1038 results about "Reference surface" patented technology

The invention provides a plate heat exchanger which is characterized in that a first plate sheet comprises a first trough and a second trough which are adjacent, the first trough and the second trough are sunken downwards relative to the same reference plane P1, and the depth of the first trough is larger than that of the second trough; the second plate sheet comprises a first wave crest and a second wave crest which are adjacent, the first wave crest and the second wave crest protrude upwards relative to the same reference plane P2, and the height of the first wave crest is larger than that of the second wave crest; the first wave crest and the first wave trough are mutually contacted and fixedly welded; the second wave crest is at least partially opposite to the second wave trough, and the height of the second wave crest is unequal to the depth of the second wave trough. According to the plate heat exchanger, through the structural design, the surfaces of the two heat exchange plates forming the inter-plate flow channel have different flow resistances, and flow channels with asymmetric sections are formed between the plates, so that the turbulence degree is larger when fluid flows through, and the heat exchange performance of the heat exchanger is improved.

The invention provides a production control method and system based on SPC alarm linkage process locking, and relates to the technical field of quality management and control, and the method comprises the steps: deploying an SPC sensing node used for collecting technological parameters at a cutting edge position where a machining tool of production equipment is in contact with a workpiece, or at a contact point where a probe of online measurement equipment is in contact with the surface of the workpiece; the method comprises the following steps: acquiring process parameter data of a key production process in real time through an SPC sensing node deployed at a cutting edge position or a contact point; inputting the process parameter data as real-time data or small sample expansion data into an SPC judgment engine; and performing statistical process control analysis on the real-time data or the small sample expansion data through an SPC judgment engine so as to model data clusters which are densely distributed and have stable parameters in the data into a virtual reference curved surface representing a normal state domain. According to the invention, the accuracy of abnormity determination can be improved, and timely management and control of quality abnormity and minimization of production loss can be realized.

The invention discloses a vibration monitoring and displacement identification method for a towering steel structure based on machine vision, and relates to the technical field of towering steel structures. Comprising the following steps: S1, visual acquisition and reference calibration: arranging visual acquisition equipment in the height direction and the circumferential direction of the towering steel structure according to mechanical characteristics of a vertical stiffness mutation region and a dynamic response sensitive part of a geometric asymmetric distribution characteristic of the structure; a three-dimensional coordinate system is established based on a structure installation reference surface, fixed reference monitoring points are arranged in a tower foot symmetric area and a mast antenna root, three-dimensional coordinate data of the reference points are synchronously collected, the collection range completely covers a node concentration area and a key stress part of a structure transparent area, and a continuous image sequence of the structure surface is captured in real time; the resolution and the sampling frequency of the visual acquisition equipment are determined according to the inherent frequency of the structure and the vibration response characteristics, and calibration is completed through reference point coordinates after the equipment is installed; s2, carrying out image preprocessing and feature enhancement; S3, carrying out feature point extraction and trajectory tracking; S4, carrying out vibration displacement calculation and twin fusion; and S5, carrying out multi-source verification and structural state linkage treatment.

The invention belongs to the technical field of image processing, and particularly relates to a PCB plug hole flatness detection method and system based on 3D point cloud data, and the method comprises the steps: obtaining the original 3D point cloud data of a PCB, and intercepting a plug hole center and a local point cloud block according to a design file; a copper ring point cloud set is extracted, and the fitting weight of each sampling point is calculated based on the distance from each sampling point in the set to the center of the plug hole, the unit normal vector of the sampling point and the original height of the sampling point; performing weighted least square fitting on all the copper ring point clouds by using the fitting weight to obtain a virtual reference curved surface; extracting an effective point cloud set, calculating the correction height of the effective point cloud, and calculating a flatness index in combination with the mean value of the correction height and the module length of the local gradient; the flatness index of the physical space is obtained, and whether the flatness of the plug hole is qualified or not is judged. According to the method, the problem of misjudgment caused by board warping is effectively solved, and the detection precision and the anti-noise capability are improved.

The utility model provides a lens antenna, which relates to the technical field of antennae and comprises a luneberg lens, an earth radiation unit, an air radiation unit, a horizontal adjusting mechanism and a tipping adjusting mechanism. The center of the Lunberg lens is located on a reference plane, and the reference plane is parallel to the horizontal plane or forms a preset included angle with the horizontal plane. The to-ground radiation unit is arranged towards the center of the luneberg lens in a radiation manner, and the to-ground radiation unit is located above the reference surface; the air radiation unit is arranged towards the center of the luneberg lens in a radiation manner, and the air radiation unit is located below the reference surface; the horizontal adjusting mechanism is used for synchronously adjusting the main radiation direction of the to-ground radiation unit and the main radiation direction of the to-air radiation unit in the horizontal direction; and the tipping adjusting mechanism is used for independently adjusting the elevation angle of the main radiation direction of the air radiation unit. The lens antenna provided by the utility model has the characteristic of multidimensional adjustability, can meet the requirements of low altitude and ground coverage at the same time, and is compact in structure and small in occupied space.

The invention belongs to the technical field of tool wear measurement, and particularly relates to a machining center tool wear state early warning method based on multi-source data fusion, and the method comprises the steps: calculating a cutting power consumption characteristic through a main shaft load energy mapping model according to the original sampling current and the real-time feeding speed of a main shaft; sliding window sampling is carried out on the cutting power consumption characteristics, and the cutting state disorder degree is calculated; performing nonlinear coupling on the power consumption gradient item and the cutting state disorder degree to obtain a grinding loss stability coefficient; and establishing a dynamic statistical reference surface, and performing cutter state early warning according to the deviation degree of the grinding loss stability coefficient monitored in real time. Instantaneous interference caused by uneven material hardness is effectively recognized and eliminated, meanwhile, signal structure disorder at the initial stage of tool failure is captured, the technical problems that in die steel machining, due to material structure segregation and variable working conditions, the false alarm rate is high, and failure precursor capturing is difficult are solved, and the machining precision is improved. And the monitoring accuracy of the precision machining process is obviously improved.

A system and method for calibrating and setting up a machine guidance system for construction assets, such as loaders or excavators, employ point cloud data from onboard optical sensors to acquire spatial measurements. Point cloud data is transformed to an asset coordinate frame, candidate pitch and roll offset values are applied, grid representations are generated, and calibration values are selected with reduced error by comparing these grids to a reference surface. The system and method support autonomous operations including obstacle avoidance and grading by modifying the point cloud data according to the determined calibration values. In addition, dual-sensor calibration, terrain mapping, and filtering techniques are disclosed.

The invention discloses a component installation real-time positioning system and method based on a laser benchmark, and the method comprises the steps: laying a laser benchmark system according to a construction lofting line, projecting a plurality of laser beams in an arch axis direction and an annular direction, and forming a space reference in an installation space; arranging an identification feature set at the arch part, the haunch, the arch foot connecting part and the node, and establishing a corresponding relation between the identification code and the component truss number, the node type and the geometric reference plane; continuously sampling the spatial geometrical relationship between the laser reference system and the identification feature set during the unfolding, hoisting and in-position period of the component to form an observation data flow; and inputting the observation data stream into the attitude resolving model, and combining the bunch constraint, the shape constraint and the hinge continuous constraint by adopting a factor graph and a graph optimization algorithm to solve the spatial attitude of each truss component and the overall arch frame. According to the method, a closed-loop laser reference and multi-truss attitude resolving system is constructed, and continuous positioning and overall contour controllability of component installation under complex working conditions are achieved.

The invention relates to a measuring arrangement for the interferometric determination of the surface shape of a test object, wherein a test wave generated from electromagnetic radiation and reflected at the test object can be superimposed with a reference wave not reflected at the test object, with a reference element (110, 210, 310, 410) having a reference surface (112, 212, 312, 412) which, in the optical beam path, splits off the reference wave from the test wave before it strikes the test object (120, 220, 320, 420) by reflection, and at least one beam shaping surface (111, 211, 311, 411, 413, 414) located in the optical beam path in front of the reference surface, wherein this beam shaping surface is designed as an aspherical distortion correction surface such that a distortion occurring in a predetermined reference plane of the measuring arrangement is reduced. The invention further relates to a method for manufacturing an optical element for such a measuring arrangement.

The invention discloses a depth estimation-based automatic railway fastener tightness detection method, which comprises the following steps of: acquiring a fastener region gray scale and a sub-pixel depth map by using a binocular line laser fusion sensor, and generating a reference three-dimensional point cloud with an absolute scale through temperature, vibration and IMU (Inertial Measurement Unit) joint correction; fitting a dynamic rail top reference surface by using a rail head web to extract an overall sinking and floating drift distance; performing lightweight instance segmentation to obtain elastic strip, bolt and rail head masks and slicing point clouds; fitting a quadric surface to extract feature points, calculating relative elevation, and performing drift compensation to obtain self-deformation quantity of the fastener; and finally, inputting the deformation quantity into a physical-residual cascade model to judge the tightness state, and binding the deformation quantity with a mileage stake mark to output a detection result. According to the invention, the real relative looseness of the fastener can be separated from the rail reference drift, so that the accuracy and reliability of tightness detection are remarkably improved.

The embodiment of the utility model provides a coupling tail fiber visual inspection packaging box which comprises an upper cover, an inner support and a bottom support. The upper cover is buckled and connected with the bottom support, a cavity is formed in the upper cover, and the inner support is arranged in the cavity; the inner support is provided with at least one protruding platform which is away from the upper cover by a preset distance and is used for placing an insertion core. A groove with a preset height is formed in the inner support and is used for accommodating an optical fiber; at least one plane is arranged at the front position of the protruding platform and serves as a datum plane, and a sticky sheet used for fixing a product to be detected is arranged on the plane. The detection accuracy and efficiency can be improved, accurate observation of product features and rejection of defective products are facilitated, detection interference is reduced, the risk of product damage can be reduced, batch transportation and management are facilitated, products are placed more orderly, and the whole device has good application value and market prospects.

A fastened member configured to be fixed to a vehicle body-side member by a screw member includes: a base including a reference surface configured to receive a bearing surface of the screw member; an insertion hole provided in the base and configured to insert the screw member therethrough, and a protruding portion protruding from the reference surface. The protruding portion includes a tilted surface tilted so as to become higher along a rotation direction in which the screw member is tightened. When the screw member is tightened, the protruding portion and the base are sandwiched between the vehicle body-side member and the bearing surface and are plastically and elastically deformed.

The invention discloses a cylindrical thin-wall part thread assembly device and method, and aims to solve the problems of low efficiency, high labor intensity and uncontrollable quality of traditional manual assembly. The device comprises an enclasping and screwing mechanism, a screwing control mechanism, a size rechecking mechanism and a horizontal carrying mechanism. The enclasping and screwing mechanism is used for enclasping a first thin-wall part, driving the first thin-wall part to rotate and temporarily bearing a second thin-wall part at the same time. The tightening control mechanism achieves grabbing of the second thin-wall part, thread pre-tightening / tightening of the first thin-wall part and process parameter monitoring through a static torsion sensor, a displacement sensor and an elastic floating structure. The dimension rechecking mechanism adapts to the levelness error of the reference surface by means of an integrated floating structure of a floating conical block, and accurately detects the dimension of the relative end surface after assembly; and the horizontal carrying mechanism drives the holding and screwing mechanism to accurately move among the stations. Full-automatic assembly of the thin-wall parts is achieved, efficiency is high, quality is good, and the automatic assembly machine is suitable for automatic production of the thin-wall parts in the aerospace and aviation fields.

The invention discloses an industrial intelligent installation and adjustment platform construction and performance optimization method based on digital twinning, and relates to the technical field of intelligent manufacturing and digital twinning, and the method comprises the following steps: building a unified time-frequency auditing base line, carrying out the continuous sampling of Ethernet switch route refresh pulse and programmable logic controller synchronization rhythm, and obtaining a unified time-frequency auditing base line; extracting a time drift curve, and constructing a time consistency reference surface; and executing causal playback based on the time consistency reference plane, reconstructing a frame sequence change track before and after the interruption of the communication chain, extracting a time sequence dislocation fingerprint and a packet loss link, and generating a pseudo operation risk distribution diagram. According to the method, through establishment of a time consistency reference surface, causal playback, sequence consistency check, time difference injection and evidence chain construction, microsecond-level beat synchronous control and pseudo operation identification are realized, and through combination of phase traction and a reversible time grid, abnormal chain fusing and self-healing are realized. And the real-time performance, the stability and the intelligent level of the digital twin installation and adjustment system are comprehensively improved.

The invention relates to the technical field of radar remote sensing monitoring, in particular to an airport runway seaworthiness intelligent evaluation method and system based on satellite-ground collaborative awareness, and the method comprises the steps: calculating the signal prominence intensity through the local saliency based on the SAR image pixel amplitude, and primarily screening highlight pixel points; a side lamp possibility index is constructed by combining double constraints of a straight line distribution rule and time sequence position reproducibility, and high-credibility side lamp pixel points are accurately identified from a low-signal-to-noise-ratio background; reversely positioning a runway pixel point area based on the matched parallel edge lamp fitting straight line; constructing a local deformation reference surface by taking an unwrapping phase of adjacent edge lamp pixel points as a benchmark, calculating the reliability of the runway and reconstructing a phase of an untrusted point, and generating a denoised image for airworthiness evaluation; according to the airport runway airworthiness evaluation method, the runway sidelight is used as a phase reference for time-space stability, the problem of phase incoherence caused by specular reflection in a flat runway area is effectively solved, and the accuracy and robustness of airport runway airworthiness evaluation are remarkably improved.

The invention discloses a method for measuring the thickness based on laser profile scanning of a 3D wheel of a conveying belt, particularly relates to the field of laser scanning thickness measurement, and is used for solving the problems that shutdown is needed and the measurement range is limited in existing conveying belt thickness detection. According to the method, three-dimensional point cloud data of the upper surface and three-dimensional point cloud data of the lower surface are collected at the same time, initial segmentation of the upper surface and the lower surface is completed through double criteria based on curvature and normal, a dynamic stability threshold value is constructed in combination with the running speed and transverse swing of the conveying belt, and a stable surface point set is formed through screening; then, a thin-plate spline algorithm of dynamic tensor weight is adopted to respectively fit continuous upper surface and lower surface reference curved surface models; and finally, the sampling points on the upper surface are projected to the lower surface along the normal direction and the Euclidean distance is calculated, so that the real thickness distribution of the conveying belt in the full width and full length range is obtained. Non-stop, non-contact and high-coverage online thickness measurement is realized, and the operation safety and maintenance management efficiency of the conveyor belt are improved.

A reference blade that allows a user to attach a reference surface to the body of a tape measuring device to allow for integrated measuring and marking / scribing a full line. The tape measuring device may be a digital linear tape measure. The reference blade couples to the body of the tape measure, which both secures the blade to the body as well as allows it to be removably detached and thereafter re-attached to the body at a specific and repeatable working location. The reference blade comes in a variety of sizes, shapes, and geometries and may be stored (in a different mounting state or attached) to the tape measure or externally. The reference blade addresses the need to provide the user with a sufficiently long surface that can be used for marking.

A light guide plate including a plate body and a plurality of optical microstructures is provided. The plate body has a first surface. The plurality of optical microstructures are formed on the first surface of the plate body. Each of the plurality of optical microstructures has an optical curved surface and a plurality of optical reference surfaces configured to divide the optical curved surface. The plurality of optical reference surfaces are perpendicular to the first surface. Intersections of the optical curved surface and the plurality of optical reference surfaces respectively form a plurality of optical profile lines. An optical angle is formed between the first surface and each of the plurality of optical profile lines, and angles of at least part of the optical angles are different from each other. A light source module and a display apparatus adopting the light guide plate are also provided.

The invention discloses a curtain wall aluminum supporting structure health monitoring method based on unmanned aerial vehicle three-dimensional surveying and mapping, and relates to the technical field of intelligent monitoring, and the method comprises the steps: obtaining building facade point cloud data through an unmanned aerial vehicle laser radar, and carrying out the three-dimensional coordinate parameterization processing of the point cloud through a curved surface parameterization expression technology, executing constraint condition setting according to geometric features of the building facade, and establishing an initial parameterized curved surface model including boundary condition limitation; geometric deviation calculation is carried out according to the initial parameterized curved surface model and a design reference surface, the spatial deviation value of each point location is obtained by adopting a residual calculation mode, differential weight assignment is carried out on deviation points of different areas through a weight coefficient distribution technology, and a target function construction expression based on weighted residual is constructed; according to the curtain wall aluminum supporting structure health monitoring method based on unmanned aerial vehicle three-dimensional surveying and mapping, the intelligent level and accuracy of curtain wall installation acceptance and long-term health monitoring are remarkably improved.

The invention discloses a measurement method and device and application, and belongs to the field of quantum chip detection. The measurement method comprises the following steps: determining a measurement set composed of at least two to-be-measured positions in a target device and an initial height of the target device relative to a reference surface; enabling a probe of the probe device to be in contact with a to-be-measured position in the measurement set so as to execute first measurement; and after the target device is lifted relative to the reference surface or under the condition that the probe feeding amount of the probe is increased, enabling the probe of the probe device to be in contact with another to-be-measured position in the measurement set so as to execute second measurement. By implementing the measurement method, a more accurate and consistent measurement result can be obtained, and the credibility of the measurement result is improved.

The invention discloses a shield segment splicing elliptic change detection method, relates to the technical field of shield segments, and breaks through the limitation that in traditional detection, elliptic change and slab staggering are detected separately, and judgment depends on artificial experience. An integrated design of circular seam point cloud accurate screening-double circular seam plane fitting correction-least square circle fitting and ellipsometry parameter linkage calculation is adopted, secondary correction is performed through a second circular seam plane equation, the problem that single circular seam plane fitting is easily influenced by model reconstruction errors is solved, the fitting precision is improved, and the fitting precision is improved. The technical closed loop of section geometric feature extraction-ellipse parameter quantization-slab staggering reference calibration is achieved, meanwhile, least square circle fitting of YZ section point clouds is combined with ellipse long axis, ellipse short axis, ellipse rate and deformation deviation calculation depth, ellipse judgment is achieved through double threshold values of ellipse rate grading and deformation deviation threshold values, the risk of misjudgment of a single parameter is avoided, and the method has the advantages of being high in practicability and high in practicability. And a high-precision reference surface is provided for subsequent slab staggering quantity calculation.

The invention discloses an AR / VR module of an integrated prescription diffraction lens, an assembly calibration method and a calibration system, which are applied to the field of AR / VR optical machine system integration and calibration. According to the scheme, the interface structure, the reference surface and the positioning structure are arranged on the mirror frame or the carrier, so that stable assembly between the prescription diffraction lens and the display source, the waveguide or the light combiner is realized; and a closed-loop process is formed through metering before assembly, positioning installation, light path alignment, locking and fixing, calibration and acquisition, error decomposition, compensation writing and acceptance and archiving, so that a traceable data packet comprising a prescription version number, an error vector, a compensation parameter, an acceptance conclusion and a signature abstract is output.

The invention belongs to the technical field of computer aided design and mechanical engineering, and relates to a parameterized three-dimensional automatic modeling and assembling system and method for a rolling bearing. The system comprises a parameter input module used for obtaining bearing design parameters; the part modeling module is used for generating an inner ring model, an outer ring model, a rolling body model and a retainer model which comprise preset assembly reference surfaces according to the parameters; the assembly logic module is used for automatically positioning the respective three-dimensional models of the multiple parts of the rolling bearing in a three-dimensional space and constructing a complete bearing assembly so as to generate a complete rolling bearing; and the auxiliary function module is used for providing model file management, modeling process visualization and data output functions. The method has the beneficial effects that the traditional dependence on a solid geometric surface is replaced by abstract association of the reference surface and the coordinate system, and high automation, stabilization and parameterization of the modeling and assembling process are realized.

A method of recovering a master calibration state of a coordinate positioning machine has a first member that is moveable relative to a second member, wherein the geometry of the machine is characterised by a set of model parameters. The machine is controlled to make point contact between multiple reference surfaces of a tool mounted on the first member and multiple reference surfaces of an artefact mounted on the second member. The separations between these contacting surfaces that would be expected from the current model parameters are determined, and these separations are recorded as a set of master separations. The contacting step is subsequently performed again in respect of at least some of the contacts for which master separations were recorded. At least one of the model parameters is updated to provide a closer correspondence between the expected separations and the master separations.

The invention relates to the technical field of waste resource recycling and automatic processing, and discloses a waste household appliance disassembling process parameter adaptive control method and system, and the method comprises the steps: carrying out the registration fusion of multi-view surface data, and obtaining a complete point cloud model; identifying a high-deformation area based on curvature features and fitting cutting reference surface parameters; performing smooth adjustment on the reference plane parameters according to the pose difference of the adjacent areas to obtain a coordinated reference plane set; generating an initial compensation vector in combination with the discrete points of the cutting path, and correcting direction mutation to obtain a preliminary compensation instruction; and real-time cutting feedback data are collected in the disassembling process, if the machining state is abnormal, the compensation vector of the follow-up path is corrected, and a target self-adaptive control instruction is obtained. According to the invention, self-adaptive precise cutting of waste household appliance parts with complex deformation and uneven material characteristics can be realized.

The invention discloses a battery module welding quality detection method and related equipment, and the method comprises the steps: carrying out the time sequence observation of a welding spot array in a preset time window after the welding is completed, and generating a to-be-detected welding spot set; acquiring three-dimensional shape data of a welding spot to be detected, setting a non-welding reference ring on the outer side of the welding spot according to a lap joint geometrical relationship between a battery cell tab and a busbar, and extracting a welding pit opening boundary and a welding pit bottom area through a robust separation method; fitting a local reference surface by using data in a range of the non-welded reference ring, and calculating the depth of the welding pit and the upheaval volume of the ring area; a plurality of welding spots in the same busbar are subjected to statistical analysis, a judgment interval is dynamically generated in combination with a historical rhythm trend, and the welding quality is judged according to parameters of all the welding spots and array consistency. According to the technical scheme, key geometric features can be stably extracted under the high-speed production condition, errors caused by warping and material differences are reduced, and efficient quantitative detection of micron-sized welding spot defects is achieved.

The invention provides an engineering quantity data identification method and system in BIM pipeline generation, and relates to the technical field of data processing, and the method comprises the steps: 1, obtaining a building information model comprising an initial pipeline layout scheme and corresponding initial engineering quantity data; 2, performing avoidance optimization operation on pipelines in the building information model, and synchronously capturing and storing pipeline geometric attribute change information and connection relation change information caused by the operation; 3, extracting a space point position sequence of the optimized pipeline according to the captured change information, and converting the space point position sequence into a pipeline contour three-dimensional coordinate set; according to the distribution range of the three-dimensional coordinate set, constructing a spatial construction reference plane of an envelope coordinate set, and defining a basic outer boundary on the spatial construction reference plane; according to the invention, automatic, accurate and efficient identification and accounting of engineering quantity data after pipeline avoidance optimization are realized.

To provide a method and a device for smoothing a work by which the working time of finish flattening is drastically shortened by predicting stress deformation in advance and roughly working the work into a shape corresponding to a finish shape in advance in a working method for smoothing the work in which the stress deformation is caused, especially the work having a bimetal structure in which thermal stress deformation is caused by temperature rise.SOLUTION: The method includes a first machining process for locally machining the surface of the workpiece based on machining data, and a second machining process which is performed after the first machining process and has a machining mechanism for preferentially removing a contact part between a machining pad having a planar machining reference surface and the workpiece, wherein stress deformation of the workpiece at the time of machining in the second machining process is predicted, and machining data of the first machining process is created from a difference between a predicted surface shape 4 at deformation and a predicted finished surface shape 5 or a difference between a final finished surface shape 7 and the pre-machining surface shape 6.SELECTED DRAWING: Figure 1

The present application provides a kind of perpendicularity detection method, system, device, equipment and readable storage medium, perpendicularity detection method is applied to including the perpendicularity detection system of measured system, indicating light source, focusing mirror, light receiving cylinder, double flat crystal, half mirror and charge coupled device, measured system includes light beam emission port and reference surface;Including: record the first light spot position of the indicating light of indicating light source projection on charge coupled device;Adjust the pitch position of measured system, determine the second light spot position of indicating light projection on charge coupled device after adjustment;In the case where first light spot position and second light spot position coincide, according to the thickness and refractive index of half mirror, the perpendicularity deviation amount of the optical axis of light beam emission port and reference surface and the perpendicularity detection result of measured system are determined.The present application realizes the perpendicularity detection of the optical axis of measured system and reference surface.

Embodiments of the present application relate to a part drawing method and device based on segmented assembly, electronic equipment and medium, the range of the cut view is determined according to the orientation information of the target segment; the position information of the part reference surface corresponding to each part located in the cut view range is determined; the parts with the same position information are expressed in the same cut view to obtain the corresponding part drawing; that is, the embodiments of the present application automatically cut the view of the parts at the same position on the segment, reduce the drawing workload, reduce the manual drawing time, realize the fast, accurate and automatic view cutting, and improve the design efficiency.