A vehicle-mounted camera in-loop test platform and method for simulating a real rainfall environment

Abstract

The present application belongs to the technical field of intelligent networked vehicle testing and verification, and specifically relates to a vehicle-mounted camera-in-the-loop testing platform and method for simulating a real rainfall environment. The platform comprises a basic framework, a framework for a hardware-in-the-loop testing platform, and a windshield wiper simulation system for placing on the framework. The windshield wiper simulation system is used to simulate rain falling on the front windshield. The rainwater simulation system is used to simulate rainwater. The wind direction and speed simulation system is used to simulate the state of raindrops under different wind direction, wind speed and vehicle speed conditions. The present application uses digital RGB images to represent road traffic environment, roads, vehicles and other elements under rainy weather conditions, and uses real water droplets to simulate a rainy weather environment. The present application solves the problem that existing methods use simple spray head methods to simulate raindrops, which cannot guarantee the shape of the raindrops when they fall, and cannot truly simulate the influence of different wind speeds and vehicle speeds on raindrops.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of intelligent networked vehicle test verification, in particular to a vehicle-mounted camera in-loop test platform and method for simulating real rainfall environment. BACKGROUND

[0002] Intelligent networked vehicles are the future development direction of the automobile industry. At present, intelligent networked vehicle technology in China is developing rapidly, and many vehicle enterprises have proposed their intelligent networked vehicle model schemes. Testing and verification has become an important obstacle to the further development of intelligent networked vehicles. Hardware-in-the-loop testing has the advantages of fast simulation environment running speed and physical hardware-in-the-loop reality in the testing system of intelligent networked vehicles, and is the most widely used in the testing and verification system. However, in terms of complex weather modeling, especially rain, which is the most common complex weather condition, the simulation environment modeling accuracy in hardware-in-the-loop still has certain problems, and it is impossible to perfectly reproduce the sensing situation of real raindrops in the camera sensor. Digital-physical fusion rainfall environment has become the development direction of intelligent networked vehicle hardware-in-the-loop testing. In view of this trend, the existing method uses a simple spray head method to simulate raindrops, which cannot guarantee the shape of the raindrops when falling, and cannot truly simulate the influence of different wind speeds and vehicle speeds on raindrops. SUMMARY

[0003] The application provides a vehicle-mounted camera in-loop test platform and method for simulating real rainfall environment, which uses digital RGB images to represent road traffic environment, road, vehicle and other elements under rainy weather environment, and uses real water droplets to simulate rainy weather environment, solving the problem that the existing method uses a simple spray head method to simulate raindrops, which cannot guarantee the shape of the raindrops when falling, and cannot truly simulate the influence of different wind speeds and vehicle speeds on raindrops.

[0004] The technical scheme of the application is explained as follows in combination with the drawings:

[0005] In a first aspect, the embodiments of the application provide a vehicle-mounted camera in-loop test platform for simulating real rainfall environment, comprising:

[0006] A basic framework for the framework of the hardware-in-the-loop test platform, capable of placing a windshield wiper simulation system, a rainwater simulation system, and a wind direction and vehicle speed simulation system;

[0007] The windshield wiper simulation system is used to simulate rain falling on the front windshield.

[0008] The rainwater simulation system is used to simulate rain.

[0009] The wind direction and vehicle speed simulation system is used to simulate the state of raindrops under different wind directions, wind speeds and vehicle speeds.

[0010] The vehicle window wiper simulation system is arranged in the base frame; the self-adapting water head 30 in the rainwater simulation system is arranged above the base frame; the water spraying head 18 in the rainwater simulation system is arranged on the inner wall of the base frame; the self-adapting water head 30 and the water spraying head 18 simulate rainwater; the water storage tank 13 in the rainwater simulation system is arranged outside the base frame to supply water for the self-adapting water head 30 and the water spraying head 18; and the wind direction and vehicle speed simulation system is arranged on the base frame.

[0011] The base frame comprises an overall outer frame 1 and a screen display system 2 arranged inside the overall outer frame 1; the screen display system 2 comprises a first screen movable support 27, a second screen movable support 28 and a screen display 20; the first screen movable support 27 and the second screen movable support 28 are both electronic guide rails; the first screen movable support 27 can move forward and backward relative to the second screen movable support 28; the second screen movable support 28 is connected with the base behind the overall outer frame 1 and can move up and down.

[0012] The vehicle window wiper simulation system comprises a measured camera 15, a front windshield 16, a wiper system 17 and a front windshield clamp 3; the front windshield clamp 3 is fixed on the base inside the overall outer frame 1; the front windshield clamp 3 clamps the front windshield 16; the measured camera 15 is fixed on one end of the front windshield 16; and the wiper system 17 is arranged on the other end of the front windshield 16.

[0013] The rainwater simulation system comprises a water storage tank 13, a first water guide pipe 4, a second water guide pipe 5, a third water guide pipe 6, a fourth water guide pipe 10, a fifth water guide pipe 11, a sixth water guide pipe 14, a controllable water pump 7, a pressure sensor 8, a pressure water chamber 9, an electromagnetic switch valve 12, a self-adapting water head 30, a water spraying head 18, an upper frame 22 and a water inlet head 23.

[0014] The controllable water pump 7 is connected with the power supply; the water in the water storage tank 13 is introduced into the pressure water chamber 9 through the controllable water pump 7, the third water guide pipe 6 and the fifth water guide pipe 11, so as to maintain the pressure in the pressure water chamber 9; the pressure sensor 8 is installed on the pressure water chamber 9, which detects the pressure in the pressure water chamber 9 at any time, and the current of the controllable water pump 7 is closed when the water pressure in the pressure water chamber 9 reaches the set value; the water flowing out of the pressure water chamber 9 is divided into three parts; the first part of the water flowing out flows into the self-adaptive water head 30 through the fourth water guide pipe 10 and the first electromagnetic switch valve 12; the first electromagnetic switch valve 12 supplies water to the self-adaptive water head 30 through the water inlet head 23; the second part of the water flowing out flows into the water jet head 18 through the first water guide pipe 4 and the second electromagnetic switch valve 31; the third part of the water flowing out flows into the water jet head 18 through the sixth water guide pipe 14 and the third electromagnetic switch valve 32; the water jet head 18 is fixed on the inner wall of the overall outer frame 1; the water jet head 18 and the self-adaptive water head 30 spray water to simulate rain; the water jet head 18 is fixed on the left and right inner walls of the overall outer frame 1; the precipitation in the overall outer frame 1 flows into the water storage tank 13 through the second water guide pipe 5 to provide water source for the water storage tank 13.

[0015] The self-adaptive water head 34 is fixed on the upper frame 22; the upper frame is arranged above the overall outer frame 1; the self-adaptive water head 34 is composed of two layers of upper water head 24 and lower water head 25 with the same aperture; the control guide rail 26 is fixed on the lower water head 25; the lower water head 25 is in sliding fit with the control guide rail 26, and moves through the control guide rail 26 to change the gap between the upper water head 24 and the lower water head 25.

[0016] The wind direction and speed simulation system includes a plurality of air blowing systems; the air blowing systems include two lateral air blowing systems 19 and one forward air blowing system 21; the lateral air blowing systems 19 are installed on the left and right sides inside the overall outer frame 1; the forward air blowing system 21 is installed in front of the self-adaptive water head 30 on the overall outer frame 1.

[0017] In the second aspect, the embodiment of the present application provides a vehicle-mounted camera in-loop test method for simulating a real rainfall environment, which comprises the following steps:

[0018] Step one, building a hardware-in-the-loop test platform for a vehicle-mounted camera of an intelligent networked automobile, including fixed connection of all components and connection between water pipes;

[0019] Step two, correcting the position of the screen display 20 in the hardware-in-the-loop test platform for a vehicle-mounted camera of an intelligent networked automobile, so that the vision of the measured camera 15 is completely coincided with the screen display 20;

[0020] Step three, output the RGB image through the screen display 20 to simulate other test scene elements outside the raindrop in the rainy day;

[0021] Step four, add 10 liters of water to the water storage tank 13, open the wiper system 17, the controllable water pump 7, the pressure sensor 8, the first electromagnetic switch valve 12, the water spray head 18, and check whether they are running normally. According to the rainfall demand and the wiper operation demand, adjust the movement speed of the wiper system 17, and adjust the opening and closing of the controllable water pump 7, the first electromagnetic switch valve 12, and the aperture opening of the adaptive water head 30. Adjust the opening of the second electromagnetic switch valve 31 and the third electromagnetic switch valve 32 to simulate the water mist generated by the movement of the tires of the surrounding traffic vehicles. According to the simulation demand of vehicle speed and wind speed, adjust the wind speed of the two lateral wind systems 19, the wind speed and direction of the forward wind system 21.

[0022] Most of the water accumulated near the front windshield 16 in the adaptive water head 30 falls on the front windshield 16 to simulate the falling rain on the windshield. The other part of the adaptive water head 30 is far from the front windshield 16 to simulate the falling rain in front of the vehicle when the autonomous vehicle is driving, which will not fall on the window. The aperture diameter near the front windshield 15 is calculated according to the Gaussian distribution, with a mean of 3 mm and a standard deviation of 1 mm. The Gaussian distribution is shown in formula (1). The farthest part of the aperture is divided into 10 rows or more, with the aperture diameter of the nearest row being 5 mm and the aperture diameter of the farthest row being 1 mm. The aperture diameter of each row is determined according to the arithmetic progression with 0.5 mm as the benchmark, as shown in formula (2).

[0023]

[0024] g(x)=d max -n d ·△d (2)

[0025] In the formula, f(x) is the aperture diameter of the adaptive water head near the windshield; σ is the standard deviation of the aperture diameter near the windshield; μ is the mean of the aperture diameter near the windshield; g(x) is the aperture diameter of the adaptive water head near the windshield, d max is the maximum aperture diameter near the windshield, and Δd is the difference of the arithmetic progression, n d is the number of the arithmetic progression of the farthest aperture row.

[0026] The opening time of the first electromagnetic switch valve 12 is regarded as the time of water droplet generation, each aperture of the adaptive water head 30 is regarded as a nozzle, the flow rate of the aperture is shown in formula (3), and the product of the flow rate and time is the volume of the water droplet flowing out of each aperture, which is shown in formula (4); the shape of each water droplet flowing out is approximated as a spherical shape, and the size of the diameter of the water droplet flowing out is obtained, which is shown in formula (5); according to the required raindrop size and the required rainfall size in the test, the opening and closing time of the first electromagnetic switch valve 12 and the opening and closing time of the controllable water pump (7) are adjusted, and then the water pressure in formula (3) and the starting time of the electromagnetic switch valve (12) in formula (4) are simultaneously controlled;

[0027]

[0028] V = Q · t (4)

[0029]

[0030] In the formula, Q is the aperture flow rate, k is the resistance coefficient calibrated according to the test, P is the water pressure, p is the density of water, t is the opening time of the first electromagnetic switch valve 12, and R is the diameter of the falling water droplet.

[0031] The blowing system mainly controls the blowing wind speed and direction, and when the vehicle is moving, the speed of the raindrop falling to the ground is about 8-9 m / s, and v w is used as the wind speed of the forward blowing system, v v is used as the wind speed of the backward blowing system, and v f is the angle between the camera and the inner bottom surface of the camera-in-loop test platform, and v f and theta are adjusted to enable formulas (6) and (7) to be satisfied, so that the forward situation during rainfall can be simulated

[0032] v f · sin theta = v v -v β · cos alpha (6)

[0033]

[0034] In the formula, g is the gravity coefficient, s is the height of the adaptive water head from the bottom surface of the camera-in-loop test platform, v β is the wind speed, and alpha is the angle between the wind and the driving direction of the vehicle.

[0035] For the control of the lateral blowing system, the wind speed v c generated by the two lateral blowing systems should satisfy formula (8);

[0036] v c = v β · sin alpha (8).

[0037] The present application has the following beneficial effects:

[0038] The present application uses digital RGB images to represent road traffic environment, roads, vehicles and other elements in rainy weather, and uses real water droplets to simulate the rainy weather environment, solving the problem that the existing method uses a simple spray head method to simulate raindrops, which cannot guarantee the shape of the raindrops when falling, and cannot truly simulate the influence of different wind speeds and vehicle speeds on raindrops. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0040] Figure 1 The present application is a schematic diagram of part of the structure;

[0041] Figure 2 The present application is a schematic diagram of the structure of the basic frame;

[0042] Figure 3 The present application is a schematic diagram of the structure of the adaptive water head and forward blowing system;

[0043] Figure 4 The present application is a schematic diagram of the structure of the adaptive water head aperture;

[0044] Figure 5 The present application is a schematic diagram of the structure of the adaptive water head;

[0045] Figure 6 The present application is a schematic diagram of the principle of simulating rainwater.

[0046] In the drawings:

[0047] 1, overall outer frame; 2, screen display system; 3, front windshield clamp; 4, first water guide pipe; 5, second water guide pipe; 6, third water guide pipe; 7, controllable water pump; 8, pressure sensor; 9, pressure water chamber; 10, fourth water guide pipe; 11, fifth water guide pipe; 12, first electromagnetic on-off valve; 13, water storage tank; 14, sixth water guide pipe; 15, measured camera; 16, front windshield; 17, adjusting wiper system; 18, water head; 19, lateral wind system; 20, screen display; 21, forward wind system; 22, upper frame; 23, water inlet head; 24, upper water head; 25, lower water head; 26, control guide rail; 27, first screen movable support; 28, second screen movable support; 30, adaptive water head; 31, second electromagnetic on-off valve; 32, third electromagnetic on-off valve. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0049] Embodiment one

[0050] Referring to Figure 1 A vehicle-mounted camera in-loop test platform simulating a real rainfall environment comprises:

[0051] A basic frame is used for the frame of the hardware-in-the-loop test platform, and can place a vehicle window wiper simulation system, a rainwater simulation system and a wind direction and speed simulation system.

[0052] The vehicle window wiper simulation system is used for simulating rain falling on the front windshield.

[0053] The rainwater simulation system is used for simulating rainwater.

[0054] The wind direction and speed simulation system is used for simulating the state of raindrops under different wind directions, wind speeds and vehicle speeds.

[0055] The basic frame comprises a whole outer frame 1 and a screen display system 2 arranged inside the whole outer frame 1.

[0056] Referring to Figure 2 The screen display system 2 comprises a first screen movable support 27, a second screen movable support 28 and a screen display 20.

[0057] The whole outer frame 1 is a cuboid, and the frame structure is designed by aluminum profiles, the frame is surrounded by thin aluminum plates as a whole, and a black light-absorbing cloth is installed inside. Bottom supports are respectively installed at four corners of the bottom, and universal wheels that can be locked are installed at the bottom of the supports for moving and fixing the rack.

[0058] The first screen movable support 27 and the second screen movable support 28 are both electronic guide rails; the first screen movable support 27 can move forward and backward relative to the second screen movable support 28; the second screen movable support 28 is connected to the base behind the whole outer frame 1 and can move up and down.

[0059] The screen display system 2 completes up, down, forward and backward movements through the first screen movable support 27 and the second screen movable support 28, so as to complete the alignment of the viewing angle between the screen display system 2 and the camera 15 to be tested.

[0060] The vehicle window wiper simulation system comprises a camera 15, a front windshield 16, a wiper system 17 and a front windshield clamp 3.

[0061] The front windshield clamp 3 can be a common plate-shaped metal clamp, which is fixed on the inner base of the overall frame 1 on one side and fixes the front windshield 16 on the other side, thereby fixing the front windshield 16 and the inner base of the overall frame 1. By adjusting the angle between the front windshield clamp 3 and the camera on the inner base plane of the overall frame 1, the angle between the front windshield 16 and the base plane can be adjusted to 40-140 degrees. The front windshield 16 and the wiper system 17 are of the same model as the measured automatic driving vehicle, and the camera 15 is of the same model as the front-view camera of the measured automatic driving system.

[0062] The rainwater simulation system comprises a water storage tank 13, a first water guide pipe 4, a second water guide pipe 5, a third water guide pipe 6, a fourth water guide pipe 10, a fifth water guide pipe 11, a sixth water guide pipe 14, a controllable water pump 7, a pressure sensor 8, a pressure water chamber 9, an electromagnetic switch valve 12, an adaptive water head 30, a water spraying head 18, an upper frame 22 and a water inlet head 23.

[0063] The water storage tank 13 can be selected from common metal or plastic water tank, and the volume needs to be greater than 10 liters, which provides water source for the whole rainwater simulation system. The water storage tank 13 needs to be filled before the test starts. The precipitation in the whole outer frame 1 flows into the water storage tank 13 through the drainage port in the platform and the second water guide pipe 5 to provide water source for the water storage tank 13 during the experiment. The controllable water pump 7 can be automatically operated through the switch power supply, which pumps the water in the water storage tank 13 into the pressure water chamber 9 to maintain the pressure in the pressure water chamber 9. The pressure sensor 8 is installed on the pressure water chamber 9, which supervises the pressure in the pressure water chamber 9 at all times. When the water pressure in the pressure water chamber 9 reaches the set value, the current of the controllable water pump 7 is turned off. The water flowing out of the pressure water chamber 9 is divided into three parts. One part flows into the first electromagnetic switch valve 12, which supplies water to the subsequent self-adaptive water head 30 through the water inlet head 23. The other two parts flow into the water spray head, which simulates the dense water mist formed by the surrounding vehicle tires pressing the road surface water when the automatic vehicle drives on the road. The self-adaptive water head 30 is fixed on the upper frame 22 by bolts, which is composed of two layers of water heads with the same porosity. The lower water head 25 can move by controlling the guide rail 26 to change the gap between the two layers of water heads, so as to change the size and speed of water droplets. The second part of the water flowing out flows into the water spray head 18 through the first water guide pipe 4 and the second electromagnetic switch valve 31. The third part of the water flowing out flows into the water spray head 18 through the sixth water guide pipe 14 and the third electromagnetic switch valve 32. The water spray head 18 is fixed on the inner wall of the whole outer frame 1. The water spray head 18 is fixed on the left and right inner walls of the whole outer frame 1. The precipitation in the whole outer frame 1 flows into the water storage tank 13 through the drainage port in the whole outer frame 1 and the second water guide pipe 5 to provide water source for the water storage tank 13.

[0064] Referring to Figure 3 , Figure 4 and Figure 5 , the self-adaptive water head 30 is fixed on the upper frame 22; the upper frame is arranged above the whole outer frame 1; the self-adaptive water head 30 is composed of the upper water head 24 and the lower water head 25 with the same porosity; the control guide rail 26 is fixed on the lower water head 25; the lower water head 25 and the control guide rail 26 are in sliding fit, and the lower water head 25 moves by controlling the control guide rail 26 to change the gap between the upper water head 24 and the lower water head 25.

[0065] Referring to Figure 6The wind direction and speed simulation system comprises a plurality of air blowing systems; the air blowing systems comprise two lateral air blowing systems 19 and one forward air blowing system 21; the lateral air blowing systems 19 are installed on the left and right sides inside the overall outer frame 1, and when in action, simulate the state when the wind direction is at a certain angle with the driving direction of the vehicle; the forward air blowing system 21 is installed in front of the self-adaptive water head 30 on the overall outer frame 1, and is used to simulate the relative movement state between the raindrops and the front windshield glass when the vehicle is driven at different speeds.

[0066] Embodiment two

[0067] A vehicle-mounted camera in-loop test method for simulating a real rainfall environment is realized by a vehicle-mounted camera in-loop test platform for simulating a real rainfall environment, and comprises the following steps:

[0068] Step one, build a hardware-in-the-loop test platform for intelligent networked vehicle-mounted cameras, including the fixed connection of all components and the connection between water pipes;

[0069] Step two, correct the position of the screen display 20 in the hardware-in-the-loop test platform for intelligent networked vehicle-mounted cameras, so that the vision of the measured camera 15 is completely coincident with the screen display 20;

[0070] Step three, output the RGB image through the screen display 20 to simulate other test scene elements outside the raindrops in a rainy day;

[0071] Step four, add 10 liters of water to the water storage tank 13, turn on the wiper system 17, the controllable water pump 7, the pressure sensor 8, the first electromagnetic switch valve 12, the water spraying head 18, and check whether they are running normally, adjust the movement speed of the wiper system 17 according to the rainfall demand and wiper operation demand, adjust the opening and closing of the controllable water pump 7, the first electromagnetic switch valve 12, and the aperture opening degree of the self-adaptive water head 30; adjust the opening degree of the second electromagnetic switch valve 31 and the third electromagnetic switch valve 32 to simulate the water mist generated by the movement of the tires of surrounding traffic vehicles; according to the simulation demand of the vehicle speed and the wind speed, adjust the wind speed of the two lateral air blowing systems 19, the wind speed and the wind direction of the forward air blowing system 21.

[0072] Reference Figure 4The effect of the adaptive water head 30 is divided into two parts. One part is close to the windshield 16, and most of the accumulated water falls on the windshield 16. In order to simulate the rainfall falling on the windshield, the size distribution of the raindrops falling on the windshield is mainly considered. The other part of the adaptive water head 30 is far away from the windshield 16, and simulates the rainfall falling in front of the vehicle when the autonomous vehicle is driving. This part of the rainfall will not fall on the window, and it mainly needs to consider the distance simulation when simulating the image. According to the principle of triangular imaging, the aperture of the aperture at a farther distance from the windshield should be smaller. The aperture diameter of the water head aperture close to the windshield 15 is calculated by referring to the Gaussian distribution. The mean value of the aperture diameter is 3 mm, and the standard deviation is 1 mm. The Gaussian distribution is shown in formula (1). The apertures far away are divided into 10 rows or more. The number of rows is determined according to the required simulation accuracy. The aperture diameter of the closest row is 5 mm, and the aperture diameter of the farthest row is 1 mm. The aperture diameter of each row is determined according to the arithmetic progression with 0.5 mm as the benchmark, as shown in formula (2).

[0073]

[0074] g(x)=d max -n d ·△d (2)

[0075] In the formula, f(x) is the aperture diameter of the adaptive water head close to the windshield; sigma is the standard deviation of the aperture diameter close to the windshield; mu is the mean value of the aperture diameter close to the windshield; g(x) is the aperture diameter of the adaptive water head close to the windshield, d max is the maximum value of the aperture diameter close to the windshield, and delta d is the difference value of the aperture arithmetic progression, and n d is the number of the arithmetic progression of the maximum aperture row.

[0076] The first electromagnetic switch valve 12 mainly controls the size of the raindrops to be formed. When the first electromagnetic switch valve 12 is completely closed, the adaptive water head 30 is completely closed, and water droplets cannot be discharged outward. The opening time of the first electromagnetic switch valve 12 can be regarded as the water droplet generation time. Each aperture of the adaptive water head 30 is regarded as a nozzle. The flow rate of the aperture is shown in formula (3). The product of the flow rate and the time is the volume of the water droplets discharged by each aperture, as shown in formula (4). The shape of each discharged water droplet is approximated as a spherical shape, and the diameter of the discharged water droplet is obtained, as shown in formula (5). According to the required raindrop size of the test, the opening and closing time of the first electromagnetic switch valve 12 is adjusted.

[0077]

[0078] V=Q·t (4)

[0079]

[0080] In the formula, Q is the pore flow rate, k is the resistance coefficient calibrated according to the test, P is the water pressure, p is the density of water, t is the opening time of the first electromagnetic on-off valve 12, and R is the diameter of the falling water droplets.

[0081] The water spray head control system is relatively simple, and it does not need to perform complex calculations, and it only needs to select the opening time according to the test needs.

[0082] The adaptive water head 30 cooperates with the electromagnetic on-off valve 12, and under the condition that the water pressure is fixed, the different raindrop size conditions are obtained by referring to formulas (3)-(5). When the rainfall and raindrop size are required at the same time, the opening and closing time of the electromagnetic on-off valve 12 and the operation time of the controllable water pump 7 are coordinated and controlled according to formulas (3)-(5), so as to obtain the rainfall conditions under different rainfall and different raindrop size.

[0083] The blowing system mainly controls the blowing speed and direction. When the vehicle is moving, the speed of the raindrops falling to the ground is about 8-9 m / s, and the blowing speed of the positive wind system is assumed to be v w When the intelligent connected vehicle speed is set to v v , the blowing speed of the positive wind system is assumed to be v f , and the angle between the camera and the inner bottom surface of the loop test platform is θ. By adjusting v f and θ, formulas (6) and (7) can be satisfied, so that the positive situation during rainfall can be simulated.

[0084] v f ·sinθ=v v -v β ·cosα (6)

[0085]

[0086] In the formula, g is the gravity coefficient, s is the height of the adaptive water head from the bottom surface of the camera loop test platform, v β is the wind speed, and a is the angle between the wind and the driving direction of the vehicle.

[0087] For the control of the side wind system, the wind speed v c generated by the two side wind systems should satisfy formula (8).

[0088] v c =v β ·sinα (8).

[0089] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the scope of protection of the present application is not limited to the specific details of the above-described embodiments. Any person skilled in the art, within the scope of the technical concept of the present application, can make equivalent replacements or changes to the technical scheme of the present application and the inventive concept according to the technical scheme of the present application, and these simple modifications all belong to the scope of protection of the present application.

[0090] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combinations.

[0091] In addition, various different embodiments of the present application can also be combined in any manner, as long as they do not deviate from the idea of the present application, and they should also be considered as disclosed by the present application.

Claims

1. A method for testing a vehicle camera in a loop simulating a real rain environment, characterized in that, The method comprises the following steps: Step one, build a hardware-in-the-loop test platform for intelligent networked vehicle onboard camera, including the fixed connection of all components and the connection between water pipes; Step two, correct the position of the screen display (20) in the hardware-in-the-loop test platform for intelligent networked vehicle onboard camera, so that the vision of the measured camera (15) is completely coincident with the screen display (20); Step three, output RGB image through the screen display (20) to simulate other test scene elements outside the raindrops in rainy days; Step four, add 10 liters of water in the water storage tank (13), open the wiper system (17), the controllable water pump (7), the pressure sensor (8), the first electromagnetic switch valve (12), and the water spray head (18), and check whether they are running normally, the water in the water storage tank (13) is introduced into the pressure water chamber (9) through the controllable water pump (7); the pressure sensor (8) is installed on the pressure water chamber (9); the water flowing out of the pressure water chamber (9) is divided into three parts; the first part of the water flowing out flows into the adaptive water head (30) through the first electromagnetic switch valve (12); the second part of the water flowing out flows into the water spray head (18) through the second electromagnetic switch valve (31); the third part of the water flowing out flows into the water spray head (18) through the third electromagnetic switch valve (32); adjust the motion speed of the wiper system (17) and the opening and closing of the controllable water pump (7), the first electromagnetic switch valve (12), and the aperture opening degree of the adaptive water head (30) according to the rainfall demand and the wiper operation demand; adjust the wind speed of the two lateral wind systems (19) and the wind speed and direction of the forward wind system (21) according to the simulation demand of vehicle speed and wind speed; Most of the water accumulated in the adaptive water head (30) near the front windshield (16) falls on the front windshield (16) to simulate the falling rain on the windshield; the other part of the adaptive water head (30) is far away from the front windshield (16) to simulate the falling rain in front of the vehicle when the autonomous vehicle is driving, which will not fall on the window; the water head aperture diameter near the front windshield (16) is calculated according to Gaussian distribution, the mean value of the aperture diameter is 3mm, and the standard deviation is 1mm; the apertures far away are divided into 10 rows or more, the aperture diameter of the nearest row is 5mm, and the aperture diameter of the farthest row is 1mm, and the aperture diameter of each row is determined according to the arithmetic progression form with 0.5mm as the benchmark.

2. The method of claim 1, wherein the method comprises: The opening time of the first electromagnetic switch valve (12) is regarded as the time of water droplet generation, each aperture of the adaptive water head (30) is regarded as a nozzle, the flow rate of the aperture is shown as formula (1), the product of the flow rate and time is the volume of the water droplet flowed out of each aperture, shown as formula (2); the shape of each water droplet is approximated as a spherical shape, the diameter of the water droplet is obtained, shown as formula (3), according to the required raindrop size and the required rainfall size, the opening and closing time of the first electromagnetic switch valve (12) and the opening and closing time of the controllable water pump (7) are adjusted, and then the water pressure in formula (1) and the starting time of the first electromagnetic switch valve (12) in formula (2) are simultaneously controlled; V = Q * t (2) In the formula, Q is the aperture flow rate, k is the resistance coefficient calibrated according to the test, P is the water pressure, p is the density of water, t is the opening time of the first electromagnetic switch valve (12), and R is the diameter of the falling water droplet.

3. The method of claim 1, wherein the method further comprises: The blowing system primarily controls the wind speed and direction. When the vehicle is moving, raindrops hit the ground at a speed of 8-9 m / s. (Using v...) w To make an alternative, when the speed of the intelligent connected vehicle is set to v v At that time, the wind speed blown out by the forward wind system is assumed to be v. f The angle between the camera and the bottom surface inside the ring test platform is θ. By adjusting v... f If θ enables the expression to satisfy formulas (4) and (5), then the positive case during rainfall can be simulated. v f • sin θ = v v -v β • cos α (4) where g is the gravity coefficient, s is the height of the adaptive water head from the bottom surface of the ring test platform to the camera, v β is the wind speed, and a is the angle between the wind and the driving direction of the vehicle. For the control of the side wind system, the wind speed v generated by the two side wind systems c Equation (6) should be satisfied; v c = v β • sin a (6).

4. The method of claim 1, wherein the method further comprises: The vehicle-mounted camera facing the simulated real rainfall environment in the loop test platform comprises: a basic frame for the frame of the hardware-in-the-loop test platform, capable of placing a vehicle window wiper simulation system, a rainwater simulation system and a wind direction and vehicle speed simulation system; the vehicle window wiper simulation system is used for simulating rainwater falling on the front windshield; the rainwater simulation system is used for simulating rainwater; the wind direction and vehicle speed simulation system is used for simulating the state of raindrops under different wind directions, wind speeds and vehicle speeds; the vehicle window wiper simulation system is arranged in the basic frame; the adaptive water head (30) in the rainwater simulation system is arranged above the basic frame; the water spraying head (18) in the rainwater simulation system is arranged on the inner wall of the basic frame; the adaptive water head (30) and the water spraying head (18) simulate rainwater; the water storage tank (13) in the rainwater simulation system is arranged outside the basic frame to supply water to the adaptive water head (30) and the water spraying head (18); and the wind direction and vehicle speed simulation system is arranged on the basic frame.

5. The method for simulating a real rainfall environment using a vehicle-mounted camera in a loop as described in claim 4, characterized in that, The basic frame comprises an overall outer frame (1) and a screen display system (2) arranged inside the overall outer frame (1); the screen display system (2) comprises a first screen movable support (27), a second screen movable support (28) and a screen display (20); the first screen movable support (27) and the second screen movable support (28) are both electronic guide rails; the first screen movable support (27) can move forward and backward relative to the second screen movable support (28); and the second screen movable support (28) is connected to the base behind the overall outer frame (1) and can move up and down.

6. The method of claim 4, wherein the method is characterized by, The vehicle window wiper simulation system comprises a measured camera (15), a front windshield (16), a wiper system (17) and a front windshield clamp (3); the front windshield clamp (3) is fixed to the base inside the overall outer frame (1); the front windshield clamp (3) clamps the front windshield (16); the measured camera (15) is fixed to one end of the front windshield (16); and the wiper system (17) is arranged at the other end of the front windshield (16).

7. The method for simulating a real rainfall environment for testing a vehicle-mounted camera in the loop as described in claim 4, characterized in that, The rainwater simulation system comprises a water storage tank (13), a first water guide pipe (4), a second water guide pipe (5), a third water guide pipe (6), a fourth water guide pipe (10), a fifth water guide pipe (11), a sixth water guide pipe (14), a controllable water pump (7), a pressure sensor (8), a pressure water chamber (9), a first electromagnetic switch valve (12), an adaptive water head (30), a water spraying head (18), an upper frame (22) and a water inlet head (23); The controllable water pump (7) is connected with a power supply; the water in the water storage tank (13) is guided into the pressure water chamber (9) through the controllable water pump (7), the third water guide pipe (6) and the fifth water guide pipe (11) to maintain the pressure in the pressure water chamber (9); the pressure sensor (8) detects the pressure in the pressure water chamber (9) at all times, and the current of the controllable water pump (7) is turned off when the water pressure in the pressure water chamber (9) reaches a set value; the water flowing out of the pressure water chamber (9) is divided into three parts; the first part of the water flowing out flows into the adaptive water head (30) through the fourth water guide pipe (10) and the first electromagnetic switch valve (12); the first electromagnetic switch valve (12) supplies water for the adaptive water head (30) through the water inlet head (23); The second part of the water flowing out flows into the water spraying head (18) through the first water guide pipe (4) and the second electromagnetic switch valve (31); the third part of the water flowing out flows into the water spraying head (18) through the sixth water guide pipe (14) and the third electromagnetic switch valve (32); the water spraying head (18) is fixed on the inner wall of the overall outer frame (1); the water spraying head (18) and the adaptive water head (30) spray water to simulate rain; the water spraying head (18) is fixed on the inner walls of the left and right sides of the overall outer frame (1); the precipitation in the overall outer frame (1) flows into the water storage tank (13) through the drainage opening in the overall outer frame (1) and the second water guide pipe (5) to provide a water source for the water storage tank (13).

8. The method of claim 4, wherein the method is a method of testing a vehicle camera in a loop simulating a real rain environment, characterized in that, The adaptive water head (30) is fixed on the upper frame (22); the upper frame is arranged above the overall outer frame (1); the adaptive water head (30) is composed of an upper water head (24) and a lower water head (25) having the same aperture; the control guide rail (26) is fixed on the lower water head (25); the lower water head (25) is in sliding cooperation with the control guide rail (26) and moves through the control guide rail (26) to change the aperture between the upper water head (24) and the lower water head (25); The wind direction and speed simulation system comprises a plurality of air blowing systems; the air blowing system comprises two lateral air blowing systems (19) and one forward air blowing system (21); the lateral air blowing systems (19) are installed on the left and right sides inside the overall outer frame (1); the forward air blowing system (21) is installed in front of the adaptive water head (30) on the overall outer frame (1).

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