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431 results about "Balance equation" patented technology

In probability theory, a balance equation is an equation that describes the probability flux associated with a Markov chain in and out of states or set of states.

Method and system for establishing multilayer oil pool inter-well connectivity model

The invention relates to a method and system for establishing a multilayer oil pool inter-well connectivity model. The multilayer oil pool inter-well connectivity model capable of simulating oil and water dynamic states is established oriented to the limitation that by means of a current connectivity model, only the dynamic change of production liquid can be predicted, the dynamic states of the oil phase and the water phase cannot be calculated respectively, and connectivity analysis cannot be carried out layer by layer. According to the model, an oil pool system is layered and scattered into a series of inter-well communication units, matter balance equation calculation is carried out with the inter-well communication units as simulating objects, pressure solving and inter-well flow calculation are achieved, an inter-well saturation degree tracking calculating method is established with the combination of the lead edge boosting theory, and the output dynamic states of oil and water of all layers at well points are obtained; a model parameter inversion method is established in a fitting mode through dynamic states based on a random disturbance approximation method, a projection gradient method and the like. Layered inter-well flow distribution coefficients, single well longitudinal production liquid and production oil splitting coefficients and other information can be obtained in real time, the oil pool plane, the longitudinal oil and water flow relation and the production measure change can be more accurately reflected to guide the practical production of an oil field.
Owner:YANGTZE UNIVERSITY

Financial analysis tree software engine

InactiveUS20060161485A1Balance be obtainFinanceSoftware engineTheoretical computer science
A Software Engine that summarizes the financial state of a business in a single hierarchical tree data structure. The root node of the tree is the balance equation of accounting, its leaf nodes are the ledger accounts of the company, and its internal nodes represent all of the sums required in preparing the balance sheet, the income statement, and the retained earnings statement. Each non-leaf node obtains its financial balance from its child nodes. Since the Income Summary and Retained Earnings are non-leaf nodes, they do not have to exist as separate ledger accounts and their respective child nodes do not need to have their balances closed and transferred to them—all accounts have a permanent (non-temporary) balance. The difference between two trees produces the income and earnings retention of the business.
Owner:INFOQOR

Method and system used for determining well control dynamic reserves of shale gas well

The invention discloses a method and a system used for determining well control dynamic reserves of a shale gas well. The method comprises the steps of obtaining an initial formation pressure of a shale gas reservoir, and calculating a well bottom flow pressure through structure data and production data of the gas well; establishing a first interpolation table based on a conversion relationship between a pressure and a pseudo-pressure to establish a corresponding relationship between the pressure p and the pseudo-pressure m(p); establishing a second interpolation table based on given basic parameters and Za(p) defined by a matter balance equation of the shale gas reservoir to establish a corresponding relationship between the pressure p and a ratio of the pressure p to Za(p); and based on the initial formation pressure, the well bottom flow pressure and the production data, determining the well control dynamic reserves of the shale gas well by adopting the first interpolation table, the second interpolation table and a productivity equation. According to the method and the system, a shut-in pressure is not needed to recover an evaluated average formation pressure in calculation; and a calculation result is suitable for various applications such as reasonable shale gas well production allocation, reasonable development technology policy making, development scheme optimization and the like.
Owner:CHINA PETROLEUM & CHEM CORP +1

Shrinkage creep and prestress loss computation method of concrete bridge

The invention provides a shrinkage creep and prestress loss computation method of a concrete bridge. According to the invention, the shrinkage creep and prestress loss computation method of the concrete bridge, in which the time variation and the uncertainty are simultaneously considered, is obtained by analyzing the time variation of concrete through utilizing an age-adjusted effective modulus method (AEMM) and analyzing the uncertainty of the concrete through utilizing an accurate and rapidly-sampled Latin hypercube sampling (LHS) method; a prestress loss computation formula in which the time variation and the uncertainty of shrinkage creep and the interaction between the shrinkage creep and reinforcement stress relaxation are simultaneously considered is deduced according to a prestressed reinforcing steel and concrete stress balance equation and deformation coordination conditions and on the basis of the AEEM method and the LHS method; and a prestress loss computation method of the concrete bridge, in which the shrinkage creep and the stress relaxation are considered, is formed. In the structural internal force value field interval computed according to the shrinkage creep and prestress loss computation method disclosed by the invention, the unfavorable stress state of the bridge structure can be considered from multiple aspects in the designing process, so that the reliability of structure computation result is higher and the structure safety is better.
Owner:WUHAN UNIV OF TECH

Vertical landing track design method for unmanned aerial vehicle

The invention provides a vertical landing track design method for an unmanned aerial vehicle, which belongs to the field of flight control and comprises the following steps of: 1, building a balance equation of the unmanned aerial vehicle landing stability state according to the kinematics relationship of the unmanned aerial vehicle; 2, adopting a non-linear plan method for designing the verticallanding track of the unmanned aerial vehicle in a glissade stage; 3, designing the height track in an index form in a leveling stage and solving the non-linear equation to obtain the vertical landingtrack of the unmanned aerial vehicle according to the designed track angle trimming value and the elevation instructions in the leveling stage; and 4, integrating the landing tracks in the glissade stage and the leveling stage to obtain the vertical landing track of the whole unmanned aerial vehicle. The method has the advantages that the safety margin of the incidence angle and the operation margin of an elevator are improved, the precise and safe landing of the unmanned aerial vehicle is convenient to guide, the method is applicable to the landing control algorithm considering all of the height, the pitch angle and the descending speed, in addition, the landing performance is fully analyzed, and mathematic software is adopted for effective design to avoid the traditional experience trial and error.
Owner:BEIHANG UNIV

Ship intelligent obstacle avoidance method and system based on artificial potential field

The invention provides a ship intelligent obstacle avoidance method based on an artificial potential field. The method comprises a step of collecting ship information, inland waterway information andobstacle information in real time, a step of establishing an inland waterway coordinate system based on the collected information and establishing a waterway boundary repulsion potential field model and an obstacle repulsion potential field model based on an artificial potential field method, a step of establishing a balance equation according to composite field effect formed by superposing a waterway boundary repulsion potential field and an obstacle repulsion potential field borne by a ship during the processing of navigation, carrying out solution to obtain position points which the ship isabout to pass in intelligent obstacle avoidance, and fitting the position points to obtain an obstacle avoidance route, and a step of controlling the heading and speed of the ship according to the obstacle avoidance route. According to the method and the system, a practical support is further provided for the realization of the ship intelligent obstacle avoidance, and the probability of collisionwith an obstacle is greatly reduced.
Owner:WUHAN UNIV OF TECH

Drive control device of hybrid vehicle

ActiveUS20140081500A1Overdischarge or overloading of the battery can be preventedEasy to controlHybrid vehiclesInternal combustion piston enginesElectrical batteryElectric power system
Objects of the present invention is to improve the control accuracy of the charge state of a battery in consideration of the electric power losses of a plurality of motor generators and, in accordance therewith, to secure the protection performance of the battery, and to increase the energy recovery efficiency according to the regeneration. According to the present invention, there is provided a drive control device of a hybrid vehicle in which an electric power loss predicting means and a target electric power calculating means are arranged, a target engine power calculating means calculates target engine power based on target driving power, target charge / discharge power, and estimated power that is an electric power loss, and a motor torque instruction value calculating means calculates torque instruction values of a plurality of motor generators using a torque balance equation including target engine torque and an electric power balance equation including the target electric power. In the electric power balance equation, electric power generated or consumed by the plurality of motor generators, the estimated power that is the electric power loss, and input / output electric power of the battery are included.
Owner:SUZUKI MOTOR CORP

Dynamic control method of linear steering engine electric loading system

The invention discloses a dynamic control method of a linear steering engine electric loading system, comprising the following steps: modeling a servo loading motor, constructing a torque balance equation, and constructing a linear steering engine mechanism model; building a ball screw pair motion model; analyzing the transfer function of the electric loading system, designing a three-closed-loop control method based on a current inner loop, a position outer loop and a force outer loop, and applying complex vector PI control in the current inner loop to enable the current of the servo loading motor to track instruction signals quickly and accurately; and finally, making feed-forward compensation for angular velocity, and verifying the control method. The method takes an electric loading system driven by a permanent magnet synchronous motor as a specific object, and considers the impact of the characteristics of the linear steering engine and the coupling degree between the linear steering engine and the electric loading system. The active force of active displacement of the linear steering engine is inhibited, and the loading precision of the linear loading system is improved. Moreover, a verification method is put forward, which makes a linear load simulator better evaluated.
Owner:NANJING UNIV OF SCI & TECH

Coaxial rigid rotor pneumatic elastic response method

The invention provides a coaxial rigid rotor coupling pneumatic elastic response analysis method, and belongs to a helicopter kinetic analysis technology. The method is characterized in that according to the operation and control characteristics of a coaxial rigid rotor helicopter, a balance equation optimization solution method is built, and an optimization solution is found according to the given target and constraint conditions. According to the characteristic of complicated coaxial rigid rotor flow field environment, a rotor flow field is calculated by using a computational fluid dynamic method based on an Euler / N-S equation; and then, the coupling pneumatic elastic response is calculated by using a computational fluid dynamic / computational structural dynamic loose coupling analysis method. The coaxial rigid rotor coupling pneumatic elastic analysis method has the advantage that when the analysis method is used, balance operation and control parameters, blade response, rotor loads and the like of the coaxial rigid rotor helicopter can be calculated. The method has good analysis precision and engineering applicability; the relying of the development process on the test can be reduced; and the design period and the development cost can be greatly reduced.
Owner:CHINA HELICOPTER RES & DEV INST

Method for calculating non-steady state yield of volume fractured horizontal well of shale gas reservoir

The invention discloses a method for calculating a non-steady state yield of a volume fractured horizontal well of a shale gas reservoir. The method comprises the following steps of dividing the reservoir into a volume fractured region and a non-transformed matrix region, and collecting basic parameters of the volume fractured region, the non-transformed matrix region and the horizontal well, wherein the volume fractured region is Darcy flow, and the non-transformed matrix region is Knudson flow; according to a mass conservation law, establishing a steady-state yield formula of the volume fractured horizontal well of the shale gas reservoir; based on a pressure propagation formula, the steady-state yield formula and a matter balance equation, calculating the non-steady state yield of the volume fractured horizontal well of the shale gas reservoir by applying a continuous quasi-steady method; and repeating the previous step, and performing calculation to obtain the non-steady state yield of the volume fractured horizontal well of the shale gas reservoir. The method fully considers a process that a pressure is propagated to a boundary gradually in a production process of the volume fractured horizontal well of the shale gas reservoir, different seepage laws of shale gas in a volume transformation region and the non-transformed matrix region, and adsorption and desorption effects of the shale gas, so that actual conditions are better met.
Owner:SOUTHWEST PETROLEUM UNIV

Lower-bound limit analysis method of ultimate bearing capacity of jointed rock slope considering rock translation and rotation effects at the same time

ActiveCN107330145AIntuitive form of destructionSimple optimization solutionClimate change adaptationDesign optimisation/simulationSlope stability analysisIterative method
The invention relates to a lower-bound limit analysis method of bearing capacity considering rock translation and rotation effects at the same time, and belongs to the technical field of rock slope stability analysis. According to the method, a rigid block unit is scattered as a geometry system of a rigid rock and a structural plane, the normal force, shearing force and bending moment of the structural plane are used as unknown quantities, a static permission stress field satisfying an equilibrium equation considering the translation and rotation effects of the rigid block unit, structural plane shear yield conditions, structural plane tensile yield conditions, structural plane rotational yield conditions and static boundary conditions is constructed, an overload coefficient is used as a target function, and a lower-bound linear mathematic programming model is built; the linear mathematic programming model is solved by means of an interior point algorithm, a strength reserve coefficient is solved by means of an iterative method at the same time, and the lower-bound solution and corresponding yield area of the overload coefficient or the strength reserve coefficient of the jointed rock slope are acquired. The method has the advantages that the concept is clear and the computational accuracy is high, and the method can be applicable to bearing capacity analysis of translational or rotational failure of the jointed rock slope.
Owner:KUNMING UNIV OF SCI & TECH

Method used for determining shale-gas multistage-fracturing horizontal-well interior-and exterior-zone dynamic reserves

ActiveCN106481332ADetermining Dynamic ReservesConstructionsMaterial balanceDesorption
The invention discloses a method used for determining shale-gas multistage-fracturing horizontal-well interior-and exterior-zone dynamic reserves. The method includes: establishing gas-well binomial productivity equation through gas testing materials, and calculating actual flowing bottomhole pressure (FBHP) through production data and gas-well structure parameters; respectively establishing matter balance equation of a fracturing transformation zone and a non-fracturing transformation zone for a multistage-fracturing horizontal well in considering of adsorption gas desorption and abnormal high pressure influence; respectively setting the dynamic reserves of the fracturing transformation zone and the non-fracturing transformation zone, adjusting the dynamic reserves by combining with the matter balance equation of the fracturing transformation zone and the non-fracturing transformation zone, interporosity flow equation between the fracturing transformation zone and the non-fracturing transformation zone and the binomial productivity equation, and determining the fracturing horizontal-well interior-and exterior-zone dynamic reserves. With the method, testing of average formation pressure by well shutdown is not needed during use, influence of adsorption gas desorption and abnormal high pressure as well as fracturing recombination zones can be considered, and the dynamic reserves of the fracturing transformation zone and the exterior non-fracturing transformation zone can be respectively determined.
Owner:CHINA PETROLEUM & CHEM CORP +1

Method for simulating water injection well water pressure drive fracture extension dynamic

ActiveCN108952660AReliable Analytical Research MethodsFluid removalFluid solid couplingFeature parameter
The invention discloses a method for simulating water injection well water pressure drive fracture extension dynamic. The method comprises the following steps that an oil reservoir geological characteristic parameter of a target water injection well with fractures is obtained according to the oil reservoir geological study; a water injection well water pressure drive hydraulic fracture extended model is established with the integration of a Darcy leak-off model, a continuity equation, a matter balance equation and an initial condition; fluid volume filtered into a stratum is used as a source item based on an oil-water two-phrase seepage model of a seepage mechanics theory, the boundary condition is established by combining the fluid pressure in the fracture, a hole elastic deformation relationship between a fluid body and a rock is established by being combined with a boundary condition established by the fluid pressure in the fracture, that is, a fluid-solid coupling model is established, and the formation pore pressure is calculated and strain and a pore penetration change which are caused by a change in the fluid pressure are obtained; and then the fracture extension dynamic after the action of the fluid-solid coupling is obtained, then the obtained new parameter is used as an initial condition to be repeated, and finally the fracture extension dynamic is obtained. Accordingto the method for simulating the water injection well water pressure drive fracture extension dynamic, the dynamic extension condition of the fracture in a water injection well and the dynamic changecondition of the parameter in a reservoir can be forecasted according to the construction and geological parameters.
Owner:SOUTHWEST PETROLEUM UNIV

Influence coefficient dynamic balance method on rotating machine with multiple plane, multiple-points and multiple revolving speed shafting

The invention discloses an influence coefficient dynamic balance method on rotating machine with multiple plane, multiple-points and multiple revolving speed shafting. The influence coefficient dynamic balance method on rotating machine with multiple plane, multiple-points and multiple revolving speed shafting comprises the steps that 1, designating a shafting balancing revolving speed point, balancing planes and numbers of measured points; 2, an initial deflection value of a spindle and an initial vibration value are measured under a slow revolving speed of 300rpm; 3, a vibration response of the measured points on a bearing after trial mass is conducted on a plurality of balancing planes on the shafting; 4, the minimum value of the residual vibration amplitude epsilon of all vibration measured points after the rotor is balanced is set as a goal, a vibration response vector equilibrium equation is established, and a size and angel of a balance weight Q on the unit shafting are obtained; 5, the vibration value of all vibration measured points are read, the above steps 2, 3, and 4 can be repeated once the value is unsatisfied. The influence coefficient dynamic balance method on rotating machine with multiple plane, multiple-points and multiple revolving speed shafting has a overall consideration on vibration with multiple plane, multiple-points and multiple revolving speed shafting, and a seesaw phenomenon in the traditional dynamic balance process is effectively avoided.
Owner:宁波丰沃增压科技股份有限公司

Lower-bound analysis method of ultimate toppling failure bearing capacity of jointed rock slope under action of seismic force

The invention provides an analysis method of ultimate toppling failure bearing capacity of a jointed rock slope under the action of seismic force, and belongs to the technical field of rock slope stability analysis. According to the method, the jointed rock slope is used as a research object to calculate horizontal or vertical seismic inertial force of rock centroids according to a principle of a pseudo-static method, that is, the seismic inertial force is a function of slope height, rock centroid height and seismic parameters; normal force, shear force and bending moments of internal force of structural surfaces of rocks are used as unknown quantities to establish force and moment balance equations of the rocks; at the same time, yield conditions of toppling failure of the rocks, shear slips of the structural surfaces and tensile detachment are established, overload coefficients of external loads are combined, and a linear mathematical programming model of the lower-bound method of the ultimate bearing capacity of the jointed rock slope on which the toppling failure occurs under the action of seism is established; and finally, a simplex method is adopted to solve ultimate status of the toppling failure of the slope, and an ultimate load or strength reserve coefficient corresponding to a toppling failure mode can be obtained.
Owner:KUNMING UNIV OF SCI & TECH

Asymptotic variational method-based method for simulating and optimizing composite material laminated plate

InactiveCN102096736AIncreased buckling critical loadHigh speedSpecial data processing applicationsTensor decompositionEngineering
The invention relates to an asymptotic variational method-based method for simulating and optimizing a composite material laminated plate, which belongs to the field of analysis of material mechanics. The method specifically comprises the following steps of: constructing a three-dimensional plate energy equation represented by a one-dimensional generalized strain and warping function on the basisof a rotation tensor decomposition concept; strictly splitting the original three-dimensional problem analysis into nonlinear two-dimensional plate analysis and cross-section analysis along a thickness direction on the basis of an asymptotic variational method; asymptotically correcting an approximate energy functional of a reduced-order model to a second order by using the inherent small parameter of the plate and converting the approximate energy functional into the form of Reissner model for practical application through an equilibrium equation; accurately reconstructing a three-dimensional stress / strain / displacement field by using an obtained global response asymptotic correction warping function; and optimizing the composite material laminated plate by using an optimization strategy of bending and torsion rigidity coefficients obtained by maximization cross-section analysis. The method has high practicability and high generality, and the resolving speed and efficiency of this type of problems can be remarkably increased.
Owner:CHONGQING UNIV

Drive control device of hybrid vehicle

Objects of the present invention is to improve the control accuracy of the SOC of the battery in consideration of the electric power losses of a plurality of motor generators and, in accordance therewith, to secure the protection performance of the battery and to increase the energy recovery efficiency according to the regeneration. In a drive control device of a hybrid vehicle including a motor torque instruction value calculating means, an electric power loss predicting means, an electric power upper limit / lower limit value calculating means, and a target electric power calculating means are arranged, and the motor torque instruction value calculating means calculates torque instruction values of a plurality of motor generators using a torque balance equation including target engine torque required at a target engine operating point and an electric power balance equation including target electric power.
Owner:SUZUKI MOTOR CORP

Fault diagnosis method for gyro measurement system

The invention discloses a fault diagnosis method for a gyro measurement system. The method comprises the steps of: (1) determine the configuration type of gyros, and then calculating the angle relationship between the gyros; (2) determining the weight coefficient of a gyro balance equation; (3) determining judgment gyro sequencing; (4) designing a balance equation according to the determined judgment gyro sequencing result in step (3); and (5) designing a fault diagnosis method. The method provided in the invention can substantially improve the probability of gyro fault diagnosis, has strong project realizability, and can adapt to fault diagnoses of gyros with any complex configuration.
Owner:BEIJING INST OF CONTROL ENG

Method for predicting well yield of sealed, unsaturated oil reservoirs through elastic driving water-flooding extraction

The invention discloses a method for predicting the well yield of sealed, unsaturated oil reservoirs through elastic driving water-flooding extraction. The method includes: measuring the initial volume coefficient Boi of crude oil and the volume coefficient Bo of the crude oil under different pressure conditions, measuring the initial oil saturation Soi and the initial water saturation Swc of the rock core, generally measuring the in-place oil compression coefficient Co, the formation water compression coefficient Cw and the rock compression coefficient Cp, obtaining the rock effective compression coefficient Ceff according to the above parameters; measuring the oil geological reserves N and the reservoir pressure under a certain injection condition according to a matter balance equation, and finally measuring the yield of an oil well according to a plane radial flow Darcy equation, wherein the yield includes oil yield and water yield. The method supplements the correspondence between injected water and oil reservoir pressure change under the water-flooding extraction condition, accordingly can predict the daily oil yield and the daily water yield under the water-flooding extraction condition, and provides reference value for oil field production cost.
Owner:CHENGDU NORTH OIL EXPLORATION DEV TECH

Load simulation method for cataplane landing gear

InactiveCN105138805ASolving design and analysis problems of landing gear loadsGuaranteed flight test verificationSpecial data processing applicationsMechanical equilibriumGravity center
The invention discloses a load simulation method for a cataplane landing gear, and belongs to the field of strength design of the cataplane landing gear. The load simulation method mainly comprises the following steps: analyzing stress on the whole cataplane, a nose gear and a main landing gear of a cataplane, so as to establish a corresponding mechanic equilibrium equation; establishing a nose gear simulation analysis model, a main landing gear simulation analysis model and a whole cataplane dynamic simulation analysis model according to the nose gear mechanic equilibrium equation; finally, correcting the whole cataplane dynamic simulation analysis model according to testing gravity center data and a front main landing gear load curve during practical catapult launching of the cataplane. The corrected model is the model capable of being used for catapult launching load simulation of the cataplane, problems in load design and analysis of the landing gear during catapult launching of the cataplane are solved, and the flight test verification of a carrier-based aircraft in an aircraft carrier platform and a land-based training ground is guaranteed.
Owner:SHENYANG AIRCRAFT DESIGN INST AVIATION IND CORP OF CHINA

Power to gas device-considered power-gas interconnection system reliability modeling method and assessment method thereof

InactiveCN107194055AReasonable quantification of the severity of wind curtailmentAccurate energy flow calculationData processing applicationsDesign optimisation/simulationAir volumeElectric power system
Aiming at the deficiencies of energy flow models, load cut-down models and reliability assessment indexes of the existing power-gas interconnection system reliability assessment, the invention discloses a power to gas (P2G) device-considered power-gas interconnection system reliability modeling method and an assessment method thereof. The method comprises the following steps of in an energy flow model, importing a wind power plant abandoned air volume, and consumed electric power and injected air volume in a P2G device model into an electric power system active balance model; adding a heat load cut-down amount and an abandoned air volume variable in a target function of an optimization model in the load cut-down model; and in a reliability assessment index, establishing a device-level index, for system reliability index contribution, of a P2G device.
Owner:CHONGQING UNIV

Method for detecting earth surface evapotranspiration based on remote sensing earth surface temperature and vegetation coverage two-stage space

A method for detecting earth surface evapotranspiration based on remote sensing earth surface temperature and vegetation coverage two-stage space comprises the following steps: 1, acquiring earth surface temperature and vegetation coverage by utilizing a remote sensing data product; 2, establishing the earth surface temperature and vegetation coverage two-stage feature space; 3, extracting the temperature of vegetation component and bare soil component by utilizing the earth surface temperature and vegetation coverage two-stage feature space; 4, calculating the evaporation ratio of vegetation and bare soil by combining the earth surface temperature and vegetation coverage two-stage feature space and a Priestley-Taylor formula; 5, calculating the available energy of the vegetation component and the available energy of the bare soil component according to a radiation income and outcome balance equation; 6, calculating the output vegetation evapotranspiration, soil evaporation and earth surface evapotranspiration through a binary pattern of earth surface evapotranspiration.
Owner:CHINA UNIV OF MINING & TECH (BEIJING)

Calculation method of tilt corridor of tilt four-rotor aircraft with periodic variable pitch at constant rotational speed

The invention discloses a calculation method of a tilt corridor of a tilt four-rotor aircraft with periodic variable pitch at constant rotational speed, which comprises the following steps: establishing flight mechanics models of various parts of the aircraft, converting all forces and moments into a body shaft system, and establishing a six-degree-of-freedom balance equation; determining the tiltcontrol mode; solving the upper and lower boundaries of the pitch angle by taking the lift characteristics of the wing as the limiting factor; obtaining the control variables and attitude angles under different state conditions by optimal trimming; finding the corresponding wing lift characteristic limit minimum speed boundary and wing lift characteristic limit high speed boundary; obtaining theavailable power limiting high-speed boundary by solving the required power at different state points. The invention is based on a flight mechanics model, takes into account the parameters of each aspect of the aircraft design, and reflects the specific attributes of each feasible flight point. The invention is also applicable to the tilt corridor calculation of tilt four-rotor aircraft under different control modes.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Yawing motion control method of four-wheel distribution type drive coach

The invention discloses a yawing motion control method of a four-wheel distribution type drive coach, and relates to the technical field of vehicle control. A layered control method is adopted, the upper layer is a motion tracking layer, steering response of a steady state of the vehicle is calculated by adopting a non-linear vehicle model and the reference understeer degree, meanwhile, a road attachment condition limiting value is adopted for constraint, and steady-state lateral force response and tire self-aligning torque response are calculated with a magic tire formula according to slip angle response at the steady state and vertical load change; needed additional yawing moment is calculated with a yawing motion balance equation; a lower layer is an actuator control layer, and generalized control force is reasonably distributed to four drive motors with an optimization algorithm through combination with the current driving condition; finally, offline distribution calculation results of different vehicle parameters needed on different upper layers are stored and looked up offline, four driving wheels are subjected to torque distribution according to road attachment conditions, yawing motion of the vehicle is controlled, and driving stability is guaranteed.
Owner:XIAMEN KING LONG UNITED AUTOMOTIVE IND CO LTD

Fracture-vug type carbonate reservoir water breakthrough early warning method

InactiveCN105956712AExtend water-free oil recovery periodEnhanced overall recoveryForecastingOil productionBottom water
A fracture-vug type carbonate reservoir water breakthrough early warning method of the present invention relates to an oil well water breakthrough early warning method, and aims to determine the water invasion time timely, optimize a working system, prolong an oil well water-free oil production period, and improve the oil well recovery efficiency. The method of the present invention comprises the following the steps of S01 obtaining the oil pressure drop under different accumulative liquid volumes according to a matter balance equation, and drawing a relational graph of the oil well pressure drop and the accumulative liquid volume; S02 for the non-water breakthrough reservoir, if a oil well pressure drop and accumulative liquid volume curve deviates, explaining three possible phenomena: (1) the crude oil is degassed in a shaft or stratum; (2) a new reservoir is exploited; (3) the edge-bottom water begins to invade; S03 excluding the two situations that the crude oil is degassed in the shaft or stratum and the new reservoir is exploited to determine that the reservoir edge-bottom water begins to invade; S04 determining the water invasion time according to the relational graph of the oil well pressure drop and the accumulative liquid volume, and carrying out the water breakthrough early warning.
Owner:恒泰艾普(北京)能源科技研究院有限公司 +1

Method for calculating pressure of passive lateral rocks for jointed rocks on outwardly-inclined bedding slope

The invention relates to a method for calculating pressure of passive lateral rocks for jointed rocks on an outwardly-inclined bedding slope, pertaining to the technical field of rock pressure analyses in rock and soil mechanics. The method comprises following steps: dispersing bedding joint rocks based on joint surfaces into rigid rocks in a definite number by taking jointed rocks on the outwardly-inclined bedding slope as an object of study; taking pressure of passive lateral rocks as an objective function and shearing force and normal force of joint surfaces as unknown quantities based on a Pan Jiazheng maximum principle to create an equilibrium equation satisfying damaged rocks, yield conditions of joint surfaces, and yield conditions of contact surfaces for rocks and supporting structures; and solving them to obtain the maximum limit value for passive lateral rocks for jointed rocks the an outwardly-inclined bedding slope. The method for calculating pressure of passive lateral rocks for jointed rocks on the outwardly-inclined bedding slope has following beneficial effects: the method is accurate in concept, high in calculation precision, and easy and convenient in engineering application and can be applied to design of structures for retaining walls on jointed rock slopes, slide-resistant piles and pile-anchor supports.
Owner:KUNMING UNIV OF SCI & TECH

Optimization and restart control method for use in outage of large-inertial-load permanent magnet synchronous motor

Disclosed is an optimization and restart control method allowing for minimum outage-restart instant impact of a large-inertial-load permanent magnet synchronous motor. Proper start parameters are obtained by updating a pre-start given rotation speed omega * and a position compensation error delta theta and by simulation with a voltage inverter, and an error limitation is provided for the given rotation speed omega *, the position compensation error delta theta, voltage inverter end voltage Uabc and counter electromotive force Eabc at the moment of start; before starting, conditions that the given rotation speed omega * and the position compensation error delta theta need to meet under minimum impact are analyzed according to a torque balance equation; the position compensation error delta theta and a difference delta omega * between the given rotation speed omega * and an actual rotation speed omega are continuously updated until starting begins according to the actual rotation speed and a amplitude difference-phase difference delta between end voltage simulated by an analog controller and the counter electromotive force Eabc; the concept of voltage analog controller is introduced, the difference between the counter electromotive force Eabc and the end voltage Uabc is analyzed, and an area allowing for minimum instant impact is obtained.
Owner:NORTHWESTERN POLYTECHNICAL UNIV

Method of estimating quantities that represent state of vehicle

The precision of the estimations of the vehicle body sideslip angle and the values related to the vehicle body sideslip angle can be improved by a simple and inexpensive method. The improved method of estimating quantities that represent the vehicle state of a vehicle comprises the steps of detecting a yaw rate and vehicle speed and calculating a vehicle body sideslip angle using three equations, which comprises an equation of equilibrium for the force in the lateral direction of the vehicle and an equation of equilibrium for the moment around a vertical axis of the vehicle, and an equation for the physical relationships of the quantities that represent the state of the vehicle movement, and which include a vehicle sideslip angle, a front wheel cornering power, and a rear wheel cornering power as unknown values.
Owner:HONDA MOTOR CO LTD

Method and device for obtaining load distribution of ball-cone mixed double-row hub bearing

ActiveCN106089993AQuickly obtain accurate bearing characteristic parametersImprove rationalityGeometric CADBall and roller bearingsAxial displacementPosition angle
The invention relates to a method and a device for obtaining load distribution of a ball-cone mixed double-row hub bearing. Firstly, a normal contact load Q1i in any position angle wi of a steel ball and a normal contact load Q2i in any position angle phi i of a conical roller with an outer ring are derived; then, total radial force Q1r, axial force Q1a and resistance torque M1 generated to the inner ring by the steel ball and total radial force Q2r, axial force Q2a and resistance torque M2 generated by the conical roller to the inner ring are obtained; a mechanical balance equation of the inner ring of the ball-cone mixed double-row hub bearing with delta r, delta a and theta as unknown quantities is built; and a Newton iteration method is applied to solve the balance equation to obtain a radial displacement delta r, an axial displacement delta a and an angular displacement theta of the inner ring of the bearing so as to obtain the load distribution conditions in each row of the bearing. The method can quickly obtain precise bearing characteristic parameters of the ball-cone mixed double-row hub bearing, can directly judge if the structural design of the ball-cone mixed double-row hub bearing is reasonable, and improves the design rationality and accuracy of the ball-cone mixed double-row hub bearing.
Owner:HENAN UNIV OF SCI & TECH

Fracture-cavern type carbonate condensate gas well development index analyzing method and device

ActiveCN105134196ASolve the problem of production dynamic forecastingForecast outputBorehole/well accessoriesMaterial balanceGas oil ratio
The invention provides a fracture-cavern type carbonate condensate gas well development index analyzing method and device. The method includes the steps of obtaining a standard parameter in a single well, calculating the dynamic reserve volume of the single well according to the standard parameter, determining the natural gas yield and natural gas accumulated yield of all production time points according to the preset natural gas yield segmented decreasing rule, determining the two-phase deviation coefficient and gas-oil ratio data according to PVT experimental data, establishing a matter balance equation, substituting the natural gas accumulated yield and the two-phase deviation coefficient into the equation, calculating stratum pressure theoretical values of all the production time points, conducting correction to generate a stratum pressure correction value according to actually-measured static pressure data, predicting the corresponding condensate oil yield according to the stratum pressure correction value and the gas-oil ratio data, calculating the condensate oil accumulated yield according to the matter balance equation with abandoned stratum pressure as a restraint, and calculating the condensate oil production degree and the natural gas production degree through the combination of the dynamic reserve volume of the single well.
Owner:PETROCHINA CO LTD
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