A transmission method, a control method, and a laser radar

Abstract

A transmission method, a control method, and a lidar are disclosed. The method includes: determining a laser pulse sequence (S101); transmitting the laser pulse sequence (S102), wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulses. By designing the transmission time intervals of adjacent laser pulses in the laser pulse sequence transmitted by the lidar, the echo signals reflected back from normal targets and the echo signals reflected back from ambiguous targets can have different characteristics. Therefore, by identifying the characteristics of the echo signals, it is possible to determine whether the target is normal or ambiguous. Furthermore, the true distance of the ambiguous target can be calculated by combining the time intervals of the laser pulse sequence, thereby improving the range ambiguity problem and enhancing the accuracy of lidar ranging.

Description

A transmission method, a control method, and a lidar

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410501734.1, filed on April 22, 2024, with the title “A method of transmission, a method of control and a lidar”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of lidar, and more particularly to a transmission method, a control method, and a lidar. Background Technology

[0004] Currently, lidar can periodically emit multiple laser pulses, accumulating multiple echo signals to increase the signal-to-noise ratio and detection accuracy. However, this detection method can lead to distance ambiguity. Distance ambiguity refers to the situation where, when the distance between the target and the lidar exceeds its ranging range, the echo signal corresponding to a particular laser pulse does not fall within the receiving time window of that pulse, but rather within the receiving time window of a later emitted laser pulse (e.g., falling within the receiving time window of the next laser pulse). This results in the lidar measuring a target distance that is not the true distance; for example, the distance measured by the lidar may be much smaller than the target's actual distance. In some scenarios, distance ambiguity can cause safety problems. For example, in driving scenarios, distant targets can easily be misidentified as close targets, causing the vehicle to brake suddenly.

[0005] Improving the distance blur problem is a technical issue that urgently needs to be addressed. Summary of the Invention

[0006] This application provides a transmission method, a control method, and a lidar, which can improve the distance ambiguity problem and enhance the accuracy of lidar ranging.

[0007] Firstly, a transmission method is provided, which can be applied to lidar or parts of lidar devices, such as a transmission module. Taking the application of the method to lidar as an example, the method includes: determining a laser pulse sequence; transmitting the laser pulse sequence, wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulses.

[0008] This scheme designs the time interval of the laser pulses emitted by the lidar (i.e., the difference between adjacent time intervals is not zero and is less than the pulse broadening), allowing the echo signals reflected from normal targets (targets within the lidar's ranging range) and ambiguous targets (targets outside the lidar's ranging range) to have different characteristics. Therefore, by identifying these echo signal characteristics, the target can be determined as either normal or ambiguous. Furthermore, for ambiguous targets, the true distance can be calculated by combining the time intervals of the laser pulse sequence. This scheme can improve (or solve) the range ambiguity problem, enhance the accuracy of lidar target detection, and improve vehicle driving safety.

[0009] In one possible design, the method further includes: receiving multiple echo signals within multiple receiving time windows; wherein the multiple echo signals are formed by a laser pulse sequence reflected from the target; and determining the distance to the target based on the multiple echo signals received within the multiple receiving time windows.

[0010] In this way, the echo signal can be received and the distance to the target can be determined based on the echo signal, thus improving the reliability of the scheme.

[0011] In one possible design, the distance to the target can be determined by the receiving time interval of adjacent echo signals among multiple echo signals, and / or by whether the receiving time interval of adjacent echo signals among multiple echo signals matches the difference between adjacent time intervals in the transmission time interval sequence; the distance to the target can then be determined based on the determination results.

[0012] For targets within the ranging range, the echo signal corresponding to each laser pulse is returned to the lidar within the receiving time window of each laser pulse. Therefore, the difference between adjacent time intervals in the transmission time interval sequence does not affect the position of the echo signal in the receiving time window, and the echo signal is located in the same position in each receiving time window. For targets outside the ranging range, the echo signal is returned to the lidar at a later time than the receiving time window of each laser pulse (the receiving time window of the next laser pulse). The difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the laser pulse broadening, which makes the position of the echo signal different in each receiving time window. Therefore, the receiving time interval of adjacent echo signals can be used to determine whether the target is within the ranging range of the lidar. This implementation method is simple and reliable.

[0013] Furthermore, for targets located outside the ranging range, the receiving time interval of adjacent echo signals should match the difference between adjacent time intervals in the transmission time interval sequence. Therefore, judging whether the target is within the ranging range of the lidar based on whether the receiving time interval of adjacent echo signals matches the difference between adjacent time intervals in the transmission time interval sequence can further improve the accuracy of target identification.

[0014] In one possible design, multiple echo signals received within multiple receiving time windows can be accumulated to obtain an accumulated signal. The accumulation process includes: aligning the echo signals from different receiving time windows according to the start time of the receiving time window and then superimposing them to obtain the accumulated signal; determining whether the target is within the ranging range of the lidar based on the accumulated signal; and determining the distance to the target based on the determination result.

[0015] By accumulating and processing multiple echo signals received within multiple receiving time windows, multiple echo signals can be located within the same receiving time window, allowing for better observation of the characteristics of the echo signals and improving target recognition efficiency.

[0016] In one possible design, if the accumulated signal satisfies a first condition, the target is determined to be outside the ranging range; or, if the accumulated signal does not satisfy the first condition, the target is determined to be within the ranging range; wherein the first condition includes: the accumulated signal has multiple peaks and multiple troughs; and / or, the interval between adjacent peaks in the multiple peaks and / or the interval between adjacent peaks in the multiple troughs are related to the difference between adjacent time intervals in the transmission time interval sequence.

[0017] When the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse, for a target located outside the ranging range, the multiple echo signals returned accumulate into the same receiving time window. There is a deviation between adjacent echo signals, and this deviation is less than the broadening of the laser pulse, meaning that adjacent signals partially overlap, thus forming obvious peaks and troughs. Therefore, by identifying whether there are multiple peaks and troughs in the accumulated signal, it is possible to easily and quickly determine whether the target is within the ranging range.

[0018] In one possible design, the first condition may also include: the broadening of the accumulated signal is related to the difference between the maximum and minimum time intervals in the transmission time interval sequence. For example, the broadening of the accumulated signal = (maximum time interval in the transmission time interval sequence - minimum time interval in the transmission time interval sequence) + the broadening of the laser pulse.

[0019] This can further enhance the accuracy of target identification.

[0020] In one possible design, the first condition may also include: the difference in photon count values ​​corresponding to different peaks among multiple peaks is within a first range.

[0021] If the difference in photon counts corresponding to different peaks within the first range indicates that the signals corresponding to the multiple peaks are signals returned from the same target, this can further enhance the accuracy of target identification.

[0022] In one possible design, if the target is within the ranging range, the distance to the target is determined based on the accumulated signal; if the target is not within the ranging range, the distance to the target is determined based on the accumulated signal and the transmission time interval sequence.

[0023] Using different algorithms to calculate distances for targets within and outside the ranging range can improve the accuracy of target identification.

[0024] Secondly, a transmission method is provided, which can be applied to lidar or parts of lidar devices, such as a transmission module. Taking the application of the method to lidar as an example, the method includes: transmitting a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulses; transmitting a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulses; wherein the first transmission time interval sequence and the second time interval sequence are different.

[0025] In the above scheme, the lidar can emit different laser pulse sequences, which helps to actively adjust the receiving position of the echo signal of the blurred target in the receiving time window when a blurred target is detected, so as to better observe the blurred target, or remove the echo signal of the blurred target to save computing resources.

[0026] In one possible design, the first transmission time interval sequence differs from the second transmission time interval sequence, including one or more of the following:

[0027] The first transmission time interval sequence and the second transmission time interval sequence have no intersection;

[0028] The difference between adjacent time intervals in the first transmission time interval sequence is different from the difference between adjacent time intervals in the second transmission time interval sequence.

[0029] Of course, the above two are just examples, and the actual situation is not limited to these.

[0030] In one possible design, the maximum time interval in the first transmission time interval sequence is less than the minimum time interval in the second transmission time interval sequence; or, the maximum time interval in the second transmission time interval sequence is less than the minimum time interval in the first transmission time interval sequence.

[0031] In this way, the time intervals of the first and second transmission time interval sequences can be significantly different, thus better meeting the detection requirements.

[0032] In one possible design, before sending the second laser pulse sequence, multiple first echo signals can be received within multiple receiving time windows; wherein, the multiple first echo signals are formed by the first laser pulse sequence after reflection from the target; and the second laser pulse sequence is determined based on the multiple first echo signals received within the multiple receiving time windows.

[0033] This design method selects the laser pulse sequence to be sent next based on the results of the previous echo reception, enabling the lidar to adaptively adjust the laser pulse sequence.

[0034] In one possible design, the target can be determined to be within the ranging range of the lidar based on multiple first echo signals; and the second laser pulse sequence can be determined based on the determination result.

[0035] In this way, the second laser pulse sequence can be selected according to different methods depending on whether the target is within the ranging range, which can further improve the reliability of the scheme.

[0036] In one possible design, the target can be determined to be within the ranging range of the lidar based on the receiving time interval of adjacent echo signals among multiple first echo signals; and / or, the target can be determined to be within the ranging range of the lidar based on whether the receiving time interval of adjacent echo signals among multiple first echo signals matches the difference between adjacent time intervals in the first transmission time interval sequence.

[0037] For targets within the ranging range, the echo signal corresponding to each laser pulse is returned to the lidar within the receiving time window of each laser pulse. Therefore, the difference between adjacent time intervals in the transmission time interval sequence does not affect the position of the first echo signal in the receiving time window, and the position of the first echo signal is the same in each receiving time window. However, for targets outside the ranging range, the first echo signal corresponding to the laser pulse is returned to the lidar at a later time than the receiving time window of each laser pulse (the receiving time window of the next laser pulse). The difference between adjacent time intervals in the transmission time interval sequence is not zero and is greater than the laser pulse broadening, which will cause the position of the first echo signal to be different in each receiving time window. Therefore, based on the receiving time interval of the first echo signals among multiple first echo signals, it can be determined whether the target is within the ranging range of the lidar. This implementation method is simple and reliable.

[0038] Furthermore, for targets located outside the ranging range, the receiving time interval of adjacent first echo signals should match the difference between adjacent time intervals in the transmission time interval sequence. Therefore, judging whether the target is within the ranging range of the lidar based on whether the receiving time interval of adjacent echo signals in multiple first echo signals matches the difference between adjacent time intervals in the transmission time interval sequence can further improve the accuracy of target identification.

[0039] In one possible design, multiple first echo signals received within multiple receiving time windows can be accumulated to obtain an accumulated signal. The accumulation process includes: aligning the first echo signals from different receiving time windows according to the start time of the receiving time window and then superimposing them to obtain the accumulated signal; and determining whether the target is within the ranging range of the lidar based on the accumulated signal.

[0040] By accumulating and processing multiple first echo signals received within multiple receiving time windows, multiple first echo signals can be located within the same receiving time window, allowing for better observation of the echo signal characteristics and improving target recognition efficiency.

[0041] In one possible design, determining whether a target is within the ranging range of the lidar based on the accumulated signal may include: if the accumulated signal meets a second condition, then the target is determined to be outside the ranging range; or, if the accumulated signal does not meet the second condition, then the target is determined to be within the ranging range; the second condition includes: the existence of multiple signals in the second accumulated signal; and / or, the time interval between adjacent signals in the second accumulated signal is correlated with the difference between adjacent time intervals in the first transmission time interval sequence.

[0042] When the difference between adjacent time intervals in the transmission time interval sequence is not zero and is greater than the laser pulse broadening, for a target located outside the ranging range, after multiple echo signals are accumulated into the same receiving time window, there is a deviation between adjacent echo signals, and this deviation is greater than the laser pulse broadening, meaning there is no overlap between adjacent signals. Therefore, by identifying whether there are multiple signals in the accumulated signal, it is possible to simply and quickly determine whether the target is within the ranging range.

[0043] In one possible design, the second condition may also include: the difference in photon count values ​​corresponding to the peaks of different signals in the second accumulated signal is within a second range.

[0044] The difference in photon counts corresponding to different peaks within the second range indicates that multiple signals are returned from the same target. This can further enhance the accuracy of target identification.

[0045] In one possible design, if the target is within the ranging range, a laser pulse sequence is randomly selected from multiple laser pulse sequences as the second laser pulse sequence; or, if the target is not within the ranging range, the flight time corresponding to the target is determined based on multiple first echo signals and a first transmission time interval sequence; and the second laser pulse sequence is determined from multiple laser pulse sequences based on the flight time.

[0046] When the target is within the ranging range, regardless of the sequence, the target can be guaranteed to be within a good observation interval, so a random sequence can be selected, saving computational resources. When the target is outside the ranging range, the flight time of the target is calculated first, and then a second laser pulse sequence is determined from multiple laser pulse sequences based on the flight time. This can ensure that the echo signal returned by the blurred target next time falls within a good observation interval or filter out the echo signal returned by the blurred target next time.

[0047] In one possible design, the second laser pulse sequence can be determined from multiple laser pulse sequences based on the flight time and the maximum speed of the vehicle where the lidar is located.

[0048] For example, the remainder obtained by taking the flight time modulo the maximum time interval in the first launch time interval sequence is less than or equal to a first threshold; the remainder obtained by taking the flight time modulo the maximum time interval in the second time interval sequence is greater than or equal to a second threshold; wherein, the second threshold is greater than or equal to the first threshold, and the first threshold and the second threshold are related to the maximum driving speed of the vehicle.

[0049] Since the movement of the vehicle may change the relative distance between the vehicle and the target, determining the second laser pulse sequence from multiple laser pulse sequences by combining the vehicle's maximum speed can make the selected second laser pulse sequence more optimal.

[0050] In one possible design, multiple second echo signals can be received within multiple receiving time windows; wherein the multiple second echo signals are formed by the reflection of a second laser pulse sequence from the target; and the distance to the target is determined based on the multiple second echo signals.

[0051] The target distance is determined more accurately based on the echo signal corresponding to the adjusted laser pulse sequence.

[0052] Thirdly, a control method is provided, which can be applied to lidar or some components of lidar, such as control devices. The method includes: determining a laser pulse sequence; controlling a transmitting module to transmit the laser pulse sequence, wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulses.

[0053] Fourthly, a control method is provided, which can be applied to lidar or some components of lidar, such as a control device. The method includes: controlling a transmitting module to transmit a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulses; controlling the transmitting module to transmit a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulses; wherein the first transmission time interval sequence and the second time interval sequence are different.

[0054] Fifthly, a lidar is provided, including a control device and a transmitting module; the control device is used to: determine a laser pulse sequence; control the transmitting module to transmit the laser pulse sequence; wherein, the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse.

[0055] In one possible design, the lidar may also include a receiving module and a processing module;

[0056] The receiving module is used to receive multiple echo signals within multiple receiving time windows; wherein the multiple echo signals are formed by the reflection of a laser pulse sequence from the target;

[0057] The processing module is used to determine the distance to the target based on multiple echo signals received within multiple reception time windows.

[0058] The specific implementation and beneficial effects of the fifth aspect can be found in the specific implementation and beneficial effects of the first aspect.

[0059] Sixthly, a lidar is provided, including a control device and a transmitting module;

[0060] The control module is used to control the transmitting module to send a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse;

[0061] The control module is also used to: control the transmitting module to send a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse;

[0062] The first transmission time interval sequence is different from the second time interval sequence.

[0063] In one possible design, the lidar also includes a receiving module and a processing module;

[0064] The receiving module is used to receive multiple first echo signals within multiple receiving time windows before the transmitting module sends the second laser pulse sequence; wherein the multiple first echo signals are formed by the first laser pulse sequence after being reflected by the target;

[0065] The processing module is used to determine the second laser pulse sequence based on multiple first echo signals received within multiple receiving time windows.

[0066] The specific implementation and beneficial effects of the sixth aspect can be found in the specific implementation and beneficial effects of the second aspect.

[0067] A seventh aspect provides a control device, including a module, unit, or technical means for performing the control method as described in the third or fourth aspect.

[0068] Eighthly, a terminal is provided, comprising the lidar shown in the fifth aspect, or including the lidar as described in the sixth aspect.

[0069] Ninth aspect, a computer-readable storage medium is provided, the storage medium storing a computer program or instructions that, when executed by a communication device, implement the method as described in the first aspect or any possible design of the first aspect, or implement the method as described in the second aspect or any possible design of the second aspect, or implement the method as described in the third aspect, or implement the method as described in the fourth aspect.

[0070] In a tenth aspect, a computer program product is provided, the computer program product storing instructions that, when run on a computer, cause the computer to perform the method as described in the first aspect or any possible design of the first aspect, or the method as described in the second aspect or any possible design of the second aspect, or the method as described in the third aspect, or the method as described in the fourth aspect.

[0071] For the specific designs and beneficial effects of the third to tenth aspects mentioned above, please refer to the corresponding designs and beneficial effects in the first and second aspects. Attached Figure Description

[0072] Figure 1 is a schematic diagram of an application scenario of a lidar provided in an embodiment of this application;

[0073] Figure 2 is a schematic diagram of the internal architecture of a lidar provided in an embodiment of this application;

[0074] Figure 3 shows a schematic diagram of two signal transmission and reception methods for lidar;

[0075] Figure 4 is a flowchart illustrating a launching method provided in an embodiment of this application;

[0076] Figure 5 is a flowchart illustrating a method for receiving and processing echo signals according to an embodiment of this application;

[0077] Figures 6A and 6B are example diagrams of signal transmission and reception provided in the embodiments of this application;

[0078] Figures 7A and 7B are example diagrams of signal transmission and reception provided in the embodiments of this application;

[0079] Figures 8A and 8B are example diagrams of signal transmission and reception provided in the embodiments of this application;

[0080] Figure 9 is a flowchart illustrating another launching method provided in an embodiment of this application;

[0081] Figure 10 is a flowchart of a method for adjusting a laser pulse sequence according to an embodiment of this application;

[0082] Figure 11 is a schematic diagram of a control device provided in an embodiment of this application. Detailed Implementation

[0083] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0084] This application can be applied to terminal devices with detection capabilities, particularly those with laser detection capabilities. The terminal device can be a smart device with laser detection capabilities, including but not limited to: smart home devices such as televisions, robot vacuums, smart lamps, audio systems, smart lighting systems, appliance control systems, home background music systems, home theater systems, intercom systems, and video surveillance; smart transportation equipment such as automobiles, ships, drones, trains, freight cars, and trucks; and smart manufacturing equipment such as robots, industrial equipment, smart logistics, and smart factories. Alternatively, the terminal device can also be a computer device with laser detection capabilities, such as a desktop computer, personal computer, or server. It should also be understood that the terminal device can also be a portable electronic device with laser detection capabilities, such as a mobile phone, tablet computer, PDA, headphones, speakers, wearable devices (such as smartwatches), in-vehicle devices, virtual reality devices, and augmented reality devices. Examples of portable electronic devices include, but are not limited to, devices equipped with... Or other portable electronic devices with different operating systems. These portable electronic devices can also include, for example, laptops with touch-sensitive surfaces (such as touch panels).

[0085] In a specific application scenario, the embodiments of this application can be applied to lidar. Figure 1 exemplarily illustrates a schematic diagram of an application scenario of lidar provided by an embodiment of this application. In this example, the lidar 100 is installed on a vehicle, and is therefore also called a vehicle-mounted lidar. In addition to vehicle-mounted lidar, lidar also includes shipborne lidar installed on ships, and airborne lidar installed on machines, etc. In one possible example, as shown in Figure 1, the lidar 100 can be specifically installed at the front of a vehicle. During the vehicle's operation, the lidar 100 can emit laser pulse signals. After the laser pulse signals illuminate objects in front of the vehicle, they are reflected by the objects to form echo signals. The reflected echo signals can be received by the lidar 100, and then the lidar 100 can detect obstacle information in front of the vehicle based on the echo signals, such as the size and distance of the obstacles, so as to use the obstacle information to realize the vehicle's driving functions, such as including but not limited to autonomous driving or assisted driving.

[0086] The lidar 100 can be one of mechanical lidar, liquid lidar, pure solid-state lidar, or hybrid solid-state lidar (also known as semi-solid-state lidar), or it can be other types of lidar. This application embodiment does not specifically limit it in this regard.

[0087] It should be noted that Figure 1 shows the lidar 100 installed at the front of the vehicle as an example, but it can also be installed in any other location such as the parking space or the vehicle body.

[0088] As further exemplarily, Figure 2 shows a schematic diagram of the internal architecture of a lidar provided in an embodiment of this application. As shown in Figure 2, in this example, the lidar 100 may include a control device 110, a transmitting module 120, a receiving module 140, and a processing module 150.

[0089] The transmitting module 120 includes a laser 121 and a transmitting optical system 122, while the receiving module 140 includes a receiving optical system 141 and a detector 142. In the lidar 100, the control device 110 can have signal control capabilities and can be connected to other components in the lidar 100 via a controller area network (CAN) bus or other means, such as, but not limited to, the transmitting module 120, the scanning mechanism 130, the receiving module 140, and the processing module 150. The laser 121 is a device capable of emitting laser light, and its type can be any of a semiconductor laser, gas laser, fiber laser, solid-state laser, dye laser, diode laser, or excimer laser. The transmitting optical system 122 and the receiving optical system 141 refer to systems composed of optical elements, including but not limited to: lenses, filters, polarizers, mirrors, beam splitters, prisms, windows, and diffusers.

[0090] It should be noted that the control device 110 and processing module 150 described above can be integrated into a single device or implemented separately in multiple devices. For example, they can be integrated into a single device, which can be an integrated circuit chip, such as a general-purpose processor, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and other integrated chips. The device may include a central processing unit (CPU), a neural network processing unit (NPU), and a graphics processing unit (GPU), and may also include an application processor (AP), a modem processor, an image signal processor (ISP), a video codec, a digital signal processor (DSP), and / or a baseband processor, etc., without being specifically limited.

[0091] Optionally, the lidar 100 may also include a scanning mechanism 130. The scanning mechanism 130 may include one or more of a multi-faceted rotating mirror, a tilting mirror, a micro-electro-mechanical system (MEMS) scanning mirror, or a prism. The detector 142 may include, but is not limited to, an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), a positive intrinsic-negative (PIN) photodiode, and a silicon photomultiplier (SiPM). The processing module 150 may have signal processing capabilities and may be connected to the detector 142 via a CAN bus or other means.

[0092] In practical implementation, the control device 110 can control the laser 121 to emit detection signals (e.g., laser pulse signals), control the transmitting optical system 122 to transmit the detection signals from the laser 121, and control the scanning mechanism 130 to scan and traverse the detection area using the detection signals. It should be noted that the scanning mechanism 130 is not a necessary component, and the traversal function that the scanning mechanism 130 can achieve can essentially be realized through the array design within the transmitting module 120 and the receiving module 140, as well as the array control device. Furthermore, after the detection signal is scanned to an object in the detection area, it will be reflected by the object. The reflected echo signal is received by the receiving optical system 141 under the control of the control device 110 and transmitted to the detector 142. The detector 142 then converts the optical echo signal into an electrical signal and sends it to the processing module 150. Under the control of the control device 110, the processing module 150 analyzes the electrical signal to generate point cloud data. This point cloud data can be used to obtain target information such as the distance, orientation, height, speed, attitude, and even shape of the object. It can also be used in conjunction with other sensor information of the vehicle to plan the autonomous driving or assisted driving of the vehicle.

[0093] It is understood that Figure 2 is only one possible structural example of a lidar, and there are other ways to implement the structure of a lidar.

[0094] The receiving architecture of lidar includes single-pulse receiving architecture and multi-pulse receiving and accumulating architecture.

[0095] A single-pulse laser receiver architecture refers to a lidar system that detects targets by sending a single laser pulse and receiving its echo signal (i.e., emitting a single laser pulse). Since objects with varying reflectivity exist in the real environment, if the lidar only sends a single laser pulse, the echo signal returned by low-reflectivity targets (such as black cars or dark-colored road signs) will be weak, resulting in a low signal-to-noise ratio. Therefore, lidar systems with a single-pulse laser receiver architecture suffer from low detection sensitivity.

[0096] The multi-pulse laser receiver-accumulator architecture refers to a lidar system that repeatedly emits multiple laser pulses, accumulating multiple echo signals to detect targets. This increases the lidar's signal-to-noise ratio and measurement accuracy. However, this architecture can lead to range ambiguity. Figure 3 below illustrates the cause of this range ambiguity problem.

[0097] Figure 3 illustrates two signal transmission and reception diagrams for lidar. Figure 3(A) shows the signal transmission and reception diagram when the lidar does not have a fuzzy distance problem, while Figure 3(B) shows the signal transmission and reception diagram when the lidar has a fuzzy distance problem.

[0098] As can be understood, the horizontal axis in Figure 3 represents time, with the time order on the horizontal axis being left first and right last. The triangular patterns above the horizontal axis represent laser pulse emission (or the emitted laser pulse), and the triangular patterns below the horizontal axis represent echo signal reception (or the received echo signal). The pattern of the echo signal corresponding to each laser pulse is the same as the pattern of that laser pulse. The position of the laser pulse on the horizontal axis represents the emission time of the laser pulse, and the position of the echo signal on the horizontal axis represents the reception time of the echo signal. A rectangle below the horizontal axis represents the reception time window. Each laser pulse emission corresponds to a reception time window (representing the time period during which the lidar receives the echo signal of that laser pulse). The start time of this reception time window is no earlier than the emission time of that laser pulse, and the end time is no later than the emission time of the next laser pulse. It can be understood that the above interpretation of Figure 3 applies to all signal transmission and reception schematic diagrams in the embodiments of this application, and will not be repeated hereafter.

[0099] The ranging range of a lidar system refers to the farthest distance that the lidar can detect within the repetition period of a laser pulse. In other words, it's the farthest distance at which the echo signal corresponding to a single laser pulse can return to the lidar within the receiving time window corresponding to that pulse. If the echo signal formed by the laser pulse emitted by the lidar and reflected by the target returns to the lidar within the receiving time window corresponding to that pulse, then the target is within the lidar's ranging range. If the echo signal formed by the laser pulse emitted by the lidar and reflected by the target cannot return to the lidar within the receiving time window corresponding to that pulse (e.g., after the receiving time window ends), then the target is outside the lidar's ranging range. In some embodiments, "ranging range" may also be referred to as "measuring range" or "effective range," etc., without limitation.

[0100] For ease of distinction, in this paper, targets within the ranging range of the lidar are referred to as "normal targets" (or near-range targets), and targets within the ranging range of the lidar are referred to as "fuzzy targets" (or far-range targets). Figure 3(A) shows a schematic diagram of signal transmission and reception when the lidar detects a normal target, and Figure 3(B) shows a schematic diagram of signal transmission and reception when the lidar detects a fuzzy target.

[0101] As shown in Figure 3, the lidar periodically sends laser pulses at time intervals of T (that is, it sends a laser pulse every T time interval, or the period of the lidar's laser pulse transmission is T).

[0102] For a target within the ranging range, as shown in Figure 3(A), the echo signal corresponding to each emitted laser pulse returns to the lidar within the receiving time window corresponding to that laser pulse. After accumulating the echo signals received within multiple receiving time windows, the lidar determines the target's true distance based on the accumulated signal. The accumulation process includes aligning the echo signals from different receiving time windows according to the start time of each receiving time window and then superimposing them (equivalent to placing the echo signals from multiple receiving time windows into the same time window). The superimposed signal is the accumulated signal.

[0103] For targets located outside the ranging range, as shown in Figure 3(B), because the target is outside the ranging range of the lidar, the return time of the echo signal corresponding to each emitted laser pulse exceeds the receiving time window corresponding to that laser pulse. Figure 3(B) takes the example where the echo signal corresponding to each emitted laser pulse returns in the next receiving time window; in reality, it may be even later (e.g., the echo signal returns to the lidar in the next receiving time window after that). However, the lidar will consider the echo signal received in each receiving time window as the echo signal generated by the current laser pulse (actually, it is the echo signal generated by the previous or even the previous laser pulse). The accumulation method of the echo signals received in multiple receiving time windows is the same as the accumulation method in (A), thus misjudging the target distance and moving the target closer. This problem of misidentifying the target distance is called the "range ambiguity" problem.

[0104] In driving scenarios, if a vehicle uses a lidar system with a multi-pulse laser receiver and aggregator architecture, it is very likely to encounter a "distance ambiguity" problem, which poses a serious safety hazard. For example, it may misidentify a distant target as a close target, causing the vehicle to brake suddenly.

[0105] Therefore, this application provides a technical solution to improve the distance ambiguity problem.

[0106] It should be noted that the technical solutions of this application can be applied to the aforementioned LiDAR, as well as other devices, components, or chips, such as smart terminals with detection functions other than the aforementioned LiDAR, or components set in other smart terminals, including but not limited to controllers, chips, cameras, and other sensors and components. Alternatively, the technical solutions of this application can be applied to the aforementioned driving scenario, as well as other imaging systems besides the aforementioned driving scenario, such as 3D building modeling systems, terrain mapping systems, or rendezvous and docking systems. Moreover, with the evolution of system architecture and the emergence of new scenarios, the technical solutions of this application are also applicable to similar technical problems, and this application does not specifically limit them in this regard.

[0107] The following will describe the specific implementation of the technical solution of this application based on the lidar shown in Figure 2 and in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0108] It should be noted that the terms "system" and "network" in the embodiments of this application can be used interchangeably. "Multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. "One or more of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, one or more of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0109] Furthermore, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the priority or importance of multiple objects. For example, the first pixel configuration, the second pixel configuration, and the third pixel configuration are only used to distinguish different pixel configurations, and do not indicate that these pixel configurations have different priorities or importance.

[0110] Figure 4 illustrates a flowchart of a launching method provided in an embodiment of this application, the method comprising:

[0111] S101. Determine the laser pulse sequence;

[0112] Specifically, determining the laser pulse sequence can refer to the lidar determining the laser pulse sequence, the lidar's transmitting module determining the laser pulse sequence, the lidar control device determining the laser pulse sequence, and so on.

[0113] A laser pulse sequence refers to a sequence of multiple laser pulse signals (referred to as laser pulses) emitted at different times. The broadening of each laser pulse in the sequence is equal. Laser pulse broadening refers to the width of the laser pulse, i.e., the duration of the emitted laser pulse, such as "L" shown in Figures 6A, 6B, 7A, 7B, 8A, or 8B. In some embodiments, laser pulse broadening may also be replaced by other names such as "pulse width" or "pulse duration".

[0114] The transmission time intervals of adjacent laser pulses in a laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero. For example, referring to Figures 6A, 6B, 7A, 7B, 8A, or 8B, an example of a laser pulse sequence consisting of four laser pulses is shown, where the transmission time intervals of adjacent laser pulses are T+δ1, T+δ2, T+δ3, and tT+δ4, respectively. Then, the differences between adjacent time intervals in the transmission time interval sequence are (T+δ2)-(T+δ1)=δ2-δ1, (T+δ3)-(T+δ2)=δ3-δ2, and (T+δ4)-(T+δ3)=δ4-δ3, where δ2-δ1, δ3-δ2, and δ4-δ3 are all non-zero.

[0115] It is understandable that Figures 6A, 6B, 7A, 7B, 8A, or 8B are examples with four laser pulses, but in practice, there can be more or fewer, without any limitation.

[0116] It is understood that when there are multiple adjacent time intervals in a transmission time interval sequence, these multiple adjacent time intervals can be the same, different, or partially the same and partially different, without restriction. For example, δ2-δ1, δ3-δ2, and δ4-δ3 in Figures 6A, 6B, 7A, 7B, 8A, or 8B can be all the same, all different, or partially the same and partially different.

[0117] S102, Send laser pulse sequence.

[0118] Specifically, sending a laser pulse sequence can refer to the lidar emitting a laser pulse sequence, the lidar's transmitting module emitting a laser pulse sequence, or the lidar's transmitting module emitting a laser pulse sequence under the control of a control device, and so on.

[0119] In practical applications, determining the laser pulse sequence in S101 above can also be replaced by determining the transmission time interval sequence. Correspondingly, S102 becomes: transmitting the laser pulse sequence according to the transmission time interval sequence.

[0120] The above scheme, through a special design of the transmission time interval between adjacent laser pulses in the laser pulse sequence emitted by the lidar (i.e., the difference between adjacent time intervals in the transmission time interval sequence is not zero), allows the echo signals reflected from normal targets (i.e., targets within the lidar's ranging range) and those reflected from ambiguous targets (i.e., targets outside the lidar's ranging range) to have different characteristics. Therefore, by identifying the characteristics of the echo signals, it is possible to determine whether the target is normal or ambiguous. Furthermore, if it is an ambiguous target, the true distance to the ambiguous target can be calculated by combining the time intervals of the laser pulse sequence. This scheme can improve (or solve) the range ambiguity problem, enhance the accuracy of lidar target detection, and improve vehicle driving safety.

[0121] Referring to Figure 5, after step S102, the following can also be performed:

[0122] S103. Receive multiple echo signals within multiple receiving time windows, wherein the multiple echo signals are formed by the reflection of a laser pulse sequence from the target.

[0123] The phrase "receiving multiple echo signals within multiple receiving time windows" can refer to the lidar receiving multiple echo signals within multiple receiving time windows, or it can refer to the lidar's receiving module receiving multiple echo signals within multiple receiving time windows under the control of the lidar's control device, or it can refer to the lidar's processing module acquiring the electrical signals corresponding to the multiple echo signals from the receiving module. There are no restrictions on this.

[0124] The multiple receiving time windows refer to the receiving time windows corresponding to each laser pulse in the laser pulse sequence. The lengths of the receiving time windows corresponding to different laser pulses can be the same or different; for ease of illustration, the figures in this paper all use the same example. For example, Figures 6A, 6B, 7A, 7B, 8A, or 8B illustrate four receiving time windows (shown as rectangular boxes in the figures). The start time of the receiving time window corresponding to each laser pulse is no earlier than the start time of that laser pulse, and the end time of the receiving time window corresponding to each laser pulse is no later than the start time of the next laser pulse adjacent to that laser pulse. Optionally, the duration of the receiving time window corresponding to each laser pulse is less than the time interval between that laser pulse and the next laser pulse.

[0125] It can be understood that receiving multiple echo signals within multiple receiving time windows means activating the echo signal reception function within multiple receiving time windows. Whether an echo signal is received within each receiving time window depends on whether the environment returns an echo signal. For example, in the scenario shown in Figure 6A, 7A, or 8A, four laser pulses are emitted, and echo signals are received within all four receiving time windows. Conversely, in the scenario shown in Figure 6B, 7B, or 8B, four laser pulses are emitted, but echo signals are received only within the last three receiving time windows.

[0126] After receiving multiple echo signals within multiple reception time windows, the target distance is determined based on the multiple echo signals received within those reception time windows. Specifically, as shown in Figure 5, after S103, the following is also executed:

[0127] S104. Based on multiple echo signals received within multiple reception time windows, determine whether the target is within the ranging range of the lidar (i.e., determine whether the target is a normal target or a blurred target). Then, determine the target's distance based on the determination result:

[0128] S105A. If the target is within the ranging range (i.e., the target is a normal target), then the distance to the normal target shall be calculated according to the ranging method for normal targets.

[0129] S105B. If the target is not within the ranging range, the distance to the fuzzy target shall be calculated according to the ranging method for fuzzy targets.

[0130] The following describes a method for determining whether a target is within the ranging range of a lidar:

[0131] In one possible design, the distance between the reception of adjacent echo signals among multiple echo signals can be used to determine whether the target is within the ranging range of the lidar. Specifically, the lidar or its processing module determines whether the target is within the lidar's ranging range by analyzing the time interval between the reception of adjacent echo signals among multiple echo signals.

[0132] For example, timing the echo signal is started at the beginning of each reception time window, and the timing restarts at the beginning of each new reception time window (or, timing the echo signal is started at the transmission time of each laser pulse, and the timing restarts at the transmission time of each laser pulse). In this case, the target is determined to be within the ranging range of the lidar based on the reception time interval between adjacent echo signals. Specifically, this can include: if there is no time interval between adjacent echo signals (or the time interval is 0), the target is determined to be a normal target (i.e., the target is within the ranging range); conversely, if there is a time interval between adjacent echo signals, the target is determined to be an ambiguous target (i.e., the target is not within the ranging range).

[0133] For example, Figure 6A shows a schematic diagram of the echo signals of a normal target. The first echo signal is received within the first receiving time window, at time t1' after the first laser pulse is emitted. The second echo signal is received within the second receiving time window, at time t2' after the second laser pulse is emitted. The third echo signal is received within the third receiving time window, at time t3' after the third laser pulse is emitted, and so on. Since the target is a normal target, the echo signal corresponding to each laser pulse returns within the receiving time window corresponding to that laser pulse. Therefore, the receiving time (position within the receiving time window) of each echo signal is the same. For example, t1' = t2' = t3', so t2' - t1' = t3' - t2' = 0, meaning there is no time interval between adjacent echo signals.

[0134] For example, Figure 6B shows a schematic diagram of the echo signal of a blurred target. The first echo signal is received within the second receiving time window, at time t1' after the second laser pulse is sent. The second echo signal is received within the third receiving time window, at time t2' after the third laser pulse is sent. The third echo signal is received within the fourth receiving time window, at time t3' after the fourth laser pulse is sent, and so on. Since the target is blurred, the echo signal corresponding to each laser pulse returns within the receiving time window corresponding to the next laser pulse. Therefore, the receiving time (position within the receiving time window) of each echo signal is different. Since the target is the same (or the distance to the target remains constant), the return time of each laser pulse is the same, i.e., t1' + T + δ1 = t2' + T + δ2 = t3' + T + δ3. Therefore, t2' - t1' = δ1 - δ2, t3' - t2' = δ2 - δ3, meaning there is a time interval between adjacent echo signals.

[0135] It is understandable that, due to space limitations in the accompanying figures, Figures 6A and 6B only illustrate the reception situation in four reception time windows, and the actual situation is not limited to these.

[0136] In another possible design, the range of the lidar can be determined by whether the receiving time interval of adjacent echo signals in multiple echo signals matches (or is related to) the difference between adjacent time intervals in the transmission time interval sequence.

[0137] As shown in Figure 6B, for a blurred target, the time interval between the first echo signal and the second echo signal is t2'-t1'=δ1-δ2, which is equal to the difference between the first time interval and the second time interval (T+δ1)-(T+δ2); the time interval between the second echo signal and the third echo signal is t3'-t2'=δ2-δ3, which is equal to the difference between the second time interval and the third time interval (T+δ2)-(T+δ3).

[0138] As shown in Figure 6A, for a normal target, the time interval between the first and second echo signals and the time interval between the second and third echo signals are both 0, while the difference between adjacent time intervals in the transmission time interval sequence is not 0.

[0139] It is understandable that the two design methods described above can be implemented separately or in combination. For example, in a combined implementation: first determine if there is a time interval between adjacent echo signals. If not, it is determined to be a normal target; if there is, and the time interval between adjacent echo signals matches the difference between adjacent time intervals in the transmission time interval sequence, it is determined to be an ambiguous target.

[0140] In one possible design, echo signals from multiple receiving time windows can be accumulated to obtain an accumulated signal. The characteristics of this accumulated signal can then be used to identify whether the target is a normal target or a blurred target. Accumulating echo signals from different receiving time windows can be understood as superimposing them into a single receiving time window. For ease of description, the receiving time window containing the accumulated signal will be referred to as the "first time window." The "first time window" can be any one of multiple receiving time windows, or it can be a virtual time window. The accumulated signal can also be referred to as the signal within the first time window.

[0141] In one specific implementation, the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the width of the laser pulse. For example, referring to Figure 7A or Figure 7B, an example of a laser pulse sequence consisting of four laser pulses is shown, where the transmission time intervals of adjacent laser pulses are T+δ1, T+δ2, T+δ3, and T+δ4, respectively. Then, the differences between adjacent time intervals in the transmission time interval sequence are (T+δ2)-(T+δ1)=δ2-δ1, (T+δ3)-(T+δ2)=δ3-δ2, and (T+δ4)-(T+δ3)=δ4-δ3, where δ2-δ1, δ3-δ2, and δ4-δ3 are all non-zero. If the width of the laser pulse is L, then δ2-δ1... <L、δ3-δ2<L、δ4-δ3<L。

[0142] In this case, it can be determined whether the accumulated signal (or the signal in the first time window) meets the first condition. If the accumulated signal meets the first condition, the target is determined to be an ambiguous target (not within the ranging range); or, if the accumulated signal does not meet the first condition, the target is determined to be a normal target (within the ranging range).

[0143] Optionally, the first condition includes: the accumulated signal has multiple peaks and multiple troughs.

[0144] If the accumulated signal contains multiple peaks and troughs, the target is an ambiguous target (i.e., the target is not within the ranging range), as shown in Figure 7B. Conversely, if the accumulated signal does not contain multiple peaks and troughs, the target is a normal target (i.e., the target is within the ranging range), as shown in Figure 7A.

[0145] In this context, a peak refers to the highest point of a signal. It can be understood that this highest point is relative to nearby signals. Multiple peaks can exist simultaneously in the accumulated signal, with the signal value at each of these locations significantly higher than the values ​​of nearby signals. The values ​​of different peaks can be the same or different. For example, Figure 7B illustrates three peaks.

[0146] In this context, a trough refers to the lowest point in a signal. It can be understood that this lowest point is relative to nearby signals. Multiple troughs can exist simultaneously in the accumulated signal, with the signal value at each of these locations significantly lower than the values ​​of nearby signals. The values ​​of different troughs can be the same or different. For example, Figure 7B illustrates two troughs.

[0147] It is understandable that, due to space limitations in the accompanying figures, Figures 7A and 7B only illustrate the superposition of three echo signals, and are not limited to this in practice.

[0148] Optionally, the first condition may also include: the interval between adjacent peaks in multiple peaks and / or the interval between adjacent peaks in multiple troughs, which are correlated (or matched) with the difference between adjacent time intervals in the transmission time interval sequence.

[0149] Specifically, if at least one of the intervals between adjacent peaks or between adjacent peaks in multiple troughs is correlated with the difference between adjacent time intervals in the transmission time interval sequence, then the target is an ambiguous target (i.e., the target is not within the ranging range). As shown in Figure 7B, the time interval between the first and second peaks is Δt1, Δt1 = (T + δ2) - (T + δ1) = δ2 - δ1, and the time interval between the second and third peaks is Δt2, Δt2 = (T + δ3) - (T + δ2) = δ3 - δ2. Of course, the above is only one possible example of how to determine correlation, and is not limited to this in practice.

[0150] This can further enhance the accuracy of identifying blurry targets.

[0151] Further optionally, the first condition may also include: the broadening of the accumulated signal is related to (or matched with) the difference between the maximum and minimum time intervals in the transmission time interval sequence.

[0152] For example, the broadening of the accumulated signal = (maximum time interval in the transmission time interval sequence - minimum time interval in the transmission time interval sequence) + the broadening of the laser pulse. Taking Figure 7B as an example, the transmission time intervals of adjacent laser pulses are T+δ1, T+δ2, T+δ3, and T+δ4, respectively, where δ1 < δ2 < δ3 < δ4. Therefore, the broadening of the accumulated signal Δt = δ4 - δ1 + L.

[0153] This can further enhance the accuracy of identifying blurry targets.

[0154] Further optionally, the first condition may also include: the difference in photon count values ​​corresponding to different peaks among the multiple peaks is within a first range.

[0155] It is understandable that if the difference in photon counts corresponding to different peaks is within the first range, it indicates that the signals corresponding to the multiple peaks are signals returned from the same target.

[0156] This can further enhance the accuracy of identifying blurry targets.

[0157] In another specific implementation, the difference between adjacent time intervals in the transmission time interval sequence is not zero and is greater than the width of the laser pulse. For example, referring to Figure 8A or Figure 8B, an example of a laser pulse sequence consisting of four laser pulses is shown, where the transmission time intervals of adjacent laser pulses are T+δ1, T+δ2, T+δ3, and tT+δ4, respectively. Then, the differences between adjacent time intervals in the transmission time interval sequence are (T+δ2)-(T+δ1)=δ2-δ1, (T+δ3)-(T+δ2)=δ3-δ2, and (T+δ4)-(T+δ3)=δ4-δ3, where δ2-δ1, δ3-δ2, and δ4-δ3 are all non-zero. If the width of the laser pulse is L, then δ2-δ1>L, δ3-δ2>L, and δ4-δ3>L.

[0158] In this case, it can be determined whether the accumulated signal (or the first time window) meets the second condition; if the accumulated signal meets the second condition, the target is determined to be an ambiguous target (not within the ranging range); or, if the accumulated signal does not meet the second condition, the target is determined to be a normal target (within the ranging range).

[0159] Optionally, the second condition includes: the existence of multiple signals in the accumulated signal (or the first time window).

[0160] If the accumulated signal contains multiple signals, that is, multiple signals that are discrete in time and not just a single continuous signal, then the target is an ambiguous target (i.e., the target is not within the ranging range), as shown in Figure 8B. Conversely, if the accumulated signal is a single signal, that is, the signal is continuous without segments, then the target is a normal target (i.e., the target is within the ranging range), as shown in Figure 8A.

[0161] Optionally, the second condition may also include: the time interval between adjacent signals in the accumulated signal (or the first time window) is correlated (or matched) with the difference between adjacent time intervals in the transmission time interval sequence.

[0162] Specifically, if the time interval between adjacent signals in the first time window is correlated with the difference between adjacent time intervals in the transmission time interval sequence, then the target is an ambiguous target (i.e., the target is not within the ranging range). As shown in Figure 8B, the time interval between the first and second signals is Δt1, Δt1 = (T + δ2) - (T + δ1) = δ2 - δ1, and the time interval between the second and third signals is Δt2, Δt2 = (T + δ3) - (T + δ2) = δ3 - δ2. Of course, the above is only one possible example of how to determine correlation, and is not limited to this in practice.

[0163] This can further enhance the accuracy of identifying blurry targets.

[0164] Optionally, the second condition may also include: the difference in photon count values ​​corresponding to the peaks of different signals in the accumulated signal (or the first time window) is within a second range.

[0165] It is understandable that the difference in photon count values ​​corresponding to the peaks of different signals within the second range indicates that the different signals in the accumulated signal are signals returned from the same target. The second range and the first range can be the same or different, without restriction.

[0166] This can further enhance the accuracy of identifying blurry targets.

[0167] The following describes a method for determining the distance to a target based on the judgment result:

[0168] Scenario 1: If the target is within the ranging range (i.e., the target is a normal target), the target distance is determined based on the accumulated signal. For example, the target distance is determined based on the time position of the accumulated signal within the first time window. This can be understood as the time difference between the time position of the accumulated signal and the start time of the first time window, which is equivalent to the time it takes for the laser pulse to travel from the laser radar to the target. The target distance is determined based on this time travel and the speed of light.

[0169] Case 2: If the target is not within the ranging range (i.e., the target is an ambiguous target), the distance to the target is determined based on the accumulated signal and the transmission time interval sequence.

[0170] For example, the time difference between the position of the first peak in the accumulated signal within the first time window and the start time of the first time window is determined, for example, as 'a'; and the receiving time window for receiving the echo signal corresponding to the first peak in the accumulated signal (i.e., the receiving time window where the first echo signal is located) is determined, and which receiving time windows (in the transmission time interval sequence or which transmission time intervals) the echo signal crosses are determined. For example, in Figure 7B, the first echo signal is received in the second receiving time window, so it crosses the first receiving time window (i.e., it crosses the first transmission time interval T+δ1). The return time of the laser pulse from the laser radar to the target is determined as a+T+δ1, and the distance to the target is determined based on this return time and the speed of light. Of course, this is only an example, and the actual method is not limited to this.

[0171] Alternatively, when the target is determined to be a blurry target, the echo signal corresponding to the blurry target can be directly filtered out to achieve the effect of filtering out blurry targets (or not recognizing blurry targets), for example, not outputting the measurement information of blurry targets (such as distance, speed, etc.).

[0172] Considering the relative movement between the lidar and the target (e.g., the vehicle carrying the lidar is in motion), the position of the echo signal within the receiving time window will change. For example, the position of the echo signal within the receiving time window may move to the critical position of the receiving time window (e.g., the start time of the receiving time window), or even move out of the receiving time window, causing the lidar to be unable to observe the target.

[0173] In view of this, this application embodiment also provides a launching method, as shown in FIG9, the method comprising:

[0174] S201, Send the first laser pulse sequence;

[0175] The transmission time intervals corresponding to the first laser pulse sequence constitute the first transmission time interval sequence. The difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse. It can be understood that when there are multiple adjacent time intervals in the first transmission time interval sequence, these multiple adjacent time intervals can be the same, different, or partially the same and partially different; there are no restrictions. For the concepts of laser pulse sequence, broadening, and time interval sequence, please refer to the relevant introduction in S101 above; they will not be repeated here. The entity executing the transmission of the first laser pulse sequence can refer to the relevant introduction to transmitting the laser pulse sequence in S101 above; it will not be elaborated upon here.

[0176] Optionally, the first laser pulse sequence is determined before emitting the first laser pulse sequence. The entity responsible for determining the first laser pulse sequence can be found in the relevant description of determining the laser pulse sequence in S101 above, and will not be elaborated upon here.

[0177] S202, Send the second laser pulse sequence.

[0178] The transmission time intervals corresponding to the second laser pulse sequence constitute the second transmission time interval sequence. The difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse. It can be understood that when there are multiple adjacent time intervals in the second transmission time interval sequence, these multiple adjacent time intervals can be the same, different, or partially the same and partially different; there are no restrictions. Similarly, the entity that performs the transmission of the second laser pulse sequence can refer to the relevant introduction to the transmission of the laser pulse sequence in S101 above, and will not be elaborated upon here.

[0179] Optionally, the second laser pulse sequence is determined before it is emitted. The entity responsible for determining the second laser pulse sequence can be found in the section above, S101, regarding the determination of the laser pulse sequence; this will not be elaborated upon here.

[0180] In the embodiments of the present application, the first transmission time interval sequence is different from the second time interval sequence. Among them, the first transmission time interval sequence is different from the second transmission time interval sequence, which may specifically include one or more of the following:

[0181] 1) The first transmission time interval sequence and the second transmission time interval sequence have no intersection;

[0182] For example, the first transmission time interval sequence is T+δ1, T+δ2, T+δ3, T+δ4, and the second transmission time interval sequence is T+δ1′, T+δ2′, T+δ3′, T+δ4′. {T+δ1, T+δ2, T+δ3, T+δ4} and {T+δ1′, T+δ2′, T+δ3′, T+δ4′} have no intersection.

[0183] 2) The difference between adjacent time intervals in the first transmission time interval sequence is different from the difference between adjacent time intervals in the second transmission time interval sequence.

[0184] For example, the first transmission time interval sequence is an arithmetic sequence, and the difference between adjacent time intervals is k1, that is, δ2 - δ1 = δ3 - δ2 = δ4 - δ3 = k1. The second transmission time interval sequence is an arithmetic sequence, and the difference between adjacent time intervals is k2, that is, δ2′ - δ1′ = δ3′ - δ2′ = δ4′ - δ3′ = k2, and k1 ≠ k2.

[0185] Optionally, the difference between the first transmission time interval sequence and the second transmission time interval sequence may further include:

[0186] 3) The maximum time interval in the first transmission time interval sequence is less than the minimum time interval in the second transmission time interval sequence; or, the maximum time interval in the second transmission time interval sequence is less than the minimum time interval in the first transmission time interval sequence.

[0187] For example, the first transmission time interval sequence is T+δ1, T+δ2, T+δ3, T+δ4, where T+δ1 < T+δ2 < T+δ3 < T+δ4, and the second transmission time interval sequence is T+δ1′, T+δ2′, T+δ3′, T+δ4′, where T+δ1′ < T+δ2′ < T+δ3′ < T+δ4′. Among them, T+δ4 < T+δ1′ or T+δ4′ < T+δ1.

[0188] Optionally, the value range of the time intervals in the first transmission time interval sequence is different from the value range of the time intervals in the second transmission time interval sequence. For example, the value range of the time intervals in the first transmission time interval sequence is (1ns, 10ns), and the value range of the time intervals in the second transmission time interval sequence is (20ns, 30ns).

[0189] It is understood that the above three examples are merely illustrations, and the actual situation is not limited to these.

[0190] In one possible design, before transmitting the second laser pulse sequence, multiple first echo signals can be received within multiple receiving time windows; wherein the multiple first echo signals are formed by the reflection of the first laser pulse sequence from the target. The second laser sequence can be determined based on the multiple first echo signals received within the multiple receiving time windows.

[0191] Specifically, the system determines whether the target is within the ranging range of the lidar based on multiple first echo signals received within multiple receiving time windows. If the target is within the ranging range, a laser pulse sequence is randomly selected from multiple laser pulse sequences as the second laser pulse sequence. Alternatively, if the target is not within the ranging range, the flight time (i.e., the return time between the lidar and the target) corresponding to the target is determined based on multiple first echo signals and the first transmission time interval sequence. The second laser pulse sequence is then determined from multiple laser pulse sequences based on the flight time.

[0192] The method for determining whether a target is within the ranging range of a lidar based on multiple first echo signals received within multiple receiving time windows can be found in the previous descriptions (e.g., the descriptions in the relevant embodiments of Figures 8A and 8B), and will not be repeated here.

[0193] Referring to Figure 10, which is a flowchart of a method for adjusting a laser pulse sequence according to an embodiment of this application, the method includes:

[0194] S301. Receive multiple echo signals (such as multiple first echo signals mentioned above) within multiple receiving time windows;

[0195] S302. Determine whether the target is within the ranging range of the lidar based on the multiple received echo signals;

[0196] If the target is within the range of the lidar, execute S303; if the target is not within the range of the lidar, execute S304 to S305.

[0197] S303, Randomly select a laser pulse sequence for transmission, then switch to S301 for the next round of laser pulse reception;

[0198] S304. Determine the flight time between the lidar and the target (or the distance to the target in the fuzzy sense) based on the received echo signal;

[0199] S305. Select one laser pulse sequence from multiple laser pulse sequences according to the flight time and send it, then proceed to S301 for the next round of laser pulse reception.

[0200] In one possible implementation, the second laser pulse sequence is determined from multiple laser pulse sequences based on the flight time. This includes determining the second laser pulse sequence from multiple laser pulse sequences based on the flight time and the maximum speed of the vehicle where the lidar is located. The maximum speed of the vehicle can refer to the upper limit of the vehicle's speed, which is related to the vehicle's factory configuration. For example, if the maximum speed specified by the manufacturer is 240 km / h, then the maximum speed is 120 km / h. It can also refer to the maximum possible speed of the vehicle in its current scenario. For example, if the vehicle is traveling on a highway with a speed limit of 120 km / h, then the maximum speed is 120 km / h. Furthermore, it can refer to the maximum speed analyzed based on the user's driving habits.

[0201] For example, after determining the flight time corresponding to the blurred target based on multiple first echo signals, the flight time is modulo the maximum time interval in the first transmission time interval sequence, i.e., (flight time modulo the maximum time interval in the first transmission time interval sequence). If the obtained remainder is less than or equal to a first threshold (indicating that the first echo signal is close to the 0 position (i.e., the start position) of the receiving time window, and if the first laser pulse sequence is used for detection, the target may not be identified), then a second time interval sequence is selected. The flight time is modulo the maximum time interval in the second time interval sequence, and the obtained remainder is greater than or equal to the second threshold (indicating that using the second laser pulse sequence for detection allows the second echo signal to be located in the middle or end of the receiving time window, enabling better target identification). The second threshold can be greater than or equal to the first threshold, and both the first and second thresholds are related to the vehicle's maximum speed.

[0202] If the echo signal only spans one receiving time window (i.e., the echo signal of each laser pulse falls within the receiving time window of one laser pulse), then the remainder of the maximum time interval in the first transmission time interval sequence can be used, or the difference of the maximum time interval in the first transmission time interval sequence can be used, i.e., (flight time - maximum time interval in the first transmission time interval sequence).

[0203] Here is a specific example:

[0204] Assume the range of the LiDAR's receiving time window is 0 to N (i.e., the start time of the receiving time window is 0, the end time of the receiving time window is N, and the length of the receiving time window is N), where N >> t car , t car The equivalent echo time (t) for the vehicle's position in each frame car(Related to the vehicle's maximum speed). Let the transmission time interval sequence corresponding to the first laser pulse sequence be Table 1 (hereinafter referred to as "Tlist1"), and the transmission time interval sequence corresponding to the second laser pulse sequence be Table 2 (hereinafter referred to as "Tlist2"). min(Tlist2) - max(Tlist1) = x, where min(Tlist2) represents the minimum time interval in Tlist2, and max(Tlist1) represents the maximum time interval in Tlist1. x is not 0, for example, x > 20*t. car .

[0205] Assuming the lidar first transmits a laser pulse sequence using Tlist2, and the measured time for the laser pulse to return between the lidar and the blurred target is t, then the nearest receiving position of the echo signal within the receiving time window is t-max(Tlist2). It can be understood that t-max(Tlist2) is a result calculated based on the echo signal crossing one receiving time window, and is not limited to this in practice.

[0206] When t-max(Tlist2)<2*t car If there is a risk that the next frame of echo signal will fall at position 0 of the receiving time window, the encoding of the emitted laser pulse sequence can be adjusted to Tlist1, so that the position of the next frame of echo signal falling in the receiving time window is tt. car -max(Tlist1)=tt car -max(Tlist1)+x>>2*t car This ensures that the echo signal can be effectively observed.

[0207] Similarly, when the receiving position of the echo signal using Tlist1 is close to the 0 position of the receiving time window, it can be adjusted to Tlist2 so that the next frame of echo signal does not fall within the receiving time window, and the lidar no longer observes the echo signal of the blurred target; or so that the next frame of echo signal falls within a good receiving and recognition range, such as falling at the end of the receiving time window (close to the N position), ensuring that the echo signal is effectively observed.

[0208] It is understandable that the above examples use two laser pulse sequences, but the actual implementation is not limited to these.

[0209] The above scheme allows the lidar to dynamically adjust its laser pulse sequence. When a blurred target is detected, the lidar can actively adjust the position of the echo signal of the blurred target within the receiving time window, so that the echo signal of the blurred target is in a good receiving and recognition range, thereby achieving the purpose of accurately identifying the blurred target. Alternatively, it can make the echo signal of the blurred target not be in the receiving and recognition range, thereby removing the echo signal of the blurred target and saving the lidar's computing resources.

[0210] Optionally, the method may further include: receiving multiple second echo signals within multiple reception time windows; wherein the multiple second echo signals are formed by the reflection of a second laser pulse sequence from the target; and determining the target distance based on the multiple second echo signals. The method for determining the target distance based on the multiple second echo signals can be found in the relevant content above (e.g., the embodiments in Figures 8A and 8B), and will not be elaborated further here.

[0211] It is understood that, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions of different embodiments are consistent and can be referenced by each other, and the technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0212] Based on the same technical concept, this application also provides a control method, including: determining a laser pulse sequence; controlling a transmitting module to transmit the laser pulse sequence, wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse.

[0213] For a detailed implementation of this method, please refer to the relevant content in the embodiment shown in Figure 4.

[0214] Based on the same technical concept, this application also provides a control method, including: controlling a transmitting module to transmit a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; controlling the transmitting module to transmit a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; wherein the first transmission time interval sequence and the second time interval sequence are different.

[0215] For a detailed implementation of this method, please refer to the relevant content in the embodiment shown in Figure 9.

[0216] Based on the same technical concept, referring to Figure 11, this application embodiment also provides a control device, including a control module 401, and optionally, a determination module 402.

[0217] When the control device is used to implement the method shown in Figure 4, the determining module 402 is used to: determine the laser pulse sequence; the control module 401 is used to: control the transmitting module to transmit the laser pulse sequence, wherein the transmission time interval of adjacent laser pulses in the laser pulse sequence constitutes a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse.

[0218] When the control device is used to implement the method shown in Figure 9, the control module 401 is used to: control the transmitting module to transmit a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; control the transmitting module to transmit a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; wherein the first transmission time interval sequence is different from the second time interval sequence.

[0219] Optionally, the determining module 402 is used to: determine the second laser pulse sequence based on the echo signal corresponding to the first laser pulse sequence.

[0220] It should be understood that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0221] Based on the same technical concept, embodiments of this application also provide a terminal, including at least one of the transmitting module, control device, receiving module, or processing module mentioned above. This terminal can be a vehicle, drone, helicopter, airplane, ship, intelligent transportation equipment, or smart home device, etc.

[0222] Based on the same technical concept, embodiments of this application also provide a computer-readable storage medium storing a computer program or instructions, which, when executed by a communication device, implements the method steps described above.

[0223] Based on the same technical concept, this application also provides a computer program product, which stores instructions that, when run on a computer, implement the method steps described above.

[0224] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0225] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0226] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0227] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0228] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of protection of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A launching method, characterized in that, include: Determine the laser pulse sequence; The laser pulse sequence is transmitted, wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse.

2. The method as described in claim 1, characterized in that, Also includes: Multiple echo signals are received within multiple receiving time windows; wherein, the multiple echo signals are formed by the laser pulse sequence after reflection from the target; The distance to the target is determined based on the multiple echo signals received within the multiple receiving time windows.

3. The method as described in claim 2, characterized in that, Determining the distance to the target based on the multiple echo signals received within the multiple receiving time windows includes: The target is determined to be within the ranging range of the lidar based on the receiving time interval of adjacent echo signals in the plurality of echo signals; and / or, the target is determined to be within the ranging range of the lidar based on whether the receiving time interval of adjacent echo signals in the plurality of echo signals matches the difference between adjacent time intervals in the transmission time interval sequence. The distance to the target is determined based on the judgment result.

4. The method as described in claim 2 or 3, characterized in that, Determining the distance to the target based on the multiple echo signals received within the multiple receiving time windows includes: The multiple echo signals received within the multiple receiving time windows are accumulated to obtain an accumulated signal; wherein, the accumulation process includes: aligning the echo signals within different receiving time windows according to the start time of the receiving time window and then superimposing them, and the superimposed signal is the accumulated signal; The cumulative signal is used to determine whether the target is within the ranging range of the lidar. The distance to the target is determined based on the judgment result.

5. The method as described in claim 4, characterized in that, Determining whether the target is within the ranging range of the lidar based on the accumulated signal includes: If the accumulated signal satisfies the first condition, then it is determined that the target is not within the ranging range; or, if the accumulated signal does not satisfy the first condition, then it is determined that the target is within the ranging range. The first condition includes: the accumulated signal has multiple peaks and multiple troughs; and / or, the interval between adjacent peaks in the multiple peaks and / or the interval between adjacent peaks in the multiple troughs are related to the difference between adjacent time intervals in the transmission time interval sequence.

6. The method as described in claim 5, characterized in that, The first condition also includes: The broadening of the accumulated signal is related to the difference between the maximum and minimum time intervals in the transmission time interval sequence.

7. The method as described in claim 5 or 6, characterized in that, The first condition also includes: The difference in photon count values ​​corresponding to different peaks among the multiple peaks is within a first range.

8. The method according to any one of claims 3-7, characterized in that, Determining the distance to the target based on the judgment result includes: If the target is not within the ranging range, the distance to the target is determined based on the accumulated signal and the transmission time interval sequence.

9. A launching method, characterized in that, include: A first laser pulse sequence is transmitted, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; A second laser pulse sequence is transmitted, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; The first transmission time interval sequence is different from the second time interval sequence.

10. The method as described in claim 9, characterized in that, The first transmission time interval sequence differs from the second transmission time interval sequence in that it includes one or more of the following: The first transmission time interval sequence and the second transmission time interval sequence have no overlap; The difference between adjacent time intervals in the first transmission time interval sequence is different from the difference between adjacent time intervals in the second transmission time interval sequence.

11. The method as described in claim 10, characterized in that, The maximum time interval in the first transmission time interval sequence is less than the minimum time interval in the second transmission time interval sequence; or, The maximum time interval in the second transmission time interval sequence is less than the minimum time interval in the first transmission time interval sequence.

12. The method according to any one of claims 9-11, characterized in that, Before sending the second laser pulse sequence, the following is also included: Multiple first echo signals are received within multiple receiving time windows; wherein, the multiple first echo signals are formed by the first laser pulse sequence after reflection from the target; The second laser pulse sequence is determined based on the multiple first echo signals received within the multiple receiving time windows.

13. The method as described in claim 12, characterized in that, Determining the second laser pulse sequence based on the plurality of first echo signals received within the plurality of receiving time windows includes: The target is determined to be within the ranging range of the lidar based on the receiving time interval of adjacent echo signals in the plurality of first echo signals; and / or, the target is determined to be within the ranging range of the lidar based on whether the receiving time interval of adjacent echo signals in the plurality of first echo signals matches the difference between adjacent time intervals in the first transmission time interval sequence. The second laser pulse sequence is determined based on the judgment result.

14. The method as described in claim 12 or 13, characterized in that, Determining the second laser pulse sequence based on the plurality of first echo signals received within the plurality of receiving time windows includes: The multiple first echo signals received within the multiple receiving time windows are accumulated to obtain an accumulated signal; wherein, the accumulation process includes: aligning the first echo signals within different receiving time windows according to the start time of the receiving time window and then superimposing them, and the superimposed signal is the accumulated signal; The cumulative signal is used to determine whether the target is within the ranging range of the lidar. The second laser pulse sequence is determined based on the judgment result.

15. The method as described in claim 14, characterized in that, Determining whether the target is within the ranging range of the lidar based on the accumulated signal includes: If the accumulated signal satisfies the second condition, then it is determined that the target is not within the ranging range; or, if the accumulated signal does not satisfy the second condition, then it is determined that the target is within the ranging range. The second condition includes: The second accumulated signal contains multiple signals; and / or, the time interval between adjacent signals in the second accumulated signal is correlated with the difference between adjacent time intervals in the first transmission time interval sequence.

16. The method as described in claim 15, characterized in that, The second condition also includes: the difference in photon count values ​​corresponding to the peaks of different signals in the second accumulated signal is within a second range.

17. The method according to any one of claims 13-16, characterized in that, The second laser pulse sequence is determined based on the judgment result, including: If the target is within the ranging range, then a laser pulse sequence is randomly selected from multiple laser pulse sequences as the second laser pulse sequence; or, If the target is not within the ranging range, the flight time corresponding to the target is determined based on the plurality of first echo signals and the first transmission time interval sequence; the second laser pulse sequence is determined from the plurality of laser pulse sequences based on the flight time.

18. The method as described in claim 17, characterized in that, Determining the second laser pulse sequence from multiple laser pulse sequences based on the time of flight includes: The second laser pulse sequence is determined from the plurality of laser pulse sequences based on the flight time and the maximum speed of the vehicle in which the lidar is located.

19. The method as described in claim 18, characterized in that, The remainder obtained by taking the flight time modulo the maximum time interval in the first launch time interval sequence is less than or equal to a first threshold. The remainder obtained by taking the flight time modulo the maximum time interval in the second time interval sequence is greater than or equal to the second threshold. Wherein, the second threshold is greater than or equal to the first threshold, and the first threshold and the second threshold are related to the maximum driving speed of the vehicle.

20. The method according to any one of claims 9-19, characterized in that, Also includes: Multiple second echo signals are received within multiple receiving time windows; wherein, the multiple second echo signals are formed by the second laser pulse sequence after reflection from the target; The distance to the target is determined based on the plurality of second echo signals.

21. A control method, characterized in that, include: Determine the laser pulse sequence; The control transmitter module transmits the laser pulse sequence, wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse.

22. A control method, characterized in that, include: The control transmitter module sends a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; The transmitting module is controlled to transmit a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; The first transmission time interval sequence is different from the second time interval sequence.

23. A lidar, characterized in that, Includes control devices and launch modules; The control device is used to: determine a laser pulse sequence; control the transmitting module to transmit the laser pulse sequence; wherein the transmission time intervals of adjacent laser pulses in the laser pulse sequence constitute a transmission time interval sequence, and the difference between adjacent time intervals in the transmission time interval sequence is not zero and is less than the broadening of the laser pulse.

24. The lidar as described in claim 23, characterized in that, It also includes a receiving module and a processing module; The receiving module is used to: receive multiple echo signals within multiple receiving time windows; wherein the multiple echo signals are formed by the laser pulse sequence after reflection from the target; The processing module is used to determine the distance to the target based on the multiple echo signals received within the multiple receiving time windows.

25. A lidar, characterized in that, Includes control devices and launch modules; The control module is used to: control the transmitting module to transmit a first laser pulse sequence, wherein the transmission time intervals corresponding to the first laser pulse sequence constitute a first transmission time interval sequence, and the difference between adjacent time intervals in the first transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; The control module is further configured to: control the transmitting module to transmit a second laser pulse sequence, wherein the transmission time intervals corresponding to the second laser pulse sequence constitute a second transmission time interval sequence, and the difference between adjacent time intervals in the second transmission time interval sequence is not zero and is greater than the broadening of the laser pulse; The first transmission time interval sequence is different from the second time interval sequence.

26. The lidar as described in claim 25, characterized in that, It also includes a receiving module and a processing module; The receiving module is configured to: receive multiple first echo signals within multiple receiving time windows before the transmitting module transmits the second laser pulse sequence; wherein the multiple first echo signals are formed by the first laser pulse sequence after reflection from the target; The processing module is used to determine the second laser pulse sequence based on the plurality of first echo signals received within the plurality of receiving time windows.

27. A terminal, characterized in that, It includes the lidar as described in claim 23 or 24, or the lidar as described in claim 25 or 26.

28. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions that, when executed by a communication device, implement the method as described in any one of claims 1-8, or the method as described in any one of claims 9-20, or the method as described in claim 21, or the method as described in claim 22.

29. A computer program product, characterized in that, The computer program product stores instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1-8, or the method as described in any one of claims 9-20, or the method as described in claim 21, or the method as described in claim 22.

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