WO2024061112A1

WO2024061112A1 - Laser radar scanning methods, devices, and storage mediums

Info

Publication number: WO2024061112A1
Application number: PCT/CN2023/118989
Authority: WO
Inventors: Qifeng Zhu; Dingxi LIU; Ziliang XU; Yongjun FANG; Zhiji DENG; Hui Wang
Original assignee: Zhejiang Dahua Technology Co., Ltd.
Priority date: 2022-09-23
Filing date: 2023-09-15
Publication date: 2024-03-28
Also published as: CN115236684B; CN115236684A

Abstract

Embodiments of the present disclosure provide a scanning method of a laser radar. The laser radar includes a galvanometer. The scanning method includes determining a scanning parameter in response to a scanning instruction. The scanning parameter includes a galvanometer drive waveform. The scanning method includes obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter. The forward scanning data includes scanning data obtained in an outbound interval of the galvanometer drive waveform, and the inverse scanning data includes scanning data obtained in a return interval of the galvanometer drive waveform. The scanning method further includes determining target scanning data based on the forward scanning data and the inverse scanning data.

Description

LASER RADAR SCANNING METHODS, DEVICES, AND STORAGE MEDIUMS

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of Chinese Patent Application No. 202211165737. X, filed on September 23, 2022, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to laser radar technology, and in particular, to laser radar scanning methods, devices, and storage mediums.

BACKGROUND

With the continuous development of laser radar technology, laser radar is now widely applied in various fields. In industrial scenarios, there is a higher and higher requirement for the angle resolution of the laser radar. The angle resolution refers to an angle step of two adjacent ranging points, including horizontal angle resolution and vertical angle resolution. However, limited by the performance of the laser itself, the scanning device, and the scanning distance, the angle resolution of the laser radar is still not high, and a point cloud density is relatively low. In order to increase the angle resolution of laser radar, there's a traditional technique which is to lower the voltage so that a scanning speed could be decreased, which leads to more scanning points in a single line and thereby improving the horizontal angle resolution. However, in this way, only the horizontal angle resolution is increased, but the elongation time is too long, resulting in a decrease in the number of scanning lines, and accordingly, a reduction in the vertical angle resolution.

Therefore, it is necessary to provide laser radar scanning methods, devices, and storage mediums for improving the angle resolution and the point cloud density of the laser radar.

SUMMARY

One of the embodiments of the present disclosure provides a scanning method of a laser radar. The scanning method includes determining a scanning parameter in response to a scanning instruction. The scanning parameter includes a galvanometer drive waveform. The scanning method includes obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter. The forward scanning data includes scanning data obtained in an outbound interval of the galvanometer drive waveform. The inverse scanning data includes scanning data obtained in a return interval of the galvanometer drive waveform. The scanning method further includes determining target scanning data based on the forward scanning data and the inverse scanning data.

One of the embodiments of the present disclosure provides a computer-readable storage medium storing computer instructions. When reading the computer instructions in the computer-readable storage medium, a computer implements the scanning method of the laser radar.

One of the embodiments of the present disclosure provides a scanning device of a laser radar. The scanning device includes a galvanometer, a transmitter, a receiver, and a controller. The galvanometer may include a fast axis and a slow axis. The fast axis is driven by a fast axis drive waveform. The slow axis is driven by a slow axis drive waveform. The transmitter is configured to transmit a laser. The receiver is configured to receive an echo laser. The controller is configured to determine target scanning data by controlling the transmitter to transmit the laser while controlling a rotation of the galvanometer. To determine the target scanning data, the controller is configured to perform operations. The operations include determining a scanning parameter in response to a scanning instruction. The scanning parameter includes a galvanometer drive waveform. The operations include obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter. The forward scanning data includes scanning data obtained in an outbound interval of the galvanometer drive waveform. The inverse scanning data includes scanning data obtained in a return interval of the galvanometer drive waveform. The operations further include determining the target scanning data based on the forward scanning data and the inverse scanning data.

The laser radar scanning method may be applied to scenarios such as robotics, self-driving cars, security surveillance, and industrial applications. When the laser radar scanning method is applied in the industrial scenarios (e.g., a foreign object detection in a guide path, etc. ) , there may be a higher demand for the angle resolution. However, due to the performance of the laser radar scanning device itself, and the limitations of the existing laser radar scanning device on the scanning distance (i.e., a linear distance from a transmitter to a detected object) , it may be difficult for the laser radar scanning device to achieve higher angle resolution on the existing basis.

In order to solve the problem of how to improve the angle resolution, after a forward scanning of the laser radar is completed, the time and path of a return process of a slow axis are used to perform an inverse scanning, and target scanning data may be obtained based on forward scanning data and inverse scanning data, which increases the data density of the target scanning data, thereby solving the problem of low angle resolution of the laser radar, and achieving the technical effect of improving the angle resolution of the laser radar.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. The drawings are not to scale. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein:

FIG. 1 is a schematic diagram illustrating an application scenario of a laser radar scanning system according to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram illustrating exemplary hardware and/or software components of an exemplary computing device according to some embodiments of the present disclosure;

FIG. 3 is a schematic diagram illustrating a laser radar scanning device according to some embodiments of the present disclosure;

FIG. 4 is a block diagram illustrating a structure of a laser radar scanning device according to some embodiments of the present disclosure;

FIG. 5 is a block diagram illustrating an exemplary processing device according to some embodiments of the present disclosure;

FIG. 6 is a flowchart illustrating an exemplary process for laser radar scanning according to some embodiments of the present disclosure;

FIG. 7 is a schematic diagram illustrating a waveform of a laser radar scanning method according to some embodiments of the present disclosure;

FIG. 8 is a flowchart illustrating an exemplary process for determining a scanning parameter according to some embodiments of the present disclosure;

FIG. 9 is a schematic diagram illustrating a waveform of a laser radar scanning method according to some other embodiments of the present disclosure;

FIG. 10 is a schematic diagram illustrating dotting of a laser radar scanning method according to some embodiments of the present disclosure;

FIG. 11 is a flowchart illustrating an exemplary process for determining a scanning parameter according to some embodiments of the present disclosure;

FIG. 12 is a schematic diagram illustrating dotting of a laser radar scanning method according to some other embodiments of the present disclosure;

FIG. 13 is a schematic diagram illustrating an exemplary process for determining a scanning parameter according to some other embodiments of the present disclosure;

FIG. 14 is a flowchart illustrating an exemplary process for laser radar scanning according to some embodiments of the present disclosure; and

FIG. 15 is a diagram illustrating an internal structure of a computer device according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant disclosure. However, it should be apparent to those skilled in the art that the present disclosure may be practiced without such details. In other instances, well-known methods, procedures, systems, components, and/or circuitry have been described at a relatively high level, without detail, in order to avoid unnecessarily obscuring aspects of the present disclosure. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the present disclosure is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the claims.

It will be understood that the terms “system, ” “engine, ” “unit, ” “module, ” and/or “block” used herein are one method to distinguish different components, elements, parts, sections, or assemblies of different levels in ascending order. However, the terms may be displaced by other expressions if they may achieve the same purpose.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a, ” “an, ” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise, ” “comprises, ” and/or “comprising, ” “include, ” “includes, ” and/or “including, ” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

These and other features, and characteristics of the present disclosure, as well as the methods of operation and functions of the related elements of structure and the combination of parts and economies of manufacture, may become more apparent upon consideration of the following description with reference to the accompanying drawings, all of which form a part of this disclosure. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended to limit the scope of the present disclosure. It is understood that the drawings are not to scale.

FIG. 1 is a schematic diagram illustrating an application scenario of a laser radar scanning system 100 according to some embodiments of the present disclosure. As shown in FIG. 1, the laser radar scanning system 100 may include a laser radar scanning device of the 110, a processing device 120, a storage device 130, a terminal 140, and a network 150.

The laser radar scanning device 110 may be a micro electromechanical system (MEMS) laser radar. The MEMS laser radar may integrate a mechanical structure of a laser radar onto a silicon-based chip through microelectronics technology. In essence, the MEMS laser radar may be a hybrid solid-state laser radar in which the mechanical structure is not canceled entirely. An optical path of the laser radar scanning device 110 may be a common optical path or a non-common optical path. The common optical path refers to that the optical path of the laser transmitted by a transmitting end and the optical path of the laser received by a receiving end is the same optical path. the non-common optical path refers to that the optical path of the laser transmitted by the transmitting end and the optical path of the laser received by the receiving end are different optical paths.

In some embodiments, the laser radar scanning device 110 includes a galvanometer 111, a transmitter 112, a receiver 113, and a controller 114. More descriptions of the laser radar scanning device 110 may be found elsewhere in the present disclosure (e.g., FIG. 3 and the descriptions thereof) .

The processing device 120 may be configured to process data related to laser radar scanning. For example, the processing device 120 may determine a scanning parameter in response to a scanning instruction, the scanning parameter including a galvanometer drive waveform. Further, the processing device 120 may obtain forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter, the forward scanning data including scanning data obtained in an outbound interval of the galvanometer drive waveform, the inverse scanning data including scanning data obtained in a return interval of the galvanometer drive waveform. The processing device 120 may obtain target scanning data based on the forward scanning data and the inverse scanning data.

In some embodiments, the processing device 120 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processing device 120 may be local or remote. In some embodiments, the processing device 120 may be implemented on a cloud platform. Merely by way of example, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-layer cloud, etc., or any combination thereof. In some embodiments, the processing device 120 may be integrated or mounted on the laser radar scanning device 110.

The storage device 130 may store data, instructions, and/or any other information. In some embodiments, the storage device may store the data and/or the instructions related to the laser radar scanning. For example, the storage device may store data obtained and generated during the laser radar scanning process, for example, the scanning parameter, the forward scanning data, the inverse scanning data, and the target scanning data. As another example, the storage device may store the instructions for processing the forward scanning data and the inverse scanning data to determine the target scanning data.

In some embodiments, the storage device 130 is connected to the network 150 to communicate with one or more other components (e.g., the laser radar scanning device 110, the processing device 120, the terminal 140, etc. ) of the laser radar scanning system 100. One or more components of the laser radar scanning system 100 may access the data or instructions stored in the storage device 130 through the network 150. In some embodiments, the storage device 130 is integrated on the processing device 120, or disposed on a cloud platform or other network servers.

The terminal 140 may include a mobile device 140-1, a tablet 140-2, a laptop 140-3, a personal computer, an Internet of Things (IoT) device, and a portable wearable device, or any combination thereof. The IoT device may be an intelligent speaker, an intelligent TV, an intelligent air conditioner, an intelligent car device, etc. The portable wearable device may be a smartwatch, a smart bracelet, a headset, etc. In some embodiments, the terminal 140 may be a portion of the processing device 120.

In some embodiments, the terminal 140 sends and/or receives information related to the laser radar scanning to and/or from the processing device 120 through a user interface. In some embodiments, the user interface is an application program for implementing the laser radar scanning on the terminal 140. The user interface may be configured to facilitate communication between the terminal 140 and a user related to the terminal 140. In some embodiments, the terminal 140 receives, through the user interface (e.g., a user interface screen) , a request from the user for performing the laser radar scanning. The terminal 140 may send the request for performing the laser radar scanning to the processing device 120 through the network 150 to obtain the target scanning data.

The network 150 may include any suitable network that may facilitate an exchange of the information and/or data of the laser radar scanning system 100. In some embodiments, one or more components of the laser radar scanning device 110, the processing device 120, the storage device 130, the terminal 140, etc. may transmit the information and/or data with one or more other components of the laser radar scanning system 100 through the network 150.

FIG. 2 is a schematic diagram illustrating exemplary hardware and/or software components of an exemplary computing device according to some embodiments of the present disclosure. In some embodiments, the processing device 120 and/or the terminal device 140 may be implemented on a computing device 200. As illustrated in FIG. 2, the computing device 200 may include a processor 210, a storage 220, an input/output (I/O) 230, and a communication port 240.

The processor 210 may execute computer instructions (e.g., a program code) and perform functions of the processing device 120 in accordance with techniques describable herein. The computer instructions may include, for example, routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions describable herein.

In some embodiments, the processor 210 may include one or more hardware processors, such as a microcontroller, a microprocessor, a reduced instruction set computer (RISC) , an application specific integrated circuits (ASICs) , an application-specific instruction-set processor (ASIP) , a central processing unit (CPU) , a graphics processing unit (GPU) , a physics processing unit (PPU) , a microcontroller unit, a digital signal processor (DSP) , a field programmable gate array (FPGA) , an advanced RISC machine (ARM) , a programmable logic device (PLD) , any circuit or processor capable of executing one or more functions, etc., or any combinations thereof.

Merely for illustration, only one processor is describable in the computing device 200. However, it should be noted that the computing device 200 in the present disclosure may also include a plurality of processors, thus operations and/or method operations that are performed by one processor as describable in the present disclosure may also be jointly or separately performed by the plurality of processors. For example, if in the present disclosure the processor of the computing device 200 executes both operation A and operation B, it should be understood that operation A and operation B may also be performed by two or more different processors jointly or separately in the computing device 200 (e.g., a first processor executes operation A and a second processor executes operation B, or the first and second processors jointly execute operations A and B) .

The storage 220 may store data obtained from one or more components of the laser radar scanning system 100. In some embodiments, the storage 220 may include a mass storage device, a removable storage device, a volatile read-and-write memory, a read-only memory (ROM) , or the like, or any combination thereof. In some embodiments, the storage 220 may store one or more programs and/or instructions to perform exemplary methods described in the present disclosure. For example, the storage 220 may store the program for the processing device 120 to execute to perform laser radar scanning.

The I/O 230 may input and/or output signals, data, information, etc. In some embodiments, the I/O 230 may enable user interaction with the processing device 120. In some embodiments, the I/O 230 may include an input device and an output device. The input device may include a keyboard, a touch screen, a speech input, an eye-tracking input, a brain monitoring system, or any other comparable input mechanism. The input information received through the input device may be transmitted to another component (e.g., the processing device 120) through, for example, a bus, for further processing. Other types of the input devices may include a cursor control device, such as a mouse, a trackball, or cursor direction keys, etc. The output device may include a display (e.g., a liquid crystal display (LCD) , a light-transmitting diode (LED) -based display, a flat panel display, a curved screen, a television device, a cathode ray tube (CRT) , a touch screen) , a speaker, a printer, etc., or a combination thereof.

The communication port 240 may be connected to a network (e.g., the network 150) to facilitate data communications. The communication port 240 may establish a connection between the processing device 120 and the terminal device 140. The connection may be a wired connection, a wireless connection, or any other communication connection that can enable data transmitting and/or reception, and/or any combination of these connections. The wired connection may include, for example, an electrical cable, an optical cable, a telephone wire, etc., or any combination thereof. The wireless connection may include, for example, a Bluetooth^TM link, a Wi-Fi^TM link, a WiMax^TM link, a WLAN link, a ZigBee^TM link, a mobile network link (e.g., 3G, 4G, 5G) , etc., or a combination thereof. In some embodiments, the communication port 240 may be and/or include a standardized communication port, such as RS232, RS485, etc. In some embodiments, the communication port 240 may be a specially designed communication port.

FIG. 3 is a schematic diagram illustrating a laser radar scanning device according to some embodiments of the present disclosure. In some embodiments, the laser radar scanning device 110 may include a galvanometer 111, a transmitter 112, a receiver 113, and a controller 114.

The galvanometer 111 may be a MEMS galvanometer. The MEMS galvanometer belongs to a kind of optical MEMS actuator chip, which can be used for deflecting, modulating, turning on and off, and controlling a phase of a laser beam under a driving action.

In some embodiments, as shown in FIG. 3, the galvanometer 111 is a dual axis MEMS galvanometer including a reflector and a MEMS driver. The reflector may be driven in two axes (i.e., a fast axis f_x and a slow axis f_y) through the MEMS driver. The fast axis f_x may be driven by a fast axis drive waveform, and the slow axis f_y may be driven by a slow axis drive waveform, and a resonance frequency of the fast axis may be much greater than a resonance frequency of the slow axis.

The transmitter 112 may be configured to transmit a laser. In some embodiments, the transmitter 112 includes an optical shaping lens and a laser diode. The laser diode may convert electrical energy into a laser beam, and the optical shaping lens may transmit the laser.

The receiver 113 may be configured to receive an echo laser. The echo laser refers to a laser that is transmitted by the transmitter 112 and reflected by an object. In some embodiments, the receiver 113 may include a receiving optical lens, a receiving photodiode, and a MEMS optical filter. The receiving photodiode may receive the laser beam and convert the laser beam into an electrical signal, and then send the electrical signal to the controller 114 for processing. The MEMS optical filter may be configured to filter out uninteresting signals, thereby improving the quality of the received signal.

The controller 114 may be configured to control the transmitter 112 to transmit the laser while controlling a rotation of the galvanometer 111, so as to determine target scanning data. A process for determining the target data may include determining a scanning parameter in response to a scanning instruction. The scanning parameter includes a galvanometer drive waveform. The process for determining the target data may include obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter. The forward scanning data includes scanning data obtained in an outbound interval of the galvanometer drive waveform, and the inverse scanning data includes scanning data obtained in a return interval of the galvanometer drive waveform. The process for determining the target data may further include determining the target scanning data based on the forward scanning data and the inverse scanning data.

The controller 114 may be a portion of the processing device 120, or a component independent from the processing device 120.

It may be understood that under control of a fast axis drive signal and a slow axis drive signal, the galvanometer 111 may cause the laser transmitted by the transmitter 112 to dot within a scanning region according to a path formed by the fast axis drive waveform and the slow axis drive waveform. The receiver 113 may receive the reflected echo laser, and the controller 114 may record point cloud data obtained by the dotting on the path that is under parallel control of the fast axis drive signal and the slow axis drive signal. Thus, dotting positions of the point cloud data are limited by the path that is under the parallel control of the fast axis drive signal and the slow axis drive signal. The scanning region refers to a region formed by a scanning trajectory of the galvanometer 111. For example, as shown in FIG. 3, the scanning region is a region ABCD.

As shown in FIG. 3, the controller 114 may control the fast axis f_x and the slow axis f_y of the galvanometer 111 to vibrate. In the vibration process of the fast axis f_x and the slow axis f_y, the controller 114 may control the transmitter 112 to transmit laser (which is referred to as the dotting) . The vibration of the galvanometer 111 may change a transmitting angle of the laser, thereby obtaining the scanning region ABCD. Through the vibration of the slow axis f_y, an angle between the galvanometer 111 and a vertical direction may be varied from -α° to α°, and the dotting in a L_y direction may be implemented. α° may be the maximum angle that can be reached between the galvanometer 111 and the vertical direction. By the vibration of the fast axis f_x, an angle between the galvanometer 111 and a horizontal direction may be varied from -β° to β°, and the dotting in an Lx direction may be implemented. β° may be the maximum angle that can be reached between the galvanometer 111 and the horizontal direction. A first process of the angle between the galvanometer 111 and the vertical direction changing from -α° to α° may correspond to a plurality of second processes in each of which the angle between the galvanometer 111 and the horizontal direction changes from -β° to β°, and then from β° to -β°. That is, in the first process of the angle between the galvanometer 111 and the vertical direction changing from -α° to α°, the angle between the galvanometer 111 and the horizontal direction changes from -β° to β° to implement a first row dotting from left to right, then the angle between the galvanometer 111 and the horizontal direction changes from β° to -β° to implement a second row dotting from right to left, then the angle between the galvanometer 111 and the horizontal direction changes from -β° to β° to implement a third row dotting from left to right, then the angle between the galvanometer 111 and the horizontal direction changes from β° to -β° to implement a fourth row dotting from right to left, . . . . . ., then the angle between the galvanometer 111 and the horizontal direction changes from -β° to β°to implement a nineth row dotting from left to right, and then the angle between the galvanometer 111 and the horizontal direction changes from β° to -β° to implement a tenth row dotting from right to left. It is to be noted that, in the second process of the angle between the galvanometer 111 and the horizontal direction changes from -β° to β°, or from β° to -β°, the angle between the galvanometer 111 and the vertical direction changes slightly, therefore each row of the dotting is not a horizontal straight line. For ease of illustration, each row of the dotting is approximated as a horizontal straight line.

In the process of controlling the vibrations of the fast axis f_x and the slow axis f_y, the controller 114 may control the transmitter 112 to transmit the laser and control the receiver 113 to receive the echo laser. Further, the controller 114 may obtain, by a time of flight (TOF) method, a z-coordinate of a straight-line distance from the transmitter 112 to the object to be detected. Then the z-coordinate of the straight-line distance may be combined with two-dimensional (2D) spatial coordinates (x, y) of the scanning trajectory of the galvanometer111 to obtain three-dimensional (3D) coordinates (x, y, z) of the object in the scanning region.

FIG. 4 is a block diagram illustrating a structure of a laser radar scanning device according to some embodiments of the present disclosure.

In some embodiments of the present disclosure, a laser radar scanning method may be applied in the laser radar scanning device as shown in FIG. 4. A transmitting module may be configured to transmit a laser based on a laser transmitting instruction. A receiving module may be configured to receive an echo laser reflected in a scanning region and send the echo laser to a data processing module. The data processing module may be configured to receive a scanning instruction and process the scanning instruction to determine a scanning parameter. The scanning parameter may include a galvanometer drive waveform. The data processing module may be further configured to send the laser transmitting instruction to the transmitting module. The data processing module may be configured to send the scanning parameter to the MEMS control module. The MEMS control module may be configured to send a drive signal to vibrate a MEMS galvanometer based on the galvanometer drive waveform, and the MEMS galvanometer may reflect the laser from the transmitter module into the scanning region. When the receiving module receives the echo laser, the data processing module may calculate dots and rangings corresponding to various points based on the laser transmitting instruction and the echo laser to generate forward scanning data and inverse scanning data, and generate target scanning data based on the forward scanning data and the inverse scanning data. It should be noted that the MEMS galvanometer may correspond to the galvanometer 111, the transmitting module may be integrated into the transmitter 112, the receiving module may be integrated into the receiver 113, and the data processing module and the MEMS control module may be integrated into the controller 114.

FIG. 5 is a block diagram illustrating an exemplary processing device according to some embodiments of the present disclosure. In some embodiments, the processing device 120 may include a determination module 510, a scanning module 520, and a processing module 530.

The determination module 510 may be configured to determine a scanning parameter in response to a scanning instruction, The scanning parameter includes a galvanometer drive waveform.

In some embodiments, the determination module 510 may be further configured to adjust a phase of a fast axis drive waveform within a return interval of a slow axis to stagger the phase from a phase of the fast axis drive waveform within an outbound interval of the slow axis. In some embodiments, the determination module 510 may be further configured to determine a target phase difference based on the fast axis drive waveform within the outbound interval and a return interval of the slow axis, and adjust the phase of the fast axis drive waveform within the return interval of the slow axis based on the phase of the fast axis drive waveform within the outbound interval of the slow axis and the target phase difference.

In some embodiments, the determination module 510 may be further configured to advance or delay a laser transmitting time within a return interval of the slow axis, so that a position of a horizontal dotting within the return interval of the slow axis is staggered from a position of the horizontal dotting within an outbound interval of the slow axis. In some embodiments, the determination module 510 may be further configured to determine a target transmitting time difference based on the fast axis drive waveform within the outbound interval of the slow axis and advance or delay the laser transmitting time within the return interval of the slow axis based on a laser transmitting time within the outbound interval of the slow axis and the target transmitting time difference.

In some embodiments, the determination module 510 may be further configured to adjust a return interval length and an outbound interval length of the slow axis drive waveform. In some embodiments, the determination module 510 may be further configured to dynamically adjust, based on a target frame, the return interval length, and the outbound interval length of the slow axis drive waveform.

The scanning module 520 may be configured to obtain forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter. The forward scanning data includes scanning data obtained in an outbound interval of the galvanometer drive waveform, and the inverse scanning data includes scanning data obtained in a return interval of the galvanometer drive waveform.

In some embodiments, the galvanometer drive waveform includes a slow axis drive waveform and a fast axis drive waveform, and the slow axis drive waveform includes an outbound interval waveform and a return interval waveform. In some embodiments, the forward scanning includes transmitting, by a transmitter, a laser, and driving, by the scanning module 520, a slow axis of the galvanometer based on the forward interval waveform of the slow axis drive waveform, while driving a fast axis of the galvanometer based on the fast axis drive waveform. In some embodiments, the inverse scanning includes transmitting, by the transmitter, a laser, and driving, by the scanning module 520, the slow axis based on the return interval waveform of the slow axis drive waveform, while driving the fast axis based on the fast axis drive waveform.

In some embodiments, the inverse scanning data includes scanning data obtained during a partial time period of the return interval of the galvanometer drive waveform. In some embodiments, the galvanometer drive waveform includes a slow axis drive waveform and a fast axis drive waveform, and the slow axis drive waveform includes the outbound interval waveform and the return interval waveform. In some embodiments, the forward scanning includes transmitting, by the transmitter, a laser, and driving, by the scanning module 520, the slow axis of the galvanometer based on the forward interval waveform of the slow axis drive waveform, while driving the fast axis of the galvanometer based on the fast axis drive waveform. In some embodiments, the inverse scanning includes driving, by the scanning module 520, the slow axis based on the return interval waveform of the slow axis drive waveform, while driving the fast axis based on the fast axis drive waveform, and transmitting, by the transmitter, the laser during a partial time period of the return interval of the slow axis drive waveform.

The processing module 530 may be configured to determine target scanning data based on the forward scanning data and the inverse scanning data.

More descriptions of the determination module 510, the scanning module 520, and the processing module 530 may be found elsewhere in the present disclosure (e.g., FIGs. 6-14 and the descriptions thereof) .

It should be noted that the above descriptions of the processing device 120 are provided for the purposes of illustration, and are not intended to limit the scope of the present disclosure. For those skilled in the art, various modifications and changes in the forms and details of the application of the above method and system may occur without departing from the principles of the present disclosure. In some embodiments, the processing device 120 may include one or more other modules and/or one or more modules described above may be omitted. Additionally or alternatively, two or more modules may be integrated into a single module and/or a module may be divided into two or more units. However, these modifications and changes also fall within the scope of the present disclosure.

FIG. 6 is a flowchart illustrating an exemplary process for laser radar scanning according to some embodiments of the present disclosure. In some embodiments, a process 600 may be executed by the laser radar scanning system 100. For example, the process 600 may be implemented as a set of instructions stored in a storage device. In some embodiments, the processing device 120 (e.g., the processor 210 of the computing device 200 and/or one or more modules illustrated in FIG. 5) may execute the set of instructions and may accordingly be directed to perform the process 600. The operations of the illustrated process presented below are intended to be illustrative. In some embodiments, the process 600 may be accomplished with one or more additional operations not described and/or without one or more of the operations discussed. Additionally, the order of the operations of process 600 illustrated in FIG. 6 and described below is not intended to be limiting.

In 610, in response to a scanning instruction, a scanning parameter may be determined. The operation 610 may be performed by the determination module 510.

The scan instruction refers to a user-initiated scan request. In some embodiments, the scanning instruction may include the scanning parameter set by the user.

The scanning parameter refers to a parameter that is used in a scanning process of a laser radar. In some embodiments, the scanning parameter may include a galvanometer drive waveform.

The galvanometer drive waveform refers to a waveform of a galvanometer drive signal. For example, the galvanometer drive waveform includes one or more of a sine wave, a triangle wave, a sawtooth wave, and a square wave.

In some embodiments, the galvanometer drive waveform includes a slow axis drive waveform and a fast axis drive waveform. The fast axis drive waveform may be configured to drive a fast axis, and the slow axis drive waveform may be configured to drive a slow axis. The fast axis drive waveform and the slow axis drive waveform may be different drive waveforms, and the fast axis or the slow axis may have different drive waveforms under the same scan period. In some embodiments, the slow axis drive waveform may include an outbound interval waveform and a return interval waveform.

As shown in FIG. 7, taking an electromagnetic galvanometer drive as an example, the fast axis may be driven by the sine wave, and one sine wave period may correspond to two horizontal rows of the scanning. As shown in FIG. 3, one sine wave period may correspond to the dotting of a first row from left to right, and the dotting of a second row from right to left. The slow axis may be driven by the triangle wave, and one triangle wave period may correspond to scanning one frame. As shown in FIG. 3, when the dotting is not performed in the return interval waveform, one triangle wave period may correspond to the scanning from the first row to the tenth row; when the dotting is performed in the return interval waveform, one triangle wave period may correspond to the scanning from the first row to the tenth row and from the tenth row to the first row. As shown in FIG. 7, a time of one triangle wave period of the slow axis may be T, a time of the outbound interval waveform may be T_a, a time of the return interval waveform may be T_b, and T = T_a + T_b.

Generally, in conventional laser radar scanning, a laser dotting may be performed in the outbound interval waveform, and the laser dotting may not be performed in the return interval waveform, that is, the fast axis drive waveform may be a sine wave superimposed on the outbound interval waveform of the slow axis drive waveform. The following describes a maximum horizontal dotting number and a maximum vertical row number.

First, the maximum horizontal dotting number is illustrated as follows.

Since the fast axis is driven by the sine wave, and one sine wave period corresponds to two horizontal rows of the scanning, in order to achieve a uniform dotting, a horizontal dotting number and an angle speed between two dots may satisfy formula (1) below:

where θ refers to the angle speed between the two dots, and N refers to the horizontal dotting number.

A rotation time t between the two dots and the sine wave period Tf may satisfy formula (2) below:

where t refers to the rotation time between the two dots, θ refers to the angle speed between the two dots, and Tf refers to the sine wave period.

The sine wave period and a sine wave frequency may satisfy formula (3) below:

where Tf refers to the sine wave period and f refers to the sine wave frequency.

Formula (4) may be obtained by substituting formulas (1) and (3) into formula (2) ,

where t refers to the rotation time between the two dots, N refers to the horizontal dotting number, and f refers to the sine wave frequency.

When a ranging is determined, the minimum rotation time between the two dots may be obtained, and a resonance frequency (i.e., the sine wave frequency f) may be determined by the material and production process of the galvanometer, which cannot be changed arbitrarily, so that the maximum horizontal dotting number N_max may be calculated through formula (4) . For example, in order to avoid interference, it may be necessary to ensure that a current echo laser has been received by a receiver when the transmitter emits the laser next time. Assuming that the ranging is 200m, the sine wave frequency f is 1.2K, and the laser goes back and forth once, the distance traveled is 400m. Since the speed of light is 3×10⁸m/s, and the minimum rotation time between the two dots isthe maximum horizontal dotting number N_max may be calculated as 199 dots.

It can be seen from formula (4) that the horizontal dotting number is related to the sine wave frequency of the galvanometer and the ranging. Since the resonant frequency (i.e., the sine wave frequency f) is determined by the material and production process of the galvanometer, which cannot be changed arbitrarily, the horizontal dotting number N is only negatively correlated with the ranging, that is the smaller the ranging, the greater the horizontal dotting number N.

Next, the maximum vertical row number is illustrated as follows.

Since one sine wave period corresponds to two horizontal rows of the scanning, and in the conventional laser radar scanning, the laser dotting is performed in the outbound interval waveform, and the laser dotting is not performed in the return interval waveform (i.e., the laser dotting is only performed in ae phase T₁, and not in a phase T₂) , the vertical row number L may be obtained through formular (5) below:

where L refers to the vertical row number, Tf refers to the sine wave period, T₁ refers to the time of the return interval waveform, and f refers to the sine wave frequency.

It can be seen from the formula (5) that the vertical row number L is related to the time of the outbound interval waveform T₁ and the sine wave frequency f. Since the resonance frequency (i.e., the sine wave frequency f) is determined by the material and production process of the galvanometer, which cannot be changed arbitrarily, the vertical row number L is only positively correlated with the time of the outbound interval waveform. That is, the maximum vertical row number T₁ may be calculated when the time of the outbound interval waveform reaches the maximum value L_max.

From the above descriptions of the maximum horizontal dotting number and the maximum vertical row number, it may be seen that, in the case of a certain sine wave frequency f, the smaller the ranging, the greater the horizontal dotting number, the greater T₁, and the greater the vertical row number. However, T₁ cannot be expanded indefinitely, and the ranging can't always be kept at a smaller value. When the horizontal dotting number and the vertical row number have reached the maximum value, it is necessary to increase the horizontal dotting number and the vertical row number in other ways to increase an angle resolution.

In some embodiments, the processing device 120 may control the transmitter to perform the laser dotting in the outbound interval waveform and the return interval waveform to improve the angle resolution.

In some embodiments, the processing device 120 may adjust a phase of the fast axis drive waveform within the return interval of the slow axis to stagger the phase from a phase of the fast axis drive waveform within the outbound interval of the slow axis, thereby increasing the vertical angle resolution. More descriptions of the adjusting of the phase of the fast axis drive waveform within the return interval of the slow axis may be found elsewhere in the present disclosure (e.g., FIGs. 8-10 and the descriptions thereof) .

In some embodiments, the processing device 120 may advance or delay a transmitting time within the return interval of the slow axis, so that a position of the horizontal dotting within the return interval of the slow axis is staggered from the position of the horizontal dotting within the outbound interval of the slow axis, thereby increasing the horizontal angle resolution. More descriptions of the advancing or delaying of the laser transmitting time within the return interval of the slow axis may be found elsewhere in the present disclosure (e.g., FIG. 11-FIG. 12 and the descriptions thereof) .

In some embodiments, the processing device 120 may adjust a return interval length and an outbound interval length of the slow axis drive waveform, thereby increasing the angle resolution of a target frame. More descriptions of the adjusting of the return interval length and the outbound interval length of the slow axis drive waveform may be found elsewhere in the present disclosure (e.g., FIG. 13 and the descriptions thereof) .

In 620, forward scanning data and inverse scanning data may be obtained by performing a forward scanning and an inverse scanning based on the scanning parameter. The operation 620 may be performed by the scanning module 520.

The forward scanning refers to the scanning of the outbound interval of the galvanometer drive waveform. For example, as shown in FIG. 7, the forward scanning may include the scanning of a time Ta phase corresponding to the outbound interval waveform of the slow axis drive waveform, that is, a scanning process in which the angle between the galvanometer and the vertical direction changes from -α° to α°.

The inverse scanning refers to the scanning of the return interval of the galvanometer drive waveform. For example, as shown in FIG. 7, the inverse scan may include the scanning of a time Tb phase corresponding to the return interval waveform of the slow axis drive waveform, that is, a scanning process in which the angle between the galvanometer and the vertical direction changes from α° to -α°.

A scanning period may include periods corresponding to the galvanometer drive waveforms of the fast axis and slow axis. The forward scanning and the inverse scanning may be the outbound interval and the return interval in the period corresponding to the slow axis drive waveform. The forward scanning may be a scanning process, in the period corresponding to the slow axis drive waveform, of running from a first position of the slow axis to a second position of the slow axis (i.e., a scanning process in which the angle between the galvanometer and the vertical direction changes from -α° to α°) . The inverse scanning may be a scanning process, in the period corresponding to the slow axis drive waveform, of running from the second position of the slow axis to the first position of the slow axis (i.e., a scanning process in which the angle between the galvanometer and the vertical direction changes from α° to -α°) . The forward scanning period and the inverse scanning period may respectively be periods of the drive waveforms of the slow axis and the fast axis during the forward scanning and the inverse scanning.

The forward scanning period may include periods of the fast axis drive waveform and the slow axis drive waveform during the forward scanning process. The inverse scanning period may include periods of the fast axis drive waveform and the slow axis drive waveform during the inverse scanning process. The galvanometer drive waveform may be the drive waveforms of the fast axis and the slow axis during the scanning. In general, the forward scanning period and the corresponding drive waveform may be obtained based on a priori knowledge, which is related to a performance parameter of the laser radar and a scanning demand.

The forward scanning data may include scanning data obtained during the outbound interval of the galvanometer drive waveform. The inverse scanning data may include scanning data obtained during the return interval of the galvanometer drive waveform.

In some embodiments, the processing device 120 may perform the forward scanning and the inverse scanning based on the scanning period and the galvanometer drive waveform. During the scanning process, the fast axis drive waveform and the slow axis drive waveform may drive the fast axis and the slow axis, respectively. The laser may be transmitted from the transmitter and reflected by the galvanometer and transmitted into a scanning region. The receiver may receive the echo laser of the scanning region and generate the forward scanning data and the inverse scanning data based on the echo laser.

As shown in FIG. 7, for example, the slow axis drive waveform is a triangle wave and the fast axis drive waveform is a sine wave, the embodiment may include one to more scanning periods, one scanning period T of the slow axis may include a forward scanning period Ta (i.e., the outbound interval) and an inverse scanning period Tb (i.e., the return interval) . The fast axis drive waveform may be superimposed on the slow axis drive waveform. The fast axis drive waveform and the slow axis drive waveform may respectively drive the fast axis and the slow axis, so as to realize the forward scanning and the reverse scanning based on the scanning parameter, thereby obtaining the forward scanning data and the reverse scanning data.

In 630, target scanning data may be determined based on the forward scanning data and the inverse scanning data. Operation 630 may be performed by the processing module 530.

The target scanning data refers to scanning data reflecting a state of an object in the scanning region. For example, the target scanning data may be 3D point cloud data.

In some embodiments, the processing device 120 may merge the forward scanning data and the inverse scanning data to generate the target scanning data. That is, the processing device 120 may obtain a z-coordinate of a straight-line distance from the transmitter to the detected object by a time of flight (TOF) method. The z-coordinate may be fused with 2D spatial coordinates (x, y) of a scanning trajectory of a MEMS galvanometer to obtain 3D coordinates (x, y, z) of the detected object in the scanning region. The 2D spatial coordinates (x, y) may be obtained by merging the forward scanning data and the inverse scanning data.

In some embodiments of the present disclosure, after the forward scanning of the laser radar is completed, the time and path of the return process of the slow axis are used to perform the inverse scanning, and target scanning data may be obtained based on forward scanning data and inverse scanning data, which increases the data density of the target scanning data, thereby solving the problem of low angle resolution of the laser radar, and achieving the technical effect of improving the angle resolution of the laser radar.

It should be noted that the above descriptions of the process 600 are merely provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. For those skilled in the art, multiple variations or modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure.

In some embodiments, the inverse scanning data includes scanning data obtained during a partial time period of the return interval of the galvanometer drive waveform. That is, the forward scanning may include transmitting, by the transmitter, the laser, and driving the slow axis of the galvanometer based on the return interval of the slow axis drive waveform, while driving the fast axis of the galvanometer based on the fast axis drive waveform, and the inverse scanning may include driving the slow axis based on the return interval waveform of the slow axis drive waveform, while driving the fast axis based on the fast axis drive waveform, and transmitting, by the transmitter, the laser in the partial time portion of the return interval of the slow axis drive waveform.

After the forward scanning of the laser radar is completed, the processing device 120 may transmit the laser through the transmitter during the partial time period of the return interval of the slow axis drive waveform, perform the inverse scanning utilizing the partial time period and path of the return process of the slow axis, and obtain the target scanning data based on the forward scanning data and the inverse scanning data, which improves the data density of the scanning data in the partial time period, thereby achieving the technical effect of improving the angle resolution of the laser radar in a region of interest. The region of interest refers to a region where the angle resolution needs to be improved. For example, when the laser radar scan is applied to a scene of a self-driving car, the region of interest is a region right ahead of the car (e.g., assuming that α is 25°, the region of interest may be the angle between the galvanometer and the vertical direction from -10° to 10°) , so that the laser may be transmitted by the transmitter during a partial time period of the return interval corresponding to the region of interest right ahead of the car to obtain the scanning data.

In some embodiments, while transmitting the laser through the transmitter during the partial time period of the return interval of the slow axis-driven waveform, the processing device 120 may further improve the angle resolution of the laser radar in the region of interest by adjusting the phase of the fast axis drive waveform within the return interval of the slow axis, and/or advancing or delaying a laser transmitting time within the return interval of the slow axis. For example, the processing device 120 may determine whether to reach the region of interest based on angle information fed back from the galvanometer, so that the processing device 120 may, in the region of interest, adjust the phase of the fast axis drive waveform within the return interval of the slow axis, and/or advance or delay the laser transmitting time within the return interval of the slow axis.

In some embodiments, while adjusting the return interval length of the slow axis-driven waveform and the outbound interval length to increase the resolution of the target frame, the processing device 120 may transmit, by the transmitter, during the partial time period of the return interval of the slow axis-driven waveform of the frame, the laser to increase the angle resolution of the laser radar in the region of interest of the target frame.

In some embodiments, when the inverse scanning data includes the scanning data obtained during the entire time period of the return interval of the galvanometer drive waveform, the processing device 120 may, in the outbound interval and the return interval of the slow axis, increase a scanning duration of time period corresponding to the region of interest and shorten a scanning duration of time periods corresponding to the other regions. For example, in the outbound interval T of the slow axis, t1 and t4 are respectively the start point and end point of the outbound interval, and t2 to t3 involve the region of interest, and accordingly, the scanning duration corresponding to t2 to t3 may be lengthened, and the scanning durations corresponding to t1 to t2 and t3 to t4 may be shortened proportionally, so as to achieve the technical effect of increasing the point cloud data density of the target scanning region and increasing the angle resolution at a physically specific region.

FIG. 8 is a flowchart illustrating an exemplary process for determining a scanning parameter according to some embodiments of the present disclosure. In some embodiments, a process 800 may be executed by the laser radar scanning system 100. For example, the process 800 may be implemented as a set of instructions stored in a storage device. In some embodiments, the processing device 120 (e.g., the processor 210 of the computing device 200 and/or one or more modules illustrated in FIG. 5) may execute the set of instructions and may accordingly be directed to perform the process 800. The operations of the illustrated process presented below are intended to be illustrative. In some embodiments, the process 800 may be accomplished with one or more additional operations not described and/or without one or more of the operations discussed. Additionally, the order of the operations of process 800 illustrated in FIG. 8 and described below is not intended to be limiting.

In 810, a target phase difference may be determined based on a fast axis drive waveform within an outbound interval and a return interval of a slow axis. Operation 810 may be performed by the determination module 510.

A phase refers to a position of a fast axis drive wave or a slow axis drive wave at a particular moment.

The target phase difference refers to a difference between the phases of the fast axis drive waveform under forward scanning and inverse scanning. The target phase difference may be used for phase adjustment of the fast axis drive waveform.

In some embodiments, the processing device 120 may preset the target phase difference based on a performance parameter of the laser radar and a scanned object, or determine the target phase difference based on a user demand according to the fast axis drive waveform within the outbound interval and the return interval of the slow axis.

It may be understood that directions of the fast axis drive waveform under the outbound interval and the return interval are opposite, and dotting positions in a direction of the fast axis may be correlated with the period of the slow axis drive waveform. Therefore, according to different durations of the slow axis drive waveform in the outbound interval and the return interval, the positions of the fast axis drive waveform at the end of the outbound interval may also be different.

In some embodiments, when the outbound interval ends and one waveform period of the fast axis drive waveform ends, the processing device 120 may determine the dotting situation during the forward scanning process based on the fast axis drive waveform in the outbound interval and further determine an expected dotting situation (i.e., dotting in a staggered way) in the scanning process of the return interval based on the dotting situation, so as to determine a target phase value.

In some embodiments, when the outbound interval ends and one waveform period of the fast axis drive waveform does not end, the processing device 120 may determine the position of the fast axis drive waveform at an end moment of the outbound interval and calculate the target phase difference based on the fast axis drive waveform within the outbound interval, the position of the fast axis drive waveform at the end moment of the outbound interval, and the target phase value.

The target phase value refers to a phase value of the fast axis drive waveform in the return interval when the fast axis drive waveform is ideally staggered in the outbound interval and the return interval. That is, the target phase value may be related to a staggered state of the dotting. The target phase value may be preset, or obtained by determining an optimal stagger state according to a waveform type of the fast axis drive waveform and the scanning period.

In some embodiments of the present disclosure, the target phase difference is determined based on the fast axis drive waveform within the outbound interval and the return interval of the slow axis, which improves the stability of the fast axis drive waveform stagger in the outbound interval and the return interval, so as to achieve the technical effect of improving the point cloud data density.

In 820, the phase of the fast axis drive waveform within the return interval of the slow axis may be adjusted based on the phase of the fast axis drive waveform within the outbound interval of the slow axis and the target phase difference. Operation 820 may be performed by the determination module 510.

In some embodiments, the processing device 120 moves the target phase difference based on the fast axis drive waveform within the outbound interval to obtain the fast axis drive waveform within the return interval. After the fast axis drive waveform within the return interval of the slow axis is adjusted based on the target phase difference, the fast axis drive waveform in the return interval of the slow axis may be staggered from the fast axis drive waveform in the outbound interval of the slow axis, so as to obtain denser point cloud data in the scanning region.

For example, as shown in FIG. 9, under a slow axis drive signal, a fast axis drive signal is superimposed on the slow axis drive signal for scanning. The processing device 120 may determine the fast axis drive waveforms (i.e., the fast axis drive signal during the return process as shown by the dotted line) in the return interval based on the fast axis drive waveform (i.e., the fast axis drive signal during the outbound process as shown by the solid line) within the outbound interval and the target phase difference, so as to achieve an effect of staggering the fast axis drive signal within the outbound interval and the return interval.

Assuming that a duty ratio (i.e., a time ratio between the outbound interval and the return interval) of the outbound interval and the return interval is 50%, the processing device 120 may determine that the target phase difference is 1/4π, so that the scanning position of the return interval may be exactly at the middle of the outbound interval, that is the effect of FIG. 10 may be realized. As shown in FIG. 10, solid circles may be an example of the outbound dotting calculated based on the fast axis drive waveform in the outbound interval, which are divided into upper and lower rows, and hollow circles may be an example of the return dotting calculated based on the fast axis drive waveform in the return interval, which are divided into upper and lower rows. By realizing the staggering of the fast axis drive waveform in the return interval and the outbound interval, superimposed twice-dotting data may be obtained, so as to realize the effect of improving the angle resolution of laser radar by adjusting the phase of the fast axis drive waveform in the return interval.

In some embodiments of the present disclosure, by adjusting the phase of the fast axis drive waveform in the return interval of the slow axis, the phase of the fast axis drive waveform in the return interval of the slow axis is staggered with the phase of the fast axis drive waveform in the outbound interval of the slow axis, which improves the point cloud data density, thereby achieving the technical effect of improving the vertical angle resolution of the laser radar.

It should be noted that the above descriptions of the process 800 are merely provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. For those skilled in the art, multiple variations or modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure.

FIG. 11 is a flowchart illustrating an exemplary process for determining a scanning parameter according to some embodiments of the present disclosure. In some embodiments, a process 1100 may be executed by the laser radar scanning system 100. For example, the process 1100 may be implemented as a set of instructions stored in a storage device. In some embodiments, the processing device 120 (e.g., the processor 210 of the computing device 200 and/or one or more modules illustrated in FIG. 5) may execute the set of instructions and may accordingly be directed to perform the process 1100. The operations of the illustrated process presented below are intended to be illustrative. In some embodiments, the process 1100 may be accomplished with one or more additional operations not described and/or without one or more of the operations discussed. Additionally, the order of the operations of process 1100 illustrated in FIG. 11 and described below is not intended to be limiting.

In 1110, a target transmitting time difference may be determined based on a fast axis drive waveform within an outbound interval of a slow axis. Operation 1110 may be performed by the determination module 510.

The transmitting time refers to a time when a transmitter transmits the laser during a scanning period. It may be understood that a ranging principle of the laser radar is that the transmitter transmits the laser to a scanning region, a receiver receives an echo laser reflected from the scanning region, and the laser radar may calculate a straight line distance between the transmitter and a detected object based on a time interval between transmitting the laser and receiving the echo laser. Therefore, the accuracy of the ranging of the laser radar depends on the accuracy of the time interval.

The transmitting time difference refers to a time difference between the time of laser emission in the outbound interval and the time of laser emission in the return interval.

In some embodiments, the processing device 120 may determine a horizontal dotting number based on the fast axis drive waveform during the outbound interval of the slow axis. For example, when the fast axis drive waveform is a sine wave, a dotting number is obtained by calculating the dotting based on an angle speed of the sine wave. After the horizontal dotting number is determined, a rotation time between two dots may be calculated by formula (4) . The processing device 120 may take half of the rotation time between the two dots as the target transmitting time difference, or the processing device 120 may take other value as the target transmitting time difference. The other value allows the positions of the horizontal dots in the return interval of the slow axis to be staggered from the positions of the horizontal dots in the outbound interval of the slow axis.

In some embodiments of the present disclosure, the target transmitting time difference is determined based on the fast axis drive waveform in the outbound interval of the slow axis, thereby improving the stability of the staggered dotting, and achieving the technical effect of improving the point cloud data density.

In 1120, the laser transmitting time within the return interval of the slow axis may be advanced or delayed based on the laser transmitting time within the outbound interval of the slow axis and the target transmitting time difference. Operation 1120 may be performed by the determination module 510.

In some embodiments, the processing device 120 may adjust the laser transmitting time within the outbound interval based on the target transmitting time difference, and determine the adjusted laser transmitting time as the laser transmitting time within the return interval.

It may be understood that under an action of the vibration of the fast and slow axes of the galvanometer, when the transmitter transmits the laser, a scanning ranging and record may be performed on the object in the scanning region by dotting. On the one hand, the dotting number may be influenced by the resonant frequency of the galvanometer and the ranging. On the other hand, in order to make the dotting result uniform, the dotting method needs to be adjusted according to the fast axis drive waveform. For example, when the fast axis drive waveform is a sine wave, the dotting needs to be calculated based on an angle speed of the sine wave. Therefore, in the outbound interval, there is a necessary interval between two dots in the dotting data generated by scanning.

By adjusting the laser transmitting time in the return interval, the processing device 120 may stagger the horizontal dotting position in the return interval from the horizontal dotting position in the outbound interval, so as to obtain more dotting positions under the same fast axis drive waveform, thereby improving the point cloud data density. That is, the effect in FIG. 12 may be implemented.

As shown in FIG. 12, solid circles may be an example of the outbound dotting calculated based on the fast axis drive waveform in the outbound interval, which are divided into upper and lower rows, and hollow circles may be an example of the outbound dotting calculated based on the fast axis drive waveform in the return interval, which are divided into upper and lower rows. By advancing or delaying the laser transmitting time within the return interval of the slow axis, under the same fast axis drive waveform, the positions of the horizontal dotting within the return interval of the slow axis may be staggered from the positions of the horizontal dotting within the outbound interval of the slow axis, so as to obtain twice-dotting data on the same fast axis drive waveform, thereby achieving the effect of improving the horizontal angle resolution of the laser radar.

In some embodiments of the present disclosure, by advancing or delaying the laser transmitting time in the return interval of the slow axis, the positions of the horizontal dotting in the return interval of the slow axis are staggered from the positions of the horizontal dotting in the outbound interval of the slow axis, thereby improving the point cloud data density under the same fast axis drive waveform, and achieving the technical effect of improving the horizontal angle resolution of the lase radar.

It should be noted that the above descriptions of the process 1100 are merely provided for the purposes of illustration, and not intended to limit the scope of the present disclosure. For those skilled in the art, multiple variations or modifications may be made under the teachings of the present disclosure. However, those variations and modifications do not depart from the scope of the present disclosure.

FIG. 13 is a schematic diagram illustrating an exemplary process for determining a scanning parameter according to some other embodiments of the present disclosure.

A target frame refers to a frame whose angle resolution needs to be improved. For example, as shown in FIG. 13, a frame formed by a time T1 of an outbound interval waveform and a time T2 of a return interval waveform is the target frame. The target frame may be one or more frames. The target frame may be determined based on a scanning instruction, or set in advance, or obtained by recording or based on analyzing data, which is not limited herein.

In some embodiments, the processing device 120 may dynamically adjust a return interval length and an outbound interval length of the slow axis drive waveform based on the target frame.

It may be understandable that, in the case of an unchanged fast axis drive waveform and an unchanged period of the fast axis drive waveform, the longer the outbound interval of the slow axis, the more rows may be obtained by scanning of a single outbound interval, and accordingly, the higher the point cloud data density. Similarly, in the case of an unchanged fast axis drive waveform and an unchanged period of the fast axis drive waveform, the longer the return interval of the slow axis, the more rows may be obtained by scanning of a single return interval, and accordingly, the higher the point cloud data density.

If the outbound interval or the return interval of the slow axis passes through the target frame, a duty ratio (i.e., a time ratio of the outbound interval and the return interval) of the outbound interval and return interval of the slow axis may be adjusted, and accordingly, the period passing the target frame may be lengthened, and the period does not pass the target frame may be shortened. For example, when data to be scanned of a pair of adjacent outbound interval and return interval is determined as the target frame, if the adjacent outbound interval and return interval belong to different frames, a duration of the adjacent outbound interval and return interval may be lengthened, and a duration of outbound interval and return interval corresponding to the adjacent outbound interval and return interval may be shortened, thereby improving the point cloud density data of a specific frame or a plurality of frames in the case of an unchanged total duration of outbound process and return process of slow axis of galvanometer.

As shown in waveform a in FIG. 13, in general, under one scanning period of the slow axis, the duration of the outbound interval (T2) is greater than the duration of the return interval (T11) , that is, the duty ratio of the outbound interval to the return interval is greater than 1.

As shown in waveform b in FIG. 13, two scanning periods are included in the present embodiment. T1 and T11 may respectively be the return intervals of the two scanning periods, and T2 and T22 may respectively be the outbound intervals of the two scanning periods. It may be seen that T2 and T11 are a pair of adjacent outbound interval and return interval. When T2 and T11 are, as one frame, determined as the target frame, T2 and T11 belong to different frames, the outbound intervals, and the return intervals in the two scanning periods may be adjusted respectively. That is, the scanning durations of T2 and T11 may be extended, and the scanning durations of T1 and T22 may be shortened, so as to improve the point cloud data density of the specific frame of T2 and T11 in the case that the durations of the two scanning periods remain unchanged.

Specifically, the first frame may be scanned as preset, that is, a number of scanning rows of T2 may be more. When the scanning of the next frame starts, that is, when the return process of the galvanometer starts, the duration of T11 is adjusted to increase the duty ratio of T11. In this way, the scanning rows of T11 during the return process may be increased. At this time, the point cloud densities of T2 and T11 are fused, thereby improving the point cloud density of the target frame. In the case that there is no need to adjust the total duration of the outbound process and the return process, the above method may reduce an outbound row number (i.e., the number of rows corresponding to T22) in the next frame. However, similarly, an increase in the duration of the return process may be implemented during the return process of the next frame. Therefore, the duty ratio may be slowly adjusted during a frame rate drive process to achieve a frame rate scanning approach with a dynamic point cloud density.

In some embodiments of the present disclosure, by dynamically adjusting the return interval length and the outbound interval length of the slow axis drive waveform based on the target frame, an improvement of the point cloud data density of the target frame may be realized without adjusting the total duration of the outbound interval and the return interval, thereby achieving the technical effect of improving the angle resolution of the target frame.

FIG. 14 is a flowchart illustrating an exemplary process for laser radar scanning according to some embodiments of the present disclosure.

In the embodiments shown in FIG. 14, a fast axis drive waveform is a sine wave and a slow axis drive waveform is a triangle wave.

The fast axis is driven by the sine wave, and one sine wave period may correspond to two horizontal scanning rows. The slow axis is driven by the triangle wave, and a triangle wave period may be considered as an outbound process and a return process.

In the embodiments, a laser radar scanning method is provided. In the laser radar scanning method, by driving the fast axis by the sine wave, and driving the slow axis by the triangle wave, a fast axis resonant scanning and a slow axis low frequency vibration may be realized, which realizes a more comprehensive scanning of the scanning region, thereby improving the integrity of the point cloud data and achieving the effect of improving the laser radar resolution.

In order to better illustrate the technical solution of the present disclosure, the present disclosure provides a detailed embodiment for further explanation.

In this embodiment, an electromagnetic galvanometer drive is adopted, the fast axis of the galvanometer is driven by the sine wave, and one sine wave period corresponds to two horizontal scanning rows, the slow axis is driven by the triangle wave, and one triangle wave period is regarded as a frame. As shown in FIG. 7, a duration of an outbound process of the slow axis is regarded as Ta, and the outbound process is the outbound interval of the slow axis; a duration of a return process is regarded as Tb, and the return process is the return interval of the slow axis. The fast axis drive waveform may be superimposed on the triangle wave of the slow axis.

As shown in FIG. 14, after the end of the outbound interval of the slow axis, a preset driving scanning may be performed when the outbound process of the slow axis deflects. In order to increase the vertical resolution, the scanning may be performed by adjusting the phase of the fast axis drive waveform; or, in order to increase the horizontal resolution, the scanning may be performed by staggering dotting drive. After the scanning data of the outbound process and return process, that is, the forward scanning data and the inverse scanning data are obtained, the forward scanning data and the inverse scanning data may be fused to realize an improvement of the point cloud density.

Specifically, in the process of performing the scanning by adjusting, during the return process, the phase of the fast axis drive waveform, since one period of the fast axis is two horizontal scanning rows, it is assumed that the positive half period is the first row and the negative half period is the second row, and the phase of the fast axis drive waveform may be adjusted in the return process. For example, when the duty ratio between the outbound interval and the return interval is 50%, the phase adjustment of the fast axis drive waveform on the return interval is changed by 1/4π, so that the fast axis drive waveform under the return interval and the fast axis drive waveform under the outbound interval is staggered to obtain the staggered forward scanning data and the inverse scanning data. The point cloud data with an increased vertical angle resolution may be output based on the fusion of the forward scanning data and the inverse scanning data.

Specifically, in the process of performing the scanning by the staggered dotting drive during the return process, the phase of the fast axis drive waveform remains unchanged, and by advancing or delaying the laser transmitting moment of the laser transmitter, the dotting of the outbound interval and the return interval may be staggered to achieve an increase of horizontal dotting, thereby achieving a higher point cloud data density when the phase is unchanged.

The above-mentioned method for increasing the vertical resolution and the above-mentioned method for increasing the horizontal resolution mentioned above may be implemented independently or in combination. For example, different resolution increasing methods are implemented in different scanning periods.

In the embodiments, the increase of the point cloud data density of the target frame may be realized by adjusting the duty ratio of the outbound interval and the return interval of the slow axis.

Specifically, the duty ratio of the outbound interval and the return interval in two adjacent scanning periods may be separately adjusted., and then the forward scanning data and the inverse scanning data may be fused after scanning to obtain the scanning data with the increased point cloud data density of the target frame. For example, the duty ratio of the outbound interval of the first scanning period is increased, and the duty ratio of the return interval of the second scanning period is increased. Further, the scanning data of the above outbound interval and return interval are fused to obtain the scanning data with increased point cloud data density of the target frame.

In the laser radar scanning method provided by the present embodiment, by adjusting the phase of the fast axis drive waveform, the waveform stagger is realized to improve the point cloud data density; by adjusting the laser transmitting time, the dotting number in the fast axis drive waveform is increased to increase the point cloud data density; by adjusting the duty ratio of the outbound interval and the return interval, the point cloud data density is increased, thereby solving the problem of low laser radar angle resolution and achieving the technical effect of improving the laser radar scanning efficiency.

It should be appreciated that although the operations in the flowcharts involved in the embodiments as described above are shown sequentially as indicated by the arrows, the operations are not necessarily performed sequentially in the order indicated by the arrows. Unless expressly stated herein, there is no strict order limitation on the execution of these operations, and the operations may be executed in other orders. Moreover, at least a portion of the operations in the flowchart involved in the embodiments as described above may include a plurality of steps or a plurality of stages. These steps or stages are not necessarily executed at the same moment, but may be executed at different moments. These steps or stages are not necessarily executed sequentially, but may be executed in turn or alternately with other operations or at least a portion of steps or phases in other operations.

For example, the processing device 120 may determine the fast axis drive waveform of the return interval based on the fast axis drive waveform of the outbound interval and the target phase difference, and determine the transmitting time of the return interval based on the laser transmitting time of the forward scanning and the target transmitting time difference. The above operations may be performed separately, or may be performed one or more times under different scanning periods. As another example, the processing device 120 may transmit, by the transmitter, the laser during a partial time period of the return interval of the slow axis drive waveform after the forward scanning of the laser radar is completed. As yet another example, the processing device 120 may, in the outbound interval and the return interval of the slow axis, increase the scanning duration of part of the outbound interval and the return interval corresponding to the period passing the region of interest, and shorten the scanning duration of the other parts of the outbound interval and the return interval of the slow axis.

Based on the same inventive concept, the embodiments of the present disclosure provide a laser radar scanning device for realizing the scanning laser radar method described above. The implementation of the solution provided by the laser radar scanning device is similar to the implementation of the solution provided by the laser radar scanning method described above, so the specific limitations in the one or more embodiments of the laser radar scanning device provided below may be referred to in the aforementioned limitations on the laser radar scanning method, which are not repeated here.

In one embodiment, a computer device is provided, which may be a server, and an internal structure of the server is shown in FIG. 15. The computer device may include a processor, a memory, and a network interface connected through a system bus. The processor of the computer device may be configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium may store an operation system, a computer program, and a database. The internal memory provides an environment for the operation of the operation system and the computer programs in the non-volatile storage medium. The database of the computer device may be configured for storing laser radar scanning data. The network interface of the computer device may be configured to communicate with an external terminal through a network connection. When executed by the processor, the computer program may implement the laser radar scanning method.

Those skilled in the art should understand that the structure illustrated in FIG. 15 is only a block diagram of partial structure related to the embodiments of the present disclosure, and does not constitute a limitation to the computer device on which the embodiments of the present disclosure are applied. A specific computer device may include more or fewer components than shown in FIG. 15, or combine certain components, or have a different arrangement of components.

In some embodiments, a computer-readable storage medium storing computer instructions. When reading the computer instructions in the computer-readable storage medium, a computer implements a scanning method including determining a scanning parameter in response to a scanning instruction, the scanning parameter including a galvanometer drive waveform; obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter, the forward scanning data including scanning data obtained in an outbound interval of the galvanometer drive waveform, the inverse scanning data including scanning data obtained in a return interval of the galvanometer drive waveform; and determining target scanning data based on the forward scanning data and the inverse scanning data.

The following beneficial effects that the embodiments of the present disclosure may realize. (1) After the forward scanning of the laser radar is completed, the time and path of the return process of the slow axis are used to perform the inverse scanning, and target scanning data may be obtained based on forward scanning data and inverse scanning data, which increases the data density of the target scanning data, thereby solving the problem of low angle resolution of the laser radar, and achieving the technical effect of improving the angle resolution of the laser radar. (2) The target phase difference is determined based on the fast axis drive waveform within the outbound interval and the return interval of the slow axis, which improves the stability of the fast axis drive waveform stagger in the outbound interval and the return interval, so as to achieve the technical effect of improving the point cloud data density. (3) By adjusting the phase of the fast axis drive waveform in the return interval of the slow axis, the phase of the fast axis drive waveform in the return interval of the slow axis is staggered with the phase of the fast axis drive waveform in the outbound interval of the slow axis, which improves the point cloud data density, thereby achieving the technical effect of improving the vertical angle resolution of the laser radar. (4) The target transmitting time difference is determined based on the fast axis drive waveform in the outbound interval of the slow axis, thereby improving the stability of the staggered dotting, and achieving the technical effect of improving the point cloud data density. (5) By advancing or delaying the laser transmitting time in the return interval of the slow axis, the positions of the horizontal dotting in the return interval of the slow axis are staggered from the positions of the horizontal dotting in the outbound interval of the slow axis, thereby improving the point cloud data density under the same fast axis drive waveform, and achieving the technical effect of improving the horizontal angle resolution of the laser radar. (6) By dynamically adjusting the return interval length and the outbound interval length of the slow axis drive waveform based on the target frame, an improvement of the point cloud data density of the target frame may be realized without adjusting the total duration of the outbound interval and the return interval, thereby achieving the technical effect of improving the angle resolution of the target frame.

Having thus described the basic concepts, it may be rather apparent to those skilled in the art after reading this detailed disclosure that the foregoing detailed disclosure is intended to be presented by way of example only and is not limiting. Various alterations, improvements, and modifications may occur and are intended to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested by this disclosure, and are within the spirit and scope of the exemplary embodiments of this disclosure.

Moreover, certain terminology has been used to describe embodiments of the present disclosure. For example, the terms “one embodiment, ” “an embodiment, ” and/or “some embodiments” may mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Therefore, it is emphasized and should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as suitable in one or more embodiments of the present disclosure.

Furthermore, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claimed processes and methods to any order except as may be specified in the claims. Although the above disclosure discusses through various examples what is currently considered to be a variety of useful embodiments of the disclosure, it is to be understood that such detail is solely for that purpose, and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover modifications and equivalent arrangements that are within the spirit and scope of the disclosed embodiments. For example, although the implementation of various components described above may be embodied in a hardware device, it may also be implemented as a software only solution, for example, an installation on an existing server or mobile device.

Similarly, it should be appreciated that in the foregoing description of embodiments of the present disclosure, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the various inventive embodiments. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed object matter requires more features than are expressly recited in each claim. Rather, inventive embodiments lie in less than all features of a single foregoing disclosed embodiment.

In some embodiments, the numbers expressing quantities or properties used to describe and claim certain embodiments of the application are to be understood as being modified in some instances by the term “about, ” “approximate, ” or “substantially. ” For example, “about, ” “approximate, ” or “substantially” may indicate ±1%, ±5%, ±10%, or ±20%variation of the value it describes, unless otherwise stated. Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the application are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable.

Each of the patents, patent applications, publications of patent applications, and other material, such as articles, books, specifications, publications, documents, things, and/or the like, referenced herein is hereby incorporated herein by this reference in its entirety for all purposes, excepting any prosecution file history associated with same, any of same that is inconsistent with or in conflict with the present document, or any of same that may have a limiting effect as to the broadest scope of the claims now or later associated with the present document. By way of example, should there be any inconsistency or conflict between the description, definition, and/or the use of a term associated with any of the incorporated material and that associated with the present document, the description, definition, and/or the use of the term in the present document shall prevail.

In closing, it is to be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the application. Other modifications that may be employed may be within the scope of the application. Thus, by way of example, but not of limitation, alternative configurations of the embodiments of the application may be utilized in accordance with the teachings herein. Accordingly, embodiments of the present application are not limited to that precisely as shown and described.

Claims

A scanning method of a laser radar, wherein

the laser radar includes a galvanometer, and

the scanning method includes:

determining a scanning parameter in response to a scanning instruction, the scanning parameter including a galvanometer drive waveform;

obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter, the forward scanning data including scanning data obtained in an outbound interval of the galvanometer drive waveform, the inverse scanning data including scanning data obtained in a return interval of the galvanometer drive waveform; and

determining target scanning data based on the forward scanning data and the inverse scanning data.
The scanning method of claim 1, wherein

the galvanometer drive waveform includes a slow axis drive waveform and a fast axis drive waveform, the slow axis drive waveform including an outbound interval waveform and a return interval waveform;

the forward scanning includes transmitting, by a transmitter, a laser, and driving a slow axis of the galvanometer based on the forward interval waveform of the slow axis drive waveform, while driving a fast axis of the galvanometer based on the fast axis drive waveform; and

the inverse scanning includes transmitting, by the transmitter, a laser, and driving the slow axis based on the return interval waveform of the slow axis drive waveform, while driving the fast axis based on the fast axis drive waveform.
The scanning method of claim 2, wherein the determining the scanning parameter in response to the scanning instruction comprises:

adjusting a phase of the fast axis drive waveform within a return interval of the slow axis to stagger the phase from a phase of the fast axis drive waveform within an outbound interval of the slow axis.
The scanning method of claim 3, wherein the adjusting the phase of the fast axis drive waveform within the return interval of the slow axis comprises:

determining a target phase difference based on the fast axis drive waveform within the outbound interval and the return interval of the slow axis; and

adjusting the phase of the fast axis drive waveform within the return interval of the slow axis based on the phase of the fast axis drive waveform within the outbound interval of the slow axis and the target phase difference.
The scanning method of claim 2, wherein the determining the scanning parameter in response to the scanning instruction comprises:

advancing or delaying a laser transmitting time within a return interval of the slow axis, so that a position of a horizontal dotting within the return interval of the slow axis is staggered from a position of the horizontal dotting within an outbound interval of the slow axis.
The scanning method of claim 5, wherein the advancing or delaying the laser transmitting time within the return interval of the slow axis comprises:

determining a target transmitting time difference based on the fast axis drive waveform within the outbound interval of the slow axis; and

advancing or delaying the laser transmitting time within the return interval of the slow axis based on a laser transmitting time within the outbound interval of the slow axis and the target transmitting time difference.
A scanning method of any one of claims 2-6, wherein the determining the scanning parameter in response to the scanning instruction comprises:

adjusting a return interval length and an outbound interval length of the slow axis drive waveform.
The scanning method of claim 7, wherein the adjusting the return interval length and the outbound interval length of the slow axis drive waveform comprises:

dynamically adjusting, based on a target frame, the return interval length and the outbound interval length of the slow axis drive waveform.
The scanning method of claim 1, wherein the inverse scanning data includes scanning data obtained during a partial time period of the return interval of the galvanometer drive waveform.
The scanning method of claim 9, wherein

the galvanometer drive waveform includes a slow axis drive waveform and a fast axis drive waveform, the slow axis drive waveform including an outbound interval waveform and a return interval waveform;

the forward scanning includes transmitting, by a transmitter, a laser, and driving a slow axis of the galvanometer based on the outbound interval waveform of the slow axis drive waveform, while driving a fast axis of the galvanometer based on the fast axis drive waveform; and

the inverse scanning includes driving the slow axis based on the return interval waveform of the slow axis drive waveform, while driving the fast axis based on the fast axis drive waveform, and transmitting, by a transmitter, a laser during a partial time period of a return interval of the slow axis drive waveform.
A computer-readable storage medium storing computer instructions, wherein when reading the computer instructions in the computer-readable storage medium, a computer implements the scanning method of claim 1.
A scanning device of a laser radar comprising a galvanometer, a transmitter, a receiver, and a controller, wherein

the galvanometer includes a fast axis and a slow axis, the fast axis being driven by a fast axis drive waveform, the slow axis being driven by a slow axis drive waveform,

the transmitter is configured to transmit a laser,

the receiver is configured to receive an echo laser,

the controller is configured to determine target scanning data by controlling the transmitter to transmit the laser while controlling a rotation of the galvanometer, wherein to determine the target scanning data, the controller is configured to perform operations including:

determining a scanning parameter in response to a scanning instruction, the scanning parameter including a galvanometer drive waveform;

obtaining forward scanning data and inverse scanning data by performing a forward scanning and an inverse scanning based on the scanning parameter, the forward scanning data including scanning data obtained in an outbound interval of the galvanometer drive waveform, the inverse scanning data including scanning data obtained in a return interval of the galvanometer drive waveform; and

determining the target scanning data based on the forward scanning data and the inverse scanning data.
The scanning device of claim 12, wherein

the galvanometer drive waveform includes a slow axis drive waveform and a fast axis drive waveform, the slow axis drive waveform including an outbound interval waveform and a return interval waveform;

the forward scanning includes transmitting, by a transmitter, a laser, and driving a slow axis of the galvanometer based on the forward interval waveform of the slow axis drive waveform, while driving a fast axis of the galvanometer based on the fast axis drive waveform; and

the inverse scanning includes transmitting, by the transmitter, a laser, and driving the slow axis based on the return interval waveform of the slow axis drive waveform, while driving the fast axis based on the fast axis drive waveform.
The scanning device of claim 13, wherein the controller is further configured to:

adjust a phase of the fast axis drive waveform within a return interval of the slow axis to stagger the phase from a phase of the fast axis drive waveform within an outbound interval of the slow axis.
The scanning device of claim 14, wherein the controller is further configured to:

determine a target phase difference based on the fast axis drive waveforms within the outbound interval and the return waveform of the slow axis; and

adjust the phase of the fast axis drive waveform within the return interval of the slow axis based on the phase of the fast axis drive waveform within the outbound interval of the slow axis and the target phase difference.
The scanning device of claim 13, wherein the controller is further configured to:

advance or delay a laser transmitting time within a return interval of the slow axis, so that a position of a horizontal dotting within the return interval of the slow axis is staggered from a position of the horizontal dotting within an outbound interval of the slow axis.
The scanning device of claim 16, wherein the controller is further configured to:

determine a target transmitting time difference based on the fast axis drive waveform within the outbound interval of the slow axis; and

advance or delay the laser transmitting time within the return interval of the slow axis based on a laser transmitting time within the outbound interval of the slow axis and the target transmitting time.
The scanning device of any one of claims 13-17, wherein the controller is further configured to:

adjust a return interval length and an outbound interval length of the slow axis drive waveform.
The scanning device of claim 18, wherein the controller is further configured to:

dynamically adjust, based on a target frame, the return interval length and the outbound interval length of the slow axis drive waveform.
The scanning device of claim 19, wherein the inverse scanning data includes scanning data obtained during a partial time period of the return interval of the galvanometer drive waveform.