Time-sharing imaging laser radar ranging method and system

Abstract

The invention discloses a time-sharing imaging laser radar ranging method and system, the method is applied to laser radar ranging, a laser radar is provided with a front side laser and two side lasers, and two sides of a camera are respectively provided with a polaroid; according to the laser radar ranging method, starting of the front side laser and the two side lasers and image processing of the data processor are controlled based on a time axis strategy of time-sharing imaging, and then the front side laser line position, the two side laser line position, the front side target distance and the two side target distance are obtained; and finally, fusing and splicing the front side laser diagram and the two side laser diagrams which are subjected to time-sharing imaging to obtain a wide-angle view laser diagram. According to the invention, the camera sends the picture to the data processor and the data processor distributes the time for image processing, so that the camera and the data processor do not conflict in time, when the camera sends the picture, the data processor receives the picture, and when the camera captures the next frame of picture, the data processor processes the currently received picture.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar data processing, and in particular relates to a time-sharing imaging laser radar ranging method and system. Background Art

[0002] The laser radar ranging technology based on triangulation is to transmit a laser beam and use a receiver to receive the reflected light signal, combine the angle information between the sensor and the target object and the known baseline length, and use the principle of triangle geometry to calculate the distance. Specifically, when the laser radar sensor emits a laser pulse and receives a reflected signal, the angle change between the laser beam and the receiver is measured, and the precise distance can be derived through trigonometric functions. Compared with the traditional time-of-flight (ToF) ranging method, this method has higher spatial resolution and accuracy, especially in dynamic scenes where the relative position of the target object needs to be measured, it can provide more accurate three-dimensional ranging data. Therefore, triangulation ranging method is widely used in fields such as autonomous driving, robot navigation, and building measurement, and can effectively improve ranging accuracy and environmental perception capabilities.

[0003] However, since the field of view of LiDAR is usually determined by the laser emission angle and scanning range of the sensor, many LiDAR devices have a relatively narrow field of view (FOV). This means that they can only perceive objects in a limited area, especially at low viewing angles or in local areas, where the ranging accuracy may be low. Small field of view perception limits the comprehensive coverage capability of LiDAR, especially in complex urban environments or dynamic scenes, which can easily produce blind spots, resulting in certain obstacles not being detected in time, thus affecting the overall perception capability of the system. Even with a wider field of view, many traditional imaging systems are usually optimized in space, increasing the image viewing angle by increasing the number of sensors. However, this approach may lead to a sharp increase in system costs, or increase the size and power consumption of the system. Summary of the invention

[0004] In order to solve the problem of incomplete detection or excessive system cost caused by small field of view perception in the above-mentioned prior art, the technical solution of the present invention provides a time-sharing imaging laser radar ranging method and system. Among them, the time-sharing imaging laser radar ranging method provided by the present invention is applied to the laser radar, which respectively sets polarizers on both sides of the camera, so that the lasers emitted by the lasers on both sides are captured by the camera after being refracted by the polarizers, effectively expanding the field of view, and solving the problem of blind spots and small field of view perception in the prior art; furthermore, the technical solution of the present invention also realizes time-sharing imaging, that is, the forward laser image is obtained at the first moment, and the laser images on both sides are obtained at the second moment, so that the two can be combined to obtain a wide-angle field of view. At the same time, this system only uses one camera, and cooperates with the time-sharing imaging method to obtain a wide-angle field of view, solving the problem of sharp increase in cost, increase in system volume and power consumption.

[0005] To this end, the present invention provides the following technical solutions:

[0006] On the one hand, the present invention provides a time-sharing imaging laser radar ranging method, which is applied to laser radar ranging, wherein the laser radar is provided with a front laser and two side lasers, and polarizers are respectively provided on both sides of the camera of the laser radar, so that the lasers emitted by the lasers on both sides are refracted by the polarizers and captured by the camera of the laser radar;

[0007] The laser radar ranging method is based on the time axis strategy of time-sharing imaging to control the opening of the front laser, the lasers on both sides and the image processing of the data processor, thereby obtaining the front laser line position, the laser line position on both sides and the front target distance, the target distance on both sides, and then fusing and splicing the front laser image and the laser image on both sides of the time-sharing imaging to obtain a wide-angle field of view laser image;

[0008] Wherein, the time axis strategy based on time-sharing imaging is:

[0009] The lasers on both sides are turned on at an alternating time with the front laser, that is, when the data processor uses the front laser image to identify the distance of the front target, the lasers on both sides are turned on and the front laser is turned off; when the data processor uses the laser images on both sides to identify the distance of the targets on both sides, the front laser is turned on and the lasers on both sides are turned off; and when the camera of the laser radar sends a laser image, the data processor receives the laser image, and when the camera captures the next frame of the picture, the data processor processes the currently received laser image.

[0010] Preferably, the process of controlling the opening of the front laser, the lasers on both sides and the image processing of the data processor based on the time axis strategy of time-sharing imaging is as follows:

[0011] First, the lasers on both sides are turned off, the front laser is turned on, and the camera captures the front laser image of the front laser and transmits it to the data processor;

[0012] Next, after the front laser image is transmitted, the data processor identifies the front target distance based on the front laser image; at the same time, the front laser is turned off, the two side lasers are turned on, and the camera captures the two side laser images of the two side lasers;

[0013] Furthermore, transmitting the laser images on both sides to the data processor;

[0014] Finally, after the transmission of the laser images on both sides is completed, the data processor identifies the distances of the targets on both sides based on the laser images on both sides, and at the same time, the lasers on both sides are turned off, the front laser is turned on, and the camera captures the front laser image of the front laser;

[0015] Repeat the above process to perform cross-shooting and distance identification.

[0016] Preferably, before the laser radar ranging method is used for ranging, front calibration and side calibration are first performed, specifically:

[0017] When performing the front calibration or the side calibration, the front laser or the side lasers of the laser radar are respectively set to the corresponding calibration positions, and the camera then captures the laser image, and the calibration position is the maximum irradiation distance of the laser;

[0018] Traverse the laser line positions of each column in the laser image, and if there is no laser line in a column, fill the laser line position, that is, find the first and last columns that are not zero and determine the laser line positions on the corresponding columns; then use two points to calculate the laser line slope k and constant b of the following formula, and then calculate the filling position of each column of laser lines without laser lines;

[0019] y=kx+b

[0020] Where y is the position information of the laser line in each column, and x is the column number of the laser image;

[0021] After the filling is completed, the laser line completes the image, and then the position of the laser line in the laser image is obtained, which is regarded as the position of the reference line;

[0022] The baseline is a reference line for the distance measurement process. During the distance measurement process, the pixel difference between the laser line in the front laser image and the laser images on both sides and the corresponding baseline and the maximum irradiation distance corresponding to the baseline are used to determine the front target distance and the target distance on both sides corresponding to the front laser image and the laser images on both sides.

[0023] The preferred scheme of the present invention also takes into account that due to the deviation in the installation of the laser, the distance d between the laser and the camera is different, which may lead to inconsistent baselines and inaccurate subsequent distance measurements. Therefore, calibration is required before measuring the distance, that is, front calibration and side calibration are performed separately; in addition, it is also considered that the calibration process may face the phenomenon that the length of the laser line cannot fill the screen, so the slope of the laser line is calculated, and the laser line that does not fill the screen is supplemented, which effectively solves the application problem.

[0024] Preferably, when the data processor uses the front laser image to identify the distance to the front target or uses the side laser images to identify the distance to the side targets, the following process is used to determine the position of the laser line in the laser image:

[0025] First, a brightness threshold is set. If the gray value of a pixel is greater than the brightness threshold, the position information of the pixel is saved. The position information is the y-axis coordinate of the pixel, that is, the row number.

[0026] Then, the position information saved in each column is filtered accordingly, that is, the position information of the pixel with the largest gray value in each column is used as the laser line position of the corresponding column, or the median of the position information of several pixel points with the largest gray value in each column is used as the laser line position of the corresponding column;

[0027] Then the position of the laser line in the laser image is obtained.

[0028] Preferably, when the data processor uses the front laser image to identify the distance to the front target or uses the side laser images to identify the distance to the side targets, the data processor uses the pixel deviation between the laser line position and the reference line in the laser image to look up the pre-stored distance table to obtain the distance to the front target or the distance to the side targets;

[0029] The index of the pre-stored distance table is the pixel deviation between the laser line position and the baseline, and the content is the distance value. The baseline is the reference line of the distance measurement process, and the front target distance and the two side target distances corresponding to the baseline are known parameters.

[0030] Preferably, the laser radar ranging method further comprises: adjusting the brightness of the laser according to the thickness of the laser line;

[0031] The thicker the laser line is, the closer the distance between the laser and the target is, which tends to reduce the brightness of the laser; the thinner the laser line is, the farther the distance between the laser and the target is, which tends to increase the brightness of the laser.

[0032] The preferred scheme of the present invention can also realize the function of adaptively changing the brightness of the laser. When the laser radar is far away from the obstacle, the brightness of the laser will increase, and when it is close to the obstacle, the brightness of the laser will decrease. This can avoid the scattering of light when the laser radar is close to the obstacle, which leads to a decrease in measurement accuracy.

[0033] In a second aspect, the present invention provides a ranging system based on the above method, comprising: a laser radar and a data processor disposed in the laser radar or an external data processor connected to the laser radar;

[0034] Among them, the laser radar is equipped with at least a front laser, two side lasers, and a camera, and polarizers are respectively arranged on both sides of the camera of the laser radar, so that the lasers emitted by the lasers on both sides are refracted by the polarizers and captured by the camera of the laser radar.

[0035] Preferably, the laser radar and the data processor are both arranged in the sweeping robot.

[0036] In a third aspect, the present invention also provides a computer-readable storage medium based on the above method, storing a computer program, wherein the computer program is called by a processor to implement: the steps of a time-sharing imaging laser radar ranging method;

[0037] The front laser and the two side lasers are turned on and the image processing of the data processor is controlled based on the time axis strategy of time-sharing imaging, so as to obtain the front laser line position, the two side laser line position, the front target distance, and the two side target distance, and then the front laser image and the two side laser image of the time-sharing imaging are fused and spliced ​​to obtain a wide-angle field of view laser image;

[0038] That is, the lasers on both sides and the front laser are controlled to turn on at different times, that is, when the data processor uses the front laser image to identify the distance of the front target, the lasers on both sides are controlled to turn on and the front laser is turned off; when the data processor uses the laser images on both sides to identify the distance of the targets on both sides, the front laser is controlled to turn on and the lasers on both sides are turned off; and when the camera of the laser radar sends a laser image, the data processor receives the laser image, and when the camera captures the next frame of the picture, the data processor processes the currently received laser image.

[0039] Beneficial Effects

[0040] Compared with the existing method, the advantages of the present invention are:

[0041] 1. Since the camera can only capture the field of view within 90 degrees in front of it, it cannot measure the information of a large field of view. The technical solution of the present invention adds two polarizers in front of the camera. The polarizers can use the principle of light refraction to enable the camera to capture a wider field of view. This simply and effectively solves the technical limitations and defects of small field of view perception.

[0042] 2. The technical solution of the present invention adopts a time axis strategy based on time-sharing imaging to control the opening of the front laser, the lasers on both sides and the image processing of the data processor, that is, the lasers on both sides and the front laser are controlled to be turned on at different times, and the camera of the laser radar captures the front laser image or the laser images on both sides and transmits them to the data processor. After the transmission is completed, when the data processor uses the front laser image to identify the distance of the front target, the lasers on both sides are controlled to be turned on; when the data processor uses the laser images on both sides to identify the distance of the targets on both sides, the front detection laser is controlled to be turned on.

[0043] 3. The present invention fully considers that processing data requires operating on the entire image, so data processing must be performed after receiving the entire picture, and after data processing, data must be received immediately to avoid data loss. Therefore, the present invention proposes the above strategy, reasonably arranges the time for receiving and processing images, and receives complete image information without losing a frame of image, and can promptly process the previous frame of image data during the camera capturing the image, thereby improving the frame rate.

[0044] Among them, the advantages of time-sharing imaging include:

[0045] Traditional imaging systems are usually optimized in space, improving image quality by increasing the number of sensors or improving resolution. However, this approach may lead to a sharp increase in system costs, or increase the size and power consumption of the system. Through time-sharing imaging, the system can alternately use different perspectives at different times. In this way, the system can effectively improve the spatial resolution of the image and reduce hardware investment.

[0046] The existing technology does not fully consider the time resolution of image processing. In some applications with extremely high real-time requirements, the response speed of the imaging system is crucial. If time-sharing imaging is not adopted, the system may find it difficult to collect enough image data within a limited time due to hardware limitations. Time-sharing imaging can improve image acquisition efficiency by optimizing the working cycle of the sensor.

[0047] With the development of imaging technology, the amount of data acquired by imaging equipment is becoming increasingly large. Traditional imaging systems have not fully considered how to effectively process these massive amounts of data, which has led to problems such as slow processing speed and high storage pressure. In systems that do not use time-sharing imaging, data traffic is usually continuous and gapless, making it difficult to flexibly schedule. Time-sharing imaging can reasonably allocate the timing of data collection and processing by controlling the working hours of imaging equipment. This can reduce fluctuations in data traffic and avoid delays or data loss caused by system overload during peak processing periods. In addition, time-sharing imaging can also optimize data storage and transmission paths and improve processing efficiency by batch processing of data in different time periods. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is a schematic diagram of the operation of a laser radar provided by an embodiment of the present invention;

[0049] Figure 2 It is a schematic diagram of the laser diagram provided by the present invention;

[0050] Figure 3 It is a schematic diagram of time-sharing imaging provided by the present invention;

[0051] Figure 4 is a schematic diagram of light scattering provided by the present invention;

[0052] Figure 5 It is a schematic diagram of installation deviation provided by the present invention;

[0053] Figure 6 It is a flow chart of a time-sharing imaging laser radar ranging method provided by the present invention;

[0054] Figure 7 It is a calibration flow chart provided by the present invention;

[0055] Figure 8 It is a schematic diagram of the laser brightness adjustment process provided by the present invention. DETAILED DESCRIPTION

[0056] The present invention provides a time-sharing imaging laser radar ranging method, which is applied to laser radar ranging. The present invention will be further described below in conjunction with embodiments.

[0057] Since the camera can only capture the field of view within a 90-degree range in front of it, it cannot measure the field of view information over a large range. Therefore, the technical solution of the present invention optimizes the structure of the laser radar, that is, polarizers are respectively arranged on both sides of the laser radar camera, so that the lasers emitted by the lasers on both sides are refracted by the polarizers and captured by the laser radar camera. Figure 1As shown, the laser radar is provided with a front laser and two side lasers, and polarizers are respectively arranged on both sides of the laser radar camera, and the polarizers can enable the camera to capture a wider field of view through the principle of light refraction. Among them, the size and position of the polarizer can be adaptively adjusted, and the present invention only constrains it to meet the requirements of: allowing the lasers emitted by the lasers on both sides to be captured by the laser radar camera after being refracted by the polarizers, expanding the field of view, and preferably not affecting the laser propagation of the front laser.

[0058] Based on the above-mentioned laser radar, the technical solution of the present invention provides a time-sharing imaging laser radar ranging method, which controls the opening of the front laser and the lasers on both sides and the image processing of the data processor based on the time axis strategy of time-sharing imaging, thereby obtaining the front laser line position, the laser line position on both sides, the front target distance, and the target distance on both sides, and finally fuses and splices the front laser image and the laser image on both sides of the time-sharing imaging to obtain a wide-angle field of view laser image (preferably including both the laser line image and the front / side target distance information). Among them, the time axis strategy based on time-sharing imaging is:

[0059] The lasers on both sides are turned on at different times from the front laser, that is, when the data processor uses the front laser image to identify the distance of the front target, the lasers on both sides are turned on and the front laser is turned off; when the data processor uses the laser images on both sides to identify the distance of the targets on both sides, the front laser is turned on and the lasers on both sides are turned off; and when the laser radar camera sends a laser image, the data processor receives the laser image, and when the camera captures the next frame, the data processor processes the currently received laser image. When the laser radar camera sends a laser image, the data processor receives the laser image, and when the camera captures the next frame, the data processor processes the currently received laser image.

[0060] The details are as follows:

[0061] First, turn on the front laser to emit the front laser. After the laser hits an object, it is reflected by the camera and captured as the front laser image. The laser image example is shown in the attached figure. Figure 2 , the white line in the figure is the laser line.

[0062] Then, the front side laser image is sent to a single chip microcomputer (data processor, preferably a single chip microcomputer in the present invention), and the single chip microcomputer receives the front side image data.

[0063] After the transmission is completed, the lasers on both sides are turned on and the front laser is turned off. The lasers are reflected to the polarizer after encountering the object, and then captured by the camera through the refraction of the polarizer to the laser images on both sides. At this time, the camera is capturing the lasers on both sides. At the same time, the microcontroller extracts the position of the laser line in the front laser image after the transmission is completed, and converts the position information into distance information to obtain the distance of the front target.

[0064] When the camera captures the laser images on both sides, it sends the laser images on both sides to the microcontroller, which receives the laser images on both sides. After the transmission is completed, the lasers on both sides are turned off, the front laser is turned on, and the camera captures the front laser image. At the same time, the microcontroller extracts the position of the laser line from the laser images on both sides, and converts the position information into distance information to obtain the distance of the targets on both sides, and repeats this cycle.

[0065] In summary, after obtaining the distance to the front target and the distance to the targets on both sides, the laser line distance information of the front laser line and the laser line distance information of the laser lines on both sides are pieced together. The distance information of the left laser line is placed on the left as the distance information between the device and the target on the left, the distance information of the middle laser line is placed in the middle as the distance information between the device and the target in front, and the distance information of the right laser line is placed on the right as the distance information between the device and the target on the right, thereby capturing the distance information of a large viewing angle, realizing the time-sharing imaging function, and obtaining the distance information of a large viewing angle. The principle is as follows: Figure 3 shown.

[0066] Based on the above theoretical statements, the following embodiment 1 is a preferred example of a time-sharing imaging laser radar ranging method provided by the present invention.

[0067] Embodiment 1:

[0068] The process of a time-sharing imaging laser radar ranging method provided by an embodiment of the present invention is as follows:

[0069] S1: Calibration and distance table establishment.

[0070] Due to the laser installation deviation, that is, Figure 5 The different distances d between the laser and the camera may lead to inconsistent baselines, resulting in inaccurate subsequent distance measurements, so calibration is required before measuring the distance. This embodiment provides an automatic calibration function. By placing the laser radar in the default calibration position (maximum laser measurement distance), the calibrated baseline can be automatically obtained, which corresponds to the maximum measurement distance. Specifically, the front side calibration and the side side calibration are performed:

[0071] S11: When performing front calibration or side calibration, the front laser or side lasers of the laser radar are respectively set to the calibration position, and the camera captures the laser image. The calibration position is the maximum irradiation distance of the laser. The laser radar of this embodiment can measure a maximum distance of 400mm, so this example uses 400mm as the reference point.

[0072] S12: First, traverse the laser line position information of each column of the image. If the value is zero, it means that there is no laser line in the column and it needs to be supplemented. Until the first non-zero column is found, the laser line position information and column number of the column are saved. Then, the last non-zero column is found and the laser line position information and column number of the column are also saved. These two points are used with the formula below to calculate the slope and constant b. The slope is the slope of the laser line. Then, the column without laser line is supplemented with its laser line position information according to this formula. The process is as follows: Figure 7 shown.

[0073] y=kx+b

[0074] Where y is the position information of the laser line in each column, x is the column number of the laser image, k is the slope of the laser line, and b is a constant;

[0075] S13: After the filling is completed, the laser line completes the screen, and then the position of the laser line in the laser image is obtained, which is regarded as the position information of the reference line, and then a distance table is established according to the triangulation method. The distance table is an array, and the array index is the pixel difference between the reference line of the laser line (the position information of the 400mm laser line) and the position information of the actual measured laser line, and the content is the distance value to the target. It should be understood that establishing a distance table according to the triangulation method is a prior art, so it will not be described in detail.

[0076] It should be noted that step S12 is the preferred method of this embodiment, that is, taking into full consideration the fact that the length of the laser line may not fill the screen during the application process, the slope of the laser line is calculated to complete the laser line that does not fill the screen. The identification of the position of the laser line in the laser image will be described in detail below.

[0077] S2: Based on the time axis strategy of time-sharing imaging, the front laser and the lasers on both sides are controlled to start, and the image processing of the data processor is performed.

[0078] First, turn on the front laser and turn off the lasers on both sides. The camera captures the front laser image and sends the image information to the single-chip microcomputer. After completion, turn on the lasers on both sides and turn off the front laser. The camera starts to capture the next frame of the image (this period is used to capture the image and the image information will not be sent to the single-chip microcomputer). During this period, the single-chip microcomputer processes the received front laser image information and finds the position information of the laser in the image. This realizes the time allocation between the camera sending the picture to the single-chip microcomputer and the single-chip microcomputer processing the picture, so that there is no conflict between the two in time. When the camera sends the picture, the single-chip microcomputer receives the picture. When the camera captures the next frame, the single-chip microcomputer processes the currently received picture.

[0079] Since there is a time interval after the camera sends the image data, the camera starts to capture the image within this interval, which is about 50ms. Therefore, this embodiment preferably sets a flag bit, which is incremented by 1 every 1ms. When the single-chip microcomputer receives data, the flag bit is cleared to 0. As long as the flag bit is always 0, it means that the single-chip microcomputer is in the image receiving stage. When the flag bit is greater than 5, that is, no data has been received for 5ms, it can be judged that the camera has finished sending the entire picture data, and it is regarded that the single-chip microcomputer can process the received entire picture data. It should be understood that 5ms is self-set, and in other feasible embodiments, it can be adaptively adjusted according to application requirements.

[0080] The technical solution of the present invention fully considers that processing data requires operating on the entire image, so data processing must be performed after receiving the entire image, and after data processing, data must be received immediately to avoid data loss. In this way, hardware resources are fully utilized, the time for receiving and processing images is reasonably arranged, and image information is completely received without losing a frame of image, and the previous frame of image data can be processed in time during the camera capturing the image, thereby improving the frame rate.

[0081] The process of the single chip microcomputer in this embodiment recognizing the laser line on the laser image is as follows:

[0082] 1. Perform the operation on each row of each column of the laser image in this way. Since the captured image is a black and white image, and the brightness of the laser line is the highest in the image, and the rest of the image except the laser line is basically black, a brightness threshold can be set (the brightness threshold is a grayscale value with a value range of 0 to 255). As long as the grayscale value of the pixel point is greater than the brightness threshold, the position information corresponding to the pixel is saved. The position information is the y-axis coordinate of the pixel in the image, that is, the row number. Because the image other than the laser line is basically black, its pixel value cannot be greater than the brightness threshold, and the brightness value of the laser line can be greater than the brightness threshold, so the position information of the laser line can be found.

[0083] 2. Then filter the saved position information of each column accordingly. Since the laser line has the largest brightness value in the entire image, first extract the position information of the pixel with the largest brightness value, and locate the pixel on the laser line. Since the laser line is thicker, each column may have multiple pixels with the largest brightness value. Take out the position information of all these pixels, and take a median for these position information as the laser line position information of this column of the image.

[0084] 3. After operating all the columns, the position information of the front laser line in the image is obtained.

[0085] 4. Then traverse each column, subtract the laser line position information of each column from the pixel value of the pixel point corresponding to a column of the baseline to obtain the pixel deviation, and convert the front laser position information into the front distance information by looking up the distance table (the index and content in the distance table are applicable to the pixel difference of each column).

[0086] It should be understood that the camera completes the capture of the laser images on both sides and sends the laser image information on both sides to the single-chip microcomputer. After the transmission is completed, the lasers on both sides are turned off, and the front laser is turned on. The camera then captures the front laser image, and the cycle continues. At the same time, the single-chip microcomputer finds the position information of the laser lines on both sides, and obtains the distance information on both sides by looking up the distance table. Then the front distance information is combined with the distance information on both sides, and the distance information on the left laser line is placed on the left as the distance information from the device to the left target, and the distance information of the middle laser line is placed in the middle as the distance information from the device to the front target. The distance information of the right laser line is placed on the right as the distance information from the device to the right target. The specific process is as follows: Figure 6 shown.

[0087] In some embodiments, the present invention also realizes the function of adaptively changing the brightness of the laser. When the laser radar is far away from the obstacle, the brightness of the laser will increase, and when it is close to the obstacle, the brightness of the laser will decrease. This can avoid the scattering of light when the laser radar is close to the obstacle, resulting in reduced measurement accuracy. Figure 4 .

[0088] Among them, this embodiment preferably records the number of pixels in each column of the image that is greater than a threshold value, and takes out the maximum value of the number of pixels in each column to indicate the thickness of the laser line. The pixel value of the picture captured by the camera is 240×320, that is, the picture is 240 lines, so it can be set that if the laser line fills less than 30 lines of the screen, it can be considered that the laser line is thin and the brightness of the laser needs to be increased. If the laser line fills more than 50 lines of the screen, it can be considered that the laser line is thick, and the brightness of the laser line is reduced. If the laser line fills more than 30 lines and less than 50 lines of the screen, it can be considered that the laser line is just right, and the brightness of the laser line is kept unchanged. The process is as follows Figure 8 It should be noted that, in practical applications, the setting standard for judging the thickness of the laser line is adjusted according to application requirements and precision requirements, and is an empirical value, and the present invention does not impose specific limitations and restrictions on this.

[0089] In some embodiments, the present invention further provides a ranging system based on the above-mentioned ranging method, the ranging system comprising: a laser radar and a data processor disposed in the laser radar or an external data processor connected to the laser radar;

[0090] Among them, the laser radar is equipped with at least a front laser, two side lasers, and a camera, and polarizers are arranged on both sides of the camera of the laser radar, so that the lasers emitted by the lasers on both sides are refracted by the polarizers and captured by the camera of the laser radar.

[0091] Preferably, the laser radar and the data processor are both arranged in the sweeping robot. That is, the technical solution of the present invention is applied to the sweeping robot. And preferably, the data processor is a single chip microcomputer.

[0092] In some embodiments, the present invention further provides a computer-readable storage medium based on the above-mentioned ranging method, storing a computer program, which is called by a processor to implement: a step of a time-sharing imaging laser radar ranging method. The implementation process of Example 1 can be referred to.

[0093] Among them, the front laser, the two side lasers and the image processing of the data processor are controlled based on the time axis strategy of time-sharing imaging, so as to obtain the front laser line position, the two side laser line position and the front target distance and the two side target distance, and then the front laser image and the two side laser images of time-sharing imaging are fused and spliced ​​to obtain a wide-angle laser image; that is, the two side lasers and the front laser are controlled to be turned on at different times, and the laser radar camera captures the front laser image or the two side laser images and transmits them to the data processor. After the transmission is completed, when the data processor uses the front laser image to identify the front target distance, the two side lasers are controlled to be turned on; when the data processor uses the two side laser images to identify the two side target distances, the front measurement laser is controlled to be turned on. It is realized that when the laser radar camera sends the laser image, the data processor receives the laser image, and when the camera captures the next frame, the data processor processes the currently received laser image.

[0094] The readable storage medium is a computer-readable storage medium, which may be an internal storage unit of the software and hardware device described in any of the aforementioned embodiments, such as a hard disk or memory of a controller. The readable storage medium may also be an external storage device of the controller, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the controller. Furthermore, the readable storage medium may also include both an internal storage unit of the controller and an external storage device. The readable storage medium is used to store the computer program and other programs and data required by the controller. The readable storage medium may also be used to temporarily store data that has been output or is to be output.

[0095] Based on this understanding, the technical solution of the present invention, in essence or in other words, the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned readable storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., various media that can store program codes.

[0096] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The present application is a device for realizing the function specified in one flow or multiple flows of the flow chart and / or one or multiple blocks of the block diagram with reference to the instructions executed by the processor according to the method, device (system) and computer program product of the embodiment of the present application. These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device, which realizes the function specified in one flow or multiple flows of the flow chart and / or one or multiple blocks of the block diagram. These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0097] It should be emphasized that the examples of the present invention are illustrative rather than restrictive, and therefore the present invention is not limited to the examples described in the specific embodiments. Any other embodiments derived by those skilled in the art based on the technical solution of the present invention that do not depart from the purpose and scope of the present invention, whether modified or replaced, also fall within the scope of protection of the present invention.

Claims

1. A time-sharing imaging laser radar ranging method, characterized in that: Applied to laser radar ranging, the laser radar is provided with a front laser and two side lasers, and polarizers are respectively arranged on both sides of the camera of the laser radar, so that the lasers emitted by the lasers on both sides are refracted by the polarizers and captured by the camera of the laser radar; The laser radar ranging method is based on the time axis strategy of time-sharing imaging to control the opening of the front laser, the lasers on both sides and the image processing of the data processor, thereby obtaining the front laser line position, the laser line position on both sides and the front target distance, the target distance on both sides, and then fusing and splicing the front laser image and the laser image on both sides of the time-sharing imaging to obtain a wide-angle field of view laser image; Wherein, the time axis strategy based on time-sharing imaging is: The lasers on both sides are turned on at an alternating time with the front laser, that is, when the data processor uses the front laser image to identify the distance of the front target, the lasers on both sides are turned on and the front laser is turned off; when the data processor uses the laser images on both sides to identify the distance of the targets on both sides, the front laser is turned on and the lasers on both sides are turned off; and when the camera of the laser radar sends a laser image, the data processor receives the laser image, and when the camera captures the next frame of the picture, the data processor processes the currently received laser image.

2. The method according to claim 1, characterized in that: The process of controlling the opening of the front laser, the lasers on both sides and the image processing of the data processor based on the time axis strategy of time-sharing imaging is as follows: First, the lasers on both sides are turned off, the front laser is turned on, and the camera captures the front laser image of the front laser and transmits it to the data processor; Next, after the front laser image is transmitted, the data processor identifies the front target distance based on the front laser image; at the same time, the front laser is turned off, the two side lasers are turned on, and the camera captures the two side laser images of the two side lasers; Furthermore, transmitting the laser images on both sides to the data processor; Finally, after the transmission of the laser images on both sides is completed, the data processor identifies the distances of the targets on both sides based on the laser images on both sides, and at the same time, the lasers on both sides are turned off, the front laser is turned on, and the camera captures the front laser image of the front laser; Repeat the above process to perform cross-shooting and distance identification.

3. The method according to claim 1, characterized in that: Before the laser radar ranging method is used for ranging, front calibration and side calibration are performed first, specifically: When performing the front calibration or the side calibration, the front laser or the side lasers of the laser radar are respectively set to the corresponding calibration positions, and the camera then captures the laser image, and the calibration position is the maximum irradiation distance of the laser; Traverse the laser line positions of each column in the laser image, and if there is no laser line in a column, fill the laser line position, that is, find the first and last columns that are not zero and determine the laser line positions on the corresponding columns; then use two points to calculate the laser line slope k and constant b of the following formula, and then calculate the filling position of each column of laser lines without laser lines; y=kx+b Where y is the position information of the laser line in each column, and x is the column number of the laser image; After the filling is completed, the laser line completes the image, and then the position of the laser line in the laser image is obtained, which is regarded as the position of the reference line; The baseline is a reference line for the distance measurement process. During the distance measurement process, the pixel difference between the laser line in the front laser image and the laser images on both sides and the corresponding baseline and the maximum irradiation distance corresponding to the baseline are used to determine the front target distance and the target distance on both sides corresponding to the front laser image and the laser images on both sides.

4. The method according to claim 1, characterized in that: When the data processor uses the front laser image to identify the distance of the front target or uses the side laser images to identify the distance of the side targets, the following process is used to determine the position of the laser line in the laser image: First, a brightness threshold is set. If the gray value of a pixel is greater than the brightness threshold, the position information of the pixel is saved. The position information is the y-axis coordinate of the pixel, that is, the row number. Then, the position information saved in each column is filtered accordingly, that is, the position information of the pixel with the largest gray value in each column is used as the laser line position of the corresponding column, or the median of the position information of several pixel points with the largest gray value in each column is used as the laser line position of the corresponding column; Then the position of the laser line in the laser image is obtained.

5. The method according to claim 4, characterized in that: When the data processor uses the front laser image to identify the distance of the front target or uses the side laser images to identify the distance of the two side targets, the pixel deviation between the laser line position and the reference line in the laser image is used to search the pre-stored distance table to obtain the distance of the front target or the distance of the two side targets; The index of the pre-stored distance table is the pixel deviation between the laser line position and the baseline, and the content is the distance value. The baseline is the reference line of the distance measurement process, and the front target distance and the two side target distances corresponding to the baseline are known parameters.

6. The method according to claim 1, characterized in that: The laser radar ranging method further includes: adjusting the brightness of the laser according to the thickness of the laser line; The thicker the laser line is, the closer the distance between the laser and the target is, which tends to reduce the brightness of the laser; the thinner the laser line is, the farther the distance between the laser and the target is, which tends to increase the brightness of the laser.

7. A distance measurement system based on the method according to any one of claims 1 to 6, characterized in that: It comprises: a laser radar and a data processor arranged in the laser radar or an external data processor connected to the laser radar; Among them, the laser radar is equipped with at least a front laser, two side lasers, and a camera, and polarizers are respectively arranged on both sides of the camera of the laser radar, so that the lasers emitted by the lasers on both sides are refracted by the polarizers and captured by the camera of the laser radar.

8. The distance measurement system according to claim 7, characterized in that: The laser radar and the data processor are both arranged in the sweeping robot.

9. A computer-readable storage medium based on the method according to any one of claims 1 to 6, characterized in that: A computer program is stored, and the computer program is called by a processor to implement: steps of a laser radar ranging method of time-sharing imaging; The front laser and the two side lasers are turned on and the image processing of the data processor is controlled based on the time axis strategy of time-sharing imaging, so as to obtain the front laser line position, the two side laser line position, the front target distance, and the two side target distance, and then the front laser image and the two side laser image of the time-sharing imaging are fused and spliced ​​to obtain a wide-angle field of view laser image; That is, the lasers on both sides and the front laser are controlled to turn on at different times, that is, when the data processor uses the front laser image to identify the distance of the front target, the lasers on both sides are controlled to turn on and the front laser is turned off; when the data processor uses the laser images on both sides to identify the distance of the targets on both sides, the front laser is controlled to turn on and the lasers on both sides are turned off; and when the camera of the laser radar sends a laser image, the data processor receives the laser image, and when the camera captures the next frame of the picture, the data processor processes the currently received laser image.

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