Operation support device of vehicle

Abstract

To provide an operation support device of a vehicle that can notify a driver of excess speed at a proper timing when own vehicle speed continues exceeding a speed limit.SOLUTION: An operation support ECU comprises speed limit obtaining parts (20 and 80) that obtain a speed limit that is applied to an own vehicle (HV) and an own vehicle speed obtaining part (93) that obtains own vehicle speed that is speed of the own vehicle, which when the own vehicle speed is higher than the speed limit, performs a first notification (first time overspeed notification). When determining that a predetermined warning condition, which is met when the own vehicle speed increases or is predicted to increase due to a relative positional relation between a preceding vehicle running in front of the own vehicle and the own vehicle in a state where the own vehicle speed continues exceeding the speed limit after the first notification, is met, the driving / operation support ECU makes an additional notification (a second time overspeed notification).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle driving support device that issues a warning to a vehicle occupant when the speed of the vehicle (i.e., vehicle speed) exceeds a speed limit (i.e., maximum speed). [Background technology]

[0002] When a conventional device determines that the vehicle has entered a different type of road based on the vehicle's current position and map data, and the accumulated distance traveled by the vehicle on the entered road is less than a predetermined distance and the vehicle's speed is higher than the speed limit (maximum speed) of the entered road, it alerts the vehicle's occupants that they are speeding (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-294707 A Summary of the Invention

[0004] However, in the conventional device, if the vehicle continues to travel on the same road at a speed higher than the speed limit after the first notification, the driver may continue driving the vehicle without realizing that the vehicle speed is exceeding the speed limit. On the other hand, if the speed limit notification is always issued, the driver may find the notification annoying.

[0005] The present invention has been made to solve the above problems. That is, one of the objects of the present invention is to provide a driving assistance device for a vehicle that can provide a speed limit warning at an appropriate timing when the vehicle speed continues to exceed the speed limit.

[0006] One aspect of the driving assistance device of the present invention is to a speed limit acquisition unit (20, 80) that acquires a speed limit applied to the vehicle; a vehicle speed acquisition unit (93) that acquires a vehicle speed, which is a speed of the vehicle; an attention notification unit that issues a first notification (first attention notification) when the host vehicle speed is higher than the speed limit (S315), and issues an additional notification (second attention notification) when a predetermined attention notification condition is satisfied (S340: Yes), the condition being satisfied when the host vehicle speed increases or is predicted to increase due to a relative positional relationship between the host vehicle and a preceding vehicle traveling in front of the host vehicle while the host vehicle speed continues to be higher than the speed limit after the first notification; Equipped with.

[0007] According to this aspect, the first notification is issued when the vehicle speed is higher than the speed limit, and then the additional notification is issued when a predetermined attention calling condition is satisfied. The attention calling condition is a condition that is satisfied when the vehicle speed increases or is predicted to increase due to the relative positional relationship between the preceding vehicle and the vehicle, and is, for example, a condition that is satisfied in the following cases. Case 1: The host vehicle moves from a state in which it is following a leading vehicle to a state in which it is performing an overtaking maneuver to overtake the leading vehicle. Case 2: When the host vehicle was traveling in a state where it was following a preceding vehicle, the preceding vehicle disappears and the host vehicle speed increases by more than the "independent acceleration judgment threshold, which is a value greater than or equal to 0" from the point at which the preceding vehicle disappeared. Case 3: When the vehicle is following a preceding vehicle and the preceding vehicle accelerates and the vehicle speed increases by more than the "following acceleration judgment threshold, which is a value greater than or equal to 0" from the point at which the preceding vehicle started to accelerate.

[0008] Therefore, when the driver of the vehicle is accelerating the vehicle or is likely to accelerate the vehicle due to the relative positional relationship with the preceding vehicle, the additional notification is made. Therefore, the driver can easily notice that the vehicle speed exceeds the speed limit. Furthermore, since the additional notification is not made all the time, the possibility of the driver feeling annoyed can be reduced.

[0009] In the above description, in order to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses with respect to the configuration of the invention corresponding to the embodiments. However, each component of the present invention is not limited to the embodiments defined by the names and / or symbols. The present invention also covers a vehicle driving assistance method (speeding notification method) and its program. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a vehicle driving assistance device according to a first embodiment of the present invention. [Diagram 2] This is a routine executed by the CPU of the driving assistance ECU shown in FIG. [Diagram 3] This is a routine executed by the CPU of the driving assistance ECU shown in FIG. [Figure 4] This is a routine executed by the CPU of the driving assistance ECU shown in FIG. [Diagram 5] (A) is a diagram showing a scene when a driving assistance device according to a first embodiment of the present invention makes an additional notification, (B) is a diagram showing a scene when a driving assistance device according to a second embodiment of the present invention makes an additional notification, and (C) is a diagram showing a scene when a driving assistance device according to a third embodiment of the present invention makes an additional notification. [Figure 6] 13 is a table used in the modified examples of the first to third embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] 1. First embodiment A vehicle driving assistance device DS (hereinafter referred to as "device DS") according to a first embodiment of the present invention includes the components shown in Fig. 1 and is applied to (mounted on) a host vehicle HV. The host vehicle HV may be any of a vehicle powered by an internal combustion engine, a vehicle powered by an electric motor (i.e., an electric vehicle), a hybrid vehicle, and the like.

[0012] In this specification, an "ECU" is an electronic control device (control unit) equipped with a microcomputer including a CPU (processor), a ROM, a RAM, a writable non-volatile memory, an interface, and the like. The ECU is also called a controller or a computer. The multiple ECUs shown in FIG. 1 are connected to each other via a CAN (Controller Area Network) so that they can exchange information with each other. Some or all of these multiple ECUs may be integrated into one ECU.

[0013] Using the components shown in FIG. 1, when the speed of the host vehicle HV (i.e., the host vehicle speed) exceeds the speed limit (i.e., the maximum speed) set and applied to the lane in which the host vehicle HV is traveling, the driving assistance ECU 10 issues a warning (speeding alert) to the occupants of the host vehicle HV (in particular, the driver) to make them aware that the host vehicle speed exceeds the speed limit.

[0014] The camera device 20 includes a camera 21 and an image ECU 22. The camera 21 captures an image of a scene ahead of the host vehicle HV at every predetermined time interval to obtain image data. The image ECU 22 generates camera information by analyzing the image data from the camera 21, and transmits the camera information to the driving assistance ECU 10. The camera information includes the image data itself, camera target information such as the position, relative longitudinal speed, relative lateral speed, and type of the captured target relative to the host vehicle HV, and lane information such as the position (lateral position) and angle of the host vehicle HV in the lane width direction relative to the dividing lines (white lines and yellow lines) of the road on which the host 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 acquired 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, and acquires the numerical value shown in the extracted pattern as the speed limit (maximum speed, speed limit for warning) set / applied to the "lane in which the host vehicle HV is currently traveling (hereinafter also referred to as the "host vehicle lane"). The image ECU 22 may acquire this vehicle speed limit.

[0015] The radar device 30 is a well-known device that acquires information about targets present around the host vehicle HV using millimeter wave band radio waves, and includes a radar 31 and a radar ECU 32. The radar 31 transmits millimeter waves within a predetermined detection range every time a predetermined time elapses, and receives millimeter waves reflected by the targets. The radar 31 transmits information about the transmitted and received millimeter waves to the radar ECU 32. The radar ECU 32 acquires 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, the target's direction, the target's relative speed, etc.

[0016] The powertrain ECU 40 controls a drive device including a power source of the host vehicle HV (not shown) by driving a powertrain actuator 41, thereby generating a drive force.

[0017] The brake ECU 50 controls a braking device (not shown) of the host vehicle HV by driving a brake actuator 51, thereby applying a braking force to the host vehicle HV.

[0018] The steering ECU 60 controls a steering device (not shown) of the host vehicle HV by driving a steering motor 61, thereby changing the steering angle of the host vehicle HV.

[0019] The notification ECU (alarm ECU) 70 is connected to a display 71 arranged at a position visible from the driver's seat and an alarm sound generating device 72 that generates an alarm sound (alarm sound), and controls these in response to an instruction (instruction signal) from the driving assistance ECU 10. The display 71 is provided with an area 71a that displays the speed limit (maximum speed). The notification ECU 70 displays the speed limit included in the instruction from the driving assistance ECU 10 in the area 71a. Furthermore, the notification ECU 70 blinks the displayed speed limit and also blinks a pattern that calls attention around the displayed speed limit, and also generates an alarm sound (for example, an alarm sound that repeats a "beep" sound) from the alarm sound generating device 72, thereby notifying the occupants of the vehicle HV (particularly the driver) that the vehicle speed exceeds the speed limit. This notification is hereinafter referred to as an "excessive speed notification," "notification for alerting the driver of excessive speed," or "attention notification." Furthermore, the notification ECU 70 is connected to a customization device 73 that is operated by the driver. By operating the customization device 73, the driver can change an "excessive speed threshold OSth for issuing an attention notification," which will be described later.

[0020] The navigation ECU 80 is connected to a GPS receiver 81, a map database 82, and a display touch panel 83 that displays touch-type buttons, and together with these constitutes an in-vehicle navigation system. The navigation ECU 80 acquires the current position of the host vehicle HV based on the GPS signal received by the GPS receiver 81, and 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 planned travel route in response to an instruction from the driver, and then executes well-known route guidance. Furthermore, the navigation ECU 80 acquires the speed limit currently set / applied to the host vehicle's lane based on the acquired current position of the host vehicle HV and the map data.

[0021] The communication ECU 90 wirelessly communicates with devices external to the host vehicle HV (for example, roadside devices and an information management center) and acquires various types of information from the external devices.

[0022] The driving assistance ECU 10 receives 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 detects a brake pedal operation amount BP of the host vehicle HV. A vehicle speed sensor 93 that detects the speed of the host vehicle HV (i.e., 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 the 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 host vehicle HV. The turn signal switch 96 generates a signal when a turn signal lever provided on a steering column (not shown) is operated by the driver. When the turn signal lever is rotated counterclockwise, the turn signal switch 96 generates a signal for flashing the direction indicator located on the left side of the host vehicle HV, and when the turn signal lever is rotated clockwise, the turn signal switch 96 generates a signal for flashing the direction indicator located on the right side of the host vehicle HV. The direction indicator flashes according to the signal of the turn signal switch 96. The driving assistance ECU 10 is also connected to other sensors (e.g., a steering torque sensor) other than those mentioned above.

[0023] (Overview of operation) The device DS acquires the speed limit (maximum speed) SPDLT of the lane in which the host vehicle HV is traveling, and performs a first speeding overrun notification when it is determined that the host vehicle speed SPD exceeds the speed limit SPDLT by an excess speed threshold OSth or more. Furthermore, the device DS performs an additional (second or subsequent) speeding overrun notification when the host vehicle speed SPD continues to exceed the speed limit SPDLT and the host vehicle HV is accelerated or is estimated to be accelerated due to the relative positional relationship between the host vehicle HV and the preceding vehicle.

[0024] (Specific operation) The CPU 10a of the driving assistance ECU 10 (hereinafter, simply referred to as "CPU") executes the routines shown in the flowcharts of Figures 2 to 4 at predetermined intervals (calculation cycles) dt. In the following description, "step" is abbreviated as "S".

[0025] <Getting the speed limit> 2, the CPU starts the process at S200 and proceeds to S210 to determine whether or not a new speed limit set for the host vehicle lane has been acquired (image recognized) based on image data transmitted from the camera device 20. The CPU may acquire the speed limit set for the host vehicle lane from the current position of the host vehicle HV and the map data stored in the map database 82 via the navigation ECU 80.

[0026] When a new speed limit is acquired, the CPU proceeds from S210 to S220, and determines whether the newly acquired speed limit in S210 is the first speed limit acquired after the ignition key switch (not shown) of the host vehicle HV is changed from the OFF position to the ON position (after the IG is turned on). If the newly acquired speed limit is the first speed limit acquired after the IG is turned on, the CPU proceeds from S220 to S240 (described later).

[0027] 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 and determines whether the attention-calling speed limit SPDLT currently recognized by the CPU (described later) differs from the newly acquired speed limit. If the attention-calling speed limit SPDLT currently recognized by the CPU differs from the newly acquired speed limit, the CPU proceeds from S230 to S240.

[0028] In S240, the CPU sets the newly acquired speed limit to the attention-calling speed limit SPDLT, and displays a pattern corresponding to the attention-calling speed limit SPDLT in the area 71a of the display 71. After that, the CPU performs "processing of S250 and S260" described below, proceeds to S295, and temporarily ends this routine.

[0029] 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," this indicates that the first speed limit notification has been made since a new caution speed limit SPDLT was set (in other words, since the caution speed limit SPDLT was changed) (see S320 in FIG. 3).

[0030] 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," this indicates that the first speed limit notification was issued after a new caution speed limit SPDLT was set, and then an additional (second) speed limit notification was issued while the vehicle speed SPD continued to exceed the speed limit SPDLT (see S350 in FIG. 3).

[0031] The values ​​of flags X1 and X2 are both set to "0" in an initialization routine executed by the CPU when the ignition key switch is changed from the OFF position to the ON position.

[0032] In addition, if the CPU determines "No" in either step S210 or S230, the CPU proceeds directly from the step where it determined "No" to step S295.

[0033] <Speeding Warning Notification (Speeding Notification)> At a predetermined timing, the CPU starts the process from S300 in FIG. 3, proceeds to S305, and determines whether the value of the first-time completion flag X1 is "0".

[0034] If the value of the first completion flag X1 is "0", the CPU proceeds from S305 to S310 and determines whether the host vehicle speed SPD is greater than "the value obtained by adding the speed limit SPDLT to the overspeed threshold OSth". Note that the overspeed threshold OSth is set to a constant value (e.g., 5 km / h) here, but may be a value equal to or greater than "0 km / h" and may be changed by operating the customization device 73 as described later. If the host vehicle speed SPD does not exceed "the value obtained by adding the speed limit SPDLT to the overspeed threshold OSth", the CPU proceeds directly from S310 to S395 and ends this routine for the time being.

[0035] On the other hand, if the vehicle speed SPD is greater than the "value obtained by adding the excess speed threshold OSth to the speed limit SPDLT," the CPU judges "Yes" in S310 and executes "the processing of S315 to S325" described below. After that, the CPU proceeds to S395.

[0036] S315: The CPU executes the initial (first) speed limit notification (attention notification) after a new attention-calling speed limit SPDLT is set. That is, the CPU blinks the speed limit (i.e., the symbol indicating the attention-calling speed limit SPDLT) displayed in the area 71a of the display 71, blinks symbols calling attention around the displayed speed limit, and generates an alarm sound from the alarm sound generation device 72. However, the notification method is not limited to this. S320: The CPU sets the value of the first-time completion flag X1 to “1”. S325: The CPU obtains the vehicle speed SPD at the current time (ie, the time when the first speed limit notification is executed) as a reference vehicle speed SPD1 and stores it in the RAM 10c.

[0037] On the other hand, if the value of the first-time completion flag X1 is not "0" when the CPU proceeds to S305, the CPU proceeds from S305 to S330 and determines whether the value of the second-time completion flag X2 is "0".

[0038] If the value of the second completion flag X2 is "0", the CPU proceeds from S330 to S335 and determines whether the host vehicle speed SPD is greater than the "value obtained by adding the speed limit SPDLT to the excess speed threshold OSth". If the host vehicle speed SPD is greater than the "value obtained by adding the speed limit SPDLT to the excess speed threshold OSth", the CPU proceeds from S335 to S340 and determines whether the "attention condition related to the preceding vehicle (one of the execution conditions for additional speeding notification)" described below is satisfied. The preceding vehicle is another vehicle traveling in the host vehicle lane, and is another vehicle traveling immediately before the host vehicle HV and within a predetermined distance from the host vehicle HV. This attention condition related to the preceding vehicle is a condition that is satisfied when both the following conditions A1 and B1 are satisfied, and for convenience, is referred to as the "first attention condition related to the preceding vehicle".

[0039] <<First caution condition related to the preceding vehicle>> (Condition A1) The state in which the host vehicle HV is following a preceding vehicle at a speed close to the actual speed Vj or at a speed substantially the same as the preceding vehicle has continued for a predetermined period of time or more. (Condition B1) After condition A1 is satisfied, the host vehicle speed SPD does not fall below the speed limit SPDLT, and the host vehicle HV is executing an operation to overtake the preceding vehicle.

[0040] Here, the actual speed Vj is the average value of the vehicle speeds of multiple other vehicles ahead of the host vehicle HV traveling in the host lane. In this example, the CPU acquires the actual speed Vj from a "roadside device acquiring the actual speed Vj" by "wireless communication using the communication ECU 90". This roadside device is provided for the host lane, detects the speed of vehicles passing through the host lane using a radar, calculates the actual speed Vj one by one, and transmits the actual speed Vj for the host vehicle HV to the host vehicle HV based on a request from the host vehicle HV. The speeds near the actual speed Vj are within a range from a speed lower than the actual speed Vj by a predetermined small speed to a speed higher than the actual speed Vj by a predetermined small speed.

[0041] Furthermore, the CPU may obtain the vehicle speeds of the preceding vehicle and the "vehicle preceding the preceding vehicle" based on the camera information and radar information, and use the average value of the speeds as the actual speed Vj. In addition, the CPU may obtain (estimate) the "speed of the preceding vehicle when the preceding vehicle is not accelerating or decelerating" based on the radar information as the actual speed Vj.

[0042] The CPU determines that the host vehicle HV is performing an operation to overtake the preceding vehicle (the above condition B1 is satisfied) when all of the following "overtaking determination conditions 1 to 4" are satisfied. (Overtaking judgment condition 1) The turn signal switch 96 generates a signal to flash the "direction indicator on either the left or right side." (Overtaking Judgment Condition 2) From the point when the overtaking judgment condition 1 is satisfied, the lateral position of the host vehicle HV has moved by a predetermined lateral position movement amount threshold or more toward the "side where the turn signal is flashing." The change amount (movement amount) of the lateral position may be acquired based on camera information or may be acquired based on the integral value of the detected yaw rate Yr. (Overtaking judgment condition 3) Since the time when the overtaking judgment condition 1 was satisfied, the host vehicle speed SPD has increased by the first host vehicle speed increase threshold (overtaking judgment vehicle speed threshold) Da or more. Note that the overtaking judgment condition 3 may be omitted. In this case, the first attention warning condition is satisfied when the host vehicle HV starts an overtaking operation and the host vehicle speed is predicted to increase.

[0043] If the first warning condition related to the preceding vehicle is satisfied (see FIG. 5A, which shows the host vehicle HV and the preceding vehicle PV), the CPU proceeds from S340 to S345, where it executes an additional speeding notification (second warning notification) to notify the host vehicle speed SPD that it exceeds the speed limit SPDLT. The method of notification is the same as the first speeding notification executed by the processing of S315. Next, the CPU proceeds to S350, where it sets the value of the second completion flag X2 to "1", and proceeds to S395.

[0044] On the other hand, when the CPU proceeds to S340 and the first attention calling condition related to the preceding vehicle is not satisfied, the CPU proceeds from S340 to S355 to determine whether or not the attention calling condition related to the host vehicle speed is satisfied. The attention calling condition related to the host vehicle speed is satisfied when all of the following conditions X1 to X3 are satisfied.

[0045] <<Caution conditions related to vehicle speed>> (Condition X1) There is no vehicle ahead. (Condition X2) The current vehicle speed SPD is higher than a value (hereinafter referred to as the "first threshold Db") obtained by adding a second vehicle speed increase threshold (increased speed determination threshold) Db to the vehicle speed at the time when the first (i.e., previous) overspeed warning was executed (i.e., the reference vehicle speed SPD1 acquired in S325). However, the first threshold Db is set to a value larger than the overspeed threshold OSth. The first threshold Db may be a fixed value or may be determined according to the reference vehicle 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 a value (1 + α) times the speed limit SPDLT for warning. Here, α is a value greater than 0 and less than 1, for example, 0.2. The second threshold value may be a fixed value or may be determined according to the speed limit SPDLT for warning.

[0046] If the warning condition related to the vehicle speed is satisfied, the CPU proceeds from S355 to S345 and S350 to execute an additional (second) speed limit warning and set the value of the second completion flag X2 to "1", and then proceeds to S395.

[0047] If the CPU determines "No" in any of steps S330, S335, and S355, the CPU proceeds directly to S395 from the step where it determined "No."

[0048] <Canceling the speed limit notification> At a predetermined timing, the CPU starts the process from S400 in FIG. 4, proceeds to S410, and determines whether the value of the first-time completion flag X1 is "1".

[0049] If the value of the first completion flag X1 is "1", the CPU proceeds from S410 to S420 and determines whether or not a cancellation condition for the speed limit notification is satisfied. This cancellation condition is satisfied when at least one of the following "conditions CACL1 and CACL2" is satisfied. If the cancellation condition is not satisfied, the CPU proceeds from S410 to S495.

[0050] <<Conditions for canceling speed limit notification>> (Condition CACL1) The vehicle speed SPD is below 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 was updated (i.e., the position of the host vehicle HV at the time S240 was executed).

[0051] If the speed limit notification cancellation condition is met, the CPU judges "Yes" in S420 and performs the "processing of S430 and S440" described below, and then proceeds to S495 to temporarily end this routine.

[0052] S430: The CPU sets the value of the first-time completion flag X1 to “0”. S440: The CPU sets the value of the second completion flag X2 to “0”.

[0053] As described above, the device DS of the first embodiment executes an additional speeding notification when the first attention calling condition related to the preceding vehicle is satisfied. The CPU may be configured not to issue a speeding notification during a period in which the host vehicle HV is straddling a "dividing line between the host lane and a lane adjacent to the host lane" after the above condition B1 is satisfied. This is because if a speeding notification is issued during a period in which the host vehicle HV is straddling a dividing line, the driver may become confused.

[0054] 2. Second embodiment The device DS according to the second embodiment of the present invention differs from the device DS according to the first embodiment only in that the CPU of the driving assistance ECU 10 determines whether or not a "second attention calling condition related to the preceding vehicle" different from the "first attention calling condition related to the preceding vehicle" is satisfied at S340 in Fig. 3. This difference will be described below.

[0055] The second attention warning condition related to the preceding vehicle is a condition that is met when all of the following conditions A2, B2, and C2 are met.

[0056] <<Second caution condition related to the preceding vehicle>> (Condition A2) The same condition as condition A1. (Condition B2) The preceding vehicle that the host vehicle HV was following is no longer present. (Condition C2) From the point in time when the preceding vehicle that the host vehicle HV was following disappeared, the host vehicle speed SPD increased by or more than the third host vehicle speed increase threshold (single acceleration judgment threshold) Dc without falling below the speed limit SPDLT.

[0057] When the second attention warning condition related to the preceding vehicle is satisfied (see FIG. 5B showing the host vehicle HV and the preceding vehicle PV), the CPU proceeds from S340 to S345 and SS350, and then proceeds to S395.

[0058] Condition C2 may be omitted. In this case, an additional speed limit warning is issued immediately when the preceding vehicle that the host vehicle HV has been following disappears. That is, the second warning condition in which condition C2 is omitted is a condition that is met when the host vehicle speed is predicted to increase because the preceding vehicle no longer exists.

[0059] 3. Third embodiment The device DS according to the third embodiment of the present invention differs from the device DS according to the first embodiment only in that the CPU of the driving assistance ECU 10 determines whether or not a "third attention calling condition related to the preceding vehicle" different from the "first attention calling condition related to the preceding vehicle" is satisfied in S340. This difference will be described below.

[0060] The third caution condition related to the preceding vehicle is a condition that is met when all of the following conditions A3, B3, and C3 are met.

[0061] <<Third caution condition related to the preceding vehicle>> (Condition A3) The same condition as condition A1. (Condition B3) The preceding vehicle that the host vehicle HV was following accelerates. Specifically, the vehicle speed of the preceding vehicle becomes greater than the "actual speed Vj plus the preceding vehicle acceleration determination threshold Pa." Note that the determination of whether the preceding vehicle has accelerated can be made based on the relative speed of the preceding vehicle or the inter-vehicle distance from the preceding vehicle, which is based on camera information, radar information, etc., and the host vehicle speed SPD. (Condition C3) After condition A1 is satisfied, the host vehicle speed SPD does not fall below the speed limit SPDLT, the host vehicle HV accelerates in response to the acceleration action of the preceding vehicle, and the host vehicle speed SPD increases by more than the fourth host vehicle speed increase threshold (following acceleration judgment threshold) Dd from the "host vehicle speed at the time the preceding vehicle started accelerating."

[0062] When the third attention warning condition related to the preceding vehicle is satisfied (see FIG. 5C showing the host vehicle HV and the preceding vehicle PV), the CPU proceeds from S340 to S345 and SS350, and then proceeds to S395.

[0063] Condition C3 may be omitted. In this case, the third attention condition is that an additional speed limit warning is issued immediately when the preceding vehicle that the host vehicle HV has been following starts accelerating. That is, the third attention condition in which condition C3 is omitted is a condition that is met when the host vehicle speed is predicted to increase due to the relative positional relationship with the host vehicle HV.

[0064] (Modification) In the modified example of the device DS according to the first to third embodiments, the driver of the host vehicle HV can set (change) the overspeed threshold OSth using the customization device 73. For example, as shown in the setting table of FIG. 6, the driver uses the customization device 73 to select one of settings 1 to 3, and uses the value determined for each setting as the overspeed threshold OSth. For example, when the driver selects setting 1, the overspeed threshold OSth is set to 10·A (km / h). Here, A (km / h) is, for example, 1 (km / h). That is, the driver can select the speed at which the first overspeed notification is issued when the host vehicle speed SPD exceeds the speed limit SPDLT.

[0065] Furthermore, 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). According to the setting table shown in FIG. 6, the higher the selected overspeed threshold OSth, the higher the first to fourth vehicle speed increase thresholds (Da, Db, Dc, Dd) are set to. Note that the values ​​shown in FIG. 6 are merely examples, and may be set to various values ​​as appropriate. Also, the number of settings that can be set is not limited to "3".

[0066] As is apparent from the above, the first to third attention calling conditions are satisfied when the vehicle speed 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 and its modified example of the present invention, the speed limit warning can be issued at an appropriate time based on the relative positional relationship between the preceding vehicle and the host vehicle HV.

[0067] The present invention is not limited to the above embodiment and modified examples, and various modified examples can be adopted within the scope of the present invention. For example, the CPU may determine in S340 whether any two or more of the first to third attention calling conditions related to the preceding vehicle are satisfied, and if it determines that at least one of the conditions determined to be satisfied is satisfied, the process may proceed from S340 to S345 to perform an additional speeding notification.

[0068] Furthermore, the device DS in each of the above embodiments may issue an additional speeding warning after the second speeding warning when at least one of the "first to third warning conditions related to the preceding vehicle and the warning condition related to the vehicle speed" is satisfied.

[0069] More specifically, for example, in the first embodiment, if the host vehicle HV performs an operation to overtake a preceding vehicle and the first warning condition related to the preceding vehicle is satisfied, thereby causing a second speeding warning to be issued, and then a new preceding vehicle is present in the adjacent lane that the host vehicle HV has newly entered to perform the overtaking, or in the original host vehicle lane to which the host vehicle HV has returned after completing the overtaking operation, and one of the first to third warning conditions related to the preceding vehicle is satisfied for the new preceding vehicle, the device DS may issue an additional speeding warning.

[0070] The same applies to the second and third embodiments, and the device DS may perform an additional speeding warning each time any one of the second and third attention conditions related to the preceding vehicle is satisfied. Furthermore, the first threshold value of the above condition X2 may be a value obtained by increasing the reference vehicle speed SPD1 by a predetermined ratio (e.g., 1.1·SPD1), and the second threshold value of the above condition X3 may be a value obtained by adding the speed limit exceeding threshold value Df to the limit vehicle speed SPDL. The first to fourth vehicle speed increase threshold values ​​(Da, Db, Dc, Dd) may be any suitable value equal to or greater than 0, including "0". [Explanation of symbols]

[0071] 10...driving assistance ECU, 20...camera device, 30...radar device, 70...alarm ECU, 93 vehicle speed sensor.

Claims

1. a speed limit acquisition unit that acquires a speed limit applied to the vehicle; a vehicle speed acquisition unit that acquires a vehicle speed, which is a speed of the vehicle; an attention calling notification unit that issues a first notification when the host vehicle speed is higher than the speed limit, and issues an additional notification when a predetermined attention calling condition is satisfied, the condition being satisfied when the host vehicle speed increases or is predicted to increase due to a relative positional relationship between the host vehicle and a preceding vehicle traveling in front of the host vehicle while the host vehicle speed continues to be higher than the speed limit after the first notification; A driving assistance device for a vehicle equipped with the above-mentioned.

2. The vehicle driving assistance device according to claim 1, The attention-calling condition includes a condition that the host vehicle has changed from a state in which the host vehicle is traveling so as to follow the preceding vehicle to a state in which the host vehicle is performing an overtaking operation to overtake the preceding vehicle. Driving assistance device.

3. The vehicle driving assistance device according to claim 1, The attention-calling condition includes a condition that the host vehicle is traveling in a state where the host vehicle is following the preceding vehicle and the preceding vehicle is no longer present. Driving assistance device.

4. The vehicle driving assistance device according to claim 1, The attention-calling condition includes a condition that the preceding vehicle accelerates from a state in which the host vehicle is traveling in a manner to follow the preceding vehicle. Driving assistance device.

5. A driving assistance device for a vehicle according to any one of claims 1 to 4, The attention calling notification unit is configured to perform an additional notification when, after the first notification, in a state in which the vehicle speed remains higher than the speed limit after the first notification and the preceding vehicle does not exist, the vehicle speed becomes higher than a first threshold value determined according to the vehicle speed at the time when the first notification is executed and becomes higher than a second threshold value determined according to the speed limit. Driving assistance device.

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