198 results about "Spiral scanning" patented technology

An x-ray computed tomography system uses a broad area x-ray emitter and detector to allow both in plane and out of plane x-ray projections not restrained to spiral or helical scans.

The invention provides a device and a method for automatically matching laser radar receiving and transmitting optical axes. The device comprises an emergent light path, a receiving light path and a data acquisition and control portion, an emergent system comprises a laser, a beam expanding system, a plurality of reflecting mirrors and lenses, laser light is emitted to air through the beam expanding system, the lenses, the reflecting mirrors and an optical antenna, a receiving system comprises a telescope, echo signals sequentially pass an optical fiber, the lenses, a light filter and a photoelectric detection element, the photoelectric detection element is arranged at an input end of a data acquisition system, and an output end of a control system controls the optical antenna with a high-accuracy servo motor through a motor driving controller. The method automatically traces the echo signals by the aid of a program design two-dimensional spiral scanning algorithm, uniaxial scanning and matrix scanning are performed to obtain the best emitting antenna position, so that an emitting antenna points to and receives collimation of the optical axis of the telescope, operators no longer need rich experience, and the method is simple and convenient to operate and high in feasibility.

The invention provides a novel high-rate rotary optical-acoustic combined imaging probe and a conduit. The probe comprises a photoconduction optical fiber, a GRIN lens, a sound generation signal lead, an electroacoustic transducer, a micromotor driving lead, a micromotor and a reflector. A detection acoustic beam produced by the electroacoustic transducer in the probe and a detection light beam produced by the optical fiber and the GRIN lens are spread to a far-end along an axial direction, then are reflected by the reflector, then are spread along a radial direction and irradiate a sample to be detected. The micromotor is used for rotating the reflector thereby changing directions of the detection acoustic beam and light beam. Through combination with probe axial motion, optical-acoustic spiral scanning imaging is realized. The imaging conduit is prepared from the probe as a core and the probe can move in an outer sheath and can be protected. The novel rotary type optical-acoustic combined imaging probe improves an optical-acoustic combined imaging rate and improves image quality.

A cargo security inspection method and system based on spiral scanning, the method including: spirally scanning an inspected object at a first precision to obtain the transmission projection data; judging whether there is a suspect area in the inspected area; scanning at least one slice of the suspect area at a second precision wherein the second precision is greater than the first precision; reconstructing a tomographic image of the at least one slice; and using the reconstructed tomographic image to judge whether there is any dangerous article in the suspect area.

The invention, which belongs to the technical field of curved surface coordinate measurement, provides a spiral scanning measurement track planning method for a cylindrical curved surface, thereby improving the measurement efficiency of cylindrical parts by reducing non-measurement movement time of a measuring head and the length of a guiding track C(t). The method comprises steps of an offset curved surface Sr forming step, a offset curved surface Sr triangularization step, a triangularized offset curved surface Sr parameterization step, a guiding line and spacing line planning step, a spiral guide line G(t) and a spiral spacing line E(t) calculating step, a guiding track C(t) calculating step, an oscillating track parameter scanning curve generation step, and an oscillating scanning track P(t) generation step. The measurement process can be completed by one reciprocating scanning movement of a pointed head of a probe of a measuring head, so that the non-measurement movement time of the measuring head and the length of the guiding track C(t) during the cylindrical curved surface measurement process are reduced and thus the measurement efficiency of the cylindrical curved surface is improved.

The invention relates to a portable ultrasonic flaw detection and scanning device capable automatically crawling on the inner wall of a pipeline and an application method of the portable ultrasonic flaw detection and scanning device. The portable ultrasonic flaw detection and scanning device comprises a crawling device, a support structure, an automatic coupling flaw detection device and a remote control part and is characterized in that the crawling device moves linearly in the pipeline, an ultrasonic probe moves circumferentially along with a probe arm, the ultrasonic probe performs spiral scanning relative to the pipe wall, probe wave beams are constantly reflected and propagated along the circumferential direction of the pipe wall, the wave beams are reflected and returned along the original propagation path when the wave beams meet an axial flaw on the pipe wall, the returned wave beams are received by the probe and displayed on the screen of an ultrasonic instrument, water is used as the coupling agent, coupling water is sprayed to a to-be-detected part through a water outlet at a probe clamp, and good coupling is guaranteed sufficiently. The portable ultrasonic flaw detection and scanning device has the advantages that traditional outer wall ultrasonic flaw detection is changed into the inner wall ultrasonic scanning and flaw detection of the different-diameter pipelines, detection speed is increased, test blind areas area reduced, detection precision is increased, detection cost is lowered greatly, labor intensity is reduced, and the safety guarantee of an inspector is enhanced.

An imaging method is for a multi-slice spiral CT scan with 3D back projection. Use is made, for the reconstruction of the absorption value of at least one voxel, of the measured and filtered data that are produced by rays which penetrate the at least one voxel. A CT unit is further used to carry out the method. In the method, the filtering of the data, required for the reconstruction, in the image of the virtual detector is performed in the direction of the projection of spiral segments imaged thereon which are produced by the spiral scanning over a prescribed angular range. The CT unit includes a device for carrying out directional filtering of this type.

The invention discloses an endoscopic OCT imaging system adopting an optical path difference external compensation common-path interference probe. The system comprises a light source, an optical path difference external compensation interferometer, a first acousto-optic frequency shifter, a second acousto-optic frequency shifter, an optical circulator, a fiber optic rotary joint, a spiral scanning mechanism, an endoscopic probe, a glass spacer, a Grin lens, a 45-degree cylinder mirror, a transparent sealing sleeve, an outer metal sheath, a diaphragm, a detector, a data acquisition card and a computer. According to the system, the front end face of the Grin lens in the endoscopic lens serves as the reference surface, and compensation of the optical path difference between the front end face of the Grin lens and a sample is achieved through the optical path difference external compensation interferometer; lesion inspection missing is reduced through spiral traversal scanning, light dispersion usually caused by the cylindrical transparent sealing sleeve is eliminated through the planar diaphragm, and false images existing in an imaging result are eliminated through combination of the acousto-optic frequency shifters and the signal filtering and demodulation technology. The system has the advantages that antijamming capability is high, the probe can be used as soon as being plugged, lesion inspection missing is reduced, interference of false images is avoided, and inlet sample light beams are not dispersed.

Multimodal imaging apparatus and methods include a rotatable gantry system with multiple sources of radiation comprising different energy levels (for example, kV and MV). Fast slip-ring technology and helical scans allow data from multiple sources of radiation to be combined or utilized to generate improved images and workflows, including for IGRT. Features include large field-of-view (LFOV) MV imaging, kV region-of-interest (ROI) imaging, and scalable field-of-view (SFOV) dual energy imaging.

In a computed tomography apparatus and a method for automatic exposure control in computed tomography scanning, an exposure controller, during a first half of a revolution of an X-ray focus around a subject, calculates an actual attenuation profile of a slice of the subject from electrical signals generated by the radiation detector in the first half of the revolution, and calculates an extrapolated attenuation profile of the slice for a second half of the revolution from the actual attenuation profile, and adjusts an operating parameter of the X-ray source, such as the tube current, to modify the radiation dose emitted by the X-ray source during the second half of the revolution dependent on the extrapolated attenuation profile. The extrapolated attenuation profile can be calculated to achieve a predetermined target pixel noise in the image for the slice currently being scanned. In a spiral scan composed of a number of such slices, respectively different target pixel noise values can be used to appropriately set a radiation dose in the scan of each slice dependent on the radiation absorption of the slice of the subject currently being scanned.

The invention provides a subcaliber-polishing contour route planning method. Through contour routes planned by the method, the inhibition of residual errors caused by convolution reaction is facilitated. The subcaliber-polishing contour route planning method comprises the following steps: (1) obtaining initial surface-shape error distribution data; (2) calculating discrete material removal quantity progressions and generating the contour route corresponding to each removal quantity; and (3) calculating coordinates of resident points and resident time of the resident points on each contour route. The subcaliber-polishing contour route planning method is capable of obtaining the appropriate material removal quantity progressions, generating the corresponding contours, obtaining dense route spacing in an area with high processed surface material removal quantity and obtaining non-dense spacing in an area with small removal quantity, so that the problem that medium-frequency errors, low-frequency surface shape and efficient convergence are difficultly achieved at the same time when an equal-spacing grating scanning method of routes or a spiral scanning method of routes is used for processing at present can be overcome.

The invention relates to a dynamic regulation method for a radial filter device in spiral multilayer CT (Computed Tomography) scanning, which comprises the following steps: conducting coordinate transformation on taper ray bundles in the projected angle direction during the spiral scanning process of multilayer CT and converting the taper ray bundles into wedge-shaped rays bundles; under geometric condition of the wedge-shaped rays bundle, analyzing the condition that projective data obtained by a projective image at each scanning Z position is used for rebuilding the image, and then building an initial mathematical model at the position of maximum layer or minimum layer of ray, which is utilized by scanning each Z position; conducting extrapolation and numerical analysis on the initial mathematical model so as to simplify the initial mathematical model and obtain a linear approximation method; and summarizing the conclusions and obtaining a final linear switch seam scheme which can be used for mechanical control, thus realizing the dynamic regulation on the filter device in the spiral CT scanning. According to the invention, the increase of dosage is avoided caused by invalid ray of the image generated in the initial and finished stages in the spiral multilayer CT scanning.

The invention discloses a method for implementing alight spot joint seal in a fiber densely-arranged line array, which comprises the following steps of: (1) taking a substrate graved with a plurality of grooves distributed in equal spacing distance on the surface; putting fibers in the grooves of the substrate respectively, and fixing the fibers and the substrate to obtain a densely-arranged fiber layer assembly; and (2) preparing a plurality of densely-arranged fiber layer assemblies with the same method as the step (1), and stacking the prepared fiber layer assemblies together in parallel up and down, wherein the fibers on the upper and lower fiber layers are staggered to ensure the projection light spots of all fiber array output light spots in a densely-arranged fiber module on a horizontal line are in joint seal or proper superposed arrangement. The invention also discloses a densely-arranged fiber module prepared with the method. The densely-arranged fiber module avoids the problems of poor output image quality and over high requirement for a focusing and imaging lens because more fibers are arranged in single-layer fiber arrangement, the arranged fiber array is widened and the lead angle is largened in spiral scanning and imaging.

The invention relates to a laser micro-hole machining cooperative control system and method based on an industrial personal computer. The system comprises the industrial personal computer, a numericalcontrol system and a cooperative control unit. The method comprises the steps that the industrial personal computer acquires machining parameters from a technological database according to operationof a user, sends a control command to the numerical control system according to the machining parameters and sends configuration parameters to the cooperative control unit; a laser is controlled to bestarted and stopped, and state information fed back by the laser is received; the numerical control system controls movement of a machine tool spindle according to the control command and controls the cooperative control unit to be started and stopped; and the cooperative control unit receives the configuration parameters, the starting and stopping quantity sent by the numerical control system and position information fed back by an adjusting motor of a machining head and sends a control signal to the laser, and circular constant-overlapping-ratio spiral scanning machining control is achieved. According to the laser micro-hole machining cooperative control system and method based on the industrial personal computer, the cooperative control unit coordinates work of the machining head and the laser and can control the whole machining process in real time, the machining reliability and high efficiency are guaranteed, and meanwhile the precision of a machined workpiece is high.

The invention discloses a machining method for an aluminum alloy turbine blade of an aero-engine, and belongs to the technical field of machining for turbine blades of aero-engines. The machining method comprises the following steps: casting the aluminum alloy turbine blade, carrying out film hole machining through a machining method of ultrafast laser annular cutting and spiral scanning, and removing a remelted layer through abrasive particle flow machining and a melted layer removal solution. According to the machining method disclosed by the invention, the film hole machining is carried outthrough the machining method of ultrafast laser annular cutting and spiral scanning, so that the heat effect can be greatly reduced and the surface integrity is improved, the machined film hole has few burrs, grooves and micro-cracks, and the maximum thickness of the remelted layer is not greater than 25[mu]m. Abrasive particles uniformly grind the surface or the corners of a channel under a pressure effect, so that allowance can be removed, the effects of deburring, chamfering and polishing can also be acted, the remelted layer can also be effectively reduced, a hole diameter increment is controlled to be 0.02mm to 0.04mm, and the remelted layer and the micro-cracks can be effectively controlled. The remelted layer is further removed through the remelted layer removal solution, so that no remelted layer residue at the inlet-outlet of the film hole can be achieved.

A 3D (three dimensional) printing process with laser beam scanning in archimedes spiral way comprises a laser and optical system, a turntable and guide rail guide frame system, a spindle motor and guide frame shift servo motor system, and a computer control system. A laser is mounted on a turntable laser disc or a turntable guide frame, or is mounted independently from a turntable, a laser beam is focused onto a printer working plane by a stationary reflector of turntable optical system and a reflector and a lens on the guide frame, or, a laser beam of a laser on the guide frame is focused onto the printer working plane by the lens; when the turntable is driven by a spindle motor to rotate in local constant angular velocity or constant angular velocity, and the guide frame is driven by a servo motor to move horizontally in constant velocity, omission-free and no-repeat archimedes spiral scanning of the laser beam on SLA, SLS, SLM and LOM printing working planes can be completed, and after layer-by-layer processing, a workpiece body is obtained. The printing process can realize no-distortion and high quality scanning of ultra large working planes and processing of ultra large workpieces, has the advantages of simple structure, low cost and excellent quality, is especially suitable for printing aerospace, aviation, electric power, marine, construction and other large complex workpieces.

The invention discloses a 3D scanning apparatus for carrying out three-dimensional scanning, imaging, and network issuing on a measured object. The apparatus comprises a rotating platform for placing a measured object and driving the measured object to make constant-speed rotation at different speeds, a scanner for scanning and shooting the measured object and obtaining a scanned image, a range finder being arranged above the rotating platform and being used for measuring the height of the measured object, and a controller for controlling the rotating platform, the scanner, and the range finder. A certain distance is formed between the scanner and the rotating platform and the scanner can make reciprocating motion in a direction parallel to an axial direction of the rotating platform. Therefore, spiral scanning and imaging of the measured object can be realized; and the controller processes the scanned image to form a 3D model that is then outputted to a display terminal.

The invention provides a spiral scanning laser machining device and method, and aims to solve the problems that an existing laser machining device is low in micropore taper adjusting precision, smallin machining hole diameter and low in machining efficiency. The spiral scanning laser machining device comprises a displacement reflector, a Dove prism, an upper deflection optical wedge, a lower deflection optical wedge and a focus lens which are sequentially arranged along an optical path, wherein the upper deflection optical wedge and the lower deflection optical wedge are arranged back to back; the central axes of the upper deflection optical wedge and the lower deflection optical wedge are coaxial with the central axis of the Dove prism; and laser beams are incident to the Dove prism after micropore taper adjustment is realized through the displacement reflector, the Dove prism increases the scanning speed of the laser beams and then enables the laser beams to enter the upper deflection optical wedge and the lower deflection optical wedge, the upper deflection optical wedge and the lower deflection optical wedge deflect the laser beams to achieve scanning of the laser beams with different diameters, and the focus lens focuses the laser beams, so that spiral scanning machining of micropores is achieved. According to the device and method, the machining precision and the machining efficiency of the laser machining device during micropore machining are improved.

The invention relates to a multi-time horizontal movement staggered spiral industrial CT scanning imaging method, and belongs to the technical field of CT scanning. The method comprises the steps that in the scanning period, a carrying rotary table rotates in one direction all the time, the rotary table only needs to transversely horizontally move in the direction parallel to a detector at the two-time spiral scanning interval and does not need to move in the radial direction, and staggered spiral scanning is achieved through a radiation source and the axial reciprocating movement of the detector. The multi-time horizontal movement staggered spiral industrial CT scanning imaging method is suitable for high-precision and rapid three-dimensional imaging of a III generation CT large-size workpiece. High-precision and rapid three-dimensional imaging is achieved through a III generation linear array detector CT system, the detector physical interpolation is not needed in the scanning process, the structure of the CT system is simplified on the premise that the detection precision is guaranteed, the manufacturing cost of the CT system is reduced, and the detecting efficiency is effectively improved.

The invention discloses a multi-degree-of-freedom cone-beam CT imaging system in the field of CT imaging technology, which includes: a six-axis mechanical arm, a C-shaped bracket with a translation device, a flat panel detector bracket with a double translation device and a rotation device, and The X-ray light source, wherein: the end of the six-axis mechanical arm is connected to the C-shaped support, and the two ends of the C-shaped support are respectively connected to the flat panel detector support and the X-ray light source. The device involved in the present invention has high flexibility, and can realize multiple scanning modes of cone beam CT axial scanning, helical scanning and non-coplanar scanning, as well as functions such as online real-time adjustment of imaging geometric parameters, and has flexible scanning methods, wide scanning range, With outstanding advantages such as adjustable imaging parameters, it is suitable for applications such as precise intraoperative navigation, adaptive radiation therapy, and early tumor screening and diagnosis.

An embodiment of the method discloses an image reconstruction method and device by oblique spiral scanning. The method specifically includes acquiring data obtained by oblique spiral scanning; according to geometrical relationship of intersection points between rays of oblique spiral scanning and a detector, calculating a channel angle and number of layers the ray corresponding to each pixel position; according to a three-dimensional spiral back projection method, performing back projection image reconstruction according to the acquired data as well as channel parameters and the number of layers of the ray corresponding to each pixel position. By the method and device, raw data are not required to be corrected and processed, data accuracy can be guaranteed, artifacts can be prevented for appearance, and accuracy of reconstructed images is guaranteed.

The image reconstruction is implemented along theoretical π-lines, wherein the theoretical π-lines not only lead to interpolated detector data but also can emanate from interpolated source positions. Interpolation thus occurs both at the detector and at the source.

The invention provides a spiral scanning method and device. The two schemes are consistent in technological thought. The method comprises the following steps: determining an overlap area between the scanning area of current spiral scanning and the scanning area of previous spiral scanning; starting current spiral scanning, controlling a bulb tube not to emit rays in the overlap area but in the non-overlap area of current spiral scanning, and scanning to obtain raw data of current spiral scanning; and performing data fusion of the raw data of current spiral scanning and the raw data obtained by previous spiral scanning. Through the technical scheme provided by the invention, in a scene of repeated spiral scanning, the scanning of a certain area can be saved, and the radiation of the scanned person is reduced to a certain degree; and more importantly, the data continuity is guaranteed through a way of data fusion, and complete data is provided for the imaging of current spiral scanning.