WO2013180561A1 - System and method for generating a 3d model of a terrain - Google Patents
System and method for generating a 3d model of a terrain Download PDFInfo
- Publication number
- WO2013180561A1 WO2013180561A1 PCT/MY2013/000103 MY2013000103W WO2013180561A1 WO 2013180561 A1 WO2013180561 A1 WO 2013180561A1 MY 2013000103 W MY2013000103 W MY 2013000103W WO 2013180561 A1 WO2013180561 A1 WO 2013180561A1
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- terrain
- laser beam
- circles
- elevation data
- rotary platform
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C15/00—Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
- G01C15/002—Active optical surveying means
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
- G01S7/4817—Constructional features, e.g. arrangements of optical elements relating to scanning
Definitions
- the present invention relates to a system and a method for generating a 3D model with terrain profile. More particularly, relates to a system provides an elevation data generation apparatus for generating contour information and the method thereof to generate a 3D model having a respective terrain profile based on the contour information.
- a realistic 3D model provides users not only a visualization of objects within an environment with enhanced comprehension, it also allows user to perform object tracking and event detection with high accuracy.
- 3D models created from the most conventional approaches in the art are merely 3D-looking images which the elevation data is usually not taken into considerations and they therefore may not appear to be sufficiently 3D to provide situational information for said uses.
- ground surface elevation data acquisition systems for providing a 3D model having terrain profile are therefore developed.
- These ground surface elevation data acquisition systems conventionally includes IFSAR (InterFerometric Synthetic Aperture Radar) and LIDAR (Light Detection And Ranging, or "laser scanning”).
- IFSAR InterFerometric Synthetic Aperture Radar
- LIDAR Light Detection And Ranging
- a system for use in generating a 3D model of a terrain preferably includes an elevation data generation apparatus configured to provide differential data of a terrain of interest, wherein said differential concentric circle data is resulted by comparing a reference concentric circle data of the terrain of interest against a series of circles of varying radius that are generated by the elevation data generation apparatus according to the actual topographical characteristic of the terrain of interest.
- the differential data is then interpreted and analyzed by a contour information processing unit operatively connected to the elevation data generation apparatus to retrieve elevation data thereof and thus presenting said retrieved elevation data in a 3D model.
- the elevation data generation apparatus embodying the present invention preferably comprises an image capturing device coupled with a wide-angle lens for providing a plurality of captured images with a substantially hemispherical field of view; a laser beam source for providing laser beam; a rotary light-reflecting device having a plurality of reflective surfaces disposed thereon and configured in such a manner that each reflective surface has a specific tilt angle relative to a fixed position of laser beam from the source to receive and thereby reflecting the laser beam from the laser beam source with a specific reflective angle on the terrain of interest; an adjustable crane structure for supporting and adjustably positioning the laser beam source and the rotary light- reflecting device that are mounted thereon in vertical direction; a rotary platform being operatively coupled with the adjustable crane structure to facilitate the rotational movement of the crane structure about the horizontal central axis of rotary platform; and a support means attached at the base of the rotary platform to support the rotary platform above the ground it lays.
- a method used in generating a 3D model of a terrain comprising the steps of providing a reference concentric circle data of a terrain of interest; generating a series of circles of varying radius according to the actual topographical characteristic of the terrain of interest; comparing the reference concentric circles data against the series of circles of varying radius formed on the terrain of interest to obtain differential information for derivation of elevation data; and assigning said elevation data to a corresponding 3D model for data presentation.
- the step of generating a series of circles of varying radius on the terrain of interest by means of the data elevation generation apparatus embodying the present invention further comprising the steps of: (a) defining the number of circles to be formed on the terrain of interest based on the reference concentric circle data; (b) projecting laser beam from the laser beam source onto a first reflective surface of the rotary light-reflecting device, and thus reflecting the laser beam there from onto the terrain of interest with a predefined reflective angle relative to the laser beam; (c) allowing the rotary platform to rotate continuously about its horizontal central axis until a complete circle is formed on the terrain as the platform rotates; (d) initiating the polygonal body of the light-reflecting device and the rotary platform to rotate simultaneously so that the laser beam strikes on the second reflective surface of the light-reflecting device is reflected with another predefined reflective angle on the terrain for generation of a second circle on the terrain of interest; and (e) repeating step (b) to (d) until the pre-defined number of circles to be formed on the terrain
- FIG. 1 illustrates an elevation data generation apparatus in accordance with one embodiment of the present invention
- Figure 2 illustrates a side profile of a polygonal body of a rotary light-reflecting device of the elevation data generation apparatus of Figure 1;
- Figure 3 illustrates the changes of tilt angles of the reflective facets on the rotaiy light- reflecting device of the preferred embodiment with respect to a fixed position of the laser beam;
- Figure 4A-4E illustrates how a series of circles of varying radius circles formed on the terrain of interest by the elevation data generation apparatus in accordance with the preferred embodiment of the present invention
- Figure 5A-5C respectively, illustrates the examples of both reference concentric circle data and the series of circles of varying radius formed on the terrain with different topographical characteristics
- Figure 6 illustrates how elevation data of the terrain of interest is derived
- Figure 7 illustrates a line graph generated by plotting the elevation data against the number of circles formed on the terrain of interest.
- the present invention relates to a system for generating three-dimensional (3D) model of terrain profile by means of elevation data that is derived from comparing a series of circles of varying radius formed on a terrain to be measured against a reference concentric circles data of the terrain.
- the system comprises an elevation data generation apparatus and a contour information processing unit connecting to the elevation data generation apparatus for generating elevated ground information of a terrain based on the differential data resulted from the elevation data generation apparatus. It should be noted that the generated elevated ground information can be inputted and presented with a standard 3D model using any known 3D graphics-rendering unit in the art.
- FIG. 1 illustrates an elevation data generation apparatus (100) adapted for the aforementioned system in accordance with one embodiment of the present invention.
- the elevation data generation apparatus (100) comprising an image capturing device (202), a laser beam source (204), a rotary light-reflecting device (206) having a plurality of reflective surfaces (208) disposed along the lateral surface of the device (206) to receive and reflect laser beam from the laser beam source (204) on a terrain to be measured, and an adjustable crane structure (210) for supporting and adjustably positioning the laser beam source (204) and the rotaiy light-reflecting device (206) that are mounted thereon in vertical direction.
- a rotary platform (212) being operatively coupled with the crane structure (210) is also provided.
- the rotary platform (212) has a support means (216) provided at its base to support the platform (212) from the ground it lays.
- the support means (216) includes a tripod or any supporting stands known in the art.
- This rotary platform (212) is adapted to facilitate the rotational movement of the crane structure (210) about the horizontal central axis of the rotary platform as it rotates. It should be noted that with such rotational movement, a single laser beam reflected from the plurality of refractive surfaces (208) of the rotary light-reflecting device (206) mounted on the crane structure (210) can be therefore directed to form a complete circle on the terrain to be measured.
- the image-capturing device (202) is preferably coupled with a wide-angle lens (214) for capturing a high quality of images, suitably the images of a plurality of concentric circles drawn on the ground where the image-capturing device (202) is positioned perpendicularly above.
- the image-capturing device (202) may include but not limited to a video camera.
- the wide-angle lens (214) preferably has a visual angle of more than 180 degrees. It is preferred that a fisheye lens is employed. Images taken from the fisheye lens generally have substantially hemispherical field of view and these are necessary for derivation of high -accuracy elevation data.
- the rotary light-reflecting device (206) includes a polygonal body (206a) connected to a motor, which causes the polygonal body to rotate. Any conventional motors known to those ordinary skilled in the art may be assembled with the polygonal body (206a) of the rotary light-reflecting device (206).
- the plurality of reflective surfaces (208) that is provided on the rotary light-reflecting device (206) is preferably disposed on the outer peripheral side facets of the polygonal body (206a).
- the outer peripheral side facets are constructed in such a configuration that each of the side facets relative to a fixed position of the emitting laser beam from the source (204) with a specific angle.
- the plurality of reflective surfaces that is disposed thereon may change the direction of the laser beam and reflects the laser beam projected thereon at different angles as the polygonal body rotates.
- reflection of the laser beam at different angles may form a series of circles with different radius as the rotary platform is rotated.
- a laser beam originating from the laser beam source (204) may be reflected at a specific reflective angle, and each resultant dot generated from such reflection will be positioned on the terrain to be measured according to the respective angle of the reflective facets relative to the emitting laser beam from the source (204).
- the laser beam could be directed onto the terrain to be measured depending on which light reflective surface of the rotary light-reflecting device the laser beam strikes on.
- the first reflective surface (208a) reflects light beam with a reflective angle of 0i when the first reflective surface having a tilt angle of 0 ° at its initial position relative to the fixed position of the laser beam
- the second reflective suiface (208b) reflects light beam with a reflective angle of 0 2 when the laser beam is projected to the second reflective surface (208b) having a tilt angle of 1 1 ° relative to the fixed position of the laser beam
- the third reflective surface (208c) reflects laser beam with a reflective angle of ⁇ 3 when the laser beam is projected to the third reflective surface (208c) having a tilt angle of 15 ° relative to the fixed position of the laser beam
- the fourth reflective surface (208d) reflects laser beam with a reflective angle of ⁇ 4 when the laser beam is projected to the fourth reflective surface (208d) having a tilt angle of 23° relative to the fixed position of the laser beam
- the fifth reflective surface (208e) reflects light beam with a reflective angle of ⁇ 5 when the laser beam is projected to the fifth reflective surface (
- the dual rotation mechanism is preferably constituted by a global rotation of the overall apparatus (100) and the local rotation of the rotary light-reflecting device (206).
- the global rotation of the overall apparatus (100) mentioned herein refers to a rotation of the rotary platform (212), preferably which is coupled with the adjustable crane structure (210) that having the laser beam source (204) and the rotary light-deflecting device (206) mounted thereon, about the central axis of the rotary platform (212) at 360" in a unidirectional and continual manner; wherein the local rotation of the rotary light- reflecting device (206) refers to the rotary movement of the polygonal body of the light- reflecting device (206) around its central axis, and by which different reflective angles with respect to the laser beam are formed. It is preferable that the rotary light-reflecting device (206) rotates bi-directionally in a discrete manner and is configured in such a manner that it does not affect the global rotation of the rotary platform (212).
- a single laser beam emitted from the laser beam source (204) may initially be projected onto a first reflective surface (208a), which has a predefined reflective angle relative to the laser beam.
- the reflection of such laser beam may form a single red dot on the ground of the terrain to be measured.
- the single red dot suitably the reflected laser beam may then be directed by means of the global rotation of the rotary platform (212) to form a circle.
- the polygonal body (206a) of the rotary light-reflecting device (206) may be initiated to rotate, either in an anti-clockwise or clockwise direction, so that the laser beam strikes on its second reflective surface (208b) and is thus reflected at another predefined reflective angle.
- a second global rotation of the rotary platform (212) may be initiated.
- the rotary platform (212) may rotate continuously until a full 360-degree circle of the second circle is formed on the ground.
- the second circle is positioned within the first circle.
- a third, fourth, fifth circle... and n th circle may be subsequently formed within the first and the second circles by repeating the procedures as described above.
- the pattern of the series of circles is not merely determined by the configuration of the rotary light-reflecting device, i.e., the number of reflective surfaces and the tilt angle of the reflective surfaces, the distance for the laser beam to travel from the reflecting surface to the ground at the respective angles is also a variable parameter. It is understood that the distance ultimately defines the radius of each circle.
- the concentric circles formed by the apparatus will be distorted as the patterns of the series of circles formed on the terrain are varied with the actual topographical characteristic of the terrain to be measured.
- Figure SB & 5C For terrain with a slope surface as depicted in Figure SB & 5C, a pattern of circles within circles that is non-concentric but within a common central point will be resulted.
- the pattern of the series of circles will remain concentric when the terrain to be measured has a substantially flat ground.
- a method for use in generating a 3D model with terrain information based on the series of circles of varying radius generated by the elevation data generation apparatus (100) of the present invention comprises obtaining differential data by comparing the series of circles of varying radius formed on the terrain to be measured using the elevation data generation apparatus (100) against a reference concentric circles data.
- the reference concentric circles data is generated by the apparatus itself and based on a substantially flat ground where each laser beam is reflected onto the ground with a same distance.
- Such reference concentric circles data once generated are suitable for use in all subsequent data analyses for elevation data generation. It should be understood that both reference data and actual data should have a same number of circles and the circles are generated based on the same horizontal central axis of the rotary platform, in order for data comparison.
- Figure 6 illustrates how the series of circles of varying radius formed on the terrain of interest and the reference concentric circles data by the elevation data generation apparatus (100) are compared to render the differential information.
- the differential information is obtained by subtracting the spacing between the lines of the reference concentric circles with its corresponding spacing between the lines of the concentric circles captured by the image-capturing device (202) of the elevation data generation apparatus (100). It should be noted that both reference concentric circles and concentric circles generated by the elevation data generation apparatus (100) are overlapping with one another at a common central point during the subtraction method.
- the resultant differential information that carries elevation data of the terrain of interest may be subsequently subjected to a contour information processing unit to retrieve the elevation data thereof for generating a corresponding 3D graphics ground with a terrain profile.
- the elevation data may be plotted in the form of a line graph as depicted in Figure 7 where the X-axis represents the concentric circles formed on the terrain of interest and the Y-axis represents the represents the height from the ground level.
- the accuracy of the elevation data is linearly dependant on the number of circles formed during the process of data acquisition. Accordingly, the number of circles to be formed and the reflective angles which the laser beam reflected at to generate said number of circles on the ground may have to be pre-defined for enhanced data acquisition.
Abstract
The present invention relates to a system for use in generating a 3D model of a terrain comprising an elevation data generation apparatus (100) for derivation of elevation data based on a series of circles of varying radius generated on the terrain by the apparatus (100) and a reference concentric circles data. Said elevation data generation apparatus (100) comprises an image-capturing device (202) coupled with a wide-angle lens (214), a rotary light-reflecting device (206) having a plurality of reflective surfaces (208) disposed thereon with different reflective angles relative to a fixed position of laser beam irradiating from a laser beam source, and a dual rotation mechanism configured to facilitate laser beams to be reflected on the terrain with different reflective angles and thereby producing the series of circles of varying radius based on the actual topographical characteristic of the terrain.
Description
SYSTEM AND METHOD FOR GENERATING A 3D MODEL OF A TERRAIN
Field of Invention The present invention relates to a system and a method for generating a 3D model with terrain profile. More particularly, relates to a system provides an elevation data generation apparatus for generating contour information and the method thereof to generate a 3D model having a respective terrain profile based on the contour information. Background
A realistic 3D model provides users not only a visualization of objects within an environment with enhanced comprehension, it also allows user to perform object tracking and event detection with high accuracy. However, 3D models created from the most conventional approaches in the art are merely 3D-looking images which the elevation data is usually not taken into considerations and they therefore may not appear to be sufficiently 3D to provide situational information for said uses.
In attempts to alleviate the above limitations, various ground surface elevation data acquisition systems for providing a 3D model having terrain profile are therefore developed. These ground surface elevation data acquisition systems conventionally includes IFSAR (InterFerometric Synthetic Aperture Radar) and LIDAR (Light Detection And Ranging, or "laser scanning"). While these currently practiced 3D ground surface
modeling system are valuable tools for measuring and recording elevation data for topographic mapping, providing a model that accurately represents an actual physical environment, they often involve extremely high operation costs due to its operation complexity and which generally requires a high degree of skilled labor to perform manually.
Summary
In one aspect of the present invention, disclosed a system for use in generating a 3D model of a terrain. Said system preferably includes an elevation data generation apparatus configured to provide differential data of a terrain of interest, wherein said differential concentric circle data is resulted by comparing a reference concentric circle data of the terrain of interest against a series of circles of varying radius that are generated by the elevation data generation apparatus according to the actual topographical characteristic of the terrain of interest. The differential data is then interpreted and analyzed by a contour information processing unit operatively connected to the elevation data generation apparatus to retrieve elevation data thereof and thus presenting said retrieved elevation data in a 3D model. The elevation data generation apparatus embodying the present invention preferably comprises an image capturing device coupled with a wide-angle lens for providing a plurality of captured images with a substantially hemispherical field of view; a laser beam source for providing laser beam; a rotary light-reflecting device having a plurality
of reflective surfaces disposed thereon and configured in such a manner that each reflective surface has a specific tilt angle relative to a fixed position of laser beam from the source to receive and thereby reflecting the laser beam from the laser beam source with a specific reflective angle on the terrain of interest; an adjustable crane structure for supporting and adjustably positioning the laser beam source and the rotary light- reflecting device that are mounted thereon in vertical direction; a rotary platform being operatively coupled with the adjustable crane structure to facilitate the rotational movement of the crane structure about the horizontal central axis of rotary platform; and a support means attached at the base of the rotary platform to support the rotary platform above the ground it lays.
In another aspect of the present invention, a method used in generating a 3D model of a terrain comprising the steps of providing a reference concentric circle data of a terrain of interest; generating a series of circles of varying radius according to the actual topographical characteristic of the terrain of interest; comparing the reference concentric circles data against the series of circles of varying radius formed on the terrain of interest to obtain differential information for derivation of elevation data; and assigning said elevation data to a corresponding 3D model for data presentation. The step of generating a series of circles of varying radius on the terrain of interest by means of the data elevation generation apparatus embodying the present invention further comprising the steps of: (a) defining the number of circles to be formed on the terrain of interest based on the reference concentric circle data; (b) projecting laser beam from the
laser beam source onto a first reflective surface of the rotary light-reflecting device, and thus reflecting the laser beam there from onto the terrain of interest with a predefined reflective angle relative to the laser beam; (c) allowing the rotary platform to rotate continuously about its horizontal central axis until a complete circle is formed on the terrain as the platform rotates; (d) initiating the polygonal body of the light-reflecting device and the rotary platform to rotate simultaneously so that the laser beam strikes on the second reflective surface of the light-reflecting device is reflected with another predefined reflective angle on the terrain for generation of a second circle on the terrain of interest; and (e) repeating step (b) to (d) until the pre-defined number of circles to be formed on the terrain is acquired.
Brief Description of the Drawings
Other objects, features, and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:
Figure 1 illustrates an elevation data generation apparatus in accordance with one embodiment of the present invention;
Figure 2 illustrates a side profile of a polygonal body of a rotary light-reflecting device of the elevation data generation apparatus of Figure 1;
Figure 3 illustrates the changes of tilt angles of the reflective facets on the rotaiy light- reflecting device of the preferred embodiment with respect to a fixed position of the laser beam;
Figure 4A-4E illustrates how a series of circles of varying radius circles formed on the terrain of interest by the elevation data generation apparatus in accordance with the preferred embodiment of the present invention;
Figure 5A-5C, respectively, illustrates the examples of both reference concentric circle data and the series of circles of varying radius formed on the terrain with different topographical characteristics;
Figure 6 illustrates how elevation data of the terrain of interest is derived; and
Figure 7 illustrates a line graph generated by plotting the elevation data against the number of circles formed on the terrain of interest.
Detailed Description
The present invention will now be described in detail with reference to the accompanying in drawings.
The present invention relates to a system for generating three-dimensional (3D) model of terrain profile by means of elevation data that is derived from comparing a series of circles of varying radius formed on a terrain to be measured against a reference concentric circles data of the terrain. The system comprises an elevation data generation apparatus and a contour information processing unit connecting to the elevation data generation apparatus for generating elevated ground information of a terrain based on the differential data resulted from the elevation data generation apparatus. It should be noted that the generated elevated ground information can be inputted and presented with a standard 3D model using any known 3D graphics-rendering unit in the art.
Figure 1 illustrates an elevation data generation apparatus (100) adapted for the aforementioned system in accordance with one embodiment of the present invention. The elevation data generation apparatus (100) comprising an image capturing device (202), a laser beam source (204), a rotary light-reflecting device (206) having a plurality of reflective surfaces (208) disposed along the lateral surface of the device (206) to receive and reflect laser beam from the laser beam source (204) on a terrain to be measured, and an adjustable crane structure (210) for supporting and adjustably positioning the laser beam source (204) and the rotaiy light-reflecting device (206) that are mounted thereon in vertical direction.
A rotary platform (212) being operatively coupled with the crane structure (210) is also provided. The rotary platform (212) has a support means (216) provided at its base to support the platform (212) from the ground it lays. The support means (216) includes a
tripod or any supporting stands known in the art. This rotary platform (212) is adapted to facilitate the rotational movement of the crane structure (210) about the horizontal central axis of the rotary platform as it rotates. It should be noted that with such rotational movement, a single laser beam reflected from the plurality of refractive surfaces (208) of the rotary light-reflecting device (206) mounted on the crane structure (210) can be therefore directed to form a complete circle on the terrain to be measured.
The image-capturing device (202) is preferably coupled with a wide-angle lens (214) for capturing a high quality of images, suitably the images of a plurality of concentric circles drawn on the ground where the image-capturing device (202) is positioned perpendicularly above. The image-capturing device (202) may include but not limited to a video camera. The wide-angle lens (214) preferably has a visual angle of more than 180 degrees. It is preferred that a fisheye lens is employed. Images taken from the fisheye lens generally have substantially hemispherical field of view and these are necessary for derivation of high -accuracy elevation data.
In accordance to the preferred embodiment, the rotary light-reflecting device (206) includes a polygonal body (206a) connected to a motor, which causes the polygonal body to rotate. Any conventional motors known to those ordinary skilled in the art may be assembled with the polygonal body (206a) of the rotary light-reflecting device (206). The plurality of reflective surfaces (208) that is provided on the rotary light-reflecting device (206) is preferably disposed on the outer peripheral side facets of the polygonal body (206a). The outer peripheral side facets are constructed in such a configuration that each
of the side facets relative to a fixed position of the emitting laser beam from the source (204) with a specific angle. As such, the plurality of reflective surfaces that is disposed thereon may change the direction of the laser beam and reflects the laser beam projected thereon at different angles as the polygonal body rotates. As will be noted, reflection of the laser beam at different angles may form a series of circles with different radius as the rotary platform is rotated.
As be readily seen in Figure 2A-2B, a laser beam originating from the laser beam source (204) may be reflected at a specific reflective angle, and each resultant dot generated from such reflection will be positioned on the terrain to be measured according to the respective angle of the reflective facets relative to the emitting laser beam from the source (204). In other words, the laser beam could be directed onto the terrain to be measured depending on which light reflective surface of the rotary light-reflecting device the laser beam strikes on.
Further to another illustrated embodiment of the polygonal body (206a) of the rotary light-reflecting device (206) in Figure 3A- 3E, it depicts reflection of the laser beams with a corresponding reflective angle as the changes of tilt angles of the plurality of reflective surfaces (208) of the polygonal body (206a) with respect to a fixed position of the laser beam. The first reflective surface (208a) reflects light beam with a reflective angle of 0i when the first reflective surface having a tilt angle of 0° at its initial position relative to the fixed position of the laser beam, the second reflective suiface (208b) reflects light beam with a reflective angle of 02 when the laser beam is projected to the
second reflective surface (208b) having a tilt angle of 1 1 ° relative to the fixed position of the laser beam, the third reflective surface (208c) reflects laser beam with a reflective angle of Θ3 when the laser beam is projected to the third reflective surface (208c) having a tilt angle of 15° relative to the fixed position of the laser beam , the fourth reflective surface (208d) reflects laser beam with a reflective angle of Θ4 when the laser beam is projected to the fourth reflective surface (208d) having a tilt angle of 23° relative to the fixed position of the laser beam, and the fifth reflective surface (208e) reflects light beam with a reflective angle of Θ5 when the laser beam is projected to the fifth reflective surface (208e) having a tilt angle of 26 relative to the fixed position of the laser beam.
In view of above, a series of circles of varying radius can therefore be formed on the terrain to be measure and by means of a dual rotation mechanism according to the preferred embodiment of the present invention. The dual rotation mechanism is preferably constituted by a global rotation of the overall apparatus (100) and the local rotation of the rotary light-reflecting device (206). For purpose of this description, the global rotation of the overall apparatus (100) mentioned herein refers to a rotation of the rotary platform (212), preferably which is coupled with the adjustable crane structure (210) that having the laser beam source (204) and the rotary light-deflecting device (206) mounted thereon, about the central axis of the rotary platform (212) at 360" in a unidirectional and continual manner; wherein the local rotation of the rotary light- reflecting device (206) refers to the rotary movement of the polygonal body of the light- reflecting device (206) around its central axis, and by which different reflective angles with respect to the laser beam are formed. It is preferable that the rotary light-reflecting
device (206) rotates bi-directionally in a discrete manner and is configured in such a manner that it does not affect the global rotation of the rotary platform (212).
Referring now to Figure 4A - 4E, which illustrates how the series of circles of varying radius as mentioned in the preceding paragraphs are formed in detail, by means of the elevation data generation apparatus (100). A single laser beam emitted from the laser beam source (204) may initially be projected onto a first reflective surface (208a), which has a predefined reflective angle relative to the laser beam. The reflection of such laser beam may form a single red dot on the ground of the terrain to be measured. The single red dot, suitably the reflected laser beam may then be directed by means of the global rotation of the rotary platform (212) to form a circle. Soon after the formation of first circle on the ground and/or after a global 360 degree rotation by the rotary platform (212), the polygonal body (206a) of the rotary light-reflecting device (206) may be initiated to rotate, either in an anti-clockwise or clockwise direction, so that the laser beam strikes on its second reflective surface (208b) and is thus reflected at another predefined reflective angle. Meanwhile, a second global rotation of the rotary platform (212) may be initiated. The rotary platform (212) may rotate continuously until a full 360-degree circle of the second circle is formed on the ground. The second circle is positioned within the first circle. A third, fourth, fifth circle... and nth circle may be subsequently formed within the first and the second circles by repeating the procedures as described above.
It should be noted that the pattern of the series of circles is not merely determined by the configuration of the rotary light-reflecting device, i.e., the number of reflective surfaces and the tilt angle of the reflective surfaces, the distance for the laser beam to travel from the reflecting surface to the ground at the respective angles is also a variable parameter. It is understood that the distance ultimately defines the radius of each circle. In other words, the concentric circles formed by the apparatus will be distorted as the patterns of the series of circles formed on the terrain are varied with the actual topographical characteristic of the terrain to be measured. For terrain with a slope surface as depicted in Figure SB & 5C, a pattern of circles within circles that is non-concentric but within a common central point will be resulted. However, as shown in Figure 5 A, the pattern of the series of circles will remain concentric when the terrain to be measured has a substantially flat ground.
In another preferred embodiment, a method for use in generating a 3D model with terrain information based on the series of circles of varying radius generated by the elevation data generation apparatus (100) of the present invention is provided. The method comprises obtaining differential data by comparing the series of circles of varying radius formed on the terrain to be measured using the elevation data generation apparatus (100) against a reference concentric circles data. The reference concentric circles data is generated by the apparatus itself and based on a substantially flat ground where each laser beam is reflected onto the ground with a same distance. Such reference concentric circles data once generated are suitable for use in all subsequent data analyses for elevation data generation. It should be understood that both reference data and actual data should have a
same number of circles and the circles are generated based on the same horizontal central axis of the rotary platform, in order for data comparison.
Figure 6 illustrates how the series of circles of varying radius formed on the terrain of interest and the reference concentric circles data by the elevation data generation apparatus (100) are compared to render the differential information. As shown, the differential information is obtained by subtracting the spacing between the lines of the reference concentric circles with its corresponding spacing between the lines of the concentric circles captured by the image-capturing device (202) of the elevation data generation apparatus (100). It should be noted that both reference concentric circles and concentric circles generated by the elevation data generation apparatus (100) are overlapping with one another at a common central point during the subtraction method.
The resultant differential information that carries elevation data of the terrain of interest may be subsequently subjected to a contour information processing unit to retrieve the elevation data thereof for generating a corresponding 3D graphics ground with a terrain profile. In addition to being presented in a 3D model, the elevation data may be plotted in the form of a line graph as depicted in Figure 7 where the X-axis represents the concentric circles formed on the terrain of interest and the Y-axis represents the represents the height from the ground level. As be apparent to one skilled in the art, the accuracy of the elevation data is linearly dependant on the number of circles formed during the process of data acquisition. Accordingly, the number of circles to be formed
and the reflective angles which the laser beam reflected at to generate said number of circles on the ground may have to be pre-defined for enhanced data acquisition.
As will be readily apparent to those skilled in the art, the present invention may easily be produced in other specific forms without departing from its essential characteristics. The present embodiments is, therefore, to be considered as merely illustrative and not restrictive, the scope of the invention being indicated by the claims rather than the foregoing description, and all changes which come within therefore intended to be embraced therein.
Claims
1. A system for generating a 3D model of a terrain, the system comprising:
an elevation data generation apparatus (100) adapted to project a series of circles of varying radius on the terrain and compare the circles against a reference concentric circles to render a differential data between the circles and the reference concentric circles, the differential data represents an elevation data that defines the actual topographical characteristic and elevation profile of the terrain; and
a contour information processing unit connected to the elevation data generation apparatus (100) for processing elevation data and rendering the 3D model of the terrain with the topographical characteristic and elevation profile.
2. A system as claimed in Claim 1 , wherein said elevation data generation apparatus (100) comprising:
an image-capturing device (202) coupled with a wide-angle lens (214) for providing a plurality of captured images with a substantially hemispherical field of view;
a laser beam source (204) for providing laser beam;
a rotary light-reflecting device (206) includes a motor and a polygonal body (206a) connected to the motor for rotating the polygonal body (206a) around the axis of rotation, wherein the polygonal body (206a) having a plurality of reflective surfaces (208) disposed on its outer periphery side facets to receive and thereby reflects laser beam from the laser beam source (204) on the terrain, wherein said outer periphery side facets arranged in such a manner that each outer periphery side facet have a specific tilt angle
different from one another whereby each reflective surface that is disposed thereon has a specific reflective angle relative to a fixed position of laser beam emitting from the laser beam source (204);
an adjustable crane structure (210) for supporting and adjustably positioning the laser beam source (204) and the rotary light-reflecting device (206) that are mounted thereon in vertical direction;
a rotary platform (212) being operatively coupled with the adjustable crane structure (210) to facilitate the rotational movement of the crane structure (210) about the horizontal central axis of rotary platform (212); and
a support means (216) attached at the base of the rotary platform (2102 to support the rotary platform (210) above the ground it lays.
3. A system as claimed in Claim 2, wherein said image-capturing device (202) includes a video camera.
4. A system as claimed in Claim 2, wherein said wide-angle lens (214) preferably includes a fisheye lens.
5. A method for use in generating a 3D model of a terrain information comprising:
providing a reference concentric circle data;
generating a series of circles of varying radius according to the actual topographical characteristic of the terrain;
comparing the reference concentric circles data against the series of circles of varying radius formed on the terrain of interest to obtain differential information for derivation of elevation data; and
assigning said elevation data to a corresponding 3D model for data presentation.
6. A method for use in generating a 3D model having respective terrain information as claimed in Claim 5, wherein the steps of providing a reference concentric circle data and generating a series of circles of varying radius on the terrain are performed by an elevation data generation apparatus (100), wherein the apparatus (100) including:
an image capturing device (202) coupled with a wide-angle lens (214) for providing a plurality of captured images of the series of circles of varying radius with a substantially hemispherical field of view;
a laser beam source (204) for providing laser beam;
a rotary light-reflecting device (206) includes a motor and a polygonal body (206a)connected to the motor to rotate the polygonal body (206a), wherein the polygonal body (206a) having a plurality of reflective surfaces (208) disposed along its outer periphery side facets to receive and thereby reflects laser beam from the laser beam source (204) on the terrain of interest, wherein said outer periphery side facets arranged in a manner that each outer periphery side facet have a specific tilt angle different from one another whereby each reflective surface that is disposed thereon has a specific reflective angle relative to a fixed position of laser beam emitting from the laser beam source (204);
an adjustable crane structure (210) for supporting and adjustably positioning the laser beam source (204) and the rotary light-reflecting device (206) that are mounted thereon in vertical direction;
a rotary platform (212) being operatively coupled with the adjustable crane structure (210) to facilitate the rotational movement of the crane structure (210) about the horizontal central axis of rotary platform (212); and
a support means (216) attached at the base of the rotary platform (212) to support the rotary platform (210) above the ground it lays.
7. A method for use in generating a 3D model having respective terrain information as claimed in Claim 6, wherein said step (b) of generating a series of circles of varying radius further comprising the steps of:
(a) defining the number of circles to be formed on the terrain of interest based on the reference concentric circle data;
(b) projecting laser beam from the laser beam source (204) onto a first reflective surface of the rotaiy light-reflecting device (206), and thus reflecting the laser beam there from onto the terrain of interest with a predefined reflective angle relative to the laser beam; (c) allowing the rotary platform (206) to rotate continuously about its horizontal central axis until a single circle is formed on the terrain as the platform rotates (206);
(d) initiating the polygonal body (206a) of the light-reflecting device (206) and the rotary platform (212) to rotate simultaneously so that the laser beam strikes on the second reflective surface of the light-reflecting device (206) is reflected with another predefined
reflective angle on the terrain for generation of a second circle on the terrain of interest; and
(e) repeating step (b) to (d) until the pre-defined number of circles to be formed on the terrain is acquired.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| MYPI2012002383A MY172087A (en) | 2012-05-29 | 2012-05-29 | A terrain profile determination system and method thereof |
| MYPI2012002383 | 2012-05-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2013180561A1 true WO2013180561A1 (en) | 2013-12-05 |
Family
ID=48795884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/MY2013/000103 WO2013180561A1 (en) | 2012-05-29 | 2013-05-23 | System and method for generating a 3d model of a terrain |
Country Status (2)
| Country | Link |
|---|---|
| MY (1) | MY172087A (en) |
| WO (1) | WO2013180561A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104809760A (en) * | 2015-05-07 | 2015-07-29 | 武汉大学 | Depth-first strategy based method for automatically constructing geo-spatial three-dimensional outline |
| CN110787445A (en) * | 2019-11-13 | 2020-02-14 | 山东领信信息科技股份有限公司 | Method for generating sandpit sandbag in virtual simulation psychological sand table game |
| CN113431997A (en) * | 2021-06-22 | 2021-09-24 | 安徽科技学院 | Geographic information system storage device capable of being used for terrain self-adaptive acquisition component |
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| US5102223A (en) * | 1988-03-31 | 1992-04-07 | Nkk Corporation | Method and apparatus for measuring a three-dimensional curved surface shape |
| US20100046004A1 (en) * | 2008-08-19 | 2010-02-25 | Samsung Electronics Co., Ltd. | Pattern projecting apparatus, three dimensional imaging apparatus having the same, and varifocal liquid lens being used in the same |
| US20110313721A1 (en) * | 2008-04-01 | 2011-12-22 | Perceptron, Inc. | Contour sensor incorporating mems mirrors |
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| US4185918A (en) * | 1975-08-27 | 1980-01-29 | Solid Photography Inc. | Arrangement for sensing the characteristics of a surface and determining the position of points thereon |
| US5102223A (en) * | 1988-03-31 | 1992-04-07 | Nkk Corporation | Method and apparatus for measuring a three-dimensional curved surface shape |
| US20110313721A1 (en) * | 2008-04-01 | 2011-12-22 | Perceptron, Inc. | Contour sensor incorporating mems mirrors |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104809760A (en) * | 2015-05-07 | 2015-07-29 | 武汉大学 | Depth-first strategy based method for automatically constructing geo-spatial three-dimensional outline |
| CN110787445A (en) * | 2019-11-13 | 2020-02-14 | 山东领信信息科技股份有限公司 | Method for generating sandpit sandbag in virtual simulation psychological sand table game |
| CN113431997A (en) * | 2021-06-22 | 2021-09-24 | 安徽科技学院 | Geographic information system storage device capable of being used for terrain self-adaptive acquisition component |
| CN113431997B (en) * | 2021-06-22 | 2023-06-20 | 安徽科技学院 | Geographic information system storage device that can self-adaptation topography collection part was used |
Also Published As
| Publication number | Publication date |
|---|---|
| MY172087A (en) | 2019-11-13 |
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