured that the gas compressor presents an expected instability mode in the experiment, and convenient and rapid pneumatic stability control and instability form identification of the gas compressor system are achieved, so that time and cost waste caused by repeated modification and trial and error of test equipment is reduced.

The invention discloses an FDEM simulation method and system for rock slope fracture instability, and relates to the technical field of geotechnical engineering. The method comprises the following steps: acquiring rock mass mechanical parameters and three-dimensional morphological parameters of a target rock slope; based on the rock mass mechanical parameters and the three-dimensional morphological parameters, constructing a numerical model of the target rock slope by using an FDEM; configuring initial conditions for the numerical model, applying initial gravitational acceleration, and configuring updating conditions when the total kinetic energy of the numerical model is reduced to a preset value; after updating condition configuration is completed, increasing the gravitational acceleration step by step until the variable quantity of the total kinetic energy meets a preset condition, and recording the final gravitational acceleration; and determining the safety coefficient of the target rock slope according to the final gravitational acceleration. According to the invention, the whole catastrophe process of the rock slope from crack initiation and extension, sliding to block macroscopic movement can be accurately simulated, and the safety coefficient with clear physical significance is obtained based on the dynamic instability critical state.

The embodiment of the invention relates to a spring valve stability judgment method considering fluid force, which comprises the following steps: determining a total fluid force calculation model of a valve core according to structure parameters and working condition parameters of a spring valve, deducing a steady-state fluid force calculation model and a transient fluid force calculation model according to the total fluid force calculation model, and constructing a nonlinear dynamic model; constructing a steady-state simulation model of the spring valve, performing steady-state simulation on a flow field of the spring valve based on the steady-state simulation model, and fitting to obtain a steady-state force coefficient of the valve core; constructing a transient simulation model of the spring valve, and performing transient simulation on the opening and closing dynamic process of the valve core by using the transient simulation model to obtain a transient fluid force coefficient curve; and constructing a dimensionless state-space equation based on the nonlinear dynamic model, the steady-state force coefficient and the transient fluid force coefficient curve, performing stability judgment on the spring valve by utilizing the dimensionless state-space equation and a stability criterion, and determining an unstable flow interval. According to the embodiment of the invention, the stability of the spring valve can be systematically judged.

The invention discloses a truncation number determination method, system and device suitable for an HSS model and a storage medium, and the method comprises the steps: carrying out the time domain simulation based on a nonlinear time-varying periodic system model, obtaining the time domain waveform of a state variable during the instability of the system, obtaining the damping and oscillation frequency based on the time domain waveform of the state variable during the instability, and determining the truncation number of the HSS model. Determining a real part and an imaginary part of the instability mode; converting the linear time-varying periodic system after the periodic trajectory linearization into an infinite-order harmonic state space model, obtaining a characteristic root which is the same as a real part and an imaginary part of a to-be-analyzed instability mode by increasing a truncation order, and determining a reasonable truncation number of the harmonic state space model; and constructing a truncated harmonic state space model based on the reasonable truncation number, and analyzing the to-be-analyzed instability mode to obtain a state variable leading system instability. According to the method, the accuracy of the model is ensured, and intrinsic errors of a small-interference stability analysis result and adoption of a relatively large truncation number can be avoided.

The invention relates to the technical field of automatic control of dry running risks, in particular to an automatic control method and system for the dry running risk of equipment operation, and the method comprises the steps: constructing an operation feature collection mechanism based on inlet pressure fluctuation, pump cavity temperature rise gradient and bearing friction state in the equipment operation process, forming a basic operation sequence reflecting the medium lubrication continuity through continuous time sampling; and on the basis of the basic operation sequence, correlation analysis is carried out on the coupling relation between the pressure micro-amplitude oscillation and the temperature rise change, and lubrication instability fragments which appear repeatedly in a short time but do not cause power abnormity are recognized. According to the method, the coupling relation between the pressure micro-amplitude oscillation and the temperature rise change is subjected to correlation analysis, so that the lubrication instability fragment which appears repeatedly in a short time but does not cause power abnormality can be effectively identified, the local intermittent dry running and low-load pseudo running state can be found in advance, and the reliability of the system is improved. Related risks are prevented from being gradually accumulated and evolved into serious faults in long-term operation.

The invention discloses a barrel type foundation design scheme comparison and selection method which comprises the steps that S1, three performance functions of foundation instability, barrel body slippage and barrel body inclination of a barrel type foundation are constructed, and when the performance function g is smaller than or equal to 0, a barrel type breakwater fails in the failure mode; s2, calculating each parameter according to engineering geological data and a design section; s3, according to the parameters, Monte Carlo simulation is repeated for one hundred thousand times, and the failure probability of the engineering barrel type foundation in three failure modes of foundation instability, barrel body slippage and barrel body inclination is calculated; and S4, comprehensively evaluating the overall failure probability of the scheme, respectively carrying out vulnerability analysis on the bucket foundations of different segments to obtain the most unfavorable damage probability, comparing the damage probability, and determining the feasibility of different schemes. According to the method, on the premise that the stability of each design scheme meets the design requirement, the optimal scheme is determined by comparing and selecting the failure probability of each scheme.

The application provides a method for judging blade separation shear layer instability of a compression system considering cross-flow effect, belongs to the field of aero-engine compression technology, and comprises the following steps: carrying out high-precision numerical calculation, obtaining dynamic characteristics of cross-flow induced vortex and instantaneous flow field fluctuation information; refining space-time evolution law and main instability of disturbance at different transition stages of the separation shear layer, including K-H instability and cross-flow induced vortex instability; determining the transition position of the dominant role of the inviscid K-H instability and the cross-flow induced vortex instability based on a preset double judgment method; constructing key parameters representing the inviscid K-H instability strength and the cross-flow induced vortex instability strength; and establishing a dominant instability criterion for the separation shear layer under the cross-flow effect based on the transition position and the key parameters. The application scheme overcomes the defect that a single parameter diagnosis method is fuzzy in identifying the complex instability competition mechanism, and improves the prediction ability of the transition trigger mechanism.

Aspects of the disclosure provide a method of mitigating liquid instability in controlled intra-well cross-flow between two, or more, zones accessed by a well. One or more embodiments define new functionalities necessary for dynamic multiphase flow (MPF) simulation to model, mitigate and control liquid instability observed in a well.

The application discloses a kind of identification method, system, device and medium of swing and instability between generating units, belong to electric power technical field.The method includes the following steps: obtaining generator power angle curve after time domain simulation;According to the obtained generator power angle curve, obtain accelerating instability machine group and the instability time of each unit;According to accelerating instability machine group and instability time, obtain the relative swing index of each generator, to realize the identification of swing and instability between generating units.The application obtains the dynamic information of generator according to time domain simulation, identifies accelerating instability machine group and the instability time of each unit therein, calculates the relative swing index suitable for stable, instability unit, can provide accurate instability machine group and its control priority for transient stability prevention control of dispatching operation.

The present application relates to a kind of planetary row needle bearing cage instability characteristic prediction method, belong to bearing characteristic analysis technical field, the instability of bearing cage in the prior art is solved in the research of most existing technology Limit to only rotation condition, and only by the method of dynamic modeling or test is predicted, the prediction method of the present application first establishes the coordinate system of planetary gear set, on this basis, the index describing cage instability characteristic is constructed;Using dynamic model, the training data of proxy model is formed;Further, the construction and training method of proxy model is proposed, the instability characteristic of planetary row needle bearing cage can be quickly obtained, can replace the large amount of dynamic calculation involved in bearing optimization design process, can reduce the consumption of computing resources and time, to support the rapid optimization design of high-performance planetary row needle bearing.