Method and device for increasing number of point cloud lines, computer equipment and storage medium

Abstract

The invention relates to the technical field of signal processing, and discloses a method and device for increasing the number of point cloud lines, computer equipment and a storage medium, and the method comprises the steps: continuously rotating a polyhedral rotating mirror according to a first preset speed, and continuously rotating a galvanometer according to a second preset speed, the time of rotating the galvanometer for one period comprises the first half-period time and the second half-period time; the multi-channel laser beam is reflected to a measured target object through each surface body of the galvanometer and the polyhedral rotating mirror in sequence; acquiring laser beams reflected to the measured target object through each surface body of the polyhedral rotating mirror in the first half-cycle time and the second half-cycle time of the galvanometer to obtain point cloud data of an upper half frame and point cloud data of a lower half frame; and combining the point cloud data of the upper half frame and the point cloud data of the lower half frame to obtain point cloud data of a preset line number. According to the method, the point cloud line number of each frame is increased, and the frame rate is kept unchanged.

Description

Technical Field

[0001] The present invention relates to the field of signal processing technology, and in particular to a method, device, computer equipment and storage medium for increasing the number of point cloud lines. Background Art

[0002] At present, the Frequency Modulated Continuous Wave (FMCW) laser radar is still in the full mechanical scanning stage (that is, mechanical scanning is required in both vertical and horizontal directions), and the scanning of the large field of view in the horizontal direction is basically inseparable from the assistance of the rotating mirror. The introduction of the rotating mirror will bring about the Doppler effect and the reduction of the signal-to-noise ratio. The faster the rotation speed, the stronger the Doppler effect and the lower the signal-to-noise ratio. The point cloud will also become wider and thicker. The frame rate and number of lines of the point cloud are limited by the rotation speed of the rotating mirror. The higher the rotation speed of the rotating mirror, the higher the frame rate and number of lines of the point cloud can be made. The rotation speed of the rotating mirror is limited by factors such as the horizontal angle resolution rate, sampling frequency and Doppler effect, and cannot be increased indefinitely. However, if you want to increase the resolution of the FMCW laser radar, increase the frame rate or increase the viewing angle, you need to increase the number of point clouds acquired per unit time. Therefore, a method to increase the number of point cloud lines is urgently needed. Summary of the invention

[0003] In view of this, the present invention provides a method, apparatus, computer device and storage medium for increasing the number of point cloud lines to solve the problem of low frame rate caused by insufficient number of point cloud lines when the number of antennas, rotation speed per second and number of rotating mirrors are fixed.

[0004] In a first aspect, the present invention provides a method for increasing the number of point cloud lines, which is applied to an FMCW laser radar, wherein the FMCW laser radar includes an FMCW chip module, a galvanometer, and a polyhedron rotating mirror, and the method includes:

[0005] The polygonal rotating mirror is continuously rotated at a first preset speed and the galvanometer mirror is continuously rotated at a second preset speed, respectively, so that the polygonal rotating mirror and the galvanometer mirror rotate according to their respective cycle times; wherein the time for the galvanometer mirror to rotate for one cycle includes a first half cycle time and a second half cycle time;

[0006] The multi-channel laser beam emitted by the FMCW chip module is emitted to the galvanometer, and is reflected to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, forming a multi-channel laser propagation optical path;

[0007] In the multi-channel laser propagation optical path, the laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the first half cycle of the galvanometer rotation is obtained to obtain the upper half frame point cloud data; at the same time, the laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the second half cycle of the galvanometer rotation is obtained to obtain the lower half frame point cloud data;

[0008] The upper half frame point cloud data is combined with the lower half frame point cloud data to obtain point cloud data with a preset number of lines.

[0009] The present invention provides a method for increasing the number of point cloud lines. In a multi-channel laser propagation optical path, a laser beam reflected by each facet of a polyhedron rotating mirror to a target object to be measured during the first half-cycle of the galvanometer rotation is obtained to obtain upper half-frame point cloud data; at the same time, a laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the second half-cycle of the galvanometer rotation is obtained to obtain lower half-frame point cloud data; the upper half-frame point cloud data is combined with the lower half-frame point cloud data to obtain point cloud data with a preset number of lines, so that when the number of antennas, the rotation speed per second and the number of rotating mirror surfaces are fixed, the number of point cloud lines per frame is increased while the frame rate is kept unchanged, thereby achieving the purpose of increasing the frame rate and vertical resolution and increasing the vertical FOV (Field of View) at the same point frequency per second, and solving the problem of low frame rate caused by insufficient point cloud line number when the number of antennas, the rotation speed per second and the number of rotating mirror surfaces are fixed.

[0010] In an optional embodiment, the method for increasing the number of point cloud lines also includes: during the continuous rotation of the polyhedron rotating mirror and the galvanometer mirror, setting stop points on the polyhedron rotating mirror according to a first preset number, and setting stop points on the galvanometer mirror according to a second preset number, and the stay time of each stop point on the galvanometer mirror is the time occupied by each facet when the polyhedron rotating mirror rotates one circle, and the ratio of the first preset number to the second preset number is a multiple relationship.

[0011] In an optional implementation, the method for increasing the number of point cloud lines further includes: when the galvanometer continuously rotates, setting the angle of each galvanometer rotation based on the field of view angle between the FMCW chip module and the target object to be measured.

[0012] In an optional embodiment, a multi-channel laser beam emitted by the FMCW chip module is emitted to a galvanometer, and is reflected to a target object through the galvanometer and each face of the polyhedron rotating mirror in turn, forming a multi-channel laser propagation optical path, including:

[0013] Obtain a multi-channel laser beam emitted by the FMCW chip module, and emit the multi-channel laser beam to the galvanometer;

[0014] A galvanometer is used to reflect the multi-channel laser beam to each face of the polygonal rotating mirror. During the galvanometer reflection process, the laser beam stops on each face of the polygonal rotating mirror according to a preset stop point, and based on the position of the stop point, the laser beam is reflected to the target object to be measured through each face of the polygonal rotating mirror. The optical path formed by the multi-channel laser beam passing through the galvanometer, the polygonal rotating mirror and the target object to be measured in sequence is used as the multi-channel laser propagation optical path.

[0015] In an optional embodiment, emitting the multi-channel laser beam emitted by the FMCW chip module onto the galvanometer, and reflecting the multi-channel laser beam onto the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, further comprises:

[0016] When the multi-channel laser beam reflected by the galvanometer mirror moves from one face of the polyhedron rotating mirror to another face, the angle of the galvanometer mirror is adjusted so that the angle between each face of the polyhedron rotating mirror and the galvanometer mirror is different;

[0017] Each face of the rotating mirror is controlled in turn to receive the multi-channel laser beam reflected by the galvanometer at different angles, and reflect it to the target object to be measured.

[0018] In an optional embodiment, obtaining the laser beam reflected by each face of the polyhedron mirror to the target object during the first half cycle of the galvanometer mirror rotation to obtain the upper half frame point cloud data includes:

[0019] When the laser beams of multiple channels are reflected from the stop points of the galvanometer to the stop points of each face of the polyhedron rotating mirror and then reflected to the target object to be measured, a line point cloud consisting of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror is formed on each channel;

[0020] The line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror on each channel during the first half cycle of the galvanometer rotation is summarized, and arranged in chronological order to obtain the upper half frame point cloud data.

[0021] In an optional implementation, obtaining the laser beam reflected by each face of the polyhedron mirror to the target object during the second half cycle of the galvanometer mirror rotation to obtain the lower half frame point cloud data includes:

[0022] When the laser beams of multiple channels are reflected from the stop points of the galvanometer to the stop points of each face of the polyhedron rotating mirror and then reflected to the target object to be measured, a line point cloud consisting of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror is formed on each channel;

[0023] The line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror on each channel during the second half cycle of the galvanometer rotation is summarized, and arranged in chronological order to obtain the point cloud data of the second half frame.

[0024] In a second aspect, the present invention provides a device for increasing the number of point cloud lines, which is applied to an FMCW laser radar, wherein the FMCW laser radar includes an FMCW chip module, a galvanometer, and a polyhedron rotating mirror, and the device includes:

[0025] A rotation module, used to continuously rotate the polyhedron rotating mirror at a first preset speed and continuously rotate the galvanometer mirror at a second preset speed, respectively, so that the polyhedron rotating mirror and the galvanometer mirror rotate according to their respective cycle times; the time for the galvanometer mirror to rotate for one cycle includes a first half cycle time and a second half cycle time;

[0026] The laser propagation module is used to transmit the multi-channel laser beam emitted by the FMCW chip module to the galvanometer, and reflect it to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn;

[0027] The point cloud data acquisition module acquires the laser beam reflected from each facet of the polyhedron rotating mirror to the target object during the first half cycle of the galvanometer rotation to obtain the upper half frame point cloud data; meanwhile, the laser beam reflected from each facet of the polyhedron rotating mirror to the target object during the second half cycle of the galvanometer rotation to obtain the lower half frame point cloud data;

[0028] The combination module is used to combine the upper half frame point cloud data with the lower half frame point cloud data to obtain point cloud data with a preset number of lines.

[0029] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method for increasing the number of point cloud lines of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0030] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for increasing the number of point cloud lines of the above-mentioned first aspect or any corresponding embodiment thereof.

[0031] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the method for increasing the number of point cloud lines according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 is a flow chart of a method for increasing the number of point cloud lines according to an embodiment of the present invention;

[0034] Figure 2is a flow chart of another method for increasing the number of point cloud lines according to an embodiment of the present invention;

[0035] Figure 3 is a flow chart of another method for increasing the number of point cloud lines according to an embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of an FMCW laser radar according to an embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of FMCW laser radar scanning according to an embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of the change of the galvanometer angle in one cycle according to an embodiment of the present invention;

[0039] FIG. 7( a ) is a schematic diagram of a line point cloud obtained in the first half cycle of a galvanometer according to an embodiment of the present invention;

[0040] FIG7( b ) is a schematic diagram of a line point cloud obtained in the second half cycle of a galvanometer according to an embodiment of the present invention;

[0041] Figure 8 is a schematic diagram of the organization of the upper half frame point cloud data and the lower half frame point cloud data according to an embodiment of the present invention;

[0042] Fig. 9 is a schematic diagram of point cloud data with a preset number of lines per frame after recombination according to an embodiment of the present invention;

[0043] Fig.10 is a schematic diagram illustrating the time required for a galvanometer to rotate one circle according to an embodiment of the present invention;

[0044] Fig.11 is a structural block diagram of a device for increasing the number of point cloud lines according to an embodiment of the present invention;

[0045] Fig.12 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0047] The point cloud frame rate f and the number of point cloud lines per frame n generally have the following relationship:

[0048] f = number of antennas * rotation speed per second * number of rotating mirrors / n.

[0049] For example, if the rotation speed is 600 revolutions per minute, the number of antennas is 4, and the number of rotating mirrors is 4, then to obtain a 32-line point cloud, the frame rate f = (600 / 60*4*4) / 32 = 5 frames per second.

[0050] Generally speaking, the larger the number of lines n per frame and the frame rate f of the point cloud, the better. However, from the formula, we can see that when the number of antennas, rotation speed per second and number of rotating mirrors are fixed, increasing the number of lines n will inevitably reduce the frame rate f.

[0051] In order to obtain a point cloud with a preset number of lines, the existing technology cannot achieve this, for the following reasons: (1) The number of surfaces that the mirror rotates in 1 second is 600 rpm / 60s×4 surfaces / revolution=40 surfaces, while the actual number of surfaces required is 32 lines / 4 channels*10fps=80 surfaces; (2) The vertical resolution is 18° / 32=0.56°> the required 0.4°; (3) From the perspective of frame rate, f=number of antennas*speed of rotation per second*number of mirror surfaces / number of lines per frame=(600 / 60*4*4) / 32=5 frames / second.

[0052] In order to solve the above problems, an embodiment of the present invention provides a method for increasing the number of point cloud lines, so as to achieve the effect of increasing the number of lines per frame n while keeping the frame rate f unchanged while keeping the number of antennas, the rotation speed per second and the number of rotating mirrors fixed, thereby increasing the frame rate and vertical resolution and increasing the vertical FOV (Field of View) at the same point frequency per second.

[0053] According to an embodiment of the present invention, a method embodiment for increasing the number of point cloud lines is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0054] In this embodiment, a method for increasing the number of point cloud lines is provided, which can be used for an FMCW laser radar, wherein the FMCW laser radar includes an FMCW chip module, a galvanometer, and a polyhedron rotating mirror. Figure 1 is a flow chart of a method for increasing the number of point cloud lines according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0055] Step S101, continuously rotating the polygon mirror at a first preset speed and the galvanometer mirror at a second preset speed, so that the polygon mirror and the galvanometer mirror rotate according to their respective cycle times; wherein the time for the galvanometer mirror to rotate for one cycle includes a first half cycle time and a second half cycle time.

[0056] Specifically, the laser in the FMCW chip module 1 is used to emit laser light of a certain frequency. Figure 4 As shown, a laser beam is emitted from the FMCW chip module 1, passes through the lens and enters the galvanometer 2, and then enters the rotating mirror 3 from the galvanometer; the galvanometer 2 controls the vertical scanning angle of the light, and the rotating mirror 3 controls the horizontal scanning angle of the light. The polyhedron rotating mirror and the galvanometer mirror in the entire FMCW laser radar are connected to the upper-level main control system. The galvanometer control module in the main control system controls the rotation of the galvanometer, and the rotating mirror control module in the main control system controls the rotation of the polyhedron rotating mirror. The main functions of the FMCW chip module are to generate laser, modulate laser, distribute laser, emit laser, measure return light, etc. The galvanometer motion of this embodiment adopts reciprocating motion, such as Fig.10 As shown in the figure, assuming that the light enters from I1, the first reflected light is O1, and as the galvanometer rotates at different angles, it changes to O2, ..., ON, and then from ON, ..., O2, back to O1, completing a cycle of action. The time it takes for the galvanometer to rotate one cycle is the time it takes to complete a cycle of action.

[0057] The first preset speed and the second preset speed are set according to the actual situation. The main control system continuously rotates the polyhedron mirror at the first preset speed and the second preset speed. The time for the galvanometer mirror to rotate one cycle can be set to be equal to the time for the polyhedron mirror to rotate two circles. The time for the galvanometer mirror to rotate one cycle is divided into the first half cycle, i.e., the first half cycle time, and the second half cycle, i.e., the second half cycle time. Figure 6 shown.

[0058] Step S102 , the multi-channel laser beam emitted by the FMCW chip module is emitted to the galvanometer, and is reflected to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, forming a multi-channel laser propagation optical path.

[0059] Step S103, in the multi-channel laser propagation optical path, obtain the laser beam reflected by each facet of the polyhedron mirror to the target object to be measured during the first half cycle of the galvanometer rotation to obtain the upper half frame point cloud data; at the same time, obtain the laser beam reflected by each facet of the polyhedron mirror to the target object to be measured during the second half cycle of the galvanometer rotation to obtain the lower half frame point cloud data.

[0060] Specifically, the horizontal scanning of the light is generated by the rotation of the rotating mirror, while the change of the vertical angle is controlled by the position of the galvanometer, e.g. Figure 5As shown. For example, the laser of channel 1 is reflected by the galvanometer point A1 and reaches the rotating mirror point B1, and then reflected from point B1 to the target point B1-L0. As the rotating mirror rotates, it scans from the target point B1-L0 to point B1-L1. After switching the galvanometer position, the laser of channel 1 is reflected by the galvanometer point A1 and reaches the rotating mirror point B1', and then reflected from point B1' to the target point B1'-L0. As the rotating mirror rotates, it scans from the target point B1'-L0 to point B1'-L1. The same applies to other channels.

[0061] The galvanometer control has 8 stop points, and the length of each stop point is the time each side takes when the mirror rotates one circle, that is, (1 / rotating mirror rotation speed per second) / 8. However, there are only four stop positions for one rotation of the mirror, which means that we get two point cloud images of different line positions in one cycle of the galvanometer, as shown in Figure 7(a) and Figure 7(b).

[0062] Step S104, combining the upper half frame point cloud data with the lower half frame point cloud data to obtain point cloud data with a preset number of lines.

[0063] Specifically, Figure 8 As shown, the upper half frame point cloud data and the lower half frame point cloud data are arranged in chronological order and combined to obtain point cloud data with a preset number of lines.

[0064] Exemplarily, assume that the polyhedron mirror is a tetrahedron with a rotation speed of 600rpm; the number of chip channels is 4; and the laser frequency is 72khz. To achieve a point cloud frame rate of 10fps, the field of view FOV: 120°×18°; the number of point cloud lines per frame is 32, and the vertical resolution: the distance between the line point cloud and the line point cloud in the middle dense part is ≤0.4° between 0° and -6° horizontally, and the distance between the line point clouds on both sides is ≤0.8°. In the first half-cycle of the galvanometer, the polyhedron mirror outputs 16 lines of point cloud data for each rotation (i.e., tetrahedron), which is the point cloud data for the upper half frame (as shown in Figure 7(a)). Similarly, in the second half-cycle of the galvanometer, the polyhedron mirror outputs 16 lines of point cloud data for each rotation (i.e., tetrahedron), which is the point cloud data for the lower half frame (as shown in Figure 7(b)). According to Figure 8 The upper half frame point cloud data and the lower half frame point cloud data are combined in time sequence to obtain 32 lines of point cloud data. Fig. 9 shown.

[0065] The method for increasing the number of point cloud lines provided in the present embodiment obtains, in a multi-channel laser propagation optical path, a laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the first half-cycle of the galvanometer rotation to obtain upper half-frame point cloud data; at the same time, a laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the second half-cycle of the galvanometer rotation is obtained to obtain lower half-frame point cloud data; the upper half-frame point cloud data is combined with the lower half-frame point cloud data to obtain point cloud data with a preset number of lines, so that when the number of antennas, the rotation speed per second and the number of rotating mirror surfaces are fixed, the number of point cloud lines per frame is increased while the frame rate is kept unchanged, thereby achieving the purpose of increasing the frame rate and vertical resolution and increasing the vertical FOV (Field of View) at the same point frequency per second, and solving the problem of low frame rate caused by insufficient point cloud line number when the number of antennas, the rotation speed per second and the number of rotating mirror surfaces are fixed.

[0066] In this embodiment, a method for increasing the number of point cloud lines is provided, which can be applied to an FMCW laser radar. The FMCW laser radar includes an FMCW chip module, a galvanometer, and a polyhedron rotating mirror. Figure 2 is a flow chart of a method for increasing the number of point cloud lines according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0067] Step S201, continuously rotating the polygon mirror at a first preset speed and the galvanometer at a second preset speed, respectively, so that the polygon mirror and the galvanometer rotate according to their respective cycle times; wherein the time for the galvanometer to rotate for one cycle includes the first half cycle time and the second half cycle time. For details, please refer to Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0068] Step S202: during the continuous rotation of the polyhedron rotating mirror and the galvanometer, a first preset number of stop points are set on the polyhedron rotating mirror, and a second preset number of stop points are set on the galvanometer, and the stop time of each stop point on the galvanometer is the time occupied by each face when the polyhedron rotating mirror rotates one circle, and the ratio of the first preset number to the second preset number is a multiple relationship. When the galvanometer continuously rotates, the angle of each galvanometer rotation is set based on the field of view angle between the FMCW chip module and the target object to be measured.

[0069] Step S203 , the multi-channel laser beam emitted by the FMCW chip module is emitted to the galvanometer, and is reflected to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, forming a multi-channel laser propagation optical path.

[0070] Specifically, the above step S203 includes:

[0071] Step S2031, obtaining a multi-channel laser beam emitted by the FMCW chip module, and emitting the multi-channel laser beam to the galvanometer.

[0072] like Figure 4 As shown, a laser beam is emitted from the FMCW chip module 1, passes through the lens and enters the galvanometer 2, and then enters the polygonal rotating mirror 3 from the galvanometer; the galvanometer 2 controls the vertical scanning angle of the light, and the rotating mirror 3 controls the horizontal scanning angle of the light. The light path indicated by the arrow is the propagation light path of the laser beam.

[0073] Step S2032, use a galvanometer to reflect the multi-channel laser beam to each face of the polygonal rotating mirror, stop on each face of the polygonal rotating mirror according to a preset stop point during the galvanometer reflection process, and reflect the laser beam to the target object to be measured through each face of the polygonal rotating mirror based on the position of the stop point, and use the optical path formed by the multi-pass laser beam passing through the galvanometer, the polygonal rotating mirror and the target object to be measured in sequence as the multi-channel laser propagation optical path.

[0074] Specifically, Figure 5 As shown, two-channel laser beams can form a 4-channel laser propagation optical path.

[0075] Step S2033, when the multi-channel laser beam reflected by the galvanometer moves from one facet of the polyhedron rotating mirror to another facet, the angle of the galvanometer is adjusted so that the angle between each facet of the polyhedron rotating mirror and the galvanometer is different; each facet of the rotating mirror is controlled in turn to receive the multi-channel laser beam reflected by the galvanometer at different angles, and reflect it to the target object to be measured.

[0076] Step S204: In the multi-channel laser propagation optical path, the laser beam reflected from each facet of the polyhedron rotating mirror to the target object during the first half-cycle of the galvanometer rotation is obtained to obtain the upper half-frame point cloud data; meanwhile, the laser beam reflected from each facet of the polyhedron rotating mirror to the target object during the second half-cycle of the galvanometer rotation is obtained to obtain the lower half-frame point cloud data. Figure 1 Step S102 of the illustrated embodiment will not be described in detail here.

[0077] Step S205: Combine the upper half frame point cloud data with the lower half frame point cloud data to obtain point cloud data with a preset number of lines. Figure 1 Step S103 of the illustrated embodiment will not be described in detail here.

[0078] The method for increasing the number of point cloud lines provided in this embodiment is to reasonably configure the dwelling position of the galvanometer. From the above figure, we can see that the vertical field of view of the combined point cloud is increased, and the vertical resolution of the central part is also improved.

[0079] In this embodiment, a method for increasing the number of point cloud lines is provided, which can be applied to an FMCW laser radar. The FMCW laser radar includes an FMCW chip module, a galvanometer, and a polyhedron rotating mirror. Figure 3 is a flow chart of a method for increasing the number of point cloud lines according to an embodiment of the present invention. Figure 3 As shown, the process includes the following steps:

[0080] Step S301, respectively, continuously rotating the polygon mirror at a first preset speed and continuously rotating the galvanometer at a second preset speed, so that the polygon mirror and the galvanometer rotate according to their respective cycle times; wherein the time for the galvanometer to rotate for one cycle includes the first half cycle time and the second half cycle time. For details, please refer to Figure 2 Step S201 of the illustrated embodiment will not be described in detail here.

[0081] Step S302, the multi-channel laser beam emitted by the FMCW chip module is emitted to the galvanometer, and is reflected to the target object through the galvanometer and each face of the polyhedron mirror in turn, forming a multi-channel laser propagation optical path. Figure 2 Step S202 of the illustrated embodiment will not be described in detail here.

[0082] Step S303, in the multi-channel laser propagation optical path, obtain the laser beam reflected by each facet of the polyhedron mirror to the target object to be measured during the first half cycle of the galvanometer rotation to obtain the upper half frame point cloud data; at the same time, obtain the laser beam reflected by each facet of the polyhedron mirror to the target object to be measured during the second half cycle of the galvanometer rotation to obtain the lower half frame point cloud data.

[0083] Specifically, the above step S303 includes:

[0084] Step S3031, when multiple channel laser beams are reflected from the stop points of the galvanometer to the stop points of each face of the polyhedron rotating mirror and then reflected to the target object to be measured, a line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror is formed on each channel, and the line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror on each channel during the first half cycle of the galvanometer rotation is summarized and arranged in chronological order to obtain the upper half frame point cloud data.

[0085] Specifically, the horizontal scanning of the multi-channel laser beam is generated by the rotation of the polygon mirror, while the change of the vertical angle is controlled by the position of the galvanometer, such as Figure 6As shown. For example, the laser of channel 1 is reflected by the galvanometer point A1 and reaches the rotating mirror point B1, and then reflected from point B1 to the target point B1-L0. As the rotating mirror rotates, it scans from the target point B1-L0 to the point B1-L1. After switching the galvanometer position, the laser of channel 1 is reflected by the galvanometer point A1 and reaches the rotating mirror point B1', and then reflected from point B1' to the target point B1'-L0. As the rotating mirror rotates, it scans from the target point B1'-L0 to the point B1'-L1. The same is true for other channels. The galvanometer control sets 8 stop points, and the length of the stay time at each stop point is the time occupied by each side when the rotating mirror rotates one circle, that is, (1 / rotating mirror rotation speed per second) / 8. There are only four stop positions for one circle of the rotating mirror, which means that we get two point cloud images of different line positions in one cycle of the galvanometer, as shown in Figure 7(a) and Figure 7(b).

[0086] Step S3032, when multiple channel laser beams are reflected from the stop points of the galvanometer to the stop points of each face of the polyhedron rotating mirror and then reflected to the target object to be measured, a line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror is formed on each channel; the line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror on each channel during the second half cycle of the galvanometer rotation is summarized, and arranged in chronological order to obtain the point cloud data of the lower half frame.

[0087] Specifically, the acquisition time is the second half cycle time of the galvanometer, and the rest of the operation process is the same as the way to obtain the upper half frame point cloud data, which will not be repeated here.

[0088] When the polyhedron mirror is a tetrahedron, the rotation speed is 600rpm, and the number of channels is 4, if the solution of the present invention is not used, then to obtain a point cloud frame rate of 10fps, the number of lines can only be sacrificed (600rps / 60s*4 faces*4 channels / 10fps=16 lines); if 32 lines of point cloud per frame are to be obtained, the frame rate can only be sacrificed (600rps / 60s*4 faces*4 channels / 32 lines=5fps). By reasonably configuring the stop position of the galvanometer, Fig. 9 It can be seen that the vertical field of view of the combined point cloud data is increased, and the vertical resolution of the central part is also improved.

[0089] Step S304: Combine the upper half frame point cloud data with the lower half frame point cloud data to obtain point cloud data with a preset number of lines. Figure 2 Step S205 of the illustrated embodiment will not be described in detail here.

[0090] The method for increasing the number of point cloud lines provided in this embodiment increases the frame rate, which is twice the original frame rate. The number of lines is increased, which is twice the original line rate. The vertical field of view is increased without reducing the frame rate. The vertical resolution of the central part is increased.

[0091] In this embodiment, a device for increasing the number of point cloud lines is also provided, which is used to implement the above embodiments and preferred implementations, and will not be repeated here. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0092] This embodiment provides a device for increasing the number of point cloud lines, which is applied to an FMCW laser radar. The FMCW laser radar includes an FMCW chip module, a galvanometer, and a polyhedron rotating mirror. Fig.11 As shown, including:

[0093] The rotation module 1101 is used to continuously rotate the polyhedron rotating mirror at a first preset speed and the galvanometer mirror at a second preset speed, so that the polyhedron rotating mirror and the galvanometer mirror rotate according to their respective cycle times; wherein the time for the galvanometer mirror to rotate for one cycle includes the first half cycle time and the second half cycle time.

[0094] The laser propagation module 1102 is used to transmit the multi-channel laser beam emitted by the FMCW chip module to the galvanometer, and reflect it to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn.

[0095] The point cloud data acquisition module 1103 obtains the laser beam reflected by each facet of the polyhedron to the target object during the first half cycle of the galvanometer rotation to obtain the upper half frame point cloud data; at the same time, it obtains the laser beam reflected by each facet of the polyhedron to the target object during the second half cycle of the galvanometer rotation to obtain the lower half frame point cloud data.

[0096] The combining module 1104 is used to combine the upper half frame point cloud data with the lower half frame point cloud data to obtain point cloud data with a preset number of lines.

[0097] In some optional embodiments, the laser propagation module 1102 includes:

[0098] The first propagation optical path unit is used to obtain the multi-channel laser beam emitted by the FMCW chip module and emit the multi-channel laser beam to the galvanometer.

[0099] The second propagation optical path unit is used to use a galvanometer to reflect the multi-channel laser beam to each face of the polygonal rotating mirror, and to stop on each face of the polygonal rotating mirror according to a preset stop point during the galvanometer reflection process, and to reflect the laser beam to the target object to be measured through each face of the polygonal rotating mirror based on the position of the stop point, and the optical path formed by the multi-pass laser beam passing through the galvanometer, the polygonal rotating mirror and the target object to be measured in sequence is used as the multi-channel laser propagation optical path.

[0100] The third propagation optical path unit is used to adjust the angle of the galvanometer when the multi-channel laser beam reflected by the galvanometer moves from one facet of the polyhedron rotating mirror to another facet, so that the angle between each facet of the polyhedron rotating mirror and the galvanometer is different; and control each facet of the rotating mirror in turn to receive the multi-channel laser beam reflected by the galvanometer at different angles, and reflect it to the target object to be measured.

[0101] In some optional implementations, the point cloud data acquisition module 1103 includes:

[0102] The upper half frame point cloud number acquisition unit is used to form a line point cloud composed of the stop points of the galvanometer and the stop points of each facet of the polyhedron rotating mirror on each channel when multiple channel laser beams are reflected from the stop points of the galvanometer to the stop points of each facet of the polyhedron rotating mirror and then reflected to the target object to be measured; the line point cloud composed of the stop points of the galvanometer and the stop points of each facet of the polyhedron rotating mirror on each channel during the first half cycle of the galvanometer rotation is summarized, and the point cloud data of the upper half frame is obtained after being arranged in chronological order.

[0103] The lower half frame point cloud number acquisition unit is used to form a line point cloud composed of the stop points of the galvanometer and the stop points of each facet of the polyhedron rotating mirror on each channel when multiple channel laser beams are reflected from the stop points of the galvanometer to the stop points of each facet of the polyhedron rotating mirror and then reflected to the target object to be measured; summarize the line point cloud composed of the stop points of the galvanometer and the stop points of each facet of the polyhedron rotating mirror on each channel during the second half cycle of the galvanometer rotation, and arrange them in chronological order to obtain the lower half frame point cloud data.

[0104] In some optional implementations, the device for increasing the number of point cloud lines further includes:

[0105] The rotation control module is used to set a first preset number of stop points on the polyhedron rotating mirror and a second preset number of stop points on the galvanometer during the continuous rotation of the polyhedron rotating mirror and the galvanometer, and the stop time of each stop point on the galvanometer is the time occupied by each face when the polyhedron rotating mirror rotates one circle, and the ratio of the first preset number to the second preset number is a multiple relationship. When the galvanometer continuously rotates, the angle of each galvanometer rotation is set based on the field of view angle between the FMCW chip module and the target object to be measured.

[0106] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0107] The device for increasing the number of point cloud lines in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0108] The embodiment of the present invention also provides a computer device having the above Fig.11 The device shown is for increasing the number of point cloud lines.

[0109] See also Fig.12 , Fig.12 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig.12 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.12 A processor 10 is taken as an example.

[0110] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0111] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0112] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0113] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0114] The computer device also includes an input device 30 and an output device 40. The processor 10, the memory 20, the input device 30 and the output device 40 may be connected via a bus or other means. Fig.12 The example of connecting through bus is taken in the following.

[0115] The input device 30 can receive input digital or character information, and generate key signal input related to the user settings and function control of the computer device, such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator bar, one or more mouse buttons, a trackball, a joystick, etc. The output device 40 may include a display device, an auxiliary lighting device (e.g., an LED) and a tactile feedback device (e.g., a vibration motor), etc. The above-mentioned display device includes but is not limited to a liquid crystal display, a light emitting diode, a display and a plasma display. In some optional embodiments, the display device can be a touch screen.

[0116] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0117] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of computer program instructions in computer-readable media includes, but is not limited to, source files, executable files, installation package files, etc., and accordingly, the way in which computer program instructions are executed by a computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0118] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for increasing the number of point cloud lines, characterized in that: Applied to an FMCW laser radar, the FMCW laser radar includes an FMCW chip module, a galvanometer and a polyhedron rotating mirror, and the method includes: The polygonal rotating mirror is continuously rotated at a first preset speed and the galvanometer mirror is continuously rotated at a second preset speed, respectively, so that the polygonal rotating mirror and the galvanometer mirror rotate according to their respective cycle times; wherein the galvanometer mirror rotates for one cycle time including a first half cycle time and a second half cycle time; The multi-channel laser beam emitted by the FMCW chip module is emitted to the galvanometer, and is reflected to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, forming a multi-channel laser propagation optical path; In the multi-channel laser propagation optical path, the laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the first half-cycle of the galvanometer rotation is obtained to obtain the upper half-frame point cloud data; at the same time, the laser beam reflected by each facet of the polyhedron rotating mirror to the target object to be measured during the second half-cycle of the galvanometer rotation is obtained to obtain the lower half-frame point cloud data; The upper half frame point cloud data and the lower half frame point cloud data are combined to obtain point cloud data with a preset number of lines.

2. The method according to claim 1, characterized in that The method also includes: during the continuous rotation of the polyhedron rotating mirror and the galvanometer mirror, setting stop points on the polyhedron rotating mirror according to a first preset number, and setting stop points on the galvanometer mirror according to a second preset number, and the stay time of each stop point on the galvanometer mirror is the time occupied by each face when the polyhedron rotating mirror rotates one circle, and the ratio of the first preset number to the second preset number is a multiple relationship.

3. The method according to claim 1, characterized in that The method further comprises: When the galvanometer continues to rotate, the angle of each galvanometer rotation is set based on the field of view angle between the FMCW chip module and the target object to be measured.

4. The method according to claim 2, characterized in that: The multi-channel laser beam emitted by the FMCW chip module is emitted to the galvanometer, and is reflected to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, forming a multi-channel laser propagation optical path, including: Acquire a multi-channel laser beam emitted by the FMCW chip module, and emit the multi-channel laser beam onto a galvanometer; A galvanometer is used to reflect the multi-channel laser beam to each face of the polygonal rotating mirror. During the galvanometer reflection process, the laser beam stops on each face of the polygonal rotating mirror according to a preset stop point, and based on the position of the stop point, the laser beam is reflected to the target object to be measured through each face of the polygonal rotating mirror. The optical path formed by the multi-pass laser beam passing through the galvanometer, the polygonal rotating mirror and the target object to be measured in sequence is used as the multi-channel laser propagation optical path.

5. The method according to claim 1, characterized in that: The method of emitting the multi-channel laser beam emitted by the FMCW chip module to the galvanometer, and reflecting the multi-channel laser beam to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn, further comprises: When the multi-channel laser beam reflected by the galvanometer mirror moves from one face of the polyhedron rotating mirror to another face, the angle of the galvanometer mirror is adjusted so that the angle between each face of the polyhedron rotating mirror and the galvanometer mirror is different; Each face of the rotating mirror is controlled in turn to receive the multi-channel laser beam reflected by the galvanometer at different angles, and reflect it to the target object to be measured.

6. The method according to claim 1, characterized in that The method of obtaining the upper half frame point cloud data by the laser beam reflected by each face of the polyhedron mirror to the target object during the first half cycle of the galvanometer mirror rotation includes: When the laser beams of multiple channels are reflected from the stop points of the galvanometer to the stop points of each face of the polyhedron rotating mirror and then reflected to the target object to be measured, a line point cloud consisting of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror is formed on each channel; The line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror on each channel during the first half cycle of the galvanometer rotation is summarized, and arranged in chronological order to obtain the upper half frame point cloud data.

7. The method according to claim 1, characterized in that The step of obtaining the laser beam reflected by each face of the polyhedron mirror to the target object during the second half cycle of the galvanometer mirror rotation to obtain the lower half frame point cloud data includes: When the laser beams of multiple channels are reflected from the stop points of the galvanometer to the stop points of each face of the polyhedron rotating mirror and then reflected to the target object to be measured, a line point cloud consisting of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror is formed on each channel; The line point cloud composed of the stop points of the galvanometer and the stop points of each face of the polyhedron rotating mirror on each channel during the second half cycle of the galvanometer rotation is summarized, and arranged in chronological order to obtain the point cloud data of the second half frame.

8. A device for increasing the number of point cloud lines, characterized in that: Applied to FMCW laser radar, the FMCW laser radar includes an FMCW chip module, a galvanometer and a polyhedron rotating mirror, and the device includes: A rotation module, used to continuously rotate the polyhedron rotating mirror at a first preset speed and continuously rotate the galvanometer mirror at a second preset speed, respectively, so that the polyhedron rotating mirror and the galvanometer mirror rotate according to their respective cycle times; wherein the time for the galvanometer mirror to rotate for one cycle includes a first half cycle time and a second half cycle time; A laser propagation module, used for transmitting the multi-channel laser beam emitted by the FMCW chip module to the galvanometer, and reflecting the multi-channel laser beam to the target object through the galvanometer and each face of the polyhedron rotating mirror in turn; The point cloud data acquisition module acquires the laser beam reflected from each facet of the polyhedron rotating mirror to the target object during the first half cycle of the galvanometer rotation to obtain the upper half frame point cloud data; meanwhile, the laser beam reflected from each facet of the polyhedron rotating mirror to the target object during the second half cycle of the galvanometer rotation to obtain the lower half frame point cloud data; The combination module is used to combine the upper half frame point cloud data with the lower half frame point cloud data to obtain point cloud data with a preset number of lines.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for increasing the number of point cloud lines according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method for increasing the number of point cloud lines according to any one of claims 1 to 7.

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