Depth imaging module and device

Abstract

The embodiment of the invention discloses a depth imaging module and device. The module comprises a receiving module and at least two transmitting modules, the at least two transmitting modules comprise a first transmitting module and a second transmitting module; the first transmitting module is used for transmitting a first optical signal to a first target area at first transmitting power; the second transmitting module is used for transmitting a second optical signal to a second target area at second transmitting power; the first target area and the second target area are sequentially distributed in the vertical direction; the second transmitting power is smaller than or equal to the first transmitting power; and the receiving module is used for receiving a first reflected light signal corresponding to the first light signal and a second reflected light signal corresponding to the second light signal, and processing the first reflected light signal and the second reflected light signal to obtain a first depth image of the first target area and a second depth image of the second target area. By adopting the embodiment of the invention, in a long-distance detection scene, the power consumption can be reduced, and the high anti-crosstalk probability can be reduced.

Description

Technical Field

[0001] This invention relates to the field of optical imaging technology, and more particularly to depth imaging modules and devices. Background Technology

[0002] In applications of Indirect Time-of-Flight (iToF) technology, scenarios include car parking, unmanned delivery robots, and service robots. For example, when a vehicle is reversing into a parking space, iToF technology is needed to identify the environmental information around the vehicle and determine its trajectory based on that information. In long-range detection scenarios, wide-angle iToF, as well as solutions that increase transmitted light power or superimpose the energy of multiple transmitters (TX), are commonly used. These solutions enhance signal transmission capabilities by increasing energy supply to meet the basic requirements of long-range detection.

[0003] However, high power and the superposition of energy from multiple units result in high power consumption, and the wide-angle iToF covers more highly reflective objects, making it easier for the sensor to capture strong reflected light from different angles, increasing the probability of crosstalk triggering and reducing the accuracy of the detection signal. Summary of the Invention

[0004] To address the aforementioned issues, embodiments of the present invention provide a depth imaging module and device that can reduce power consumption and lower the probability of high back-crosstalk in long-distance detection scenarios.

[0005] In a first aspect, embodiments of the present invention provide a depth imaging module, the module comprising a receiving module and at least two transmitting modules; the at least two transmitting modules are used to transmit optical signals toward a target area; the at least two transmitting modules include a first transmitting module and a second transmitting module; the target area includes a first target area and a second target area; the first target area and the second target area are distributed sequentially along a vertical direction; the maximum detection distance of the first target area is greater than or equal to the maximum detection distance of the second target area; The first transmitting module is used to transmit a first optical signal to the first target area at a first transmitting power; The second transmitting module is used to transmit a second optical signal to the second target area at a second transmitting power; the second transmitting power is less than or equal to the first transmitting power; The receiving module is used to receive a first reflected light signal corresponding to the first light signal and a second reflected light signal corresponding to the second light signal, and to process the first reflected light signal and the second reflected light signal to obtain a first depth image of the first target area and a second depth image of the second target area.

[0006] Secondly, embodiments of the present invention provide a depth imaging device, comprising: The device body and the depth imaging module as described in the first aspect, the depth imaging module being mounted on the device body, the depth imaging module being used to provide navigation depth information and obstacle avoidance depth information to the device body.

[0007] Implementing the embodiments of this application has the following beneficial effects: In this application embodiment, the depth imaging module receiving module and at least two transmitting modules are used to transmit optical signals to a target area. The at least two transmitting modules include a first transmitting module and a second transmitting module. The target area includes a first target area and a second target area. The first target area and the second target area are distributed sequentially along the vertical direction. The maximum detection distance of the first target area is greater than or equal to the maximum detection distance of the second target area. Firstly, by replacing the traditional wide-angle transmitting module with two transmitting modules, the field of view is reduced, and thus each transmitting module reflects less light, which can reduce the probability of high crosstalk. Specifically, the first transmitting module is used to transmit a first optical signal to the first target area with a first transmitting power, and the second transmitting module is used to transmit a second optical signal to the second target area with a second transmitting power. The second transmitting power is less than or equal to the first transmitting power. Therefore, when the second transmitting power is less than the first transmitting power, the transmitting power can be reduced from twice the first transmitting power to the sum of the first and second transmitting powers, thereby reducing power consumption. Furthermore, the receiving module is used to receive a first reflected light signal corresponding to the first light signal and a second reflected light signal corresponding to the second light signal, and to process the first reflected light signal and the second reflected light signal to obtain a first depth image of the first target area and a second depth image of the second target area, thereby enabling depth imaging to be completed with lower power consumption and lower crosstalk probability. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the drawings used in the embodiments of the present invention or the background art will be described below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram illustrating an application scenario of a depth imaging module provided in an embodiment of this application; Figure 2 This is a schematic diagram of a first decoding region provided in an embodiment of this application; Figure 3 This is a schematic diagram of a second decoding region provided in an embodiment of this application; Figure 4 This is a flowchart of a dynamic switching method for a transmission module provided in an embodiment of this application; Figure 5 This is a schematic diagram of an adjustable pitch angle provided in an embodiment of this application; Figure 6 This is a schematic diagram of a driving circuit based on a pulse resistor provided in an embodiment of this application; Figure 7 This is a schematic diagram of the structure of an emission module based on a vertical cavity surface-emitting laser provided in an embodiment of this application; Figure 8 This is a schematic diagram of a detection distance provided in an embodiment of this application. Detailed Implementation

[0010] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0011] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the listed steps or modules, but may optionally include steps or modules not listed, or may optionally include other steps or modules inherent to these processes, methods, products, or devices.

[0012] In this document, the term "embodiment" means that a particular feature, result, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0013] The following describes the relevant content, concepts, technical issues, technical solutions, and beneficial effects involved in the embodiments of this application.

[0014] Field of View (FOV): The angle between the two edges of the maximum range of the image of the target that can be seen through the lens of an optical instrument, with the lens as the vertex.

[0015] In current iToF technology applications, wide-angle iToF solutions with a typical angle of 120×90° possess unique technical characteristics. These solutions typically employ global illumination and chip readout. Taking a 640×480 resolution as an example, their working mechanism involves a single exposure and readout. In this method, the entire chip exposes the scene simultaneously, acquires the light signal, and reads out the accumulated data in a single operation.

[0016] In principle, when an iToF device is working, the vertical-cavity surface-emitting laser (VCSEL) at the transmitting end emits modulated infrared light signals into the scene. Within this 120×90° wide-angle range, the light covers the target scene at a certain angle and intensity. Objects in the scene reflect these infrared light signals back, which are captured by the image sensor at the receiving end. Because it is global emission, the reflected light from objects throughout the entire field of view is simultaneously received. During the exposure time, the image sensor performs photoelectric conversion on the received reflected light, converting the light signal into an electrical signal, and storing it as a charge in the pixel unit. After the exposure, the chip reads out this stored charge data all at once, converts it into a digital signal through an analog-to-digital converter, and then transmits it to the computing unit for subsequent phase difference calculation and depth information extraction.

[0017] Traditional single-transmitter modules with large vertical field of view have the following drawbacks: there is a problem of ambiguity in over-cycle ranging, where the spatial Euclidean distance of the target under a large field of view is likely to exceed the unambiguous distance of iToF, leading to incorrect ranging results; there is a problem of power and accuracy mismatch, where the single-transmitter power cannot simultaneously meet the requirements of high power in the far field to ensure signal strength and low power in the near field to avoid signal saturation, thus limiting imaging accuracy.

[0018] This solution adopts a vertical FOV combination design, which addresses the above problems through partitioned field of view and independent power control. The smaller field of view after splitting can reduce the spatial Euclidean distance of the target and alleviate the ambiguity of the super-period ranging. The first and second launch modules can be independently matched with high power in the far field and low power in the near field, while ensuring the detection capability in the far field and the imaging accuracy in the near field.

[0019] Specifically, this application adopts a dual-zone vertical field-of-view stitching scheme. An embodiment of this application provides a depth imaging module, including a receiving module and at least two transmitting modules. The at least two transmitting modules are used to transmit light signals to a target area. The at least two transmitting modules include a first transmitting module and a second transmitting module. The target area includes a first target area and a second target area. The first target area and the second target area are distributed sequentially along the vertical direction. The maximum detection distance of the first target area is greater than or equal to the maximum detection distance of the second target area. The first transmitting module is used to transmit a first light signal to the first target area at a first transmitting power. The second transmitting module is used to transmit a second light signal to the second target area at a second transmitting power. The second transmitting power is less than or equal to the first transmitting power. The receiving module is used to receive a first reflected light signal corresponding to the first light signal and a second reflected light signal corresponding to the second light signal, and to process the first reflected light signal and the second reflected light signal to obtain a first depth image of the first target area and a second depth image of the second target area.

[0020] Specifically, the vertical direction refers to the direction perpendicular to the horizontal plane, that is, the vertical direction parallel to the direction of Earth's gravity. The second launch module can be set below the first launch module along this vertical direction to form a dual-launch detection structure distributed vertically to achieve layered coverage of different spatial areas. Alternatively, the second launch module can be set at different horizontal positions on the left, right, or same side of the first launch module along a direction parallel to the horizontal plane to form a horizontally parallel or horizontally staggered arrangement. Or, the second launch module can be arranged along an inclined direction at a preset angle to the horizontal plane to form an obliquely layered structure with the first launch module. The preset angle can be 30°, 45°, 60°, etc.

[0021] In this scheme, the boundary line between the first target area and the second target area is set to be offset horizontally or downwardly, that is, the lower edge of the field of view of the first launch module is not higher than the horizontal direction. The advantage of this design is that it can adapt to actual detection scenarios, such as the detection needs of ground equipment for far-field air and near-field ground, so that the first target area can cover the far-field space above and the second target area can cover the near-field ground area below, avoiding the ground area detection blind spot caused by the boundary line being too high.

[0022] The transmitting module is a component that integrates optical signal generation, modulation, and transmission functions, used to output optical signals with specific parameters to the target space; the receiving module is a component with optical signal reception, photoelectric conversion, and data processing functions, used to capture the optical signals reflected by the target and convert them into effective depth information; the optical signal is modulated light suitable for depth detection, such as near-infrared modulated light, which has identifiable phase or amplitude characteristics, making it easy to calculate the distance through the reflected signal; the target area is the spatial range that the optical signals of the transmitting module can cover. The first target area and the second target area form a spatially layered coverage based on the vertical distribution of the two transmitting modules, and there may be some overlapping areas between them to ensure the continuity of detection.

[0023] Optionally, the optical signal emitted by each of the at least two transmitting modules is a modulated optical signal generated by indirect time-of-flight technology; and / or, each of the at least two transmitting modules uses an array light source as the emission source.

[0024] The area array light source is an array of light-emitting devices arranged in an array, and in this scheme, a vertical cavity surface-emitting laser (VCSEL) array is preferred. Compared with traditional single-point light sources, area array light sources can output a planar light spot with higher uniformity. After being projected onto the target area, it can achieve coverage without dead angles, effectively avoiding problems such as depth image noise and blind spots caused by uneven light spots. At the same time, the light-emitting units of the area array light source can be independently driven and controlled, and the shape and coverage of the light spot can be adjusted according to the detection requirements to adapt to the detection tasks of target areas of different sizes.

[0025] Optionally, the transmitting module can also use a dot matrix light source as the transmitting light source. A dot matrix light source consists of multiple discretely distributed light-emitting points, and the density and spacing of these points can be designed according to different actual detection scenarios. In long-distance detection scenarios, a dot matrix light source can enhance the long-distance propagation capability of the modulated optical signal by concentrating the energy of the light-emitting points; in high-precision short-distance detection scenarios, the uniformity of the light spot, similar to that of a planar array light source, can be achieved by densifying the arrangement of the light-emitting points.

[0026] Specifically, the transmitting module generates a periodic modulated light signal at a specific frequency and transmits it to the target area. After the modulated light signal is reflected by the target object, the receiving module collects the reflected signal. By calculating the phase difference between the transmitted and reflected signals and combining this with the frequency parameters of the modulated light signal, the distance between the transmitting module and the target object can be calculated, thus achieving depth imaging. In this scheme, each transmitting module is equipped with a modulation and transmission unit based on indirect time-of-flight technology. The frequency parameters of the modulated light signal can be adjusted according to the detection requirements of the corresponding target area, such as ranging range and accuracy requirements, ensuring reliable and accurate depth detection in different zones.

[0027] Furthermore, the first transmitting module transmits a first optical signal directionally to its corresponding first target area at a preset first transmitting power. This transmitting power is adapted to the detection distance and ambient light interference intensity of the first target area. The second transmitting module transmits a second optical signal to the second target area at a second transmitting power, and the second transmitting power is less than or equal to the first transmitting power. This power differentiation design can optimize energy consumption according to the detection requirements of the upper and lower target areas, while avoiding interference from the optical signal of the lower transmitting module to the upper detection. When the first and second optical signals respectively illuminate the surface of the object in the corresponding target area, a first reflected light signal and a second reflected light signal carrying target distance information are formed. These two types of reflected light signals propagate in the opposite direction along the original transmission path and are eventually acquired by the optical receiving unit of the receiving module. After acquiring the reflected light signals, the receiving module first converts the light signals into electrical signals through a photoelectric conversion component, and then performs noise reduction, phase demodulation, or amplitude analysis on the electrical signals to extract feature parameters related to the target distance. This allows the generation of a first depth image of the first target area and a second depth image of the second target area, respectively. Each pixel in the depth image corresponds to the distance information of a certain spatial point in the target area, thereby realizing a three-dimensional spatial representation of the target area.

[0028] In a specific embodiment, see Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of a depth imaging module provided in this application. The dual-zone vertically stitched field-of-view architecture of this application is illustrated using two transmitting modules as an example. These two transmitting modules are the upper and lower transmitters shown in the diagram. Each transmitting module has a single transmission field of view (the upper and lower field of view are shown in the diagram), both 120×45°. A total field of view of 120×90° is achieved through vertical stitching and adjustment of the two transmitting mechanisms. The upper transmitter emits light signals through the upper field of view for long-range aerial object recognition, for example, within a 10m range. The lower transmitter emits light signals through the lower field of view for mid-range ground object recognition, for example, within a 5m range. Reducing the field of view of a single transmitting module allows for energy concentration, reducing power consumption and heat, avoiding iToF over-cycle issues, and mitigating crosstalk problems in application scenarios, thus improving outdoor detection range. Simultaneously, the optical power of a single transmitting module can vary, with the upper module having a higher power and the lower module a lower power, corresponding to different application distances, such as long and medium range.

[0029] In this embodiment, the depth imaging module optimizes energy consumption while achieving full coverage detection of target areas at different levels through the vertical distribution and power differentiation of the dual-transmitter modules. Combined with the independent processing of dual reflected light signals by the receiving module, high crosstalk is reduced, ensuring the accuracy of depth images of different target areas.

[0030] Optionally, the vertical coordinates of all spatial points in the second target region are less than the minimum vertical coordinates corresponding to the first target region. Here, the vertical coordinates are coordinate parameters based on the Z-axis in a three-dimensional coordinate system, used to characterize the height position of a spatial point; the minimum vertical coordinates corresponding to the first target region are the minimum Z-axis coordinates of all spatial points within the first target region, reflecting the lowest height boundary of that region. The overall height range of the second target region is lower than that of the first target region, avoiding signal interference caused by overlapping detection ranges, while simultaneously enabling detection of spaces with different height dimensions.

[0031] Specifically, the second target area can be a ground area, and the first target area is an aerial area. The ground area can be the plane supporting the scene where the depth imaging module is located, such as the ground of an outdoor parking lot or a park road. The aerial area can be a three-dimensional space above the ground, including targets such as suspended obstacles and surrounding buildings. The first transmitting module detects targets in the aerial area, and its emitted first light signal covers the space above the ground, adapting to the depth information acquisition needs of targets such as aerial obstacles and distant objects. The second transmitting module, on the other hand, detects targets in the ground area in a directional manner, and its emitted second light signal focuses on the ground and near-ground space, which can accurately capture the depth information of targets such as ground undulations and ground obstacles.

[0032] This layered detection design, combining air and ground-based approaches, along with the vertical arrangement of the two transmitting modules, allows the propagation paths of the first and second optical signals to better align with their respective target areas, reducing mutual interference between detection signals from different regions.

[0033] Optionally, the receiving module is further configured to split the received image region into a first received image region and a second received image region, wherein the first received image region corresponds to a first target region and the second received image region corresponds to a second target region; when the first transmitting module transmits, the receiving module only outputs the image corresponding to the first received image region; when the second transmitting module transmits, the receiving module only outputs the image corresponding to the second received image region.

[0034] In this scheme, the correspondence between the received image area and the target area includes two forms: complete correspondence and slight overlap. For a complete correspondence, the range of the received image area is exactly the same as the field of view of the target area, achieving a redundancy-free match between the transmitted and reflected light signals. For a slight overlap, the range of the received image area is slightly larger than the corresponding target area, allowing an overlapping area to form between the two received image areas. When the same overlapping area is repeatedly probed by two transmitting modules, multiple sets of depth data are acquired. Calibration and alignment are then performed based on the data from the overlapping area, improving the overall depth image stitching accuracy. When the first and second transmitting modules work alternately, the receiving module only outputs the image of the corresponding received area, avoiding signal crosstalk from non-target areas and enhancing imaging accuracy through the optional overlapping area.

[0035] For example, when the first received image region corresponds to the first target region, they may be completely matched or slightly cover the first target region. Similarly, when the second received image region corresponds to the second target region, they may be completely matched or slightly cover the second target region. There may be overlapping areas between the first received image region and the second received image region.

[0036] Furthermore, the first received image area is the first decoding area, used to decode the received first reflected light signal to obtain a first depth image; the second received image area is the second decoding area, used to decode the received second reflected light signal to obtain a second depth image.

[0037] Optionally, in processing the first reflected light signal and the second reflected light signal to obtain a first depth image of the first target region and a second depth image of the second target region, the receiving module is specifically configured to: acquire a first decoding region corresponding to the first transmitting module; acquire a second decoding region corresponding to the second transmitting module; decode the first reflected light signal based on the first decoding region to obtain a first depth image of the first target region; and decode the second reflected light signal based on the second decoding region to obtain a second depth image of the second target region.

[0038] In one possible embodiment, the decoding region of each transmitting module is determined through calibration. Specifically, a first calibration parameter of the first transmitting module and a second calibration parameter of the second transmitting module are obtained; a first decoding region corresponding to the first transmitting module is determined based on the first calibration parameter; and a second decoding region corresponding to the second transmitting module is determined based on the second calibration parameter. The first calibration parameter includes a first elevation angle and a first calibration relationship of the first transmitting module, and the second calibration parameter includes a second elevation angle and a second calibration relationship of the second transmitting module. Based on the first calibration relationship, the second calibration relationship, the first elevation angle, and the second elevation angle, the first reflected light signal and the second reflected light signal can be partitioned and decoded to obtain a first depth image and a second depth image; the first calibration relationship reflects the mapping relationship between the first elevation angle and the first decoding region; and the second calibration relationship reflects the mapping relationship between the second elevation angle and the second decoding region.

[0039] In this system, the decoding area for each transmitting module is the output area. For example, only the first reflected light signal in the first decoding area is decoded, while other areas are considered invalid and do not require calculation. Similarly, only the second reflected light signal in the second decoding area is decoded, while other areas are considered invalid and do not require calculation. The pitch angle is the angle between the principal optical axis of the emitted light signal from the transmitting module and the horizontal baseline, used to characterize the emission direction of the light signal. The first pitch angle corresponds to the light signal direction of the first transmitting module, and the second pitch angle corresponds to the light signal direction of the second transmitting module. The calibration relationship refers to the mapping rules established in advance through calibration steps, reflecting the pitch angle and the decoding area within the detection field of view of the receiving module, ensuring that the light signal reflection data at a specific pitch angle can be accurately allocated to the corresponding processing area. The decoding area refers to the subset of pixels in the photosensitive array of the receiving module used to process the reflected light signal from a specific transmitting module. Partitioning can avoid aliasing interference between signals from different transmitting modules, and reducing the decoding area can further improve decoding efficiency.

[0040] Specifically, the receiving module first acquires the current first elevation angle of the first transmitting module and the current second elevation angle of the second transmitting module. This can be achieved through a sensor associated with the angle adjustment mechanism of the transmitting module, such as an angle encoder, to ensure real-time acquisition of the actual transmission direction parameters of the optical signal. Then, the receiving module calls a preset calibration relationship and, in conjunction with the two elevation angles, spatially partitions the raw reflected light signal data received by the photosensitive array. Based on the mapping rules between elevation angles and decoding areas in the calibration relationship, it determines the corresponding first and second decoding areas. After partitioning, the receiving module performs decoding processing on the signals within the first decoding area. Through depth algorithms such as phase difference calculation and amplitude analysis, it transforms the optical signal data into a first depth image of the first target area. Simultaneously, it performs the same decoding processing on the signals within the second decoding area to obtain a second depth image of the second target area. Throughout this process, the partitioning logic dynamically adapts to changes in the elevation angle, ensuring that the decoding areas match synchronously when the transmitting module's direction is adjusted, thus guaranteeing the accuracy of the depth image decoding.

[0041] In a specific embodiment, see Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of a first decoding region provided in an embodiment of this application. Figure 3 This is a schematic diagram of a second decoding region provided in an embodiment of this application. Combining the two diagrams, the corresponding partitioning relationship of the upper and lower field of view angles can be clearly defined, wherein, for Figure 2 and Figure 3 The invalid region of the reflected light received by the receiving module includes the overlapping portion of the reflected light from the first and second transmitting modules. For the first transmitting module located above, the first decoding region is located above the invalid region; for the second transmitting module located below, the second decoding region is located below the invalid region. Since the receiving chip of the receiving module operates in global mode, upper and lower field-of-view areas can be mapped one-to-one using soft masking. The core logic of the soft masking is as follows: during the calibration and mapping stage, for different transmitting modules, the portions of the data that do not require subsequent processing or analysis are marked as invalid regions using a mask. In subsequent decoding, detection, and other processes, these invalid regions are automatically ignored to avoid interference from invalid data with the processing results.

[0042] Furthermore, each decoding region is determined through calibration. This involves dividing the photosensitive area of ​​the receiving module into two independent sub-regions, corresponding to the detection areas of the first and second transmitting modules, respectively. During calibration, the range of each decoding region can be reflected by pixel coordinates. For example, with a resolution of 640×480, the pixel range is (0,0) to (640,480). For both the first and second transmitting modules, (0,0) to (640,480) is divided into two, corresponding to the first and second transmitting modules respectively. The coordinates of the decoding regions differ for each transmitting module. Figure 2 For example, the top left corner corresponds to (0,0), the bottom left corner corresponds to (0,480), the top right corner corresponds to (640,0), and the bottom right corner corresponds to (640,480). The first decoding region can be (0,0) to (640,240). For the first transmitting module, only the valid signal of the first decoding region is retained, and the invalid signal of the lower region (0,240) to (640,480) is blocked. Finally, the depth image corresponding to the first target region is output. Figure 3 For example, the second decoding region can be (0, 240) ~ (640, 480). For the second transmitting module, only the valid signal of the second decoding region is retained, while the invalid signal of the upper region is blocked, and the depth image corresponding to the second target region is finally output. Through this soft partitioning method, different sub-regions of the receiving chip are matched with the fields of view of different transmitting modules, avoiding crosstalk of reflected light signals from different transmitting modules at the receiving end, while accurately corresponding to the depth imaging of the upper and lower target regions, thus improving the accuracy of partitioned detection.

[0043] In this embodiment, a design that outputs images from the upper and lower field of view separately is adopted. Compared with the traditional large field of view simultaneous detection scheme, it can avoid the crosstalk problem caused by the difference in high and low reflection signals of the target object when detecting simultaneously within a large field of view, thus improving the accuracy of the detection data. In addition, the computing power requirement of the back-end image decoding stage is reduced, improving the decoding efficiency. Furthermore, after the vertical field of view is reduced by masking, the energy distribution is more concentrated, which can increase the detection distance and improve the impact of noise interference on the detection results.

[0044] In one possible embodiment, patches may appear in the depth image. These patches are anomalous points, which are regions of pixels in the depth image where the depth data is invalid or the deviation exceeds a threshold. Their causes include, but are not limited to, signal saturation caused by high-reflectivity objects within the target area, signal loss due to dirt or occlusion. For example, these patches may be caused by dirt adhesion, dust dispersion, or obstacle obstruction within the target area, leading to scattering, diffuse reflection, or path obstruction of the light signal emitted by the transmitting module. This results in patchy areas with blurred edges, noise, or no effective depth data on the depth image, severely affecting the depth imaging accuracy of the target area. To address this patch problem, this solution employs a strategy of reducing the transmitting power of the transmitting module. By detecting the affected area and adjusting the transmitting power, effective depth imaging of the anomalous area can be restored.

[0045] Optionally, the receiving module is further configured to: determine the depth corresponding to each pixel in the first depth image based on the first depth image; determine whether there are patches in the first depth image based on the depth corresponding to each pixel in the first depth image; determine the depth corresponding to each pixel in the second depth image based on the second depth image; determine whether there are patches in the second depth image based on the depth corresponding to each pixel in the second depth image; if there are patches in the first depth image, reduce the first transmission power to obtain a third transmission power, and control the first transmission module to transmit a third optical signal to the first target area at the third transmission power; if there are patches in the second depth image, reduce the second transmission power to obtain a fourth transmission power, and control the second transmission module to transmit a fourth optical signal to the second target area at the fourth transmission power; if there are no patches in either the first depth image or the second depth image, the receiving module is further configured to control the first transmission module and the second transmission module to transmit alternately.

[0046] The pixel depth is the straight-line distance between the spatial point corresponding to each pixel in the depth image and the depth imaging module. This data is generated by the receiving module after decoding the reflected light signal. A patch is a set of pixels in the depth image that has continuous spatial distribution characteristics and meets specific distance conditions. Patches can be dirt, dust, occlusion, etc. The first preset condition is a pre-set rule for judging patches, including distance range threshold, pixel continuity threshold, distance change rate threshold, etc. For example, the distance range threshold can be a distance of less than 1 cm, the pixel continuity threshold can be a number of consecutive pixels of not less than 5, and the distance change rate threshold is the maximum change in distance information between adjacent pixels in the same set of consecutive pixels or between consecutive frames of the same pixel, which can be set to 2 cm. The third and fourth transmission powers are lower than the initial transmission power corresponding to the patch. For example, the third transmission power is lower than the first transmission power, and the fourth transmission power is lower than the second transmission power. The third and fourth transmission powers can also be set to 0. In this way, the transmission module with patches stops transmitting light signals.

[0047] For example, when neither the first nor the second transmitting module has any patches, the first and second transmitting powers alternately transmit optical signals. When a patch is present in either the first or second transmitting module, the transmitting power of the module with the patch is reduced to 0, and depth information detection stops. The transmitting power of the module without patches remains unchanged. In this way, the detection power consumption of the module can be reduced when patches are present. The alternating transmission mode can avoid optical signal crosstalk caused by simultaneous transmission from both modules, further improving imaging accuracy. At the same time, alternating transmission can reduce the overall power consumption of the module, extend the device's battery life, and prevent overheating problems caused by continuous module operation.

[0048] Specifically, the receiving module first extracts the distance information corresponding to the coordinates of each pixel from the generated first and second depth images, forming a distance dataset covering the entire detection area. Then, the receiving module compares the distance information of each pixel with a first preset condition: for a single pixel, it determines whether its distance is within a preset range; for multiple continuously distributed pixels, it further determines whether they meet spatial continuity requirements, such as the distance difference between adjacent pixels being within a preset threshold. When the pixel set of a certain area simultaneously meets the above conditions, the receiving module determines that a patch exists in that area and records the target area to which the patch belongs, i.e., whether the first or second transmitting module is responsible for detection. If a patch is identified, the receiving module sends a control command to the transmitting module corresponding to the patch, triggering it to transmit a light signal to the target area where the patch is located at a lower transmission power. The transmission direction of the reduced-power light signal remains consistent with the field of view of the original transmitting module, while avoiding energy waste caused by indiscriminate high-power transmission when patches are present.

[0049] In a specific embodiment, see Figure 4 , Figure 4 This is a flowchart of a dynamic switching method for a transmitter module provided in an embodiment of this application. First, the two transmitters work alternately. Then, an image algorithm traverses the depth image to obtain distance and coordinate information. Based on the distance, coordinate, and time information, it is determined whether patches exist. If patches exist, the corresponding transmitter is identified, and the single transmitter is controlled to operate. Specifically, when there are no patches, a dual-transmitter alternating operation mode is adopted. When patches exist, the transmitter corresponding to the patch can be controlled to stop working. For example, if in the second depth image corresponding to the second transmitter module, five consecutive pixels with a distance of less than 1 cm are detected for 3 seconds, or for two consecutive detection cycles, then it is determined that the second transmitter module has patches, and the second transmitter module is controlled to stop working. This avoids the problem that traditional single-transmitter large field-of-view methods become unusable when there are abnormal image areas.

[0050] In this embodiment of the application, by using patch recognition based on distance information and dynamic power adjustment, the accuracy of depth information acquisition in the target area is ensured while reducing unnecessary power consumption.

[0051] Optionally, the first elevation angle of the first launch module is an adjustable angle greater than or equal to 0°; the second elevation angle of the second launch module is an adjustable angle less than or equal to 0°.

[0052] The pitch angle is the angle between the main optical axis of the transmitted optical signal and the horizontal reference line. The sign of the angle value is used to define the transmission direction of the optical signal. With the horizontal reference line as the 0° reference, when the pitch angle is greater than 0°, the optical signal is transmitted at an upward tilt; when the pitch angle is less than 0°, the optical signal is transmitted at a downward tilt; when the pitch angle is equal to 0°, the optical signal is transmitted in the horizontal direction.

[0053] In a specific embodiment, see Figure 5 , Figure 5 This is a schematic diagram of an adjustable pitch angle provided in an embodiment of this application. Two transmitters, each with a field of view of 120×45°, are combined to achieve a 120×90° field of view by adjusting the pitch angle of each transmitter, thus covering a wider range of obstacles. For example, for a given object, the coverage area of ​​a conventional horizontal field of view is the ground and the front of the object, while the coverage area of ​​the tilted field of view can be the ground, the front, top, left, and right sides of the object, resulting in more accurate identification of ground obstacle contours. By having the upper and lower transmitters work in sections, a coverage angle of over 90° can be achieved. Within a distance of 1 meter, the lower transmitter can identify more contour information of obstacles, leading to more accurate obstacle avoidance judgments.

[0054] Optionally, the receiving module is also used to: determine the target field of view of each transmitting module based on the target area of ​​each transmitting module; obtain the initial field of view of each transmitting module; and determine the pitch timing of each transmitting module based on the initial field of view and the target field of view of each transmitting module.

[0055] Among them, the target field of view refers to the range of light signal coverage angles required for the light signal of the transmitting module to completely cover its corresponding target area. This parameter is determined based on the spatial size of the target area, the detection distance, and the module installation position. The initial field of view is the inherent coverage angle range of the light signal when the transmitting module has not adjusted its pitch angle. It is determined by the optical design of the transmitting module, such as lens parameters and laser arrangement, and is a fixed initial value. The pitch angle timing refers to the set of adjustment parameters of the pitch angle of the transmitting module at different time points, including information such as adjustment timing, adjustment range, and holding time, which is used to realize the dynamic adjustment of the pitch angle.

[0056] Specifically, the receiving module first determines the target field of view (FLA) required for each transmitting module based on the target area corresponding to each transmitting module, such as the air area of ​​the first transmitting module and the ground area of ​​the second transmitting module, combined with parameters such as the spatial boundary and detection distance of the target area. This is achieved through geometric modeling and field-of-view calculation algorithms. For example, if the first target area is a long-distance air range, larger horizontal and vertical coverage angles need to be calculated to meet the detection requirements, thus obtaining the FLA of the first transmitting module. If the second target area is a short-distance ground range, the corresponding FLA of the second transmitting module is determined. Then, the receiving module obtains the current initial FLA of each transmitting module through the communication interface with the transmitting modules. This initial FLA is an inherent parameter calibrated at the factory and stored in the control unit of the transmitting module. The receiving module can retrieve it by reading the parameter through commands. Finally, the receiving module compares the initial field of view of each transmitting module with the target field of view: if the initial field of view can cover the target field of view, the elevation angle timing is determined to maintain the current elevation angle unchanged; if the initial field of view cannot meet the target field of view requirement, such as the coverage area of ​​the initial field of view being smaller than the target field of view, the required elevation angle adjustment range is calculated based on the mapping relationship between the field of view and the elevation angle. Simultaneously, considering the real-time requirements of the detection scenario, such as the rate of change of the dynamic target area or the movement rate of the device carrier, the adjustment time and holding duration of the elevation angle are determined, resulting in the elevation angle timing. This elevation angle timing can be converted into control commands and sent to the angle adjustment mechanism of the transmitting module, driving the transmitting module to dynamically adjust the elevation angle according to the timing sequence, thereby achieving the detection of the target area.

[0057] In this embodiment, the detection range of the transmitting module can be dynamically adapted to the needs of the target area, and interference between multiple transmitting modules can be avoided through time-sequential adjustment.

[0058] Since the second transmission power needs to be less than the first transmission power, the module may optionally include a target resistor; one end of the target resistor is connected to the second transmission module, and the other end of the target resistor is connected to a power supply, which is also connected to the first transmission module; the target resistor is used to adjust the driving parameters of the second transmission module.

[0059] The target resistor can be a passive electronic component with a fixed resistance value, and the electrical parameters of the associated module can be adjusted by changing the circuit impedance. The drive parameters are key electrical indicators to ensure the normal operation of the transmitting module, specifically including drive current, drive voltage, and power output amplitude.

[0060] The target resistor can be a pulse resistor. The pulse resistor controls the driving parameters of the second transmitting module through circuit impedance adjustment and is suitable for pulsed power supply scenarios. A pulse resistor is a special resistive element capable of withstanding pulse current and pulse voltage. Its resistance remains stable in pulsed operating mode, adapting to the intermittent power supply requirements of the transmitting module's pulsed optical signal transmission. Compared to ordinary fixed resistors, it is better able to withstand instantaneous current surges, ensuring the long-term reliability of the circuit. Correspondingly, the driving parameters include driving current, driving voltage, pulse amplitude, pulse width, and other electrical indicators related to pulsed power supply, affecting the transmission power and waveform characteristics of the second transmitting module's pulsed optical signal. The power supply provides continuous or pulsed power to the module, adapting to the operating mode requirements of the dual-transmitter module.

[0061] Specifically, when the power supply outputs pulsed electrical energy, the pulse resistor changes the impedance characteristics of the power supply circuit of the second transmitting module through its inherent resistance. Based on Ohm's law and the working principle of pulse circuits, it regulates the peak value and duration of the pulse driving current and voltage. For example, by selecting a pulse resistor with a specific resistance value, the peak value of the pulse driving current can be limited, preventing damage to the laser devices of the second transmitting module from instantaneous large currents. Simultaneously, the amplitude of the pulse voltage can be fine-tuned, ensuring that the power of the pulsed optical signal output by the second transmitting module accurately matches the detection requirements of the second target area, and meeting the design requirement that the second transmitting power is less than or equal to the first transmitting power. If the power supply is in continuous power supply mode, the pulse resistor can still adjust the driving parameters of the second transmitting module through current limiting and voltage division. Its resistance to pulse impacts can also cope with instantaneous current fluctuations during the start-up and shutdown of the transmitting module, further improving circuit stability. The resistance value of the pulse resistor can be pre-calibrated according to the module's pulse power supply parameters and driving parameter design targets to ensure its impedance stability under pulsed operating conditions.

[0062] In a specific embodiment, see Figure 6 , Figure 6This is a schematic diagram of a pulse resistor-based driving circuit provided in an embodiment of this application. When the upper and lower transmitters use different optical powers, for example, the upper transmitter is 8W×2=16W and the lower transmitter is 8W, with the same input voltage, the circuit design defaults to driving high power, high voltage, and high current. The lower transmitter is a low-power laser, which will be overdriven due to the high voltage and high current, resulting in heat generation, decreased optical power, affecting performance and lifespan, and damage. This application uses a pulse resistor voltage divider to realize different optical power circuit driving modes. Based on a dual-transmitter single-supply design scheme, it addresses the different threshold differences in the supply voltage of the two laser transmitters with different powers, where a single power supply cannot meet the simultaneous power supply requirements. Therefore, a series pulse resistor voltage divider and current limiting are used. The pulse resistor value is calculated as: VIN=I×R1+V2, where VIN is the input voltage, which also matches the voltage threshold of the upper transmitter, V2 is the voltage of the lower transmitter when it is working, I is the current of the lower transmitter when it is working, and R1 is the pulse resistor value. Pulsed resistors offer high instantaneous power, small size, short transmitter operating time, and long idle time, and their instantaneous peak power meets design requirements.

[0063] Optionally, both the first and second transmitting modules are provided with at least one vertical cavity surface-emitting laser.

[0064] The number of activated vertical-cavity surface-emitting lasers (VCSELs) is used to control the emission power of each emission module. The first emission module has at least one first VCSEL; the second emission module has at least one second VCSEL; the receiving module is further configured to determine a first activation number of the at least one first VCSEL based on the first emission power, and control the first emission module to emit a first optical signal to a first target region at the first emission power based on the first activation number; the receiving module is further configured to determine a second activation number of the at least one second VCSEL based on the second emission power, and control the second emission module to emit a second optical signal to a second target region at the second emission power based on the second activation number.

[0065] The power of a single vertical-cavity surface-emitting laser (VCSEL) can be 8W, 4W, etc. When the first transmitting power of the first transmitting module needs to be greater than the second transmitting power of the second transmitting module, the first transmitting module can be equipped with two 8W VCSELs, and the second transmitting module can be equipped with one 8W VCSEL; or, the first transmitting module can be equipped with one 8W VCSEL, and the second transmitting module can be equipped with one 4W VCSEL; or, the first transmitting module can be equipped with two 4W VCSELs, and the second transmitting module can be equipped with one 4W VCSEL, and so on.

[0066] The receiving module calculates the first number of lasers to be activated based on a preset first transmission power and the rated output power of a single first vertical-cavity surface-emitting laser (VCSEL). For example, if the rated power of a single first VCSEL is 5W, and the first transmission power needs to be set to 15W, the receiving module controls the activation of three first VCSELs. Through power superposition of multiple lasers, the target transmission power is achieved. Subsequently, the first transmitting module transmits a first optical signal to the first target area at this power. Similarly, the receiving module calculates the second number of lasers to be activated based on a preset second transmission power and controls the corresponding number of second VCSELs to operate, enabling the second transmitting module to transmit a second optical signal to the second target area at the second transmission power. When detecting close-range, high-precision targets, the transmission power can be reduced to decrease the number of activated lasers, avoiding saturation of the receiving module due to excessively strong optical signals. When detecting long-range, low-reflectivity targets, the transmission power can be increased to increase the number of activated lasers. Through power superposition, the long-distance propagation capability of the optical signal is enhanced, ensuring that the reflected optical signal has a sufficient signal-to-noise ratio. Meanwhile, the power control of each transmission module is performed independently, and the optimal transmission power can be matched according to the different detection requirements of the first and second target areas, thereby improving the module's adaptability to zone detection.

[0067] Among them, the vertical cavity surface-emitting laser is a semiconductor laser device in which the laser emission direction is perpendicular to the chip surface. Compared with traditional edge-emitting lasers, it has the characteristics of small size, high luminous efficiency, good beam quality, high reliability and easy array integration, and is the core component for optical signal emission in depth imaging modules.

[0068] Specifically, both the first and second transmitting modules are equipped with at least one vertical-cavity surface-emitting laser (VCSEL). This configuration can be flexibly adjusted according to the detection requirements of the target area: when the target area is small or the detection distance is short, a single VCSEL can output a light signal with sufficient power and coverage to meet basic detection requirements; when the target area is large or the detection distance is long, a multi-device array can be used to enhance the transmission power and coverage angle of the light signal, ensuring that the light signal can fully cover the target area. The operating state of the VCSEL is controlled by the driving circuit of the transmitting module. The driving circuit receives instructions from the receiving module and adjusts the laser's operating current, voltage, and other parameters, thereby controlling the power, frequency, and other characteristics of its emitted light signal. This ensures that the first transmitting module outputs a first light signal with a first transmission power, and the second transmitting module outputs a second light signal with a second transmission power. The installation position and emission direction of the laser must be compatible with the module's pitch angle adjustment mechanism to ensure that the light signal can accurately point to the corresponding first or second target area.

[0069] By configuring vertical cavity surface-emitting lasers (VCSELs) for the first and second transmitting modules, their advantages of small size, high efficiency, and high reliability are utilized to ensure the quality and coverage of optical signal transmission while simplifying the structural design of the transmitting modules and adapting to the power differences and spatial arrangement requirements of the dual transmitting modules.

[0070] In a specific embodiment, see Figure 7 , Figure 7 This is a schematic diagram of a transmitting module based on a vertical-cavity surface-emitting laser (VCSEL) according to an embodiment of this application. The optical power configuration can be larger at the top and smaller at the bottom, and can be achieved through a combination of single or multiple VCSELs. The two VCSELs in the upper transmitter operate in series simultaneously, which can enhance energy density and increase detection range. The lower transmitter can have a dual-VCSEL configuration or a single VCSEL configuration, with a detection range equal to or less than that of the upper transmitter. For example, the upper transmitter uses a power configuration of 8W × 2 = 16W, and the lower transmitter uses a power configuration of 8W, or vice versa. Each transmitter uses a planar array light source, and the diffusion optics use lenses and diffusers to achieve a field of view of 120 × 45°. The VCSELs operate in the 905-940nm wavelength range, with a specific wavelength error of ±15nm. In this embodiment, the power density of the vertical cavity surface-emitting laser of the lower transmitter is lower than that of the upper transmitter, which can reduce the erroneous noise signal generated by ground reflection; after the power of the vertical cavity surface-emitting laser of the upper transmitter is increased, the outdoor low-reflection detection distance can be improved; at the same time, after alternating operation, the vertical cavity surface-emitting laser has a short period of non-firing time, which can improve heat dissipation.

[0071] Optionally, at least one vertical cavity surface-emitting laser has a heat-dissipating ceramic substrate at its bottom.

[0072] Among them, heat dissipation ceramic substrate is a thermally conductive structure with ceramic as the base. It has high thermal conductivity, excellent electrical insulation and thermal stability. It can quickly conduct the heat generated when the device is working and avoid local overheating. Vertical cavity surface emission lasers generate significant heat when operating at high frequency pulses or outputting high power. If the heat accumulates, it may lead to an increase in the threshold current of the device, a decrease in luminous efficiency or even permanent damage. Therefore, it is necessary to dissipate heat.

[0073] Specifically, at least one vertical-cavity surface-emitting laser (VCSEL) has its bottom tightly bonded to a heat-dissipating ceramic substrate. This bonding can be achieved using thermally conductive adhesive or welding, ensuring that the heat generated during laser operation is rapidly transferred to the ceramic substrate via thermal conduction. The heat-dissipating ceramic substrate, by increasing its heat dissipation area, further conducts heat to the housing of the emission module or external heat dissipation structures, forming a complete heat dissipation path. For emission modules with multi-laser arrays, the heat-dissipating ceramic substrate can simultaneously provide heat dissipation support for multiple lasers, avoiding localized hotspots by uniformly distributing heat and ensuring consistent operating conditions for all lasers in the array. This design is suitable for high-frequency, high-power operation of VCSELs in depth imaging modules, especially when the second and first emission modules operate in tandem, ensuring that both lasers remain within a stable temperature range.

[0074] By placing a heat-dissipating ceramic substrate at the bottom of the vertical cavity surface-emitting laser, the heat dissipation efficiency of the device is improved, avoiding performance degradation or damage caused by heat accumulation, and improving photoelectric conversion efficiency.

[0075] In one possible embodiment, the optical signals emitted by each transmitting module employ a dual-frequency combination. This dual-frequency combination design enables detection at greater distances, and the dual-frequency range of 45° zone is greater than that of a single 90° zone.

[0076] Specifically, based on the first target area, a first frequency combination is determined, which includes a preset first signal frequency and a second signal frequency; based on the first signal frequency and the second signal frequency, the first transmitting module is controlled to generate a first optical signal; based on the second target area, a second frequency combination is determined, which includes a preset third signal frequency and a fourth signal frequency; based on the third signal frequency and the fourth signal frequency, the second transmitting module is controlled to generate a second optical signal.

[0077] In this scheme, the first frequency combination and the second frequency combination are suitable for the over-cycle suppression requirements of the target area. The theoretical maximum unambiguous distance of iToF is... Where c is the speed of light, f is the frequency, and in actual detection, the Euclidean distance of the target is... Where a is the theoretical unambiguous distance. and Let L be the horizontal and vertical field of view, respectively. When L > d, over-cycle ambiguity occurs. For example, when the modulation frequency f = 7.65 MHz, the theoretical ambiguity-free distance 'a' is approximately 19.92 m. If the field of view of the first target area is 120 × 45°, the actual Euclidean distance L is approximately 9.75 m. In this case, a low-frequency combination needs to be matched to increase 'a' and mitigate over-cycle ambiguity. If the field of view of the second target area is 120 × 90°, the actual Euclidean distance L is approximately 8.91 m, requiring a higher-frequency combination to balance accuracy and over-cycle risk. Therefore, the receiving module determines L based on the field of view of the first and second target areas, and then determines the appropriate dual-frequency combination. Through differentiated frequency configuration, the actual Euclidean distance L of each target area does not exceed the theoretical ambiguity-free distance 'd' of the corresponding frequency, thereby suppressing the over-cycle problem.

[0078] Taking the first target area as an example, the first signal frequency and the second signal frequency are determined based on the first target area. Based on the detection distance, environmental interference intensity, and imaging accuracy requirements of the first target area, the first and second signal frequencies are determined. If the first target area is a long-range detection range, such as a detection distance of 10m to 30m, and the ambient light interference in this area is relatively weak, with the range requirement higher than the accuracy requirement, the first signal frequency can be determined to be 10MHz. The maximum unambiguous distance of this low-frequency signal can reach 15m, covering the basic range of long-range detection. The second signal frequency can be determined to be 20MHz, forming a low-frequency combination with the first signal frequency. Through dual-frequency phase difference fusion calculation, the maximum unambiguous distance is extended to 30m, while simultaneously canceling phase noise in long-range detection. Finally, the first transmitting module generates a first optical signal containing both 10MHz and 20MHz frequencies and projects it onto the first target area. If the first target area is a medium-to-long-range detection range, such as a detection distance of 5m to 15m, and the ambient light interference is moderate, the first signal frequency can be adjusted to 15MHz and the second signal frequency to 25MHz, balancing range and anti-interference capability.

[0079] For the second target area, if the second target area is a close-range detection range, such as a detection distance of 0m to 10m, and the requirement for imaging accuracy in this area is higher than the range requirement, such as an accuracy requirement of ≤1cm, the frequency of the third signal can be determined to be 80MHz. This high-frequency signal has a higher ranging resolution and can meet the requirements for high-precision close-range detection. The frequency of the fourth signal can be determined to be 100MHz, which forms a high-frequency combination with the frequency of the third signal. The multipath reflection error in close-range detection is eliminated through dual-frequency verification. Finally, the second transmitting module generates a second optical signal containing two frequencies, 80MHz and 100MHz, and projects it onto the second target area.

[0080] In this configuration, the first signal frequency is less than or equal to the third signal frequency, and the second signal frequency is less than or equal to the fourth signal frequency. For example, the first frequency combination can be 37 MHz and 45 MHz, and the preset first signal frequency can be 37 MHz and the second signal frequency can be 45 MHz. The second frequency combination can be 37 MHz and 45 MHz, 60 MHz and 52 MHz, or 60 MHz and 48 MHz. Correspondingly, the preset third signal frequency can be 37 MHz or 60 MHz, and the fourth signal frequency can be 37 MHz, 52 MHz, or 48 MHz.

[0081] The frequency of the modulated optical signal is negatively correlated with the detection distance. Low-frequency signals have a larger maximum unambiguous range and are more suitable for long-distance detection; high-frequency signals have higher ranging accuracy and are more suitable for high-precision short-range detection. Based on this, when the first target area is the long-range detection range and the second target area is the short-range detection range, the average frequency of the first dual-frequency combination is lower, which can ensure the range and accuracy of long-range detection; the average frequency of the second dual-frequency combination is higher, which can meet the high-precision requirements of short-range detection, ultimately achieving layered and accurate detection of different target areas.

[0082] The detection range of a single-frequency modulated optical signal is limited by its frequency characteristics, with a maximum unambiguous distance threshold. Exceeding this threshold can easily lead to ranging ambiguity. Dual-frequency combination, by fusing the phase difference between the two frequency signals, overcomes the single-frequency threshold limitation and achieves accurate ranging at greater distances. Furthermore, the two frequency signals can cross-check each other, effectively offsetting ranging errors caused by differences in ambient light and target object reflectivity, making it suitable for detecting distant, low-reflectivity targets.

[0083] In one possible embodiment, the operating timing of the two transmitters is staggered. For different transmitters configured with frequencies, the upper field of view is configured with a low-frequency combination, and the lower field of view is configured with a mid-to-high frequency combination, or the same as the upper field of view. For example, the upper transmitter is configured with a low-frequency combination of 37 and 45 MHz for 10-meter aerial object detection, and the lower transmitter is configured with a mid-to-high frequency combination of 37 and 45 MHz or higher for high-precision obstacle avoidance of objects on the ground at a height of 5 meters.

[0084] In one possible embodiment, see [reference] Figure 8 , Figure 8 This is a schematic diagram of a detection distance provided in an embodiment of this application.

[0085] For frequencies of 37.65 MHz and 45.18 MHz, the theoretical maximum detection distance of iTof is d, which is 19.92 meters. As shown in the figure, since iTof has horizontal and vertical field of view angles, according to spatial projection relationships, the vertical detection distance of the module is: ,in, , ,therefore, The theoretical overcycle distance is 8.91 meters for a 120×90° field of view and 9.75 meters for a 120×45° field of view. Therefore, a small vertical field of view for a single transmitter can mitigate the overcycle problem caused by the greatest common divisor of the iTof frequency.

[0086] In one possible embodiment, at least two transmitting modules further include a third transmitting module; the third transmitting module is used to transmit a third optical signal to a third target region at a fifth transmitting power; the third target region is located on one side of the first target region or on one side of the second target region along the vertical direction; the receiving module is further used to receive a third reflected optical signal corresponding to the third optical signal, and process the third reflected optical signal to obtain a third depth image of the third target region.

[0087] This solution adds a third transmission module to the first and second transmission modules. This module maintains the same hardware architecture as the first two, and can be equipped with a vertical-cavity surface-emitting laser as the light-emitting device, supporting dual-frequency modulated optical signal transmission using indirect time-of-flight technology. The fifth transmission power can be independently configured according to the detection requirements of the third target area, such as distance and target reflectivity, and does not need to be consistent with the first and second transmission powers.

[0088] The third launch module is used to extend the detection range and fill in detection blind spots. The third target area can be located above the first target area. In this case, the three target areas, vertically from top to bottom, are the third target area, the first target area, and the second target area, corresponding to the high-altitude, mid-altitude, and low-altitude detection ranges, respectively, suitable for scenarios requiring full-altitude coverage. Alternatively, the third target area can be located below the second target area. In this case, the three target areas, vertically from top to bottom, are the first target area, the second target area, and the third target area, corresponding to the mid-altitude, low-altitude, and near-ground detection ranges, respectively, suitable for scenarios requiring precise detection of ground and near-ground targets.

[0089] The receiving module is adapted to the detection requirements of the third transmitting module, adding the function of receiving and processing the third reflected light signal. After acquiring the third reflected light signal reflected by the target object in the third target area, the receiving module uses the same processing logic as the first and second reflected light signals, such as phase difference calculation, distance conversion, and depth image generation, to obtain the third depth image of the third target area. At the same time, the receiving module can fuse the depth images of the three target areas to output a complete depth image covering the first, second, and third target areas; it can also output the depth image of a specific target area as needed.

[0090] In this embodiment, for detection scenarios with a large altitude range, there is no need to rely on the wide-angle projection of a single transmitting module. By using multi-module layered coverage, the problem of light spot energy dispersion caused by wide-angle projection can be avoided, ensuring the detection accuracy of each altitude range. Each transmitting module is only responsible for the detection of the corresponding target area and can independently optimize parameters such as power and frequency. Compared with the single-module full coverage scheme, it has stronger anti-interference ability and is suitable for the detection needs of complex environments.

[0091] In this embodiment, the depth imaging module includes a receiving module and at least two transmitting modules, including a first transmitting module and a second transmitting module. Firstly, by replacing the traditional wide-angle transmitting module with two transmitting modules, the field of view is reduced, resulting in less reflected light from each transmitting module and lowering the probability of high crosstalk. Specifically, the first transmitting module transmits a first optical signal to a first target area at a first transmitting power, and the second transmitting module transmits a second optical signal to a second target area at a second transmitting power. The first and second target areas are distributed vertically, and the second transmitting power is less than or equal to the first transmitting power. Thus, when the second transmitting power is less than the first transmitting power, the transmitting power can be reduced from twice the first transmitting power to the sum of the first and second transmitting powers, reducing power consumption. Further, the receiving module receives a first reflected optical signal corresponding to the first optical signal and a second reflected optical signal corresponding to the second optical signal, and processes the first and second reflected optical signals to obtain a first depth image of the first target area and a second depth image of the second target area. Ultimately, depth imaging can be completed with lower power consumption and a lower probability of high crosstalk.

[0092] This application embodiment also provides a depth imaging device, including: a device body and any of the above-mentioned depth imaging modules, wherein the depth imaging module is assembled on the device body and is used to provide navigation depth information and obstacle avoidance depth information to the device body.

[0093] The depth imaging device can be a robot, and the device itself can be the robot body. The robot body is the core supporting structure of the robot, including the body frame, motion execution mechanism, main control unit, and power system, and is the basic carrier for the robot to complete various actions and functions. The navigation depth information is distance data that characterizes the three-dimensional structure of the robot's surrounding spatial environment. It is used by the robot's main control unit to plan the travel path and locate its own position. The obstacle avoidance depth information is the distance, outline, position and other feature data of potential obstacles on the robot's travel path. It is used to trigger the robot's obstacle avoidance actions.

[0094] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this application.

[0095] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0096] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or modules may be electrical or other forms.

[0097] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0098] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software program modules.

[0099] If the integrated module is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0100] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A depth imaging module, characterized in that, The module includes a receiving module and at least two transmitting modules; the at least two transmitting modules are used to transmit optical signals to a target area; the at least two transmitting modules include a first transmitting module and a second transmitting module; the target area includes a first target area and a second target area; the first target area and the second target area are distributed sequentially along a vertical direction; the maximum detection distance of the first target area is greater than or equal to the maximum detection distance of the second target area; The first transmitting module is used to transmit a first optical signal to the first target area at a first transmitting power; The second transmitting module is used to transmit a second optical signal to the second target area at a second transmitting power; the second transmitting power is less than or equal to the first transmitting power; The receiving module is used to receive a first reflected light signal corresponding to the first light signal and a second reflected light signal corresponding to the second light signal, and to process the first reflected light signal and the second reflected light signal to obtain a first depth image of the first target area and a second depth image of the second target area.

2. The module as described in claim 1, characterized in that, The optical signals emitted by each of the at least two transmitting modules are modulated optical signals generated by indirect time-of-flight technology; and / or, each of the at least two transmitting modules uses an area array light source as the emission light source.

3. The module as described in claim 1, characterized in that, The receiving module is also used for: Based on the first depth image, determine the depth corresponding to each pixel in the first depth image; Based on the depth corresponding to each pixel in the first depth image, determine whether there are patches in the first depth image; Based on the second depth image, determine the depth corresponding to each pixel in the second depth image; Based on the depth corresponding to each pixel in the second depth image, determine whether there are patches in the second depth image; If there are patches in the first depth image, reduce the first emission power to obtain a third emission power, and control the first emission module to emit a third light signal towards the first target area with the third emission power; If there are patches in the second depth image, reduce the second emission power to obtain a fourth emission power, and control the second emission module to emit a fourth optical signal towards the second target area with the fourth emission power; If there are no patches in either the first depth image or the second depth image, the receiving module is further configured to control the first transmitting module and the second transmitting module to transmit alternately.

4. The module as described in claim 1, characterized in that, The receiving module is further configured to split the received image region into a first received image region and a second received image region, wherein the first received image region corresponds to the first target region and the second received image region corresponds to the second target region. When the first transmitting module transmits, the receiving module only outputs the image corresponding to the first received image area; When the second transmitting module transmits, the receiving module only outputs the image corresponding to the second received image area.

5. The module as described in claim 1, characterized in that, The receiving module is also used for: Based on the first target area, a first frequency combination is determined; the first frequency combination includes a preset first signal frequency and a preset second signal frequency. Based on the first signal frequency and the second signal frequency, the first transmitting module is controlled to generate the first optical signal; Based on the second target area, a second frequency combination is determined; the second frequency combination includes a preset third signal frequency and a fourth signal frequency. Based on the third signal frequency and the fourth signal frequency, the second transmitting module is controlled to generate the second optical signal.

6. The module as described in claim 5, characterized in that, The first signal frequency is less than or equal to the third signal frequency; the second signal frequency is less than or equal to the fourth signal frequency.

7. The module as described in claim 1, characterized in that, The module also includes a target resistor; one end of the target resistor is connected to the second transmitting module, and the other end of the target resistor is connected to a power supply; the target resistor is used to regulate the transmitting power of the second transmitting module.

8. The module as described in claim 1, characterized in that, The at least two transmitting modules also include a third transmitting module; The third transmitting module is used to transmit a third optical signal toward a third target region at a fifth transmitting power; the third target region is located on one side of the first target region or on one side of the second target region along the vertical direction. The receiving module is further configured to receive a third reflected light signal corresponding to the third light signal, and process the third reflected light signal to obtain a third depth image of the third target region.

9. The module as described in claim 1, characterized in that, The first transmitting module is provided with at least one first vertical cavity surface-emitting laser; the second transmitting module is provided with at least one second vertical cavity surface-emitting laser. The receiving module is further configured to determine a first number of activations of the at least one first vertical cavity surface-emitting laser based on the first transmission power, and control the first transmitting module to transmit the first optical signal to the first target area at the first transmission power based on the first number of activations. The receiving module is further configured to determine a second number of activations of the at least one second vertical cavity surface-emitting laser based on the second transmission power, and to control the second transmitting module to transmit the second optical signal to the second target region at the second transmission power based on the second number of activations.

10. A depth imaging device, characterized in that, include: The device body and the depth imaging module as described in any one of claims 1 to 9, wherein the depth imaging module is mounted on the device body and is used to provide navigation depth information and obstacle avoidance depth information to the device body.

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