WO2022257138A1

WO2022257138A1 - Calibration method and apparatus, and laser radar, detection system and storage medium

Info

Publication number: WO2022257138A1
Application number: PCT/CN2021/099837
Authority: WO
Inventors: 许友; 陈涵; 吴特思
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2021-06-11
Filing date: 2021-06-11
Publication date: 2022-12-15

Abstract

Provided are a calibration method, a calibration apparatus, a laser radar, a detection system and a storage medium. The method is applied to a coaxial laser radar. The method comprises: after an instruction to start calibration is acquired, respectively emitting optical pulses in a plurality of directions in a field of view, and receiving, within a time window of each optical pulse, an echo signal corresponding to the optical pulse (302); and if it is determined, according to the received echo signal, that a first signal and a second signal are not fused, recording a correspondence between the first signal and the emission direction of the current optical pulse, and at least one of the following waveform parameters of the first signal: intensity, pulse width, and slope, wherein the first signal is an echo signal reflected by a laser radar itself, and the second signal is an echo signal reflected by a detected object (304). By means of the method, the calibration of an echo signal reflected by a laser radar itself can be conveniently and quickly completed without the need for a strict site condition or an expensive measurement instrument.

Description

Calibration method and device, laser radar, detection system and storage medium

technical field

The present application relates to the technical field of laser radar, and in particular to a calibration method, a calibration device, laser radar, a detection system and a computer-readable storage medium.

Background technique

LiDAR is an optical ranging device that can actively transmit light pulses to the measured object and obtain the echo signal corresponding to the light pulse reflected back by the measured object. According to the time difference between the moment when the light pulse is emitted and the moment when the echo signal is received, the depth information between the measured object and the lidar can be calculated. According to the known outgoing direction when the light pulse is emitted, the angle information of the measured object relative to the lidar can be obtained. Combining the measured depth information and angle information, the point cloud point corresponding to the position where the light pulse arrives can be obtained. By emitting light pulses in different directions, the point cloud corresponding to the current scene can be obtained, and the spatial three-dimensional information of the measured object relative to the lidar can be reconstructed. Here, the point cloud is a collection of multiple point cloud points.

Contents of the invention

In view of this, embodiments of the present application provide a calibration method, a calibration device, a laser radar, a detection system, and a computer-readable storage medium, one of the purposes of which is to provide convenience for calibration of echo signals reflected by the laser radar itself.

The first aspect of the embodiment of the present application provides a calibration method, which is applied to coaxial laser radar, and the method includes:

After obtaining the instruction to start calibration, transmit light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : Intensity, pulse width, slope, wherein the first signal is an echo signal reflected by the lidar itself, and the second signal is an echo signal reflected by a measured object.

The second aspect of the embodiment of the present application provides a calibration method, which is applied to coaxial laser radar, and the method includes:

After obtaining the instruction to start the calibration, enter the calibration mode, wherein, in the calibration mode, the light outlet of the laser radar is provided with a shield, and the shield forms a block to the field of view of the laser radar;

Sending light pulses to multiple directions in the field of view respectively, and receiving an echo signal corresponding to the light pulse within a time window corresponding to each light pulse;

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, and slope, wherein the first signal is an echo signal reflected by the lidar itself.

The third aspect of the embodiment of the present application provides a calibration method, which is applied to a detection system. The detection system includes a laser radar and a host computer. The transmitting optical path of the laser radar is partly the same as the receiving optical path. The method includes:

The host computer establishes a connection with the laser radar;

The host computer sends a self-calibration command to the lidar;

The lidar enters a self-calibration mode in response to the self-calibration command;

In the self-calibration mode, the laser radar emits light pulses in multiple directions in the field of view, and calibrates the first signals corresponding to the multiple directions, and the first signal is the laser The echo signal reflected by the radar itself.

The fourth aspect of the embodiment of the present application provides a calibration device, which is applied to a coaxial laser radar. The calibration device includes: a processor and a memory storing a computer program, and the processor implements the following steps when executing the computer program :

The fifth aspect of the embodiment of the present application provides a calibration device, which is applied to coaxial laser radar. The calibration device includes: a processor and a memory storing a computer program, and the processor implements the following steps when executing the computer program :

After obtaining the instruction to start the calibration, enter the calibration mode, wherein, in the calibration mode, the light outlet of the laser radar is provided with a shield, and the shield blocks the field of view of the laser radar;

The sixth aspect of the embodiment of the present application provides a laser radar, including:

a light source for emitting a sequence of light pulses;

The optical system is used to adjust the outgoing direction of the light pulse emitted by the light source, and the emitting optical path of the laser radar is partly the same as the receiving optical path;

The receiving circuit is used to receive the echo signal corresponding to the optical pulse;

A processor and a memory storing a computer program, the processor, when executing the computer program, implements the following steps:

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : intensity, pulse width, slope, wherein, the first signal is an echo signal reflected by the optical system itself, and the second signal is an echo signal reflected by a measured object.

The seventh aspect of the embodiment of the present application provides a laser radar, including:

a light source for emitting a sequence of light pulses;

The eighth aspect of the embodiment of the present application provides a detection system, including: a laser radar and a host computer, the laser radar is a coaxial laser radar;

The host computer is used to establish a connection with the laser radar, and send a self-calibration command to the laser radar;

The lidar is configured to enter a self-calibration mode in response to the self-calibration command; in the self-calibration mode, the lidar emits light pulses to multiple directions in the field of view respectively, and The first signals corresponding to the two directions are respectively calibrated, and the first signals are the echo signals reflected by the lidar itself.

A ninth aspect of the embodiments of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any calibration method provided in the embodiments of the present application is implemented.

The calibration method provided by the embodiment of the present application can determine whether the fusion of the first signal and the second signal occurs according to the received echo signal, and can record the waveform of the first signal when the fusion of the first signal and the second signal does not occur parameters and the corresponding relationship between the first signal and the outgoing direction of the current light pulse to complete the calibration of the first signal corresponding to the current direction. It can be seen that, the method provided by the embodiment of the present application does not require the use of external instruments or a specific site, and the user can realize the calibration of the first signal characteristic of the laser radar during the use of the laser radar, thereby greatly improving the reliability of the laser radar. reliability.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a coaxial laser radar provided by an embodiment of the present application.

Fig. 2 is a schematic diagram of the generation of the first signal and the second signal provided by the embodiment of the present application.

Fig. 3 is a first flow chart of the calibration method provided by the embodiment of the present application.

FIG. 4A is a signal waveform diagram of fusion of a first signal and a second signal provided by an embodiment of the present application.

FIG. 4B is a signal waveform diagram of an unfused first signal and a second signal provided by the embodiment of the present application.

Fig. 5 is a second flowchart of the calibration method provided by the embodiment of the present application.

Fig. 6 is a schematic diagram of the installation of the mask provided by the embodiment of the present application.

Fig. 7 is a third flow chart of the calibration method provided by the embodiment of the present application.

FIG. 8 is a schematic structural diagram of a calibration device provided in an embodiment of the present application.

FIG. 9 is a schematic structural diagram of a detection system provided by an embodiment of the present application.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Lidar usually includes a transmitting optical path and a receiving optical path. Coaxial lidar means that the transmitting optical path and receiving optical path inside the laser radar are partly the same, that is, the path passed by the emitted light pulse is the path passed by the reflected echo signal. The path part is the same. Reference can be made to FIG. 1 , which is a schematic structural diagram of a coaxial lidar provided in an embodiment of the present application. Among them, the light source is used to emit light pulse sequences, and the emitted light pulses pass through the optical system, exit in different directions under the refraction of the optical system, and reflect after reaching the measured object. The reflected echo signal reaches the receiving circuit through part of the same optical path, and the receiving circuit transmits the collected signal to the processor for analysis and processing.

Since the transmitting optical path and the receiving optical path of the coaxial lidar are partly the same, after the coaxial lidar emits a beam of optical pulses, the receiving circuit of the lidar may receive two echo signals corresponding to the optical pulse, among which the first One kind of echo signal is the echo signal reflected by the laser radar itself, which can be called the first signal, and the second echo signal is the echo signal reflected by the measured object, which can be called The signal is called the second signal.

Reference may be made to FIG. 2 , which is a schematic diagram of the generation of the first signal and the second signal provided by the embodiment of the present application. Wherein, the first signal is an echo signal reflected by the optical system of the laser radar itself, and the generation of the first signal is related to factors such as materials, manufacturing, and installation of the optical system of the laser radar. The so-called optical system, in one embodiment, may at least include optical devices on the optical path, such as lenses, prisms, glass for light exit windows, etc., and in one embodiment, may also include supports for supporting these optical devices pieces.

It can be understood that since the first signal is an echo signal reflected inside the lidar, it cannot be used to calculate the depth information of the measured object relative to the lidar, but in some examples, the first signal may have other applications. For example, in an example, the first signal can be used to detect the state of the internal components of the laser radar. Here, the internal components can be, for example, the aforementioned optical devices, and the state of the internal components can be, for example, the cleanliness of the optical components (whether there is oil or dirt) , dust, etc.), it can also be the integrity of the optical device (whether there is damage, etc.). In one example, the second signal can be restored from the fusion signal of the first signal and the second signal by using the first signal with accurate calibration, so as to improve the measurement blind area of the lidar for close-range objects, that is, to improve the detection of close-range objects. measurement accuracy.

Considering that the first signal characteristic of the lidar has many valuable applications, it is necessary to calibrate the first signal characteristic of the lidar, specifically, the first signal characteristics corresponding to the multiple directions of the lidar in the field of view The signal is calibrated.

When calibrating the first signal characteristic of the lidar, in one embodiment, an external instrument can be used for measurement. Specifically, the emission power of the lidar can be measured externally through an external instrument such as a laser power meter, so that it can be measured according to The comparison result between the power and the actual transmission power of the lidar calibrates the first signal characteristic of the lidar. However, this method requires a lot of manual participation, and requires the help of expensive external instruments, and there are many limitations in calibration.

In one embodiment, a controllable scene can be used for calibration. For example, the lidar can be placed in an open scene. At this time, because there is no measured object or the measured object is too far away, the lidar cannot detect The second signal means that the echo signal received by the lidar only contains the first signal, so that the calibration of the characteristics of the first signal can be realized. But again, this method has strict restrictions on the scene where the lidar is located during calibration.

When the laser radar is used by the user, with the increase of the operating time of the laser radar, it is inevitable that the laser transmit power will be reduced, and the internal optical devices of the radar will be aged. At this time, the real first signal characteristics and factory calibration The first signal characteristics are far away from each other. If the relevant algorithm is still implemented based on the original calibrated first signal characteristics at this time, the accuracy of the algorithm will be greatly reduced. At this time, the user has to return the lidar to the factory for calibration. , very inconvenient, also greatly increased cost.

The embodiment of the present application provides a calibration method, which can conveniently complete the calibration of the first signal characteristic of the lidar. Reference may be made to FIG. 3 , which is a first flow chart of the calibration method provided by the embodiment of the present application. The method can be applied to laser radar, and the laser radar is a coaxial laser radar, that is, its transmitting optical path is partly the same as the receiving optical path, and the method includes the following steps:

S302. After acquiring the instruction to start the calibration, respectively transmit light pulses to multiple directions in the field of view, and receive an echo signal corresponding to the light pulse within the time window of each light pulse.

S304. If it is determined according to the received echo signal that the first signal and the second signal have not merged, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one waveform of the first signal parameter.

After the laser radar acquires the instruction to start the calibration, it may start to calibrate the first signals corresponding to multiple directions in the field of view. Here, in an implementation manner, the lidar can be calibrated direction by direction. Specifically, after entering the calibration process corresponding to a direction, the lidar can emit light pulses in that direction, and receive echo signals corresponding to the light pulses within the time window corresponding to the light pulses. According to the received echo signal, regardless of whether the first signal corresponding to the direction is successfully calibrated, the calibration process corresponding to the direction can be ended and the calibration process corresponding to the next direction can be entered. At this time, the laser radar can move towards the next direction. emit light pulses in the direction.

As mentioned above, the first signal is the echo signal reflected by the lidar itself, and the second signal is the echo signal reflected by the measured object. It can be understood that the receiving time of the second signal is positively correlated with the distance of the measured object, the farther the distance of the measured object is, the later the receiving time of the second signal is, and the closer the distance of the measured object is, the The sooner it is received. The receiving time of the first signal is relatively fixed, usually in the early stage of the time window. Therefore, when the distance of the measured object is relatively short, and the receiving time of the second signal and the first signal is close, the number of received echo signals may be one, and the echo signal may be the first signal and the second signal. The fusion of signals obtained can refer to Fig. 4A. And when the distance of the measured object is far away, the receiving time of the second signal can be different from the receiving time of the first signal, so that the number of received echo signals can be two, and the echo signal received earlier The signal may be the first signal, and the echo signal received later may be the second signal, and the two signals will not be fused, as shown in FIG. 4B .

It should be noted that when the measured object is too far away or there is no measured object, since the lidar cannot receive the second signal in this case, the first signal and the second signal are not fused.

Whether the fusion of the first signal and the second signal can be determined according to the received echo signal, if it is determined according to the received echo signal that the fusion of the first signal and the second signal does not occur, then at least the first signal can be recorded. A waveform parameter. Here, the waveform parameter of the first signal may include: intensity, pulse width, and slope. In addition, the corresponding relationship between the first signal and the outgoing direction of the current light pulse can be recorded, so as to complete the calibration of the first signal corresponding to the direction.

When determining whether the fusion of the first signal and the second signal occurs according to the received echo signals, in an implementation manner, it may be determined according to the number of echo signals received within the time window of the optical pulse. It can be seen from the above that when the measured object is far away, the receiving time of the second signal will be relatively late, while the receiving time of the first signal is usually relatively short. Therefore, if two signals are received successively within the time window of the optical pulse echo signal, it can be determined that the first signal and the second signal have not merged, and it can be determined that the echo signal received earlier is the first signal, and the waveform parameters of the first signal and the first signal can be recorded. The corresponding relationship between the signal and the outgoing direction of the current light pulse.

If only one echo signal is received within the time window of the light pulse, it may correspond to two situations. The first situation is that the first signal and the second signal are fused, and the second situation is that the measured object is too far away. The object to be measured is far away or does not exist in the outgoing direction, so that the second signal cannot be received. Considering that the first signal and the second signal exist at the same time, and when the first signal and the second signal are fused, there will be a large difference in waveform between the fused echo and the unfused normal echo, therefore, in a In an implementation manner, it may be determined according to the waveform of the received echo signal whether fusion occurs between the first signal and the second signal.

Normal echoes have strong regularity in waveform parameters such as intensity, slope, and pulse width. Therefore, the lidar can be used to pre-record the preset waveform parameters of normal echoes. When an echo signal is received within the time window, the waveform parameters of the echo signal can be extracted, and the waveform parameters of the echo signal can be compared with the preset waveform parameters of the normal echo, so that it can be determined according to the comparison result Whether the fusion of the first signal and the second signal occurs. Specifically, the difference between the waveform parameter of the received echo signal and the preset waveform parameter can be calculated. If the calculated difference is greater than a threshold, it can be determined that the fusion of the first signal and the second signal has occurred. If the calculated If the difference is smaller than the threshold, it can be determined that the first signal and the second signal are not fused. At this time, the received echo signal itself is the first signal, and the corresponding relationship and waveform parameters can be directly recorded.

When comparing the waveform parameters of the received echo signal with the preset waveform parameters, since the comparable waveform parameters include intensity, pulse width, slope, etc., a feasible way is to compare each waveform parameter Compare them separately. In an implementation manner, if the comparison result of any one of the waveform parameters indicates that the first signal and the second signal have merged, it may be determined that the first signal and the second signal have merged.

As mentioned above, in the process of calibrating the first signal corresponding to a direction, the first signal corresponding to the direction may be successfully calibrated, or may fail to be calibrated. Specifically, when calibrating the first signal corresponding to a certain direction, if it is determined according to the received echo signal that the first signal and the second signal have not merged, then the first signal corresponding to the direction can be successfully calibrated. Conversely, if it is determined according to the received echo signal that the fusion of the first signal and the second signal has occurred, then the first signal corresponding to the direction has not been successfully calibrated in this calibration process in this direction. At this time, in a In an implementation manner, the outgoing direction of the current light pulse may be marked as an unmarked direction, and a calibration process corresponding to the next outgoing direction may be entered.

After completing a round of calibration for each direction in the field of view, that is, after completing the calibration process corresponding to the last outgoing direction, it can be determined whether there is an uncalibrated direction that was not successfully calibrated in this round of calibration. If there is such a If the unmarked direction of the laser radar is changed, the calibration of the first signal can be performed again for each unmarked direction.

It can be understood that whether the calibration can be successful in a calibration process depends on whether the first signal and the second signal are fused, and whether the first signal and the second signal are fused depends on the direction in which the current light pulse is emitted. The distance of the measured object, when the distance of the measured object is relatively close, the second signal reflected by the measured object will be fused with the first signal reflected by the lidar itself, resulting in the failure of the calibration of the first signal. Therefore, for the uncalibrated directions that have not been successfully calibrated before, the scanning scene of the lidar can be changed, and the change of the scanning scene will cause the change of the distance of the measured object in the unmarked direction, so that the unmarked directions can be recalculated for the first time. When a signal is calibrated, there will be a possibility of successful calibration.

If after changing the scanning scene of the laser radar, the unmarked direction still exists, then the scanning scene of the laser radar can be continued to be changed, and the unmarked direction is calibrated again until all directions in the field of view have completed the detection of the first signal. calibration.

There are many ways to change the scanning scene of the lidar. In one embodiment, the lidar can be mounted on a movable platform, for example, the lidar can be a vehicle-mounted lidar, so that when it is determined that the scanning scene of the lidar needs to be changed, it can be realized by moving the movable platform, for example, If the movable platform is a vehicle, the orientation of the vehicle can be adjusted in various ways. For example, if the vehicle has an automatic driving function, the vehicle can be directly controlled to adjust its orientation; if the vehicle does not have an automatic driving function, the user can be prompted to control the vehicle in various ways such as images and sounds to change the orientation of the vehicle.

In one embodiment, the instruction to start calibration acquired by the lidar may be sent to the lidar by the control device of the movable platform. The control device of the movable platform can be the upper computer of the laser radar, which can generate an instruction to start calibration according to the trigger of the user, and send the instruction to start the calibration to the laser radar. After receiving the instruction to start the calibration, the laser radar can Enter the automatic calibration mode, so as to realize the calibration method provided by the embodiment of this application.

As mentioned earlier, the first signal characteristic of lidar can have various applications. In one application, after the calibration of the first signal corresponding to each direction in the field of view is completed, the waveform parameters of the newly calibrated first signal can be compared with the waveform parameters of the previously calibrated first signal, and can be based on The gap between the two evaluates the current state of the optical system of lidar. In one application, after the calibration of the first signal corresponding to each direction in the field of view is completed, when performing distance measurement, if it is determined that the fusion of the first signal and the second signal occurs (the measured object is closer), Then the received echo signal can be restored according to the calibrated first signal, and the required second signal can be restored, so that the accurate distance of the measured object can be calculated by using the restored second signal, which greatly improves the laser radar. Measurement accuracy of nearby objects.

In one embodiment, when calibrating the first signal, it is not necessary to distinguish each direction in the field of view, and it is considered that the first signals corresponding to each direction are the same, so that only a specific direction in the field of view can be calibrated. The first signal of the specific direction is used as the first signal corresponding to each outgoing direction. In this way, although the calibrated first signal can also be used to restore the fusion signal of the first signal and the second signal, since the difference between the first signals in different outgoing directions is ignored, the accuracy of the restored second signal is relatively low. Low, resulting in low accuracy of the final calculated distance. However, in the embodiment of the present application, the first signals in each direction in the field of view are calibrated separately, so that when restoring the second signal, the first signal corresponding to the current outgoing direction can be used to restore the fused signal, which greatly improves the restoration. The accuracy of the second signal, thus also increasing the ranging accuracy.

Referring to FIG. 5 below, FIG. 5 is a second flowchart of the calibration method provided by the embodiment of the present application. The method can be applied to a coaxial laser radar, and the transmitting light path of the laser radar is partly the same as the receiving light path. The method includes the following steps:

S502. Enter a calibration mode after acquiring the instruction to start calibration.

When the lidar is in the calibration mode, a shield is provided at the light outlet of the lidar, and the shield blocks the field of view of the lidar.

S504. Send light pulses to multiple directions in the field of view respectively, and receive an echo signal corresponding to the light pulse within a time window corresponding to each light pulse.

S506. Acquire a first signal from the received echo signal based on the shielding member, and record a corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one waveform parameter of the first signal.

Wherein, the waveform parameters of the first signal may include: intensity, pulse width, and slope. The first signal has the same meaning as above, that is, the echo signal reflected by the laser radar itself.

When calibrating the first signal characteristics of the lidar, a feasible idea is that if the second signal corresponding to each outgoing direction is determined, even if the first signal and the second signal are fused, the known The second signal separates the first signal from the received echo signal to realize the calibration of the first signal. According to this idea, an implementation manner is that a shielding member may be provided at the light outlet of the lidar.

Since the occluder is set at the light outlet of the lidar and forms a complete shield to the field of view of the lidar, the light pulses emitted by the lidar in all directions are reflected after encountering the occluder, so the received In the echo signal, if there is a second signal, the second signal is the echo signal reflected by the shield (which is also the object under test), and because the shield is very close, the second signal must occur with the first signal fusion.

The occluder is a pre-designed occluder, and its reflectivity and distance are known. Therefore, for light pulses emitted in all directions, the second signal reflected back after encountering the occluder can be based on the reflection of the occluder The rate and the distance are determined, so that when calibrating the first signal corresponding to each direction, the first signal can be obtained from the received echo signal based on the shielding member, so as to realize the calibrating of the first signal.

The calibration method provided in the embodiment of the present application can block the field of view of the laser radar through the blocking member, so that when calibrating the first signal, the first signal can be obtained from the received echo signal based on the blocking member, and the laser radar can be detected. Calibration of the first signal of the radar. This calibration method can complete the calibration of the first signal corresponding to each direction in the field of view at one time, and there is no possibility of calibration failure, and the setting of the occluder is also very convenient. Users can also pass this during the use of the laser radar. The shield completes the calibration of the first signal characteristic of the lidar.

In one embodiment, the shield can be made of materials with extremely low reflectivity, that is, the reflectivity of the shield can be lower than a preset value. At this time, because the reflectivity of the shield is extremely low, the laser radar The echo signal reflected by the light pulse after encountering the blocking member is negligible, that is, the second signal is negligible. Then, for the echo signal received within the time window, although it is obtained by fusion of the first signal and the second signal, because the second signal can be ignored, the received echo signal itself is the first signal , so that the currently received echo signal can be directly determined as the first signal corresponding to the current outgoing direction, and the calibration of the first signal in the current outgoing direction is completed.

In an implementation manner, the shielding member may also have a certain reflectivity, that is, its reflectivity may be higher than a preset value, and at this time, the second signal reflected by the shielding member cannot be ignored. However, since the reflectivity and distance of the occluder are known, for light pulses emitted in all directions, the second signal returned after encountering the occluder can be directly calculated, so that even if the received echo signal It is obtained by fusing the first signal and the second signal, and the first signal can also be restored from the received echo signal according to the reflectivity of the shielding member, so as to realize the calibration of the first signal.

When restoring the first signal according to the reflectivity of the shield, in an embodiment, the energy of the second signal reflected by the shield may be calculated according to the reflectivity of the shield and the distance of the shield. For the received echo signal, the corresponding energy can be calculated, and the calculated energy can be subtracted from the energy of the second signal to obtain the energy of the first signal. Using the energy of the first signal, the waveform of the first signal can be recovered, so that various waveform parameters of the first signal can be obtained from the waveform of the first signal, and the calibration of the first signal can be completed. When calculating the energy of the second signal according to the reflectivity and distance of the occluder, the following formula can be referred to:

E _intensity =k*r/R ²

Among them, E _intensity is the echo energy, r is the reflectivity, R is the detection distance, k is the scaling factor, k is related to the lidar circuit and optical characteristics, and is a fixed value.

In one embodiment, the blocking member may be a mask, which may be detachably attached to the light outlet of the lidar. Reference can be made to FIG. 6 , which is a schematic diagram of the installation of the mask provided by the embodiment of the present application. Certainly, the shielding member may also have other structures than those shown in FIG. 6 , as long as it can shield the field of view of the lidar.

Optionally, the instruction to start calibration is triggered by a user.

Optionally, the instruction to start calibration is sent to the laser radar by the control device of the movable platform.

Reference may be made to FIG. 7 , which is a third flowchart of the calibration method provided by the embodiment of the present application. The method is applied to a detection system, and the detection system may include a laser radar and a host computer, wherein the laser radar is a coaxial laser radar, and its transmitting optical path is partly the same as the receiving optical path. The method includes the following steps:

S702. The host computer establishes a connection with the lidar.

S704. The host computer sends a self-calibration command to the lidar.

S706. The lidar enters a self-calibration mode in response to the self-calibration command.

The detection system, in one embodiment, may be deployed on a mobile platform. Wherein, the upper computer may be a control device of a movable platform, which may send various commands to the lidar, such as a self-calibration command.

As mentioned above, after completing a round of calibration of the first signal in each direction, if there is an uncalibrated direction that has not been successfully calibrated, the uncalibrated direction can be re-calibrated after the scanning scene of the lidar is changed. Calibration of the first signal is performed. When changing the scanning scene of the lidar, in one embodiment, the lidar or the host computer can prompt the user to change the scanning scene of the lidar, for example, if the lidar is a vehicle-mounted lidar, the lidar or the host computer can prompt The user adjusts the orientation of the movable platform.

In a manner of calibrating the first signal characteristic of the laser radar, the field of view of the laser radar can be blocked by means of a shielding member, so as to eliminate the influence of the second signal on the calibration of the first signal. Therefore, in one embodiment, before sending the self-calibration command, the upper computer can send prompt information, and the prompt information can be used to remind the user to install the shield, and after the user completes the installation of the shield, it can then send the self-calibration command. calibration command.

Optionally, the laser radar respectively transmits light pulses to multiple directions in the field of view, and respectively calibrates the first signals corresponding to the multiple directions, including:

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, slope.

Send light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : intensity, pulse width, slope, wherein, the second signal is an echo signal reflected by the measured object.

Regarding how to calibrate the first signal of the lidar, since it has been described in detail above, it will not be repeated here.

In the calibration method provided by the embodiment of this application, the laser radar can enter the self-calibration mode in response to the instructions of the host computer, thereby automatically completing the calibration, without requiring a harsh calibration site or complicated external equipment, and the user only needs to prepare the shield in advance Or the calibration of the first signal characteristic of the lidar can be realized anytime and anywhere without any preparation.

Reference may be made to FIG. 8 , which is a schematic structural diagram of a calibration device provided in an embodiment of the present application. The calibration device can be applied to a coaxial laser radar, the transmitting optical path of the laser radar is the same as the receiving optical path, and the calibration device includes: a processor 810 and a memory 820 storing computer programs.

In one embodiment, the processor implements the following steps when executing the computer program:

Optionally, whether fusion occurs between the first signal and the second signal is determined according to the number of echo signals received within the time window.

Optionally, when the processor determines according to the received echo signal that no fusion occurs between the first signal and the second signal:

If two echo signals are received within the time window, it is determined that no fusion occurs between the first signal and the second signal.

Optionally, whether the fusion of the first signal and the second signal occurs is determined according to the waveform of the received echo signal.

Optionally, the processor is configured to: when determining whether fusion occurs between the first signal and the second signal according to the waveform of the received echo signal:

Comparing the waveform parameters of the received echo signal with the preset waveform parameters, and determining whether fusion occurs between the first signal and the second signal according to the comparison result.

Optionally, the processor is also used for:

If it is determined according to the received echo signal that the fusion of the first signal and the second signal occurs, mark the outgoing direction of the current light pulse as an unmarked direction, and enter the calibration process corresponding to the next outgoing direction.

Optionally, the processor is also used for:

After the calibration procedure corresponding to the last outgoing direction is completed, if there is the unmarked direction, after the scanning scene of the lidar is changed, the calibration of the first signal is performed on the unmarked direction.

Optionally, the lidar is carried on a movable platform, and the scanning scene of the lidar is changed through the movement of the movable platform.

Optionally, the instruction to start calibration is triggered by a user.

The various implementations of the above calibration device, the specific realization of which has been described in detail above, and will not be repeated here.

The calibration device provided in the embodiment of the present application can determine whether the fusion of the first signal and the second signal occurs according to the received echo signal, and can record the waveform of the first signal when the fusion of the first signal and the second signal does not occur parameters and the corresponding relationship between the first signal and the outgoing direction of the current light pulse to complete the calibration of the first signal corresponding to the current direction. It can be seen that, the method provided by the embodiment of the present application does not require the use of external instruments or a specific site, and the user can realize the calibration of the first signal characteristic of the laser radar during the use of the laser radar, thereby greatly improving the reliability of the laser radar. reliability.

The embodiment of the present application also provides a calibration device, whose structure can still refer to FIG. 8 , which can be applied to a coaxial laser radar, and the transmitting optical path of the laser radar is partly the same as the receiving optical path. The processor of the calibration device can realize the following steps when executing the computer program:

Optionally, the reflectivity of the shielding member is lower than a preset value, and the processor is configured to: when acquiring the first signal from the received echo signal based on the shielding member:

The received echo signal is determined as the first signal corresponding to the outgoing direction of the current light pulse.

Optionally, the reflectivity of the shielding member is higher than a preset value, and the processor is configured to: when acquiring the first signal from the received echo signal based on the shielding member:

The first signal is recovered from the received echo signal according to the reflectivity of the shielding member.

Optionally, when the processor restores the first signal from the received echo signal according to the reflectivity of the shielding member, it is used to:

calculating the energy of the second signal according to the reflectivity of the baffle, where the second signal is an echo signal reflected by the baffle;

calculating the energy of the first signal according to the energy of the received echo signal and the energy of the second signal;

The first signal is recovered according to the energy of the first signal.

Optionally, the shielding member includes a shield, and the shield is detachably attached to the light outlet.

Optionally, the instruction to start calibration is triggered by a user.

The embodiment of the present application also provides a laser radar, whose structure can refer to Figure 1, the laser radar can include:

a light source for emitting a sequence of light pulses;

Optionally, the processor is also used for:

After the calibration process corresponding to the last outgoing direction is completed, if there is the unmarked direction, after the scanning scene of the lidar is changed, the calibration of the first signal is performed on the unmarked direction.

Optionally, the instruction to start calibration is triggered by a user.

The specific implementations of the various implementations of the above lidar have been described in detail above, and will not be repeated here.

The lidar provided in the embodiment of the present application can determine whether the first signal and the second signal are fused according to the received echo signal, and can record the waveform of the first signal when the first signal and the second signal are not fused parameters and the corresponding relationship between the first signal and the outgoing direction of the current light pulse to complete the calibration of the first signal corresponding to the current direction. It can be seen that, the method provided by the embodiment of the present application does not require the use of external instruments or a specific site, and the user can realize the calibration of the first signal characteristic of the laser radar during the use of the laser radar, thereby greatly improving the reliability of the laser radar. reliability.

a light source for emitting a sequence of light pulses;

The first signal is recovered according to the energy of the first signal.

Optionally, the instruction to start calibration is triggered by a user.

The laser radar provided in the embodiment of the present application can block the field of view of the laser radar through the shielding member, so that when the first signal is calibrated, the first signal can be obtained from the received echo signal based on the shielding member, and the laser radar can be detected. Calibration of the first signal of the radar. This calibration method can complete the calibration of the first signal corresponding to each direction in the field of view at one time, and there is no possibility of calibration failure, and the setting of the occluder is also very convenient. Users can also pass this during the use of the laser radar. The shield completes the calibration of the first signal characteristic of the lidar.

Reference can be made to FIG. 9 below. FIG. 9 is a schematic structural diagram of a detection system provided by an embodiment of the present application. The detection system includes: a laser radar 910 and a host computer 920, and the laser radar is a coaxial laser radar;

Optionally, the laser radar is also used to prompt the user to change the laser radar if there is an uncalibrated direction that failed to be calibrated after performing a calibration process for each of the multiple directions. scanning scene.

Optionally, the lidar is mounted on a movable platform, and the lidar is used when prompting the user to change the scanning scene of the lidar:

The user is prompted to adjust the orientation of the movable platform.

Optionally, the host computer is also used for:

Before sending the self-calibration command, a prompt message for prompting the user to install a shield is sent, and the shield is configured to be arranged at the light outlet of the lidar to shield the field of view of the lidar.

Optionally, the lidar is used for:

Various implementations of the detection system above have been described in detail above, and will not be repeated here.

In the detection system provided by the embodiment of the present application, the laser radar can enter the self-calibration mode in response to the instructions of the host computer, thereby automatically completing the calibration, without requiring a harsh calibration site or complicated external equipment, and the user only needs to prepare the shield in advance Or the calibration of the first signal characteristic of the lidar can be realized anytime and anywhere without any preparation.

The embodiment of the present application further provides a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any calibration method provided in the embodiment of the present application can be implemented.

A variety of implementations are provided above for each protection subject. On the basis of no conflict or contradiction, those skilled in the art can freely combine various implementations according to actual conditions, thus forming various technical solutions. . However, the document of the present application is limited in length, and it is not possible to explain all the combined technical solutions, but it can be understood that these technical solutions that cannot be developed also belong to the scope of the disclosure of the embodiments of the present application.

Embodiments of the present application may take the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having program code embodied therein. Computer usable storage media includes both volatile and non-permanent, removable and non-removable media, and may be implemented by any method or technology for information storage. Information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for computers include, but are not limited to: phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Flash memory or other memory technology, Compact Disc Read-Only Memory (CD-ROM), Digital Versatile Disc (DVD) or other optical storage, Magnetic tape cartridge, tape magnetic disk storage or other magnetic storage device or any other non-transmission medium that can be used to store information that can be accessed by a computing device.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. The term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements but also other elements not expressly listed elements, or also elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The methods and devices provided by the embodiments of the present invention have been described in detail above. The principles and implementation methods of the present invention have been explained by using specific examples in this paper. The descriptions of the above embodiments are only used to help understand the methods and methods of the present invention. core idea; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be construed as limiting the present invention .

Claims

A kind of calibration method, is characterized in that, is applied to coaxial lidar, and described method comprises:

After obtaining the instruction to start calibration, transmit light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : Intensity, pulse width, slope, wherein the first signal is an echo signal reflected by the lidar itself, and the second signal is an echo signal reflected by a measured object.
The method according to claim 1, characterized in that whether the fusion of the first signal and the second signal occurs is determined according to the number of echo signals received within the time window.
The method according to claim 2, wherein the determining that no fusion occurs between the first signal and the second signal according to the received echo signal comprises:

If two echo signals are received within the time window, it is determined that no fusion occurs between the first signal and the second signal.
The method according to claim 1, characterized in that whether the fusion of the first signal and the second signal occurs is determined according to the waveform of the received echo signal.
The method according to claim 4, wherein determining whether fusion of the first signal and the second signal occurs according to the waveform of the received echo signal comprises:

Comparing the waveform parameters of the received echo signal with the preset waveform parameters, and determining whether fusion occurs between the first signal and the second signal according to the comparison result.
The method according to claim 1, further comprising:

If it is determined according to the received echo signal that the fusion of the first signal and the second signal occurs, mark the outgoing direction of the current light pulse as an unmarked direction, and enter the calibration process corresponding to the next outgoing direction.
The method according to claim 6, further comprising:

After the calibration procedure corresponding to the last outgoing direction is completed, if there is the unmarked direction, after the scanning scene of the lidar is changed, the calibration of the first signal is performed on the unmarked direction.
The method according to claim 7, wherein the lidar is mounted on a movable platform, and the scanning scene of the lidar is changed through the movement of the movable platform.
The method according to claim 1, characterized in that the instruction to start calibration is triggered by a user.
The method according to claim 1, wherein the instruction to start calibration is sent to the laser radar by a control device of a movable platform.
A kind of calibration method, is characterized in that, is applied to coaxial lidar, and described method comprises:

After obtaining the instruction to start the calibration, enter the calibration mode, wherein, in the calibration mode, the light outlet of the laser radar is provided with a shield, and the shield blocks the field of view of the laser radar;

Sending light pulses to multiple directions in the field of view respectively, and receiving an echo signal corresponding to the light pulse within a time window corresponding to each light pulse;

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, and slope, wherein the first signal is an echo signal reflected by the lidar itself.
The method according to claim 11, wherein the reflectivity of the occluder is lower than a preset value, and the obtaining the first signal from the received echo signal based on the occluder comprises:

The received echo signal is determined as the first signal corresponding to the outgoing direction of the current light pulse.
The method according to claim 11, wherein the reflectivity of the occluder is higher than a preset value, and the obtaining the first signal from the received echo signal based on the occluder comprises:

The first signal is recovered from the received echo signal according to the reflectivity of the shielding member.
The method according to claim 13, wherein the restoring the first signal from the received echo signal according to the reflectivity of the shielding member comprises:

calculating the energy of the second signal according to the reflectivity of the baffle, where the second signal is an echo signal reflected by the baffle;

calculating the energy of the first signal according to the energy of the received echo signal and the energy of the second signal;

The first signal is recovered according to the energy of the first signal.
The method according to claim 11, wherein the shielding member comprises a mask, and the mask is detachably attached to the light outlet.
The method according to claim 11, wherein the instruction to start calibration is triggered by a user.
The method according to claim 11, wherein the instruction to start calibration is sent to the laser radar by a control device of a movable platform.
A calibration method is characterized in that it is applied to a detection system, the detection system includes a laser radar and a host computer, the transmitting optical path of the laser radar is partly the same as the receiving optical path, and the method includes:

The host computer establishes a connection with the laser radar;

The host computer sends a self-calibration command to the lidar;

The lidar enters a self-calibration mode in response to the self-calibration command;

In the self-calibration mode, the laser radar emits light pulses in multiple directions in the field of view, and calibrates the first signals corresponding to the multiple directions, and the first signal is the laser The echo signal reflected by the radar itself.
The method according to claim 18, further comprising:

After performing a calibration process for each of the multiple directions, if there is an uncalibrated direction that cannot be successfully calibrated, the user is prompted to change the scanning scene of the lidar.
The method according to claim 19, wherein the lidar is mounted on a movable platform, and the prompting the user to change the scanning scene of the lidar includes:

The user is prompted to adjust the orientation of the movable platform.
The method according to claim 18, further comprising:

Before the host computer sends the self-calibration command, it sends out a prompt message for prompting the user to install a shield, and the shield is used to be arranged at the light outlet of the laser radar to control the laser radar. The field of view is blocked.
The method according to claim 21, wherein the lidar emits light pulses in multiple directions in the field of view respectively, and calibrates the first signals corresponding to the multiple directions, including:

Sending light pulses to multiple directions in the field of view respectively, and receiving an echo signal corresponding to the light pulse within a time window corresponding to each light pulse;

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, slope.
The method according to claim 18, wherein the lidar emits light pulses in multiple directions in the field of view respectively, and calibrates the first signals corresponding to the multiple directions, including:

Send light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : intensity, pulse width, slope, wherein, the second signal is an echo signal reflected by the measured object.
A calibration device is characterized in that it is applied to coaxial laser radar, and the calibration device includes: a processor and a memory storing a computer program, and the processor implements the following steps when executing the computer program:

After obtaining the instruction to start calibration, transmit light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : Intensity, pulse width, slope, wherein the first signal is an echo signal reflected by the lidar itself, and the second signal is an echo signal reflected by a measured object.
The device according to claim 24, wherein whether the fusion of the first signal and the second signal occurs is determined according to the number of echo signals received within the time window.
The device according to claim 25, wherein the processor is configured to: when determining that the fusion of the first signal and the second signal does not occur according to the received echo signal:

If two echo signals are received within the time window, it is determined that no fusion occurs between the first signal and the second signal.
The device according to claim 24, wherein whether the fusion of the first signal and the second signal occurs is determined according to the waveform of the received echo signal.
The device according to claim 27, wherein the processor is configured to: when determining whether fusion occurs between the first signal and the second signal according to the waveform of the received echo signal:

Comparing the waveform parameters of the received echo signal with the preset waveform parameters, and determining whether fusion occurs between the first signal and the second signal according to the comparison result.
The device according to claim 24, wherein the processor is further configured to:

If it is determined according to the received echo signal that the fusion of the first signal and the second signal occurs, mark the outgoing direction of the current light pulse as an unmarked direction, and enter the calibration process corresponding to the next outgoing direction.
The device according to claim 29, wherein the processor is further configured to:

After the calibration procedure corresponding to the last outgoing direction is completed, if there is the unmarked direction, after the scanning scene of the lidar is changed, the calibration of the first signal is performed on the unmarked direction.
The device according to claim 30, wherein the lidar is mounted on a movable platform, and the scanning scene of the lidar is changed through the movement of the movable platform.
The device according to claim 24, wherein the instruction to start calibration is triggered by a user.
The device according to claim 24, wherein the instruction to start calibration is sent to the laser radar by the control device of the movable platform.
A calibration device is characterized in that it is applied to coaxial laser radar, and the calibration device includes: a processor and a memory storing a computer program, and the processor implements the following steps when executing the computer program:

After obtaining the instruction to start the calibration, enter the calibration mode, wherein, in the calibration mode, the light outlet of the laser radar is provided with a shield, and the shield blocks the field of view of the laser radar;

Sending light pulses to multiple directions in the field of view respectively, and receiving an echo signal corresponding to the light pulse within a time window corresponding to each light pulse;

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, and slope, wherein the first signal is an echo signal reflected by the lidar itself.
The device according to claim 34, wherein the reflectivity of the shielding member is lower than a preset value, and the processor is used for obtaining the first signal from the received echo signal based on the shielding member :

The received echo signal is determined as the first signal corresponding to the outgoing direction of the current light pulse.
The device according to claim 34, wherein the reflectivity of the shielding member is higher than a preset value, and the processor is used for obtaining the first signal from the received echo signal based on the shielding member :

The first signal is recovered from the received echo signal according to the reflectivity of the shielding member.
The device according to claim 36, wherein the processor is configured to: when restoring the first signal from the received echo signal according to the reflectivity of the shielding member:

calculating the energy of the second signal according to the reflectivity of the baffle, where the second signal is an echo signal reflected by the baffle;

calculating the energy of the first signal according to the energy of the received echo signal and the energy of the second signal;

The first signal is recovered according to the energy of the first signal.
The device according to claim 34, wherein the shielding member comprises a shield, and the shield is detachably attached to the light outlet.
The device according to claim 34, wherein the instruction to start calibration is triggered by a user.
The device according to claim 34, wherein the instruction to start calibration is sent to the laser radar by the control device of the movable platform.
A laser radar, is characterized in that, comprises:

a light source for emitting a sequence of light pulses;

The optical system is used to adjust the outgoing direction of the light pulse emitted by the light source, and the emitting optical path of the laser radar is partly the same as the receiving optical path;

The receiving circuit is used to receive the echo signal corresponding to the optical pulse;

A processor and a memory storing a computer program, the processor, when executing the computer program, implements the following steps:

After obtaining the instruction to start calibration, transmit light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : intensity, pulse width, slope, wherein, the first signal is an echo signal reflected by the optical system itself, and the second signal is an echo signal reflected by a measured object.
The lidar according to claim 41, wherein whether the fusion of the first signal and the second signal occurs is determined according to the number of echo signals received within the time window.
The laser radar according to claim 42, wherein the processor is used for:

If two echo signals are received within the time window, it is determined that no fusion occurs between the first signal and the second signal.
The lidar according to claim 41, wherein whether the fusion of the first signal and the second signal occurs is determined according to the waveform of the received echo signal.
The laser radar according to claim 44, wherein the processor is used for:

Comparing the waveform parameters of the received echo signal with the preset waveform parameters, and determining whether fusion occurs between the first signal and the second signal according to the comparison result.
The laser radar according to claim 41, wherein the processor is also used for:

If it is determined according to the received echo signal that the fusion of the first signal and the second signal occurs, mark the outgoing direction of the current light pulse as an unmarked direction, and enter the calibration process corresponding to the next outgoing direction.
The laser radar according to claim 46, wherein the processor is also used for:

After the calibration procedure corresponding to the last outgoing direction is completed, if there is the unmarked direction, after the scanning scene of the lidar is changed, the calibration of the first signal is performed on the unmarked direction.
The lidar according to claim 47, wherein the lidar is mounted on a movable platform, and the scanning scene of the lidar is changed through the movement of the movable platform.
The lidar according to claim 41, wherein the instruction to start calibration is triggered by a user.
The laser radar according to claim 41, wherein the instruction to start calibration is sent to the laser radar by the control device of the movable platform.
A laser radar, is characterized in that, comprises:

a light source for emitting a sequence of light pulses;

The optical system is used to adjust the output direction of the light pulse emitted by the light source, and the emission optical path of the laser radar is partially the same as the receiving optical path;

The receiving circuit is used to receive the echo signal corresponding to the optical pulse;

A processor and a memory storing a computer program, the processor, when executing the computer program, implements the following steps:

After obtaining the instruction to start the calibration, enter the calibration mode, wherein, in the calibration mode, the light outlet of the laser radar is provided with a shield, and the shield blocks the field of view of the laser radar;

Sending light pulses to multiple directions in the field of view respectively, and receiving an echo signal corresponding to the light pulse within a time window corresponding to each light pulse;

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, and slope, wherein the first signal is an echo signal reflected by the lidar itself.
The lidar according to claim 51, wherein the reflectivity of the occluder is lower than a preset value, and the processor uses the occluder to obtain the first signal from the received echo signal based on the occluder At:

The received echo signal is determined as the first signal corresponding to the outgoing direction of the current light pulse.
The lidar according to claim 51, wherein the reflectivity of the occluder is higher than a preset value, and the processor uses the occluder to obtain the first signal from the received echo signal based on the occluder At:

The first signal is recovered from the received echo signal according to the reflectivity of the shielding member.
The laser radar according to claim 53, wherein the processor is used to restore the first signal from the received echo signal according to the reflectivity of the shielding member:

calculating the energy of the second signal according to the reflectivity of the baffle, where the second signal is an echo signal reflected by the baffle;

calculating the energy of the first signal according to the energy of the received echo signal and the energy of the second signal;

The first signal is recovered according to the energy of the first signal.
The lidar according to claim 51, wherein the shielding member comprises a mask, and the mask is detachably attached to the light outlet.
The lidar according to claim 51, wherein the instruction to start calibration is triggered by a user.
The lidar according to claim 51, wherein the instruction to start calibration is sent to the lidar by the control device of the movable platform.
A detection system, characterized in that it includes: a laser radar and a host computer, the laser radar is a coaxial laser radar;

The host computer is used to establish a connection with the laser radar, and send a self-calibration command to the laser radar;

The lidar is configured to enter a self-calibration mode in response to the self-calibration command; in the self-calibration mode, the lidar emits light pulses to multiple directions in the field of view respectively, and The first signals corresponding to the two directions are respectively calibrated, and the first signals are the echo signals reflected by the lidar itself.
The detection system according to claim 58, wherein the lidar is also used for: after performing a calibration process for each of the multiple directions, if there is an unidentified object that has not been successfully calibrated Mark the direction and prompt the user to change the scanning scene of the lidar.
The detection system according to claim 59, wherein the laser radar is mounted on a movable platform, and the laser radar is used to prompt the user to change the scanning scene of the laser radar:

The user is prompted to adjust the orientation of the movable platform.
The detection system according to claim 58, wherein the host computer is also used for:

Before sending the self-calibration command, a prompt message for prompting the user to install a shield is sent, and the shield is configured to be arranged at the light outlet of the lidar to shield the field of view of the lidar.
The detection system according to claim 61, wherein the laser radar is used for:

Sending light pulses to multiple directions in the field of view respectively, and receiving an echo signal corresponding to the light pulse within a time window corresponding to each light pulse;

Obtain a first signal from the received echo signal based on the occluder, and record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal: intensity , pulse width, slope.
The detection system according to claim 58, wherein the laser radar is used for:

Send light pulses to multiple directions in the field of view, and receive the echo signal corresponding to the light pulse within the time window of each light pulse;

If it is determined according to the received echo signal that no fusion occurs between the first signal and the second signal, record the corresponding relationship between the first signal and the outgoing direction of the current light pulse and at least one of the following waveform parameters of the first signal : intensity, pulse width, slope, wherein, the second signal is an echo signal reflected by the measured object.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the calibration method according to any one of claims 1-10 is implemented.
A computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the calibration method according to any one of claims 11-17 is implemented.