223 results about "Surface equation" patented technology

The invention discloses a construction method for a digital elevation model for discrete expression of landform on the earth surface. The construction method comprises the following steps of: extracting elevation values of sampling points from the original data of the earth surface and performing spatial discretization on the elevation values to generate a plurality of landform curved surface grid points of the known elevation values of the sampling points; solving the elevation values of the landform curved surface grid points of non-sampling points; calculating first fundamental quantity and second fundamental quantity of each landform curved surface grid point according to the elevation values of all landform curved surface grid points and establishing a landform curved surface equation set by using a Gauss equation and elevation sampling points; solving the landform curved surface equation set by using a Gauss-Seidel iterative algorithm, wherein a simulation result of the digital elevation model is obtained after each iteration is finished; judging whether the simulation result of the digital elevation model meets the accuracy requirement; if the simulation result meets the requirement, stopping the iterative computation and outputting a group of ordered values to express the digital elevation model of a ground elevation entity in an array form, wherein the digital elevation model is used for the discrete expression of the landform on the earth surface; and if the simulation result does not meet the requirement, repeating the iterative computation.

The 3D human limb model building method based on image outline adopts rotating conic curved surface, and has joint points and line segments connecting the joint points to constitute skeleton layer to represent the human limb skeleton structure and rotating conic curved surface to represent the skin layer, with human limb skin deformation being reflected in two deforming parameters. Human limb edge contour information is first extracted from human limb image sequence obtained with binocular stereo vision system, the limb contours of the right and left images in different times are fitted with 2D conic curve, the deformation parameters of 2D conic curve equation are found out, corresponding 3D conic curve equation is found out and made to rotate around the skeleton line to find out the 3D rotating conic curved surface equation, and three spherical bodies and two rotating conic curved surfaces are adopted to draw human limb model. The method is simple and easy to realize.

The invention discloses a dynamic measurement method for train wheel diameter. The dynamic measurement method comprises the following steps of: symmetrically arranging line-structured light vision sensors along a train track and acquiring light bar images of fracture surface contours of a train wheel and an axle; determining an inner side surface equation of a rim through the light bar of the fracture surface contour of the wheel and a straight segment corresponding to the inner side of the rim, determining an axis equation of the axle through the light bar of the fracture surface contour of the axle, and calculating projection coordinates of the inner side surface of the center of a vertex circle of a wheel flange through the intersection of the axis and the inner side surface of the rim; calculating the diameter of the vertex circle of the wheel flange through projection coordinates of the center of the vertex circle of the wheel flange and the vertex of the wheel flange in the inner side surface of the rim; recovering complete fracture surface contour of the wheel through the light bars of the local contours of the inner side and the outer side of fracture surface of the wheel, and calculating the height of the wheel flange; and subtracting the height of the wheel flange twice from the diameter of the vertex circle of the wheel flange to obtain the diameter of the wheel. The invention discloses a dynamic measurement system for the train wheel diameter simultaneously. The dynamic measurement method and the dynamic measurement system provided by the invention can be adopted for non-contact high-precision dynamic measurement of the train wheel diameter.

The invention discloses an obstacle avoiding method and system for a super-redundant flexible robot, and a computer storage medium. The obstacle avoiding method comprises the following steps: modelingan obstacle in a space by using a space super quadratic curved surface equation and a space geometric model respectively; partitioning the space around the obstacle into a safety area, an early-warning area and a danger area by taking the obstacle as the center, wherein a boundary between the safety area and the early-warning area is an early-warning boundary expressed by a super quadratic function, and a boundary between the early-warning area and the dangerous area is a danger boundary expressed by a geometric function; detecting whether the minimum pseudo-distance between the super-redundant flexible robot and the early-warning boundary is less than or equal to zero or not in real time, if so, judging that the super-redundant flexible robot reaches the early-warning area; implementingobstacle avoiding processing on the super-redundant flexible robot; detecting whether the minimum Euclidean distance between the super-redundant flexible robot and the danger boundary is larger than zero or not in real time, and if so, judging that the super-redundant flexible robot avoids the obstacle successfully; finishing the obstacle avoiding plan of the super-redundant flexible robot.

The invention provides a multibeam depth measuring method based on a roll stabilization strategy and a system thereof. The multibeam depth measuring method comprises the steps of: a step 101), forming a receiving wavebeam according to a phase control angle beta after rolling stabilization; a step 102) estimating an echo arriving time T0 by means of amplitude phase information of a signal after wave beam formation; a step 103) determining a synthetic wavebeam angle-of-spread gamma of an echo arriving time according to an emitting surface equation and a receiving surface equation; and a step 104) using the synthetic wavebeam angle-of-spread gamma as an initial incidence angle alpha0 of a sound ray, and utilizing echo time T0 for performing sound speed correction and coordinate homing. The step 101) further comprises steps of: step 101-1) receiving a relative gesture yawing phi, a pitch P and a roll R through a sensor in system operation period; and a step 101-2) operating a receiving phase control angle betan=thetan+R according to the roll angle R, and performing time shift wavebeam forming according to the obtained phase control angle.

The present invention belongs to a filtering method and particularly relates to a ground multiline three-dimensional laser radar point cloud data filtering method. The method comprises: 1, establishing a ground curve surface equation, i.e. firstly, determining a ground point, then establishing the ground curve surface equation, and finally, fitting relevant parameters to obtain the ground curve surface equation; and 2, filtering out a misjudgement point. The ground multiline three-dimensional laser radar point cloud data filtering method has the effects that the ground multiline three-dimensional laser radar point cloud data filtering method is simple in implementation, is fast in operation speed, overcomes a limitation of a conventional airborne laser radar and ground single-line laser radar point cloud filtering method, and effectively solves the problem of separation between the ground point and a non-ground point of ground multiline laser radar point cloud data; and a filtering effect of the point cloud data is improved.

The invention relates to a tracking and positioning method four double-synchronization underwater cooperative targets, wherein the system according to the method comprises a sea-level underwater acoustic buoy measurement array and a measurement mother ship. The tracking and positioning method finishes positioning through the following steps: laying the sea-level underwater acoustic buoy measurement array; transmitting a double-synchronization cooperative acoustic signal by underwater targets; receiving returned data of the sea-level underwater acoustic buoy measurement array by the measurement mother ship through a mounted antenna, and finishing target time delay period matching, target position combined resolving, spherical surface equation set solved value returning and target position depth interval by a base station which is composed of a master control computer and an on-ship comprehensive processor, thereby realizing resolving and display to the target position, and realizing tracking and positioning for each underwater target in an area. The tracking and positioning method has functions of effectively reducing frequency band resource required in tracking and positioning multiple underwater targets, reducing confliction or interference between frequency bands used by a positioning system and other mounted equipment, reducing risk in engineering practice, saving designing cost, effectively reducing calculation amount, effectively reducing power consumption of a hardware circuit, and reducing size of the mounted equipment.

The invention relates to a face gear hobbing cutter design method based on repeatable cutter grinding, which is characterized by comprising the following steps of: (1) selecting basic parameters of a face gear and an involute straight gear meshed with the face gear; (2) according to the point contact face gear transmission gear, confirming the number of teeth of a slotting cutter of the face gear; (3) analyzing and establishing face gear hobbing principle, and establishing face gear hobbing processing coordinate system; (4) according to the face gear slotting cutter tooth surface equation and slotting cutter tooth surface parameters, establishing face gear slotting cutter molded surface fundamental equation; (5) analyzing and studying the face gear slotting cutter molded surface boundary limiting condition, and establishing face gear slotting cutter molded surface parameter numeric area; (6) according to face gear slotting cutter molded surface equation and the slotting cutter molded surface parameter numeric area, discretizing the numerical value of the face gear slotting cutter molded surface equation, and obtaining slotting cutter molded surface integer value point; (7) by meshing discrete digitizing curved surfaces, establishing a face gear slotting cutter worm basic model; and (8) according to the processing accuracy of the face gear, confirming the accuracy grade of the face gear slotting cutter, confirming other cutting parameters of the face gear slotting cutter according to the basic parameters of the face gear slotting cutter, and designing an engineering drawing of the face gear slotting cutter with repeatable cutter grinding. The invention establishes a set of complete face gear hobbing cutter design method, and the designed slotting cutter improves processing accuracy and efficiency of the face gear, has repeatable cutter grinding, prolongs the service life of the cutter, and lays foundation for grinding the face gear.

The invention discloses a high-rockfill-dam transient-rheological-parameter inversion method based on the response surface method.The method includes the steps that a rockfill-dam three-dimensional finite element model is built in combination with dam body material sections and construction grading conditions, the sensitivity of the transient parameters and the rheological parameters of rockfill of the material sections is analyzed, and the transient parameters with the high sensitivity and the rheological parameters with the high sensitivity are selected as to-be-inversed parameters jointly; a material static force model is a Duncan EB model, and a rheological model is a Nanjing-Hydraulic-Research-Institute five-parameter model; the implicit relationship between the finite-element-calculated settling volume and the calculation parameters is represented through a specific-form response surface function, undetermined coefficients of a response surface equation set are solved through several times of finite element calculation, and therefore the nonlinear mapping relationship between the settling volume and the calculation parameters is built.On the bases of the response surface equation, the objective function aims at obtaining the minimum root-mean-square error between the calculated settling volume and the practically-measured settling volume, the transient parameters and the rheological parameters are inversed with the genetic algorithm at the same time, and the obtained set of optimal calculation parameters are the inversion result.

The invention discloses an unmanned plane three dimensional route program method based on a disturbed fluid dynamic system. An unmanned plane low-attitude flight three dimensional route program problem under a complex landform environment containing enemy ground air defence firepower is abstracted into a three dimensional streamline solution problem during fluid obstacle avoidance. Through the method, solution of a fluid equation having complex boundary conditions is not required, a flow field equation generated by obstacle disturbance is directly constructed, and computational complexity is relatively low. The unmanned plane three dimensional route program method specifically comprises steps that: (1), equivalent processing on an landform obstacle, an enemy radar and a ground firepower threat in an unmanned plane flight area is carried out through regular geometries such as cylinders, cones, balls and parallelepipeds to acquire positions and surface equations of the geometry obstacles; (2), point convergence is set at a target point to acquire a flow field flow velocity under the conditions of no obstacle disturbance; (3), when the obstacle position and the obstacle surface equation are known, a flow field flow velocity after obstacle disturbance is constructed according to non-penetrable conditions of the obstacle; (4), integration for the flow field flow velocity is carried out from a start point to acquire an obstacle avoidance streamline from the start point to a target point, and the obstacle avoidance streamline is taken as the unmanned plane flight route; and (5), the unmanned plane is controlled to flight along the programmed route.

The invention discloses a wall-mounted projectile targeting coordinates testing system with a large target surface, which comprises a testing light curtain array of six intersected light curtains, a data collecting and analyzing system, a computer and display processing software. The wall-mounted projectile targeting coordinates testing system adopts an LED array that is arranged in an approximate arc as a light source (L) and forms a lens-typed light curtain detector (D) by coordinating an optical lens with a rectangular slit diaphragm and a photoelectric receiving device, thus forming a single large light curtain detecting scene (S); six array light sources and the lens-typed light curtain detector are hung on a wall with indoor target lanes and arranged in a certain geometrical shape, and the testing light curtain array is formed in the target lane space. When a projectile runs through the light curtain array, the data collecting and analyzing system collects a projectile targeting signal, and according to a spatial curtain surface equation, the targeting coordinates of the projectile running through the target surface are obtained. The wall-mounted structure of the wall-mounted projectile targeting coordinates testing system with the large target surface has convenient protection, avoids the damage of the target body that is caused by a live firing test, greatly saves the space of the target lane, and can successfully solve the indoor target lane testing problem of heavy-caliber projectiles, exuviates bullets and flame tracers.

The invention discloses an ABS real-time rendering method based on NR iterative algorithm, comprising seven steps: 1) inputting the relevant information of ABS to be rendered and calculating the Lipschitz constant, and converting ABS into piecewise Bezier surface patches; 2) using MC algorithm to extract the iso-surface of ABS; 3) calculating the polar surface of ABS in real time; 4) rendering iso-surface to obtain the iso-surface and the initial values of the silhouette contour line of the iso-surface; 5) aggregating the initial values of the silhouette contour line of the iso-surface, according to ABS and the polar surface equation thereof, using NR iterative algorithm to calculate the initial silhouette contours, so as to be obtain the silhouette contour line with floating point precision, and correcting the silhouette contour line; 6) calculating the intersections of each pixel sight line of the silhouette contour line and Bezier surface; 7) by NR iterative algorithm, using adjacent Bezier surfaces information to iterate and get accuracy, so as to obtain right intersections of all light and algebra B-spline surface, and then using the intersections information, the relative location of light source and viewpoint, and the material of a curved surface itself to calculate illumination. The method of the invention can realize the rendering of an algebraic surface for arbitrary frequency.

The invention relates to a calibration method of a linear structured light three-dimensional measurement system. According to the calibration method, a camera is calibrated according to a conventionalmethod, so that the internal parameters and external parameters of the camera can be obtained; coded structured light is projected onto the plane plate of a calibration system through using a projector; the sub-pixel-level coordinates of all lines in a photo which are projected by the projector are obtained by means of image processing or decoding; a line-plane equation is established according to the internal parameters and the external parameters of the camera; the three-dimensional coordinates of all the projected lines on the plane plate are calculated through line-plane intersection points; after the three-dimensional measurement system or the plane plate is moved, the three-dimensional coordinates of all the projected lines after the system or the plane plate is moved are obtained;and surface fitting is performed on each projected line according to the obtained three-dimensional coordinate data, and the surface equations of light surfaces formed by all the projected lines are obtained; and a surface coefficient table is established with the coefficients of the surface equations, and calibration is completed. With the calibration method adopted, the influence of the bendingof a line source can be eliminated. The method has the advantages of simple and quick calibration process, easiness in operation, error small and high calibration accuracy.

The invention discloses a method for achieving scene three-dimensional reconstruction by directly using a phase with a non-linear error. The method comprises the steps of for each given absolute phase value, calculating three-dimensional coordinates of spatial points with the absolute phase value in different depths in a scene area, and carrying gout surface fitting. When reconstruction is carried out, a corresponding surface equation is found according to the phase values of spatial points to be reconstructed, the surface equation and a sight line equation determined by video camera image pixel coordinates are combined, the three-dimensional coordinates of the spatial points are obtained through solution, and therefore the scene three-dimensional reconstruction is achieved. According to the method, the three-dimensional reconstruction is carried out by directly using the phase with the non-linear error, the situation that errors are generated due to the fact that an assumptive model does not conform to actual response situations of a projector in a phase correction method is avoided, and the precision of reconstruction is improved.

The invention relates to a 3D point cloud recognition method based on B-spline surface similarity detection, which is characterized in that the method comprises the following steps of1 modeling and fitting the three-dimensional point cloud by using B-spline surface equation; 2 sampling that fitting B-spline surface by adopt different parameter sampling methods; 3 calculating a similar point by defining a geometric local characteristic of a description point, and carry out point-to-point matching; 4 calculating the equidistant distance between the features of the calculated point pairs; 5 classifying that equidistant transformation types of two point in a point pair; 6 comparing equidistant point pairs after equidistant classification; 7 applying that spectral clustering algorithm to obtainthe local correspond similar parts among the objects, and completing the detection of the similar area; 8 judging whether the proportion of the similarity point cloud and the sampling point cloud islarger than the set threshold value to complete the identification of the whole point cloud. The method of the invention realizes efficient and accurate object recognition.

The invention discloses a method for measuring the contour of a large-caliber aspheric surface optical element at the grinding stage, and relates to the field of aspheric surface optical element measurement. A contour line of the large-caliber aspheric surface optical element at the grinding stage is divided into sections, the number of the sections is set to be M, and overlapping areas need to be reserved between every two adjacent sections and are set to be p1, p2, ..., pm-1. The divided M sections are respectively measured through a measuring device, and the measuring data of each section are obtained. The measuring data of the divided M sections of the large-caliber aspheric surface optical element are spliced based on the multi-body system theory, the Taylor series, the principle of least squares and the data of the overlapping areas. Redundant data, produced when the sections are spliced, of the overlapping areas are removed based on the curvature principle and the aspheric surface equation least square fit method. The contour of all the sections with the redundant data removed is comprehensively optimized, and the overall measuring result of the contour of all the sections is obtained.

The invention discloses an electric inspection robot operating posture control method and device. The control method comprises the steps that an electric inspection robot operating posture linearizedmodel is built, and a sliding mode surface equation is calculated based on the linearized model; a basic sliding mode control law is calculated on the basis of the sliding mode surface equation, a preset lyapunov function and a preset index reaching law, the sliding mode surface equation is processed through a generalized type two fuzzy sliding mode control model built in advance, and a preliminary processing result is output; and the preliminary processing result is substituted into an expression of the basic sliding mode control law, a final sliding mode control law is obtained, and accordingly, control over the electric inspection robot operating posture is completed based on the final sliding mode control law. In this way, through the electric inspection robot operating posture controlmethod and device, the anti-jamming capability of an electric inspection robot in the inspection moving process can be effectively improved, the slip resistance and the obstacle avoidance performanceare good, and accordingly, the safety performance of the electric inspection robot in the inspection moving process is effectively improved.

The invention relates to a foundation pit flexible support active earth pressure calculating method considering action point position. The method overcomes the shortcomings of a coulomb earth pressure calculating method and a rankine earth pressure calculating method. The method includes the following steps: determining accuracy control quantity eps, foundation pit geometric elements and earth body physical dynamic parameters; determining the position coefficient na of the active earth pressure resultant force action point; utilizing the curve y=s(x) to represent the earth body slip surface; determining the minimum value phi min of the function phi (x0,s0) to judge whether phi min is smaller than or equal to eps; finally calculating the resultant force of the slip surface equation and the active earth pressure. The foundation pit flexible support active earth pressure calculating method is line with reality, high in reliability and favorable for reasonable design and scientific management of pit foundation engineering.