Vehicle driving assistance devices

Abstract

This invention enables more precise route planning for overcoming obstacles than ever before. The map creation unit creates a road surface elevation map along the direction of travel, starting from the vehicle's position, based on the direction of travel determined by the steering angle. The forward determination unit calculates the climbing force based on the road surface elevation map and the forward grip of each wheel. Furthermore, the forward determination unit determines whether forward movement is possible based on the climbing force. The interference determination unit determines whether there is interference between the vehicle and the road surface based on the road surface elevation map and the vehicle body structure. A warning device (speaker and display) outputs a warning in at least one of the following situations: when the forward determination unit determines that forward movement is impossible, or when the interference determination unit determines that interference exists.

Description

Technical Field

[0001] This specification discloses a vehicle driving assistance device. Background Technology

[0002] Patent documents 1 and 2 disclose a driving assistance device for so-called uneven surfaces with irregularities. In patent document 1, the driving assistance device identifies obstacles in the direction of travel. Then, the driving assistance device creates a path to avoid the obstacle. In patent document 2, the driving assistance device determines the likelihood of avoiding the rough road. Then, if it is determined that avoiding the rough road is difficult, the driving assistance device calculates a recommended speed for driving on the rough road.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2012-145998

[0004] Patent Document 2: Japanese Patent Application Publication No. 2020-50193 Summary of the Invention

[0005] However, there are sometimes situations where obstacles exist across a wide area along the direction of travel, making it difficult to avoid them. Therefore, this specification discloses a vehicle driving assistance device that can perform route planning for overcoming obstacles with higher precision than before.

[0006] This specification discloses a driving assistance device. The device includes a map creation unit, a forward determination unit, an interference determination unit, and a warning device. The map creation unit creates a road surface elevation map along the forward direction, starting from the vehicle's position, based on the direction of travel determined by the steering angle. The forward determination unit calculates the climbing force based on the road surface elevation map and the forward grip of each wheel. Furthermore, the forward determination unit determines whether forward movement is possible based on the climbing force. The interference determination unit determines whether there is interference between the vehicle and the road surface based on the road surface elevation map and the vehicle body structure. The warning device outputs a warning in at least one of the following situations: when the forward determination unit determines that forward movement is impossible, or when the interference determination unit determines that interference exists.

[0007] Based on the above structure, the ability to overcome the obstacle is determined from two aspects: climbing force and whether there is interference.

[0008] Furthermore, in the above structure, when it is determined that the vehicle cannot move forward, the forward determination unit can output a warning signal urging the driver to turn in another direction.

[0009] Based on the above structure, the driver is urged to make changes to the route plan used to overcome obstacles.

[0010] Furthermore, in the aforementioned structure, the forward determination unit can estimate the obstruction point where further progress is impossible by calculating the change in the climbing force along the direction of travel. Moreover, the forward determination unit will notify the warning device of the distance from the vehicle to the obstruction point.

[0011] Based on the above structure, the vehicle can be driven to a point where it can no longer proceed.

[0012] Furthermore, in the above structure, the forward determination unit can calculate the lifting amount of each wheel when the vehicle moves forward. If the specified lifting amount of a wheel exceeds the wheel articulation amount of the vehicle, the forward determination unit performs a ground clearance determination on the other wheels.

[0013] Based on the above structure, it is possible to perform ground clearance determination based on the vehicle structure.

[0014] Furthermore, in the above structure, based on the correspondence between the specified wheel lift amount and the change in ground load of other wheels, the forward determination unit can determine the wheel with the smallest ground load among the other wheels as being in a ground-lift state during the ground-lift determination.

[0015] Based on the above structure, tires in their off-ground state can be selected.

[0016] Invention Effects

[0017] According to the driving assistance device disclosed in this specification, route planning for overcoming obstacles can be performed with greater precision than ever before. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the hardware structure of the driving assistance device according to this embodiment.

[0019] Figure 2 This is a functional block diagram illustrating the driving assistance device according to this embodiment.

[0020] Figure 3 This is a diagram illustrating the driving determination process (1 / 2) based on the driving assistance device.

[0021] Figure 4 This is a diagram illustrating the driving determination process (2 / 2) based on the driving assistance device.

[0022] Figure 5 This is an example of a road surface elevation map.

[0023] Figure 6 This is a diagram illustrating a ground load estimation model.

[0024] Figure 7 This is a diagram illustrating a suspension travel estimation model.

[0025] Figure 8It is a diagram illustrating the climbing force and the compaction force.

[0026] Figure 9 It is a graph illustrating the change in climbing force along the direction of travel.

[0027] Figure 10 This is a diagram illustrating a rigid body vehicle model. Detailed Implementation

[0028] 1. Vehicle structure

[0029] exist Figure 1 The illustration shows a driving assistance device and its peripheral equipment mounted on a vehicle 100. The driving assistance device includes various sensors 30A, 30B, 30C, 30F, a start switch 30D, a stereo camera 30E, a transceiver 30G, a vehicle control ECU 10, a speaker 20A, and a display 20B.

[0030] The GPS receiver 30A receives GPS signals as positioning signals from GPS satellites (not shown). GPS signals include, for example, location coordinates such as latitude, longitude, and altitude. By receiving GPS signals, the vehicle's location can be determined.

[0031] Steering angle sensor 30B, for example, detects the steering angle based on the amount of steering wheel input by the driver. Vehicle speed sensor 30C detects the vehicle's speed at 100 km / h. Start switch 30D toggles the start / stop function. Figure 3 , Figure 4 The driving determination process is shown in the example for enabling / disabling. The start switch 30D is located, for example, around the steering wheel.

[0032] The stereo camera 30E is, for example, mounted on the windshield. The stereo camera 30E captures images of the area in front of the vehicle 100. The stereo camera 30E also functions as a rangefinder camera. That is, it determines the shape of the road surface in front of the vehicle 100 using the stereo camera 30E.

[0033] A laser sensor 30F is positioned at the front of the vehicle. The laser sensor 30F has a ranging function. The laser sensor 30F is, for example, a millimeter-wave radar. The laser sensor 30F performs distance measurement, for example, in conjunction with a stereo camera 30E. For example, distance measurement based on the stereo camera 30E is performed specifically in clear weather. Furthermore, distance measurement based on the laser sensor 30F is performed specifically in inclement weather. Through the stereo camera 30E and the laser sensor 30F, the road surface shape in front of the vehicle 100 can be acquired regardless of weather conditions.

[0034] Furthermore, it is capable of receiving road surface shape data from external sources. The transceiver 30G receives road surface shape data from the data center 30H or the shape measuring device 30I.

[0035] For example, vehicle 100 may sometimes travel on unpaved routes for recreational purposes. The operating company of the unpaved routes stores the road surface shape data of the unpaved routes in data center 30H. This road surface shape data is then provided to vehicle 100.

[0036] Furthermore, on unpaved routes, the road surface shape changes depending on vehicle passage or weather conditions. For example, a shape measuring device 30I, such as a measuring machine, is installed next to the unpaved route. Road surface shape data based on the shape measuring device 30I is transmitted to the vehicle 100 in real time, for example.

[0037] Both speaker 20A and display 20B are warning devices. As described later, in Figure 3 and Figure 4 In the illustrated driving determination process, it is determined that vehicle 100 cannot move forward. Alternatively, it is determined that the vehicle is interfering with an obstacle. If at least one of these determinations is output, a warning is output in at least one of speaker 20A and display 20B.

[0038] The vehicle control ECU 10 is composed of a computing device. The vehicle control ECU 10 includes a CPU 10A, RAM 10B, storage device 10C, ROM 10D, and input / output controller 10E.

[0039] CPU 10A is the central processing unit, also known as a processor. RAM 10B is a volatile storage device that temporarily stores data during operation. ROM 10D is a storage device capable of reading data. Storage device 10C is a storage device capable of writing and reading data. Storage device 10C may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0040] By executing a program stored in storage device 10C or ROM 10D by CPU 10A, a system is constructed in vehicle control ECU 10 such as... Figure 2 The functional blocks illustrated are as follows. Specifically, the vehicle control ECU 10 includes a map creation unit 11, a forward movement determination unit 12, an interference determination unit 13, a road surface data storage unit 14, and a vehicle characteristic storage unit 15. These functional blocks execute... Figure 3 , Figure 4 The driving determination process is illustrated in the example.

[0041] The road surface data storage unit 14 stores three-dimensional shape data of the road surface. The vehicle characteristic storage unit 15 stores information about the characteristics of the vehicle 100. For example, the so-called specification information of the vehicle 100 is stored in the vehicle characteristic storage unit 15. The specification information includes track width, wheelbase, tire stiffness, and center of gravity height. Furthermore, the vehicle characteristic storage unit 15 stores vehicle stiffness, suspension characteristic data, and wheel articulation amount, which will be described later.

[0042] 2. Driving Determination Process

[0043] The driving determination process is executed by turning on the start switch 30D. (Reference) Figures 2-4 The map creation unit 11 receives road surface shape data from the data center 30H or the shape measuring device 30I (S10). The road surface shape data includes the three-dimensional shape data (height information) of the road surface. Furthermore, the three-dimensional shape data of the road surface also includes the friction coefficient μ of the road surface. The received road surface shape data is stored in the road surface data storage unit 14.

[0044] In addition, if high-precision road surface shape data can be obtained through the stereo camera 30E and the laser sensor 30F, step S10 can be omitted.

[0045] Referring to the GPS signal received by the GPS receiver 30A, the map creation unit 11 obtains the vehicle's position information (S12). Next, the map creation unit 11 obtains the steering angle of the steering wheel from the steering angle sensor 30B. The map creation unit 11 determines the direction of travel of the vehicle 100 based on the steering angle (S14).

[0046] Once the vehicle's location and direction of travel are determined, the map creation department 11 will create a map as follows: Figure 5 The road surface elevation map 40 (S16) is shown in the example. The road surface elevation map 40 is unfolded along the direction of travel, starting from the vehicle's position. Figure 5 In this context, the X-axis refers to the direction of travel, and the Y-axis refers to the width direction of the vehicle. For example, the center of the Y-axis corresponds to the center of the width direction of vehicle 100. Furthermore, the Y-axis is set to the total width of vehicle 100 plus a specified allowance.

[0047] exist Figure 5 In the road surface elevation map 40, relatively high areas are represented by regions with relatively high shaded line density. For example, in Figure 5 In the middle, five convex protrusions are arranged along the direction of travel.

[0048] The road surface height map 40 is obtained by extracting a portion of the road surface shape data stored in the road surface data storage unit 14. For example, road surface data is extracted from a range of 3m to 7m along the direction of travel from the vehicle's position.

[0049] As described later, a warning is output from the warning device when at least one of the following conditions is met: the forward determination unit 12 determines that forward movement is impossible, or the interference determination unit 13 determines that interference exists. The warning device includes a speaker 20A and a display 20B.

[0050] 2-1. Moving Forward Decision

[0051] Forward determination unit 12 determines the direction of travel based on the road surface height map (reference). Figure 5 ) and the forward grip force Gf of each wheel, calculate the climbing force Fm (refer to) Figure 8 Furthermore, the forward determination unit 12 determines whether forward movement is possible based on the climbing force Fm.

[0052] The forward determination unit 12 sets the count k to an initial value of 1 (S18). Each time a forward determination and interference determination are repeated, the count k increments. For example, the range for forward / interference determination is set within a 5m radius of the vehicle's position. Furthermore, within this range, forward / interference determination is performed at predetermined distance increments (10cm). In this case, corresponding to a forward / interference determination at a location 5m ahead of the vehicle's position, the final value k_end of the count k becomes 50.

[0053] The forward determination unit 12 calculates the Z-coordinates and tilt angles θ of the four wheels when the vehicle 100 moves forward a predetermined step distance (10 cm) from its position (S20). The Z-coordinate represents the height direction. For example, the forward determination unit 12 calculates the Z-coordinates and tilt angles θ of the contact points of each of the four wheels. Here, the tires are actually in contact with the road surface, but to reduce the computational load, the center of the contact point is set as the contact point. For example, the tangent angle of the contact point is called the tilt angle θ. The Z-coordinates and tilt angles θ can be calculated based on the contact points of the four wheels and the road surface height map 40.

[0054] Next, the forward determination unit 12 calculates the wheel lift amount Lf and the ground load cf (S22). The wheel lift amount Lf refers to the height displacement of the wheel when the vehicle moves forward a specified step distance. When the wheel lift amount Lf is negative, it means that the wheel is in a state of descent (falling).

[0055] Here, the vehicle characteristic storage unit 15 stores, for example, Figure 6 The ground load estimation model 42 is illustrated below. In the ground load estimation model 42, the correspondence between the specified wheel lift amount Lf and the changes in ground load Δcf of the other three wheels is stored. Alternatively, instead of the ground load estimation model 42, the correspondence between the specified wheel lift amount Lf and the changes in ground load Δcf of the other wheels can be stored as a line graph. Qualitatively, if a specified wheel is lifted, the ground load of the wheels on its diagonal increases. Furthermore, the ground load of the remaining two wheels decreases.

[0056] Step S22 is performed on each of the four wheels. For example, the change in ground load of the other three wheels 42B-42D when wheel 42A is initially lifted is determined. Then, with wheel 42A lifted, wheel 42B is lifted. The forward determination unit 12 calculates the change in ground load Δcf for wheels 42A, 42C, and 42D.

[0057] Thus, if all four wheels are raised, in other words, if the vehicle moves forward a predetermined distance from its initial position, the forward determination unit 12 determines whether there is a wheel whose lifting amount Lf becomes the wheel articulation amount WAT (S24).

[0058] Wheel articulation distance (WAT) refers to the amount of travel of the suspension in the reverse phase. Wheel articulation distance (WAT) is an indicator of how easily a wheel is likely to leave the road surface. When the lift (Lf) exceeds the wheel articulation distance (WAT), either wheel will leave the ground.

[0059] The forward determination unit 12 determines whether there is a wheel whose lift amount Lf exceeds the wheel articulation amount WAT (S24). If one of the four wheels has a lift amount Lf > WAT, the forward determination unit 12 determines whether the wheel with the smallest ground contact load cf is off the ground (S26). The ground contact load cf of the wheel determined to be off the ground is set to 0. Furthermore, the forward grip force Gf and resistance Rf of that wheel are set to 0.

[0060] Next, the forward determination unit 12 calculates the forward grip force Gf, resistance Rf, and suspension travel st for each of the four wheels (S28). (Reference) Figure 8 The friction force is calculated based on the ground load cf at the contact point of the wheel and the friction coefficient μ. When the wheel is on an inclined surface, the friction force is decomposed into forward grip force Gf and resistance Rf. The forward determination unit 12 calculates the forward grip force Gf and resistance Rf based on the ground load of each wheel. In addition, the ground load cf of the wheel determined to be off the ground in step S26 is 0, so the forward grip force Gf=0 and resistance Rf=0 are maintained.

[0061] exist Figure 7 The example shown is a suspension travel estimation model 44. Qualitatively, the more the ground load increases, the more the suspension travel increases. That is, the contraction of suspensions 44A-44D increases. The vehicle characteristic storage unit 15 stores a line graph (mapping) showing the correspondence between ground load and suspension travel st. The forward determination unit 12 calculates the suspension travel of each wheel based on this mapping. The suspension travel st is used for interference determination (steps S48-S56) described later.

[0062] Next, the forward determination unit 12 identifies wheels where Gf > Rf (S30). (See reference) Figure 8The difference between Gf and Rf is decomposed into a horizontal component Fm and a vertical component Fp. The horizontal component Fm = (Gf - Rf)cosθ is also known as the climbing force. And the vertical component Fp = (Gf - Rf)sinθ is also known as the clamping force.

[0063] Based on the actual behavior of the vehicle, the clamping force Fp of the wheels with Gf > Rf is distributed to the other wheels. In particular, the clamping force Fp is distributed to the wheels with Gf < Rf. The forward determination unit 12 extracts the wheels with Gf > Rf and calculates the clamping force Fp for each of them (S32).

[0064] Next, the forward determination unit 12 selects the wheels whose Gf < Rf (S34). Then, the forward determination unit 12 adds the clamping force Fp of the other wheels to the forward grip force Gf of the selected wheels (S36).

[0065] In this calculation, when there are multiple wheels with Gf < Rf, the clamping force Fp is distributed according to their respective resistance Rf. For example, if the two front wheels have Gf > Rf and the two rear wheels have Gf < Rf, the clamping force Fp of the two front wheels is calculated. This calculated value ΣFp is added to the forward grip force Gf of each rear wheel (S36).

[0066] For example, when the ratio of the resistance Rf of the right rear wheel to the resistance Rf of the left rear wheel is 1:2, the distribution ratio of the total clamping force ΣFp becomes right rear wheel: left rear wheel = 1:2. Furthermore, the resistance Rf of the wheel determined to be off the ground is 0, therefore no clamping force Fp is distributed.

[0067] Next, the forward determination unit 12 calculates the climbing force Fm = (Gf - Rf)cosθ (S38) for each wheel. (Reference) Figure 4 The forward determination unit 12 determines whether the total climbing force Fm of the four wheels, ΣFm, is greater than or equal to the threshold Fm_th (S40). If ΣFm ≥ Fm_th, the forward determination unit 12 determines that the vehicle 100 can move forward (S42). If ΣFm < Fm_th, the forward determination unit 12 determines that the vehicle 100 cannot move forward (S44).

[0068] If the forward determination unit 12 determines that the vehicle cannot move forward, it outputs a warning signal to the warning device (S46). For example, the forward determination unit 12 outputs a warning sound to the speaker 20A. Furthermore, the forward determination unit 12 outputs an instruction to the warning device prompting the driver to turn in another direction. For example, a message indicating steering wheel operation is displayed on the display 20B. Additionally, the forward determination unit 12 displays a message indicating that the vehicle 100 should reverse on the display 20B.

[0069] Furthermore, the forward determination unit 12 displays the distance from the vehicle to the obstruction point on the display 20B. The obstruction point refers to a location where the vehicle 100 is estimated to be unable to move forward. Calculated, the obstruction point is a location where ΣFm < Fm_th. Figure 9 In the diagram, the obstructed area (the section from X1 to X2) is indicated by a shaded line. Furthermore, X1 and X2 represent the distances from the vehicle. By displaying the distance from the vehicle's position to the obstructed location, the driver is provided with information to decide whether to immediately change steering wheel direction or proceed until the obstructed location is reached.

[0070] 2-2. Interference Determination

[0071] Interference determination is performed in parallel with the forward determination. Interference determination unit 13 (reference) Figure 2 According to the road surface elevation map (reference) Figure 5 Based on the vehicle body structure, determine whether there is any interference between the vehicle and the road surface.

[0072] exist Figure 10 The rigid vehicle model 50 is illustrated below. In this model, the underside structure of the vehicle body is modeled. The rigid vehicle model 50 includes a front bumper 54A, a front right wheel 51A, a front left wheel 52A, a front axle 53A, and a lower skid plate 56. Furthermore, the rigid vehicle model 50 includes lower side beams 55A and 55B, a rear right wheel 51B, a rear left wheel 52B, a rear axle 53B, and a rear bumper 54B. An interference determination unit 13 determines whether these components interfere with the road surface.

[0073] The interference determination unit 13 generates a rigid vehicle model 50 based on the vehicle characteristic information stored in the vehicle characteristic storage unit 15 (S48). Furthermore, the interference determination unit 13 calculates the tilt angle of the vehicle 100 based on the suspension travel of each wheel calculated in step S28. Moreover, the interference determination unit 13 calculates the clearance distance between the rigid vehicle model 50 and the road surface based on the tilt angle of the vehicle 100 and the road surface shape data (S50).

[0074] The interference determination unit 13 determines whether the gap distance is below a predetermined gap threshold (S52). If the gap distance is below the gap threshold, the interference determination unit 13 determines that the vehicle 100 is in contact with the road surface (S54). If the gap distance exceeds the threshold, the interference determination unit 13 determines that there is no contact (S56).

[0075] If interference is detected, the interference determination unit 13 outputs a warning (S46). For example, the interference determination unit 13 causes the speaker 20A to emit a warning sound. Furthermore, the interference determination unit 13 causes the display 20B to show... Figure 10 Rigid body vehicle model 50. Additionally, rigid body vehicle model 50 and road surface height map 40 (for reference). Figure 5 The X coordinates in the diagram are displayed together on monitor 20B.

[0076] Furthermore, the interference determination unit 13 causes the warning device to output an instruction urging the driver to turn in another direction or reverse. For example, a message indicating that the steering wheel should be operated is displayed on the display 20B. Moreover, the interference determination unit 13 displays a message indicating that the vehicle 100 should be reversed on the display 20B.

[0077] The rigid vehicle model 50 is given a shaded line corresponding to the amount of clearance between it and the road surface. For example, the position coordinates of the vehicle 100 and the rigid vehicle model 50 in those position coordinates are displayed on the display 20B.

[0078] exist Figure 10 In this diagram, the interference area is represented by a densely packed, diagonally oriented shading line. For example, in this case, the front bumper 54A and lower guard plate 56 interfere with the protrusion 40A of the road surface. Thus, when interference is predicted, the location of the interference is visualized.

[0079] refer to Figure 4 The vehicle control ECU 10 determines whether the start switch 30D has switched from the on state to the off state (S58). If the start switch 30D is disconnected, Figure 3 , Figure 4 The driving determination process illustrated in the example ends. While keeping the start switch 30D on, the vehicle control ECU 10 acquires vehicle speed data from the vehicle speed sensor 30C. Then, it determines whether the vehicle speed is above the prescribed threshold V_th (S60). If the vehicle is traveling at a high speed of 100 on the road, the driving determination cannot keep up, therefore the driving determination process ends.

[0080] Furthermore, the vehicle control ECU 10 acquires steering angle data from the steering angle sensor 30B. Then, the vehicle control ECU 10 determines whether there is steering wheel operation (S62). If the steering wheel has been operated, the process returns to step S12 in order to recreate the road surface height map.

[0081] Without steering wheel operation, the vehicle control ECU 10 determines whether the vehicle 100 has traveled a predetermined distance from its initial position (S64). This predetermined distance could be, for example, […]. Figure 5 The distance along the X-axis in the road surface elevation map 40 is shown as half the value. If the vehicle 100 has traveled a specified distance, the process returns to step S12 to recreate the road surface elevation map.

[0082] If the vehicle 100 has not traveled the specified distance, the vehicle control ECU 10 determines whether the count k has reached the final value k_end (S66). When the count k reaches the final value k_end, the process returns to step S58. When the count k has not reached the final value k_end, the count k is incremented (S68). Then, the process returns to step S20.

[0083] By calculating the climbing force and the presence or absence of interference along the direction of travel, high-precision route planning for drivers to cross obstacles can be achieved. Figure 9 The graph illustrates the variation of the climbing force along the direction of travel. The horizontal axis X represents distance, and the vertical axis represents the climbing force Fm.

[0084] The graph illustrates the change in climbing force from the starting point to the calculated endpoint (x(k_end)). For example, in the interval from location X1 to location X2, the climbing force is less than the threshold Fm_th. That is, the interval from location X1 to location X2 becomes an obstruction point. The forward determination unit 12 displays this change on the display 20B. Furthermore, the forward determination unit 12 displays the distance from the vehicle's position to the obstruction point X1 on the display 20B. Thus, information such as where the current direction of travel can reach can be provided to the driver.

[0085] Thus, in this embodiment, when the vehicle 100 is traveling on an uneven road surface, driving assistance based on forward movement determination and interference determination is performed. This driving assistance can, for example, in disaster situations or rescue operations, provide appropriate driving routes to drivers without experience driving on unpaved roads.

[0086] Furthermore, in the above embodiment, the vehicle control ECU 10 executes both the forward determination and the interference determination in parallel, but it may also execute only one of them. For example, if the display 20B is a touch panel, the determination to be executed can be displayed on the display 20B, including both the forward determination and the interference determination. Through this display, the driver can choose whether to execute both the forward determination and the interference determination, or only one of them.

[0087] Symbol Explanation

[0088] 10-Vehicle Control ECU, 11-Map Creation Unit, 12-Forward Decision Unit, 13-Interference Decision Unit, 14-Road Data Storage Unit, 15-Vehicle Characteristic Storage Unit, 20A-Speaker (Warning Device), 20B-Display (Warning Device), 30A-GPS Receiver, 30B-Steering Angle Sensor, 30C-Vehicle Speed ​​Sensor, 30D-Start Switch, 30E-Stereo Camera, 30F-Laser Sensor, 30G-Transceiver, 40-Road Height Map, 42-Ground Load Estimation Model, 42A-42D-Wheels, 44-Suspension Travel Estimation Model, 50-Rigid Body Vehicle Model.

Claims

1. A vehicle driving assistance device, characterized in that, have: The map creation unit creates a road surface elevation map along the direction of travel, starting from the vehicle's position, based on the direction of travel determined by the steering angle. The forward determination unit calculates the climbing force based on the road surface height map and the forward grip of each wheel, and determines whether forward movement is possible based on the climbing force. The interference determination unit determines whether there is interference between the vehicle and the road surface based on the road surface height map and the vehicle body structure. and A warning device that outputs a warning in at least one of the following situations: when the forward determination unit determines that forward movement is impossible and when the interference determination unit determines that there is interference.

2. The vehicle driving assistance device according to claim 1, characterized in that, When it is determined that the vehicle cannot move forward, the forward determination unit will output an instruction to the warning device urging the driver to turn in another direction.

3. The vehicle driving assistance device according to claim 1, characterized in that, The forward determination unit performs the following processing: The points of obstruction where further progress is impossible are estimated by calculating the change in the climbing force along the direction of travel; and The distance from the vehicle to the obstructed location will be communicated to the warning device.

4. The vehicle driving assistance device according to claim 1, characterized in that, The forward movement determination unit calculates the lifting amount of each wheel when the vehicle moves forward. If the specified lifting amount of the wheel exceeds the wheel articulation amount of the vehicle, the forward determination unit performs a ground clearance determination on the other wheels.

5. The vehicle driving assistance device according to claim 4, characterized in that, Based on the prescribed relationship between the lifting amount of the wheel and the change in ground load of the other wheels, in the ground clearance determination, the forward determination unit determines the wheel with the smallest ground load among the other wheels as being in a ground clearance state.

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