323 results about "Shape function" patented technology

A method and system for data modeling that incorporates the advantages of both traditional response surface methodology (RSM) and neural networks is disclosed. The invention partitions the parameters into a first set of s simple parameters, where observable data are expressible as low order polynomials, and c complex parameters that reflect more complicated variation of the observed data. Variation of the data with the simple parameters is modeled using polynomials; and variation of the data with the complex parameters at each vertex is analyzed using a neural network. Variations with the simple parameters and with the complex parameters are expressed using a first sequence of shape functions and a second sequence of neural network functions. The first and second sequences are multiplicatively combined to form a composite response surface, dependent upon the parameter values, that can be used to identify an accurate model.

There is provided a method for obtaining at least one calibration filter for a Mass Spectrometry (MS) instrument system. Measured isotope peak cluster data in a mass spectral range is obtained for a given calibration standard. Relative isotope abundances and actual mass locations of isotopes corresponding thereto are calculated for the given calibration standard. Mass spectral target peak shape functions centered within respective mass spectral ranges are specified. Convolution operations are performed between the calculated relative isotope abundances and the mass spectral target peak shape functions to form calculated isotope peak cluster data. A deconvolution operation is peformed between the measured isotope peak cluster data and the calculated isotope peak cluster data after the convolution operations to obtain the at least one calibration filter.

A circuit and method provides for the protection of transducers from over excursion, particularly for the protection of transducers for audio loudspeakers. A frequency dependent excursion limiter circuit has an initial summing stage followed by a shaping filter stage. A clamping function is provided at the summing stage, or at a separate stage between the summing stage and the shaping filter stage, for clamping the driving signal at a predetermined maximum voltage if the driving signal exceeds the predetermined maximum voltage level. The shaping filter stage provides a frequency response shaping function based on a predetermined frequency response shaping criteria which is related to the frequency dependent excursion limits of the transducers being protected from mechanical overload. An inverse shaping filter function is provided at the initial summing stage by providing feedback from the shaping filter stage, thus eliminating the need for a separate inverse shaping filter circuit before clamping. The inverse shaping filter function allows low level signals below clamping to pass through the circuit unaffected.

A frequency dependent excursion limiter circuit is also provided in the closed loop circuit of servo feedback system for protecting transducers in a servo feedback system from over excursion.

The present invention relates to a phase change material for thermal energy storage and a preparation method thereof. The phase change material for thermal energy storage adopts expanded graphite phase as a carrier to adsorb organic fatty acids of different ratios, and then a composite coating agent is coated on the outside of the prepared material. The adsorption of organic fatty acids into the expanded graphite carrier improves the thermal conductivity of the organic acids as the phase change material, and suppresses the liquid leakage problem of the organic acids when the organic acids are applied in thermal storage techniques; and the composite coating agent further performs reinforcing and shaping functions.

Abstract of Disclosure A calibration factor for a sensor including a material-containing conduit and a plurality of motion transducers operative to generate motion signals representing motion of the conduit is determined from a normal modal dynamic characterization of motion of the conduit. The calibration factor may be generated by generating a solution to a modal differential equation of motion in a modal domain including a plurality of normal modes of motion of the conduit, and by generating the calibration factor from this solution. The normal modal dynamic characterization may characterize motion of the conduit as a function of a modal Coriolis term that describes coupling among a plurality of normal modes of the conduit responsive to mass flow in the conduit. The modal Coriolis term may be determined from a mode shape function that describes modal motion of the conduit as a function of location on the conduit. The invention may be embodied as methods, apparatus and computer program products.

The invention discloses a fuzzy nerve network control method for an automobile driving robot system. The method comprises: performing speed tracking on a test vehicle from the characteristic parameters of an automobile driving robot gearshift manipulator, a throttle mechanical leg, a brake mechanical leg and a clutch mechanical leg; utilizing a Sugeno fuzzy nerve network to realize the speed tracking and control of an automobile driving robot, inputting characteristic parameters, adopting a generalized bell-shaped function for a membership function in terms of type, using a mixing learning algorithm to train and optimize network parameters, and determining optimum network parameters; and according to the optimum network parameters and four characteristic parameters detected in real time of the automobile driving robot, using the Sugeno fuzzy nerve network to perform speed tracking and accurate control on the automobile driving robot. The method disclosed by the invention is provided with an on-line self-learning capability, can accurately track a given target speed, and has good robustness in various test conditions.

The invention relates to a method for regulating a speed of a brushless direct current motor supplied with power by a four-switch three-phase inverter, and belongs to the field of speed regulation of a direct current motor. The method solves the problem that unfixed switch frequency of hysteresis loop modulation in the control of the conventional brushless direct current motor. The method is realized based on a speed loop PI regulator, a speed calculation unit, a current shape function unit, a given current coordinate conversion unit, an alpha-axis current PI regulator, a beta-axis current PI regulator, a flux linkage tracing PWM unit, a feedback current coordinate conversion unit, a four-switch three-phase inverter, a current sensor and a Hall pole sensor, and adopts rotational speed and current double closed-loop control; an outer loop is a rotational speed ring; the outputs of the rotational speed ring are given as current values; the method multiples the current values by the current shape function unit respectively to realize the preset of three-phase 120-degree symmetrical square-wave current, establishes a current closed loop in a two-phase stationary coordinate system by coordinate conversion, and realizes the control of the four-switch three-phase inverter through the flux linkage tracing PWM unit. The method is used for controlling the speed regulation of the brushless direct current motor.

The invention relates to a meshless cloth-based simulation method. The method comprises the following steps of: (a) parameterizing a given cloth model omega onto a middle surface lambda and determining a configuration before deformation and a reference configuration when calculation is started; (b) selecting a limited number of nodes in the parameterized middle surface lambda and determining a local subdomain omega s of each node; (c) calculating a shape function phi I in a definition domain of each node and calculating a derivative of the shape function; (d) determining Gauss integral points of all nodes, calculating a numerical integral and assembling a stiffness matrix; (e) assembling a node mass matrix and a viscosity matrix; and (f) determining the number of cycles according to the simulation time t and the set time step interval delta t to cycle the following steps for t/delta t times: calculating a rotated global stiffness matrix, implementing constraints on the global stiffness matrix, the node mass matrix and the viscosity matrix, obtaining and solving a system linear equation set according to time integral to obtain nodal displacement, implementing meshless collision detection and a response algorithm to modify the nodal displacement, and generating the displacement of all sampling points of each time step after re-sampling.

The invention relates to a vibration response simulation analyzing method for a rolling bearing with single-point failures. On the basis of a Hertz contact theory, related knowledge about kinematics and kinetics are utilized to establish a five-degree-of-freedom nonlinear vibration mode of a rolling bearing and kinetic differential equations of the rolling bearing while influencing factors like slipping of rolling balls, oil slick rigidity and the like are taken into consideration, according to that the rolling balls change due to contact deformation is caused when the rolling balls roll through partial failures, a partial failure model of the rolling bearing is introduced into the kinetic differential equations of the rolling bearing, and the single-point failures of the rolling bearing are classified according to length-width ratios of the failures and size ratios between the failures and the rolling balls so as to establish different failure shape functions; the differential equations are solved by an ode solver in MATLAB (matrix laboratory) software, and vibration responses of the rolling bearing are simulated when an inner ring, an outer ring and the rolling balls of the rolling bearing are suffered from the single-point failures. By the aid of the vibration response simulation analyzing method, vibration responses of the bearings with failures in different sizes can be simulated. Compared with traditional methods for acquiring vibration responses of failed bearings, the vibration response simulation analyzing method has the advantages that an experimental period is short and experimental cost is saved. The computation for the vibration responses for the failed rolling bearings can lay the foundation of late failure diagnosis for the rolling bearings.

The invention discloses a switch voltage-stabilizing circuit with frequency spectrum shaping function and a method. On the basis of a switch voltage-stabilizer and a method, the frequency spectrum shaping range can be adjusted according to the change of switch frequency, when the switch frequency becomes high, the frequency spectrum shaping range becomes wider; and when the witch frequency becomes low, the frequency spectrum shaping range is reduced. The Switch voltage-stabilizing circuit and the method can effectively reduce the electromagnetic interference.

The invention discloses a method for designing a special wind turbine airfoil profile and a special wind turbine wing profile obtained by the designing method. In the invention, a corresponding airfoil profile can be obtained by expressing the geometrical shape of an airfoil profile with a simple high-order polynomial shape function and altering the coefficient of the shape function polynomial according to a special constraint condition. The special wind turbine airfoil profile is in a Reynolds number range with Re=1*106-3*106, has low-airfoil profile surface roughness sensitivity, higher lift coefficient and maximum lift drag ratio, as well as high lift drag ratio and favorable structural property in a larger attack angle range, and has favorable compatibility and acoustical property compared with other wind turbine airfoil profiles.

The invention discloses a system for processing operation and maintenance (OAM) message on a regular basis and a method thereof for sending, receiving and detecting OAM messages. The system comprises a CPU module for creating a dispatch queue list and a detection queue list of OAM messages, a memory module for storing the dispatch queue list and the detection queue list of the OAM messages, and a network processer module for sending and detecting the OAM messages on a regular basis, respectively. The method comprises the following steps: the CPU module writes an OAM template message into the network processor module; and the network processor module reads the OAM messages according to the address information in the OAM template message, sends or detects the OAM messages, and sends an alarming signal to the CPU module according to the detection result. The system and the method carry out the dispatch/detection of messages through the network processor on a regular basis, so as to reduce the load of the CPU, realize the dispatch/detection of messages on a regular basis by using the traffic shaping function of the network processer module, and support mixed dispatch/detection of multiple types of OAM messages with multiple cycles.

The invention relates to a stereoscopic visual structure three-dimensional distortion full-field measurement method, aiming at solving the problems that the existing N-R method is large in calculating amount, more time-consuming, low in accuracy and poor in robustness, a larger error of the result is produced due to the improper selection of initial value calculated by using a least square method. The method comprises the following processes: 1, collecting an image of a civil experiment test piece so as to obtain initial three-dimensional coordinates of all grid nodes; 2, carrying out subdivision matching on all the grid nodes; if mismatching occurs during the subdivision matching, performing the step 3; if the subdivision matching is correct, obtaining coordinates of the matched grid nodes; 3, carrying out image matching on the mismatched nodes under the condition of large deformation so as to obtain coordinates of the matched grid nodes; 4, constructing a shape function so as to obtain a displacement field; 5, calculating the displacement field obtained in the step 4 by using a Green strain tensor so as to obtain a strain field, and outputting the displacement field and the strain field. The stereoscopic visual structure three-dimensional distortion full-field measurement method is used for the field of structure measurement.

The invention discloses a wing design method considering pneumatic and structural multi-type design variables, which comprises the following steps of: firstly, constructing a parameterized shape by utilizing a three-dimensional category/shape function according to a shape control variable obtained in a pneumatic design process, obtaining Cartesian coordinates of a pneumatic shape point, and generating a smooth pneumatic shape curved surface on the basis of the shape point; By picking up controllable design variables in the wing structure tree, the internal structure arrangement of the wing under a given appearance is realized; By utilizing a neighborhood interpolation technology represented by RBF interpolation and taking an aerodynamic shape as a constraint, efficient follow-up matching of the structure arrangement and the shape parameters is realized; and finally completing the three-dimensional wing design under the coupling effect of the pneumatic/structural subject according to the independent or dependency relationship of different types of design variables on the model tree through a file positioning analysis method. Contents of two subjects of a pneumatic/structure are considered, linkage updating of the model is achieved, and the method has the advantages of being high in universality, wide in application range and convenient to use.

Methods and systems for conducting numerical simulation of structural behaviors in solid mechanics using smoothed particle Galerkin formulation are disclosed. A meshfree model representing a physical domain defined by a plurality of particles is received in a computer system. Each particle is configured for material properties of portion of the physical domain it represents. A smoothed displacement field of the physical domain subject to defined boundary condition is obtained by conducting a time-marching simulation using the meshfree model based on smoothed particle Galerkin formulation. The smoothed displacement field is derived from a set of smoothed meshfree shape functions that satisfies linear polynomial reproduction condition. The set of smoothed meshfree shape functions is constructed by convex meshfree approximation scheme and configured to avoid calculation second order derivatives. The set of smoothed meshfree shape functions is a combination of regular meshfree shape function and a displacement smoothing function for the particles.

The invention is suitable for the field of geometric modeling and provides a fitting optimization method of triangular mesh data and a system for achieving the fitting optimization method. The fitting optimization method comprises the steps of: A, fitting a shape function according to shape characteristics of a three-dimensional model area selected on the original three-dimensional model; B, generating an optimized fitting triangular mesh according to the shape function; and C, splicing the fitting triangular mesh back into a triangular mesh of the original three-dimensional model. According to the fitting optimization method, the selected three-dimensional model area can be subjected to the fitting optimization.

A method is proposed for identifying an anatomical structure within a spatial-temporal image (i.e. a series of frames captured as respective times). A current frame of spatial-temporal medical image is processed using information from one or more previous and/or subsequent temporal frames, to aid in the segmentation of an object or a region of interest (ROI) in a current frame. The invention is applicable to both two- and three-dimensional spatial-temporal images (i.e., 2D+time or 3D+time), and in particular to cardiac magnetic resonance (CMR images). An initialisation process for this method segments the left ventricle (LV) in a CMR image by a fuzzy c-means (FCM) clustering algorithm which employs a circular shape function as part of the definition of the dissimilarity measure.