TW201432222A - Three-dimensional range finding method and system thereof - Google Patents

Abstract

The present invention provides a three-dimensional range finding method and system thereof, which includes the following steps: providing at least one lighting set forming a projection plane to project onto the surface of an object to be measured, in which the lighting set comprises a plurality of light beams emitted onto the surface of the object to be measured with a predetermined first path function along a linear arrangement to form the measurement points; the light beams of the lighting set reflected by the surface of the object to be measured passes the focus of a focusing element to from a sensing image on a photosensitive memory element; obtaining a corresponding second path function according to each imaging position by the light beams on the photosensitive memory element and the position of the focus of the focusing element; and, calculating the intersection positions of each corresponding first path function and second path function, which is the spacial positions of the detection points for the object to be measured.

Description

Stereo distance measuring method and system thereof

The invention relates to a distance measuring method and a system thereof, in particular to a stereo distance measuring method and a system using the optical image computing.

Commonly used distance measurement methods include direct measurement and indirect measurement. In terms of direct measurement, the measurer can measure the distance between the object and the object directly with the ruler, and this measurement method often produces errors due to the different operation modes of the measurer. In terms of indirect measurement, the instrument can be used to measure with the standard, and the distance between the object and the object can be calculated by calculating the corresponding angle. Although the accuracy of this method is higher than that of the direct use of the ruler, it is still inconvenient in practical operation due to the limitation of the site and the two measurers.

In recent years, many other distance detection methods have been developed, such as using sound waves, radio waves, or laser light. Among them, the laser light distance measurement method is widely used in transportation, construction, terrain survey and the like because of its high accuracy, clear calibration point, and convenient measurement. Taking a laser range finder as an example, the basic principle is that a laser light emitter emits a laser beam to a target object, and then passes through a laser receiver to receive a signal reflected by the target object. The obtained signal is calculated and analyzed to emit the time difference between the laser beam and the received reflected signal, and the distance between the laser range finder and the target can be obtained. However, the general laser range finder can only measure the distance between a single target point and the laser range finder at one time, and cannot measure the distance between the detection points for a plurality of detection points, and still limits the laser ranging method. Application area.

The main object of the present invention is to solve the problem that the conventional laser range finder cannot perform distance measurement between multiple detection points. To achieve the above object, the present invention provides a stereo distance measuring system comprising a light source emitting device, a focusing component, a photosensitive memory component, and an arithmetic unit electrically connected to the photosensitive memory component. The light source emitting device emits at least one light group forming a projection plane to be projected onto a surface of the object to be tested, the light group including a plurality of predetermined first path functions and aligned along a straight line to the surface of the object to be tested A beam line that forms a detection point. The focusing element includes a focus through which a beam of light of the group of rays reflected by the surface of the object to be measured passes. The photosensitive memory element receives a beam line of a group of rays passing through the focus of the focusing element and forms a sensing image. The operation unit obtains a sensing image of the photosensitive memory element, and calculates a second path function corresponding to a focus position of each of the beam lines on the photosensitive memory element according to a focus position of the focusing element, and calculates each corresponding first The intersection of the path function and the second path function.

In one embodiment, the light source emitting device includes a light source that emits the light group by a light emitting path, and a first diffractive optical element located on the light path. The light source emitting device includes a second diffractive optical element located between the light source and the first diffractive optical element.

In an embodiment, the beam line projected by the group of rays has a pattern code for interpretation by the operation unit.

In an embodiment, the focus of the focusing element is on the projection plane.

In one embodiment, the plurality of projection planes formed by the plurality of groups of rays intersect each other on an intersecting axis that passes through a focus of the focusing element. The light source emitting device includes a light emitting source that emits the light group by a light emitting path, and a first diffractive optical element located in the light emitting path, and an intersecting axis intersecting the projection planes passes through the first diffractive optical element.

In one embodiment, the stereo distance measuring system further includes a filter disposed between the focusing element and the surface of the object to be tested, the filter allowing light having only the beam line frequency to enter the focusing element.

In one embodiment, the stereo distance measuring system further includes a housing that houses the light source emitter, the focusing component, the photosensitive memory, and the computing unit.

The invention further provides a method for measuring a stereo distance, comprising the steps of:

Step a): providing at least one light group forming a projection plane to be projected onto a surface of the object to be tested, the light group comprising a plurality of respective first path functions and arranged in a straight line to the surface of the object to be tested a beam line forming a detection point;

Step b): the beam line of the group of rays reflected by the surface of the object to be tested forms a sensing image on a photosensitive memory element through a focus of a focusing element;

Step c): obtaining a second path function corresponding to each of the beamline imaging positions on the photosensitive memory element and a focus position of the focusing element;

Step d): calculating a position of the intersection of each corresponding first path function and the second path function, that is, a spatial position of the detection point of the object to be tested.

In an embodiment, the step b) further comprises the step of allowing light having only the beam line frequency to enter the focusing element.

In an embodiment, the stereo distance measuring method further comprises the step f): obtaining a natural light image reflected by the surface of the object to be tested through the photosensitive memory element.

In an embodiment, the stereo distance measuring method further comprises, between the step b) and the step c), a natural light image of the photosensitive memory element in step f) and a sensing image of the photosensitive memory element in step b). , to obtain a step of only the image of the light group.

In an embodiment, the stereo distance measuring method further comprises the step e): calculating a distance between the different detection points according to different spatial positions of the object to be detected.

The method for measuring a stereo distance of the present invention and a system thereof, by emitting a beam line having a plurality of straight line alignments to form a light group of a projection plane to a surface of an object to be measured, the line of the beam line arranged to reflect through a focus of a focusing element The photosensitive memory element forms a sensing image in which the beam lines of a single light group are still aligned in the same order. Calculating the first path function and the first path function preset by the beam line and the second path function corresponding to the focus position of the beam line on the photosensitive memory element and the focus position of the focusing element The intersection position of the second path function can obtain the spatial position of the detection point of the object to be tested. Therefore, the present invention only needs to image the sensing image to the photosensitive memory element in a single time, and can obtain the spatial position of each detection point of the object to be tested, thereby obtaining the relative distance between each detection point. And achieve the effect of stereo distance measurement.

FIG. 1 is a schematic flow chart showing the steps of an embodiment of the stereo distance measuring method of the present invention.

2 is a schematic diagram of a planar optical path architecture of an embodiment of a stereo distance measuring system of the present invention.

Fig. 3 is a schematic view showing the components of the light source emitting device of the improved resolution embodiment of the stereo distance measuring system of the present invention.

4 is a schematic diagram of the coordinated single beam line optical path architecture of an embodiment of the stereo distance measuring system of the present invention.

FIG. 5 is a schematic diagram of a three-dimensional optical path architecture of an embodiment of the stereo distance measuring system of the present invention.

FIG. 6 is a schematic diagram of sensing image imaging of a photosensitive memory element according to an embodiment of the stereo distance measuring system of the present invention.

The detailed description and technical contents of the present invention will now be described as follows:

Please refer to FIG. 1 , which is a schematic flow chart of the method for measuring the stereo distance of the present invention. As shown in the figure, the present invention discloses a method for measuring a stereo distance, comprising the steps of: step a): projecting a light group to an object to be tested. a surface (S10); projecting at least one light group forming a projection plane onto a surface of the object to be tested, the light group including a plurality of predetermined first path functions and respectively arranged in a straight line to the surface of the object to be tested A beam line that forms a detection point. Step b): reflecting the light group is imaged by a focus on a photosensitive memory element (S20); the beam line of the light group reflected by the surface of the object to be tested forms a focus on a photosensitive memory element through a focus of a focusing element Sensing the image. Step c): obtaining a path function for each beamline reflection (S30); obtaining a second path function corresponding to each of the beamline imaging positions on the photosensitive memory element and the focus position of the focusing element. Step d): calculating a spatial position of the detection point of the object to be tested (S40); calculating a intersection position of each corresponding first path function and the second path function, that is, a detection point of the object to be tested Spatial location. After step d) is completed, the user may selectively perform step e): calculating a distance between the different detection points according to different spatial positions of the object to be detected (S50).

On the other hand, please refer to FIG. 2, which is a schematic diagram of a planar optical path structure of the stereo distance measuring system of the present invention. As shown in the figure, the present invention discloses a stereo distance measuring system including a light source emitting device 10, a focusing component, A photosensitive memory element 30, and an arithmetic unit 40 electrically connected to the photosensitive memory element 30. The light source emitting device 10 emits at least one light group 11 forming a projection plane to be projected onto a surface of an object to be tested 50. The light group 11 includes a plurality of predetermined first path functions and is arranged in a straight line to the The surface of the object to be tested 50 forms beam lines 12a, 12b of the detection points P1, P2. In the present embodiment, the light source emitting device 10 includes a light source 13 that emits the light group 11 by a light-emitting path R, and a first diffractive optical element 14 that is located on the light-emitting path R. The light emitted by the light source 13 is laser light. The focusing element includes a focus 21 through which the beam lines 12a, 12b of the group of rays 11 reflected by the surface of the object 50 to be measured pass. The photosensitive memory element 30 receives the beam lines 12a, 12b of the light group 11 passing through the focus element focus 21 and forms a sensing image. The computing unit 40 obtains the sensing image received by the photosensitive memory device 30, and the computing unit 40 can use the image processing method of the digital image to find the spot of each of the beam lines 12a, 12b in the sensing image, according to a second path function corresponding to the position of the focusing element focus 21 of each of the beam lines 12a, 12b on the photosensitive memory element 30, and calculating an intersection of each corresponding first path function and the second path function position. The components of the stereo distance measuring system of the present invention may be separately provided, and the light source emitter, the focusing component, the photosensitive memory and the arithmetic unit may be integrated into a hand-held measuring device through a casing.

In the present invention, the photosensitive memory element 30 can also obtain a natural light image reflected by the surface of the object 50 to be tested. When the stereo distance measurement is performed, the photosensitive memory element 30 can continuously acquire two sensing images, one is a natural light image without a projected light group, and the other is a light group 11 having a reflection passing through the focus 21. Sensing the image. The operation unit 40 compares the natural light real image received from the photosensitive memory element 30 and the sensing image imaged by the light group 11 to each other to obtain a spot information of only the beam lines 12a and 12b in the light group 11. Alternatively, the stereo distance measuring system of the present invention may further comprise a filter disposed between the focusing element and the surface of the object to be tested 50, the filter allowing light having only the frequency of the beam line 12a, 12b to enter the focusing element. Therefore, only light rays that match the frequency of the beam lines 12a, 12b can be imaged on the photosensitive memory element 30, so that the arithmetic unit 40 can easily obtain the spot information of the beam lines 12a, 12b in the light group 11. After obtaining the spot information of each beam line 12a, 12b, the natural light real image can be used to determine the corresponding detection point of each spot in the actual image, thereby assisting the user to select between different detection points or single detection. The basis for measuring the distance.

On the other hand, in order to improve the resolution of the present invention, as shown in FIG. 3, the light source emitting device 10 includes a second winding of a light-emitting path between the light source 13 and the first diffractive optical element 14. The optical element 15 and a refractor 16 are injected. For example, the first diffractive optical element 14 can circulate 4 times of the beam line 12, and the second diffractive optical element 15 can circulate 2 times of the beam line. When the laser beam is emitted from the illuminating source 13 After the second diffractive optical element 15, four laser beams are generated, and the laser beam generated by the second diffractive optical element 15 is refracted into a parallel beam by the refractor 16 and then enters the first diffractive optical element 14, Finally, 8 laser beams are projected onto the surface of an object to be tested 50, so that the degree of resolution of the measurement can be effectively improved.

In order to further illustrate the measurement principle of the present invention, please refer to FIG. 4, which is a schematic diagram of the optical path structure of the coordinated single beam line of the present invention. It is known that the starting coordinate of a beam line 12 of the light group 11 is (0, 0, 0), and the beam line 12 is projected onto the surface of an object to be tested 50 by the first path function (1) on the YZ plane. Detect point P. The first path function (1) is:

Z = Tan懲θ× Y = (b/a) × Y ...... (1)

The beam line 12 reflected by the surface of the object to be tested 50 is imaged on the photosensitive memory element 30 by a focusing element focus 21 located at coordinates (0, 0, zf), and the coordinates of the imaging position are (0, -a, z). A second path function (2) is obtained based on the focus 21 coordinates (0, 0, zf) and the imaging position coordinates (0, -a, z). The second path function (2) is:

Z = [(zf-z)/a] × Y+zf ...... (2)

By decoupling the first path function (1) and the second path function (2), the coordinates (0, A, B) of the detection point P can be obtained.

Where Z of the first path function (1) is brought into the second path function (2), A(3.1) can be obtained:

A = a × zf / (z+b-zf) ...... (3.1)

Then, the Y of the first path function (1) is brought into the second path function (2), and B(3) can be obtained:

B = b × zf / (z+b-zf) ...... (3.2)

Therefore, the coordinates of the detection point P are (0, a × zf / (z + b - zf), b × zf / (z + b - zf)). It can be seen that the detection point P of each beam line 12 projected on the surface of the object to be tested can be known by its method.

The present invention can be applied to a plurality of light groups 11a, 11b (in this embodiment, only two light groups are taken as an example), and each of the light groups 11a, 11b has a phase formed by a plurality of beam lines 12 which are respectively arranged in a line. For the projection planes S1 and S2, see Figure 5 in the figure. The projection planes S1 and S2 intersect with each other on an intersecting axis. In FIG. 5, the intersecting axis is superimposed on the Z axis. The focus 21 of the focusing element is located on the projection plane S1, S2, and the intersecting axis passes through the focus 21 of the focusing element and the first diffractive optical element 14 of the light source emitting device 10. After the beam line 12 of each of the light groups 11a, 11b is reflected from the surface of the object to be tested, it passes through the focus 21 on the intersecting axis and is imaged on the photosensitive memory element 30 to form a sensing image. The image of the beam line 12 of each of the groups of rays 11a, 11b being imaged on the photosensitive memory element 30 will be aligned in a reverse order, that is, the beam line 12 of each group of rays 11a, 11b is on the photosensitive memory element 30. Arrange in a straight line. The computing unit 40 electrically connected to the photosensitive memory element 30, as shown in FIG. 2, can identify each beam line of the light group 11a, 11b according to the regularity of the sorting, and obtain each beam line. The first path function. In order to speed up the recognition of the speed of each beam line by the computing unit 40 and to enhance the accuracy of the operation unit 40 for identifying each beam line, the beam lines projected by the group of rays 11a, 11b have an interpretation for the operation unit 40. The graphic code can be presented in different shapes, different areas or different bright spots, such as a square shape, a circular shape, a high brightness diamond shape, and the like. Alternatively, different laser beams can be changed to different frequencies when passing through the first diffractive optical element 14, and the effect of quickly identifying the beam line can be achieved by the addition of a filter on the beam line reflection path.

In another embodiment, when there are N light beam groups and each of the light groups has N beam lines, the sensing image on the photosensitive memory element 30 will present an M x N matrix, where M and N are greater than The integer of 1 is shown in Figure 6. The N beam lines appear at the spots on the photosensitive memory element 30 in a straight line. The operation unit obtains the M x N matrix of the sensing image, and analyzes the position coordinates of each beam line reflected and projected on the photosensitive memory element 30, so that each beam line is projected onto the surface of the object to be tested by using the foregoing measurement principle. Detect the spatial location of the point.

The stereo distance measuring method and system thereof of the present invention can obtain the spatial position of each detecting point of the object to be tested by using a single shooting method to image the sensing image on the photosensitive memory element, thereby obtaining any position The relative distance between the two points of detection points, and the effect of the stereo distance measurement, is quite convenient and efficient for the measurer.

The present invention has been described in detail above, but the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Variations and modifications are still within the scope of the patents of the present invention.

10. . . Light source emitting device

11, 11a, 11b. . . Light group

12, 12a, 12b. . . Beam line

13. . . Light source

14. . . First diffractive optical element

15. . . Second diffractive optical element

16. . . Refracting mirror

twenty one. . . focus

30. . . Photosensitive memory element

40. . . Arithmetic unit

50. . . Object to be tested

P, P1, P2. . . Detection point

R. . . Illuminated path

S1, S2. . . Projection plane

S10, S20, S30, S40, S50. . . step

S10, S20, S30, S40, S50. . . step

Claims (16)

A stereo distance measuring system includes:
a light source emitting device that emits at least one light group forming a projection plane to be projected onto a surface of an object to be measured, the light group including a plurality of predetermined first path functions and aligned along a straight line to the object to be tested a beam line forming a detection point on the surface;
a focusing element comprising a focus through which a beam of light of the group of rays reflected by the surface of the object to be tested passes;
a photosensitive memory element receiving a beam line of a light group passing through a focus of the focusing element and forming a sensing image; and an arithmetic unit electrically connected to the photosensitive memory element to obtain the sensing image, according to the photosensitive memory element A second path function corresponding to each of the beamline imaging positions and the focus position of the focusing element is obtained, and an intersection position of each corresponding first path function and the second path function is calculated. The stereo distance measuring system according to claim 1, wherein the light source emitting device comprises a light emitting source that emits the light group by a light emitting path, and a first diffractive optical element located on the light emitting path. The stereo distance measuring system of claim 2, wherein the light source emitting device comprises a second diffractive optical element located between the light source and the first diffractive optical element. The stereo distance measuring system according to claim 1, wherein the beam line projected by the light group has a graphic code for interpretation by the operation unit. The stereo distance measuring system according to claim 1, wherein the focus of the focusing element is located on the projection plane. The stereo distance measuring system according to claim 1, wherein the plurality of projection planes formed by the plurality of light groups intersect each other on an intersecting axis, and the intersecting axis passes through a focus of the focusing element. The stereo distance measuring system of claim 6, wherein the light source emitting device comprises a light source that emits the light group by a light emitting path, and a first diffractive optical element located in the light emitting path, the projection The intersecting axes of the planes intersecting each other pass through the first diffractive optical element. The stereo distance measuring system according to claim 1, further comprising a filter disposed between the focusing element and the surface of the object to be tested, the filter allowing light having only the beam line frequency to enter the focusing element. The stereo distance measuring system according to claim 1, further comprising a housing that accommodates the light source emitter, the focusing component, the photosensitive memory, and the arithmetic unit. A method for determining a stereo distance, comprising the steps of:
Step a): providing at least one light group forming a projection plane to be projected onto a surface of the object to be tested, the light group comprising a plurality of respective first path functions and arranged in a straight line to the surface of the object to be tested a beam line forming a detection point;
Step b): the beam line of the group of rays reflected by the surface of the object to be tested forms a sensing image on a photosensitive memory element through a focus of a focusing element;
Step c): obtaining a second path function corresponding to each of the beamline imaging positions on the photosensitive memory element corresponding to a focus position of the focusing element; and step d): calculating each corresponding first path function and the The intersection position of the second path function is the spatial position of the detection point of the object to be tested. The stereo distance measuring method according to claim 10, wherein the focus of the focusing element is located on the projection plane. The method for determining a stereo distance according to claim 10, wherein the plurality of projection planes formed by the plurality of groups of rays intersect each other on an intersecting axis, and the intersecting axis passes through a focus of the focusing element. The method for determining a stereo distance according to claim 10 further includes the step e): calculating a distance between the different detection points according to different spatial positions of the object to be detected. The method for determining a stereo distance according to claim 10, wherein in the step b), the step further comprises: allowing light having only the beam line frequency to enter the focusing element. The method for measuring a stereo distance according to claim 10, further comprising the step f): obtaining a natural light image reflected by the surface of the object to be tested through the photosensitive memory element. The method for determining a stereo distance according to claim 14, wherein the step b) and the step c) further comprise: comparing the step f) the natural light image of the photosensitive memory element and the step b) The sensing image of the memory component acquires an image of only the light group.