Lidar, mobile system and laser detection method

Abstract

A lidar, a mobile system and a laser detection method. The lidar comprises: a rotating platform (10), at least two transceiver modules (11) fixed on the rotating platform (10), and a driving module configured to drive the rotating platform (10) to rotate about an axis of rotation (L) as a center, wherein each transceiver module (11) comprises a transmitting assembly configured to emit at least two laser beams having different exit angles, and a receiving assembly configured to receive echo signals of the emitted laser beams that are reflected by an object; the at least two transceiver modules (11) are arranged around the axis of rotation (L); the field-of-view ranges of at least two detection modules in a direction perpendicular to the axis of rotation (L) are staggered; and at least two annular field-of-view ranges respectively formed by the at least two transceiver modules (11) during rotation are stitched to form a larger annular field-of-view range. The lidar is low in terms of costs and can flexibly form different field-of-view ranges.

Description

A lidar, a mobile system, and a laser detection method Technical Field

[0001] This application relates to the field of laser detection, and more particularly to a lidar, a mobile system, and a laser detection method. Background Technology

[0002] LiDAR (Light Detection and Ranging) is a sensor that detects the position, velocity, reflectivity, and other information of objects in the surrounding environment by emitting laser beams. Its working principle involves emitting a laser beam towards the target detection area, then calculating the time difference between the received reflected echo and the emitted laser beam. This time difference, along with the beam's velocity, is used to calculate the distance to the object, thus detecting the external environment. LiDAR generally consists of a laser emitter and a receiver. There are still areas for improvement in existing LiDAR systems.

[0003] Summary of the Invention

[0004] This application provides a lidar, a mobile system, and a laser detection method that can be flexibly configured with different field-of-view ranges.

[0005] In a first aspect, this application provides a lidar, comprising:

[0006] A rotating platform, at least two transceiver modules fixed on the rotating platform, and a drive module for driving the rotating platform to rotate about a rotation axis;

[0007] Each of the transceiver modules includes a transmitting component for emitting at least two laser beams with different emission angles, and a receiving component for receiving the echo signal of the emitted laser beam reflected by an object.

[0008] The at least two transceiver modules are arranged around the rotation axis, the field of view of the at least two detection modules is staggered in the direction perpendicular to the rotation axis, and the at least two annular field of view formed by the at least two transceiver modules during rotation are spliced ​​together to form a larger annular field of view.

[0009] Optionally, at least some of the transmitting components in the transceiver module include at least two transmitting units for emitting at least two laser beams with different emission angles, and at least two switches corresponding to the at least two transmitting units.

[0010] The at least two transmitting units are respectively connected to the same transmitting power module via corresponding switches;

[0011] The lidar also includes a transmission control component, which controls the on and off states of at least two switches in the transmission component to allow at least two transmission units in the transmission component to be connected to the transmission power module at different times via corresponding switches, so that at least two transmission units in the transmission component emit beams at different times.

[0012] Optionally, all transmitting units in the at least two transceiver modules are connected to the same transmitting power module via corresponding switches; the transmitting control component is used to control each transmitting unit in the at least two transmitting components to sequentially connect to the transmitting power module via corresponding switches, so as to sequentially emit beams.

[0013] Furthermore, the transmitting power module and / or the transmitting control component are fixed outside the at least two transceiver modules and located on the rotating platform.

[0014] Optionally, the transmitting power module includes a first transmitting power supply and a second transmitting power supply, which are used to provide different transmitting energies respectively;

[0015] The transmission control component is used to control at least one of the at least two transceiver modules to be connected to the transmission power module at least twice consecutively. The first transmission unit is connected to the first transmission power supply in the first of the at least two times, and to the second transmission power supply in the second time, so that the first transmission unit emits laser beams of different energies twice consecutively.

[0016] Optionally, the receiving unit corresponding to the first transmitting unit in the at least two transceiver modules is used to receive the echo signal of the laser beam emitted sequentially by the first transmitting unit at least twice in a row;

[0017] The lidar also includes a signal processing module, used to obtain at least two initial ranging values ​​based on the at least two received echo signals.

[0018] The lidar also includes a calculation module, used to obtain a final ranging value corresponding to the at least two consecutive launches based on a weighted average of the at least two initial ranging values; or, to select one of the at least two initial ranging values ​​as a final ranging value corresponding to the at least two consecutive measurements.

[0019] Optionally, the calculation module is further configured to filter based on the initial ranging value or the final ranging value corresponding to a plurality of adjacent transmitting units when the difference between the at least two initial ranging values ​​is greater than a preset difference, so as to filter out at least one of the at least two initial ranging values, wherein the filtered initial ranging value is not used to calculate the final ranging value.

[0020] Optionally, at least a portion of the transceiver module includes at least one column of transmitting units arranged along the direction of the rotation axis.

[0021] Optionally, at least a portion of the transceiver module includes at least two columns of transmitting units arranged along the direction of the rotation axis, and the at least two columns of transmitting units are staggered in the direction of the rotation axis.

[0022] Optionally, at least some of the receiving components in the transceiver module include at least two receiving units and at least two switches corresponding to the at least two receiving units, each receiving unit being used to convert the received echo signal into an electrical signal;

[0023] The at least two receiving units are respectively connected to the same group of signal processing modules through corresponding switches, and the signal processing modules include an amplification circuit and a sampling circuit.

[0024] The lidar also includes a receiving control component, which controls the on and off states of the at least two switches to allow the at least two receiving units to connect to the signal processing module at different times via corresponding switches, so that the signal processing module amplifies and samples the electrical signals from the receiving units.

[0025] Optionally, all receiving units in the at least two transceiver modules are connected to the same group of signal processing modules via corresponding switches;

[0026] Furthermore, the signal processing module is fixed outside the at least two transceiver modules and is located on the rotating platform.

[0027] Optionally, the receiving component further includes at least two first-stage amplifier circuits, respectively located between the at least two switches and the at least two receiving units, and respectively used to amplify the electrical signals output by the corresponding receiving units for the first time;

[0028] The amplification circuit in the signal processing module includes a two-stage amplification circuit, which amplifies the electrical signal output by the first-stage amplification circuit corresponding to the switch a second time through the turned-on switch.

[0029] Optionally, the receiving component further includes a first-stage amplifier circuit connected to the at least two switches in the receiving component. Different receiving units in the receiving component multiplex the first-stage amplifier circuit at different times, so that the first-stage amplifier circuit amplifies the electrical signal output by the receiving unit corresponding to the turned-on switch for the first time.

[0030] The amplification circuit in the signal processing module includes a two-stage amplification circuit, which is used to amplify the electrical signal output by the first-stage amplification circuit a second time.

[0031] Optionally, the light emitting surface of the transmitting component and the light receiving surface of the receiving component in each transceiver module are arranged side by side on the surface of the transceiver module, such that the transmitting optical path and the receiving optical path of the transceiver module are staggered.

[0032] Optionally, the transmitting component of each of the at least two transceiver modules includes at least two transmitting units.

[0033] Furthermore, in the laser emission timing of the lidar, at least some of the laser beams emitted in two consecutive transmissions are emitted by emission units in different emission components.

[0034] Optionally, the lidar further includes a signal processing module and a correction module;

[0035] The signal processing module is used to generate a ranging value based on the echo signal received by the receiving components of the at least two transceiver modules;

[0036] The correction module is used to obtain the corrected distance measurement value based on the correction model and the distance measurement value.

[0037] Optionally, the correction module also stores theoretical distance values;

[0038] The signal processing module is also used to generate a reference ranging value based on the echo signal within a first field of view when the lidar is installed on the mobile device. The echo within the first field of view is formed by the reflection of the laser beam by a portion of the surface of the mobile device, and the theoretical distance value characterizes the distance between the lidar and the portion of the surface of the mobile device.

[0039] The correction module is also used to adjust the correction model according to the reference ranging value and the theoretical distance value, and to correct the ranging values ​​obtained by subsequent detection according to the adjusted correction model.

[0040] Optionally, the correction model includes scaling factors and offset values.

[0041] The correction module obtains the corrected distance value by scaling the distance measurement value using the scaling factor and then adjusting it according to the offset value.

[0042] Secondly, this application provides a mobile system, comprising:

[0043] Mobile devices, including driving control modules;

[0044] The lidar described in any one of the claims is fixed on the mobile device body and is used to detect the surrounding environment information of the mobile device to obtain a point cloud, and to send the point cloud to the driving control module;

[0045] The driving control module is also used to control the driving path of the mobile device based on the point cloud sent by the lidar.

[0046] Optionally, the mobile device is a wheelchair;

[0047] The lidar includes a first lidar located at the left armrest of the wheelchair, a second lidar located at the right armrest of the wheelchair, and a third lidar located at the rear of the wheelchair.

[0048] The first and second lidars each have a field of view that is an annular region along the horizontal direction, while the third lidar has a field of view that is an annular region with an angle of less than 90 degrees to the horizontal direction.

[0049] Optionally, the mobile system further includes a plurality of time-of-flight (ToF) based area array ranging sensors located on the mobile device, distributed on both sides of the mobile device, with a field of view below the field of view of the first lidar and the second lidar, and covering at least a portion of the ground within 2 meters of the wheelchair.

[0050] Optionally, the mobile device is a wheelchair including a left front wheel and a right front wheel;

[0051] The lidar includes a fourth lidar and a fifth lidar located above the left front wheel and the right front wheel, respectively. The field of view of the fourth lidar and the fifth lidar are respectively annular areas along the horizontal direction; or, the field of view of the fourth lidar and the fifth lidar are respectively annular areas along the vertical direction.

[0052] Optionally, the ratio of the distance from the ground at the light emission position of the lidar to the distance from the bottom of the lidar to the ground is between 1.11 and 1.22.

[0053] Optionally, the mobility system further includes a plurality of ToF-based area array ranging sensors located on the left and right sides of the wheelchair, respectively, and at least one ToF-based area array ranging sensor located on the rear side of the wheelchair.

[0054] The combined field of view of multiple ToF-based area array ranging sensors located on the left side of the wheelchair covers at least 90 degrees from the left side of the wheelchair to the front of the wheelchair.

[0055] The combined field of view of multiple ToF-based area array ranging sensors located on the right side of the wheelchair covers at least 90 degrees from the right side of the wheelchair to the front of the wheelchair.

[0056] The combined field of view of at least one ToF-based area array ranging sensor located at the rear of the wheelchair covers at least 60 degrees of the rear of the wheelchair.

[0057] Optionally, multiple ToF-based area array ranging sensors located on the left side of the wheelchair are positioned above the left front wheel of the wheelchair, at the left armrest of the wheelchair, or on the left side below the seat surface of the wheelchair.

[0058] Multiple ToF-based area array ranging sensors located on the right side of the wheelchair are positioned above the right front wheel of the wheelchair, on the right armrest of the wheelchair, or on the right side below the seat surface of the wheelchair.

[0059] Optionally, among the multiple ToF-based area array ranging sensors located on the left side of the wheelchair, at least some sensors are set at different heights on the wheelchair, and / or, at least some sensors have different angles between their field of view centerline and the ground.

[0060] Among the multiple ToF-based area array ranging sensors located on the right side of the wheelchair, at least some sensors are set at different heights on the wheelchair, and / or, at least some sensors have different angles between their field of view centerline and the ground.

[0061] Optionally, two layers of brackets are respectively arranged above the left front wheel and the right front wheel of the wheelchair, wherein each layer of brackets is equipped with at least one ToF-based area array ranging sensor, and the angle between the center line of the field of view of the area array ranging sensor in the two layers of brackets and the ground is different.

[0062] Optionally, the wheelchair has a left support extending outward from the left edge of the left armrest and a right support extending outward from the right edge of the right armrest; or, the wheelchair has a left support extending outward from the left edge below the seat surface and a right support extending outward from the right edge below the seat surface.

[0063] At least one ToF-based area array ranging sensor is located on the left support, and at least one ToF-based area array ranging sensor is located on the right support.

[0064] Optionally, the plurality of ToF-based area array ranging sensors located on the left side of the wheelchair include two ToF-based area array ranging sensors that are respectively facing the front and the front and lower front of the wheelchair, and a ToF-based area array ranging sensor that is facing the left and / or the lower left of the wheelchair.

[0065] The plurality of ToF-based area array ranging sensors located on the left side of the wheelchair include two ToF-based area array ranging sensors that are respectively facing the front and the lower front of the wheelchair, and a ToF-based area array ranging sensor that is facing the right and / or the lower right of the wheelchair.

[0066] Optionally, among the multiple ToF-based area array ranging sensors located on the left side of the wheelchair, the angle between the central axis of the field of view of some sensors and the ground is between 40° and 60°, and the angle between the central axis of the field of view of some sensors and the ground is between 50° and 70°.

[0067] Among the multiple ToF-based area array ranging sensors located on the right side of the wheelchair, the angle between the central axis of the field of view of some sensors and the ground is between 40° and 60°, while the angle between the central axis of the field of view of some sensors and the ground is between 50° and 70°.

[0068] Optionally, the mobile device further includes an interaction module;

[0069] The driving control module is also used to determine the second field of view of each lidar based on the point cloud sent by each lidar. The second field of view is the field of view that is not blocked by the mobile device when the lidar is fixed on the mobile device for detection.

[0070] The driving control module is also used to prompt the user, through the interaction module, that the LiDAR is dirty or obstructed, and / or the location of the LiDAR being dirty or obstructed, when the distance value of the point cloud within the second field of view of the LiDAR is continuously less than a preset value for a preset duration.

[0071] Thirdly, this application provides a laser detection method, including:

[0072] Control at least two transceiver modules in the lidar to rotate around the rotation axis;

[0073] The transmitting components in the at least two transceiver modules are controlled to emit laser beams in sequence. The at least two transceiver modules are arranged around the rotation axis, the field of view of the at least two detection modules is staggered in the direction perpendicular to the rotation axis, and the at least two annular field of view formed by the at least two transceiver modules during rotation can be spliced ​​into a continuous annular field of view.

[0074] Receive the echo signal reflected by the object from the emitted laser beam;

[0075] A point cloud is generated based on the echo signal.

[0076] Optionally, generating a point cloud based on the echo signal includes:

[0077] A ranging value is generated based on the received echo signal;

[0078] The corrected distance value is obtained based on the measured distance value and the correction model;

[0079] The point cloud is generated based on the corrected distance value.

[0080] Optionally, the method further includes:

[0081] A reference ranging value is generated based on the echo within the first field of view;

[0082] A theoretical distance value is obtained, which represents the distance between the laser radar and a portion of the surface of the mobile device. The laser radar is fixed on the mobile device, and the echo within the first field of view is formed by the reflection of the laser beam by a portion of the surface of the mobile device.

[0083] The calibration model is adjusted based on the reference distance value and the theoretical distance value;

[0084] The ranging value generated by the subsequent echo within the second field of view is corrected according to the adjusted correction model. The second field of view is the field of view of the lidar that is not blocked by the mobile device.

[0085] Optionally, the method further includes:

[0086] When the distance value of the point cloud within the second field of view of the lidar is continuously less than a preset value for a preset duration, the user is prompted by the interaction module that the lidar is dirty or obstructed, and / or the location of the lidar being dirty or obstructed; wherein, the lidar is fixed on the mobile device, and the second field of view is the field of view of the lidar that is not obstructed by the mobile device.

[0087] Optionally, at least some of the transmitting components in the transceiver module include at least two transmitting units for emitting at least two laser beams with different emission angles;

[0088] The control of the transmitting components in the at least two transceiver modules to sequentially emit laser beams includes:

[0089] Control at least the first transmitting unit of the at least two transceiver modules to continuously emit laser beams of different energies at least twice.

[0090] Optionally, the method further includes:

[0091] The echo signal of the laser beam emitted sequentially by the first transmitting unit is received at least twice consecutively;

[0092] At least two initial ranging values ​​are obtained based on the at least two received echo signals;

[0093] A final ranging value corresponding to the at least two consecutive launches is obtained by weighted average of the at least two initial ranging values; or, one of the at least two initial ranging values ​​is selected as the final ranging value corresponding to the at least two consecutive measurements.

[0094] Optionally, the method further includes:

[0095] When the difference between the at least two initial ranging values ​​is greater than a preset difference, filtering is performed based on the initial ranging values ​​or final ranging values ​​corresponding to the multiple adjacent transmitting units of the first transmitting unit to filter out at least one of the at least two initial ranging values. The filtered initial ranging value is not used to calculate the final ranging value.

[0096] In this embodiment, by using different emission angles for the transmitting units with different line sequences within the same transceiver module, a wider field of view can be achieved within a single transceiver module. Furthermore, by arranging at least two transceiver modules around a rotation axis and staggering their field of view along the extension direction of the rotation axis, the rotating platform is controlled to rotate around the rotation axis during detection. Moreover, each transceiver module performs multi-line scanning, enabling the creation of a lidar with a wide field of view in the longitudinal direction and 360-degree detection in the lateral direction at a lower cost, while also maintaining a high scanning density. When used on low-speed mobile devices, this application can simultaneously meet the requirements of low cost and detection accuracy. In addition, compared to the single-array multi-line repetitive scanning in the prior art, this application uses a combined array multi-line repetitive scanning, which facilitates the free combination of lidars with different field of view angles according to different usage scenarios during the manufacturing and assembly process. Attached Figure Description

[0097] Figure 1 is a partial structural schematic diagram of an embodiment of the lidar of this application;

[0098] Figure 2 is a schematic diagram of the structure of an embodiment of the lidar of this application;

[0099] Figure 3 is a partial structural schematic diagram of the transceiver component of an embodiment of the lidar of this application;

[0100] Figure 4A is a logical schematic diagram of a portion of the structure of the lidar of this application;

[0101] Figure 4B is a diagram of the wireless communication topology within the lidar of this application;

[0102] Figure 5 is a schematic diagram of the structure of an embodiment of the mobile system of this application;

[0103] Figure 6 is a schematic diagram of the field of view of the lidar in the mobile system shown in Figure 5.

[0104] Figures 7A and 7B are a top view and a side view of the arrangement of the TOF sensors in the field of view of a wheelchair in one embodiment.

[0105] Figure 7C is a side view showing the arrangement of the TOF sensors in the field of view of a wheelchair in another embodiment;

[0106] Figure 7D is a top view showing the arrangement of 8 of the 12 TOF sensors in the field of view of a wheelchair in another embodiment;

[0107] Figure 7E is a top view showing the arrangement of the other four of the twelve TOF sensors in the field of view on the wheelchair.

[0108] Figure 8 is a schematic diagram of an embodiment of the laser detection method of this application. Detailed Implementation

[0109] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0110] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0111] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0112] Figure 1 shows a partial structural schematic diagram of an embodiment of the lidar of this application. The lidar includes a rotating platform 10, at least two transceiver modules 11, and a drive module 12. The at least two transceiver modules 11 are fixed to the rotating platform 10, and their light-emitting surfaces are not located on the same plane but are arranged around a rotation axis L. The drive module 12 drives the rotating platform to rotate around the rotation axis L, thereby causing the at least two transceiver modules 11 to rotate together, achieving 360-degree omnidirectional scanning. Optionally, the drive module 12 may include a brushed motor or a brushless electrode.

[0113] Each transceiver module 11 includes a transmitting component for emitting at least two laser beams with different emission angles, and a receiving component for receiving the echo signal reflected by an object from the emitted laser beams. Therefore, each transceiver module can perform scanning of at least two lines. Optionally, for any one of the transceiver modules, the scanning of the at least two lines in the transceiver module can be simultaneous or sequential; that is, the at least two beams in the transceiver module can be emitted simultaneously or sequentially.

[0114] Figure 1 illustrates an example with four transceiver modules. At least two transceiver modules are arranged around the rotation axis, and the field of view of the at least two detection modules is staggered along the rotation axis, so that the at least two annular field of view formed by the at least two transceiver modules during rotation are combined to form a larger annular field of view. The field of view of the at least two transceiver modules can be the same or different. The field of view of any two adjacent transceiver modules can be contiguous or discontinuous, partially overlapping or completely non-overlapping. Optionally, the at least two annular field of view formed by the at least two transceiver modules during rotation are combined to form a continuous annular field of view. Alternatively, the at least two annular field of view formed by the at least two transceiver modules during rotation form a discontinuous annular field of view, and the field of view of each transceiver module can be specifically set according to different application scenarios.

[0115] In some examples, the at least two transceiver modules include a first transceiver module and a second transceiver module, whose fields of view partially overlap or are continuous in the direction perpendicular to the rotation axis. For example, both transceiver modules cover a horizontal line for measuring obstacles in the horizontal direction; optionally, the field of view of the first transceiver module is slightly higher, and the field of view of the second transceiver module is slightly lower. In some examples, the at least two transceiver modules also include a third transceiver module and a fourth transceiver module. Optionally, the field of view of the third transceiver module and the field of view of the first transceiver module partially overlap or are continuous in the direction perpendicular to the rotation axis, and the field of view of the fourth transceiver module and the field of view of the second transceiver module partially overlap or are continuous. For example, the field of view of the third transceiver module is above the horizontal line for measuring obstacles located above the horizontal line where the lidar is located; the field of view of the fourth transceiver module is below the horizontal line for measuring obstacles located below the horizontal line where the lidar is located. Alternatively, the fields of view of the third and fourth transceiver modules may both be located on the side of the first transceiver module facing away from the second transceiver module, or on the side of the second transceiver module facing away from the first transceiver module. For example, the fields of view of the third and fourth transceiver modules may both be below the horizontal line, used for detecting the ground near the lidar.

[0116] In the embodiment shown in Figure 1, the first and second transceiver modules are back-to-back, detecting in two opposite directions; the third and fourth transceiver modules are also back-to-back, detecting in two opposite directions. In some examples, the first and fourth transceiver modules may be located on either side of the second transceiver module, with the second and third transceiver modules back-to-back, so that the field of view of at least two transceiver modules are connected pairwise, forming a spiral field of view. This makes the point cloud detected by adjacent transceiver modules more spatially continuous when the lidar rotates.

[0117] In some examples, the number of transceiver modules can also be an even number, such as two. Figure 2 shows a schematic diagram of an embodiment of the lidar of this application. Unlike the embodiment shown in Figure 1, the lidar in this application only has a first transceiver module 211 and a second transceiver module 212. These two transceiver modules face away from each other, detecting in two opposite directions, and the two annular fields of view formed after rotation are connected. Alternatively, the number of transceiver modules can also be an odd number, as long as the arrangement of each transceiver module ensures that the center of mass during rotation is located on the rotation axis, maintaining dynamic balance during rotation.

[0118] In this embodiment, by using different emission angles for the transmitting units with different line sequences within the same transceiver module, a wider field of view can be achieved within a single transceiver module. Furthermore, by arranging at least two transceiver modules around a rotation axis and staggering their field of view along the extension direction of the rotation axis, the rotating platform is controlled to rotate around the rotation axis during detection. Each transceiver module performs multi-line scanning, enabling a lidar with a wide field of view in the longitudinal direction and 360-degree detection in the lateral direction while maintaining scanning density at a lower cost. This allows for simultaneous low cost and detection accuracy when used in low-speed mobile devices. Additionally, compared to the single-array multi-line repetitive scanning in existing technologies, this application uses a combined array multi-line repetitive scanning, facilitating the free combination of lidars with different field of view angles during manufacturing and assembly according to different usage scenarios. Moreover, by changing a large field of view lidar to a combination of multiple small field-of-view transceiver modules, the optical lenses used in each transceiver module can be reduced in size and placed closer to the light emission window, reducing the influence of stray light.

[0119] In each transceiver module, the transmitting component includes at least two transmitting units for emitting at least two laser beams with different emission angles, and the receiving component includes at least two receiving units corresponding to the at least two transmitting units. In some examples, the at least two transmitting units and the at least two receiving units may be in a one-to-one correspondence. In some examples, each receiving unit corresponds to at least two transmitting units, or each transmitting unit corresponds to at least two receiving units. Each receiving unit is used to receive the echo signal of the emitted beam from one or more corresponding transmitting units, and to convert the echo signal into an electrical signal.

[0120] Optionally, this lidar is an off-axis lidar, meaning the optical paths of the transmitting and receiving components are different. As shown in Figure 1, the light-emitting surface 111 of the transmitting component and the light-receiving surface 112 of the receiving component of each transceiver module 11 are arranged side-by-side on the surface of the transceiver module, thus misaligning the transmitting and receiving optical paths of the transceiver module. Off-axis lidar can avoid the near-field blind zone problem of coaxial lidar. Low-speed mobile devices have higher requirements for near-field detection, and using off-axis lidar can better meet the detection requirements of low-speed mobile devices.

[0121] In some examples, each transmitting assembly further includes at least two transmitting power modules respectively connected to the at least two transmitting units. Different transmitting assemblies correspond to different transmitting power modules, and each transmitting power module is used to power the connected transmitting unit so that the transmitting power module emits a laser beam. In some examples, each transmitting unit in at least two transmitting assemblies simultaneously emits a sequence of laser beams. The lidar also includes a transmitting control assembly for controlling the on and off of each switch. This transmitting control assembly controls the different transmitting units in the transmitting assembly to be turned on sequentially through their corresponding switches and transmitting power modules, so that each transmitting unit in the transmitting assembly emits a beam at different times. Optionally, the switches connected to each transmitting unit are located inside the transmitting assembly, and the transmitting control assembly and transmitting power modules are located on a rotating platform, independent of the at least two transceiver assemblies. By placing the switches inside the transmitting assembly and close to the transmitting units, the parasitic capacitance of the switches can be reduced, while keeping the transmitting control assembly and transmitting power modules independent of the at least two transceiver assemblies allows for a more compact arrangement of different structures within the lidar, which is beneficial for miniaturization.

[0122] The timing of beam emission from different emitting components can be the same or staggered. In some examples, some emitting units on one emitting component and some emitting units on another emitting component emit beams simultaneously to increase the density of the scanned point cloud. The frequencies of the beam emission from different emitting components can be the same or different. For example, in an example where the lidar is fixed to a slow-moving device, in certain scenarios where the lidar needs to focus on checking obstacles underfoot, the frequency of the beam emission from the fourth emitting component can be increased, where the timing of the fourth emitting component's beam emission can coincide with or stagger the timing of the beam emission from other groups of emitting components. Alternatively, in some scenarios where the focus is more on obstacles in the area covered by the field of view of the first and second emitting components, the emission frequencies of the first and second emitting components are both higher than the emission frequencies of the third and fourth emitting components.

[0123] Different emitting components do not reuse the same power supply module, which makes it easier to control the beam emission time and frequency between different emitting components. Alternatively, in some examples, different emitting components can time-division multiplex the same power supply module, as shown in Figure 1. The laser emission times of different emitting units in each emitting component are staggered, and the same power supply module 13 is time-division multiplexed through a switch, which can reduce costs and reduce the size of the lidar. The power supply module 13 and the emission control component 14 are located outside of at least two transceiver modules. The power supply module 13 and / or the emission control component 14 can be located on the rotating platform 10. As shown in Figure 3, Figure 3 is a partial structural schematic diagram of the transceiver component of an embodiment of the lidar of this application. Optionally, each emitting unit 101 in at least two emitting components 23 in the lidar corresponds to a switch 102 and is connected to the same power supply module 13 through the corresponding switch 102. The emission control component 14 is used to control each emitting unit in the at least two emitting components to sequentially turn on the corresponding switch to emit beams sequentially.

[0124] In some examples, the power supply module contains only one power supply for powering the transmitting unit of the emitted laser beam in each emitted beam of the lidar. In other examples, the power supply module includes a first power supply and a second power supply, which respectively provide emission energy to a portion of the laser beam emitted by the lidar. Optionally, the first and second power supplies provide different emission energies, such that the energy of the laser beam emitted by the transmitting unit powered by the first power supply differs from the energy of the laser beam emitted by the transmitting unit powered by the second power supply. This allows for different detection ranges for different emitted laser beams, enabling different detection ranges for different application scenarios or different field-of-view ranges.

[0125] For example, in some examples, the transmission control component is used to control at least a first transmitting unit among the at least two transceiver modules to be connected to the transmitting power supply module at least twice consecutively. The first transmitting unit is connected to the first transmitting power supply in the first of the at least two connections, and to the second transmitting power supply in the second, so that the first transmitting unit emits laser beams of different energies twice consecutively. Correspondingly, the receiving unit corresponding to the first transmitting unit is used to receive the echo signals of the laser beams emitted sequentially by the first transmitting unit at least twice consecutively. The receiving unit corresponding to the first transmitting unit can be one or at least two, without limitation. The lidar also includes a signal processing module for obtaining at least two initial ranging values ​​based on the at least two received echo signals. The lidar also includes a calculation module for obtaining a final ranging value corresponding to the at least two consecutive emissions based on a weighted average of the at least two initial ranging values; or, selecting one of the at least two initial ranging values ​​as the final ranging value corresponding to the at least two consecutive emissions. This allows for at least two detections of different energies at the same location. These detections improve ranging accuracy, increase the dynamic range of the ranging, and enhance interference resistance. Optionally, the transmission control component controls each transmitting unit in each transceiver module to sequentially connect to the first and second transmitting power supplies, so that each transmitting unit continuously emits two laser beams of different energies.

[0126] Because the echo signal reflected from a low-energy laser beam is too weak when it hits a distant object, it may be undetectable or the detected signal may be too weak to be accurately detected. Low-energy laser beams are more suitable for detecting close-range objects. Conversely, the echo signal from a high-energy laser beam is too strong when it hits a close-range object, which may cause distortion and make it impossible to accurately calculate the laser beam's time of flight. High-energy laser beams are more suitable for detecting distant objects. In this example, by controlling the same transmitting unit to emit laser beams of different energies at least twice consecutively, due to the limited rotational speed of the rotating platform and the limited time interval between adjacent emission, these at least two consecutive laser beams are highly likely to hit the same location on the same object. By detecting different energies at the same location on the same object and fusing the initial results of multiple detections into a final detection result, the distance measurement of the object can be made more accurate.

[0127] To avoid data redundancy, when generating a point cloud based on the detection results of each emission, the initial results of multiple consecutive detections of the same unit can optionally be fused into a single final detection result as a point cloud point. During fusion, the initial results of multiple detections can be weighted and averaged, or the initial result with the highest accuracy can be selected as the final detection result for that position of the object. In some examples, when at least two initial ranging values ​​are less than a first threshold, the initial ranging value corresponding to the lowest energy emitted laser beam is used as a single final ranging value corresponding to the at least two consecutive measurements, or when weighting the at least two initial ranging values, the initial ranging value corresponding to the lowest energy emitted laser beam is given a greater weight. In some examples, when at least two initial ranging values ​​are greater than a second threshold, the initial ranging value corresponding to the highest energy emitted laser beam is used as a single final ranging value corresponding to the at least two consecutive measurements, or when weighting the at least two initial ranging values, the initial ranging value corresponding to the highest energy emitted laser beam is given a greater weight. In some examples, when the at least two initial ranging values ​​are not less than a first threshold and not greater than a second threshold, a final ranging value corresponding to the at least two consecutive launches is obtained by weighted averaging of the at least two initial ranging values. This can take into account the detection of both near-range and far-range objects, thus improving the detection range.

[0128] In some examples, the calculation module is also used to filter, based on the initial or final ranging values ​​corresponding to multiple adjacent transmitting units of the first transmitting unit, when the difference between the at least two initial ranging values ​​is greater than a preset difference, to filter out at least one of the at least two initial ranging values. The filtered initial ranging value is not used to calculate the final ranging value. Since the at least two initial ranging values ​​correspond to the same object, when the difference between the at least two initial ranging values ​​is greater than the preset difference, it indicates that at least one of the initial ranging values ​​is inaccurate. Due to the continuity of the object's surface, the initial ranging value of the first transmitting unit can be filtered based on the initial or final ranging values ​​corresponding to multiple adjacent transmitting units of the first transmitting unit to filter out at least one of the at least two initial ranging values, thereby achieving anti-interference. Alternatively, when the difference between the at least two initial ranging values ​​is greater than the preset difference, the at least two initial ranging values ​​can be directly discarded, and the measurement result at that location cannot be included in the output point cloud.

[0129] The arrangement of the transmitting units in each transmitting assembly can be varied. Optionally, all transmitting units in each transmitting assembly 23 can be arranged in an array. Optionally, the transmitting units can be arranged in at least one column along the rotation axis. In this application, since a large field-of-view lidar is changed to a combination of multiple small field-of-view transceiver modules, it is possible to arrange each column of transmitting units in the transmitting assembly along the rotation axis. Compared to an arrangement where each column is perpendicular to the rotation axis, arranging the transmitting units in columns along the rotation axis can reduce the overall rotation axis height of the lidar, improve space utilization, and also reduce the overall rotation radius, thus optimizing stray light issues.

[0130] As shown in Figure 3, which illustrates two rows of transmitting units as an example, the transmitting units in each row of the same transmitting assembly are staggered along the rotation axis to ensure that their scanning paths are staggered during rotation, thereby increasing the point cloud scanning density of the lidar. Furthermore, the transmitting units in different transmitting assemblies can also be staggered along the rotation axis to further increase the point cloud scanning density of the lidar. Correspondingly, each receiving unit 103 in the receiving assembly corresponds one-to-one with each transmitting unit 101 in the transmitting assembly, so that each receiving unit 103 is also arranged in at least two rows and staggered. Optionally, the transmitting and receiving units in each transmitting and receiving assembly are arranged in two rows. Compared to more rows, this makes it easier to set up the wiring layout, and compared to a single row, it makes the structure of each assembly more compact, which is beneficial for the miniaturization of the lidar.

[0131] Each emitting component's emitting unit array can include a VCSEL laser array. Thanks to advancements in VCSEL fabrication technology, the number of VCSEL lasers in the array can be freely customized using photolithography masks to achieve low-cost laser arrays. Alternatively, the emitting unit array can also include an EEL (Edge Emitting Laser) array, or other laser arrays capable of high-density integration; no limitations are imposed here. Optionally, the laser array is soldered onto the PCB using mature surface mount technology. The emitting component also includes a collimating lens placed above the PCB. After focusing and calibration, the PCB and collimating lens are fixed together to ensure the laser is on the focal plane of the collimating lens.

[0132] In some examples, each receiving component also includes a signal processing module connected to each of the at least two receiving units. Each receiving unit converts the received echo signal into an electrical signal, and the signal processing module amplifies and samples the electrical signal from the receiving unit.

[0133] Optionally, different receiving units correspond to different signal processing modules, and each signal processing module is used to process electrical signals from the corresponding receiving unit. Alternatively, in some examples, each receiving component also includes switches connected to different receiving units, all receiving units in the same receiving component are connected to the same signal processing module through switches, and different receiving components are connected to different signal processing modules. The lidar also includes a receiving control component, used to control the on and off states of each switch in each receiving component to allow at least two receiving units to connect to the signal processing module at different times through their corresponding switches, so that the signal processing module can process the electrical signals from the connected receiving units accordingly.

[0134] Alternatively, in some examples, different receiving components can time-division multiplex the same signal processing module, which can further reduce the cost and size of the lidar. For example, as shown in Figure 3, optionally, the signal processing module 15 and / or the receiving control component 16 can be located on the rotating platform 10, independent of at least two receiving components. Each receiving unit 103 in the at least two receiving components of the lidar corresponds to a switch 104 and is connected to the same signal receiving circuit 15 through the corresponding switch 104. The receiving control component 16 is used to control the on and off of each switch so that each receiving unit is connected to the signal processing module through the corresponding switch at different times, so that the optical signal received by the receiving unit can be converted into point cloud point information by the signal processing module. Optionally, the switches connected to each receiving unit are located within the receiving component, which can reduce the parasitic capacitance of the switches. Optionally, the transmit control component and the receive control component can be integrated together, as shown in the control component 14 in Figure 1.

[0135] Optionally, the signal processing module may include analog circuitry and a TDC calculation module. The analog circuitry includes functions for converting electrical signals from the receiving unit into signals that the TDC calculation module can process. Optionally, the analog circuitry includes signal amplification circuitry and analog-to-digital conversion circuitry. The signal amplification circuitry may be a combination of a TIA amplifier and a comparator, or a combination of a TIA amplifier and an analog-to-digital converter. The TDC calculation module is used to calculate the time difference between the reception and transmission times of the echo reflected by the object. This time difference is used to calculate point cloud information. Each point cloud point represents a point on the object, and the point cloud information may include the object's ranging value, reflectivity, etc.

[0136] Optionally, at least two receiving components may further include a first-stage amplifier circuit connected to each receiving unit, each first-stage amplifier circuit being used to amplify the electrical signal output by the connected receiving unit for the first time. Each first-stage amplifier circuit is connected to the signal processing module via a switch. Alternatively, in some examples, the signal amplification circuit in the signal processing module may include a first-stage amplifier circuit and a second-stage amplifier circuit, that is, different receiving components may multiplex the same first-stage amplifier circuit and second-stage amplifier circuit at different times.

[0137] Alternatively, different receiving units can multiplex the first-stage amplifier circuit. For example, as shown in Figure 4A, which is a logical schematic diagram of a portion of the lidar structure of this application, one of the transceiver modules is an N-line transceiver module. The transmitting component includes N-line transmitting units, each reflecting unit being a transmitter. These N transmitters emit N-line beams, which are emitted at different times. The receiving component includes N-line receiving units, each receiving unit being a receiver. These N receivers correspond one-to-one with the N-line transmitters, and each receiver receives the echo of the emitted beam from its corresponding transmitter. Each receiver 103 in each receiving component is connected to the same first-stage amplifier circuit 105 via switches 104. That is, different receivers in the same receiving component multiplex the same first-stage amplifier circuit at different times. Different receiving components have different first-stage amplifier circuits. The signal amplification circuit in the signal processing module is specifically a second-stage amplifier circuit, used to amplify the electrical signal output by the first-stage amplifier circuit through the switched-on switches. Compared to either not reusing the first-stage amplifier circuit in all transmitting units or reusing the same first-stage amplifier circuit in all of them, this example can reduce costs while improving the signal-to-noise ratio of the circuit by keeping the trace distance between each receiving unit and the first-stage amplifier circuit short.

[0138] Each receiving component's receiving unit array can include an APD array. Thanks to advancements in APD manufacturing processes, the number of APD arrays can be freely customized using photolithography masks to achieve low-cost receiver arrays. Alternatively, the receiving unit array can also include a PD array, a SPAD array, or other receiver arrays capable of high-density integration; no limitations are imposed here. Optionally, the transmitter array and receiver array are soldered onto the PCB using mature surface mount technology. The transmitting component also includes a collimating lens 41 placed above the PCB, and the receiving component includes a converging lens 42 placed above the PCB. After focusing and calibration, the PCB and the converging lens are fixed together to ensure the receiver is on the focal plane of the converging lens. Because both the laser array and receiver array utilize mature, high-precision chip photolithography mask technology, the laser spacing on the laser array and the receiver spacing on the receiver array are highly consistent. Furthermore, the laser spacing and receiver spacing are also highly consistent, thus achieving an accurate one-to-one correspondence between the laser and receiver after passing through the collimating and focusing lenses.

[0139] The switches in this application can be MOSFETs, which have smaller parasitic capacitances and are more suitable for high-speed digital circuits; alternatively, they can be integrated multi-channel analog switches, without limitation. The transmit control component and / or receive control component can also be implemented by a microcontroller, FPGA, or other processor. Optionally, the transmit control component and receive control component can be implemented by the same or different processors.

[0140] In some examples, the timing of the emitted laser beams from each transmitting unit in the lidar can be as follows: first, the transmitting units in one transmitting component are controlled to emit laser beams sequentially; then, the transmitting units in the next transmitting component are controlled to emit laser beams sequentially, and so on, until all transmitting units in at least two transmitting components have emitted laser beams sequentially once, at which point the four sets of transmitting components begin a new round of emission. Alternatively, in some examples, the emission timing of the transmitting units in at least two transmitting components can be shuffled. For example, optionally, between the emitted laser beams of two or any two transmitting units in the same transmitting component, at least one or more other transmitting units in another transmitting component emit laser beams sequentially. Optionally, in the emission timing, at least two partially adjacent or any two adjacent emitted laser beams of the lidar are emitted by transmitting units in different transmitting components.

[0141] Optionally, in the emission timing sequence, the laser beams emitted by any four consecutive times from the lidar are emitted by transmitting units from different transmitting components of at least two transmitting modules. In a specific emission timing example, the first transmitting unit of the first transmitting module emits a laser beam, then the first transmitting unit of the second transmitting module emits a laser beam, then the first transmitting unit of the third transmitting module emits a laser beam, and then the first transmitting unit of the fourth transmitting module emits a laser beam; then the second transmitting unit of the first transmitting module emits a laser beam, then the second transmitting unit of the second transmitting module emits a laser beam, then the second transmitting unit of the third transmitting module emits a laser beam, then the second transmitting unit of the fourth transmitting module emits a laser beam, and so on. By interleaving the emission timings between the transmitting modules, crosstalk between different transmitting modules can be reduced.

[0142] In some examples, the lidar also includes a calibration module. After the signal processing module generates ranging values ​​based on the echo signals received by each receiving component, the calibration module obtains a corrected ranging value based on a calibration model and the ranging values. This ensures the ranging accuracy of the lidar during long-term use and resolves ranging accuracy deviations caused by aging of circuits or mechanical components due to prolonged use. The calibration model can be pre-calibrated and set within the lidar before it leaves the factory.

[0143] In some examples, certain modules are located outside the rotating platform of the lidar to reduce the number of components on the rotating platform. This module also communicates with modules located outside the rotating platform within the lidar. For example, the transmit control and receive control components located on the lidar's rotating platform also communicate with a scan control module located outside the rotating platform. This scan control module sends control signals to the transmit and receive control components, respectively instructing the transmit control component to control the emitted beam from the transmit unit and instructing the receive unit to convert the echo signal. As another example, the receive component located on the lidar's rotating platform also transmits detected data to modules located outside the rotating platform.

[0144] Due to the movement of the rotating platform, wired communication is not feasible. Optionally, modules located outside the rotating platform of the lidar transmit information via optical communication. However, optical communication has several drawbacks, such as unstable emission power, difficulty in maintaining the long lifespan of the light-emitting devices, and gain drift of the photodetector. Optionally, modules located outside the rotating platform of the lidar transmit information via wireless communication. Specifically, the lidar also includes a first communication module located on the rotating platform and a second communication module located outside the rotating platform, and the first communication module and the second communication module transmit data wirelessly.

[0145] Figure 4B is a wireless communication topology diagram within the lidar in an embodiment of this application. As shown in Figure 4B, the physical architecture of the first communication module and the second communication module is the same. One of the two communication modules includes a host 401, a coupling antenna 402, a driver 403, and a receiver 404. The driver 403 is connected to both the host 401 and the coupling antenna 402, and the receiver 404 is also connected to both the host 401 and the coupling antenna 402. The other of the two communication modules includes a slave 405, a coupling antenna 406, a driver 407, and a receiver 408. The driver 407 is connected to both the slave 405 and the coupling antenna 406, and the receiver 408 is also connected to both the slave 405 and the coupling antenna 406. The host 401 and slave 405 are used to process wireless communication signals. The driver in each end is used to drive the coupling antenna to transmit electromagnetic waves, and the receiver is used to receive the electromagnetic waves received by the coupling antenna. In this communication topology, the host 401 is defined as a communication endpoint with higher priority, and the slave 405 has a lower priority than the host. The two coupling antennas for communication are located on the rotating platform and inside the lidar, respectively, excluding the rotating platform. In some examples, both coupling antennas 402 and 406 can be located on the straight line of the rotation axis of the rotating platform. For example, one of coupling antennas 402 and 406 can be located on the rotating platform at the connection point of the rotation axis, while the other is located outside the rotating platform and on the rotation axis L, allowing the coupling antennas 402 and 406 to be as close as possible, for example, within 5 mm.

[0146] In this system, both the host 401 and the slave 405 can initiate communication requests at any time. Data transmission can only proceed after a communication request is approved. When both the host 401 and the slave 405 initiate communication requests simultaneously, both detect the other's transmission signal, which conflicts with their own transmission, and therefore stop transmitting, aborting the communication request. The host 401, with higher communication priority, will initiate a second communication request within a first preset time period, while the slave 405 waits for the host 401's second communication request. When the slave 405 receives the host 401's second communication request within the first preset time period, communication with the host 401 is established. Optionally, if the slave 405 determines that it has not received the host 401's second communication request within the first preset time period, the slave 405 can initiate a communication request again after a second preset time period. The first and second preset time periods can be the same or different.

[0147] Optionally, the wireless transmitter driver and the wireless receiver at both ends of the communication include ordinary amplifiers, and ordinary PCBs are used as coupling antennas at both ends of the communication. With the cooperation of a self-designed communication protocol, it has the characteristics of low power consumption, low latency, low packet loss rate, and low resource consumption, which can avoid the problems of high latency, high packet loss rate, high processor resource consumption, and high cost in existing wireless communication methods.

[0148] Optionally, the lidar also includes a self-calibration mode. In this self-calibration mode, the lidar can calibrate a correction model or update an already calibrated correction model. Optionally, the calibration module also stores theoretical distance values; the signal processing module is further configured to generate a reference ranging value based on the echo within a first field of view when the lidar is mounted on a mobile device. The echo within the first field of view is formed by the reflection of the laser beam from a portion of the surface of the mobile device, and the theoretical distance value represents the distance between the lidar and the portion of the surface of the mobile device. The calibration module is further configured to adjust the correction model based on the reference ranging value and the theoretical distance value, and to correct subsequent ranging values ​​obtained from detection based on the adjusted correction model.

[0149] Taking a wheelchair as an example, when a LiDAR is fixed to a wheelchair, its first field of view is obstructed by the wheelchair. The LiDAR's second field of view, excluding the first, is used for normal environmental detection. The position of the LiDAR on the mobile device represents a theoretical distance value, which is stored as prior information within the LiDAR. Optionally, this theoretical distance value can be fixed in the LiDAR before it leaves the factory based on its known position on the mobile device, or it can be obtained and stored through detection when the LiDAR is first fixed to the mobile device.

[0150] During use, when the lidar enters its self-calibration mode, the ranging value within the first field of view can be collected as a reference ranging value. The deviation between this reference ranging value and the theoretical ranging value is compared to analyze whether there is a systematic error in the ranging lidar's results. If so, the correction model is optimized based on this systematic error.

[0151] Optionally, the correction model includes a scaling factor and an offset value. The correction module obtains the corrected distance value by scaling the ranging value using the scaling factor and then adjusting it according to the offset value. For example, the correction model includes: d correct =scale*d measure +offset, where d correct This refers to correcting the ranging value; scale refers to the scaling factor; offset refers to the offset value; d measureThis refers to the ranging value. When optimizing the correction model based on system error, the lidar can obtain multiple d values ​​within the first field of view. measure And using the theoretical distance value as d correct Then, the least squares method is used to optimize Δd = d measure -d reference The values ​​of are used to obtain the parameters offset and scale in the optimized calibration model.

[0152] This application also provides a mobile system. As shown in Figure 5, Figure 5 is a structural schematic diagram of an embodiment of the mobile system of this application. The mobile system 50 includes a mobile device 51 and at least one lidar fixed to the mobile device 51. The mobile device 51 also includes a driving control module (not shown), the at least one lidar being used to detect environmental information around the mobile device to obtain a point cloud, and to send the point cloud to the driving control module. The driving control module is also used to control the driving path of the mobile device based on the point cloud sent by the lidar. Specifically, the driving control module can perform at least one of localization, mapping, perception, and path planning based on the point cloud. In the example shown in Figure 5, the mobile device is a wheelchair. In other examples, the mobile device can also be a mobile robot, a mobile platform, a mobile vehicle, etc. The at least one lidar 52 can be arranged in various ways on the mobile device.

[0153] In some examples, the at least one lidar includes a first lidar 521 located on the left armrest of the wheelchair, a second lidar 522 located on the right armrest of the wheelchair, and a third lidar 523 located behind the wheelchair. Figure 6 shows a schematic diagram of the field of view of the lidars in the mobility system shown in Figure 5. Each of the three lidars has two transceiver modules and a field of view angle of 32 degrees. Optionally, the field of view of the first and second lidars is a horizontal annular region 61, used to detect the surrounding environment of the wheelchair. Optionally, the field of view angles of the two lidars are -16 degrees to 16 degrees. The field of view of the third lidar includes an annular region 62, which is tilted upwards at an angle not greater than 90 degrees to the horizontal direction, to detect the area at the height of the back of the user's head when seated in the wheelchair. Alternatively, in some examples, the annular region may be tilted downwards at an angle not greater than 90 degrees to the horizontal direction, to detect the area below and behind the user when seated in the wheelchair.

[0154] Optionally, the mobile system further includes multiple Time-of-Flight (TOF) based area array ranging sensors distributed on both sides of the mobile device, with their field of view below that of the first and second lidar sensors, and covering at least a portion of the ground within 2 meters of the wheelchair. Here, the TOF-based area array ranging sensor refers to a sensor without a scanning mechanical structure, which achieves simultaneous ranging across multiple areas by using an area array photodetector to receive the emitted light signal. For ease of description below, the TOF-based area array ranging sensor will be simply referred to as a TOF sensor. TOF sensors have lower size and power consumption than lidar, lower detection range and resolution, and lower cost. By combining lidar and TOF sensors to detect the surrounding environment of the wheelchair, costs can be reduced while meeting detection requirements.

[0155] Optionally, as shown in Figures 7A and 7B, which are a top view and a side view respectively, illustrating the arrangement of the TOF sensors' field of view on the wheelchair in one embodiment. Three TOF sensors 71 are also fixed to each side of the wheelchair 70, with the field of view 72 of the three TOF sensors on each side pointing towards the ground near the wheelchair. Optionally, the TOF sensor combination in this example, in conjunction with a LiDAR mounted on the armrest, can complement the LiDAR.

[0156] In some examples, the wheelchair is equipped with two lidar units (referred to as the fourth and fifth lidar units for convenience) located above the left and right front wheels, respectively. The field of view of the fourth and fifth lidar units is a horizontal annular region. Alternatively, the field of view of the fourth and fifth lidar units can also be vertical annular regions. In examples where the fourth and fifth lidar units have the structure described above, when mounted on the wheelchair, the rotation axis of the rotating platform within the lidar units can be arranged horizontally, so that the field of view of the fourth and fifth lidar units can also be vertical annular regions. Optionally, the ratio of the distance from the ground at the lidar's light emission point to the distance from the bottom of the lidar unit to the ground is between 1.11 and 1.22, enabling the lidar to cover a wider field of view. In some examples, the wheelchair's front wheel diameter is 180mm, the distance from the top of the front wheel to the bottom of the lidar is 128.41mm, and the lidar's emission position is 355.47mm above the ground.

[0157] In some examples, to supplement the fourth and fifth lidar sensors, or the first to third lidar sensors mentioned above, the wheelchair also includes multiple Time-of-Flight (TOF) sensors located on the left and right sides of the mobile device, respectively, and at least one TOF sensor located at the rear of the wheelchair. Specifically, the combined field of view of the multiple TOF sensors located on the left side of the mobile device covers at least 90 degrees from the left side to the front of the wheelchair; the combined field of view of the multiple TOF sensors located on the right side of the mobile device covers at least 90 degrees from the right side to the front of the wheelchair; and the combined field of view of the at least one TOF sensor located at the rear of the wheelchair covers at least 60 degrees from the rear of the wheelchair.

[0158] In some examples, multiple ToF sensors located on the left side of the wheelchair are positioned above the left front wheel, at the left armrest, or below the seat surface on the left side of the wheelchair; multiple ToF sensors located on the right side of the wheelchair are positioned above the right front wheel, at the right armrest, or below the seat surface on the right side of the wheelchair. Optionally, among the multiple ToF sensors located on the left side of the wheelchair, at least some sensors are positioned at different heights on the wheelchair, and / or, at least some sensors have different angles between their field of view center axis and the ground. Optionally, among the multiple ToF sensors located on the right side of the wheelchair, at least some sensors are positioned at different heights on the wheelchair, and / or, at least some sensors have different angles between their field of view center axis and the ground.

[0159] In some examples, the plurality of ToF sensors located on the left side of the wheelchair include four ToF sensors that detect towards the left, lower left, front, and lower front of the wheelchair, respectively; the plurality of ToF sensors located on the right side of the wheelchair include four ToF sensors that detect towards the right, lower right, front, and lower front of the wheelchair, respectively. Optionally, the left side of the wheelchair may also include a ToF sensor covering the diagonally front left or lower left front of the wheelchair, and the right side of the wheelchair may also include a ToF sensor covering the diagonally front right or lower right front of the wheelchair. Optionally, in some examples, to further reduce costs, only one of the two ToF sensors facing the left and lower left of the wheelchair may be provided; only one of the two ToF sensors facing the right and lower right of the wheelchair may be provided.

[0160] For example, as shown in Figure 7C, which is a left view of a wheelchair in one embodiment, the wheelchair 73 has five ToF sensors on its left side, all located below the seat surface. These include two ToF sensors located on the front side below the seat surface, with fields of view 74 and 75 facing the front and lower front of the wheelchair, respectively; two ToF sensors located on the left side below the seat surface, with fields of view 76 and 77 facing the left and lower left of the wheelchair, respectively; and a ToF sensor located on the rear side of the seat surface, with a field of view 78 facing the rear and lower rear of the wheelchair. Optionally, the wheelchair 73 has five ToF sensors symmetrically arranged on its right side. Optionally, the field of view of the ToF sensor located on the rear side of the wheelchair surface may not face the rear and lower rear of the wheelchair, but rather the rear of the wheelchair.

[0161] In some examples, among the multiple ToF sensors located on the left side of the wheelchair, the angle between the central axis of the field of view of some sensors and the ground is between 40° and 60°, and the angle between the central axis of the field of view of some sensors and the ground is between 50° and 70°; among the multiple ToF sensors located on the right side of the wheelchair, the angle between the central axis of the field of view of some sensors and the ground is between 40° and 60°, and the angle between the central axis of the field of view of some sensors and the ground is between 50° and 70°.

[0162] For example, in one specific example, five TOF sensors are positioned above the left and right front wheels respectively, and two TOF sensors are positioned at the rear of the wheelchair (e.g., behind the seat surface), for a total of 12 TOF sensors. Each TOF sensor has a field of view of 45 degrees. The fields of view of any two adjacent TOF sensors on each of the five front wheels partially overlap, together covering the area directly in front of and to the side of the left front wheel. As shown in Figures 7D and 7E, Figure 7D is a top view illustrating the arrangement of the field of view of eight of the twelve TOF sensors on the wheelchair in one embodiment, and Figure 7E is a top view illustrating the arrangement of the field of view of the remaining four of the twelve TOF sensors on the wheelchair. Of the five Time-of-Flight (TOF) sensors on the left front wheel, as shown in Figure 7D, one TOF sensor 702 detects towards the lower left side of the left front wheel, one TOF sensor 703 detects towards the lower left front side of the left front wheel, and one TOF sensor 704 detects towards the lower front front side of the left front wheel. As shown in Figure 7E, one TOF sensor 706 detects towards the front of the left front wheel, and another TOF sensor 706 detects towards the left side of the left front wheel. The five TOF sensors on the right front wheel are arranged symmetrically with the five TOF sensors on the left.

[0163] Optionally, in Figure 7E, among the two TOF sensors located on the left side of the wheelchair, the central axis of the field of view of TOF sensor 705 is located between TOF sensors 702 and 703, and the central axis of the field of view of TOF sensor 706 is located between TOF sensors 703 and 704.

[0164] In Figure 7D, there is another TOF sensor 701 on the left side located behind the seat surface of the wheelchair, and another TOF sensor symmetrically distributed with TOF sensor 701 on the right side located behind the seat surface of the wheelchair. Optionally, the angle between the central axis of the field of view of the two TOF sensors located behind the wheelchair frame and the front-back direction of the wheelchair is between 15° and 25°.

[0165] Optionally, the five TOF sensors on one front wheel are evenly spaced. Optionally, among any two adjacent TOF sensors, one sensor detects towards the front or top of the TOF sensor, for example, the angle between the central axis of the field of view and the ground is between 50° and 70°; the other sensor detects towards the ground below the TOF sensor, for example, the angle between the central axis of the field of view and the ground is between 40° and 60°. For example, among the five TOF sensors on one front wheel, the angle between the central axis of the field of view of the three TOF sensors in Figure 7D and the ground is between 40° and 60°, for example, 50°; the angle between the central axis of the field of view of the two TOF sensors in Figure 7E and the ground is between 50° and 70°, for example, 60°. Optionally, the detection directions of at least two adjacent TOF sensors on one side are staggered vertically, that is, one detection direction of two adjacent TOF sensors faces downwards from the TOF sensor, and the other detection direction faces forwards from the TOF sensor.

[0166] Optionally, the five TOF sensors can be positioned at the same or different heights on the wheelchair. For example, TOF sensors with the same angle between their central axis and the ground can be positioned at the same height, while TOF sensors with different angles between their central axis and the ground can be positioned at different heights.

[0167] In some examples, two layers of supports are adjacent to each other above the left and right front wheels of the wheelchair. Each layer of the support contains at least one Time-of-Flight (ToF) based area array ranging sensor, and the angles between the central axis of the field of view of the area array ranging sensors in the two layers of the support and the ground are different. For example, in Figure 7E, the two ToF sensors are located in the upper layer of the support space, and in Figure 7D, the three ToF sensors are located in the lower layer of the support space.

[0168] Understandably, the number of TOF sensors deployed on the wheelchair can be determined based on the field of view of the TOF sensors. For example, in an example where the field of view of the TOF sensors is 60 degrees, the number of TOF sensors on one side of the front wheelchair can be reduced from five to three. These three TOF sensors can be positioned at the same or different heights on the wheelchair.

[0169] In some examples, at least some of the TOF sensors can also be located under the seat surface of the wheelchair. Since the TOF sensors under the seat surface may be obstructed when the user is seated in the wheelchair, optionally, a left bracket extends outward from the left edge of the underside of the wheelchair seat surface, and a right bracket extends outward from the right edge of the underside of the wheelchair seat surface. For example, these left and right brackets can be positioned at an outward extension of 5-10 cm. At least some of the TOF sensors are respectively mounted on these left and right brackets; for example, TOF sensors located on the left and right sides of the wheelchair with a field of view facing forward and downward are respectively mounted on these left and right brackets.

[0170] In some examples, at least some of the TOF sensors can also be located on the armrests. Since the TOF sensors on the armrests may be obstructed when the user is seated in a wheelchair, optionally, a left support extends outward from the left edge of the left armrest of the wheelchair, and a right support extends outward from the right edge of the right armrest. For example, these left and right supports can be located 5-10 cm outward. At least some of the TOF sensors are respectively located on the left and right supports, for example, at least one of the TOF sensors whose field of view faces the front, lower front, left, and lower left of the wheelchair is located on the left and right supports. Optionally, the ground clearance of the TOF sensors can be between (562±150) mm and (782±150) mm. For example, in some examples, the ground clearance of a TOF sensor is between 459.7 mm and 559.7 mm, and the angle between the central axis of the TOF sensor's field of view and the ground is between 31.58° and 51.58°, for example, 41.58°.

[0171] In some examples, three Time-of-Flight (TOF) sensors are installed on each armrest, located at the front, middle, and rear of the armrest, respectively. Optionally, of the multiple TOF sensors installed on each armrest, at least one faces the front of the wheelchair, and at least one faces the side of the wheelchair. Optionally, the central axis of the field of view of the TOF sensors facing the front and side of the wheelchair is parallel to the ground. Optionally, among the TOF sensors installed on each side, the angle between the central axis of the field of view of the front and rear TOF sensors and the ground is between 40° and 60°, for example, 50°; the angle between the central axis of the field of view of the middle TOF sensor and the ground is between 50° and 70°, for example, 60°.

[0172] It should be noted that the above examples of TOF sensor installation locations can be used in combination. For example, some TOF sensors can be installed on the front wheels, some on the armrests, and some under the wheelchair seat.

[0173] In some examples, the LiDAR on the mobile device includes a sixth and a seventh LiDAR, with the structure of these two LiDARs as described above, and each LiDAR containing four transceiver modules. Each transceiver module is capable of N-line scanning, with N lines scanning at different angles, and each transceiver module has a field of view of M degrees. For example, if N is 16, and the scanning angles between different lines differ by 1 degree, one transceiver module has a 16-degree field of view, and one LiDAR has a 64-degree field of view.

[0174] Optionally, the sixth lidar is fixed to the front of the mobile device, and the seventh lidar is fixed to the rear of the mobile device. Taking a wheelchair as an example, the sixth lidar is fixed to the left or right armrest of the wheelchair, and the seventh lidar is fixed to the right or left side of the backrest of the wheelchair. In some examples, the sixth lidar is fixed to the right armrest of the wheelchair, responsible for detecting a field of view of 270 degrees from 90 degrees to the left and directly behind, while the seventh lidar is fixed to the left rear of the wheelchair, responsible for detecting a field of view of 270 degrees from 90 degrees to the right and directly in front.

[0175] Optionally, the first and second transceiver modules of the sixth LiDAR have a combined field of view of 2M degrees, used for object detection in the central frontal field of view of the mobile device. The scanned point cloud information can be used for positioning. The third and fourth transceiver modules have a combined field of view of 2M degrees, used for object detection in the downward frontal field of view, mainly for detecting near objects, such as objects under the user's feet in a wheelchair. Optionally, the first and second transceiver modules of the seventh LiDAR have a combined field of view of 2M degrees, used for object detection in the central rearal field of view of the mobile device. The scanned point cloud information can be used for positioning. The third and fourth transceiver modules have a combined field of view of 2M degrees, used for object detection in the upper rearal field of view. Of course, the field of view of each transceiver module does not need to be the same, and this is not a limitation. Compared with the example shown in Figure 5, in this example, the third and fourth transceiver modules of the LiDAR can be used to detect the near-foot area of ​​the mobile device, eliminating the need for a separate TOF sensor.

[0176] Optionally, the driving control module on the wheelchair is also used to detect whether the surface of the lidar is dirty or whether there is obstruction within the second field of view. This second field of view is the area of ​​view that is not obstructed by the wheelchair when the lidar is fixed to it. Since the point cloud detected by the lidar is a crucial basis for the driving control module to control the wheelchair's path, the module can use this point cloud to identify the location of obstacles and control the wheelchair to avoid them. By detecting dirt or obstruction, potential dangers caused by erroneous lidar readings can be avoided.

[0177] Specifically, the driving control module is further configured to determine the second field of view of each lidar based on the point cloud transmitted by each lidar. The driving control module is also configured to determine that the lidar is dirty or obstructed when the distance value of the point cloud within the second field of view of the lidar is continuously less than a preset value for a preset duration. This preset value can be 0 or a value close to 0. Optionally, the mobile device is also equipped with an interaction module, which can be a screen or speaker on the mobile device. The driving control module also prompts the user that the lidar is dirty or obstructed through the interaction module. Further optionally, the driving control module also prompts the user of the location of the dirty or obstructed lidar through the interaction module.

[0178] This application also provides a laser detection method. As shown in Figure 8, Figure 8 is a structural schematic diagram of an embodiment of the laser detection method of this application. The method includes:

[0179] Step S801: Control at least two transceiver modules in the lidar to rotate around the rotation axis.

[0180] Step S802: Control the transmitting components in the at least two transceiver modules to sequentially emit laser beams.

[0181] The at least two transceiver modules are arranged around the rotation axis, the field of view of the at least two detection modules is staggered in the direction perpendicular to the rotation axis, and the at least two annular field of view formed by the at least two transceiver modules during rotation can be spliced ​​into a continuous annular field of view.

[0182] Step S803: Receive the echo signal reflected by the object from the emitted laser beam;

[0183] Step S804: Generate a point cloud based on the echo signal.

[0184] Optionally, at least some of the transmitting components in the transceiver module include at least two transmitting units for emitting at least two laser beams with different emission angles;

[0185] Step S802 includes controlling each of the transmitting units in the at least two transceiver modules to sequentially emit laser beams, wherein at least some of the laser beams emitted in two adjacent transmissions are emitted by transmitting units in different transmitting components. This can reduce crosstalk between two adjacent emitted laser beams.

[0186] Optionally, step S804 includes: generating a ranging value based on the received echo; obtaining a corrected distance value based on the ranging value and the correction model; and generating the point cloud based on the corrected distance value.

[0187] Optionally, the method further includes:

[0188] A reference ranging value is generated based on the echo within the first field of view;

[0189] A theoretical distance value is obtained, which represents the distance between the laser radar and a portion of the surface of the mobile device. The laser radar is fixed on the mobile device, and the echo within the first field of view is formed by the reflection of the laser beam by a portion of the surface of the mobile device.

[0190] The calibration model is adjusted based on the reference distance value and the theoretical distance value;

[0191] The ranging value generated by the subsequent echo within the second field of view is corrected according to the adjusted correction model. The second field of view is the field of view of the lidar that is not blocked by the mobile device.

[0192] Optionally, the method further includes:

[0193] When the distance value of the point cloud within the second field of view of the lidar is continuously less than a preset value for a preset duration, the user is prompted by the interaction module that the lidar is dirty or obstructed, and / or the location of the lidar being dirty or obstructed; wherein, the lidar is fixed on the mobile device, and the second field of view is the field of view of the lidar that is not obstructed by the mobile device.

[0194] Optionally, at least some of the transmitting components in the transceiver module include at least two transmitting units for emitting at least two laser beams with different emission angles.

[0195] Optionally, controlling the transmitting components in the at least two transceiver modules to sequentially emit laser beams includes controlling at least the first transmitting unit in the at least two transceiver modules to continuously emit laser beams of different energies at least twice.

[0196] Optionally, the method further includes:

[0197] The echo signal of the laser beam emitted sequentially by the first transmitting unit is received at least twice consecutively;

[0198] At least two initial ranging values ​​are obtained based on the at least two received echo signals;

[0199] A final ranging value corresponding to the at least two consecutive launches is obtained by weighted average of the at least two initial ranging values; or, one of the at least two initial ranging values ​​is selected as the final ranging value corresponding to the at least two consecutive measurements.

[0200] Optionally, the method further includes:

[0201] When the difference between the at least two initial ranging values ​​is greater than a preset difference, filtering is performed based on the initial ranging values ​​or final ranging values ​​corresponding to the multiple adjacent transmitting units of the first transmitting unit to filter out at least one of the at least two initial ranging values. The filtered initial ranging value is not used to calculate the final ranging value.

[0202] For an explanation of laser detection methods, please refer to the above explanation of lidar and mobile systems, which will not be repeated here.

[0203] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A lidar, characterized in that, include: A rotating platform, at least two transceiver modules fixed on the rotating platform, and a drive module for driving the rotating platform to rotate about a rotation axis; Each of the transceiver modules includes a transmitting component for emitting at least two laser beams with different emission angles, and a receiving component for receiving the echo signal of the emitted laser beam reflected by an object. The at least two transceiver modules are arranged around the rotation axis, the field of view of the at least two detection modules is staggered in the direction perpendicular to the rotation axis, and the at least two annular field of view formed by the at least two transceiver modules during rotation are spliced ​​together to form a larger annular field of view.

2. The lidar according to claim 1, characterized in that, The transmitting component in at least part of the transceiver module includes at least two transmitting units for emitting at least two laser beams with different emission angles, and at least two switches corresponding to the at least two transmitting units. The at least two transmitting units are respectively connected to the same transmitting power module via corresponding switches; The lidar also includes a transmission control component, which controls the on and off states of at least two switches in the transmission component to allow at least two transmission units in the transmission component to be connected to the transmission power module at different times via corresponding switches, so that at least two transmission units in the transmission component emit beams at different times.

3. The lidar according to claim 2, characterized in that, All transmitting units in the at least two transceiver modules are connected to the same transmitting power module via corresponding switches; the transmitting control component is used to control each transmitting unit in the at least two transmitting components to sequentially connect to the transmitting power module via corresponding switches so as to sequentially emit beams. Furthermore, the transmitting power module and / or the transmitting control component are fixed outside the at least two transceiver modules and located on the rotating platform.

4. The lidar according to claim 2 or 3, characterized in that, The transmitting power module includes a first transmitting power supply and a second transmitting power supply, which are used to provide different transmitting energies respectively; The transmission control component is used to control at least one of the at least two transceiver modules to be connected to the transmission power module at least twice consecutively. The first transmission unit is connected to the first transmission power supply in the first of the at least two times, and to the second transmission power supply in the second time, so that the first transmission unit emits laser beams of different energies twice consecutively.

5. The lidar according to claim 4, characterized in that, The receiving unit corresponding to the first transmitting unit in the at least two transceiver modules is used to receive the echo signal of the laser beam emitted sequentially by the first transmitting unit at least twice in a row. The lidar also includes a signal processing module, used to obtain at least two initial ranging values ​​based on the at least two received echo signals. The lidar also includes a calculation module, used to obtain a final ranging value corresponding to the at least two consecutive launches based on a weighted average of the at least two initial ranging values; or, to select one of the at least two initial ranging values ​​as a final ranging value corresponding to the at least two consecutive measurements.

6. The lidar according to claim 5, characterized in that, The calculation module is further configured to filter based on the initial ranging value or the final ranging value corresponding to a plurality of adjacent transmitting units when the difference between the at least two initial ranging values ​​is greater than a preset difference, so as to filter out at least one of the at least two initial ranging values, and the filtered initial ranging value is not used to calculate the final ranging value.

7. The lidar according to claim 1, characterized in that, At least a portion of the transceiver module includes at least one column of transmitting units arranged along the direction of the rotation axis.

8. The lidar according to claim 7, characterized in that, At least a portion of the transceiver module includes at least two columns of transmitting units arranged along the direction of the rotation axis, and the at least two columns of transmitting units are staggered in the direction of the rotation axis.

9. The lidar according to claim 1, characterized in that, The receiving component in at least part of the transceiver module includes at least two receiving units and at least two switches corresponding to each of the at least two receiving units. Each receiving unit is used to convert the received echo signal into an electrical signal. The at least two receiving units are respectively connected to the same group of signal processing modules through corresponding switches, and the signal processing modules include an amplification circuit and a sampling circuit. The lidar also includes a receiving control component for controlling the on and off states of the at least two switches to enable the... At least two receiving units are connected to the signal processing module at different times via corresponding switches, so that the signal processing module amplifies and samples the electrical signals from the receiving units.

10. The lidar according to claim 9, characterized in that, All receiving units in the at least two transceiver modules are connected to the same group of signal processing modules via corresponding switches. Furthermore, the signal processing module is fixed outside the at least two transceiver modules and is located on the rotating platform.

11. The lidar according to claim 10, characterized in that, The receiving component also includes a first-stage amplifier circuit connected to the at least two switches in the receiving component. Different receiving units in the receiving component multiplex the first-stage amplifier circuit at different times, so that the first-stage amplifier circuit amplifies the electrical signal output by the receiving unit corresponding to the turned-on switch for the first time. The amplification circuit in the signal processing module includes a two-stage amplification circuit, which is used to amplify the electrical signal output by the first-stage amplification circuit a second time.

12. The lidar according to any one of claims 1 to 3 and 5 to 11, characterized in that, The light emitting surface of the transmitting component and the light receiving surface of the receiving component in each transceiver module are arranged side by side on the surface of the transceiver module, so that the transmitting optical path and the receiving optical path of the transceiver module are staggered.

13. The lidar according to any one of claims 1 to 3 and 5 to 11, characterized in that, The transmitting component of each of the at least two transceiver modules includes at least two transmitting units. Furthermore, in the laser emission timing of the lidar, at least some of the laser beams emitted in two consecutive transmissions are emitted by emission units in different emission components.

14. The lidar according to any one of claims 1 to 3 and 5 to 11, characterized in that, The lidar also includes a signal processing module and a correction module; The signal processing module is used to generate a ranging value based on the echo signal received by the receiving components of the at least two transceiver modules; The correction module is used to obtain the corrected distance measurement value based on the correction model and the distance measurement value.

15. The lidar according to claim 14, characterized in that, The correction module also stores theoretical distance values; The signal processing module is also used to generate a reference ranging value based on the echo signal within a first field of view when the lidar is installed on the mobile device. The echo within the first field of view is formed by the reflection of the laser beam by a portion of the surface of the mobile device, and the theoretical distance value characterizes the distance between the lidar and the portion of the surface of the mobile device. The correction module is also used to adjust the correction model according to the reference ranging value and the theoretical distance value, and to correct the ranging values ​​obtained by subsequent detection according to the adjusted correction model.

16. The lidar according to claim 14, characterized in that, The correction model includes scaling factors and offset values. The correction module obtains the corrected distance value by scaling the distance measurement value using the scaling factor and then adjusting it according to the offset value.

17. The lidar according to claim 14, characterized in that, The lidar also includes a first communication module located on the rotating platform and a second communication module located outside the rotating platform. The first communication module and the second communication module transmit data wirelessly. One of the first module and the second communication module includes a host and a corresponding coupling antenna, as well as a driver and a receiver connecting the host and the corresponding coupling antenna; Another module in the first module and the second communication module includes a slave device and a corresponding coupled antenna, as well as a driver and a receiver connecting the slave device and the corresponding coupled antenna.

18. The lidar according to claim 17, characterized in that, When the host and the slave initiate a communication request simultaneously, the slave is used to suspend transmitting the communication request, and the host is used to initiate a communication request again within a first preset time period after the communication request. When the slave receives the communication request from the host within the first preset time period, communication with the host is established.

19. The lidar according to claim 18, characterized in that, The slave device is configured to initiate a communication request again after a second preset time period if it determines that it has not received a second communication request from the master device within the first preset time period.

20. A mobile system, characterized in that, include: Mobile devices, including driving control modules; The lidar as described in any one of claims 1 to 19 is fixed on the mobile device body and is used to detect the surrounding environment information of the mobile device to obtain a point cloud, and to send the point cloud to the driving control module. The driving control module is also used to control the driving path of the mobile device based on the point cloud sent by the lidar.

21. The mobile system according to claim 20, characterized in that, The mobile device is a wheelchair; The lidar includes a first lidar located at the left armrest of the wheelchair, a second lidar located at the right armrest of the wheelchair, and a third lidar located at the rear of the wheelchair. The first and second lidars each have a field of view that is an annular region along the horizontal direction, while the third lidar has a field of view that is an annular region with an angle of less than 90 degrees to the horizontal direction.

22. The mobile system according to claim 21, characterized in that, The mobile system also includes multiple time-of-flight (ToF) based area array ranging sensors located on the mobile device, distributed on both sides of the mobile device, with a field of view below the field of view of the first lidar and the second lidar, and covering at least a portion of the ground within 2 meters of the wheelchair.

23. The mobile system according to claim 20, characterized in that, The mobile device is a wheelchair that includes a left front wheel and a right front wheel; The lidar includes a fourth lidar and a fifth lidar located above the left front wheel and the right front wheel, respectively. The field of view of the fourth lidar and the fifth lidar are respectively annular areas along the horizontal direction; or, the field of view of the fourth lidar and the fifth lidar are respectively annular areas along the vertical direction.

24. The mobile system according to claim 23, characterized in that, The ratio of the distance from the ground at the light emission point of the lidar to the distance from the ground at the bottom of the lidar is between 1.11 and 1.

22.

25. The mobile system according to claim 21 or 23, characterized in that, The mobility system also includes multiple ToF-based area array ranging sensors located on the left and right sides of the wheelchair, and at least one ToF-based area array ranging sensor located at the rear of the wheelchair. The combined field of view of multiple ToF-based area array ranging sensors located on the left side of the wheelchair covers at least 90 degrees from the left side of the wheelchair to the front of the wheelchair. The combined field of view of multiple ToF-based area array ranging sensors located on the right side of the wheelchair covers at least 90 degrees from the right side of the wheelchair to the front of the wheelchair. The combined field of view of at least one ToF-based area array ranging sensor located at the rear of the wheelchair covers at least 60 degrees of the rear of the wheelchair.

26. The mobile system according to claim 25, characterized in that, Multiple ToF-based area array ranging sensors located on the left side of the wheelchair are positioned above the left front wheel of the wheelchair, on the left armrest of the wheelchair, or on the left side below the seat surface of the wheelchair. Multiple ToF-based area array ranging sensors located on the right side of the wheelchair are positioned above the right front wheel of the wheelchair, on the right armrest of the wheelchair, or on the right side below the seat surface of the wheelchair.

27. The mobile system according to claim 26, characterized in that, Among the multiple ToF-based area array ranging sensors located on the left side of the wheelchair, at least some sensors are set at different heights on the wheelchair, and / or, at least some sensors have different angles between their field of view centerline and the ground. Among the multiple ToF-based area array ranging sensors located on the right side of the wheelchair, at least some sensors are set at different heights on the wheelchair, and / or, at least some sensors have different angles between their field of view centerline and the ground.

28. The mobile system according to claim 27, characterized in that, Two layers of supports are respectively arranged above the left front wheel and the right front wheel of the wheelchair. Each layer of the support contains at least one ToF-based area array ranging sensor, and the angle between the center line of the field of view of the area array ranging sensor in the two layers of the support and the ground is different.

29. The mobile system according to claim 26, characterized in that, The wheelchair has a left support extending outward from the left edge of the left armrest and a right support extending outward from the right edge of the right armrest; or, the wheelchair has a left support extending outward from the left edge below the seat surface and a right support extending outward from the right edge below the seat surface. At least one ToF-based area array ranging sensor is located on the left support, and at least one ToF-based area array ranging sensor is located on the right support.

30. The mobile system according to claim 26, characterized in that, The plurality of ToF-based area array ranging sensors located on the left side of the wheelchair include two ToF-based area array ranging sensors that are respectively facing the front and the front and lower front of the wheelchair, and a ToF-based area array ranging sensor that is facing the left and / or the lower left of the wheelchair. The plurality of ToF-based area array ranging sensors located on the left side of the wheelchair include two ToF-based area array ranging sensors that are respectively facing the front and the lower front of the wheelchair, and a ToF-based area array ranging sensor that is facing the right and / or the lower right of the wheelchair.

31. The mobile system according to claim 26, characterized in that, Among the multiple ToF-based area array ranging sensors located on the left side of the wheelchair, the angle between the central axis of the field of view of some sensors and the ground is between 40° and 60°, and the angle between the central axis of the field of view of some sensors and the ground is between 50° and 70°. Among the multiple ToF-based area array ranging sensors located on the right side of the wheelchair, the angle between the central axis of the field of view of some sensors and the ground is between 40° and 60°, while the angle between the central axis of the field of view of some sensors and the ground is between 50° and 70°.

32. The mobile system according to claim 20, characterized in that, The mobile device also includes an interaction module; The driving control module is also used to determine the second field of view of each lidar based on the point cloud sent by each lidar. The second field of view is the field of view that is not blocked by the mobile device when the lidar is fixed on the mobile device for detection. The driving control module is also used to prompt the user, through the interaction module, that the LiDAR is dirty or obstructed, and / or the location of the LiDAR being dirty or obstructed, when the distance value of the point cloud within the second field of view of the LiDAR is continuously less than a preset value for a preset duration.

33. A laser detection method, characterized in that, include: Control at least two transceiver modules in the lidar to rotate around the rotation axis; The transmitting components in the at least two transceiver modules are controlled to emit laser beams in sequence. The at least two transceiver modules are arranged around the rotation axis, the field of view of the at least two detection modules is staggered in the direction perpendicular to the rotation axis, and the at least two annular field of view formed by the at least two transceiver modules during rotation can be spliced ​​into a continuous annular field of view. Receive the echo signal reflected by the object from the emitted laser beam; A point cloud is generated based on the echo signal.

34. The laser detection method according to claim 33, characterized in that, The step of generating a point cloud based on the echo signal includes: A ranging value is generated based on the received echo signal; The corrected distance value is obtained based on the measured distance value and the correction model; The point cloud is generated based on the corrected distance value.

35. The laser detection method according to claim 34, characterized in that, The method further includes: A reference ranging value is generated based on the echo within the first field of view; A theoretical distance value is obtained, which represents the distance between the laser radar and a portion of the surface of the mobile device. The laser radar is fixed on the mobile device, and the echo within the first field of view is formed by the reflection of the laser beam by a portion of the surface of the mobile device. The calibration model is adjusted based on the reference distance value and the theoretical distance value; The ranging value generated by the subsequent echo within the second field of view is corrected according to the adjusted correction model. The second field of view is the field of view of the lidar that is not blocked by the mobile device.

36. The laser detection method according to claim 34, characterized in that, The method further includes: When the distance value of the point cloud within the second field of view of the lidar is continuously less than a preset value for a preset duration, the user is prompted by the interaction module that the lidar is dirty or obstructed, and / or the location of the lidar being dirty or obstructed; wherein, the lidar is fixed on the mobile device, and the second field of view is the field of view of the lidar that is not obstructed by the mobile device.

37. The laser detection method according to claim 33, characterized in that, The transmitting component in at least part of the transceiver module includes at least two transmitting units for emitting at least two laser beams with different emission angles; The control of the transmitting components in the at least two transceiver modules to sequentially emit laser beams includes: Control at least the first transmitting unit of the at least two transceiver modules to continuously emit laser beams of different energies at least twice.

38. The laser detection method according to claim 37, characterized in that, The method further includes: The echo signal of the laser beam emitted sequentially by the first transmitting unit is received at least twice consecutively; At least two initial ranging values ​​are obtained based on the at least two received echo signals; A final ranging value corresponding to the at least two consecutive launches is obtained by weighted average of the at least two initial ranging values; or, one of the at least two initial ranging values ​​is selected as the final ranging value corresponding to the at least two consecutive measurements.

39. The laser detection method according to claim 38, characterized in that, The method further includes: When the difference between the at least two initial ranging values ​​is greater than a preset difference, filtering is performed based on the initial ranging values ​​or final ranging values ​​corresponding to the multiple adjacent transmitting units of the first transmitting unit to filter out at least one of the at least two initial ranging values. The filtered initial ranging value is not used to calculate the final ranging value.

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