Driving assistance device for vehicle

Abstract

A driving support ECU includes a speed limit acquisition unit that acquires a speed limit suitable for a host vehicle, and a host vehicle speed acquisition unit that acquires a host vehicle speed, which is a speed of the host vehicle, and performs a first notification (first overspeed notification) when the host vehicle speed is higher than the speed limit. In a state in which the vehicle speed is higher than the limit speed after the first notification continues, the driving assistance ECU performs an additional notification (second overspeed notification) when it is determined that a predetermined attention-inducing condition is satisfied, the predetermined attention-inducing condition being satisfied when the predetermined attention-inducing condition is not satisfied, and the second overspeed notification is not satisfied when the predetermined attention-inducing condition is satisfied. That is, the vehicle speed of the host vehicle increases or is predicted to increase due to the relative positional relationship between a preceding vehicle traveling ahead of the host vehicle and the host vehicle.

Description

Technical Field

[0001] The present invention relates to a vehicle driving assistance device for notifying an occupant of the vehicle to call attention when the speed of the vehicle (ie, the vehicle speed) exceeds a speed limit (ie, a maximum speed). Background Art

[0002] An existing device notifies the occupants of the vehicle of speeding when it determines that the vehicle has entered a different type of road based on the vehicle's current position and map data, and when the vehicle's cumulative driving distance on the road is less than a specified distance and the vehicle's speed is higher than the speed limit (maximum speed) of the road (see Japanese Patent Laid-Open No. 2009-294707). Summary of the invention

[0003] However, the conventional device does not make a second or subsequent notification if the vehicle continues to travel on the same road at a speed higher than the speed limit after making a notification once. Therefore, the driver may continue to drive the vehicle without noticing that the vehicle speed exceeds the speed limit. On the other hand, if the notification of speeding is made continuously, the driver may feel annoyed by the notification.

[0004] The present invention is made to solve the above-mentioned problems. That is, one of the objects of the present invention is to provide a driving support device for a vehicle that can notify the driver of speeding at an appropriate time when the vehicle speed continues to exceed the speed limit.

[0005] One embodiment of the driving assistance device of the present invention comprises: A speed limit acquisition unit (20, 80) that acquires a speed limit applicable to the vehicle; A vehicle speed acquisition unit (93) for acquiring the speed of the vehicle, that is, the vehicle speed; and An attention calling notification unit performs a first notification (first attention calling notification) (S315) when the speed of the vehicle is higher than the speed limit, and performs an additional notification (second attention calling notification) (S345) when a prescribed attention calling condition is met (S340: "Yes") after the first notification, when the speed of the vehicle continues to be higher than the speed limit. The prescribed attention calling condition is met in the following situation, namely, the speed of the vehicle increases or is predicted to increase due to the relative position relationship between the preceding vehicle traveling in front of the vehicle and the vehicle.

[0006] According to this method, a first notification is made when the speed of the vehicle exceeds the speed limit, and thereafter, an additional notification is made when a predetermined attention-calling condition is satisfied. The attention-calling condition is a condition that is satisfied when the speed of the vehicle increases or is predicted to increase due to the relative positional relationship between the preceding vehicle and the vehicle, for example, a condition that is satisfied in the following cases. Case 1: A case where the state changes from the state where the host vehicle is traveling to follow the preceding vehicle to the state where the host vehicle is executing an overtaking action to overtake the preceding vehicle. Case 2: The state where the host vehicle is traveling following the preceding vehicle changes to a state where the preceding vehicle ceases to exist, and the host vehicle speed increases by more than the "individual acceleration determination threshold value of 0 or more" since the preceding vehicle ceases to exist. Case 3: The state where the host vehicle is traveling following the preceding vehicle changes to the state where the preceding vehicle accelerates, and the host vehicle speed increases by more than the "following acceleration determination threshold value of 0 or more" since the preceding vehicle starts accelerating.

[0007] Therefore, when the driver of the host vehicle is accelerating the host vehicle or the possibility of accelerating the host vehicle is high due to the relative position relationship with the preceding vehicle, additional notification is performed. Therefore, the driver is easily aware that the speed of the host vehicle exceeds the speed limit. In addition, since the additional notification is not performed all the time, the possibility of annoying the driver can be reduced.

[0008] In the above description, in order to facilitate understanding of the present invention, the names and / or figure marks used in the embodiments are added in brackets to the configuration of the invention corresponding to the embodiments described later. However, the constituent elements of the present invention are not limited to the embodiments specified by the names and / or figure marks. The present invention also relates to a driving assistance method (speeding notification method) for a vehicle and a program thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, advantages and technical and industrial significance of exemplary embodiments of the present invention are described with reference to the accompanying drawings, in which like reference numerals represent like parts, and in which: Figure 1 It is a schematic diagram of the configuration of a driving assistance device for a vehicle according to the first embodiment of the present invention. Figure 2 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown. Figure 3 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown. Figure 4 yes Figure 1The routine executed by the CPU of the driving assistance ECU shown. Figure 5A A scenario is shown in which the driving assistance device according to the first embodiment of the present invention performs additional notification. Figure 5B A scenario is shown in which the driving assistance device according to the second embodiment of the present invention performs additional notification. Figure 5C A scenario is shown in which the driving assistance device according to the third embodiment of the present invention performs additional notification. Figure 6 This is a table used in the modified examples of the first to third embodiments of the present invention. DETAILED DESCRIPTION 1. First Implementation

[0010] A "driving assistance device DS for a vehicle (hereinafter referred to as "device DS")" according to a first embodiment of the present invention comprises Figure 1 The components shown are applicable to (mounted on) this vehicle HV. This vehicle HV may be any of a vehicle powered by an internal combustion engine, a vehicle powered by an electric motor (ie, a battery electric vehicle), and a hybrid electric vehicle.

[0011] In this specification, "ECU" is an electronic control unit (control unit) including a microcomputer including a CPU (processor), ROM, RAM, a nonvolatile memory capable of writing data, an interface, etc. ECU is also called a controller or a computer. Figure 1 The multiple ECUs shown are connected via a CAN (Controller Area Network) so as to be able to exchange information with each other. Some or all of the multiple ECUs may also be integrated into one ECU.

[0012] Driving assistance ECU 10 use Figure 1 The components recorded in the description are used to alert the occupants of the vehicle HV (especially the driver) to the fact that "the speed of the vehicle has exceeded the speed limit" (speeding notification) when the speed of the vehicle HV (i.e., the vehicle speed of the vehicle) exceeds the speed limit set / applied to the lane in which the vehicle HV is traveling (i.e., the maximum speed).

[0013] The camera device 20 includes a camera 21 and an image ECU 22. The camera 21 captures the scene in front of the vehicle HV every predetermined time and obtains image data. The image ECU 22 generates camera information by analyzing the image data from the camera 21, and sends the camera information to the driving assistance ECU 10. The camera information includes the image data itself, the camera target information such as the "position relative to the vehicle HV, relative longitudinal speed, relative lateral speed and type" of the captured target. The camera information also includes lane information such as the position (lateral position) and angle of the lane width direction of the vehicle HV relative to the dividing line (white line and yellow line) of the road on which the vehicle HV is traveling. The types of targets include moving objects such as other vehicles and pedestrians, as well as structures such as guardrails and utility poles. Based on the image data obtained by the camera device 20, the driving assistance ECU 10 extracts a pattern similar to a road sign indicating a speed limit (maximum speed) contained in the image data. The driving assistance ECU 10 obtains the value shown in the extracted pattern as the speed limit (maximum speed, speed limit for attention call) set / applied to the lane where the host vehicle HV is currently traveling (hereinafter also referred to as the "host lane") . The acquisition of the vehicle speed limit can also be performed by the image ECU 22.

[0014] The radar device 30 is a well-known device that uses radio waves in the millimeter wave band to obtain information related to a target object that exists around the vehicle HV, and includes a radar 31 and a radar ECU 32. The radar 31 transmits millimeter waves within a specified detection range every specified time, and receives millimeter waves reflected by the target object. The radar 31 transmits information related to the transmitted and received millimeter waves to the radar ECU 32. The radar ECU 32 obtains radar information based on the information from the radar 31, and transmits the radar information to the driving assistance ECU 10. The radar information includes the distance to the target object, the direction of the target object, and the relative speed of the target object.

[0015] The powertrain ECU 40 controls a driving device including a power source of the host vehicle HV (not shown) by driving a powertrain actuator 41 to generate a driving force.

[0016] The brake ECU 50 controls a brake device of the host vehicle HV (not shown) by driving the brake actuator 51 , thereby applying a braking force to the host vehicle HV.

[0017] The steering ECU 60 controls a steering device of the host vehicle HV (not shown) by driving a steering motor 61 , thereby changing the steering angle of the host vehicle HV.

[0018] The notification ECU (alarm ECU) 70 is connected to a display 71 disposed at a position that can be visually recognized from the driver's seat and an alarm sound generating device 72 that generates an alarm sound (notification sound), and controls them according to the instruction (instruction signal) from the driving assistance ECU 10. An area 71a for displaying the speed limit (maximum speed) is provided on the display 71. The notification ECU 70 displays the speed limit included in the instruction from the driving assistance ECU 10 in the area 71a. In addition, the notification ECU 70 flashes the displayed speed limit and flashes a pattern that calls attention around the displayed speed limit. In addition, the notification ECU 70 generates a notification sound (for example, a notification sound that repeats a sound such as "bang") from the alarm sound generating device 72. Thus, the notification ECU 70 notifies the occupants (especially the driver) of the vehicle HV that the speed of the vehicle exceeds the speed limit. Hereinafter, the notification is referred to as "speeding notification", "notification for calling attention to speeding" or "attention calling notification". In addition, the notification ECU 70 is connected to a custom device 73 operated by the driver. The driver can change the “speeding threshold value OSth when executing the attention call notification” described later by operating the customization device 73 .

[0019] The navigation ECU 80 is connected to a GPS receiver 81, a map database 82, and a display touch panel 83 displaying touch buttons, and together with them constitutes a vehicle navigation system. The navigation ECU 80 obtains the current position of the vehicle HV based on the GPS signal received by the GPS receiver 81. The navigation ECU 80 generates a recommended route from the current position to the "destination input via the display touch panel 83" based on the map data stored in the map database 82. The navigation ECU 80 sets one of the recommended routes as a predetermined driving route according to the driver's instructions, and performs a known route guidance on this basis. In addition, the navigation ECU 80 obtains the speed limit set / applied to the lane at the current moment based on the current position of the vehicle HV and the map data obtained.

[0020] The communication ECU 90 performs wireless communication with devices external to the host vehicle HV (for example, roadside equipment, an information management center, etc.), and acquires various information from the external devices.

[0021] The driving support ECU 10 inputs detection values ​​(output values) of the following “sensors and switches”. An accelerator pedal operation amount sensor 91 that detects an accelerator pedal operation amount AP of the host vehicle HV. A brake pedal operation amount sensor 92 that detects the brake pedal operation amount BP of the host vehicle HV. A vehicle speed sensor 93 that detects the speed of the host vehicle HV (ie, the host vehicle speed SPD). A yaw rate sensor 94 that detects the yaw rate Yr of the host vehicle HV. A steering angle sensor 95 that detects a steering angle St of the host vehicle HV. A turn signal switch 96 that generates a signal indicating the flashing state of the direction indicator of the vehicle HV. The turn signal switch 96 generates a signal when the driver operates the turn signal lever provided on the steering column (not shown). When the turn signal lever is turned in the counterclockwise direction, the turn signal switch 96 generates a signal for flashing the direction indicator arranged on the left side of the vehicle HV. When the turn signal lever is turned in the clockwise direction, the turn signal switch 96 generates a signal for flashing the direction indicator arranged on the right side of the vehicle HV. The direction indicator flashes according to the signal of the turn signal switch 96. In addition, the driving assistance ECU 10 is also connected to other sensor types other than those mentioned above (for example, a steering torque sensor). Overview of the Action

[0022] The device DS obtains the speed limit (maximum speed) SPDLT of the lane in which the host vehicle HV is traveling, and when it is determined that the vehicle speed SPD exceeds the speed limit SPDLT by more than the speeding threshold OSth, the device DS performs the first speeding notification. In addition, when the state in which the vehicle speed SPD exceeds the speed limit SPDLT continues, and the host vehicle HV is accelerated or estimated to be accelerated due to the relative position relationship between the host vehicle HV and the preceding vehicle, the device DS performs an additional (second or subsequent) speeding notification. Specific actions

[0023] The CPU 10a (hereinafter referred to as "CPU") of the driving support ECU 10 executes the following operation every time a predetermined time (operation cycle) dt elapses. Figures 2 to 4 The routine is shown in the flowchart of . In addition, "step" is denoted as "S" below. Obtaining speed limit

[0024] When the specified time comes, the CPU Figure 2 The process starts from S200 and proceeds to S210 to determine whether the speed limit set for the own lane has been newly acquired (image recognition) based on the image data sent from the camera device 20. Alternatively, the CPU may acquire the speed limit set for the own lane based on the current position of the own vehicle HV and the map data stored in the map database 82 via the navigation ECU 80.

[0025] When a new speed limit is obtained, the CPU proceeds from S210 to S220. The CPU determines whether the new speed limit obtained in S210 is the first speed limit obtained after the ignition key / switch (not shown) of the vehicle HV is changed from the off position to the on position (after the IG is turned on). When the new speed limit is the first speed limit obtained after the IG is turned on, the CPU proceeds from S220 to S240 described later.

[0026] On the other hand, if the newly acquired speed limit is not the first speed limit acquired after the IG is turned on, the CPU proceeds from S220 to S230. The CPU determines whether the speed limit SPDLT for attention calling, which is described later and recognized by the CPU at the current moment, is different from the newly acquired speed limit. If the speed limit SPDLT for attention calling recognized at the current moment is different from the newly acquired speed limit, the CPU proceeds from S230 to S240.

[0027] In S240, the CPU sets the newly acquired speed limit as the speed limit SPDLT for attention calling, and displays a pattern corresponding to the speed limit SPDLT for attention calling in the area 71a of the display 71. Thereafter, the CPU performs the "processing of S250 and S260" described below, proceeds to S295, and temporarily terminates this routine.

[0028] S250: The CPU sets the value of the first completion flag X1 to "0". As described later, when the value of the first completion flag X1 is "1", it means that the first speeding notification (see Figure 3 S320).

[0029] S260: The CPU sets the value of the second completion flag X2 to "0". As described later, when the value of the second completion flag X2 is "1", it means that the first speeding notification was made after the new speed limit SPDLT for attention was set, and then an additional (second) speeding notification was made while the vehicle speed SPD continued to exceed the speed limit SPDLT (see Figure 3 S350).

[0030] Note that the values ​​of the flag X1 and the flag X2 are both set to "0" in the initialization routine executed by the CPU when the ignition key / switch is changed from the OFF position to the ON position.

[0031] It should be noted that when the CPU makes a "No" determination in any of steps S210 and S230, the CPU directly proceeds to S295 from the step where the "No" determination is made. Speeding warning notification (speeding notification)

[0032] When the specified time comes, the CPU Figure 3 The process starts from S300 and proceeds to S305 to determine whether the value of the first completion flag X1 is "0".

[0033] When the value of the first completion flag X1 is "0", the CPU enters S310 from S305 to determine whether the vehicle speed SPD is greater than the "value obtained by adding the speed limit SPDLT to the speeding threshold OSth". In addition, although the speeding threshold OSth is set to a fixed value (for example, 5km / h) here, it can be a value greater than "0km / h" and can also be changed by operating the customization device 73 as described later. When the vehicle speed SPD does not exceed the "value obtained by adding the speed limit SPDLT to the speeding threshold OSth", the CPU directly enters S395 from S310 to temporarily end this routine.

[0034] On the other hand, when the vehicle speed SPD is greater than "the value obtained by adding the speed limit SPDLT to the overspeed threshold OSth", the CPU makes a "Yes" determination in S310 and executes "the processing of S315 to S325" described below. Thereafter, the CPU proceeds to S395.

[0035] S315: The CPU executes the first (first) overspeed notification (attention-calling notification) after the new speed limit SPDLT for attention-calling is set. That is, the CPU flashes the speed limit (that is, the pattern indicating the speed limit SPDLT for attention-calling) displayed in the area 71a of the display 71. The CPU flashes the pattern for calling attention around the displayed speed limit. The CPU generates a notification sound from the alarm sound generating device 72. However, the notification method is not limited to this. S320: The CPU sets the value of the first completion flag X1 to "1". S325: The CPU obtains the vehicle speed SPD of the host vehicle at the current time (ie, the time when the first speeding notification is executed) as the reference vehicle speed SPD1 and stores it in the RAM 10c.

[0036] On the other hand, if the value of the first completion flag X1 is not "0" when the CPU enters S305, the CPU proceeds from S305 to S330 to determine whether the value of the second completion flag X2 is "0".

[0037] When the value of the second completion flag X2 is "0", the CPU enters S335 from S330 to determine whether the vehicle speed SPD is greater than the "value obtained by adding the speed limit SPDLT to the speeding threshold OSth". When the vehicle speed SPD is greater than the "value obtained by adding the speed limit SPDLT to the speeding threshold OSth", the CPU enters S340 from S335. The CPU determines whether the "attention calling condition related to the preceding vehicle (one of the execution conditions of the additional speeding notification)" described below is met. The preceding vehicle is another vehicle traveling in the lane, and is another vehicle traveling immediately in front of the vehicle HV and within a specified distance from the vehicle HV. The attention calling condition related to the preceding vehicle is a condition that is met when both the following conditions A1 and B1 are met. For convenience, it is called the "first attention calling condition related to the preceding vehicle". First attention-awakening conditions related to the preceding vehicle

[0038] (Condition A1) The host vehicle HV continues to travel following the preceding vehicle at a speed close to the actual speed Vj or at a speed substantially the same as that of the preceding vehicle for a predetermined time or longer. (Condition B1) After the condition A1 is satisfied, the host vehicle speed SPD is not lower than the speed limit SPDLT, and the host vehicle HV is performing an operation for overtaking the preceding vehicle.

[0039] Here, the actual speed Vj is the average of the speeds of multiple other vehicles ahead of the own vehicle HV traveling in the own lane. In this example, the CPU obtains the actual speed Vj from the "roadside device that obtains the actual speed Vj" through "wireless communication using the communication ECU 90". The roadside device is set relative to the own lane, uses radar to detect the speed of vehicles passing through the own lane, calculates the above-mentioned actual speed Vj one by one, and sends the actual speed Vj for the own vehicle HV to the own vehicle HV based on a request from the own vehicle HV. In addition, the speed near the actual speed Vj is a speed within a range from a speed that is a predetermined small speed lower than the actual speed Vj to a speed that is a predetermined small speed higher than the actual speed Vj.

[0040] In addition, the CPU may obtain the speeds of the preceding vehicle and the "preceding vehicle of the preceding vehicle" based on the camera information and the radar information, and use their average value as the actual speed Vj. Furthermore, the CPU may obtain (estimate) "the speed of the preceding vehicle when the preceding vehicle is not accelerating or decelerating" as the actual speed Vj based on the radar information.

[0041] When all of the following “overtaking determination conditions 1 to 3” are satisfied, the CPU determines that the host vehicle HV is performing an operation for overtaking the preceding vehicle (the above-mentioned condition B1 is satisfied). (Overtaking determination condition 1) The turn signal switch 96 generates a signal to flash “either the left or right direction indicator”. (Overtaking determination condition 2) The lateral position of the host vehicle HV has moved to the "side where the direction indicator is flashing" by more than a predetermined lateral position movement amount threshold value since the time when the overtaking determination condition 1 is satisfied. The amount of change (movement amount) of the lateral position can be obtained based on the camera information or based on the integrated value of the detected yaw rate Yr. (Overtaking determination condition 3) The vehicle speed SPD of the host vehicle has increased by more than the first vehicle speed increase threshold value (overtaking determination speed threshold value) Da since the overtaking determination condition 1 was satisfied. In addition, the overtaking determination condition 3 may be omitted. In this case, the first attention calling condition becomes a condition that is satisfied when the host vehicle HV starts the overtaking action and it is predicted that the vehicle speed of the host vehicle will increase.

[0042] When the first attention calling condition related to the preceding vehicle is satisfied (refer to the diagram showing the vehicle HV and the preceding vehicle PV), Figure 5A ), the CPU enters S345 from S340, and executes an additional overspeed notification (second attention call notification) to notify that the vehicle speed SPD exceeds the speed limit SPDLT. The notification method is the same as the first overspeed notification executed by the processing of S315. Then, the CPU enters S350, sets the value of the second completion flag X2 to "1", and enters S395.

[0043] On the other hand, when the CPU enters S340, if the first attention calling condition related to the preceding vehicle is not satisfied, the CPU enters S355 from S340 to determine whether the attention calling condition related to the vehicle speed of the own vehicle is satisfied. The attention calling condition related to the vehicle speed of the own vehicle is a condition that is satisfied when all of the following conditions X1 to X3 are satisfied. Attention-awakening conditions related to the vehicle's speed

[0044] (Condition X1) There is no preceding vehicle. (Condition X2) The current vehicle speed SPD is higher than the value obtained by adding the second vehicle speed increase threshold (increase speed determination threshold) Db to the vehicle speed at the time when the first (i.e., previous) speeding notification was executed (i.e., the reference speed SPD1 obtained in S325) (hereinafter referred to as the "first threshold"). The second vehicle speed increase threshold Db is set to a value greater than the speeding threshold OSth. Db may be a fixed value or may be determined based on the reference speed SPD1. (Condition X3) The current vehicle speed SPD is higher than a threshold value (hereinafter referred to as the "second threshold value") equal to (1+α) times the speed limit SPDLT for attention calling. α is a value greater than 0 and less than 1, for example, 0.2. α may be a fixed value or may be determined according to the speed limit SPDLT for attention calling.

[0045] When the attention calling condition related to the vehicle speed is satisfied, the CPU proceeds from S355 to S345 and S350, executes an additional (second) speeding notification, and sets the value of the second completion flag X2 to "1", and then proceeds to S395.

[0046] When the CPU makes a "No" determination in any of steps S330, S335, and S355, the CPU directly proceeds to S395 from the step where the "No" determination is made. Cancellation of speeding notice

[0047] When the specified time comes, the CPU Figure 4 The process starts from S400 and proceeds to S410 to determine whether the value of the first completion flag X1 is "1".

[0048] When the value of the first completion flag X1 is "1", the CPU enters S420 from S410 to determine whether the cancellation condition of the overspeed notification is met. The cancellation condition is met when at least one of the following "conditions CACL1 and CACL2" is met. When the cancellation condition is not met, the CPU enters S495 from S420. Conditions for cancellation of speeding notice

[0049] (Condition CACL1) The vehicle speed SPD of the host vehicle becomes equal to or less than the speed limit SPDLT. (Condition CACL2) The host vehicle HV has traveled a predetermined distance threshold or more from the point where the speed limit SPDL is updated (that is, the position of the host vehicle HV at the time of executing S240).

[0050] When the cancellation condition of the overspeed notification is satisfied, the CPU makes a "YES" determination in S420, performs "the processing of S430 and S440" described below, and then proceeds to S495 to temporarily terminate this routine.

[0051] S430: The CPU sets the value of the first completion flag X1 to "0". S440: The CPU sets the value of the second completion flag X2 to "0".

[0052] As described above, the device DS of the first embodiment performs an additional speeding notification when the first attention-calling condition related to the preceding vehicle is satisfied. In addition, the CPU may be configured such that after the moment when the above-mentioned condition B1 is satisfied, the speeding notification is not performed during the period when the host vehicle HV crosses the "dividing line between the host lane and the lane adjacent to the host lane". This is because if the speeding notification is performed during the period when the host vehicle HV crosses the dividing line, the driver may be confused. 2. Second Implementation

[0053] In the device DS according to the second embodiment of the present invention, the CPU of the driving assistance ECU 10 is Figure 3 In S340 of , it is determined whether the "second attention calling condition related to the preceding vehicle" different from the "first attention calling condition related to the preceding vehicle" is satisfied. The device DS involved in the second embodiment is different from the device DS involved in the first embodiment only in this point. This difference is described below.

[0054] The second attention calling condition related to the preceding vehicle is a condition that is satisfied when all of the following conditions A2, B2, and C2 are satisfied. Second attention-awakening conditions related to the leading vehicle

[0055] (Condition A2) The same condition as Condition A1. (Condition B2) The preceding vehicle that the host vehicle HV had been following no longer exists. (Condition C2) Since the preceding vehicle that the host vehicle HV had been following ceased to exist, the host vehicle speed SPD is not lower than the speed limit SPDLT, and the host vehicle speed SPD has increased by more than the third host vehicle speed increase threshold value (individual acceleration determination threshold value) Dc.

[0056] When the second attention calling condition related to the preceding vehicle is satisfied (refer to the diagram showing the vehicle HV and the preceding vehicle PV), Figure 5B )The CPU enters S345 and S350 from S340, and then enters S395.

[0057] In addition, condition C2 may be omitted. In this case, when the preceding vehicle that the host vehicle HV was following ceases to exist, an additional speeding notification is immediately executed. That is, the second attention calling condition with condition C2 omitted becomes a condition that is satisfied when it is predicted that the host vehicle speed will increase due to the disappearance of the preceding vehicle. 3. Third Implementation

[0058] In the device DS according to the third embodiment of the present invention, the CPU of the driving assistance ECU 10 determines in S340 whether a "third attention calling condition related to the preceding vehicle" different from the "first attention calling condition related to the preceding vehicle" is satisfied. The device DS according to the third embodiment is different from the device DS according to the first embodiment only in this point. This difference will be described below.

[0059] The third attention calling condition related to the preceding vehicle is a condition that is satisfied when all of the following conditions A3, B3, and C3 are satisfied. Third attention-awakening condition related to the preceding vehicle

[0060] (Condition A3) The same condition as Condition A1. (Condition B3) The preceding vehicle that the host vehicle HV was following has accelerated. Specifically, the speed of the preceding vehicle has become greater than "the value obtained by adding the preceding vehicle acceleration determination threshold Pa to the actual speed Vj". In addition, the determination of whether the preceding vehicle has accelerated can be made based on the relative speed of the preceding vehicle or the distance to the preceding vehicle based on camera information and radar information, etc., and the host vehicle speed SPD. (Condition C3) After condition A1 is satisfied, the host vehicle speed SPD is not less than the speed limit SPDLT, and the host vehicle HV accelerates according to the acceleration action of the preceding vehicle. The host vehicle speed SPD has increased by more than the fourth host vehicle speed increase threshold value (following acceleration determination threshold value) Dd from the "host vehicle speed at the moment when the preceding vehicle starts to accelerate".

[0061] When the third attention calling condition related to the preceding vehicle is satisfied (refer to the Figure 5C )The CPU enters S345 and S350 from S340, and then enters S395.

[0062] In addition, condition C3 may be omitted. In this case, when the preceding vehicle that the host vehicle HV has been following starts to accelerate, an additional speeding notification is immediately executed. That is, the third attention calling condition with condition C3 omitted becomes a condition that is satisfied when it is predicted that the speed of the host vehicle will increase due to the relative position relationship with the preceding vehicle PV. Modifications

[0063] In the modified example of the device DS according to the first to third embodiments, the driver of the vehicle HV can set (change) the speeding threshold value OSth using the customization device 73. Figure 6As shown in the setting table of FIG. 1 , the driver selects one of setting 1 to setting 3 by using the customization device 73, and the value specified for each setting is used as the speeding threshold value OSth. For example, when the driver selects setting 1, the speeding threshold value OSth is set to 10·A (km / h). Here, A (km / h) is, for example, 1 (km / h). That is, the driver can select how much the vehicle speed SPD exceeds the speed limit SPDLT before the first speeding notification is issued.

[0064] In addition, the CPU automatically changes the first to fourth vehicle speed increase thresholds (Da, Db, Dc, Dd) according to the set (selected) overspeed threshold OSth. For example, when the driver selects setting 1, the first to fourth vehicle speed increase thresholds (Da, Db, Dc, Dd) are set to 15·A (km / h). Figure 6 In the setting table shown, the higher the selected speeding threshold OSth is, the higher the first to fourth vehicle speed increase thresholds (Da, Db, Dc, Dd) are set to. Figure 6 The numerical values ​​shown are examples, and various values ​​can be set as appropriate. In addition, the number of settings that can be set is not limited to "3".

[0065] As can be seen from the above, the first to third attention-calling conditions are conditions that are satisfied when the speed of the host vehicle increases or is predicted to increase due to the relative positional relationship between the preceding vehicle and the host vehicle HV. Therefore, according to the embodiment of the present invention and its modified example, the speeding notification can be made at an appropriate time based on the relative positional relationship between the preceding vehicle and the host vehicle HV.

[0066] In addition, the present invention is not limited to the above-mentioned embodiments and variations, and various variations can be adopted within the scope of the present invention. For example, the CPU determines in S340 whether any two or more of the first to third attention-calling conditions related to the preceding vehicle are satisfied. The CPU may also proceed from S340 to S345 to perform an additional speeding notification when at least one of the conditions for determining whether the conditions are satisfied is determined to be satisfied.

[0067] Furthermore, the device DS according to each of the above embodiments may make an additional speeding notification after the second speeding notification when at least one of the first to third attention calling conditions related to the preceding vehicle and the attention calling condition related to the vehicle speed of the own vehicle is satisfied.

[0068] More specifically, for example, in the first embodiment, the vehicle HV performs an action for overtaking a preceding vehicle. The first attention-calling condition related to the preceding vehicle is satisfied. Thus, a second overspeed notification is performed. After that, a new preceding vehicle exists in the adjacent lane that the vehicle HV newly enters for the overtaking, or in the original lane that the vehicle HV returns to after the overtaking action is completed. For the new preceding vehicle, the device DS may also perform an additional overspeed notification when one of the first to third attention-calling conditions related to the preceding vehicle is satisfied.

[0069] In the second and third embodiments, the device DS may also perform an additional speeding notification whenever any of the second and third attention-calling conditions related to the preceding vehicle is satisfied. In addition, the first threshold of the condition X2 may be a value obtained by increasing the reference speed SPD1 by a predetermined ratio (e.g., 1.1·SPD1), and the second threshold of the condition X3 may be a value obtained by adding the speeding limit threshold Df to the speed limit SPDL. The first to fourth vehicle speed increase thresholds (Da, Db, Dc, Dd) may be any appropriate value greater than 0 including "0".

Claims

1. A driving assistance device for a vehicle, comprising: a speed limit acquisition unit for acquiring a speed limit applicable to the vehicle; A host vehicle speed acquisition unit that acquires the speed of the host vehicle, that is, the host vehicle speed; and An attention calling notification unit performs a first notification when the vehicle speed is higher than the speed limit, and performs an additional notification when a prescribed attention calling condition is met if the vehicle speed continues to be higher than the speed limit after the first notification. The prescribed attention calling condition is met in the following situation, namely, the vehicle speed increases or is predicted to increase due to the relative positional relationship between a preceding vehicle traveling in front of the vehicle and the vehicle.

2. The driving assistance device for a vehicle according to claim 1, wherein: The attention calling condition includes a condition that a state changes from a state in which the host vehicle travels to follow the preceding vehicle to a state in which the host vehicle performs an overtaking action to overtake the preceding vehicle.

3. The driving assistance device for a vehicle according to claim 1, wherein: The attention calling condition includes a condition of changing from a state in which the host vehicle is traveling to follow the preceding vehicle to a state in which the preceding vehicle no longer exists.

4. The driving assistance device for a vehicle according to claim 1, wherein: The attention calling condition includes a condition that a state changes from a state in which the host vehicle is traveling to follow the preceding vehicle to a state in which the preceding vehicle is accelerating.

5. The driving assistance device for a vehicle according to any one of claims 1 to 4, wherein: The attention calling notification unit is configured to make an additional notification after the first notification, when the state in which the vehicle speed is higher than the speed limit continues after the first notification and the leading vehicle does not exist, and when the vehicle speed becomes greater than a first threshold and greater than a second threshold, the first threshold is determined based on the vehicle speed at the moment of executing the first notification, and the second threshold is determined based on the speed limit.

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