621 results about "Analytic expression" patented technology

A method for enabling intelligence at the edge. Features include: triggering by sensor data in a software layer hosted on either a gateway device or an embedded system. Software layer is connected to a local-area network. A repository of services, applications, and data processing engines is made accessible by the software layer. Matching the sensor data with semantic descriptions of occurrence of specific conditions through an expression language made available by the software layer. Automatic discovery of pattern events by continuously executing expressions. Intelligently composing services and applications across the gateway device and embedded systems across the network managed by the software layer for chaining applications and analytics expressions. Optimizing the layout of the applications and analytics based on resource availability. Monitoring the health of the software layer. Storing of raw sensor data or results of expressions in a local time-series database or cloud storage. Services and components can be containerized to ensure smooth running in any gateway environment.

Estimates of spectral magnitude and phase are obtained by an estimation process using spectral information from analysis filter banks such as the Modified Discrete Cosine Transform. The estimation process may be implemented by convolution-like operations with impulse responses. Portions of the impulse responses may be selected for use in the convolution-like operations to trade off between computational complexity and estimation accuracy. Mathematical derivations of analytical expressions for filter structures and impulse responses are disclosed.

A robot direct teaching control method based on moment balance is characterized in that current values of joint motors of a robot under some specific poses and moving states are calculated through measurement and modeling, and an analytic expression of the current values required by balancing of the gravity and the friction of joints under any pose and any moving state of the robot is obtained. During robot teaching, the current values calculated through the analytic expression are directly utilized to control the joint motors to enable the robot to be located under the environment similar to the environment without gravity and friction, and direct teaching can be conducted on the robot at the moment. The method has the advantages of being simple in control, low in system cost, convenient to operate and the like.

The invention discloses a balance control method of a multi-leg robot, applied for balance control of the multi-leg robot during movement under the condition of non-structured terrain, wherein the control flow is simple and clear. The balance control method of the multi-leg robot comprises the following specific steps of: if finding out unstability of the robot, quickly calculating the landing positions of the tail ends of the legs in next movement period, and after executing a control policy, quickly switching the unstable state of the robot to a static stable state. A constraint condition that the landing positions of the ends of the legs should satisfy and the landing positions of the ends of the legs both are given by an analytic expression; the calculation efficiency is high; and the method is suitable for online real-time calculation and real-time control. The whole set of control method performs position control on the movement of each leg of the robot by means of the angle information of each joint of the robot, the gesture information of the body and the leg strength information at the ends of the legs; and the control method is suitable for balance control of the multi-leg robot in non-structured environment.

The invention discloses a life evaluation method for a modular multilevel converter (MMC). The life evaluation method comprises the following steps: reading year-round temperature data of a running natural environment of the MMC and power data input into the MMC; performing analytic calculation on the average value and the effective value of the current of sub-modules IGBT and Diode of the MMC; calculating the average loss power Ploss,T and Ploss,D of the sub-modules IGBT and Diode of the MMC within the fundamental frequency period; calculating the average temperature rise Tja of a semiconductor device within the working frequency period by use of a Forster network model to obtain the average junction temperature value Tj of IGBT modules (IGBT modules, IGBTs, including IGBT and Diode); modifying fitting calculation of loss of the IGBTs according to the average junction temperature of the IGBTs; calculating the extreme values of the function temperature within the working frequency and counting the year-round fundamental frequency junction temperature cycle; counting fluctuation information of the year-round low-frequency junction temperature; and calculating the failure number Nf of the fundamental frequency and the low frequency of the semi-conductor device by use of a Bayerer life model, and obtaining the life of the MMC in combination with operation conditions. The life evaluation method can reliably forecast the life of the MMC, can effectively improve the forecasting calculation speed through obtaining an analytical expression of both current and the junction temperature, and has the characteristics of project operational capability and the like.

The present invention discloses a decomposition method for a random quantum bit gate, and belongs to the field of the quantum state manipulating technology. The method includes: the bit gate U of a random quantum n is decomposed into a plurality of uninterrupted Cn (U) and the decomposition of a random quantum bit gate is achieved by adopting an index decomposition mode and a polynomial decomposition mode with circuit complexities of O (2n) and O (n2) respectively through the fundamental segment and the correcting segment of the structure and utilizing the mode of nested recursion. The present invention achieves that a random quantum bit gate is decomposed into a qubit index form and a polynomial form of complexities, gives the quantum circuit and the relevant analytical expression containing only two quantum bit CNOTs and a single quantum bit accurately, thereby achieving an arbitrary operation to a quantum state in the transmission process of the quantum state, figures out the number of a basic logic gate that the two decomposed forms need, uses a phaseshift approximate gate to replace the Toffolin gate and reduces the complexity of the circuit greatly.

The invention discloses a five-axis side milling machining process parameter design method, belongs to the technology of numerical control (NC) machining, and solves the problem that real machining conditions cannot be reflected in cutting force calculation in the conventional process parameter design method. The method comprises the following steps of: tool path planning, cutting force calculation and process parameter optimization; in the tool path planning step, an NC code is generated by using computer-aided manufacturing (CAM) software; in the cutting force calculation step, first, a continuous tool path is generated from the NC code; then, a cutting thickness is obtained; and finally, the cutting force is calculated according to the cutting thickness; and in the process parameter optimization step, whether the calculated cutting force is not greater than a design threshold is judged; if the calculated cutting force is not greater than the design threshold, the NC code, the cutting depth and a feed rate are taken as input parameters; and otherwise, an NC code is regenerated. In the method, the real machining conditions are reflected by utilizing a tool enveloping surface analytical expression and the obtained transient cutting thickness is more accurate, so that the accuracy of the calculation of the cutting thickness and the cutting force is improved, and reliable assurance is provided for precisely and efficiently machining a spatial curved surface.

The invention provides a satellite-machine combined frequency domain imaging method of Bistatic Synthetic Aperture Radar (Bistatic SAR), which utilizes characteristics of the SA-BSAR system to obtain the analytical expression of two-dimensional spectrum of the system, and then utilizes Omega-k algorithm thought to obtain SA-BSAR two-dimensional Stolt mapping relation according to the expression of the two-dimensional spectrum; finally, two-dimensional Stolt interpolation can be approximately achieved by using inverse scale Fourier transform and phase multiplication in frequency domain through studying the two-dimensional Stolt mapping relation, so as to complete the compensation for the two-dimensional space variance of the system; the method can avoid the problem of huge calculation and high complexity caused by two-dimensional Stolt interpolation, thereby effectively achieving SA-BSAR imaging with high resolution.

The present invention provides a method for determining the Frequency Response Function for a collection of tools in a CNC machine by taking four measurements (three of which are independent) on a single tool, held in the same or similar tool holder, spindle and CNC machine. The method uses inverse Receptance Coupling Substructure Analysis (RCSA) to obtain the receptances of the system, exclusive of the single tool. Standard (forward) RCSA is then used with these receptances and certain analytic expressions for the receptances of a freely supported tool to obtain the FRF for each tool in the collection of tools. This information can be used to predict stable, chatter-free depths of cut over a range of spindle speeds in CNC machining, identifying both the limiting depth of cut at any speed as well as special spindle speeds where unusually large, chatter-free depths of cut are available.

A method for automatically determining an avoidance maneuver in an automatic collision avoidance system of an aircraft. A maximum kinematic acceleration envelope is determined by determining a multitude of avoidance maneuver angle kinematic acceleration pairs in a kinematic acceleration plane, and interpolating gaps between points, thus creating a curve. The curve is called maximum kinematic acceleration envelope. The curve may also be approximated by an analytical expression. An adjusted kinematic acceleration envelope is formed in the plane by forming a new envelope. The new envelope at each point laying closer to or at the same distance from an origin as the points of the maximum kinematic acceleration envelope and such that there is only one value of the kinematic acceleration a for a given avoidance maneuver angle. An avoidance maneuver angle is received for which a suitable bank angle and a suitable normal load is to be determined. Determining The magnitude of the kinematic acceleration a corresponding to the adjusted kinematic acceleration envelope for the avoidance maneuver angle is determined by reading the envelope curve, or if the curve is an analytical expression, calculating the curve by using the analytical expression. The normal load is determined based on the kinematic acceleration, and the avoidance maneuver angle. The bank angle is determined based on the kinematic acceleration and the avoidance maneuver angle.

The invention provides a residual life prediction method for a non-stationary degradation process with uncertain impact and belongs to the technical field of reliability engineering. The impact effect is combined with a continuous degradation process, thereby more reasonably describing the actual degradation process. In a state estimation phase, a new online state estimation algorithm is provided to identify the real system state and to provide a necessary support for subsequent residual life prediction. In a parameter estimation stage, unknown parameters in a model are obtained by adopting an expectation maximization algorithm. For residual life production, the uncertainty of state estimation and the influence of the impact effect are considered at the same time, and an expression is analyzed to give a probability density function and a cumulative probability density function of residual life prediction distribution. The provided model meets the actual degradation condition, a more accurate residual life prediction result can be obtained, and the residual life prediction method is of great significance in fault prediction and health management in engineering.

The invention discloses a power system transient stability simulating method based on implicit numerical integration. Compared with an existing power system transient stability numerical simulation implicit trapezoidal integration method, the power system transient stability simulating method employs a power-angle integration formula with a smaller local truncation error, namely, enables a non-linear differential equation set for describing a power system transient process to be expressed as a linear portion and a non-linear portion. An accurate analysis expression of a state transition matrix is obtained by reasonably selecting a system matrix of the linear portion as a singular matrix, and a group of implicit integration formulas is obtained by leading linear integrable functions to be approximate to the non-linear portion of the differential equation set. The local truncation error of the power-angle implicit integration formulas of the generator refers to O (h5) which is larger than a local truncation error O (h3) of implicit trapezoidal integration, the calculated quantity of integration each time is equivalent to that of the implicit trapezoidal integration. By means of the high-precision implicit integration formulas, iteration times of each integration step under the same iteration precision condition are decreased, so that the simulated calculated quantity is remarkably decreased.

The invention relates to a high-precision method for quickly positioning centers of two-dimensional Gaussian distribution spot images, which includes obtaining an approximate two-dimensional Gaussian distribution image through defocused imaging of a CCD (charge coupled device) camera, processing the image to preliminarily split multiple light spots in the image and mark serial numbers, determining the integer pixel coordinate of the light spot center before setting up local image coordinate system with the integer pixel coordinate serving as an origin, calculating variance of the Gaussian light spot and sub-pixel coordinate components of the light spot center in the x and y directions, and compositing the integer pixel coordinate with the sub-pixel coordinate to obtain the actual precise coordinate of the light spot center. All pixel grayscale information in a window is comprehensively utilized by the method, position of the sub-pixel center of the Gaussian distribution light spot canbe directly calculated through an analytic expression, solving of a generalized inverse matrix is not needed, efficiency is improved by more than 200 times and precision loss is avoided as compared with those of the traditional Gaussian quadrics fitting method, and real-time extracting of multiple light spot centers can be realized.

The invention belongs to a method for detecting reservoir fissure development direction in the field of petroleum seismic exploration and oil gas field development, particularly relating to an analytical expression of an included angle between an acquisition system coordinate system and a natural system coordinate system by utilizing multiple wave seismic data, an orthogonality principle formula and an Alford rotation formula; an angle analytical formula inverts the main direction of the fissure and analyzes the fissure development density so as to detect the reservoir fissure development. The angel has a specific physical significance, back calculation is simple and convenient, and an algorithm is not affected by fast and slow shear wave delay time. Even if the polarization of the fast and slow shear wave does not strictly satisfy the relationship of cross polarization, the angle of the inversion angle analytical expression is still within the acceptable error range. The precision of the inversion angle more approaches the real result along with the improvement of the signal to noise ratio of the multi-component data.

The invention provides an electro-thermal simulation method for FS (Field Stop) type IGBT (Insulated Gate Bipolar Transistor) transient temperature characteristic. An FS type IGBT switching transient working process is actually tested and is analyzed by being combined with an IGBT working principle and a semiconductor physical principle to determine that the IGBT transient temperature characteristic is mainly influenced by life of internal excess carrier, so that the electro-thermal simulation method is established. The method comprises the following steps of: actually testing carrier life values extracted at different temperatures to acquire a relational expression of the carrier life and temperature; calculating through an empirical value formula to acquire a relational expression amongthreshold voltage, transconductance, emitter saturation and current as well as the temperature; and adding temperature related parameters into an FS type IGBT current tailing stage current analyticalexpression and a switching transient model equation set and calculating to acquire transient working waveform of the FS type IGBT at different temperatures. The electro-thermal model simulation method provided by the invention simultaneously has the advantages of simple parameter calculation and high accuracy.

The invention provides a method for assessing voltage sag sensitivity of sensitive equipment. The method includes steps of determining an uncertain region of voltage tolerance curves of the sensitive equipment to be assessed; creating an entropy model and a maximum entropy model for the uncertain region by the aid of a probability density function; importing historical monitoring data and solving the maximum entropy model by an optimization algorithm to obtain analytic expressions of the probability density function; integrating the analytic expressions of the probability density function to obtain the voltage sag sensitivity of the sensitive equipment to be assessed. Artificial assumption that voltage sag amplitudes and duration are independent from one another is omitted in the entropy model and the maximum entropy model. The method has the advantages that the type of the probability density function is not set in advance, the artificial assumption that variables, namely the voltage sag amplitudes and the duration, are independent from one another is omitted, and the accuracy of the voltage sag sensitivity, which is assessed on the basis, of the sensitive equipment can be improved.

A method for calculating long-range image contributions from mask polygons. An algorithm is introduced having application to Optical Proximity Correction in optical lithography. A finite integral for each sector of a polygon replaces an infinite integral. Integrating over two triangles, rather than integrating on the full sector, achieves a finite integral. An analytical approach is presented for a power law kernel to reduce the numerical integration of a sector to an analytical expression evaluation. The mask polygon is divided into regions to calculate interaction effects, such as intermediate-range and long-range effects, by truncating the mask instead of truncating the kernel function.

The invention relates to a time-optimal bridge crane track planning method based on differential flatness and a B-spline, and aims at solving the automatic control problem of a nonlinear bridge crane. The method is good in performance of locating a trolley and eliminating the swinging of a load. The method comprises the following steps of proposing system flatness output which is used for processing a coupling relation between the motion of the trolley and the swinging of the load; converting track parameters to a B-spline curve form with to-be-optimized parameters by utilizing the continuity and smoothness of the B-spline curve; obtaining a time-optimal track by utilizing a polygonal optimization algorithm by considering constraints such as the swinging angle of the load and the acceleration of the trolley. The track planning is carried out by utilizing the differential flatness characteristics of a bridge crane system, so that the analysis on the complicated coupling characteristics of the system can be avoided; moreover, the selected track form has an analytic expression; meanwhile, the time-optimal track is obtained by utilizing the optimization algorithm. The simulation and experimental result shows that the control effect is good, and the real application value is good.

The invention discloses a light source and mask optimization method for a lithography machine. The method comprises the following steps: taking the square of Euclidean distance between an ideal pattern and a photoresist image which corresponds to the mask under exposure of the current light source illumination mode as an evaluation function by utilizing a pixilated light source illumination mode and a mask, calculating gradient information of the evaluation function by utilizing a stochastic parallel gradient descent algorithm, guiding the light source and mask optimization process through the gradient information of the evaluation function, and thus obtaining the optimal light source illumination mode and mask pattern. According to the method, solution of a gradient analysis expression of the evaluation function is avoided, the optimization complexity is reduced, the optimization efficiency is improved, and the resolution ratio of the lithography machine is effectively improved.

The invention provides a method for accurately calculating the real adsorption quantity of methane on shale. The method comprises the following steps: crushing muddy shale samples; drying in a thermostat; obtaining the change data of quality of the muddy shale samples along the gas pressure, and calculating the initial volume and quality of samples and a sample cylinder; calculating the excessive adsorption quantity of the samples under different pressures; making a plot of the quality and gas density of measured samples at high-pressure section in a rectangular Cartesian coordinate system, and fitting to obtain an analytic expression, requiring fitting R<2>=1; calculating the saturated adsorption quality and saturated adsorption phase volume of the samples, wherein the ratio of the two is density value of an adsorption phase; and correcting the excessive adsorption quantity of saturated adsorption points on an absolute line through the adsorption phase volume, and correcting the excessive adsorption quantity on front other points through adsorption phase density, thus obtaining the true adsorption quantity of methane on shale.

The present invention relates to the technical field of reservoir description in oil field development, in particular to a fracture-cavity inter-well communication passage and flow parameter characterization method. The method comprises the following steps of: (A) establishing an analytical expression of describing a fracture-cavity reservoir inter-well flow rule; (B) establishing a tracing production concentration curve fitting mathematical model; (C) performing curve fitting model solution; and according to principles of the three steps, compiling fracture-cavity reservoir tracing curve fitting software, performing fitting on a theoretical tracing curve and an actually measured tracing curve by a method of adjusting a parameter on a software interface, and simultaneously carrying out calculation to obtain mass mik, a flow velocity vik, an orifice area Aik and a flow duct length lik of a fracture-cavity injection tracer so as to implement characterization on a communication passage and a flow parameter. According to the present invention, an established model of describing the flow rule of the fracture-cavity reservoir tracer further accords with the true situations; quantitative calculation characterization on the fracture-cavity reservoir inter-well communication passage and the flow parameter is implemented; and in the fitting process, automatic fitting of a computer and parameter regulation of a worker are combined.