34 results about "Analytical equations" patented technology

The present invention is related to a method intended for manufacturing a composite structure, preferably for an aircraft. The method comprises training a set of artificial neural networks (3.1, 3.2, 3.3) to obtain a composite structure which fulfills certain specification requirements (material properties, shear loads, compression loads, buckling constraints). Said neural networks are trained with data obtained from analytical equations and from a finite element model. The invention is also related to a computer program product and a computer-readable storage medium which perform some steps of such a method. Finally, the invention further provides an aircraft (12) which comprises composite structures (13, 14, 15) manufactured by means of said method.

The invention discloses a method for rapidly judging the surrounding rock stability of a shallow-buried large-span tunnel in an upper-soft and lower-hard stratum, and relates to the technical field of tunnel engineering design. Constructing a physical plane graph according to the engineering design drawing; mapping the physical plane graph to an image plane through a conformal mapping function; generating a stress field analytic equation corresponding to the physical plane according to each parameter in the image plane graph and the complex variable function analytic form; calculating a plurality of different principal stresses of the surrounding rock through the stress field analytic equation, calculating a shear failure stress according to the plurality of different principal stresses, and obtaining an expression between the normal stress and the shear stress of the surrounding rock; and defining the shear failure shear stress as tau c, the shear stress as tau and the shear safety coefficient as s = tau / tau c, judging whether s is greater than 1 or not, and if so, considering that the unit rock mass meets the failure condition. The method aims at quickly and accurately evaluating the surrounding rock stability of the large-span tunnel in the upper-soft and lower-hard stratum, and the safety risk and the cost pressure faced by tunnel construction are reduced.

The invention provides an emergency cutting method and related device for a wind-thermal bundled delivery system, and the method comprises the steps: calculating the system acceleration area of the wind-thermal bundled delivery system according to a cutting power angle of the wind-thermal bundled delivery system when a fault generator set is cut off, and a pre-constructed power angle characteristic curve of the wind-thermal bundled delivery system, and calculating the system acceleration area of the wind-thermal bundled delivery system according to the power angle characteristic curve of the wind-thermal bundled delivery system. A system deceleration area calculation expression can be constructed according to the transient stability critical power angle, the cutting power angle and the power angle characteristic curve of the wind-thermal bundled delivery system, and power angle stability constraint conditions are constructed according to the system acceleration area and the system deceleration area calculation expression. The target function with the purpose of minimizing the generator tripping amount of the wind-thermal bundled delivery system is solved by adopting the power angle stability constraint condition, so that a target emergency generator tripping strategy with the minimum generator tripping amount can be obtained. Therefore, the generator tripping combination can be directly determined through analytical equation optimization calculation, and all generator tripping combinations do not need to be traversed through time domain simulation, so that the optimization generation speed of the generator tripping combination can be effectively improved.

The invention belongs to the technical field of engineering protection and treatment, and discloses an anchoring structure internal force calculation method for an internal anchoring type anchor rod, and the method comprises the steps: building a first shear stress coupling relation between axial displacement and an anchor rod mortar interface according to the stress balance condition, axial stress and axial displacement of the anchor rod; presetting a load transfer mode from an anchor rod to a mortar body to a surrounding rock body in the anchoring structure based on the shear hysteresis model, and constructing a second shear stress coupling relationship between the axial displacement and the shear stress of the anchor rod mortar interface and the shear stress of the mortar surrounding rock interface according to the load transfer mode; based on the first shear stress coupling relation, the second shear stress coupling relation and stress boundary conditions of the anchoring structure, an anchor rod axial force analytical equation and an internal shear stress analytical equation set of the anchoring structure are constructed; and calculating the axial force and the internal shear stress of the anchor rod of the anchoring structure according to the physical parameters and the construction parameters of the anchoring structure. According to the invention, the transmission analysis of the drawing load in the anchoring structure is realized, and the displacement axial force and interface shear stress distribution of the internal anchoring type anchor rod can be calculated.

The invention provides a seismic wave field analytical simulation method, which comprises the following steps of: constructing a seabed interface analytical equation according to a displacement potential function and a boundary condition of reflected / transmitted waves; obtaining a first function relationship; obtaining a second function relationship; converting the seabed interface analytical equation by using the first function relationship and the second function relationship to obtain a function relationship between the reflection / transmission coefficient and the influence factor, and determining the function relationship as a third function relationship; a plurality of influence factors are obtained, and reflection / transmission coefficients corresponding to the influence factors are obtained based on the third function relation; and obtaining seabed seismic wave field data through forward modeling based on the influence factors and the reflection / transmission coefficients which are in one-to-one correspondence. According to the seismic wave field analysis simulation method, the obtained seabed seismic wave field is highly similar to real data, and a theoretical model can be provided for prediction and attenuation of seabed multiples and ghost waves.

The present invention discloses a method and system for arc extinguishing of stator winding ground fault based on ground transition resistance, comprising the following steps: S1. Real-time acquisition of fundamental voltage of neutral point and machine end during normal operation and after ground fault; S2. Calculation of fault phase potential E A1 , and calculate the fault phase potential E A1 Neutral point to ground voltage U N1 Phase angle d S3. Construct an analytical equation for locating the fundamental-wave fault in the generator stator winding grounding, substituting the aforementioned measurements and calculations to complete the fundamental-wave fault location. S4. If multiple solutions are found for the fundamental-wave fault location, introduce a low-frequency injection calibration criterion to select the correct transition resistance value. S5. High-resistance grounding is used to extinguish the arc at the fault point. This invention significantly improves the accuracy and reliability of fault location, eliminates the possibility of misjudgment, and provides an accurate compensation basis for arc extinguishing.

The invention belongs to the technical field of coal mining, and relates to a deep gob-side entry driving support method based on plastic zone control, which comprises the following steps: acquiring roadway radius, principal stress ratio, principal stress deflection angle, support stress and cohesive force and internal friction angle of roadway surrounding rock before support; substituting into a preset equation; according to a preset equation, roadway surrounding rock cohesion and internal friction angles under different supporting stresses are determined, and then the roadway radius, the main stress ratio, the main stress deflection angle, the different supporting stresses and the corresponding roadway surrounding rock cohesion and internal friction angles are substituted into a constructed roadway surrounding rock plastic zone boundary analytical equation. The method comprises the following steps: determining surrounding rock plastic zone boundary forms corresponding to different support stresses, then determining the support stress corresponding to a stable form in a plurality of surrounding rock plastic zone boundary forms as the optimal support stress, and finally obtaining the optimal row distance between anchor rods and cables, thereby determining the number and the arrangement mode of the anchor rods and cables according to the optimal row distance between the anchor rods and cables. And stable control of deep gob-side entry driving surrounding rock is realized.

The invention discloses a discontinuous displacement fracture phase field calculation method for a composite material. The method comprises the following steps: S1, establishing a strain energy density model of the composite material; s2, based on the strain energy density model, calculating a displacement control equation, a phase field control equation and a damage control equation according to a variational method; s3, performing one-dimensional analysis on the strain energy density model, the stress in the displacement control equation, the phase field control equation and the damage control equation to obtain an analytic equation; and S4, calculating the discontinuous displacement fracture phase field of the composite material based on the analytical equation. And S5, compiling the steps S1 to S4 into a UEL user subprogram, integrating the UEL user subprogram to an ABAQUS finite element platform, and outputting a crack path diagram of the composite material. According to the method, fracture behaviors such as interface debonding facing the composite material can be correctly captured without a particularly small grid scale while the numerical precision is ensured, and a composite material crack path prediction map is obtained.

The present application belongs to the technical field of mine safety management and control, and specifically discloses a method and system for predicting the supporting time of a deep broken mine roadway. The method collects geological, indoor mechanical, and field displacement data to form multi-source basic parameters, and constructs a modified creep analytical model containing four correction terms: blasting disturbance, structural plane weakening, cross-section size, and ground stress. Based on the modified creep analytical model, a three-dimensional numerical model is constructed and an analytical equation set is generated. The three-dimensional numerical model generates a simulation supplementary sample, which is combined with the measured sample to perform a weighted least squares inversion to calibrate the equation set. Using the creep rate and the limit total deformation amount as the double boundary conditions, and combining with the surrounding rock breaking grade switching control priority, the calibrated equation set is used to solve the supporting exposure limit time and the safety lag distance. The working condition grade is distinguished during the excavation process, and the supporting time is iteratively updated in stages. The present application realizes objective and quantitative prediction of the supporting time, and takes into account the prediction accuracy and the practicality of the field construction.

This invention relates to the field of eccentric cone feature measurement technology, specifically to a method for measuring and evaluating the eccentric cone features of a triple-eccentric butterfly valve. The method includes: uniformly selecting several measurement sections within the axial range of the point cloud to be measured, and extracting the point cloud subsets corresponding to the measurement sections; performing robust circle fitting on the projection of the point cloud subsets onto the XY plane to obtain a set of section parameters, and calculating the section residuals based on the center coordinates and radius; establishing a linear regression model of the axis center changing with height, solving for the eccentricity and axis inclination slope, and calculating the axis eccentricity distance and axis inclination angle; automatically selecting the optimal generatrix model from a preset model library; performing Fourier series expansion on the residuals of each section, calculating the second-order amplitude, and identifying higher-order distortion terms from the second-order amplitude; and outputting the analytical equation of the cone point cloud based on pose and topography parameters. This invention can accurately identify the nonlinear generatrix features and section distortion of the key sealing surface of a triple-eccentric butterfly valve.

The present application relates to the technical field of traffic safety, and discloses a data processing method and system based on a vehicle and pedestrian lower limb collision analysis model to realize rapid prediction of lower limb injury. The method comprises the following steps: constructing a vehicle and pedestrian lower limb collision analysis model, setting a collision point on a calf mass block when subjected to a collision force brought by a vehicle head, the calf mass block moving along a collision direction under impact load, and establishing a coordinate system with the calf mass point as a system coordinate origin; and in the movement process of the vehicle and pedestrian lower limb collision, the whole lower limb system moves as a projectile relative to the coordinate system and the thigh rotates around the calf, and when the thigh collides with the front edge of the vehicle engine cover, the thigh rotates to a limit position; obtaining an analytical equation of the pedestrian lower limb freedom degree model and an acceleration solving formula of the thigh mass point, and then solving the acceleration of the pedestrian thigh and calf in the collision process according to the vehicle and pedestrian lower limb collision analysis model to perform injury assessment.

An analytical method for the reflection coefficient of acoustic waves excited by a fluid-porous solid interface seismic source, including Step 1: deriving the general forms of the potential functions of the fast and slow longitudinal waves and the transverse wave excited by a point source in a porous solid medium; Step 2: using the fluid-porous solid boundary conditions and the relationships between displacement and displacement potential, and stress and strain, to derive the equation relationships between the potential functions of the incident acoustic wave, the reflected acoustic wave, the transmitted fast and slow longitudinal waves, and the transmitted transverse wave excited by a point source; Step 3: solving the displacement fields of the incident and reflected acoustic waves in the fluid medium at the fluid-porous solid seabed interface excited by a point source; Step 4: deriving the analytical equation for the reflection coefficient of acoustic waves excited by a point source at the fluid-porous solid seabed interface. It can accurately characterize the reflection characteristics of acoustic waves excited by a point source at the fluid-porous solid seabed interface, and is of great significance for seabed sound field simulation, underwater target detection, and seabed resource exploration.

This invention discloses a design method for an isostressed arch bridge, relating to the field of bridge engineering design. The method includes: Step 1: Establishing a mathematical model of the rational arch axis of the arch bridge and determining the analytical equation of the rational arch axis of the isostressed arch bridge under dead load; Step 2: Introducing known quantities of the isostressed arch bridge and iteratively solving the analytical equation of the rational arch axis of the isostressed arch bridge using either a method based on the design arch crown stress or a method based on the design arch crown area; Step 3: Determining the design parameters of the isostressed arch bridge based on the solution results of Step 2. This invention overcomes the technical limitations of traditional arch axis design methods, optimizes the stress performance and engineering practicality of arch bridges, and provides an efficient and scientific new solution for the design of long-span arch bridges.

This invention proposes a photovoltaic (PV) system active power reserve point tracking (EPP) control method and tracking control system based on a composite parameter mathematical model. The method includes: establishing a composite parameter mathematical model of the PV system; constructing an analytical equation set based on the composite parameter mathematical model; solving the analytical equation set using currently measured PV operating parameters to obtain real-time parameters such as current environmental irradiance and temperature; determining the maximum power point of the PV system under the current environment; and evaluating the current real-time active power reserve rate of the PV system based on this, thus achieving EPP tracking. This method overcomes the problems of high cost for multi-point, large-scale measurements of irradiance and temperature, and low accuracy for single-point measurements of irradiance and temperature.

A method intended for manufacturing a composite structure for an aircraft. The method includes training a set of artificial neural networks (3.1, 3.2, 3.3) to obtain a composite structure which fulfills certain specification requirements (material properties, shear loads, compression loads, buckling constraints). The neural networks are trained with data obtained from analytical equations and from a finite element model.

The application discloses a deep-sea stratum space drilling robot positioning device, method, equipment, medium and product, relates to the field of submarine robot positioning, and the method comprises the following steps: acquiring magnetic beacon data and fiber Bragg grating grating area node wavelength change data; according to the fiber Bragg grating grating area node wavelength change data, an initial coordinate of a target position based on the fiber grating sensing array is determined by using a circular arc model method; according to the magnetic beacon data, an analytical equation group of the target position is constructed by using two groups of orthogonal transmitting coils and one group of receiving coils; and according to the analytical equation group of the target position and the initial coordinate of the target position, the position and attitude information of the deep-sea stratum space drilling robot in the stratum are determined by using an L-M algorithm. The application effectively improves the positioning accuracy of the deep-sea stratum space drilling robot.

The present application relates to a kind of method and device for calculating the nonlinear noise of Raman amplification scene.The method part mainly includes: obtaining the equivalent in-fiber optical power spectrum of each channel according to Raman coupling equation or obtaining the equivalent in-fiber optical power spectrum of each channel according to Raman analytical equation;According to the equivalent in-fiber optical power spectrum of each channel and related fiber parameters, the equivalent nonlinear noise signal ratio of each channel is obtained by calculation, and the equivalent signal noise ratio caused by nonlinearity in Raman amplification scene is finally obtained.The present application can solve the problem that traditional model is too complex and backward Raman amplification scene is difficult to solve, and is more practical.

The present invention provides a power management and decomposition method for a renewable energy DC hydrogen production island system, including Step 1: establishing a static and dynamic model of the electrolyzer, determining the static and dynamic response characteristics of the electrolyzer, and obtaining the dynamic response analytical equation of the electrolyzer; Step 2: determining the power management method of the renewable energy DC hydrogen production island system; Step 3: taking into account the dynamic response characteristics of the electrolyzer, proposing a power command decomposition method for the renewable energy and hydrogen production unit; Step 4: determining the control methods for the wind power generation unit, photovoltaic power generation unit, hydrogen production unit, and battery energy storage unit under different operating modes; Step 5: determining the control architecture of the renewable energy DC hydrogen production island system. The present invention ensures the stability of the system under the condition of limited energy storage capacity configuration, flexibly adjusts the power of the hydrogen production unit through the distribution coefficient, avoids the control mode switching between the battery energy storage unit and the renewable energy power generation unit, and reduces the complexity of the coordinated control of the wind-solar-hydrogen storage system.

The invention provides a three-dimensional magnetic field coil design method suitable for magnetic compensation of a brain magnetic test area. The method comprises the following steps: S1, constructing an analytical model cylindrical coordinate system in the brain magnetic test area; s2, constructing a magnetic field analytical equation; s3, linearly superposing the barrel bottom fan-shaped coil pair and the barrel side saddle-shaped coil to form a radial coil based on a magnetic field analytical equation, and superposing the barrel side annular coil pair to form an axial coil, then optimizing the structural parameters of the radial coil and the axial coil based on an intelligent optimization algorithm, and constructing to obtain three groups of shimming coils and five groups of mutually independent linear gradient coils; and S4, describing interference magnetic field distribution in the brain magnetic test area through a vector spherical harmonic function, and adjusting the magnitude of current flowing in the coil so as to be matched with the interference magnetic field distribution. The method has the beneficial effects that the compensation coil capable of being highly matched with the magnetic field distribution trend of the brain magnetic test area under the interference condition can be designed, and the residual magnetic field in the single-end-opened cylindrical alloy barrel is accurately compensated.

The invention discloses a method for constructing a spatial stress model of a composite beam based on shear hysteresis deflection. The method comprises the following steps of: establishing a basic assumption and displacement mode function of an analytical equation considering the shear hysteresis deflection of the composite beam; establishing a total deflection function of the composite beam based on shear hysteresis deflection under the combined action of axial bending; respectively establishing longitudinal displacement functions of the concrete slab under the action of the bending moment and the axial force; respectively establishing longitudinal displacement functions under different shear lag displacement functions of the upper flange, the web and the lower flange of the box-type steel girder under the action of the bending moment and the axial force; respectively establishing a total potential energy function of the composite beam under the action of bending moment and axial force; respectively establishing control differential equations and boundary conditions under the action of bending moment and axial force; constructing a combined beam space stress model under the axial bending combined action; verifying the correctness of the model; according to the method, the bending deflection + shear hysteresis deflection superposition model of the total deflection is established, the displacement contribution of the shear hysteresis effect is clarified, and the physical significance of a complex mechanical phenomenon is concrete.

The present invention relates to a method, particularly a computer-implemented method, for performing optimization of a scaffold design (h) for enhancing bone healing, comprising the steps of: a) inputting a set of parameters including information on the geometry and material of the scaffold (3) into a computational model, the computational model including a finite element model and a mechanobiology computational model, the finite element model determining a set of mechanical information data for the set of parameters and providing it to the mechanobiology computational model, the mechanobiology computational model determining a regenerated bone volume from the set of mechanical information data; b) determining a plurality of regenerated bone volumes for the set of parameters according to step a) to generate scaffold bone data relating the regenerated bone volumes to the corresponding set of parameters; c) determining a computational surrogate model consisting of an analytical equation configured to relate the regenerated bone volume to the set of parameters from the scaffold bone data; and d) determining from the computational surrogate model an optimal set of parameters for which the computational surrogate model outputs a maximum regenerated bone volume. The present invention also relates to a computer program and a method for manufacturing a scaffold (3).

The application discloses a kind of hyperbolic-like front angle remodeling terminal guidance strategy based on relative distance, including the following steps: establishing the kinematic model of missile in two-dimensional plane intercepts stationary target;Design guidance strategy based on hyperbolic equation, solve the geometric parameters of hyperbolic according to the initial conditions of missile and target, obtain the analytical equation of guidance strategy about design parameter;According to the kinematic relationship inverse solution specified angle of different launch angle parameters.The guidance strategy in the application uses equation constraint to front angle information, meets the attack angle constraint under the condition of zero miss distance strike, and end view angle rate converges to 0, and guidance parameters are obtained by numerical integration calculation, without linearization to model, simplify the design of guidance system.The application improves the applicability of guidance system, and the design method is simple and applicable.

An analytical method and an analytical apparatus for quantitatively calculating line edge roughness of plasmon super diffraction photolithography. The method includes: determining a theoretical point spread function of a light source based on field intensity distribution of the light source at an exit plane of a focusing element of the plasmon super diffraction photolithography; determining multiple transverse widths of spots in a spot-mapping pattern based on the spot-mapping pattern; determining actual point spread functions corresponding to the multiple transverse widths, based on the theoretical point spread function and the multiple transverse widths; and establishing an analytical equation of line edge roughness of the plasmon super diffraction photolithography based on the variation due to line edge roughness, an exposure dose of each line pattern, the near-field photoresist contrast, and the logarithmic slope of each line pattern. Applicability of surface plasma super diffraction photolithography technology is greatly improved.

The application provides a seismic wave field analytical simulation method, comprising the following steps: constructing a seabed interface analytical equation according to a displacement potential function of a reflection / transmission wave and a boundary condition; obtaining a first function relationship; obtaining a second function relationship; transforming the seabed interface analytical equation by using the first function relationship and the second function relationship to obtain a function relationship formula of a reflection / transmission coefficient and an influence factor, and determining the function relationship formula as a third function relationship; obtaining a plurality of influence factors, and obtaining the reflection / transmission coefficients corresponding to the influence factors based on the third function relationship; and obtaining seabed seismic wave field data through forward modeling based on the one-to-one corresponding influence factors and reflection / transmission coefficients. The seabed seismic wave field obtained by the above seismic wave field analytical simulation method is highly similar to the real data, and can provide a theoretical model for the prediction and attenuation of seabed multiple waves and ghost waves.

A method performed by a controller of an electric motor, including generating control parameters, the step of generating control parameters selected from: inputting a given reference torque (Tref) and a speed command to a torque generation lookup table (LUT) such that the step of generating the control parameters includes the torque generation lookup table at the given reference torque and the speed command; or utilizing an analytical model that includes one or more analytical equations or one or more functions; inputting the control parameters to a DC-link current ripple, torque ripple, and radial force ripple minimization lookup table; inputting position to the DC-link current ripple, torque ripple, and radial force ripple minimization lookup table; generating a reference current profile from the DC-link current ripple, torque ripple, and radial force ripple minimization lookup table; and inputting the reference current profile to the electric motor. Additional methods are disclosed.

The invention belongs to the field of ultrasonic non-destructive testing, and particularly relates to an ultrasonic stress coupling parameter calculation method which comprises the steps of establishing a critical refraction longitudinal wave velocity analytical equation of a to-be-tested material, carrying out stretching and ultrasonic testing experiments, and obtaining the critical refraction longitudinal wave velocity of the material. Carrying out nonlinear fitting by utilizing an L-M nonlinear fitting algorithm to obtain equivalent engineering constants and equivalent elastic coefficients of the to-be-tested material in different tensile stress directions, and finally generating an ultrasonic stress coupling parameter data set of the to-be-tested material; the method can solve the problem that key parameters of an ultrasonic stress coupling field cannot be obtained, is suitable for ultrasonic stress coupling simulation of structures such as alloys and composite materials with anisotropic mechanical properties, and greatly improves the accuracy, applicability and consistency of simulation calculation results of wave velocity changes of ultrasonic critical refraction longitudinal waves caused by stress.

The present invention proposes a structured light three-dimensional vertical line measurement device and method. The method of the present invention calibrates the CCD camera parameters by Zhang Zhengyou camera calibration method; calibrates the laser plane parameters by line structured light calibration method based on chessboard; calculates the calibration parameters of the vertical line direction vector by placing two chessboards in vertical postures; the computer controls the CCD camera to collect panoramic images, extracts the image coordinates of the light point where the laser plane in the horizontal direction intersects the vertical line and the center point of the ball, and constructs the analytical equation of the vertical line and the light equation of the projection imaging of the center point of the ball in combination with the calibration parameters, and solves them together to obtain the coordinates of the center point of the ball. The change in the coordinates of the center point of the ball is the displacement of the vertical line in the three directions of X, Y, and Z. The advantages of the present invention are that there is no need to configure three sets of light sources and sensors of the same structure in three directions, simplifying the structure and improving stability; using high-resolution cameras and lenses, making full use of the field of view, and improving measurement accuracy and measurement range.

The present invention belongs to the field of engineering protection and governance technology, and discloses a method for calculating the internal force of an anchor structure of an internally anchored anchor rod. The method constructs a first shear stress coupling relationship between the axial displacement and the anchor rod mortar interface based on the anchor rod's force balance condition, axial stress, and axial displacement. The method presets a load transfer mode from the anchor rod to the mortar body to the surrounding rock body in the anchor structure based on a shear lag model, and constructs a second shear stress coupling relationship between the axial displacement and the shear stress of the anchor rod mortar interface and the shear stress of the mortar surrounding rock interface based on the load transfer mode. Based on the first shear stress coupling relationship, the second shear stress coupling relationship, and the force boundary conditions of the anchor structure, an analytical equation for the anchor rod axial force and a group of analytical equations for the internal shear stress are constructed. The method calculates the anchor rod axial force and internal shear stress of the anchor structure based on the physical parameters and construction parameters of the anchor structure. The present invention realizes the transfer analysis of the pullout load in the anchor structure and can calculate the displacement axial force and interface shear stress distribution of the internally anchored anchor rod.

The application discloses a design method of a conical face drill tip with controllable lag amount, and belongs to the technical field of metal cutting tools. In view of the problem that the tail root turning point of the existing drill tip relief surface is prone to "warping back" (the lag amount is negative), which leads to interference with the hole bottom, cutting vibration, short tool life and other problems, the application first changes the "lag amount" from an uncontrollable random result into a quantifiable and preset core design parameter. The technical scheme comprises the following steps: establishing a drill tip coordinate system and a relief surface mathematical model; establishing a design parameter and a grinding parameter analytical equation; taking the target lag amount as a core constraint for solving; obtaining a unique grinding parameter through iterative approximation; and performing numerical control machining based on the solved parameter. The application realizes accurate control of the lag amount, eliminates the warping back of the relief surface from the root, and significantly improves the drilling stability, machining quality and tool life, and is particularly suitable for a large-length-diameter-ratio deep hole twist drill.

The application relates to a discrete dynamics modeling method for a space solar panel servo motor system, and belongs to the technical field of dynamics modeling of mechanical and electrical systems of space vehicles. The method aims to solve the problems of mechanical and electrical separation, neglect of flexible load dynamic reaction and lack of external disturbance response mechanism in existing modeling. The technical scheme is as follows: a global explicit analytical equation is established by integrating the electromagnetic characteristics of a permanent magnet synchronous motor, the transmission of a harmonic reducer and the load characteristics of a solar panel, and a response model of the solar panel to space disturbance force is constructed. The model can truly reflect the coupling influence of a large-inertia flexible load on the system, realize high-precision mechanical and electrical joint simulation, quantitatively analyze the action of external disturbance and internal dissipation, and derive low-dimensional explicit dynamics equations, which are convenient for combination with a control system and provide a reliable theoretical model basis for servo control algorithm design.