A system for controlling laser beam emission using multiple scanning patterns by an optical sensing device

Abstract

Embodiments of the present specification provide a system for controlling laser beam emission by an optical sensing device using a plurality of scan patterns. The plurality of scan patterns overlap the field of view of the optical sensing device in a staggered manner. The system includes a controller configured to detect an object within a functional distance range from the optical sensing device based on reflected light of a first laser beam received by the optical sensing device. The first laser beam is emitted in a first scan pattern toward a first scan point. The controller is further configured to determine an aperture extending from the first scan point and control the optical sensing device to emit a second laser beam in a second scan pattern toward a second scan point and skip scan points in the aperture between the first scan point and the second scan point.

Description

[0001] CLAIM OF PRIORITY

[0002] This application claims priority to U.S. Patent Application No. 17 / 476,157, filed September 15, 2021. TECHNICAL FIELD

[0003] This specification relates to light detection and ranging (LiDAR) systems, and more specifically, to systems and methods for dynamic laser emission control in LiDAR systems. BACKGROUND

[0004] Optical sensing systems such as LiDAR systems have been widely used in autonomous driving and high-definition mapping. For example, a typical LiDAR system measures the distance to a target by illuminating the target with a pulsed laser beam and measuring the reflected pulses with a sensor such as a photodetector. The difference in laser return times, wavelengths, and / or phases can then be used to construct a digital three-dimensional (3D) representation of the target. Because using a narrow laser beam as incident light can map physical features with very high resolution, LiDAR systems are particularly suitable for sensing applications in autonomous driving and / or high-definition mapping measurement.

[0005] LiDAR systems can use transmitters to transmit signals (e.g., pulsed laser light) into the surrounding environment and use receivers to collect returned signals (e.g., laser light reflected by surrounding objects). The LiDAR system can then calculate parameters such as the distance between the object and the LiDAR system based on the speed of light and the signal propagation time (e.g., the duration between the time of signal transmission and the time of receiving the returned signal), and use these parameters to construct a three-dimensional map and / or model of the surroundings. In order to improve the detection range and signal-to-noise ratio, high-energy laser is usually required. However, on the other hand, the energy of the signal also needs to be limited to avoid potential harm to the eyes. Therefore, it is a challenge to balance the performance requirements and regulatory safety requirements in the development of LiDAR systems.

[0006] Embodiments of the present specification address the above challenges by providing improved systems and methods for dynamically controlling laser emission used in LiDAR systems. SUMMARY

[0007] The embodiments of the present specification provide a system for controlling laser beam emission by an optical sensing device using multiple scan patterns. The multiple scan patterns interleave to cover a field of view of the optical sensing device, the system comprising: a controller configured to: detect an object within a functional distance range from the optical sensing device based on reflected light of a first laser beam received by the optical sensing device, wherein the first laser beam is emitted toward a first scan point in a first scan pattern; determine an aperture extending from the first scan point; and control the optical sensing device to emit a second laser beam toward a second scan point in a second scan pattern and skip scan points in the aperture between the first scan point and the second scan point.

[0008] The embodiments of the present specification also provide a method for controlling laser beam emission by an optical sensing device using multiple scan patterns. The multiple scan patterns interleave to cover a field of view of the optical sensing device, comprising: detecting an object within a functional distance range from the optical sensing device based on reflected light of a first laser beam received by the optical sensing device, wherein the first laser beam is emitted toward a first scan point in a first scan pattern; determining an aperture extending from the first scan point; and controlling the optical sensing device to emit a second laser beam toward a second scan point in a second scan pattern and skip scan points in the aperture between the first scan point and the second scan point.

[0009] The embodiments of the present specification also provide a non-transitory computer readable medium having instructions stored thereon. When the instructions are executed by at least one processor, the at least one processor is caused to perform a method for controlling laser beam emission by an optical sensing device using multiple scan patterns, wherein the multiple scan patterns interleave to cover a field of view of the optical sensing device, the method comprising: detecting an object within a functional distance range from the optical sensing device based on reflected light of a first laser beam received by the optical sensing device, wherein the first laser beam is emitted toward a first scan point in a first scan pattern; determining an aperture extending from the first scan point; and controlling the optical sensing device to emit a second laser beam toward a second scan point in a second scan pattern and skip scan points in the aperture between the first scan point and the second scan point.

[0010] It should be understood that all the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present specification. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a schematic diagram of an exemplary vehicle equipped with a lidar system according to embodiments of the present specification.

[0012] Figure 2A is a schematic diagram of an exemplary lidar system according to embodiments of the present specification.

[0013] Figure 2Bis a schematic diagram of an exemplary controller for controlling laser emission in a lidar system, according to embodiments shown in the specification.

[0014] Figure 3A is an object detected in a field of view (FOV) of an exemplary lidar system, according to embodiments shown in the specification.

[0015] Figure 3B is a change in size of a laser beam relative to a distance of movement in a field of view of an exemplary lidar system, according to embodiments shown in the specification.

[0016] Figure 3C is an exemplary emission scheme for a lidar system, according to embodiments shown in the specification.

[0017] Figure 3D is another exemplary emission scheme for a lidar system, according to embodiments shown in the specification.

[0018] Figure 3E is a sub-aperture in an aperture, according to embodiments shown in the specification.

[0019] Figures 4A-4G are exemplary scenario diagrams for controlling laser emission in a lidar system, according to embodiments shown in the specification.

[0020] Figure 5A is a flowchart of an exemplary method for controlling laser emission in a scanning pattern in a lidar system, according to embodiments shown in the specification.

[0021] Figure 5B and 5C is a flowchart of an exemplary method for controlling laser emission in another scanning pattern in a lidar system, according to embodiments shown in the specification. DETAILED DESCRIPTION

[0022] The exemplary embodiments will now be described in detail with reference to the drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. Reference Character List

[0023] Figure 1 is a schematic diagram of an exemplary vehicle 100 equipped with a lidar system 102, according to embodiments shown in the specification. As shown, the vehicle 100 can be equipped with the lidar system 102 by mounting a mounting structure 108 to a vehicle body 104. The mounting structure 108 can be an electromechanical device that mounts or otherwise connects to the vehicle body 104 of the vehicle 100. In some embodiments of the specification, the mounting structure 108 can use screws, adhesives, or other mounting mechanisms. It can be appreciated that the manner in which the lidar system 102 is mounted on the vehicle 100 is not subject to limitation and can be varied as desired. Figure 1 The mounting structure 108 can be mounted to the vehicle body 104 of the vehicle 100 using a variety of mounting mechanisms. In some embodiments of the specification, the mounting structure 108 can be mounted to the vehicle body 104 of the vehicle 100 using screws, adhesives, or other mounting mechanisms. It can be appreciated that the manner in which the mounting structure 108 is mounted to the vehicle body 104 of the vehicle 100 is not subject to limitation and can be varied as desired.Figure 1 The limitations of the illustrated example, and can be modified according to the type of lidar system 102 and / or vehicle 100 to achieve desired three-dimensional sensing performance.

[0024] Consistent with some embodiments, the lidar system 102 can be configured to capture data as the vehicle 100 moves along a trajectory. For example, the emitters of the lidar system 102 are configured to scan around and acquire a point cloud. The lidar system 102 measures the distance to a target by illuminating the target with a pulsed laser and measuring the reflected pulse with a receiver. The laser used by the lidar system 102 can be ultraviolet, visible, or near infrared. In some embodiments of the present description, the lidar system 102 can capture a point cloud. The lidar system 102 can continuously emit / scan a laser beam and receive the returned laser beam as the vehicle 100 moves along a trajectory.

[0025] Consistent with the present description, a controller can be included for processing and / or analyzing the collected data for various operations. For example, the controller can process the received signals and control any operations based on the processed signals. The controller can also communicate with a remote computing device, such as a server (or any suitable cloud computing system) for operating the lidar system 102. The components of the controller can be located in an integrated device or distributed in different locations but can communicate with each other over a network. In some embodiments, the controller can be located entirely within the lidar system 102. In some embodiments, one or more components of the controller can be located in the lidar system 102, within the vehicle 100, or also in a mobile device, in the cloud, or another remote location.

[0026] In some embodiments, the controller can process the received signals locally. In some alternative embodiments, the controller is connected to a server to process the received signals. For example, the controller can transmit the received signals to a server for data processing and receive the processed data from the server (e.g., a laser emission scheme for controlling the laser power in the aperture). In some embodiments, the received signals are processed and a laser emission scheme can be generated in real time. The distance between the object and the lidar system 102 can be updated in real time to determine the laser emission scheme.

[0027] Figure 2A is a schematic diagram of an example lidar system according to embodiments of the present description. As Figure 2AAs shown, the lidar system 102 has a transmitter 202 for transmitting laser beams 209 and a receiver 204 for collecting data of detected laser beams including return laser beams 211 reflected by an object 212. The transmitter 202 can include any suitable light source that transmits laser beams 209 outwardly around the lidar system 102. In some embodiments, the laser beams 209 include pulsed laser signals with a scan angle, as Figure 2A As shown.

[0028] The transmitter 202 can include any suitable components for producing laser beams 209 of a desired wavelength and / or intensity. For example, the transmitter 202 can include a laser source 206 that produces a native laser beam 207 in the ultraviolet, visible, or near-infrared wavelength range. The transmitter 202 can also include a light modulator 208 that collimates the native laser beam 207 to produce the laser beams 209. A scanner 210 can scan the laser beams 209 at a desired scan angle and a desired scan rate. Each laser beam 209 can form a scan spot on a surface facing the transmitter 202 and maintain a distance from the lidar system 102. The laser beams 209 can be incident on the object 212, reflected back, and collected by a lens 214. The object 212 can be made of a variety of materials, for example, including charged objects, non-metallic objects, rocks, rain, compounds, aerosols, clouds, and even single molecules. The wavelength of the laser beams 209 can vary depending on the composition of the object 212. In some embodiments of the present description, the scanner 210 can include optical components (e.g., lenses, mirrors) that can focus pulsed laser light into narrow laser beams to improve scan resolution.

[0029] The receiver 204 can be configured to detect return laser beams 211 (e.g., return signals) reflected from the object 212. Upon contact, the laser light can be reflected by the object 212 through backscattering. The receiver 204 can collect the return laser beams 211 and output an electrical signal indicative of the intensity of the return laser beams 211. As Figure 2A As shown, the receiver 204 can include a lens 214 and a light detector 216 (e.g., a photodetector or an array of photodetectors). The lens 214 can be configured to collect light from various directions in its field of view (FOV).

[0030] The light detector 216 can be configured to detect the return laser beam 211 reflected by the object 212. The light detector 216 can convert the laser light collected by the lens 214 (e.g., the return laser beam 211) into a receiver signal 218 (e.g., a current or voltage signal). The receiver signal 218 can be generated when a photon is absorbed in the light detector 216. The receiver signal 218 can be sent to a data processing unit, e.g., the controller 252 of the lidar system 102, for processing and analysis. The controller 252 can be configured to control the transmitter 202 and / or the receiver 204 to perform detection / sensing operations.

[0031] The receiver signal 218 can include power data (e.g., an electrical signal) of the return laser beam 211, e.g., converted from the optical signal of the return laser beam 211. The return laser beam 211 can be due to the reflection of the laser beam 209 from the object 212 in the field of view of the lidar system 102. As shown, the scanner 210 can emit / scan the laser beam 209 in various directions of the surrounding environment. The laser beam 209 can be incident on the object 212, causing the return laser beam 211 to form and reflect back to the lidar system 102. The light detector 216 can receive the return laser beam 211 through the lens 214. The light detector 216 can convert the return laser beam 211 into an electrical signal (e.g., the receiver signal 218) that is transmitted to the controller 252. The controller 252 can further determine data and / or operations, e.g., the distance of the object 212 from the lidar system 102 and subsequent laser emission schemes for the laser beam 209. Figure 2A

[0032] ​To achieve the desired coverage of the environment and / or resolution of the scanning / sensing results, the energy of the laser beam 209 needs to be high enough for the lidar system 102 to have a desired long detection range. Objects 212 far away from the lidar system 102 can then be detected. At the same time, the energy of the laser beam 209 should also be controlled below a safety limit to ensure that the human eye is not affected by the scanning. For example, in three-dimensional space, the scanning angle span of the laser beam 209 also needs to be large enough to cover the required surrounding range in both lateral and vertical directions. The angular resolution of the lidar system 102, e.g., the ability of the lidar system 102 to measure the angular separation of points, needs to be high enough to ensure the ideal spatial resolution of detecting objects 212 far away from the lidar system 102. The scanner 210 can perform two-dimensional scanning to cover the field of view of the lidar system 102. In some embodiments, the scanner 210 can scan the laser beam 209 in three-dimensional space at a desired scanning rate along a lateral scanning direction and a vertical scanning direction, e.g., row by row from left to right and from top to bottom. The laser beam 209 can be emitted at various scanning points along the lateral and vertical scanning directions. In some applications, the field of view of the lidar system 102 is covered with more than one scanning pattern, e.g., to increase the angular resolution without increasing the switching frequency of the laser source 206. In each frame, the lidar system 102 can scan all the scanning patterns to cover the entire field of view. The details of the scanning patterns and the method for controlling the laser emission scheme of the scanning patterns are described below.

[0033] Controller 252 can determine the distance of object 212 from lidar system 102 based on receiver signal 218 and data of laser beam 209. For example, the distance between object 212 and lidar system 102 can be calculated based on the speed of light, the scan angle of laser beam 209, the round trip time of laser beam 209 / 211 (e.g., from transmitter 202 to object 212 and back to receiver 204), and / or the power of returned laser beam 211 (e.g., the intensity of the light signal converted by light detector 216 into receiver signal 218). When the distance between object 212 and lidar system 102 is equal to or less than a distance tolerance value (e.g., a distance where an unadjusted laser beam 209 emission scheme in a subsequent emission would result in potential harm, when object 212 is a person or other safety concern), controller 252 can sense object 212 and adjust the laser emission scheme of laser beam 209. For example, to reduce or avoid potential harm to a human eye, the adjusted laser emission scheme can result in a total power incident on an area of a size of a human eye pupil that is no higher than (e.g., lower than or equal to) a predetermined safety limit. In some embodiments, the adjustment of the laser emission scheme is performed in real-time or near real-time. For example, if the distance between object 212 and lidar system 102 changes, controller 252 can dynamically adjust the laser emission scheme to ensure that the total power incident on the area at the changed distance is less than the predetermined safety limit. For example, if the distance decreases, controller 252 can adjust the laser emission scheme so that the total power incident on the area does not exceed the predetermined safety limit. In conjunction with Figure 2B The functions of controller 252 for determining distances or other triggers related to potential harm and adjusting the laser emission scheme of laser beam 209 are described in more detail.

[0034] Figure 2B is a schematic diagram of an example controller for controlling laser emission in a lidar system, consistent with embodiments shown in this specification. Controller 252 can receive receiver signal 218 (e.g., containing power data of returned laser beam 211) from light detector 216, consistent with this specification.

[0035] In some embodiments, as Figure 2BAs shown, the controller 252 can include the communication interface 228, the processor 230, the storage 240, and the memory 242. In some embodiments, the controller 252 can have the different modules in a single device, such as an integrated circuit (IC) chip (e.g., implemented as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA)) or separate devices with specialized functionality. In some embodiments, one or more components of the controller 252 can be located in the cloud, or can alternatively be located in a single location (e.g., inside the vehicle 100 or a mobile device) or distributed locations. The components of the controller 252 can be located in integrated devices, or distributed in different locations but in communication with each other over a network.

[0036] The communication interface 228 can transmit data to and receive data from components such as the light detector 216 through wired communication methods, such as serializer / deserializer (SerDes), low-voltage differential signaling (LVDS), serial peripheral interface (SPI), etc. In some embodiments, the communication interface 228 can optionally use wireless communication methods, such as wireless local area network (WLAN), wide area network (WAN), wireless communication links, such as radio waves, cellular networks, and / or local or short-range wireless networks (e.g., Bluetooth™), etc. The communication interface 228 can transmit and receive electrical, electromagnetic, or optical signals that carry digital data streams representing various types of information.

[0037] Consistent with some embodiments, the communication interface 228 can receive the receiver signal 218 (e.g., containing data of the returned laser beam 211). In some embodiments, the communication interface 228 can sequentially receive the receiver signal 218 as the scanner 210 continues to scan the laser beam 209 at a scan rate. The communication interface 228 can transmit the received receiver signal 218 to the processor 230 for processing.

[0038] The processor 230 can include any appropriate type of general purpose or special purpose microprocessor, digital signal processor, or microcontroller. The processor 230 can be configured as a standalone processor module dedicated to analyzing signals (e.g., the receiver signal 218) and / or controlling scanning schemes. Alternatively, the processor 230 can be configured as a shared processor module for performing other functions unrelated to signal analysis / scanning scheme control.

[0039] In many lidar systems with laser wavelengths in the near-infrared range, laser energy is strictly regulated due to its potential harm to the human eye. According to laser safety standards, such as the international standard IEC 60285-1, the energy of a laser pulse (e.g., in non-pulse train mode) needs to satisfy the standard description Epulse≤ AELClassl, where Epulse is the energy of the laser pulse / beam, and AELClassl is the accessible emission limit for a Class 1 laser product. If the laser pulse is in a pulse train mode where laser pulses are emitted continuously, the energy of the laser pulse needs to satisfy the standard description Epulse≤ AELClassl x C5, where C5 represents a correction factor related to the number of pulses (N) in T2, which is about 10 seconds for near-infrared laser pulses. If N is much higher than the upper limit of laser pulses emitted in T2 (e.g., 600), C5 is set to be equal to 0.4. That is, in the pulse train mode, the energy of each pulse should be reduced to 40% of its original value (e.g., the value in non-pulse train mode). For high-resolution and long-range lidar systems, this is detrimental because the reduction of laser power results in a shortened detection range.

[0040] The present specification provides a system and method for dynamically reducing the number of laser beams (or angular resolution) scanned toward an object when the object is detected to be at a short distance from a lidar system having a field of view covered by multiple scan patterns. Using the disclosed system and method, the energy of the laser beams / pulses does not need to be reduced even if the lidar system is in a pulse train mode. When the lidar system scans the field of view using one of the scan patterns and detects an object 212 to be at a short distance, the lidar system (e.g., through a controller) can determine an aperture covering the size of a human eye pupil and adjust the laser emission scheme to a low-resolution emission scheme in the aperture, ensuring that the total energy of the laser beams incident on the aperture does not exceed a predetermined safety limit (calculation details are below). In some embodiments, according to the low-resolution emission scheme, no laser beam is scanned toward the aperture for the current scan pattern. The lidar system scans the laser beams using a high-resolution emission scheme outside the aperture. If no object is detected at a short distance, the lidar system can continue to scan the laser beams using the high-resolution emission scheme. Thus, without reducing the energy of the laser beams, the disclosed system and method ensure that the human eye is not easily harmed by the lidar system. Details of the embodiments are described in more detail below.

[0041] As Figure 2BAs shown, the processor 230 can include a number of functional units or modules, which can be implemented using software, hardware, middleware, firmware, or any combination thereof. For example, the processor 230 can include an object detection unit 260, a transmitter adjustment module 250, etc. In some embodiments, the transmitter adjustment module 250 includes a functional distance range determination unit 232, a transmission scheme determination unit 234, a transmitter scan control unit 236, and a sub-aperture determination unit 238. In some embodiments, the processor 230 determines a laser transmission scheme based on the receiver signal 218 to ensure that the total energy of laser pulses incident on the aperture is below a predetermined safety limit. Specifically, if the processor 230 determines that the object 212 is within the functional distance range, the processor 230 can switch the laser transmission to a low resolution transmission scheme to ensure that the total energy incident on the aperture does not exceed the predetermined safety limit; if the processor 230 determines that the object 212 is beyond the functional distance range, the processor 230 can maintain a high resolution transmission scheme.

[0042] For ease of illustration, Figures 3A-3E are described together. Figure 2B Figure 3A is a field of view 300 of an exemplary lidar system 102 shown in accordance with embodiments of the present specification. Figure 3B is a change in size of a laser beam 209 relative to a distance of movement in an exemplary lidar system field of view shown in accordance with embodiments of the present specification. Figure 3C and 3D is an exemplary transmission scheme of a lidar system shown in accordance with embodiments of the present specification. Figure 3E is a sub-aperture in an aperture shown in accordance with embodiments of the present specification.

[0043] The object detection unit 260 can determine whether the object 212 is potentially harmed by the laser beam 209 and send an alert signal to the transmitter adjustment module 250 upon determining that the object 212 is potentially harmed. The transmitter adjustment module 250 can adjust the laser transmission scheme accordingly. In some embodiments, the object detection unit 260 also sends any data usable to adjust the laser transmission scheme to the transmitter adjustment module 250, such as the distance between the object 212 and the lidar system 102. In some embodiments, the object detection unit 260 determines that the object 212 is located in the field of view of the lidar system 102 based on the receiver signal 218. The object detection unit 260 can determine the distance between the object 212 and the lidar system 102 based on, for example, the round trip time of the laser beams 209 and 211 and the scan angle of the scanner 210.

[0044] ​The object detection unit 260 can compare the distance between the lidar system 102 and the object 212 to the distance tolerance value, for example, in real time. For example, when the distance between the lidar system 102 and the object 212 is greater than the distance tolerance value, it can be determined that the laser beam 209 will not cause harm. On the other hand, when the object detection unit 260 determines that the distance between the lidar system 102 and the object 212 is equal to or less than the distance tolerance value, the object detection unit 260 can send an alert signal to the emitter adjustment module 250 to warn of a potential risk. The distance tolerance value can be an upper limit of the functional distance range and can be determined by the functional distance range determination unit 232. Details of the functional distance range are described below.

[0045] The functional distance range determination unit 232 can determine a distance tolerance value as an upper limit of the functional distance range. When it is detected that the distance between the object 212 and the lidar system 102 is less than the distance tolerance value, it can be determined that the object 212 is within the functional distance range; when it is detected that the distance between the object 212 and the lidar system 102 is greater than the distance tolerance value, it can be determined that the object 212 is beyond the functional distance range. As described above, the functional distance range determination unit 232 can determine the distance tolerance value based on the distance between the lidar system 102 and the object 212. Figure 3AAs shown, the controller 252 (not shown) can control the emitter 202 to scan the laser beam 209 from the emitter 202 across the field of view 300 of the lidar system 102. The controller 252 can control the emitter 202 to scan the laser beam 209 in various directions / angles within the field of view 300 of the lidar system 102. In some embodiments, the emitter 202 (e.g., via the scanner 210) can scan the laser beam 209 in a lateral scan direction (e.g., x-direction) and a vertical scan direction (e.g., y-direction). In one example, a scan angle of the laser beam 209 can include a vertical scan angle and a lateral scan angle. The vertical scan angle can represent a direction of the laser beam 209 relative to a vertical direction (e.g., y-direction), while the lateral scan angle can represent a direction of the laser beam 209 relative to a lateral direction (e.g., x-direction). At a given lateral scan angle, the emitter 202 can change the vertical scan angle of the laser beam 209 by a vertical increment angle increment so that the laser beam 209 and the laser beam 209 immediately following it can be separated from each other by the vertical increment angle. The vertical increment angle can be any suitable value, such as 0.01°, 0.02°, 0.05°, 0.1°, 0.2°, 0.5°, 1°, etc. In some embodiments, the emitter 202 scans the laser beam 209 from top to bottom in three-dimensional space at each lateral scan angle. After scanning the laser beam 209 at one lateral scan angle, the emitter 202 can scan the laser beam 209 from top to bottom in three-dimensional space at another lateral scan angle, which can form a lateral increment angle with the previous lateral scan angle. The lateral increment angle can be any suitable value, such as 0.01°, 0.02°, 0.05°, 0.1°, 0.2°, 0.5°, 1°, etc. In some embodiments, the laser beam 209 is scanned along a vertical scan direction (referred to as a “column”) and along a lateral scan direction (referred to as a “row”). In the field of view 300, the rows and columns are perpendicular to each other.

[0046] In some embodiments, the transmitter 202 repeatedly scans the laser beam 209 vertically and laterally to cover the field of view 300. The laser beam 209, when scanned, can emit within the field of view 300 along its respective scanning direction. At any location in the field of view 300, in a vertical plane facing the laser beam 209, the scanning pattern of the laser beam 209 can be formed by a plurality of scan points, each corresponding to a location where the scanned laser beam 209 intersects the vertical plane. In other words, the laser beam 209 emitted or to be emitted at a plurality of angles can be projected to a vertical plane to form a plurality of scan points. In some embodiments, the transmitter 202 can scan the laser beam 209 at one lateral scan angle multiple times (e.g., at different vertical scan angles) at a desired scan rate before moving to the next lateral scan angle. In some embodiments, the transmitter 202 can scan the laser beam 209 at one vertical scan angle multiple times (e.g., at different lateral scan angles) before moving to the next vertical scan angle. In some embodiments, the lateral scan angle, the vertical scan angle, the lateral delta angle, the vertical delta angle, the scan rate, and / or the divergence characteristics of the laser beam 209 can be used to determine the spatial / geometrical distribution of the laser beam 209 in the three-dimensional space and the distribution of the scan points at any suitable surface / location.

[0047] In some embodiments, the controller 252 can control the transmitter 202 to scan the laser beam 209 into the field of view 300 in a plurality of scan patterns in one frame. Each scan pattern can include a plurality of scan points (e.g., an array) distributed in the field of view 300, and then the scan points of all scan patterns fill / cover the field of view 300. In some embodiments, the scan patterns are interleaved in the three-dimensional space. For example, in one frame, the controller 252 can scan a first scan pattern into the field of view 300, and after the scanning of the first scan pattern is completed, scan a second scan pattern into the unsanned three-dimensional space in the field of view 300. The controller 252 can continue to scan until all scan patterns are scanned to cover the field of view 300 in a single frame. The scan patterns can be scanned in the same or different scanning directions. In some embodiments, the scan points of different scan patterns do not overlap with each other in the three-dimensional space, and the delta angle (e.g., lateral and / or vertical) between adjacent scan points (e.g., of different scan patterns) can desirably be small to ensure that a sufficiently high angular resolution can be obtained in the field of view 300. In various embodiments, the number of scan patterns can be a suitable integer, for example, between 2 and 10. In some embodiments, the number can be less than or equal to 6. In one example, the number is equal to 4. Details of exemplary scan patterns in the field of view 300 will be described in Figure 3C .

[0048] Each scan point can propagate and diverge in the 3D space of the field of view 300. As Figure 3AAs shown, D0 represents a distance tolerance value, which is the upper limit of the functional distance range from transmitter 202. If object 212 is detected at position 302, where the distance to transmitter 202 is less than distance tolerance value D0, then object 212 is determined to be within the functional distance range. If object 212 is detected at position 304, where the distance to transmitter 202 is greater than distance tolerance value D0, then object 212 is detected to be outside the functional distance range.

[0049] Functional distance range determination unit 232 can determine a distance tolerance value D0. As previously described, in pulse train mode, it is typically necessary to reduce the energy of each laser pulse to 40% of its original value (e.g., by multiplying by a correction factor C5) to ensure that the total energy of all laser pulses incident on an aperture covering the size of the pupil does not exceed a predetermined safety limit. In the present application, when an object 212 is detected within the functional distance range, controller 252 does not reduce the energy of laser beam 209. Instead, it maintains the original energy of each laser beam 209 and reduces the number of pulses / scan points directed toward the aperture so that the total energy of laser beam 209 incident on the aperture does not exceed a predetermined safety limit. In some embodiments, unscanned scan points of the current scan pattern in the aperture are skipped during scanning of the current scan pattern, rather than detecting the current scan point of object 212 within the functional distance range. Functional distance range determination unit 232 can determine distance tolerance value D0 based on the divergence characteristics of laser beam 209. In some embodiments, functional distance range determination unit 232 determines the value of distance tolerance value D0. At the distance tolerance value D0, the total energy incident on the human eye (or aperture) does not reach a harmful level even if the number of pulses / scan points is not reduced. In some embodiments, the functional distance range determination unit 232 is an optional part of the processor 230, and the distance tolerance value D0 is a predetermined value and stored in the controller 252 (e.g., in the storage 240 and / or memory 242). For example, D0 can be a constant value determined before the scanning process. In some embodiments, the divergence characteristics of the laser beam 209 are determined during the design of the lidar system 102, and the distance tolerance value D0 is determined during the design, for example, as a fixed value. In operation, the processor 230 can access the storage 240 and / or memory 242, obtain the distance tolerance value D0, and use the distance tolerance value D0 in the calculation.

[0050] like Figure 3BAs shown, the laser beam 209 can propagate in the z-direction during two-dimensional scanning. Due to the divergence property of the laser beam 209, the beam size (e.g., area) of the laser beam 209 in the x-y plane (e.g., a vertical plane facing the laser beam 209) can increase as the laser beam 209 travels away from the emitter 202. Assuming the beam size of the laser beam 209 at the emitter 202 is A0, and at a distance tolerance value D0 is Al, then Al is greater than A0. It can be assumed that A0 is comparable to the size / area of a human pupil, e.g., equal to or greater than the size / area of a human pupil. When Al is increased to 2.5 times A0 (e.g., Al / A0 = 2.5), the per-area laser energy at Al is 40% of that at A0. That is, even without reducing any scan points, the total energy incident on a human eye at the distance tolerance value D0 is reduced to 40% of the total energy at the emitter 202 for each pulse. In other words, if the distance between the object 212 and the emitter 202 is at least D0, then the object 212 is not easily harmed by the laser beam 209 even without energy reduction or skipping of scan points. The distance tolerance value D0 determined by the functional distance range determination unit 232 can then have a value of Al that is 2.5 times the value of A0.

[0051] The emission scheme determination unit 234 can determine a laser scanning scheme in which the laser beam 209 is scanned into the field of view 300. Specifically, the emission scheme determination unit 234 can determine an emission scheme for the laser beam 209 upon detecting that the object 212 is within the functional distance range. The emission scheme can ensure that the total energy of the laser beam 209 incident on a human eye does not exceed a predetermined safety limit before the laser beam 209 propagates to the upper limit of the functional distance range. The predetermined safety limit of the aperture energy determined by the emission scheme determination unit 234 can be calculated as the total energy incident on an aperture within the functional distance, with a minimum number of scan points for all scan patterns for a high resolution scan, and a pulse energy of 40%. For example, the emission scheme determination unit 234 can assume that the laser beam 209 is scanned toward an aperture (e.g., a 7 mm circular area) covering a human pupil with a minimum number of scan points within T2 (e.g., 10 seconds). In some embodiments, the emission scheme determination unit 234 determines the minimum number of scan points (e.g., for all scan patterns in one frame) to be 600. Assuming a frame rate of the lidar system 102 of 10 frames per second (fps), the predetermined safety limit can be equal to the total energy of the laser beam 209 at its original energy and 6 scan points per frame toward the aperture. The emission scheme determination unit 234 can determine an emission scheme that includes up to six scan points distributed in a frame that cover the aperture of the 7 mm circular area. In some embodiments, the number of scan patterns in a frame is 4, and at most one scan point per scan pattern is determined in the aperture in the frame. In some embodiments, the aperture has a 7x7 mm square in a two-dimensional scan with a horizontal scan direction and a vertical scan direction. In some other embodiments, the aperture can be determined based on the scan direction and can have other shapes, such as a rectangle or a circle.

[0052] In some embodiments, the field of view 300 is covered by a plurality of scan patterns. The total energy in an aperture can include the energy of the laser beam 209 at the scan points of all scan patterns in a frame. Assume that the field of view 300 is covered by a first scan pattern, a second scan pattern, a third scan pattern, and a fourth scan pattern arranged in an interleaved order. The controller 252 can continuously scan the four scan patterns in this order. When an object 212 is detected within the functional distance range at a scan point of the first scan pattern, the remaining scan points of the first scan pattern in the first aperture extending from the scan point are skipped. The next scan point to be scanned in the aperture can be the first scan point of the second scan pattern in a sub-aperture of the first aperture. If an object 212 is detected within the functional distance range at the scan point of the second scan pattern in the sub-aperture, a second aperture extending from the scan point of the second scan pattern is determined, and the remaining scan points of the second scan pattern in the second aperture are skipped. If an object 212 is not detected within the functional distance range at the scan point of the second scan pattern, the next scan point of the second scan pattern in the sub-aperture is scanned, and the scan point is not skipped. The controller 252 can resume scanning of the third and fourth scan patterns using the same criteria as the first and second scan patterns. If an object 212 is detected within the functional distance range at the first scan point of each of the second, third, and fourth scan patterns in the first aperture, the maximum number of scan points in the first aperture is four. That is, if an object 212 is detected within the functional distance range in the aperture, the laser beam 209 can be scanned at no more than 4 (e.g., the total number of scan patterns) scan points per frame in the aperture, assuming a frame rate of 10 fps for the lidar system 102. By reducing the number of scan points of the scan field, the risk of injuring a human eye within the aperture coverage area is minimized. At the same time, if an object 212 is not continuously detected within the functional distance range in the aperture, the scan points of the rest of the aperture are not skipped before an object 212 is detected. According to the present specification, the number of skipped scan points can be minimized, and the angular resolution of the lidar system 102 can be maximized.

[0053] Figure 3C A portion of an example emission scheme 320 is shown, according to which, according to embodiments, the laser beam 209 is emitted when an object 212 is not detected within the functional distance range at any scan point. Assume a frame rate of 10 fps for the lidar system 102. The emission scheme 320 can be referred to as a high resolution emission scheme. As Figure 3CAs shown, the transmission scheme 320 includes a plurality of scanning points 306-1, 306-2, 306-3, and 306-4 that are continuously distributed in the transverse scanning direction and the vertical scanning direction (e.g., no skipped scanning points). Specifically, the scanning point 306-1 forms a first scanning pattern, the scanning point 306-2 forms a second scanning pattern, the scanning point 306-3 forms a third scanning pattern, and the scanning point 306-4 forms a fourth scanning pattern. The first, second, third, and fourth scanning patterns are staggered in the vertical scanning direction (e.g., the y-direction) in the field of view 300. In some embodiments, the controller 252 scans the first, second, third, and fourth scanning patterns in this order. For example, in the vertical scanning direction, the controller 252 may scan the scanning point 306-1 in the column when scanning the first scanning pattern, scan the scanning point 306-2 in the column when scanning the second scanning pattern, and so on for the third and fourth scanning patterns. When all four scan patterns are scanned at the end of the frame, the scan points 306-1, 306-2, 306-3, and 306-4 may cover the field of view 300 in an interleaved order, as shown in FIG. Figure 3C The scanning points in each scanning pattern can be scanned along the same or different scanning directions. Figure 3C As shown, object 212 is not detected within the functional distance range by scanning performed at any of scan points 306-1, 306-2, 306-3, and 306-4. In one example, when object 212 is detected at position 304 (e.g., outside functional distance range D0), controller 252 can apply transmission scheme 320. In another example, when object 212 is not detected at all (e.g., at position 302 or position 304), controller 252 can apply transmission scheme 320.

[0054] Figure 3D An exemplary firing scheme 321 is shown, according to which, according to some embodiments, laser beam 209 is fired when object 212 is detected within the functional distance range under the scanning pattern. Firing scheme 321 may be referred to as a low-resolution firing scheme. Figure 3D As shown, scan point 310 represents a scan point at which object 212 is detected within the functional distance range, and emission scheme 321 may include a scan point (e.g., scan point 310 or current scan point) in aperture 323, which extends from (e.g., covers) scan point 310 under the current scan pattern. Scan point 310 may be Figure 3CThe illustrated example of any one of the scan points 306-1, 306-2, 306-3, and 306-4. That is, under the current scan pattern, the scan point 310 can be the first and only scan point in the aperture 323, and the laser beam 209 can not scan along the scan direction to any other scan point in the aperture 323. In other words, when the object 212 is detected within the functional distance range in any one of the first, second, third, and fourth scan patterns, the remaining scan points of the current scan pattern can be skipped in the aperture 323. The aperture 323 can extend from (e.g., cover) the scan point 310 and along the two-dimensional scan directions, e.g., the lateral and vertical scan directions. The aperture 323 has an area / size sufficient to cover the area of a human pupil, which is generally considered to be a 7-millimeter circular area. In some embodiments, the aperture 323 has a square shape that can cover the 7-mm circular area and includes the least skipped scan points in a frame. For example, the lateral dimension LI of the aperture 323 can be about 7 mm, and the vertical dimension L2 of the aperture 323 can be about 7 mm. In one example, when the object 212 is detected at the location 302 based on the returned laser beam 211 at the scan point 310, the controller 252 can apply the emission scheme 321 to the current scan pattern.

[0055] For ease of illustration, reference is returned to Figure 3C , the aperture 322 is depicted as having the same shape and size as the aperture 323 in Figure 3D . As illustrated in Figure 3C and 3D , one or more scan points along the same pattern in the lateral scan direction and / or the vertical scan direction are skipped in the aperture 323. That is, in the same area (e.g., the area covered by the aperture 323), the total number (e.g., one) of scan points (306-1, 306-2, 306-3, 306-4) of a single scan pattern is reduced. In one frame, the total number of scan points in the aperture 323 is a subset of the total number of scan points in the aperture 322.

[0056] Reference is returned to Figure 2BThe transmitter scan control unit 236 can determine the transmit scheme to be applied by the transmitter 202. For each scan point, after receiving an alert signal from the object detection unit 260, the transmitter scan control unit 236 can determine whether the current transmit scheme needs to be changed or maintained. In one example, if the lidar system 102 is scanning the field of view 300 according to the scan pattern of the transmit scheme 320 and the alert signal indicates that an object 212 is detected within the functional distance range of the current scan point, the transmitter scan control unit 236 can control the transmitter 202 to scan the laser beam 209 from one or more unswept scan points of the current scan pattern using the transmit scheme 321, e.g., skipping the remaining scan points of the current scan pattern in the most recently determined aperture. In another example, if the lidar system 102 is scanning the laser beam 209 toward the most recently determined aperture and the alert signal indicates that an object 212 is not detected within the functional distance range of the current scan point of the current scan pattern, the transmitter scan control unit 236 can control the transmitter 202 to scan the laser beam 209 using the transmit scheme 320 until an object 212 is detected within the functional distance range. In some embodiments, the transmitter scan control unit 236 also controls the transmitter 202 to scan the laser beam 209 outside the aperture using the transmit scheme 320 if an object 212 is detected within the functional distance range of the current scan point.

[0057] The sub-pore determination unit 238 can determine a sub-pore of the recent pore for scanning the next scan pattern. The size / area of the sub-pore is smaller than the size / area of the pore. For example, if the object 212 is detected at a scan point within the functional distance range during scanning of the first scan pattern, the emitter scan control unit 236 can apply the emission scheme 321 from the scan point by skipping the rest of the scan points of the first scan pattern in the pore extending from the first scan point. For scanning of a second scan pattern, e.g., a scan pattern following the first scan pattern, the sub-pore determination unit 238 can determine a sub-pore of the pore, and the emitter scan control unit 236 can control the emitter 202 to start scanning the laser beam 209 from a first scan point of the second scan pattern in the sub-pore along the scan direction. The emitter scan control unit 236 can control the emitter 202 to scan the laser beam 209 to the scan points of the second scan pattern according to the emission scheme 320 in the sub-pore, and adjust to the emission scheme 321 if the object 212 is detected within the functional distance range in the sub-pore or outside the pore. If the object 212 is not detected within the functional distance range in the sub-pore, the sub-pore determination unit 238 can determine a second sub-pore of the pore when scanning a third scan pattern. The third scan pattern can follow the second scan pattern. The size / area of the second sub-pore is smaller than the size / area of the sub-pore. The emitter scan control unit 236 can control the emitter 202 to start scanning the laser beam 209 from a first scan point of the third scan pattern in the second sub-pore along the scan direction.

[0058] Figure 3E A pore, a sub-pore, a second sub-pore, and a third sub-pore are shown in accordance with some embodiments. As previously described, the scan point 310 represents a scan point (of the first scan pattern) at which the object 212 is detected within the functional distance range, and the pore 323 extends from the scan point 310. For ease of illustration, it is assumed that the scan point 310 is scanned in the first scan pattern, and the pore 323 covers only one scan point 310 of the first scan pattern.

[0059] Sub-pore 324 (e.g., a first sub-pore) can be positioned in pore 323 and can have a smaller size / area than pore 323. Scan point 312 represents a first scan point of the second scan pattern in sub-pore 324. In some embodiments, sub-pore 324 is determined by skipping one or more rows and / or columns of scan points of the second scan pattern along the scan direction in pore 323. In some embodiments, along the vertical scan direction, a first boundary (e.g., an upper boundary) of sub-pore 324 can be Dl away from a first boundary (e.g., an upper boundary) of pore 323, Dl being equal to (1 / 4) x L2; and along the lateral scan direction, a second boundary (e.g., a left boundary) of sub-pore 324 can be D2 away from a second boundary (e.g., a left boundary) of pore 323, D2 being equal to (1 / 4) x LI. A third (e.g., lower) and a fourth (e.g., right) boundary of sub-pore 324 can be aligned with the boundaries of pore 323. A length of sub-pore 324 in the lateral scan direction can be L3, which is equal to (3 / 4) x LI, and a length of sub-pore 324 in the vertical scan direction can be L4, which is equal to (3 / 4) x L2. That is, the size / area of sub-pore 324 can be equal to (3 / 4) x (3 / 4) x LI x L2.

[0060] Assuming no object 212 is detected within the functional distance range of any scan point of the second scan pattern in sub-pore 324. To scan the third scan pattern, sub-pore determination unit 238 can determine a second sub-pore 326 located in sub-pore 324 (and pore 323) and can have a smaller size / area than sub-pore 324. Scan point 314 represents a first scan point of the third scan pattern in second sub-pore 326. In some embodiments, second sub-pore 326 is determined by skipping one or more rows and / or columns of scan points of the third scan pattern along the scan direction in sub-pore 324 (and pore 323). In some embodiments, along the vertical scan direction, a first boundary (e.g., an upper boundary) of second sub-pore 326 can be D3 away from a first boundary of pore 323, D3 being equal to (1 / 2) x L2; and along the lateral scan direction, a second boundary (e.g., a left boundary) of second sub-pore 326 can be D4 away from a second boundary of pore 323, D4 being equal to (1 / 2) x LI. A third (e.g., lower) and a fourth (e.g., right) boundary of second sub-pore 326 can be aligned with the boundaries of pore 323. A length of second sub-pore 326 in the lateral scan direction can be L5, which is equal to (1 / 2) x LI, and a length of second sub-pore 326 in the vertical scan direction can be L6, which is equal to (1 / 2) x L2. That is, the size / area of second sub-pore 326 can be equal to (1 / 2) x (1 / 2) x LI x L2.

[0061] Assume that no object 212 is detected within the functional distance range of any scan point of the third scan pattern in the second sub-pore 326. To scan the fourth scan pattern, the sub-pore determination unit 238 can determine a third sub-pore 328 located in the second sub-pore 326 (and the pore 323), and can have a smaller size / area than the second sub-pore 326. Scan point 316 represents a first scan point of the fourth scan pattern in the third sub-pore 328. In some embodiments, the third sub-pore 328 is determined by skipping one or more rows and / or columns of scan points of the fourth scan pattern along the scan direction in the second sub-pore 326 (and the pore 323). In some embodiments, along the vertical scan direction, a first boundary (e.g., an upper boundary) of the third sub-pore 328 can be D5 away from the first boundary of the pore 323, D5 being equal to (3 / 4) x L2; and along the lateral scan direction, a second boundary (e.g., a left boundary) of the second sub-pore 326 can be D6 away from the second boundary of the pore 323, D6 being equal to (3 / 4) x LI. A third (e.g., lower) and a fourth (e.g., right) boundary of the third sub-pore 328 can be aligned with the boundaries of the pore 323. A length of the third sub-pore 328 in the lateral scan direction can be L7, which is equal to (1 / 4) x LI, and a length of the third sub-pore 328 in the vertical scan direction can be L8, which is equal to (1 / 4) x L2. That is, the size / area of the third sub-pore 328 can be equal to (1 / 4) x (1 / 4) x LI x L2.

[0062] The sub-pore determination unit 238 can continue to determine a respective sub-pore for scanning each subsequent scan pattern in the pore 323 until all patterns are scanned or an object 212 is detected within the functional distance range. If an object 212 is detected within the functional distance range of any scan point (e.g., similar to scan point 310) of any scan pattern, the transmitter scan control unit 236 can switch back to the transmit scheme 321 at the scan point, and the sub-pore determination unit 238 can determine a sub-pore (e.g., similar to sub-pore 324) based on the most recently determined pore (e.g., similar to pore 323) for scanning the next scan pattern. Assume that the scan pattern corresponding to the sub-pore is N away from the scan pattern that determines the most recent pore, then the size of the sub-pore along the scan direction can be equal to L is the pore size in the same scan direction, and N is equal to one of 1, 2, and 3. The area / size of the sub-pore can be calculated as S is the size / area of the most recently determined pore. In some embodiments, if the field of view 300 is covered by M scan patterns, M being a positive integer greater than 2, then the size of the sub-pore along the scan direction can be equal to N is a positive integer smaller than M. The area / size of the sub-pore can be calculated as

[0063] Units 232-238 (and any corresponding sub-modules or sub-units) and module 250 can be hardware units (e.g., portions of integrated circuits) of processor 230 designed for independent operation, or operate in conjunction with other components or software units implemented by processor 230 through execution of at least a portion of a program. The program can be stored on a computer-readable medium. When the program is executed by processor 230, the executed program can cause processor 230 to perform one or more functions or operations. Although Figure 2B Units 232-238 are shown as all being within one processor 230, it is contemplated that these units can be distributed among multiple processors, either proximate to or remote from each other. The following is a more detailed description of units 232-238 and module 250. Figure 4A -4G describes the functions of units 232-238 and module 250 in more detail.

[0064] Storage 240 and memory 242 can include any suitable type of mass storage that provides for the storage of any type of information that processor 230 can need for operation. Storage 240 and / or memory 242 can be volatile or non-volatile, magnetic, semiconductor, tape-based, optical, removable, non-removable, or other types of storage devices or tangible (i.e., non-transitory) computer- readable media, including but not limited to ROM, flash memory, dynamic RAM, static RAM, hard disks, SSDs, optical disks, etc. Storage 240 and / or memory 242 can be configured to store one or more computer programs that can be executed by processor 230 to perform the functions of the present specification. For example, storage 240 and / or memory 242 can be configured to store programs that can be executed by processor 230 to analyze lidar signals and control a scanning scheme of a laser beam.

[0065] Storage 240 and / or memory 242 can be further configured to store / cache information and data received and / or used by processor 230. For example, storage 240 and / or memory 242 can be configured to store / cache receiver signals 218, data of laser beam 209, respective tolerance values indicative of safety limits, and computational results obtained by different units of processor 230. Various types of data can be stored permanently, deleted periodically, or disregarded immediately after processing each frame of data.

[0066] Figures 4A-4G are exemplary fields of view 300 of lidar system 102 shown in accordance with embodiments of the present specification. Specifically, Figure 4A , 4B , 4D, and 4F show scenarios in which object 212 is detected within a functional range of distances, Figure 4C , 4EFigures 4G respectively show scenarios in which no object 212 is detected within the functional distance range. In some embodiments, the field of view 300 is covered by scan points of four scan patterns staggered in the vertical scan direction. For ease of illustration, scan points to be scanned, being scanned, or scanned are represented by solid circles, and scan points to be skipped or skipped are represented by dashed circles. In Figure 4A In the embodiment shown in Figure 4G, it is assumed that the frame rate of the lidar system 102 is 10 fps.

[0067] As shown in Figure 4H, the transmitter scan control unit 236 can control the transmitter 202 to start scanning the laser beam 209 according to a second scan pattern along the lateral scan direction and the vertical scan direction according to a second transmission scheme. The second transmission scheme can be an example of the transmission scheme 322. The transmitter scan control unit 236 can also control the energy of the laser beam 209 emitted by the transmitter 202 to be below the respective safety limit, e.g., AEL Class 1. Scan points 406 represent points at which the laser beam 209 is scanned according to the second transmission scheme. In some embodiments, the scan points 406 can be examples of the scan points 310. Figure 4A In some embodiments, at the scan point 406, the object 212 is detected to be within the functional distance range based on the returned laser beam 211. In some embodiments, the scan point 406 is located at the i-th row and the j-th column of the first scan pattern, i and j each being a non-negative integer. The scan point 406 can be an example of the scan point 310. The object detection unit 260 can send an alert signal indicating the detection result to the transmitter adjustment module 250. In response to the alert signal, the transmitter scan control unit 236 can switch from the first transmission scheme to the second transmission scheme along the lateral scan direction and the vertical scan direction. The second transmission scheme can be an example of the transmission scheme 321.

[0068] In some embodiments, to initiate the second transmission scheme, the transmitter scan control unit 236 controls the transmitter 202 to skip the remaining scan points of the first scan pattern towards the aperture 402 extending from the scan point 406. In some embodiments, the aperture 402 is an example of the aperture 323. In one example, the transmitter 202 scans the laser beam 209 at a column of scan points along the vertical scan direction before moving to the next column along the lateral scan direction. As shown in Figure 4H, the aperture 402 is located at the i-th row and the j-th column of the second scan pattern.

[0069] Figure 4A ​As shown, according to the first emission scheme, the emitter scan control unit 236 can control the emitter 202 to skip the remaining scan points in the aperture 402 in the vertical scan direction and start scanning the laser beam 209 at a first scan point outside the aperture 402 (e.g., scan point 404 below the aperture 402). The emitter scan control unit 236 can continue the first emission scheme for scanning the next column of scan points (e.g., 404) until switching to the second emission scheme for scanning the laser beam 209 toward the aperture 402. That is, the emitter 202 can skip all scan points in the next column in the aperture 402 and start continuously scanning the laser beam 209 in the same column outside the aperture 402 (e.g., without skipped scan points). The emitter scan control unit 236 can control the emitter 202 to continue skipping the scan points of the first scan pattern in the aperture 402 until the scanning of the first scan pattern is completed.

[0070] The emitter scan control unit 236 can then start scanning a second scan pattern along the lateral and vertical scan directions. In some embodiments, the emitter 202 scans the second scan pattern in the same scan directions (e.g., from left to right and from top to bottom) in the field of view 300.

[0071] Figure 4BA scenario is shown in which object 212 is detected within the functional distance range at a scan point of the second scan pattern. Emitter scan control unit 236 can control emitter 202 to begin scanning laser beam 209 at a scan point of the second scan pattern in field of view 300. Scan point 414 can represent a scan point according to the first emission scheme and can be an example of scan point 306-2. Emitter scan control unit 236 can skip one or more rows and / or columns in aperture 402 along the transverse and vertical scan directions and begin scanning laser beam 209 at the first scan point of the second scan pattern in a sub-aperture 418 of aperture 402. Sub-aperture 418 can be determined by sub-aperture determination unit 238. In some embodiments, the size of sub-aperture 418 in the transverse scan dimension is ¾ of aperture 402, and the size of sub-aperture 418 in the vertical scan dimension is ¾ of aperture 402. Object detection unit 260 can determine whether object 212 is detected within the functional distance range for each scan point in sub-aperture 418. If object 212 is not detected within the functional distance range at scan point 416 in sub-aperture 418, transmitter scan control unit 236 may apply a first transmission scheme to transmitter 202 to scan the next scan point in sub-aperture 418. If object 212 is detected within the functional distance range at scan point 416, transmitter scan control unit 236 may apply a second transmission scheme to transmitter 202. In some embodiments, the second transmission scheme is an example of transmission scheme 321. In some embodiments, scan point 416, where object 212 is detected within the functional distance range, is located in row i+m and column j+n of the second scan pattern, where m and n are both positive integers. When applying the second transmission scheme, transmission scheme determination unit 234 may determine a new aperture extending from the current scan point at which object 212 is detected within the functional distance, and skip the remainder of all scan points of the current scan pattern in the new aperture. The new aperture, such as aperture 412, is an example of aperture 323.

[0072] like Figure 4B As shown, object 212 can be detected within the functional distance range at scan point 416 of the second scan pattern in sub-aperture 418. For ease of explanation, scan point 416 is described as the first scan point of the second scan pattern in sub-aperture 418. The first scan point of the second scan pattern can be an example of scan point 310. Aperture 412 extending from scan point 416 (e.g., the current scan point) can be determined. Transmitter scan control unit 236 can skip all remaining scan points of the second scan pattern in aperture 412 (according to the second transmission scheme) and continue scanning outside aperture 412 in the lateral and vertical scanning directions (according to the first transmission scheme).

[0073] Figure 4CThe scenario is shown where any scan point of the second scan pattern in the sub- aperture 418 does not detect the object 212 within the functional distance range. The transmitter scan control unit 236 can control the transmitter 202 to skip one or more rows and / or columns of scan points of the second scan pattern in the aperture 402 along the scan direction and to scan the laser beam 209 from a first scan point (e.g., scan point 416) of the second scan pattern in the sub-aperture 418. If the object 212 is not detected within the functional distance range at the scan point 416 in the sub-aperture 418, the transmitter scan control unit 236 can apply the first transmission scheme to scan the next (e.g., immediately following) scan point in the sub-aperture 418. In some embodiments, the transmitter 202 continues to scan the laser beam 209 at the scan points in the sub-aperture 418 according to the first transmission scheme until the scanning of all scan points 416 is completed. In some embodiments, the transmitter scan control unit 236 switches to the second transmission scheme and controls the transmitter 202 to scan the laser beam 209 accordingly when the object 212 is detected within the functional distance range of one of the scan points 416, similar to the scenario shown in FIG. 3B. Meanwhile, the transmitter scan control unit 236 can control the transmitter 202 to continuously scan the laser beam 209 outside the aperture 402 according to the first transmission scheme. Figure 4B

[0074] After the scanning of the second scan pattern is completed, the transmitter scan control unit 236 can start to scan a third scan pattern in the field of view 300. For example, assume that the object 212 is not detected within the functional distance range of any scan point 416 of the second scan pattern. The transmitter scan control unit 236 can control the transmitter 202 to continuously scan the laser beam 209 outside the aperture 402 according to the first transmission scheme, skipping one or more rows and / or columns of scan points in the aperture 402, and starting to scan from a first scan point of the third scan pattern in a second sub-aperture of the aperture 402. Figure 4D The scenario is shown where the object 212 is detected at one scan point in a second sub-aperture 428 of the aperture 402 within the functional distance range. The second sub-aperture 428 can be an example of the second sub-aperture 326. Scan point 424 represents a scan point of the third scan pattern according to the first transmission scheme, and scan point 426 represents a scan point of the third scan pattern in the second sub-aperture 428. The scan point 424 can be an example of the scan point 306-3. In some embodiments, the size of the sub-aperture 428 in the lateral scan dimension is ½ of the aperture 402, and the size of the sub-aperture 428 in the vertical scan dimension is ½ of the aperture 402.

[0075] ​For example, an object 212 is detected at a first scan point (e.g., 426) of a third scan pattern in a second sub-aperture 428. The first scan point of the third scan pattern can be an example of the scan point 310. The emitter scan control unit 236 can determine a second aperture 430 extending from the current scan point (e.g., the first scan point of the third scan pattern in the second sub-aperture 428) and extending in the scan direction. The second aperture 430 can be an example of the aperture 323. The emitter scan control unit 236 can adjust a second emission scheme for scan points in the second aperture 430, e.g., skip the rest of all scan points in the second aperture 430. In some embodiments, the emitter scan control unit 236 controls the emitter 202 to continuously scan the laser beam 209 to scan points outside the second aperture 430 according to the first emission scheme. For example, as shown in FIG. 3B, the emitter 202 can scan the laser beam 209 to scan points 424 outside the second aperture 430 in the same column as the current scan point and in subsequent (e.g., next column) columns of the current scan point according to the first emission scheme. In some embodiments, if an object 212 is detected at any scan point 426 within the functional distance range of the sub-aperture 428, and the scan point 426 is located in the ktrow and the lcolumn of the second scan pattern, the scan point (e.g., 426) at which the object 212 is detected within the functional distance range of the second sub-aperture 428 is located in the k+prow and the l+qcolumn, k, l, p, q are all positive integers. Figure 4D

[0076] Figure 4E A scenario is shown in which no object 212 is detected within the functional distance range of any scan point in the second sub-aperture 428 of the aperture 402. Unlike the scenario shown in FIG. 3B, when no object 212 is detected at a scan point 426 in the second sub-aperture 428, the emitter scan control unit 236 controls the emitter 202 to scan the laser beam 209 to a next scan point 426 in the second sub-aperture 428 according to the first emission scheme. When no object 212 is detected within the functional distance range of any scan point 426 in the second sub-aperture 428, the emitter 202 can scan each scan point 426 according to the first emission scheme. Meanwhile, the emitter 202 can scan the laser beam 209 to scan points 424 outside the aperture 402 according to the first emission scheme. Figure 4D

[0077] ​​Upon completion of scanning of the third scan pattern, the transmitter scan control unit 236 can begin scanning four scan patterns in the field of view 300. For example, assume that no object 212 is detected within the functional distance range of one of the scan points 426 of the third scan pattern, the transmitter scan control unit 236 can control the transmitter 202 to scan the laser beam 209 according to a fourth scan pattern. The transmitter 202 can continuously scan the laser beam 209 outside the aperture 402 according to the first firing scheme, skipping one or more rows and / or columns of scan points in the aperture 402, and starting scanning from a first scan point of the fourth scan pattern in the third sub-aperture of the aperture 402. Figure 4F A scenario is shown in which an object 212 is detected within the functional distance range of one of the scan points in the third sub-aperture 438 in the aperture 402. The third sub-aperture 438 can be an example of the third sub-aperture 328. Scan point 434 represents a scan point of the fourth scan pattern according to the first firing scheme, and scan point 436 represents a scan point of the fourth scan pattern in the third sub-aperture 438. Scan point 434 can be an example of scan point 306-4. In some embodiments, the size of the third sub-aperture 438 in the lateral scan dimension is ¼ of the size of the aperture 402, and the size of the third sub-aperture 438 in the vertical scan dimension is ¼ of the size of the aperture 402.

[0078] For example, an object 212 is detected within the functional distance range at a first scan point (e.g., 436) of the fourth scan pattern in the third sub-aperture 438. The first scan point of the fourth scan pattern in the third sub-aperture 438 can be an example of scan point 310. The transmitter scan control unit 236 can determine a third aperture 440 extending from the current scan point (e.g., the first scan point of the fourth scan pattern in the third sub-aperture 438) and extending in the scan direction. The third aperture 440 can be an example of the aperture 323. The transmitter scan control unit 236 can apply the second firing scheme to scan points in the third aperture 440, e.g., skipping the rest of all scan points in the third aperture 440. In some embodiments, the transmitter scan control unit 236 controls the transmitter 202 to continuously scan the laser beam 209 to scan points outside the third aperture 440 according to the first firing scheme. For example, as shown, the transmitter 202 can scan the laser beam 209 to scan points 434 outside the third aperture 440 in the same column as the current scan point and in a subsequent (e.g., next column) column of the current scan point according to the first firing scheme. Figure 4F

[0079] Figure 4G A scenario is shown in which no object 212 is detected within the functional distance range of any scan point in the third sub-aperture 438 in the aperture 402. As with the scenario shown in FIG. 6, the transmitter scan control unit 236 can determine a third aperture 440 extending from the current scan point (e.g., the first scan point of the fourth scan pattern in the third sub-aperture 438) and extending in the scan direction. The third aperture 440 can be an example of the aperture 323. The transmitter scan control unit 236 can apply the second firing scheme to scan points in the third aperture 440, e.g., skipping the rest of all scan points in the third aperture 440. In some embodiments, the transmitter scan control unit 236 controls the transmitter 202 to continuously scan the laser beam 209 to scan points outside the third aperture 440 according to the first firing scheme. For example, as shown, the transmitter 202 can scan the laser beam 209 to scan points 434 outside the third aperture 440 in the same column as the current scan point and in a subsequent (e.g., next column) column of the current scan point according to the first firing scheme. Figure 4F ​different from the scenario shown in FIG. 4G, when no object 212 is detected within the functional distance range at one of the scan points 436 in the third sub-aperture 438, the emitter scan control unit 236 controls the emitter 202 to scan the laser beam 209 according to the first emission scheme to the next scan point 436 in the third sub-aperture 438. The emitter 202 can scan each of the scan points 436 according to the first emission scheme when no object 212 is detected within the functional distance range at any of the scan points 436 in the third sub-aperture 438. Meanwhile, the emitter 202 can scan the laser beam 209 to the scan point 434 outside the aperture 402 according to the first emission scheme.

[0080] In some embodiments, if no object 212 is detected within the functional distance range at any of the scan points (e.g., 404, 414, 424, and 434), the emitter scan control unit 236 can control the emitter 202 to continuously scan the laser beam 209 in the field of view 300, e.g., according to the first emission scheme, as shown in FIG. 4H, or until an object 212 is detected within the functional distance range. Figure 3C

[0081] As shown in FIG. 4H, the emitter scan control unit 236 can control the emitter 202 to scan the next pattern in the aperture from the same first scan point of the next scan pattern, regardless of the detection result of the subsequent scan pattern, when an object 212 is detected within the functional distance range of the first scan pattern. That is, in the most recently determined aperture, the scan of the next pattern starts from the first scan point of the next pattern in the corresponding sub-aperture of all subsequent scan patterns. Thus, if an object 212 is repeatedly detected within the functional distance range from the first time an object 212 is detected, the total number of scan points in the aperture is equal to four in one frame. By reducing the number of scan points in the field of view, the total energy of the laser beam is limited, and thus the human eye is less likely to be harmed by the lidar system 102. Figures 4A-4G

[0082] It should be noted that the positions of the apertures can be arbitrary and determined based on the position of the object 212, and should not be limited by the embodiments of the present specification. For illustrative purposes, in Figure 4A In FIG. 4G, the apertures are described as extending from each scan point below the first scan point of the column. However, in various embodiments, if an object 212 is detected within the functional distance range at the first scan point of the column, the emitter scan control unit 236 can apply the second emission scheme from the first scan point (e.g., the current scan point) and control the emitter 202 to skip all remaining scan points in the aperture extending from the first scan point.

[0083] ​​It should also be noted that the shape and extension direction of the aperture should be determined based on the scanning direction of the lidar system 102 and should not be limited by the embodiments of this specification. According to the second transmission scheme, the current scanning point, such as the scanning point at which object 212 is detected within the functional range, should be the first and only scanning point in the aperture. The aperture should include / cover the current scanning point and extend along the scanning direction. The shape of the aperture can be selected to minimize the number of scan points that are skipped.

[0084] It should also be noted that the number of scan points skipped in an aperture should be determined based on the design of the lidar system 102 and should not be limited by the embodiments of this specification. The number of scan points skipped in an aperture can be determined in part or in whole based on a predetermined safety limit, which is a value that ensures that there is no potential damage to the human eye even if the human eye is located at the same position as the object 212. The predetermined safety limit is determined in part or in whole based on the frame rate of the lidar system 102. For example, different frame rates can result in different predetermined safety limits. The predetermined safety limit can also be determined using any suitable method and have other suitable values. In other embodiments, if the aperture covers multiple scan points, the distribution of the scan points can optimize the spatial resolution and / or detectability of the object 212 in the aperture.

[0085] Figure 5A FIG. 5 is a flow chart of an exemplary method 500 for controlling the emission scheme of the laser beam 209 to limit its pulse energy incident on the aperture in a scanning pattern according to an embodiment of the present specification. Figure 5B and 5C FIG. 5 is a flow chart of an exemplary method 501 for controlling the emission scheme of the laser beam 209 to limit its pulse energy incident on the aperture in another scanning pattern according to an embodiment of the present specification. Figure 5C yes Figure 5B 5B and 5C are described together. For ease of description, methods 500 and 501 are described together. Figures 3A-3E and Figures 4A-4G Describe together.

[0086] Figure 5A shows the Figure 5A Method 500 for controlling the emission scheme of laser 209 in the first scanning pattern in FIG. Figure 3C and 3E And related descriptions according to some embodiments. Figure 5A As shown, in step 502, a laser beam of a first scanning pattern is emitted according to a first emission scheme, and the energy of the laser beam (e.g., pulse energy) is controlled within a safe limit. The controller 252 can control the emitter 202 to emit the first scanning pattern (e.g., 320) to the field of view 300 according to the first emission scheme (e.g., 320) as a high-resolution emission scheme.Figure 4A The controller 252 can control the energy of the laser beam 209 to be below a predetermined safety limit. The laser beam is emitted towards the surrounding environment and is reflected by one or more objects in the environment. The reflected laser beam returns to the optical sensing system.

[0087] At step 504, it is determined whether an object is detected within the functional distance range based on the returned laser beam. The controller 252 can determine whether an object 212 is detected within the functional distance range based on the receiver signal 218. The controller 252 can determine whether an object 212 is detected within the functional distance range based on a comparison between the distance from the object 212 to the receiver 204 and the distance tolerance value Do. At step 506, it is determined whether an object 212 is detected within the functional distance range at the current scan point. If the distance from the object 212 to the receiver 204 is less than the distance tolerance value Do, it is determined that the object 212 is within the functional distance range at the current scan point, and the method 500 proceeds to step 508. If no object is detected within the distance tolerance value Do, the method 500 proceeds to step 510.

[0088] At step 508, it is determined that an aperture extends from the current scan point in the scan direction. The controller 252 can determine an aperture that extends from the current scan point (e.g., the aperture 323 or 402) and extends in the lateral and vertical scan directions. The aperture can have a size that covers the area of a human pupil. In some embodiments, the aperture has a shape of a square. At step 510, the emission scheme of the emitter 202 is switched to a second emission scheme for scanning the laser beam in the aperture (e.g., at the next scan point). The controller 252 can switch the emission scheme to a second emission scheme (e.g., the emission scheme 321), which is a low resolution emission scheme to scan the laser beam 209 towards the aperture. In some embodiments, the second emission scheme defines a scan pattern that includes only the current scan point (e.g., scanned) and skips all remaining scan points in the aperture that are not scanned.

[0089] After step 510, the method 500 proceeds to step 524, in which the laser beam is moved to the next scan point. The controller 252 can control the emitter to move the laser beam 209 to the desired direction and maintain the second emission scheme. In some embodiments, the controller 252 can determine the direction of the laser beam 209 based on the coordinates of the current scan point. After step 524, the method 500 is directed to step 502 (for the first emission scheme) or step 516 (for the second emission scheme) depending on whether the next scan of the laser beam 209 is according to the first emission scheme or the second emission scheme.

[0090] At step 512, the first emission scheme is maintained. If no object is detected within the functional distance range, the controller 252 can maintain the first emission scheme. At step 514, it is determined whether the current scan point is the last scan point of the first scan pattern. The controller 252 can determine whether the current scan point is the last scan point of the current scan pattern in the frame, for example, based on the coordinates of the current scan point and / or the number of previously scanned scan points in the current frame. If the current scan point is determined to be the last scan point of the current scan pattern, the method 500 is directed to step 503 of method 500, which will be described later. Otherwise, the operation is directed to step 524. Figure 5B

[0091] At step 516, the controller 252 can determine whether the current scan point is the last scan point in the current aperture along the scan direction (e.g., the vertical scan direction). In some embodiments, the current scan point is a skipped (e.g., unscanned) scan point at which the laser beam 209 is not emitted. The controller 252 can determine the location of the current scan point and determine whether it is located at the boundary of the current aperture such that the next scan point is the first scan point outside the current aperture (e.g., along the vertical scan direction).

[0092] If it is determined that the current scan point is the last scan point in the current aperture (e.g., a skipped scan point), the method 500 proceeds to step 520. Otherwise, the method 500 proceeds to step 518. At step 518, the second emission scheme is maintained. From step 518, the method 500 can proceed to step 524, in which the laser beam is moved to the next scan point 4. At step 520, the emission scheme is adjusted to the first emission scheme. The controller 252 can control the emitter 202 to adjust the emission scheme to the first emission scheme. From step 520, the method 500 proceeds to step 514, which is described above.

[0093] Figure 5B 5C A method 501 for controlling an emission scheme of a laser 209 in another scan pattern following a scan pattern in Figure 5A is shown, according to some embodiments. Figure 5C is a continuation of Figure 5B . Figure 5B 5C The scan pattern in Figure 3C and 3E and related descriptions. As Figure 5B ​​​As shown, the method 501 can start from step 503, in which a laser beam 209 is emitted to a first scanning point of a current scanning pattern. After step 503, based on whether the first emission scheme or the second emission scheme is to be employed, the method 501 proceeds to step 505 (for the first emission scheme) or step 521 (for the second emission scheme).

[0094] At step 505, it is determined whether the current scanning point is in a current aperture. In some embodiments, the current aperture represents an aperture determined in a previous scanning pattern (e.g., the first scanning pattern). The controller 252 can determine the relative position of the current scanning point with respect to the current aperture. If it is determined that the current scanning point is located in the current aperture, the method 501 proceeds to step 529. Otherwise, the method 501 proceeds to step 507. At step 507, the laser beam for the next scanning pattern is emitted according to the first emission scheme, and the energy (e.g., pulse energy) of the laser beam is controlled below a safety limit. In some embodiments, the controller 252 controls the emitter 202 to emit the laser beam 209 for the second scanning pattern (e.g., the second scanning pattern 325) toward the field of view 300 according to the first emission scheme (e.g., the emission scheme 320), which is a high-resolution emission scheme. The controller 252 can control the energy of the laser beam 209 to be below a predetermined safety limit. At step 509, it is determined whether an object is detected within a functional distance range. Step 509 can be similar to step 504, which is not repeated here. At step 511, if an object is detected within the functional distance range, the method 501 proceeds to step 513. Otherwise, the method 501 proceeds to step 517. Figure 4B

[0095] At step 513, another aperture extending from the current scanning point along the scanning direction is determined. The controller 252 can determine another aperture extending from the current scanning point (e.g., the aperture 323) and extending in the lateral and vertical scanning directions. The size of the other aperture can cover the area of a human pupil. In some embodiments, the other aperture has a square shape. At step 515, the emission scheme of the emitter 202 is switched to the second emission scheme for scanning the laser beam in the other aperture. The controller 252 can switch to the second emission scheme (e.g., the emission scheme 321), which is a low-resolution emission scheme, to scan the laser beam 209 toward the other aperture. After step 515, the method 501 proceeds to step 503, in which the laser beam is moved to the next scanning point. The controller 252 can control the emitter to move the laser beam 209 in a desired direction and maintain the second emission scheme. In some embodiments, the controller 252 can determine the direction of the laser beam 209 based on the coordinates of the current scanning point.

[0096] ​At step 517, the first emission scheme is maintained. If no object 212 is detected within the functional distance range, the controller 252 can maintain the first emission scheme. From step 517, the method 501 also proceeds to step 503 to scan the next scan point. If the current scan point is the last scan point of the current scan pattern, the "next scan point" will be the first scan point of the next scan pattern.

[0097] At step 521, the controller 252 can determine whether the current scan point is the last scan point in the current aperture along the scan direction (e.g., the vertical scan direction). In some embodiments, the current scan point is a skipped (e.g., unscanned) scan point at which the laser beam 209 is not emitted. The controller 252 can determine the location of the current scan point and determine whether it is at the boundary of the current aperture such that the next scan point is the first scan point outside the current aperture (e.g., along the vertical scan direction).

[0098] If it is determined that the current scan point is the last scan point in the current aperture along the scan direction, the method 501 proceeds to step 525. Otherwise, the method 501 proceeds to step 523. At step 523, the second emission scheme is maintained. At step 525, the emission scheme is adjusted to the first emission scheme. From steps 523 and 525, the method 501 can continue to step 503.

[0099] At step 529, the respective sub-aperture of the current aperture is determined. The controller 252 can determine the sub-aperture at the current scan pattern before scanning the laser beam 209 toward the current aperture, as shown in 418 and related description in Figure 3E , Figure 4B and 4C . At step 531, if it is determined that the current scan point is located in the sub-aperture, the method 501 proceeds to step 507. Otherwise, the method 501 proceeds to step 521.

[0100] Although the above description is made in the context of protecting human eyes, and the example embodiments involve human pupil sizes, it is contemplated that the disclosed systems and methods can be readily adapted to protect the eyes of other objects, such as animals (e.g., pets). Thus, embodiments can be modified to use the pupil sizes of the respective objects that are sought to be protected.

[0101] Another aspect of the present specification relates to a non-transitory computer- readable medium storing instructions that, when executed, cause one or more processors to perform the above-described methods. The computer-readable medium can include volatile or non-volatile, magnetic, semiconductor, tape, optical, removable, non-removable, or other types of computer- readable media or computer-readable storage devices. For example, as disclosed, the computer-readable medium can be a storage device or storage module having computer instructions stored thereon. In some embodiments, the computer-readable medium can be a disk or flash drive having computer instructions stored thereon.

[0102] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed systems and associated methods. Other embodiments will be apparent to those of ordinary skill in the art from consideration of the specification and practice of the disclosed systems and associated methods.

[0103] The present specification and examples are to be considered exemplary and the true scope of the application is indicated by the following claims and their equivalents.

Claims

1. A system for controlling laser beam emission using a plurality of scanning patterns by an optical sensing device, characterized in that The plurality of scanning patterns are staggered to cover the field of view of the optical sensing device, and the system comprises: The controller is configured as: detecting an object within a functional distance range of the optical sensing device based on reflected light of a first laser beam received by the optical sensing device, wherein the first laser beam is emitted toward a first scanning point in a first scanning pattern; determining an aperture extending from the first scan point; and controlling the optical sensing device to emit a second laser beam toward a second scanning point in a second scanning pattern, and skipping scanning points between the first scanning point and the second scanning point in the aperture; The aperture extends from the first scanning point along a scanning direction.

2. The system according to claim 1, wherein: Each scanning pattern includes scanning points arranged in a plurality of rows and columns, wherein the scanning points skipped between the first scanning point and the second scanning point include a row of scanning points in each of the plurality of scanning patterns.

3. The system according to claim 2, characterized in that The second scanning pattern immediately follows the first scanning pattern in an alternating order.

4. The system according to claim 3, characterized in that The first scanning point is located at the i-th row and j-th column of the first scanning pattern, and the second scanning point is located at the i+m-th row and j+n-th column of the second scanning pattern, where i and j are non-negative integers, and m and n are positive integers.

5. The system according to claim 1, wherein: The optical sensing device performs two-dimensional scanning, and the aperture extends from the first scanning point in two scanning directions.

6. The system according to claim 5, characterized in that The aperture is large enough to cover the pupil area of ​​the object.

7. The system according to claim 1, wherein: The area of ​​the laser beam at the distance limit of the functional distance range is equal to 2.5 times the area of ​​the laser beam at the optical sensor device.

8. The system according to claim 7, characterized in that The aperture is a square area with a length of 7 mm along the transverse scanning direction and a width of 7 mm along the vertical scanning direction.

9. The system according to claim 1, wherein: The controller is configured to control the optical sensing device to emit the laser beam to scanning points in the plurality of scanning patterns outside the aperture without skipping any scanning point.

10. The system according to claim 1, wherein: The controller is further configured to: detecting an object within the functional distance range of the optical sensing device based on the reflected light of the second laser beam received by the optical sensing device; as well as The optical sensing device is controlled to emit a third laser beam to a third scanning point in a third scanning pattern, and to skip scanning points between the second scanning point and the third scanning point in the aperture.

11. The system according to claim 10, wherein: The third scanning pattern immediately follows the second scanning pattern in an alternating order.

12. The system according to claim 11, wherein: The second scanning point is located in the kth row and lth column of the second scanning pattern, wherein the third scanning point is located in the k+pth row and l+qth column of the third scanning pattern, where k, l, p and q are all positive integers.

13. The system according to claim 1, wherein: The controller is further configured to: determining a subaperture covering the second scanning point based on reflected light of the second laser beam received by the optical sensing device and in response to no object being detected within the functional distance range from the optical sensing device; as well as The optical sensing device is controlled to emit a laser beam to each scanning point in the sub-aperture until an object is detected.

14. The system according to claim 13, wherein: The second scanning pattern is the Nth one starting from the first scanning pattern in an interleaved order, and the area of ​​the sub-pore is equal to the area of ​​the pore. 。 15. A method for controlling laser beam emission using a plurality of scanning patterns by an optical sensing device, characterized in that: The plurality of scanning patterns staggeredly cover the field of view of the optical sensing device, including: detecting an object within a functional distance range of the optical sensing device based on reflected light of a first laser beam received by the optical sensing device, wherein the first laser beam is emitted toward a first scanning point in a first scanning pattern; determining an aperture extending from the first scan point; and controlling the optical sensing device to emit a second laser beam toward a second scanning point in a second scanning pattern, and skipping scanning points between the first scanning point and the second scanning point in the aperture; The aperture extends from the first scanning point along a scanning direction.

16. The method according to claim 15, characterized in that Each scanning pattern includes scanning points arranged in a plurality of rows and columns, wherein the scanning points skipped between the first scanning point and the second scanning point include a row of scanning points in each of the plurality of scanning patterns.

17. The method according to claim 16, characterized in that The second scanning pattern immediately follows the first scanning pattern in an alternating order.

18. The method according to claim 17, characterized in that The first scanning point is located at the i-th row and the j-th column of the first scanning pattern, and the second scanning point is located at the i+m-th row and the j+n-th column of the second scanning pattern.

19. The method according to claim 15, comprising: performing a two-dimensional scan, wherein the aperture extends from the first scanning point along two scanning directions; as well as The aperture is large enough to cover the pupil area of ​​the object.

20. A non-transitory computer readable medium having instructions stored thereon, characterized in that: When the instructions are executed by at least one processor, the at least one processor is caused to perform a method for controlling emission of a laser beam using a plurality of scanning patterns by an optical sensing device, wherein the plurality of scanning patterns are staggered to cover a field of view of the optical sensing device, the method comprising: detecting an object within a functional distance range of the optical sensing device based on reflected light of a first laser beam received by the optical sensing device, wherein the first laser beam is emitted toward a first scanning point in a first scanning pattern; determining an aperture extending from the first scan point; and controlling the optical sensing device to emit a second laser beam toward a second scanning point in a second scanning pattern, and skipping scanning points between the first scanning point and the second scanning point in the aperture; The aperture extends from the first scanning point along a scanning direction.

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