56 results about "Curvilinear coordinates" patented technology

It is a common practice with orthodontists in planning treatment for a patient to prescribe dental changes to cure the malocclusion condition of the patient in terms of mesial or distal, buccal or lingual, and occlusal (coronal) or gingival translational displacements; and facial or lingual torque; mesial or distal angulation and mesial or distal rotation displacements. A method and workstation for measuring the dental displacements, or conversely placing the dental elements in desired positions as per the prescriptions for their displacements in a consistent, reproducible and accurate manner is disclosed. A novel orthogonal curvilinear coordinate system is disclosed that enables the measurement of the tooth displacements in conjunction with the individual tooth axes system.

The invention discloses a fingerprint identification method. A modified fingerprint partitioning algorithm is provided in order to overcome the defects of a variance method used for carrying out fingerprint partitioning, an appropriate Log Gabor filter is built to achieve the reinforcement of a fingerprint image, and finally a node relationship representation method under a curvilinear coordinate system is provided. The modified fingerprint partitioning algorithm is provided in order to overcome the defects of the variance method used for carrying out fingerprint partitioning, and the fingerprint partitioning algorithm makes full use of the advantages of a simple algorithm and high calculation speed of the variance method, overcomes the defect that the variance method is easily affected by noise, and obtains a more accurate fingerprint portioning image. The appropriate Log Gabor filter is built to achieve the reinforcement of the fingerprint image, and the node relationship representation method under the curvilinear coordinate system can be effectively matched with deformed fingerprints. The system distinguishes the identification of each person by utilizing the characteristics such as uniqueness and forgery difficulty of the fingerprints, and has the advantages that allograph is avoided and paper is not used.

Modeling and simulation of free and forced structural vibrations is essential to an overall structural health monitoring capability. In the various embodiments, a first principles finite-difference approach is adopted in modeling a structural subsystem such as a mechanical gear by solving elastodynamic equations in generalized curvilinear coordinates. Such a capability to generate a dynamic structural response is widely applicable in a variety of structural health monitoring systems. This capability (1) will lead to an understanding of the dynamic behavior of a structural system and hence its improved design, (2) will generate a sufficiently large space of normal and damage solutions that can be used by machine learning algorithms to detect anomalous system behavior and achieve a system design optimization and (3) will lead to an optimal sensor placement strategy, based on the identification of local stress maxima all over the domain.

The invention discloses a method for rapidly drawing curves multiple times, which relates to the drawing field of vector graphic images. The method comprises the following steps: according to a curve starting point-middle point-ending point sequence, sequentially computing the reciprocal of the length of a connecting line, and taking the reciprocal as the initial value of an interval value of actual drawing points of a curve to be drawn, selecting a value t according to the interval value, and sequentially obtaining the values of curve points according to a multi-time curve formula; judging whether the calculated coordinate is same as the previous coordinate, if so, doubling the interval value, otherwise, storing the coordinate result into the tail of a curve coordinate column, and continuing to carry out calculation and judgment. According to the invention, based on the optimization of a bezier curve algorithm, through controlling the number of times of recursive iteration and excluding similar points, the number of drawing points is reduced so as to improve the curve drawing speed, therefore, an effect of rapidly drawing curves multiple times under a large amount of data can be achieved.

There is disclosed a graphic processing method in which a first figure skeleton apart from an outline of a figure by each equal distance in a central direction of the figure is calculated using at least one of a medial axis and a chordal axis with respect to a figure representing the outline of the object shape reflected in a digital image by a set of points, branch lines to the skeleton from a vertex of the figure in the calculated first figure skeleton are removed to obtain a second figure skeleton, and a curve coordinate system is defined using the second figure skeleton as one coordinate axis and using a distance between the second figure skeleton and the outline of the figure as the other coordinate axis with respect to data obtained by one circulation of the outline of the figure using one end point of the second figure skeleton as a start point and using the other end point as a terminal point to transform the coordinate of points on the outline of the figure into the other coordinate axis of the curve coordinate system.

The invention provides a free curved surface detection method comprising the following steps: a test structure is provided, the test structure has an optical free curved surface, a central position ofthe optical free curved surface is obtained, a plurality of curved lines are lined out on the optical free curved surface, a three dimensional coordinate system is built while the central position isused as an origin of coordinates, curve coordinate data of the plurality of curved lines is obtained, a simulated curved surface is fitted according to the curve coordinate data, the simulated curvedsurface is compared with a theoretical optical free curved surface, and a surface shape error value of the optical free curved surface is obtained. Via the free curved surface detection method, the optical free curved surface can be effectively measured, and detection precision is improved.

The invention relates to a method for high-precision reverse time migration imaging based on severe relief surface ground penetrating radar data. The method comprises the following steps of 1) generating a body-fitted grid discrete relief surface model; 2) decoupling from a Maxwell equation, so as to obtain a Cartesian coordinate system TM (transverse magnetic) wave equation; 3) performing reverse time extrapolation on a receiving wave field in a curvilinear coordinate system from maximum time to zero time; 4) using a sub-wave with setting certain frequency in the curvilinear coordinate system as a forward modeling sub-wave, and performing forward modeling to calculate the positive continuation wave field value at each time; 5) repeating the steps 3) and 4) on the whole profile, removing the low-frequency interference, and finally superposing, so as to obtain the complete migration profile. The method has the advantages that the frequency dispersion effect caused by the step grid at the relief surface in the Cartesian coordinate system is decreased, the interference by the low-frequency noise in the reverse time migration imaging process is favorably reduced, the reflective wave and diffracted wave in the ground penetrating radar data at the relief surface are accurately migrated and regressed, and the underground structure information is truly reflected.

The invention discloses a method for detecting cutter tooth flank surface wear characteristics of a high-feed milling cutter, and belongs to the field of milling cutter detection. Cutter tooth flank surface wear characteristics cannot be completely revealed in the prior art. The method comprises the steps of carrying out cutter tooth flank surface wear testing of the high-feed milling cutter to obtain a cutter tooth flank surface wear state, carrying out structure and cutter tooth error measurement to obtain cutter tooth error distribution characteristics, carrying out cutting vibration testing to obtain variation characteristics of milling vibration signals, carrying out cutter tooth flank surface wear boundary measurement to obtain cutter tooth cutting edge and flank surface wear boundary curve coordinate values, constructing a cutter tooth flank surface wear boundary curve, extracting cutter tooth cutting edge and flank surface wear boundary curve characteristic parameters, and analyzing cutter tooth flank surface wear characteristics to obtain the influence characteristics of the cutter tooth error distribution on cutter tooth cutting edge and flank surface wear and obtain theinfluence characteristics of the milling vibration on cutter tooth cutting edge and flank surface wear. The change characteristics of the cutter tooth cutting edge and flank surface wear along with the cutting stroke can be completely revealed.

The invention provides a machine state acquisition method and system based on image identification; the method comprises the following steps: capturing an image of a machine display in real time; comparing the image with image templates in a template database, invoking the image template matched with the image, and dividing the received image into a plurality of identification areas according to the matched image template; extracting a curve identification area from the identification areas; using a curve coordinate system and coordinate axis scales to determine the curve type in the curve identification area; converting image points in the curve identification area into data, filing the data into a monitoring data table, and sending the monitoring data table to a storage database, whereinsaid data conversion is carried out according to the image point data format and storage format that are defined by the matched image template for the curve type. The method and system can format andoutput the machine state information, are easy in monitoring and low in cost, and can identify and convert different curves into data for easy query.

Described are a method and system for describing a position of an entity in a three-dimensional coordinate system with respect to the reference model. The reference model is of a three-dimensional curved surface defined in the three-dimensional coordinate system. The three-dimensional curved surface is divided into a set of cells. Each cell is a subset of the three-dimensional curved surface and has a curved surface. A three-dimensional curvilinear coordinate system is defined for each cellin the set of cells. The three-dimensional curvilinear coordinate system for each cell has a curvilinear axis that extends along the curved surface of that cell.

Provided is a method for enhancing fingerprint image recognition. The method includes following steps: (1) enhancing a fingerprint image by employing a Gabor filter; (2) calculating the grayscale variance, the variance gradient, the gradient modulus, and the pixel number of the low grayscale grade of a fingerprint grayscale image; (3) introducing a linear combination characteristic of the variance and the gradient modules, selecting a proper threshold according to the relation between the characteristic and a mean value, and preliminarily distinguishing a foreground area and a background area of a fingerprint; and (4) performing segmented processing by employing open-close operation in mathematical morphology to obtain the accurate and complete fingerprint foreground area. According to the method, the fingerprint image is enhanced by employing the Gabor filter, the node relation representation method in a curve coordinate system is finally proposed, the advantages of simple algorithm and fast calculating speed of the variance method are fully utilized, the defect that the method is easily influenced by noise is overcome, and more accurate fingerprint segmentation image is obtained.

A thermal image analysis device and a thermal image analysis method. The thermal image analysis method comprises: according to a plurality of selected thermal image data frames, performing analysis to obtain feature data of a specified frame; and based on frame time-sequence information about the specified frame and the feature data of the specified frame obtained by analysis, forming in a feature curvilinear coordinate system a feature curve formed by feature points or by connecting the feature points. The thermal image analysis device and the thermal image analysis method enable an observer to rapidly and directly know conditions of shot objects corresponding to these thermal image data frames by observing the feature curve.

The invention discloses a big data image curve reverse analysis method. The method comprises following steps of S1: loading an image file, reading image data and acquiring RGB data of the image file;S2: filtering the image file, carrying out binarization operation and converting the RGB data into black color and white color data; S3: extracting curves in the image according to the black color andwhite color data; S4: recognizing reference point coordinate data marked on the image file; S5: selecting recognized two reference point coordinates and constructing coordinate registering; and S6: converting the image curve coordinates into physical coordinates. The invention also discloses a big data image curve reverse analysis system. According to the invention, by use of the image recognition technology and the text recognition technology, curves on the image are automatically recognized, and then, according to coordinate information of the text recognition, coordinate registering is added to the curves, so the coordinates can be converted into the actual physical x, y coordinates according to image pixel coordinates on the curves, the analysis speed is quick and the curve coordinateanalysis is accurate.

The present invention discloses an electronic whiteboard trace tracking method and apparatus. The method comprises the steps of: marking at least one to-be-tracked trace curve; calculating distances between each sample coordinates and curvilinear coordinates of the last point in each trace curve successively, and determining a distance minimum among the distances; setting a distance threshold; and comparing the distance minimum with the distance threshold, and if the distance minimum is greater than the distance threshold, setting the sample coordinates corresponding to the distance minimum as a starting point of a new trace curve, or otherwise setting the sample coordinates corresponding to the distance minimum as new curvilinear coordinates of the trace curve where the curvilinear coordinates corresponding to the distance minimum are located. The apparatus comprises a calculation module and a comparison module which are successively connected. According to the method and apparatus provided by the present invention, the distance threshold and an angle threshold are set for further determination of the calculated distances and a vectorial angle during the electronic whiteboard touch trace tracking process, so that the sample coordinates can be matched on the trace curve more accurately, and tracking errors such as point breaking and track crossing are avoided.

The invention discloses an equipment state detecting method used for a thermal power plant, wherein the method comprises the following steps of: 1) obtaining at least two indexes of equipment of the thermal power plant under different conditions at the same time point; 2) describing a curve by using one of at least two indexes as a horizontal coordinate and using the other index of at least two indexes as a vertical coordinate; and 3) analyzing a relationship between different indexes and / or a relationship between the indexes and other conditions by using the curve. By using the method provided by the invention, the relationship between different indexes and / or the relationship between the indexes and other conditions can be directly obtained through a non-time domain curve diagram; and thereby, an equipment condition can be analyzed and judged more comprehensively and visually, which is convenient for comprehensively judging the whole state of the equipment.

The invention relates to a curved surface measuring device and a measuring method thereof. The measuring device comprises a lanyard and a camera device, wherein, the lanyard is tightly stretched on the surface of an object to be measured and coincides with the profile curve of the object to be measured; the measuring method includes the following steps: step one, a parameter set of the measuring device is determined; step two, the lanyard is tightly stretched on the surface of the object to be measured; step three, a picture of the lanyard is taken and the image is input into a computer; step four, the image of the lanyard is analyzed and curvilinear coordinate data of the centerline of the lanyard are calculated; and step five, the centerline of the lanyard is processed by equidistant offset calculation towards one side of the object to be measured while the offset amount is equal to the semidiameter of the lanyard and then a curve is obtained, namely the profile curve of the corresponding position of the object to be measured. By utilizing a certain amount of the lanyards, the curved surface data of the object to be measured is obtained.

The invention relates to a machining method in the field of machinery, in particular to a three-dimensional cutting machining method for mould machining of optical articles. By the three-dimensional cutting machining method, the position of a tool is corrected by using a more accurate correction term, and the machining precision is higher. In the three-dimensional cutting machining method, an object is machined by a tool which is installed on a central rotating shaft according to designed machining track, wherein the machining position of the tool is a curvilinear coordinate (r, theta) which takes a point on the central rotating shaft as an original point; the position coordinate of the tool is provided with a correction term; the correction term is in direct proportion with sin (2phi); and phi is the included angle between a tangent of the tool to a machining plane to which a working machining point belongs and the horizontal plane. By the three-dimensional cutting machining method, the error of a machining position due to bending of the tool is effectively reduced.

The invention relates to a method of three-coordinate machine measuring a free-form curve. A normal vector of a middle point between two adjacent points is calculated, and is defined as a normal vector of a to-be-measured point, and therefore a problem of a measuring machine without a digital-analog processing capability or a part without a mathematical model of measuring curve coordinate points is solved The problem of the three-coordinate machine of inability of detecting the free-form curve correctly is effectively solved, even when the part does not have the digital-analog model or the three-coordinate machine does not have a model processing module.

The invention discloses a button force measurement curvometer comprising a frame, a workbench, a protective cover, a test host machine and a button test mechanism. The protective cover is provided with a display screen and control buttons. The test host machine is installed in the frame. The button test mechanism is arranged on the workbench. Data tested by the button test mechanism is processed by the test host machine and then reflected by the display screen. According to the scheme of the invention, a to-be-tested product is placed on a product carry tool; and then the button test mechanism tests the to-be-tested product; comfortableness of traditional buttons is quantified; the whole process of button triggering is effectively reflected in the mode of curve coordinates in terms of a push stroke and counterforce. Indexes such as a maximum counterforce, a minimum counterforce and press down displacements are tested so as to provide more convenience for quality management and control in a production process.

The invention discloses a method for measuring the image principal point coordinates and distortion coefficient of a linear target. The method comprises the following steps of: 10, imaging a symmetry axis linear equation of a curve target: fitting the measured object, and calculating the slope of the symmetry axis of the measured object; converting the image points of the measured object to the coordinates of the curve coordinate system; reckoning the coefficient of a parabolic equation; converting the vertex of the parabola to the coordinates of the image coordinate system; and establishing a linear equation of the symmetry axis of the measured object; 20, reckoning the principal point coordinates of the image; and 30, measuring the image distortion coefficient: selecting an image point from the measured object, and obtaining two-dimensional coordinates of the image point in the image coordinate system; establishing a distortion coefficient equation; recovering the distortion so that the measured object becomes a line from a curve; giving the normal equation of the measured object; and establishing the normal equation of the measured object and reckoning the distortion coefficient of the image. The measuring method can be used for measuring the image distortion coefficient and principal point coordinates of the imaged picture.

Provided is a method for calculating side displacement of an arc-shaped underground continuous wall. The method comprises the steps that the arc-shaped underground continuous wall is simplified as a cylindrical shell, a curvilinear coordinate system is established, the relationship between surface strain in the arc-shaped underground continuous wall and the displacement is established according to a classical shell theory, the relationship between stress of any point of the arc-shaped underground continuous wall and the displacement and a balance differential equation of any infinitesimal in the arc-shaped underground continuous wall are determined according to the Hooke's law, a balance differential equation of the arc-shaped underground continuous wall is deduced, and therefore the side displacement of the arc-shaped underground continuous wall is determined according to boundary conditions of corresponding working conditions.

The invention discloses a button force measurement curvometer characterized in that the button force measurement curvometer comprises a frame, a data acquisition system cabinet, an electrical control cabinet and a button test mechanism; the data acquisition system cabinet is installed above the frame; the electrical control cabinet is installed below the frame; the button test mechanism is arranged between the data acquisition system cabinet and the electrical control cabinet; the electrical control cabinet controls running of the button test mechanism; and data tested by the button test mechanism is displayed and reflected by the data acquisition system cabinet. According to the scheme of the invention, through the data acquisition system cabinet, the electrical control cabinet and the button test mechanism, comfortableness of traditional buttons is quantified; and the whole process of button triggering is effectively reflected in the mode of curve coordinates in terms of a push stroke and counterforce. Indexes such as a maximum counterforce, a minimum counterforce and press down displacements are tested so as to provide more convenience for quality management and control in a production process.

The invention discloses a key testing mechanism, and the mechanism comprises a workbench, a portal frame support, an X-ray movement mechanism, a Z-axis movement mechanism, and a product carrier. The portal frame support and a Y-axis movement mechanism are disposed on the workbench. The X-axis movement mechanism is disposed on the portal frame support. The Z-axis movement mechanism is disposed on the X-axis movement mechanism. The product carrier is disposed on the Y-axis movement mechanism. The Y-axis movement mechanism can move back and forth on the workbench. The Z-axis movement mechanism can move left and right on the X-axis movement mechanism. The Z-axis movement mechanism is also provided with a detection module group. According to the scheme of the invention, the comfortableness of a conventional key is quantified, and the whole triggering process of the key is effectively reflected in a mode of curve coordinates through a press stroke and a bounce force. The mechanism detects the maximum bounce force and the minimum bounce force of the key and the downward pressing displacements of all feature points in a press process, thereby facilitating the quality control of a production process.

The invention discloses a curvature-continuous path planning method, system and equipment. The method comprises the following steps: acquiring an original path point, generating a natural parameter curve with a continuous curvature change rate, and defining a coordinate frame used for local planning; obtaining the pose of a robot in a Cartesian coordinate system, and obtaining corresponding point of the robot in the coordinate frame based on the pose; calculating the pose of the robot in a curve coordinate system with the coordinate frame as the horizontal axis; sampling a plurality of target points under the curve coordinate system, calculating a parameter curve of a plurality of paths by using the sum of the plurality of target points as a boundary condition, and converting each path from the curve coordinate system to the Cartesian coordinate system; and evaluating each path by adopting a loss function, and taking the path with the minimum loss as the current optimal path. The curvature continuity of the planned path can still be ensured by planning in the curve coordinate system, and local obstacle avoidance can be realized while the global navigation path trend is complied.

The invention discloses an implement method for 3D virtual reality page turning. The implement method for 3D virtual reality page turning comprises the steps of obtaining the coordinates of a known separation point when the coordinates of a finger separation point are received, calculating the coordinates of a lower locus point of a page corner, the coordinates of an upper locus point of the page corner and the coordinates of an upper locus point of an extra page corner according to the received coordinates of the finger separation point and the obtained coordinates of the known separation point, inputting the coordinates of the separation points into a 3D spatial Bezier curve equation according to the conditions to calculate the page turning curve coordinates, calculating the page turning curve texture coordinates according to the texture coordinate rule of OpenGL, and carrying out rendering according to the separation points, the page turning curve coordinates and the page turning curve texture coordinates.

The invention provides a power adjusting system of a plunger type duplex tilting tray variable pump. The system comprises a pressure sensing transmitter set, the plunger type duplex tilting tray variable pump, a power adjusting module, a computer host controller and an engine. A measurement numerical value of the pressure sensing transmitter set is transmitted to the computer host controller; the computer host controller adjusts the plunger type duplex tilting tray variable pump through the power adjusting module; the computer host controller comprises a three-dimensional dot-matrix type MCU constant power controller composed of a single chip microcomputer; curvilinear coordinate parameters with lattice parameters composed of three-dimensional arrays are searched according to numerical numbers, collected by the pressure sensing transmitter set, of pressure output by the plunger type duplex tilting tray variable pump, then the power adjusting module is controlled to adjust flow output by the plunger type duplex tilting tray variable pump, so that power, absorbed by the plunger type duplex tilting tray variable pump, of the engine keeps constant, the plunger type duplex tilting tray variable pump is adjusted in a mode approaching to a real constant power curve in the practical work process, the capacity of the engine can be played fully, the flow of the plunger type duplex tilting tray variable pump when a system overflows can be lowered greatly, power loss is reduced and fuel oil is saved.

The invention discloses a deformed fingerprint matching method based on a curvilinear coordinate system and transference of reference minutiae. The method comprises the following steps: (1). a fingerprint image is represented that I(m*n),O(i, j) belonging to [0, pi) is the local ridge orientation at the pixel (i,j), and each minutia in the fingerprint image I is described by coordinate, direction and type; (2). X axis and Y axis of the curvilinear coordinate axes are extracted from each minutia by taking each minutia as an origin based on a ridge mode and an orientation field of the minutiae; (3). scales of the curvilinear coordinate axes are computed; (4). the coordinate relation between every two minutiae mi and mj are computed; and (5). The minutiae are matched by the method based on the transference of the reference minutiae: provided that a template fingerprint image T and an input fingerprint image Q contain p minutiae and q minutiae respectively, C(T) equals (Ci, j<T>), C(Q) equals (Ci, j<T>), wherein, i is not less than 0 and j is less than q; T and Q are matched by utilizing the minutiae of the C(T) and C(Q) pair to compute the matching minutiae. The method has the advantages of high identification accuracy rate, high efficiency and simple algorithm.