Depth camera and mobile robot

Abstract

The present application provides a depth camera and a mobile robot. The depth camera includes: a line laser emission unit for emitting a plurality of line laser beams with a preset width; a dot matrix emission unit disposed on the side of the line laser emission unit for emitting dot matrix beams, the dot matrix emission unit including multiple rows of dot matrix light sources, and at least two rows of dot matrix light sources are arranged in a regular staggered manner and circularly arranged; an optical element disposed on the light-emitting paths of the line laser emission unit and the dot matrix emission unit, the line laser beam passes through the optical element and projects a uniform light pattern towards the space to be measured for close-range detection, and the dot matrix beam passes through the optical element and projects a speckle pattern towards the space to be measured; a receiving unit disposed on the side of the line laser emission unit and the dot matrix emission unit. The depth camera of the present application can obtain close-range obstacle avoidance depth information for high-precision close-range obstacle avoidance, identify black material objects and small objects, and can also achieve three-dimensional positioning navigation and three-dimensional height measurement, and solve the problem of multi-path.

Description

Technical Field

[0001] This application relates to the technical field of depth acquisition, and particularly to a depth camera and a mobile robot. Background Art

[0002] With the gradual development of technologies such as machine vision and autonomous driving, there are more and more applications related to object recognition and scene modeling using depth cameras. It can be said that depth cameras are the eyes of robots. Currently, there are three common depth camera solutions on the market: structured light cameras, binocular cameras, and time-of-flight (TOF) cameras. The principles of the above three depth cameras are different, and the applicable application scenarios are also different. They often need to cooperate with each other to meet the requirements of complex application scenarios.

[0003] For example, when a mobile robot realizes the mapping and navigation function, it mainly achieves 2D mapping and navigation through LDS (Laser Direct Structuring); when a mobile robot realizes the obstacle avoidance function, it mainly uses TOF technology to detect the depth information of objects at close range to achieve the close-range obstacle avoidance recognition function. In addition, it is also impossible to accurately measure the height of low objects in the space. However, existing mobile robots cannot perform simultaneous three-dimensional positioning and navigation, close-range high-precision obstacle avoidance, and three-dimensional height measurement. Summary of the Invention

[0004] In view of the above, it is necessary to provide a depth camera and a mobile robot to solve the problem that existing depth cameras cannot simultaneously achieve three-dimensional positioning and navigation, close-range high-precision obstacle avoidance, and three-dimensional height measurement.

[0005] A first aspect of an embodiment of the present application provides a depth camera, including: a line laser emission unit configured to emit a plurality of line laser beams with a preset width, where the plurality of line laser beams do not intersect in the projection area and the angle with the vertical direction is less than 30 degrees, and at least one of the line laser beams has an angle with the vertical direction greater than 0 degrees in the projection area; a dot matrix emission unit disposed on the side of the line laser emission unit and configured to emit dot matrix beams, the dot matrix emission unit including multiple rows of dot matrix light sources, and at least two rows of the dot matrix light sources are arranged in a regular staggered manner and arranged in a cycle; an optical element disposed on the light emission paths of the line laser emission unit and the dot matrix emission unit, the line laser beams pass through the optical element and project a uniform light pattern toward the space to be measured for short-distance detection, the dot matrix beams pass through the optical element and project a speckle pattern toward the space to be measured, both the uniform light pattern and the speckle pattern are projected onto the obstacle avoidance area for obstacle avoidance, and the speckle pattern is projected onto the navigation area for navigation; a receiving unit disposed on the side of the line laser emission unit and the dot matrix emission unit, configured to receive the optical signals corresponding to the uniform light pattern and the speckle pattern to obtain the obstacle avoidance depth information at a short distance, so as to perform three-dimensional height measurement and short-distance obstacle avoidance, and configured to receive the optical signals corresponding to the speckle pattern to obtain the navigation depth information, so as to perform three-dimensional positioning and navigation.

[0006] In the depth camera provided by the embodiment of the present application, the plurality of line laser beams do not intersect in the projection area and the angle with the vertical direction is less than 30 degrees, and at least one of the line laser beams has an angle with the vertical direction greater than 0 degrees in the projection area. The dot matrix emission unit includes multiple rows of dot matrix light sources, and at least two rows of the dot matrix light sources are arranged in a regular staggered manner and arranged in a cycle. Both the uniform light pattern and the speckle pattern are projected onto the obstacle avoidance area for obstacle avoidance, and the speckle pattern is projected onto the navigation area for navigation. When performing short-distance detection, the depth information obtained by projecting with the plurality of line laser beams is the main information, and the depth information obtained by projecting with the dot matrix beams can be used as a supplement for the area not covered by the line laser beams, so that more complete obstacle contour information can be obtained, realizing high-precision obstacle avoidance at a short distance, solving problems such as short-distance blind areas, multi-path, black material recognition, and small object recognition, and having the characteristics of high precision at the same time; and when performing long-distance detection, the depth information obtained by projecting with the dot matrix beams can be used for three-dimensional positioning and navigation. Since at least two rows of the dot matrix light sources in the multiple rows of dot matrix light sources are arranged in a regular staggered manner and arranged in a cycle, the interval blind area between two adjacent dot matrix light sources in each row of the dot matrix light sources can be supplemented by the dot matrix light sources in the next row, so that the resolution of the depth camera is relatively high. In addition, through the cooperation of the line laser emission unit and the dot matrix emission unit, the depth information obtained by projecting with the plurality of line laser beams and the depth information obtained by projecting with the dot matrix beams can complement each other, and three-dimensional height measurement of the objects in the space can be performed with relatively high precision.

[0007] In a possible implementation, when the multiple line laser light beams are projected into the space to be measured, the height information of the obstacles in the space to be measured can be obtained; when the dot matrix light beams are projected into the space to be measured, the contour information of the obstacles in the space to be measured can be obtained; and the receiving unit receives light signals corresponding to the height information and the contour information to perform stereo height measurement.

[0008] In the solution provided in the embodiment of the present application, the height information of the obstacles in the space to be measured is obtained when multiple line laser beams are projected into the space to be measured, and the contour information of the obstacles in the space to be measured is obtained when the dot matrix beams are projected into the space to be measured. The receiving unit processes the optical signals corresponding to the height information and the contour information, and can perform stereoscopic height measurement of the obstacles in the space to be measured.

[0009] In a possible embodiment, the depth camera also includes a substrate and a bottom plate, the substrate is arranged on one side of the bottom plate, the dot matrix emitting unit and the receiving unit are arranged on a side of the substrate away from the bottom plate, and the line laser emitting unit includes two line laser emitting modules, the two line laser emitting modules are arranged on the bottom plate and located on opposite sides of the substrate, wherein the two line laser emitting modules, the dot matrix emitting unit and the receiving unit are arranged side by side.

[0010] In the solution provided in the embodiment of the present application, by providing two line laser emission modules on the bottom plate and on opposite sides of the substrate, wherein the two line laser emission modules, the dot matrix emission unit and the receiving unit are arranged side by side, the space utilization rate can be improved, the cost is low and the appearance is more beautiful.

[0011] In a possible embodiment, the depth camera also includes a substrate and a bottom plate, the substrate is arranged on one side of the bottom plate, the dot matrix emitting unit and the receiving unit are arranged on a side of the substrate away from the bottom plate, and the line laser emitting unit includes two line laser emitting modules, the two line laser emitting modules are arranged on the bottom plate and located on opposite sides of the substrate, wherein the two line laser emitting modules and the substrate are arranged side by side in the horizontal direction, and the dot matrix emitting unit and the receiving unit are arranged side by side in the vertical direction.

[0012] In the solution provided in the embodiment of the present application, by providing two line laser emission modules on the bottom plate and on opposite sides of the substrate, wherein the two line laser emission modules, the dot matrix emission unit and the receiving unit are arranged side by side, the space utilization rate can be improved, the cost is low and the appearance is more beautiful.

[0013] In a possible implementation, the line laser emitting unit and the dot matrix emitting unit are alternately lit up in time-sharing to alternately project the uniform light pattern and the speckle pattern.

[0014] In the solution provided by the embodiments of the present application, by alternately illuminating the line laser emission unit and the dot matrix emission unit, the mutual interference when the two beams are irradiated simultaneously can be avoided, ensuring that each beam can be independently projected and received, thereby improving the accuracy and reliability of the measurement. If the two beams are projected simultaneously, they may overlap and interfere with each other in the space to be measured, making it difficult for the receiving unit to distinguish and accurately measure the optical signals of each beam. Alternate projection can avoid this interference and ensure that the measurement data of each beam is independent and accurate.

[0015] In a possible implementation manner, the line laser emission unit and the dot matrix emission unit are two light sources.

[0016] In a possible implementation manner, the line laser emission unit and the dot matrix emission unit are one light source, and the optical element includes a light homogenization functional area and a line laser functional area. The light homogenization functional area is used to shape a part of the light beam emitted by the light source into a light homogenization pattern, and the line laser functional area is used to shape another part of the light beam emitted by the light source into a speckle pattern.

[0017] In a possible implementation manner, the photosensitive surface of the receiving unit includes a line laser receiving area and a dot matrix receiving area. The line laser receiving area is used to obtain a first depth image corresponding to the lighting and extinguishing of multiple line laser beams through the triangulation ranging principle, and is used to obtain a second depth image corresponding to multiple line laser beams through the TOF ranging principle, and obtain the obstacle avoidance depth information according to the fused first depth image and the second depth image; the dot matrix light beams emitted by the dot matrix emission unit include at least two different frequencies. The at least two different frequencies are first sequentially short-exposed and then sequentially long-exposed. The dot matrix receiving area is used to obtain a third depth image during the short exposure and a fourth depth image during the long exposure, and obtain the navigation depth information according to the third depth image and the fourth depth image.

[0018] In the solution provided by the embodiments of the present application, by obtaining a first depth image corresponding to the lighting and extinguishing of multiple line laser beams, and obtaining a second depth image corresponding to multiple line laser beams through the TOF ranging principle, the interference of background noise and ambient light can be effectively eliminated, and the accuracy of the obstacle avoidance depth information can be improved. During short exposure, the depth image captured by the dot matrix receiving area mainly contains details of high-brightness areas and is suitable for processing surfaces with high reflectivity. During long exposure, the depth image captured by the dot matrix receiving area mainly contains details of low-brightness areas and is suitable for processing surfaces with low reflectivity. By receiving the short-exposure and long-exposure depth images of different frequencies of the dot matrix emission unit, the problems of dynamic range and signal-to-noise ratio can be effectively processed, and the reliability of the navigation depth information can be improved.

[0019] In a possible implementation manner, the at least two different frequencies include a first frequency and a second frequency, the first frequency is greater than the second frequency, and a transmission sequence of the first frequency takes precedence over a transmission sequence of the second frequency.

[0020] In the solution provided in the embodiment of the present application, by preferentially transmitting the first frequency and then transmitting the second frequency, the data corresponding to the first frequency can be used when performing depth calculation, and the data corresponding to the second frequency can be used for period expansion, thereby ensuring the real-time nature of the depth data.

[0021] In a possible embodiment, the dot matrix transmitting unit includes one or more dot matrix transmitting areas, and the multiple dot matrix transmitting areas can be illuminated at one time or in sequence. The photosensitive surface of the receiving unit includes a line laser receiving area and a dot matrix receiving area. The line laser receiving area is used to collect light signals corresponding to the line laser light beam to obtain obstacle avoidance depth information, and the dot matrix receiving area is used to collect light signals corresponding to the dot matrix transmitting area in sequence to obtain navigation depth information.

[0022] In the solution provided in the embodiment of the present application, the dot matrix transmitting unit can be divided into one dot matrix transmitting area or into multiple dot matrix transmitting areas. The multiple dot matrix transmitting areas can be illuminated at one time or in sequence. The time-sharing transmission method in which the multiple dot matrix transmitting areas are illuminated in sequence can ensure that the light beams of each dot matrix transmitting area are independently projected and received, avoiding light beam overlap and interference caused by simultaneous transmission; the dot matrix receiving area of ​​the receiving unit collects the light signals corresponding to each dot matrix transmitting area, and can generate a high-density depth map, which can improve the accuracy and resolution of navigation depth information.

[0023] In a possible implementation, when the line laser emitting unit is turned on, only the corresponding line laser receiving area in the photosensitive surface of the receiving unit works and outputs; when the dot matrix emitting unit is turned on, both the line laser receiving area and the dot matrix receiving area in the photosensitive surface of the receiving unit work and output.

[0024] In the solution provided by the embodiment of the present application, when the line laser emitting unit is turned on, only the corresponding line laser receiving area in the photosensitive surface of the receiving unit works and outputs, so that the amount of data and processing time can be reduced. When the dot matrix emitting unit is turned on, both the line laser receiving area and the dot matrix receiving area in the photosensitive surface of the receiving unit work and output, so that the accuracy and reliability of the overall measurement are improved.

[0025] A second aspect of an embodiment of the present application provides a mobile robot, comprising: a robot body; and a depth camera as described in the above technical solution, wherein the depth camera is mounted on the robot body.

[0026] The mobile robot provided by the embodiment of the present application includes the above-mentioned depth camera, so the mobile robot also includes the technical effects of the above-mentioned depth camera. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the mobile robot provided by the embodiment of the present application.

[0028] Figure 2 It is a schematic structural diagram of the depth camera provided by the embodiment of the present application.

[0029] Figure 3 It is Figure 2 A simulated spatial projection scene diagram of the line laser beam and the dot matrix beam emitted by the depth camera in

[0030] Figure 4 It is Figure 2 An example of the line laser spot collected by the photosensitive chip in the depth camera shown in

[0031] Figure 5 It is Figure 1 A schematic structural diagram of the depth camera when the line laser emitting unit includes two line laser emitting modules.

[0032] Figure 6 It is Figure 1 Another schematic structural diagram of the depth camera when the line laser emitting unit includes two line laser emitting modules.

[0033] Figure 7 It is Figure 1 A layout diagram of the multi-row dot matrix light sources of the dot matrix emitting unit of the depth camera.

[0034] Main element symbol description: Mobile robot 1000, depth camera 100, line laser emitting unit 10, line laser beam 101, line laser emitting module 11, dot matrix emitting unit 20, dot matrix beam 201, dot matrix light source 21, optical element 30, receiving unit 40, photosensitive chip 41, photosensitive surface 410, laser receiving area 411, dot matrix receiving area 412, optical lens 42, substrate 50, bottom plate 60, robot body 200. Detailed Embodiments

[0035] The following describes in detail the embodiments of the present invention. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below with reference to the drawings are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

[0036] In the description of the present invention, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0037] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, an electrical connection, or a connection that can communicate with each other; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present invention can be understood according to specific circumstances.

[0038] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0039] The embodiments of the present application will be described in detail below with reference to the drawings.

[0040] Please refer to Figure 1 , the embodiment of the present application provides a mobile robot 1000, which includes a depth camera 100 and a robot body 200. The depth camera 100 is assembled on one side of the robot body 200. The depth camera 100 is used to provide the navigation depth information and obstacle avoidance depth information for the robot body 200, so as to implement the navigation function and the obstacle avoidance function. It can be understood that although the robot body 200 of the mobile robot 1000 in the embodiment of the present application takes a floor sweeping robot as an example in the drawings, it is not limited thereto, and can also be implemented as other robots that require navigation and obstacle avoidance.

[0041] Specifically, please refer to Figure 2 and Figure 3 simultaneously. The depth camera 100 includes a line laser emitting unit 10, a dot matrix emitting unit 20, an optical element 30, and a receiving unit 40.

[0042] The line laser emitting unit 10 is configured to emit a plurality of line laser beams 101 with a preset width. The plurality of line laser beams 101 do not intersect in the projection area and the angle with the vertical direction is less than 30 degrees. At least one of the line laser beams has an angle with the vertical direction greater than 0 degrees in the projection area. The preset width of each laser beam is 1 mm - 4.5 mm, and the position where the angles are set is at a short distance for short-distance obstacle avoidance. Preferably, the plurality of line laser beams 101 do not intersect in the projection area and the angle with the vertical direction is 10 degrees. In some embodiments, one of the line laser beams 101 may have an angle of 0 degrees with the vertical direction, and the other line laser beams 101 may have an angle of 10 degrees with the vertical direction. In some embodiments, the angles of the plurality of line laser beams 101 with the vertical direction in the projection area are all 10 degrees.

[0043] The dot matrix emitting unit 20 is disposed on the side of the line laser emitting unit 10 and is configured to emit dot matrix beams 201. The dot matrix emitting unit 20 includes multiple rows of dot matrix light sources 21. At least two rows of dot matrix light sources 21 are arranged in a regular staggered and cyclic manner. The projection area of the multiple rows of dot matrix light sources partially overlaps with the projection area of the plurality of line laser beams 101. In this embodiment, among at least two rows of dot matrix light sources 21, the central angular resolution of each row of dot matrix light sources 21 is less than or equal to 2°, the edge angular resolution is less than or equal to 2.5°, and the edge angular resolution is greater than the central angular resolution. Under the regular and cyclic staggered arrangement of at least two rows of dot matrix light sources 21, when viewed from above, the central angular resolution can reach less than or equal to 0.66°, and the edge angular resolution is less than or equal to 0.83°, improving the resolution in the horizontal direction.

[0044] The optical element 30 is disposed on the light emitting paths of the line laser emitting unit 10 and the dot matrix emitting unit 20. The line laser beam 101 passes through the optical element 30 and projects a uniform light pattern toward the space to be measured for short-distance detection. The dot matrix beam 201 passes through the optical element 30 and projects a speckle pattern toward the space to be measured. Both the uniform light pattern and the speckle pattern are projected onto the obstacle avoidance area for obstacle avoidance, and the speckle pattern is projected onto the navigation area for navigation. In this embodiment, the obstacle avoidance area is a short-distance detection area, and the navigation area is a long-distance detection area. It can be understood that the uniform light pattern can also be projected onto the navigation area.

[0045] The receiving unit 40 is disposed on the side of the line laser emitting unit 10 and the dot matrix emitting unit 20, and is configured to receive the optical signals corresponding to the homogenized light pattern and the speckle pattern to obtain the obstacle avoidance depth information at a short distance, so as to perform three-dimensional height measurement and short-distance obstacle avoidance, and is configured to receive the optical signals corresponding to the speckle pattern to obtain the navigation depth information, so as to perform three-dimensional positioning and navigation.

[0046] In the depth camera 100 provided by the embodiment of the present application, a plurality of the line laser beams 101 do not intersect in the projection area and the included angle with the vertical direction is less than 30 degrees, at least one of the line laser beams has an included angle greater than 0 degrees with the vertical direction in the projection area, the dot matrix emitting unit includes multiple rows of dot matrix light sources, at least two rows of dot matrix light sources are arranged in a regular staggered manner and are circularly arranged, the homogenized light pattern and the speckle pattern are both projected onto the obstacle avoidance area for obstacle avoidance, the speckle pattern is projected onto the navigation area for navigation. When detecting at a short distance, the depth information obtained by projecting with a plurality of line laser beams is mainly used, and the depth information obtained by projecting with dot matrix beams can be used as a supplement for the area not covered by the line laser beams, so that a more complete obstacle contour information can be obtained, realizing high-precision obstacle avoidance at a short distance, solving the problems of short-distance blind area, multi-path, black material recognition, and small object recognition, and having the characteristics of high precision at the same time; and when detecting at a long distance, the depth information obtained by projecting with dot matrix beams can be used for three-dimensional positioning and navigation. Since at least two rows of dot matrix light sources 21 in the multiple rows of dot matrix light sources 21 are arranged in a regular staggered manner and are circularly arranged, the interval blind area between two adjacent dot matrix light sources 21 in each row of dot matrix light sources 21 can be supplemented by the dot matrix light sources 21 in the next row, so that the depth camera 100 has a relatively high resolution. In addition, through the cooperation of the line laser emitting unit 10 and the dot matrix emitting unit 20, the depth information obtained by projecting with a plurality of line laser beams 101 and the depth information obtained by projecting with dot matrix beams 201 can be mutually supplemented, and three-dimensional height measurement of the objects in the space can be performed with relatively high precision.

[0047] It can be understood that the line laser emitting unit 10 adopts the triangulation measurement technology. When the line laser beam 101 reaches the surface of the obstacle, the receiving unit 40 collects the reflected line laser information, and then, according to the change of the line laser information caused by the obstacle, using the principle of trigonometry, the distance between the line laser emitting module and the obstacle in front of it can be calculated through trigonometric functions; so that the mobile robot 1000 can judge whether there is an obstacle in front according to the deformation of the line laser, thereby realizing the obstacle avoidance function.

[0048] The dot matrix emission unit 20 adopts TOF measurement technology. The emission bands of the line laser emission unit 10 and the dot matrix emission unit 20 are the same. The Time Of Flight (TOF) measures the time interval t from the emission to the reception of the pulse signal emitted by the dot matrix emission unit 20 (often referred to as the direct time of flight method, Direct TOF, abbreviated as D-TOF) or the phase generated by the dot matrix light beam 201 traveling back and forth to the environmental target once (often referred to as the indirect time of flight method, Indirect TOF, abbreviated as I-TOF) to realize the measurement of the three-dimensional structure or three-dimensional contour of the environmental target. In this embodiment, the duty cycle of the line laser emission unit 10 is greater than that of the dot matrix emission unit 20.

[0049] In a possible implementation manner, when multiple line laser beams are projected onto the space to be measured, the height information of the obstacles in the space to be measured can be obtained. When the dot matrix light beam is projected onto the space to be measured, the contour information of the obstacles in the space to be measured can be obtained. The receiving unit receives the optical signals corresponding to the height information and the contour information for three-dimensional height measurement.

[0050] In the solution provided by the embodiment of the present application, through the height information of the obstacles in the space to be measured obtained when multiple line laser beams are projected onto the space to be measured, and the contour information of the obstacles in the space to be measured obtained when the dot matrix light beam is projected onto the space to be measured, the receiving unit processes the optical signals corresponding to the height information and the contour information, and can perform three-dimensional height measurement on the obstacles in the space to be measured.

[0051] The receiving unit 40 includes a photosensitive chip 41 and an optical lens 42 disposed on the photosensitive path of the photosensitive chip 41, so that the optical signals are first received by the optical lens 42 and then modulated by the photosensitive chip 41 to obtain depth information. The photosensitive chip 41 can be an I-TOF chip or a D-TOF chip.

[0052] Please refer to Figure 4 , the photosensitive surface 410 of the photosensitive chip 41 of the receiving unit 40 includes a line laser receiving area 411 and a dot matrix receiving area 412. The line laser receiving area 411 is used to receive the optical signals corresponding to the line laser beams 101 to collect gray-scale information and calculate the obstacle avoidance depth information; the dot matrix receiving area 412 is used to receive the optical signals corresponding to the dot matrix light beam 201 to obtain the navigation depth information.

[0053] In this embodiment, there are two laser beams, and the projection areas of the two laser beams are vertical and arranged at an angle. The projection area of the multi-row dot matrix light sources partially overlaps with the projection areas of the two line laser beams 101.

[0054] The dot matrix transmitting unit 20 is used to project the dot matrix light beam 201 horizontally so as to project it into a farther area, so as to meet the needs of mapping and navigation applications. The emission wavelength range of the dot matrix transmitting unit 20 is 850nm~1200nm, and 940±15nm is preferred. The optical power of the dot matrix transmitting unit 20 is greater than 1w. The horizontal field of view of the dot matrix transmitting unit 20 is 135°, and the vertical field of view is 12°~60°.

[0055] See also Figure 5 The depth camera 100 further includes a substrate 50 and a bottom plate 60. The substrate 50 is disposed on one side of the bottom plate 60, the dot matrix emitting unit 20 and the receiving unit 40 are disposed on the side of the substrate 50 away from the bottom plate 60, and the line laser emitting unit 10 includes two line laser emitting modules 11, which are disposed on the bottom plate 60 and located on opposite sides of the substrate 50, wherein the two line laser emitting modules 11, the dot matrix emitting unit 20 and the receiving unit 40 are disposed side by side. In this way, the space utilization rate can be improved, the cost is low, and the appearance is more beautiful.

[0056] Specifically, when each line laser emission module 11 irradiates into space at an inclination angle of 20°~50° toward the receiving unit 40, the minimum ground blind area is 0.06m. The emission wavelength range of the line laser emission module 11 is 850nm~1200nm, and 940±15nm is preferred. The optical power of the line laser emission module 11 is less than 1w. The horizontal field of view angle of the line laser emission module 11 is 1°~2°, and the vertical field of view angle is 60°.

[0057] In some embodiments, see Figure 6 , the depth camera 100 also includes a substrate 50 and a bottom plate 60. The substrate 50 is arranged on one side of the bottom plate 60, the dot matrix emitting unit 20 and the receiving unit 40 are arranged on the side of the substrate 50 away from the bottom plate 60, and the line laser emitting unit 10 includes two line laser emitting modules 11, and the two line laser emitting modules 11 are arranged on the bottom plate 60 and are located on opposite sides of the substrate 50, wherein the two line laser emitting modules 11 and the substrate 50 are arranged side by side in the horizontal direction, and the dot matrix emitting unit 20 and the receiving unit 40 are arranged side by side in the vertical direction. In this way, the space utilization rate can be improved, the cost is low, and the appearance is more beautiful. The value range of the distance between each line laser emitting module 11 and the receiving unit 40 is 0.05m~0.15m.

[0058] See also Figure 7 The dot matrix light sources 21 are arranged in multiple rows, wherein the dot matrix light sources 21 in every three rows are arranged in a staggered and cyclic manner. In this way, the interval blind area between two adjacent dot matrix light sources 21 in each row of dot matrix light sources 21 can be supplemented by the dot matrix light sources 21 in the next row, thereby making the resolution of the depth camera 100 higher.

[0059] In a possible implementation, the line laser emitting unit 10 and the dot matrix emitting unit 20 are alternately turned on in a time-sharing manner to alternately project a uniform light pattern and a speckle pattern. Among them, the receiving unit 40 is electrically connected to the line laser emitting unit 10 and the dot matrix emitting unit 20, and controls the line laser emitting unit 10 and the dot matrix emitting unit 20 to alternately emit light.

[0060] In the solution provided by the embodiment of the present application, by alternately turning on the line laser emitting unit 10 and the dot matrix emitting unit 20, the mutual interference when the two light beams are irradiated simultaneously can be avoided, ensuring that each light beam can be independently projected and received, thereby improving the accuracy and reliability of the measurement. If the two light beams are projected simultaneously, they may overlap and interfere with each other in the space to be measured, making it difficult for the receiving unit 40 to distinguish and accurately measure the optical signals of each light beam. Alternate projection can avoid this interference and ensure that the measurement data of each light beam is independent and accurate.

[0061] In a possible implementation, the photosensitive chip 41 can be an I-TOF chip. The line laser receiving area 411 is used to obtain the corresponding first depth images when multiple line laser beams 101 are turned on and off through the triangulation ranging principle, and to obtain the corresponding second depth images of multiple line laser beams 101 through the TOF ranging principle; and the obstacle avoidance depth information is obtained according to the fused first depth image and the second depth image; the dot matrix light beams 201 emitted by the dot matrix emitting unit 20 include at least two different frequencies. The at least two different frequencies are first sequentially subjected to short exposure, and then sequentially subjected to long exposure. The dot matrix receiving area 412 is used to obtain the third depth image during short exposure and the fourth depth image during long exposure, and to obtain the navigation depth information according to the third depth image and the fourth depth image.

[0062] In the solution provided by the embodiment of the present application, by obtaining the corresponding first depth images when multiple line laser beams 101 are turned on and off, and obtaining the corresponding second depth images of multiple line laser beams 101 through the ITOF ranging principle, the interference of background noise and ambient light can be effectively eliminated, and the accuracy of the obstacle avoidance depth information can be improved. During short exposure, the depth image captured by the dot matrix receiving area 412 mainly contains details of high-brightness regions and is suitable for processing surfaces with high reflectivity. During long exposure, the depth image captured by the dot matrix receiving area 412 mainly contains details of low-brightness regions and is suitable for processing surfaces with low reflectivity. By obtaining the short-exposure and long-exposure depth images of different frequencies of the dot matrix emitting unit 20, the problems of dynamic range and signal-to-noise ratio can be effectively processed, and the reliability of the navigation depth information can be improved.

[0063] In this embodiment, the lighting time for each of the multiple line laser beams 101 to obtain the corresponding first depth image through the triangulation ranging principle is 2 phases, and the extinguishing time is also 2 phases; the time for each of the multiple line laser beams 101 to obtain the corresponding second depth image through the ITOF ranging principle is 4 phases.

[0064] In a possible implementation manner, at least two different frequencies may first perform long exposure in sequence, and then perform short exposure in sequence. The dot matrix receiving area 412 is used to obtain the depth images during long exposure and short exposure and calculate the obtained navigation depth information; or at least two different frequencies may perform short exposure, long exposure, long exposure, and short exposure in sequence; or at least two different frequencies may perform short exposure, long exposure, short exposure, and short exposure in sequence; or at least two different frequencies may perform long exposure, short exposure, short exposure, and short exposure in sequence; but not limited thereto.

[0065] In a possible implementation manner, at least two different frequencies include a first frequency and a second frequency, the first frequency is greater than the second frequency, and the emission order of the first frequency takes precedence over the emission order of the second frequency.

[0066] In the solution provided by the embodiment of the present application, by preferentially emitting the first frequency and then emitting the second frequency, data corresponding to the first frequency can be used during depth calculation, and the data corresponding to the second frequency can be used for cycle extension, thereby ensuring the real-time nature of the depth data.

[0067] In this embodiment, at least two different frequencies are two frequencies, which can avoid the super-cycle problem and achieve long-distance ranging. The two frequencies can be selected from 1MHZ - 100MHZ. For example, the frequency combination of 37.65MHZ / 45.18MHZ can be selected to achieve a detection distance of 20m, the frequency combination of 60.24MHZ / 48.192MHZ can be selected to achieve a detection distance of 12.5m, and the frequency combination of 60.24MH / 52.71MH can be selected to achieve a detection distance of 20m.

[0068] In this embodiment, the short exposure time for each frequency is 4 phases, and the long exposure time for each frequency is 4 phases.

[0069] In this embodiment, when the line laser emitting unit 10 includes two line laser emitting modules, the two line laser emitting modules are sequentially lit for 1 phase.

[0070] In a possible implementation, the photosensitive chip 41 may be a D-TOF chip, the dot matrix transmitting unit 20 includes a plurality of dot matrix transmitting areas (not shown), the plurality of dot matrix transmitting areas are sequentially lit up and have the same transmitting frequency, the line laser receiving area 411 is used to collect the light signal corresponding to the line laser beam 101 to obtain obstacle avoidance depth information, and the dot matrix receiving area 412 is used to sequentially collect the light signal corresponding to the dot matrix transmitting area to obtain navigation depth information. It can be understood that the obstacle avoidance depth information and the navigation depth information can be output at one time.

[0071] In the solution provided in the embodiment of the present application, the dot matrix transmitting unit 20 can be divided into one dot matrix transmitting area or divided into multiple dot matrix transmitting areas. The multiple dot matrix transmitting areas can be illuminated at one time or in sequence. The time-sharing transmission method in which the multiple dot matrix transmitting areas are illuminated in sequence can ensure that the light beams of each dot matrix transmitting area are independently projected and received, avoiding light beam overlap and interference caused by simultaneous transmission; the dot matrix receiving area 412 of the receiving unit 40 collects the light signals corresponding to each dot matrix transmitting area in sequence, and can generate a high-density depth map, which can improve the accuracy and resolution of navigation depth information.

[0072] In this embodiment, the frequency of the dot matrix transmitting unit 20 can be selected from 1 MHZ to 10 MHZ, for example, 5 MHZ can be selected to achieve a detection distance of 30 m.

[0073] In one possible implementation, when the line laser emitting unit 10 is turned on, only the corresponding line laser receiving area 411 in the photosensitive surface 410 of the receiving unit 40 works and outputs, thereby reducing the amount of data and processing time; when the dot matrix emitting unit 20 is turned on, both the line laser receiving area 411 and the dot matrix receiving area 412 in the photosensitive surface 410 of the receiving unit 40 work and output, thereby improving the accuracy and reliability of the overall measurement.

[0074] In a possible implementation, the function of the optical element 30 is to perform spatial light modulation on each incident light beam, that is, to split and replicate each light beam to form a speckle pattern or a uniform light pattern. The optical element 30 can be a DOE or a super lens. In some embodiments, there is one optical element 30, and one optical element 30 is arranged in the light-emitting path of the line laser emitting unit 10 and the dot matrix emitting unit 20. In some embodiments, there are two optical elements 30, one of which is a DOE and the other is a super lens, the DOE is arranged in the light-emitting path of the line laser emitting unit 10, and the super lens is arranged in the light-emitting path of the dot matrix emitting unit 20.

[0075] Among them, the obstacle avoidance strategy of the mobile robot 1000 is as follows: when the vertical field of view angle of the dot matrix emission unit 20 is less than 30°, its blind area is larger than that of the line laser emission unit 10. At this time, the dot matrix emission unit 20 can be preset to judge obstacle avoidance first. After detecting an obstacle, the mobile robot 1000 is decelerated, and then the line laser emission unit 10 with a smaller blind area is used for precise obstacle avoidance to achieve perfect obstacle avoidance. If the vertical field of view angle of the dot matrix emission unit 20 is greater than or equal to 30°, its blind area is smaller than that of the line laser emission unit 10. At this time, the line laser emission unit 10 judges obstacle avoidance, and the dot matrix emission unit 20 obtains the three-dimensional information of the obstacle. The depth information at the point-line coincidence position can complement and perfect each other, so as to complete precise obstacle avoidance. In addition, for the scheme of presetting and judging obstacle avoidance by the dot matrix emission unit 20 for space height measurement, its visual field range in the vertical field of view angle direction is set to 12° to 60°, which can detect some low objects in time, so as to judge whether it can enter.

[0076] The embodiment of the present application also provides a method for obtaining depth information, including the steps of:

[0077] S10, sequentially emit a plurality of line laser beams 101 with a preset width and at least two rows of staggered dot matrix beams 201. The plurality of line laser beams 101 are vertical and angled in the projection area. The line laser beams 101 pass through the optical element and project a uniform light pattern towards the space to be measured, and the dot matrix beams 201 pass through the optical element and project a speckle pattern towards the space to be measured;

[0078] S20, receive the optical signal corresponding to the uniform light pattern and the optical signal corresponding to the speckle pattern returned from the space to be measured;

[0079] S30, obtain the obstacle avoidance depth information according to the optical signal corresponding to the uniform light pattern; and obtain the navigation depth information according to the optical signal corresponding to the speckle pattern.

[0080] In the depth information acquisition method provided by the embodiments of the present application, first, a plurality of line laser beams 101 with a preset width and an included angle are emitted in the horizontal direction. The line laser beams 101 pass through an optical element and project a uniform light pattern onto the space to be measured. Then, according to the optical signal corresponding to the uniform light pattern, the obstacle avoidance depth information is obtained, and more complete obstacle contour information can be obtained, realizing high-precision obstacle avoidance at close range, solving problems such as close-range blind areas, multi-path, black material recognition, and small object recognition, and having high precision at the same time. Then, at least two rows of staggered dot matrix beams 201 are emitted in the horizontal direction. The dot matrix beams 201 pass through an optical element and project a speckle pattern onto the space to be measured. Then, according to the optical signal corresponding to the speckle pattern, the navigation depth information is obtained, so as to identify the height of the object in the space to be measured for three-dimensional height measurement and three-dimensional positioning navigation, and the problem of three-dimensional height measurement for identifying low objects can be solved. By making at least two of the multiple rows of dot matrix light sources included in the dot matrix emission unit be staggered, the interval blind area between adjacent two dot matrix light sources in each row of dot matrix light sources can be supplemented by the dot matrix light sources in the next row, so that the resolution of the depth camera is relatively high. Therefore, by combining the emission of the line laser beams 101 and the emission of the dot matrix beams 201, the problem that the existing technology cannot simultaneously achieve three-dimensional positioning navigation and high-precision obstacle avoidance at close range can be solved.

[0081] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to cover all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved. In addition, obviously, the word "including" does not exclude other units or steps, and the singular does not exclude the plural.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A depth camera, characterized in that, Including: A line laser emission unit for emitting a plurality of line laser beams with a preset width. The plurality of line laser beams do not intersect in the projection area and the angle with the vertical direction is less than 30 degrees, and at least one of the line laser beams has an angle greater than 0 degrees with the vertical direction in the projection area. A dot matrix emission unit provided on the side of the line laser emission unit for horizontally emitting a dot matrix beam. The dot matrix emission unit includes multiple rows of dot matrix light sources. At least two rows of the dot matrix light sources are arranged in a regular staggered and cyclic manner, and the projection areas of the multiple rows of dot matrix light sources partially overlap with the line laser beams in the projection area. An optical element provided on the light emitting paths of the line laser emission unit and the dot matrix emission unit. The line laser beam passes through the optical element and projects a uniform light pattern towards the space to be measured, and the dot matrix beam passes through the optical element and projects a speckle pattern towards the space to be measured. Both the uniform light pattern and the speckle pattern are projected onto the obstacle avoidance area for obstacle avoidance, and the speckle pattern is projected onto the navigation area for navigation. A receiving unit provided on the side of the line laser emission unit and the dot matrix emission unit for receiving the optical signals corresponding to the uniform light pattern and the speckle pattern to obtain the obstacle avoidance depth information at a short distance, so as to perform three-dimensional height measurement and short-distance obstacle avoidance, and for receiving the optical signals corresponding to the speckle pattern to obtain the navigation depth information, so as to perform three-dimensional positioning and navigation. The photosensitive surface of the receiving unit includes a line laser receiving area, which is used to obtain the first depth images corresponding to the lighting and extinguishing of the plurality of line laser beams through the triangulation ranging principle, and is used to obtain the second depth images corresponding to the plurality of line laser beams through the TOF ranging principle, and obtain the obstacle avoidance depth information according to the fused first depth image and the second depth image.

2. The depth camera according to claim 1, characterized in that When the plurality of line laser beams are projected into the space to be measured, the height information of the obstacles in the space to be measured can be obtained, and when the dot matrix beam is projected into the space to be measured, the contour information of the obstacles in the space to be measured can be obtained. The receiving unit receives the optical signals corresponding to the height information and the contour information to perform three-dimensional height measurement.

3. The depth camera according to claim 1, wherein, The depth camera further includes a substrate and a bottom plate. The substrate is provided on one side of the bottom plate, and the dot matrix emission unit and the receiving unit are provided on the side of the substrate facing away from the bottom plate. The line laser emission unit includes two line laser emission modules, and the two line laser emission modules are provided on the bottom plate and on the opposite sides of the substrate, and the two line laser emission modules, the dot matrix emission unit and the receiving unit are arranged side by side.

4. The depth camera according to claim 1, wherein The depth camera further includes a substrate and a bottom plate. The substrate is provided on one side of the bottom plate, and the dot matrix emission unit and the receiving unit are provided on the side of the substrate facing away from the bottom plate. The line laser emission unit includes two line laser emission modules, and the two line laser emission modules are provided on the bottom plate and on the opposite sides of the substrate. The two line laser emission modules and the substrate are arranged side by side in the horizontal direction, and the dot matrix emission unit and the receiving unit are arranged side by side in the vertical direction.

5. The depth camera according to claim 1, characterized in that The line laser emitting unit and the dot matrix emitting unit are alternately lit up in time-sharing to alternately project the uniform light pattern and the speckle pattern.

6. The depth camera according to claim 1, characterized in that, The photosensitive surface of the receiving unit also includes a dot matrix receiving area; The dot matrix light beam emitted by the dot matrix transmitting unit includes at least two different frequencies, and the at least two different frequencies are first subjected to short exposure and then to long exposure in sequence. The dot matrix receiving area is used to obtain a third depth image during the short exposure and a fourth depth image during the long exposure, and the navigation depth information is obtained according to the third depth image and the fourth depth image.

7. The depth camera according to claim 6, characterized in that, The at least two different frequencies include a first frequency and a second frequency, the first frequency is greater than the second frequency and a transmission order of the first frequency takes precedence over a transmission order of the second frequency.

8. The depth camera according to claim 1, wherein The dot matrix transmitting unit includes one or more dot matrix transmitting areas, and multiple dot matrix transmitting areas can be lit up at one time or in sequence. The photosensitive surface of the receiving unit includes a line laser receiving area and a dot matrix receiving area. The line laser receiving area is used to collect light signals corresponding to the line laser light beam to obtain obstacle avoidance depth information, and the dot matrix receiving area is used to collect light signals corresponding to the dot matrix transmitting area to obtain navigation depth information.

9. The depth camera according to claim 8, wherein When the line laser emitting unit is turned on, only the corresponding line laser receiving area in the photosensitive surface of the receiving unit works and outputs; when the dot matrix emitting unit is turned on, both the line laser receiving area and the dot matrix receiving area in the photosensitive surface of the receiving unit work and output.

10. A mobile robot, characterized in that, include: Robot body; and The depth camera according to any one of claims 1 to 9, wherein the depth camera is mounted on the robot body.

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