15 results about "Iterative approximation" patented technology

The invention relates to the technical field of submersible pump testing, and discloses a permanent magnet variable frequency submersible pump testing method and system. The method comprises the following steps: acquiring an original response signal cluster of the submersible pump in multi-stage variable-speed operation by constructing an integrated test environment; decoupling and enhancing the signal cluster based on time sequence dependence, and separating out an independent hydraulic performance characteristic signal group and an independent electromagnetic vibration characteristic signal group; and inputting the characteristic signal group into a dynamic working condition simulator, and restoring an internal flow field pressure cloud picture and a rotor stress distribution picture of the submersible pump under the simulated working condition through an iterative approximation algorithm. The two are fused to deduce a potential failure mode and its evolution trajectory, and an enhanced test procedure is generated accordingly. According to the method, accurate separation of multi-physics field test signals and visualization of internal states are realized, and the accuracy of fault attribution and the advance of failure prediction are improved.

The invention belongs to the field of robot trajectory optimization, and particularly relates to a trajectory optimization method and system considering redundancy characteristics of a robot macro-micro force control grinding and polishing system. The method comprises the following steps: S1, generating an initial grinding and polishing track based on a CAD model, and providing a discrete point curvature estimation method to estimate the curvature of each path point; s2, on the basis of the curvature of the discrete points, a mixed optimization target of a curve energy item and a curvature change rate about curvature square is constructed, arc length and redundancy direction optimization constraints are considered, and an adjusted grinding and polishing track is generated through a nonlinear optimization method; s3, on the basis of the optimized initial points, an initial dominant point selection method based on an angle-chord height-chord length joint criterion is adopted, and the trajectory precision is kept while the number of dominant points is reduced; and S4, on the basis of the optimized curved surface dominant points, an improved least square iterative approximation method is provided to generate a parameterized B-spline grinding and polishing path generation method, and final grinding and polishing track generation is achieved.

The invention belongs to the field of mechanical arm control, and relates to a method and device for controlling a mechanical arm by utilizing double-macro lens constraint, and the method comprises the following steps: carrying out system calibration on a double-macro endoscope and the tail end of the mechanical arm to obtain transformation parameters; acquiring an image of a target object in the working space to obtain an original image; performing preprocessing and target detection on the original image to obtain a preprocessed image containing target object features; performing attitude estimation on the preprocessed image to obtain pose information of the target object in a lens coordinate system; a hierarchical iterative approximation strategy of visual feedback is adopted, and a mechanical arm is controlled to drive a double-macro endoscope to gradually approach a target object; the pose information of the target object under the lens coordinate system is converted into a base coordinate system of the mechanical arm; based on the pose information of the target object under the base coordinate system, a mechanical arm joint rotation angle instruction is solved and generated, and a mechanical arm is controlled to complete grabbing operation on the target object; therefore, the fine operation requirement of the manipulator in a narrow working space is met.

The invention provides a vibration reduction LOS guidance method for curve tracking control of an underactuated unmanned ship, and relates to the field of robustness artificial intelligence. The method comprises the following steps: acquiring an optimal path parameter corresponding to the underactuated unmanned ship based on an iterative approximation numerical solution method; introducing a tracking error item and a tracking error speed item into drift angle estimation compensation; based on the drift angle estimation compensation, designing a self-adaptive vibration reduction LOS algorithm, and obtaining an expected heading angle of the unmanned ship by combining optimal path parameters; designing a sliding mode surface in combination with the expected heading angle, designing a nonlinear sliding mode controller, and generating a control torque; and carrying out expected heading tracking on the underactuated unmanned ship based on the control moment. According to the invention, the problem that accurate path tracking and stable navigation are difficult to realize in the prior art in the case of time-varying environment interference is solved.

The invention discloses a high-precision and low-delay arbitrary bottom logarithmic function calculation system and method, and the method comprises the steps: carrying out the preprocessing of an input bottom number and a true number, generating an initial value of an iteration variable, introducing an iteration direction factor, and carrying out the iteration operation, and finally obtaining a logarithmic function result. According to the method, multiple bits are processed through single iteration through radix-8-base decomposition, the speed of approaching an accurate value in each iteration is increased, the total number of iterations is remarkably reduced, and meanwhile considerable calculation precision is kept.

This invention discloses a factor graph-based distributed spaceborne radar network air target altitude estimation algorithm, comprising the following steps: Step 1, constructing an air target motion model and a spaceborne radar measurement model in the geocentric fourth equatorial coordinate system, and constructing a factor graph-based spaceborne radar target tracking model; Step 2, based on the factor graph, introducing the coupling function relationship between local variables of the air target, and obtaining the posterior marginal distribution of the local variables; using a nonparametric confidence propagation algorithm to calculate the posterior marginal distribution of the local variables, and obtaining the estimated value of the local variables based on the calculation result of the posterior marginal distribution; Step 3, based on the estimated value of the local variables, using an iterative approximation method to obtain the target altitude of the air target in the geodetic coordinate system. This solves the problems in existing technologies such as large elevation angle measurement errors for single spaceborne radars, difficulty in accurately tracking air targets, and inaccurate altitude estimation.

The invention discloses a registration system and method based on a multi-modal medical image, and belongs to the technical field of medical image registration. The system comprises a data acquisition and model construction module for constructing a three-dimensional model for acquired static medical image data, calculating a geometric feature map and acquiring real-time dynamic positioning data; the rough registration module is used for obtaining an initial rigid transformation matrix and transforming all data points of the real-time dynamic positioning data based on the initial rigid transformation matrix; the fine registration target construction module is used for constructing a first target function for calculating target deviation and constructing a registration transformation model; the iterative registration and real-time fusion module is used for updating parameters of the registration transformation model by using an iterative approximation algorithm; the result output module is used for superposing the final registration real-time positioning data onto the three-dimensional model; therefore, a doctor can carry out mapping on the three-dimensional model superposed with the final registration real-time positioning data. According to the invention, the mapping time can be significantly reduced.

The invention discloses a rapid calculation method for a flight envelope of a high-subsonic-speed fixed-wing aircraft. The rapid calculation method comprises the following steps: acquiring basic input parameters of a dynamic model of the high-subsonic-speed fixed-wing aircraft; based on the basic input parameters of the kinetic model, performing iterative approximation calculation on the flight attack angle by taking the condition that the available thrust of an engine is not less than the flight resistance as an iteration constraint condition, and determining a boundary parameter set for defining a flight envelope boundary; and based on the boundary parameter set, obtaining a flight envelope of the high-subsonic-speed fixed-wing aircraft. Traversal iterative approximation is implemented by using the high-speed calculation capability of a computer, and the balance relationship between thrust and resistance is verified in real time in each iteration, so that the calculation efficiency of the flight envelope boundary of the high-subsonic-speed fixed-wing aircraft and the adaptability to a complex nonlinear pneumatic system are remarkably improved; the problems that a traditional method depending on an analytic formula and experience is insufficient in calculation precision under the working conditions of strong nonlinearity and full coupling, and seriously depends on step iteration and a large number of experimental verification are solved.

The application discloses a periodic description blade profile global fairing reconstruction method. First, the application generates initial profile fitting curves according to curve control vertex data and node vector data, and refines the node vector of the profile fitting curve in a least square progressive iterative approximation fitting process by using a curvature guided profile subdivision method according to the discrete curvature distribution of the profile value points, so that the curve control vertex distribution is fitted to the profile shape characteristics, thereby obtaining the subdivided profile fitting curve. Finally, according to the local support of the base function, the subdivided profile fitting curve is updated and fitted in a region-by-region and successive manner by using a curvature constraint adaptive local fitting method until a global fairing periodic reconstruction curve meeting the accuracy requirement is obtained. The application finally generates a global fairing reconstruction curve which highly accurately approximates the profile value points, guarantees the reconstruction fitting efficiency, and realizes the closed characteristic by the periodic base function, and can be effectively used for subsequent T-spline blade surface modeling.

A multiply-accumulate successive approximation (MASAR) array is provided. The MASAR array includes a plurality of MASAR cells, each MASAR cell including a multiplier configured to perform a digital multiplication between an input activation received for an input and an operand to calculate a result, and a unit capacitor configured to store the result as an analog charge. The MASAR array further includes digital logic configured to perform an analog summation of the analog charges of the unit capacitors of the plurality of MASAR cells to determine a digital output of the multiplication.

The application relates to an alternating current-direct current hybrid power distribution network dynamic scheduling method and device, which comprises the following steps: adjusting load demand according to real-time electricity price and constructing a multi-source uncertainty set; constructing first and second stage optimization scheduling models according to the adjusted load demand; constructing a total expected scheduling cost function according to the first and second stage optimization scheduling models; traversing all scene sets in the multi-source uncertainty set, adopting an improved column constraint generation algorithm based on total constraint conditions, and solving the first and second stage optimization scheduling models through strong duality transformation and iterative approximation of optimal solutions, so that the total expected scheduling cost function is minimized under the worst scene set, and a scheduling strategy which can keep the scheduling cost minimum under all scene sets is obtained. The application ensures that the system can still keep high efficient operation under the worst condition, improves the adaptability of the power grid to renewable energy and load fluctuation, and improves the economy and reliability of the whole system.

The invention provides a limiter construction method and system based on WENO physical characteristics, and the method comprises the steps: constructing a WENO limiter which is used for suppressing the non-physical oscillation of a neural network in a process of solving a partial differential equation; carrying out semi-discretization processing on the time domain, and realizing discretization of time steps by adopting an implicit Runge-Kutta method; a neural network structure fused with the WENO limiter is constructed, the neural network comprises a plurality of time step modules, and each module is composed of a feedforward neural network, an iterative approximation unit FNN + IA and the WENO limiter; training the neural network by minimizing the loss function containing the physical constraint to obtain a numerical solution of a partial differential equation; the method is deployed in an actual application occasion, and any one or more tasks of target detection, image classification, defect identification and target positioning are executed. According to the method, the limiter based on WENO physical characteristics is constructed and embedded into the neural network structure, and the non-physical oscillation phenomenon occurring in the hyperbolic partial differential equation solving process is remarkably inhibited.

The invention discloses a carbon emission intensity consistency analysis method based on power flow tracking and carbon flow tracking, and belongs to the technical field of power system carbon metering and optimization. The method comprises the following steps: acquiring network parameters of a power system, and constructing a power flow tracking and carbon flow tracking model; judging whether the network is of an acyclic structure or not, and if yes, calculating node carbon strength based on any one of the mathematical equivalence of the two methods; if the network is a looped network, selecting a carbon flow tracking model to carry out accurate calculation or a power flow tracking model to carry out iterative approximation according to the differences of the two in solving mode, loop processing, efficiency and interpretability; and finally, generating a carbon intensity report or adjusting a system operation mode according to a calculation result so as to optimize carbon emission. According to the method, the problems of unclear application conditions and blind selection of two existing methods are solved, the optimal balance of calculation precision, efficiency and interpretability is realized, carbon intensity analysis can be directly converted into carbon reduction regulation action, and low-carbon optimization operation of a power system is powerfully supported.

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 invention relates to a method for setting up and operating a machine for processing plasticizable materials, comprising at least one electric motor for at least one machine shaft, the motor characteristic (K), in particular the torque-rotational speed characteristic M (n) of which is present as part of a machine-dependent mathematical model (190). In the method, a machine-independent process parameter curve of the ideal filling process is determined from a filling simulation (200) taking into account the field of the mould (10) and the material (Mat). In the process, in the simulation, machine-related setting parameters and machine-independent process parameters of a real filling process are determined by an iterative approach process based on the machine-independent process parameter curve of the ideal filling process and the machine-related mathematical model (190). During machine setup, machine-related setup parameters can be taught at least in part by an operator, and the machine, on the basis of the determined and optionally taught machine-specific setup parameters and the determined machine-independent process parameters, enables the setup parameters to be taught at least partially by the operator without requiring manual input of the parameters. The method is operated at an optimal operating point (WP) of the filling process, said optimal operating point being dependent on the process stage.