Method and device for vehicle wading safety

Abstract

Techniques and examples are described regarding vehicle wading safety. A processor that may be implemented in a vehicle approaching a body of water may receive data related to the body of water from one or more above-water or underwater sensors. The processor may determine a top surface and a bottom contour of the body of water, and if the vehicle is to wade through the body of water by crossing the bottom contour, calculate one or more critical tracks of water-sensitive components of the vehicle. The processor may then determine wading safety based on the critical tracks and the top surface of the body of water. The processor may further determine a wading route, and autonomously drive the vehicle to wade through the body of water via an optimal wading route.

Description

Technical Field

[0001] The present invention relates generally to motor vehicles and, more particularly, to methods and apparatus for safely wading a motor vehicle through a body of water. Background Art

[0002] Flash flooding or rapid flooding is a common phenomenon in low-lying areas of the landscape or in areas where the microclimate may change rapidly and become unpredictable. For example, heavy rainfall due to thunderstorms or melting snow and ice can cause a body of water (stationary or flowing) to form or otherwise appear in an area. A body of water may happen to cut off an intersection or interfere with a traffic road (hereinafter referred to as a "road"), and motor vehicles (e.g., cars, trucks, buses, etc.) using the road may be hindered thereby. In the event that at least a portion of a road is submerged by a body of water, it is difficult for a driver of a motor vehicle to determine the flooding situation and whether it is safe to "wade through" the water body (i.e., drive a vehicle through the water body from one side of the water body to the other side of the water body). Summary of the invention

[0003] According to the present invention, there is provided a method comprising:

[0004] determining, by a processor, one or more aspects of a body of water;

[0005] calculating, by the processor, one or more critical trajectories for a vehicle wading through a body of water based at least in part on the one or more aspects; and

[0006] A determination is made, by a processor, whether it is safe for the vehicle to ford through the body of water based on the one or more critical trajectories and the one or more aspects.

[0007] According to one embodiment of the present invention, determining one or more aspects of a body of water comprises:

[0008] receiving data representing one or more edges of a body of water from one or more above-water sensors disposed on the vehicle; and

[0009] One or more depths and bottom contours of the body of water are determined based on the edges and topographic information of the location associated with the body of water.

[0010] According to one embodiment of the present invention, one or more of the above-water sensors include a visible light camera, an infrared camera, a stereo camera, a time-of-flight (TOF) camera, a light detection and ranging (LIDAR) transceiver, a radio detection and ranging (RADAR) transceiver, an ultrasonic transceiver, or a combination thereof.

[0011] According to one embodiment of the present invention, determining one or more aspects of a body of water comprises:

[0012] receiving a first reflected signal and a second reflected signal from one or more above-water sensors disposed on the vehicle, the first reflected signal being a first portion of the sensed signal reflected by a top surface of the body of water and the second reflected signal being a second portion of the sensed signal reflected by a ground surface beneath the body of water; and

[0013] One or more depths and bottom profiles of the body of water are calculated, by the processor, based at least in part on the first reflected signal and the second reflected signal.

[0014] According to one embodiment of the present invention, the one or more above-water sensors include a time-of-flight (TOF) camera, a light detection and ranging (LIDAR) transceiver, a radio detection and ranging (RADAR) transceiver, an ultrasonic transceiver, or a combination thereof.

[0015] According to one embodiment of the present invention, the method further comprises:

[0016] One or more statistical filters are used to analyze the first reflection signal and the second reflection signal prior to calculating one or more depths and bottom profiles of the body of water.

[0017] According to one embodiment of the present invention, determining one or more aspects of a body of water comprises:

[0018] deploying one or more underwater sensors into a body of water;

[0019] controlling one or more underwater sensors to transmit sensing signals to a top surface of a body of water and to a ground surface beneath the body of water;

[0020] controlling one or more underwater sensors to receive a first reflection signal and a second reflection signal, the first reflection signal being a first portion of the sensing signal reflected by a top surface of the body of water, the second reflection signal being a second portion of the sensing signal reflected by a ground surface below the body of water; and

[0021] One or more depths and bottom profiles of the body of water are calculated based at least in part on the first reflection signal and the second reflection signal.

[0022] According to one embodiment of the present invention, wherein:

[0023] One or more aspects of a body of water include the bottom contour of the body of water,

[0024] The calculation of one or more critical trajectories is based on the bottom contour and the spatial model of the vehicle,

[0025] The spatial model of the vehicle contains a spatial relationship of each of one or more critical components of the vehicle relative to a fixed reference point of the vehicle, each of the one or more critical components being susceptible to water damage, and

[0026] Each of the one or more critical trajectories includes a trajectory of movement of a corresponding one of the one or more critical components as the vehicle traverses a bottom contour of the body of water.

[0027] According to one embodiment of the invention, wherein the one or more aspects of the body of water include one or more depths of the body of water, the one or more depths of the body of water collectively defining a top surface of the body of water, and wherein determining whether it is safe for a vehicle to wade through the body of water includes:

[0028] Determining that it is safe for the vehicle to ford through the body of water with each critical track being above the top surface of the body of water; and

[0029] In the event that at least a portion of one of the critical trajectories is below the top surface of the body of water, it is determined that it is unsafe for the vehicle to wade through the body of water.

[0030] According to one embodiment of the present invention, the method further comprises:

[0031] determining, by the processor, a fording route in which the vehicle can safely ford the body of water in response to determining that it is safe for the vehicle to ford the body of water; and

[0032] In response to determining that it is unsafe for the vehicle to wade through the body of water, an alternate route is determined, by the processor, for the vehicle to avoid the body of water.

[0033] According to one embodiment of the present invention, the method further comprises:

[0034] The vehicle is controlled by a processor to autonomously wade through a body of water via a wading route.

[0035] According to one embodiment of the present invention, the method further comprises:

[0036] deploying one or more underwater sensors into a body of water via a processor to measure the velocity of a current in the body of water,

[0037] Determining whether it is safe for a vehicle to wade through a body of water is further based on the velocity of the water flow and the buoyancy model of the vehicle.

[0038] According to one embodiment of the present invention, the method further comprises:

[0039] estimating, by the processor, a velocity of a current in the body of water based on input from one or more waterborne sensors disposed on the vehicle, the one or more waterborne sensors being configured to track floating objects carried by the current,

[0040] Determining whether it is safe for a vehicle to wade through a body of water is further based on the velocity of the water flow and the buoyancy model of the vehicle.

[0041] According to the present invention, there is provided a device comprising:

[0042] a memory capable of storing one or more sets of instructions and a spatial model of the vehicle; and

[0043] A processor coupled to execute one or more sets of instructions stored in the memory such that upon execution of the one or more sets of instructions, the processor performs operations comprising:

[0044] determining one or more depths and bottom contours of a body of water;

[0045] calculating one or more key trajectories of the vehicle based on a bottom contour of the body of water and a spatial model of the vehicle; and

[0046] A determination is made as to whether it is safe for the vehicle to wade through the body of water based on the one or more depths of the body of water and the one or more critical tracks.

[0047] According to one embodiment of the present invention, the device further comprises:

[0048] one or more above-water sensors disposed on the vehicle, the one or more above-water sensors being capable of sensing one or more edges of a body of water,

[0049] wherein the memory is further capable of storing topographic information of a location associated with the body of water, and

[0050] Wherein the processor determines one or more depths and bottom contours of the body of water based on the edge and terrain information.

[0051] According to one embodiment of the present invention, the device further comprises:

[0052] one or more above-water sensors disposed on the vehicle to transmit a sensing signal to a body of water and receive a first reflected signal and a second reflected signal from the body of water,

[0053] wherein the first reflected signal comprises a first portion of the sensed signal reflected by the top surface of the body of water,

[0054] wherein the second reflected signal comprises a second portion of the sensing signal reflected by the ground beneath the body of water,

[0055] Wherein the processor determines one or more depths and bottom contours of the body of water based at least in part on the first reflection signal and the second reflection signal.

[0056] According to one embodiment of the present invention, the device further comprises:

[0057] one or more underwater sensors disposed on the vehicle to transmit a sensing signal when submerged in the body of water and to receive a first reflected signal and a second reflected signal from the body of water,

[0058] wherein the first reflected signal comprises a first portion of the sensed signal reflected by the top surface of the body of water,

[0059] wherein the second reflected signal comprises a second portion of the sensed signal reflected by the ground beneath the body of water, and

[0060] Wherein the processor determines one or more depths and bottom contours of the body of water based at least in part on the first reflection signal and the second reflection signal.

[0061] According to one embodiment of the present invention, the device further comprises:

[0062] one or more above-water sensors disposed on the vehicle to estimate the velocity of the body of water by tracking floating objects carried by the body of water,

[0063] The memory is also capable of storing a buoyancy model of the vehicle, and

[0064] Determining whether it is safe for a vehicle to wade through a body of water is further based on the flow velocity of the body of water and a buoyancy model of the vehicle.

[0065] According to one embodiment of the present invention, the device further comprises:

[0066] one or more underwater sensors disposed on the vehicle to measure a flow velocity of the body of water when submerged in the body of water,

[0067] The memory is also capable of storing a buoyancy model of the vehicle, and

[0068] The determination of whether it is safe for a vehicle to wade through a body of water is further based on the flow velocity of the body of water and the buoyancy model of the vehicle.

[0069] According to one embodiment of the present invention, the operation further comprises:

[0070] Determine a fording route by which a vehicle can safely ford across a body of water and a fording speed at which a vehicle can safely ford across a body of water via the fording route; or

[0071] Identify alternate routes where vehicles can avoid bodies of water. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0073] Figure 1 is a diagram that describes an example scenario in which an embodiment according to the present invention may be used;

[0074] Figure 2 is a diagram describing an example method for determining one or more aspects of a body of water according to an embodiment of the present invention;

[0075] Figure 3 is a diagram depicting example critical trajectories of water-sensitive components of a vehicle as the vehicle wades through a body of water in accordance with an embodiment of the present invention;

[0076] Figure 4 is a diagram describing another example method for determining one or more aspects of a body of water according to an embodiment of the present invention;

[0077] Figure 5 is a block diagram depicting an example apparatus according to an embodiment of the present invention;

[0078] Figure 6 is a flow chart describing an example process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0079] In the following description, reference is made to the accompanying drawings, which form a part of the description and in which are shown by way of illustration specific exemplary embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the concepts disclosed herein, and it should be understood that the various disclosed embodiments may be modified and other embodiments may be utilized without departing from the scope of the present invention. Therefore, the following specific embodiments should not be considered limiting.

[0080] As described above, due to unpredictable microclimates, roads may be flooded or otherwise disturbed by temporary static or flowing bodies of water. In the event that at least a portion of the road surface is covered by a body of water, a driver of a motor vehicle approaching the body of water may not be able to easily observe the conditions of the road surface and determine whether it is safe to drive the vehicle through the body of water. Figure 1 Example scenes 110 and 120 are shown in which embodiments according to the present invention may be used. For each of the example scenes 110 and 120, the vehicle 10 is traveling on a road 20 disturbed by a body of water 30. In scene 110, the body of water 30 may be a pool of water and appear to be stationary. On the other hand, the body of water 30 of scene 120 may be a stream of flowing water carrying floating objects (e.g., branches 38 and wooden boxes 39).

[0081] In order to avoid or otherwise improve the above-mentioned difficulties in determining whether it is safe for the vehicle 10 to wade through the body of water 30 from one side to the other side, the present invention proposes techniques, schemes, processes and devices for making determinations by sensing, observing or otherwise characterizing one or more aspects of the body of water 30 using one or more sensors disposed on the vehicle 10. For example, a device may be installed in the vehicle 10 or otherwise implemented to the vehicle 10 to sense, observe or characterize the water depth of the body of water 30, or at least a portion of the body of water 30 that intersects or overlaps with the road 20. Under the proposed scheme, as shown in scenes 110 and 120, the vehicle 10 may be provided with one or more sensors disposed thereon, such as an above-water sensor 50 that is capable of operating above the water surface (i.e., the top surface of the body of water 30), and an underwater sensor 60 that is capable of operating below the water surface. As will be described in further detail below, certain sensors may be operable both above and below the water, and thus may serve the vehicle 10 as both an above-water sensor and an underwater sensor.

[0082] For a motor vehicle (e.g., vehicle 10), there are certain critical components (hereinafter interchangeably referred to as "water-sensitive components") that are susceptible to water damage. Therefore, in order to ensure the normal operation of the motor vehicle, these critical components must be prevented from contacting and / or being submerged in water. As an example, the critical components may include components of the vehicle's powertrain. For example, the air intake of the motor vehicle is considered a critical component. If, when the vehicle 10 is wading through the body of water 30, the air intake of the vehicle 10 passes below the surface of the body of water 30 for a period of time, the engine of the vehicle 10 may be starved of air and stall. In addition, because water is incompressible, water that reaches the engine of the vehicle 10 through the air intake will cause catastrophic damage to the engine. As another example, the spark plugs and unprotected electronic devices of the vehicle 10 should also be avoided from contacting water when wading through the body of water 30 because they are susceptible to water damage. Finally, although at a lower level of concern, water intrusion into the trunk or passenger compartment of the vehicle 10 during wading may cause damage to the interior of the vehicle.

[0083] In order to determine whether one or more of the critical components will suffer water damage when the vehicle 10 wades through the body of water 30, it is necessary to use various above-water sensors and / or underwater sensors (e.g., above-water sensor 50 and underwater sensor 60) disposed on the vehicle 10 to sense, observe, determine, or characterize one or more aspects of the body of water 30. The one or more aspects of the body of water 30 may include one or more water depths at one or more locations throughout the body of water 30. The one or more aspects of the body of water 30 may also include a bottom contour of the body of water, i.e., the shape or topography of the surface of the road 20 covered by the body of water 30. The present invention proposes at least three schemes (which will be described in detail below) to determine or estimate one or more aspects of the body of water 30, including one or more water depths at various locations throughout the body of water 30 and the bottom contour of the body of water 30. After the water depth and bottom contour of the body of water 30 are determined, a corresponding critical trajectory is calculated for each of the critical components of the vehicle 10. The critical trajectory represents the movement trajectory of the corresponding critical component as the vehicle 10 passes through the bottom contour to wade through the body of water 30. Based on the critical trajectory and one or more aspects of the body of water 30 , a determination may be made as to whether it is safe for vehicle 10 to wade through body of water 30 .

[0084] Under the first proposed approach, the depth and bottom contour of the body of water 30 may be measured using data from one or more surface sensors (e.g. Figure 1 The topographic information may be determined based on data from a water sensor 50 and topographic information about the location of the body of water 30. In some embodiments, the topographic information may be data representing a high-definition (HD) three-dimensional (3D) map of the area where the body of water is located. The HD 3D map is characterized when the road 20 is free of temporary water bodies caused by microclimates, and is often digitized and stored in a memory on the vehicle or accessed remotely by the vehicle via one or more wireless mobile communication links (e.g., satellites and / or wireless communication stations / towers). The one or more water sensors may detect one or more edges of the body of water 30 as part of one / more boundaries of the body of water 30 (e.g., such as Figure 1 As a result of the detection, one or more above-water sensors may generate data representing edges 31 and 32, which may be compared to the HD 3D map (e.g., by finding corresponding locations of edges 31 and 32 on the HD 3D map), and the bottom contour of body of water 30, or equivalently, the shape or topography of road 20 beneath body of water 30, may thus be found or otherwise identified on the HD 3D map.

[0085] exist Figure 2 The first proposed solution is further illustrated in Figure 2In the embodiment, the vehicle 10 is equipped with one or more water sensors 50. For simplicity, the following description is provided in the context of a single water sensor 50, although multiple water sensors 50 may also be used. In order to obtain a better perception of the body of water 30 that the vehicle 10 is approaching, the water sensor 50 may preferably be disposed at a high position of the vehicle 10 facing in the forward direction of the vehicle 10. This arrangement of the water sensor 50 is particularly true if it is necessary to establish a line of sight (LOS) between the water sensor 50 and the body of water 30 so that the water sensor 50 can be used to more effectively sense, observe, determine, or characterize the body of water 30. There may be various options for the water sensor 50. For example, the water sensor 50 may be a visible light camera, an infrared camera, a stereo camera, a time-of-flight (TOF) camera, a light detection and ranging (LIDAR) transceiver, or an ultrasonic camera, each of which requires establishing a LOS, such as Figure 2 In the case where it is not necessary to establish LOS between the water sensor 50 and the body of water 30, for example, the water sensor 50 is a radio detection and ranging (RADAR) transceiver, the water sensor 50 can be conveniently disposed at other locations of the vehicle 10.

[0086] Under the first proposed approach, the above-water sensor 50 may detect one or more edges of the body of water 30, such as Figure 1 and 2 The near edge 31 and the far edge 32 shown. For example, the water sensor 50 can be a stereo camera, and can generate data representing the near edge 31 and the far edge 32 as one or more pictures of the body of water 30 taken at different focal depths using the stereo camera 50. The pictures can be used to estimate the spatial relationship of each of the edges 31 and 32 relative to the vehicle 10, including the distance. The vehicle 10 can be equipped with a global positioning system (GPS), and the corresponding position of the vehicle 10 on the HD 3D map can therefore be determined or otherwise located using the GPS. Using the estimated relative spatial relationship of each of the edges 31 and 32, it can be concluded that the corresponding position of each of the near edge 31 and the far edge 32 can also be located on the HD 3D map. Based on the corresponding positions of the edges 31 and 32 located on the HD 3D map, the terrain of the road 20 between the edges 31 and 32 (which is currently covered under the body of water 30 and is therefore not visible to the driver of the vehicle 10) can be determined using the HD 3D map. In this manner, the bottom contour 35 of the body of water 30 may be found or otherwise identified on the HD 3D map. Additionally, the water depth at various locations of the body of water 30 (e.g., Figure 2The maximum water depth D) shown in FIG. 3 can also be determined in the same manner. Assuming that each water body has a substantially flat top surface, the water depths at various locations of the water body 30 can be collectively used to define the top surface 33 of the water body 30 .

[0087] It is worth noting that Figure 1 The body of water 30 shown in the scene 110 of FIG. 1 , although relatively stationary relative to the road 20 , may still be unstable at its top surface. For example, Figure 2 The top surface 33 of the body of water 30 may have waves or ripples due to the local strong winds. Due to the waves and ripples, the edges 31 and 32 may move back and forth, showing changes 311 and 322, respectively, as shown in FIG. Figure 2 As shown. In addition, the depth of the water body 30 at various locations (including the maximum depth D) may also vary over time. In this case, a statistical filter may be used to analyze the data representing the edges 31 and 32 (e.g., a number of pictures of the water body 30 taken over a period of time by the stereo camera 50) and determine the best estimate of the depth of the water body 30 (including the maximum depth D) and the edges 31 and 32 (regardless of the variations 311 and 322).

[0088] In a second proposed approach, the depth and bottom contour of the body of water 30 may be measured using one or more above-water sensors (e.g. Figure 1 and 2 The one or more above-water sensors may include a TOF camera, a LIDAR transceiver (or simply "LIDAR"), a RADAR transceiver (or simply "RADAR"), an ultrasonic transceiver, or a combination thereof. The second proposed solution also uses Figure 2 In an example embodiment, the above-water sensor 50 may include a LIDAR that can transmit a light beam as a sensing signal along the LOS (e.g. Figure 2 The LOS 53 of the LIDAR is transmitted to the water body 30. As the light emitted by the LIDAR travels in the air and Figure 2 When the light reaches the top surface 33 of the water body 30 at point A, part of the light (referred to as the "first reflected signal") may be reflected back to the LIDAR 50 along the LOS 53, while part of the light may be refracted into the water body 30 along the refraction path 531 according to Snell's law. Figure 2As shown, the incident angle θ1 can be defined between the LOS 53 and the normal 55 perpendicular to the top surface 33, and the refraction angle θ2 can be defined between the refraction path 531 and the normal 55. The angles θ1 and θ2 follow Snell's law and satisfy the mathematical relationship of n1·sin(θ1)=n2·sin(θ2), where n1 is the refractive index of air (typically 1) and n2 is the refractive index of the water body (typically 1.33 at 25°C). As the refracted light travels in the water body 30 and reaches point B of the road surface or ground 26 of the road 20 currently hidden under the water body 30, part of the refracted light (referred to as the "second reflected signal") can be reflected by the ground 26 at point B and travel along the refraction path 531 to point A before being refracted again at point A and returning to the LIDAR 50 along the LOS 53. The first and second reflected signals can then be used to determine the distance between point A and point B. The distance between point A and point B can be determined based on the time difference between the time when the LIDAR 50 receives the first reflected signal and the time when the LIDAR 50 receives the second reflected signal. Specifically, the distance between point A and point B can be determined as the time difference multiplied by the speed of light in the water body 30, and the speed of light in the water body 30 is the speed of light in the air divided by the refractive index of the water body. The LIDAR 50 can be used to scan the top surface 33 throughout the water body 30 in this manner. That is, for each of a plurality of locations throughout the top surface 33, the LIDAR 50 can transmit sensing light at a given location and then receive the corresponding first and second refracted signals, and thus the AB distance (i.e., the distance between A and B) of the location can be determined as described above. In this way, the bottom profile 35 of the water body 30 and one or more water depths (including the maximum water depth D) can therefore be inferred, calculated, estimated, determined, reconstructed, or otherwise indirectly measured using the AB distance determined for each of the plurality of locations and θ1 and θ2 for each of the plurality of locations.

[0089] Similar to the first proposed scheme, in the case where the top surface 33 of the water body 30 is unstable due to waves or ripples, the second proposed scheme may also use a statistical filter to analyze the first and second reflection signals before calculating the water depth (e.g., maximum depth D) and the bottom profile 35 of the water body 30. However, unlike the case of the first proposed scheme, an infrared camera and a visible light camera including a stereo camera may not satisfy the second proposed scheme because the reflectivity of the water at the top surface 33 of the water body 30 may make stereo imaging for 3D mapping difficult using an infrared or visible light camera. In contrast, the infrared camera and the visible light camera may be the main sensor for the first proposed scheme.

[0090] As described above, in order for the vehicle 10 to safely wade through the body of water 30, the water-sensitive components (i.e., key components) of the vehicle 10 (e.g., Figure 2 It is necessary that the critical components 40) do not contact the water body 30. As also described above, the critical trajectory (e.g. Figure 2 A critical trajectory 44 of the vehicle 10 may be calculated, wherein the critical trajectory represents the predicted movement path of corresponding critical components of the vehicle 10 as the vehicle 10 wades through the body of water 30. Figure 2 As shown, the critical trajectory 44 represents the path of movement of the critical component 40 as the vehicle 10 fords through the body of water 30 by traveling over the bottom contour 35 of the body of water 30 .

[0091] It is worth noting that in Figure 2 , since the bottom contour 35 of the water body 30 is quite smooth, the critical track 44 follows the bottom contour 35 (or equivalently, the ground 26 below the water body 30) almost at a constant distance H, which is essentially the distance between the critical component 40 and the road 20. In theory, as long as the distance H is greater than the maximum water depth D, it can be determined that it is safe for the vehicle 10 to wade through the water body 30 without damaging the critical component 40. In practice, due to possible waves, ripples, or water splashes at the top surface 33 of the water body 30, it can be determined that it is safe for the vehicle 10 to pass through the water body 30 if the distance H is greater than the maximum water depth D by a safety margin that accounts for possible waves, ripples, or water splashes. As described above, the vehicle 10 may have multiple critical components and therefore multiple critical tracks, and when each critical track is determined to be above the top surface 33 of the water body 30, it can be determined that it is safe for the vehicle 10 to wade through the water body 30. On the other hand, when it is determined that a portion of any critical trajectory may be located below the top surface 33 of the body of water 30 , it may be determined that it is unsafe for the vehicle 10 to wade through the body of water 30 .

[0092] However, when the water body does not have a relatively flat or smooth bottom contour, the critical trajectory may not simply follow the bottom contour through a constant height or distance. To illustrate this, Figure 3 Two contrasting scenarios are described in . Figure 3In the scenario 310 of FIG. 3 , the vehicle 10 is wading through a body of water 30 that submerges the road 20 by crossing over a bottom contour 35 of the body of water 30. The bottom contour 35 is relatively flat because the road 20 is relatively flat in the submerged area. It follows that the critical trajectory 44 corresponding to the critical component 40 of the vehicle 10 is also a relatively straight line that is spaced apart from the bottom contour 35 by a substantially constant distance H equal to the height of the position of the critical component 40 relative to the road 20. Because the critical trajectory 44 of the vehicle 10 remains above the top surface 33 of the body of water 30 as the vehicle 10 crosses the bottom contour 35, it can be determined that it is safe for the vehicle 10 to wade through the body of water 30.

[0093] In contrast, Figure 3 In scene 320, vehicle 10 is wading through a body of water 30 that submerges a portion of a rough road 30. Although the maximum water depth of body of water 30 is substantially the same as the water depth of scene 310 (as shown by depth D in scenes 310 and 320, respectively), the bottom contour 35 of body of water 30 in scene 320 has a rather rough and uneven terrain. Because vehicle 10 itself has a certain length and height, as vehicle 10 crosses bottom contour 35 and wades through body of water 30, critical trajectory 44 corresponding to critical component 40 of vehicle 10 in scene 320 may not simply follow bottom contour 35 through a constant distance H. For scene 320, a mathematical model of vehicle 10, referred to as a "spatial model," is needed to estimate or calculate critical trajectory 44. Specifically, the spatial model of vehicle 10 may define the position of each critical component of vehicle 10 (including critical component 40) relative to a fixed reference point of the vehicle (e.g., a point at the bottom of the front wheels of vehicle 10). Figure 3The reference point 14) of the vehicle 10 can be selected as any fixed position of the vehicle 10. For example, in some embodiments, the reference point 14 of the vehicle 10 can be selected as the middle point of the front bumper of the vehicle 10. Alternatively, the fixed position of the water sensor 50 can work just as well as the reference point 14. In some embodiments, the spatial model can also include the spatial relationship of other non-critical components relative to the fixed reference point. Non-critical components can include wheels, bumpers and chassis, and unlike critical components, non-critical components may not be susceptible to water damage. However, including non-critical components in the spatial model may be essential for improving the accuracy of calculating critical trajectories. Since the spatial position of each of the critical and non-critical components relative to the reference point 14 has been predetermined by the design of the vehicle 10, the spatial model can be known by the design of the vehicle 10. For example, some models of the vehicle may have a snorkel air intake located at a height of 3-5 feet above the ground, and the spatial model is used to capture this feature. In combination with the spatial model of the vehicle 10 and the known topology of the ground surface of the road 20 (or at least the bottom contour 35 of the body of water 30 as previously determined), the critical trajectory of the vehicle 10 (including Figure 3 The critical trajectory 44 of the scene 320 can be calculated or otherwise predicted. In the case where all the critical trajectories of the vehicle 10 are calculated and the top surface 33 of the body of water 30 is determined as described above, it can therefore be determined whether it is safe for the vehicle 10 to wade through the body of water 30 based on the critical trajectories and the top surface 33 as described above. Figure 3 As shown in the scenario 320, although the critical component 40 appears to be located above the road 20 at a height H greater than the maximum water depth D of the water body 30, a portion of the critical trajectory 44 as calculated will reach below the top surface 33 of the water body 30 due to the rough terrain of the road 20. Therefore, it can be determined that it is unsafe for the vehicle 10 to wade through the water body 30.

[0094] Because all water-sensitive components may not be equally critical to the operation of the vehicle, in some embodiments, each critical trajectory may be given a different "weight" in determining whether it is safe to ford through a body of water. For example, it may be absolutely critical to keep the vehicle's air intake above the water to prevent the engine from stalling. However, it may not be critical whether some unprotected electronics (such as a collision avoidance radar transceiver) are below the water surface, because the vehicle can still be driven even if the collision avoidance function is lost.

[0095] The present invention further provides a third method for determining one or more depths and bottom contours of a body of water. Figure 4As shown in scenes 410 and 420 of FIG. 4 , in addition to the above-water sensor 50, the vehicle 10 is also equipped with one or more underwater sensors, such as an underwater sensor 60. For simplicity, the following description is provided in the context of a single underwater sensor 60, although multiple underwater sensors 60 may also be used. While the above-water sensor 50 may be used to sense, determine, or otherwise characterize one or more aspects of the body of water 30 (e.g., the edge, one or more depths, or the top surface 33 of the body of water 30, as described above), the underwater sensor 60 may be deployed into the body of water 30 to perform direct measurements of one or more aspects of the body of water 30. The one or more above-water sensors may include a LIDAR, a RADAR, a sound navigation and ranging (SONAR) transceiver (or simply "sonar"), a depth sensor, or a combination thereof. The underwater sensor 60 operates in a similar manner to the above-water sensor 50 as described in the second proposed solution, except that the underwater sensor 60 operates to sense or directly measure one or more depths and bottom contours of the body of water 30 when submerged in the body of water 30 or otherwise deployed in the body of water 30. The underwater sensor 60 may preferably be provided on the vehicle 10 at a location where the underwater sensor 60 is easily submerged in the body of water 30 when deployed (eg, on the underside of the front bumper of the vehicle 10 ).

[0096] In an example embodiment, the underwater sensor 60 may include an active SONAR (hereinafter referred to as "SONAR 60") that may be controlled to transmit sound waves as sensing signals when the SONAR 60 is submerged within the body of water 30. The sensing sound signal may reach the top surface 33 of the body of water 30 and the ground 26 of the road 20 below the body of water 30. A portion of the sensing sound signal may be reflected by the top surface 33 and then received by the SONAR 60 as a first reflection signal, while another portion of the sensing sound signal may be reflected by the ground 26 and then received by the SONAR 60 as a second reflection signal. The first reflection signal may then be used to determine the position of the top surface 33 relative to the SONAR 60, while the second reflection signal may be used to determine the position and topography of the ground 26 relative to the SONAR 60, which in turn may be used to determine the bottom profile 35 of the body of water 30. In combination with the position and topography of the ground 26 and the position of the top surface 33, the water depth at various locations of the body of water 30 may be determined accordingly.

[0097] Compared to the second proposed scheme, the third proposed scheme may exhibit the advantage of providing more accurate measurements of one or more aspects of the body of water 30 (e.g., the top surface 33 and the bottom profile 35) because the measurements are made directly from within the body of water rather than indirectly from outside the body of water. Compared to the first proposed scheme, the third proposed scheme may exhibit the advantage of capturing in-situ topographic variations of the ground 26 beneath the body of water 30 that may not be captured by pre-characterized topographic information of the location associated with the body of water 30 (e.g., the HD 3D map used in the first proposed scheme). For example, Figure 4 As shown in scenario 420 of FIG. 4 , the ground 26 may have been eroded by the flash flood that created the body of water 30 and is therefore recessed deeper than its pre-characterized ground 266. The first proposed scheme would not capture the topographic change from the ground 266 to the ground 26, while the third proposed scheme would correctly identify the ground 26 due to its direct measurement nature. Advantageously, a vehicle 10 equipped with both one or more above-water sensors 50 and one or more below-water sensors 60 can use one, some, or all of the first, second, and third proposed schemes disclosed above to determine the depth and bottom profile 35 of the body of water 30. For example, in scenario 420, utilizing the above-water sensors 50 and using only the first proposed scheme, the vehicle 10 may not recognize that the bottom profile 35 has changed from where it was before the flash flood (i.e., the ground 266) to where it is now (i.e., the ground 26). The vehicle 10 may therefore determine that it is safe to wade through the body of water 30, and therefore it continues to travel. However, after the vehicle 10 begins wading, the third proposed solution may be invoked (as long as the underwater sensor 60 is deployed into the body of water 30 during wading), and the actual ground surface 266 may be detected. At this point, the vehicle 10 may determine that it is unsafe to continue wading, and eventually return to and exit the body of water 30. That is, by invoking the first and third solutions in scenario 420, the vehicle 10 may be able to avoid unsafe wading, which would not be avoided if relying solely on the first solution.

[0098] In some cases where a body of water flows at a significant flow rate or has a strong current, determining whether it is safe for a vehicle to wade through the body of water may become more complicated. That is, in addition to considering whether any of the critical trajectories of the vehicle during wading will reach below the top surface of the water body, it may also be necessary to consider whether the vehicle may be pushed laterally and out of position by the strong current during wading. The buoyancy model of the vehicle (which simulates the behavior of the vehicle when subjected to flowing water) is needed to determine the safety of the vehicle during the wading process. Similar to the spatial model, the buoyancy model can be predetermined by the design of the vehicle. In some embodiments, the vehicle can be equipped with various sensors to update or otherwise adjust the buoyancy model in situ. For example, due to the different weights carried by the vehicle, the vehicle may exhibit slightly different buoyancy behaviors. A weight sensor provided in the vehicle can be used to measure the actual carrying weight of the vehicle and adjust the buoyancy model accordingly.

[0099] In addition to the buoyancy model, it is necessary to measure or at least estimate the velocity of the flowing water flow of the water body so that the buoyancy model can be used to determine the safety of wading. One method is to use a flow meter as an underwater sensor 60, which is deployed into the water body 30 according to the third proposed scheme as disclosed above. That is, the underwater sensor 60 can be used to directly measure the velocity of the water flow 30 of the water body 30 when submerged or otherwise deployed into the water body 30. Various types of flow meters can be used as the underwater sensor 60 to measure the flow rate, such as a mechanical flow meter (e.g., a pendulum piston flow meter or a turbine flow meter), an optical flow meter (e.g., a laser-based flow meter), and / or a pressure-based flow meter (e.g., a venturi flow meter or a Dall tube). Another method is to estimate the flow velocity of the water body 30 by using an above-water sensor 50 of the first or second proposed scheme disclosed above. For example, as Figure 1 As shown in scene 120 of FIG. 1 , the above-water sensor 50 can be used to track one or more floating objects, such as a branch 38 or a wooden box 39, in the body of water 30 by capturing motion pictures over a period of time as the floating objects are carried downstream by the current of the body of water 30. Subsequently, based on the motion pictures, it can be estimated how far the floating objects have been carried during the period of time, and the speed of the current can be determined accordingly.

[0100] Figure 5 An example device or water safety device 500 according to an embodiment of the present invention is shown. The water safety device 500 can perform various functions related to the techniques, methods and systems described herein, including those described above for the first, second and third solutions for determining the water depth and bottom contour of the body of water 30 and determining whether it is safe for the vehicle 10 to wade through the body of water 30, and below for Figure 6 The water safety device 500 may include the functions described in the process 600. Figure 5At least some of the components shown in .

[0101] Reference Figure 5 , the wading safety device 500 may include a processor 510 and a memory 520. The memory 520 may store the HD 3D 524 map used by the first proposed solution, the spatial model 526 for calculating the critical trajectory, and the buoyancy model 528 for determining the wading safety, as described above. The memory 520 may also store one or more sets of instructions 522 for the processor 510 to perform and implement various determination, estimation, and calculation functions (including those performed in the first, second, and third solutions) described above in the present invention. For example, upon executing one or more sets of instructions 522, the processor 510 may determine the bottom profile 35 and various water depths of the water body 30, calculate the critical trajectory 44 of each critical component 40 corresponding to the vehicle 10, and determine whether it is safe for the vehicle 10 to wade through the water body 30 based on the top surface 33 of the water body 30 and the critical trajectory 44 of the vehicle 10.

[0102] In some embodiments, the water safety device 500 may include one or more water sensors 550(1)-550(N). Each of the water sensors 550(1)-550(N) may be Figure 1-4 The above-water sensor 50 is an embodiment of the present invention and is used by the processor 510 to perform various determination, estimation and calculation functions described above in the present invention, including those functions performed in the first, second and third embodiments. In some embodiments, the water safety device 500 may include one or more underwater sensors 560(1)-560(M). Each of the underwater sensors 560(1)-560(M) may be Figure 1 , 2 and 4 of the underwater sensor 60 and is used by the processor 510 to perform the various determination, estimation and calculation functions described above in the present invention, including those functions performed in the first, second and third schemes.

[0103] In some embodiments, the processor 510, upon executing one or more sets of instructions 522, may further determine a fording route in response to determining that it is safe for the vehicle to ford through the body of water 30, so that the vehicle 10 can safely ford through the body of water 30 via the fording route. For example, the underwater sensors 560(1)-560(M) may detect a rock of significant size on the right side of the road 20 submerged below the top water surface 33. The processor 510 may therefore determine a fording route that travels slightly to the left side of the road 20 to avoid the submerged rock. In some embodiments, the processor 510, upon executing one or more sets of instructions 522, may further determine a fording speed after determining the fording route, so that the vehicle 10 can safely ford through the body of water 30 via the fording route at the fording speed. Depending on the particular topography of the bottom profile 35 of the body of water 30, it may be safer to ford through the body of water 30 at a particular speed or according to a particular speed profile. For example, if the bottom profile 35 of the body of water 30 is substantially the same as the topography of the body of water 30, the vehicle 10 may be able to ford through the body of water 30 at a particular speed or according to a particular speed profile. Figure 4 The terrain 26 shown is very rough and it may be safer to drive at a low speed so that the water does not splash high and damage some critical components or stall the engine.

[0104] In some embodiments, processor 510 upon executing one or more sets of instructions 522 may further determine an alternate route in response to determining that it is unsafe for vehicle 10 to wade through body of water 30, so that vehicle 10 can avoid body of water 30 by driving through the alternate route. The alternate route may be determined based on information (e.g., historical flood data, historical weather information, and information about current crowd sources provided by other vehicles in the area, etc.). The alternate route may also be determined based on information about current microclimate, weather forecasts, and estimated time to possible flood zones. As disclosed below, these various information or data may be received or otherwise accessed via communication device 530.

[0105] In some embodiments, the water safety device 500 may include a communication device 530 capable of wirelessly transmitting and receiving data. For example, the communication device 530 may be used by the processor 510 to remotely access a data server and update the 3D map 524 stored in the memory 520, particularly when the vehicle 10 drives to a new area where the 3D map 524 needs to be updated for the new area. In some embodiments, the communication device 530 may be used by the processor 510 to receive microclimate information for the location of the water body 30. The microclimate information may be used to facilitate the determination of water safety. For example, even if it is determined that it is safe to wade through the water body 30 based on the calculated critical trajectory 44 and the flow speed of the water body 30, the microclimate information received by the communication device 530 may show a thunderstorm and a flash flood that is coming into the water body 30, and therefore the processor 510 may determine that it is unsafe to wade through the water body 30.

[0106] In some embodiments, the vehicle 10 may be an autonomous vehicle, and the processor 510 of the water wading safety device 500 may also directly control the vehicle 10 to wade through the water body 30 via a wading route. In some embodiments, the processor 510 of the water wading safety device 500 may further control the vehicle 10 to wade through the water body 30 via a wading route according to a wading speed or a speed profile.

[0107] In some embodiments, the water wading safety device 500 may include a user interface 540 capable of conducting communication with a user (e.g., a driver of the vehicle 10). The user interface 540 may communicate with the user through visual display, sound, voice, voice synthesis / recognition, touch, tactile or other human perception methods. In some embodiments, the water wading safety device 500 may be able to present the failure probability of each key component in the case where the vehicle 10 is to wade through the water body 30 through the user interface 540, so that the driver of the vehicle 10 can make a comprehensive decision on whether to wade through the water body 30 based on the failure probability of the key components presented through the user interface 540.

[0108] Figure 6 An example process 600 for determining whether a vehicle should wade through a body of water is shown in accordance with the present invention. Process 600 may include one or more operations, actions, or functions illustrated as blocks (e.g., 610, 620, 630, 640, 650, 660, 670, and 680). Although illustrated as discrete blocks, the various blocks of process 600 may be separated into additional blocks, combined into fewer blocks, or eliminated, depending on the desired implementation. Process 600 may be performed by Figure 5 In addition, the process 600 can be implemented using the water safety device 500. Figure 1-4 The first, second, and third proposed approaches for determining one or more aspects of the body of water 30 are shown previously in FIG.

[0109] At 610, process 600 may involve processor 510 receiving data related to a body of water (e.g., body of water 30) from one or more sensors (e.g., above-water sensor 50 and underwater sensor 60). The data related to the body of water may include one or more edges of the body of water (e.g., edges 31 and 32 of body of water 30), first and second reflection signals from the body of water (e.g., the second and second reflection signals in the second and third proposed solutions disclosed above), floating objects in the body of water (e.g., Figure 1 The process 600 may be performed from 610 to 620.

[0110] At 620, process 600 may involve processor 510 determining one or more aspects of a body of water based on data received from one or more sensors. The one or more aspects of a body of water may include water depth at various locations in the body of water (e.g., Figure 2 and 3 the maximum water depth D) and the bottom contour of the water body (e.g. Figure 2-4 In some embodiments, at 620, process 600 may involve processor 510 determining a flow velocity of the body of water. Process 600 may proceed from 620 to 630.

[0111] At 630 , process 600 may involve processor 510 calculating one or more critical trajectories (eg, critical component 40 ) of one or more critical components of a vehicle susceptible to water damage. Figure 2 and 3 The calculation of the critical trajectory is based at least in part on the bottom contour of the water body (e.g., bottom contour 35) and a spatial model of the vehicle. The spatial model defines the position of each critical component relative to a fixed reference point of the vehicle (e.g., Figure 3 The process 600 may proceed from 630 to 640.

[0112] At 640, process 600 may involve processor 510 generating a flow chart based on one or more key tracks and a top surface of the body of water (e.g., Figure 2-4 In some embodiments, the process 600 may involve the processor 510 determining that it is safe for the vehicle to wade through the water body if each of the critical tracks is above the top surface of the water body. On the other hand, the processor 510 determines that it is unsafe for the vehicle to wade through the water body if at least a portion of one of the critical tracks is below the top surface of the water body. In some embodiments, the process 600 may involve the processor 510 determining whether it is safe based on the current speed of the vehicle and the buoyancy model. As previously described, the buoyancy model simulates the behavior of the vehicle when it is subject to flowing water. In the event that the processor 510 determines that it is safe for the vehicle to wade through the water body, the process 600 may proceed from 640 to 650. Alternatively, in the event that the processor 510 determines that it is unsafe for the vehicle to wade through the water body, the process 600 may proceed from 640 to 670.

[0113] At 650, process 600 may involve processor 510 determining a fording route at which the vehicle can safely ford through the body of water. In some embodiments, at 650, process 600 may further involve processor 510 determining a fording speed at which the vehicle can safely ford through the body of water via the fording route. Process 600 may proceed from 650 to 660.

[0114] At 660, process 600 may involve processor 510 controlling the vehicle to autonomously wade through the body of water via a fording route. In some embodiments, at 660, process 600 may further involve processor 510 controlling the vehicle to autonomously wade through the body of water safely via a fording route at a fording speed.

[0115] At 670 , process 600 may involve processor 510 determining an alternate route that the vehicle can take that avoids the body of water. Process 600 may proceed from 670 to 680 .

[0116] At 680 , process 600 may involve processor 510 controlling the vehicle to autonomously navigate through the alternate route and avoid bodies of water.

[0117] In the case where the vehicle approaching the body of water is an autonomous vehicle, the present invention provides a feasible solution to ensure its wading safety. Without the present invention, the autonomous vehicle may proceed blindly (which may endanger the occupants of the vehicle as well as the vehicle itself) or refuse to proceed completely (which may result in unnecessary rerouting).

[0118] In the event that there are other vehicles wading through a body of water, above-water sensors may be employed to observe those other vehicles and collect information from them to help determine one or more aspects of the body of water.

[0119] Although the disclosure presented above is described in the context of flooding situations where a temporary body of water is created or formed due to flooding, the techniques, methods, schemes, and apparatus described herein may also be applied in situations where the body of water is not temporary. For example, a vehicle (e.g., a ruggedized exploration jeep) may cross a road and wade through a permanent body of water, such as a river or pond. The methods and apparatus disclosed in the present invention are equally applicable in such situations.

[0120] In the above disclosure, reference is made to the accompanying drawings, which form a part of the present invention, and in which specific embodiments in which the present invention may be practiced are shown by way of example. It should be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. References to "one embodiment", "an embodiment", "an exemplary embodiment", etc. in the specification indicate that the described embodiment may include specific features, structures or characteristics, but each embodiment may not necessarily include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when specific features, structures, or characteristics are described with respect to one embodiment, it can be claimed that, whether or not explicitly described, it is within the scope of the knowledge of those skilled in the art to affect such features, structures or characteristics with respect to other embodiments.

[0121] Embodiments of the systems, devices, equipment, and methods disclosed herein may include or utilize a special-purpose or general-purpose computer including computer hardware, e.g., one or more processors and system memory, as discussed herein. Embodiments within the scope of the present invention may also include physical and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media may be any available media that can be accessed by a general-purpose or special-purpose computer system. A computer-readable medium that stores computer-executable instructions is a computer storage medium (device). A computer-readable medium that carries computer-executable instructions is a transmission medium. Therefore, by way of example, and not limitation, embodiments of the present invention may include at least two distinct types of computer-readable media: a computer storage medium (device) and a transmission medium.

[0122] Computer storage media (devices) include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), compact disk-read-only memory (CD-ROM), solid-state drives ("SSD") (e.g., RAM-based), flash memory, phase change memory ("PCM"), other types of memory, other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code means in the form of computer-executable instructions or data structures and that can be accessed by a general or special purpose computer.

[0123] The embodiments of the device, system and method disclosed herein can communicate on a computer network. "Network" is defined as one or more data links that realize the transmission of electronic data between a computer system and / or module and / or other electronic devices. When information is transmitted or provided to a computer through a network or another communication connection (hard-wired connection, wireless, or a combination of hard-wired connection or wireless), the computer appropriately regards the connection as a transmission medium. Transmission media may include networks and / or data links that can be used to carry the required program code means in the form of computer executable instructions or data structures and can be accessed by general or special computers. The above combination should also be included within the scope of computer-readable media.

[0124] Computer executable instructions include, for example, instructions and data, which, when executed at a processor, enable a general-purpose computer, a special-purpose computer, or a special-purpose processing device to perform certain functions or groups of functions. Computer executable instructions can be, for example, binary, intermediate format instructions of, for example, assembly language, or even source code. Although the subject matter of the present invention has been described in the language for structural features and / or methodological actions, it should be understood that the subject matter of the invention defined in the appended claims is not necessarily limited to the described features or the actions described above. On the contrary, the described features and actions are disclosed as example forms of implementing the claims.

[0125] Those skilled in the art will appreciate that the present invention can be practiced in a network computing environment by many types of computer system configurations, including built-in vehicle computers, personal computers, desktop computers, laptop computers, message processors, handheld devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network personal computers (PCs), minicomputers, mainframe computers, mobile phones, personal digital assistants (PDAs), tablet computers, pagers, routers, switches, various storage devices, etc. The present invention can also be practiced in a distributed system environment where both local and remote computer systems perform tasks, and the local and remote computer systems are linked by a network (or by a hardwired data link, a wireless data link, or a combination of hardwired and wireless data links). In a distributed system environment, program modules can be located in local and remote memory storage devices.

[0126] In addition, where appropriate, the functions described herein may be performed in one or more of the following: hardware, software, firmware, digital components, or analog components. For example, one or more application specific integrated circuits (ASICs) may be programmed to perform one or more of the systems and programs described herein. Throughout the specification and claims, certain terms are used to refer to specific system components. It will be appreciated by those skilled in the art that components may be referred to by different names. It is not intended herein to distinguish between components with different names but the same function.

[0127] It should be noted that the sensor embodiments discussed above may include computer hardware, software, firmware, or any combination thereof to perform at least a portion of their functionality. For example, the sensor may include computer code configured to be executed in one or more processors, and may include hardware logic / electronic circuits controlled by the computer code. These example devices are provided herein for illustrative purposes and are not intended to be limiting. Embodiments of the present invention may be implemented in other types of devices, as will be known to those skilled in the relevant art.

[0128] At least some embodiments of the present invention are directed to a computer program product containing such logic (e.g., in the form of software) stored on any computer usable medium. Such software, when executed in one or more data processing devices, causes the devices to operate as described herein.

[0129] Although various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, not limitation. It will be apparent to those skilled in the relevant art that various changes in form and detail can be made without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should only be limited according to the following claims and their equivalents. For the purpose of illustration and description, the foregoing description has been presented. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed. In view of the above teachings, many modifications and variations are possible. In addition, it should be noted that any or all of the aforementioned alternative embodiments can be used in any desired combination to form additional hybrid embodiments of the present invention.

Claims

1. A method for vehicle wading safety, comprising: determining, by a processor, one or more aspects of a body of water; calculating, by the processor, one or more critical trajectories for a vehicle wading through the body of water based at least in part on the one or more aspects; determining, by the processor, whether it is safe for the vehicle to wade through the body of water based on the one or more critical trajectories and the one or more aspects; and estimating, by the processor, a velocity of a current in the body of water based on input from one or more above-water sensors disposed on the vehicle, the one or more above-water sensors being configured to track floating objects carried by the current, Wherein determining whether it is safe for the vehicle to wade through the body of water is further based on the speed of the water flow and a buoyancy model of the vehicle.

2. The method of claim 1, wherein determining the one or more aspects of the body of water comprises: receiving data representing one or more edges of the body of water from one or more above-water sensors disposed on the vehicle; and One or more depths and bottom contours of the body of water are determined based on the edge and topographic information of a location associated with the body of water.

3. The method of claim 2, wherein the one or more above-water sensors comprise a visible light camera, an infrared camera, a stereo camera, a time-of-flight (TOF) camera, a light detection and ranging (LIDAR) transceiver, a radio detection and ranging (RADAR) transceiver, an ultrasonic transceiver, or a combination thereof.

4. The method of claim 1, wherein determining the one or more aspects of the body of water comprises: receiving a first reflected signal and a second reflected signal from one or more above-water sensors disposed on the vehicle, the first reflected signal being a first portion of a sensing signal reflected by a top surface of the body of water and the second reflected signal being a second portion of the sensing signal reflected by a ground surface beneath the body of water; and One or more depths and bottom profiles of the body of water are calculated, by the processor, based at least in part on the first reflected signal and the second reflected signal.

5. The method of claim 4, wherein the one or more above-water sensors comprise a time-of-flight (TOF) camera, a light detection and ranging (LIDAR) transceiver, a radio detection and ranging (RADAR) transceiver, an ultrasonic transceiver, or a combination thereof.

6. The method according to claim 4, further comprising: Prior to calculating the one or more depths and the bottom profile of the body of water, the first and second reflection signals are analyzed using one or more statistical filters.

7. The method of claim 1, wherein determining the one or more aspects of the body of water comprises: deploying one or more underwater sensors into the body of water; controlling the one or more underwater sensors to transmit sensing signals to a top surface of the body of water and to a ground surface below the body of water; controlling the one or more underwater sensors to receive a first reflection signal and a second reflection signal, the first reflection signal being a first portion of the sensing signal reflected by the top surface of the water body, and the second reflection signal being a second portion of the sensing signal reflected by the ground below the water body; and One or more depths and bottom profiles of the body of water are calculated based at least in part on the first reflected signal and the second reflected signal.

8. The method according to claim 1, wherein: The one or more aspects of the body of water include a bottom contour of the body of water, calculating the one or more critical tracks based on the bottom contour and a spatial model of the vehicle, The spatial model of the vehicle includes a spatial relationship of each of one or more critical components of the vehicle relative to a fixed reference point of the vehicle, each of the one or more critical components being susceptible to water damage, and Each of the one or more critical trajectories includes a trajectory of movement of a corresponding one of the one or more critical components as the vehicle traverses the bottom contour of the body of water.

9. The method of claim 1, wherein the one or more aspects of the body of water include one or more depths of the body of water, the one or more depths of the body of water collectively defining a top surface of the body of water, and wherein determining whether it is safe for the vehicle to wade through the body of water includes: determining that it is safe for the vehicle to wade through the body of water with each of the critical tracks being above the top surface of the body of water; and In an instance where at least a portion of one of the critical trajectories is below the top surface of the body of water, it is determined that it is unsafe for the vehicle to wade through the body of water.

10. The method according to claim 9, further comprising: determining, by the processor, a fording route by which the vehicle can safely ford through the body of water in response to determining that it is safe for the vehicle to ford through the body of water; and In response to determining that it is unsafe for the vehicle to wade through the body of water, determining, by the processor, an alternate route for the vehicle that can avoid the body of water.

11. The method according to claim 10, further comprising: The vehicle is controlled by the processor to autonomously wade through the body of water via the wading route.

12. The method according to claim 1, further comprising: deploying, by the processor, one or more underwater sensors into the body of water to measure a velocity of a current in the body of water, Wherein determining whether it is safe for the vehicle to wade through the body of water is further based on the speed of the water flow and a buoyancy model of the vehicle.

13. A device for vehicle wading safety, comprising: a memory capable of storing one or more sets of instructions and a spatial model of the vehicle; a processor coupled to execute the one or more sets of instructions stored in the memory, such that upon execution of the one or more sets of instructions, the processor performs operations comprising: determining one or more depths and bottom contours of a body of water; calculating one or more critical trajectories of the vehicle based on the bottom contour of the body of water and the spatial model of the vehicle; and Do one or more of the following: determining whether it is safe for the vehicle to wade through the body of water based on the one or more depths of the body of water and the one or more critical tracks; determining a fording route at which the vehicle can safely ford through the body of water and a fording speed at which the vehicle can safely ford through the body of water via the fording route; as well as determining an alternate route for the vehicle that avoids the body of water; as well as a first above-water sensor disposed on the vehicle to estimate a flow velocity of the body of water by tracking floating objects carried by the body of water, Wherein the memory is further capable of storing a buoyancy model of the vehicle, and wherein determining whether it is safe for the vehicle to wade through the body of water is further based on the flow velocity of the body of water and the buoyancy model of the vehicle.

14. The apparatus of claim 13, further comprising one or more of the following: a second above-water sensor disposed on the vehicle, the first above-water sensor being capable of sensing one or more edges of the body of water, wherein the memory is further capable of storing topographic information of a location associated with the body of water, and wherein the processor determines the one or more depths and the bottom contour of the body of water based on the edge and the topographic information; a third above-water sensor disposed on the vehicle to transmit a sensing signal to the body of water and receive a first reflection signal and a second reflection signal from the body of water, wherein the first reflected signal comprises a first portion of the sensing signal reflected by a top surface of the body of water, wherein the second reflected signal comprises a second portion of the sensing signal reflected by the ground below the body of water, wherein the processor determines the one or more depths and the bottom profile of the body of water based at least in part on the first reflected signal and the second reflected signal; a first underwater sensor disposed on the vehicle to transmit a sensing signal when submerged in the body of water and to receive a first reflected signal and a second reflected signal from the body of water, wherein the first reflected signal comprises a first portion of the sensing signal reflected by a top surface of the body of water, wherein the second reflected signal comprises a second portion of the sensing signal reflected by the ground beneath the body of water, and wherein the processor determines the one or more depths and the bottom profile of the body of water based at least in part on the first reflected signal and the second reflected signal; a second underwater sensor disposed on the vehicle to measure a flow velocity of the body of water when submerged in the body of water, wherein the memory is further capable of storing a buoyancy model of the vehicle, and Wherein determining whether it is safe for the vehicle to wade through the body of water is further based on the flow velocity of the body of water and the buoyancy model of the vehicle.

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