54 results about "Projection Principle" patented technology

The invention provides an unfolding method for restoration of a fisheye image, and relates to the restoration and correction of a fisheye image based on the equidistant projection principle of a spherical model. The method comprises the following steps of: establishing a spherical imaging model, consistent with the equidistant projection principle, of the fisheye image(including the establishment of a fisheye image coordinate system and a camera coordinate system); establishing an unfolded window coordinate system and an unfolded image coordinate system, and calculating the relationship between the two coordinate systems; establishing the relationship between the unfolded image coordinate system and the camera coordinate system; calculating the relationship between the unfolded image coordinate system and the fisheye image coordinate system; and finally obtaining a whole image unfolded in any specified direction. The method can overcome the defect of the methods that can unfold only the top part information of fisheye lenses and can not only restore the top part information, but also restore all information in any direction, The method can be applied to the equidistant projection principle based fisheye lenses as well as other projection principle based fisheye lenses, so that the method has a wide application prospect in fields of image tracking, monitoring, video conference and the like.

The invention discloses a soft measurement method for detecting the temperature distribution of billet inside a metallurgy heating furnace. The method selects a plurality of key variables affecting the temperature distribution of billet inside the furnace to form a process detection variable set, applies partial least square technology based on multivariate statistics projection principle to establish a soft measurement model between the temperature distribution variable of billet of the metallurgy heating furnace and the process detection variable and determines the optimal pivot numbers through cross check technology. The method avoids complicated process mechanism analysis, has convenient field implementation and high soft measurement precision and is particularly applicable to such industrial occasions similar to the temperature distribution detection inside the metallurgy heating furnace with high dimension and very rich process data. The soft measurement method can be used for monitoring in real time or directing actual production, improve the product quality, increase the yield and realize the energy conservation and consumption reduction of the metallurgy heating furnace overall.

The invention provides a point cloud initial registration method combined with a two-dimensional sequence image in order to solve the problem that an existing algorithm is difficult to accurately register point clouds large in initial position difference and small in overlapping area. The method comprises the following steps: acquiring a real object surface grayscale image and three-dimensional data based on a mobile three-dimensional measurement method; positioning the position of the camera in a point cloud local coordinate system according to a perspective projection principle; and obtaining a transformation matrix from the point cloud to a corresponding camera coordinate system, taking the feature points of the grayscale images and the matching points thereof as matching pairs, globally optimizing the camera external parameters by reconstructing the sequence images, and realizing initial registration of the point cloud according to an initial registration formula. According to themethod, point clouds with large initial position differences and small overlapping regions can be correctly registered, and the robustness and the registration efficiency of the registration process can be remarkably improved.

The invention discloses an interference suppression method for a multi-user MIMO collaborative relay system, mainly solving the problem that each user has multiple antennas in a common-channel multi-user relay system. The interference suppression method comprises the steps that: a user determines a beamforming vector by adopting a signal space alignment method, and sends out a signal after weighting the signal with the beamforming vector in a multiple-access time slot; a relay constructs a precoding matrix based on an orthogonal projection principle, and amplifies and sends the received signal after precoding; the user receives the signal and suppresses interference signals between user pairs by adopting a decoding vector, and conducts a maximum likelihood detection to obtain the needed signal. According to the invention, a network transmission rate and a resource utilization rate are improved, diversity gains of multiple antennas are achieved, channel fading resisting capability of the system is enhanced, and a bit error ratio is decreased. Further, the interference suppression method of the invention can be applied in a transmission mode under centralized management and control of a wireless ad hoc network and base station, wherein data can be exchanged directly through user-relay-user mode.

The invention discloses a substation three-dimensional live-action monitoring stationing method based on nonlinear parameter optimization calibration. The method comprises the steps that a three-dimensional substation physical model is imported; an area coverage to be monitored is acquired based on the model, and the type and the physical parameters of a camera are determined; a position hypothesis test based on the area to be monitored is carried out: three monitor points are selected on the boundary of the area to be monitored, and the coordinates of the points are calculated; based on the relationship between a model coordinate system and a camera coordinate system, the physical position and the orientation of the camera in a three-dimensional space are derived; hypothesis verification based on camera object positioning is carried out: based on a perspective projection principle, the relationship between the imaging picture of camera motion trajectory and a covered three-dimensional space entity area is analyzed; and through visualization, the three-dimensional space entity area of camera projection and the area to be monitored is compared. Compared with a traditional method, the method has the advantages that the monitor area of the same size is ensured, and at the same time the system configuration is optimized, and unnecessary device input is saved.

The invention discloses a novel asphalt pavement damage comprehensive intelligent detecting vehicle which comprises a vehicle body, a pavement damage detecting instrument, a pavement deformation detecting instrument, a GPS (Global Positioning System) device and a mileage distance measuring device, wherein the pavement damage detecting instrument is installed at the front end of the vehicle body and is used for acquiring pavement damage information by shooting pavement images; the pavement deformation detecting instrument is installed at the tail end of the vehicle body and is used for determining pavement deformation information by the deformation of at least three beams of parallel laser rays and at least three beams of laser rays vertical to the parallel laser rays projected on the pavement; the GPS device is installed at the top part of the vehicle body; and the mileage distance measuring device is installed on the wheel shaft of the detecting vehicle. According to the invention, continuous or interval shooting is carried out on the pavement at day and night; a structured light projection principle is used for quickly detecting the three-dimensional deformation of the pavement, and effectively overcoming the interference of sunlight in the daytime; and the pavement damage regions are positioned, the accurate pile number position of the pavement damage relative to a route is obtained, and the damage and deformation data of the asphalt pavement can be simultaneously obtained at a normal running speed.

The invention discloses a maximum likelihood direction-of-arrival direction estimation method based on a quadratic sum and a semi-definite program and relates to the array signal processing field. The method comprises the following steps of step1, according to a receiving signal model of an array antenna and a maximum likelihood criterion, establishing a direction estimation optimization problem, and using a coordinate transmigration method and an alternative projection principle to convert the problem into a series of optimization subproblems; step2, substituting a direction angle variable in the subproblems as a real number variable t, and constructing the subproblems into a fractional polynomial optimization problem; step3, using a quadratic sum characteristic to convert the polynomial optimization problem into a semi-definite program problem so as to solve; and step4, using an acquired optimal solution to construct a unitary high order equation group about t and solving, wherein an original direction variable corresponding to a solution value t is signal-source direction-of-arrival estimation; and when iteration convergence is generated, acquiring a signal-source direction of arrival. The method is mainly used for an array signal processing scene so as to solve a problem that a calculated amount of maximum likelihood direction-of-arrival estimation is large in the prior art.

The invention provides a calibration method and calibration system of a fish eye camera, and a calibration plate. The calibration method of a fish eye camera is characterized in that a fish eye camera shoots the characteristic pattern of a cylindrical stereo calibration plate, calls a nonlinear optimization algorithm, inputs the coordinates of characteristic points, and obtains parameters of the fish eye camera, based on a mathematical model for calibration; the characteristic pattern is obtained based on a spot pattern and based on a fish eye projection principle, and is arranged on a cylindrical surface; the calibration method of a fish eye camera can obtain the intrinsic parameters of the fish eye camera, by means of only less times of imaging of the calibration plate, such as one time, so that the intrinsic parameters of the fish eye camera can be used for correction of distortion of the fish eye camera.

The invention relates to a three-dimensional visual measuring system based on high-speed triangle wave fringe projection principle. The system mainly comprises a DMD (Digital Micro-mirror Device) projector, a high speed industrial camera and a computer, wherein the DMD projector consists of a DMD micromirror array, an LED (Light Emitting Diode) light source, a triggering circuit and a main controlcircuit. During the work, a black and white pattern is projected at the surface of an object to be measured by the DMD projector; meanwhile, the high speed camera is triggered for performing image shooting. The computer performs data processing and three-dimensional resolving on the shot image; the morphology information at the surface of the object to be measured is obtained. A specific black and white pattern is projected; a plurality of patterns are superimposed into a triangle wave fringe; the high-speed projection is realized. Compared with that of a traditional sinusoidal grating projection method, the speed is improved by 12 times or higher. Meanwhile, a triangular wave phase resolving method of a phase shifting method is used; after the provided high-speed measuring principle is concretely implemented, the high-speed three-dimensional measurement can be realized.

The invention provides a high-relief stone inscription cultural relic rubbing relaying technology. The technology is carried out in the manner that the orthographic projection principle and the painting art are combined and comprises the steps of paper feeding, paper smashing, inking, uncovering, bonding and repairing. The problem of the high-relief work rubbing relaying is creatively solved in practice, the condition that in the prior art, only characters are rubbed through the rubbing relaying technology while images and patterns are lacked is changed. Scientificity, systematicness and integrity of ancient stone inscription culture information are well embodied. An ancient sculpture work is successfully converted to a plane painting text from three-dimensional convex and concave. A batch of excellent Buddhism paintings are recovered in the Gong county grotto, the extremely precious real evidence is provided for studying the chinization process of the eastward transmission of western sciences of the Buddhism art in the Northern and Southern Dynasties, and the vacancy of the rubbing history in all ages is filled up. In addition, a brand new method is brought to the high-relief stone inscription cultural relic rubbing relaying technology, and economic development value is high.

The invention relates to a high spectral image end member automatic extraction method. Based on the phenomenon that high spectral data possesses characteristics approximate to low dimensional manifold data, and by employing the orthogonal projection principle, the method comprises expanding extracted end members to an orthogonal projection operator; analyzing the p norm value of each image element vector after projection; and automatically estimating end member quantity so as to extract end members. The method can automatically extract end members, increase the decomposition automatic degree of mixed image elements to a certain degree, and reduce manual intervention; the method possesses stronger robustness, and can still accurately estimate end member quantity at a low signal to noise ratio, and extract end members.

The invention discloses a perspective projection-based method for measuring spatial rotary moving parameters of a circular object, belonging to the field of rotating parameter measuring of the circular object. The method comprises the following steps: firstly calculating an effective focal distance of a camera; obtaining a change of a diameter of the circular object by using a method of geometricreasoning based on the perspective projection principle of the camera when a rotary motion occurs in different rotating modes, i.e. in-plane rotating and non in-plane rotating; calculating a rotatingangle of the object and judging a rotating direction; and then calculating a rotating angular velocity of the object. The method disclosed by the invention has the advantages of high measuring accuracy, good reliability and easiness in realizing and is particularly suitable for measuring three-dimensional rotary moving parameters of objects based on image analysis.

The invention relates to a method used for measuring the area and the shape of a forest gap in the field of forestry and ecology which includes the steps of: using a digital camera with a fish-eye lens to vertically upwards shoot a semi-spherical image at a certain position in the forest gap; measuring the parameters of the forest gap; processing the semi-spherical image and recording the coordinate of the highest point of the edge wood of the forest gap in the image; calculating the area and the shape of the forest gap according to the projection principle of the fish-eye lens as well as each coordinate point and the parameters of the forest gap. The invention firstly provides a method for measuring the shape of the forest gap and fills in the blank in the researching field. The method can be adopted to fast measure the area and the shape of the forest gap, thus avoiding the effect of anthropic factors in the existing method and improving the estimation precision of the area of the forest gap; the method is easily operated and the measuring result is not affected by the measuring position.

The invention relates to a point position association method of ipsilateral aberrant breast molybdenum target images. The method has the advantages that lesion points in a CC-view compressed image aresubstituted into a mathematical model to obtain the positions of the rotated lesion points on an MLO-view compressed image which is ipsilateral aberrant to the CC-view compressed image, the CC-view compressed image with the lesion points and the MLO-view compressed image are used as the input images to recover a three-dimensional breast image in a free state, the lesion points of the CC-view compressed image are recovered into a lesion curve formed in the free state, MLO angle rotation is performed on the three-dimensional breast image and the lesion curve, MLO-view compression is performed on the rotated three-dimensional breast image and lesion curve, and the projection principle is used to project the lesion curve to the MLO-view compressed image to obtain the positions of the lesion points on the MLO-view compressed image. By the method, correspondence of the same lesion points of the two images is achieved, the point position association relationship of the ipsilateral aberrant breast molybdenum target images is built, and a doctor can be helped to comprehensively analyze the lesion points.

The invention relates to a motion planning method for additional shafts in working units of a gantry hoisting robot. On the basis of addition of the gantry external linear additional shafts, redundant working units linked with six joints of the industrial robot, and a fixed working platform, two of a section of machining path points monotonously changing along a motion direction of each slide table which is fixedly connected with a robot base on the corresponding additional shaft are manually selected as end points of a preferred interval. A movable initial point of each slide table is obtained through a projection principle of a straight line from a point to a space. A movable middle point and a movable termination point of each slide table are obtained through setting a step length of the slide table, that is, distances from movable positions corresponding to the machining path points in the corresponding preferred interval, of each slide table, to a zero point of the corresponding additional shaft, are obtained. Movements of the slide tables are in preference to motions of the joints of the robot when the robot machines the path points in the preferred intervals. The method is capable of reducing the change amplitudes of the joints of the robot, so that the motion of the robot is continuous and stable; and the method is suitable for machining the continuous and dense path points by the robot.

The invention provides a color three-dimensional imaging system based on three cameras and a calibration method thereof, and the method comprises the steps: respectively collecting a first image, a second image and a third image containing a target through a left camera, a right camera and a color camera, and obtaining pixel coordinates of a mark point in the first image, the second image and thethird image; calibrating a binocular system consisting of the left camera and the right camera by utilizing a backward projection principle of the left camera and the right camera according to pixel coordinates of the mark point in the first image and the second image to obtain a first calibration parameter; and calibrating the color camera by utilizing a forward projection principle of the colorcamera according to the external parameter matrix of the left camera and the pixel coordinates of the mark points in the third image to obtain a second calibration parameter. An imaging model is reconstructed for the left camera and the right camera through backward projection, and binocular system calibration is completed. Forward projection is utilized to complete color camera calibration on thecolor camera reconstruction imaging model, so that the calibration optimization objective function is consistent with the color three-dimensional reconstruction process, and the calibration precisionis improved.

Disclosed are a multifunctional three-side projection box and a projection display method. The multifunctional three-side projection box consists of multiple projection sides, a top plate and a physical model. The projection side H, the projection side V and the projection W are perpendicular one another. The top plate is fixed above the projection side V and the projection side W. A projection side V1 is movable and can be fixed between the projection H and the top plate and perpendicular to the projection side H. The physical model is provided with multiple small holes used for tying hanging lines, and the hanging lines are fixed on the top plate through plugs. By adjusting the number and the length of the hanging lines on the physical model and the positions on the top plate of the hanging lines and observing the physical model from the direction perpendicular to the projection sides, linear and planar projections of different positions of the projection sides and three-side projection of a body can be displayed, and the right-angled projection principle, straight lines of special positions on a general position plane and projection relations of the surface changing method can be displayed. The multifunctional three-side projection box can fully display projection, is convenient to use and capable of helping students learn projection relations in geometric drawing classes.

An object three-dimension surface shape measuring system and a method based on a fringe projection principle belong to the object three dimensional measuring technical fields. The method fixes a miniature optical projection element on a mobile phone flash lamp cover, so a sine fringe raster built in the optical projection element can be projected on the surface of a to-be-measured object when theflash lamp is opened; in addition, the intelligent mobile phone can gather deformed fringes obtained by modulating the surface of the to-be-measured object; a data processing module can process the data so as to display the object three dimensional surface shape information on the intelligent mobile phone display screen. Compared with a conventional three-dimension surface shape measuring system based on fringe projection, the measuring system is economical and portable; the measuring method is simple in operation, fast in measuring speed, thus applying the three-dimension surface shape measuring system in daily lives.

The invention provides a seismic frequency spectrum reconstruction method, and relates to the field of geophysical exploration. The method comprises the following steps: (1) obtaining a seismic signal x (t) and carrying out Fourier transformation on the seismic signal x (t) to obtain an amplitude spectrum X (f) of the seismic signal; (2) selecting a wavelet spectrum formula and picking up an original value of a peak frequency m of a wavelet spectrum; (3) calculating a peak amplitude a of the wavelet spectrum; (4) according to a maximum matching projection principle, carrying out local optimization on the peak amplitude a of the wavelet spectrum and the peak frequency m of the wavelet spectrum to obtain the locally-optimal peak amplitude of the wavelet spectrum and peak frequency of the wavelet spectrum; (5) substituting the peak amplitude a of the wavelet spectrum and the peak frequency m of the wavelet spectrum into the wavelet spectrum formula to obtain an amplitude spectrum of wavelets; and using the locally-optimal peak amplitude a of wavelet spectrum and peak frequency m of the wavelet spectrum to reconstruct a seismic spectrum X(f) to obtain a reconstructed seismic frequency spectrum and residuals.

The invention discloses an intersection safety auxiliary system based on holographic projection and a control method thereof. The control method comprises steps that: a sound wave velocity measurementprinciple is adopted to determine whether a vehicle falls into a dilemma area, and a holographic projection principle is combined for speed guiding and warning; a ground lamp group arranged under a pavement marking is consistent with a traffic signal lamp for controlling passing of pedestrians, and the green lamp of the ground lamp group is controlled to flicker before the green lamp of the traffic signal lamp is about to turn; an auxiliary lamp group paved on a left side canalization line of each lane is consistent with the traffic signal lamp for controlling the passing of the pedestrians,and the green lamp of the auxiliary lamp group is controlled to flicker before the green lamp of the traffic signal lamp is about to turn. The invention is advantageous in that strong practicability is provided, intersection delay is reduced, and the cooperation between the pedestrians and the vehicles is effectively facilitated, and reasonable speed guidance is given to the vehicles, which are about to enter the dilemma area, so as to help drivers to avoid falling into the dilemma area by controlling the speed change.

The invention provides a cylindrical surface back projection transformation method. According to a perspective projection principle, a line on a cylindrical surface is projected to a secondary curve. Imaging characteristic of the cylindrical surface is represented through fitting the secondary curve. Correction is performed in the vertical direction and the horizontal direction, and furthermore cylindrical image back projection transformation is realized. When a target object displaces in a front-and-back direction and a left-and-right direction relative to a camera, imaging characteristic change is adapted through correcting the coefficient of a secondary curve, and calibration is not required. Experiment results prove a fact only one calibration is required and a requirement for image transformation in movement of the target object in a small range can be satisfied. Scene adaptability is improved. Furthermore the precision of the cylindrical surface back projection transformation method is equivalent with that of a traditional method.

The invention relates to a handmade soap model gradual change technology. The handmade soap model gradual change technology comprises steps as follows: 1), making of a first draft: a graphical solution to be represented finally is made with 3D making software, the graphical solution is taken as a core, and double graphs are obliquely extended and amplified in the upward and downward directions in animation and projection principles; 2), 3D printing: 3D printing equipment is used to print a high-precision sample; 3), molding: the 3D printed sample is made into an edible silicone auxiliary mold, and the mold is used for making a soap center body; 4), making of a main soap body: a soap liquid is poured into the auxiliary mold, and the mold is removed after the soap liquid becomes the solid soap center part through periodic curing; 5), forming: the main soap center body is put in a square main mold, the pearl white soap liquid is poured into the square main mold to fill the peripheral unoccupied parts, and demolding forming is performed after the soap liquid is periodically cured and becomes solid. A unique technology is adopted, and the loss of handmade soap is reduced in the use process, so that a combination of an another model is displayed after the consumed surface models gradually reach the center position of the soap and realize butt joint, and the user experience is enhanced.

The invention provides a method for improving the target scoring precision in bow-and-arrow image scanning target scoring, which comprises the steps of firstly installing and debugging a target scoring system, and enabling an arrow target imaging straight line to be mutually parallel to a camera view horizontal center line through adjusting a first camera and a second camera of the target scoring system; then constructing a first rectangular coordinate system and a second rectangular coordinate system, building a first straight-line equation in the first rectangular coordinate system, and building a second straight-line equation in the second rectangular coordinate system; unifying the first straight-line equation and the second straight-line equation to the same rectangular coordinate system through coordinate transformation so as to acquire coordinates of an actual arrow landing point; and finally calculating the straight-line distance between the actual arrow landing point and a first assistant positioning member, comparing the straight-line distance with the spacing of each ring of an arrow target, and determining a target score of the arrow. An arc projection principle is adopted to determine the actual position of the arrow landing point, and thus the target score is measured and calculated, so that the target scoring precision is improved. In addition, the method is low in implementation cost.

The invention applies to the technical field of medical instruments and relates to a full-scale breast measurer and a breast symmetry assessing method based on the same. The full-scale breast measurer comprises a fixing frame, a travel suspension is mounted below the fixing frame, and a laser generator, a laser digital-display measuring scale and a light generator are mounted on the travel suspension. The invention also provides the breast symmetry assessing method based on the full-scale breast measurer; the breast symmetry assessing method comprises: allowing a human body to stand still, measuring sizes of breasts, selecting suitable implants to reconstruct the breasts, turning on the light generator to irradiate the healthy breast and the affected breast, taking photos, and performing symmetry analysis on the breasts to obtain similarity of the heathy and affected breasts. A stable measuring platform is constructed herein using the simple mechanical principle, precise measurement is performed by means of a laser measuring technique, three-dimensional information of the breasts is converted into two-dimensional information according to the point light projection principle, and the device and method which are simple, practical and accurate and include three-dimensional information of breasts are clinically provided.

The invention relates to a method for measuring position information of a carrier relative to the sun by using a sun sensor, the method is based on the new sun sensor for measuring the velocity difference of the edge of the sun, and the new sun sensor can simultaneously acquire the apparent direction of the sun and the included angle theta of the apparent direction of the sun and the rotation axisof the sun. The sun sensor uses four spectrometers to measure the velocity difference between two sets of mutually-perpendicular points on the disk edge of the sun, and obtains the apparent directionof the sun from the direction of the central axis. Based on a solar rotation model and a projection principle, a function relationship between the velocity difference and the included angle theta ofthe apparent direction of the sun and the rotation axis of the sun is established, and the included angle theta can be solved. Compared with a traditional sun sensor which can only provide the attitude information of the carrier relative to the sun, the sun sensor can also provide the position information of the carrier relative to the sun.

The invention discloses a ground object height calculation method based on a panoramic picture. The method comprises the steps of firstly, obtaining a starting point and an end point for marking the height of the object to be solved from the picture, wherein the point of the bottom of the object should be on the ground or quite close to the ground; then calculating the three-dimensional point position of the point of the bottom based on the projection principle, then three-dimensional point positions of the point of the top, and finally calculating the height of the object. According to the method, data processing difficulty can be reduced, the calculation speed can be improved, and the application cost can be reduced.

The invention relates to a motion planning method for additional shafts in working units of a gantry hoisting robot. On the basis of addition of the gantry external linear additional shafts, redundant working units linked with six joints of the industrial robot, and a fixed working platform, two of a section of machining path points monotonously changing along a motion direction of each slide table which is fixedly connected with a robot base on the corresponding additional shaft are manually selected as end points of a preferred interval. A movable initial point of each slide table is obtained through a projection principle of a straight line from a point to a space. A movable middle point and a movable termination point of each slide table are obtained through setting a step length of the slide table, that is, distances from movable positions corresponding to the machining path points in the corresponding preferred interval, of each slide table, to a zero point of the corresponding additional shaft, are obtained. Movements of the slide tables are in preference to motions of the joints of the robot when the robot machines the path points in the preferred intervals. The method is capable of reducing the change amplitudes of the joints of the robot, so that the motion of the robot is continuous and stable; and the method is suitable for machining the continuous and dense path points by the robot.

The invention provides a lens increasing the beam propagation scattering convergence angle and a manufacturing method thereof. The lens comprises a curved surface. Groups of concave-convex lenses are arranged on one side of the curved surface. In each group, a concave lens is connected with a convex lens. A number of regions are arranged on one side of the curved surface, and a group of concave-convex lens is arranged in a region. The radial height of each concave lens is greater than the radial height of each convex lens in each group. According to the invention, a geometric projection principle is combined to analyze the incident angle variation distribution of a beam on an incidence surface. The incidence longitudinal section high-order continuous curve is simulated to design a reasonable concave / convex lens combination. The beam diffusion effect is verified through optical software simulation. The incidence surface is constantly adjusted for optimization. An infrared light source made of PC is used to provide the beam, wherein the wavelength of the infrared light source is 960nm. Experiments are carried out on designed lens, and then optimization design is carried out. Finally, the FFT.Ken lens is provided.

The invention relates to the technical field of automobile lamp illumination, in particular to an intelligent headlamp based on the projection principle. A light source constituting the headlamp is formed by arranging multiple LED lamps horizontally, light rays emitted by all the LED lamps are emitted by a reflector and a lens and then reach a light distribution screen and form continuous illumination areas, the LED lamps are turned on and turned off independently, and after any LED lamp is turned off, a dark region appears in the illumination area corresponding to the LED lamp to be used for being kept away from other vehicles or pedestrians. The headlamp is formed by multiple LED lamps, the LED lamps can be turned on and turned off according to different road conditions, influences on other vehicles or pedestrians can be avoided, the view of the driver of a current vehicle cannot be influenced, and traffic safety is further improved.

The invention provides a building surveying and mapping method and system based on a projection principle. According to the method, the projection principle is taken as the basis, a GPS positioning system is used for auxiliary computation of an orthographic projection time and a solar altitude at a given time and place, and the data measurement of the horizontal distance, height and the like of irregular points, surfaces and the like on the same horizontal elevation of abuilding is achieved by measuring the position of a plane projection point based on this.