CN112995486A

CN112995486A - Binocular camera and robot

Info

Publication number: CN112995486A
Application number: CN202110401481.7A
Authority: CN
Inventors: 陈展耀; 周宗华; 罗德国; 戴书麟; 刘风雷
Original assignee: Dongguan Ekos Technology Co Ltd
Current assignee: Dongguan Ekos Technology Co Ltd
Priority date: 2021-04-14
Filing date: 2021-04-14
Publication date: 2021-06-18
Also published as: WO2022218081A1

Abstract

The application discloses two mesh cameras and robot relates to machine vision technical field. The binocular camera comprises a substrate and a fixing frame arranged on the substrate, wherein dot matrix projection modules are arranged on the fixing frame at intervals, emergent light paths of the two dot matrix projection modules form a preset included angle, and the vertical distances between the two dot matrix projection modules and the substrate are equal; the binocular camera further comprises a first light receiving module and a second light receiving module which are arranged on the substrate, and the first light receiving module and the second light receiving module are used for respectively collecting light reflection information of the two dot matrix projection modules. The field angle can be improved, and the three-dimensional space reconstruction capability is further improved.

Description

Binocular camera and robot

Technical Field

The application relates to the technical field of machine vision, in particular to a binocular camera and a robot.

Background

Binocular Stereo Vision (Binocular Stereo Vision) is an important form of machine Vision, and is a method for acquiring three-dimensional geometric information of an object by acquiring two images of the object to be measured from different positions by using imaging equipment based on a parallax principle and calculating position deviation between corresponding points of the images.

In the prior art, the binocular stereo vision mostly adopts an active binocular structured light scheme to reconstruct the space three-dimension. In the existing active binocular structure optical camera, the visual angle is small due to the field angle transmitted by the dot matrix projector, so that the operable space is inevitably small, the detection of large-range three-dimensional obstacles cannot be realized, and the functions of obstacle avoidance, instant positioning and mapping (SLAM) or navigation of the robot and the like are influenced.

Disclosure of Invention

An object of the application is to provide a binocular camera and robot, can promote the angle of view, and then promote the three-dimensional reconstruction ability in space.

The embodiment of the application is realized as follows:

on one hand, the binocular camera comprises a substrate and a fixing frame arranged on the substrate, wherein dot matrix projection modules are arranged on the fixing frame at intervals, emergent light paths of the two dot matrix projection modules form a preset included angle, and the vertical distances between the two dot matrix projection modules and the substrate are equal; the binocular camera further comprises a first light receiving module and a second light receiving module which are arranged on the substrate, and the first light receiving module and the second light receiving module are used for respectively collecting light reflection information of the two dot matrix projection modules.

Optionally, the fixing frame is in an isosceles triangle structure, and the two dot matrix projection modules are respectively located on two opposite waists of the isosceles triangle.

Optionally, the binocular camera still includes the closed housing to and set up the transparent cover in casing one side, the base plate the mount the dot matrix is thrown the module first light receiving module with the second light receiving module all is located in the closed housing, just the base plate with transparent cover parallel arrangement.

Optionally, the distance between the two dot matrix projection modules is

And d is the distance between the two dot matrix projection modules, 2 beta is the angle of view of the dot matrix projection modules, 2 theta is the angle of view of the binocular camera, and h is the expected minimum application distance of the binocular camera.

Optionally, the dot matrix projection module comprises at least one dot matrix projector; when the number of the dot matrix projectors is larger than or equal to two, the dot matrix projectors of each dot matrix projection module are on the same straight line, and the two straight lines are parallel to each other.

Optionally, the dot matrix projector comprises a light source, and a collimating lens and a diffractive optical element located on an exit light path of the light source.

Optionally, the fixing frame includes positioning seats arranged at intervals, the two dot matrix projection modules are respectively located on positioning surfaces of the positioning seats, and the two positioning surfaces are respectively overlapped with two waists of the isosceles triangle.

Optionally, the first light receiving module and the second light receiving module are respectively located at two opposite sides of the two dot matrix projection modules.

Optionally, the fixing frame is made of a heat conducting material.

In another aspect of the embodiments of the present application, there is provided a robot including the binocular camera according to any one of the above.

The beneficial effects of the embodiment of the application include:

the binocular camera that this application embodiment provided, through the base plate to and the mount of setting on the base plate, in order to provide stable support to dot matrix projection module, first light receiving module and second light receiving module, in order to guarantee that the dot matrix projects the stability of relative position between module, first light receiving module and the second light receiving module. The emergent light path of the two dot matrix projection modules arranged on the fixing frame is arranged at a preset included angle, and compared with a single projector, the emergent light path is favorable for improving the field angle of the binocular camera. Under the condition that the field angle of the binocular camera is increased, the first light receiving module and the second light receiving module are favorable for receiving speckle pattern information in a wider range, the depth reconstruction range of the binocular camera is enlarged, and further the three-dimensional space reconstruction capability is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is one of schematic structural diagrams of a binocular camera provided in an embodiment of the present application;

fig. 2 is a second schematic structural diagram of a binocular camera provided in the embodiment of the present application;

fig. 3 is a diagram illustrating a positional relationship between the dot matrix projection module and the transparent cover plate according to an embodiment of the disclosure;

FIG. 4 is a schematic structural diagram of a connection between a fixing frame and a dot matrix projector according to an embodiment of the present disclosure;

fig. 5 is a schematic structural view illustrating a connection between the positioning seat and the dot matrix projection module according to an embodiment of the present application.

Icon: 100-binocular camera; 120-a fixed mount; 122-a positioning seat; 1222-a positioning surface; 130-a dot matrix projection module; 132-a dot matrix projector; 140-a first light receiving module; 150-a second light receiving module; 160-a closed housing; 170-transparent cover plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

With the improvement of living standard of people, the indoor robot based on the intelligent navigation scheme gradually enters the life of people, and the 3D sensing system is the most core part of the indoor robot to realize functions of SLAM, obstacle avoidance and the like. At present, the binocular stereo vision mostly adopts an active binocular structured light scheme to reconstruct the space three-dimension. However, in practical use, the effect is strong, the main problem is that the obstacle avoidance capability is poor, the main sensors are located at the top of the robot, the visual angle is small, the visual range is small, the operable space is small, and the detection of large-range three-dimensional obstacles cannot be realized.

And the depth field angle of the active binocular structured light depends on the field angle of the camera. The existing field angle is about 60 multiplied by 80 at most under the premise of ensuring the optical performance due to the micro-nano optical technology, and the method can be applied to certain specific scenes such as door control, door lock and the like. In an application scene of intelligent robot navigation, the required depth reconstruction field angle can reach 120 multiplied by 80, and the existing camera obviously cannot reach such a large field angle, so that the three-dimensional reconstruction capability in practical application is limited. Based on this, the following scheme is specifically proposed in the embodiments of the present application to improve the field angle and further improve the spatial three-dimensional reconstruction capability.

Referring to fig. 1, the present embodiment provides a binocular camera 100, including a substrate and a fixing frame 120 disposed on the substrate, wherein dot matrix projection modules 130 are disposed on the fixing frame 120 at intervals, an emergent light path of the dot matrix projection modules 130 forms a predetermined included angle, and vertical distances between the dot matrix projection modules 130 and the substrate are equal; the binocular camera 100 further includes a first light receiving module 140 and a second light receiving module 150 disposed on the substrate, and the first light receiving module 140 and the second light receiving module 150 are used for respectively collecting light reflection information of the two-dot matrix projection module 130.

Specifically, the parameters of the two-dot matrix projection modules 130 spaced apart from each other on the fixing frame 120 are the same, and the vertical distances between the two-dot matrix projection modules 130 and the substrate are the same. Therefore, the two-dot matrix projection module 130 is located at the same installation height, and when the two-dot matrix projection module is used, the speckle patterns projected by the two-dot matrix projection module 130 are equal in position and size at the same distance, which is beneficial to ensuring the consistency of the patterns projected by the two-dot matrix projection module 130, so that the calculation difficulty is reduced. In practical applications, the dot matrix projection module 130 with different parameter information can be set according to the requirements to meet the diversified requirements.

The binocular camera 100 of the present application is implemented based on the principle of optical triangulation of active binocular structured light three-dimensional vision. When the two-dot array projection module 130 is used, structured light in a certain mode is projected on the surface of an object, so that a three-dimensional image of light bars modulated by the surface shape of the object to be measured is formed on the surface of the object. The three-dimensional image is collected by the first light receiving module 140 and the second light receiving module 150, so as to obtain a two-dimensional distorted image of the light bar. The degree of distortion of the light bar depends on the relative position and the object surface profile (height) between the dot matrix projection module 130 and the first light receiving module 140 and the second light receiving module 150, respectively. When the relative positions of the dot matrix projection module 130, the first light receiving module 140 and the second light receiving module 150 are fixed, the three-dimensional profile of the object surface can be reproduced by the distorted two-dimensional light strip image coordinates, so as to achieve the purpose of spatial three-dimensional reconstruction.

It should be noted that, when the active binocular structured light is used to perform spatial three-dimensional reconstruction, the projection range of the speckle pattern of the binocular camera 100, that is, the field angle, cannot be calculated in the area where the speckle pattern is not projected. In the embodiment of the present application, the exit light path of the two-dot matrix projection module 130 forms a preset included angle, so that the field angle of the binocular camera 100 can be increased, the parallax offset of the same-name point is calculated through the light reflection information (image information) collected by the first light receiving module 140 and the second light receiving module 150, and finally, the depth calculation and the depth compensation are performed, so as to generate the high-resolution and high-precision image depth information. The first light receiving module 140 and the second light receiving module 150 may employ a receiving camera, and the photosensitive chips thereof are Complementary Metal-Oxide-Semiconductor (CMOS) or Charge Coupled Device (CCD) to collect the speckle pattern of the space to be measured.

The binocular camera 100 provided by the embodiment of the present application, through the substrate and the fixing frame 120 disposed on the substrate, is convenient for providing stable support for the dot matrix projection module 130, the first light receiving module 140 and the second light receiving module 150, so as to ensure stability of relative positions among the dot matrix projection module 130, the first light receiving module 140 and the second light receiving module 150. The exit light path of the two-dot matrix projection module 130 disposed on the fixing frame 120 is set to have a predetermined included angle, which is advantageous to increase the field angle of the binocular camera 100 compared with the case of using a single projector. Under the condition that the field angle of the binocular camera 100 is increased, the first light receiving module 140 and the second light receiving module 150 are favorable for receiving speckle pattern information in a wider range, the depth reconstruction range of the binocular camera 100 is expanded, and the three-dimensional space reconstruction capability is improved.

As shown in fig. 1, the fixing frame 120 is an isosceles triangle structure, and the two-dot matrix projection modules 130 are respectively located on two opposite sides of the isosceles triangle.

Specifically, the fixing frame 120 is an isosceles triangle structure, that is, the fixing frame 120 adopts an isosceles triangle bracket, so that the structure of the fixing frame 120 is more stable and reliable. In addition, the two-dot matrix projection module 130 is respectively positioned on two opposite waists of the isosceles triangle, so that the two-dot matrix projection module 130 is stably connected with the fixing frame 120, when the two-dot matrix projection module is fixedly installed, the emergent light path of the two-dot matrix projection module 130 is perpendicular to the waists of the isosceles triangle, and thus, the base angle degree of the isosceles triangle determines the size of the preset included angle of the emergent light path of the two-dot matrix projection module 130, when the binocular cameras 100 of different models are assembled, the adjustment of the required emergent light path angle can be realized by replacing different fixing frames 120, the assembly structure is facilitated to be simplified, the operation difficulty is reduced, and the assembly efficiency is improved.

As shown in fig. 2, the binocular camera 100 further includes a closed housing 160 and a transparent cover plate 170 disposed on one side of the housing, the substrate, the fixing frame 120, the dot matrix projection module 130, the first light receiving module 140 and the second light receiving module 150 are all disposed in the closed housing 160, and the substrate and the transparent cover plate 170 are disposed in parallel.

Specifically, adopt above-mentioned form, be favorable to throwing components and parts such as module 130, first light receiving module 140 and second light receiving module 150 to the dot matrix through transparent cover 170 and closed housing 160 and protect to guarantee the stability when binocular camera 100 uses, for example sealed, prevent the entering of dust or steam, thereby avoid receiving external environment's interference. It should be noted that the arrangement form of the close housing 160 is not specifically limited in the embodiment of the present application, and for example, the close housing 160 may be a cylinder, and may also be a truncated cone or other shapes, as long as it can be ensured that the field angle of the binocular camera 100 is not affected, and the first light receiving module 140 and the second light receiving module 150 are not shielded from the line of sight.

As shown in fig. 2 and 3, the distance between the two-dot matrix projection modules 130Is composed of

Where d is the distance between the two dot matrix projection modules 130, 2 β is the angle of view of the dot matrix projection modules 130, 2 θ is the angle of view of the binocular camera 100, and h is the minimum application distance expected by the binocular camera 100.

Specifically, fig. 3 is a simplified geometric model of the dot matrix projection module 130 and the fixing frame 120 in fig. 2, assuming that the two dot matrix projection modules 130 are respectively the points B and E in fig. 3. The plane of the straight line GN is the plane of the transparent cover 170, and the fixing frame 120 is an isosceles triangle of Δ JCI. Wherein, angle GBF and angle NEF are the field angles of the two-dot matrix projector 132, respectively, and are set to be 2 β, the straight line BP and the straight line EM are the angular bisectors of angle GBF and angle NEF, respectively, and when the emergent light path of the dot matrix projection module 130 is perpendicular to the waists of the isosceles triangle, the straight line BP and the straight line EM are perpendicular to CJ and IJ. And (3) extending the straight line GB and the straight line NE, comparing the straight line GB and the straight line NE with the point A, knowing from the geometrical relationship that the intersection points F, J and A are in the same straight line, and setting the angle GAN as the angle of view required to be spliced finally as 2 theta. The edge rays BF and EF of the two dot matrix projectors 132 will intersect at point F, meaning that the minimum application distance of the product is FJ, set to h, otherwise there is a region without scattered spots (e.g., the region surrounded by FBJE shown in the figure), resulting in failure of depth reconstruction.

Under the premise that the field angle 2 β of the single dot matrix projector 132 is known and the field angle 2 θ and the minimum application distance h are finally spliced, an isosceles triangle angle a (angle JCI in fig. 3) and a distance BE between the two dot matrix projection modules 130 can BE obtained.

From the geometric relationship of the triangle:

∠PBJ＝∠PBF+∠FBJ (1)

∠BJF＝∠BDJ+∠DBJ (2)

∠ABE+∠EBJ+∠PBJ+∠GBP＝180 (3)

∠JCI＝∠JBE (4)

∠FBJ+∠BJF+∠BFJ＝180 (5)

substituting ═ PBJ ═ 90 into the above equation to obtain:

∠BFJ＝2β-θ，∠FBJ＝90-β，∠JCI＝α＝θ-β

in Δ BFJ, there are, by the triangular sine theorem:

as can be seen from equation (6):

in Δ BDJ, there is a constant equation:

as can be seen from the equations (7) and (8), the distance d between the two-dot matrix projection modules 130 is:

as can be seen from the above formula, as long as the viewing angle 2 β of a single dot matrix projection module 130, the desired splicing viewing angle 2 θ and the desired minimum application distance h are determined, the relative distance between the isosceles triangular fixing frame 120 and the left and right dot matrix projection modules 130 can be designed according to the above formula. Wherein the desired minimum application distance h may be determined according to the installation application environment of the product.

As shown in fig. 1 and 4, the dot matrix projection module 130 includes at least one dot matrix projector 132; when the number of the dot matrix projectors 132 is greater than or equal to two, the dot matrix projectors 132 of each dot matrix projection module 130 are on the same straight line, and the two straight lines are parallel to each other.

Specifically, each dot matrix projection module 130 may only include one dot matrix projector 132, and also may be configured to have two or more dot matrix projectors 132 according to the complexity of the object, so as to facilitate increasing the density of the speckle patterns in the unit area, and further improve the three-dimensional reconstruction capability. It can be understood that the area projected by the dot matrix projector 132 is generally rectangular, and when the dot matrix projector 132 of each dot matrix projection module 130 is on the same straight line and the two straight lines are parallel to each other, the projection areas between the two dot matrix projection modules 130 can be better distributed, so as to improve the utilization rate of the projected light beams and avoid the light-emitting area of the binocular camera 100 without the light beam projection area.

In an alternative embodiment of the present application, the dot matrix projector 132 includes a light source, and a collimating lens and diffractive optical element positioned in the path of the light source's exit light.

Specifically, the light source may be any one of a Light Emitting Diode (LED), a semiconductor Laser (LD), and a Vertical Cavity Surface Emitting Laser (VCSEL). The light beam emitted from the light source is collimated by the collimating lens to be emitted in parallel, and then is shaped and diffracted by the diffractive optical element to form a specific speckle pattern.

As shown in fig. 5, the fixing frame 120 includes positioning bases 122 disposed at intervals, the two-dot matrix projection module 130 is respectively located on positioning surfaces 1222 of the positioning bases 122, and the two positioning surfaces 1222 are respectively overlapped with two waists of the isosceles triangle.

Specifically, in the above form, it is considered that the isosceles triangle is cut off at a position where it is not necessary, and only two corners of the triangle are reserved, so as to reduce the cost. It can be understood that the positioning seat 122 may also be in the form of a right trapezoid, so as to perform heightening processing and the like on the installation position of the lattice projection module 130 according to actual needs.

As shown in fig. 1, the first light receiving module 140 and the second light receiving module 150 are respectively located at two opposite sides of the two-dot matrix projection module 130. In this way, the first light receiving module 140 and the second light receiving module 150 can collect information respectively, and the depth information can be measured by integrating information of different dimensions.

Optionally, the fixing frame 120 is made of a heat conductive material. For example, the fixing frame 120 may be made of copper or aluminum, or may be made of thermal conductive silicon or ceramic, and may be flexibly configured according to the actual use environment.

The embodiment of the application also discloses a robot, which comprises the binocular camera 100 in the embodiment. The robot includes the same structure and advantageous effects as the binocular camera 100 in the foregoing embodiment. The structure and the advantageous effects of the binocular camera 100 have been described in detail in the foregoing embodiments, and are not described in detail herein.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A binocular camera is characterized by comprising a substrate and a fixing frame arranged on the substrate, wherein dot matrix projection modules are arranged on the fixing frame at intervals, emergent light paths of the two dot matrix projection modules form a preset included angle, and the vertical distances between the two dot matrix projection modules and the substrate are equal; the binocular camera further comprises a first light receiving module and a second light receiving module which are arranged on the substrate, and the first light receiving module and the second light receiving module are used for respectively collecting light reflection information of the two dot matrix projection modules.

2. The binocular camera according to claim 1, wherein the fixing frame is an isosceles triangle structure, and the two dot matrix projection modules are respectively located on two opposite sides of the isosceles triangle.

3. The binocular camera according to claim 2, further comprising a closed housing and a transparent cover plate disposed on one side of the housing, wherein the base plate, the fixing frame, the dot matrix projection module, the first light receiving module and the second light receiving module are all located in the closed housing, and the base plate and the transparent cover plate are disposed in parallel.

4. The binocular camera of claim 3, wherein the distance between the two dot matrix projection modules is

5. The binocular camera of any one of claims 1-4, wherein the dot matrix projection module comprises at least one dot matrix projector; when the number of the dot matrix projectors is larger than or equal to two, the dot matrix projectors of each dot matrix projection module are on the same straight line, and the two straight lines are parallel to each other.

6. The binocular camera of claim 5, wherein the dot matrix projector includes a light source, and a collimating lens and diffractive optical element positioned in an exit light path of the light source.

7. The binocular camera according to claim 1, wherein the fixing frame includes positioning seats arranged at intervals, the two dot matrix projection modules are respectively located on positioning surfaces of the positioning seats, and the two positioning surfaces are respectively overlapped with two waists of the isosceles triangle.

8. The binocular camera according to any one of claims 1 to 4, wherein the first light receiving module and the second light receiving module are respectively located at opposite sides of the two dot matrix projection modules.

9. The binocular camera of any one of claims 1-4, wherein the mount is made of a thermally conductive material.

10. A robot comprising the binocular camera of any one of claims 1 to 9.