A scanning laser radar automatic cleaning device

Abstract

The application provides a kind of scanning laser radar automatic cleaning device.The scanning laser radar automatic cleaning device includes window module, horizontal rotation motor group, pitch rotation motor group, horizontal rotation module and pitch rotation module for supporting laser radar window module rotation, window module, spray module for cleaning optical window in window module, the horizontal rotation motor group and pitch rotation motor group are respectively connected with horizontal rotation module and pitch rotation module transmission, the horizontal rotation module is connected with pitch rotation module, the pitch rotation module is connected with window module, the horizontal rotation module is arranged on horizontal rotation motor group, the window module includes optical window, temperature measuring element and heating element, the spray module includes water tank, micro high-pressure water pump, air pump and spray assembly, the water tank is connected with micro high-pressure water pump, the micro high-pressure water pump, air pump is respectively connected with spray assembly.The scanning laser radar automatic cleaning device provided by the application can solve the cleaning problems such as dust, rain, snow and bird droppings, while supporting radar three-dimensional scanning, and the structure is compact, which meets the needs of long-term operation and automatic maintenance of laser radar in desert, gobi or desert area.

Description

Technical Field

[0001] This invention relates to the field of atmospheric detection lidar technology, specifically to an automatic cleaning device for scanning lidar. Background Technology

[0002] LiDAR, due to its high precision and high spatiotemporal resolution, is widely used in atmospheric detection in meteorology, wind power, aviation, and navigation. The detection principle of lidar is to remotely sense the location, velocity, concentration, and distance of targets by emitting a laser beam and receiving its reflected signal. Since both the emitted beam and the received light signal must pass through an optical window, the cleanliness of the optical window significantly affects the radar's detection performance. LiDAR typically operates in outdoor environments, especially in deserts and arid regions, where dust, snow, and other pollutants often accumulate on the optical window, affecting the radar's effective data acquisition rate and causing it to malfunction. This necessitates manual cleaning of the optical window by maintenance personnel, which not only increases the workload but also results in delayed maintenance response and cannot meet the real-time cleaning requirements of unattended operation. Therefore, researchers have conducted research on automatic cleaning control methods and devices for lidar.

[0003] Traditional automatic cleaning methods for lidar primarily rely on automatic wipers to clean the optical window (Patent Publication No.: CN120294781A). Similar to car windshield wipers, this method, in windy and sandy environments, accelerates lens wear due to friction. Furthermore, aging of the rubber strips also affects the cleaning effect. Long-term use leads to scratches and blurring of the window surface, reducing light transmittance and impacting radar detection performance. Liu Sihan et al. from Nanjing University of Information Science and Technology proposed a combined air-heat cleaning method (Patent Publication No.: CN119870052B). This method uses a high-pressure air pump to blow air into the optical window, removing surface impurities and heating the airflow to prevent condensation on the lens. However, this pure airflow method is more suitable for clean southern regions. In desert and Gobi areas, after rain or snow, dust in the air mixes with raindrops or snow, forming pollutants that adhere to the lens, creating mud-like stains that cannot be removed by air blowing.

[0004] Furthermore, in detection scenarios such as low-altitude wind shear, micro-downbursts, low-altitude jet streams, and atmospheric turbulence, lidar is required to achieve multiple scanning modes such as PPI, RHI, DBS, LOS, and VAD. Its optical window will change position during the scanning process. At the same time, in order to achieve lightweight, miniaturization, and modularization, the equipment structure is required to be compact, which also brings challenges to the design of lidar fully automatic cleaning systems.

[0005] In summary, how to provide an automatic cleaning device for scanning lidar that is applicable to deserts, Gobi, or wastelands, can perform 3D scanning, has a compact structure, and can be fully automated is a technical issue of great concern to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to propose an automatic cleaning device for scanning lidar, which can cope with cleaning problems such as sandstorms, rain and snow, and bird droppings. It also supports three-dimensional scanning of the lidar and has a compact structure, meeting the needs of long-term automatic maintenance of lidar in desert, Gobi or arid regions.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention provides an automatic cleaning device for scanning lidar, which includes a window module, a horizontal rotation motor assembly, a pitch rotation motor assembly, a horizontal rotation module and a pitch rotation module for supporting the rotation of the window module of the lidar, and a spray module for cleaning the optical window in the window module. The horizontal rotation motor assembly and the pitch rotation motor assembly are respectively connected to the horizontal rotation module and the pitch rotation module. The horizontal rotation module is connected to the pitch rotation module, and the pitch rotation module is connected to the window module. The pitch rotation module is mounted on the horizontal rotation module, and the horizontal rotation module is mounted on the horizontal rotation motor assembly. The window module includes an optical window, a temperature measuring element, and a heating element. The spray module includes a water tank, a miniature high-pressure water pump, an air pump, and a spray assembly. The water tank is connected to the miniature high-pressure water pump, and the miniature high-pressure water pump and the air pump are respectively connected to the spray assembly.

[0008] As a further improvement, the miniature high-pressure water pump and air pump in the spray module are installed on the side of the drawer slide rail, and the water tank is installed on the drawer slide rail for horizontal movement.

[0009] As a further improvement, the horizontal rotation module is mounted on top of the horizontal rotation motor assembly, and the drawer slide rail is mounted on the side of the horizontal rotation motor assembly.

[0010] As a further improvement, a camera is mounted on the side of the drawer slide to monitor contaminants on the optical window.

[0011] As a further improvement, the horizontal rotary motor unit is bolted inside the side-open horizontal rotary motor unit cover. The top of the horizontal rotary motor unit cover has a through hole for mounting the horizontal rotary module on the horizontal rotary motor unit. The top of the horizontal rotary motor unit cover is equipped with a pitch rotary motor unit, a pitch rotary module, and a window module, which are respectively connected to the horizontal rotary module. The side of the horizontal rotary motor unit cover is bolted to a cover side plate, and the drawer slide rail is installed on the side of the horizontal rotary motor unit cover.

[0012] As a further improvement, the drawer slide, the miniature high-pressure water pump, and the air pump are bolted to the inside of the spray module outer box, which is open on the side. The side of the spray module outer box is bolted to a side door panel. After the side door panel is opened, the drawer slide can be pulled out to add water to the water tank. The side of the spray module outer box is provided with a through hole two for the gas sprayed by the air pump to pass through and a through hole three for the liquid sprayed by the miniature high-pressure water pump to pass through.

[0013] As a further improvement, the spray assembly is installed on the side of the outer casing of the horizontal rotating motor unit.

[0014] As a further improvement, the automatic cleaning device for scanning lidar also includes a software module for controlling the operation of the window module, the horizontal rotation motor group, the pitch rotation motor group, and the spray module.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] (1) It solves the problem of automatic cleaning of the optical window of lidar, and is especially suitable for desert, Gobi or arid areas. The window module has built-in temperature sensing element and heating element, which can prevent the optical window from freezing, frosting, condensing and fogging at low temperatures. The spraying and blowing method can effectively solve various cleaning problems such as sand, mud stains and bird droppings, while avoiding scratches and wear on the optical window and extending the working life of the equipment.

[0017] (2) By combining the automatic cleaning cycle and threshold judgment in the software module, the optical window is fully automatically cleaned without the need for manual on-site operation, which reduces the operation and maintenance costs and ensures the timeliness of pollutant cleaning. In addition, the pollution status of the optical window and the effect after cleaning can be viewed remotely at any time, which helps to grasp the status of the optical mirror and ensure the efficient operation of the lidar.

[0018] (3) Suitable for cleaning the optical window of three-dimensional scanning lidar, it solves the contradiction between optical window rotation and cleaning, and makes the structure as compact as possible with limited volume and mass, while having sufficient water storage and reducing the number of water additions. Attached Figure Description

[0019] Figure 1 This is a disassembly diagram of an automatic cleaning device for scanning lidar according to the present invention;

[0020] Figure 2 This is a perspective view of the exterior of an automatic cleaning device for scanning lidar according to the present invention;

[0021] Figure 3 This is a flowchart of a precipitation identification method for an automatic cleaning device using scanning lidar according to the present invention;

[0022] Figure 4 This is an example diagram of the precipitation identification echo power spectrum of an automatic cleaning device using scanning lidar according to the present invention.

[0023] 1-Pitch rotation motor unit; 2-Horizontal rotation module; 3-Pitch rotation module; 4-Window module; 5-Horizontal rotation motor unit outer cover; 6-Spray assembly; 7-Outer cover side panel; 8-Camera; 9-Water tank; 10-Drawer slide rail; 11-Spray module outer box; 12-Side door panel; 13-Miniature high-pressure water pump; 14-Air pump; 15-Horizontal rotation motor unit. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0025] refer to Figure 1-2 This invention relates to an automatic cleaning device for scanning lidar. The automatic cleaning device includes a window module 4, a horizontal rotation motor assembly 15, a pitch rotation motor assembly 1, a horizontal rotation module 2 and a pitch rotation module 3 for supporting the rotation of the lidar window module, and a spray module for cleaning the optical window in the window module. The horizontal rotation motor assembly 15 and the pitch rotation motor assembly 1 are respectively connected to the horizontal rotation module 2 and the pitch rotation module 3. The horizontal rotation module 2 is connected to the pitch rotation module 3, and the pitch rotation module 3 is connected to the window module 4. The pitch rotation module 3 is mounted on the horizontal rotation module 2, and the horizontal rotation module 2 is mounted on the horizontal rotation motor assembly 15. The window module 4 includes an optical window, a temperature measuring element, and a heating element. The spray module includes a water tank 9, a miniature high-pressure water pump 13, an air pump 14, and a spray assembly 6. The water tank 9 is connected to the miniature high-pressure water pump 13, and the miniature high-pressure water pump 13 and the air pump 14 are respectively connected to the spray assembly 6. Both the horizontal rotation motor assembly 15 and the pitch rotation motor assembly 1 contain an independent motor, which drives the horizontal rotation module 2 to rotate horizontally and the pitch rotation module 2 to rotate vertically, thereby driving the window module 4 to rotate in three dimensions to a fixed cleaning position, thus achieving the cleaning of the optical window. The motor can be purchased according to the actual speed requirements, and there are no restrictions on the model of the motor, as long as it meets the speed requirements. The spray assembly 6 can be a spray (air) pipe and a spray (air) head bolted to the spray pipe, used to spray (air) the optical window. Multiple sets of spray assembly 6 can be set as needed, such as 2 sets, 3 sets, etc.

[0026] The horizontal rotary motor assembly 15 is placed inside the horizontal rotary motor assembly cover 5. The top of the cover 5 has a through hole for mounting the horizontal rotary module 2 onto the motor assembly 15. The top of the cover 5 is equipped with a pitch rotary motor assembly 1, a pitch rotary module 3, and a window module 4, all connected to the horizontal rotary module 2. Side plates 7 are bolted to the sides of the cover 5. The drawer slide 10 is mounted on the side of the cover 5. A water tank 9 from the spray module is mounted on the drawer slide 10 for horizontal movement. A miniature high-pressure water pump 13 and an air pump 14 from the spray module are mounted on the side of the drawer slide 10. When the drawer slide 10 is pulled out, only the water tank 9 moves horizontally. The water tank 9 is made of lightweight and durable plastic, and its capacity is selected based on the installation space; the specific model is not limited. The miniature high-pressure water pump 13 and air pump 14 are selected from devices with high water (air) pressure, which can work together with the spray assembly 6 to spray high-pressure water (air) flow. The specific models are not limited.

[0027] The water tank 9, drawer slide 10, miniature high-pressure water pump 13, and air pump 14 are housed inside the spray module outer casing 11, which has an open side. A side door panel 12 is bolted to the side of the spray module outer casing 11 for opening when water is added to the water tank 9. The side of the spray module outer casing 11 has a second through-hole for the gas ejected by the air pump 14 and a third through-hole for the liquid ejected by the miniature high-pressure water pump 13. A bracket is mounted on the side of the drawer slide 10, and a camera protrudes from the top of the spray module outer casing 11 to monitor contaminants on the optical window.

[0028] The automatic cleaning device for scanning lidar also includes a software module for controlling the operation of the window module, the horizontal rotation motor group, the pitch rotation motor group, and the spray module.

[0029] In window module 4, both the temperature sensing element and the heating element are installed inside the optical window. The heating threshold of the optical window is set to 5°C to 10°C. The temperature sensing element heats the optical window when the temperature is below 5°C and stops heating when the temperature is above 10°C. This is to prevent the optical window from freezing, frosting, fogging, or condensing at low temperatures. The heating element can be a common heater, which is not specifically described in this embodiment.

[0030] Fully Automatic Cleaning Solution 1: This solution uses a software module to set fixed-cycle cleaning. The cleaning cycle can be remotely set based on the atmospheric dryness and cleanliness of different regions, such as once a week, twice a month, or once a month. This device is suitable for desert, Gobi, and arid regions where sandstorms are severe in spring and autumn, with a cycle set to once a month, and twice a month in summer and winter.

[0031] Fully Automatic Cleaning Solution 2: For areas contaminated within a cycle, the echo signal received by the lidar will be severely attenuated. The following three logic checks determine if contamination exists, triggering a cleaning command to achieve remote, fully automatic cleaning:

[0032] (1) When the signal-to-noise ratio of the first range gate in the near field is greater than -10dB and the signal-to-noise ratio of the second range gate is less than -32dB, and this lasts for 1 hour, a cleaning cycle is initiated.

[0033] (2) If the data detection distance is lower than 80% of the nominal detection range for 24 consecutive hours, start the spray once;

[0034] (3) When a precipitation signal is detected in the power spectrum of the echo signal, a spraying operation is initiated 12 hours after the precipitation signal ends. The precipitation signal determination method is referenced in "Xiong Bingjie. Research on the Method of Detecting Raindrop Spectral Distribution by Coherent Doppler LiDAR [D]. Xi'an University of Technology, 2024: 17-30." On sunny days, the power spectrum follows a single-peak Gaussian distribution; during precipitation, the power spectrum does not satisfy this distribution. Precipitation is identified by fitting a single-peak Gaussian distribution. See [link to relevant documentation]. Figure 3-4 .

[0035] Fully automatic cleaning solution 3: Use a remote video monitoring module (i.e., camera) to observe the optical window and determine whether there are contaminants. When contaminants are present, send instructions through the software module to achieve remote fully automatic cleaning.

[0036] The fully automatic cleaning process is as follows: When the lidar receives a cleaning command, it first stops emitting laser light. The horizontal rotation motor assembly 15 and the pitch rotation motor assembly 1 then rotate the horizontal rotation module 2 and the pitch rotation module 3, causing the window module 4 to return to its initial position through horizontal and pitch rotation. Next, it switches to automatic cleaning mode, and the horizontal rotation motor assembly 15 again rotates the horizontal rotation module 2, causing the window module 4 to rotate horizontally to the cleaning position, aligning the optical window to be cleaned with the spray assembly 6. Finally, the miniature high-pressure water pump 13 starts, spraying high-pressure water onto the optical window to rinse away contaminants for 10 seconds. After the miniature high-pressure water pump 13 stops, the air pump 14 starts, spraying high-pressure air onto the optical window to clean residual water stains for 10 seconds, thus completing the cleaning process. It is worth noting that in winter, antifreeze glass cleaner needs to be added to the water tank to prevent the tank and delivery pipes from freezing.

[0037] As can be seen from the above results, the present invention can remotely and automatically clean the optical window of a three-dimensional scanning lidar, effectively cleaning stubborn pollutants such as sand, snow, and bird droppings. It is suitable for desert, Gobi, and wasteland areas. The automatic cleaning system has a compact structure, is integrated with the lidar scanning head, has sufficient water storage capacity, low water replenishment frequency, and simple automatic control method, making it easy to implement in engineering.

[0038] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the protection scope of the present invention.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. An automatic cleaning device for scanning lidar, characterized in that, The automatic cleaning device for the scanning lidar includes a window module (4), a horizontal rotation motor assembly (15), a pitch rotation motor assembly (1), a horizontal rotation module (2) and a pitch rotation module (3) for supporting the rotation of the lidar window module, and a spray module for cleaning the optical window in the window module. The horizontal rotation motor assembly (15) and the pitch rotation motor assembly (1) are respectively connected to the horizontal rotation module (2) and the pitch rotation module (3). The horizontal rotation module (2) and the pitch rotation module (3) are connected to each other. 3) Connection: The pitch rotation module (3) is connected to the window module (4). The horizontal rotation module (2) is set on the horizontal rotation motor unit (15). The window module (4) includes an optical window, a temperature measuring element and a heating element. The spray module includes a water tank (9), a micro high-pressure water pump (13), an air pump (14) and a spray assembly (6). The water tank (9) is connected to the micro high-pressure water pump (13). The micro high-pressure water pump (13) and the air pump (14) are respectively connected to the spray assembly (6).

2. The automatic cleaning device for scanning lidar according to claim 1, characterized in that, The miniature high-pressure water pump (13) and air pump (14) are installed on the side of the drawer slide (10), and the water tank (9) is installed on the horizontally moving drawer slide (10).

3. The automatic cleaning device for scanning lidar according to claim 2, characterized in that, The horizontal rotation module (2) is installed on the top of the horizontal rotation motor assembly (15), and the drawer slide rail (10) is installed on the side of the horizontal rotation motor assembly (15).

4. The automatic cleaning device for scanning lidar according to claim 2, characterized in that, A camera (8) is mounted on the side of the drawer slide (10) to monitor contaminants on the optical window.

5. The automatic cleaning device for scanning lidar according to claim 2, characterized in that, The horizontal rotary motor assembly (15) is bolted inside the horizontal rotary motor assembly cover (5) which is open on the side. The top of the horizontal rotary motor assembly cover (5) has a through hole for mounting the horizontal rotary module (2) on the horizontal rotary motor assembly (15). The top of the horizontal rotary motor assembly cover (5) is equipped with a pitch rotary motor assembly (1), a pitch rotary module (3) and a window module (4) which are respectively connected to the horizontal rotary module (2). The side of the horizontal rotary motor assembly cover (5) is bolted with a cover side plate (7). The drawer slide rail (10) is installed on the side of the horizontal rotary motor assembly cover (5).

6. The automatic cleaning device for scanning lidar according to claim 1, characterized in that, The drawer slide (10), the miniature high-pressure water pump (13), and the air pump (14) are bolted to the inside of the spray module outer box (11) which is open on the side. The side of the spray module outer box (11) is bolted to a side door panel (12). After the side door panel (12) is opened, the drawer slide (10) can be pulled out to add water to the water tank (9). The side of the spray module outer box (11) is respectively provided with a through hole two for the gas sprayed by the air pump (14) and a through hole three for the liquid sprayed by the miniature high-pressure water pump (13).

7. The automatic cleaning device for scanning lidar according to claim 1, characterized in that, The spray assembly (6) is installed on the side of the outer cover (5) of the horizontal rotating motor unit.

8. The automatic cleaning device for scanning lidar according to claim 1, characterized in that, The automatic cleaning device for scanning lidar also includes a software module for controlling the operation of the window module (4), the horizontal rotation motor group (15), the pitch rotation motor group (1), and the spray module.

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