CN117572439A - Laser radar control method, laser radar and method for controlling laser radar - Google Patents

Laser radar control method, laser radar and method for controlling laser radar Download PDF

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Publication number
CN117572439A
CN117572439A CN202210943782.7A CN202210943782A CN117572439A CN 117572439 A CN117572439 A CN 117572439A CN 202210943782 A CN202210943782 A CN 202210943782A CN 117572439 A CN117572439 A CN 117572439A
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China
Prior art keywords
intensity
detection
laser
echo
control method
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Chinese (zh)
Inventor
赵文雅
向少卿
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Hesai Technology Co Ltd
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Hesai Technology Co Ltd
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Priority to CN202210943782.7A priority Critical patent/CN117572439A/en
Priority to PCT/CN2023/077351 priority patent/WO2024031954A1/en
Publication of CN117572439A publication Critical patent/CN117572439A/en
Pending legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements
    • G01S7/4814—Constructional features, e.g. arrangements of optical elements of transmitters alone
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Electromagnetism (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

The invention provides a laser radar control method, a laser radar and a method for controlling the laser radar, wherein the laser radar is provided with an adjustable light source, and the laser radar control method comprises the following steps: s101: controlling the adjustable light source to emit detection laser at a first intensity; s102: receiving an echo of the detection laser; s103: judging whether the intensity of the echo is larger than a threshold value or not; s104: when the intensity of the echo is greater than the threshold value, calculating the spatial position of the obstacle according to the echo; when the intensity of the echo does not exceed the threshold value, the tunable light source is controlled to emit the detection laser light at an increased intensity, and steps S102 to S103 are repeated. According to the embodiment of the invention, the light source of the laser radar is controlled to emit detection laser with different intensities, the intensity of the detection laser is increased according to the echo intensity, stronger echo is prevented from being generated at the position of the high-reflection plate, other detection channels of the laser radar are influenced, and the laser radar is ensured to accurately acquire the information of the surrounding environment.

Description

Laser radar control method, laser radar and method for controlling laser radar
Technical Field
The invention relates to the technical field of laser radars, in particular to a laser radar control method and a laser radar.
Background
The laser radar transmits detection laser and receives echoes of the detection laser by utilizing a corresponding detector so as to acquire the spatial position of the obstacle and realize detection of the surrounding environment. In practical applications, the surrounding environment of the lidar is complex, when the lidar works, if there is a high reflection plate in the field of view, i.e. an object with very high reflectivity, for example, a polished metal surface, such as a guideboard on a highway, because the energy reflected by the high reflection plate is strong, the echoes of the detection laser directly or indirectly incident on the high reflection plate will affect the detectors of other detection channels, thereby causing ghosts or noise points, reflected in the point cloud data, appearing as if there is an object further at the position where there is no object, resulting in misjudgment and decision of the device for acquiring the surrounding environment information by means of the lidar, and therefore improvement on the lidar and the control method is needed.
The matters in the background section are only those known to the inventors and do not, of course, represent prior art in the field.
Disclosure of Invention
In view of one or more of the drawbacks of the prior art, the present invention provides a laser radar control method, the laser radar having an adjustable light source, the laser radar control method comprising:
S101: controlling the adjustable light source to emit detection laser at a first intensity;
s102: receiving an echo of the detection laser;
s103: judging whether the intensity of the echo is larger than a threshold value or not; and
s104: calculating the spatial position of an obstacle according to the echo when the intensity of the echo is greater than the threshold value; and when the intensity of the echo does not exceed the threshold value, controlling the adjustable light source to emit detection laser with increased intensity, and repeating the steps S102-S104.
According to one aspect of the invention, the tunable light source has a plurality of intensity levels, and the echoes in step 103 have corresponding thresholds when the tunable light source emits the detection laser light at different intensity levels.
According to one aspect of the invention, the first intensity corresponds to a lowest intensity gear of the plurality of intensity gears;
the step of controlling the tunable light source to emit the detection laser light at an increased intensity includes: and controlling the adjustable light source to emit detection laser at an intensity gear which is one level higher than the current intensity gear.
According to an aspect of the present invention, the lidar control method further includes: when the adjustable light source emits detection laser with the maximum intensity gear, if the intensity of the echo is lower than the threshold value corresponding to the maximum intensity gear, ending one detection period of the adjustable light source.
According to one aspect of the invention, the threshold values corresponding to the different intensity shift positions are the same, or the threshold values corresponding to the different intensity shift positions decrease with the increase of the intensity shift positions.
According to one aspect of the invention, the lidar comprises a plurality of adjustable light sources, the plurality of adjustable light sources being divided into one or more groups, each group of adjustable light sources being controlled to emit light synchronously; the laser radar control method comprises the following steps: the steps S101-S104 are performed for each of a set of tunable light sources, completing one detection period of the set of tunable light sources.
According to an aspect of the present invention, the lidar control method further includes: when multiple sets of tunable light sources are included, one detection cycle of each set of tunable light sources is completed sequentially.
According to one aspect of the invention, each group of tunable light sources is distributed in a one-dimensional or two-dimensional array.
According to one aspect of the invention, each group of the adjustable light sources is controlled to emit light synchronously;
the laser radar control method comprises the following steps: in the step S101: controlling each group of adjustable light sources to respectively emit detection lasers with the same intensity gear; in the step S104: for a tunable light source whose echo intensity does not exceed a threshold value, it is controlled to emit the detection laser light with the same increased intensity level.
According to one aspect of the invention, the lidar comprises a plurality of adjustable light sources, and the steps S101-S104 are performed for each adjustable light source in turn until the next adjustable light source is switched after one detection period is completed for the adjustable light source.
According to one aspect of the present invention, the step S104 includes: and ending one detection period of the adjustable light source when the intensity of the echo is greater than the threshold value.
According to one aspect of the invention, the laser radar has a single tunable light source, a light homogenizing device and an optical switch array, wherein detection laser light emitted by the single tunable light source is uniformly irradiated onto the optical switch array after passing through the light homogenizing device; the laser radar control method further comprises the following steps:
and opening the corresponding optical switch according to a preset time sequence.
According to one aspect of the invention, the optical switches in the optical switch array are divided into one or more groups, and each group of optical switches is controlled to be synchronously turned on or off; the laser radar control method comprises the following steps: each optical switch in the same group of optical switches is turned on, the steps S101-S104 are performed, and one detection cycle of the group of optical switches is completed.
According to an aspect of the present invention, the lidar control method further includes: when the optical switch array includes a plurality of sets of optical switches, one detection cycle of each set of optical switches is completed sequentially.
According to one aspect of the present invention, the lidar control method includes: and starting one of the optical switches, wherein the rest optical switches are in a closed state, and executing the steps S101-S104 aiming at the started optical switches, and switching to the next optical switch after completing one detection period of the started optical switches until completing one detection period of all the optical switches.
According to one aspect of the invention, each group of optical switches is distributed in a one-dimensional or two-dimensional array.
The present invention also provides a laser radar including:
an emission unit including an adjustable light source configured to emit a detection laser light with an adjustable intensity;
a detection unit including a detector configured to be able to receive an echo of the detection laser on an obstacle; and
a control system in communication with the tunable light source and the detector and configured to perform a lidar control method as described above.
The invention also provides a method for controlling a lidar comprising one or more detection channels formed by a laser and a detector, wherein the luminescence intensity of the laser is adjustable, wherein the method comprises: for one detection period of one detection channel,
S301: controlling the laser of the detection channel to emit detection laser light at a first intensity;
s302: receiving an echo generated by the detection laser through a detector of the detection channel; and
s303: and controlling the laser of the detection channel to increase the luminous intensity or ending one detection period of the detection channel according to the output of the detector.
According to one aspect of the present invention, the step S303 includes: ending a detection period of the detection channel when the intensity of the echo is greater than a threshold value, and calculating the spatial position of the obstacle according to the output; when the intensity of the echo does not exceed the threshold value, the laser is controlled to emit detection laser light at an increased luminous intensity, and the steps S302 to S303 are repeated.
According to one aspect of the present invention, the light emission intensity of the laser has a plurality of intensity steps, and when the laser emits the detection laser light in different intensity steps, the echo in step S303 has a corresponding threshold value.
According to one aspect of the invention, the first intensity corresponds to a lowest intensity gear of the plurality of intensity gears;
the step of controlling the laser to emit the detection laser light at an increased luminous intensity includes: and controlling the laser to emit detection laser at an intensity gear which is one level higher than the current intensity gear.
According to one aspect of the invention, the method further comprises: when the laser emits detection laser light in the maximum intensity gear, if the intensity of echo is lower than the threshold value corresponding to the maximum intensity gear, one detection period of the detection channel is ended.
Compared with the prior art, the embodiment of the invention provides a laser radar control method, which is used for controlling a light source of a laser radar to emit detection laser with different intensities, detecting echo intensity, determining whether to increase the intensity of the detection laser according to the comparison between the echo intensity and a threshold value, avoiding generating stronger echo at the position of a high-reflection plate, affecting other detection channels of the laser radar, and ensuring that the laser radar can comprehensively and accurately acquire information of surrounding environment. The invention also comprises an embodiment of the laser radar and a method for controlling the laser radar, wherein in one detection period of one detection channel, the laser is controlled to emit detection laser light with different intensities, and according to the output of the detector of the detection channel, the luminous intensity of the laser is increased or the detection period of the detection channel is ended, so that the high-intensity detection laser is prevented from generating stronger echo at the position of a high-reflection plate, other detection channels of the laser radar are influenced, and the detection accuracy of the laser radar is improved.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:
FIG. 1 is a flow chart of a lidar control method in an embodiment of the invention;
FIG. 2 is a flow chart of a laser radar control method for detecting laser light with maximum intensity range emission including an adjustable light source according to an embodiment of the present invention;
FIG. 3 is a flow diagram of a method for controlling a lidar in an embodiment of the invention;
FIGS. 4A-4F are schematic diagrams of a plurality of tunable optical distances according to various embodiments of the present invention;
FIG. 5 is a block diagram of a lidar in an embodiment of the invention;
FIG. 6 is an image schematic of regions of different reflectivity in an environment.
Detailed Description
Hereinafter, only certain exemplary embodiments are briefly described. As will be recognized by those of skill in the pertinent art, the described embodiments may be modified in various different ways without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be fixedly connected, detachably connected, or integrally connected, and may be mechanically connected, electrically connected, or may communicate with each other, for example; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is less level than the second feature.
The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings, it being understood that the preferred embodiments described herein are for illustration and explanation of the present invention only, and are not intended to limit the present invention.
Fig. 1 shows a specific flow of a lidar control method 100 according to an embodiment of the invention, which is described in detail below in connection with fig. 1.
In this embodiment, the laser radar has an adjustable light source, such as a laser, for example, and the output power of the laser can be changed by changing the intensity of the driving current passing through the laser, so that the laser emits detection laser light with different intensities. Specifically, according to different embodiments of the present invention, the adjustable light source may emit detection laser light with different intensities at a certain preset gear, or may generate detection laser light with intensity capable of continuously changing within a certain intensity range.
As shown in fig. 1, in step S101, the tunable light source is controlled to emit a detection laser light at a first intensity. The first intensity may be a preset intensity gear of the adjustable light source, or may be selected arbitrarily within an intensity range of the adjustable light source, where in this embodiment, the first intensity is only required to be not the maximum intensity that the adjustable light source can output. Preferably, the tunable light source has a plurality of output intensity levels, for example, N levels, and intensities of the detection lasers corresponding to the plurality of output intensity levels are L1 and L2 … … LN, respectively, where LN is an intensity of the detection laser output by the tunable light source in the maximum intensity level, as shown in table one, for example. The first intensity may select any output intensity level other than the output intensity level to which the LN corresponds, and according to a preferred embodiment of the present invention, the first intensity corresponds to the output intensity level at which the adjustable light source is smallest.
In embodiments of the invention, the power of the tunable light source or laser is used interchangeably with the intensity of the detection laser. The power of the tunable light source or laser determines the intensity of the emitted detection laser light. The intensity of the emitted detection laser light can be increased or decreased by increasing or decreasing the power of the tunable light source or laser.
Further, according to a preferred embodiment of the present invention, the tunable light source has three output intensity levels, and the intensities of the corresponding detection lasers are L1, L2 and L3, respectively, where L3 has the strongest intensity, L2 is an intermediate level, and the intensity is, for example, 1/10 of the strongest intensity, and L1 has the weakest intensity, for example, 1/100 of the strongest intensity.
In step S102, an echo of the detection laser light is received. The detection laser emitted at the first intensity is incident into the radar external environment and reflected by the object, and part of the reflected light (echo) returns to the laser radar, is received by a detector of the laser radar, and is converted into an electric signal.
In step S103, it is determined whether the intensity of the echo is greater than a threshold. After the laser radar obtains the retrieval, corresponding signal conversion and processing are carried out, and whether the received echo intensity is larger than a threshold value can be judged according to whether the electric signal converted by the echo is larger than a preset electric signal threshold value. In the invention, whether the electric signal is larger than the threshold value of the electric signal or not is equivalent to whether the intensity of the echo is larger than the threshold value or not, and the electric signal and the echo can be interchanged. According to an embodiment of the invention, when the tunable light source emits the detection laser light with different intensity levels, the echoes have corresponding thresholds, respectively, in step 103. As shown in table one, the detected laser intensities corresponding to the output intensity levels of the adjustable light source are L1 and L2 … … LN, respectively, and the thresholds corresponding to the different output intensity levels are T1 and T2 … … TN, respectively, as shown in table one, for example. The threshold values corresponding to different output intensity gears may be the same or different, and according to a preferred embodiment of the present invention, the threshold value corresponding to the output intensity gear decreases as the intensity of the output detection laser increases, for example, the threshold value T1 corresponding to the 1-level output intensity gear is greater than the threshold value T2 corresponding to the 2-level output intensity gear. This is because the high reflection plate has extremely strong reflection capability for the detection laser, and even if the high reflection plate is irradiated with a lower intensity, the intensity of the reflected echo may still exceed the peak value of the normal energy echo, so in the preferred embodiment of the present invention, the threshold value corresponding to the output intensity shift is reduced as the intensity of the detection laser increases. According to another embodiment of the invention, the lowest output intensity gear has the highest threshold value and the other output intensity gears than the lowest output intensity gear have the same threshold value, i.e. in table one, T1 has the maximum value and T2 … … TN has the same value. This is only an example, and a person skilled in the art can set this according to the actual situation of the lidar, which is within the scope of the present invention.
In step S103, a threshold corresponding to the output intensity level is determined, and then the intensity of the actually obtained echo is compared with the threshold, for example, the first intensity is the level 2 output intensity level in table one, and in step S103, it is determined whether the intensity of the echo is greater than T2. The intensity value corresponding to the output intensity gear and the corresponding threshold value shown in the table one can be written into firmware or software of the laser radar in advance, and can be inquired or called in the working process of the laser radar.
Table one: output intensity gear and threshold value mapping
In step S104, different processing methods are adopted according to the determination result in step S103. Specifically, when the intensity of the echo is greater than the corresponding threshold, in step S104-1, the spatial position of the obstacle is calculated from the echo, and one point in the point cloud is generated. After the laser radar obtains the reflected echo, if the intensity of the echo is higher than a threshold value, the echo is indicated to be effective echo and not ambient light noise, so that the distance between the obstacle and the laser radar can be obtained through calculation by detecting the information of the echo of the laser, including parameters such as echo receiving time, phase and the like, and the space position of the obstacle can be obtained by combining with detecting the emitting angle of the laser. When the intensity of the echo is not greater than the threshold value, the tunable light source is controlled to emit the detection laser light at an increased intensity in step S104-2, and steps S102-S104 are repeatedly performed. For example, the tunable light source has a plurality of output intensity levels, wherein the first intensity corresponds to the lowest output intensity level of the plurality of output intensity levels, and when the intensity of the echo corresponding to the first intensity is not greater than the threshold corresponding to the first intensity, the tunable light source is controlled to emit the detection laser at the output intensity level higher than the first intensity level in step S104-2, and if the corresponding echo is still not greater than the corresponding threshold, the tunable light source is controlled to continue to emit the detection laser at the output intensity level higher than the current output intensity level.
The lidar control method 100 shown in fig. 1 may be applied to control of multiple lasers of a lidar. Lidar typically includes a plurality of lasers and a plurality of detectors that form a plurality of detection channels, each detection channel typically including at least one laser and at least one detector. For the laser of each detection channel, the intensity of the emitted detection laser may be gradually increased in order of the output intensity from small to large until the echo received by the detector of the detection channel is higher than the threshold corresponding to the output intensity, which indicates that the detection channel detects an obstacle, so that the detection period of the detection channel (or the laser) may be completed. The plurality of detection channels may detect in a sequential manner, i.e. after one detection channel completes a detection cycle, the detection of the next detection channel is performed. Or alternatively, multiple detection channels may be detected in parallel, for example all transmitting from a smaller output intensity level, and if in a first round of transmit-receive, the detectors of some detection channels receive above a threshold corresponding to the output intensity, the detection period of these detection channels is completed, and in the next round of transmit-receive, only the lasers of those detection channels that do not receive a valid echo are transmitted-received in an increased intensity level until all detection channels are completed.
In the invention, the 'detection period' refers to the whole process of completing the detection task at the current position and generating a point by one detection channel. In a detection cycle, the detection channel may perform a transmit-receive operation, or may need to perform multiple transmit-receive operations because no valid echo is received.
Because the high-reflection plate has strong reflection capability on detection laser, namely the echo energy of the detection laser irradiated on the high-reflection plate is too strong, the too strong echo can influence a detector in a nearby detection channel in the laser radar, ghost or noise is generated, and the laser radar point cloud data is inaccurate. However, if the detection laser is emitted with a lower output intensity, the intensity of the echo energy in the area of the non-high-reflection plate is too low, and the laser radar cannot acquire the echo or cannot screen the echo, so that the laser radar cannot work normally.
According to the embodiment of the invention, the detection laser is emitted by the adjustable light source in the order of low intensity, when the intensity of the detection laser is low, the reflection capability of the high reflection plate on the detection laser is strong, the intensity of the reflected echo exceeds the threshold value, the laser radar can receive and acquire the reflected echo, and further the spatial position of the reflection point of the detection laser can be calculated and acquired, and the output intensity is low, so that the influence of the echo of the current detection channel on other detection channels in the laser radar can be reduced even when the laser is irradiated on the high plate, and ghost images or noise points are avoided. The detection laser irradiated on the obstacle with weak reflecting capability has weak echo energy and does not exceed the corresponding threshold value, and in order to ensure the detection precision of the laser radar, the adjustable light source is controlled to emit the detection laser with higher output intensity. The laser radar control method in the embodiment of the invention can reduce the influence of the high-reflection plate area on other detection channels in the laser radar, reduce the probability of inaccurate laser radar point cloud data, and simultaneously can ensure that echoes are acquired at the position of the obstacle with poor reflection capability and ensure that the laser radar can be normally used. As shown in fig. 6, when the same light intensity is used, loop0 corresponds to a high-reflection region, loop1 corresponds to a medium-reflectivity region, and Loop2 corresponds to a low-reflectivity region. The high-reflection plate exists in the loop0 region, and is shown as high in brightness in an image, but the echo intensity at the position of the high-reflection plate is high, so that the crosstalk effect on other detection channels is large, and the high-reflection plate is shown as a noise point in the image or is shown as an obstacle at the position where no obstacle exists. The loop1 area has rich details, which indicates that the output intensity at the corresponding position is proper, and can comprehensively reflect the obstacle information at the corresponding position. The loop2 region has insufficient image details due to the fact that the echo intensity is too weak, and accurate obstacle information cannot be obtained under the condition that the output intensity is not improved. By using the laser radar control method in the embodiment, detection laser with lower intensity is emitted at the loop0 region, so that the high-reflection plate is displayed as a normal obstacle. And the detection laser with higher intensity is emitted at the loop2 area, so that the loop2 area displays more details, and the detection accuracy of the laser radar in the whole field of view is improved.
Fig. 2 shows a specific flow of the lidar control method 200 according to the preferred embodiment of the present invention, in which the process of detecting laser light with the maximum intensity level of the tunable light source is included, specifically, steps S201, S202, S203, S204 (S204-1 and S204-2) in the lidar control method 200 are substantially the same as steps S101, S102, S103, S104 (S104-1 and S104-2) in the lidar control method 100 shown in fig. 1, respectively, and are not repeated here.
The difference from the embodiment of fig. 1 is that the lidar control method 200 in fig. 2 further includes: when the adjustable light source emits detection laser with the maximum intensity gear, if the intensity of the echo is lower than the threshold value corresponding to the maximum intensity gear, ending one detection period of the adjustable light source.
In view of factors such as eye safety, the output intensity of the tunable light source cannot be infinitely increased, and must have a maximum value, and when the tunable light source emits the detection laser at the maximum intensity, if a valid echo is still not obtained, the output intensity of the tunable light source cannot be continuously increased. It is now generally indicated that no obstacle or an object with very high absorption (a very dark object) is present in this detection position of the lidar, so that the detection laser emitted at maximum intensity still does not produce a sufficiently strong echo.
As shown in fig. 2, if it is determined in step S203 that the echo intensity is less than the threshold value, the process proceeds to step S205. In step S205, it is determined whether the tunable light source emits the detection laser light at the maximum intensity, and in the case where the tunable light source has a plurality of output intensity steps, it is determined whether the tunable light source emits the detection laser light at the maximum intensity step. When the output intensity of the adjustable light source does not reach the maximum value, the following step S204-2 is continued. When the tunable light source has emitted the detection laser light at the maximum intensity, the process proceeds to step S206, where the detection period of the tunable light source is ended. After step S204-1, the spatial position of the obstacle is calculated from the effective echo, and the process proceeds to step S206 as well, to end the detection period of the tunable light source.
In various embodiments of the invention, the lidar includes a plurality of tunable light sources, the plurality of tunable light sources being divided into one or more groups, and each group of tunable light sources being capable of controlled simultaneous illumination. For the mechanical rotary laser radar, a plurality of light sources rotate around a vertical axis in a horizontal plane to acquire surrounding obstacle information, and the light sources of the mechanical rotary laser radar are arranged in a row in a direction parallel to a rotation axis. One detection cycle of a set of tunable light sources is completed for each tunable light source of the set of tunable light sources in accordance with lidar control method 100 or 200 in the previous embodiment. Preferably, the adjustable light sources in the same group can be controlled to emit light simultaneously, so as to complete the detection period of each adjustable light source. Specifically, each group of adjustable light sources is controlled to emit detection laser respectively at the same output intensity level. For a tunable light source in which the echo intensity does not exceed the threshold value, it is controlled to emit the detection laser light with the same increased output intensity level. For example, 10 tunable light sources are included in a group of tunable light sources of the lidar, and the 10 tunable light sources can emit detection lasers at the same time with the same output intensity. In a specific lidar control method, 10 adjustable light sources within the group are controlled to emit detection laser light at the same time with the same intensity, and for the adjustable light sources in which the corresponding echoes exceed a threshold value, the spatial position of the obstacle is calculated from the corresponding echoes. For the adjustable light sources, for example, the echoes corresponding to the 5 adjustable light sources do not exceed the threshold value, the output intensities of the 5 adjustable light sources are simultaneously improved, and preferably, one output intensity gear is improved. And completing one detection period of the group of adjustable light sources until the echoes corresponding to all the adjustable light sources exceed a threshold value or are raised to the highest output intensity of the adjustable light sources. The echo threshold values of different adjustable light sources in the same group under the same output intensity can be selected to be the same value, or different values can be selected, for example, stronger ambient light interference exists around a receiving channel corresponding to part of adjustable light sources in the same group, and the corresponding echo threshold values can be correspondingly improved so as to ensure the detection accuracy of the laser radar.
For a plurality of adjustable light sources in the same group, the light sources can emit light sequentially according to a preset sequence, after one of the adjustable light sources completes a detection period, the light sources are switched to the next adjustable light source in the preset sequence, and the laser radar control method is executed to complete the corresponding detection period. Further, for a lidar including multiple sets of tunable light sources, one detection period of each set of tunable light sources may be sequentially completed in a preset order.
Thus, with the above-described embodiments of the present invention, for a plurality of tunable light sources, the plurality of tunable light sources may be driven to start emitting light and detecting at a lower first intensity, and as the detection proceeds, detectors corresponding to some of the tunable light sources receive valid echoes, and thus the detection period will end; the detectors corresponding to the other tunable light sources will still continue to transmit-receive operation because no valid echo is received.
Fig. 3 shows a specific flow of a method 300 for controlling a lidar according to a preferred embodiment of the invention, wherein the lidar comprises one or more detection channels formed by lasers and detectors, and wherein the light intensity of the lasers is adjustable, preferably the lasers and the detectors are in a one-to-one correspondence.
In the method 300 for controlling a lidar, for a detection period of a detection channel, in step S301, the laser of the detection channel is controlled to emit detection laser light at a first intensity, where the first intensity is the same as in the previous embodiment, may be a preset intensity gear of the laser, or one of the intensity values in the range of the laser light emission intensity, and the first intensity is not the maximum light emission intensity of the laser. According to a preferred embodiment of the invention, the luminous intensity of the laser has a plurality of intensity steps. In case the laser has an intensity level with a plurality of luminous intensities, according to a preferred embodiment of the invention, the first intensity corresponds to the lowest of said intensity levels.
In step S302, the echo generated by the detection laser is received by the detector of the detection channel, and in this embodiment, for one detection channel, the laser corresponds to the detector, and the detection laser undergoes diffuse reflection after striking the surface of the obstacle, where part of the reflected light (echo) can be received by the corresponding detector and converted into an electrical signal.
In step S303: and controlling the laser of the detection channel to increase the luminous intensity or ending one detection period of the detection channel according to the output of the detector. Specifically, in step S303, it may be determined whether the intensity of the echo is greater than a threshold value, and when the intensity of the echo is greater than the threshold value, it is indicated that the probe has received a valid echo, so that one detection cycle of the detection channel may be ended, and the spatial position of the obstacle may be calculated according to the output of the probe; when the intensity of the echo is not greater than the threshold value, the laser is controlled to emit the detection laser light with increased luminous intensity, and the steps S302 and S303 are repeatedly executed until the echo energy acquired by the detector is greater than the corresponding threshold value, or the laser emits the detection laser light with maximum luminous intensity. The step of controlling the laser to emit the detection laser light at an increased luminous intensity includes: the laser is controlled to emit detection laser light at an intensity level higher than the current intensity level by one level. If the laser emits the detection laser with the maximum intensity, the detector in the detection channel still cannot acquire the echo with the energy larger than the corresponding threshold value, one detection period of the detection channel is ended, and the spatial position corresponding to the detection channel is considered to be beyond the detection range of the laser radar, for example, in the position corresponding to the detection channel, the distance between the obstacle and the laser radar is too far, or in the position corresponding to the detection channel, an obstacle with extremely strong light absorption capability exists, and most of the energy of the detection laser is absorbed by the obstacle, so that the energy of the echo cannot reach the threshold value.
When the laser emits the detection laser light with different intensity levels, wherein the echoes of the detection laser light have corresponding thresholds, the specific values of the echo thresholds may be the same or different, preferably, as the light emission intensity of the laser increases, the threshold of the echo intensity gradually decreases, as in the embodiment described with reference to fig. 1 and 2.
In lidar with different structures, tunable light sources, such as lasers, may be grouped in multiple groupings, preferably, lasers within the same group are distributed in a one-dimensional array or a two-dimensional array, and different embodiments of the present invention are described below with reference to fig. 4A-4F, respectively.
In one embodiment of the present invention, the lidar is a mechanical rotary lidar, as shown in fig. 4A and 4B, where a plurality of lasers are disposed on the lidar, and at least include a one-dimensional addressable array, for example, vertically aligned in a direction parallel to the rotation axis, each of the lasers corresponds to a specific angle in the vertical direction, and the detection angles of the plurality of lasers together form a field of view in the vertical direction of the lidar. The lidar is rotatable about a rotation axis O so as to cover a field of view of 360 ° in the horizontal direction. When the laser radar works, the lasers in the same array can synchronously emit, the obstacle information on the horizontal angle direction can be acquired, and after the detection process of one angle is completed, the lasers are controlled to rotate by a preset angle to perform the detection process of the next angle. Specifically, in the initial state, the laser radar is in an angular orientation of 0 ° in the horizontal direction, at this position, a plurality of lasers and corresponding detectors are respectively emitted and detected according to the method of the embodiment shown in fig. 1 and 2, until each of the corresponding detectors of the lasers receives an effective echo, or the laser emits and detects laser light with maximum intensity, so as to end the detection period of all the detection channels in the 0 ° orientation, the laser radar rotates to an angular orientation of 0.2 ° (assuming that the angular resolution of the laser radar is 0.2 °), and the above-mentioned process is repeated until the laser radar rotates once, and detection of the horizontal field of view range of 360 ° is completed.
Specifically, one laser array of the mechanical rotary laser radar includes, for example, 16 lasers, denoted by LD1-LD16 in fig. 4B, which are sequentially arranged from top to bottom, and after the detection laser light emitted by each laser is collimated by a lens, a different vertical field of view is corresponding to each of the 16 lasers, for example, as shown in fig. 4C, and each of the 16 lasers corresponds to a different field of view in the vertical direction, so as to form a vertical field of view of-15 ° to +15° together. The laser radar is also provided with detectors corresponding to the lasers, which are shown by DE1-DE16 in FIG. 4B and are in one-to-one correspondence with LD1-LD16, and preferably, the detectors are also arranged in a one-dimensional array, and one detector and one laser form one detection channel to form 16 detection channels in total.
At the current angle, the first detection process is performed, and 16 lasers in the same array are controlled to emit detection laser light at the lowest intensity level at the same time, and under the intensity level, even if a high reflection plate exists in the field of view of the lasers, the crosstalk to adjacent detection channels can be eliminated or reduced. For example, if there is a high reflection plate at the corresponding field positions of LD1, LD5, LD9, LD13, and the reflectivity to the detection laser is strong, the detectors DE1, DE5, DE9, DE13 corresponding to LD1, LD5, LD9, LD13 detect the echo, and the processing unit of the laser radar determines that the echo intensity is greater than the corresponding threshold, calculates the spatial position of the obstacle corresponding to LD1, LD5, LD9, LD13 according to the corresponding echo, and controls the lasers LD1, LD5, LD9, LD13 to stop emitting the detection laser, so as to complete the first detection process. And the detectors corresponding to the other 12 lasers except the 4 lasers do not detect echoes, or the echo intensity is not greater than a corresponding threshold value, in the second detection process, the other 12 lasers are controlled to increase the first output intensity level to continuously emit detection laser, for example, in the detection process, the detectors DE2, DE6, DE10 and DE14 corresponding to the lasers LD2, LD6, LD10 and LD14 detect echoes, and the processing unit judges that the echo intensity is greater than the corresponding threshold value, calculates the positions of the obstacles in the fields corresponding to the lasers LD2, LD6, LD10 and LD14 according to the echoes, and meanwhile, the lasers LD2, LD6, LD10 and LD14 stop reflecting the detection laser to finish the second detection process. And then controlling the rest 8 lasers to continuously increase one output intensity gear, emitting detection laser, and carrying out a third detection process in the same way. Until all the detectors DE1-DE16 corresponding to the 16 lasers can acquire echoes with intensities greater than the corresponding threshold values, or the output intensities of part or all of the lasers reach the maximum intensity, the corresponding detectors still cannot acquire echoes greater than the threshold values, and one detection period of the current angle is completed. Further, according to a preferred embodiment of the present invention, the current angle may be detected multiple times to obtain a more accurate detection result. And then controlling the laser radar to rotate by a preset angle, for example, controlling the horizontal resolution of the laser radar to be A degrees, controlling the laser radar to rotate by A degrees, and detecting the next angle by using the same laser radar control method until the detection of 360 degrees horizontally is completed, so as to generate a point cloud of one frame.
In some embodiments of the invention, the lidar is a rotary mirror lidar, for example as shown in fig. 4D, the detection range of which is extended by rotation of the rotary mirror, wherein the distribution of lasers and corresponding detectors may equally be arranged in a one-dimensional array as shown in fig. 4B, oriented parallel to the rotation axis of the rotary mirror. The control method which is the same as that of the mechanical rotary laser radar can be adopted for the rotary mirror type laser radar, so that the channel crosstalk generated by the high-reflection plate is reduced or avoided. For example, the horizontal resolution of the laser radar is A DEG, after the detection of all detection channels is completed in one angle direction of the rotating mirror, the rotating mirror is controlled to rotate by A DEG/2, the next angle is detected by the same laser radar control method until the detection of the horizontal view field range is completed, and a frame of point cloud is generated.
One or more of the tunable light source arrays and detector arrays shown in fig. 4B may be included in the lidar, and the number of tunable light sources (and detectors) may be 16, 32, 40, 64, 128, 256, or other numbers. Each array may be provided on the same circuit board, for example. The lidar control method shown in fig. 1-3 may be implemented separately for each array. And will not be described in detail herein.
Of course, for the laser array arranged in one-dimensional array shown in fig. 4B, for example, the laser radar may include 16 lasers arranged in one-dimensional array, and may be divided into four groups according to a preset sequence, each group of 4 lasers may be 4 lasers arranged continuously, or may be divided into other groups, for example, the lasers with 3 lasers being separated into one group, the labels LE1, LE5, LE9, LE13 in fig. 4B are divided into one group, LE2, LE6, LE10, LE14 are divided into one group, LE3, LE7, LE11, LE15 are divided into one group, and LE4, LE8, LE12, LE16 are divided into one group. The lasers in each group emit light synchronously, and after one detection period of one group of lasers is completed, the next group of lasers can be detected according to a preset sequence.
According to the specific embodiment of the invention, each laser can be independently controlled to execute a detection period according to a preset sequence, and the detection periods of all lasers are sequentially completed.
When the laser radar control method provided in the embodiment of the invention is applied to the solid-state radar, since the solid-state radar has no scanning device, the lasers can be arranged into a two-dimensional addressable array to obtain the field of view range in the horizontal direction and the vertical direction, and the arrangement form of the lasers can be shown as shown in fig. 4E.
Specifically, lasers in the laser radar are arranged in a two-dimensional array, and M rows and N columns are shared, wherein the lasers are respectively marked as LD 11 、LD 12 …LD 1N 、…LD MN The lasers in the same row or column may be used as the same group, and the lasers in each group may be detected according to the method in the foregoing embodiment, and after the group of lasers completes the detection process, the detection of the next group of lasers is performed in a preset sequence, for example, from top to bottom or from left to right.
According to various embodiments of the present invention, for a lidar in which lasers are arranged in a two-dimensional matrix as shown in fig. 4E, it is also possible to group all the lasers, and control all the lasers to emit detection laser light with minimum intensity. The lasers arranged in a two-dimensional array correspond to the view field direction of the front aspect range, if a high-reflection plate area exists in the view field range, the corresponding detector can acquire echoes with intensity larger than a threshold value, and the spatial position of the obstacle is calculated according to the echoes. Further, in the detection channel in which the echo with the intensity greater than the threshold value is obtained, the laser stops emitting the detection laser, and one detection period of one detection channel is completed. All other lasers in the two-dimensional array that do not acquire intensities above the threshold continue to emit detection lasers at higher luminous intensities. Until all the corresponding detectors of the lasers receive echoes with the intensity greater than the threshold value, or the detection laser is emitted with the maximum luminous intensity.
As shown in fig. 4E, each laser in the two-dimensional array corresponds to a fixed position in the overall field of view of the lidar, so in this embodiment, a complete detection cycle is performed on all lasers to determine whether there is a high reflection plate at the spatial position corresponding to the laser. However, the time for each laser in the two-dimensional array to complete the detection period is different, for example, the corresponding spatial position of one laser is a high-reflection plate, and when the detection laser is emitted with lower luminous intensity, the corresponding detector can receive the echo, and the laser completes the detection period and stops emitting the detection laser. The space positions corresponding to the other lasers are low-reflection objects, and the echo with the intensity larger than the threshold value can be obtained only by gradually increasing the luminous intensity, so that the time for obtaining the space position of the point is relatively prolonged, and after all lasers complete one detection period, in the embodiment, the space positions corresponding to the lasers are fused, so that the point cloud data with a higher dynamic range can be obtained.
According to a preferred embodiment of the invention, the lidar has a single tunable light source and the tunable light source, after passing through the light homogenizing device, is uniformly illuminated on a one-or two-dimensional array of optical switches covering the entire range of the array of optical switches, wherein each optical switch can be individually addressed and controlled, for example, by a digital micromirror or a liquid crystal. Taking a two-dimensional optical switch array as an example, as shown in fig. 4F, the two-dimensional optical switch array includes M rows and N columns, which can be specifically denoted as S 11 、S 12 、…S 1N 、…S MN In this embodiment, the laser radar control method further includes controlling light on or off at a preset position according to a preset time sequence. In this embodiment, one detection channel includes an optical switch in addition to the tunable light source and detector. Thus, the detection period of one detection channel may also be expressed as the detection period of an optical switch.
For example, the optical switches in the optical switch array are divided into one or more groups, and the optical switches in the same group can be controlled to be turned on or off simultaneously. Specifically, each optical switch in one group of optical switches is turned on, and meanwhile, the adjustable optical source is controlled to gradually increase the intensity of detection laser according to the steps in the laser radar control method, the detection laser emitted by the adjustable optical source uniformly irradiates on the optical switch array after being subjected to light homogenization, and at the position corresponding to the on optical switch, the detection laser passes through the optical switch array and can be used for detecting the surrounding environment, the illumination intensity of the detection laser also increases along with the increase of the output intensity of the adjustable optical source, namely, the single adjustable optical source is subjected to light splitting and time sharing control by utilizing the optical switch array, and in the view field range corresponding to the optical switch array, each optical switch corresponds to one detection position in the view field.
The control of the tunable light source according to the laser radar control method in the foregoing embodiment may obtain information of an obstacle at a detection position of each light switch in the group of light switches, and further, each light switch may be controlled to be turned on or off separately, for example, after a return signal with an intensity greater than a threshold is obtained, the light switch at a corresponding position is turned off, so as to complete a detection period of the light switch, after all the light switches in the group complete a detection period, the next light switch in a preset sequence is turned on until all the light switches complete a detection period, and point cloud data is obtained by using echo calculation. Specifically, the optical switches in the same row or column can be used as a group, and a plurality of groups of optical switches can be controlled to be turned on or off in sequence.
According to different embodiments of the present invention, one optical switch in the optical switch array may be turned on, and the remaining optical switches may be turned off, for the turned on optical switches, the output intensity of the adjustable light source is controlled by using the laser radar control method in the foregoing embodiment, to complete one detection period of the optical switch, then the optical switch is turned off, and the next optical switch is turned on according to a preset sequence, and the laser radar control method in the foregoing embodiment is sequentially executed until all the optical switches in the optical switch array complete one detection period.
For one-dimensional arrays of optical switches, the same method can be used for grouping and individual control according to the grouping.
As shown in fig. 5, the present invention also relates to a lidar 1, wherein the lidar 1 comprises a transmitting unit 10 and a detecting unit 20, the transmitting unit 10 comprising an adjustable light source 11, the adjustable light source 11 being capable of transmitting the detection laser light with an adjustable intensity. The detection unit 20 comprises a detector 21, the detector 21 being capable of receiving echoes of the detection laser light on the obstacle. Preferably, the adjustable light sources 11 are in one-to-one correspondence with the detectors 21. The lidar 1 further comprises a control system 30, the control system 30 being in communication with the adjustable light source 11 and the detector 21 and being capable of performing the lidar control method of the previous embodiment to reduce cross-talk between different detection channels of the lidar caused by the highly reflective plate.
A plurality of tunable light sources is schematically illustrated in fig. 5, as will be readily appreciated by those skilled in the art, a single tunable light source may also be used. For example, the lidar 1 further includes a light equalizing device and an optical switch array, and the detection laser light emitted from the single adjustable light source is uniformly irradiated on the one-dimensional or two-dimensional optical switch array after passing through the light equalizing device. The optical switch array includes a plurality of optical switches arranged in one dimension or in two dimensions, each of which is individually addressable and controllable to achieve the same effect as a plurality of adjustable light sources. And will not be described in detail herein.
The invention also includes an embodiment of a computer-readable storage medium comprising computer-executable instructions stored thereon that, when executed by a processor, implement a lidar control method as described in the previous embodiment.
Finally, it should be noted that: the foregoing description is only a preferred embodiment of the present invention, and the present invention is not limited thereto, but it is to be understood that modifications and equivalents of some of the technical features described in the foregoing embodiments may be made by those skilled in the art, although the present invention has been described in detail with reference to the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (22)

1. A lidar control method, the lidar having an adjustable light source, the lidar control method comprising:
s101: controlling the adjustable light source to emit detection laser at a first intensity;
s102: receiving an echo of the detection laser;
s103: judging whether the intensity of the echo is larger than a threshold value or not; and
s104: calculating the spatial position of an obstacle according to the echo when the intensity of the echo is greater than the threshold value; and when the intensity of the echo does not exceed the threshold value, controlling the adjustable light source to emit detection laser with increased intensity, and repeating the steps S102-S104.
2. The lidar control method according to claim 1, wherein the adjustable light source has a plurality of intensity levels, and the echo in step 103 has a corresponding threshold when the adjustable light source emits the detection laser at different intensity levels.
3. The lidar control method of claim 2, wherein the first intensity corresponds to a lowest intensity gear of the plurality of intensity gears;
the step of controlling the tunable light source to emit the detection laser light at an increased intensity includes: and controlling the adjustable light source to emit detection laser at an intensity gear which is one level higher than the current intensity gear.
4. The lidar control method according to claim 2, further comprising: when the adjustable light source emits detection laser with the maximum intensity gear, if the intensity of the echo is lower than the threshold value corresponding to the maximum intensity gear, ending one detection period of the adjustable light source.
5. The lidar control method according to claim 2, wherein the threshold values corresponding to the different intensity shift positions are the same or decrease with an increase in intensity shift position.
6. The lidar control method according to any of claims 1 to 5, wherein the lidar comprises a plurality of adjustable light sources, the plurality of adjustable light sources being divided into one or more groups, each group of adjustable light sources being controlled to emit light synchronously; the laser radar control method comprises the following steps: the steps S101-S104 are performed for each of a set of tunable light sources, completing one detection period of the set of tunable light sources.
7. The lidar control method according to claim 6, further comprising: when multiple sets of tunable light sources are included, one detection cycle of each set of tunable light sources is completed sequentially.
8. The lidar control method of claim 6, wherein each group of tunable light sources is distributed in a one-dimensional or two-dimensional array.
9. The lidar control method of claim 6, wherein the each set of adjustable light sources is controlled to emit light synchronously comprises: wherein in the step S101: controlling each group of adjustable light sources to respectively emit detection lasers with the same intensity gear; in the step S104: for a tunable light source whose echo intensity does not exceed a threshold value, it is controlled to emit the detection laser light with the same increased intensity level.
10. The lidar control method according to any of claims 1 to 5, wherein the lidar comprises a plurality of adjustable light sources, wherein the steps S101 to S104 are performed sequentially for each adjustable light source until after one detection period for the adjustable light source is completed, switching to the next adjustable light source.
11. The lidar control method according to any of claims 1 to 5, wherein the step S104 comprises: and ending one detection period of the adjustable light source when the intensity of the echo is greater than the threshold value.
12. The lidar control method according to any of claims 1 to 5, wherein the lidar has a single tunable light source, a dodging device, and an optical switch array, wherein the detection laser light emitted by the single tunable light source is uniformly irradiated onto the optical switch array after passing through the dodging device; the laser radar control method further comprises the following steps:
and opening the corresponding optical switch according to a preset time sequence.
13. The lidar control method of claim 12, wherein the optical switches in the array of optical switches are grouped into one or more groups, each group of optical switches being controlled to be turned on or off synchronously; the laser radar control method comprises the following steps: each optical switch in the same group of optical switches is turned on, the steps S101-S104 are performed, and one detection cycle of the group of optical switches is completed.
14. The lidar control method according to claim 13, further comprising: when the optical switch array includes a plurality of sets of optical switches, one detection cycle of each set of optical switches is completed sequentially.
15. The lidar control method according to claim 12, wherein the lidar control method comprises: and starting one of the optical switches, wherein the rest optical switches are in a closed state, and executing the steps S101-S104 aiming at the started optical switches, and switching to the next optical switch after completing one detection period of the started optical switches until completing one detection period of all the optical switches.
16. The lidar control method of claim 14, wherein each set of optical switches is distributed in a one-dimensional or two-dimensional array.
17. A lidar, comprising:
an emission unit including an adjustable light source configured to emit a detection laser light with an adjustable intensity;
a detection unit including a detector configured to be able to receive an echo of the detection laser on an obstacle; and
a control system in communication with the tunable light source and the detector and configured to perform the lidar control method of any of claims 1-16.
18. A method for controlling a lidar comprising one or more detection channels formed by a laser and a detector, wherein the light-emitting intensity of the laser is adjustable, wherein the method comprises: for one detection period of one detection channel,
s301: controlling the laser of the detection channel to emit detection laser light at a first intensity;
s302: receiving an echo generated by the detection laser through a detector of the detection channel; and
s303: and controlling the laser of the detection channel to increase the luminous intensity or ending one detection period of the detection channel according to the output of the detector.
19. The method of claim 18, wherein said step S303 comprises: ending a detection period of the detection channel when the intensity of the echo is greater than a threshold value, and calculating the spatial position of the obstacle according to the output; when the intensity of the echo does not exceed the threshold value, the laser is controlled to emit detection laser light at an increased luminous intensity, and the steps S302 to S303 are repeated.
20. The method of claim 19, wherein the light emission intensity of the laser has a plurality of intensity steps, and the echoes in step S303 have corresponding thresholds when the laser emits detection laser light at different intensity steps.
21. The method of claim 20, wherein the first intensity corresponds to a lowest intensity gear of the plurality of intensity gears;
the step of controlling the laser to emit the detection laser light at an increased luminous intensity includes: and controlling the laser to emit detection laser at an intensity gear which is one level higher than the current intensity gear.
22. The method of claim 20 or 21, further comprising: when the laser emits detection laser light in the maximum intensity gear, if the intensity of echo is lower than the threshold value corresponding to the maximum intensity gear, one detection period of the detection channel is ended.
CN202210943782.7A 2022-08-08 2022-08-08 Laser radar control method, laser radar and method for controlling laser radar Pending CN117572439A (en)

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