Method for eliminating and preventing forward vision channel obstacles in automatic driving of automobile
Through the combination of rain sensor and camera detection, combined with heating and defog removal, vibration removal and electrostatic adsorption and other technical means, the problems of inaccurate identification of obstacles in the forward visual channels of autonomous vehicles, slow defog removal speed and insufficient removal of stubborn stains are solved, and the functions of fast, energy-saving, noise-free obstacle removal and fog prevention are achieved.
Patent Information
- Application Number
- CN202510215225.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-04-25
AI Technical Summary
The prior art has problems in the forward visual channels of autonomous vehicles that identify obstacles inaccurate locations, slow defog removal speed and high noise, insufficient removal of stubborn stains, and lack of mechanisms to prevent fog.
The rain and snow are sensed through the rain sensor and automatically start the wiper; the camera detects whether there is fog on the lens and glass surface, and uses heating and defog, vibration of piezoelectric ceramic film or electrostatic adsorption functions to remove the fog; use laser head to irradiate and decompose stubborn stains, and prevents fog on the glass and camera surfaces from fog again during the vehicle operation.
It realizes accurate identification and rapid removal of obstacles in forward visual channels of autonomous vehicles, enhances the ability to remove stubborn stains, and is noise-free, and has the function of preventing fog.
Smart Images
Figure CN119872466A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of vision technology for autonomous driving vehicles, and in particular to a method for removing and preventing various dirty visual obstacles in a visual channel of a front-view camera for an autonomous driving vehicle. Background Art
[0002] At present, the perception components of the car's automatic driving mainly rely on the solution of collecting visual images with millimeter-wave radar and laser radar signals for fusion perception, or there is also a pure visual solution that only relies on the camera to collect visual images for perception. Among them, the forward visual image is mainly obtained by one or more cameras installed on the inner side of the top of the car's front windshield. The forward visual channel of these cameras mainly includes the camera itself and the front windshield area within the black edge of the glass. The forward visual channel is often blocked by water mist, fallen leaves, mud spots, bird droppings, shellac, etc., causing visual obstructions, thereby causing functional abnormalities, driving safety risks and customer complaints of the automatic driving car. Therefore, for the water mist on the inner surface of the glass: the existing technology considers heating the heating wire in the camera visual area and the inner surface of the front windshield to eliminate the water mist; or introducing a heating element or fan near the camera and in the area inside the glass to eliminate the water mist obstacle by heating the element or blowing the fan. For the water mist or other dirt obstacles on the outer surface, it is mainly eliminated by wipers. The method for judging whether the visual obstruction appears on the inner or outer surface of the glass mainly relies on the color and shape of the obstacle: white ones with unclear outlines are identified as water mist on the inner surface of the glass, which is removed by blowing air or heating from the inside; non-white ones with obvious outlines are identified as dirt on the outer surface of the glass, which is removed by scraping with wipers.
[0003] However, the prior art has the following problems and shortcomings: 1. If it only relies on color and contour clarity, the identification of the above-mentioned forward visual obstruction and position is not accurate enough; 2. The defog speed of component heating and blowing is slow and accompanied by noise; 3. The wipers are weak in clearing the stubborn dirt on the outer surface of the glass, such as bird droppings, mud, etc.; 4. There are no targeted removal measures for camera fogging; 5. In the scheme of arranging heating wires on the inner surface of the front windshield, the opaque heating wires will leave traces of interference in the camera image, affecting the accuracy of visual perception; 6. The existing scheme has no early prevention mechanism for fogging. It is only after the glass is fogged and blocks the field of vision and is recognized by the camera that the measures to remove the fogging are started. The field of vision obstruction formed during this period will cause potential safety accidents; 7. There is no separate removal of visual obstacles for rainy and snowy environments and rainless and snowless environments. On this basis, the applicant proposes a method for eliminating and preventing obstacles in the forward visual channel of autonomous driving. Summary of the invention
[0004] The present invention mainly provides a method for eliminating and preventing obstacles in the forward visual channel of autonomous driving. The method can accurately identify the interface position where obstacles block the vehicle, and adopt a faster and more energy-saving solution to remove water mist. The water mist on the camera can also be removed, and a stronger removal solution is also adopted for the more stubborn dirt on the outer surface of the glass. It will not leave any traces in the camera image, and at the same time prevent the glass and camera surfaces from fogging up again during the driving of the vehicle.
[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving includes the following steps: When the car is powered on and waiting to be started or running, the rain sensor senses rain and snow. If the rain sensor recognizes rain or snow, the wiper is automatically started according to the amount of rain and snow. At the same time, the camera detects whether the lens is blocked by fogging. If it is identified that the lens is fogged, the lens heating and defogger are started until the field of view is restored to be unobstructed, the heating is stopped and the water mist electrostatic adsorption function of the lens anti-fog film is started; if it is identified that the lens is not fogged, it is further identified whether there is fogging on the inner surface of the windshield. If it is identified that the inside of the glass is fogged, the piezoelectric ceramic film oscillator is started to vibrate until the field of view is restored to be unobstructed, the vibration is stopped and the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is started; if the wiper is in the sweeping state and there is no obstruction in the camera field of view (if it is identified that there is no fogging on the inside of the glass), the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is directly started; If the rain sensor detects that there is no rain or snow, it will detect whether the camera field of view is blocked. If there is no blockage, it will directly start the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass and the water mist electrostatic adsorption function of the lens anti-fog film; if there is blockage, it will detect whether the camera lens is fogged. If it is identified that the lens is fogged, it will start the lens heating and defog until the field of view is restored to be unobstructed, stop heating and start the water mist electrostatic adsorption function of the lens anti-fog film; If the lens is identified as not fogged, the system further identifies whether the inner and outer surfaces of the windshield are blocked. If the inner side of the glass is identified as fogged, the piezoelectric ceramic film vibrator is activated to vibrate until the field of view is restored to be unobstructed, then the vibration is stopped and the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is activated. If the outer surface of the glass is identified as blocked, the wiper function is activated. When the blockage on the outer side of the glass is cleared and the field of view is restored, the wiper function is turned off and the water mist electrostatic adsorption function of the anti-fog film is activated. After the obstacle is removed, turn on the electrostatic adsorption anti-fog function of the glass and lens, and repeat the above obstacle removal method until the car is powered off.
[0006] A further improvement is that when the camera detects whether the lens is blocked by fogging, if there are fixed black spots or black lines in the camera image and the light entering the aperture becomes significantly darker, it is recognized that the lens is fogged.
[0007] A further improvement is that if the lens is identified as fogged, the lens heating and defogger is started until the fixed black spots or black lines in the image disappear and the light entering the aperture returns to be consistent with the ambient light, and then the lens heating is exited.
[0008] A further improvement is that if the image in the field of view is still blocked and the grayscale of the diamond-shaped calibration pattern on the inner surface of the glass decreases and the star-shaped calibration pattern on the outer surface of the glass is blurred, it is recognized as fogging on the inside of the glass.
[0009] A further improvement is that if the image in the field of view is still blocked and the diamond-shaped calibration pattern on the inner surface of the glass is clear, and there is a halo on the edge of the star-shaped calibration pattern on the outer surface of the glass or the edge contour of the local blocker is clear, it is recognized that there is blockage on the outside of the glass.
[0010] Further improvements are: the end faces of the camera mounting plastic shell and the glass are coated with sealant to form a sealed cavity, a rubber ring is installed on the mating surface of the camera mounting to block water vapor, a small hole is opened on the camera mounting plastic shell, and a waterproof and breathable film is attached to the small hole.
[0011] Further improvement is that the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is realized as follows: In the field of view area on the inner surface of the windshield, silver nanowire ink is printed into 5-micron fine lines with a line spacing of 2mm using nanoimprinting or inkjet printing technology to form a horizontal strip grid. After the grid is covered, the transmittance is >95% and does not affect the forward field of view; The flexible circuit boards (FPCs) are attached to the black edges of the left and right glass and overlapped at the end of each silver nanowire. The left and right FPC circuits are connected to the positive and negative poles of 5V DC respectively, so that positive and negative electrodes are generated at the left and right ends of each silver nanowire to form a conductive layer. Silicon dioxide or transparent polyurethane is applied to the surface of the transparent silver nanowire grid by spraying or vacuum coating process to form a 0.1 mm thick transparent insulating protective layer.
[0012] Further improvements are to calibrate the pattern image distortion and identify the location where fogging occurs. The specific steps are: Outside the edge of the camera's driving field of view and within the black edge of the glass, a 2mm star-shaped calibration pattern is printed on the outer surface of the glass using reflective ink, with a reflectivity greater than 70%. A 2mm diamond-shaped calibration pattern is printed on the inner surface of the glass using matte ink, with a reflectivity less than 20%.
[0013] Further improvements are: a PZT piezoelectric film array is embedded in the flexible silicone glass interlayer, which emits high-frequency vibrations to remove fog on the glass surface when powered on, and the cavitation effect peels off and removes water mist.
[0014] A further improvement is that if the wipers wipe three times and the obstruction on the outside of the glass is not cleared and the field of vision is still obstructed, it is identified as a stubborn stain. The wipers continue to wipe and the wiper laser head is turned on to irradiate and decompose the stain when the wipers enter the black edge of the camera glass. The obstruction on the outside of the glass is cleared and the field of vision is restored. Then the wipers and their laser function are turned off and the water mist electrostatic adsorption function enters the anti-fog film.
[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Relying on the innovative design of the algorithm flowchart, the camera field of view obstructions are monitored in different areas, and targeted measures are taken to remove the obstructions and prevent the formation of fogging obstructions, so as to accurately identify the location of obstructions and dirt, and adopt corresponding removal plans; 2. Print a silver nanowire grid on the lens surface and the inner surface of the glass in the transparent window area of the camera to prevent fogging on the lens surface and the glass surface through the electrostatic adsorption anti-fog function generated by the silver nanowire grid electrode; 3. The laser head has a strong ability to remove stubborn stains on the outer surface of the glass, so that stubborn stains can be removed quickly, avoiding affecting people's sight and being more energy-efficient; 4. The PZT piezoelectric film array is embedded in the flexible silicone glass interlayer. When powered on, it emits high-frequency vibration (20kHz-1MHz) to remove fog on the glass surface, and removes water mist by cavitation effect, without any perceptible noise. 5. The shell sealing design prevents water vapor from entering the cavity while maintaining air permeability, and the built-in desiccant absorbs moisture to reduce the possibility of fogging.
[0016] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is an algorithm flow chart of the method for eliminating and preventing obstacles in the forward visual channel of an autonomous driving system provided by the present invention; Figure 2 It is a schematic diagram of the cab installation structure provided by the present invention; Figure 3 is a schematic diagram of the silver nanowire grid on the inner surface of glass provided by the present invention; Figure 4 It is a top view of the windshield, a schematic diagram of the wiper sweeping stroke and the effective stroke of the laser head of the present invention; Figure 5 The present invention Figure 4 Middle AA section; Figure 6 The present invention Figure 4 Middle BB section. DETAILED DESCRIPTION
[0018] To facilitate understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings, but the present invention can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the content disclosed in the present invention more thorough and comprehensive.
[0019] Reference Figure 1-6 This embodiment provides a method for eliminating and preventing obstacles in the forward visual channel of an autonomous driving, which monitors the camera field of view obstructions in different regions, and adopts targeted measures to remove the obstructions and prevent the formation of fogging obstructions. The image distortion and imaging characteristics of the glass surface calibration pattern and water mist in the camera are used, and the functions of the rain sensor 1 and the wiper are combined to use an algorithm flow chart to identify whether the field of view obstruction appears on the camera lens surface, the inner surface of the windshield, or the outer surface of the windshield, as well as stubborn stains on the outer surface of the glass; the algorithm process and technical measures are used to remove the obstructions in a targeted and directional manner, and after the field of view is restored, the corresponding measures are initiated to prevent fogging from obstructing again until the car is powered off and shut down; Specifically, when the vehicle is powered on and ready to start or is running, rain or snow is sensed by the rain sensor 1; If the rain sensor 1 recognizes that there is rain or snow, the automatic wiper is started and the wiper frequency is automatically adjusted according to the amount of rain or snow until the wiper function is exited when the rain or snow stops. The rain sensor 1 and the automatic wiper cooperate with each other and can be implemented using existing technology; At the same time, camera 2 will detect whether the lens is fogged: If camera 2 (such as Figure 6 The camera lens shown contains a lens heating ring) If there are fixed black spots or black lines in the image and the light entering the aperture becomes significantly darker, it is recognized that the lens is fogged, and the lens heating and defogging are started until the fixed black spots or black lines in the image disappear and the light entering the aperture is restored to be consistent with the ambient light, then the lens heating is exited and the water mist electrostatic adsorption function of the lens anti-fog film is started; if it is recognized that the lens is not fogged, it is further identified whether there is fog on the inner surface of the windshield. Since the wiper is in a sweeping state due to rain and snow, the obstruction of the glass surface can be eliminated. However, if there is still obstruction in the field of view and the grayscale of the diamond calibration pattern 3 decreases, it is recognized that the inside of the glass is fogged, and the piezoelectric ceramic film vibrator 4 in the glass interlayer is started to vibrate, and the vibration is transmitted to the inner surface of the glass through the flexible silicone in the glass interlayer, and the fog is quickly removed until the field of view is restored to be unobstructed. The vibration of the piezoelectric ceramic film vibrator 4 stops, and the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is started at the same time; if the wiper is in a sweeping state in a rainy and snowy environment and there is no obstruction in the field of view of the camera 2, the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is directly started.
[0020] If the rain sensor 1 recognizes that there is no rain or snow, it will detect whether the field of view of camera 2 is blocked: if there is no blockage, the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass and the water mist electrostatic adsorption function of the lens anti-fog film will be directly activated; if there is blockage, it will detect whether the lens of camera 2 is blocked by fogging. If there are fixed black spots or black lines in the image of camera 2 and the light entering the aperture becomes obviously darker, it is recognized that the lens is fogged, and the lens heating and defogger will be activated until the fixed black spots or black lines in the image disappear and the light entering the aperture returns to the same level as the ambient light, then the lens heating will be exited and the water mist electrostatic adsorption function of the lens anti-fog film will be activated; If it is identified that the lens is not fogged, further identify whether the inner and outer surfaces of the windshield are blocked. If the image in the field of view is still blocked and the grayscale of the diamond-shaped calibration pattern 3 on the inner surface of the glass decreases, and the star-shaped calibration pattern on the outer surface of the glass is blurred, it is identified as fogging on the inner side of the glass, and the piezoelectric ceramic film vibrator 4 in the glass interlayer is started to vibrate, and the vibration is transmitted to the inner surface of the glass through the flexible silicone in the glass interlayer to quickly remove the fogging until the field of view is restored to be unobstructed. The vibration of the piezoelectric ceramic film vibrator 4 stops, and the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is started at the same time. If the image in the field of view is still blocked and the diamond-shaped calibration pattern 3 on the inner surface of the glass is clear, and the star-shaped calibration pattern on the outer surface of the glass is blurred, it is identified as fogging on the inner side of the glass. If there is a halo on the edge of the calibration pattern 5 or the edge of the local obstruction is clear, it is recognized as water mist or local obstruction on the outside of the glass. The wiper is started to sweep three times. When the obstruction on the outside of the glass is cleared and the field of vision is restored, the wiper function is turned off and the water mist electrostatic adsorption function of the anti-fog film is activated. However, if the obstruction on the outside of the glass is not cleared after three wipers and the field of vision is still obstructed, it is recognized as stubborn stains. The wiper is continued to sweep, and the wiper laser head is turned on when the wiper enters the black edge of the camera glass to decompose stubborn stains such as bird droppings, mud, and shellac until the obstruction on the outside of the glass is cleared and the field of vision is restored. Then the wiper and its laser function are turned off and the water mist electrostatic adsorption function of the anti-fog film is activated.
[0021] After the above-mentioned detection and removal process enters the electrostatic adsorption anti-fog stage, it will detect in real time whether rain or snow appears outside the car or the field of vision is blocked again and take corresponding process measures until the car is powered off, which can effectively prevent the formation of fog during driving.
[0022] Focus on reference Figure 2 Considering the installation method of the camera 2, the end surface of the plastic housing 6 for the camera 2 and the glass is coated with sealant to form a sealed cavity, thereby reducing the entry of water vapor into the passenger compartment, and a rubber ring is installed on the mating surface for the camera 2 to block water vapor; a small hole 7 is opened on the housing, and a waterproof and breathable film is attached to the small hole 7, thereby preventing the gas in the sealed cavity from expanding due to heat and blocking water vapor from entering the sealed cavity; A plugging cover 8 with sealing rings around is clamped near the lower edge of the shell. A desiccant bag is clamped in the middle of the plugging cover 8 to absorb excess moisture in the sealed cavity and trace water droplets that slide down by electrostatic adsorption. Regular vehicle maintenance requires disassembling the plugging cover and replacing the desiccant bag to ensure its drying function.
[0023] Focus on reference Figure 2-3 Considering the installation method of the anti-fog film on the lens and the inner surface of the glass, the silver nanowire ink is printed into thin lines of about 5 microns and 2mm in spacing between lines in the field of view area of the inner surface of the windshield corresponding to the camera 1, and the horizontal horizontal strip grid is formed. After the grid is covered, the transmittance is >95% and does not affect the forward field of view. The flexible circuit board FPC is attached to the black edges of the left and right sides of the glass and overlapped at the end of each silver nanowire. The left and right FPC circuits are respectively connected to the positive and negative electrodes 9 of 5V DC, so that the left and right ends of each silver nanowire generate positive and negative electrodes 9 and form a conductive layer; silicon dioxide or transparent polyurethane is applied to the surface of the transparent silver nanowire grid 10 by spraying or vacuum coating process to form a 0.1mm thick transparent insulating protective layer to prevent water vapor, dust, etc. from damaging the conductive layer of the silver nanowire grid; a 2mm wide water backflow groove 11 is engraved by laser on the inner surface of the glass near the black edge of the field of view, and its lower end faces the desiccant bag.
[0024] The corresponding technical principle is: when the water mist electrostatic adsorption function of the anti-fog film on the lens and the inner surface of the glass is started, the left and right FPC circuits are respectively connected to 5V DC, so that positive and negative electrodes 9 are generated at the left and right ends of each silver nanowire, and a conductive field is formed on the surface of the transparent insulating layer; the small water droplets in the mist are charged and are pushed to the water backflow groove at the black edge of the glass under the attraction of the electric field. The accumulated water flows down the backflow groove and is absorbed by the desiccant bag.
[0025] Among them, the water mist electrostatic adsorption function and structure of the anti-fog film on the lens surface are similar to those of the inner surface of the glass. In the field of view area of the lens surface, nanoimprinting or inkjet printing technology is used to print silver nanowire ink into fine lines of about 5 microns with a line spacing of 1mm, forming a horizontal strip grid. After the grid is covered, the transmittance is >95% and does not affect the forward field of view.
[0026] The FPC electrodes on the left and right sides are made into arcs along the edge of the lens, and the flexible circuit boards FPC are attached to the black edges of the left and right glass and overlapped at the end of each silver nanowire. The left and right FPC circuits are respectively connected to the positive and negative poles of 2V DC, so that positive and negative electrodes 9 are generated at the left and right ends of each silver nanowire to form a conductive layer; silicon dioxide or transparent polyurethane is applied to the surface of the transparent silver nanowire grid 10 by spraying or vacuum coating process to form a 0.1mm thick transparent insulating protective layer to prevent water vapor, dust, etc. from damaging the conductive layer of the silver nanowire grid; a 2mm wide water backflow groove 11 is laser engraved on the inner surface of the glass near the black edge of the field of view, and its lower end is facing the desiccant bag. The above process prevents small water droplets from accumulating to form a fogging obstacle.
[0027] Taking into account the realization of calibration pattern image distortion and the realization of distinguishing the position where fogging occurs, a circle of star-shaped calibration pattern 5 (such as a five-pointed star calibration pattern) of about 2 mm is printed on the outer surface of the glass using reflective ink (such as ink containing fine metal powder particles or fluorescent powder) outside the edge of the driving field of view of camera 2 and within the black edge of the glass, and the reflectivity is greater than 70%. A circle of diamond-shaped calibration pattern of about 2 mm is printed on the inner surface of the glass using matte ink, and the reflectivity is less than 20%.
[0028] Corresponding technical principles: When there are obstructions such as fallen leaves, bird droppings, mud, and shellac attached to the outer surface of the glass, it is often only partially obstructed and the outline of the obstruction is clear; when the outer surface of the glass is fogged, the halo at the edge of the five-pointed star in the image diffuses, while the grayscale of the diamond does not change; when the inner surface of the glass is fogged, the five-pointed star in the image is obstructed, so the shape is blurred, and the grayscale or contrast of the diamond decreases. Combined with the algorithm process to monitor the image distortion characteristics of the above calibration patterns, it can accurately identify whether the fogging appears on the inner or outer surface of the glass, and can also identify local obstructions on the outer surface of the glass.
[0029] The PZT piezoelectric film array is embedded in the flexible silicone glass interlayer. After power is turned on, it emits high-frequency vibration (20kHz-1MHz) to remove fog on the glass surface. The cavitation effect removes water mist. Considering the installation method of the piezoelectric ceramic film oscillator, it is important to refer to Figure 6, the glass interlayer 16 within the black edge of the glass adopts 0.5mm thick transparent flexible silicone to replace the traditional PVB film. In the glass interlayer 16 in the black edge of the glass outside the edge of the camera driving field of view, a PZT piezoelectric film sheet (size is about 5mm*5mm, piezoelectric constant d33>600pC / N, thickness is 0.2mm) is embedded, the spacing between the PZT piezoelectric film sheets is 3mm, and the PZT piezoelectric film sheet electrodes are led to the edge of the glass for power supply through the flexible circuit board FPC; the PZT piezoelectric film sheet is embedded in the surface of the silicone waveguide layer, and together as an interlayer, it is synchronously hot-pressed with the inner glass 17 and the outer glass 18. When fog is detected on the glass surface, the PZT piezoelectric film is energized to emit high-frequency vibrations (20kHz-1MHz) and transmitted through the tightly fitting silicone interlayer. The elastic properties of the silicone (low hardness, high damping) convert the vibrations into elastic waves, which diffuse to the fogged surface of the glass, produce cavitation effect and peel off and remove water mist. The PZT piezoelectric film is energized to emit high-frequency vibrations >20kHz, which is beyond the hearing range of the human ear (the upper limit of the human ear is about 20kHz) so there is no noise.
[0030] The front driving field of view of camera 2 is in the projection area of the front windshield, which is normally surrounded by the black edge of the glass to form a transparent window area of camera 2. The transparent window area overlaps with the auxiliary wiper blade rod 12, and several laser heads 13 are installed side by side in the blade rod; refer to Figure 5 The auxiliary wiper is equipped with a double-sweeping lip wiper blade, two sweeping lips 14 are respectively located on both sides of the laser head 13, and a laser head mounting hole 14 is opened in the brush blade groove; the stroke section of the auxiliary wiper sweeping across the transparent window area of the camera is called the effective stroke of the laser head; when it is recognized that the outer surface of the glass in the transparent window area of the camera 2 is partially blocked, the wiper sweeps three times, and the outer side of the glass is not cleared and the field of vision is still blocked, it is identified as a stubborn stain, then the wiper continues to sweep, and when the wiper stroke enters the effective stroke section of the laser head, the wiper laser head is turned on to irradiate and decompose stubborn stains such as bird droppings, mud, and shellac, that is, the wiper blade is rotated to Figure 4 The laser is turned on when the angle is within the two boundary lines of the camera's field of view, and the wiper and its laser function are turned off until the outside of the glass is cleared and the field of view is restored. The black edge of the glass and the base cover block the laser, which can prevent the laser from shining into the car and affecting people's vision, and also play a role in energy saving.
[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for eliminating and preventing obstacles in the forward visual channel of an autonomous driving system, characterized in that: The following steps are involved: When the car is powered on and waiting to start or running, the rain sensor senses rain and snow. If the rain sensor identifies rain or snow, the wiper is automatically started according to the amount of rain and snow. At the same time, the camera detects whether the lens is fogged. If it is identified that the lens is fogged, the lens heating and defogger are started until the field of view is restored to be unobstructed, the heating is stopped and the water mist electrostatic adsorption function of the lens anti-fog film is started; if it is identified that the lens is not fogged, it is further identified whether the inner surface of the windshield is fogged. If it is identified that the inner side of the glass is fogged, the piezoelectric ceramic film vibrator is started to vibrate until the field of view is restored to be unobstructed, the vibration is stopped and the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is started; If the rain sensor detects that there is no rain or snow, it will detect whether the camera's field of view is blocked. If it is detected that the lens is fogged, it will start heating and defogging the lens until the field of view is clear. Then it will stop heating and start the water mist electrostatic adsorption function of the lens anti-fog film. If the lens is identified as not fogged, the system further identifies whether the inner and outer surfaces of the windshield are blocked. If the inner side of the glass is identified as fogged, the piezoelectric ceramic film vibrator is activated to vibrate until the field of view is restored to be unobstructed, then the vibration is stopped and the water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is activated. If the outer surface of the glass is identified as blocked, the wiper function is activated. When the blockage on the outer side of the glass is cleared and the field of view is restored, the wiper function is turned off and the water mist electrostatic adsorption function of the anti-fog film is activated. After the obstacle is removed, turn on the electrostatic adsorption anti-fog function of the glass and lens, and repeat the above obstacle removal method until the car is powered off.
2. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: When the camera detects whether the lens is blocked by fog, if there are fixed black spots or black lines in the camera image and the light entering the aperture becomes significantly darker, it is recognized that the lens is fogged.
3. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: If the lens is identified as fogged, the lens heating and defogger function is activated until the fixed black spots or black lines in the image disappear and the light entering the aperture returns to be consistent with the ambient light, and then the lens heating function is exited.
4. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: If the image in the field of view is still blocked and the grayscale of the diamond-shaped calibration pattern on the inner surface of the glass decreases and the star-shaped calibration pattern on the outer surface of the glass is blurred, it is recognized as fogging on the inside of the glass.
5. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: If the image in the field of view is still blocked and the diamond-shaped calibration pattern on the inner surface of the glass is clear, and there is a halo on the edge of the star-shaped calibration pattern on the outer surface of the glass or the edge outline of the local blocker is clear, it is recognized that the outer side of the glass is blocked.
6. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: The camera mounting plastic shell is coated with sealant on the end face where it matches the glass to form a sealed cavity, a rubber ring is added to the matching surface where the camera is mounted to block water vapor, a small hole is opened on the camera mounting plastic shell, and a waterproof breathable film is attached to the small hole.
7. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: The water mist electrostatic adsorption function of the anti-fog film on the inner surface of the glass is realized as follows: In the field of view area on the inner surface of the windshield, silver nanowire ink is printed into 5-micron fine lines with a line spacing of 2mm using nanoimprinting or inkjet printing technology to form a horizontal strip grid. After the grid is covered, the transmittance is >95% and does not affect the forward field of view; The flexible circuit boards (FPCs) are attached to the black edges of the left and right glass and overlapped at the end of each silver nanowire. The left and right FPC circuits are connected to the positive and negative poles of 5V DC respectively, so that positive and negative electrodes are generated at the left and right ends of each silver nanowire to form a conductive layer. Silicon dioxide or transparent polyurethane is applied to the surface of the transparent silver nanowire grid by spraying or vacuum coating process to form a 0.1 mm thick transparent insulating protective layer.
8. The method for eliminating and preventing obstacles in the forward visual channel of an autonomous driving according to claim 1 or 4, characterized in that: Calibrate the pattern image distortion and identify the location where fogging occurs. The specific steps are as follows: Outside the edge of the camera's driving field of view and within the black edge of the glass, a 2mm star-shaped calibration pattern is printed on the outer surface of the glass using reflective ink, with a reflectivity greater than 70%. A 2mm diamond-shaped calibration pattern is printed on the inner surface of the glass using matte ink, with a reflectivity less than 20%.
9. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: A PZT piezoelectric film array is embedded in the flexible silicone glass interlayer. When powered on, it emits high-frequency vibration to remove fog on the glass surface, and the cavitation effect removes water mist.
10. The method for eliminating and preventing obstacles in the forward visual channel of autonomous driving according to claim 1, characterized in that: If the wipers wipe three times and the obstruction on the outside of the glass is not cleared and the field of vision is still obstructed, it is identified as a stubborn stain. The wipers will continue to wipe and the wiper laser head will be turned on to decompose the stains when the wipers enter the black edge of the camera glass. The obstruction on the outside of the glass is cleared and the field of vision is restored. The wipers and their laser function will be turned off and the water mist electrostatic adsorption function will enter the anti-fog film.