Lidar ranging method, apparatus, system, and autonomous vehicle

Abstract

The present disclosure provides a laser radar ranging method, device, system and autonomous vehicle, relates to the technical field of autonomous driving, and particularly relates to the field of autonomous driving hardware. The implementation scheme is: determining a laser signal for emission and a timing start time at which the laser signal is emitted for ranging, wherein the laser signal is configured to have at least two emission intensities that alternately change; acquiring the laser signal reflected from an object; determining a timing end time by triggering a logic level flip based on a comparison between a reception intensity of the reflected laser signal and an adjustable reference threshold value, wherein the adjustable reference threshold value is determined based on the reception intensity of the laser signal; and determining a distance between the laser radar and the object based on the timing start time and the timing end time.

Description

Technical Field

[0001] This disclosure relates to the field of autonomous driving technology, and more particularly to the field of autonomous driving hardware, specifically to a lidar ranging method, apparatus, system, electronic device, computer-readable storage medium, computer program product, FPGA chip, and autonomous vehicle. Background Technology

[0002] With the development of autonomous driving technology, users have placed higher demands on radar ranging in autonomous vehicles. In radar ranging for autonomous vehicles, the transmission process of laser signals needs to be timed. In some cases, the timing circuit uses a large number of comparators, making the circuit very complex and the signal difficult to control, significantly affecting the accuracy of radar ranging in autonomous vehicles, and also increasing costs. How to achieve more efficient radar ranging for autonomous vehicles, improve the accuracy of radar ranging, and reduce the cost remains one of the research hotspots and challenges in the industry.

[0003] The methods described in this section are not necessarily methods that had been previously conceived or adopted. Unless otherwise specified, no method described in this section should be assumed to be prior art simply because it is included in this section. Similarly, unless otherwise specified, the issues mentioned in this section should not be considered to be accepted in any prior art. Summary of the Invention

[0004] This disclosure provides a lidar ranging method, apparatus, system, electronic device, computer-readable storage medium, computer program product, FPGA chip, and autonomous vehicle.

[0005] According to one aspect of this disclosure, a lidar ranging method is provided, comprising: determining a laser signal for emission and a timing start time for the laser signal to be emitted for ranging, wherein the laser signal is configured to have at least two emission intensities that alternately change; acquiring a laser signal reflected from an object; determining a timing end time by triggering a logic level flip based on a comparison between the received intensity of the reflected laser signal and the adjustable reference threshold, wherein the adjustable reference threshold is determined based on the received intensity of the laser signal; and determining the distance between the lidar and the object based on the timing start time and the timing end time.

[0006] According to another aspect of this disclosure, a lidar ranging device is provided, comprising: a laser emission determination module configured to determine a laser signal for emission and a timing start time for the laser signal to be emitted for ranging, wherein the laser signal is configured to have at least two emission intensities that alternately change; a laser reflection acquisition module configured to acquire a laser signal reflected from an object; a time determination module configured to determine a timing end time by triggering a logic level flip based on a comparison result between the received intensity of the reflected laser signal and the adjustable reference threshold, wherein the adjustable reference threshold is determined based on the received intensity of the laser signal; and a distance determination module configured to determine the distance between the lidar and the object based on the timing start time and the timing end time.

[0007] According to another aspect of this disclosure, a lidar system is provided, comprising: an FPGA chip configured to perform the method provided above; a transmitting device for transmitting a laser signal and connected to the FPGA chip, wherein the laser signal and a timing start time for transmitting the laser signal are determined by the FPGA chip, and the laser signal is configured to have at least two alternating intensities; a receiving device for receiving a laser signal reflected from an object and connected to the FPGA chip to provide the reflected laser signal to the FPGA chip; a scanning device including a microelectromechanical system (MEMS) galvanometer and connected to the FPGA chip, the MEMS galvanometer being configured to adjust the scanning angle of the laser signal by rotating on a horizontal and vertical axis, wherein the scanning angle is determined by the FPGA chip; and a voltage regulating device for generating an adjustable reference threshold and connected to the FPGA chip to provide the adjustable reference threshold to the FPGA chip, the adjustable reference threshold being used to determine the timing end time for the lidar to perform ranging; wherein at least one of the FPGA chip, the transmitting device, the receiving device, the scanning device, and the voltage regulating device is monitored in a closed loop.

[0008] According to another aspect of this disclosure, an electronic device is provided, including at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the methods provided above in this disclosure.

[0009] According to another aspect of this disclosure, a non-transitory computer-readable storage medium is provided storing computer instructions, wherein the computer instructions are used to cause a computer to perform the methods provided above in this disclosure.

[0010] According to another aspect of this disclosure, a computer program product is provided, including a computer program, wherein the computer program, when executed by a processor, implements the methods provided above in this disclosure.

[0011] According to another aspect of this disclosure, an FPGA chip is provided, including circuitry that implements the methods provided above.

[0012] According to another aspect of this disclosure, an autonomous vehicle is provided, including an FPGA chip, wherein the FPGA chip is configured to perform the methods provided above in this disclosure.

[0013] According to one or more embodiments of this disclosure, more accurate laser ranging can be achieved at a lower cost.

[0014] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0015] The accompanying drawings exemplify embodiments and form part of the specification, serving together with the textual description to explain exemplary implementations of the embodiments. The illustrated embodiments are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to similar but not necessarily identical elements.

[0016] Figure 1 A schematic diagram of an exemplary system in which the various methods described herein may be implemented according to embodiments of the present disclosure is shown;

[0017] Figure 2 A flowchart of a lidar ranging method according to an embodiment of the present disclosure is shown;

[0018] Figure 3 A schematic diagram is shown illustrating how a timing end time is determined by comparing the received intensity of a laser signal with an adjustable reference threshold according to an embodiment of the present disclosure.

[0019] Figure 4 A schematic diagram of ranging between near and far objects according to embodiments of the present disclosure is shown;

[0020] Figure 5 A schematic diagram of the scanning waveform of the transverse axis of a MEMS galvanometer according to an embodiment of the present disclosure is shown;

[0021] Figure 6 A schematic diagram showing the superposition of horizontal and vertical scanning waveforms of a MEMS galvanometer according to an embodiment of the present disclosure is shown.

[0022] Figure 7 A structural block diagram of a lidar ranging device according to an embodiment of the present disclosure is shown;

[0023] Figure 8A structural block diagram of a lidar ranging device according to another embodiment of the present disclosure is shown;

[0024] Figure 9 A schematic diagram of the structure of a lidar system according to an embodiment of the present disclosure is shown;

[0025] Figure 10 A structural block diagram of an exemplary electronic device that can be used to implement embodiments of the present disclosure is shown. Detailed Implementation

[0026] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0027] In this disclosure, unless otherwise stated, the use of terms such as "first," "second," etc., to describe various elements is not intended to limit the positional, temporal, or importance relationships of these elements; such terms are merely used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of that element, while in other cases, based on the context, they may refer to different instances.

[0028] The terminology used in the description of the various examples described in this disclosure is for the purpose of describing particular examples only and is not intended to be limiting. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is specifically limited. Furthermore, the term "and / or" as used in this disclosure covers any one of the listed items and all possible combinations thereof.

[0029] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0030] Figure 1 A schematic diagram of an exemplary system 100 in which the various methods and apparatus described herein can be implemented according to embodiments of this disclosure is shown. Reference Figure 1 The system 100 includes a motor vehicle 110, a server 120, and one or more communication networks 130 that couple the motor vehicle 110 to the server 120.

[0031] In embodiments of this disclosure, the motor vehicle 110 may include a computing device according to embodiments of this disclosure and / or be configured to perform a method according to embodiments of this disclosure.

[0032] Server 120 may run one or more services or software applications that enable the implementation of the lidar ranging method according to embodiments of the present disclosure. In some embodiments, server 120 may also provide other services or software applications, which may include non-virtual environments and virtual environments. Figure 1 In the configuration shown, server 120 may include one or more components that implement the functions performed by server 120. These components may include software components, hardware components, or combinations thereof that can be executed by one or more processors. A user of motor vehicle 110 may sequentially interact with server 120 using one or more client applications to utilize the services provided by these components. It should be understood that various different system configurations are possible and may differ from system 100. Therefore, Figure 1 This is an example of a system used to implement the various methods described herein, and is not intended to be limiting.

[0033] Server 120 may include one or more general-purpose computers, special-purpose server computers (e.g., PC (personal computer) servers, UNIX servers, mid-range servers), blade servers, mainframe computers, server clusters, or any other suitable arrangement and / or combination. Server 120 may include one or more virtual machines running a virtual operating system, or other computing architectures involving virtualization (e.g., one or more flexible pools of logical storage devices that can be virtualized to maintain virtual storage devices for servers). In various embodiments, server 120 may run one or more services or software applications that provide the functionality described below.

[0034] The computing unit in server 120 can run one or more operating systems, including any of the aforementioned operating systems and any commercially available server operating system. Server 120 can also run any of a variety of additional server applications and / or middleware applications, including HTTP servers, FTP servers, CGI servers, JAVA servers, database servers, etc.

[0035] In some implementations, server 120 may include one or more applications to analyze and merge data feeds and / or event updates received from vehicle 110. Server 120 may also include one or more applications to display data feeds and / or real-time events via one or more display devices of vehicle 110.

[0036] Network 130 can be any type of network well known to those skilled in the art, and can support data communication using any of a variety of available protocols (including, but not limited to, TCP / IP, SNA, IPX, etc.). By way of example only, one or more networks 130 can be satellite communication networks, local area networks (LANs), Ethernet-based networks, token ring networks, wide area networks (WANs), the Internet, virtual networks, virtual private networks (VPNs), intranets, extranets, blockchain networks, public switched telephone networks (PSTNs), infrared networks, wireless networks (including, for example, Bluetooth, WiFi), and / or any combination of these with other networks.

[0037] System 100 may also include one or more databases 150. In some embodiments, these databases may be used to store data and other information. For example, one or more of the databases 150 may be used to store information such as audio files and video files. The data repository 150 may reside in various locations. For example, a data repository used by server 120 may be local to server 120, or it may be located away from server 120 and may communicate with server 120 via a network-based or dedicated connection. The data repository 150 may be of different types. In some embodiments, the data repository used by server 120 may be a database, such as a relational database. One or more of these databases may store, update, and retrieve data from and from the database in response to commands.

[0038] In some embodiments, one or more of the databases 150 may also be used by an application to store application data. The databases used by the application may be of different types, such as key-value stores, object stores, or regular stores supported by a file system.

[0039] Motor vehicle 110 may include sensors 111 for sensing the surrounding environment. Sensors 111 may include one or more of the following sensors: a visual camera, an infrared camera, an ultrasonic sensor, a millimeter-wave radar, and a lidar (LiDAR). Different sensors can provide different detection accuracy and range. Cameras may be mounted in front of, behind, or at other locations on the vehicle. Visual cameras can capture the situation inside and outside the vehicle in real time and present it to the driver and / or passengers. In addition, by analyzing the images captured by the visual cameras, information such as traffic light indications, intersection conditions, and the operating status of other vehicles can be obtained. Infrared cameras can capture objects in night vision conditions. Ultrasonic sensors may be mounted around the vehicle to measure the distance of objects outside the vehicle using the strong directionality of ultrasound. Millimeter-wave radar may be mounted in front of, behind, or at other locations on the vehicle to measure the distance of objects outside the vehicle using the characteristics of electromagnetic waves. LiDAR may be mounted in front of, behind, or at other locations on the vehicle to detect the edges and shape information of objects, thereby performing object recognition and tracking. Due to the Doppler effect, the radar device can also measure the speed changes of the vehicle and moving objects.

[0040] The motor vehicle 110 may also include a communication device 112. The communication device 112 may include a satellite positioning module capable of receiving satellite positioning signals (e.g., BeiDou, GPS, GLONASS, and GALILEO) from satellite 141 and generating coordinates based on these signals. The communication device 112 may also include a module for communicating with a mobile communication base station 142. The mobile communication network can implement any suitable communication technology, such as current or emerging wireless communication technologies (e.g., 5G technology) like GSM / GPRS, CDMA, and LTE. The communication device 112 may also have a vehicle-to-everything (V2X) module, configured to enable vehicle-to-the-world communication, for example, vehicle-to-vehicle (V2V) communication with other vehicles 143 and vehicle-to-infrastructure (V2I) communication with infrastructure 144. Furthermore, the communication device 112 may also have a module configured to communicate with a user terminal 145 (including but not limited to smartphones, tablets, or wearable devices such as watches) via, for example, a wireless local area network conforming to the IEEE 802.11 standard or Bluetooth. Using the communication device 112, the motor vehicle 110 can also access the server 120 via the network 130.

[0041] The motor vehicle 110 may also include a control unit 113. The control unit 113 may include a processor, such as a central processing unit (CPU) or a graphics processing unit (GPU), or other dedicated processors, that communicates with various types of computer-readable storage devices or media. The control unit 113 may include an autonomous driving system for automatically controlling various actuators in the vehicle. The autonomous driving system is configured to control the powertrain, steering system, and braking system of the motor vehicle 110 (not shown) via multiple actuators in response to inputs from multiple sensors 111 or other input devices to control acceleration, steering, and braking respectively, without human intervention or with limited human intervention. Some processing functions of the control unit 113 can be implemented via cloud computing. For example, some processing can be performed using an onboard processor while other processing can be performed using cloud computing resources. The control unit 113 may be configured to perform methods according to this disclosure. Furthermore, the control unit 113 may be implemented as an example of a computing device on the motor vehicle side (client) according to this disclosure.

[0042] Figure 1 The system 100 can be configured and operated in various ways to enable the application of various methods and apparatuses described in this disclosure. The following describes in detail a lidar ranging method according to embodiments of this disclosure.

[0043] Figure 2 A flowchart of a lidar ranging method 200 according to an embodiment of the present disclosure is shown. Figure 2 As shown, method 200 includes steps S201, S202, S203 and S204.

[0044] In step S201, the laser signal to be emitted and the timing start time for the laser signal to be emitted for ranging are determined. The laser signal is configured to have at least two emission intensities that alternate.

[0045] In the example, the laser signal can be emitted by an emitting module for emitting laser light, and the emitting module can include at least one laser. The laser can emit the laser signal directly at the object, or it can emit the laser signal at the object through reflection by a device such as a micro-electro-mechanical systems (MEMS) galvanometer.

[0046] In the example, the current time can be recorded at the same time the laser is emitted by the transmitting module, and used as the start time for ranging. Alternatively, the current time can be recorded at the same time the laser emitted by the transmitting module is reflected on a device such as a MEMS galvanometer, and used as the start time for ranging.

[0047] In the example, the laser signal can be emitted in an alternating pattern of strong and weak beams. The emission intensity of the laser signal can be adjusted by regulating the power supply voltage of the transmitting module, which in turn can be adjusted by changing the duty cycle of the PWM (Pulse Width Modulation).

[0048] In the ranging method according to embodiments of this disclosure, the emission intensity of the laser signal is positively correlated with the distance between the object and the lidar, thereby automatically balancing ranging accuracy for both distant and near objects. For example, a higher intensity laser signal, due to its longer detection range, is configured for ranging distant objects; a lower intensity laser signal, due to less interference from reflection at the protective glass of the transmitting module, is configured for ranging near objects. Furthermore, the laser signal can also be configured to include two or more emission intensities, such as three intensities in descending order, for ranging distant, medium-distance, and near objects, respectively.

[0049] In step S202, the laser signal reflected from the object is acquired.

[0050] In the example, the laser signal reflected from the object can be received by a receiving module, which may include at least one photoelectric converter for converting the received laser signal into an electrical signal.

[0051] In the example, since the transmitting module can be equipped with protective glass, when the laser signal is emitted onto the protective glass, it will be reflected. The reflected laser signal may be received by the receiving module, thus affecting the determination of the distance between the lidar and the object. The laser signal reflected from the protective glass by a high-intensity laser signal has a particularly large impact on the laser signal of a lower-intensity laser signal, and may even obliterate the lower-intensity laser signal. Therefore, by emitting laser signals in an alternating pattern of strong and weak signals, the adverse effects of laser signal reflection at non-range-finding targets such as protective glass can be reduced.

[0052] In step S203, the timing end time is determined by triggering a logic level flip by comparing the received intensity of the reflected laser signal with an adjustable reference threshold. The adjustable reference threshold is determined based on the received intensity of the laser signal.

[0053] In the example, upon acquiring a laser signal reflected from an object, the range of received laser signal intensity can be determined, such as whether it is a strong or weak signal, and an adjustable reference threshold can be determined based on this received intensity. For example, the range of received laser signal intensity can be determined by pre-setting several thresholds and comparing the received intensity with each threshold.

[0054] In the example, the intensity of the received reflected laser signal can be compared with an adjustable reference threshold. If the intensity of the received reflected laser signal is greater than or equal to the adjustable reference threshold, a logic level toggle is triggered to end the ranging timer; if the intensity of the received reflected laser signal is less than the adjustable reference threshold, no logic level toggle is triggered, meaning no valid ranging is obtained at this time.

[0055] In the example, the current time can be recorded simultaneously with the logic level transition, serving as the end time for distance measurement timing. The logic level can include both "0" and "1" states. The current time can be recorded simultaneously with the logic level changing from "0" to "1", serving as the end time for distance measurement timing; alternatively, the current time can be recorded simultaneously with the logic level changing from "1" to "0".

[0056] In the example, the adjustable reference threshold can be a light intensity value, used to compare with the intensity of the received laser signal to determine whether a logic level toggle is triggered, thereby determining the timing end time. Alternatively, the adjustable reference threshold can be a voltage value determined based on the light intensity value, used to compare with the voltage of the electrical signal converted from the received laser signal to determine whether a logic level toggle is triggered, thereby determining the timing end time.

[0057] In the ranging method according to embodiments of the present disclosure, determining an adjustable reference threshold based on the intensity of the received laser signal enables more dynamic ranging, resulting in more accurate ranging results. For example, if the intensity of the received laser signal is low, it means that the laser signal may originate from a nearby object, and therefore a smaller adjustable reference threshold can be used accordingly. Similarly, if the intensity of the received laser signal is high, it means that the laser signal may originate from a distant object, and therefore a larger adjustable reference threshold can be used accordingly.

[0058] In step S204, the distance between the lidar and the object is determined based on the timing start time and timing end time.

[0059] In the example, the total length of the optical path from the emission of the laser signal to its reception can be calculated by multiplying the difference between the start and end times of the timing by the speed of light. Therefore, the distance between the lidar and the object can be calculated by half the length of the optical path.

[0060] According to the lidar ranging method of this disclosure, by emitting laser signals with at least two alternating emission intensities, the ranging accuracy for both distant and near objects can be automatically balanced. Simultaneously, by determining an adjustable reference threshold based on the received intensity of the reflected laser signal, and by triggering a logic level flip based on a comparison between the received intensity of the reflected laser signal and the adjustable reference threshold to determine the timing end time, not only can more dynamic ranging be achieved for both near and far objects, but the influence of interference signals from non-ranged target objects can also be eliminated to a certain extent, thereby achieving more accurate lidar ranging results.

[0061] The following further describes various aspects of the lidar ranging method according to embodiments of the present disclosure.

[0062] According to some embodiments, determining the timing end time by triggering a logic level flip based on a comparison between the received intensity of the reflected laser signal and an adjustable reference threshold may include: determining the time when the reflected laser signal is received as the timing end time in response to the received intensity of the reflected laser signal being greater than or equal to the adjustable reference threshold.

[0063] In the example, the intensity of the received reflected laser signal can be compared with an adjustable reference threshold. If the intensity of the received reflected laser signal is greater than or equal to the adjustable reference threshold, the current time can be recorded as the end time for ranging. If the intensity of the received reflected laser signal is less than the adjustable reference threshold, no logic level toggles will be triggered, meaning that a valid ranging measurement has not yet been obtained. Therefore, the received reflected laser signal can continue to be received, and the comparison process can be repeated until a valid ranging measurement is obtained.

[0064] Figure 3 A schematic diagram is shown illustrating a method for determining the timing end time based on a comparison between the received intensity of a laser signal and an adjustable reference threshold, according to an embodiment of this disclosure. This process for determining the timing end time can, for example, correspond to... Figure 2 Step S203.

[0065] As mentioned earlier, the adjustable reference threshold is determined based on the received intensity of the laser signal. In this example, the adjustable reference threshold could be a voltage value, used to compare with the voltage of the electrical signal converted from the received laser signal to determine whether a logic level flip is triggered, thereby determining the timing end time.

[0066] like Figure 3 As shown, in the example, the received reflected laser signal can be converted into a pulse signal in the form of a voltage. Figure 3The diagram schematically illustrates the reception of a low-intensity laser signal L1 and a high-intensity laser signal L2. The electrical signal converted from laser signal L1 can have a voltage V1, and the electrical signal converted from laser signal L2 can have a voltage V2. A first adjustable reference threshold V can be determined based on voltages V1 and V2, respectively. th1 Second adjustable reference threshold V th2 The voltages V1 and V2 of laser signals L1 and L2 can be compared with a first adjustable reference threshold V. th1 Second adjustable reference threshold V th2 The comparisons are made to determine the end time of the timing.

[0067] In the example, the voltage V1 of the electrical signal converted from the low-intensity laser signal L1 is less than the first adjustable reference threshold V. th1 Therefore, no logic level flip will be triggered, and the time T1 when the laser signal L1 is received will not be recorded as the timing end time. The voltage V2 of the electrical signal converted from the high-intensity laser signal L2 is greater than the second adjustable reference threshold V. th2 Therefore, the logic level is triggered to flip, and the time T2 when the laser signal L2 is received can be recorded as the timing end time.

[0068] In the example, the logic level can include both "0" and "1" states. Logic level toggling can include the case where the logic level changes from a state of "0" to "1"; it can also include the case where the logic level changes from a state of "1" to "0".

[0069] Understandable. Figure 3 This illustrates one scenario where the received intensity of the reflected laser signal is compared to an adjustable reference threshold. The adjustable reference threshold can also be a light intensity value, used to compare with the intensity of the received laser signal to determine whether a logic level toggle is triggered, thereby determining the timing end time. The received laser signal can also be at other times and / or have other intensities. The adjustable reference threshold can also have other values ​​and / or representations.

[0070] In some embodiments, vehicles may perform lidar ranging in special weather conditions such as rain, snow, or dense fog. In these conditions, nearby water droplets or snowflakes may reflect strong laser signals intended for ranging distant objects, affecting the accuracy of lidar ranging. In such special weather conditions, the adjustable reference threshold for distant objects can be set higher than in normal clear weather to avoid interference from water droplets or snowflakes, thus preventing any impact on the ranging results.

[0071] According to the process for determining the timing end time according to the embodiments of this disclosure, by determining the time when the received intensity of the reflected laser signal is greater than or equal to the adjustable reference threshold as the timing end time, the timing end of the ranging can be accurately triggered, thereby achieving more accurate lidar ranging results.

[0072] According to some embodiments, the distance between the lidar and the object can be calculated using the formula L = c * (t2 - t1) / 2, where L is the distance, c is the speed of light, t1 is the start time of timing, and t2 is the end time of timing.

[0073] In the example, the total length of the optical path of the laser signal from emission to reception can be calculated by multiplying the difference between the start and end times of the timing by the speed of light. The distance between the lidar and the object can be calculated by half the length of the optical path.

[0074] According to the calculation process of the distance between the lidar and the object in the embodiments of this disclosure, the accurate distance between the lidar and the object can be obtained by using the propagation time of the light path and the speed of light.

[0075] According to some embodiments, the laser signal can be emitted alternately at a first intensity and a second intensity, wherein the second intensity is greater than the first intensity.

[0076] In the example, the power supply voltage of the transmitting module can be adjusted by changing the duty cycle of the PWM, thereby adjusting the intensity of the emitted laser signal to either the first or second intensity.

[0077] In the example, the second intensity laser signal can be used to measure the distance of objects at a greater distance because of its larger detection range; the first intensity laser signal can be used to measure the distance of objects at a closer distance because of its smaller reflection at the protective glass of the transmitting module.

[0078] Figure 4 A schematic diagram of ranging between near and far objects according to an embodiment of the present disclosure is shown.

[0079] like Figure 4 As shown, a vehicle 410 performing lidar ranging using the lidar ranging method of this disclosure embodiment is illustrated, along with an object 420 at a small distance from the vehicle 410 and an object 430 at a large distance from the vehicle 410.

[0080] In the example, vehicle 410 can emit multiple laser signals, each laser signal being configured to have an alternating first and second intensity, the second intensity being greater than the first intensity. (The following is a continuation of the previous sentence.) Figure 4The first laser signal 411 and the second laser signal 412 are illustrated schematically in the diagram for illustration.

[0081] In the example, the first laser signal 411, with its lower first intensity, has less reflection at the protective glass of the transmitting module, making it more accurate for ranging nearby objects, and can be used to range objects 420 that are relatively close. However, because of its lower intensity, the first laser signal 411 also has a shorter detection range, and therefore may not be able to detect objects 430 that are farther away. On the other hand, the second laser signal 412, with its higher second intensity, has a longer detection range and can detect objects 430 that are farther away, and can therefore be used to accurately range objects 430.

[0082] According to the ranging process for near and far objects in the embodiments of this disclosure, by emitting laser signals with two alternating intensities, the accuracy of lidar ranging for both near and far objects can be achieved in a simple manner.

[0083] According to some embodiments, a lidar may include a MEMS mirror with a horizontal axis and a vertical axis, wherein the emitted laser signal is scanned on the horizontal and vertical axes respectively by the MEMS mirror. The laser signal is scanned on the horizontal axis at non-equal time intervals so that the scanning angle between the two scan paths of two adjacent laser signal emissions is the same.

[0084] The horizontal and vertical axes of a MEMS galvanometer are also referred to as the fast and slow axes. That is, the scanning frequency on the horizontal axis is fast, while the scanning frequency on the vertical axis is slow.

[0085] In some embodiments, the emitted laser signal can scan an angle range of 30 degrees on the horizontal axis, such as a range of 15 degrees above and below the horizontal position of the MEMS mirror.

[0086] In some embodiments, the scanning angle between the two scanning paths of two adjacent laser signals emitted on the horizontal axis can be, for example, 0.1 degrees, 0.2 degrees, etc.

[0087] According to the scanning process of the lidar in the embodiments of this disclosure, by making the scanning angle between the two scanning paths of two adjacent laser signal emission the same during the scanning process, the point cloud distribution of the laser signal can be made uniform, which is beneficial to subsequent data processing, so that the lidar ranging result can be calculated more conveniently.

[0088] According to some embodiments, the scanning waveform on the horizontal axis can be a sine wave, and the scanning waveform on the vertical axis can be a triangular wave.

[0089] Figure 5 A schematic diagram of the scanning waveform of the horizontal axis of a MEMS galvanometer according to an embodiment of the present disclosure is shown.

[0090] like Figure 5 As shown, this schematically illustrates a continuous scanning process involving the emission of laser signals over a time interval from t0 to t4. The scanning waveform on the horizontal axis can be a sine wave, and the points on the sine wave can represent the emitted laser signals.

[0091] In the example, during the time period from t0 to t1, in order to make the scanning angle between the two scanning paths of two adjacent laser signal emission events the same, the time interval of the laser signal scanning on the horizontal axis can be gradually reduced during the time period from t0 to t1, that is, the point frequency becomes more dense.

[0092] In the example, during the time period from t1 to t2, in order to make the scanning angle between the two scanning paths of two adjacent laser signal emission the same, the time interval of the laser signal scanning on the horizontal axis can be gradually increased during the time period from t1 to t2, that is, the point frequency becomes sparser.

[0093] In the example, during the time period from t2 to t3, in order to make the scanning angle between the two scanning paths of two adjacent laser signal emission events the same, the time interval of the laser signal scanning on the horizontal axis can be gradually reduced during the time period from t2 to t3, that is, the point frequency becomes more dense.

[0094] In the example, during the time period from t3 to t4, in order to make the scanning angle between the two scanning paths of two adjacent laser signal emission events the same, the time interval of the laser signal scanning on the horizontal axis can be gradually increased during the time period from t3 to t4, that is, the point frequency becomes sparser.

[0095] Understandable. Figure 5 The diagram shows one cycle of the scanning waveform on the horizontal axis. During the scanning time outside the shown time period, the emitted laser signal can follow the same pattern.

[0096] Similarly, it can be understood that laser signals can be like... Figure 5 As shown, the signal is emitted several times, for example, dozens of times, within one scan cycle of the horizontal axis according to the scan cycle of the horizontal axis.

[0097] Figure 6 A schematic diagram showing the superposition of horizontal and vertical scanning waveforms of a MEMS galvanometer according to an embodiment of the present disclosure is shown.

[0098] like Figure 6 As shown, the scanning waveform on the horizontal axis can be a sine wave, and the scanning waveform on the vertical axis can be a triangular wave. The time period from t5 to t7 can represent one cycle of the scanning waveform on the vertical axis, and the frequency can be, for example, 10 to 20 Hz.

[0099] In the example, such as Figure 6As shown, the frequency of the scanning triangular wave on the vertical axis can be much greater than the frequency of the scanning sine wave on the horizontal axis. In this way, within one scanning cycle on the vertical axis, for example, within the time period from t5 to t7, a large number of laser signal emissions can be performed, forming a dense laser signal point cloud.

[0100] According to the scanning process of the lidar in the embodiments of this disclosure, by setting the scanning waveform on the horizontal axis to a sine wave and the scanning waveform on the vertical axis to a triangular wave, it is beneficial to process the laser signal and make it easier to calculate the lidar ranging result.

[0101] According to some embodiments, the operations of determining the timing end time for ranging and determining the distance between the lidar and the object can be performed during the first waveform portion of the triangular wave with a slope greater than zero.

[0102] See also Figure 6 ,like Figure 6 As shown, the first waveform portion can be the time period from t5 to t6 when the slope of the triangular wave is greater than zero. That is, the operations of determining the timing end time for ranging and determining the distance between the lidar and the object can be performed during the time period from t5 to t6.

[0103] In the example, within one scan cycle on the vertical axis, for example, the time period from t5 to t7, the first waveform portion where the slope of the triangular wave is greater than zero, i.e., the time period from t5 to t6, can be set to be much longer than the period where the slope of the triangular wave is less than zero, i.e., the time period from t6 to t7. This allows for a larger proportion of time allocated to determining the timing end time for ranging and determining the distance between the lidar and the object, resulting in more efficient lidar ranging.

[0104] According to embodiments of this disclosure, by setting the operation of timing the end time for ranging and the operation of determining the distance between the lidar and the object to be performed during the first waveform portion of the triangular wave with a slope greater than zero, it is possible to avoid the impact of errors arising from bottom-to-top and top-to-bottom scanning on the vertical axis on data processing, thereby improving the accuracy of lidar ranging.

[0105] According to some embodiments, the lidar ranging method may further include monitoring the transmission and reception of a laser signal during a second waveform portion in which the slope of the triangular wave is less than zero.

[0106] See also Figure 6 ,like Figure 6 As shown, the second waveform portion can be, for example, the time period t6 to t7 during which the slope of the triangular wave is less than zero. For example, the emission and reception of the laser signal can be monitored during the time period t6 to t7.

[0107] According to embodiments of this disclosure, by monitoring the emission and reception of the laser signal during the second waveform portion where the slope of the triangular wave is less than zero, parameters such as the emission intensity and adjustable reference threshold of the laser signal can be adjusted in a timely manner based on the emission and reception status of the laser signal, thereby improving the accuracy of lidar ranging.

[0108] Therefore, within one cycle of the vertical axis scanning waveform, a period of time (e.g., the time interval from t5 to t6) can be used for ranging, while another period of time (e.g., from t6 to t7) can be left unused for ranging. This unused period of time can be 1 / 20 to 1 / 8 of the cycle. The switching between these two operations can be performed, for example, using an analog switch selector.

[0109] According to some embodiments, at least two intensities of the laser signal can be controlled by at least two duty cycles generated by PWM.

[0110] In the example, the amplitude of the pulse width modulation signal can be, for example, 3.3V, and the pulse frequency can be, for example, 400kHz. When emitting a low-intensity laser signal, the high-level time of the pulse width modulation signal can be, for example, greater than or equal to 20ns and less than or equal to 40ns. When emitting a high-intensity laser signal, the high-level time of the pulse width modulation signal can be, for example, greater than or equal to 40ns and less than or equal to 150ns.

[0111] According to the laser signal intensity control process of the present disclosure, the intensity of the laser signal is controlled by utilizing the duty cycle generated by pulse width modulation, which can conveniently and reliably achieve control of the laser signal intensity.

[0112] According to another aspect of this disclosure, a lidar ranging device is also provided.

[0113] Figure 7 A structural block diagram of a lidar ranging device 700 according to an embodiment of the present disclosure is shown.

[0114] like Figure 7As shown, the lidar ranging device 700 includes: a laser emission determination module 710 configured to determine a laser signal to be emitted and a timing start time for the laser signal to be emitted for ranging, wherein the laser signal is configured to have at least two emission intensities that alternately change; a laser reflection acquisition module 720 configured to acquire a laser signal reflected from an object; a time determination module 730 configured to determine a timing end time by triggering a logic level flip based on a comparison result between the received intensity of the reflected laser signal and an adjustable reference threshold, wherein the adjustable reference threshold is determined based on the received intensity of the laser signal; and a distance determination module 740 configured to determine the distance between the lidar and the object based on the timing start time and the timing end time.

[0115] Since the laser emission determination module 710, laser reflection acquisition module 720, time determination module 730, and distance determination module 740 in the lidar ranging device 700 can respectively correspond to, as Figure 2 The details of steps S201 to S204 are not elaborated here.

[0116] Furthermore, the lidar ranging device 700 and its included modules may also include further sub-modules, which will be combined as follows Figure 8 A detailed explanation will be provided.

[0117] According to embodiments of this disclosure, by emitting laser signals with at least two alternating emission intensities, ranging accuracy for both distant and near objects can be automatically balanced. Simultaneously, by determining an adjustable reference threshold based on the received intensity of the reflected laser signal, and by triggering a logic level flip based on a comparison between the received intensity of the reflected laser signal and the adjustable reference threshold to determine the timing end time, not only can more dynamic ranging be achieved for both near and far objects, but the influence of interference signals from non-ranged targets can also be eliminated to some extent, thereby achieving more accurate lidar ranging results.

[0118] Figure 8 A structural block diagram of a lidar ranging device 800 according to another embodiment of the present disclosure is shown.

[0119] like Figure 8 As shown, the lidar ranging device 800 may include a laser emission determination module 810, a laser reflection acquisition module 820, a time determination module 830, and a distance determination module 840. The laser emission determination module 810, laser reflection acquisition module 820, time determination module 830, and distance determination module 840 can be coupled with... Figure 7The laser emission determination module 710, laser reflection acquisition module 720, time determination module 730 and distance determination module 740 shown correspond to each other, so their details will not be described again here.

[0120] In the example, the time determination module 830 may include: an execution module 831 configured to determine the time when the reflected laser signal is received as the timing end time in response to the received intensity of the reflected laser signal being greater than or equal to an adjustable reference threshold.

[0121] Therefore, by determining the time when the reflected laser signal is received as the timing end time when the received intensity of the reflected laser signal is greater than or equal to the adjustable reference threshold, the timing end of the ranging can be accurately triggered, thereby achieving more accurate lidar ranging results.

[0122] In the example, the distance between the lidar and the object can be calculated using the formula L = c * (t2 - t1) / 2, where L is the distance, c is the speed of light, t1 is the start time of the timing, and t2 is the end time of the timing.

[0123] Therefore, by using the propagation time of light and the speed of light to calculate the distance between the lidar and the object, the accurate distance between the lidar and the object can be obtained.

[0124] In the example, the laser signal can be emitted alternately at a first intensity and a second intensity, with the second intensity being greater than the first intensity.

[0125] Therefore, by emitting laser signals with alternating intensities, it is possible to achieve accurate lidar ranging for both distant and near objects in a simple manner.

[0126] In the example, the lidar may include a MEMS mirror with a horizontal axis and a vertical axis, and the emitted laser signal may be scanned on the horizontal axis and the vertical axis respectively via the MEMS mirror. The laser signal is scanned on the horizontal axis at non-equal time intervals so that the scanning angle between the two scanning paths of two adjacent laser signal emissions is the same.

[0127] Therefore, by making the scanning angles of the two scanning paths that emit laser signals in two adjacent scans the same during the scanning process, the point cloud distribution of the laser signal can be made uniform, which is beneficial to subsequent data processing and makes it easier to calculate the laser radar ranging results.

[0128] In the example, the scanning waveform on the horizontal axis can be a sine wave, and the scanning waveform on the vertical axis can be a triangular wave.

[0129] Therefore, by setting the scanning waveform on the horizontal axis to a sine wave and the scanning waveform on the vertical axis to a triangular wave, it is beneficial to process the laser signal and make it easier to calculate the laser radar ranging result.

[0130] In the example, the operations of determining the end time of the timing and determining the distance between the lidar and the object can be performed during the first waveform portion of the triangular wave when the slope is greater than zero.

[0131] Therefore, by setting the operation of timing the end time for ranging and the operation of determining the distance between the lidar and the object to be performed during the first waveform portion of the triangular wave with a slope greater than zero, the impact of errors caused by the scanning from bottom to top and from top to bottom on the vertical axis on data processing can be avoided, thereby improving the accuracy of lidar ranging.

[0132] In the example, the lidar ranging device 800 may also include a laser signal monitoring module 850, configured to monitor the transmission and reception of the laser signal during the second waveform portion of the triangular wave when the slope is less than zero.

[0133] Therefore, by monitoring the emission and reception of the laser signal during the second waveform portion of the triangular wave when the slope is less than zero, parameters such as the emission intensity and adjustable reference threshold of the laser signal can be adjusted in a timely manner according to the emission and reception status of the laser signal, thereby improving the accuracy of lidar ranging.

[0134] In the example, at least two intensities of the laser signal can be controlled by at least two duty cycles generated by pulse width modulation.

[0135] Therefore, by using the duty cycle generated by pulse width modulation to control the intensity of the laser signal, it is possible to conveniently and reliably control the intensity of the laser signal.

[0136] According to another aspect of this disclosure, a lidar system is also provided.

[0137] Figure 9 A schematic diagram of the structure of a lidar system 900 according to an embodiment of the present disclosure is shown.

[0138] like Figure 9As shown, the lidar system 900 includes: an FPGA chip 910 configured to perform the methods described in the above embodiments; a transmitting device 920 for transmitting a laser signal and connected to the FPGA chip 910, wherein the laser signal and the timing start time for transmitting the laser signal are determined by the FPGA chip 910, and the laser signal is configured to have at least two alternating intensities; a receiving device 930 for receiving a laser signal reflected from an object and connected to the FPGA chip 910 to provide the reflected laser signal to the FPGA chip 910; and a scanning device 940 including a MEMS galvanometer and... Connected to the FPGA chip 910, the MEMS galvanometer is configured to adjust the scanning angle of the laser signal by rotating on the horizontal and vertical axes, wherein the scanning angle is determined by the FPGA chip 910; and a voltage adjustment device 950 is used to generate an adjustable reference threshold and is connected to the FPGA chip 910 to provide the adjustable reference threshold to the FPGA chip 910, the adjustable reference threshold being used to determine the timing end time for the lidar to perform ranging; wherein at least one of the FPGA chip 910, the transmitting device 920, the receiving device 930, the scanning device 940 and the voltage adjustment device 950 is monitored in a closed loop.

[0139] In the example, such as Figure 9 As shown, the FPGA chip 910 can be interconnected with the transmitter 920, the receiver 930, the scanner 940, and the voltage regulator 950.

[0140] In this example, the FPGA chip 910 and the transmitting device 920 can have bidirectional information transmission. For example, the FPGA chip 910 can send information to the transmitting device 920 indicating the intensity of the laser signal and the timing start time for laser signal transmission. The FPGA chip 910 can adjust the transmission power supply boost circuit (transmitter charging and discharging circuit) via PWM to cause the transmitting device 920 to emit laser signals with at least two alternating intensities. For example, the transmitting device 920 can send information to the FPGA chip 910 indicating the intensity of the actually emitted laser signal and the actual emission time of the laser signal. The transmitting device 920 can feed back the generated laser signal to the FPGA chip 910 via an optocoupler (voltage amplitude, for example, 1.5V). In this way, the transmitting device 920 is monitored in a closed loop, enabling more accurate timing and avoiding the adverse effects of electromagnetic interference on timing and ranging.

[0141] In this example, the FPGA chip 910 and the receiving device 930 can have a one-way information transmission relationship. For example, the receiving device 930 can send information to the FPGA chip 910 that indicates the intensity of the received laser signal and the reception time of the laser signal.

[0142] In this example, the FPGA chip 910 and the scanning device 940 can have a bidirectional information transmission relationship. For example, the FPGA chip 910 can send information (e.g., scanning angle, frequency, period, etc.) to the scanning device 940 that instructs the laser signal to scan along the horizontal and vertical axes of the MEMS galvanometer. The scanning device 940, for example, can transmit the feedback voltage to the FPGA chip 910 via a built-in feedback module through a D / A (Digital / Analog Converter). In this way, the scanning device 940 is monitored in a closed loop, enabling more precise control of the scanning angle and improving the accuracy of the lidar ranging.

[0143] In this example, the FPGA chip 910 and the voltage regulator 950 can have bidirectional information transmission. For example, the FPGA chip 910 can send information to the voltage regulator 950 indicating the intensity of the received laser signal. The voltage regulator 950 can, for example, send to the FPGA chip 910 the magnitude of an adjustable reference threshold determined based on the intensity of the received laser signal. In this way, the voltage regulator 950 is monitored in a closed loop, enabling more accurate control of the adjustable reference threshold.

[0144] In the example, an adjustable reference threshold can be generated using a D / A converter and an operational amplifier. A weaker adjustable reference threshold can be set, for example, to 0.4–0.5V, while a stronger adjustable reference threshold can be set, for example, to 0.6–0.7V, to be used for different received laser signal intensities, i.e., different distances. The received laser signal and the adjustable reference threshold can be compared at the LVDS (Low-Voltage Differential Signaling) terminal of the FPGA chip 910 to trigger a logic level toggle, thereby triggering the end of the ranging timing.

[0145] In the example, the lidar system 900 may also include a power monitoring module connected to the FPGA chip 910 to achieve closed-loop monitoring of the power supply through D / A conversion.

[0146] In the example, the FPGA chip 910 can perform closed-loop monitoring via an external watchdog program or chip. This enables closed-loop monitoring of the entire LiDAR system 900.

[0147] According to the lidar system of the present disclosure, by monitoring the FPGA chip, transmitting device, receiving device, scanning device and voltage adjustment device in the lidar system in a closed loop, the system can adjust the intensity of the laser signal and the timing of transmission, the power supply voltage, the scanning direction and data processing in a timely manner according to the actual situation, thereby improving the accuracy of lidar ranging.

[0148] According to another aspect of this disclosure, an electronic device is also provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the methods described above.

[0149] According to another aspect of this disclosure, a non-transitory computer-readable storage medium storing computer instructions is also provided, wherein the computer instructions are used to cause a computer to perform the methods described above.

[0150] According to another aspect of this disclosure, a computer program product is also provided, including a computer program, wherein the computer program implements the methods described in the above embodiments when executed by a processor.

[0151] According to another aspect of this disclosure, an FPGA chip is also provided, including circuitry for implementing the methods described in the above embodiments.

[0152] According to another aspect of this disclosure, an autonomous vehicle is also provided, including an FPGA chip, wherein the FPGA chip is configured to perform the methods described above.

[0153] refer to Figure 10 The present invention describes a structural block diagram of an electronic device 1000 that can serve as a server or client of the present disclosure, which is an example of a hardware device that can be applied to various aspects of the present disclosure. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0154] like Figure 10As shown, the electronic device 1000 includes a computing unit 1001, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 1002 or a computer program loaded from a storage unit 1008 into a random access memory (RAM) 1003. The RAM 1003 may also store various programs and data required for the operation of the electronic device 1000. The computing unit 1001, ROM 1002, and RAM 1003 are interconnected via a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0155] Multiple components in electronic device 1000 are connected to I / O interface 1005, including: input unit 1006, output unit 1007, storage unit 1008, and communication unit 1009. Input unit 1006 can be any type of device capable of inputting information to electronic device 1000. Input unit 1006 can receive input digital or character information and generate key signal inputs related to user settings and / or function control of electronic device, and may include, but is not limited to, a mouse, keyboard, touchscreen, trackpad, trackball, joystick, microphone, and / or remote control. Output unit 1007 can be any type of device capable of presenting information, and may include, but is not limited to, a monitor, speaker, video / audio output terminal, vibrator, and / or printer. Storage unit 1008 may include, but is not limited to, a hard disk and an optical disk. The communication unit 1009 allows the electronic device 1000 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks, and may include, but is not limited to, modems, network cards, infrared communication devices, wireless communication transceivers and / or chipsets, such as Bluetooth™ devices, 802.11 devices, WiFi devices, WiMax devices, cellular communication devices and / or the like.

[0156] The computing unit 1001 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 1001 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 1001 performs the various methods and processes described above, such as the lidar ranging method. For example, in some embodiments, the lidar ranging method can be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as storage unit 1008. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 1000 via ROM 1002 and / or communication unit 1009. When the computer program is loaded into RAM 1003 and executed by the computing unit 1001, one or more steps of the lidar ranging method described above can be performed. Alternatively, in other embodiments, the computing unit 1001 may be configured to perform a lidar ranging method by any other suitable means (e.g., by means of firmware).

[0157] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0158] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0159] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0160] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0161] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or middleware components (e.g., application servers), or frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), the Internet, and blockchain networks.

[0162] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0163] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0164] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the methods, systems, and devices described above are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A lidar ranging method, comprising: The laser signal to be emitted and the timing start time for the laser signal to be emitted for ranging are determined, wherein the laser signal is configured to have at least two emission intensities that vary alternately, the lidar includes a microelectromechanical system (MEMS) galvanometer having a horizontal axis and a vertical axis, the emitted laser signal being scanned by the MEMS galvanometer on the horizontal axis and the vertical axis respectively, wherein the laser signal is scanned on the horizontal axis at non-equal time intervals such that the scanning angle between the two scan paths of two adjacent laser signal emitting is the same; Acquire the laser signal reflected from the object; The timing end time is determined by triggering a logic level flip through a comparison between the received intensity of the reflected laser signal and an adjustable reference threshold, wherein the adjustable reference threshold is determined based on the received intensity of the laser signal, and the determination of the timing end time includes: Based on the received intensity of the laser signal, a corresponding threshold is selected from at least two preset thresholds as the adjustable reference threshold; In response to the received intensity of the reflected laser signal being greater than or equal to the adjustable reference threshold, the time at which the reflected laser signal is received is determined as the timing end time; and The distance between the lidar and the object is determined based on the timing start time and the timing end time.

2. The method according to claim 1, wherein, The distance between the lidar and the object is calculated using the formula L=c×(t2-t1) / 2, where L is the distance, c is the speed of light, t1 is the start time of the timing, and t2 is the end time of the timing.

3. The method according to claim 1 or 2, wherein, The laser signal is emitted alternately at a first intensity and a second intensity, wherein the second intensity is greater than the first intensity.

4. The method according to claim 1, wherein, The scanning waveform on the horizontal axis is a sine wave, and the scanning waveform on the vertical axis is a triangular wave.

5. The method according to claim 4, wherein, The operations of determining the end time of the timing and the operations of determining the distance between the lidar and the object are performed during the first waveform portion of the triangular wave when the slope is greater than zero.

6. The method according to claim 4, further comprising: The emission and reception of the laser signal are monitored during the second waveform portion of the triangular wave when the slope is less than zero.

7. The method according to claim 1 or 2, wherein, The at least two emission intensities of the laser signal are controlled by at least two duty cycles generated by pulse width modulation.

8. A lidar ranging device, comprising: A laser emission determination module is configured to determine a laser signal to be emitted and a timing start time for the laser signal to be emitted for ranging, wherein the laser signal is configured to have at least two emission intensities that alternately vary, the lidar includes a microelectromechanical system (MEMS) galvanometer having a horizontal axis and a vertical axis, the emitted laser signal being scanned by the MEMS galvanometer on the horizontal axis and the vertical axis respectively, wherein the laser signal is scanned on the horizontal axis at non-equal time intervals such that the scanning angle between the two scan paths of two adjacent laser signal emissions is the same; A laser reflection acquisition module is configured to acquire the laser signal reflected from the object; A timing determination module is configured to determine a timing end time by triggering a logic level flip based on a comparison between the received intensity of the reflected laser signal and an adjustable reference threshold, wherein the adjustable reference threshold is determined based on the received intensity of the laser signal. The timing determination module includes a threshold determination module and an execution module. The threshold determination module is configured to select one of at least two preset thresholds as the adjustable reference threshold based on the received intensity of the laser signal. The execution module is configured to determine the time when the reflected laser signal is received as the timing end time in response to the received intensity of the reflected laser signal being greater than or equal to the adjustable reference threshold; and The distance determination module is configured to determine the distance between the lidar and the object based on the timing start time and the timing end time.

9. The apparatus according to claim 8, wherein, The distance between the lidar and the object is calculated using the formula L=c×(t2-t1) / 2, where L is the distance, c is the speed of light, t1 is the start time of the timing, and t2 is the end time of the timing.

10. The apparatus according to claim 8 or 9, wherein, The laser signal is emitted alternately at a first intensity and a second intensity, wherein the second intensity is greater than the first intensity.

11. The apparatus according to claim 8, wherein, The scanning waveform on the horizontal axis is a sine wave, and the scanning waveform on the vertical axis is a triangular wave.

12. The apparatus according to claim 11, wherein, The operations of determining the end time of the timing and the operations of determining the distance between the lidar and the object are performed during the first waveform portion of the triangular wave when the slope is greater than zero.

13. The apparatus of claim 11, further comprising: A laser signal monitoring module is configured to monitor the transmission and reception of the laser signal during the second waveform portion of the triangular wave when the slope is less than zero.

14. The apparatus according to claim 8 or 9, wherein, The at least two emission intensities of the laser signal are controlled by at least two duty cycles generated by pulse width modulation.

15. A lidar system, comprising: An FPGA chip is configured to perform the method according to any one of claims 1-7; A transmitting device for emitting a laser signal and connected to the FPGA chip, wherein the laser signal and the timing start time for emitting the laser signal are determined by the FPGA chip, and the laser signal is configured to have at least two alternating intensities; A receiving device is configured to receive the laser signal reflected from an object and to connect to the FPGA chip to provide the reflected laser signal to the FPGA chip. A scanning device includes a microelectromechanical system (MEMS) galvanometer and is connected to the FPGA chip. The MEMS galvanometer is configured to adjust the scanning angle of the laser signal by rotating on a horizontal and vertical axis, wherein the scanning angle is determined by the FPGA chip. A voltage regulation device is used to generate an adjustable reference threshold and is connected to the FPGA chip to provide the adjustable reference threshold to the FPGA chip. The adjustable reference threshold is used to determine the timing end time for the lidar to perform ranging. Among them, at least one of the FPGA chip, the transmitting device, the receiving device, the scanning device, and the voltage regulating device is monitored in a closed loop.

16. An electronic device comprising: At least one processor; as well as A memory that is communicatively connected to the at least one processor; in The memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method of any one of claims 1-7.

17. A non-transitory computer-readable storage medium storing computer instructions, wherein, The computer instructions are used to cause the computer to perform the method according to any one of claims 1-7.

18. A computer program product comprising a computer program, wherein, The computer program, when executed by a processor, implements the method according to any one of claims 1-7.

19. An FPGA chip comprising circuitry implementing the method according to any one of claims 1-7.

20. An autonomous vehicle, comprising an FPGA chip, wherein, The FPGA chip is configured to perform the method according to any one of claims 1-7.

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