A Method and Device for Detecting the Contamination of a Lidar Transmissive Dome

Abstract

The present invention relates to the technical field of lidar, and more specifically, to a method and device for detecting dirt on the light-transmitting cover of a lidar, which is applied to a non-coaxial lidar. The non-coaxial lidar is provided with a light-transmitting cover and a main laser module for generating a main laser. The device further includes a first emission module for generating a first laser, a second emission module for generating a second laser, a first receiving module, and a second receiving module. The first laser and the second laser transmit through the dirt on the light-transmitting cover, so as to obtain the attenuation influence information of the dirt on the laser. Then, the obtained attenuation influence information is used to correct the main laser, and the main laser information not affected by the dirt is obtained, thereby improving the recognition accuracy of the detected object. This solution can not only identify the dirt on the light-transmitting cover, but also help reduce the influence of the dirt on the discrimination of the material of the non-coaxial lidar on the object, thereby improving the recognition accuracy of the lidar.

Description

Technical Field

[0001] The present invention relates to the technical field of lidar, and more specifically, to a lidar light-transmitting cover dirt detection device and method. Background Art

[0002] Lidar is widely used in various tasks such as ranging and virtual modeling. Especially now with the booming development of new energy vehicles and autonomous driving technologies, lidar has been widely applied. The measurement principle of lidar is that a laser emitter emits a laser, which passes through the light-transmitting cover and then irradiates the object to be measured. The laser is reflected back to the laser receiver by the object to be measured, and the distance and material of the object are estimated through the time difference of the laser return and the difference in laser intensity attenuation, so as to achieve the purpose of object detection. Lidar can be divided into two categories: coaxial lidar and non-coaxial lidar. Among them, the detection laser emission point and the reception point of coaxial lidar are the same, and the laser passes through the light-transmitting cover along the same path; while the laser emission point and the laser reception point of non-coaxial lidar are respectively located at two places, and the laser passes through the light-transmitting cover along different paths. In the actual application of lidar, such as autonomous driving of new energy vehicles, the protective cover of lidar will inevitably be contaminated by pollutants such as dust, sewage, and soil. These pollutants will interfere with the intensity of the laser passing through the protective cover, thus affecting the judgment of material and color during data processing, reducing the model judgment accuracy, and affecting the safety of autonomous driving. Therefore, the detection and interference elimination of the dirt on the lidar protective cover is a topic of profound significance.

[0003] CN112099045A disclosed in the Chinese patent divides the laser for ranging into a secondary optical path and passes it through the protective cover along another optical path. If there are pollutants on the protective cover, the laser in the secondary optical path will be reflected to the secondary optical path receiver, thereby determining that there are dirt on the protective cover, thus avoiding the dirt misleading the imaging result. This setting method does not require an additional dirt detection light source, but it has a better applicable effect on coaxial lidar and is not completely applicable to non-coaxial lidar.

[0004] CN111551946B obtains a larger range for detecting dirt through a movable second light source for detecting dirt, and it is also applicable to non-coaxial lidar. However, these dirt detection schemes can only detect dirt and cannot eliminate the influence caused by dirt. Although an external associated control cleaning device can also be used for decontamination, being adhered by small dirt such as dust is the norm in some working scenarios, such as a driving car. In this case, the cleaning device cannot continuously remove pollutants. Therefore, a device that can reduce the influence of dirt on the light-transmitting cover on the laser measurement result is needed. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a method and device for detecting dirt on the light-transmitting cover of a lidar, which can eliminate the influence of dirt on the light-transmitting cover on the intensity of the detection laser within a certain range.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is:

[0007] Provide a dirt detection device for the light-transmitting cover of a lidar, which is applied to a non-coaxial lidar. The non-coaxial lidar includes a main laser module for emitting and receiving the main laser, a light-transmitting cover, a turntable, and a processing module. The main laser module is installed on the turntable, the light-transmitting cover is fixedly arranged, the turntable is located inside the light-transmitting cover, and the processing module is communicatively connected to the main laser module; characterized in that, the position where the main laser exits and passes through the light-transmitting cover is defined as the first light-transmitting area, and the position where the main laser enters and passes through the light-transmitting cover is defined as the second light-transmitting area; and it further includes

[0008] A first emission module for emitting a first laser;

[0009] A first receiving module for receiving the first laser and converting the first laser into a first electrical signal. The first laser passes through the light-transmitting cover in the first light-transmitting area and is received by the first receiving module;

[0010] A second emission module for emitting a second laser;

[0011] A second receiving module for receiving the second laser and converting the second laser into a second electrical signal. The second laser passes through the light-transmitting cover in the second light-transmitting area and is received by the second receiving module;

[0012] The first emission module, the second emission module, the first receiving module, and the second receiving module are all installed on the turntable. The first receiving module and the second receiving module are also communicatively connected to the processing module. The first laser, the second laser, and the main laser do not interfere with each other.

[0013] The main laser emits from the main laser module to the detection target, which is the emission. The main laser reflects back to the main laser module from the detection target, which is the incidence. The main laser module contains a main laser emission unit and a main laser reception unit, and the main laser emission unit and the main laser reception unit are not coaxially arranged. Through this setting method, when the main laser module works, the first emission module emits the first laser, which passes through the first light-transmitting area of the light-transmitting cover and is received by the first reception module, and is converted into the first electrical signal and transmitted to the processing module; the second emission module emits the second laser, the second laser passes through the second light-transmitting area of the light-transmitting cover and is received by the second reception module, and is converted into the second electrical signal and transmitted to the processing module; the processing module analyzes the first electrical signal and the second electrical signal respectively, judges whether there is dirt on the light-transmitting cover through the attenuation degree of the first laser and the second laser, and respectively compares the reflection results of the main laser through the attenuation rates of the first laser and the second laser to restore the main laser reflection intensity not affected by dirt, so as to avoid the influence of dirt on the main laser intensity.

[0014] Furthermore, the light-transmitting cover is of a cylindrical structure and a convex platform layer is provided at the bottom, the diameter of the convex platform layer is larger than the diameters of other sections of the light-transmitting cover, and the first reception module and the second reception module are located inside the convex platform layer.

[0015] Through this setting method, the first reception module and the second reception module are located inside the convex platform layer. The first laser passes through the first light-transmitting area and then passes through the convex platform layer and is received by the first reception module, and the second laser passes through the second light-transmitting area and then passes through the convex platform layer and is received by the second reception module.

[0016] Preferably, the first emission module includes a first laser generator and a first laser reflector, the second emission module includes a second laser generator and a second laser reflector, the first laser generator and the second laser generator are both installed on the turntable, and the first laser reflector and the second laser reflector are both installed on the top of the main laser module and are both rotatably connected to the main laser module.

[0017] Through this setting method, when the main laser module changes, the positions of the first light-transmitting area and the second light-transmitting area will also change. At this time, the first laser reflector can rotate to adjust the reflection angle of the first laser emitted by the first laser generator to make it pass through the light-transmitting cover at the first light-transmitting area; the second laser reflector can rotate to adjust the second laser reflection angle to make it pass through the light-transmitting cover at the second light-transmitting area, so as to ensure that the first laser and the second laser can monitor the dirt at the emission position and the incidence position where the main laser passes through the light-transmitting cover.

[0018] Furthermore, a dust-proof cover is provided on the convex platform layer, and an inclined light-transmitting groove is opened on the dust-proof cover, and the light-transmitting groove is used to allow the first laser and the second laser to pass through the dust-proof cover and enter the convex platform layer.

[0019] With this setting method, the dust cover can reduce the probability of external dirt entering the light transmission groove, thereby keeping the boss layer at the light transmission groove clean and reducing the influence of dirt at the boss layer on the first laser and the second laser. Moreover, by adjusting the tilt angles of the first laser mirror and the second laser mirror, it is possible to ensure that the first laser and the second laser pass through the dust cover along the light transmission groove.

[0020] Preferably, the processing module includes an electrical signal amplification unit and a micro-control unit. The electrical signal amplification unit is used to amplify the first electrical signal and the second electrical signal respectively returned by the first receiving module and the second receiving module, and the micro-control unit is used to analyze the amplified electrical signals.

[0021] With this setting method, the electrical signal amplifier can amplify the first electrical signal and the second electrical signal converted from the received first laser and second laser, avoiding the situation where the intensities of the first laser and the second laser are small after attenuation by the dirt on the light transmission cover, and the converted electrical signals are small, making it impossible for the micro-control unit to identify them.

[0022] Furthermore, the processing module further includes a code disk for recording the rotation angle of the turntable, and the code disk is communicatively connected to the micro-control unit. Since the first laser and the second laser are not coaxially arranged with the main laser, the detection positions of the first laser and the second laser are not the positions where the main laser passes through the light transmission cover at the current moment. With this setting method, the code disk can provide the current rotation angle of the turntable to the micro-control unit, and the micro-control unit records the dirt influence coefficients measured by the first laser and the second laser with the rotation angle as the coordinate. When the main laser rotates to a certain angle, the micro-control unit retrieves the dirt influence coefficient recorded under the coordinate of this angle and corrects the main laser.

[0023] Preferably, the first emission module and the first receiving module are arranged in the area where the main laser axis deflects clockwise by 45° to 135°; the second emission module and the second receiving module are arranged in the area where the main laser axis deflects counterclockwise by 45° to 135°.

[0024] With this setting method, it is possible to fully avoid the mutual interference caused by the overlapping of the optical paths of the first laser, the second laser and the main laser when they work simultaneously, and improve the accuracy of laser imaging and correction.

[0025] Preferably, the processing module pre-sets a first standard value Va, which is defined as the voltage value converted by the first receiving module when receiving the first laser under the clean state of the light transmission cover; a second standard value Vb, which is defined as the voltage value converted by the second receiving module when receiving the second laser under the clean state of the light transmission cover.

[0026] The processing module is configured to: compare the first standard value Va with the first electrical signal, and when Va > the voltage value of the first electrical signal, determine that there is dirt in the first light-transmitting area; compare the second standard value Vb with the second electrical signal, and when Vb > the voltage value of the second electrical signal, determine that there is dirt in the second light-transmitting area.

[0027] The clean state means that the light-transmitting cover is clean without dirt, and the state where the laser has almost no loss after passing through the light-transmitting cover. Through this setting method, by comparing Va with the first laser intensity received in real time, the dirt influence coefficient of the light-transmitting cover at the first light-transmitting area can be deduced, and by comparing Vb with the second laser intensity received in real time, the dirt influence coefficient of the light-transmitting cover at the second light-transmitting area can be deduced. It can not only judge whether there is dirt on the light-transmitting cover, but also combine the dirt influence coefficients of the two places to correct the main laser intensity received in real time, and offset the influence of the dirt on the light-transmitting cover on the main laser.

[0028] A method for detecting dirt on a light-transmitting cover of a lidar, which is detected by using the lidar light-transmitting cover dirt detection device described in any one of the above, and the detection method includes:

[0029] S1. The processing module receives an external start command and enters the dirt detection mode;

[0030] In the dirt detection mode, the turntable rotates, the first emission module emits the first laser to the first reception module, the second emission module emits the second laser to the second reception module, the processing module records the attenuation information of the first laser and the second laser with the position as the coordinate, and judges whether there is dirt on the light-transmitting cover according to the attenuation information;

[0031] After the turntable rotates one week, the working mode is turned on:

[0032] In the working mode, the main laser module emits the main laser and receives the reflected main laser. The main laser module converts the main laser into an electrical signal and transmits it to the processing module. The processing module calls the attenuation information of the first laser and the second laser at the position where the main laser is located, corrects the main laser electrical signal, and outputs the corrected electrical signal.

[0033] When the working mode is turned on, the dirt detection mode remains on, and the newly obtained attenuation information of the first laser and the second laser by the processing module is used to overwrite the original recorded information;

[0034] S4. Loop to execute S3 until the processing module receives an external stop command, and then enters the stop state.

[0035] With this setting method, as the turntable rotates, the first emission module, the second emission module, the first reception module, the second reception module, and the main laser module all rotate accordingly. The first laser scans the light-transmitting cover within the first light-transmitting area, the second laser scans the light-transmitting cover within the second light-transmitting area, the main laser exits from the light-transmitting cover at the first light-transmitting area and enters the light-transmitting cover at the second light-transmitting area, and the processing module obtains and records the feedback of the first laser and the second laser; subsequently, the main laser starts to work. There are three intensity attenuation nodes in the main laser optical path: the first light-transmitting area, the reflection of the detection object, and the second light-transmitting area. Among them, the reflection of the detection object is the required item. The processing module calls the pre-recorded attenuation information of the first laser and the second laser to correct the reflection result of the main laser, which can eliminate the attenuation influence of the dirt at the first light-transmitting area and the second light-transmitting area on the main laser, ensure that the corrected value is only affected by the reflection of the detection object, and output the corrected value for the computer to generate the accurate object material; meanwhile, the first reception module and the second reception module continue to update the attenuation information of the first laser and the second laser to the processing module, and the processing module covers the original record with the new attenuation information of the first laser and the second laser to achieve the update.

[0036] Preferably, in step S2, specifically:

[0037] S21. The first emission module emits the first laser, the second emission module emits the second laser, and the turntable rotates;

[0038] S22. The first reception module receives the first laser, converts it into an electric current, obtains the corresponding voltage value V1 and transmits it to the processing module. The second reception module receives the second laser, converts it into an electric current, obtains the corresponding voltage value V2 and transmits it to the processing module;

[0039] S23. The processing module compares V1 and V2 with the first standard value Va and the second standard value Vb respectively, obtains the outgoing dirt attenuation ratio R1 and the incoming dirt attenuation ratio R2, then calls the rotation angle recorded in the code disk, and records R1 and the angle where the first laser is located, and R2 and the angle where the second laser is located respectively;

[0040] R1 = V1 / Va, R2 = V2 / Vb; Va is the voltage value converted when the first reception module receives the first laser in the clean state of the light-transmitting cover; Vb is the voltage value converted when the second reception module receives the second laser in the clean state of the light-transmitting cover.

[0041] With this setting method, the outgoing attenuation ratio R1 and the incoming attenuation ratio R2 within a week are pre-recorded in the processing module. When the working mode is turned on, the processing module can directly call R1 and R2 at the position of the main laser to correct the main laser, improving the imaging accuracy.

[0042] Preferably, in step S3, specifically:

[0043] After the turntable rotates one full circle, the working mode is enabled:

[0044] S31. The main laser module emits the main laser;

[0045] S32. The main laser module receives the reflected main laser, converts it into a voltage value V3 and transmits it to the processing module;

[0046] S33. The processing module retrieves the outgoing dirt attenuation ratio R1 and the incoming dirt attenuation ratio R2 of the current position of the main laser, and performs interference correction on V3 through the correction formula to obtain the corrected value V4,

[0047] V4 = V3 / (R2 * R1);

[0048] S34. The first laser module and the second laser module still emit the first laser and the second laser respectively. After the processing module receives the first electrical signal and the second electrical signal converted from the first laser and the second laser respectively, it calculates to obtain the new R1 and the new R2, and uses the new R1 to overwrite the original R1 at the position where the first laser is located, and uses the new R2 to overwrite the original R2 at the position where the second laser is located.

[0049] Define one full rotation of the turntable as one cycle. Through this setting method, the processing module refers to the R1 and R2 recorded in the previous cycle of the dirt detection mode to correct V3 converted by the main laser at the current position. The corrected V4 can be approximately regarded as the voltage value converted by the main laser that is only affected by the reflection attenuation of the detection object. The ratio between V4 and the voltage value converted by the non-attenuated main laser reflects the true reflectivity of the detection object, and then the material of the detection object can be judged; in addition, the dirt detection mode and the working mode work synchronously. The R1 and R2 obtained by the dirt detection mode in the current cycle replace the R1 and R2 recorded in the previous cycle, so as to update the dirt condition of the light-transmitting cover in real time and optimize the correction effect.

[0050] Preferably, in step S3, the processing module performs amplification preprocessing on V1, V2, Va, and Vb through the electrical signal amplification unit.

[0051] Through this setting method, it can be avoided that the intensities of the first laser and the second laser are too small after attenuation, resulting in the converted first electrical signal or second electrical signal being too weak, affecting the subsequent recognition and processing of the first electrical signal and the second electrical signal by the processing module, and improving the correction accuracy of the processing module for the main laser.

[0052] Preferably, in step S3, the type of dirt on the light-transmitting cover is further judged according to R1 and R2. When R1 or R2 is equal to 1, it is determined that the corresponding position of the light-transmitting cover is in a clean state; when 0.9 ≤ R1 < 1 or 0.9 ≤ R2 < 1, it is determined that there is water stain at the corresponding position of the light-transmitting cover; when 0.85 ≤ R1 < 0.9 or 0.85 ≤ R2 < 0.9, it is determined that there is oil stain at the corresponding position of the light-transmitting cover; when 0.8 ≤ R1 < 0.85 or 0.8 ≤ R2 < 0.85, it is determined that there is dust or mild obscuring stain at the corresponding position of the light-transmitting cover; when 0.7 ≤ R1 < 0.8 or 0.7 ≤ R2 < 0.8, it is determined that there is sediment or moderate obscuring stain at the corresponding position of the light-transmitting cover; when R1 < 0.7 or R2 < 0.7, it is determined that there is severe stain on the light-transmitting cover, and the processing module sends a signal to be cleaned.

[0053] Through this setting method, when there are some dirt such as water stains and dust on the light-transmitting cover that have little impact on the laser intensity, the processing module will correct the intensity of the reflected main laser according to the results of the first laser and the second laser, avoiding the influence of the dirt on the main laser intensity; when there is some dirt on the light-transmitting cover that has a great impact on the laser intensity, the main laser imaging is seriously affected. At this time, the processing module sends a signal to remind the user to clean the light-transmitting cover; the processing module corrects the main laser based on the degree of dirt influence, which can not only improve the detection accuracy of the main laser, but also reduce the cleaning pressure, greatly improving the applicable scenarios and accuracy of the lidar.

[0054] An intelligent vehicle includes a lidar. The lidar adopts the lidar light-transmitting cover dirt detection method as described in any one of the above, and further includes a central processing module and an automatic navigation module. The lidar is used to obtain information about the surrounding environment of the vehicle; the central processing module is used to generate a model of the surrounding environment of the vehicle according to the lidar and issue an instruction to the driver according to the detection result of the lidar light-transmitting cover dirt detection device; the automatic navigation module is used to provide route planning according to the model generated by the central processing module.

[0055] Through this setting method, the intelligent vehicle can reduce the influence of the dirt on the lidar on the light-transmitting cover, thereby improving the modeling accuracy of the central processing module, and further improving the accuracy of route planning, which is beneficial to improving driving safety.

[0056] Compared with the prior art, the beneficial effects of the present invention are:

[0057] (1) By obtaining the laser intensity attenuation information of the first light-transmitting area and the second light-transmitting area on the light-transmitting cover through the first laser and the second laser and correcting it with the main laser, to a certain extent, the influence of the dirt on the light-transmitting cover on the intensity of the main laser is excluded, improving the detection accuracy of the main laser, and there is no need to clean the light-transmitting cover frequently, improving the applicable scenarios of the lidar.

[0058] (2) Real - time update of the dirt information on the light - passing cover further improves the accuracy of calibration.

[0059] (3) Optimize the dirt recognition ability: By setting different recognition thresholds, the present invention can distinguish different types of dirt, such as oil and sweat, dust, and sediment, improving the dirt recognition accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a schematic diagram of the external structure of a dirt detection device for a lidar light - passing cover according to the present invention;

[0061] Figure 2 It is a schematic diagram of the internal structure of a dirt detection device for a lidar light - passing cover according to the present invention;

[0062] Figure 3 It is a schematic diagram of the main laser light path of a dirt detection device for a lidar light - passing cover according to the present invention;

[0063] Figure 4 It is a schematic diagram of the first laser and second laser light paths of a dirt detection device for a lidar light - passing cover according to the present invention.

[0064] The illustration marks are explained as follows:

[0065] 1. Main laser module; 11. Main laser; 2. Turntable; 3. Light - passing cover; 31. First light - transmitting area; 32. Second light - transmitting area; 33. Convex platform layer; 34. Dust - proof cover; 341. Light - passing groove; 4. First emission module; 41. First laser generator; 42. First laser reflector; 43. First laser; 5. First receiving module; 6. Second emission module; 61. Second laser generator; 62. Second laser reflector; 63. Second laser; 7. Second receiving module; 8. Detection object. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0066] The present invention will be further described below in conjunction with the detailed embodiments. Among them, the drawings are only for illustrative purposes, showing only schematic diagrams, not physical diagrams, and should not be construed as a limitation to this patent; for better illustration of the embodiments of the present invention, some components in the drawings will be omitted, enlarged, or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well - known structures and their descriptions in the drawings may be omitted.

[0067] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0068] Embodiment 1

[0069] As Figures 1 to 4 shown in the first embodiment of a dirt detection device for the light-transmitting cover of a lidar according to the present invention, which is used for a non-coaxial lidar. The non-coaxial lidar includes a main laser module 1 for emitting and receiving a main laser 11, a light-transmitting cover 3, a turntable 2, and a processing module. The main laser module 1 is installed on the turntable 2, the light-transmitting cover 3 is fixedly arranged, the turntable 2 is located inside the light-transmitting cover 3, and the processing module is communicatively connected to the main laser module 1; it is defined that the place where the main laser 11 exits through the light-transmitting cover 3 is the first light-transmitting area 31, and the place where the main laser 11 enters through the light-transmitting cover 3 is the second light-transmitting area 32; it further includes

[0070] a first transmitting module 4 for emitting a first laser 43;

[0071] a first receiving module 5 for receiving the first laser 43 and converting the first laser 43 into a first electrical signal, and obtaining a voltage value V1. The first laser 43 passes through the light-transmitting cover 3 at the first light-transmitting area 31 and is received by the first receiving module 5;

[0072] a second transmitting module 6 for emitting a second laser 63;

[0073] a second receiving module 7 for receiving the second laser 63 and converting the second laser 63 into a second electrical signal, and obtaining a voltage value V2. The second laser 63 passes through the light-transmitting cover 3 at the second light-transmitting area 32 and is received by the second receiving module 7;

[0074] The first transmitting module 4, the second transmitting module 6, the first receiving module 5, and the second receiving module 7 are all installed on the turntable 2. The first receiving module 5 and the second receiving module 7 are also communicatively connected to the processing module. The first laser 43, the second laser 63, and the main laser 11 do not interfere with each other.

[0075] The main laser 11 is emitted from the main laser module 1 to the detection target for emission, and the main laser 11 is reflected back from the detection target to the main laser module 1 for incidence. The main laser module 1 includes a main laser emitting unit and a main laser receiving unit, and the main laser emitting unit and the main laser receiving unit are arranged non-coaxially. With this setting method, when the main laser module 1 is working, the first emitting module 4 emits the first laser 43, which passes through the first light-transmitting area 31 of the light-transmitting cover 3 and is received by the first receiving module 5, and is converted into a first electrical signal and transmitted to the processing module; the second emitting module 6 emits the second laser 63, and the second laser 63 passes through the second light-transmitting area 32 of the light-transmitting cover 3 and is received by the second receiving module 7, and is converted into a second electrical signal and transmitted to the processing module; the processing module analyzes the first electrical signal and the second electrical signal of the first laser 43 and the second laser 63 respectively, and judges whether there is dirt on the light-transmitting cover 3 by the attenuation degree of the first laser 43 and the second laser 63, and respectively compares the reflection results of the main laser 11 through the attenuation rates of the first laser 43 and the second laser 63, and restores the reflection intensity of the main laser 11 that is not affected by dirt, so as to avoid the influence of dirt on the intensity of the main laser 11.

[0076] As an embodiment of the present invention, the light-transmitting cover 3 is a cylindrical structure and a boss layer 33 is provided at the bottom, and the diameter of the boss layer 33 is larger than the diameters of other sections of the light-transmitting cover 3. The first receiving module 5 and the second receiving module 7 are located in the boss layer 33.

[0077] With this setting method, the first receiving module 5 and the second receiving module 7 are located in the boss layer 33. The first laser 43 passes through the first light-transmitting area 31 and then passes through the boss layer 33 and is received by the first receiving module 5, and the second laser 63 passes through the second light-transmitting area 32 and then passes through the boss layer 33 and is received by the second receiving module 7.

[0078] As an embodiment of the present invention, the first emitting module 4 includes a first laser generator 41 and a first laser reflector 42, the second emitting module 6 includes a second laser generator 61 and a second laser reflector 62. The first laser generator 41 and the second laser generator 61 are both installed on the turntable 2, and the first laser reflector 42 and the second laser reflector 62 are both installed on the top of the main laser module 1 and are both rotatably connected to the main laser module 1.

[0079] With this setting method, when the main laser module 1 changes, the positions of the first light-transmitting area 31 and the second light-transmitting area 32 also change. At this time, the first laser mirror 42 can rotate to adjust the reflection angle of the first laser 43 emitted by the first laser 43 emitter, so that it passes through the light-transmitting cover 3 at the first light-transmitting area 31; the second laser mirror 62 can rotate to adjust the reflection angle of the second laser 63, so that it passes through the light-transmitting cover 3 at the second light-transmitting area 32, thereby ensuring that the first laser 43 and the second laser 63 can monitor the dirt at the exit position and the incident position where the main laser 11 passes through the light-transmitting cover 3.

[0080] As an embodiment of the present invention, a dust-proof cover 34 is provided on the boss layer 33, and an inclined light-transmitting groove 341 is provided on the dust-proof cover 34. The light-transmitting groove 341 is used to allow the first laser 43 and the second laser 63 to pass through the dust-proof cover 34 and enter the boss layer 33.

[0081] With this setting method, the dust-proof cover 34 can reduce the probability of external dirt entering the light-transmitting groove 341, thereby keeping the boss layer 33 at the light-transmitting groove 341 clean and reducing the influence of the dirt at the boss layer 33 on the first laser 43 and the second laser 63; and by adjusting the tilt angles of the first laser mirror 42 and the second laser mirror 62, it can be ensured that the first laser 43 and the second laser 63 pass through the dust-proof cover 34 along the light-transmitting groove 341.

[0082] As an embodiment of the present invention, the processing module includes an electrical signal amplification unit and a micro-control unit. The electrical signal amplification unit is used to amplify the first electrical signal and the second electrical signal respectively returned by the first receiving module 5 and the second receiving module 7, and the micro-control unit is used to analyze the amplified first electrical signal or second electrical signal.

[0083] With this setting method, the electrical signal amplifier can amplify the first electrical signal and the second electrical signal converted from the received first laser 43 or second laser 63, avoiding the situation that the intensities of the first laser 43 and the second laser 63 are small after attenuation by the dirt on the light-transmitting cover 3, resulting in small intensities of the converted first electrical signal or second electrical signal and the micro-control unit being unable to identify them.

[0084] The processing module further includes a code disk for recording the rotation angle of the turntable 2, and the code disk is communicatively connected to the micro-control unit. Since the first laser 43 and the second laser 63 are not coaxially arranged with the main laser 11, the detection positions of the first laser 43 and the second laser 63 are not the positions where the main laser 11 passes through the light-transmitting cover 3 at the current moment; with this setting method, the code disk can provide the current rotation angle of the turntable 2 to the micro-control unit, and the micro-control unit records the dirt influence coefficient measured by the first laser 43 and the second laser 63 with the rotation angle as the coordinate. When the main laser 11 rotates to a certain angle, the micro-control unit retrieves the dirt influence coefficient recorded at the angle coordinate and corrects the main laser 11.

[0085] As an embodiment of the present invention, the first emission module 4 and the first reception module 5 are arranged within the area where the axis of the main laser 11 deflects 90° clockwise; the second emission module 6 and the second reception module 7 are arranged within the area where the axis of the main laser 11 deflects 90° counterclockwise.

[0086] Through this setting method, it is possible to fully avoid the mutual interference caused by the overlapping of the optical paths of the first laser 43, the second laser 63 and the main laser 11 when they work simultaneously, and improve the accuracy of laser imaging and calibration.

[0087] As an embodiment of the present invention, the processing module presets the standard value Va of the electrical signal converted after the first reception module 5 receives the first laser 43 in a clean state, and the standard value Vb of the electrical signal converted after the second reception module 7 receives the second laser 63 in a clean state; the processing module is configured to: compare the first standard value Va with the first electrical signal, and when Va > the voltage value of the first electrical signal, it is determined that the first light-transmitting area 31 is dirty; compare the second standard value Vb with the second electrical signal, and when Vb > the voltage value of the second electrical signal, it is determined that the second light-transmitting area 32 is dirty.

[0088] The clean state means that the light-transmitting cover 3 is cleaned and there is no dirt, and the state where the laser has almost no loss after passing through the light-transmitting cover 3. Through this setting method, by comparing Va with the intensity of the first laser 43 received in real time, the dirt influence coefficient of the light-transmitting cover 3 at the first light-transmitting area 31 can be deduced, and by comparing Vb with the intensity of the second laser 63 received in real time, the dirt influence coefficient of the light-transmitting cover 3 at the second light-transmitting area 32 can be deduced. At this time, combining the dirt influence coefficients of the two places, the intensity of the main laser 11 received in real time can be corrected to offset the influence of the dirt on the light-transmitting cover 3 on the main laser 11.

[0089] As an embodiment of the present invention, the rotation speed of the turntable 2 is 600 r / min.

[0090] Embodiment 2

[0091] The following is the first embodiment of a method for detecting dirt on the light-transmitting cover of a lidar according to the present invention. The method uses the lidar light-transmitting cover dirt detection device described in any of the above to perform detection. The detection method includes:

[0092] S1. The processing module receives an external start command and enters the dirt detection mode;

[0093] In the pollution detection mode, the turntable 2 rotates. The first emission module 4 emits a first laser 43 towards the first reception module 5, and the second emission module 6 emits a second laser 63 towards the second reception module 7. The processing module records the attenuation information of the first laser 43 and the second laser 63 with the position as the coordinate, and judges whether the light-transmitting cover 3 is dirty based on the attenuation information. After the turntable 2 rotates one week, the working mode is turned on;

[0094] Specifically:

[0095] S21. The first emission module 4 emits the first laser 43, the second emission module 6 emits the second laser 63, and the turntable 2 rotates;

[0096] S22. The first reception module 5 receives the first laser 43 and converts it into a voltage value V1 and transmits it to the processing module. The second reception module 7 receives the second laser 63 and converts it into a voltage value V2 and transmits it to the processing module;

[0097] S23. The processing module compares V1 and V2 with the first standard value Va and the second standard value Vb respectively, obtains the outgoing pollution attenuation ratio R1 and the incoming pollution attenuation ratio R2, and calls the code disk to obtain the rotation angle, and records the angle where R1 is located with the first laser 43 and the angle where R2 is located with the second laser 63 respectively;

[0098] R1 = V1 / Va, R2 = V2 / Vb;

[0099] Va is the voltage value converted when the first reception module 5 receives the first laser 43 in the clean state of the light-transmitting cover 3;

[0100] Vb is the voltage value converted when the second reception module 7 receives the second laser 63 in the clean state of the light-transmitting cover 3.

[0101] Through this setting method, the outgoing attenuation ratio R1 and the incoming attenuation ratio R2 within one week are pre-recorded in the processing module. When the working mode is turned on, the processing module can directly call R1 and R2 at the position of the main laser 11 to correct the main laser 11, improving the imaging accuracy.

[0102] S3. In the working mode, the main laser module 1 emits the main laser 11 and receives the reflected main laser 11. The main laser module 1 converts the main laser 11 into an electrical signal and transmits it to the processing module. The processing module calls the attenuation information of the first laser 43 and the second laser 63 at the position of the main laser 11 to correct the electrical signal of the main laser 11 and outputs the corrected electrical signal,

[0103] When the working mode is turned on, the pollution detection mode remains on, and the newly obtained attenuation information of the first laser 43 and the second laser 63 by the processing module is used to overwrite the original recorded information;

[0104] S31. The main laser module 1 emits the main laser 11;

[0105] S32. The main laser module 1 receives the reflected main laser 11, converts it into a voltage value V3 and transmits it to the processing module;

[0106] S33. The processing module retrieves the outgoing dirt attenuation ratio R1 and the incoming dirt attenuation ratio R2 of the current position of the main laser 11, and performs interference correction on V3 through the correction formula to obtain the corrected value V4.

[0107] V4 = V3 / (R2 * R1);

[0108] S34. The first laser 43 module and the second laser 63 module still emit the first laser 43 and the second laser 63 respectively. After the processing module receives the first electrical signal and the second electrical signal converted from the first laser 43 and the second laser 63, it calculates to obtain the new R1 and the new R2, and uses the new R1 to overwrite the original R1 at the position where the first laser 43 is located, and uses the new R2 to overwrite the original R2 at the position where the second laser 63 is located.

[0109] Define one rotation of the turntable 2 as one cycle. Through this setting method, the processing module refers to the R1 and R2 recorded in the previous cycle of the dirt detection mode, and corrects the V3 converted by the main laser 11 at the current position. The corrected V4 can be approximately regarded as the voltage value converted by the main laser 11 that is only affected by the reflection attenuation of the detection object. The ratio between V4 and the voltage value converted by the non-attenuated main laser 11 reflects the true reflectivity of the detection object 8, and then the material of the detection object 8 is judged; in addition, the dirt detection mode and the working mode work synchronously. The R1 and R2 obtained by the dirt detection mode in the current cycle replace the R1 and R2 recorded in the previous cycle, so as to update the dirt condition of the light-transmitting cover 3 in real time and optimize the correction effect.

[0110] S4. Loop to execute S3 until the processing module receives an external stop instruction, and then enter the stop state.

[0111] With this setting method, as the turntable 2 rotates, the first emission module 4, the second emission module 6, the first reception module 5, the second reception module 7, and the main laser module 1 all rotate accordingly. The first laser 43 scans the light-transmitting cover 3 within the first light-transmitting area 31, and the second laser 63 scans the light-transmitting cover 3 within the second light-transmitting area 32. The main laser 11 emits from the light-transmitting cover 3 at the first light-transmitting area 31 and enters the light-transmitting cover 3 at the second light-transmitting area 32. The processing module acquires and records the feedback of the first laser 43 and the second laser 63; subsequently, the main laser 11 starts to work, and the processing module corrects the reflection result of the main laser 11 by invoking the pre-recorded attenuation information of the first laser 43 and the second laser 63; at the same time, the first reception module 5 and the second reception module 7 continue to update the attenuation information of the first laser 43 and the second laser 63 to the processing module, and the processing module overwrites the original record with the new attenuation information of the first laser 43 and the second laser 63 to achieve the update.

[0112] Embodiment 3

[0113] The following is the second embodiment of a method for detecting dirt on the light-transmitting cover of a lidar according to the present invention. This embodiment is similar to Embodiment 1, and the difference lies in that step S2 is different.

[0114] As an embodiment of the present invention, in step S2, the processing module performs amplification preprocessing on V1, V2, Va, and Vb through the electrical signal amplification unit.

[0115] With this setting method, it is possible to avoid the situation where the intensities of the first laser and the second laser are too small after attenuation, resulting in the converted first electrical signal or second electrical signal being too weak, affecting the subsequent recognition and processing of the first electrical signal or second electrical signal by the processing module, and improving the calibration accuracy of the processing module for the main laser 11.

[0116] As an embodiment of the present invention, in step S2, the dirt type on the surface of the light-transmitting cover 3 is also judged based on R1 and R2. When R1 or R2 is equal to 1, it is determined that the corresponding position of the light-transmitting cover 3 is in a clean state; when R1 or R2 is greater than or equal to 0.9 and less than 1, it is determined that there is water stain at the corresponding position of the light-transmitting cover 3; when R1 or R2 is greater than or equal to 0.85 and less than 0.9, it is determined that there is oil stain at the corresponding position of the light-transmitting cover 3; when R1 or R2 is greater than or equal to 0.8 and less than 0.85, it is determined that there is dust or mild covering stain at the corresponding position of the light-transmitting cover 3; when R1 or R2 is greater than or equal to 0.7 and less than 0.8, it is determined that there is sediment or moderate covering stain at the corresponding position of the light-transmitting cover 3; when R1 or R2 is less than 0.7, it is determined that the light-transmitting cover 3 has severe stains. At this time, the processing module sends out a signal to remind the user to clean the light-transmitting cover 3.

[0117] With this setting method, when there is some dirt on the optical mask 3, such as water stains and dust, which has a relatively small impact on the laser intensity, the processing module will correct the intensity of the main laser 11 after reflection according to the results of the first laser 43 and the second laser 63, so as to avoid the influence of the dirt on the intensity of the main laser 11. When there is some dirt on the optical mask 3 that has a relatively large impact on the laser intensity, the imaging of the main laser 11 is seriously affected. At this time, the processing module sends a signal to the user to remind the user to clean the optical mask 3. The processing module corrects the main laser 11 based on the degree of dirt influence, which can not only improve the detection accuracy of the main laser 11, but also reduce the cleaning pressure, greatly improving the applicable scenarios and accuracy of the lidar.

[0118] Embodiment 4

[0119] The following is an embodiment of an intelligent vehicle of the present invention, including a lidar, the lidar adopts the lidar optical mask dirt detection device of Embodiment 1 and the lidar optical mask dirt detection method of Embodiment 2 or 3, and further includes a central processing module and an automatic navigation module. The lidar is used to obtain information about the surrounding environment of the vehicle; the central processing module is used to generate a model of the surrounding environment of the vehicle according to the lidar and issue an instruction to the driver based on the detection result of the lidar optical mask dirt detection device; the automatic navigation module is used to provide route planning according to the model generated by the central processing module.

[0120] With this setting method, the intelligent vehicle can reduce the influence of dirt on the lidar on the optical mask, thereby improving the modeling accuracy of the central processing module, and further improving the accuracy of route planning, which is beneficial to improving driving safety.

[0121] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A laser radar light shield dirt detection device, applied to a non-coaxial laser radar, the non-coaxial laser radar comprising a main laser module (1) for transmitting and receiving a main laser (11), a light shield (3), a turntable (2) and a processing module, wherein the main laser module (1) is mounted on the turntable (2), the light shield (3) is fixedly arranged, the turntable (2) is located inside the light shield (3), and the processing module is communicatively connected with the main laser module (1); characterized in that: The method defines a first light-transmitting area (31) where the main laser (11) passes through the light-transmitting cover (3) when emitted, and a second light-transmitting area (32) where the main laser (11) passes through the light-transmitting cover (3) when incident; and further includes: A first emission module (4), used for emitting a first laser (43); A first receiving module (5) is used to receive a first laser (43) and convert the first laser (43) into a first electrical signal, wherein the first laser (43) passes through the light-transmitting cover (3) in the first light-transmitting area (31) and is received by the first receiving module (5); A second emission module (6), used for emitting a second laser (63); A second receiving module (7) is used to receive a second laser (63) and convert the second laser (63) into a second electrical signal, wherein the second laser (63) passes through the light-transmitting cover (3) in the second light-transmitting area (32) and is received by the second receiving module (7); The first transmitting module (4), the second transmitting module (6), the first receiving module (5), and the second receiving module (7) are all mounted on the turntable (2); the first receiving module (5) and the second receiving module (7) are also connected to the processing module for communication; the first laser (43), the second laser (63) and the main laser (11) do not interfere with each other.

2. The laser radar light shield dirt detection device according to claim 1, characterized in that: The first emission module (4) comprises a first laser generator (41) and a first laser reflection mirror (42), and the second emission module (6) comprises a second laser generator (61) and a second laser reflection mirror (62). The first laser generator (41) and the second laser generator (61) are both mounted on a turntable (2), and the first laser reflection mirror (42) and the second laser reflection mirror (62) are both mounted on the top of a main laser module (1) and are rotatably connected to the main laser module (1).

3. The laser radar light shield dirt detection device according to claim 1, characterized in that: The processing module comprises: An electrical signal amplifying unit, used to amplify the first electrical signal and the second electrical signal returned by the first receiving module (5) and the second receiving module (7) respectively; A micro control unit, used for analyzing the amplified first electrical signal and the second electrical signal; The electric signal amplifying unit is communicatively connected with the first receiving module (5), the second receiving module (7) and the micro control unit.

4. The laser radar light shield dirt detection device according to claim 3 is characterized in that: The processing module also includes a code disk for recording the rotation angle of the turntable (2), and the code disk is communicatively connected with the micro control unit.

5. The laser radar light shield dirt detection device according to claim 1, characterized in that: The processing module is preset with a first standard value Va, which is defined as the voltage value of the current converted by the first laser (43) received by the first receiving module (5) when the light shield (3) is in a clean state; A second standard value Vb is defined as a voltage value of a current converted by the second laser (63) when the second receiving module (7) receives the current when the light shield (3) is in a clean state; The processing module is configured to: compare the first standard value Va with the first electrical signal, and when Va is greater than the voltage value of the first electrical signal, determine that dirt exists in the first light-transmitting area (31); and compare the second standard value Vb with the second electrical signal, and when Vb is greater than the voltage value of the second electrical signal, determine that dirt exists in the second light-transmitting area (32).

6. A method for detecting contamination of a laser radar light shield, characterized in that: The detection is performed using the laser radar light shield dirt detection device described in any one of claims 1 to 5, and the detection method includes: S1. The processing module receives an external startup command and enters the pollution detection mode; S2. In the dirt detection mode, the turntable (2) rotates, the first transmitting module (4) emits a first laser (43) to the first receiving module (5), and the second transmitting module (6) emits a second laser (63) to the second receiving module (7). The processing module records the attenuation information of the first laser (43) and the second laser (63) with the position as the coordinate, and determines whether the light shield (3) is dirty based on the attenuation information; S3. After the turntable (2) rotates one circle, the working mode starts: In the working mode, the main laser module (1) emits the main laser (11) and receives the reflected main laser (11). The main laser module (1) converts the main laser (11) into an electrical signal and transmits it to the processing module. The processing module calls the attenuation information of the first laser (43) and the second laser (63) at the position where the main laser (11) is located, performs correction processing on the electrical signal of the main laser (11), and outputs the corrected electrical signal. When the working mode is turned on, the pollution detection mode remains turned on, and the attenuation information of the first laser (43) and the second laser (63) newly obtained by the processing module is used to overwrite the original recorded information; S4. Execute S3 in a loop until the processing module receives a shutdown command from the outside, and then enters the shutdown state.

7. The method for detecting contamination of a laser radar light shield (3) according to claim 6, characterized in that: In step S2, specifically: S21. The first emitting module (4) emits a first laser (43), the second emitting module (6) emits a second laser (63), and the turntable (2) rotates; S22. The first receiving module (5) receives the first laser (43) and converts it into current, obtains a corresponding voltage value V1 and transmits it to the processing module, and the second receiving module (7) receives the second laser (63) and converts it into current, obtains a corresponding voltage value V2 and transmits it to the processing module; S23. The processing module compares V1 and V2 with the first standard value Va and the second standard value Vb respectively, obtains the outgoing dirt attenuation ratio R1 and the incident dirt attenuation ratio R2, then calls the rotation angle recorded in the code disk, and respectively records the angle between R1 and the first laser (43), and the angle between R2 and the second laser (63); Among them, R1 = V1 / Va, R2 = V2 / Vb; Va is a voltage value converted by the first receiving module (5) receiving the first laser (43) when the light shield (3) is in a clean state; Vb is the voltage value converted by the second receiving module (7) receiving the second laser (63) when the light shield (3) is in a clean state.

8. The method for detecting dirtiness of a laser radar light shield (3) according to claim 7, characterized in that: In step S3, specifically: After the turntable (2) rotates one circle, the working mode starts: S31. The main laser module (1) emits a main laser (11); S32. The main laser module (1) receives the reflected main laser (11), converts it into a voltage value V3 and transmits it to the processing module; S33. The processing module retrieves the emission dirt attenuation ratio R1 and the incident dirt attenuation ratio R2 of the current position of the main laser (11), and performs interference correction on V3 through the correction formula to obtain the correction value V4. V4 = V3 / (R2 * R1); S34. The first laser (43) module and the second laser (63) module still emit the first laser (43) and the second laser (63) respectively. After receiving the electrical signals converted by the first laser (43) and the second laser (63), the processing module calculates and obtains the new R1 and the new R2, and uses the new R1 to cover the original R1 at the angle of the first laser (43), and uses the new R2 to cover the original R2 at the angle of the second laser (63).

9. The method for detecting contamination of a laser radar light shield according to claim 7, characterized in that: In step S2, the type of dirt on the surface of the light shield (3) is also judged based on R1 and R2. When R1 or R2 is equal to 1, it is determined that the corresponding position of the light shield (3) is in a clean state; when 0.9≤R1<1 or 0.9≤R2<1, it is determined that there is water stain at the corresponding position of the light shield (3); when 0.85≤R1<0.9 or 0.85≤R2<0.9, it is determined that there is oil stain at the corresponding position of the light shield (3). When 0.8≤R1<0.85 or 0.8≤R2<0.85, it is determined that dust or lightly concealed stains exist at the corresponding position of the light shield (3); when 0.7≤R1<0.8 or 0.7≤R2<0.8, it is determined that mud or moderately concealed stains exist at the corresponding position of the light shield (3); when R1<0.7 or R2<0.7, it is determined that heavy stains exist at the light shield (3), and the processing module sends a signal to be cleaned.

10. A smart car, characterized in that: It includes a laser radar, which adopts the laser radar light cover dirtiness detection method as described in any one of claims 5-9 above, and also includes a central processing module and an automatic navigation module. The laser radar is used to obtain the information of the surrounding environment of the car; the central processing module is used to generate a model of the surrounding environment of the car according to the laser radar, and to issue instructions to the driver according to the detection results of the laser radar light cover dirtiness detection device; the automatic navigation module is used to provide route planning according to the modeling generated by the central processing module.

Images