CN118294977A

CN118294977A - Laser radar echo receiving method and device and laser radar

Info

Publication number: CN118294977A
Application number: CN202310008351.6A
Authority: CN
Inventors: 张树强; 夏冰冰; 石拓
Original assignee: Zvision Technologies Co Ltd
Current assignee: Zvision Technologies Co Ltd
Priority date: 2023-01-04
Filing date: 2023-01-04
Publication date: 2024-07-05

Abstract

The application discloses an echo receiving method and device of a laser radar and the laser radar, wherein the method comprises the following steps: acquiring a first echo signal of an ith scanning point in a laser radar view field range; determining the detection distance of the ith scanning point according to the first echo signal of the ith scanning point; according to the detection distance of the ith scanning point, determining a receiving channel corresponding to the (i+1) th scanning point; and receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point. In the application, the receiving channel corresponding to the (i+1) th scanning point is dynamically determined according to different detection distances of the (i) th scanning point, and compared with the receiving of the echo signal of the (i+1) th scanning point by adopting a fixed receiving channel, the matching degree of the (i) th scanning point and the receiving channel is improved, thereby increasing the number of effective scanning points in the point cloud, improving the laser radar scanning efficiency and improving the ranging performance of the laser radar.

Description

Laser radar echo receiving method and device and laser radar

Technical Field

The present application relates to the field of laser radar technologies, and in particular, to a method and an apparatus for receiving echoes from a laser radar, and a laser radar.

Background

The data form of a laser radar (light detection AND RANGING, light) is a point cloud. The point cloud data includes various characteristic information, for example: three-dimensional coordinate information, color information, reflected intensity information, and the like.

At present, with the wide application of the laser radar, higher and higher requirements are put forward on the measurement accuracy of the laser radar, and higher requirements are put forward on the reliability of point cloud data. For the non-coaxial laser radar, when the detection distance changes, the receiving channel of the echo signal changes, the signal energy of the echo signal becomes weak or even no, so that the echo cannot be detected, and the number of effective scanning points in the scanned point cloud becomes small, and the ranging performance of the laser radar is affected.

Disclosure of Invention

The application provides an echo receiving method and device of a laser radar and the laser radar, which are used for improving the scanning efficiency of the laser radar and improving the ranging performance of the laser radar.

In a first aspect, the present application provides an echo receiving method of a laser radar, including: acquiring a first echo signal of an ith scanning point in a laser radar view field range, wherein the value of i is a positive integer; determining the detection distance of the ith scanning point according to the first echo signal of the ith scanning point; according to the detection distance of the ith scanning point, determining a receiving channel corresponding to the (i+1) th scanning point, wherein the receiving channels corresponding to the detection distances of different value ranges are different; and receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point.

In some possible embodiments, determining the receiving channel corresponding to the (i+1) th scanning point according to the detection distance of the (i) th scanning point includes: determining a first value range of the detection distance of the ith scanning point; determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel; and determining the receiving channel corresponding to the first value range as the receiving channel corresponding to the (i+1) th scanning point.

In some possible embodiments, the variation of the receive channel slows with increasing detection distance.

In some possible embodiments, receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point includes: determining whether the (i+1) th scanning point is an effective scanning point in the point cloud of the previous frame; determining a first gain mode of the (i+1) th scanning point when the third echo signal in the previous frame point cloud is received; and determining a second gain mode for receiving a second echo signal of the (i+1) th scanning point according to the first gain mode and whether the (i+1) th scanning point is an effective scanning point in the previous frame point cloud.

In some possible embodiments, determining the second gain mode for receiving the second echo signal for the (i+1) th scan point comprises: determining the (i+1) th scanning point as an invalid scanning point in the point cloud of the previous frame; a second gain mode is determined based on the first gain mode.

In some possible embodiments, determining the (i+1) th scan point as an invalid scan point in the previous frame scan includes: acquiring a third echo signal of the (i+1) th scanning point in the previous frame point cloud; and when the signal energy of the third echo signal is smaller than the first threshold value, determining that the (i+1) th scanning point is an invalid scanning point in the previous frame point cloud.

In some possible embodiments, determining the second gain mode for receiving the second echo signal for the (i+1) th scan point comprises: determining the (i+1) th scanning point as an effective scanning point in the point cloud of the previous frame;

Determining whether the third echo signal is saturated; and determining a second gain mode according to the first gain mode and whether the third echo signal is saturated.

In a second aspect, the application provides an echo receiving device of a laser radar, which comprises a first acquisition module, a second acquisition module and a third acquisition module, wherein the first acquisition module is used for acquiring a first echo signal of an ith scanning point in a laser radar view field range, and the value of i is a positive integer; the first determining module is used for determining the detection distance of the ith scanning point according to the first echo signal of the ith scanning point; the second determining module is used for determining a receiving channel corresponding to the (i+1) th scanning point according to the detection distance of the (i) th scanning point, wherein the receiving channels corresponding to the detection distances of different value ranges are different; and the receiving module is used for receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point.

In some possible embodiments, the second determining module is further configured to determine a first value range in which the detection distance of the ith scanning point is located; determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel; and determining the receiving channel corresponding to the first value range as the receiving channel corresponding to the (i+1) th scanning point.

In some possible implementations, the receiving module is further configured to determine whether the (i+1) th scanning point is a valid scanning point in the previous frame point cloud; determining a first gain mode of the (i+1) th scanning point when the third echo signal in the previous frame point cloud is received; and determining a second gain mode for receiving a second echo signal of the (i+1) th scanning point according to whether the (i+1) th scanning point is a valid scanning point in the previous frame point cloud and the first gain mode.

In some possible implementations, the receiving module is further configured to determine that the (i+1) th scanning point is an invalid scanning point in the previous frame point cloud; a second gain mode is determined based on the first gain mode.

In some possible embodiments, the receiving module is further configured to obtain, in a previous frame point cloud, a third echo signal of the (i+1) th scanning point; and when the signal energy of the third echo signal is smaller than the first threshold value, determining that the (i+1) th scanning point is an invalid scanning point in the previous frame point cloud.

In some possible implementations, the receiving module is further configured to determine that the (i+1) th scanning point is a valid scanning point in the previous frame point cloud; determining whether the third echo signal is saturated; and determining a second gain mode according to the first gain mode and whether the third echo signal is saturated.

In a third aspect, the present application provides a lidar comprising: a memory storing computer executable instructions; a processor, coupled to the memory, for executing computer-executable instructions to perform a method as in the first aspect and any possible implementation thereof.

In a fourth aspect, the present application provides a computer storage medium having stored thereon computer executable instructions which, when executed by a processor, are capable of carrying out the method of the first aspect and any of its possible embodiments.

Compared with the prior art, the technical scheme provided by the application has the beneficial effects that:

According to the method, different receiving channels corresponding to the (i+1) th scanning point are determined according to different detection distances of the (i) th scanning point, and echo signals of the (i+1) th scanning point are received through the determined receiving channels corresponding to the (i+1) th scanning point. In this way, the receiving channel corresponding to the (i+1) th scanning point is dynamically determined according to different detection distances of the (i) th scanning point, and compared with the receiving of the echo signal of the (i+1) th scanning point by adopting a fixed receiving channel, the matching degree of the (i) th scanning point and the receiving channel is improved, so that the number of effective scanning points in the point cloud is increased, the laser radar scanning efficiency is improved, and the ranging performance of the laser radar is improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

FIG. 1 shows a schematic composition of a lidar system according to an embodiment of the application;

FIG. 2a shows an example of laser light emission point distribution when a laser radar system performs a field of view scan according to an embodiment of the present application;

FIG. 2b shows an example of a received field of view of a lidar system according to an embodiment of the application;

Fig. 2c shows a structural example of an optical receiver of a lidar system according to an embodiment of the application;

FIG. 2d shows an example of a laser light emission point and received field of view correspondence for a lidar system according to an embodiment of the application;

FIG. 3a shows a schematic optical path of a laser beam of a laser radar receiving an echo signal in an embodiment according to the application;

FIG. 3b shows another schematic optical path of a laser beam of a laser radar receiving an echo signal in an embodiment according to the application;

fig. 4 shows a flowchart of an echo receiving method of a lidar according to an embodiment of the present application;

FIG. 5 shows a schematic diagram of a lidar scanning target object in an embodiment in accordance with the application;

FIG. 6 is a diagram illustrating a relationship between a probe distance and a receiving channel in accordance with an embodiment of the present application;

fig. 7 shows a flowchart of an echo receiving method of a lidar according to an embodiment of the present application;

Fig. 8 is a schematic diagram showing a structure of an echo receiving device of a laser radar in an embodiment according to the present application;

FIG. 9 shows a schematic composition of a vehicle incorporating a lidar system according to an embodiment of the application;

Fig. 10 shows a block diagram of a configuration of an electronic device according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. The following detailed description is made with reference to the accompanying drawings and is provided to aid in a comprehensive understanding of various example embodiments of the application. The following description includes various details to aid in understanding, but these are to be considered merely exemplary and not intended to limit the application, which is defined by the appended claims and their equivalents. The words and phrases used in the following description are only intended to provide a clear and consistent understanding of the application. In addition, descriptions of well-known structures, functions and configurations may be omitted for clarity and conciseness. Those of ordinary skill in the art will recognize that various changes and modifications of the examples described herein can be made without departing from the scope of the application.

Fig. 1 illustrates an exemplary lidar system 100 to which the techniques of the present application may be applied. Lidar system 100 may include a light source 102, a scanner 104, a light receiver 106, and a controller 108. The light source 102 emits an emission beam for scanning the target object 120. The light source 102 may be a laser, for example, a solid state laser such as an Edge Emitting Laser (EEL) or a Vertical Cavity Surface Emitting Laser (VCSEL) or an external cavity semiconductor laser (ECDL), a laser diode, a fiber laser. The light source 102 may also include an LED. The light source 102 may emit light beams of different forms, including pulsed light (TOF), continuous light (CW), and quasi-continuous light. The operating wavelength of the light source may be 650nm to 1150nm, 800nm to 1000nm, 850nm to 950nm, or 1300nm to 1600nm. In one or more embodiments, the light source 102 may further include an optical assembly optically coupled to the light source 102 for collimating or focusing the light beam emitted by the light source 102. In one or more embodiments, the light source 102 includes at least one fiber laser. Each emitted light beam emitted by the light source 102 may be continuous light for a certain time or may be one or more light pulses.

The scanner 104 is configured to deflect the direction of the emitted light beam from the light source 102 to scan the target object 120 for a wider emitted or scanned field of view. The scanner 104 may have any number of optical mirrors driven by any number of drivers. For example, the scanner 104 may include a planar mirror, a prism, a mechanical galvanometer, a polarization grating, an Optical Phased Array (OPA), a microelectromechanical system (MEMS) galvanometer. For MEMS galvanometers, the mirror surface is rotated or translated in one or two dimensions under electrostatic/piezoelectric/electromagnetic actuation. Under drive of the driver, the scanner 104 directs the light beam from the light source to various locations within the field of view to effect scanning of the target object 120 within the field of view.

After reflecting off target object 120, a portion of the reflected light returns to lidar system 100 and is received by light receiver 106. The light receiver 106 receives and detects a portion of the reflected light from the target object 120 and generates a corresponding electrical signal. The optical receiver may include a receiving unit and associated receiving circuitry. Each receiving circuit may be adapted to process the output electrical signal of the corresponding receiving unit. The receiving unit comprises various forms of photodetectors or one-dimensional or two-dimensional arrays of photodetectors, and accordingly the receiving circuit may be a circuit or an array of circuits. The photodetector measures the power, phase or time characteristics of the reflected light and produces a corresponding current output. The photodetector may be an avalanche diode (APD), single Photon Avalanche Diode (SPAD), PN photodiode, or PIN photodiode.

The controller 108 is communicatively coupled to one or more of the light source 102, the scanner 104, and the light receiver 106. The controller 108 may control whether and when the light source 102 emits a light beam. The controller 108 may control the scanner 104 to scan the light beam to a specific location. The controller 108 may process and analyze the electrical signals output by the optical receiver to ultimately determine the position, velocity, etc. characteristics of the target object 120. The controller 108 may include an Integrated Circuit (IC), an Application Specific Integrated Circuit (ASIC), a microchip, a microcontroller, a central processing unit (cpu), a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or other suitable circuitry for executing instructions or performing logic operations. The instructions executed by the controller 108 may be preloaded into an integrated or separate memory (not shown). The memory may store configuration data or commands for the light source 102, the scanner 104, or the light receiver 106. The memory may also store the electrical signal output from the optical receiver 106 or an analysis result based on the output electrical signal. For example, the memory may store information regarding stray light signals detected during the calibration period for use in subsequent operation periods. The memory may include Random Access Memory (RAM), read Only Memory (ROM), hard disk, optical disk, magnetic disk, flash memory or other volatile or non-volatile memory, and the like. The controller 108 may include a single or multiple processing circuits. In the case of multiple processing circuits, the processing circuits may have the same or different configurations and may interact or cooperate with each other electrically, magnetically, optically, acoustically, mechanically, etc.

In one or more embodiments, lidar system 100 may also include a transmit lens 110. The emission lens 110 may be used to expand the light beam emitted by the light source 102 and diverted by the scanner 104. The emission lens 110 may include a Diffractive Optical Element (DOE) for shaping, separating, or diffusing the light beam. The emission lens 110 may be present alone or may be integrated into other components (e.g., the scanner 104 or the light source 102). The position of the emission lens 110 in the emission light path from the light source to the target object is not limited to that shown in fig. 1, but may be changed to other positions. For example, an emission lens may be disposed between the light source 102 and the scanner 104 such that the light beam emitted by the light source 102 is first expanded by the emission lens and then diverted by the scanner.

In one or more embodiments, lidar system 100 may also include a receive lens 112. The receive lens 112 is positioned in front of the optical receiver 106 on the receive path of the emitted light from the target object 120 to the optical receiver 106. The receiving lens 112 may include an imaging system lens such that the focal point of the reflected beam is either in front of or behind the detection surface of the photodetector or photodetector array or is located directly above the detection surface. In some cases, instead of being present as a separate component, the receiving lens 112 may also be integrated into the optical receiver 106.

In one or more embodiments, lidar system 100 may also include a housing 114 for enclosing one or more of the foregoing components therein for protection. In some embodiments, the housing 114 is an opaque material, and a transparent area or window 116 may be provided in the housing 114 to allow the emitted or reflected light beam to pass through. In other embodiments, the housing 114 itself is a transparent material, thereby allowing the emitted or reflected light beam to pass through any location.

In some embodiments, lidar system 100 may include a coaxial optical transceiver system. The in-line optical transceiver system means that the transmit path from the light source 102 to the target object 120 at least partially overlaps with the receive path from the target object 120 to the light receiver 106. For example, unlike that shown in FIG. 1, the reflected beam may reach the optical receiver 106 via the scanner 104 in a reverse direction. For the coaxial optical transceiver system, not only the outgoing angle of the emitted light beam changes with the deflection of the scanner, but also the receiving angle of the light which can be received by the light receiver synchronously changes with the deflection of the scanner, that is, the receiving field of view always keeps equal to the scanning range of the emitted light beam.

In other embodiments, lidar system 100 may include a non-coaxial optical transceiver system. A non-coaxial optical transceiver system refers to a system in which the transmit path from the optical source 102 to the target object 120 does not overlap with the receive path from the target object 120 to the optical receiver 106. For example, as shown in FIG. 1, the reflected light beam does not reach the light receiver 106 via the scanner 104. For a non-coaxial optical transceiver system, although the exit angle of the emitted light beam varies with the deflection of the scanner, the total received field of view of the light receiver is fixed and does not vary with the deflection of the scanner.

The lidar system may control the scanner to direct the emitted beam in a predetermined scanning pattern. Typically, the scanner spatially presents a closed scan pattern as it scans, and periodically repeats the scan. Common scan patterns include line and column raster, lissajous patterns, spiral patterns, and the like. Fig. 2a shows an example of a cloud of laser points when the lidar system is scanned in a line and column raster scan pattern. Each pixel point 204 in the point cloud represents a position in the emission field of view (or scan field of view) at which the scanner directs the emission beam. The aggregate set of all pixels 204 forms the field of view 202 of the lidar system. The emission field of view 202 may have a variety of different shapes depending on the predetermined scan pattern, and is not limited to the rectangular shape shown in fig. 2 a. Each pixel 204 may be associated with one or more emitted light beams or one or more measurements.

Fig. 2b shows an example of a receive field of view distribution of a lidar system comprising a non-coaxial optical transceiver system. In this example, the optical receiver of the lidar system is made up of a plurality of receiving sub-modules, each of which includes one or more receiving units and their respective receiving circuits. Each receiving sub-module is capable of receiving reflected light over a relatively small range. For example, each rectangle 208 in FIG. 2b represents the range of reflected light that a respective one of the receiving sub-modules of the lidar system is capable of receiving, also referred to as the receiving field of view of the respective receiving sub-module. The aggregate of the receive fields of view of all the receive sub-modules constitutes the total receive field of view 206 of the optical receiver.

Fig. 2c shows a schematic composition of an optical receiver in order to provide the receiving field of view lidar system of fig. 2 b. The optical receiver includes one or more receiving units 210 and corresponding one or more receiving circuits 214. The receiving units 210 are connected to respective receiving circuits 214 through electrical connections 212. For example, the receive field of view 208 in fig. 2b corresponds to the receive sub-module of the receive unit 216 and corresponding receive circuitry 218 in fig. 2 c.

Fig. 2d shows an example of the correspondence between lasing and receiving fields of view of the lidar system with the scanning laser point cloud of fig. 2a and the receiving field of view of fig. 2b in normal operation. During normal operation, with the deflection of the scanner, the emitted light beam is directed to different positions in the emitted view field, and the controller instructs the receiving sub-module corresponding to the position in the receiving view field in the light receiver to be started so as to receive the reflected light beam, so that measurement is completed. For example, pixel 218 may correspond to pixel 204 in FIG. 2a and receive field of view 220 may correspond to receive field of view 208 in FIG. 2 b. When the lidar system generates a transmitted beam directed at the pixel 218, the receiving sub-module corresponding to the receiving field of view 220 needs to be turned on, i.e. the receiving sub-module comprising the receiving unit 216 and the receiving circuit 218 in fig. 2c may be turned on. The receiving sub-modules of the optical receiver other than the receiving sub-module corresponding to the receiving field of view 220 may be turned off or dormant.

It should be appreciated that the transmit field of view, receive field of view, and corresponding receive sub-module distribution shown in fig. 2 a-2 d are merely illustrative. The lidar system according to the application may have different scan patterns, transmit fields of view, receive field of view distributions, shapes, numbers and distributions of the receive sub-modules, and correspondence of transmit fields of view and receive fields of view.

In order to illustrate the technical scheme of the application, the following description is made by specific examples.

Lidar is an object detection technique. The laser radar emits laser beams through the laser, the laser beams are diffusely reflected after encountering a target object, the reflected beams are received through the detector, and the characteristic quantities such as the distance, the azimuth, the height, the speed, the gesture and the shape of the target object are determined according to the emitted beams and the reflected beams.

The application field of laser radar is very wide. In addition to its use in the military field, it is now widely used in the life field, including but not limited to: intelligent piloting vehicles, intelligent piloting airplanes, three-dimensional (3D) printing, virtual reality, augmented reality, service robots, and the like. Taking intelligent driving technology as an example, a laser radar is arranged in an intelligent driving vehicle, and the laser radar can scan the surrounding environment by rapidly and repeatedly emitting laser beams so as to obtain a point cloud reflecting the morphology, the position, the movement and the like of one or more target objects in the surrounding environment.

The intelligent driving technique may refer to unmanned, automatic, auxiliary, and the like.

In practical applications, when the distance between the target objects changes in the non-coaxial lidar scheme, the receiving channel of the receiver receiving the light source may change. The non-coaxial laser radar can adopt micro-electro-MECHANICAL SYSTEM (MEMS) scanning and prism scanning, and the problem that a receiving channel changes along with the distance change of a target object can be solved no matter what scanning mode is adopted as long as the non-coaxial laser radar adopts a non-coaxial scheme. Fig. 3a is a schematic diagram of an optical path of a laser beam of a laser radar receiving an echo signal according to an embodiment of the present application, and fig. 3b is another schematic diagram of an optical path of a laser beam of a laser radar receiving an echo signal according to an embodiment of the present application. The emission angles of the emitters in fig. 3a and fig. 3b are the same, the distances between the first target object and the second target object are different from each other, and the reflection angles of the laser beams with the same emission angles after being reflected by the scanning points with different detection distances deviate, and the laser beams reach different receiving channels through the lenses of the receiver. Therefore, if the same receiving channel is used to receive the echo signal, when the detection distance changes, the energy of the signal received by the receiver may be weakened or not, so that the receiver may not detect the echo, and further the number of effective scanning points in the formed point cloud becomes smaller, which affects the ranging performance of the laser radar.

In order to solve the above problems, an embodiment of the present application provides an echo receiving method of a lidar. The method can be applied to a laser radar with a non-coaxial scheme, such as a MEMS scanning laser radar.

Fig. 4 is a flowchart of a method for receiving an echo of a lidar according to an embodiment of the present application. Referring to fig. 4, the method includes steps S401 to S404.

S401, acquiring a first echo signal of an ith scanning point in the laser radar field range.

Wherein, the value of i is a positive integer.

It will be appreciated that the lidar may obtain point cloud data for describing the relevant characteristics of the target object by scanning the target object, that is, the point cloud data formed by a plurality of laser beams emitted by the lidar irradiating different positions (scanning points) of the target object and being reflected by the target object and being received by a receiver of the lidar. The ith scanning point is the position of the ith laser beam emitted by the laser radar when scanning the target object on the target object. Typically, the laser beam emitted by the lidar system will be reflected by the object to form a unique echo signal, where the first echo signal refers to the unique echo signal. In addition, since the laser beam emitted by the lidar system may be reflected by the earth's surface and/or objects on the earth's surface, such as vegetation, buildings, bridges, and the like. The emitted one laser beam may be returned to the lidar sensor in the form of one or more echo signals. Any emitted laser beam, when propagating towards the ground, may be split into as many echo signals as there are reflecting surfaces if it encounters multiple reflecting surfaces. But since the first returned echo signal is typically the most important echo signal, it is typically associated with the highest element of the earth's surface, such as the roof of a tree or building. Thus, the first echo signal described herein may also be the first echo signal received by the laser radar after it has transmitted the laser beam to the i-th scanning spot.

S402, determining the detection distance of the ith scanning point according to the first echo signal of the ith scanning point.

It will be appreciated that the detection distance of the ith scan point is the distance of the lidar from the ith scan point. The laser radar can emit a laser beam which is reflected back after being hit by an obstacle on the light path and received by the laser receiver, and the time of receiving the laser beam after being emitted and reflected back, that is, the flight time of the laser beam, can be obtained, and the distance between the laser radar and the obstacle can be calculated according to the flight time.

The i-th scanning point is an obstacle on the optical path of the laser beam, after the laser beam emitted by the laser radar is reflected by the scanning point, the laser radar receives the reflected echo signal through the receiver, at this time, the time taken from the emission of the laser beam to the reception of the echo signal by the laser radar can be calculated, and the detection distance of the i-th scanning point can be determined because the speed of the laser beam in the air is constant. Or the detection distance of the ith scanning point can also be determined by a phase ranging method, and the specific implementation mode of the phase ranging method is as follows: the laser transmitter performs intensity modulation of the continuous laser beam signal and the laser beam is reflected back after being irradiated by the obstacle. The measuring beam will produce a phase change in the round trip. The conversion is performed by calculating the phase difference between the laser signal in the lidar and the object flown back and forth by the obstacle, and the distance of the obstacle.

S403, according to the detection distance of the ith scanning point, determining a receiving channel corresponding to the (i+1) th scanning point.

Wherein, the corresponding receiving channels of the detection distances in different value ranges are different.

It will be appreciated that the (i+1) th scanning point is the scanning point closest to the (i) th scanning point, and that since the laser radar performs scanning on the target object by periodically emitting laser beams, for example, the MEMS scanning laser radar described above, in which the vibrating mirror continuously resonates and vibrates, the emitter continuously periodically emits laser beams, a certain number of consecutive scanning points form a point cloud, and adjacent scanning points have continuity in space.

Referring to fig. 5, fig. 5 is a schematic diagram of a laser radar scanning a target object according to an embodiment of the present application, where the laser radar performs resonant vibration to periodically emit laser light, and adjacent scanning points d1 and d2 may be regarded as scanning points closest to each other. The detection distances of the adjacent scanning points are usually close, and the larger deviation of the angle of the reflected echo is not caused by the change of the detection distances, so that the application can determine the receiving channel of the (i+1) th scanning point based on the detection distance of the (i) th scanning point.

It can be understood that, when the detection distance of the scan point changes, the reflection angle of the echo reflected by the scan point does not actually have a significant deviation within a certain range, or even if the deviation occurs, the reflection angle is still within the receiving range of the same receiving channel, and at this time, the receiving channel capable of receiving the echo signal does not change, based on this, the step S403 may include:

S4031, determining a first value range of the detection distance of the ith scanning point;

S4032, determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel;

S4033, determining the receiving channel corresponding to the first value range as the receiving channel corresponding to the (i+1) th scanning point.

In some embodiments, the mapping relationship between the value range of the detection distance and the receiving channel may be pre-stored in the laser radar, and after the laser radar obtains the detection distance of the ith scanning point according to the first echo signal, the receiving channel corresponding to the scanning point under the detection distance is directly determined based on the mapping relationship according to the value range of the detection distance.

For example, referring to the schematic diagram of the laser radar scanning target object shown in fig. 5, the scanning point d1 is the closest scanning point of the scanning point d2, each scanning point may correspond to the first receiving channel and the second receiving channel, when the detection distance of the scanning point is greater than or equal to the preset threshold, the echo signal of the corresponding scanning point is received through the first receiving channel, and when the detection distance of the scanning point is less than the preset threshold, the echo signal of the corresponding scanning point is received through the first receiving channel. In the embodiment of the present application, the scan point d2 is adjacent to the scan point d1, so that the detection distances of the scan point d2 and the scan point d1 are generally closer, and at this time, if the detection distance of the scan point d1 is smaller than the preset threshold, the detection distance of the scan point d2 is also more likely to be smaller than the preset threshold, and similarly, if the detection distance of the scan point d1 is greater than or equal to the preset threshold, the detection distance of the scan point d2 is also more likely to be greater than or equal to the preset threshold. Therefore, in the embodiment of the application, the receiving channel of the scanning point d2 can be determined directly based on the mapping relation between the receiving channel and the value range preset in the laser radar according to the value range of the detection distance d1, the receiving channel of the next scanning point is predicted according to the distance between the last scanning point and the receiving channel, and the proper receiving channel is selected according to the difference of the detection distances, so that the adaptation degree of the determined receiving channel is higher, the number of effective scanning points in the point cloud of the laser radar is increased, and the ranging performance of the laser radar is improved.

In some embodiments, a plurality of receiving channel tables may be preconfigured in the lidar, where the receiving channel tables are calibrated in advance according to the energy of the echo signals received by different receiving channels of the receiver when the lidar emits the laser beams with the same emission angle under different detection distances.

For a laser radar, each scanning point in a point cloud of the laser radar corresponds to each receiving channel table one by one, and each receiving channel table is correspondingly associated with one value range of the detection distance. In practical application, the laser radar determines a receiving channel table corresponding to the (i+1) th point according to the value range of the detection distance of the (i) th scanning point, and determines a receiving channel corresponding to the (i+1) th scanning point by inquiring the receiving channel table.

In some embodiments, the variation of the receive channel slows with increasing detection distance. Referring to fig. 6, fig. 6 is a schematic diagram of a relationship between a detection distance and a receiving channel according to an embodiment of the present application, wherein an abscissa in fig. 6 represents different receiving channels, including X, X +1, x+2, x+3, and x+4, respectively, and an ordinate represents the detection distance.

It can be understood that, as the detection distance increases, the reflection angle of the laser beam at the corresponding scanning point changes, so that the receiving channels corresponding to the scanning points change, as shown in fig. 6, the receiving channels corresponding to the scanning points change sequentially from X, X +1, x+2, x+3, and x+4, but for the same scanning point, the farther the detection distance is, the slower the corresponding reflection angle changes, for example, the echo signal will be infinitely gradually biased toward the emission direction of the laser beam as the detection distance increases, but will not overlap, so that, after the detection distance exceeds a certain threshold, the change of the receiving channel corresponding to the scanning point will gradually slow down when the detection distance is continuously increased. As shown in fig. 6, before the detection distance reaches a preset threshold (dist_ BDRY shown in fig. 6), the reception channel corresponding to the scanning point is changed to X, X +1, x+2, x+3 accordingly, and when the detection distance reaches the preset threshold, no change occurs after the reception channel corresponding to the scanning point is changed to x+4.

The preset threshold value may be, for example, 0.1m to 20m.

S404, receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point.

In the embodiment of the application, the receiving channel corresponding to the (i+1) th scanning point is dynamically determined according to different detection distances of the (i) th scanning point, and compared with the receiving channel which is used for receiving the echo signal of the (i+1) th scanning point, the matching degree of the (i+1) th scanning point and the receiving channel is improved, so that the number of effective scanning points in the point cloud is increased, the laser radar scanning efficiency is improved, and the ranging performance of the laser radar is improved.

In some embodiments, gain adjustment may also be increased in the lidar system, further increasing the number of effective scan points in the point cloud. Based on this, the above method may further include: determining whether the (i+1) th scanning point is an effective scanning point in the point cloud of the previous frame; determining a first gain mode of the (i+1) th scanning point when the third echo signal in the previous frame point cloud is received; and determining a second gain mode for receiving a second echo signal of the (i+1) th scanning point according to the first gain mode and whether the (i+1) th scanning point is an effective scanning point in the previous frame point cloud.

It can be understood that the point cloud of the previous frame is the point cloud obtained when the laser radar scans the target object last time. For example, the target object may be an object in a moving state or a stationary state, and since the laser radar periodically emits a laser beam to scan the target object, the laser radar can obtain a frame of point cloud image for describing the target object after emitting the laser beam. And the laser radar emits scanning points again in the next scanning period, namely the i+1th scanning point is the same as or very close to the i+1th scanning point in the point cloud of the previous frame. When the target object is in a static state relative to the laser radar, the i+1th scanning point is the same as the i+1th scanning point in the previous frame point cloud, and if the target object is shifted relative to the laser radar, the i+1th scanning point and the i+1th scanning point in the previous frame point cloud have different detection distances.

In some embodiments, determining the second gain pattern for receiving the second echo signal for the (i+1) th scan point may include: determining the (i+1) th scanning point as an invalid scanning point in the point cloud of the previous frame; a second gain mode is determined based on the first gain mode.

For example, the first gain mode and the second gain mode may include a low gain mode or a high gain mode, and the second gain mode may be the same as the first gain mode, e.g., the second gain mode and the first gain mode are both a low gain mode or a high gain mode. Or the second gain mode may be fixed to a high gain mode in order to increase the probability that the (i+1) th scanning point is a valid scanning point. The low gain mode may be a mode in which the lidar is operated in a state meeting the normal operating power requirement, or may be a mode in which the lidar is operated in a default operating power, or the like. The high gain mode may be any mode of increasing the energy of the echo signal, for example, in a stage of transmitting the laser beam by the laser radar, by increasing the transmitting power of the laser beam, etc. Or a signal amplifying module is arranged on the laser radar device at the stage of receiving the echo signals, when the (i+1) th scanning point is determined to be an invalid scanning point in the previous frame point cloud, the signal amplifying module is used for amplifying the second echo signals before the second echo signals are received through the receiving channels corresponding to the (i+1) th scanning point, and the amplified second echo signals are received. Alternatively, the high gain mode may be a higher gain than the i+1th scanning point in the previous frame point cloud, for example, the amplification factor of the echo signal at the i+1th scanning point in the previous frame point cloud is 2 when amplifying, and in this case, the amplification factor may be adjusted to be 4 when receiving the echo signal at the i+1th scanning point, or any other amplification factor with a larger value. Or the high gain mode may be any other mode capable of improving the receiving of the second echo signal, and the comparison of the embodiment of the present application is not limited in particular.

In some embodiments, the method for determining that the (i+1) th scan point is an invalid scan point in the previous frame scan may include: acquiring a third echo signal of the (i+1) th scanning point in the previous frame point cloud; and when the signal energy of the third echo signal is smaller than the first threshold value, determining that the (i+1) th scanning point is an invalid scanning point in the previous frame point cloud.

It should be noted that, the size of the first threshold may be a preset fixed threshold, or may also be an empirical value, or may also be actually calculated according to a specific parameter of the lidar device.

In other embodiments, the determining the second gain mode for receiving the second echo signal of the (i+1) th scanning point may further include: determining the (i+1) th scanning point as an effective scanning point in the point cloud of the previous frame; determining whether the third echo signal is saturated; and determining a second gain mode according to the first gain mode and whether the third echo signal is saturated.

It is understood that when the signal energy of the third echo signal is greater than or equal to the first threshold, the (i+1) th scanning point may be determined to be a valid scanning point in the previous frame point cloud. At this time, it is necessary to determine the second gain mode for receiving the second echo signal of the i+1th scanning point together from the signal saturation state of the i+1th scanning point when the corresponding third echo signal is received in the previous frame point cloud and the first gain mode when the echo signal is received.

For example, the i+1th scanning point is in the low gain mode when the third echo signal in the previous frame point cloud is received, and then the second gain mode may also be the low gain mode, where the second echo signal of the current i+1th scanning point is received in the low gain mode. If the i+1th scanning point is in the high gain mode when receiving the third echo signal in the previous frame point cloud, determining whether the third echo signal is saturated, if the third echo signal is saturated, the second gain mode may be the low gain mode, and in this case, in the low gain mode, receiving the second echo signal through the receiving channel corresponding to the i+1th scanning point; if the third echo signal is not saturated, the second gain mode may be a high gain mode, where in the high gain mode, the second echo signal is received through the receiving channel corresponding to the i+1th scanning point.

In some embodiments, fig. 7 is a flowchart of a method for receiving an echo of a lidar according to an embodiment of the present application. As shown in fig. 7, the echo receiving method of the lidar may include the steps of:

s701, acquiring a first echo signal of an ith scanning point;

S702, determining the detection distance of the ith scanning point according to the first echo signal;

s703, determining a first value range of the detection distance of the ith scanning point;

S704, determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel;

S705, determining whether the (i+1) th scanning point is an invalid scanning point in the point cloud of the previous frame; if yes, go to step S708, otherwise, go to step S706;

s706, determining whether the first gain mode of the (i+1) th scanning point at the time of receiving the third echo signal in the previous frame point cloud is low gain; if yes, go to step S709, otherwise, go to step S707

S707, determining whether the third echo signal is saturated; if yes, go to step S709, otherwise, go to step S708;

S708, in the high gain mode, receiving a second echo signal through a receiving channel corresponding to the (i+1) th scanning point;

s709, in the low gain mode, the second echo signal is received through the receiving channel corresponding to the (i+1) th scanning point.

In the embodiment of the application, according to different detection distances of the ith scanning point, different receiving channels corresponding to the (i+1) th scanning point are determined, and echo signals of the (i+1) th scanning point are received through the determined receiving channels corresponding to the (i+1) th scanning point. In this way, the receiving channel corresponding to the (i+1) th scanning point is dynamically determined according to different detection distances of the (i) th scanning point, compared with the receiving channel which is used for receiving the echo signals of the (i+1) th scanning point, the matching degree of the (i) th scanning point and the receiving channel is improved, meanwhile, the number of effective scanning points in the point cloud of the laser radar is improved based on different gain mode selections, the laser radar scanning efficiency is improved, and the ranging performance of the laser radar is improved.

Based on the same inventive concept, the embodiments of the present application provide an echo receiving device of a laser radar, which may be a chip or a system on a chip in a laser radar device, and may also be a functional module in the laser radar device for implementing the method of each embodiment described above. The device can realize the echo receiving function of the laser radar in the above embodiments, and the functions can be realized by hardware executing corresponding software. Such hardware or software includes one or more modules corresponding to the functions described above. Fig. 8 is a schematic structural diagram of an echo receiving device of a lidar according to an embodiment of the present application, and referring to fig. 8, the echo receiving device 800 may include: a first obtaining module 801, configured to obtain a first echo signal of an ith scanning point in a laser radar field of view, where the value of i is a positive integer; a first determining module 802, configured to determine a detection distance of the ith scanning point according to the first echo signal of the ith scanning point; a second determining module 803, configured to determine a receiving channel corresponding to the (i+1) th scanning point according to the detection distance of the (i) th scanning point, where the receiving channels corresponding to the detection distances in different value ranges are different; the receiving module 804 is configured to receive the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point.

In some possible embodiments, the second determining module 803 is further configured to determine a first value range in which the detection distance of the i-th scanning point is located; determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel; and determining the receiving channel corresponding to the first value range as the receiving channel corresponding to the (i+1) th scanning point.

In some possible implementations, the receiving module 804 is further configured to determine that the (i+1) th scanning point is an invalid scanning point in the previous frame point cloud; in the high gain mode, the second echo signal is received through the receiving channel corresponding to the (i+1) th scanning point.

In some possible embodiments, the receiving module 804 is further configured to obtain, in a previous frame point cloud, a third echo signal of the (i+1) th scanning point; and when the signal energy of the third echo signal is smaller than the first threshold value, determining that the (i+1) th scanning point is an invalid scanning point in the previous frame point cloud.

In some possible implementations, the receiving module 804 is further configured to determine that the (i+1) th scanning point is a valid scanning point in the previous frame point cloud; in the low gain mode, the second echo signal is received through the receiving channel corresponding to the (i+1) th scanning point.

In some possible implementations, the receiving module 804 is further configured to obtain a number of valid scanning points in the point cloud of the previous frame; when the number of effective scanning points is smaller than a second threshold value, in a high gain mode, receiving a second echo signal through a receiving channel corresponding to the (i+1) th scanning point; and when the number of the effective scanning points is greater than or equal to a second threshold value, in the low gain mode, receiving a second echo signal through a receiving channel corresponding to the (i+1) th scanning point.

It should be noted that, the specific implementation processes of the data first obtaining module 801, the first determining module 802, the second determining module 803, and the receiving module 804 may refer to the detailed descriptions of the embodiments of fig. 4 to 7, and are not repeated herein for brevity of the description.

The first obtaining module 801, the first determining module 802, the second determining module 803, and the receiving module 804 mentioned in the embodiment of the present application may be one or more processors.

Based on the same inventive concept, an embodiment of the present application provides a laser radar including: a memory storing computer executable instructions; and the processor is connected with the memory and is used for executing the computer-executable instructions and realizing the echo receiving method of the laser radar according to one or more embodiments.

Fig. 9 shows a schematic composition of a vehicle 900 incorporating a lidar system as described above according to an embodiment of the application. Vehicle 900 may include at least a lidar system 902, a vehicle controller 904, and a motorized system 906. Lidar system 902 may be implemented using lidar system 100 in fig. 1. Accordingly, the light source 912, scanner 914, light receiver 916, and controller 918 correspond to the light source 102, scanner 104, light receiver 106, and controller 108, respectively, of the lidar system 100. Except that the vehicle controller 904 may be communicatively coupled to the light source 912, the scanner 914, and the light receiver 916 by a controller 918. In other embodiments, the vehicle controller 904 may also be communicatively coupled directly to the light source 912, the scanner 914, and the light receiver 916. In some embodiments, lidar system 902 may not include controller 918. Techniques for calibrating a lidar system according to embodiments of the present application may be implemented independently by vehicle controller 904 or cooperatively by vehicle controller 904 and controller 918 in part. The motorized system 906 may include a power subsystem, a braking subsystem, a steering subsystem, and the like. Vehicle controller 904 may adjust maneuvering system 906 based on the detection results of lidar system 902.

Fig. 10 shows a block diagram of a configuration of an electronic device 1000 according to an embodiment of the application. The electronic device 1000 may be any type of general-purpose or special-purpose computing device, such as a desktop computer, laptop computer, server, mainframe computer, cloud-based computer, tablet computer, wearable device, vehicle electronics, and the like. As shown in fig. 10, the electronic device 1000 includes an Input/Output (I/O) interface 1001, a network interface 1002, a memory 1004, and a processor 1003.

I/O interface 1001 is a collection of components that can receive input from a user and/or provide output to a user. The I/O interface 1001 may include, but is not limited to, buttons, a keyboard, a keypad, an LCD display, an LED display, or other similar display devices, including display devices having touch screen capabilities enabling interaction between a user and an electronic device.

The communication interface 1002 may include various adapters and circuitry implemented in software and/or hardware to enable communication with a lidar system using a wired or wireless protocol. The wired protocol is, for example, any one or more of a serial port protocol, a parallel port protocol, an ethernet protocol, a USB protocol, or other wired communication protocol. The wireless protocol is, for example, any IEEE 802.11Wi-Fi protocol, cellular network communication protocol, or the like.

Memory 1004 includes a single memory or one or more memories or storage locations including, but not limited to, random Access Memory (RAM), dynamic Random Access Memory (DRAM), static Random Access Memory (SRAM), read Only Memory (ROM), EPROM, EEPROM, flash memory, logic blocks of an FPGA, a hard disk, or any other layer of a memory hierarchy. The memory 1004 may be used to store any type of instructions, software, or algorithms, including instructions 1005 for controlling the general functions and operations of the electronic device 1000.

The processor 1003 controls the general operation of the electronic device 1000. The processor 1003 may include, but is not limited to, a CPU, a hardware microprocessor, a hardware processor, a multi-core processor, a single-core processor, a microcontroller, an Application Specific Integrated Circuit (ASIC), a DSP, or other similar processing device capable of executing any type of instructions, algorithms, or software for controlling the operation and functions of the electronic device 1000 in accordance with embodiments described herein. The processor 1003 may be a variety of implementations of digital circuitry, analog circuitry, or mixed-signal (a combination of analog and digital) circuitry that performs functions in a computing system. The processor 1003 may include, for example, a portion or circuit such as an Integrated Circuit (IC), an individual processor core, an entire processor core, an individual processor, a programmable hardware device such as a Field Programmable Gate Array (FPGA), and/or a system including multiple processors.

Internal bus 1006 may be used to establish communications among the components of electronic device 1000.

The electronic device 1000 is communicatively coupled to a lidar system to be calibrated to control operation of the lidar system. For example, the calibration method according to the application may be stored on the memory 1004 of the electronic device 1000 in the form of computer readable instructions. The processor 1003 implements the calibration method by reading stored computer readable instructions.

Although the electronic device 1000 is described using particular components, in alternative embodiments, different components may be present in the electronic device 1000. For example, electronic device 1000 may include one or more additional processors, memory, network interfaces, and/or I/O interfaces. In addition, one or more of the components may not be present in the electronic device 1000. Additionally, although separate components are shown in fig. 10, in some embodiments, some or all of a given component may be integrated into one or more of the other components in electronic device 1000.

The present application may be implemented as any combination of an apparatus, a system, an integrated circuit, and a computer program or program product on a non-transitory computer readable medium.

It should be appreciated that computer-executable instructions in a computer-readable storage medium or program product according to embodiments of the present application may be configured to perform operations corresponding to the above-described apparatus and method embodiments. Embodiments of a computer readable storage medium or program product will be apparent to those skilled in the art when referring to the above-described apparatus and method embodiments, and thus the description will not be repeated. Computer readable storage media and program products for carrying or comprising the above-described computer-executable instructions are also within the scope of the present application. Such a storage medium may include, but is not limited to, floppy disks, optical disks, magneto-optical disks, memory cards, memory sticks, and the like.

In addition, it should be understood that the series of processes and devices described above may also be implemented in software and/or firmware. In the case of implementation by software and/or firmware, a corresponding program constituting the corresponding software is stored in a storage medium of the relevant device, and when the program is executed, various functions can be performed.

For example, a plurality of functions included in one unit in the above embodiments may be implemented by separate devices. Alternatively, the functions realized by the plurality of units in the above embodiments may be realized by separate devices, respectively. In addition, one of the above functions may be implemented by a plurality of units. Such a configuration is included in the technical scope of the present application.

In the present application, the steps described in the flowcharts include not only processes performed in time series in the order described, but also processes performed in parallel or individually, not necessarily in time series. Further, even in the steps of time-series processing, the order may be appropriately changed.

The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The term "or" in this disclosure means an inclusive "or" rather than an exclusive "or". References to a "first" component do not necessarily require the provision of a "second" component. Furthermore, unless explicitly indicated otherwise, reference to "a first" or "a second" component does not mean that the referenced component is limited to a particular order. The term "based on" means "based at least in part on.

Claims

1. An echo receiving method of a laser radar, comprising:

Acquiring a first echo signal of an ith scanning point in a laser radar view field range, wherein the value of i is a positive integer;

Determining the detection distance of the ith scanning point according to the first echo signal of the ith scanning point;

According to the detection distance of the ith scanning point, determining a receiving channel corresponding to the (i+1) th scanning point, wherein the receiving channels corresponding to the detection distances of different value ranges are different;

and receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point.

2. The method according to claim 1, wherein the determining the receiving channel corresponding to the (i+1) th scanning point according to the detection distance of the (i) th scanning point includes:

Determining a first value range of the detection distance of the ith scanning point;

Determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel;

And determining the receiving channel corresponding to the first value range as the receiving channel corresponding to the (i+1) th scanning point.

3. The method of claim 2, wherein the variation of the receive channel slows as the detection distance increases.

4. The method according to claim 1, wherein the receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point includes:

determining whether the (i+1) th scanning point is an effective scanning point in the previous frame point cloud;

Determining a first gain mode of the (i+1) th scanning point when a third echo signal in the previous frame point cloud is received;

And determining a second gain mode for receiving a second echo signal of the (i+1) th scanning point according to the first gain mode and whether the (i+1) th scanning point is an effective scanning point in the previous frame point cloud.

5. The method of claim 4, wherein said determining a second gain pattern for receiving a second echo signal for the (i+1) th scan point comprises:

determining the (i+1) th scanning point as an invalid scanning point in the previous frame point cloud;

And determining the second gain mode according to the first gain mode.

6. The method of claim 5, wherein the determining that the (i+1) th scan point is an invalid scan point in a previous frame scan comprises:

acquiring a third echo signal of the (i+1) th scanning point in the previous frame point cloud;

and when the signal energy of the third echo signal is smaller than a first threshold value, determining that the (i+1) th scanning point is an invalid scanning point in the point cloud of the previous frame.

7. The method of claim 4, wherein said determining a second gain pattern for receiving a second echo signal for the (i+1) th scan point comprises:

determining the (i+1) th scanning point as an effective scanning point in the previous frame point cloud;

determining whether the third echo signal is saturated;

And determining the second gain mode according to whether the first gain mode and the third echo signal are saturated or not.

8. An echo receiving device of a laser radar, comprising:

The first acquisition module is used for acquiring a first echo signal of an ith scanning point in the laser radar view field range, and the value of i is a positive integer;

The first determining module is used for determining the detection distance of the ith scanning point according to the first echo signal of the ith scanning point;

The second determining module is used for determining a receiving channel corresponding to the (i+1) th scanning point according to the detection distance of the (i) th scanning point, wherein the receiving channels corresponding to the detection distances of different value ranges are different;

and the receiving module is used for receiving the second echo signal of the (i+1) th scanning point through the receiving channel corresponding to the (i+1) th scanning point.

9. The apparatus of claim 8, wherein the second determining module is further configured to determine a first range of values for a detection distance of the ith scan point; determining a receiving channel corresponding to the first value range according to the mapping relation between the value range of the detection distance and the receiving channel; and determining the receiving channel corresponding to the first value range as the receiving channel corresponding to the (i+1) th scanning point.

10. The apparatus of claim 8, wherein the receiving module is further configured to determine whether the i+1st scan point is a valid scan point in a previous frame point cloud; determining a first gain mode of the (i+1) th scanning point when a third echo signal in the previous frame point cloud is received; and determining a second gain mode for receiving a second echo signal of the (i+1) th scanning point according to whether the (i+1) th scanning point is an effective scanning point in the previous frame point cloud and the first gain mode.

11. The apparatus of claim 10, wherein the receiving module is further configured to determine the i+1st scan point as an invalid scan point in a previous frame point cloud; and determining the second gain mode according to the first gain mode.

12. The apparatus of claim 11, wherein the receiving module is further configured to obtain a third echo signal of the i+1th scanning point in the previous frame point cloud; and when the signal energy of the third echo signal is smaller than a first threshold value, determining that the (i+1) th scanning point is an invalid scanning point in the point cloud of the previous frame.

13. The apparatus of claim 10, wherein the receiving module is further configured to determine the i+1st scan point as a valid scan point in a previous frame point cloud; determining whether the third echo signal is saturated; and determining the second gain mode according to whether the first gain mode and the third echo signal are saturated or not.

14. A lidar, comprising:

A memory storing computer executable instructions;

A processor, coupled to the memory, for implementing the method of any of claims 1 to 7 by executing the computer-executable instructions.

15. A computer storage medium having stored thereon computer executable instructions which, when executed by a processor, are capable of carrying out the method of any one of claims 1 to 7.