TW202130972A - Distance measurement device - Google Patents

Abstract

An object of the invention is to provide a distance measurement device that can be constructed using fewer components than a conventional device. The distance measurement device of the invention comprises a prism, a lens, and an imaging element. Light from an imaging subject enters the prism from two different directions. The prism sends the first light and second light that have entered from the two different directions to the lens. The lens forms images of the first light and second light sent from the prism on an imaging surface of the imaging element. The imaging surface is divided equally into an adjacent right side region and left side region. The first light sent from the lens forms an image in the right side region, and the second light sent from the lens forms an image in the left side region. The imaging element sends the right side image that is an image of the first light and the left side image that is an image of the second light to a control section. The control section measures the distance between the imaging subject and the distance measurement device based on the right-side image and the left-side image sent from the imaging element.

Description

Distance measuring device

The present invention relates to a distance measuring device using a stereo camera.

As a technique for measuring the distance between the vehicle and the vehicle ahead, or the distance between the vehicle and an obstacle, for example, a stereo camera is used. In the conventional stereo camera, the position information of the object is calculated based on the images taken by two imaging elements that have parallax to the object.

In recent years, a stereo camera has been proposed that can capture the same stereoscopic image as a stereo camera equipped with two imaging elements by using one imaging element (for example, refer to Patent Document 1 and Patent Document 2).

According to the stereo camera of Patent Document 1, a pair of mirror portions (first mirror portion and second mirror portion) are provided, and the (shooting area) of one imaging element is divided into a first area and a second area. The first area of the device captures the first image reflected by the first mirror, and the second area of the capture device captures the second image reflected by the second mirror.

In addition, in the stereo camera according to Patent Document 2, the optical paths of two images having parallaxes with different polarization directions in the vertical direction are superimposed into one by combining a beam and a beam splitter, and the superimposed image is One imaging element forms the image.

[Patent Literature]

[Patent Document 1] JP 2014-199241 A [Patent Document 2] JP 2002-347517 A

[The problem to be solved by the invention]

Here, the stereo camera according to the above-mentioned Patent Document 1 and Patent Document 2 (hereinafter, also referred to as a conventional stereo camera) is mainly installed in a steam, and used for measurement of the distance between a vehicle and the like. However, the application program for measuring distance with a stereo camera is not only for in-vehicle use, but also in demand in various industrial fields. In addition to in-vehicle applications, for example, it is assumed that a stereo camera is installed at the tip of the robotic arm of an industrial robotic arm used to manufacture fine parts, or the distance between the robotic arm and the object (subject) handled by the robotic arm is measured. The distance and other uses.

In addition, the distance between a few meters to several tens of meters, such as the inter-vehicle distance measured by an in-vehicle stereo camera, and the distance to the subject measured by the stereo camera for the robot arm, is, for example, a short tens of cm. the distance. In addition, in a stereo camera for a robot arm, a measurement accuracy with a margin of error of, for example, a few millimeters or several hundreds of micrometers is required.

In the conventional stereo camera, when an image with parallax is obtained by one imaging element, the number of parts constituting the optical system will increase. As a result, in the conventional stereo camera, the size of the entire stereo camera becomes larger. Therefore, it is not advantageous in terms of cost, and for example, when it is installed on the front end of the robot arm, it will have space constraints. In addition, the conventional stereo camera uses a large number of parts. Therefore, when combining the parts, it is necessary to coordinate the optical axis between the parts. In addition to time-consuming precision adjustment, it is more difficult to achieve.

In addition, the object of the present invention is to provide a stereo camera suitable for short-distance measurement, which is a distance measuring device using "a stereo camera with one imaging element" and can be constructed with fewer parts than conventional devices . [Technical means to solve the problem]

In order to solve the above-mentioned problems, the distance measuring device according to the present invention has a configuration including: a lens, a lens, and an imaging element arranged linearly in order to make the center line coincide with each other, and a control unit connected to the imaging element. In 稜鏡, the light from the subject enters from two different directions. In addition, the first light beam and the second light beam incident from two different directions are respectively directed to the lens. The lens makes the first light beam and the second light beam emitted from the lens image on the photographing surface of the photographing element. The photographing surface includes adjacent right and left areas, and serves as an area that divides the photographing surface into equal parts. In addition, the first light ray emitted from the lens is imaged in the right area, and the second light ray emitted from the lens is imaged in the left area. The imaging element sends the right image formed by the first light and the left image formed by the second light to the control part. The control unit measures the distance between the subject and the distance measuring device based on the right and left images sent from the imaging element. [Effects of Invention]

In the distance measuring device of the present invention, by using one lens, one lens, and one imaging element, the distance to the subject can be measured even if the number of parts is small compared with the past. Therefore, in the distance measuring device of the present invention, it is advantageous for miniaturization. In addition, in the distance measuring device of the present invention, it is only necessary to align the optical axis between the lens and the lens, and between the lens and the imaging element, and it is easier to maintain accuracy than before. Therefore, the distance measuring device of the present invention can also be used for short-distance measurement, such as being installed on the tip of the hand of a robot arm, etc., which is limited in space and requires a small measurement accuracy.

Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the shape, size, and arrangement relationship of each constituent element are only schematic representations of the extent to which the present invention can be understood. In addition, in the following, a suitable configuration example of the present invention will be described, but the material and numerical conditions of each component are only preferred embodiments. Therefore, the present invention is not limited to the following embodiments, and various changes or modifications that can achieve the effects of the present invention can be made without departing from the scope of the constitution of the present invention.

(constitute) 1 and 2, the structure of the distance measuring device of the present invention will be described. Fig. 1 is a schematic diagram showing a distance measuring device. Fig. 2 (A) and (B) are schematic diagrams showing the scallops included in the distance measuring device. Fig. 2(A) is a front view of the 稜鏡 viewed from the direction of the arrow A1 shown in Fig. 1, and Fig. 2(B) is a side view of the 稜鏡 viewed from the direction of the arrow A2 shown in Fig. 1.

The distance measuring device 100 is configured to include a lens 10, a lens 20, a main body 50, and a control unit 40. The main body 50 includes the imaging element 30.

The center line of the lens 10, the lens 20, and the imaging element 30 are aligned and arranged in a straight line in this order.

A pair of bottom surfaces (the upper bottom surface 111 and the lower bottom surface 112) of the 稜鏡 10 on the opposite side are in the shape of a triangular column of an isosceles triangle. Therefore, the 稜鏡 10 has three faces along the height direction, that is, between the bottom faces 111 and 112, the first face 101 is sandwiched between one of the isosceles on the opposite side, and the first face 101 is on the opposite side. The second surface 102 is sandwiched between the other sides of the waist, and the third surface 103 is sandwiched between the bottom edges of the opposite sides.

In addition, in the following description, the direction along the upper bottom surface 111, the lower bottom surface 112, and the third surface 103 of the 稜鏡 10 is set as the X-axis direction, and the direction perpendicular to the third surface 103 of the 稜鏡 10 is set as Y Axis direction, and the direction along the first surface 101, the second surface 102, and the third surface 103 of the scallop 10 (the height direction of the scallop 10) is referred to as the Z-axis direction.

Here, when the distance measuring device 100 is used to measure the distance between the subject 200 and the distance measuring device 100, the side of the first surface 101 and the second surface 102 (X-axis-Y-axis plan view) The top corner sides of the upper bottom surface 111 and the bottom bottom surface 112) face the subject 200. The light from the subject 200 enters the light beam 10 from two different directions. Among the light rays from the subject 200, the first light ray R1 from one side direction enters the beam 10 from the first surface 101. In addition, among the light rays from the subject 200, the second light ray R2 from the other side direction enters the beam 10 from the second surface 102.

The first light ray R1 incident from the first surface 101 is refracted on the first surface 101 and exits from the third surface 103. The path of the light rays exiting from the third surface 103 through the first surface 101 is regarded as the first path. Furthermore, the second light ray R2 incident from the second surface 102 is refracted on the second surface 102 and exits from the third surface 103. The path of the light rays exiting from the third surface 103 through the second surface 102 is regarded as the second path.

In addition, the ridge 10 is arranged so that the third surface 103 thereof is located on the opposite side to the incident side surface 21 of the lens 20. In addition, the lens 10 is optically connected to the lens 20 on the third surface 103 side. The light rays emitted from the ridge 10 through the first path and the light rays emitted from the ridge 10 through the second path are both shot to the lens 20. In addition, in the frame 10, in order to make the third surface 103 face the incident side 21 of the lens 20, and to adjust the position of the subject in the image captured by the imaging element 30 described later, the frame 10 can be adjusted slightly. For the opposite configuration of the lens 20.

The lens 20 is arranged at a position where the first light ray R1 and the second light ray R2 form an image on the imaging surface 31 of the imaging element 30 described later. The lens 20 forms an image on the imaging surface 31 of the imaging element 30 with the light (the first light ray R1 and the second light ray R2) radiated from the lens 10.

The main body 50 includes an imaging element 30, such as a digital camera, which is connected to the control unit 40. The imaging element 30 sends the captured image (image formed on the imaging surface 31) to the control unit 40 as digital data.

The photographing surface 31 is a plane looking down along the X axis-the Z axis. The imaging surface 31 includes a right side area and a left side area adjacent to each other in the X-axis direction, as areas that divide the imaging surface 31 into equal parts. In addition, the first light ray R1 emitted from the ridge 10 via the first path is imaged on the right side area of the imaging surface 31. In addition, the second light ray R2 emitted from the scorpion 10 via the second path is imaged on the left area of the imaging surface 31. Therefore, the image captured by the imaging element 30 includes: a right image formed on the right area of the photographing surface 31 and a left image formed on the left area.

The control unit 40 is constituted by, for example, a CPU (Central Processing Unit), and controls the overall operation of the distance measuring device 100. The control unit 40 executes various processes in accordance with a predetermined control program. The results of these processes are appropriately stored in RAM and other storage means.

The control unit 40 measures the distance between the subject 200 and the distance measuring device 100 based on the right and left images emitted from the imaging element 30.

Here, although illustration is omitted in FIG. 1, in addition to the control unit 40, a "control means for appropriately processing the image of the imaging element 30 "may be provided in the main body 50. At this time, the control means of the main body 50 may be connected to the control section 40, and the digitally documented image can be sent to the control section 40 from the control means of the main body 50.

(action) In addition to FIGS. 1 and 2, referring to FIGS. 3 and 4, the operation of the distance measuring device of the present invention will be described. Fig. 3 is a flowchart showing the flow of processing performed by the control unit of the distance measuring device. In addition, FIG. 4 is a schematic diagram showing an image obtained by the control unit of the distance measuring device.

First, the control unit 40 obtains the image 60 including the right image 61 and the left image 62 sent from the imaging element 30 (S1).

As described above, the right image 61 is an image of the light rays emerging from the scorpion 10 through the first path, which is imaged on the right area of the photographing surface 31. In addition, the left image 62 is an image of the light rays emitted from the scorpion 10 through the second path, which is imaged on the left area of the photographing surface 31. Therefore, the right image 61 and the left image 62 are images of the subject 200 taken from two different directions. Therefore, there will be a deviation (that is, parallax) between the imaging position of the subject 200 included in the right image 61 and the imaging position of the subject 200 obtained as the left image 62.

Next, the control unit 40 obtains the position of the right partial image 611 in the right image 61 and the position of the left partial image 612 in the left image 62 (S2).

The image 611 on the right is an image of the subject 200 included in the image 61 on the right. In addition, the left partial image 612 is an image of the subject 200 included in the left image 62. In FIG. 4, the part of the text marked "A" of the subject 200 is used as the right partial image 611 and the left partial image 612.

When extracting the right partial image 611 and the left partial image 612 from the right image 61 and the left image 62, software for processing images such as Blob (binary large object) can be used.

In this process, the position coordinates along the X-axis of the right partial image 611 and the left partial image 612 are respectively obtained. FIG. 4 shows an example of obtaining "position coordinates in the direction from the left end to the right end of each image 61 and 62" as "the first position coordinate CR of the right partial image 611 and the second position coordinate CL of the left partial image 612" .

Next, the control unit 40 obtains "the difference between the first position coordinate CR of the right partial video 611 and the second position coordinate CL of the left partial video 612" as the parallax (S3).

Next, the control unit 40 converts the above-mentioned parallax into a distance (S4). As a result, in the distance measuring device 100, the distance between the subject 200 and the distance measuring device 100 (the separation distance between the subject 200 and the distance 10) can be measured based on the acquired image 60.

As described above, the distance measuring device 100 can measure the distance to the subject 200 by using one lens 10, one lens 20, and one imaging element 30, even with a smaller number of parts than before. Therefore, the distance measuring device 100 is advantageous for miniaturization. In addition, in the distance measuring device 100, it is only necessary to align the optical axis between the lens 10 and the lens 20, and the optical axis between the lens 20 and the imaging element 30, so that it is easier to maintain accuracy than before. Therefore, the distance measuring device 100 can also be used for, for example, being installed on the tip of a robot arm and used for short distance measurement where space is limited and minute measurement accuracy is required.

10: 稜鏡 100: Distance measuring device 101: first side 102: second side 103: The third side 111: upper bottom 112: bottom surface 20: lens 200: Subject 21: Incident side 30: Camera components 31: shooting surface 40: Control Department 50: body part 60: Image 61: Right image 611: Part of the image on the right 612: Left part of the image 62: Left image A1: Arrow A2: Arrow R1: First light R2: second light S1~S4: Processing flow X: X axis direction Y: Y axis direction Z: Z axis direction

[Fig. 1] A schematic diagram showing a distance measuring device. [Fig. 2] (A) and (B) are schematic diagrams showing the scallops included in the distance measuring device. [Fig. 3] A flowchart showing the flow of processing performed by the control unit of the distance measuring device. [Fig. 4] A schematic diagram showing an image obtained by the control unit of the distance measuring device.

10: 稜鏡

100: Distance measuring device

101: first side

102: second side

103: The third side

111: upper bottom

20: lens

200: Subject

21: Incident side

30: Camera components

31: shooting surface

40: Control Department

50: body part

A1: Arrow

A2: Arrow

R1: First light

R2: second light

X: X axis direction

Y: Y axis direction

Claims (2)

A distance measuring device, including: Make the centerline of the lens, the lens, and the imaging element coincide with each other and arrange them in a straight line according to the aforementioned sequence; and The control part is connected with the imaging element; The light from the subject is incident on the beam from two different directions; The prism sends the first light and the second light incident from two different directions to the lens respectively; The lens makes the first light beam and the second light beam emitted from the beam image on the photographing surface of the photographing element; The photographing surface includes adjacent right and left areas as areas that equally divide the photographing surface; the first light ray emitted from the lens is imaged on the right area, and the second light ray emitted from the lens is imaged In the left area; The imaging element sends the right image formed by the first light and the left image formed by the second light to the control part; The control unit measures the distance between the subject and the distance measuring device based on the right image and the left image sent from the imaging element. The distance measuring device described in claim 1, wherein: The control unit performs the following processing: Obtain the image of the subject included in the right image, that is, the first position coordinate of the right part of the image in the right image, and the image of the subject included in the left image, that is, the position of the left part of the image The second position coordinate in the left image; Obtaining the difference between the first position coordinate and the second position coordinate as the parallax; and Convert the disparity to distance; In this way, the distance between the subject and the distance measuring device is measured.

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