33 results about "Stress estimation" patented technology

A method of estimating a formation pressure in a wellbore is provided that in one aspect includes measuring a hydrostatic pressure at a selected location in the wellbore, and estimating supercharge pressure as a function of time using a forward model that utilizes the hydrostatic pressure and at least one property of mud in the wellbore that is a function of time. In another aspect, the method may estimate an initial formation pressure at a selected location in a wellbore by obtaining a hydrostatic pressure and at least three formation pressure measurements at three separate times at the selected location, and estimating the initial formation pressure using the hydrostatic pressure, the three pressure measurements and an internal mudcake parameter.

The invention provides a skeletal muscle stress estimation method based on posture recognition and human body biomechanics. The skeletal muscle stress estimation method comprises the following steps:acquiring image data of at least one target user through an image data acquisition device; inputting image data of a target user into a body key feature point monitoring deep learning neural network,outputting predicted body key feature point data, and predicted body key feature points are key feature points needed for human body biomechanical analysis of interested parts of the target user; processing the image data of the target user and the predicted body key feature point data to obtain estimated human body three-dimensional posture information; and analyzing the stress state of the interested part by inputting the human body three-dimensional posture information into a pre-established human body stress analysis model.

The invention discloses a reliability life evaluation method of a long-life electronic device under multiple stresses based on a depth belief network, which estimates reliability characteristics by obtaining device failure data under different environmental stresses through an accelerated life test, and then establishes a reliability derivation model to complete the reliability life derivation under a constant stress level. The evaluation method comprises the following steps: firstly, determining the environmental stress which affects the working reliability of the electronic components; secondly, designing the accelerated life test; thirdly, performing statistical analysis in the test data to obtain the reliability life estimated values of components under different stress levels; and finally, determining the reliability derivation model by using the accelerated life test data. The invention solves the problems of sample shortage and limited test time, adopts a novel constant stress reliability characteristic derivation model, solves the problem that the traditional single stress estimation method is prone to model nesting risk, and realizes the establishment of the life derivation model under multiple stress levels.

The invention discloses a Barkhausen signal stress estimation method based on slow feature analysis. Barkhausen signals under different stresses are used, Barkhausen slow signals are extracted througha slow feature analysis algorithm, and eigenvalues of the Barkhausen slow signals are extracted, and finally the obtained eigenvalues are used to fit stress data. Because residual stress is an inherent property of a material, the slow feature analysis method has higher accuracy. The method comprises the following steps: step 1, combining Barkhausen signals under different stresses into a vector;step 2, performing slow feature analysis on the combined Barkhausen signal to obtain the Barkhausen slow signal; step 3, extracting an upper envelope of the Barkhausen slow signal, and obtaining a Barkhausen signal slowly varying feature; step 4, averaging the slow feature of the Barkhausen slow signal, to form a feature vector; step 5, performing linear regression on different stresses and eigenvectors to obtain an expression model of features and stress of the Barkhausen slow signal.

The invention provides a foundation temperature difference stress estimation method and an upper-lower layer temperature difference stress estimation method for mass concrete. Each of a foundation temperature difference stress and an upper-lower layer temperature different stress is comprehensively estimated according to multiple factors such as a maximum concrete temperature, a concrete elasticity modulus, a pouring block length, a basic elasticity modulus and a water cooling condition, for example, a first stage and a second stage are watered for cooling, or the first stage is watered for cooling or not watered for cooling. A typical concrete thermodynamic parameter summarized by an academician Bofang Zhu and a common water cooling measure generally used in engineering are used, and a finite element computing method is used for verifying estimation results. Compared with existing estimation methods, the methods provided by the invention can achieve more accurate and reasonable estimation results, and can be applied to actual engineering for scientifically guiding engineering practice and improving engineering quality.

The invention provides an ecological restoration method for submerged plants in a lake of a city. The method includes the steps that the target lake is selected; estimation is performed in reference to the stress of the submerged plants in the lake; the environment and sediment of the target lake are investigated and analyzed, and the target lake is divided into regions; the restored types of thesubmerged plants in the target lake are obtained. The problem that the submerged plants in the lake of the city are difficult to restore because of existing wind waves and other factors is solved. Byperforming the procedures of stress estimation of the submerged plants, scientific region division of the target lake and others, the submerged plants in the lake of the city are restored. The methodhas the advantages of being safe, simple, feasible, low in cost and the like.

The invention discloses a stress estimation method for carbon rock tunnel anchor rods based on a feedback algorithm transfer function. The stress estimation method comprises the steps of 1, selectingmonitoring sections of a tunnel; 2, arranging monitoring equipment; 3, collecting monitoring data; 4, establishing an artificial neural network model; 5, training the artificial neural network model;6, estimating and predicting the stress of the anchor rods; and 7, selecting the diameter of the anchor rods according to the grade of surrounding rock. According to the stress estimation method, thestress of the anchor rods is estimated by using a feedback artificial neural network analysis method with three parameters of the surrounding rock pressure, the seepage pressure and the surrounding rock deformation, and the tunnel anchor rods are designed according to the stress of the anchor rods, so that the problem of resource waste caused by the fact that the anchor rods are designed by relying on a similar engineering method or a semi-empirical and semi-theoretical method is solved; and due to the fact that the accuracy of the feedback artificial neural network analysis method for estimating the stress of the anchor rods is high, resources are saved during the design of the tunnel anchor rods, the concept of sustainable development is met, and the stress estimation method has wide application prospects.

The invention discloses a method for quickly predicting critical failure stress of subgrade soil. The method comprises the following steps: firstly, carrying out a static triaxial test on a subgrade soil test piece to obtain breaking stress under corresponding working conditions, and determining bias stress during repeated loading in a dynamic triaxial test by selecting a stress level on the basisof a static triaxial test result, thereby obtaining critical breaking stress of the subgrade soil test piece under the corresponding working conditions. Besides, a subgrade soil critical failure stress estimation model comprehensively considering confining pressure, water content, relative dry density ratio and plasticity index weight is established, and estimated model parameters are obtained through fitting according to dynamic triaxial test data, so critical failure stress values of different subgrade soil under corresponding working conditions are estimated through the established estimation model. According to the method, the influence of confining pressure, water content, relative dry density ratio, plasticity index weight and roadbed soil basic physical property parameters on subgrade soil critical failure stress is considered at the same time, so estimation precision and estimation efficiency are improved, and the problems that an existing estimation method is not comprehensive enough in consideration and a prediction process is complex are solved.

Disclosed are a tire pressure estimating method and a tire pressure estimating device. The tire pressure estimating method of a tire pressure estimating device that stores a PCA weighting coefficient to perform the Principle Component Analysis (PCA) and an LDA discriminant coefficient to perform the Linear Discriminant Analysis (LDA) for an FFT signal pattern of a resonance frequency band of an Fast Fourier Transform (FFT) signal obtained through the FFT of a wheel speed signal, in order to distinguish between a plurality of tire pressure states, may include: detecting the wheel speed signal through a wheel speed sensor; performing the FFT for the detected wheel speed signal; projecting an FFT signal pattern of the resonance frequency band of the FFT signal onto a PCA space by using the PCA applied with the stored PCA weighting coefficient; and performing the LDA applied with the stored LDA discriminant coefficient with respect to the data that is projected onto the PCA space to then determine a tire pressure state corresponding to the data projected onto the PCA space.

The invention provides a CFG pile concrete pump displacement calculation method. The method comprises the steps of data processing, empty pump pumping calibration, quantitative pumping calibration andpumping displacement calculation. The invention relates to electronic equipment and a storage medium. The electronic equipment and the storage medium are used for executing the CFG pile concrete pumpdisplacement calculation method. According to the method, a synchronous real pump quantitative calibration algorithm in the construction period is used, the problem of parameter influences under different construction environments and pump material compositions is solved, and pump machine running state monitoring and pump machine displacement estimation which are closer to the reality are obtained; more accurate estimation of the working state of a piston in a pump machine is obtained based on pressure tracker pressure estimation of a sensor pressure change rate and a sensor pressure measurement value, so that the actual stroke of the piston for actually discharging pump materials outwards is calculated; and the starting and ending positions of each piston operation cycle are judged by using a hysteresis comparison algorithm based on the sensor pressure change rate, and the empty real pump judgment of the current piston operation cycle is distinguished in combination with sensor pressure data.

The invention provides an impact instability judgment method for an asymmetric island working face. The impact instability judgment method comprises the following steps of (S1) obtaining the spatial distribution characteristics of overlying strata of the working face, and revealing the control influence of conglomerate on the movement of the overlying strata on the working face through a micro-seismic monitoring result; (S2) dividing the earth surface into three types of areas, analyzing stress transfer rules of overlying strata in different areas to the island working face, and establishing an average bearing pressure estimation model; and (S3) establishing a relation among the equivalent mining depth, the damage degree of the working face and the average bearing pressure of the working face, and judging the possibility of impact instability of the working face according to the relation. The invention further provides an anti-impact mining method for the asymmetric island working face. According to the method, the asymmetric island working face in the condition of the huge thick conglomerate is used as a research object, and the relation among the equivalent mining depth, the damage degree of the working face and the average bearing pressure is put forward and is used as the basis for judging the danger degree of the working face, so that safe mining of the working face is effectively guaranteed.

A stress estimation apparatus 1 acquires a biosignal of a measurement subject, which includes acceleration information of an action of at least one part of the measurement subject. A moving average is calculated from the acceleration information included in the acquired biosignal, and a threshold of an activity state of the measurement subject is calculated from the calculated moving average. Then, an activity state in a specific period is identified from the calculated moving average and the calculated threshold. Per-activity state data is generated by categorizing chronological data pieces of the acquired biosignal other than the acceleration information by identified activity state, and stress is estimated from the generated per-activity state data.

The invention provides a main cylinder pressure estimation and control method and device and a computer storage medium. The main cylinder pressure estimation method comprises: obtaining feedforward control pressure according to expected pressure of a driver; acquiring a vehicle deceleration braking force and a wheel deceleration braking force; obtaining model main cylinder pressure according to the feedforward control pressure, the vehicle deceleration braking force, the wheel deceleration braking force and a conversion coefficient between the braking pressure and the friction force; and adjusting the main cylinder pressure of the brake according to the model main cylinder pressure. The main cylinder pressure of the brake is estimated on the basis of information such as the vehicle speed and the wheel speed of the whole vehicle, then closed-loop control is conducted according to the estimated main cylinder pressure and the expected pressure of a driver, and the inductive performance and consistency of the brake pedal are improved.