Lidar calibration parameter determination method and apparatus, storage medium, and electronic device

Abstract

The application provides a laser radar calibration parameter determination method and device, a storage medium and an electronic device. The laser radar calibration parameter determination method comprises the following steps: controlling a polygonal mirror to rotate at a preset rotating speed; adjusting the light-emitting time of pulse light emitted by a laser to a reflecting surface of the polygonal mirror; acquiring an image of a light spot generated by the reflecting surface reflecting the pulse light to a target plate; determining the light-emitting time of the pulse light corresponding to the target position of the light spot in the image as a first time corresponding to a first reflecting surface; calculating the time corresponding to other reflecting surfaces; adjusting the frequency of the pulse light emitted by the laser to match the preset rotating speed; capturing images of light spots generated by the reflecting surfaces reflecting the pulse light to the target plate; calculating the included angle between the light spots corresponding to the reflecting surfaces according to the positions of the light spots corresponding to the reflecting surfaces and the angular resolution of an image acquisition device; and determining the angle calibration value of the reflecting surfaces relative to the first reflecting surface according to the included angle. The embodiment of the application can improve the pointing accuracy of the laser radar light beam.

Description

Technical Field

[0001] This invention relates to the field of lidar technology, and in particular to a method, apparatus, storage medium, and electronic device for determining lidar calibration parameters. Background Technology

[0002] Currently, there are four common LiDAR ranging and angle measurement schemes: mechanical scanning, MEMS (Micro-Electro-Mechanical System) micromirrors, OPA (Optical Phased Array), and Flash. Mechanical scanning includes pure mechanical rotation scanning and rotating mirror scanning. Rotating mirror scanning includes rotating mirrors, rotating prisms, and rotating wedge mirrors. Mechanical scanning is affected by the rotation of the motor and the machining precision of some mechanical and optical parts, causing the beam pointing accuracy of the mechanically scanned LiDAR to deviate from the design value. This affects the point cloud data output by the LiDAR, leading to distortion of the measured target and jitter in the point cloud.

[0003] The multifaceted prism is based on a ranging module. Rotating the multifaceted prism reflects the light path to achieve one-dimensional ranging at different angles. It is then combined with another scanning mirror or prism to achieve two-dimensional scanning. The rotating multifaceted prism is a combination of a motor and a multifaceted prism.

[0004] A crucial parameter for rotating multifaceted prisms is dynamic jitter error. This error causes the light beam to reflect off the prism's reflective surfaces, resulting in angular errors perpendicular to these surfaces. This error affects the final beam pointing accuracy of the lidar. If such a multifaceted prism is used directly for scanning and ranging, the direction of the beam after reflection will differ from the designed direction, leading to pointing errors in the lidar. The lidar beam will be unevenly distributed in one dimension. Since the errors of multiple prism reflective surfaces are usually unknown, this ultimately causes jitter in the lidar point cloud data, affecting target detection and identification.

[0005] Currently, the angular resolution of common lidar systems is in the range of 0.1°-0.5°, while the dynamic jitter error of rotating faceted prisms is in the range of 0.01°-0.1°. The dynamic jitter error of rotating faceted prisms is smaller than that of lidar systems, and lidar systems have not yet undergone rigorous calibration. With technological advancements, the angular resolution of lidar systems is increasing, with some reaching 0.1° and below. This places increasingly higher demands on scanning devices, making it difficult to achieve extremely small dynamic jitter errors solely through manufacturing and assembly precision, thus requiring higher costs. Summary of the Invention

[0006] In view of this, one or more embodiments of the present invention provide a method, apparatus, storage medium and electronic device for determining lidar calibration parameters, which can improve the pointing accuracy of lidar beams.

[0007] One or more embodiments of the present invention provide a method for determining lidar calibration parameters, comprising: controlling a multifaceted prism equipped with an encoder to rotate at a preset rotational speed; after acquiring the initial angle signal of the encoder, adjusting the emission time of the pulsed light emitted by the laser to the reflecting surface of the multifaceted prism within a preset time period; capturing an image of a light spot generated by the pulsed light reflected from the reflecting surface to a target plate using an image acquisition device; determining the emission time of the pulsed light corresponding to the target position of the light spot in the image as the first moment corresponding to the first reflecting surface of the multifaceted prism; and determining the required emission time based on the central angle corresponding to the multifaceted prism rotating through one reflecting surface. Based on the time and the first moment, the corresponding moments of the other reflective surfaces of the multifaceted prism are calculated respectively; after acquiring the initial angle signal of the encoder again, the frequency of the pulse light emitted by the laser is adjusted to match the preset rotation speed; images of the light spots generated by the pulse light reflected by each reflective surface onto the target plate are captured by the image acquisition device to obtain the position of the light spot corresponding to each reflective surface; the included angle between the light spots corresponding to each reflective surface is calculated based on the position of the light spot corresponding to each reflective surface and the angular resolution of the image acquisition device; the angle calibration value of each reflective surface relative to the first reflective surface is determined based on the included angle.

[0008] Optionally, the center of the horizontal field of view of the image acquisition device coincides with the center of the optical path of the laser, and the target position is the position of the horizontal center in the image.

[0009] Optionally, within the preset time period, the rotation angle of the multifaceted prism is equal to the center angle corresponding to one of the reflecting surfaces of the multifaceted prism.

[0010] Optionally, the method further includes: after determining that the emission time of the pulse light corresponding to the target position of the light spot in the image is the first moment corresponding to the first reflecting surface of the multifaceted prism, calculating the product of the preset rotation speed and the first moment, and determining the product as the angle of the encoder corresponding to the first reflecting surface.

[0011] Optionally, the initial angle signal is the Z signal of the encoder.

[0012] One or more embodiments of the present invention also provide a lidar calibration parameter determination device, comprising: a control module configured to control a multifaceted prism equipped with an encoder to rotate at a preset rotation speed; an adjustment module configured to, after acquiring an initial angle signal from the encoder, adjust the emission time of pulsed light emitted by a laser to the reflecting surface of the multifaceted prism within a preset time period; an acquisition module configured to capture an image of a light spot generated by the pulsed light reflected from the reflecting surface to a target plate using an image acquisition device; a first determination module configured to determine the emission time of the pulsed light corresponding to the target position of the light spot in the image as a first moment corresponding to the first reflecting surface of the multifaceted prism; and a first calculation module configured to calculate the emission time of the pulsed light corresponding to the first reflecting surface of the multifaceted prism as the multifaceted prism rotates past a reflecting surface. The time required for the center angle and the first moment are used to calculate the corresponding moments for the other reflective surfaces of the multifaceted prism; the matching module is configured to, after acquiring the initial angle signal of the encoder again, adjust the frequency of the pulse light emitted by the laser to match the preset rotation speed; the imaging module is configured to, through the image acquisition device, capture images of the light spots generated by the pulse light reflected by each reflective surface onto the target plate, and obtain the position of the light spot corresponding to each reflective surface; the second calculation module is configured to, based on the position of the light spot corresponding to each reflective surface and the angular resolution of the image acquisition device, calculate the included angle between the light spots corresponding to each reflective surface; the second determination module is configured to, based on the included angle, determine the angle calibration value of each reflective surface relative to the first reflective surface.

[0013] Optionally, the center of the horizontal field of view of the image acquisition device coincides with the center of the optical path of the laser, and the target position is the position of the horizontal center in the image.

[0014] Optionally, the device further includes: a third calculation module, configured to, after determining that the emission time of the pulse light corresponding to the target position of the light spot in the image is a first moment corresponding to the first reflecting surface of the multifaceted prism, calculate the product of the preset rotation speed and the first moment, and determine the product as the angle of the encoder corresponding to the first reflecting surface.

[0015] One or more embodiments of the present invention also provide an electronic device, the electronic device comprising: a housing, a processor, a memory, a circuit board, and a power supply circuit, wherein the circuit board is disposed inside the space enclosed by the housing, and the processor and the memory are disposed on the circuit board; the power supply circuit is used to supply power to various circuits or devices of the electronic device; the memory is used to store executable program code; the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, for executing any of the above-described methods for determining lidar calibration parameters.

[0016] One or more embodiments of the present invention also provide a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute any of the above-described lidar calibration parameter determination methods.

[0017] The present invention discloses a method, apparatus, storage medium, and electronic device for determining lidar calibration parameters in one or more embodiments. First, it determines the first moment corresponding to the first reflecting surface of a multifaceted prism corresponding to the initial angle of the encoder. Then, based on this moment and the time required for the multifaceted prism to rotate through one reflecting surface, it calculates the moments corresponding to the other reflecting surfaces of the multifaceted prism. After reacquiring the initial signal from the encoder, it acquires the position of the light spots generated by the reflected pulse light from each reflecting surface to the target plate in the image. Based on the position of the light spots corresponding to each reflecting surface in the image and the angular resolution of the image acquisition device, it calculates the angle between the light spots corresponding to each reflecting surface. Based on this angle, it determines the angle calibration value of each reflecting surface relative to the first reflecting surface, thus obtaining the lidar calibration parameters. During the rotation of the multifaceted prism in the lidar, the laser beam is reflected by different reflecting surfaces of the multifaceted prism. By calibrating the angles of the reflecting surfaces of the multifaceted prism using calibration parameters, the laser beam exit angle can be consistent with the actual reflection angle direction, improving the lidar beam pointing accuracy. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a lidar calibration system according to one or more embodiments of the present invention.

[0020] Figure 2 This is a flowchart illustrating a method for determining lidar calibration parameters according to one or more embodiments of the present invention.

[0021] Figure 3 This is a schematic diagram of a rotating multifaceted prism according to one or more embodiments of the present invention.

[0022] Figure 4 This is a schematic diagram of a lidar calibration system according to one or more embodiments of the present invention.

[0023] Figure 5 This is a schematic diagram of a lidar calibration parameter determination device according to one or more embodiments of the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of an electronic device according to one or more embodiments of the present invention. Detailed Implementation

[0025] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0026] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] For lidar based on rotating multifaceted prisms (including motors and multifaceted prisms) scanning, the inventors analyzed the technical principles of rotating multifaceted prisms and attributed the causes of dynamic jitter errors in multifaceted prism scanning to the following aspects: prism spire difference (angular deviation of each reflecting surface of the prism), installation deviation between the prism and the motor shaft, bearing error, non-perpendicularity of the rotating shaft mounting base to the rotating shaft, dynamic balance, and prism rotation speed. Among these, bearing error is determined by bearing selection; suitable bearing precision can fully meet the requirements. Dynamic balance, which involves final adjustment of the counterweight, is also relatively easy to meet. Prism rotation speed is determined by motor drive control, and its precision is generally sufficient. Therefore, the optimized factors in this invention's embodiments include: prism spire difference, installation deviation between the prism and the motor shaft, and non-perpendicularity of the rotating shaft mounting base to the rotating shaft. Through analysis and testing, the inventors found that these three errors are all manufacturing and assembly errors, and after the prism is assembled and adjusted according to certain requirements, these three errors are basically fixed and are the main sources of dynamic jitter errors in rotating multifaceted prisms. Therefore, the present invention aims to determine and calibrate the dynamic jitter error of a rotating multifaceted prism, so as to match the angle of the beam reflected by the multifaceted prism with its true angle, obtain stable calibration parameters, use the calibration parameters to calibrate the multifaceted prism, and assemble the calibrated multifaceted prism into the lidar to improve the pointing accuracy of the lidar beam.

[0028] Figure 1 This is a schematic diagram of a lidar calibration system according to one or more embodiments of the present invention, such as... Figure 1As shown, the main control board 2 is connected to the rotating multifaceted prism 1 and is used to control the rotating multifaceted prism 1 to rotate at the required speed and to acquire the angle information of the encoder 13 in real time. Then, based on the angle value of the encoder 13, it controls the pulsed laser 3 (hereinafter referred to as the laser) to emit a pulsed light beam. The pulsed light is reflected by the rotating multifaceted prism 1 onto the target plate 6, forming a light spot on the target plate 6. The computer 4 is used to control the image acquisition device 5 to take pictures to acquire images of the target plate 6 and to identify the position of the light spot in the image through image algorithms. The computer 4 can also control the main control board 2 to adjust the emission time of the pulsed light. Knowing the rotational speed of the rotating multifaceted prism 1, the angle of each reflecting surface of the multifaceted prism 11 can be determined. The pulsed laser 3 can emit light at a certain repetition frequency, which matches the rotational speed of the rotating multifaceted prism 1. For example, if the rotational speed of the rotating multifaceted prism 1 is M r / s, then the repetition frequency of the pulsed laser 3 is M Hz, which can ensure that the beam emitted by the pulsed laser 3 hits the same position on the same reflecting surface of the rotating multifaceted prism 1.

[0029] Figure 2 This is a flowchart illustrating a method for determining lidar calibration parameters according to one or more embodiments of the present invention. The method can be based on... Figure 1 The lidar calibration system shown is implemented as follows: Figure 2 As shown, the method includes:

[0030] Step 201: Control the multifaceted prism equipped with the encoder to rotate at a preset speed;

[0031] Figure 3 This is a schematic diagram of a rotating multifaceted prism according to one or more embodiments of the present invention, such as... Figure 3 As shown, the rotating polyhedron 1 includes a polyhedron 11, an encoder 13, and a motor 12. The multifaceted prism 11 can be controlled to rotate at a preset speed by controlling the motor 12. The multifaceted prism 11, motor 12, and encoder 13 are connected in sequence... Figure 3 After the assembly is completed as shown, the output angle value of the encoder 13 and the multiple reflecting surfaces of the multifaceted prism 11 have a definite correspondence. Therefore, the angular position of each reflecting surface of the multifaceted prism 11 can be obtained through the output angle value of the encoder 13.

[0032] Step 202: After acquiring the initial angle signal of the encoder, adjust the emission time of the pulse light emitted by the laser to the reflective surface of the multifaceted prism within a preset time period; wherein, after the pulse light is emitted to the reflective surface of the multifaceted prism, it is reflected by the reflective surface of the multifaceted prism onto the target plate to form a light spot.

[0033] The aforementioned preset time period can be, for example, no less than the time period required for the center angle corresponding to the rotation of one reflective surface of the multifaceted prism. Therefore, within this time period, there must be an angle value corresponding to the center of one reflective surface of the multifaceted prism. Adjusting the emission time of the laser during this time period allows the pulse light emitted by the laser to be reflected by one of the surfaces of the multifaceted prism onto the target plate, forming multiple light spots. By identifying the positions of these light spots, the laser can be controlled to stop emitting pulse light when the light spot appears at a specified position.

[0034] Assuming the number of facets of the polyprism is n, then the angle α between each reflecting facet and the central axis of the motor is:

[0035]

[0036] Taking a regular hexagonal prism as an example, the angle between each reflecting surface and the central axis of the motor is 60°.

[0037] Assuming the rotating multifaceted prism rotates at a speed of Mr / s, the time Δt required to rotate 60° is:

[0038]

[0039] In this example, the preset time period can be no less than Δt.

[0040] Step 203: Take an image of the light spot generated by the reflection of the pulsed light from the reflective surface onto the target plate using an image acquisition device;

[0041] by Figure 1 Taking the lidar calibration system shown as an example, the image acquisition device can be fixed opposite the target plate to ensure that the field of view of the image acquisition device is consistent each time it takes an image, thereby capturing the changes in the position of the light spot corresponding to different reflective surfaces of the multifaceted prism in the image.

[0042] Step 204: Determine the emission time of the pulse light corresponding to the target position of the light spot in the image as the first moment corresponding to the first reflecting surface of the multifaceted prism;

[0043] Still with Figure 1 Taking the lidar calibration system shown as an example, the target position in the image acquired by the image acquisition device 5 can be determined in advance based on the positional relationship between the optical path of the pulse light emitted by the laser 3 and the horizontal field of view of the image acquisition device 5.

[0044] Step 205: Based on the time required for the multifaceted prism to rotate through the central angle corresponding to one reflecting surface and the first moment, calculate the times corresponding to the other reflecting surfaces of the multifaceted prism.

[0045] Given the rotational speed of the rotating polyhedron, the time required for the polyhedron to rotate through the center angle corresponding to one of the reflecting surfaces can be calculated. Adding this time to the first moment gives the moment corresponding to the second reflecting surface of the polyhedron. Similarly, the moments corresponding to the other reflecting surfaces of the polyhedron can be calculated.

[0046] Step 206: After acquiring the initial angle signal of the encoder again, adjust the frequency of the pulse light emitted by the laser to match the preset rotation speed;

[0047] For example, laser 3 can emit pulsed light at a repetition frequency that matches the rotational speed of the rotating polyhedron 1. For example, if the rotational speed of the rotating polyhedron 1 is M r / s, then the repetition frequency of laser 3 is M Hz. This ensures that the beam emitted by laser 3 is emitted to the same position on the same reflecting surface of the polyhedron 11.

[0048] Step 207: Use the image acquisition device to capture images of the light spots generated by the pulsed light reflected from each reflective surface onto the target plate, thereby obtaining the position of the light spot corresponding to each reflective surface;

[0049] Still with Figure 1 Taking the lidar calibration system shown as an example, since the angle between each reflector and the central axis of the motor is 60° (an example of the aforementioned center angle), there must be an angle value between the encoder signal 0° (an example of the aforementioned encoder initial signal) and 60° that corresponds to the center of one of the reflectors of the multi-faceted prism. Therefore, the main control board 2 can be controlled by computer 4 to continuously fine-tune the emission time of the laser pulse light within the time interval 0-Δt after the 0° signal of encoder 13 (the 0° signal corresponds to time zero). Then, computer 4 identifies whether the generated light spot is at the horizontal center position of the image. Finally, a time t0 can be obtained. If the light spot generated at time t0 is at the horizontal center position of the image, then the prism reflector corresponding to time t0 can be set as face 1 (an example of the aforementioned first reflector). Similarly, the prism reflector corresponding to time t0+Δt is set as face 2, ..., the prism reflector corresponding to time t0+5Δt is set as face 6. After determining the time corresponding to each reflector, the image acquisition device can be controlled to capture images at the corresponding time of each reflector. Alternatively, the image acquisition device can be controlled to periodically capture images at fixed time intervals.

[0050] Step 208: Calculate the angle between the light spots corresponding to each reflective surface based on the position of the light spot corresponding to each reflective surface and the angular resolution of the image acquisition device;

[0051] Step 209: Determine the angle calibration value of each reflecting surface relative to the first reflecting surface based on the included angle.

[0052] In one or more embodiments of the present invention, before calibrating the angles of the prism's reflecting surfaces using the aforementioned calibration parameters, it is assumed that the vertical angles of the multiple reflecting surfaces of the multifaceted prism are consistent. However, due to manufacturing and assembly deviations, the multiple reflecting surfaces may exhibit different vertical angles during rotation. By calibrating the angles of the multiple reflecting surfaces of the multifaceted prism, such as using the aforementioned first reflecting surface as a reference, the angle calibration values ​​of each reflecting surface relative to the first reflecting surface can be obtained.

[0053] like Figure 4 As shown, taking a hexagonal prism as an example, assuming the angle between facet 1 (an example of the first reflecting surface mentioned above) and facet 2 is θ, the beam emitted by laser 3, after reflection, has an angle of 2θ between the outgoing light spots. The distance between the reflecting surface and the target plate 6 is L1. The perpendicular distance D between the two light spots can be calculated using the following formula:

[0054] D = tan2θ·L1;

[0055] Assuming the angular resolution of the camera (an example of the image acquisition device described above) is δ, the number of pixels in the vertical direction between the centers of the two light spots processed by the image algorithm is N, and the distance between the camera and the target plate is L2, then the distance D between the two light spots can be calculated using the following formula:

[0056] D = tan(N·δ)·L2;

[0057] From the two formulas above, we can see that the angle θ between face 1 and face 2 can be calculated using the following formula:

[0058]

[0059] Similarly, the included angles θ1, θ2, θ3, and θ4 between face 1 and faces 3-6 can be obtained respectively.

[0060] By calibrating different reflective surfaces based on the calculated angle calibration values ​​of each reflective surface relative to the first reflective surface, the true reflection angle of each reflective surface of the multifaceted prism with respect to the laser beam can be obtained.

[0061] In one or more embodiments of the present invention, the lidar calibration parameter determination method may further include: after determining that the emission time of the pulse light corresponding to the target position of the light spot in the image is a first moment corresponding to the first reflecting surface of the multifaceted prism, calculating the product of the preset rotation speed and the first moment, and determining the product as the angle of the encoder corresponding to the first reflecting surface. Following the above example, the encoder angle value ω corresponding to time t0 can be calculated using the following formula:

[0062] ω=t0·M;

[0063] In other words, when the encoder angle value is ω, it corresponds to the first reflecting surface of the multifaceted prism.

[0064] The calibration parameters determined by the lidar calibration parameter determination method according to one or more embodiments of the present invention include, but are not limited to, the parameters shown in Table 1 below.

[0065]

[0066]

[0067] The lidar calibration parameter determination method of one or more embodiments of the present invention first determines the first moment corresponding to the first reflecting surface of the multifaceted prism corresponding to the initial angle of the encoder. Then, based on this moment and the time required for the multifaceted prism to rotate through one reflecting surface, the moments corresponding to the other reflecting surfaces of the multifaceted prism are calculated respectively. After the initial signal of the encoder is acquired again, the position of the light spot generated by the reflected pulse light from each reflecting surface to the target plate in the image is acquired. Based on the position of the light spot corresponding to each reflecting surface in the image and the angular resolution of the image acquisition device, the angle between the light spots corresponding to each reflecting surface is calculated. Based on this angle, the angle calibration value of each reflecting surface relative to the first reflecting surface is determined, thus obtaining the lidar calibration parameters. During the rotation of the multifaceted prism of the lidar, the laser beam is reflected by different reflecting surfaces of the multifaceted prism. By calibrating the angle of the reflecting surfaces of the multifaceted prism using calibration parameters, the laser beam exit angle can be consistent with the actual reflection angle direction, improving the lidar beam pointing accuracy.

[0068] In one or more embodiments of the present invention, the center of the horizontal field of view of the image acquisition device coincides with the center of the optical path of the laser, and the target position is the position of the horizontal center in the image. Figure 1 Taking the lidar calibration system shown as an example, the angle between a certain reflecting surface of the rotating multifaceted prism 1 and the laser 3 is 45°. The pulsed light emitted by the laser 3 follows... Figure 1 The light emitted is directed in the direction of the dashed line shown, with the center of the horizontal field of view of the image acquisition device 5 coinciding with the center of the optical path of the laser 3 in the figure. By pre-arranging the positional relationship between the rotating multifaceted prism 1, the image acquisition device 5, and the laser 3, the pulsed light emitted by the laser 3, when incident on the center of the first reflecting surface of the multifaceted prism 11, is reflected by the first reflecting surface onto the target plate 3, resulting in a light spot at the horizontal center of the image. Therefore, when the light spot is detected at the horizontal center of the image, the corresponding moment of the first reflecting surface can be determined.

[0069] In one or more embodiments of the present invention, within the preset time period, the rotation angle of the multifaceted prism can be equal to the center angle corresponding to one of its reflecting surfaces. That is, the preset time period can be the time required for the multifaceted prism to rotate through the center angle corresponding to one reflecting surface. In the above example, the multifaceted prism is a hexagonal prism, then the center angle corresponding to one of its reflecting surfaces is 60°, and the corresponding preset time period is the time required for the multifaceted prism to rotate 60°.

[0070] In one or more embodiments of the present invention, the initial angle signal may be the Z signal of the encoder. An encoder typically has A, B, and Z signals. The encoder outputs a Z signal every 360° of rotation. The angle corresponding to the Z signal is taken as 0°. Since the 0° direction of the encoder and the reflecting surface of the multifaceted prism cannot be perfectly aligned during the manufacturing and assembly process, the reflecting surface corresponding to the 0° angle must be found first. Therefore, the Z signal is used as the initial signal of the encoder to determine the first reflecting surface.

[0071] Figure 5 This is a schematic diagram of a lidar calibration parameter determination device according to one or more embodiments of the present invention, as shown below. Figure 5 As shown, the device 50 includes:

[0072] Control module 51 is configured to control a multifaceted prism equipped with an encoder to rotate at a preset speed;

[0073] The adjustment module 52 is configured to adjust the emission time of the pulse light emitted by the laser to the reflecting surface of the multifaceted prism within a preset time period after acquiring the initial angle signal of the encoder.

[0074] The acquisition module 53 is configured to capture an image of the light spot generated by the reflection of the pulsed light from the reflective surface onto the target plate using an image acquisition device;

[0075] The first determining module 54 is configured to determine the emission time of the pulse light corresponding to the target position of the light spot in the image as the first moment corresponding to the first reflecting surface of the multifaceted prism;

[0076] The first calculation module 55 is configured to calculate the times corresponding to the other reflective surfaces of the multifaceted prism based on the time required for the multifaceted prism to rotate through the central angle corresponding to one reflective surface and the first time.

[0077] The matching module 56 is configured to, after acquiring the initial angle signal of the encoder again, adjust the frequency of the pulse light emitted by the laser to match the preset rotation speed;

[0078] The imaging module 57 is configured to capture images of the light spots generated on the target plate by the image acquisition device, thereby obtaining the position of the light spot corresponding to each reflective surface;

[0079] The second calculation module 58 is configured to calculate the angle between the light spots corresponding to each reflective surface based on the position of the light spot corresponding to each reflective surface and the angular resolution of the image acquisition device.

[0080] The second determining module 59 is configured to determine the angle calibration value of each reflecting surface relative to the first reflecting surface based on the included angle.

[0081] In one or more embodiments of the present invention, the center of the horizontal field of view of the image acquisition device coincides with the center of the optical path of the laser, and the target position is the position of the horizontal center in the image.

[0082] In one or more embodiments of the present invention, the lidar calibration parameter determination device may further include: a third calculation module, configured to, after determining that the emission time of the pulse light corresponding to the target position of the light spot in the image is a first moment corresponding to the first reflecting surface of the multifaceted prism, calculate the product of the preset rotation speed and the first moment, and determine the product as the angle of the encoder corresponding to the first reflecting surface.

[0083] One or more embodiments of the present invention provide an electronic device, the electronic device comprising: a housing, a processor, a memory, a circuit board, and a power supply circuit, wherein the circuit board is disposed within the space enclosed by the housing, and the processor and the memory are disposed on the circuit board; the power supply circuit is used to supply power to various circuits or devices of the electronic device; the memory is used to store executable program code; the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, for executing any of the above-described methods for determining lidar calibration parameters.

[0084] One or more embodiments of the present invention provide a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute any of the above-described methods for determining lidar calibration parameters.

[0085] Correspondingly, such as Figure 6As shown, the electronic device provided by one or more embodiments of the present invention may include: a housing 61, a processor 62, a memory 63, a circuit board 64, and a power supply circuit 65, wherein the circuit board 64 is disposed inside the space enclosed by the housing 61, and the processor 62 and the memory 63 are disposed on the circuit board 64; the power supply circuit 65 is used to supply power to various circuits or devices of the electronic device; the memory 63 is used to store executable program code; the processor 62 runs a program corresponding to the executable program code by reading the executable program code stored in the memory 63, for executing any of the laser radar calibration parameter determination methods provided in the foregoing embodiments.

[0086] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0088] In particular, the device embodiment is basically similar to the method embodiment, so the description is relatively simple. For relevant details, please refer to the description of the method embodiment.

[0089] For ease of description, the above apparatus is described by dividing it into various functional units / modules. Of course, in implementing this invention, the functions of each unit / module can be implemented in one or more software and / or hardware.

[0090] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0091] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for determining lidar calibration parameters, characterized in that, include: Control the multifaceted prism equipped with an encoder to rotate at a preset speed; After acquiring the initial angle signal of the encoder, the emission time of the pulse light emitted by the laser to the reflecting surface of the multifaceted prism is adjusted within a preset time period. An image of the light spot generated by the reflection of the pulsed light from the reflective surface onto the target plate is captured by an image acquisition device; The emission time of the pulse light corresponding to the target position of the light spot in the image is determined as the first moment corresponding to the first reflecting surface of the multifaceted prism; Based on the time required for the multifaceted prism to rotate through the central angle corresponding to one reflecting surface and the first moment, the moments corresponding to the other reflecting surfaces of the multifaceted prism are calculated respectively. After acquiring the initial angle signal of the encoder again, the frequency of the pulse light emitted by the laser is adjusted to match the preset rotation speed; The image acquisition device captures images of the light spots generated on the target plate by reflecting pulsed light from each reflective surface, thereby obtaining the position of the light spot corresponding to each reflective surface. Calculate the included angle between the light spots corresponding to each reflective surface based on the position of the light spot corresponding to each reflective surface and the angular resolution of the image acquisition device; The angular calibration value of each reflective surface relative to the first reflective surface is determined based on the included angle.

2. The method according to claim 1, characterized in that, The center of the horizontal field of view of the image acquisition device coincides with the center of the optical path of the laser, and the target position is the position of the horizontal center in the image.

3. The method according to claim 1, characterized in that, During the preset time period, the rotation angle of the multifaceted prism is equal to the center angle corresponding to one of the reflecting surfaces of the multifaceted prism.

4. The method according to claim 1, characterized in that, The method further includes: After determining that the emission time of the pulse light corresponding to the target position of the light spot in the image is the first moment corresponding to the first reflecting surface of the multifaceted prism, the product of the preset rotation speed and the first moment is calculated, and the product is determined as the angle of the encoder corresponding to the first reflecting surface.

5. The method according to claim 1, characterized in that, The initial angle signal is the Z signal of the encoder.

6. A device for determining calibration parameters for a lidar system, characterized in that, include: The control module is configured to control a multifaceted prism equipped with an encoder to rotate at a preset speed; The adjustment module is configured to adjust the emission time of the pulsed light emitted by the laser to the reflecting surface of the multifaceted prism within a preset time period after acquiring the initial angle signal of the encoder. The acquisition module is configured to capture an image of the light spot generated by the reflection of the pulsed light from the reflective surface onto the target plate using an image acquisition device; The first determining module is configured to determine the emission time of the pulse light corresponding to the target position of the light spot in the image as the first moment corresponding to the first reflecting surface of the multifaceted prism; The first calculation module is configured to calculate the times corresponding to the other reflective surfaces of the multifaceted prism based on the time required for the multifaceted prism to rotate through the central angle corresponding to one reflective surface and the first time. The matching module is configured to, after acquiring the initial angle signal of the encoder again, adjust the frequency of the pulse light emitted by the laser to match the preset rotation speed; The imaging module is configured to capture images of the light spots generated on the target plate by the image acquisition device, thereby obtaining the position of the light spot corresponding to each reflective surface; The second calculation module is configured to calculate the angle between the light spots corresponding to each reflective surface based on the position of the light spot corresponding to each reflective surface and the angular resolution of the image acquisition device. The second determining module is configured to determine the angle calibration value of each reflecting surface relative to the first reflecting surface based on the included angle.

7. The apparatus according to claim 6, characterized in that, The center of the horizontal field of view of the image acquisition device coincides with the center of the optical path of the laser, and the target position is the position of the horizontal center in the image.

8. The apparatus according to claim 6, characterized in that, The device further includes: The third calculation module is configured to, after determining that the emission time of the pulse light corresponding to the target position of the light spot in the image is the first moment corresponding to the first reflecting surface of the multifaceted prism, calculate the product of the preset rotation speed and the first moment, and determine the product as the angle of the encoder corresponding to the first reflecting surface.

9. An electronic device, characterized in that, The electronic device includes: a housing, a processor, a memory, a circuit board, and a power supply circuit, wherein the circuit board is disposed inside the space enclosed by the housing, and the processor and the memory are disposed on the circuit board; the power supply circuit is used to supply power to various circuits or devices of the electronic device; the memory is used to store executable program code; the processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, for executing the laser radar calibration parameter determination method according to any one of claims 1 to 5.

10. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions for causing the computer to execute the lidar calibration parameter determination method according to any one of claims 1 to 5.

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