Driving support device, driving support method, and computer program for driving support

Abstract

To support vehicle driving according to attention levels that fluctuate according to surrounding conditions.SOLUTION: A driving support device determines whether the speed of a vehicle is higher than the allowable speed, which is determined using a representative value of the speeds of other vehicles that have passed a predetermined point in front of the vehicle during a predetermined period and a standard deviation of the speeds of the other vehicles. When the speed of the vehicle is determined to be higher than the allowable speed, the driving support device suggests a driver of the vehicle to change the speed set as the speed at which the vehicle is traveling to a lower speed or hold a steering member that accepts steering operations to steer the vehicle.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a driving assistance device, a driving assistance method, and a driving assistance computer program that assist a driver in driving a vehicle. [Background technology]

[0002] A driving control device that automatically controls at least one of the driver's operations for driving the vehicle based on surrounding data that represents the conditions surrounding the vehicle may request that the driver change control of at least some of the controlled operations depending on the conditions in which the vehicle is placed.

[0003] The mode switching assistance device described in Patent Document 1 acquires surrounding data that represents the surrounding conditions of the vehicle, and calculates a recommended mode switching position, which is a recommended position for mode switching to switch the vehicle's driving mode between a manual driving mode and an autonomous driving mode, based on the surrounding data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-146552 A Summary of the Invention [Problem to be solved by the invention]

[0005] A vehicle traveling at high speed in an area where other vehicles are traveling at low speed due to poor visibility or the presence of obstacles on the road is more likely to have an accident or other unforeseen event than other vehicles. Therefore, in such a situation, it is preferable for the vehicle to travel with a high level of caution. There is a demand for driving assistance that corresponds to the attention level that changes depending on such surrounding conditions.

[0006] An object of the present disclosure is to provide a driving assistance device that can assist in driving a vehicle in accordance with an attention level that changes depending on the surrounding situation. [Means for solving the problem]

[0007] The gist of the present disclosure is as follows.

[0008] (1) a speed determination unit that determines whether the speed of a vehicle is higher than an allowable speed that is calculated using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point ahead of the vehicle for a predetermined period of time; a suggestion unit that, when it is determined that the speed of the vehicle is higher than the permissible speed, suggests to a driver of the vehicle to lower a set speed set as a speed at which the vehicle travels, or to hold a steering member that accepts a steering operation for steering the vehicle; A driving assistance device comprising:

[0009] (2) A visibility determination unit that determines the presence or absence of poor visibility in an area including the specified point based on meteorological information indicating the presence or absence of weather conditions that cause poor visibility for each specified area, The driving assistance device described in (1) above, wherein, when it is determined that there is no poor visibility in the area including the specified point, the speed determination unit calculates the permissible speed by adding the product of the standard deviation of the speeds of the other vehicles and a first distribution coefficient to the average speeds of the other vehicles, and when it is determined that there is poor visibility in the area including the specified point, the speed determination unit calculates the permissible speed by adding the product of the standard deviation of the speeds of the other vehicles and a second distribution coefficient smaller than the first distribution coefficient to the average speeds of the other vehicles.

[0010] (3) The driving assistance device described in (2) above, wherein the suggestion unit suggests to the driver to change the set speed to a first speed when it is determined that there is no poor visibility in the area including the specified point, and suggests to the driver to change the set speed to a second speed lower than the first speed when it is determined that there is poor visibility in the area including the specified point.

[0011] (4) A driving assistance device, determining whether the speed of the vehicle is higher than an allowable speed calculated using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point ahead of the vehicle for a predetermined period of time; When it is determined that the speed of the vehicle is higher than the permissible speed, a suggestion is made to the driver of the vehicle to change a set speed set as a speed at which the vehicle travels to a lower speed or to hold a steering member that accepts a steering operation for steering the vehicle. A driving assistance method comprising:

[0012] (5) determining whether the speed of the vehicle is higher than an allowable speed calculated using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point ahead of the vehicle during a predetermined period of time; When it is determined that the speed of the vehicle is higher than the permissible speed, suggesting to a driver of the vehicle to lower a set speed set as a speed at which the vehicle travels, or to hold a steering member that accepts a steering operation for steering the vehicle; A driving assistance computer program for causing a computer installed in the vehicle to execute the above-mentioned.

[0013] According to the driving assistance device according to the present disclosure, it is possible to assist in driving a vehicle in accordance with the attention level that changes depending on the surrounding situation. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic configuration diagram of a data collection and distribution system. [Diagram 2] 1 is a schematic configuration diagram of a vehicle equipped with a driving assistance device; [Diagram 3] FIG. 2 is a hardware configuration diagram of the driving assistance device. [Figure 4] FIG. 2 is a functional block diagram of a processor included in the driving assistance device. [Diagram 5] 4 is a flowchart of a driving assistance process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a driving support device capable of supporting driving of a vehicle according to an attention level that varies according to surrounding conditions will be described in detail with reference to the drawings. The driving support device judges whether the speed of the vehicle is higher than an allowable speed obtained by using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point in front of the vehicle for a predetermined period of time. If it is judged that the speed of the vehicle is higher than the allowable speed, the driving support device suggests to the driver of the vehicle to lower the set speed set as the speed at which the vehicle travels, or to hold a steering member that accepts a steering operation to steer the vehicle.

[0016] 1 is a schematic diagram of a data collection and distribution system. The data collection and distribution system 1 has a plurality of vehicles 2 and a data collection and distribution device 3. Each of the plurality of vehicles 2 is communicatively connected to the data collection and distribution device 3 via the wireless base station WBS and the communication network NW by accessing a wireless base station WBS connected via a gateway (not shown) or the like to a communication network NW to which the data collection and distribution device 3 is connected. Hereinafter, one of the plurality of vehicles 2 is also referred to as "vehicle 2". In the data collection and distribution system 1, a plurality of wireless base stations WBS may be connected to the communication network NW.

[0017] Each of the multiple vehicles 2 generates surrounding data that indicates the surrounding conditions of each vehicle, such as the speed of other vehicles traveling in the vicinity, and transmits the data to the data collection and distribution device 3 via the wireless base station WBS and the communication network NW. The data collection and distribution device 3 generates road condition data that indicates the conditions, such as the representative speed and standard deviation of the vehicle at each position on the road, based on the surrounding data received from each of the multiple vehicles 2. Then, the data collection and distribution device 3 transmits the road condition data to each of the multiple vehicles 2 via the communication network NW and the wireless base station WBS. The surrounding data may include surrounding weather information that indicates the weather in the vicinity. The road condition data may include weather information that indicates the presence or absence of weather conditions that cause poor visibility for each predetermined area on the road. The data collection and distribution device 3 may obtain weather information from a weather information server (not shown) that has weather information for each predetermined area connected to the communication network NW, and transmit the road condition data to each of the multiple vehicles 2 by including the weather information in the road condition data.

[0018] FIG. 2 is a schematic configuration diagram of the vehicle 2.

[0019] The vehicle 2 includes a peripheral camera 21, a steering wheel 22, a steering controller 23, a speaker device 24, a vehicle speed sensor 25, a data communication module (DCM) 26, a GNSS (Global Navigation Satellite System) receiver 27, a storage device 28, and a driving support device 29. The peripheral camera 21, the steering controller 23, the vehicle speed sensor 25, the data communication module 26, the GNSS receiver 27, the storage device 28, and the driving support device 29 are communicatively connected to each other via an in-vehicle network conforming to a standard such as a controller area network.

[0020] The peripheral camera 21 is an example of a peripheral sensor for generating peripheral data representing the peripheral situation of the vehicle 2. The peripheral camera 21 has a two-dimensional detector configured with an array of photoelectric conversion elements sensitive to visible light, such as a CCD or a C-MOS, and an imaging optical system for forming an image of an area to be photographed on the two-dimensional detector. The peripheral camera 21 is disposed, for example, at the front upper part of the vehicle interior, facing forward. The peripheral camera 21 photographs the peripheral situation of the vehicle 2 through the windshield or rear window at a predetermined photographing period (for example, 1 / 30 seconds to 1 / 10 seconds), and outputs a peripheral image representing the peripheral situation. The vehicle 2 may have, as a peripheral sensor, a LiDAR (Light Detection And Ranging) sensor that generates a distance image in which each pixel has a value corresponding to the distance to an object represented in the pixel. The LiDAR sensor outputs the distance image as peripheral data.

[0021] The steering wheel 22 is an example of a steering member that accepts a steering operation by the driver to steer the vehicle 2. The steering wheel 22 outputs to the steering controller 23 a signal corresponding to an operation by the driver requesting the operation of a steering mechanism to steer the vehicle 2. An operation requesting the operation of the steering mechanism is, for example, an operation of rotating the steering wheel 22 clockwise or counterclockwise.

[0022] The steering controller 23 is an ECU (Electronic Control Unit) having a communication interface, a memory, and a processor. The steering controller 23 is an example of a control device provided in the vehicle 2, and receives a signal corresponding to the driver's operation and a steering hold signal from the steering wheel 22, and transmits them to the driving assistance device 29.

[0023] The speaker device 24 is an example of an output device, and includes, for example, an amplifier and a speaker unit. The speaker device 24 outputs a sound representing a message according to a signal received from the driving assistance device 29 via the in-vehicle network. The vehicle 2 may include, as an output device, a display device having a display for visibly displaying characters and figures. The output device may also be a light source that lights up in a pattern according to the content of the message, a vibrator that vibrates in a pattern according to the content of the message, or the like.

[0024] The vehicle speed sensor 25 generates a vehicle speed signal indicating the current speed of the vehicle 2 according to the rotation speed of the drive shaft. The vehicle speed sensor 25 outputs the vehicle speed signal to the driving assistance device 29 via the in-vehicle network at predetermined intervals. The vehicle speed sensor 25 may be connected to the in-vehicle network via a predetermined microprocessor.

[0025] The data communication module 26 is an example of a communication interface, and is a device that executes wireless communication processing conforming to a predetermined wireless communication standard such as 4G (4th Generation) or 5G (5th Generation). For example, the data communication module 26 accesses a wireless base station WBS, and is communicably connected to the data collection and distribution device 3 via the wireless base station WBS and the communication network NW. The data communication module 26 passes data included in a wireless signal received from the data collection and distribution device 3 to the driving assistance device 29. In addition, the data communication module 26 includes peripheral data received from the driving assistance device 29 in the wireless signal, and transmits the wireless signal to the data collection and distribution device 3. The data communication module 26 may be implemented as a part of the driving assistance device 29.

[0026] The GNSS receiver 27 is an example of a positioning sensor, and receives GNSS signals from GNSS satellites at predetermined intervals by a GNSS antenna (not shown), and determines the own position of the vehicle 2 based on the received GNSS signals. The GNSS receiver 27 outputs a positioning signal representing the positioning result of the own position of the vehicle 2 based on the GNSS signals to the driving assistance device 29 via the in-vehicle network at predetermined intervals.

[0027] The storage device 28 is an example of a storage unit, and includes, for example, a non-volatile semiconductor memory or a hard disk device. The storage device 28 stores a high-precision map. The high-precision map includes, for example, information representing lane markings that divide lanes in a predetermined area shown on the high-precision map. The high-precision map may further include information representing a speed limit set in the area.

[0028] The driving support device 29 is an ECU including a communication interface circuit, a memory, and a processor. The driving support device 29 calculates an allowable speed using a representative value and a standard deviation of the speeds of other vehicles, and when the speed of the vehicle 2 is higher than the allowable speed, makes a predetermined suggestion to the driver of the vehicle 2.

[0029] 3 is a diagram showing a hardware configuration of the driving support device 29. The driving support device 29 includes a communication interface circuit 291, a memory 292, and a processor 293.

[0030] The communication interface circuit 291 is an example of a communication interface, and has an interface circuit for connecting the driving support device 29 to the communication network NW. The communication interface circuit 291 is configured to be able to communicate with other devices via the communication network NW. That is, the communication interface circuit 291 passes data and the like received from other devices via the communication network NW to the processor 293. In addition, the communication interface circuit 291 transmits data and the like received from the processor 293 to other devices via the communication network NW.

[0031] The memory 292 is another example of a storage unit, and includes a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 292 stores various data used in processing by the processor 293, such as a distribution coefficient used to calculate an allowable speed for determining whether or not to make a predetermined suggestion to the driver based on the speed of the vehicle 2. The memory 292 also stores various application programs, such as a driving assistance computer program that makes a predetermined suggestion to the driver of the vehicle 2.

[0032] The processor 293 includes one or more central processing units (CPUs) and their peripheral circuits. The processor 293 may further include other arithmetic circuits such as a logic arithmetic unit or a numeric arithmetic unit.

[0033] FIG. 6 is a functional block diagram of the processor 293 included in the driving support device 29. As shown in FIG.

[0034] The processor 293 of the driving assistance device 29 has a driving control unit U1, a speed determination unit U2, and a proposal unit U3 as functional blocks. Each of these units of the processor 293 is a functional module implemented by a program executed on the processor 293. A computer program that realizes the functions of each unit of the processor 293 may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium, or an optical recording medium. Alternatively, each of these units of the processor 293 may be implemented in the driving assistance device 29 as an independent integrated circuit, a microprocessor, or firmware.

[0035] The travel control unit U1 causes the vehicle 2 to travel along the travel route at a speed equal to or less than a set speed.

[0036] The driving control unit U1 reads out information on lane markings in the vicinity of the vehicle's position, which is indicated in the positioning signal received from the GNSS receiver 27, from a storage device 28 that stores a high-precision map. The driving control unit U1 detects surrounding lane markings by inputting the surrounding images received from the surrounding camera 21 to a classifier. The driving control unit U1 also detects surrounding objects, such as other vehicles, by inputting the surrounding images received from the surrounding camera 21 to a classifier. The driving control unit U1 creates a driving route that maintains a predetermined distance from the lane markings and surrounding objects.

[0037] The classifier can be a convolutional neural network (CNN) having multiple convolution layers connected in series from the input side to the output side, such as YOLO (You Only Look Once) or SSD (Single Shot MultiBox Detector). Using a large number of images depicting objects such as vehicles and features such as lane markings as training data, the CNN is trained in advance according to a predetermined learning method such as backpropagation, so that the CNN operates as a classifier that detects lane markings and objects from images.

[0038] The driving control unit U1 determines the set speed as the speed at which the vehicle travels, according to information indicating the speed limit included in the high-precision map read from the storage device 28. The driving control unit U1 may determine the set speed according to the driver's operation to a speed setting reception unit (not shown). For example, the driving control unit U1 may determine the speed of the vehicle 2 when the driver's operation to the speed setting reception unit is detected as the set speed.

[0039] The travel control unit U1 outputs a control signal to a travel mechanism (not shown) of the vehicle 2 so that the vehicle 2 travels along the travel route at a speed equal to or less than a set speed. The travel mechanism includes, for example, an engine or a motor that supplies power to the vehicle 2, a brake that reduces the travel speed of the vehicle 2, and a steering mechanism that steers the vehicle 2.

[0040] The driver is not required to operate the driving mechanisms controlled by the driving control unit U1. For example, when the driving control unit U1 controls the steering mechanism, the driver can take his / her hands off the steering wheel 22 since there is no need to operate the steering wheel 22 to control the steering mechanism.

[0041] The functions executed by the driving control unit U1 may be implemented in an ECU different from the driving support device 29 connected to the in-vehicle network.

[0042] The speed determination unit U2 obtains road condition data including a representative value and a standard deviation of the speed of other vehicles that have traveled a predetermined point ahead on the travel route during a predetermined period from the data collection and distribution device 3 via the communication interface circuit 291 and the data communication module 26. The speed determination unit U2 may obtain the speeds of one or more other vehicles that have traveled a predetermined point ahead on the travel route during a predetermined period from the data collection and distribution device 3 as road condition data, and may obtain the representative value and the standard deviation. The representative value may be a statistical representative value such as an arithmetic mean value or a median value in the distribution of the speeds of other vehicles.

[0043] In addition, the speed determination unit U2 acquires a vehicle speed signal from the vehicle speed sensor 25 via the communication interface circuit 291.

[0044] The predetermined point ahead on the travel route is, for example, a position on the travel route of the vehicle 2 a predetermined time (e.g., one minute) later, which is estimated based on the speed indicated by the vehicle speed signal acquired from the vehicle speed sensor 25. The predetermined period is, for example, a period from a predetermined time before the current time to the current time.

[0045] The speed determination unit U2 determines the permissible speed using the representative value and standard deviation of the speeds of other vehicles acquired via the communication interface circuit 291 and the data communication module 26. For example, the speed determination unit U2 determines the permissible speed by multiplying the standard deviation of the speeds of other vehicles by a distribution coefficient (e.g., 1.0) stored in the memory 292, and adding the representative value of the speeds of other vehicles to the resultant value.

[0046] The speed determination unit U2 determines whether or not the speed of the vehicle 2 indicated by the vehicle speed signal acquired from the vehicle speed sensor 25 is higher than an allowable speed.

[0047] When it is determined that the speed of the vehicle 2 is higher than the allowable speed, the suggestion unit U3 suggests to the driver of the vehicle 2 to lower the set speed used in the driving control of the vehicle 2 by the driving control unit U1. Instead of or in addition to changing the set speed described above, the suggestion unit U3 may suggest to the driver to hold the steering wheel 22.

[0048] The suggestion unit U3 makes suggestions to the driver by playing, from the speaker device 24, suggestion voices including suggestion messages such as "Please change the set speed to a lower speed" or "Please hold the steering wheel."

[0049] The suggestion unit U3 may make a suggestion to the driver by displaying a suggestion image including a suggestion message such as "Please lower the set speed" or "Please hold the steering wheel" on the display device. The suggestion unit U3 may also make a suggestion to the driver by lighting a light source in a pattern corresponding to the content of the message or vibrating a vibrator in a pattern corresponding to the content of the message.

[0050] When suggesting to the driver to change the set speed to a lower value, the suggestion unit U3 may indicate a specific change amount to the driver. For example, the suggestion unit U3 suggests to the driver to change the set speed to an allowable speed. In this case, the suggestion unit U3 may indicate the changed set speed as a specific speed (e.g., 100 km / h) or may indicate the difference from the current set speed (e.g., a speed reduction of 10 km / h).

[0051] Fig. 5 is a flowchart of the driving support process. The processor 293 of the driving support device 29 executes the driving support process shown in Fig. 5 at a predetermined time interval (e.g., 1 / 10 second interval) while the driving of the vehicle 2 is controlled by the driving control unit U1 of the processor 293.

[0052] First, the speed determination unit U2 of the processor 293 determines the allowable speed using a representative value and standard deviation of the speeds of other vehicles that have traveled through a specified point ahead on the travel route during a specified period of time, which are obtained via the communication interface circuit 291 (step S1).

[0053] Next, the speed determination unit U2 determines whether or not the speed of the vehicle 2 indicated in the vehicle speed information acquired from the vehicle speed sensor 25 is higher than the allowable speed (step S2). If it is determined that the speed of the vehicle 2 is not higher than the allowable speed (step S2: N), the processor 293 ends the driving assistance process.

[0054] If it is determined that the speed of the vehicle 2 is higher than the permissible speed (step S2: Y), the suggestion unit U3 of the processor 293 suggests to the driver to lower the set speed or to hold the steering wheel 22 (step S3).

[0055] The driving control unit U1 of the processor 293 causes the vehicle 2 to drive along the driving route at a speed equal to or lower than the set speed (step S4), and ends the driving assistance process.

[0056] By executing the driving assistance process in this manner, the driving assistance device 29 can assist in driving the vehicle in accordance with the attention level that changes depending on the surrounding situation.

[0057] According to a modified example, the processor of the driving assistance device further includes a visibility determination unit as a functional block. The visibility determination unit determines whether or not there is poor visibility in an area including a predetermined point based on meteorological information included in the road condition data acquired via the communication interface circuit 291 and the data communication module 26.

[0058] For example, if the weather information for a certain area indicates fog or rain, the visibility determining unit determines that there is poor visibility in that area.

[0059] In this modification, the speed determination unit U2 changes the distribution coefficient used to calculate the permissible speed depending on the presence or absence of poor visibility in the area including the specified point. Specifically, when it is determined that there is poor visibility in the area including the specified point, the speed determination unit U2 calculates the permissible speed using a distribution coefficient (e.g., 0.3) smaller than the distribution coefficient (e.g., 1.0) when it is determined that there is no poor visibility. The distribution coefficient when it is determined that there is no poor visibility is an example of a first distribution coefficient, and the distribution coefficient when it is determined that there is poor visibility is an example of a second distribution coefficient.

[0060] In this modified example, the suggestion unit U3 may change the set speed that is proposed to be changed to the driver depending on the presence or absence of poor visibility in the area including the specified point. Specifically, when it is determined that there is poor visibility in the area including the specified point, the suggestion unit U3 suggests to the driver to change the set speed (for example, a representative value of the speed of other vehicles) that is lower than the set speed (for example, an allowable speed) when it is determined that there is no poor visibility. The speed proposed when it is determined that there is no poor visibility is an example of a first speed, and the speed proposed when it is determined that there is poor visibility is an example of a second speed.

[0061] The driving assistance device according to the modified example can assist in driving a vehicle according to the attention level that changes depending on the presence or absence of visibility.

[0062] It should be understood that those skilled in the art can make various changes, substitutions, and alterations thereto without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0063] 29 Driving support devices U1 Driving control unit U2 Speed ​​judgment section U3 Proposal Department

Claims

1. a speed determination unit that determines whether the speed of the vehicle is higher than an allowable speed that is calculated using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point ahead of the vehicle during a predetermined period of time; a suggestion unit that, when it is determined that the speed of the vehicle is higher than the permissible speed, suggests to a driver of the vehicle to lower a set speed set as a speed at which the vehicle travels, or to hold a steering member that accepts a steering operation for steering the vehicle; A driving assistance device comprising:

2. A visibility determination unit determines whether or not there is poor visibility in an area including the predetermined point based on meteorological information indicating whether or not there is a weather condition that causes poor visibility for each predetermined area, 2. The driving assistance device according to claim 1, wherein, when it is determined that there is no poor visibility in the area including the specified point, the speed determination unit calculates the permissible speed by adding a product of the standard deviation of the speeds of the other vehicles and a first distribution coefficient to an average of the speeds of the other vehicles, and when it is determined that there is poor visibility in the area including the specified point, the speed determination unit calculates the permissible speed by adding a product of the standard deviation of the speeds of the other vehicles and a second distribution coefficient smaller than the first distribution coefficient to the average of the speeds of the other vehicles.

3. 3. The driving assistance device according to claim 2, wherein the suggestion unit suggests to the driver to change the set speed to a first speed when it is determined that there is no poor visibility in the area including the specified point, and suggests to the driver to change the set speed to a second speed lower than the first speed when it is determined that there is poor visibility in the area including the specified point.

4. Driving assistance devices, determining whether the speed of the vehicle is higher than an allowable speed calculated using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point ahead of the vehicle for a predetermined period of time; When it is determined that the speed of the vehicle is higher than the permissible speed, a suggestion is made to the driver of the vehicle to change a set speed set as a speed at which the vehicle travels to a lower speed or to hold a steering member that accepts a steering operation for steering the vehicle. A driving assistance method comprising:

5. Determining whether the speed of the vehicle is higher than an allowable speed obtained using a representative value and a standard deviation of the speeds of other vehicles that have passed a predetermined point ahead of the vehicle for a predetermined period of time; When it is determined that the speed of the vehicle is higher than the permissible speed, suggesting to a driver of the vehicle to lower a set speed set as a speed at which the vehicle travels, or to hold a steering member that accepts a steering operation for steering the vehicle; A driving assistance computer program for causing a computer installed in the vehicle to execute the above-mentioned.

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