Adaptive transmitter and receiver for lidar systems

Abstract

A Lidar system and method for adaptive control are provided. The Lidar system includes: an array of transmitters (111), each transmitter being individually addressable and controllable to transmit a multipulse sequence, at least a subset of the transmitters being activated to transmit the multipulse sequence in parallel according to a transmission mode; an array of photodetectors (121), each photodetector being individually addressable, at least a subset of the photodetectors being capable of receiving light pulses according to a sensing mode, each subset of the photodetectors being configured to detect returned light pulses and generate an output signal representing the light energy associated with at least a subset of the light pulses; and one or more processors electrically coupled to the transmitter array and the photodetector array and configured to generate a transmission mode and a sensing mode based on one or more real-time conditions.

Description

Background Technology

[0001] Lidar (Light Detection and Ranging) technology can be used to acquire three-dimensional information about the environment by measuring the distance to an object. A Lidar system can include at least a light source configured to emit light pulses and a detector configured to receive returning light pulses. The returning light pulse, or beam, can be called an echo beam. The distance can be obtained based on the time interval (i.e., time of flight) between the emitted light pulse and the detection of the returning light pulse. The light pulse can be generated by a laser emitter and then focused by a lens or lens assembly. The returning light pulse can be received by a detector located near the laser emitter. The returning light pulse can be scattered light from the surface of an object.

[0002] Several types of Lidar systems exist. Solid-state Lidar systems, unlike beam-scanning Lidar systems, may not have moving mechanical parts. Some solid-state Lidar systems do not rotate within the scene, but instead flash the entire portion of the scene they intend to capture with light and sense the reflected light. In such systems, the emitters can include an array of emitters (e.g., surface-emitting laser diodes), all of which simultaneously emit light to illuminate the scene. When the entire scene is illuminated simultaneously, the sensor pixel array of the Lidar system's receiving device can be used to capture the signal in parallel, much like a camera. Crosstalk can occur between sensor pixels because multiple reflections, especially those from adjacent pixels, may not be isolated. Furthermore, current flash Lidar systems may require high power to operate because all emitters or detectors are activated simultaneously, and they require significant processing power to handle signals from all pixel detectors concurrently. The large amount of emitted light also introduces unwanted stray light, which can introduce noise at the receiver, reducing the signal-to-noise ratio of the sensed signal and causing image blurring or blind spots. For example, the laser pulse echo signal reflected from near-field obstacles may be submerged in the stray light delay base due to detector saturation, which may make it impossible to determine the location information of near-field obstacles and cause measurement blind spots. Invention Overview

[0004] There is a need for a LiDAR system for 3D measurement with higher optical ranging accuracy and energy efficiency. Further, there is a need for a LiDAR system based on surface emitters or sensor arrays with higher dynamic range and signal-to-noise ratio (SNR). The LiDAR system provided in this application can meet the above requirements by employing dynamically configurable emitter and detector modules.

[0005] The emission module of the Lidar system in this application may include an emitter array, such as a VCSEL (Vertical-Cavity Surface-Emitting Laser) or VECSEL (Vertical-External-Cavity Surface-Emitting Laser) array, where each emitter in the array can be individually addressed or controlled. In some embodiments, the emission module may be dynamically configured to adapt to different distance ranges. For example, the emission module can be configured at the pixel level by varying the laser pulse energy emitted by a single emitter corresponding to a pixel. In some cases, the emission module may be dynamically configured or adjusted per image frame or per distance measurement during Lidar system operation.

[0006] Individually addressable transmitters allow a subset of transmitters in a transmitter array to be activated to excite optical pulses in parallel according to excitation or emission modes in the time dimension and spatial domain (e.g., a two-dimensional array plane, xy direction). By synchronizing this emission mode with the sensing mode of the detection module, a mapping between the expected signal locations of the transmitter array and the detectors can be established, enabling only those detectors that are expected to sense signals.

[0007] The detection module of the Lidar system in this application may include a photoelectric sensor with a higher dynamic range, enabling the Lidar system to image with high imaging resolution and a longer measurement range. The photoelectric sensor converts light into an electrical signal. The photoelectric sensor may correspond to a specific pixel at a resolution in the ranging measurement. In some embodiments of this disclosure, the photoelectric sensor may include multiple photodetectors, such as single-photon avalanche diodes (SPADs). The detection module may be configured at the pixel level or sub-pixel level, and / or may be adjusted per frame or per distance measurement.

[0008] In some cases, a photodetector may include an array of photodetectors, such as a photodetector array, with the ability to dynamically enable / disable individual photodetectors within the array. As described above, the light emitter array and the photodetector array can operate synchronously, so that when one or more light emitters are activated, one or more corresponding photodetectors can be activated / enabled and generate sensor output signals (e.g., pixel values). In some cases, pixels outside the intended detection location may be disabled and not combined, thus preventing a decrease in the signal-to-noise ratio (SNR) due to noise or ambient light from outside the region of interest.

[0009] In some cases, the detection module can be configured at the pixel level, such that one or more photodetectors (e.g., SPADs) corresponding to a pixel can be activated / deactivated according to the sensing mode. In some cases, the operation of a set of photodetectors (e.g., SPADs) or a single photodetector corresponding to a pixel can be configurable, so that the light energy received by the set of photodetectors (e.g., SPADs) or the single photodetector can be controlled, thereby controlling the sensor output signal. In some cases, the light energy to be converted into an electrical signal can be controlled by controlling the number of SPADs enabled in the set of SPADs corresponding to the signal, and / or by controlling the number of light pulses selected from a set of returned light pulses. For example, the detection module may include a pulse detection circuit configured to convert an optical signal into an electrical signal. The pulse detection circuit can be configured to generate a sensor output signal by changing the received photon energy that is converted into at least one electrical signal. Alternatively, when the electrical signal corresponds to a single light pulse, the pulse detection circuit can generate a sensor output signal by accumulating different combinations of electrical signals used to generate the sensor output signal. In some cases, the pulse detection circuit can generate a sensor output signal representing the light energy associated with a selected subset of returned light pulses. The photon energy can be changed by altering the number / count of returned light pulses accumulated to generate the output signal, and / or by changing the selection of a subset of returned light pulses, thereby allowing selection of the corresponding total light energy.

[0010] In some embodiments, an adaptive control mechanism is provided to the LiDAR system. This adaptive control mechanism can be configured to control the excitation mode of a two-dimensional light emitter array, for example, by activating only a subset of light emitters at a time, and to control the sensing mode of the two-dimensional array of photodetectors by synchronizing / deactivating the individual photodetectors within the array with the excitation of their respective light emitters in parallel. In some cases, the sensing mode can be synchronized with the excitation mode in terms of the two-dimensional position / address (e.g., row and column indices) of the activated emitters / photodetectors relative to the emitter / photodetector array, and one or more operating parameters. For example, the light energy received by a group of photodetectors (e.g., SPADs) corresponding to a pixel can be adjusted based on the intensity of the emitted light pulses, and the light energy can be adjusted by controlling the number of SPADs enabled / disabled in the group and / or the number of light pulses accumulated to generate the sensor output signal.

[0011] In some cases, each transmitter in the transmitter array can be individually addressed with suitable transmitter-specific drive circuitry so that the transmitter module can operate to excite a selected group of transmitters that match the activation / deactivation of the corresponding photodetector. Alternatively or additionally, each photodetector in the detector array can be individually addressed and controlled with suitable pixel-level circuitry so that the detector module can operate to enable a selected group of photodetectors that match the activation / deactivation of the corresponding transmitter. In some cases, an optimal mode (e.g., an optimal sparse mode) can be provided to reduce crosstalk between signal channels and improve energy efficiency.

[0012] In one aspect of the invention, this application provides a light detection and ranging system with an adaptive control mechanism. The light detection and ranging system may include: a transmitter array, each transmitter individually addressable and controllable to transmit a multi-pulse sequence into a three-dimensional environment, and at least a subset of the transmitters being activated to transmit the multi-pulse sequence in parallel according to a transmission mode; a photoelectric sensor array, each photoelectric sensor individually addressable, and at least a subset of the photoelectric sensors being enabled to receive light pulses according to a sensing mode, and each subset of photoelectric sensors being configured to detect light pulses returning from the three-dimensional environment and generate an output signal representing the light energy associated with at least a subset of the light pulses; and one or more processors electrically coupled to the transmitter array and the photoelectric sensor array, and the one or more processors being configured to generate a transmission mode and a sensing mode based on one or more real-time conditions.

[0013] In some embodiments, each emitter includes a set of laser diodes. In some cases, the set of laser diodes is electrically connected and controlled by a driving circuit.

[0014] In some embodiments, the transmission mode includes the address of the transmitter to be activated and the timing characteristics of the multi-pulse sequence transmitted by the transmitter. In some cases, the timing characteristics include one or more of the following: the amplitude of each pulse in the multi-pulse sequence, the duration of each pulse in the multi-pulse sequence, the time interval between multiple pulses, and the number of multiple pulses in the multi-pulse sequence.

[0015] In some embodiments, each photodetector includes a set of photodetectors. In some cases, each photodetector in the set of photodetectors can be individually addressed and controlled. In some cases, a subset of photodetectors from the set of photodetectors is enabled to receive light pulses according to a sensing mode. In some cases, the sensing mode includes the address of the photodetector to be enabled, the address of the photodetector to be enabled, or one or more parameters for selecting a subset of light pulses. The one or more parameters include the number of light pulses in the subset or parameters representing combinations of non-adjacent light pulses.

[0016] In some embodiments, the one or more real-time conditions are obtained based on detected light pulses. In some embodiments, the one or more real-time conditions include the detection of an object within a predetermined distance threshold. In some embodiments, the one or more processors are also configured to calculate distances based on the time of flight associated with a subset of light pulses. In some cases, the time of flight is determined by matching the timing characteristics of the light pulses returning from the three-dimensional environment with the emission patterns.

[0017] Another aspect of this disclosure provides a method for providing adaptive control for an optical detection and ranging system. The method may include: generating a transmission mode and a sensing mode based on one or more real-time conditions; activating at least one subset of transmitters from a transmitter array, according to the transmission mode, to transmit a multi-pulse sequence in parallel, wherein each of the transmitter arrays is individually addressable and controllable to transmit the multi-pulse sequence into a three-dimensional environment; and enabling at least one subset of photoelectric sensors from an individually addressable photoelectric sensor array to receive optical pulses according to the sensing mode, wherein each photoelectric sensor in the photoelectric sensor subset is configured to detect optical pulses returning from the three-dimensional environment and generate an output signal representing the optical energy associated with at least one subset of the optical pulses.

[0018] In some embodiments, each transmitter in the transmitter array includes a set of laser diodes. In some cases, the sets of laser diodes are electrically connected and controlled by a driving circuit.

[0019] In some embodiments, the transmission mode includes the address of the transmitter to be activated and the timing characteristics of the multi-pulse sequence transmitted by the transmitter. In some cases, the timing characteristics include one or more of the following: the amplitude of each pulse in the multi-pulse sequence, the duration of each pulse in the multi-pulse sequence, the time interval between multiple pulses, and the number of multiple pulses in the multi-pulse sequence.

[0020] In some embodiments, each photodetector in the photodetector array includes a set of photodetectors. In some cases, each photodetector in the set of photodetectors can be individually addressed and controlled. In some cases, a subset of photodetectors from the set of photodetectors is enabled to receive light pulses according to a sensing mode. In some cases, the sensing mode includes the address of the photodetector to be enabled, the address of the photodetector to be enabled, or one or more parameters for selecting a subset of light pulses. In this case, the one or more parameters include the number of light pulses in the subset of light pulses or parameters representing non-adjacent combinations of light pulses.

[0021] In some embodiments, the one or more real-time conditions are obtained based on detected light pulses. In some embodiments, the one or more real-time conditions include the detection of an object within a predetermined distance threshold.

[0022] In some embodiments, the method further includes calculating the distance based on the time of flight associated with a subset of optical pulses. In some cases, the time of flight is determined by matching the timing characteristics of the optical pulses returning from the three-dimensional environment with the emission mode.

[0023] Other aspects and advantages of this disclosure will immediately become apparent to those skilled in the art from the following detailed description. This disclosure only shows and describes exemplary embodiments, and only illustrates the best mode contemplated for carrying out this disclosure. It should be understood that other different embodiments of this disclosure may be possible, and its various details may be modified in a variety of obvious ways, all without departing from this disclosure. Therefore, the drawings and description are to be considered illustrative in nature and not restrictive. Attached Figure Description

[0024] The novel features of the invention are particularly set forth in the appended claims. A detailed understanding of the features and advantages of the invention will be obtained by referring to the following detailed description. These descriptions establish several illustrative embodiments utilizing the principles of the invention, along with a detailed description of the accompanying drawings, which include:

[0025] Figure 1 An example of a Lidar system according to some embodiments of the present invention is illustrated schematically.

[0026] Figure 2 Examples of transmitter arrays and detector arrays according to some embodiments of the present invention are shown.

[0027] Figure 3 An example of a transmitter array having transmitters that can be individually addressed and controlled is shown according to some embodiments of the present invention.

[0028] Figure 4 The sparse excitation mode of the emission module is schematically shown.

[0029] Figure 5 An example of a transmitter array is shown, in which a subset of transmitters can be addressed and controlled individually.

[0030] Figure 6 An example of a detector array with individually addressable and controllable photoelectric sensors is shown according to some embodiments of the present invention.

[0031] Figure 7 An example of a photoelectric sensor is shown, including a SPAD that can be enabled / disabled by pixel-level circuitry.

[0032] Figure 8 An example of a detector array is shown, comprising at least one set of SPADs grouped together to generate pixels.

[0033] Figure 9 An example of a SPAD array group is shown, where each group can be configured, addressed, and controlled individually.

[0034] Figure 10 An example is shown of accumulating a subset of returned pulses selected from a returned multi-pulse sequence to generate a sensor output signal, according to some embodiments of the present invention.

[0035] Figure 11 A Lidar system including a pattern generator is illustrated schematically according to some embodiments of the present invention. Invention Details

[0037] While preferred embodiments of the invention have been shown and described herein, it will be apparent to those skilled in the art that these embodiments are provided by way of example only. Many variations, modifications, and substitutions will now occur to those skilled in the art without departing from the invention. It will be understood that various alternatives may be made to the embodiments described herein when practicing the invention.

[0038] Lidar systems, also known as laser ranging systems, lidar systems, LIDAR systems, or laser / optical detection and ranging (LADAR or Ladar) systems, are ranging sensors characterized by long detection range, high resolution, and low susceptibility to environmental interference. Lidar systems are widely used in intelligent robots, drones, autonomous driving, and other fields. The working principle of Lidar is to estimate distance based on the round-trip time (e.g., flight time or delay time) between the electromagnetic wave and the target.

[0039] As used herein, the term "multipulse sequence" may generally refer to a sequence of optical pulses or a sequence of signals, and is used interchangeably throughout the specification unless the context otherwise requires. As used herein, unless the context otherwise requires, the term "measurement signal" generally refers to an emitted optical pulse or an optical pulse emitted from the transmitting device of a LiDAR system. As used herein, unless the context otherwise requires, the term "echo beam" generally refers to a return signal or a return optical pulse, and is used interchangeably throughout the specification unless the context otherwise requires. Delay time can refer to the time interval between the departure of the optical pulse sequence from the transmitter and the receipt of the reflected optical pulse sequence at the receiver. The delay time can then be used to calculate a distance measurement. Delay time may also be referred to as time of flight, and is used interchangeably throughout the specification.

[0040] A light pulse sequence can comprise multiple pulses emitted within a short duration, allowing the light pulse sequence to be used to acquire distance measurement points. For example, LiDAR can be used for three-dimensional (3D) imaging (e.g., 3D point clouds) or obstacle detection. In this case, the distance measurement associated with the light pulse sequence can be considered as a pixel, and the continuously emitted and captured set of pixels (i.e., a "point cloud") can be presented as an image or analyzed for other reasons (e.g., obstacle detection). Light pulse sequences can be generated and emitted within durations not exceeding 10 ns, 20 ns, 30 ns, 40 ns, 50 ns, 60 ns, 70 ns, 80 ns, 90 ns, 100 ns, 200 ns, 300 ns, 400 ns, 500 ns, 600 ns, 700 ns, 800 ns, 900 ns, 1 μs, 2 μs, 3 μs, 4 μs, and 5 μs. The time interval between sequences can be constant or variable.

[0041] In some cases, a multi-pulse sequence emitted by the transmitter can be modulated according to preset timing characteristics. These timing characteristics can be specified by the excitation mode of the transmitting module. The term "excitation mode" can also be referred to as "transmission mode," and these terms are used interchangeably throughout the specification. One or more parameters of the excitation mode (e.g., the amplitude of the specified optical pulses) can be specified based on the timing characteristics. In some cases, the timing characteristics can be defined by multiple factors, including but not limited to the number of pulses in the sequence, the time interval, the pulse duration, the pulse amplitude, the ratio between the amplitudes of any two pulses (e.g., amplitude ratio), the ratio between the durations of any two pulses (e.g., duration ratio), the duty cycle (e.g., the ratio between the duration of the multi-pulse sequence and the time interval between sequences), and various other derivative parameters. Preset timing characteristics can also help suppress crosstalk between channels or between different LiDAR systems.

[0042] In some cases, a multi-pulse sequence can be emitted to a single point in a 3D environment, and subsequent multi-pulse sequences can be emitted to different points in the 3D environment. In some cases, all pixels (e.g., distance measurements) are obtained using a multi-pulse sequence. In some cases, a selected subset of pixels is obtained using a multi-pulse sequence, and the remaining pixels can be obtained using an uncoded signal (e.g., a single light pulse). For example, a selected subset of pixels in a 3D imaging can be obtained using a coded signal, allowing each pixel to be generated based on a multi-pulse sequence, and another subset of pixels can be obtained using an uncoded signal, allowing each pixel to be generated using a single light pulse. In some cases, the measurement signal can be encoded at a coding frequency, allowing the multi-pulse sequence to be interspersed with uncoded signals at the coding frequency. For example, depending on the coding frequency, a multi-pulse sequence can be followed by one or more uncoded signals (e.g., a single pulse). The coding frequency can be specified by an excitation mode or an emission mode. In some cases, selected portions of multiple pulses returned in the sequence can be used to obtain pixel values ​​(e.g., intensity) and / or to calculate distance.

[0043] The output beam or signal beam can then be directed into space for measurement. As an example, the output beam can have an average power of approximately 1mW, 10mW, 100mW, 1W, or 10W, or any other suitable average power. As another example, the output beam can include pulses with pulse energies of approximately 0.1μJ, 1μJ, 10μJ, 100μJ, or any other suitable pulse energies. As yet another example, the output beam can include pulses with peak power of approximately 10W, 100W, 1kW, 2kW, 5kW, or 10kW, or any other suitable peak power. A light pulse with a duration of 400ps and a pulse energy of 1μJ has a peak power of approximately 2.5kW. If the pulse repetition frequency is 500kHz, the average power of an output beam with a 1μJ pulse is approximately 0.5W. In some cases, the wavelength of the output beam can be in the range of 800nm ​​to 1600nm, or any other suitable range. In some cases, the wavelength of the output beam can be in the range of 1530 nm to 1570 nm to provide eye-safe laser light. In an example of a VCSEL array, the duration of a light pulse characterized by full width at half maximum (FWHM) can be approximately a few nanoseconds (ns), such as 3 ns, with a duty cycle (e.g., the ratio between the duration of a multi-pulse sequence and the time interval between sequences) of approximately 0.1%, a center wavelength of approximately 850 nm, a peak power of 1 W / VCSEL, and a wavelength variation of no more than 1 nm throughout the emitter array.

[0044] The detector can be a photodetector or a photosensitive detector. The detector may include one or more photosensors, each capable of converting light into an electrical signal. Photosensors may include multiple photodetectors, such as single-photon avalanche diodes (SPADs). A photosensor may correspond to a specific pixel at a resolution in the ranging measurement. The detector may have the ability to dynamically enable / disable individual pixels in the array, and / or dynamically enable / disable a subset of SPADs within the pixels, thereby configuring the detector at the pixel level or sub-pixel level.

[0045] In some embodiments, the provided methods and systems can be implemented as solid-state Lidar systems with higher performance. As mentioned above, a solid-state Lidar system can refer to a Lidar form without moving mechanical parts. Compared to rotating Lidar systems or other electromechanically intensive conventional Lidar systems with lasers and / or detectors mounted on a rotating head, solid-state Lidar systems offer advantages such as stronger vibration resistance, lower manufacturing costs, and smaller size.

[0046] However, traditional solid-state LiDAR systems also have their drawbacks. For example, flash technology is a conventional method used in solid-state LiDAR. Flash LiDARs can flash an entire portion of the scene they intend to capture with light and sense the reflected light. In such a LiDAR system, the transmitter can include an array of emitters (e.g., surface-emitting laser diodes) that simultaneously emit light to illuminate the scene, and the sensor pixel array of the receiving device in the LiDAR system can be used to capture signals in parallel, much like a camera. However, crosstalk can occur between sensor pixels because multiple reflections, especially those from adjacent pixels, may not be isolated. Furthermore, traditional solid-state LiDAR systems may require high power to operate because all emitters or detectors are activated simultaneously, and they may require significant processing power to process signals from all pixel detectors concurrently. The large amount of emitted light can also introduce unwanted stray light, which can generate noise at the receiver, reducing the signal-to-noise ratio of the sensed signal and causing image blurring or blind spots. For example, the laser pulse echo signal reflected from near-field obstacles can be overwhelmed by the delay base of stray light due to detector saturation, making it impossible to determine the location information of near-field obstacles and causing measurement blind spots.

[0047] By employing surface emitters with higher dynamic range and signal-to-noise ratio (SNR) and sensor array-based LiDAR systems, the provided LiDAR systems can achieve higher performance than conventional solid-state LiDARs. In some embodiments, the emitter module of the LiDAR system may include an emitter array, such as a VCSEL (Vertical-Cavity Surface-Emitting Laser) or VECSEL (Vertical-External-Cavity Surface-Emitting Laser) array, where each emitter in the array can be individually addressed or controlled. VCSEL arrays enable power scaling and can provide very short pulses at higher power densities. A VCSEL is a semiconductor laser diode in which light is emitted perpendicular to the surface of a semiconductor substrate. Compared to other types of light sources, VCSELs require a lower current threshold to turn on and can be less sensitive to temperature.

[0048] The provided LiDAR detection module may include an array of photoelectric sensors, such as single-photon avalanche diodes (SPADs). Conventional SPADs may not be very efficient photodetectors. SPAD arrays can impose varying degrees of variation on the optical signal due to signal power and temporal distribution, an effect known as "stacking." In stacked scenarios, many SPADs acting as individual pixels may be triggered at the leading edge of a high-power reflected signal pulse, thus reducing the number of SPADs that can be triggered at the trailing edge of the reflected signal, as an increasing percentage of SPADs within a pixel remain in a dead-time state after initial triggering. The SPAD array disclosed herein can be individually addressed and controlled, thereby providing higher performance.

[0049] In some cases, the photoelectric sensor may include an array of SPADs that can be individually addressed and controlled, such that the SPAD array corresponding to a pixel can be powered on / off. Alternatively or otherwise, one or more operating parameters of a single photoelectric sensor can be controlled or dynamically configured by powering on / off one or more subsets of SPADs selected from the SPAD arrays corresponding to the pixels.

[0050] Figure 1An example of a Lidar system 100 according to some embodiments of the present invention is illustrated schematically. In some embodiments, the Lidar system 100 may include a transmitter module 110, a detector module 120, and a control unit 130. The detector module 120 may include a detector array 121, which may be a two-dimensional array of photodetectors, such as photoelectric sensors, wherein each photoelectric sensor can be individually addressed and / or controlled. The photoelectric sensors may correspond to specific pixels at a resolution in ranging measurements. The detector array 121 may be operatively coupled to a detector circuit 123 configured to dynamically enable / disable individual pixels in the array, thereby providing the detector module 120 with improved dynamic range and improved immunity to crosstalk effects. In some cases, the detector circuit 123 may be configured to control the on / off state of a subset of photodetectors (e.g., SPADs) selected from a set of SPAD arrays corresponding to pixels, thereby configuring the operating state / performance of the detectors at the sub-pixel level. The transmitter module 110 may include a transmitter array 111, each transmitter in the transmitter array being individually addressable and / or controllable. Individually addressable transmitters can activate a subset of transmitters in a transmitter array to excite multipulse sequences, thereby forming excitation or emission modes in the time domain (e.g., the timing characteristics of the multipulse sequence) and the two-dimensional (e.g., the xy direction) spatial domain.

[0051] In some embodiments, the emitting module 110 may include at least one light source configured to generate a laser beam or light pulse. In some embodiments, the light source may include an emitter array 111. The emitter array 111 may be a two-dimensional array or a linear array. The emitter array 111 may include an array of individually addressable lasers. In some cases, the light source may include multiple electrically connected surface-emitting laser diodes, such as an array of VCSELs (vertical external cavity surface-emitting lasers), each emitter in the emitter array being individually addressable or controllable. Other types of pulsed laser arrays may also be used, such as other surface-emitting or edge-emitting laser diodes, other types of semiconductor lasers, or non-semiconductor lasers. (See reference...) Figure 2 The layout and arrangement of the transmitter array and transmitter modules are described in detail.

[0052] In some cases, the transmitter module 110 may include a driver circuit 113 configured to control multiple lasers / emitters in the transmitter array. For example, multiple driver transistors may be arranged in an array such that each driver transistor is connected to a column or row (or other subset) of VCSELs, thereby enabling individual control of each individual VCSEL. For example, the transmitter array may be configured as a two-dimensional m×n array of transmitters with m columns and n rows, and the layout of the driver circuit 113 may be designed such that each address (e.g., row index, column index) of the m×n array can be selected by the row selector and column selector of the driver circuit 113. In some cases, the driver circuit 113 may receive control signals from the control unit 130 for configuring or controlling a selected set of one or more transmitters. The following references... Figure 3 Details of the circuitry used to individually control VCSELs are described.

[0053] In some embodiments, the detection module 120 may include a detector array 121, which may be a two-dimensional array of photodetectors, such as photoelectric sensors, each of which can be individually addressed and / or controlled. The photoelectric sensors may correspond to specific pixels at a resolution in the ranging measurement. The detector array may include an array of photoelectric sensors, each of which can convert light into an electrical signal. The photoelectric sensors may include multiple photodetectors, such as single-photon avalanche diodes (SPADs). The photodetectors may be single-photon avalanche diodes (SPADs), single-photon detectors, or other types of sensors, as long as the sensor can be individually controlled and used to output a sensor output signal. In some cases, the photoelectric sensors may include an array of photodetectors that can be individually addressed and controlled, such that the photodetector array corresponding to a pixel can be energized / de-energized. Alternatively or additionally, one or more operating parameters of a single photoelectric sensor can be controlled or dynamically configured by energizing / de-energizing one or more subsets of photodetectors selected from the photodetector array corresponding to the pixel.

[0054] The detection module 120 may have the ability to dynamically enable / disable individual pixels in the detector array 121. The detection module 120 may have the ability to dynamically enable / disable individual pixels in the array, and / or dynamically enable / disable subsets of photodetectors (e.g., SPADs) within the pixels, thereby configuring the detection module at the pixel level or sub-pixel level. In some embodiments, the detector array 121 may be operatively coupled to a detector circuit 123 configured to dynamically enable / disable individual pixels in the array, thereby providing the detection module 120 with high dynamic range and improved immunity to crosstalk effects.

[0055] Detector circuit 123 can be configured to individually control multiple photodetectors in detector array 121. In some cases, detector circuit 123 may include multiple pixel-level circuits, allowing the photodetector array to be configured at the pixel level. For example, one or more photodetectors (e.g., SPADs) corresponding to a pixel can be powered on / off or activated / deactivated according to a sensing mode. In some cases, the operating parameters or operating states of the set of one or more photodetectors (e.g., SPADs) corresponding to a pixel can be configurable, allowing control of the light energy received by the set of one or more photodetectors (e.g., SPADs), thereby adjusting the sensor output signal (e.g., the amplitude of the signal).

[0056] The light energy to be converted into an electrical signal can be controlled by controlling the number of photodetectors (e.g., SPADs) activated in a set of SPADs corresponding to the signal, and / or by controlling the selection of a subset of light pulses from a set of returned light pulses. In some embodiments, detector circuit 123 can be configured to enable / turn on a subset of photodetectors from a set of photodetectors corresponding to a pixel for receiving a certain amount of light energy. In some embodiments, detector circuit 123 can be configured to select the number / count of accumulated returned light pulses or a subset of returned light pulses to generate an output signal, such that the corresponding total light energy used to generate the output signal can be controlled. For example, detector circuitry may include pulse detection circuitry configured to convert light signals into electrical signals. By varying the received photon energy converted into electrical signals, pulse detection circuitry can be configured to generate a sensor output signal with a configurable or controllable amplitude / intensity. In some cases, when the electrical signal is generated based on a single light pulse, pulse detection circuitry can generate a sensor output signal by accumulating different combinations of electrical signals used to generate the sensor output signal. The sensor output signal can be generated based on the light energy of a selected subset of consecutive returned light pulses or a combination of non-adjacent returned light pulses. Details regarding the detector circuitry and detector array will be described below.

[0057] In some embodiments, the transmitting module 110 and the detecting module 120 may be communicatively coupled to the control unit 130. The control unit 130 may be configured to generate command or control signals to the transmitting module 110 and / or the detecting module 120, and to receive output signals generated by the detecting module 120. Example commands may include commands to activate or deactivate a selected subset of transmitters in the transmitter array, specify an excitation mode for the transmitting module, specify a sensing mode for the detecting module synchronized with the excitation mode, specify one or more operating parameters for the detector array at the pixel level (e.g., a subset of SPADs activated in a pixel, or a selection of a subset of return signals used to generate sensor output), and other operating parameters of the detector array, such as bias, sampling duration, and signal processing. The control unit 130 may also receive sensor output signals from the detecting module 120 for further data processing (e.g., final distance calculation or generation of 3D images).

[0058] Control units, functions, algorithms, operations, circuits, or methods can be implemented using software, hardware, firmware, or a combination thereof. In some embodiments, a control unit may include one or more processors and at least one memory for storing program instructions. The processor may be a component of the Lidar system. Alternatively, the processor may be external to the Lidar system but communicate with it. The processor may be a single or multiple microprocessors, field-programmable gate arrays (FPGAs), or digital signal processors (DSPs) capable of executing a specific instruction set. Computer-readable instructions may be stored on a tangible, non-transitory computer-readable medium, such as a floppy disk, hard disk, CD-ROM (optical disc read-only memory) and MO (magneto-optical), DVD-ROM (digital universal disk read-only memory), DVD RAM (digital universal disk random access memory), or semiconductor memory. The control unit may be a separate device or system that communicates with the Lidar system. Alternatively, the control unit may be a component of the Lidar system. The methods disclosed herein, such as generating emission modes and / or generating sensing modes in response to real-time conditions, may be implemented in hardware components or a combination of hardware and software, such as ASICs, special-purpose computers, or general-purpose computers.

[0059] In some cases, the control unit 130 may implement or include multiple functional components, such as a pattern generator and a signal analysis module. In some cases, the pattern generator may be configured to dynamically generate excitation modes for the two-dimensional array transmitter, such that a selected subset of the transmitters is activated at once and emits light pulses based on the timing characteristics specified by the excitation mode, and dynamically generates corresponding sensing modes for the two-dimensional photoelectric sensor array by synchronizing the activation / deactivation of each photoelectric sensor with the excitation of the corresponding transmitter according to a predetermined mapping relationship. The signal analysis module may be configured to process the output signal received from the detection module. Details regarding the pattern generator and the signal analysis module will be described below.

[0060] Figure 2 Examples of a transmitting module 200 and a detection module 210 according to some embodiments of the present invention are shown. In some cases, the transmitting module 200 may include a plurality of surface-emitting laser diodes 201, such as an array of VCSELs, and driving circuitry 113. The transmitting module 200 may optionally include an associated transmitting optics system 203, such as an optical lens, or in optical communication with it. In one embodiment, an aperture 205 may be placed at the focal point of the optical lens 203. In some cases, the detection module 210 may include a plurality of individually addressable and controllable photoelectric sensor arrays and detector circuitry 123, such as an array of SPADs 211. The detection module 210 may optionally include an associated receiving optics system 213 or in optical communication with it. Individual addressable and controllable transmitter arrays or detector arrays allow the transmitting / transmitting module to have a less complex design (e.g., a simple optical system).

[0061] In some embodiments, the VCSEL array 201 may be a two-dimensional m×n array of VCSELs having m rows and n columns. In some embodiments, subarrays of VCSELs may be grouped to form emitters, such that the m×n VCSEL array may be configured as an a×b emitter array (a<=m, b<=n). The VCSEL array may be arranged on a substantially flat surface, and the laser beam emitted from the VCSEL array may be collimated by associated emission optics 203, 205. The plurality of VCSELs may be angled or may not be angled. In some cases, the plurality of VCSELs may be fabricated on a flat substrate at a predetermined angle relative to the substrate surface, thereby affecting the direction of the light pulse emitted from the VCSELs. Alternatively, the VCSEL array may be arranged on a non-flat surface, such as an integral curved surface with segmented inclined portions, and each VCSEL may have an angle (e.g., pitch angle, yaw angle, etc.) relative to a horizontal or vertical direction.

[0062] The dimensions and / or configuration of the transmitter array 207 (e.g., length, width, and / or diameter, spacing, effective area, VCSEL angle, etc.), the dimensions and / or configuration of the detector array 215 (e.g., length, width, and / or diameter, spacing, effective area, etc.), the arrangement of the transmitting optics 203, 205 (e.g., aperture size 209, focal length 208), and the arrangement of the receiving optics 213 (e.g., aperture size 219, focal length 217, position relative to the transmitting optics, etc.) can be designed such that the return path of the returned optical pulse is predictable, and the transmitter array and detector array are mappable. The transmitter array and detector array can be spatially mapped, for example, relative to a two-dimensional array plane (e.g., a transmitting surface). For example, one or more VCSELs in the transmitter array and one or more SPADs in the detector array can be spatially mapped relative to the expected returned signal.

[0063] In some cases, a mapping relationship can be established between the transmitting and detecting modules. This mapping relationship can be fixed for a period of time. It can also change dynamically over time (e.g., due to performance drift in the LiDAR system, such as thermal expansion). In some cases, the detector array may not move relative to the transmitter array. Alternatively, the transmitter array can be movable relative to the detector array. The transmitting or detecting module may or may not include movable components (e.g., scanners, rotating platforms), as long as the path of the returning light can be predicted or the expected signal position of the detector can be determined based on a predetermined mapping relationship.

[0064] In the example shown, the VCSEL array 201 can have dimensions defined by dimensions 207 such as length, width, and / or diameter. For example, the VCSEL array can have a diameter of approximately 10 millimeters (mm) or a length × width dimension of 10 mm × 5 mm (e.g., length, width, and / or diameter). The size of the VCSEL array can be in any suitable range, such as from 0.1 mm to 100 mm. The VCSEL array can include at least one, two, three, four, five, six, seven, eight, nine, ten, or more columns or rows. The number of rows and columns may be limited by the VCSEL size, the spacing or pitch between adjacent VCSELs, and the overall size of the VCSEL array. In the case of surface-emitting laser diodes (e.g., VCSELs), the spacing or pitch between adjacent VCSELs can be any number of approximately 50 micrometers (μm) or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 1 μm or less, 0.1 μm or less, or greater than 50 μm. The aperture size 209 of the emitting optics system can have any length / width / diameter value, ranging from approximately 20 μm or less, 10 μm or less, 1 μm or less, 0.1 μm or less, to greater than 20 μm. In some cases, the emitter array 200 can be designed such that it can include a higher density (e.g., thousands) of VCSELs or other laser diodes. For example, the diameter of the aperture (which is the active region that generates laser light) of the VCSEL die can be from approximately 10 μm to approximately 20 μm. By reducing or eliminating wasted (inactive) areas and by reserving a few micrometers of combined chip length for the anode and cathode contacts, the die length can be reduced to the aperture diameter plus a few micrometers.

[0065] In some embodiments, the transmitters of the transmitter array may correspond to one or more VCSELs. In some cases, the transmitters may be configured to send light pulses into a different field of view than their neighboring transmitters. In some cases, the light pulses sent from the transmitters may correspond to pixels or points in a 3D image. The high density of VCSELs allows a set of VCSELs to correspond to a single transmitter, and this set of VCSELs may be addressable and individually controllable. This can advantageously provide dynamic excitation modes with configurable resolution (e.g., temporal and spatial resolution), light intensity, beam shape, or size, allowing individual control of the beams used for measurements at different distance ranges without introducing interference. For example, the excitation mode may be a sparse mode, such that transmitters corresponding to adjacent pixels do not excite in parallel, thereby reducing crosstalk or interference.

[0066] In some cases, a transmitter can be mapped to a photoelectric sensor corresponding to a specific pixel in the ranging measurement at a specific resolution. Alternatively or otherwise, a transmitter or beamspot can be mapped to multiple pixels in the ranging measurement. As described above, the mapping relationship can be based on the geometric configuration of the transmitting and detecting modules. For example, the mapping relationship can be based at least in part on the dimensions and / or configuration of the transmitter array (e.g., length, width, and / or diameter, spacing, effective area, VCSEL angle, etc.), the dimensions and / or configuration of the detector array (e.g., length, width, and / or diameter, spacing, effective area, etc.), the arrangement of the transmitting optics (e.g., aperture size, focal length), and the arrangement of the receiving optics (e.g., aperture size, focal length, position relative to the transmitting optics, etc.).

[0067] In some embodiments, the mapping relationship can be dynamically updated and changed to account for variations in the Lidar system, such as offset / drift caused by system thermal expansion or changes in Lidar system performance, such as beam quality (e.g., beam shape or size). In some cases, updating the mapping relationship may include updating the address of a set of photodetectors mapped to a specified emitter (e.g., selecting a set of SPADs offset from the original set of SPADs to accommodate the offset, increasing or decreasing the number of SPADs in the active region to accommodate changes in beam spot shape or size), altering pixel-related signal processing (e.g., accumulating fewer or more light pulses for the output sensor signal), and various other methods.

[0068] A photodetector array, such as SPAD array 211, can receive returned light pulses via an associated optical system 213 configured to focus light energy onto the photodetector array. In some embodiments, SPAD array 211 can be arranged on a substantially flat substrate. Alternatively, the photodetector array can be arranged on a curved surface, which simplifies the optical requirements regarding focusing and spot size / shape. In particular, by arranging the photodetectors on a curved surface, the use of simple spherical optics may be sufficient compared to aspherical optics.

[0069] The dimensions and size of the detector array 215 can be designed such that one or more photoelectric sensors (e.g., SPADs) can be assigned to the active region reached by the beam spot. For example, one or more photoelectric sensors can be matched to a region defined by the size / shape of the beam spot incident on the detector array. For example, the array can be designed with a spacing or interval of approximately 50 micrometers (μm) or less, 40 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 1 μm or less, 0.1 μm or less, or any value greater than 50 μm. The number of SPADs corresponding to the beam spot size / shape can be at least 2, 3, 4, 5, 6, 7, 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100 or more. A high-density SPAD array can make one set of SPADs correspond to one pixel. This can facilitate the provision of dynamic sensing modes with configurable resolution (e.g., temporal and spatial resolution) or configurable output signals (e.g., amplitude), thereby avoiding unwanted optical effects (e.g., blind spots or crosstalk).

[0070] SPAD array 211 can be a two-dimensional p×q array of SPADs having p rows and q columns. In some embodiments, subarrays of SPADs can be grouped to form photodetectors, such that a p×q SPAD array can be configured as a c×d photodetector array (c<=p, d<=q). The number of columns / rows of SPAD array 211 may not need to match the number of columns / rows of VCSEL array 201. SPAD array 211 can have a size defined by dimension 215, such as length, width, and / or diameter. For example, SPAD array 211 can have a size of approximately 15 mm (e.g., diameter) or 300 mm × 150 mm (e.g., length × width) (e.g., length, width, and / or diameter). The length or width of the SPAD array can be in any suitable range, for example, from 0.1 mm to 1000 mm. SPAD arrays can include at least one, two, three, four, five, six, seven, eight, nine, ten, or more columns or rows. As described above, the number of rows and columns can be limited by the SPAD size (e.g., approximately 10 μm), the spacing or pitch between adjacent SPADs. The aperture size 219 of the receiving optical system can have any number of lengths and / or widths, such as approximately 20 μm or less, 10 μm or less, 1 μm or less, 0.1 μm or less, or greater than 20 μm.

[0071] In some embodiments, one or more photodetectors, such as SPADs, can be grouped and correspond to pixels or sensing channels. Sensing channels can measure light pulses corresponding to pixels. In some cases, a group of photodetectors can constitute a photodetector corresponding to a specific pixel at a resolution in a ranging measurement. In some cases, the photodetector can include a set of photodetectors, such as SPADs, capable of dynamically enabling / disabling individual pixels in the detector array, or enabling / disabling a subset of the set of SPADs corresponding to a specified pixel. Besides turning the entire photodetector on / off to adjust pixel performance or the output signal (e.g., amplitude) of the sensing channel, this can advantageously enable control of one or more operating parameters of a single photodetector. As described above, one or more photodetectors (e.g., a set of SPADs) of a detector array can be mapped to one or more transmitters of a transmitter array, such that the photodetector can be configured to receive light pulses emitted from the corresponding transmitter, and the sensor output signal can be generated by the corresponding sensing channel to produce pixel values.

[0072] Photodetectors (e.g., SPADs) can be highly dense, and the spacing between adjacent active photodetectors can be configurable, thereby reducing crosstalk that may occur between adjacent sensing channels due to the close spacing of the photodetector array. The spacing between adjacent active photodetectors (e.g., pixel pitch) can be configured by enabling / disabling the respective sets of photodetectors, such that the enabled sets of photodetectors are spaced at an optimal interval (e.g., vertically, horizontally). For example, in a SPAD array with adjacent SPADs spaced 50 micrometers apart, the pixel pitch can be approximately 200 micrometers or 400 micrometers.

[0073] In some cases, a single beam spot can correspond to multiple pixels, and each pixel can correspond to one or more SPADs. The high density of the photodetector array allows an assembly of SPADs to correspond to a single emitter, thereby enabling the adjustment of one or more operating parameters of the sensing channel. For example, a subset of the SPADs corresponding to a sensing channel / pixel can be enabled or energized to receive light pulses, thereby adjusting the light energy used to generate the output signal. Furthermore, the selection of the subset used to generate the return signal from the sensor readout can also be adjusted through signal processing (e.g., changing the number of light pulses accumulated to generate the output signal).

[0074] Figure 3An example of a transmitter array 301 with individually addressable and controllable transmitters according to some embodiments of the present invention is shown. The transmitter array 301 may include a two-dimensional array of laser diodes 301-1, 301-2, and 301-3, each laser diode being individually addressable and controllable by driving circuitry. In some cases, the driving circuitry may include row driver circuitry 310-1 and column driver circuitry 310-2. The driving circuitry may be coupled with… Figure 1 The driving circuit shown is the same. For example, multiple driving transistors can be arranged in an array such that each driving transistor 311-1, 311-2 can be connected to a column or row (or other subset) of laser diodes (e.g., VCSELs), enabling individual control of each individual VCSEL.

[0075] The driving circuits 310-1 and 310-2 can be semiconductor devices that control the current flow through the emitter array, such as field-effect transistors (FETs), FPGAs, ASICs, etc. In the illustrated example, the driving transistors can be arranged in arrays 310-2, 310-2 such that each driving transistor can be connected in series with a column or row (or other subset) of VCSELs connected (or connected to a shared or common cathode / anode), allowing individual control of each respective VCSEL. Different trigger signals can be applied to the terminals of each VCSEL. Figure 3 As shown, the trigger signal can be H (high voltage), L (low voltage), or Z (high impedance). For example, the trigger signal applied to the positive or anode terminal of each VCSEL can be H (high voltage) or L (low voltage), and the trigger signal applied to the cathode of the VCSEL can be L (low voltage) or Z (high impedance), thereby controlling the activation of each VCSEL. For example, when the anode terminal of VCSEL 301-3 is connected to H and the cathode is connected to L, a large current can flow through VCSEL 301-3, thus activating the VCSEL. In another case, when the anode terminal of VCSEL 301-1 is connected to H and the cathode is Z, the current flowing through VCSEL 301-3 decreases and the VCSEL is not activated. In a further example, when the anode terminal of the VCSEL is connected to L and the cathode is Z or low, the current flowing through VCSELs 301-3 and 301-4 decreases and the VCSELs are not activated. VCSELs can be quickly turned on / off by individually changing the voltage level of the anode or cathode.

[0076] In some cases, introducing high impedance can advantageously protect the VCSEL while enabling rapid turn-on / off. In other cases, when a low voltage is applied to the anode and a high voltage to the cathode, the VCSEL may experience reverse breakdown due to the high reverse voltage. The provided emitter array allows the VCSEL to be turned on by simultaneously applying a high voltage level to the anode and a low voltage level to the cathode, and turned off by simultaneously applying a low voltage level to the anode and a high impedance voltage level to the cathode. This advantageously allows for rapid, individual turn-on and turn-off of the VCSEL without experiencing reverse breakdown. The VCSEL array can be used with… Figure 2 The VCSEL arrays described herein are the same.

[0077] In some embodiments, drive transistor arrays (e.g., drive transistor arrays 310-1 and 310-2) can be mounted on a substrate close to the laser diode for dynamically adjusting or controlling the operation and / or emission power of individual VCSELs or subsets of VCSELs in different regions of the emitter array. The emitter array can have any suitable connection configuration. The flexibility of the connection configuration can be used to control current and / or increase or maximize performance. For example, fewer or more drive transistors can be configured to control the respective VCSELs or groups of VCSELs (with various group sizes) and / or output power. In the example shown, each VCSEL can be individually addressed and controlled. In other cases, the set of VCSELs can be individually addressed and controlled.

[0078] Figure 5 An example of a transmitter array is illustrated, where a subset of transmitters can be addressed and controlled individually. For example, such as... Figure 5 As shown, multiple VCSELs can be grouped (e.g., a 2×2 grid of VCSELs) to correspond to transmitters and / or addresses. The group of VCSELs can be electrically connected in series and / or parallel, and the group can be individually addressed and controlled. In some cases, the group of VCSELs can correspond to transmitters, pixels, or points in a 3D image. The VCSEL groups can form an m×n array of transmitters with m rows and n columns. For example, driver circuit 310-1 can include m transistors connected to the anodes of the VCSEL group, and the number of anodes can correspond to the number of rows in the group / emitter, i.e., m. Similarly, driver circuit 310-2 can include n transistors connected to the cathodes of the VCSEL group, and the number of cathodes can correspond to the number of columns in the group / emitter, i.e., n. The number of VCSELs in a group may be the same or different throughout the transmitter array. In some cases, the optical characteristics of the beam or light pulse generated by a group of VCSELs / emitters may be the same or different from those generated by another group of VCSELs / emitters.

[0079] In some cases, the driving transistor array can be addressed separately using column and row signals generated by controller 330. Controller 330 can be connected to... Figure 1 The control unit described herein is the same. For example, drive transistors (e.g., transistors 311-1, 311-2) can be individually activated (e.g., biased to conduct) to change the power / current supplied to one or more corresponding VCSELs (e.g., VCSEL 301-1). In the illustrated example, one or more VCSELs corresponding to an address can be controlled by a pair of transistors connected to the anode and cathode of one or more VCSELs to function as row selectors and column selectors. In some embodiments, the driver circuitry can receive control signals and / or commands generated by controller 330. Commands may include, for example, activating / deactivating the individual VCSELs / emitters specified by the address, specifying an excitation mode or one or more parameters of the excitation mode (e.g., the address of the VCSEL / emitter to be activated, the timing characteristics of the multiple sequences emitted by the selected emitter, etc.), or other information.

[0080] In some cases, the driver circuit may include other electronic components, such as switches, energy storage devices (e.g., capacitors or similar energy storage devices), for generating pulses more quickly. In other cases, the driver circuit may include multiple charging units configured to charge the energy storage element sequentially or jointly. The multiple charging units can be controlled to provide a certain amount of electrical energy to the energy storage element in response to a control signal generated by the controller 330.

[0081] As an example, the peak power of the output beam generated by the transmitter (e.g., selected by address) can be approximately 10mW, 100mW, 1W, 10W, or any other suitable average power. As an example, the output beam can have an average power of approximately 1mW, 10mW, 100mW, 1W, 10W, or any other suitable average power. As another example, the output beam can include pulses with pulse energies of approximately 0.1μ.1, 1μ.1, 10μ.1, 100μ.1, 1mJ, or any other suitable pulse energies. As yet another example, the output beam can include pulses with peak power of approximately 10W, 100W, 1kW, 2kW, 5kW, 10kW, or any other suitable peak power.

[0082] This application allows for pixel / emitter level control of the output beam power, enabling measurements across various ranges (e.g., far-field, near-field). The output beam power can be adjusted by modifying the distribution of the laser diodes and / or the timing characteristics of the light pulses generated by the respective emitters / laser diodes. For example, the distribution of laser diodes on the substrate surface can be selected, and / or the operation of the laser diodes can be dynamically adjusted or otherwise controlled (via transistors) to reduce the optical power density, thereby providing eye safety at long distances and at desired operating wavelengths (e.g., approximately 905 nm for GaAs VCSELs; approximately 1500 nm for InP VCSELs).

[0083] The flexibility and configurability of the transmitter array arrangement can improve the performance of a LiDAR system. For example, the spacing between active transmitters can be optimized to provide thermal management and improve heat dissipation during operation. Furthermore, excitation modes can be determined to provide low operating temperatures.

[0084] Figure 3 The circuit embodiments and connection configurations described herein are merely examples of how transmitter arrays can be configured to be individually addressable. However, the embodiments described herein are not limited to this particular arrangement. Other wiring connections or layouts of the circuitry can also be employed to achieve highly configurable and adaptive transmitter modules.

[0085] In some cases, the excitation mode of the emission module can be dynamically generated to adapt to different measurement ranges, channel conditions (e.g., SNR), environmental complexity, eye safety requirements, etc. For example, the excitation mode can specify timing characteristics, where a first optical pulse has a low peak power and a second optical pulse has a high peak power, and these two optical pulses can be separated by a time interval greater than a predetermined time threshold (e.g., 10 ns), so that when an object is detected within a distance corresponding to the time threshold (e.g., 1.5 m), the second optical pulse with the higher peak power may not be emitted. In another example, a larger proportion of the pulse energy can be provided to a selected subset of VCSELs to change the far-field mode of the emitted output beam, so that a larger power value can be received in the direction corresponding to the far-field measurement. However, in some cases, such high-power optical pulses for long-distance or far-field measurements may cause undesirable effects, such as interference between adjacent pixels or overexposure in 3D images. In this case, a sparse excitation mode can be generated so that adjacent pixels cannot be excited in parallel, thereby eliminating the aforementioned optical effects.

[0086] Figure 4 The sparse excitation mode of the emitter module is schematically illustrated. (See reference above.) Figure 3Similarly, transmitters in a transmitter array can be individually addressed or controlled. The transmitter array can be controlled to excite optical pulses according to the excitation mode. In some cases, at a given moment, the excitation mode can be sparse in a two-dimensional spatial domain (e.g., the transmitter array plane), thereby reducing crosstalk between adjacent signal channels and improving energy efficiency. For example, transmitters corresponding to adjacent pixels may not be excited in parallel, thereby reducing crosstalk or interference. As shown in the example, at a given moment, transmitters 401, 403, and 405 can be activated in parallel, and the active transmitters 401, 403, and 405 can be separated by an optimal interval, such that overlap or interference between the measurement beams excited in parallel by these transmitters can be greatly reduced. Activated transmitters can be spaced apart along a row direction (e.g., transmitters 401, 403) or a column direction (e.g., transmitters 403, 405). Simultaneously, activated transmitters can be spaced apart by one or more inactive transmitters.

[0087] As described above, the excitation mode can define the activation or deactivation of a selected set of transmitters used to simultaneously excite optical pulses. The excitation mode can also specify the timing characteristics of multiple sequences emitted by a single transmitter. The excitation mode can be generated by controller 330, as described elsewhere herein, and control signals can be transmitted to driver circuitry (e.g., 310-1 and 310-2) to control the emission of optical pulses generated by each individual transmitter.

[0088] Sensing modes for the detection module can be generated based on a predetermined mapping between the transmitter array and the detector array, as well as one or more real-time conditions. A sensing mode can define multiple parameters for controlling the detector array. For example, the sensing mode can specify the address of the photoelectric sensor to be activated for simultaneous measurement (i.e., one or more SPADs corresponding to a pixel), pixel-level operating parameters for the detector array (e.g., selection of a subset of SPADs to be activated in a pixel or a subset for generating the return signals from the sensor readouts), and other operating parameters for the detector array, such as bias voltage, sampling duration, and signal processing.

[0089] Figure 6 An example of a detector array 600 with individually addressable and controllable photoelectric sensors is shown according to some embodiments of the present invention. The detector array 600 may include an array of photoelectric sensors 601, 603, 605, each of which can be individually addressed and controlled by pixel-level circuitry 601-2. For example, each photoelectric sensor 601 may be connected to pixel-level circuitry, thereby enabling individual control of each photoelectric sensor. The output signals generated by the photoelectric sensors may be transmitted to processing circuitry 610 to generate pixel values ​​(e.g., amplitude) or for further signal processing (e.g., distance measurement).

[0090] As described elsewhere in this document, a photoelectric sensor may correspond to a specific pixel of resolution in a ranging measurement. A detector may include one or more photoelectric sensors, each capable of converting light into an electrical signal. A photoelectric sensor may include multiple photodetectors, such as single-photon avalanche diodes (SPADs). The photoelectric sensor may correspond to a specific pixel of resolution in a ranging measurement. The detector may have the ability to dynamically enable / disable individual pixels in the array, and / or dynamically enable / disable subsets of SPADs within pixels, thereby configuring the detector at the pixel level or sub-pixel level. In some cases, the photoelectric sensor may include an array of SPADs that can be individually addressed and controlled, such that the SPAD array corresponding to a pixel can be energized / de-energized. Alternatively or additionally, one or more operating parameters of a single photoelectric sensor can be controlled or dynamically configured by energizing / de-energizing one or more subsets of SPADs selected from the SPAD array corresponding to the pixel. The photoelectric sensor, detector array, and photodetector may be the same as those described elsewhere in this document.

[0091] Pixel-level circuitry 601-2 can be electrically connected to a photodetector to enable / disable a single pixel in detector array 600. Pixel-level circuitry 601-2 can be connected to one or more SPADs corresponding to a pixel. In the example shown, a photodetector, such as SPAD 601-1, can be individually controlled by pixel-level circuitry 601-2 and output a sensor output signal. Figure 7 An example of a photoelectric sensor 700 is shown, including SPADs that can be enabled / disabled by pixel-level circuitry. Each SPAD may have analog front-end circuitry for biasing, quenching, and recharging. SPADs are typically biased using a bias voltage higher than their breakdown voltage. In the example shown, a SPAD can be disabled or powered off by controlling switch CTL2 (CTL2 on), switch CTL3 (CTL3 off), and CTL1 (CTL1 off) to lower the SPAD's bias voltage below its breakdown voltage. Similarly, a SPAD can be enabled or powered on by turning on CTL1 and CTL3 and turning off CTL2. By selectively disabling SPADs corresponding to inactive emitters, the system's power consumption can be reduced.

[0092] Back Figure 6 In the example shown, multiple pixel-level circuits can be arranged in an array such that each pixel-level circuit can be connected to a corresponding photoelectric sensor comprising one or more SPADs. The SPADs array can be connected to... Figure 2 The SPAD array described herein is the same.

[0093] In some embodiments, pixel-level circuitry can be mounted on a substrate close to the SPAD array and used to dynamically turn one or more sets or subsets of SPADs on / off or enable / disable them in different regions of the detector array. The detector array can have any suitable connectivity configuration. This flexibility in connectivity configuration allows for configuring the resolution of the SPAD array. For example, an array of individually addressable and controllable SPADs can be further grouped so that a group of SPADs can form a pixel. This can advantageously enable finer configuration of the performance of the photoelectric sensor / pixel or with respect to the operating parameters of the pixel.

[0094] The detection module can be configured or dynamically adjusted at various levels. For example, the detection module can have configurable power levels by enabling / disabling selected sets of photodetectors, adjustable or high dynamic range (e.g., sparse sensing mode to reduce crosstalk), or pixel-level configurable operating parameters (e.g., activating selected subsets of photodetectors in a pixel, accumulating selected subsets of returned light pulses received by the photodetectors to generate an output signal). Individually addressable and controllable photodetectors also provide flexibility in configuring and modifying sensing modes to adapt to real-time conditions, including but not limited to considering drift introduced by thermal expansion, variations in returned light flux, and requirements related to detecting objects in the environment or eye safety.

[0095] Figure 8 An example of a detector array 800 is illustrated, which includes at least one set of photodetectors, such as SPADs grouped to form pixels. In some embodiments, each photodetector (e.g., SPAD) can be individually addressable and controllable. For example, a set of individually addressable SPADs 801-1, 801-2, 801-3, 801-4 can function as a single pixel, and the output signal generated by this set of SPADs 801 can be transmitted to processing circuitry (e.g., ...). Figure 6 The processing circuit 610 in the SPAD array 801 generates pixel values ​​(e.g., amplitude). In some cases, each SPAD 801-1, 801-2, 801-3, 801-4 in the SPAD array 801 can be connected to... Figure 6 The pixel-level circuit electrical connections described herein allow the corresponding set of pixel-level circuits to receive control signals (from the controller) and transmit output signals to processing circuitry used as individual pixels. When multiple SPADs are grouped to function as pixels, each circuit associated with a SPAD can also be referred to as a sub-pixel-level circuit. Alternatively or additionally, the set of SPADs 801-1, 801-2, 801-3, and 801-4 can be connected with… Figure 6The SPADs array 801 is electrically connected to the same pixel-level circuitry described herein, thus enabling it to be addressable and controllable. In this case, an address may correspond to a set of SPADs, such as a 2×2 grid of SPADs 801-1, 801-2, 801-3, or 801-4. This group or set of SPADs may be electrically connected in series and / or parallel, and each group may be individually addressable and controllable. Groups of SPADs 801, 803, or 805 may correspond to points in photoelectric sensors, pixels, or 3D images.

[0096] In some cases, a group of SPADs may correspond to the region in a detector array used to receive returned light pulses. This group of SPADs can be enabled or disabled, thereby changing the active region used for the output signal. The area, shape, and / or position of the active region can be changed or configured by controlling the selection of SPADs to be enabled. In some cases, the area and / or shape of the working area can be adjusted by changing the size of the SPAD array corresponding to the working area (e.g., the number of SPADs). The sensing mode of the working area or a specified working area can be dynamically adjusted or configured during the operation of the Lidar system.

[0097] Figure 9 An example of a SPADs array group is illustrated, where each group is individually configurable, addressable, and controllable. For example, a 3×3 array of SPADs can be grouped to form pixels. The area of ​​working area 901 can be larger than the area of ​​a working area comprising a 2×2 array. In some cases, the shape or area of ​​the working area can be controlled by activating a selected subset of SPADs from a specified group. For example, the shape and area of ​​the working area can be changed by selecting a subset of SPADs from a 3×3 array 903. This can advantageously accommodate beam quality drift (e.g., beam shape or spot size). In some cases, the position of the working area can be controlled by activating / deactivating SPADs arrays from different groups. This flexibility in controlling the position of the working area can advantageously accommodate probe drift caused by thermal expansion. The number of SPADs comprising a group can be configured without changing the wiring connections. This can be advantageous for dynamically adjusting the area of ​​the working area or configuring the image resolution.

[0098] In some cases, one or more photodetectors corresponding to a pixel (e.g., SPADs) can be activated / deactivated depending on the sensing mode. For example, ... Figure 8As shown, SPADs groups (i.e., photodetectors) 801, 803, and 805 can be activated in parallel to detect light pulses. In some cases, the activated photodetectors 801, 803, and 805 can be spaced optimally to significantly reduce overlap or interference between adjacent sensing channels. The activated photodetectors can be spaced apart in the row direction (e.g., groups 801, 803), the column direction (e.g., groups 801, 805), or both. The selection of the activated group or photodetector to be enabled can be synchronized with the excitation / emission mode.

[0099] In some cases, the operating state of a set of photodetectors in a group can be controlled individually, thereby controlling the operating parameters of the photodetector / pixel. For example, when the luminous flux reaches a certain level, such as too low or too high, fewer or more photodetectors in the group can be enabled. For example, the operation of a set of photodetectors (e.g., SPADs) corresponding to a pixel can be configurable, allowing adjustment of the light energy received by that set of photodetectors (e.g., SPADs), thereby controlling the sensor output signal (e.g., the amplitude of the output signal). For example, when the luminous flux received by the active region 803 is high, the working area 801 can be configured with more working SPADs than the working area 803.

[0100] Back Figure 6 The output signal generated by the photoelectric sensor can be transmitted to processing circuitry 610 to generate a pixel value (e.g., amplitude) or a measurement value. The amplitude of the output signal can be proportional to the number of photons detected in the light energy received by the photoelectric sensor / group. This enables a photoelectric sensor with a high dynamic range. For example, the light energy to be converted into at least an electrical signal can be changed by varying the number of energized SPADs in the set of SPADs corresponding to a pixel, and / or by varying the number of light pulses selected from the set of returned light pulses. The number of SPADs or a subset of SPADs selected from the set for outputting the sensor signal can be controlled by pixel-level circuitry or a controller as described elsewhere herein. The number / count of returned light pulses accumulated for generating the output signal, and / or the selection of the subset of returned light pulses, can be determined or controlled by processing circuitry (e.g., processing circuitry 610) or pulse detection circuitry of the detector array.

[0101] In some cases, the detector circuitry may include a pulse detection circuit configured to convert optical signals into electrical signals. The pulse detection circuitry may be configured to generate a sensor output signal by varying the energy of received photons that have been converted into at least one electrical signal. Alternatively, when the electrical signal corresponds to a single optical pulse, the pulse detection circuitry may generate a sensor output signal by accumulating different combinations of electrical signals used to generate the sensor output signal. In some cases, the pulse detection circuitry may generate a sensor output signal representing the optical energy associated with a selected subset of the returning optical pulses.

[0102] In some cases, the pulse detector circuitry may include a counter that can use a binary signal to count the number of photodetectors in a given pixel that have been triggered by one or more photons. The pulse detector circuitry and / or processing circuitry may accumulate a selected subset of returned optical pulses. For example, for each photodetector or group of photodetectors corresponding to a pixel, the memory (e.g., SRAM) of the circuitry (e.g., an ASIC or FPGA) may accumulate the count of detected photons within a time window corresponding to a subset of pulses in a multi-pulse sequence. In some cases, the pulse detection circuitry may implement a per-pixel time-to-digital converter (TDC) architecture, a shared TDC architecture, or a shared TDC in a dynamic reallocation scheme, or any other suitable architecture. In some cases, an event-driven readout method may be used to improve readout efficiency, where only valid events are transmitted off-chip (e.g., to the system controller). This can be achieved by synchronizing the sensing and transmission modes of the LiDAR system.

[0103] In some cases, the pulse detection circuitry can be coupled to the processing circuitry 610. Alternatively, the pulse detection circuitry can be a component or part of the processing circuitry 610. The processing circuitry 610 can communicate with the controller of the LiDAR system to receive data (e.g., operating parameters representing the accumulation of selected return light pulses) and transmit data to the controller for further signal processing (e.g., final distance calculation or generation of a 3D image). In some cases, the processing circuitry 610 can be mounted on the same substrate as or connected to the detector array (e.g., using CMOS). The processing circuitry 610 can be an integrated circuit, such as field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), or digital signal processors (DSPs). The processing circuitry can receive readouts from the detector array and perform signal processing. The processing circuitry can implement suitable functional modules, such as matched filters and peak detection processing, to timely identify return signals. As described above, the processing circuitry can transmit only valid events to the system controller (e.g., using an event-driven readout method). Figure 1The control unit 130 in the controller performs further signal processing to improve readout efficiency. This can be enabled by receiving the sensing mode from the controller and reading the sensor output only from the enabled photoelectric sensor.

[0104] As described above, the number / count of returned optical pulses accumulated to generate the output signal and / or the selection of a subset of returned optical pulses can be dynamically configured or changed during the measurement. Figure 10 An example is shown of accumulating a selected subset of returned pulses from a returned multi-pulse sequence 1020 to generate a sensor output signal 1030. The multi-pulse sequence 1011 may include multiple pulses. The multi-pulse sequence 1011 may be a measurement signal emitted from a transmitter of a transmitter array (e.g., a VCSEL or a collection of VCSELs). The multi-pulse sequence may be emitted to a point in 3D space or along substantially the same direction. The multi-pulse sequence, or at least a portion thereof, may be used to generate the measurement signal. The multi-pulse sequence may be a sequence of pulses modulated according to predetermined timing characteristics. Returned pulses may be received in a working area corresponding to one or more individually addressable photodetectors in a detector array. The multi-pulse sequence may include any number of pulses. For example, at least one, two, three, four, five, six, seven, eight, nine, ten, or more pulses may be generated within a short time period to form a multi-pulse sequence. The duration can be, for example, no more than 10 ns, 20 ns, 30 ns, 40 ns, 50 ns, 60 ns, 70 ns, 80 ns, 90 ns, 100 ns, 200 ns, 300 ns, 400 ns, 500 ns, 600 ns, 700 ns, 800 ns, 900 ns, 1 μs, 2 μs, 3 μs, 4 μs, or 5 μs. Different multipulse sequences can have the same or different durations. In some cases, adjacent multipulse sequences can have different durations. The number of pulses in consecutive multipulse sequences can be the same or different. Multiple pulses within a multipulse sequence 1011 can have varying amplitudes or constant amplitudes.

[0105] In some cases, the subset of return pulses used to generate the sensor output signal can be selected based on one or more parameters. These parameters determine the amplitude or intensity of the sensor output signal. These parameters can be controlled by a controller, such as that of a LiDAR system (e.g., Figure 1 Control unit 130 or Figure 3The parameters are generated by the computing unit of the controller 330. The one or more parameters can be specified by the sensing mode of the detection module. In some cases, the one or more parameters can be determined based on the timing characteristics of the multi-pulse sequence and one or more real-time conditions. As mentioned above, the timing characteristics of the sequence can be defined by the number of pulses in the sequence, the time interval, the duration of the sequence, the amplitude of the pulses, or a combination thereof. The one or more real-time conditions can include the estimated measurement range (e.g., far field, near field), objects detected in the near field, etc. In some cases, the number of pulses accumulated for generating the signal or the selection of pulses can be determined based on the estimated detection range. For example, a larger number of pulses can be accumulated for long-distance measurements, and a smaller number of pulses can be accumulated for measurements in short-distance or higher reflectivity scenarios.

[0106] The one or more parameters may include, for example, parameters representing a selected subset of pulses. For instance, the one or more parameters may include a pulse count accumulated for generating the sensor output signal, or parameters representing a selected combination of pulses for generating the sensor output signal. The one or more parameters may include any other factors that can determine the total optical energy of the selected subset of pulses (e.g., the time window for receiving the returned optical pulses). For example, when multiple pulses in a multi-pulse sequence have constant amplitudes, the optical energy converted into the sensor output signal can be determined by the number of pulses. For example, as... Figure 10 As shown, the number / count of returned light pulses 1020 can be selected and accumulated to generate a sensor output signal. The number / count of light pulses selected from each multi-sequence 1021, 1023 can be controlled individually, so that the sensor output signal 1030 can have adjustable amplitude / intensity 1031, 1033. In some cases, when multiple pulses in a multi-pulse sequence have different amplitudes, the light energy converted into a sensor output signal can be determined by selecting a combination of pulses from the returned light pulses. In this case, by selecting different combinations of light pulses, a cumulative amount of multiple light energy values ​​can be generated. The subset of light pulses selected for generating the sensor output signal can be or may not be a sequence of adjacent light pulses.

[0107] In some embodiments, an adaptive control mechanism is provided to the Lidar system, enabling the Lidar system's transmitting and / or receiving modules to adapt to various real-time conditions or requirements. The adaptive control mechanism can be configured to control the excitation mode of a two-dimensional array of optical emitters, for example, by activating only a subset of the optical emitters at a time, and to control the sensing mode of a two-dimensional array of photodetectors, by synchronizing / deactivating the individual photodetectors in parallel with the excitation of the corresponding optical emitters. In some cases, the sensing mode can be synchronized with the excitation mode in terms of position relative to the emitter / detector array and one or more operating parameters.

[0108] In some embodiments, the adaptive control mechanism may provide a pattern generator configured to generate emission patterns for a two-dimensional array of transmitters, such that a selected subset of transmitters is activated at a time, and each transmitter emits light pulses based on timing characteristics specified by the emission pattern. The pattern generator also generates corresponding sensing patterns for a two-dimensional array of photodetectors, synchronizing the activation / deactivation of individual photodetectors with the excitation of their respective transmitters according to a predetermined mapping. The mapping between the emission patterns for the synchronous emission module and the sensing patterns for the detection module can define a mapping between the transmitter array and the detector array in both the spatial domain (e.g., photodetectors are associated with transmitters) and the temporal domain (e.g., the operating parameters of a single photodetector are configured based on timing characteristics such as the amplitude of the light pulse).

[0109] In some embodiments, the adaptive control mechanism may include an adaptive transmit module and an adaptive receive module that communicate with the pattern generator. Figure 11 A Lidar system 1100 with an adaptive control mechanism according to some embodiments of the present invention is schematically illustrated. In some embodiments, the adaptive control mechanism may include a pattern generator 1131 communicating with a transmitter module 1110 and a detector module 1120. The transmitter module 1110 may include a transmitter array 1111 and a drive circuit 1113. The transmitter module and its components may be compatible with... Figure 1 The same as described elsewhere in this document. Detection module 1120 may include detector array 1121 and detector circuitry 1123. The detection module and its components may be compatible with... Figure 1 The same as described elsewhere in this document. In some embodiments, the pattern generator 1131 may be implemented by a controller or control unit 1130 of the Lidar system. The control unit 1130 may be connected to... Figure 1 The control unit described herein is the same. In some embodiments, the control unit may further include a signal analysis module 1133 configured to receive an output signal from the detection circuit 1123.

[0110] The pattern generator 1131 can be configured to dynamically generate excitation / emission modes and sensing modes. The emission mode can be transmitted to the emission module for controlling the transmitter array as described above. Alternatively or additionally, control signals can be generated and transmitted to the emission module in response to changes in one or more parameters of the excitation mode. The excitation mode can define multiple parameters for controlling the transmitter array. For example, the excitation mode can specify the address of the transmitter to be activated and / or the timing characteristics of the light pulses emitted by the specified transmitter.

[0111] In some embodiments, excitation patterns can be generated based on one or more real-time conditions, such as estimated / target measurement range (e.g., near-field obstacle detection or imaging, far-field obstacle detection or imaging), environmental complexity (e.g., density of objects in the environment, distribution of potential objects, etc.), eye safety constraints, etc. For example, for far-field measurements, the peak power or amplitude of the light pulse can be increased, and the peak power or amplitude of the light pulse can be decreased when a near-field object is detected (e.g., for eye safety purposes or to avoid near-field blind spots). In another example, the modes of simultaneously activated emitters can be designed to reduce crosstalk effects (e.g., sparse excitation modes).

[0112] Pattern generator 1131 can generate sensing patterns to be transmitted to the detection module for controlling the detector array as described above. Alternatively or otherwise, in response to a change in one or more parameters of the sensing pattern, a control signal can be generated and transmitted to the transmitter module. The control signal can be transmitted to the detection module synchronously, such that the activation / deactivation of the individual photoelectric sensors in the array is synchronized with the excitation of the corresponding light emitters.

[0113] Sensing modes can define multiple parameters used to control the detector array. For example, a sensing mode can specify the address of the photoelectric sensor to be activated for simultaneous measurement (i.e., corresponding to one or more SPADs for a pixel), pixel-level detector array operating parameters, such as the subset of SPADs to be activated in a pixel, or the selection of the subset of return signals used to generate sensor readouts, other operating parameters for the detector array (e.g., bias voltage, sampling duration), and signal processing.

[0114] The pattern generator 1131 can generate a sensing pattern based on a predetermined mapping relationship between the transmitter array and the detector array, as well as one or more real-time conditions. One or more parameters of the sensing pattern can be determined based on the mapping relationship. For example, the addresses of one or more SPADs can be selected for simultaneous measurement based on the emission pattern and the mapping relationship, and the selection can be flexibly changed during the measurement process. In another example, one or more operating parameters, such as the selection of a subset of SPADs to be activated in a pixel, or the selection of a subset of return signals used to generate sensor readouts, can be determined based on the emission pattern (e.g., the temporal characteristics of multiple sequences), one or more detected real-time conditions, or a combination of both.

[0115] The emission module, detection module, and LiDAR system can be configurable and dynamically adaptable to various conditions, including, for example, spontaneous events (e.g., object detection) or slowly changing events (e.g., system performance drift). One or more parameters of the emission mode (e.g., the address of the transmitter to be activated and / or the timing characteristics of the light pulses associated with a specified transmitter) and / or one or more parameters of the sensing mode can be dynamically adjusted at the pixel or sub-pixel level during measurement or LiDAR system operation. In some cases, the emission mode and / or sensing mode can be adjusted or generated per image frame, per distance measurement, or periodically. Alternatively or additionally, the emission mode and / or sensing mode can be adjusted or generated upon detection of real-time conditions.

[0116] In some cases, one or more parameters of the sensing mode can be dynamically determined based on one or more detected real-time conditions and emission modes. For example, the position and / or address of one or more SPADs selected for simultaneous measurement can be dynamically adjusted periodically or at predetermined intervals to accommodate system performance drift. For example, a group of SPADs corresponding to a specified transmitter (e.g., address / position, shape of the working area) can be dynamically adjusted in response to detected drift introduced by thermal expansion. In some cases, one or more parameters of the sensing mode can be dynamically determined based solely on detected real-time conditions. For example, operating parameters for a single photoelectric sensor, such as the number of pulses accumulated for generating a signal or the selection of pulses, can be determined based on previous distance measurements generated by a signal analysis module. For example, based on the measurement range and / or signal strength obtained from previous readouts, a larger number of pulses can be accumulated for long-distance measurements, while a smaller number of pulses can be accumulated for measurements in short-distance or higher reflectivity scenarios. In another example, when the previously readout indicated that the object was in the near field, the emission mode (e.g., the lower peak power / energy of the light pulse) can be dynamically adjusted, and the corresponding sensing mode can be adjusted so that fewer light pulses or light pulses with lower peak power can be selected to output the sensor signal.

[0117] In some cases, the mapping may be updated as one or more parameters of the sensing mode change. For example, different SPADs can be associated with the transmitter in response to the detection of a probe drift. Alternatively or otherwise, the mapping may not be updated when one or more parameters of the sensing mode change. For example, the mapping may not be updated when one or more parameters of the sensing mode are changed to accommodate transient, temporary, or spontaneous events such as changes in returned luminous flux.

[0118] The signal analysis module 1133 can receive sensor output signals from the detection module and generate images. In some cases, the signal analysis module 1133 can be configured to correlate the returned signal with a sequence of measured signals and calculate the distance based on the time delay between the correlated signals. In some embodiments, the time of flight associated with a multi-pulse sequence can be used to calculate the distance. In some cases, the average time of flight associated with each pulse within the sequence can be used to determine the time of flight associated with the multi-pulse sequence. The signal analysis module 1133 can calculate the distance based on the time of flight associated with a subset of light pulses and can determine the time of flight by determining that the detected light pulse sequence matches the timing characteristics. The measurements or results generated by the signal analysis module 1133 can also be used to determine one or more parameters of the sensing mode or emission mode as described above.

[0119] The provided adaptive control mechanism can be used in conjunction with various LiDAR systems and in a variety of applications. A LiDAR system equipped with this adaptive control mechanism can be mounted on a moving object to sense its surrounding environment. Alternatively, the LiDAR system can be mounted on a stationary object.

[0120] The movable object of the present invention can be configured to move in any suitable environment, such as in the air (e.g., a fixed-wing aircraft, a rotary-wing aircraft, or an aircraft without either a fixed or a rotary wing), in water (e.g., a boat or submarine), on land (e.g., a motor vehicle, such as a car, truck, bus, van, motorcycle, bicycle; a movable structure or frame, such as a stick, fishing rod; or a train), underground (e.g., a subway), in space (e.g., a spaceplane, satellite, or probe), or any combination of these environments. The movable object can be a means of transportation, such as those described elsewhere herein. In some embodiments, the movable object can be carried by a living body or removed from a living body, such as a person or animal.

[0121] In some cases, a movable object can be an autonomous vehicle, which may be referred to as an autonomous car, driverless car, self-driving car, robotic car, or driverless vehicle. In other cases, an autonomous vehicle can refer to a vehicle configured to perceive its environment and navigate or drive with little or no human input. For example, an autonomous vehicle can be configured to drive to any suitable location throughout the journey and control or perform all safety-critical functions (e.g., driving, steering, braking, parking) without the driver constantly in control of the vehicle. As another example, an autonomous vehicle allows the driver to safely divert their attention from driving tasks in a specific environment (e.g., on a highway), or an autonomous vehicle can provide control of the vehicle in all but a few environments, requiring little or no driver input or attention.

[0122] In some cases, LiDAR systems can be integrated into a vehicle as part of its autonomous driving system. For example, a LiDAR system can provide information about the surrounding environment to the autonomous vehicle's driving system. In one example, the LiDAR system can provide the vehicle with a wide range of horizontal and vertical fields of view. The autonomous vehicle's driving system may include one or more computing systems that receive information about the surrounding environment from the LiDAR system, analyze the received information, and provide control signals (e.g., steering wheel, accelerator, brake, or turning signals) to the vehicle's driving system.

[0123] As used herein, A and / or B includes one or more of A or B, and combinations thereof, such as A and B. It should be understood that although the terms “first,” “second,” “third,” etc., are used herein to describe various elements, components, regions, and / or portions, these elements, components, regions, and / or portions should not be limited by these terms. These terms are used only to distinguish one element, component, region, or portion from another. Therefore, without departing from the teachings of the invention, the first element, component, region, or portion discussed herein may be referred to as the second element, component, region, or portion.

[0124] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that, when used in this specification, the terms “comprising” and / or “including” or “comprises” and / or “including” designate the stated features, regions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0125] Throughout this specification, references to "some embodiments" or "one embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, the phrases "some embodiments" or "one embodiment" appearing in various places in this specification do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0126] While preferred embodiments of the invention have been shown and described herein, these embodiments will be apparent to those skilled in the art if provided by way of example only. Many variations, modifications, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of the invention. Many different combinations of the embodiments described herein are possible, and such combinations are considered part of this disclosure. Furthermore, all features discussed in connection with any embodiment herein can be readily applied to other embodiments herein. The following claims are intended to define the scope of the invention and are thereby covered by the methods and structures within the scope of these claims and their equivalents.

Claims

1. A light detection and ranging system, comprising: A transmitter array, each transmitter being individually addressable, for transmitting multipulse sequences into a three-dimensional environment, wherein at least a subset of the transmitters is configured to transmit multipulse sequences in parallel according to a transmission mode; An array of photoelectric sensors, each photoelectric sensor being individually addressable, wherein at least a subset of the photoelectric sensors is configured to receive light pulses according to a sensing mode, wherein each photoelectric sensor in the subset of photoelectric sensors is configured to detect light pulses returning from a three-dimensional environment and generate an output signal representing the light energy associated with at least a subset of the light pulses; as well as One or more processors are electrically coupled to the transmitter array and the photoelectric sensor array, wherein the one or more processors are configured to generate the transmission mode and the sensing mode based on one or more real-time conditions; The photoelectric sensor includes multiple photodetectors; each photodetector is individually addressable; the one or more processors are configured to determine a mapping relationship between a transmission mode and a sensing mode by determining the address of the photodetector mapped to a specified transmitter, wherein the address of the one or more photodetectors is determined at least based on the size, shape, and / or position of the light pulse spot.

2. The optical detection and ranging system according to claim 1, wherein, Each of the transmitters includes a set of laser diodes.

3. The optical detection and ranging system according to claim 2, wherein, The laser diode array is electrically connected and controlled by a driving circuit.

4. The optical detection and ranging system according to claim 1, wherein, The transmission mode includes the address of the transmitter to be activated, and the timing characteristics of the multi-pulse sequence transmitted by the transmitter.

5. The optical detection and ranging system according to claim 4, wherein, The timing characteristics include one or more of the following: the amplitude of each pulse in the multipulse sequence, the duration of each pulse in the multipulse sequence, the time interval between multiple pulses, and the number of multiple pulses in the multipulse sequence.

6. The optical detection and ranging system according to claim 1, wherein, Each of the aforementioned photoelectric sensors includes a set of photodetectors.

7. The optical detection and ranging system according to claim 6, wherein, Each of the photodetectors in the set can be addressed individually.

8. The optical detection and ranging system according to claim 6, wherein, A subset of photodetectors in the set of photodetectors is configured to receive light pulses according to the sensing mode.

9. The optical detection and ranging system according to claim 6, wherein, The sensing mode includes the address of the photoelectric sensor to be enabled, the address of the photoelectric detector to be enabled, or one or more parameters for selecting the subset of light pulses.

10. The optical detection and ranging system according to claim 9, wherein, The one or more parameters include the number of optical pulses in the optical pulse subset, or parameters representing a combination of non-adjacent optical pulses.

11. The optical detection and ranging system according to claim 1, wherein, The one or more real-time conditions are obtained based on the detected light pulses.

12. The optical detection and ranging system according to claim 1, wherein, The one or more real-time conditions include detecting an object within a predetermined distance threshold.

13. The optical detection and ranging system according to claim 1, wherein, The one or more processors are also configured to calculate distances based on the time of flight associated with the subset of optical pulses.

14. The optical detection and ranging system according to claim 13, wherein, The flight time is determined by matching the timing characteristics of the light pulses returning from the three-dimensional environment with the emission mode.

15. A method for providing adaptive control of a light detection and ranging system, the method comprising: Generate transmission and sensing modes based on one or more real-time conditions; At least one subset of transmitters in the transmitter array is activated according to the transmission mode to transmit multi-pulse sequences in parallel, wherein each transmitter in the transmitter array is individually addressable to transmit the multi-pulse sequence into a three-dimensional environment; as well as According to the sensing mode, at least a subset of photodetectors in an individually addressable photodetector array is enabled to receive light pulses, wherein each photodetector in the subset of photodetectors is configured to detect light pulses returning from the three-dimensional environment and generate an output signal representing the light energy associated with the at least a subset of the light pulses; wherein the photodetectors include a plurality of photodetectors; the photodetectors are individually addressable; By determining the address of the photodetector mapped to the specified transmitter, the mapping relationship between the emission mode and the sensing mode is determined, wherein the address of one or more photodetectors is determined based at least on the size, shape, and / or position of the light pulse spot.

16. The method according to claim 15, wherein, Each transmitter in the transmitter array includes a set of laser diodes.

17. The method according to claim 16, wherein, The laser diode array is electrically connected and controlled by a driving circuit.

18. The method according to claim 15, wherein, The transmission mode includes the address of the transmitter to be activated, and the timing characteristics of the multi-pulse sequence transmitted by the transmitter.

19. The method according to claim 18, wherein, The timing characteristics include one or more of the following: the amplitude of each pulse in the multipulse sequence, the duration of each pulse in the multipulse sequence, the time interval between the multiple pulses, and the number of multiple pulses in the multipulse sequence.

20. The method of claim 15, wherein, Each photoelectric sensor in the photoelectric sensor array includes a set of photodetectors.

21. The method according to claim 20, wherein, Each photodetector in the set of photodetectors can be addressed individually.

22. The method according to claim 20, wherein, A subset of photodetectors in the set of photodetectors is enabled to receive light pulses according to the sensing mode.

23. The method according to claim 20, wherein, The sensing mode includes the address of the photoelectric sensor to be enabled, the address of the photoelectric detector to be enabled, or one or more parameters for selecting the subset of light pulses.

24. The method according to claim 23, wherein, The one or more parameters include the number of light pulses in the light pulse subset or a parameter representing a combination of non-adjacent light pulses.

25. The method according to claim 15, wherein, The one or more real-time conditions are obtained based on the detected light pulses.

26. The method according to claim 15, wherein, The one or more real-time conditions include detecting an object within a predetermined distance threshold.

27. The method of claim 15, further comprising calculating the distance based on the time of flight associated with the subset of optical pulses.

28. The method according to claim 27, wherein, The flight time is determined by matching the timing characteristics of the light pulses returning from the three-dimensional environment with the emission mode.

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