Travel supporting system

Abstract

To enable appropriate control of a driving force of a vehicle when a first wheel of the vehicle passes through a step.SOLUTION: A travel supporting system 10 comprises a driving control device 44 that sets a driving force of a target vehicle based on step related information which is information acquired when a first vehicle 201 of a plurality of vehicles 20 passes through the step and is information regarding the step when at least one target vehicle of a plurality of vehicles 20 passes through a step.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a driving assistance system that assists driving of a vehicle. [Background technology]

[0002] Patent Document 1 discloses a driving support device that supports the driving of a vehicle in a driving area where a step exists. The driving support device stores, as reference information, a first driving force, which is a driving force required for a first wheel of the vehicle to overcome the step, or a change in the driving state of the vehicle when the first wheel passes over the step. Then, when a second wheel of the vehicle passes over the step, the driving support device generates a second driving force based on the reference information. This prevents the vehicle from suddenly accelerating when the second wheel passes over the step, or prevents the time required for the second wheel to overcome the step from becoming longer. The first wheel is one of the front and rear wheels that is located in the traveling direction of the vehicle. The second wheel is one of the front and rear wheels that is not the first wheel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-15439 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned driving assistance device, when the first wheel passes over a step, the driving force cannot be appropriately controlled, and therefore the vehicle may suddenly accelerate when the first wheel goes over the step. [Means for solving the problem]

[0005] A driving assistance system for solving the above problem is a system that assists a vehicle in driving in a driving area where a step exists. The driving assistance system includes a driving control device that, when at least one target vehicle among a plurality of vehicles including a first vehicle and a second vehicle different from the first vehicle passes through the step, sets a driving force of the target vehicle based on step-related information that is information regarding the step and is acquired when the first vehicle passes through the step. Effect of the Invention

[0006] The driving assistance system described above has an effect of being able to appropriately control the driving force of the vehicle when the first wheel of the vehicle passes over a step. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an outline of the configuration of a driving assistance system according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a state in which a wheel of a vehicle goes over a step. [Diagram 3] FIG. 3 is a flowchart showing a process flow when the parking assistance process is executed in a state where there is no step-related information in the driving assistance system of the first embodiment. [Figure 4] FIG. 4 is a flowchart showing a step passing process executed by the driving assistance system of the first embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing a state in which a first wheel of the vehicle comes into contact with a step. [Figure 6] FIG. 6 is a flowchart showing a process flow when the parking assistance process is executed in a state where step-related information is present in the driving assistance system of the first embodiment. [Figure 7] FIG. 7 is a timing chart in the case where there is no step-related information in the driving assistance system of the first embodiment. [Figure 8] FIG. 8 is a timing chart in the case where step-related information is present in the driving assistance system of the first embodiment. [Figure 9] FIG. 9 is a timing chart in the case where step-related information is present in the driving assistance system of the second embodiment. [Figure 10] FIG. 10 is a schematic diagram showing the configuration of a server included in the driving assistance system of the third embodiment. [Figure 11] FIG. 11 is a flowchart showing a process flow when the parking assistance process is executed in the driving assistance system of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (First embodiment) Hereinafter, a driving assistance system according to a first embodiment will be described with reference to FIGS. As shown in Fig. 1, a driving support system 10 includes a plurality of vehicles and a server 11 installed outside the vehicles. The server 11 corresponds to an "external device." Various types of information are transmitted and received between the server 11 and the plurality of vehicles via a communication network 100.

[0009] The multiple vehicles include a first vehicle 201, a second vehicle 202 different from the first vehicle 201, and a third vehicle 203 different from the first vehicle 201 and the second vehicle 202. In the following description, when there is no need to distinguish between the multiple vehicles 201 to 203, ..., they will be referred to as "vehicles 20."

[0010] As shown in Fig. 2, the driving assistance system 10 assists the vehicle 20 in driving an area 70 that has a step 71. In the example shown in Fig. 2, the driving assistance system 10 assists the vehicle 20 in parking in a parking lot that has a step 71.

[0011] The step 71 in this specification is a step that the wheels of the vehicle 20 may overcome. Examples of such steps include lock plates installed in coin parking lots and the boundary between a roadway and a sidewalk. The step 71 may be in the form of steps or a slope. On the other hand, the step 71 does not include steps that are not suitable for the wheels to overcome, such as steps for car stops installed in parking lots.

[0012] <Server> 1, the server 11 includes a communication device 12 and a server control device 13. The communication device 12 receives information transmitted from the vehicle 20 via a communication network 100. Then, the communication device 12 transmits the received information to the server control device 13. In addition, the communication device 12 transmits information output from the server control device 13 to the vehicle 20 via the communication network 100.

[0013] The server control device 13 includes a processing circuit 14. An example of the processing circuit 14 is an electronic control device. In this case, the processing circuit 14 includes a CPU 15, a first memory 16, and a second memory 17. The first memory 16 stores a control program executed by the CPU 15.

[0014] The second memory 17 stores step-related information collected from the vehicle 20. The step-related information is information related to the step 71. For example, the step-related information includes information related to the height of the step 71 and information related to the position where the step 71 is installed. Furthermore, the step-related information may include image data of an image in which the step 71 is shown. An image in which the step 71 is shown may also be referred to as an "image of the step 71."

[0015] Although the details will be described later, the processing circuit 14 generates information necessary for the vehicle 20 to pass over the step 71. Then, the processing circuit 14 outputs the generated information to the communication device 12. Then, the communication device 12 transmits the information to the vehicle 20.

[0016] <Vehicle> Each of the vehicles 20 has a front wheel 21F and a rear wheel 21R as wheels. Of the front wheel 21F and the rear wheel 21R, the wheel located in the traveling direction X1 of the vehicle 20 corresponds to the first wheel 211, and the wheel other than the first wheel 211 corresponds to the second wheel 212. For example, when the vehicle 20 is moving backward as shown in FIG. 2, the rear wheel 21R corresponds to the first wheel 211, and the front wheel 21F corresponds to the second wheel 212.

[0017] Each of the multiple vehicles 20 includes a driving device 22 and a braking device 23. The driving device 22 generates a driving force Fd in the vehicle 20 to cause the vehicle 20 to travel. For example, the driving device 22 has at least one of an engine and an electric motor as a power source for the vehicle 20. The braking device 23 generates a braking force Fb in the vehicle 20 to decelerate or stop the vehicle 20.

[0018] Each of the vehicles 20 includes a position information acquisition unit 25 and a navigation device 27. The position information acquisition unit 25 is a device that acquires position coordinates that indicate the current position of the vehicle 20. One example of the position information acquisition unit 25 is a device that acquires position coordinates by communicating with a satellite for GNSS. "GNSS" is an abbreviation for "Global Navigation Satellite System." The navigation device 27 displays the current position of the vehicle 20 on a map on a display based on the position coordinates of the vehicle 20 acquired by the position information acquisition unit 25.

[0019] Each of the multiple vehicles 20 is equipped with an imaging device 28 and multiple sensors 29. The imaging device 28 captures an image of the surroundings of the vehicle 20. For example, the imaging device 28 captures an image of the road surface in the traveling direction X1 of the vehicle 20. Image data, which is data of an image captured by the imaging device 28, is transmitted to a control system 40, which will be described later.

[0020] The multiple sensors 29 detect state quantities of the vehicle 20 and transmit signals according to the detection results to the control system 40. For example, the multiple sensors 29 include a sensor that detects the longitudinal acceleration of the vehicle 20 and a sensor that detects the rotation speed of the wheels.

[0021] Each of the vehicles 20 includes a communication device 30 and a control system 40. The communication device 30 receives information transmitted from the server 11 via the communication network 100. The communication device 30 then outputs the received information to the control system 40. The communication device 30 also transmits information output from the control system 40 to the server 11 via the communication network 100.

[0022] The control system 40 includes a plurality of control devices that are configured to be able to communicate with each other. An example of the plurality of control devices is an electronic control device. The plurality of control devices includes a drive control device 41, a braking control device 42, an image analysis device 43, and a driving control device 44.

[0023] The drive control device 41 controls the drive device 22. The brake control device 42 controls the brake device 23. The image analysis device 43 analyzes the image data received from the imaging device 28. When the vehicle 20 travels through a travel area 70 in which a step 71 exists as shown in FIG. 2, the image analysis device 43 analyzes the image data of an image captured in the traveling direction X1 of the vehicle 20 to determine whether or not the step 71 exists in the traveling direction X1 of the vehicle 20. When the image analysis device 43 detects the step 71 existing in the traveling direction X1 of the vehicle 20, it transmits to the travel control device 44 a notice that the step 71 exists. At this time, the image analysis device 43 may estimate the distance from the vehicle 20 to the step 71 and transmit the distance to the travel control device 44. In this respect, the image analysis device 43 corresponds to a "step detection device."

[0024] The driving control device 44 sets the driving force Fd and braking force Fb of the vehicle 20 when the vehicle 20 travels in a travel area 70 where a step 71 exists. In particular, when assisting parking of the vehicle 20, the driving control device 44 derives a driving force command value FdTr which is a command value for the driving force Fd and a braking force command value FbTr which is a command value for the braking force Fb so that the actual vehicle speed follows a target vehicle speed which is set to an extremely low speed. Then, the driving control device 44 transmits the driving force command value FdTr to the driving control device 41. The driving control device 44 transmits the braking force command value FbTr to the brake control device 42.

[0025] When the drive control device 41 receives the driving force command value FdTr from the travel control device 44, it drives the drive device 22 based on the driving force command value FdTr. When the brake control device 42 receives the braking force command value FbTr from the travel control device 44, it drives the brake device 23 based on the braking force command value FbTr.

[0026] <Parking assistance processing> The parking assistance process, which is a series of processes performed when parking the vehicle 20, will now be described. When the driver of the vehicle 20 permits the vehicle 20 to start, the cruise control device 44 sets a driving force command value FdTr so that the actual vehicle speed VS approaches the target vehicle speed VSTr, and transmits the driving force command value FdTr to the drive control device 41. The drive control device 41 operates the drive device 22 based on the driving force command value FdTr, causing the vehicle 20 to start. In other words, the vehicle 20 equipped with the cruise control device 44 corresponds to the "target vehicle."

[0027] When the vehicle 20 (target vehicle) is traveling in this manner, the image analyzer 43 determines whether or not the vehicle 20 has reached a parking position by analyzing image data of an image in the traveling direction X1 of the vehicle 20. When the image analyzer 43 determines that the vehicle 20 has reached a parking position, it transmits a message to that effect to the driving control device 44.

[0028] When the driving control device 44 receives the notification that the vehicle 20 has reached the parking position, the driving control device 44 derives a braking force command value FbTr to stop the vehicle 20. Then, the driving control device 44 transmits the braking force command value FbTr to the brake control device 42. The brake control device 42 operates the brake device 23 based on the braking force command value FbTr. As a result, the vehicle 20 stops at the parking position.

[0029] Here, when a step 71 exists in the traveling direction X1 of the vehicle 20 as shown in FIG. 2, the cruise control device 44 needs to make the vehicle 20 pass the step 71. However, in this case, since the target vehicle speed VSTr is set to a relatively low speed, a small value is set as the driving force command value FdTr. Therefore, when the rear wheel 21R of the vehicle 20, which is the first wheel 211, comes into contact with the step 71, the actual vehicle speed VS decreases. Thereafter, the driving force command value FdTr increases, so that the rear wheel 21R passes over the step 71. Depending on the setting mode of the driving force command value FdTr at this time, the vehicle 20 may suddenly accelerate when the rear wheel 21R passes over the step 71, or the time required for the rear wheel 21R to pass over the step 71 may become longer.

[0030] Therefore, when the vehicle 20 passes over a step 71, the cruise control device 44 sets a driving force command value FdTr and a braking force command value FbTr based on step-related information, which is information related to the step. When the vehicle 20 passes over a step 71, the cruise control device 44 sets a driving force command value FdTr and a braking force command value FbTr based on step-related information related to the step 71 corresponding to the position of the vehicle 20. For example, the cruise control device 44 sets the driving force command value FdTr such that the higher the height of the step 71 indicated by the step-related information, the greater the rate at which the driving force command value FdTr increases.

[0031] When the rear wheel 21R, which is the first wheel 211, passes over the step 71, the actual vehicle speed VS increases. Then, the cruise control device 44 increases the braking force command value FbTr and decreases the driving force command value FdTr so that the actual vehicle speed VS does not exceed the target vehicle speed VSTr.

[0032] <Processing flow when step-related information is not available> With reference to FIG. 3, a process flow in the case where there is no step-related information related to the step 71 through which the vehicle 20 (target vehicle) will pass during the current parking will be described.

[0033] When the driver allows the vehicle 20 to start, the parking assistance process is started prior to the start of the vehicle 20. In step S11, the driving control device 44 of the vehicle 20 causes the communication device 30 to transmit current position information of the vehicle 20 to the server 11. In this respect, the communication device 30 of the vehicle 20 corresponds to an "information transmission device."

[0034] In step S41, the server control device 13 of the server 11 determines whether or not the communication device 12 has received the position information transmitted by the vehicle 20 in step S11. If the communication device 12 has not received the position information (S41: NO), the server control device 13 repeats the determination in step S41 until the communication device 12 receives the position information. On the other hand, if the communication device 12 has received the position information (S41: YES), the server control device 13 transitions the process to step S43.

[0035] In step S43, the server control device 13 searches for step-related information related to the step 71 corresponding to the current position of the vehicle 20 indicated by the position information received by the communication device 12 from among the multiple step-related information stored in the second memory 17.

[0036] In the example described with reference to FIG. 3, the step-related information related to the step 71 through which the vehicle 20 passes during the current parking is not stored in the second memory 17. Therefore, in the next step S45, the server control device 13 causes the communication device 12 to transmit a message indicating that there is no step-related information to the vehicle 20. Then, the server control device 13 shifts the process to step S47.

[0037] When the location information is transmitted to the server 11, the driving control device 44 of the vehicle 20 shifts the process to step S13. In step S13, the driving control device 44 determines whether or not the communication device 30 has received the information transmitted by the server 11 to the vehicle 20 in step S45. If the communication device 30 has not received the information (S13: NO), the driving control device 44 repeatedly executes the determination in step S13 until the communication device 30 receives the information. On the other hand, if the communication device 30 has received the information (S13: YES), the driving control device 44 shifts the process to step S15.

[0038] In step S15, the driving control device 44 starts the vehicle 20. Specifically, the driving control device 44 derives a driving force command value FdTr and a braking force command value FbTr so that the actual vehicle speed VS follows the target vehicle speed VSTr. Then, the driving control device 44 transmits the driving force command value FdTr to the driving control device 41 and transmits the braking force command value FbTr to the braking control device 42.

[0039] In the following step S17, the cruise control device 44 executes a step passing process. The step passing process will be described with reference to FIGS. As shown in Fig. 4, in step S171, the cruise control device 44 determines whether or not the first wheel 211 of the traveling vehicle 20 has come into contact with the step 71. For example, if the actual vehicle speed VS of the vehicle 20 decreases, it can be considered that the first wheel 211 has come into contact with the step 71. If the cruise control device 44 determines that the first wheel 211 has not come into contact with the step 71 (S171: NO), it repeats the determination in step S171 until it can determine that the first wheel 211 has come into contact with the step 71. On the other hand, if the cruise control device 44 determines that the first wheel 211 has come into contact with the step 71 (S171: YES), the process proceeds to step S173.

[0040] In step S173, the driving control device 44 calculates the step height Hd, which is the height of the step 71 with which the first wheel 211 is in contact. As shown in Fig. 5, a first force Mmg, which is a force due to gravity, and a second force Mf, which is a force due to driving force Fd, act on a contact point P between the first wheel 211 and the step 71. The first force Mmg can be expressed by the following relational expression (D1). The second force Mf can be expressed by the following relational expression (D2). In the relational expressions (D1) and (D2), "m" is the vehicle weight, and "g" is the gravitational acceleration. "θ" is the gradient of the road surface on which the vehicle 20 travels, and "R" is the radius of the first wheel 211.

[0041]

number

[0042] When the first wheel 211 climbs over the step 71, the second force Mf is equal to the first force Mmg. Therefore, the cruise control device 44 calculates the step height Hd when "Mmg = Mf". Then, when the cruise control device 44 calculates the step height Hd, it ends the step passing process.

[0043] Returning to FIG. 3, when the driving control device 44 ends the step passing process in step S17, the process proceeds to step S19. In step S19, the driving control device 44 causes the communication device 30 to transmit step-related information to the server 11. That is, the step-related information includes information acquired when the vehicle 20 passes over the step 71. The step-related information includes current position information of the vehicle 20, the step height Hd calculated in step S17, and image data of the image of the step 71. In the following step S21, the driving control device 44 also registers the step-related information transmitted to the server 11 in its own memory. Then, the driving control device 44 ends the series of processes.

[0044] In step S47, the server control device 13 of the server 11 judges whether or not the communication device 12 has received the step-related information transmitted from the vehicle 20 in step S19. If the communication device 12 has not received the step-related information (S47: NO), the server control device 13 repeats the judgment of step S47 until the communication device 12 receives the step-related information. On the other hand, if the communication device 12 has received the step-related information (S47: YES), the server control device 13 shifts the process to step S49. In step S49, the server control device 13 registers the step-related information received by the communication device 12 in the second memory 17. Then, the server control device 13 ends the series of processes.

[0045] <Processing flow when step-related information is present> With reference to FIG. 6, a process flow will be described in the case where there is step-related information related to the step 71 through which the vehicle 20 (target vehicle) will pass during the current parking.

[0046] When the driver allows the vehicle 20 to start, the parking assistance process is started before the vehicle 20 starts. In step S111, the cruise control device 44 of the vehicle 20 determines whether or not step-related information related to the step 71 present at the current position of the vehicle 20 is stored in its own memory. If the step-related information is stored in its own memory (S111: YES), the cruise control device 44 shifts the process to step S119. On the other hand, if the step-related information is not stored in its own memory (S111: NO), the cruise control device 44 shifts the process to step S113.

[0047] In step S113, the driving control device 44 causes the communication device 30 to transmit the current position information of the vehicle 20 to the server 11, similarly to step S11 described above. In step S141, the server control device 13 of the server 11 determines whether or not the communication device 12 has received the position information transmitted by the vehicle 20 in step S113. If the communication device 12 has not received the position information (S141: NO), the server control device 13 repeatedly executes the determination in step S141 until the communication device 12 receives the position information. On the other hand, if the communication device 12 has received the position information (S141: YES), the server control device 13 transitions the process to step S143.

[0048] In step S143, the server control device 13 searches for step-related information related to the step 71 corresponding to the current position of the vehicle 20 indicated by the position information received by the communication device 12 from among the multiple step-related information stored in the second memory 17.

[0049] In the example described with reference to FIG. 6, step-related information related to the step 71 through which the vehicle 20 passes during the current parking operation is stored in the second memory 17. Therefore, in the next step S145, the server control device 13 causes the communication device 12 to transmit, to the vehicle 20, step-related information related to the step 71 corresponding to the current position of the vehicle 20 indicated by the position information received by the communication device 12. Then, the server control device 13 transitions the process to step S147.

[0050] When the position information is transmitted to the server 11, the driving control device 44 of the vehicle 20 shifts the process to step S115. In step S115, the driving control device 44 determines whether or not the communication device 30 has received the step-related information transmitted by the server 11 in the above step S145. If the communication device 30 has not received the step-related information (S115: NO), the driving control device 44 repeatedly executes the determination of step S115 until the communication device 30 receives the step-related information. On the other hand, if the communication device 30 has received the step-related information (S115: YES), the driving control device 44 shifts the process to step S117.

[0051] In step S117, the driving control device 44 judges whether the step 71 detected in the traveling direction X1 of the vehicle 20 and the step indicated by the received step-related information are consistent. For example, the driving control device 44 judges whether they are consistent by comparing image data of the image of the step 71 with image data included in the step-related information. The image data of the image in which the step 71 is shown is set as the "latest image data", and the image data included in the step-related information is set as the "old image data". At this time, if the shape of the step 71 indicated in the latest image data is substantially the same as the shape of the step indicated in the old image data, it can be considered that the step 71 detected in the traveling direction X1 of the vehicle 20 and the step indicated by the step-related information are consistent. On the other hand, if the shape of the step 71 indicated in the latest image data is different from the shape of the step indicated in the old image data, it can be considered that the step 71 detected in the traveling direction X1 of the vehicle 20 and the step indicated by the step-related information are not consistent. If the driving control device 44 determines that the step 71 detected in the traveling direction X1 of the vehicle 20 and the step indicated by the step-related information are consistent (S117: YES), the processing proceeds to step S119. On the other hand, if the driving control device 44 determines that the step 71 detected in the traveling direction X1 of the vehicle 20 and the step indicated by the step-related information are not consistent (S117: NO), the processing proceeds to step S123.

[0052] In step S119, similarly to step S15, the driving control device 44 starts the vehicle 20. In the following step S121, the driving control device 44 executes a first step passage process.

[0053] An example of the first step passage process will be described with reference to FIG. 8(A), (B), (C), and (D), when the vehicle 20 starts moving at timing t11, the driving force Fd increases, and therefore the actual vehicle speed VS increases. When the vehicle 20 is traveling in this manner, the cruise control device 44 acquires the distance La from the first wheel 211 to the step 71. The imaging device 28 continuously transmits image data to the control system 40. Therefore, it is preferable for the cruise control device 44 to estimate the distance La based on, for example, a change in the size of the step 71 in the image data.

[0054] The driving control device 44 judges whether the distance La has become equal to or smaller than the distance judgment value LaTh. The distance that is the criterion for judging whether the first wheel 211 has come close to the step 71 is set as the distance judgment value LaTh. At the timing t12, the driving control device 44 judges that the distance La has become equal to or smaller than the distance judgment value LaTh. Then, the driving control device 44 increases the driving force command value FdTr based on the step height Hd included in the step-related information. For example, the driving control device 44 increases the driving force command value FdTr so that the driving force command value FdTr becomes a driving force corresponding to the step height Hd at the time when the first wheel 211 comes into contact with the step 71. The "driving force corresponding to the step height Hd" here is the driving force Fd when "Mmg=Mf".

[0055] The cruise control device 44 sets the braking force command value FbTr so that the actual vehicle speed VS does not exceed the target vehicle speed VSTr, thereby preventing the actual vehicle speed VS from significantly exceeding the target vehicle speed VSTr.

[0056] 8, the first wheel 211 comes into contact with the step 71 at timing t13. Then, the actual vehicle speed VS decreases, so the cruise control device 44 reduces the braking force command value FbTr to make the actual vehicle speed VS approach the target vehicle speed VSTr. As a result, the first wheel 211 goes over the step 71 at timing t14.

[0057] After the first wheel 211 has overcome the step 71, the cruise control device 44 reduces the driving force command value FdTr and increases the braking force command value FbTr in order to suppress sudden acceleration of the vehicle 20.

[0058] Then, at a subsequent timing t15, the vehicle 20 reaches the parking position, and the driving control device 44 stops the vehicle 20. Returning to FIG. 6, once the cruise control device 44 of the vehicle 20 has executed the first step passage process, the series of processes ends.

[0059] In step S123, the cruise control device 44 starts the vehicle 20, similar to step S15 described above. In the following step S125, the cruise control device 44 executes a second step passage process. The content of the second step passage process is similar to the step passage process of step S17 described above.

[0060] When the driving control device 44 ends the second step passing process, the process proceeds to step S127. In step S127, the driving control device 44 causes the communication device 30 to transmit step-related information to the server 11. The step-related information includes the current position information of the vehicle 20, the step height Hd calculated in step S125, and image data of the image of the step 71. In the following step S129, the driving control device 44 also registers the step-related information transmitted to the server 11 in its own memory. Then, the driving control device 44 ends the series of processes.

[0061] In step S147, the server control device 13 of the server 11 judges whether or not the communication device 12 has received the step-related information transmitted by the vehicle 20 in step S127 above. If the communication device 12 has not received the step-related information (S147: NO), the server control device 13 repeats the judgment of step S147 until the communication device 12 receives the step-related information. On the other hand, if the communication device 12 has received the step-related information (S147: YES), the server control device 13 shifts the process to step S149. In step S149, the server control device 13 registers the step-related information received by the communication device 12 in the second memory 17. Then, the server control device 13 ends the series of processes.

[0062] <Actions and Effects of the Present Embodiment> The operation and effects of this embodiment will be described with reference to FIGS. FIG. 7 is a timing chart in the case where there is no step-related information. As shown in (A), (B), (C), and (D) of FIG. 7, when the vehicle 20 starts at timing t1, the driving force Fd increases, and the actual vehicle speed VS increases. At timing t2 while the vehicle 20 is traveling, the first wheel 211 of the vehicle 20 contacts the step 71. Then, as shown in (A) of FIG. 7, the actual vehicle speed VS decreases. Then, the vehicle 20 stops at timing t3. This is because the driving force Fd of the vehicle 20 is less than the driving force corresponding to the height of the step 71. After timing t2, the driving force Fd of the vehicle 20 is increased. Then, the first wheel 211 goes over the step 71 at timing t3. At the subsequent timing t4, the vehicle 20 reaches the parking position, and the vehicle 20 stops.

[0063] In this way, without the step-related information, the length of the crossing completion period TM, which is the period from when the first wheel 211 comes into contact with the step 71 until the first wheel 211 crosses over the step 71, becomes long.

[0064] FIG. 8 is a timing chart in the case where there is step-related information. In the example shown in FIG. 8, the prescribed driving force FdB, which is the driving force Fd required for the first wheel 211 to get over the step 71, is known in advance. Therefore, the driving force Fd is increased toward the prescribed driving force FdB before the first wheel 211 comes into contact with the step 71. As a result, when the first wheel 211 comes into contact with the step 71, the first wheel 211 can get over the step 71 immediately. That is, in the example shown in FIG. 8, the length of the time of the getting-over completion period TM can be shortened compared to the example shown in FIG. 7. In the example shown in FIG. 8, the timing t13 is the time when the first wheel 211 comes into contact with the step 71. The timing t14 immediately after the timing t13 is the time when the first wheel 211 gets over the step 71.

[0065] Therefore, the driving assistance system 10 can appropriately control the driving force Fd when the vehicle 20 passes over the step 71. That is, the driving assistance system 10 can suppress sudden acceleration of the vehicle 20 when the first wheel 211 passes over the step 71, and suppress an increase in the time required for the first wheel 211 to pass over the step 71.

[0066] In this embodiment, the following effects can be further obtained. (1-1) When the vehicle 20 passes over a step 71, the driving control device 44 controls the driving force Fd and the braking force Fb based on step-related information related to the step 71 corresponding to the current position of the vehicle 20. This allows the driving support system 10 to more appropriately adjust the driving force Fd and the braking force Fb when the vehicle 20 passes over the step 71.

[0067] (1-2) The server 11 collects step-related information from a plurality of vehicles 20. Therefore, for example, when the first vehicle 201 is the target vehicle, step-related information generated by vehicles other than the first vehicle 201 can be provided to the cruise control device 44 of the first vehicle 201. In this case, the other vehicles are the second vehicle 202 and the third vehicle 203. As a result, even when the first vehicle 201 is caused to go over a step 71 that the first vehicle 201 has never gone over before, the cruise control device 44 of the first vehicle 201 can appropriately control the driving force Fd and braking force Fb of the first vehicle 201.

[0068] (1-3) The step-related information received from the server 11 is information acquired in the past. Therefore, the current shape of the step 71 may have changed significantly from the shape of the step when the step-related information was acquired in the past.

[0069] In this regard, in the driving support system 10, when the driving control device 44 acquires the step-related information from the server 11, it determines whether or not the step 71 detected in the traveling direction X1 of the vehicle 20 matches the step indicated by the step-related information. When the step 71 detected in the traveling direction X1 of the vehicle 20 matches the step indicated by the step-related information, the driving control device 44 controls the driving force Fd and the braking force Fb based on the step-related information. On the other hand, when the step 71 detected in the traveling direction X1 of the vehicle 20 does not match the step indicated by the step-related information, the driving control device 44 does not control the driving force Fd and the braking force Fb based on the step-related information. This allows the driving support system 10 to suppress unnatural behavior of the vehicle 20 when controlling the driving force Fd and the braking force Fb based on the step-related information.

[0070] (1-4) In the driving assistance system 10, step-related information relating to the step 71 present in the traveling direction X1 of the vehicle 20 may be stored in the memory of the driving control device 44. In this case, the driving control device 44 controls the driving force Fd and the braking force Fb based on the step-related information in its own memory. This allows the driving assistance system 10 to prevent communication between the vehicle 20 and the server 11 from increasing more than necessary.

[0071] Second embodiment A second embodiment of the driving support system will be described with reference to Fig. 9. In the second embodiment, the method of setting the driving force based on the step-related information is different from that of the first embodiment. In the following description, the parts different from the first embodiment will be mainly described, and the same reference numerals will be used to designate the same members as in the first embodiment, and duplicated description will be omitted.

[0072] The drive unit 22 of the vehicle 20 equipped with the cruise control device 44 includes an electric motor as a power source for the vehicle 20 . An example of the first step passage process will be described with reference to FIG.

[0073] As shown in (A), (B), (C), and (D) of Fig. 9, when the vehicle 20 starts moving at timing t21, the driving force Fd increases, and the actual vehicle speed VS increases. In the example shown in Fig. 9, the first wheel 211 comes into contact with the step 71 at timing t22. Then, the actual vehicle speed VS decreases, and the cruise control device 44 detects that the first wheel 211 has come into contact with the step 71. Then, the cruise control device 44 increases the driving force command value FdTr in one go to the specified driving force FdB, which is the driving force corresponding to the step height Hd.

[0074] Then, at timing t23, the first wheel 211 goes over the step 71. After the first wheel 211 goes over the step 71, the cruise control device 44 decreases the driving force command value FdTr and increases the braking force command value FbTr in order to suppress rapid acceleration of the vehicle 20. Then, at subsequent timing t24, the vehicle 20 reaches the parking position, so the cruise control device 44 stops the vehicle 20.

[0075] In this embodiment, it is possible to obtain the same functions and effects as the above-described embodiment. Third embodiment A third embodiment of the driving assistance system will be described with reference to Figures 10 and 11. The third embodiment differs from the above embodiments in that the server has a trained model, etc. In the following description, differences from the above embodiments will be mainly described, and the same reference numerals will be used to designate the same components as the above embodiments, and duplicated description will be omitted.

[0076] FIG. 10 illustrates the configuration of a server 11A of a driving support system 10A. The server 11A includes a communication device 12 and a server control device 13A. The server control device 13A includes a processing circuit 14A and a learning device 19. An example of the processing circuit 14A is an electronic control device. In this case, the processing circuit 14A includes a CPU 15, a first memory 16, and a second memory 17. The first memory 16 stores a control program executed by the CPU 15.

[0077] The learning device 19 has a trained model LM that has been subjected to machine learning to estimate the driving force Fd when the wheel goes over the step 71. For example, the trained model LM is a forward propagation type neural network. A learning method of the trained model LM will be described later.

[0078] The processing circuit 14A inputs image data included in the step-related information received from the vehicle 20 to the learned model LM. The learned model LM then outputs an index Y of the driving force Fd when the wheels go over the step 71. The processing circuit 14A generates generation information based on the index Y output from the learned model LM. For example, the processing circuit 14A generates the driving force Fd that can be estimated from the index Y as the generation information.

[0079] The index Y is output from the learned model LM when the step-related information is input to the learned model LM. Therefore, it can be said that the generated information generated from the index Y is information generated from the step-related information.

[0080] <Processing flow when passing a step> With reference to FIG. 11, the flow of processing when the vehicle 20 (target vehicle) passes through the step 71 will be described.

[0081] When the driver allows the vehicle 20 to start, in step S211, the cruise control device 44 of the vehicle 20 captures an image of the step 71 present in the traveling direction X1 of the vehicle 20. In the following step S213, the cruise control device 44 causes the communication device 30 to transmit step-related information including image data of the image of the step 71 and current position information of the vehicle 20 to the server 11A.

[0082] In step S241, the server control device 13A of the server 11A judges whether or not the communicator 12 has received the step-related information (i.e., the position information and image data) transmitted by the vehicle 20 in step S213 above. If the communicator 12 has not received the step-related information (S241: NO), the server control device 13A repeatedly executes the judgment of step S241 until the communicator 12 receives the step-related information. On the other hand, if the communicator 12 has received the step-related information (S241: YES), the server control device 13A transitions the process to step S243.

[0083] In step S243, the server control device 13A inputs the image data included in the received step-related information into the learned model LM. In the following step S245, the server control device 13A acquires the index Y output from the learned model LM. In the next step S247, the server control device 13A generates generation information based on the index Y. Then, in step S249, the server control device 13A causes the communication device 12 to transmit the generation information to the vehicle 20 (target vehicle). The driving force indicated by the generation information is referred to as the "learned driving force FdL."

[0084] In step S215, the driving control device 44 of the vehicle 20 (target vehicle) determines whether or not the communication device 30 has received the generation information transmitted by the server 11A in step S249. If the communication device 30 has not received the generation information (S215: NO), the driving control device 44 repeatedly executes the determination in step S215 until the communication device 30 receives the generation information. On the other hand, if the communication device 30 has received the generation information (S215: YES), the driving control device 44 transitions the process to step S217.

[0085] In step S217, the cruise control device 44 starts the vehicle 20, similarly to step S15 above. In the next step S219, the cruise control device 44 executes a step passing process. In the step passing process, the cruise control device 44 increases the driving force command value FdTr to the learned driving force FdL. At this time, the cruise control device 44 sets the braking force command value FbTr so that the actual vehicle speed VS does not exceed the target vehicle speed VSTr.

[0086] The cruise control device 44 acquires the driving force Fd at the time when the first wheel 211 goes over the step 71. If a braking force Fb is generated in the vehicle 20 at the time when the first wheel 211 goes over the step 71, the cruise control device 44 may acquire a value obtained by subtracting the braking force command value FbTr from the driving force command value FdTr at the time when the first wheel 211 goes over the step 71 as the driving force Fd at the time when the first wheel 211 goes over the step 71.

[0087] It is possible that even if the braking force Fb is 0 (zero) and the driving force Fd becomes the learned driving force FdL, the first wheel 211 will not overcome the step 71. In this case, the cruise control device 44 makes the first wheel 211 overcome the step 71 by making the driving force command value FdTr greater than the learned driving force FdL. Then, the cruise control device 44 acquires the driving force Fd at the time when the first wheel 211 overcomes the step 71. The driving force Fd acquired by the cruise control device 44 in the step passing process is referred to as the "passing braking force FdA."

[0088] When the travel control device 44 ends the step passing process, the process proceeds to step S221. In step S221, the travel control device 44 causes the communication device 30 to transmit the passing braking force FdA to the server 11A. Then, the travel control device 44 ends the series of processes.

[0089] When the generation information is transmitted in step S249, the server control device 13A of the server 11A shifts the process to step S251. In step S251, the server control device 13A judges whether or not the communication device 12 has received the passing braking force FdA transmitted by the vehicle 20 in the above step S221. If the communication device 12 has not received the passing braking force FdA (S251: NO), the server control device 13A repeats the judgment of step S251 until the communication device 12 receives the passing braking force FdA. On the other hand, if the communication device 12 has received the passing braking force FdA (S251: YES), the server control device 13A shifts the process to step S253.

[0090] In step S253, the server control device 13A applies machine learning to the learned model LM using the passing braking force FdA. For example, when the learned driving force FdL generated as the generation information in step S247 deviates from the passing braking force FdA, the server control device 13A applies machine learning so that the learned driving force FdL approaches the passing braking force FdA. When the learned model LM is a neural network, the server control device 13A may update the weight of the connection between each neuron and the threshold value of each neuron so that the learned driving force FdL approaches the passing braking force FdA. In other words, the server control device 13 re-learns the learned model LM. When the machine learning of the learned model LM is completed, the server control device 13A ends the series of processes.

[0091] <Actions and Effects of the Present Embodiment> (3-1) In the driving assistance system 10A, image data of an image showing a step 71 in the traveling direction X1 of the vehicle 20 (target vehicle) is input to the learned model LM to estimate a driving force required for the wheels of the vehicle 20 to overcome the step 71. That is, a learned driving force FdL is derived. Then, the driving device 22 of the vehicle 20 drives based on the learned driving force FdL, so that the wheels of the vehicle 20 can overcome the step 71. That is, even if step-related information related to the step 71 in the traveling direction X1 of the vehicle 20 (target vehicle) is not collected in the server 11A, the driving assistance system 10A can appropriately control the driving force Fd when the vehicle 20 passes over the step 71.

[0092] (3-2) In the driving assistance system 10, machine learning can be performed on the learned model LM using image data transmitted to the server 11A from multiple vehicles 20. This can improve the estimation accuracy of the driving force based on the index Y output from the learned model LM.

[0093] (Example of change) The above-described embodiments may be modified as follows: The above-described embodiments and the following modifications may be combined with each other to the extent that they are not technically inconsistent.

[0094] In the third embodiment, the trained model LM does not have to be a neural network. For example, the trained model may be a random forest that determines an index by majority voting of multiple decision trees.

[0095] In the third embodiment, the trained model may be a model that outputs an index of the height of the step 71 when image data is input. In this case, the server 11A estimates the height of the step 71 that exists in the traveling direction X1 of the vehicle 20 (target vehicle) based on the index of the trained model. Then, the server 11A or the cruise control device 44 estimates the driving force required for the wheels to overcome the step 71 based on the estimated height of the step 71.

[0096] In the third embodiment, the step-related information does not need to include position information of the vehicle 20 so long as it includes image data of the image of the step 71 . In the first and second embodiments, even if step-related information is stored in the memory of the cruise control device 44 of the vehicle 20 (target vehicle), the cruise control device 44 may perform a determination equivalent to the above step S117. That is, the cruise control device 44 may determine whether or not the step 71 detected in the traveling direction X1 of the vehicle 20 matches the step indicated by the step-related information stored in the cruise control device 44 itself.

[0097] In the first and second embodiments, the determination in step S117 in the series of processes executed by the cruise control device 44 shown in FIG. 6 may be omitted. In the first and second embodiments, the step-related information may include the driving force Fd when the wheels go over the step 71.

[0098] In the first and second embodiments, when the server 11 receives step-related information from the first vehicle 201 of the multiple vehicles 20, the server 11 may provide the step-related information to other vehicles other than the first vehicle 201. The other vehicles here are the second vehicle 202 and the third vehicle 203. It is preferable that the cruise control devices 44 of the other vehicles 202, 203 register the step-related information provided by the server 11 in their own memories. With this configuration, the vehicle 20 does not request the step-related information from the server 11 when the parking assistance process is executed.

[0099] In the first and second embodiments, the cruise control device 44 does not need to register step-related information in its own memory. In the first and second embodiments, when the server control device 13 acquires step-related information transmitted from the vehicle 20, the server control device 13 may calculate a specified driving force FdB, which is a driving force Fd required for the vehicle 20 to overcome the step 71, based on the step height Hd included in the step-related information. Then, the server control device 13 may register the specified driving force FdB in the second memory 17 together with the step-related information as generated information.

[0100] When reading out the step-related information from the second memory 17, the server control device 13 reads out generated information corresponding to the step-related information. Then, the server control device 13 may transmit the step-related information and the generated information to the vehicle 20 (target vehicle).

[0101] In this case, the driving control device 44 of the vehicle 20 (target vehicle) may control the driving force Fd using only the step-related information out of the step-related information and the generated information received from the server 11, or may control the driving force Fd using only the generated information. Of course, the driving control device 44 may control the driving force Fd using both the step-related information and the generated information.

[0102] The driving control device 44 and the processing circuits 14, 14A of the server control devices 13, 13A may be configured as circuits including one or more processors operating according to a computer program, one or more dedicated hardware circuits such as dedicated hardware for performing at least some of the various processes, or a combination of these. An example of the dedicated hardware is an ASIC, which is an application specific integrated circuit. The processor includes a CPU and memory such as RAM and ROM, and the memory stores program code or instructions configured to cause the CPU to perform the processes. The memory, i.e., the storage medium, includes any available medium accessible by a general-purpose or dedicated computer.

[0103] <Other technical ideas> The technical ideas that can be understood from the above-described embodiments and modifications will be described below. (i) It is preferable that the step-related information includes information indicating a change in driving force of the first vehicle when a wheel of the first vehicle goes over the step.

[0104] The term "at least one" used herein means "one or more" of the desired options. As an example, the term "at least one" used herein means "only one option" or "both of two options" if the number of options is two. As another example, the term "at least one" used herein means "only one option" or "any combination of two or more options" if the number of options is three or more. [Explanation of symbols]

[0105] 10,10A…Drive assistance system 11, 11A…Server (external device) 12...Communication device 13...Server control device 14, 14A…Processing circuit 19...Learning device 20, 201, 202, 203…Vehicles 28...Imaging device 30...Communication device (an example of an information transmission device) 40…Control system 43...Image analysis device (an example of a step detection device) 44...Drive control device 70…Driving area 71...Step LM: trained model

Claims

1. A driving assistance system that assists a vehicle in driving in a driving area having a step, and a driving control device that, when at least one target vehicle among a plurality of vehicles including a first vehicle and a second vehicle different from the first vehicle passes through the step, sets a driving force of the target vehicle based on step-related information that is information regarding the step and is acquired when the first vehicle passes through the step. Driving assistance system.

2. The step-related information includes information regarding a position where the step is provided, The driving control device sets a driving force of the target vehicle based on the step-related information related to the step corresponding to the position of the target vehicle when the target vehicle passes through the step. The driving assistance system according to claim 1 .

3. an information transmitting device provided in the first vehicle and configured to transmit the step-related information to an outside of the first vehicle; an external device that is provided outside the vehicle and receives the step-related information transmitted from the information transmission device, and when the target vehicle passes over the step, transmits at least one of the step-related information related to the step and generated information that is information generated from the step-related information to the target vehicle; The driving control device sets a driving force of the target vehicle based on at least one of the step-related information received from the external device and the generated information when the target vehicle passes over the step. The driving assistance system according to claim 2 .

4. A step detection device is provided in the target vehicle and detects a step that exists in a traveling direction of the target vehicle, When the step detected by the step detection device and the step indicated by the step-related information related to the step corresponding to the position of the target vehicle are consistent, the driving control device sets a driving force of the target vehicle based on the step-related information. The driving assistance system according to claim 2 or 3.

5. An imaging device is provided in the target vehicle and captures an image of a step that exists in a traveling direction of the target vehicle, the step-related information includes data of an image of the step, The external device is a trained model that outputs an index of a driving force when the target vehicle goes over the step when image data of the step is input; The generation information is generated based on the index output from the trained model when data of the image of the step captured by the imaging device is input to the trained model. The driving assistance system according to claim 3.

6. The trained model is a model that has been subjected to machine learning based on the step-related information transmitted from the information transmission device to the external device. The driving assistance system according to claim 5.

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