Depth measurement module

Abstract

The application discloses a depth measurement module and relates to the technical field of intelligent robots, wherein the depth measurement module comprises the following: a light beam emitted by a linear array light-emitting light source forms a linear laser after passing through a light adjusting element; a light path deflection scanning module is used for deflecting and scanning the linear laser in a direction perpendicular to the long side of the linear laser and within a preset angle range and forming a scanning area, and the laser energy of a scanning center area is greater than that of a scanning edge area; and a linear receiving camera, wherein the calculated depth information corresponding to the reflection light spots of the scanning center area and the scanning edge area is used for obstacle avoidance, and the calculated depth information corresponding to the reflection light spots of the scanning center area is also used for navigation. The depth measurement module provided by the technical scheme can be used for robot navigation and obstacle avoidance simultaneously, the structure is simplified, and material and assembly costs are reduced.

Description

Technical Field

[0001] This invention relates to the field of intelligent robot technology, and in particular to a depth measurement module. Background Technology

[0002] With the rapid development of intelligent robot technology, its application in fields such as industrial automation, logistics warehousing, and service robots is becoming increasingly widespread. Intelligent robots need to accurately perceive their surrounding environment, especially the position and distance information of target objects. A good navigation and obstacle avoidance system is a core element of robot intelligence. The navigation system generates a map model of the surrounding environment by measuring the distance between the robot and objects in the environment, thereby enabling the robot to perform self-localization and global path planning.

[0003] To achieve good navigation and obstacle avoidance (ranging accuracy), current robots typically employ multiple vision technologies in combination. For example, the most common robot uses a LaserDirect Structuring (LDS) sensor in its head to generate an environmental map through 360° rotational scanning for navigation. One or two 3D structured light modules or ITOF modules are used on the sides to monitor surrounding obstacles in real time for obstacle avoidance. Such systems require multiple measurement systems to coordinate navigation and obstacle avoidance, resulting in high overall material and assembly costs, increased power consumption, and a large space requirement for multiple modules, leading to complex structural designs and difficulties in system miniaturization. Summary of the Invention

[0004] The main objective of this invention is to provide a depth measurement module that addresses the technical problem that current robots require multiple systems to cooperate in navigation and obstacle avoidance, resulting in complex robot structures and high costs.

[0005] To achieve the above objectives, the depth measurement module proposed in this invention includes: A linear laser projector includes a linear array light source and a dimming element, wherein the light beam emitted by the linear array light source is converted into a line laser after passing through the dimming element, wherein at least one linear array light source is provided, and the linear array light source includes a central area light source and edge area light sources located on both sides of the central area light source. An optical path deflection scanning module is used to deflect and scan the linear laser line along a direction perpendicular to its long side within a preset angle range to form a scanning area. The scanning direction includes a first direction and a second direction, with the first direction and the second direction perpendicular to each other. In the first direction, the scanning area includes a central scanning area and two edge scanning areas, with the two edge scanning areas located on opposite sides of the central scanning area. The laser energy in the central scanning area is greater than the laser energy in the edge scanning areas. A linear receiving camera includes a receiving chip and an imaging lens. Laser light in the scanning area is reflected by environmental objects to form a reflected light spot. This reflected light spot is focused by the imaging lens onto the photosensitive surface of the receiving chip. The receiving chip responds to the reflected light spot and converts the light signal of the reflected light spot into an avalanche electrical signal. The depth information of the object is obtained by calculating the time difference between the pulse signal of the laser spot projected by the linear laser projector and the avalanche electrical signal received by the linear receiving camera. The depth information calculated for the reflected light spots corresponding to both the scanning center region and the scanning edge region is used for obstacle avoidance. The depth information calculated for the reflected light spot corresponding to the scanning center region is also used for navigation.

[0006] In one embodiment, the linear array light source is a single-hole light-emitting chip, and multiple such chips are provided, with the multiple single-hole light-emitting chips arranged in a linear line. When the scanning direction is parallel to the first direction, the single-aperture light emission power of the central region light source is less than that of the single-aperture light emission power of the edge region light source, and the power of the same single-aperture light emission chip when the line laser scans to the scanning center region is greater than that when the line laser scans to the scanning edge region. When the scanning direction is parallel to the second direction, the single-aperture luminous power of the central region light source is greater than that of the single-aperture luminous power of the edge region light source.

[0007] In one embodiment, when the scanning direction is parallel to the first direction, the driving current of the single-aperture light-emitting chip of the intermediate region light source is less than the driving current of the single-aperture light-emitting chip of the edge region light source; and / or, the number of active region junctions of the single-aperture light-emitting chip of the intermediate region light source is less than the number of active region junctions of the single-aperture light-emitting chip of the edge region light source; and / or, the aperture of the light-emitting hole of the single-aperture light-emitting chip of the intermediate region light source is less than the aperture of the light-emitting hole of the single-aperture light-emitting chip of the edge region light source. When the scanning direction is parallel to the second direction, the driving current of the single-aperture light-emitting chip of the intermediate region light source is greater than the driving current of the single-aperture light-emitting chip of the edge region light source; and / or, the number of active region junctions of the single-aperture light-emitting chip of the intermediate region light source is greater than the number of active region junctions of the single-aperture light-emitting chip of the edge region light source; and / or, the aperture of the light-emitting hole of the single-aperture light-emitting chip of the intermediate region light source is greater than the aperture of the light-emitting hole of the single-aperture light-emitting chip of the edge region light source.

[0008] In one embodiment, the linear light source is an integrated linear light-emitting array; When the scanning direction is parallel to the first direction, the total luminous power of the central area light source is less than the total luminous power of the edge area light source. When the linear laser scans to the scanning center area, the power of the central area light source and the edge area light source is greater than the power when the linear laser scans to the scanning edge area. When the scanning direction is parallel to the second direction, the total luminous power of the central area light source is greater than the total luminous power of the edge area light source.

[0009] In one embodiment, when the scanning direction is parallel to the first direction, the driving current of the light-emitting aperture of the intermediate region light source is less than the driving current of the light-emitting aperture of the edge region light source; and / or, the light-emitting aperture density of the intermediate region light source is less than the light-emitting aperture density of the edge region light source; and / or, the aperture diameter of the light-emitting aperture of the intermediate region light source is less than the aperture diameter of the light-emitting aperture of the edge region light source; and / or, the number of active region junctions of the light-emitting apertures in the intermediate region light source is less than the number of active region junctions of the light-emitting apertures in the edge region light source. When the scanning direction is parallel to the second direction, the driving current of the light-emitting aperture of the intermediate region light source is greater than the driving current of the light-emitting aperture of the edge region light source; and / or, the light-emitting aperture density of the intermediate region light source is greater than the light-emitting aperture density of the edge region light source; and / or, the aperture diameter of the light-emitting aperture of the intermediate region light source is greater than the aperture diameter of the light-emitting aperture of the edge region light source; and / or, the number of active region junctions of the light-emitting apertures of the intermediate region light source is greater than the number of active region junctions of the light-emitting apertures of the edge region light source.

[0010] In one embodiment, when the scanning direction is parallel to the second direction, the TDC range of the pixel unit used to calculate navigation depth information is designed to be greater than the TDC range of the pixel unit used to calculate obstacle avoidance depth information.

[0011] In one embodiment, there are N linear array light sources and N receiving chips, with each linear array light source corresponding to a receiving chip, and the receiving chip being elongated. Adjacent light sources are staggered by 1 / N adjacent light-emitting point spacing along their long side, and the corresponding receiving chips are staggered by 1 / N adjacent pixel unit spacing along their long side.

[0012] In one embodiment, the depth measurement module includes M linear array light source groups and M receiving chip groups. Each linear array light source group includes N linear array light sources. Adjacent linear array light source groups are staggered along their long side, and the minimum interval is 0-1 adjacent light-emitting point spacing. Each receiving chip group includes N receiving chips. Adjacent receiving chip groups are staggered along their long side, and the minimum interval is 0-1 adjacent pixel units.

[0013] In one embodiment, within a measurement cycle, the light-emitting apertures in the middle region and the light-emitting apertures in the edge region of the linear array light source are lit simultaneously or at different times. When the light is applied in a time-division manner, within one measurement cycle, the interval between two illuminations of the light-emitting holes in the middle area is equal to or greater than the interval between two illuminations of the light-emitting holes in the edge area.

[0014] In one embodiment, the optical path deflection scanning module is a rotating prism. When the long side of the line laser is parallel to the first direction, the rotating prism ensures that the line laser's scanning field of view in the second direction is ≥120°; when the long side of the line laser is parallel to the second direction, the rotating prism ensures that the line laser's scanning field of view in the first direction is ≥40°; or, The optical path deflection scanning module is a rotating mechanical structure with a rotation angle of 360°, and the scanning direction is parallel to the second direction.

[0015] This invention employs a laser projector to project a linear laser beam, which, after reflection from environmental objects, is focused onto the photosensitive surface of a receiving chip via an imaging lens. The receiving chip converts the echo signal into an avalanche electrical signal. The depth information of the object is obtained by calculating the time difference between the pulse signal projected by the laser projector and the received avalanche signal. Specifically, the linear laser projector forms a scanning area through a deflection module. The calculated depth information corresponding to the center area of ​​the scanning area is used for navigation, while the calculated depth information corresponding to the center and edge areas is used for obstacle avoidance. Compared to existing technologies that require radar and structured light modules for navigation and obstacle avoidance, this invention uses a single depth measurement module to acquire depth information that can be used simultaneously for robot navigation and obstacle avoidance. This simplifies the structure, reduces material and assembly costs, significantly reduces product power consumption, and facilitates product promotion and widespread adoption. Furthermore, the single depth measurement module saves space and is conducive to miniaturization design. Additionally, it avoids calibration and synchronization problems associated with multi-module collaboration. The system outputs images in separate obstacle avoidance and navigation frames, saving computing power and improving obstacle avoidance and navigation speed. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of the line laser and scanning area in an embodiment of the depth measurement module provided by the present invention; Figure 2 A schematic diagram of the optical path of a single-line laser projector provided in this application; Figure 3 A schematic diagram of the optical path of another linear laser projector provided for this application; Figure 4 A schematic diagram of the optical path of another linear laser projector provided in this application; Figure 5 A diagram showing the relationship between relative illumination and field of view in an embodiment of the depth measurement module provided by the present invention; Figure 6 A schematic diagram of the linear array light source provided by the present invention; Figure 7 A schematic diagram of the linear array light source provided by the present invention; Figure 8 A schematic diagram of the receiver chip for the linear receiver camera provided in this application; Figure 9 A schematic diagram of a linear array light source and a corresponding elongated receiving chip provided in this application; Figure 10 A schematic diagram of another linear array light source and a corresponding elongated receiving chip provided in this application; Figure 11 A schematic diagram of the lighting timing for one measurement cycle of the depth measurement module provided by the present invention; Figure 12 Another schematic diagram of the lighting timing for one measurement cycle of the depth measurement module provided by the present invention; Figure 13 This is a schematic diagram of the structure of an embodiment of the depth measurement module provided by the present invention; Figure 14 This is a schematic diagram of another embodiment of the depth measurement module provided by the present invention.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] In the existing technology, in order to achieve better navigation and obstacle avoidance (range measurement accuracy), existing robots generally use a combination of multiple vision technologies to complete navigation and obstacle avoidance functions. The system requires multiple measurement systems to work together to complete navigation and obstacle avoidance, which leads to high overall material and assembly costs for the robot, increases the overall power consumption of the robot, and uses multiple modules that occupy a large space, resulting in complex structural design and difficulty in miniaturizing the system.

[0023] This invention proposes a depth measurement module.

[0024] In one embodiment of the present invention, the depth measurement module includes: a linear laser projector, an optical path deflection module, and a linear receiving camera. The linear laser projector includes a linear array light source and a dimming element. The light beam emitted by the linear array light source is processed by the dimming element to form a line laser. At least one linear array light source is provided, including a central light source and edge light sources located on either side of the central light source. The optical path deflection scanning module is used to deflect and scan the line laser along a direction perpendicular to the long side of the line laser within a preset angle range to form a scanning area. The scanning direction includes a first direction and a second direction, with the first direction and the second direction perpendicular to each other. In the first direction, the scanning area includes a scanning center area and two scanning edge areas. The scanning edge regions are located on opposite sides of the scanning center region. The laser energy in the scanning center region is greater than that in the scanning edge regions. The linear receiving camera includes a receiving chip and an imaging lens. The laser in the scanning area is reflected by environmental objects to form a reflected light spot. The reflected light spot is focused onto the photosensitive surface of the receiving chip by the imaging lens. The receiving chip responds to the reflected light spot and converts the reflected light spot light signal into an avalanche electrical signal. The depth information of the object is obtained by calculating the time difference between the pulse signal of the laser spot projected by the linear laser projector and the avalanche electrical signal received by the linear receiving camera. The depth information calculated for the reflected light spots corresponding to the scanning center region and the scanning edge region is used for obstacle avoidance. The depth information calculated for the reflected light spot corresponding to the scanning center region is also used for navigation.

[0025] In practical implementation, a linear laser projector is used to generate a pulsed line laser. Specifically, the beam emitted by the linear array light source is adjusted by a dimming element, i.e., collimated, uniformly diffused, or shaped to form a line laser. The dimming element can include a collimating lens or a combination of a collimating lens and a wave mirror / Powell prism / diffuser. In the direction parallel to the long side of the line laser, the distribution of the central and edge light sources of the linear array light source is: one edge light source, one central light source, and another edge light source. The long side of the line laser is the extension direction of the linear array light source.

[0026] The line laser can be either a line flood or a line speckle, and specifically, there are several implementation schemes for obtaining a line laser using a linear laser projector. When the linear laser projector projects a line flood, it is a combination of a linear array light source (VCSEL / EEL) + a collimating lens + a wave mirror / Powell prism / diffuser. When the linear laser projector projects a line speckle, it is a combination of a linear array light source (with multiple light-emitting points) + a short-focal-length collimating lens. Line speckle has high energy density per unit area, a long ranging range, and a specific speckle pattern, making it suitable for high-precision depth calculations based on speckle matching.

[0027] In practical implementation, the optical path deflection module can be a rotating prism or a rotating mechanical structure, etc., so that the linear laser line deflects and scans along the direction perpendicular to the long side of the linear laser line within a preset angle range. The scanning directions are a first direction and a second direction that are perpendicular to each other. The arrangement of the linear laser line and the scanning direction are adapted to each other; that is, when scanning along the second direction, the long side direction of the linear laser line is referenced... Figure 1 In (a), when scanning along the first direction, the long side direction of the line laser is referenced. Figure 1 In (b), of course, the first direction can also be the opposite of the first direction shown in the diagram, and the second direction can also be the opposite of the second direction shown in the diagram. Figure 1 In the diagram (c), the scanning center region and the scanning edge region are distributed, and the laser energy of the scanning center region is greater than that of the scanning edge region. Parallel to the first direction, the scanning region is arranged as a scanning edge region, a scanning center region, and another scanning edge region.

[0028] Figure 2 This application provides a schematic diagram of the optical path of a linear laser projector; 101 is a linear array light source, and 102 is a dimming element, wherein the dimming element 102 includes a collimating lens 102a and a wave mirror 102b; the linear array light source 101 can be a VCSEL (vertical cavity surface-emitting laser) or an EEL (edge-emitting laser), and the wavelength of the laser emitted is in the infrared band, generally 850nm, 905nm, 940nm, 1550nm, etc.; the wave mirror can be understood as multiple cylindrical lenses connected together, and the surface shape of the cylindrical lens can be spherical, sine / cosine, ellipsoidal, or other curves. The shape of the wave mirror is such that the ripple direction is perpendicular to the extension direction of the cylindrical surface. When the long side (arrangement of light-emitting points) of the linear array light source is aligned with the ripple direction of the wave mirror (both are the Y direction in the figure), the short side direction (X direction in the figure) of the linear array light source is collimated into parallel light by the collimating lens 102a, and then emitted in parallel by the wave mirror 102b (the wave mirror does not change the width of the beam emitted by the laser source in the short side direction). The long side direction of the beam of the linear array light source is collimated into parallel light by the collimating lens 102a, and then homogenized and expanded by the wave mirror 102b into a line laser with a larger field of view. When parallel light (i.e., parallel light in the short side direction) is incident on the surface of the wave mirror, the curvature of the parallel light incident at different positions is the same, and the refraction direction of the parallel light incident at different positions is consistent. Therefore, the wave mirror does not change the width of the beam emitted by the laser source in the short side direction. When parallel light (i.e., parallel light in the long side direction) is incident on the surface of the wave mirror perpendicular to the wave mirror, because the surface of the cylindrical lens is curved, the refraction direction of the parallel beam incident at different positions on the cylindrical lens is different. The beam in the long side direction diverges, forming a line laser emission with better uniformity.

[0029] In some embodiments, 102b can also be a Powell prism; when 102b is a Powell lens, the ridge surface of the Powell lens is placed facing the side of the laser source, and the top of the ridge surface is generally an aspherical surface, which can fan out the collimated beam and convert it into a uniformly distributed line beam.

[0030] against Figure 2 , Figure 3 , Figure 4 The linear laser projector can be considered as a linear laser with its long side along the second direction by rotating the entire structure of the linear laser projector by 90°. This will not be described in detail here.

[0031] Figure 3 This application provides another schematic diagram of the optical path of a linear laser projector; 201 is a linear array light source, 202 is a dimming element, wherein the dimming element 202 includes a cylindrical collimating lens 202a and a diffuser 202b. The diffuser microstructure can be fabricated by direct etching, laser direct writing, or plasma direct writing on the corresponding substrate, or by spin-coating photoresist on the substrate and fabricating it through nanoimprinting, or by precision injection molding. The corresponding substrate can be glass (such as quartz), plastic (such as PC, PMMA), etc. The diffuser can shape the incident beam into a linear beam; in this embodiment, 202a is a collimating lens, compared to... Figure 2 The difference is, Figure 2 It collimates the light in both the X and Y directions of the beam. Figure 3 In (a), the collimating lens collimates the light in the short side direction (i.e., the X direction in the figure) of the linear array light source. The light in the long side direction of the linear array light source is diffused after passing through the collimating lens. The shaping diffuser 202b has no modulation function for the beam in the short side direction (X direction in the figure) of the linear array light source (parallel light is still emitted in parallel after passing through the shaping diffuser 202b). It further diffuses the light in the long side direction (i.e., the Y direction in the figure) of the linear array light source, and finally obtains a line laser.

[0032] for Figure 3 In (a) and (b), the laser projector projects a single-line floodlight. In some cases, the cylindrical collimating lens 202a and the shaping diffuser 202b can be integrated into an optical element, which is also within the scope of protection of this application.

[0033] Figure 4 This is a schematic diagram of the optical path of another linear laser projector provided in this application; in this embodiment, the laser projection is a linear speckle pattern, and the linear array light source 301 is compared to... Figure 3The difference is that the linear array laser emits more apertures; the collimating lens 302 has a shorter focal length (preferably ≤2.5mm), and the linear array light source 301 projects a larger speckle pattern after being collimated by the collimating lens 302, with the center of the speckle being bright and the four corners being dark; the one-line speckle has a high unit energy density, a long ranging range, and a speckle distribution with a specific pattern, which is suitable for high-precision depth calculation based on speckle matching.

[0034] The receiving chip of a linear receiving camera is elongated. The camera also includes a filter that filters out unwanted ambient light (especially natural light), allowing only specific structured light or laser light to pass through, thus ensuring the accuracy and stability of depth measurement. In practice, the elongated receiving chip has several implementation schemes: first, the receiving chip is an elongated SPAD chip; second, the receiving chip is multiple individual SiPM chips arranged in an elongated pattern, in which case the risk of crosstalk between multiple discrete pixel units is lower compared to integrated pixel units; third, the receiving chip is an integrated elongated SiPM chip.

[0035] This invention employs a laser projector to project a linear laser beam, which, after reflection from environmental objects, is focused onto the photosensitive surface of a receiving chip via an imaging lens. The receiving chip converts the echo signal into an avalanche electrical signal. The depth information of the object is obtained by calculating the time difference between the pulse signal projected by the laser projector and the received avalanche signal. Specifically, the linear laser projector forms a scanning area through a deflection module. The calculated depth information corresponding to the center area of ​​the scanning area is used for navigation, while the calculated depth information corresponding to the center and edge areas is used for obstacle avoidance. Compared to existing technologies that require radar and structured light modules for navigation and obstacle avoidance, this invention uses a single depth measurement module to acquire depth information that can be used simultaneously for robot navigation and obstacle avoidance. This simplifies the structure, reduces material and assembly costs, significantly reduces product power consumption, and facilitates product promotion and widespread adoption. Furthermore, the single depth measurement module saves space and is conducive to miniaturization design. Additionally, it avoids calibration and synchronization problems associated with multi-module collaboration. The system outputs images in separate obstacle avoidance and navigation frames, saving computing power and improving obstacle avoidance and navigation speed.

[0036] Example 1 In this embodiment, the linear array light source is a single-hole light-emitting chip, and there are multiple such chips arranged in a linear line.

[0037] When the scanning direction is parallel to the first direction, the single-aperture light emission power of the light source in the middle area is less than that of the light source in the edge area, and the power of the same single-aperture light emission chip when the line laser scans to the center area is greater than that when the line laser scans to the edge area.

[0038] Specifically, when the scanning direction of the linear laser is parallel to the first direction, the power of the same single-aperture light-emitting chip differs in different scanning areas (the scanning center area and the scanning edge area). Here, power refers to the emitted power of the single-aperture light-emitting chip. Specifically, when the linear laser scans to the scanning center area, the power of the single-aperture light-emitting chip is power one; when the linear laser scans to the scanning edge area, the power of the same single-aperture light-emitting chip is power two, with power one being greater than power two. Thus, the luminous power of the linear array light source is greater in the scanning center area than in the scanning edge area. For example, increasing the power of all light-emitting holes within the -5° to 5° field of view of the scanning center area ensures that the energy of the light spot used for navigation is greater than the energy of the light spot used for obstacle avoidance.

[0039] To ensure the uniformity of light spot energy in the second direction, the single-aperture luminous power of the central region light source of the linear array light source is less than the single-aperture luminous power of the edge region light source, such as... Figure 5 In (a) and (b) of the diagram, the relative illumination (RI) curve of the lens is generally bright in the center and dark at the four corners. To ensure that the laser spot emitted by the linear laser projector is imaged as a uniformly bright line on the infrared receiving chip, which is beneficial to the accuracy of depth measurement, the following specific implementation methods can be used: First, the driving current of the single-aperture light-emitting chip in the central region is less than that in the edge region; second, the number of active junctions in the single-aperture light-emitting chip in the central region is less than that in the edge region; third, the aperture of the single-aperture light-emitting chip in the central region is smaller than that in the edge region. It should be noted that one or more of the above three implementation methods can coexist. In this embodiment, the linear laser projected by the linear laser projector is designed to be dark in the center and bright at the edges. The light spot projected by the light-emitting chip in the central region is used for navigation, and the light spots projected by the light-emitting chips in both the central and edge regions are used for obstacle avoidance.

[0040] When the scanning direction is parallel to the second direction, the single-aperture emission power of the light source in the middle region is greater than that of the light source in the edge region. The light spot projected by the light-emitting chip in the middle region is used for navigation, while the light spots projected by the light-emitting chips in both the middle and edge regions are used for obstacle avoidance. Specifically, this can be achieved in three ways: First, the driving current of the single-aperture light-emitting chip in the middle region is greater than that in the edge region; second, the number of active junctions in the single-aperture light-emitting chip in the middle region is greater than that in the edge region; third, the aperture of the single-aperture light-emitting chip in the middle region is larger than that in the edge region. It should be noted that one or more of these three implementation methods can coexist.

[0041] refer to Figure 6 Four schematic diagrams of a midline array light source. Figure 6 The arrangement direction of the mid-line array light source is such that when the scanning direction is parallel to the second direction, that is, the long side direction of the linear laser is... Figure 1 The situation shown in (a) is as follows.

[0042] like Figure 6 In (a), the multiple independent single-aperture light-emitting chips are of the same specification. The difference lies in the different currents used to drive the light-emitting chips in the central and edge regions. Specifically, driving current 1 drives the light-emitting chip in the central region, and driving current 2 drives the light-emitting chip in the edge region, with driving current 1 > driving current 2. The light-emitting chips in the central and edge regions can share a common cathode (electrically connected to the same cathode pad), and the anodes of each light-emitting chip in the central / edge region can be electrically connected to the same anode pad (not shown in the figure, but similar). Figure 6 As shown in (c) in the paper, each of the light-emitting chips can also be electrically connected to a separate anode pad. In some cases, the anodes of each light-emitting chip in the middle area light source / edge area light source can also be electrically connected to different driver ICs or different driver pins of the same driver IC to individually control the lighting of each light-emitting chip, all of which are within the scope of this application.

[0043] like Figure 6 (b) in the middle, and Figure 6 The difference in (a) is that the light-emitting chip of the single aperture in the middle region light source is different from the edge light-emitting chip in the edge region. The number of active region junctions of the light-emitting chip in the middle region light source is greater than that of the light-emitting chip in the edge region light source, and / or the aperture of the light-emitting hole in the middle region light source is larger than that of the light-emitting hole in the edge region light source. The driving current 1 and the driving current 2 can be equal or unequal.

[0044] like Figure 6 (c) in the middle, and Figure 6 Unlike (b), the anodes of each light-emitting chip in the middle area light source / edge area light source can be electrically connected to the same anode pad, and each light-emitting chip in the middle area light source / edge area light source can be driven by the same driving circuit.

[0045] like Figure 6 (d) in the middle, and Figure 6 Unlike (c), the anodes of all the light-emitting chips in the middle area light source / edge area light source can be electrically connected to the same anode pad, and all the light-emitting chips in the middle area light source / edge area light source can be driven by the same driving circuit.

[0046] Understandable, can Figure 6 After rotation, the scanning direction is parallel to the first direction, resulting in the linear array light source's aperture settings, but the parameter settings are reversed, as shown in the reference. Figure 6 (e) in the middle is Figure 6 (a) shows the result after rotating 90 degrees, i.e., when the scanning direction is parallel to the first direction. Figure 6 In (e), driving current 1 < driving current 2, and the number of active junctions in the middle region light-emitting chip is less than the number of active junctions in the edge region light-emitting chip. And for... Figure 6 (b) Figure 6 (c) and Figure 6 The diagrams after rotating (d) are no longer shown; the parameter settings are simply the opposite. Figure 6 (b) Figure 6 (c) and Figure 6 In (d), the number of active region junctions of the light-emitting chip in the middle region is less than the number of active region junctions of the light-emitting chip in the edge region, and the aperture of the light-emitting hole in the middle region is less than the aperture of the light-emitting hole in the edge region.

[0047] This embodiment adjusts the beam energy of different regions of the linear laser projector by controlling the output power of the single-aperture light-emitting chip. Compared with adjusting the beam energy distribution of a linear beam by changing the design of the dimming element, this method offers greater flexibility and scalability. The ratio of light power between the central and edge light sources can be adjusted according to actual application requirements to further optimize system performance.

[0048] Example 2 In this embodiment, the linear light source is an integrated linear light-emitting array.

[0049] When the scanning direction is parallel to the first direction, the total luminous power of the central light source is less than that of the edge light source. Furthermore, when the linear laser scans the central region, the power of both the central and edge light sources is greater than the power when the linear laser scans the edge region. Specific implementation methods include: first, the driving current of the central light source's aperture is less than that of the edge light source's aperture; second, the aperture density of the central light source is less than that of the edge light source; third, the aperture diameter of the central light source's aperture is smaller than that of the edge light source's aperture; and fourth, the number of active junctions in the central light source's aperture is less than that of the edge light source's aperture. It should be noted that one or more of these four implementation methods can coexist.

[0050] When the scanning direction is parallel to the second direction, the total luminous power of the light source in the middle region is greater than that of the light source in the edge region. Specific implementation methods include: first, the driving current of the light-emitting apertures in the middle region is greater than that in the edge region; second, the aperture density of the light-emitting apertures in the middle region is greater than that in the edge region; third, the aperture diameter of the light-emitting apertures in the middle region is greater than that in the edge region; and fourth, the number of active junctions in the light-emitting apertures in the middle region is greater than that in the edge region. It should be noted that any one of these four implementation methods can exist, or all four methods can coexist.

[0051] refer to Figure 7 Four schematic diagrams of a midline array light source. Figure 7 The arrangement direction of the mid-line array light source is such that when the scanning direction is parallel to the second direction, that is, the long side direction of the linear laser is... Figure 1 The situation shown in (a) is as follows.

[0052] like Figure 7 In (a), the linear light-emitting array has at least three zones, with multiple zones sharing a common cathode but not a common anode. The difference lies in the different currents used to drive the light-emitting chips in the central and edge zones. Driving current 1 drives the light-emitting chip in the central zone, while driving current 2 drives the light-emitting chip in the edge zone, with driving current 1 > driving current 2. The light-emitting apertures in the central and edge zones differ, for example, the number of active junctions in the central zone is greater than that in the edge zone, and / or the aperture diameter of the central zone is larger than that of the edge zone, and / or the aperture density of the central zone is greater than that of the edge zone (e.g., ...). Figure 7 (b) in the middle); like Figure 7 In (c) and (d), the linear light-emitting array is unpartitioned, all light-emitting holes share a common cathode and anode, and are driven by the same driving current. The number of active junctions of the light-emitting holes in the middle region is greater than that in the edge region, and / or the aperture of the light-emitting holes in the middle region is greater than that in the edge region, and / or the density of the light-emitting holes in the middle region is greater than that in the edge region, so that the total luminous power of the light source in the middle region is greater than that of the light source in the edge region.

[0053] Understandable, can Figure 7 After rotation, the scanning direction is parallel to the first direction, resulting in the linear array's light-emitting apertures being set up, but the parameter settings are reversed, such as driving current 1 < driving current 2. Figure 7 (a) Figure 7 In (c), the number of active junctions in the light-emitting aperture of the intermediate region is less than that in the light-emitting aperture of the edge region, and the aperture diameter of the light-emitting aperture of the intermediate region is smaller than that of the light-emitting aperture of the edge region. Figure 7(b) Figure 7 In (d), the density of light-emitting apertures in the middle region is less than that in the edge region, and the number of active region junctions of light-emitting apertures in the middle region is less than that in the edge region.

[0054] Integrated design facilitates miniaturization and weight reduction of modules, meeting the urgent need for compact structures in modern mobile robots. Adjusting the energy of the linear laser beam in different regions by controlling the output power of a single-aperture light-emitting chip offers greater flexibility and scalability compared to adjusting the energy distribution of a linear beam by changing the design of the dimming element. The power ratio between the central and edge light sources can be adjusted according to actual application requirements, further optimizing system performance.

[0055] Example 3 refer to Figure 8 As shown, in this embodiment, the receiving chip of the linear receiving camera is elongated, such as: 1) an elongated SPAD chip; 2) multiple individual SiPM chips arranged in an elongated pattern, where multiple discrete pixel units have a lower risk of crosstalk compared to integrated pixel units; 3) an integrated elongated SiPM chip.

[0056] In practical implementation, when the scanning direction is parallel to the second direction, the TDC range of the pixel unit used to calculate navigation depth information is designed to be larger than the TDC range of the pixel unit used to calculate obstacle avoidance depth information. This TDC component range design for pixel units in different regions ensures both long-distance measurement range and avoids excessive unused storage space and wiring design during short-distance measurements, thus saving hardware resources. When the scanning direction is parallel to the first direction, the TDC range of all pixel units is the same.

[0057] Example 4 In this embodiment, the linear laser projector includes multiple linear array light sources, and the linear receiving camera includes multiple elongated receiving chips corresponding to the linear array light sources. In specific implementation, there are N linear array light sources and N receiving chips, with each linear array light source and receiving chip corresponding one-to-one, and the receiving chip is elongated. Adjacent light sources are staggered along their long side by 1 / N adjacent light-emitting point spacing, and corresponding receiving chips are staggered along their long side by 1 / N adjacent pixel unit spacing.

[0058] When the long side of the linear laser is parallel to the first direction, the linear array light source and the receiving chip are each arranged in N columns. The linear array light sources in different columns are staggered by 1 / N adjacent light-emitting point spacing in the long side direction. The corresponding two columns of elongated receiving chips are also staggered by 1 / N adjacent pixel unit spacing in the long side direction, where N≥2. For example, two columns of linear array light sources + two columns of elongated receiving chips, the two light sources are staggered by 1 / 2 adjacent light source spacing in the long side direction, and the corresponding two columns of elongated receiving chips are also staggered by 1 / 2 adjacent pixel unit spacing in the long side direction. The projector projects speckle (the number and position of speckle are the same as the distribution of the light source). The position of the projected speckle corresponds one-to-one with the pixel unit of the elongated receiving chip (the position of the speckle and the position of the corresponding pixel unit are conjugate with respect to the object position of the imaging lens).

[0059] When the long side of the linear laser beam is parallel to the second direction, the linear array light source and the receiving chip are arranged in N rows. The linear array light sources in different rows are staggered by 1 / N adjacent light-emitting point spacing along the long side. The corresponding two rows of elongated receiving chips are also staggered by 1 / N adjacent pixel unit spacing along the long side, where N≥2. For example, two rows of linear array light sources + two rows of elongated receiving chips, the two rows of light sources are staggered by 1 / 2 adjacent light source spacing along the long side, and the corresponding two rows of elongated receiving chips are also staggered by 1 / 2 adjacent pixel unit spacing along the long side. Furthermore, the projector projects speckle (e.g.,...) Figure 6 As shown, the number and location of speckles are the same as the distribution of the light source. The position of the projected speckles corresponds one-to-one with the pixel unit of the elongated receiving chip (the position of the speckles and the position of the corresponding pixel unit are conjugate with respect to the object position of the imaging lens).

[0060] Taking the example of a line laser beam with its long side parallel to the first direction, it's understandable that rotating the system by 90° results in a line laser beam with its long side parallel to the second direction. This will not be explained in detail here. It should be noted that when the long side of the line laser beam is parallel to the first direction... Figure 8 The TDC range in the central region can be set to be larger than or equal to that in the edge region. However, when the laser beam is parallel to the second direction, the TDC range in the central region is equal to that in the edge region. When the long side of the linear laser beam is parallel to the first direction: Figure 8 Schematic diagrams of the three elongated receiving chips provided in this application; Figure 8(a) is a strip-shaped SPAD chip, which is composed of P rows and Q columns of SPAD pixel units (where P > Q). Since the size of a single SPAD pixel unit is small, in order to improve the receiving energy of a single imaging unit, multiple SPAD pixel units can be combined into a superpixel unit as an imaging unit to collect light signals. A single pixel unit can contain Q*Q SPAD pixel units (generally Q≤10). Multiple SPAD pixel units in a superpixel unit share a TDC module. The photon arrival time is directly recorded by the TDC without the need for external ADC analog-to-digital conversion. Figure 8 (b) shows multiple individual SiPM chips arranged in a long strip. A single SiPM pixel unit is usually composed of hundreds to thousands of SPAD pixels and capacitors and resistors connected in parallel. Each SPAD pixel can independently capture photon signals. Each measurement channel connects multiple SPAD pixel units in parallel and adds them to the analog signals to form the final accumulated signal output, which is then converted into a digital signal by an external ADC. SPAD chips can achieve higher acquisition resolution, while SiPM has a larger micro-unit spacing and better optical isolation, avoiding the influence of optical crosstalk on the measurement. Figure 8 (c) in the figure represents an integrated elongated SiPM chip, which integrates multiple SiPM pixel units onto a single chip, resulting in higher integration and easier production. Figure 8 In (a), (b), and (c), the TDC of pixel units in different regions can be set to different values. For example, the TDC range of pixel units used to calculate navigation depth information (such as pixel units located in the middle region) can be designed to be greater than the TDC range of pixel units used to calculate obstacle avoidance depth information at the edge. In this way, the TDC component range design for pixel units in different regions ensures both the measurement range at long distances and avoids excessive unused storage space and wiring design during close-range measurements, thus saving hardware resources.

[0061] In some embodiments, the number of columns of the linear array light source and the number of columns of the linear array receiving chip are both Q, and Q≥2. Adjacent columns of light sources are staggered along the long side of the linear array light source, with a stagger distance = 1 / Q * the center distance between adjacent light sources. Figure 9 As shown, Figure 9 This application provides a schematic diagram of a linear array light source and a corresponding elongated receiving chip. Figure 9 Taking Q=2 as an example, we can see that the laser projector contains two linear array light sources. In each array, the light power in the central region is greater than the light power in the edge region (which could be...). Figure 6 and Figure 7(any one of the following implementation methods), and each column of light sources is staggered along the long side of the linear array light sources, with a stagger distance = 1 / 2 * the center distance between adjacent light sources. The linear array receiver camera also includes two columns of elongated receiving chips (which can be...). Figure 8 In any one of the embodiments, the pixel units on the elongated receiving chip correspond one-to-one with the light-emitting points of the two linear array light sources, which is equivalent to the measurement step size received in the column direction being half of the original, thus doubling the resolution.

[0062] In this embodiment, without significantly increasing hardware costs and power consumption, an N-fold increase in resolution is achieved through optimization of optical and structural design, enhancing the system's ability to perceive details. This is particularly suitable for application scenarios with high requirements for navigation map accuracy and obstacle avoidance fine-grainedness. Furthermore, compared to solutions that directly increase the system's measurement resolution by increasing the density of light-emitting points and the ratio of receiving pixel units, the solution in this application offers better heat dissipation performance, improving module stability and lifespan.

[0063] Example 5 Based on Embodiment 4 above, an additional set of linear array light sources is added along the long side of the linear laser beam. Unlike Embodiment 4, the length of the linear laser beam in this embodiment is formed by splicing together multiple sets of linear array light sources. In this embodiment, the depth measurement module includes M sets of linear array light sources and M sets of receiving chips. Each set of linear array light sources includes N linear array light sources. Adjacent sets of linear array light sources are staggered along their long side, with a minimum interval of 0-1 adjacent light-emitting point spacing. Each set of receiving chips includes N receiving chips. Adjacent sets of receiving chips are staggered along their long side, with a minimum interval of 0-1 adjacent pixel units.

[0064] It should be noted that this embodiment is a further limitation based on embodiment four. In this embodiment, each linear array light source group includes N linear array light sources, and the design of the N linear array light sources is as described in embodiment four.

[0065] In practical implementation, in addition to having multiple linear array light sources and elongated receiving chips perpendicular to the long side, Q columns can also be set parallel to the long side, where Q ≥ 2, such as... Figure 10 As shown, Figure 10 The following is a schematic diagram of another linear array light source and the corresponding elongated receiving chip provided in this application. Q=2 and P=3 are used for explanation. At this time, the length of the light source in the long side direction is approximately the length of two linear array light sources. Using multi-line lasers in the long side direction can improve the field of view of the single-line laser. Setting multi-line lasers in a staggered manner in the short side direction can improve the resolution of the depth map output.

[0066] The single-line laser projector emits a linear laser with a small long-side field of view, resulting in a significant obstacle avoidance blind spot for depth cameras using single-line lasers. In this embodiment, using multi-line lasers increases the long-side field of view of the linear laser, significantly reducing the obstacle avoidance blind spot and improving the robot's obstacle avoidance reliability and safety in complex environments, demonstrating high practical value.

[0067] Example 6 In this embodiment, the laser projector projects a line of speckle, and the speckle spots correspond one-to-one with the measurement units of the receiving chip. In this embodiment, all light-emitting points of the light source can be lit simultaneously, meaning the high-power and low-power light-emitting areas operate concurrently. In some cases, it can also be configured so that within a single measurement cycle, the light-emitting holes in the middle and edge areas are lit in a time-sharing manner. Figure 11 The diagrams provided by this invention illustrate two lighting timing sequences. A single measurement cycle includes multiple repeated tests, i.e., multiple lighting cycles. Within one measurement cycle, the light-emitting apertures in the central and edge regions of the linear array light source are simultaneously or sequentially illuminated. When illuminated sequentially, within one measurement cycle, the interval between two lighting cycles for the central light-emitting aperture is equal to or greater than the interval between two lighting cycles for the edge light-emitting aperture.

[0068] In one embodiment, when the long side of the linear laser is parallel to either the first or the second direction, within one measurement cycle, the light-emitting apertures in the middle and edge regions are illuminated sequentially. The interval between two illuminations of the light-emitting aperture in the middle region is equal to the interval between two illuminations of the light-emitting aperture in the edge region. Figure 11 In (a), t1=t2, and in two adjacent illumination sessions, the time interval between the illumination of the central area light source and the illumination of the edge area light source is less than the time interval between the two illumination sessions of the central or edge area light source apertures. When different apertures are turned on, the corresponding receiving pixel units are also turned on synchronously. Without affecting the depth map output frame rate, the apertures in different areas are driven in a time-division manner. In this way, the driving capability of the driving chip and driving circuit can distribute more energy evenly to a single aperture when driving fewer apertures, which can make the apertures reach higher peak light power and measure farther distances. It should be noted that when the long side of the line laser is parallel to the second direction, the illumination power of all apertures when illuminating the scanning edge area is smaller than the illumination power when illuminating the scanning center area.

[0069] Furthermore, in another embodiment, when the long side of the linear laser is parallel to the first direction, within one measurement cycle, the light-emitting holes in the middle area and the edge area are illuminated in a time-division manner, and the interval between two illuminations of the light-emitting holes in the middle area is greater than the interval between two illuminations of the light-emitting holes in the edge area. Figure 11In (b), that is, t2 > t1; when the interval between two illuminations by the light-emitting aperture in the middle region is equal to the interval between two illuminations by the light-emitting aperture in the edge region, that is... Figure 11 In the case shown in (a), the time interval between two illuminations of the light source in the middle area or the light source in the edge area is greater than the flight time corresponding to the ranging range. Therefore, the illumination interval for close-range measurement should also be set to be relatively large, reducing the number of close-range illumination measurements within a measurement cycle. This embodiment can also increase the number of close-range illumination measurements and improve the accuracy of close-range measurement by reducing the illumination time interval for close-range measurement.

[0070] It should be noted that, Figure 11 The diagram shows the case where the long side of the linear laser line is parallel to the first direction. Figure 11 In the middle, low-power lighting corresponds to the lighting of the light-emitting apertures in the edge area, while high-power lighting corresponds to the lighting of the light-emitting apertures in the center area. Figure 11 The diagram shows that the low-power lighting is applied before the high-power lighting, but in practice, the high-power lighting can be applied first. Figure 12 This refers to the case where the long side of the linear laser beam is parallel to the second direction. Figure 12 In the middle, low-power lighting corresponds to lighting the light-emitting aperture in the central area of ​​the light source, while high-power lighting corresponds to lighting the light-emitting aperture in the edge area of ​​the light source. Furthermore, Figure 12 It also shows that when the long side of the linear laser is parallel to the second direction, the light emission power of all the light-emitting holes when the edge area is illuminated is smaller than the light emission power of the hole when the center area is illuminated.

[0071] Additionally, it should be noted that for the case of multiple linear array light sources and multiple elongated receiving chips in Embodiment 5, refer to... Figure 9 and Figure 10 With each linear array light source and each elongated receiving chip capable of being lit in a time-division manner in the high-power and low-power light-emitting regions, different linear laser sources and their corresponding elongated receiving chips can also be started in pairs in a time-division manner, which can also improve the peak optical power of each illumination.

[0072] Example 7 In this embodiment, the optical path deflection scanning module is a rotating prism. When the long side of the line laser is parallel to the first direction, the rotating prism makes the line laser scan a field of view of ≥120° in the second direction.

[0073] When the long side of the linear laser is parallel to the second direction, rotating the prism ensures that the linear laser scans a field of view ≥40° in the first direction. Compared to the second direction, the scanning angle in the first direction does not need to be large. This results in faster scanning speed and a higher output depth map frame rate. Furthermore, at the same output frame rate, the angular resolution is higher, leading to higher image output resolution. Additionally, at the same output frame rate, the number of illumination attempts per measurement per unit angle range can be set higher, improving measurement accuracy.

[0074] Figure 13 The depth measurement module shown includes a linear laser projector (TX) 100, a linear receiving camera (RX) 200, and a rotating prism 300. The rotating prism 300 includes a multifaceted prism and a rotating shaft. The rotating shaft rotates the multifaceted prism. In this schematic diagram, the rotating prism 300 is a four-sided rotating mirror. The multifaceted prism can also be a two-sided prism, a three-sided prism, a five-sided prism, or a prism with more or more faces. The rotation direction of the rotating shaft is set at a certain angle with the direction of the laser projector projecting the line, preferably 90°. A linear laser projector emits a probe beam towards the target, and a linear receiving camera receives the echo beam. A rotating prism, equipped with multiple reflective surfaces, changes the angle of the beam incident on the multifaceted prism. The rotating prism deflects the probe beam to form a scanning field of view, expanding the horizontal measurement range of the depth measurement module. The solid and dashed lines in the figure represent the optical paths of the probe beam and echo beam under different rotation angles of the rotating prism 300. By adjusting the rotation angle of the rotating prism, the horizontal measurement range of the depth measurement module can be expanded; preferably, the horizontal measurement field of view angle is ≥120°. The motor can drive the rotating prism 300 to rotate at a uniform speed or to perform non-uniform motion, such as following a preset motion pattern. Additionally, it should be noted that... Figure 13 The image shows an embodiment of horizontal scanning; the vertical scanning scheme is different. Figure 13 The only difference shown is that the placement of TX and RX relative to the rotating prism and / or the rotation direction of the rotating prism are different. Preferably, the vertical scanning field of view is ≥40°.

[0075] Example 8 The optical path deflection scanning module is a rotating mechanical structure with a rotation angle of 360° and a scanning direction parallel to the second direction.

[0076] When the long side of the linear laser line is parallel to the first direction, that is, when the scanning direction is parallel to the second direction, refer to Figure 14 As shown, another depth measurement module is provided, including a linear laser projector 100, a linear receiving camera 200, a rotating platform 300, a motor 400, a motor shaft, and a gear 500. Figure 14In (a) the motor 400 is used to generate driving torque and thereby drive the gear 500 to rotate. The gear 500 rotates the rotating platform 300, thereby causing the linear laser projector 100 and the linear receiving camera 200 to rotate synchronously. Specifically, the synchronous rotation angle generated is 0°-360°. Figure 14 In (b), the torque generated by the motor directly drives the rotating platform 300 to rotate via the rotating shaft, thereby causing the linear laser projector 100 and the linear receiving camera 200 to rotate at an angle of 0°-360°; the rotating shaft rotates the module horizontally by 360°, realizing horizontal full-field scanning measurement. Other methods that rotate the depth measurement module as a whole by 0°-360° are all within the scope of protection of this application.

[0077] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the inventive concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A depth measurement module, characterized in that, include: A linear laser projector includes a linear array light source and a dimming element, wherein the light beam emitted by the linear array light source is converted into a line laser after passing through the dimming element, wherein at least one linear array light source is provided, and the linear array light source includes a central area light source and edge area light sources located on both sides of the central area light source. The optical path deflection scanning module is used to deflect the line laser along a direction perpendicular to the long side of the line laser within a preset angle range to form a scanning area. The scanning direction includes a first direction and a second direction, and the first direction and the second direction are perpendicular to each other. In the first direction, the scanning area includes a scanning center area and two scanning edge areas. The two scanning edge areas are located on opposite sides of the scanning center area, and the laser energy of the scanning center area is greater than that of the scanning edge areas. as well as A linear receiving camera includes a receiving chip and an imaging lens. Laser light in the scanning area is reflected by environmental objects to form a reflected light spot. This reflected light spot is focused by the imaging lens onto the photosensitive surface of the receiving chip. The receiving chip responds to the reflected light spot and converts the light signal of the reflected light spot into an avalanche electrical signal. The depth information of the object is obtained by calculating the time difference between the pulse signal of the laser spot projected by the linear laser projector and the avalanche electrical signal received by the linear receiving camera. The depth information calculated for the reflected light spots corresponding to both the scanning center region and the scanning edge region is used for obstacle avoidance. The depth information calculated for the reflected light spot corresponding to the scanning center region is also used for navigation.

2. The depth measurement module as described in claim 1, characterized in that, The linear array light source is a single-hole light-emitting chip, and there are multiple chips, which are arranged in a linear line. When the scanning direction is parallel to the first direction, the single-aperture light emission power of the central region light source is less than that of the single-aperture light emission power of the edge region light source, and the power of the same single-aperture light emission chip when the line laser scans to the scanning center region is greater than that when the line laser scans to the scanning edge region. When the scanning direction is parallel to the second direction, the single-aperture luminous power of the central region light source is greater than that of the single-aperture luminous power of the edge region light source.

3. The depth measurement module as described in claim 2, characterized in that, When the scanning direction is parallel to the first direction, the driving current of the single-aperture light-emitting chip of the intermediate region light source is less than the driving current of the single-aperture light-emitting chip of the edge region light source; and / or, the number of active region junctions of the single-aperture light-emitting chip of the intermediate region light source is less than the number of active region junctions of the single-aperture light-emitting chip of the edge region light source; and / or, the aperture of the light-emitting hole of the single-aperture light-emitting chip of the intermediate region light source is less than the aperture of the light-emitting hole of the single-aperture light-emitting chip of the edge region light source. When the scanning direction is parallel to the second direction, the driving current of the single-aperture light-emitting chip of the intermediate region light source is greater than the driving current of the single-aperture light-emitting chip of the edge region light source; and / or, the number of active region junctions of the single-aperture light-emitting chip of the intermediate region light source is greater than the number of active region junctions of the single-aperture light-emitting chip of the edge region light source; and / or, the aperture of the light-emitting hole of the single-aperture light-emitting chip of the intermediate region light source is greater than the aperture of the light-emitting hole of the single-aperture light-emitting chip of the edge region light source.

4. The depth measurement module as described in claim 1, characterized in that, The linear light source is an integrated linear light-emitting array; When the scanning direction is parallel to the first direction, the total luminous power of the central area light source is less than the total luminous power of the edge area light source. When the linear laser scans to the scanning center area, the power of the central area light source and the edge area light source is greater than the power when the linear laser scans to the scanning edge area. When the scanning direction is parallel to the second direction, the total luminous power of the central area light source is greater than the total luminous power of the edge area light source.

5. The depth measurement module as described in claim 4, characterized in that, When the scanning direction is parallel to the first direction, the driving current of the light-emitting aperture of the intermediate region light source is less than the driving current of the light-emitting aperture of the edge region light source; and / or, the light-emitting aperture density of the intermediate region light source is less than the light-emitting aperture density of the edge region light source. And / or, the aperture of the light-emitting hole in the intermediate region light source is smaller than the aperture of the light-emitting hole in the edge region light source; and / or, the number of active region junctions in the light-emitting holes of the intermediate region light source is smaller than the number of active region junctions in the light-emitting holes of the edge region light source; When the scanning direction is parallel to the second direction, the driving current of the light-emitting aperture of the intermediate region light source is greater than the driving current of the light-emitting aperture of the edge region light source; and / or, the light-emitting aperture density of the intermediate region light source is greater than the light-emitting aperture density of the edge region light source; and / or, the aperture diameter of the light-emitting aperture of the intermediate region light source is greater than the aperture diameter of the light-emitting aperture of the edge region light source; and / or, the number of active region junctions of the light-emitting apertures of the intermediate region light source is greater than the number of active region junctions of the light-emitting apertures of the edge region light source.

6. The depth measurement module as described in claim 1, characterized in that, When the scanning direction is parallel to the second direction, the TDC range of the pixel unit used to calculate navigation depth information is designed to be greater than the TDC range of the pixel unit used to calculate obstacle avoidance depth information.

7. The depth measurement module as described in claim 1, characterized in that, The linear array light source and the receiving chip are provided in N units respectively. The linear array light source and the receiving chip are in one-to-one correspondence, and the receiving chip is elongated. Adjacent light sources are placed at a distance of 1 / N adjacent light-emitting point spacing along their long side, and the corresponding receiving chips are placed at a distance of 1 / N adjacent pixel unit spacing along their long side.

8. The depth measurement module as described in claim 7, characterized in that, The depth measurement module includes M linear array light source groups and M receiving chip groups. Each linear array light source group includes N linear array light sources. Adjacent linear array light source groups are staggered along their long side, and the minimum interval is 0-1 adjacent light-emitting point spacing. Each receiving chip group includes N receiving chips. Adjacent receiving chip groups are staggered along their long side, and the minimum interval is 0-1 adjacent pixel units.

9. The depth measurement module as described in claim 1, characterized in that, Within one measurement cycle, the light-emitting apertures in the middle region and the light-emitting apertures in the edge region of the linear array light source are lit simultaneously or at different times. When the light is applied in a time-division manner, within one measurement cycle, the interval between two illuminations of the light-emitting holes in the middle area is equal to or greater than the interval between two illuminations of the light-emitting holes in the edge area.

10. The depth measurement module as described in claim 1, characterized in that, The optical path deflection scanning module is a rotating prism. When the long side of the line laser is parallel to the first direction, the rotating prism ensures that the line laser's scanning field of view in the second direction is ≥120°; when the long side of the line laser is parallel to the second direction, the rotating prism ensures that the line laser's scanning field of view in the first direction is ≥40°; or... The optical path deflection scanning module is a rotating mechanical structure with a rotation angle of 360°, and the scanning direction is parallel to the second direction.

Images