Driving assistance method and driving assistance system

Abstract

The present disclosure relates to a driving assistance method and a driving assistance system. A driving assistance method applied to a vehicle includes: reading out a speed limit at a travel position of the vehicle from map information in which the speed limit is registered; displaying the speed limit read out from the map information on a display device; and in a first section in which a temporary speed limit is set, invalidating an update of the speed limit displayed on the display device based on the map information even if the speed limit registered in the map information has changed.

Description

Technical Field

[0001] This disclosure relates to driving assistance methods and systems applied to vehicles. In particular, this disclosure relates to techniques for displaying speed limits on a display device. Background Technology

[0002] Japanese Patent Application Publication No. 2012-164254 discloses a sign recognition device mounted on a vehicle. The sign recognition device identifies road signs based on image data obtained through an onboard camera. Based on the location of the identified road sign and map information, the device determines whether the identified road sign is a fixed sign or a temporary sign.

[0003] Japanese Patent Application Publication No. 2017-215902 discloses a speed limit display device for vehicles. The speed limit display device includes a display unit capable of displaying the speed limit of the road on which the vehicle is traveling.

[0004] Information regarding the speed limit at the vehicle's location is useful for both the driver and remote operator. From a driver assistance perspective, it is preferable to display the speed limit on the display device for the benefit of both the driver and remote operator. In this case, map information containing speed limits can be utilized. Specifically, the speed limit at the vehicle's location can be read from map information and displayed on the display device. This allows speed limit information to be displayed even in areas where no speed limit signs are present.

[0005] On the other hand, there are also scenarios where temporary speed limits are set in place of pre-set speed limits. For example, temporary speed limits are sometimes set in road construction zones instead of pre-set speed limits. Other examples include setting temporary speed limits based on weather conditions or time of day. Such temporary speed limits are not registered in the map information. Therefore, when updating the speed limits displayed on the display device based on pre-set speed limits read from the map information, an incorrect speed limit deviating from the actual (temporary) speed limit may be displayed. Summary of the Invention

[0006] This disclosure provides a driving assistance method and a driving assistance system that can suppress erroneous speed limits that deviate from actual conditions and display them on a display device.

[0007] The first solution of this disclosure, a driving assistance method for a vehicle, includes: reading the speed limit at the vehicle's driving position from map information that registers speed limits; displaying the speed limit read from the map information on a display device; and in a first interval where a temporary speed limit is set, even if the speed limit registered in the map information changes, invalidating the update of the speed limit displayed on the display device based on the map information.

[0008] Alternatively, the driving assistance method of the first embodiment of this disclosure may further include: identifying the first interval based on images of the vehicle’s surroundings obtained by a camera mounted on the vehicle.

[0009] Alternatively, in the driving assistance method of the first embodiment of this disclosure, identifying the first interval includes: identifying a first marker indicating the start of the first interval based on the image, thereby identifying the start of the first interval.

[0010] Alternatively, in the driving assistance method of the first embodiment of this disclosure, the first sign may be any of the following: a road construction sign indicating the start of a road construction section; a variable electro-optical sign that may variably display the speed limit; and a speed limit sign with an auxiliary sign indicating the application conditions of the speed limit.

[0011] Alternatively, the driving assistance method of the first embodiment of this disclosure may further include: displaying the temporary speed limit on the display device in the first interval when the first sign indicates the temporary speed limit.

[0012] Alternatively, in the driving assistance method of the first embodiment of this disclosure, identifying the first interval includes: identifying a second marker indicating the end of the first interval based on the image, thereby identifying the end of the first interval.

[0013] Alternatively, the driving assistance method of the first embodiment of this disclosure may further include: determining that the first interval has ended when the termination condition is met. Alternatively, the termination condition may include at least one of the following conditions: the vehicle has made a left turn or a right turn; the vehicle has traveled a certain distance from the beginning of the first interval; and a sign indicating the end of the first interval has been identified.

[0014] Alternatively, the driving assistance method of the first embodiment of this disclosure may further include: issuing a warning to the driver of the vehicle when the vehicle's speed exceeds the speed limit displayed on the display device.

[0015] The second aspect of this disclosure provides a driver assistance system for vehicles, comprising: one or more storage devices configured to store map information with registered speed limits; and one or more processors. The one or more processors are configured to: read the speed limit at the vehicle's location from the map information; display the speed limit read from the map information on a display device; and, within a first interval where temporary speed limits are set, invalidate updates to the speed limits displayed on the display device based on the map information even if the speed limit registered in the map information changes.

[0016] According to this disclosure, in a first interval where a temporary speed limit is set, even if the speed limit registered in the map information changes, the speed limit displayed on the display device will not be updated. This prevents erroneous speed limits that deviate from the actual situation from being displayed. Attached Figure Description

[0017] Hereinafter, with reference to the accompanying drawings, the features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described, wherein the same reference numerals denote the same elements, wherein:

[0018] Figure 1 This is a conceptual diagram used to illustrate an overview of a driver assistance system applied to a vehicle according to embodiments of the present disclosure.

[0019] Figure 2 This is a conceptual diagram used to illustrate the map-based speed limit display processing of embodiments of this disclosure.

[0020] Figure 3 This is a conceptual diagram used to illustrate an example of a temporarily restricted speed range.

[0021] Figure 4 It is a concept map used to illustrate comparative examples.

[0022] Figure 5 This is a conceptual diagram illustrating an example of a display update invalidation process for an embodiment of this disclosure.

[0023] Figure 6 This is a block diagram illustrating an example configuration of a driving assistance system according to an embodiment of the present disclosure.

[0024] Figure 7 This is a block diagram illustrating an example of driving environment information according to an embodiment of the present disclosure.

[0025] Figure 8 This is a flowchart illustrating the process associated with the speed limit display process in an embodiment of this disclosure.

[0026] Figure 9 This is a flowchart illustrating the process associated with the speed limit display process in an embodiment of this disclosure. Detailed Implementation

[0027] The embodiments of this disclosure will be described with reference to the accompanying drawings.

[0028] 1. Summary

[0029] Figure 1 This is a conceptual diagram illustrating an overview of the driving assistance system 10 applied to vehicle 1 according to this embodiment. The driving assistance system 10 assists in driving vehicle 1. For example, the driving assistance system 10 is mounted on vehicle 1. Alternatively, at least a portion of the driving assistance system 10 may be included in a remote system external to vehicle 1, remotely assisting in driving vehicle 1. That is, the driving assistance system 10 may also be distributed between vehicle 1 and the remote system. Vehicle 1 may also be the object of remote operation performed by a remote operator. In this case, vehicle 1 communicates with a remote operator terminal on the remote operator side, exchanging information required for remote operation. Furthermore, the driving assistance system 10 of this disclosure can also be applied to vehicle 1 performing partially automated driving.

[0030] In the following description, we consider the case where a driver is riding in vehicle 1 and driving vehicle 1. In the case of remote operation by a remote operator, "driver" will be replaced with "remote operator" and "display device mounted on vehicle 1" will be replaced with "display device of remote operator terminal on the remote operator side".

[0031] The driver assistance system 10 includes a display device 30 mounted on the vehicle 1. The driver assistance system 10 assists the driver in driving the vehicle 1 by displaying various information on the display device 30. For example, the driver assistance system 10 displays the speed limit at the vehicle 1's current position on the display device 30. This speed limit information is useful to the driver of the vehicle 1. Hereinafter, the process of displaying the speed limit on the vehicle 1's display device 30 will be referred to as "speed limit display processing".

[0032] Speed ​​limit information is obtained, for example, from speed limit signs S0 set along the road. A camera C is installed in vehicle 1 to capture images of the surroundings of vehicle 1. Driving assistance system 10 acquires images of the surroundings of vehicle 1 using camera C. Driving assistance system 10 identifies the speed limit sign S0 based on the acquired images. Furthermore, driving assistance system 10 identifies (reads) the speed limit recorded on speed limit sign S0 based on the acquired images. Then, driving assistance system 10 displays the speed limit obtained from speed limit sign S0 on display device 30.

[0033] However, the frequency of setting speed limit signs S0 along the road is not necessarily high. In addition, depending on the situation, the speed limit sign S0 may not be accurately identified by camera C.

[0034] Therefore, according to this embodiment, a "map information MAP" is also utilized in the speed limit display processing. The map information MAP registers pre-set speed limits for roads. Hereinafter, the speed limit registered in the map information MAP will be referred to as the "prescribed speed limit LM". That is, the map information MAP represents the location and the prescribed speed limit LM in a correlated manner. In other words, the map information MAP represents the prescribed speed limit LM as a function of location. Here, "location" includes concepts such as intervals and regions. Location and road category can also be correlated in the map information MAP. It should be noted that the map information MAP can be stored either in the vehicle 1's storage device or in the storage device of an external map management system for the vehicle 1.

[0035] Figure 2 This is a conceptual diagram illustrating the speed limit display processing based on map information (MAP). The driver assistance system 10 reads the prescribed speed limit LM at the vehicle 1's current location from the map information (MAP). The driver assistance system 10 displays the prescribed speed limit LM read from the map information (MAP) on the display device 30. The speed limit boundary (BD) is the location where the prescribed speed limit LM is switched. If the road category changes, the prescribed speed limit LM will generally also change. However, the switching of the prescribed speed limit LM is not limited to this. The driver assistance system 10 updates the prescribed speed limit LM displayed on the display device 30 in conjunction with the vehicle 1 passing through the speed limit boundary (BD). For example, the driver assistance system 10 updates the prescribed speed limit LM displayed on the display device 30 immediately before or immediately after the vehicle 1 passes through the speed limit boundary (BD).

[0036] By utilizing map information (MAP) in this way, the prescribed speed limit (LM) can be displayed even in areas where no speed limit sign (S0) is set. Furthermore, the prescribed speed limit (LM) can be displayed even when the speed limit sign (S0) cannot be identified by camera (C).

[0037] However, there are also scenarios where a temporary speed limit is set instead of the prescribed speed limit LM. Hereinafter, the temporary speed limit that is not the prescribed speed limit LM will be referred to as the "temporary speed limit LMtemp". The interval with the temporary speed limit LMtemp will be referred to as the "temporary speed limit interval X1" (first interval).

[0038] Figure 3This is a conceptual diagram used to illustrate an example of a temporary speed limit zone X1. For instance, generally, the speed limit in a road construction zone is set lower than the prescribed speed limit LM. The start of a road construction zone is usually indicated by a road construction sign. A speed limit sign indicating the temporary speed limit LMtemp applied to that road construction zone is sometimes also attached to the road construction sign.

[0039] As another example, the temporary speed limit LMtemp may sometimes be set variably based on weather conditions and time of day. Such a temporary speed limit LMtemp may be indicated, for example, by displaying a variable electro-optical sign. As another example, auxiliary signs indicating the application conditions of the temporary speed limit LMtemp may sometimes be attached to the speed limit sign.

[0040] The temporary speed limit LMtemp is not registered in the map information MAP. Therefore, when the speed limit displayed on the display device 30 is updated based on the specified speed limit LM read from the map information MAP, an incorrect speed limit that deviates from the actual situation (temporary speed limit LMtemp) will be displayed.

[0041] Figure 4 This is a conceptual diagram used to illustrate a comparative example. A temporary speed limit zone X1 exists in front of vehicle 1. Within this temporary speed limit zone X1, there is a speed limit boundary BD where the prescribed speed limit LM is switched. In the comparative example, when vehicle 1 passes through the speed limit boundary BD, the speed limit displayed on display device 30 is updated based on map information MAP. However, the prescribed speed limit LM read from map information MAP differs from the temporary speed limit LMtemp set for the temporary speed limit zone X1. That is, an incorrect speed limit deviating from the actual situation (temporary speed limit LMtemp) is displayed on display device 30. From a driver assistance point of view, it is not preferable for a speed limit deviating from the actual situation (temporary speed limit LMtemp) to be displayed on display device 30.

[0042] Therefore, the driving assistance system 10 of this embodiment is configured to suppress the display of erroneous speed limits that deviate from the actual situation on the display device 30. More specifically, even if the prescribed speed limit LM registered in the map information MAP changes within the temporary speed limit range X1, the driving assistance system 10 invalidates the update of the speed limit displayed on the display device 30 (based on the map information MAP). Hereinafter, this process will be referred to as "display update invalidation processing".

[0043] Figure 5This is a conceptual diagram illustrating an example of display update invalidation processing. A temporary speed limit zone X1 exists in front of vehicle 1. Near the start of the temporary speed limit zone X1, there is a first marker S1 indicating the start of the temporary speed limit zone X1. An example of the first marker S1 is shown below. Figure 3 The sign shown. The driver assistance system 10 uses camera C to identify the first sign S1, thereby identifying the start of the temporary speed limit zone X1. When the first sign S1 indicates a temporary speed limit LMtemp, the driver assistance system 10 can display the temporary speed limit LMtemp read from the first sign S1 on the display device 30. While driving in the temporary speed limit zone X1, the vehicle 1 passes through the speed limit boundary BD. That is, while the vehicle 1 is driving in the temporary speed limit zone X1, the prescribed speed limit LM changes. Even in this case, the driver assistance system 10 invalidates the speed limit updated and displayed on the display device 30 based on map information MAP.

[0044] As explained above, according to this embodiment, within the temporary speed limit range X1 where a temporary speed limit LMtemp is set, even if the specified speed limit LM registered in the map information MAP changes, the speed limit displayed on the display device 30 will not be updated. Therefore, erroneous speed limits that deviate from the actual situation (temporary speed limit LMtemp) are prevented from being displayed on the display device 30.

[0045] The driving assistance system 10 of this embodiment will be described in further detail below.

[0046] 2. Examples of driver assistance systems

[0047] 2-1. Example of composition

[0048] Figure 6 This is a block diagram illustrating an example configuration of the driving assistance system 10 according to this embodiment. The driving assistance system 10 includes a sensor group 20, a display device 30, an alarm device 40, a driving device 50, and a control device 100.

[0049] The sensor group 20 is mounted on the vehicle 1. The sensor group 20 includes an identification sensor 21, a vehicle status sensor 22, a position sensor 23, etc.

[0050] The identification sensor 21 identifies (detects) the surrounding conditions of the vehicle 1. The identification sensor 21 includes a camera C. The identification sensor 21 may also include a LIDAR (Laser Imaging Detection and Ranging) sensor, radar, etc.

[0051] The vehicle status sensor 22 detects the status of the vehicle 1. For example, the vehicle status sensor 22 includes a speed sensor, an acceleration sensor, a yaw rate sensor, a rudder angle sensor, etc.

[0052] Position sensor 23 detects the position and orientation of vehicle 1. For example, a GPS (Global Positioning System) sensor is shown as position sensor 23.

[0053] The display device 30 (shower) is mounted on the vehicle 1 and displays various information. The display device 30 is positioned in a location visible to the driver of the vehicle 1. For example, the display device 30 is included in the instrument panel. As another example, the display device 30 may also be a head-up display (HUD).

[0054] Alarm device 40 is mounted on vehicle 1 and outputs an alarm via visual or audible means. For example, alarm device 40 includes a display device. As another example, alarm device 40 includes a speaker. Alarm device 40 may also be identical to display device 30.

[0055] The driving mechanism 50 includes a steering mechanism, a drive mechanism, and a braking mechanism. The steering mechanism turns the wheels. For example, the steering mechanism includes an electric power steering (EPS) system. The drive mechanism is the power source that generates driving force. Examples of drive mechanisms include engines, electric motors, and in-wheel motors. The braking mechanism generates braking force.

[0056] The control device 100 controls the vehicle 1. The control device 100 includes one or more processors 110 (hereinafter simply referred to as processor 110) and one or more storage devices 120 (hereinafter simply referred to as storage device 120). The processor 110 performs various processes. For example, the processor 110 includes a CPU (Central Processing Unit). The storage device 120 stores various information. Examples of storage devices 120 include volatile memory, non-volatile memory, HDD (Hard Disk Drive), SSD (Solid State Drive), etc. The control device 100 may also include one or more ECUs (Electronic Control Units). A portion of the control device 100 may also be an external information processing device to the vehicle 1. In this case, a portion of the control device 100 communicates with the vehicle 1 and remotely controls the vehicle 1.

[0057] The driver assistance program PROG is a computer program used to control vehicle 1. The processor 110 executes the driver assistance program PROG to perform various processes via the control device 100. The driver assistance program PROG is stored in the storage device 120. Alternatively, the driver assistance program PROG may be recorded on a computer-readable recording medium.

[0058] 2-2. Driving Environment Information

[0059] The control device 100 acquires driving environment information 200 representing the driving environment of the vehicle 1. The driving environment information 200 is stored in the storage device 120.

[0060] Figure 7 This is a block diagram representing an example of driving environment information 200. Driving environment information 200 includes map information MAP, surrounding conditions information 210, vehicle status information 220, and vehicle location information 230.

[0061] The map information MAP includes general navigation maps. The map information MAP can also represent lane configurations and road shapes. The map information MAP can also include location information for structures, traffic lights, signs, etc. Furthermore, the speed limit LM is registered in the map information MAP. That is, the map information MAP represents a location and the speed limit LM in a correlated manner. Location and road category can also be correlated in the map information MAP. The control device 100 retrieves the map information MAP for the required zone from the map information database. The map information database can be stored either in the storage device 120 or in a map management system external to the vehicle 1. In the latter case, the control device 100 communicates with the map management system to retrieve the required map information MAP.

[0062] Surrounding conditions information 210 is information indicating the conditions surrounding vehicle 1. Control device 100 uses recognition sensor 21 to recognize the conditions surrounding vehicle 1 and acquire surrounding conditions information 210. For example, surrounding conditions information 210 includes an image (IMG) captured by camera C. As another example, surrounding conditions information 210 includes point cluster information obtained by a LiDAR sensor.

[0063] The surrounding environment information 210 also includes object information related to objects around vehicle 1. Examples of objects include pedestrians, bicycles, other vehicles (vehicles ahead, parked vehicles, etc.), white lines, signs, traffic lights, structures, etc. Object information represents the relative position and relative speed of an object relative to vehicle 1. For example, objects can be identified and their relative positions calculated by analyzing an image (IMG) obtained by camera C. Alternatively, objects can be identified and their relative positions and speeds obtained based on point cluster information obtained by a LiDAR sensor.

[0064] In particular, the sign information SGN is object information related to signs present around vehicle 1. Signs include general speed limit signs S0 placed along the road (see reference). Figure 1 Furthermore, the sign includes a first sign S1 indicating the start of a temporary speed limit zone X1. Examples of the first sign S1 include a road construction sign indicating the start of a road construction zone, a variable-speed electro-optical sign that variably displays the speed limit, and a speed limit sign with an auxiliary sign indicating the application conditions of the speed limit (see reference). Figure 3 Furthermore, the sign includes a second sign indicating the end of the temporary speed limit interval X1. The sign information SGN indicates the relative position and type of the sign. The sign information SGN can also indicate the content of the sign (speed limit, etc.). The control device 100 acquires the sign information SGN based on the image IMG obtained through the camera C. For example, the control device 100 can utilize image recognition AI (Artificial Intelligence) obtained through machine learning to identify the signs, their type, and their content within the image IMG.

[0065] Vehicle status information 220 indicates the status of vehicle 1. Vehicle status information 220 includes vehicle speed, acceleration, yaw rate, steering angle, etc. Control device 100 acquires vehicle status information 220 from vehicle status sensor 22.

[0066] Vehicle position information 230 indicates the current position of vehicle 1. Control device 100 obtains vehicle position information 230 from the detection results obtained by position sensor 23. In addition, control device 100 can also obtain high-precision vehicle position information 230 by utilizing well-known localization processing that utilizes object information and map information (MAP).

[0067] 2-3. Speed ​​Limit Display Processing

[0068] The control device 100 performs speed limit display processing to display the speed limit on the display device 30. For example, the control device 100 displays the speed limit obtained from the speed limit flag S0 on the display device 30 based on the flag information SGN. As another example, the control device 100 may also display the temporary speed limit LMtemp obtained from the first flag S1 on the display device 30 based on the flag information SGN. Moreover, the control device 100 performs speed limit display processing based on map information MAP. The speed limit display processing based on map information MAP will be explained again in Section 3 below.

[0069] 2-4. Warning Handling

[0070] The control device 100 can issue a warning to the driver via the alarm device 40. For example, the control device 100 compares the current speed of the vehicle 1 with the speed limit at the current driving position. The current speed of the vehicle 1 is obtained from the vehicle status information 220. The speed limit is the speed limit displayed on the display device 30, which is either a fixed speed limit LM or a temporary speed limit LMtemp. If the current speed of the vehicle 1 exceeds the speed limit, the control device 100 issues a warning to the driver via the alarm device 40.

[0071] 2-5. Vehicle Driving Control

[0072] The control device 100 performs vehicle driving control to control the movement of the vehicle 1. The vehicle driving control includes steering control, acceleration control, and deceleration control. The control device 100 performs vehicle driving control by controlling the driving device 50 (steering device, drive device, and braking device).

[0073] The control device 100 can also perform adaptive speed control based on a speed limit to control the speed of the vehicle 1. The speed limit here is the speed limit displayed on the display device 30, which is either a predetermined speed limit LM or a temporary speed limit LMtemp. For example, the control device 100 performs adaptive cruise control (ACC) based on the speed limit. As another example, the control device 100 can also automatically control the vehicle speed below the speed limit.

[0074] 3. Processing associated with speed limit display processing

[0075] Figure 8 This is a flowchart illustrating the process used to identify the temporary speed limit zone X1. It can begin when vehicle 1 starts moving. Figure 8 The process.

[0076] In step S110, the control device 100 determines, based on the sign information SGN, whether a first sign S1 exists around the vehicle 1 (typically in front of the vehicle 1). The first sign S1 is a sign indicating the beginning of a temporary speed restriction zone X1. For example, the first sign S1 is any of the following signs: a road construction sign indicating the beginning of a road construction zone; a variable electro-optical sign that variably displays a speed limit; and a speed restriction sign with an auxiliary sign indicating the application conditions of the speed limit (see reference). Figure 3 As described above, the first marker S1 can be identified based on the image IMG obtained by the camera C mounted on the vehicle 1. If the first marker S1 is present around the vehicle 1 (step S110: Yes), the process proceeds to step S120. Otherwise (step S110: No), the processing in this loop ends.

[0077] In step S120, the control device 100 identifies the area following the first marker S1 as a temporary speed limit area X1. If vehicle 1 is located within the area following the first marker S1, the control device 100 determines that vehicle 1 is within the temporary speed limit area X1. Then, the process proceeds to step S130.

[0078] In step S130, the control device 100 determines whether the termination condition is met. The termination condition is used to determine the end of the temporary speed limit interval X1.

[0079] The first example of the termination condition is "Vehicle 1 made a right or left turn". The right or left turn of Vehicle 1 can be sensed based on vehicle position information 230 and map information MAP. Alternatively, the right or left turn of Vehicle 1 can also be sensed based on vehicle status information 220 (vehicle speed, steering angle, etc.).

[0080] The second example of the termination condition is "identifying a second marker indicating the end of the temporary speed limit zone X1". The second marker explicitly indicates the end (release) of the temporary speed limit zone X1. As mentioned above, the second marker can be identified based on the image IMG obtained by the camera C mounted on vehicle 1.

[0081] The third example of the termination condition is "Vehicle 1 has traveled a certain distance from the beginning of the temporary speed limit interval X1". Whether Vehicle 1 has traveled a certain distance can be determined based on the vehicle position information 230 and the map information MAP. Alternatively, whether Vehicle 1 has traveled a certain distance can also be determined based on the integral of the vehicle speed.

[0082] The termination condition includes any one of the first to third examples described above. If the termination condition is not met (step S130: No), the process returns to step S120. On the other hand, if the termination condition is met (step S130: Yes), the control device 100 determines that the temporary speed limit range X1 has ended.

[0083] Figure 9 This is a flowchart illustrating the process associated with the speed limit display. It can begin when vehicle 1 starts moving. Figure 9 The process.

[0084] In step S140, the control device 100 determines whether a display update trigger has been triggered.

[0085] The first instance of an update being triggered is "Vehicle 1 passes through the speed limit boundary BD". The speed limit boundary BD is the location where the speed limit LM is switched. Vehicle 1 passing through the speed limit boundary BD can be sensed based on vehicle position information 230 and map information MAP.

[0086] The second instance of an update being triggered is either "Speed ​​limit sign S0 identified" or "First sign S1 identified". As mentioned above, speed limit sign S0 and first sign S1 can be identified based on an image IMG obtained by a camera C mounted on vehicle 1.

[0087] If no display update is triggered (step S140: No), the processing in this loop ends. On the other hand, if a display update is triggered (step S140: Yes), the processing proceeds to step S150.

[0088] In step S150, the control device 100 determines whether vehicle 1 is within the temporary speed limit range X1. Whether vehicle 1 is within the temporary speed limit range X1 is determined by the above... Figure 8 The processing flow shown is used to determine this.

[0089] If vehicle 1 is not within the temporary speed limit range X1 (step S150: No), the process proceeds to step S160. In step S160, the control device 100 reads the prescribed speed limit LM at the driving position of vehicle 1 from the map information MAP. Then, in step S170, the control device 100 displays the prescribed speed limit LM read from the map information MAP on the display device 30. That is, in response to a display update trigger, the control device 100 updates the speed limit displayed on the display device 30.

[0090] On the other hand, if vehicle 1 is within the temporary speed limit range X1 (step S150: Yes), the process proceeds to step S180. In step S180, the control device 100 performs a display update invalidation process. That is, even if a display update is triggered, the control device 100 invalidates the speed limit update displayed on the display device 30 (based on map information MAP).

[0091] It should be noted that the first marker S1, indicating the start of the temporary speed limit range X1, sometimes indicates the temporary speed limit LMtemp applied to that temporary speed limit range X1 (see reference). Figure 3 In this case, when vehicle 1 is in the temporary speed limit range X1 (step S150: yes), control device 100 can also display the temporary speed limit LMtemp obtained from the first flag S1 on display device 30.

[0092] If the first indicator S1 does not indicate a temporary speed limit LMtemp, the control device 100 may maintain the speed limit displayed on the display device 30 as it was before the temporary speed limit interval X1. Alternatively, the control device 100 may temporarily turn off the speed limit display processing until the temporary speed limit interval X1 ends. In this case, the display device 30 may not display the speed limit until the temporary speed limit interval X1 ends.

[0093] 4. Effects

[0094] As explained above, according to this embodiment, within the temporary speed limit range X1 where a temporary speed limit LMtemp is set, even if the specified speed limit LM registered in the map information MAP changes, the speed limit displayed on the display device 30 will not be updated. Therefore, erroneous speed limits that deviate from the actual situation are suppressed from being displayed on the display device 30.

[0095] Furthermore, it prevents the erroneous determination that vehicle 1 is exceeding the speed limit. As a result, it prevents false warnings from being issued to the driver.

[0096] Furthermore, in adaptive speed control based on speed limits, erroneous speed settings are prevented. As a result, the accuracy of adaptive speed control is improved.

Claims

1. A driving assistance method applied to a vehicle, characterized in that, include: Read the speed limit at the vehicle's location from the map information that records the speed limit; The speed limit read from the map information is displayed on the display device; In a first interval with a temporarily limited speed, even if the limited speed registered in the map information changes, the update of the limited speed displayed on the display device based on the map information is invalidated; The first interval is identified based on images of the vehicle's surroundings obtained by a camera mounted on the vehicle. Identifying the first interval includes identifying a first marker indicating the start of the first interval based on the images, thereby identifying the start of the first interval. When the first flag indicates the temporary speed limit, the temporary speed limit is displayed on the display device within the first interval; as well as If the first flag does not indicate a temporary speed limit, the display of the speed limit is temporarily turned off until the first interval ends.

2. The driving assistance method according to claim 1, characterized in that, The first symbol is any one of the following symbols: Road construction sign indicating the start of a road construction section; A variable electro-optical sign that can variably display the speed limit; and A speed limit sign is provided, which includes auxiliary signs indicating the application conditions for the speed limit.

3. The driving assistance method according to claim 1 or 2, characterized in that, Identifying the first interval includes: identifying a second marker indicating the end of the first interval based on the image, thereby identifying the end of the first interval.

4. The driving assistance method according to claim 1 or 2, characterized in that, Also includes: If the termination condition is met, the first interval is considered to have ended. The termination condition includes at least one of the following conditions: The vehicle made a left or right turn; The vehicle traveled a certain distance from the beginning of the first interval; and Identify the marker indicating the end of the first interval.

5. The driving assistance method according to claim 1 or 2, characterized in that, Also includes: If the vehicle's speed exceeds the speed limit displayed on the display device, a warning is issued to the driver of the vehicle.

6. A driving assistance system applied to a vehicle, comprising: One or more storage devices are configured to store map information with a registered speed limit; as well as One or more processors, The one or more processors are configured to: The speed limit at the vehicle's location is read from the map information; The speed limit read from the map information is displayed on the display device; In a first interval with a temporarily limited speed, even if the limited speed registered in the map information changes, the update of the limited speed displayed on the display device based on the map information is invalidated; The first interval is identified based on images of the vehicle's surroundings obtained by a camera mounted on the vehicle. Identifying the first interval includes identifying a first marker indicating the start of the first interval based on the images, thereby identifying the start of the first interval. When the first flag indicates the temporary speed limit, the temporary speed limit is displayed on the display device within the first interval; as well as If the first flag does not indicate a temporary speed limit, the display of the speed limit is temporarily turned off until the first interval ends.

Images