Water-driving method and system based on unmanned aerial vehicle

Abstract

The present invention discloses a method and system for driving in water based on an unmanned aerial vehicle. The method comprises: obtaining a water accumulation area A1 on a driving route, calculating a longitudinal distance S1 between the water accumulation area A1 and the vehicle and a length AS1 of the water accumulation area, and determining a flight path of the unmanned aerial vehicle; the unmanned aerial vehicle flies along a specified flight path, obtains a real-time water depth H, and obtains a water depth distribution map of the water accumulation area A1 and a slope α of each road section in the water accumulation area A1; when the water depth of the water accumulation area A1 is higher than H, the unmanned aerial vehicle is driven into the water depth distribution map ... V *k area, the current path is abandoned and the driving path is replanned; where H V is the height of the wading line, and the coefficient k is less than 1; otherwise, the vehicle is controlled to travel at a speed less than or equal to V on each road section in the flooded area A1. α Go ahead, V α The vehicle is driving in the flooded area A1 at a slope of α. When it reaches the deepest point, the height of the water wave pushed away is H. V The invention can accurately measure water depth, is applicable to complex road conditions, and can prevent water waves from exceeding the wading line and flowing back into the engine room due to water pushing.

Description

Technical Field

[0001] The present invention belongs to the technical field of water-wading vehicles, and in particular relates to a water-wading vehicle method and system based on an unmanned aerial vehicle. Background Art

[0002] Most existing urban waterlogging detection systems use on-board image processing systems to identify the angle between waterlogging and the road surface, and then calculate the water depth based on the road surface inclination to confirm whether the vehicle can pass. Another solution is to release a mobile water surface device in the urban area, detect the water depth through ultrasonic radar, and transmit the information to drones, which are used only as warning alarm devices to warn vehicles to detour.

[0003] These solutions have the following problems:

[0004] The depth of water on the vehicle's route is not accurately estimated;

[0005] For complex road conditions, such as flooded roads in the wild and pothole-ridden old roads in the city, the existing technology cannot obtain detailed depth information under the water as a reference for vehicle wading;

[0006] If you have to pass through a flooded road, how can you give the driver prompts or let the intelligent driving system intervene to control the vehicle to pass, as each vehicle has a different chassis and air intake design?

[0007] Common drones are used for water depth measurement and underwater terrain detection, which require the assistance of high-precision positioning equipment such as RTK (Real Time Kinematic, real-time dynamic measurement technology, which is a real-time differential GPS technology based on carrier phase observation. It is a breakthrough in the development of measurement technology. It consists of three parts: base station receiver, data link, and mobile station receiver. It can obtain accurate field positioning. It cannot be used in areas such as cities with dense buildings. Summary of the invention

[0008] The purpose of the present invention is to provide a method and system for wading vehicles based on an unmanned aerial vehicle to solve the problem of vehicle passage when the road is flooded.

[0009] The present invention proposes a method for wading a vehicle based on an unmanned aerial vehicle, comprising the following steps:

[0010] Determine the length of the flooded road section and the width of the area overlapping with the vehicle's driving path, and obtain the flooded area A1 on the driving route;

[0011] Calculate the longitudinal distance S1 between the waterlogged area A1 and the vehicle and the length AS1 of the waterlogged area, and determine the relative distance between the UAV flight path and the vehicle, that is, from the longitudinal distance S1 to the vehicle position to AS1+S1, the UAV measures back and forth at least once and the lateral position is different each time;

[0012] The UAV flies along the designated flight path and makes the water depth measuring probe touch the water surface to obtain the real-time water depth H; at the same time, the relative position of the UAV when measuring the water depth is obtained to obtain the water depth distribution map of the flooded area A1 and the slope α of each road section in the flooded area A1;

[0013] When the water depth of the water accumulation area A1 is higher than H V *k area, the current path is abandoned and the driving path is replanned; where H V is the height of the wading line, and the coefficient k is less than 1; otherwise, the vehicle is controlled to travel at a speed less than or equal to V on each road section in the flooded area A1. α Go ahead, V α The vehicle is driving in the flooded area A1 at a slope of α. When it reaches the deepest point, the height of the water wave pushed away is H. V The speed of time.

[0014] Furthermore, the UAV measures back and forth three times, and each time the lateral position is 0.75W, 0W, and -0.75W relative to the center axis of the vehicle, where W is the width of the vehicle.

[0015] Furthermore, the coefficient k is determined based on the front bumper shape of the vehicle and the vehicle's tolerance to long-term wading.

[0016] Furthermore, the drone's water depth probe uses ultrasound, millimeter wave radar or laser to measure water depth.

[0017] Furthermore, when the UAV measures the water depth, the UAV maintains a height of 0.95h from the water surface, where h is the vertical height of the UAV's water depth measuring probe from the UAV.

[0018] Furthermore, the vehicle obtains the relative position of the drone when measuring water depth based on the azimuth and distance of the drone relative to the vehicle, or the drone obtains the relative position of the drone when measuring water depth based on the azimuth and distance of the vehicle relative to the drone.

[0019] A drone-based wading driving system for implementing the drone-based wading driving method, comprising:

[0020] The vehicle-side perception and recognition module is used to identify the flooded road ahead in advance and determine the flooded area;

[0021] The strategy processing module is used to determine the flight path of the drone, and to adjust the vehicle's forward route and the vehicle's speed target value according to the drone's detection results;

[0022] The vehicle control module is used to control the vehicle and the release and recovery of the drone according to the strategy processing module;

[0023] The UAV flight control module is used to control the UAV to fly according to the specified flight path and altitude;

[0024] Water depth detection module, used to measure water depth;

[0025] The drone perception and identification module is used to identify the water surface area and determine the position of the drone relative to the vehicle.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] 1) On-site measurement of water depth on the vehicle route. The depth measurement is accurate and the slope of each section of the underwater road can be obtained;

[0028] 2) For complex road conditions, such as flooded roads in the wild and pothole-ridden old roads in the city, detailed distribution of water depth can be obtained as a reference for vehicle wading;

[0029] 3) When the vehicle has to pass through the wading condition, the vehicle is controlled to pass according to different calibration values ​​V according to different vehicle models to prevent the water waves from exceeding the wading line and flowing back into the cabin;

[0030] 4) It does not require the assistance of high-precision positioning equipment such as RTK, and can also be used in areas such as cities with dense buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a block diagram of the wading driving system based on UAV;

[0032] Figure 2 It is a schematic diagram of the waterlogging area;

[0033] Figure 3 This is a schematic diagram of the drone’s flight path;

[0034] Figure 4 This is a schematic diagram of the height of the water waves pushed away by the vehicle when it reaches the deepest point. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] The wading driving system based on the unmanned aerial vehicle of the embodiment of the present invention is as follows: Figure 1As shown, it consists of the following parts: 1. A vehicle-side perception and recognition module, which is used to identify the flooded road section ahead in advance and the horizontal distance between the drone and the vehicle; 2. A strategy processing module, which determines the route adjustment of the vehicle and adjusts the target speed of the vehicle based on the path planning of the vehicle and the depth of the water ahead and the road surface information under the water detected by the drone; the strategy processing module also sends route instructions to the drone; 3. A vehicle control module, which controls the output power of the vehicle's motor and engine according to the strategy processing module, and also controls the release and recovery of the drone; 4. A drone flight control module, which controls the drone to fly according to the required route and altitude; 5. An ultrasonic detection module, which measures the water depth and underwater terrain through the principle of ultrasonic reflection; 6. A perception and recognition module, which identifies the water surface area and the position of the drone relative to the vehicle.

[0037] The system works as follows: When the vehicle reaches a waterlogged area ahead, it stops automatically. Through visual recognition in the perception and recognition module, the length of the waterlogged road section and the width of the area overlapping with the vehicle's driving path are determined to obtain the waterlogged area A1 on the driving route. The A1 information is sent to the strategy processing module, which determines the relative distance between the drone's flight path and the vehicle by calculating the distance S1 between the waterlogged area A1 and the vehicle, the length AS1 of the waterlogged area, and the width W of the vehicle, i.e., from the longitudinal distance S1 from the vehicle's camera position to (AS1+S1), such as Figure 2 The measurement was repeated three times, each time at a lateral position of 0.75W, 0W, and -0.75W relative to the center axis of the vehicle, to obtain the detailed distribution of the underwater depth of the water on the driving path, as shown in the figure. Figure 3 Of course, depending on the different ultrasonic depth measurement characteristic values ​​and the width of the vehicle, you can also choose not to deviate horizontally and measure back and forth once or multiple times.

[0038] After the vehicle releases the drone fixed on the roof or other parts, the drone suspends the ultrasonic probe or uses a telescopic rod to place it downward, and the probe is at a vertical height h from the drone. When the drone flies along the specified path, it maintains a height of 0.95h from the water surface (explanation of 0.95h: if the probe is not vertically downward, in order to make the probe just touch the water surface, the height of the drone needs to be lowered; this value can be calibrated, or the vehicle-mounted visual perception module can be used to determine whether it has entered the water), so that the probe touches the water surface, obtains the real-time water depth H, and determines the azimuth and distance of the drone relative to the vehicle at this time, and transmits it back to the vehicle via Bluetooth, DSRC or WiFi.

[0039] Among them, the drone can use ultrasonic waves, millimeter wave radar, laser and other means to measure the distance between the drone and the water surface, so that the flight control module can control the body to maintain 0.95h. At the same time, the drone perception and recognition module can judge the angle and distance of the vehicle from itself through visual recognition or visual and radar fusion solutions. As a general solution, the details are not repeated here.

[0040] The vehicle uses the perception and recognition module to identify the relative position of the drone to itself, and after comparing it with the information sent back by the drone, it records the depth H of this point. After the drone completes its flight path, the water depth at various locations in the A1 area can be obtained. The slope of each section in A1 can be obtained from the change in water depth at each point, and a water depth distribution map G of each section on the flooded route can be obtained.

[0041] When the water depth in area A1 is higher than the designed wading line height H of the vehicle V *k area, the current route is abandoned and the driving route is re-planned. The coefficient k (<1) is calibrated by each OEM according to the front bumper shape of the vehicle and the vehicle's tolerance to wading for a long time. When the water depth in area A1 is lower than the designed wading line height H of the vehicle V *k area, then try to wade through, the vehicle control module controls the vehicle to follow the planned route in each section of the A1 area at a speed less than or equal to V α Go forward. Among them, V α is the calibration quantity. According to the slope x of the road section in Figure G, the vehicle drives at the deepest point and pushes away the water wave height no more than H V Select the standard. When calibrating, select the partial underwater slope α, control the vehicle to move forward according to V, and the water depth in front does not exceed the designed maximum wading height. Record V at this time. α ,like Figure 4 As shown, the vehicle speed V corresponding to other slope values ​​is selected according to the linear difference to obtain the calibration value curve of the maximum vehicle speed V of each slope.

[0042] After the vehicle reaches the end of the A1 area, the drone returns to the fixed point on the vehicle. When the vehicle is wading through water, the automatic control of the vehicle can be avoided, and the driver can be assisted in controlling the speed through operation reminders.

[0043] To sum up, the key points of the present invention are: 1) the vehicle-mounted drone flies to the driving path and detects the depth of water through ultrasound; 2) the water depth distribution of the water accumulation area is obtained by scanning the water depth, which is used as a reference for vehicle wading; 3) through the vehicle-mounted perception and drone perception information, comprehensive judgment is made to lock the detection flight area, avoid meaningless detection of areas outside the driving route, save time; no RTK high-precision positioning equipment is required, saving costs; 4) when passing through wading conditions, according to the slope of the underwater section and the different vehicle models, different calibration values ​​V are used to control the vehicle to pass, to prevent water from being pushed over the wading line and flowing back into the cabin.

[0044] It will be easily understood by those skilled in the art that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wading driving method based on an unmanned aerial vehicle, characterized in that: The method comprises the following steps: Determine the length of the flooded road section and the width of the area overlapping with the vehicle's driving path, and obtain the flooded area A1 on the driving route; Calculate the longitudinal distance S1 between the waterlogged area A1 and the vehicle and the length AS1 of the waterlogged area, and determine the relative distance between the UAV flight path and the vehicle, that is, from the longitudinal distance S1 to the vehicle position to AS1+S1, the UAV measures back and forth at least once and the lateral position is different each time; The UAV flies along the designated flight path and makes the water depth measuring probe touch the water surface to obtain the real-time water depth H; at the same time, the relative position of the UAV when measuring the water depth is obtained to obtain the water depth distribution map of the flooded area A1 and the slope α of each road section in the flooded area A1; When the water depth of the water accumulation area A1 is higher than H V *k area, the current path is abandoned and the driving path is replanned; where H V The wading line is high, and the coefficient k is less than 1. The coefficient k is determined according to the front bumper shape of the vehicle and the vehicle's tolerance to wading for a long time. Otherwise, the vehicle is controlled to travel at a speed less than or equal to V on each section of the road in the flooded area A1. α Go ahead, V α The vehicle is driving in the flooded area A1 at a slope of α. When it reaches the deepest point, the height of the water wave pushed away is H. V The speed of time.

2. The method for wading based on a drone according to claim 1, characterized in that: The drone measures back and forth three times, and each time the lateral position is 0.75W, 0W, and -0.75W relative to the center axis of the vehicle, where W is the width of the vehicle.

3. The method for wading based on a drone according to claim 1, characterized in that: The drone's water depth probe uses ultrasound, millimeter wave radar or laser to measure water depth.

4. The method for wading based on a drone according to claim 1, characterized in that: When the drone measures water depth, the drone maintains a height of 0.95h from the water surface, where h is the vertical height of the drone's water depth measuring probe from the drone.

5. The method for wading based on a drone according to claim 1, characterized in that: The vehicle obtains the relative position of the UAV when measuring the water depth based on the azimuth and distance of the UAV relative to the vehicle, or the UAV obtains the relative position of the UAV when measuring the water depth based on the azimuth and distance of the vehicle relative to the UAV.

6. A UAV-based wading driving system for implementing the UAV-based wading driving method according to any one of claims 1 to 5, characterized in that: The system includes: The vehicle-side perception and recognition module is used to identify the flooded road ahead in advance and determine the flooded area; The strategy processing module is used to determine the flight path of the drone, and to adjust the vehicle's forward route and the vehicle's speed target value according to the drone's detection results; The vehicle control module is used to control the vehicle and the release and recovery of the drone according to the strategy processing module; The UAV flight control module is used to control the UAV to fly according to the specified flight path and altitude; Water depth detection module, used to measure water depth; The drone perception and identification module is used to identify the water surface area and determine the position of the drone relative to the vehicle.

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