Start notification device and start notification method

Abstract

To provide a start notification device and a start notification method which accurately detect flying start of a preceding vehicle as much as possible to be capable of reducing possibility of performing unnecessary start notification of the preceding vehicle.SOLUTION: A start notification device DS comprises: information acquisition devices 21, 22L, 22R, 24, 25L, 25R which acquire information of a preceding vehicle that stops in front of an own vehicle; and controllers 10, 50 which perform, when detecting starting of the preceding vehicle based on the information, a start notification of a preceding vehicle to notify the starting of the preceding vehicle to a driver of the own vehicle. The controllers 10, 50 calculate a determination value related to possibility of flying start of the preceding vehicle based on any two or more of a plurality of index values regarding the preceding vehicle and compare the determination value with a permission threshold to determine whether start notification of the preceding vehicle is performed or not based on the comparison result.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a departure notification device and a departure notification method for notifying a driver of a preceding vehicle that the preceding vehicle has started moving. [Background technology]

[0002] Conventionally, there has been known a departure notification device that notifies the driver of a host vehicle that a preceding vehicle has started moving when the host vehicle is stopped immediately behind a preceding vehicle that is stopped immediately before the host vehicle and the preceding vehicle starts moving. One such departure notification device (hereinafter referred to as a "conventional device") determines that a departure notification is unnecessary when the preceding vehicle that has started moving is about to turn right or left, and suppresses the departure notification (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6583166 Summary of the Invention

[0004] However, situations in which a departure notification is unnecessary are not limited to when the leading vehicle is about to turn right or left. For example, if the leading vehicle starts moving before the traffic lights ahead of the vehicle and the leading vehicle change from red to green (i.e., when a so-called "premature departure of the leading vehicle" occurs), the driver of the vehicle may feel uneasy if a preceding vehicle departure notification is issued.

[0005] The present invention has been made to solve the above problems. That is, one object of the present invention is to provide a departure notification device and a departure notification method that can detect an early departure of a preceding vehicle as accurately as possible and reduce the possibility of unnecessary preceding vehicle departure notifications being made.

[0006] One aspect of the departure notification device according to the present invention includes an information acquisition device (21, 22L, 22R, 24, 25L, 25R) that acquires information about a preceding vehicle that is stopped immediately in front of the host vehicle, and a controller (10, 50) that, when it detects that the preceding vehicle has started moving based on the information, issues a preceding vehicle departure notification to notify the driver of the host vehicle that the preceding vehicle has started moving.

[0007] Further, the controller A judgment value (P) correlating with the possibility that the preceding vehicle has made an early departure is calculated based on a plurality of index values ​​(any two or more of W, T, θ, N, and A) for the preceding vehicle obtained from the information (S430-S450, S510, S520, S620); The control unit 100 determines whether or not to notify the preceding vehicle of departure based on the result of comparison between the determination value (P) and a predetermined permission threshold (Path) (S335, S345).

[0008] Therefore, the departure notification device of the above aspect can effectively reduce the possibility that a preceding vehicle departure notification will be issued when the preceding vehicle starts when it should not have started (i.e., when the preceding vehicle makes an early start), thereby reducing the possibility that the driver of the vehicle will feel uneasy about the preceding vehicle departure notification.

[0009] In the above description, to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses for the configurations of the invention corresponding to those embodiments. However, the components of the present invention are not limited to the embodiments defined by the names and / or symbols. The present invention also covers a departure notification method and a program therefor. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a departure notification device according to an embodiment of the present invention; [Figure 2] A routine executed by the CPU of the driving assistance ECU shown in Figure 1. [Figure 3] A routine executed by the CPU of the driving assistance ECU shown in Figure 1. [Figure 4] A routine executed by the CPU of the driving assistance ECU shown in Figure 1. [Figure 5] A routine executed by the CPU of the driving assistance ECU shown in Figure 1. [Figure 6] A routine executed by the CPU of the driving assistance ECU shown in Figure 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] The vehicle departure notification device DS (hereinafter referred to as "this notification device") according to the embodiment of the present invention shown in Fig. 1 is mounted on the vehicle itself. The vehicle itself may be any of a vehicle powered by an internal combustion engine, an electric vehicle powered by an electric motor, a hybrid vehicle, etc.

[0012] This notification device DS includes a driving assistance ECU 10 (hereinafter referred to as "DSECU"), a powertrain ECU 30, a brake ECU 40, and a notification ECU 50. These ECUs are connected to each other via a communication and sensor system CAN (Controller Area Network) to enable data exchange. ECU is an abbreviation for electronic control unit, and is also called a controller or computer. The ECU is an electronic control circuit that has a microcomputer as its main component. The microcomputer includes a CPU (processor), ROM, RAM, and an interface. The CPU executes instructions (routines) stored in the memory (ROM) to realize various functions, which will be described later.

[0013] As shown in Fig. 1, the notification device DS includes a plurality of radar devices (21, 22L, 22R, 23L, 23R) and a plurality of camera devices (24, 25L, 25R, 26). These devices can also exchange data with the DSECU via the CAN. Furthermore, the DSECU receives output signals from a vehicle speed sensor 27 and a shift position sensor 28.

[0014] Each of the radar devices (21, 22L, 22R, 23L, 23R) is a well-known device that acquires information about targets present around the vehicle using millimeter-wave band radio waves, and includes a radar transceiver unit and a processing unit (radar ECU). The radar transceiver unit transmits millimeter waves within a predetermined detection range every time a predetermined time elapses and receives millimeter waves reflected by the targets. The radar transceiver unit transmits information about the transmitted and received millimeter waves to the processing unit. Every time a predetermined time elapses, the processing unit acquires radar target information based on the information from the radar transceiver unit and transmits the radar target information to the DSECU. The radar target information includes the distance between the position where the radar transceiver unit is located and the target, the azimuth of the target relative to the radar transceiver unit, and the relative speed of the target with respect to the radar transceiver unit.

[0015] The front radar device 21 acquires radar target information about targets present in front of the vehicle. The left front-side radar device 22L acquires radar target information about targets present on the left front side of the vehicle. The right front-side radar device 22R acquires radar target information about targets present on the right front side of the vehicle. The left rear-side radar device 23L acquires radar target information about targets present on the left rear side of the vehicle. The right rear-side radar device 23R acquires radar target information about targets present on the right rear side of the vehicle.

[0016] The DSECU integrates the radar target information transmitted from these radar devices to generate radar integrated target information about targets present around the host vehicle. Similar to the fusion target information described later, the radar integrated target information is expressed using an XY coordinate system with the origin at the center position in the vehicle width direction of the front end of the host vehicle. The X coordinate axis of the XY coordinate system is an axis extending in the longitudinal direction of the host vehicle. The Y coordinate axis of the XY coordinate system is an axis perpendicular to the X coordinate axis.

[0017] Each of the camera devices (24, 25L, 25R, 26) includes a "camera with a wide-angle lens and an image ECU" (not shown). However, the cameras may also be equipped with normal lenses. The cameras capture images of a scene within a predetermined capture area set for each camera at predetermined time intervals to obtain image data. The image ECU recognizes lane markings on the road on which the vehicle is traveling based on the image data from the cameras. Furthermore, the image ECU generates camera target information based on the image data from the cameras at predetermined time intervals and transmits the information to the DSECU. The camera target information includes the "position (longitudinal and lateral positions), width, projected area in the longitudinal direction, and type" of targets present around the vehicle.

[0018] The front camera device 24 generates camera target information for targets present in the area ahead of the vehicle. The left camera device 25L generates camera target information for targets present in the area to the left of the vehicle. The right camera device 25R generates camera target information for targets present in the area to the right of the vehicle. The rear camera device 26 generates camera target information for targets present in the area behind the vehicle.

[0019] The DSECU generates fusion target information, which is final target information about targets around the vehicle, by integrating the radar-integrated target information and the camera-integrated target information every time a predetermined time elapses. The fusion target information includes the "longitudinal distance (distance in the longitudinal direction of the vehicle), direction, relative speed, width, projected area, and type" of the target relative to the vehicle.

[0020] Furthermore, the DSECU assigns a target ID to the recognized target. If a newly recognized target is the same as a target recognized a predetermined time ago, the DSECU assigns the "target ID assigned to the target recognized a predetermined time ago" to the newly recognized target.

[0021] The vehicle speed sensor 27 outputs a signal indicating the speed of the host vehicle (host vehicle speed) Vh. The shift position sensor outputs a signal representing the shift position of the host vehicle.

[0022] The powertrain ECU 30 receives detection signals from powertrain sensors 31, including an accelerator pedal operation amount sensor. The powertrain ECU 30 controls a drive device of the host vehicle (not shown) using a powertrain actuator 32 to adjust the drive force of the host vehicle.

[0023] The brake ECU 40 receives a detection signal from a brake sensor 41, which includes a brake pedal operation amount sensor. The brake ECU 40 controls a braking device of the host vehicle (not shown) by driving a brake actuator 42, and adjusts the braking force applied to the host vehicle.

[0024] The notification ECU 50 changes the characters and figures displayed on a display 51. The notification ECU 50 causes a sound generating device 52 to generate a notification sound or a voice message.

[0025] (Overview of operation) When the notification device DS detects that the preceding vehicle has started moving while the preceding vehicle is stopped and the host vehicle is stopped immediately behind the preceding vehicle, the notification device DS notifies the driver of the host vehicle that the preceding vehicle has started moving using the display 51 and / or the sound generation device 52. This notification is called a "preceding vehicle departure notification."

[0026] However, there are cases where a leading vehicle starts moving earlier than the timing at which the leading vehicle should start moving (for example, the timing at which the traffic light ahead changes from red to green). Such a start is called a "premature start." When the leading vehicle makes a premature start, the leading vehicle departure notification should not be executed immediately.

[0027] Therefore, the notification device DS acquires "plurality of index values" for the preceding vehicle, and acquires a notification permission determination value P (also simply referred to as "determination value") that correlates with "the possibility that the preceding vehicle has made an early departure" based on the index values. The notification device DS determines whether to issue a notification of the departure of the preceding vehicle based on the result of comparing the notification permission determination value P with a permission threshold value Pth.

[0028] (Specific operation) The CPU of the DSECU (hereinafter, when written as "CPU," it refers to the CPU of the DSECU unless otherwise specified) is configured to execute the routines shown in the flowcharts of Figures 2 to 6 every time a predetermined time has elapsed. Below, steps may be written as "S."

[0029] 1. Determining preconditions for preceding vehicle departure notification At a predetermined timing, the CPU starts processing from S200 in Fig. 2 and determines in S210 whether the preceding vehicle departure notification is not being executed (a state in which the preceding vehicle departure notification is not being executed). If the preceding vehicle departure notification is not being executed, the CPU proceeds from S210 to S220 and determines whether the value of the notification prerequisite flag XPRC is "0". The value of the notification prerequisite flag XPRC is set to "1" when the prerequisite for the preceding vehicle departure notification is met (see S280 described later), and is set to "0" when the preceding vehicle departure notification is executed or when the preceding vehicle departure notification is no longer necessary (see S345 described later).

[0030] The values ​​of the notification prerequisite flag XPRC and other flags are set to "0" by an initialization routine executed by the CPU when the vehicle's start switch (e.g., ignition key switch) is changed from the OFF position to the ON position.

[0031] If the value of the notification prerequisite flag XPRC is "0", the CPU proceeds from S220 to S230 to determine whether the host vehicle is stopped (i.e., whether the host vehicle speed Vh is "0"). If the host vehicle is stopped, the CPU proceeds from S230 to S240 to determine whether the preceding vehicle located immediately before the host vehicle is a "vehicle other than a notification-prohibited vehicle". Notification-prohibited vehicles will be described later (see S360 in FIG. 3).

[0032] If the preceding vehicle is a "vehicle other than a vehicle subject to notification prohibition," the CPU proceeds from S240 to S250, where it determines whether the preceding vehicle located immediately in front of the host vehicle is stopped based on the relative speed of the preceding vehicle and the host vehicle speed Vh. If the preceding vehicle located immediately in front of the host vehicle is stopped, the CPU proceeds from S250 to S260, where it saves (stores) the inter-vehicle distance D between the preceding vehicle and the host vehicle at that time in RAM as an "initial inter-vehicle distance value D0."

[0033] Next, the CPU proceeds to S270 to determine whether the initial inter-vehicle distance D0 is equal to or less than the prerequisite distance threshold D1th. The prerequisite distance threshold D1th is set to a predetermined distance between 6 m and 10 m, for example. If the initial inter-vehicle distance D0 is equal to or less than the prerequisite distance threshold D1th, the CPU proceeds from S270 to S280 to set the value of the notification prerequisite flag XPRC to "1." In other words, the CPU determines that the prerequisite conditions for issuing a preceding vehicle departure notification are met. Thereafter, the CPU proceeds to S295 to temporarily end this routine.

[0034] If the CPU determines "No" in any of steps S210 to S250 and S270, the CPU proceeds directly from the step where it determined "No" to step S295.

[0035] 2. Announcement of preceding vehicle departure At a predetermined timing, the CPU starts processing from S300 in FIG. 3 and proceeds to S305. In S305, the CPU determines whether the preceding vehicle departure notification is not currently being executed (is not being executed). If the preceding vehicle departure notification is not currently being executed, the CPU proceeds from S305 to S310 and determines whether the value of the notification prerequisite flag XPRC is "1." If the value of the notification prerequisite flag XPRC is "1," the CPU proceeds from S310 to S315 and determines whether the inter-vehicle distance D between the host vehicle and the preceding vehicle at that time is longer than the "distance obtained by adding the initial inter-vehicle distance value D0 to the positive notification distance threshold D2th (=D0+D2th)." That is, in S315, the CPU determines whether the preceding vehicle has started moving. The above distance (=D0+D2th) is also referred to as the "alert start allowable distance."

[0036] If the inter-vehicle distance D is longer than the distance obtained by adding the initial inter-vehicle distance D0 to the notification distance threshold D2th (=D0+D2th), the CPU proceeds from S315 to S320 to determine whether the host vehicle speed Vh is equal to or less than the notification vehicle speed threshold Vhth. That is, the CPU determines whether the host vehicle is maintaining a substantially stopped state. The notification vehicle speed threshold Vhth may be "0" or a value slightly greater than "0" (e.g., 3 km / h). If the host vehicle speed Vh is equal to or less than the notification vehicle speed threshold Vhth, the CPU proceeds from S320 to S325 to determine whether the shift position is "either a forward position (e.g., D range) or a neutral position."

[0037] If the shift position is "either the forward position or the neutral position," the CPU proceeds from S325 to S330, and calculates "a notification permission determination value P correlated with an early departure of the preceding vehicle" using the "routines shown in Figures 4 to 6" described below. In this example, the notification permission determination value P is calculated so that it approaches "0" as the possibility of the preceding vehicle having made an early departure increases, and so that it increases as the possibility of the preceding vehicle having made an early departure decreases.

[0038] Next, the CPU proceeds to S335 and determines whether the notification permission determination value P is equal to or greater than the permission threshold value Path. If the notification permission determination value P is equal to or greater than the permission threshold value Path, the CPU proceeds from S335 to S340 and determines whether the preceding vehicle is not a notification-prohibited vehicle, as described below. If the preceding vehicle is a notification-prohibited vehicle, as described below, the CPU proceeds directly from S340 to S350. On the other hand, if the preceding vehicle is not a notification-prohibited vehicle, as described below, the CPU proceeds from S340 to S345 and executes a preceding vehicle departure notification for a certain period of time using at least one of the display device 51 and the sound generating device 52 to notify (announce) the driver of the host vehicle that the preceding vehicle has started moving. In this case, the CPU may display a "pattern or message" indicating that the preceding vehicle has started moving on the display device 51. Furthermore, the CPU may cause the sound generating device 52 to emit a "buzzer sound or a message indicating that the preceding vehicle has started moving."

[0039] Next, the CPU proceeds to S350, where it sets the value of the notification prerequisite flag XPRC to 0. After that, the CPU proceeds to S395, where it temporarily ends this routine.

[0040] On the other hand, when the CPU proceeds to S335, if the notification permission determination value P is less than the permission threshold Pth, the CPU proceeds from S335 to S355. In S355, the CPU determines whether the notification permission determination value P is less than the prohibition threshold Pbth, which is smaller than the permission threshold Pbth. If the notification permission determination value P is less than the prohibition threshold Pbth, the CPU proceeds from S355 to S360, and identifies the current preceding vehicle (in other words, the preceding vehicle whose notification permission determination value P is less than the prohibition threshold Pbth) as a "vehicle prohibited from preceding vehicle departure notification (i.e., a vehicle prohibited from notification)" (see S240 in FIG. 2 and S340 in FIG. 3). Thereafter, the CPU proceeds to S350, and then to S395, where it temporarily ends this routine. If the notification permission determination value P is equal to or greater than the prohibition threshold Pbth, the CPU proceeds directly from S355 to S395.

[0041] If the CPU determines "No" in any of steps S305 to S315, it proceeds directly from that step to S395. Furthermore, if the CPU determines "No" in any of steps S320 and S325, it proceeds directly from that step to S350, and then proceeds to S395.

[0042] 3. Calculation of notification permission threshold P As described above, when the CPU proceeds to S330 in Fig. 3, it executes the routines shown in Fig. 4 to Fig. 6 to calculate the notification permission determination value P. More specifically, when the CPU proceeds to S330 in Fig. 3, it starts processing from S400 in Fig. 4 and proceeds to S410.

[0043] In S410, the CPU determines whether the currently recognized preceding vehicle is the same vehicle as the preceding vehicle recognized the previous time this routine was executed. If the currently recognized preceding vehicle is the same vehicle as the preceding vehicle recognized the previous time this routine was executed, the CPU proceeds directly from S410 to S430.

[0044] If the currently recognized preceding vehicle is not the same vehicle as the preceding vehicle recognized the previous time this routine was executed, the CPU proceeds from S410 to S420, where it sets the value of the notification permission determination value P to 0. Then, the CPU proceeds to S430.

[0045] Next, the CPU sequentially performs the processes of "S430 to S450, S510 to S540 in FIG. 5, and S610 in FIG. 6" described below to determine the "nth determination element value Pn (n is an integer from 1 to 8)" used when calculating the notification permission determination value P. The nth determination element value Pn is a value greater than "0" and equal to or less than "1", and is determined so that the closer the value is to "0", the higher the possibility that the preceding vehicle has made an early departure. The processing at each step for determining the nth determination element value Pn will be described below.

[0046] S430 (FIG. 4): The CPU acquires a first determination element value P1 based on the "size (W) of the preceding vehicle," which is one of the index values ​​for the preceding vehicle.

[0047] More specifically, the CPU acquires a value indicating the size of the leading vehicle (for example, the width of the leading vehicle or the projected area of ​​the leading vehicle in the longitudinal direction) based on the fusion target information. The CPU acquires a first determination element value P1 by applying the value indicating the size of the leading vehicle to map M1 described in S430. According to map M1, the first determination element value P1 becomes a positive value Pa closer to "0" than "1" when the size of the leading vehicle is equal to or smaller than a value W1. When the size of the leading vehicle exceeds value W1, the first determination element value P1 rapidly increases from value Pa toward "1." When the size of the leading vehicle exceeds "a value W2 greater than value W1," the first determination element value P1 becomes "1."

[0048] The reason why the first determination element value P1 is calculated in this manner is that motorcycles, bicycles, kick scooters, pedestrians, and the like are small in size and have a high possibility of making a false start.

[0049] S440 (FIG. 4): The CPU acquires the second determination element value P2 based on the "recognition time (T) after the preceding vehicle has stopped," which is one of the index values ​​for the preceding vehicle. The recognition time after the preceding vehicle has stopped is the length of time the CPU has continued to recognize the preceding vehicle immediately before the host vehicle since it was determined that the preceding vehicle had stopped.

[0050] More specifically, the CPU separately measures the "recognition time after the preceding vehicle has stopped." The CPU obtains the second determination element value P2 by applying the "recognition time after the preceding vehicle has stopped" to map M2 described in S440. According to map M2, the second determination element value P2 rapidly increases from a positive value Pb closer to "0" than "1" to "1" as the recognition time after the preceding vehicle has stopped increases from "0" toward a value T1, and becomes "1" when the recognition time after the preceding vehicle has stopped is equal to or greater than the value T1.

[0051] The reason for calculating the second judgment element value P2 in this manner is that motorcycles, bicycles, kick scooters, etc. are likely to overtake the host vehicle from behind, stop for a moment just in front of the host vehicle, and then immediately make a false start.

[0052] S450 (FIG. 4): The CPU acquires a third determination element value P3 based on the magnitude of the travel angle (θ) of the leading vehicle relative to the axis extending in the fore-and-aft direction of the vehicle (i.e., the planned travel direction of the vehicle), which is one of the index values ​​for the leading vehicle. The magnitude of the travel angle of the leading vehicle is the magnitude of the angle between the planned travel direction of the leading vehicle and the straight-ahead direction of the vehicle.

[0053] More specifically, the CPU acquires the "magnitude of the traveling angle of the preceding vehicle" based on the latest fusion target information and the fusion target information acquired a predetermined time ago. The CPU acquires the third determination element value P3 by applying the "magnitude of the traveling angle of the preceding vehicle" to map M3 described in S450. According to map M3, the third determination element value P3 is "1" when the magnitude of the traveling angle of the preceding vehicle is equal to or less than θ1, and rapidly decreases from "1" to a positive value Pc as the magnitude of the traveling angle of the preceding vehicle increases between θ1 and θ2. When the magnitude of the traveling angle of the preceding vehicle is equal to or greater than θ2, the third determination element value Pc is reached. The value Pc is a positive value closer to "0" than "1."

[0054] The reason for calculating the third judgment element value P3 in this manner is that if the travel angle of the preceding vehicle is large, the preceding vehicle may be moving in a direction different from the longitudinal direction of the lane in which the vehicle is stopped (for example, toward a parking lot such as a convenience store or home), and therefore the preceding vehicle is likely to have made an early departure.

[0055] S510 (FIG. 5): The CPU acquires a fourth determination element value P4 based on the "speed fluctuation correlation value (N) of the leading vehicle," which is one of the index values ​​for the leading vehicle. The speed fluctuation correlation value of the leading vehicle is a value that correlates with the degree of fluctuation in the speed of the leading vehicle after the leading vehicle starts moving. For example, the speed fluctuation correlation value of the leading vehicle increases as the speed of the leading vehicle repeatedly increases and decreases, and is represented by the number of maximum values ​​of the vehicle speed of the leading vehicle after the leading vehicle starts moving.

[0056] More specifically, the CPU acquires the "number of maximum vehicle speed values ​​of the leading vehicle after the leading vehicle has started" based on the history of fusion target information after the leading vehicle has started. The CPU acquires the fourth determination element value P4 by applying the "number of maximum vehicle speed values ​​of the leading vehicle after the leading vehicle has started" to map M4 described in S510. According to map M4, the fourth determination element value P4 is "1" when the number of maximum vehicle speed values ​​of the leading vehicle after the leading vehicle has started is equal to or less than value N1. As the number of maximum vehicle speed values ​​of the leading vehicle after the leading vehicle has started increases between value N1 and value N2, the fourth determination element value P4 rapidly decreases from "1" to a positive value Pd. When the number of maximum vehicle speed values ​​of the leading vehicle after the leading vehicle has started is equal to or greater than value N2, the fourth determination element value P4 becomes Pd. The value Pd is a positive value closer to "0" than "1."

[0057] The reason why the fourth determination element value P4 is calculated in this manner is that when the number of maximum values ​​of the vehicle speed of the leading vehicle after the leading vehicle starts is large (i.e., when the speed fluctuation correlation value of the leading vehicle is large), there is a high possibility that the leading vehicle has not made a clear start, and therefore, there is a high possibility that the leading vehicle has started prematurely. This situation is likely to occur, for example, when the driver of the leading vehicle repeatedly performs driving operations such as stepping on the brake pedal to stop the leading vehicle, and then releasing the brake pedal to start creeping.

[0058] S520 (FIG. 5): The CPU acquires a fifth determination element value P5 based on the "acceleration correlation value (A) when the leading vehicle starts," which is one of the index values ​​for the leading vehicle. The acceleration correlation value when the leading vehicle starts is a value that correlates with the acceleration of the leading vehicle when it starts (a value that increases as the acceleration increases). For example, the acceleration correlation value when the leading vehicle starts is the "average or maximum value" of the acceleration of the leading vehicle during the period in which the inter-vehicle distance D between the leading vehicle and the subject vehicle increases from the initial inter-vehicle distance value D0 to the notification start allowable distance (=D0+D2th).

[0059] More specifically, the CPU acquires either the average value of the acceleration of the leading vehicle during the aforementioned period or the maximum value of the acceleration of the leading vehicle during the aforementioned period as the "acceleration correlation value at the start of the leading vehicle" based on the history of the fusion target information and the history of the host vehicle speed Vh. The CPU acquires the fifth determination element value P5 by applying the "acceleration correlation value at the start of the leading vehicle" to map M5 described in S520. According to map M5, the fifth determination element value P5 is "1" when the acceleration correlation value at the start of the leading vehicle is equal to or less than value A1. As the acceleration correlation value at the start of the leading vehicle increases between value A1 and value A2, the fifth determination element value P5 rapidly decreases from "1" to a positive value Pd. When the acceleration correlation value at the start of the leading vehicle is equal to or greater than value A2, the fifth determination element value Pd is the positive value Pd. The value Pd is closer to "0" than "1."

[0060] The reason why the fifth judgment element value P5 is calculated in this way is that "motorcycles and vehicles driven by drivers who are trying to reach their destination in a hurry," which frequently make false starts, often have a certain degree of acceleration immediately after starting.

[0061] S530 (FIG. 5): The CPU acquires a sixth determination element value P6 based on the running state (RT) of vehicles located around the host vehicle and traveling in the same direction as the host vehicle (hereinafter simply referred to as "surrounding vehicles") and the lookup table LT6 described in S530. The surrounding vehicles include, for example, other vehicles located to the left in front of the host vehicle, other vehicles located to the right in front of the host vehicle, other vehicles located to the left of the host vehicle, and other vehicles located to the right of the host vehicle.

[0062] More specifically, if all of the recognized surrounding vehicles are moving (vehicle speed is greater than "0"), the CPU sets the sixth judgment element value P6 to "1". If any of the recognized surrounding vehicles is moving, the CPU sets the sixth judgment element value P6 to value P6a. If no surrounding vehicles are present (not recognized), the CPU sets the sixth judgment element value P6 to value P6b. If all of the recognized surrounding vehicles are stopped, the CPU sets the sixth judgment element value P6 to value P6c. The relationship of the following inequality (1) holds between the values ​​P6a, P6b, and P6c. The value P6c is a positive value closer to "0" than to "1". 0 <P6c<P6b<P6a<1 …(1)

[0063] The reason why the sixth judgment element value P6 is calculated in this manner is that if the surrounding vehicles are already moving when the preceding vehicle starts moving, it is unlikely that the preceding vehicle is making a false start, and conversely, if the surrounding vehicles are stopped when the preceding vehicle starts moving, it is highly likely that the preceding vehicle is making a false start.

[0064] S540 (FIG. 5): The CPU acquires a seventh determination element value P7 based on the presence or absence of a crossing vehicle or a cutting-in vehicle (CIN) and the lookup table LT7 described in S540. A crossing vehicle is a vehicle that crosses between the host vehicle and a preceding vehicle that was stopped just before the host vehicle. A cutting-in vehicle is a vehicle that cuts in between the host vehicle and a preceding vehicle that was stopped just before the host vehicle.

[0065] More specifically, if neither a crossing vehicle nor a cutting-in vehicle is detected, the CPU sets the seventh determination element value P7 to "1." On the other hand, if either a crossing vehicle or a cutting-in vehicle is detected, the CPU sets the seventh determination element value P7 to a value P7a. The value P7a is a positive value closer to "0" than to "1."

[0066] The reason for calculating the seventh judgment element value P7 in this way is that when a crossing vehicle or a cutting-in vehicle is detected, the CPU may recognize it as a preceding vehicle, but since these vehicles often start moving regardless of the traffic conditions ahead of the vehicle, if it recognizes them as a preceding vehicle, it is more appropriate to determine that the preceding vehicle is making a false start.

[0067] S610 (FIG. 6): The CPU acquires an eighth determination element value P8 based on the recognition state (RS) of the preceding vehicle after the preceding vehicle has stopped and the look-up table LT8 described in S610.

[0068] More specifically, if the preceding vehicle has been continuously recognized since it stopped, the CPU sets the eighth determination element value P8 to "1." On the other hand, if the preceding vehicle has been temporarily blocked from recognition since it stopped, the CPU sets the eighth determination element value P8 to a value P8a. The value P8a is a positive value closer to "0" than to "1."

[0069] The reason why the eighth determination element value P8 is calculated in this manner is that, for example, if a pedestrian, a bicycle, or the like crosses between the leading vehicle and the host vehicle while the leading vehicle and the host vehicle are stopped, recognition of the leading vehicle may be temporarily blocked after the leading vehicle stops. In such a situation, even if the leading vehicle has not made an early start, issuing a leading vehicle departure notification may cause the host vehicle to start, which could result in the host vehicle approaching the pedestrian, the bicycle, or the like, so it is preferable to suppress the vehicle departure notification.

[0070] Once the nth judgment element value Pn has been obtained by the processing of the above steps, the CPU proceeds to S620, where it calculates the notification permission judgment value P based on a function f(Pn) (n is an integer from 1 to 8) having the nth judgment element value Pn as a variable. The function f is basically a function that approaches 1 as the value of the nth judgment element value Pn increases, and approaches 0 as the value of the nth judgment element value Pn decreases. For example, the function f is any of the following: Note that Max is a function that selects the maximum value from the variables, and MapP is a lookup table that defines the relationship between the variables and the notification permission judgment value P.

[0071] Example 1) f=(P1+P2+P3+P4+P5+P6+P7+P8) / 8 Example 2) f=Max(P1,P2,P3)·(P4+P5+P6+P7+P8) / 5 Example 3) f=P1・P2・P3・P4・P5・P6・P7・P8 Example 4) f=Max(P1,P2,P3,P4,P5,P6,P7,P8) Example 5) f=MapP(P1,P2,P3,P4,P5,P6,P7,P8)

[0072] As explained above, the notification device DS calculates a judgment value (notification permission judgment value P) that correlates with the possibility that the preceding vehicle has made an early departure based on multiple index values ​​(W, T, θ, N, A) for the preceding vehicle, and determines whether to issue a preceding vehicle departure notification based on the result of comparing the judgment value (P) with the permission threshold (Path). Thus, it is possible to reduce the possibility that a preceding vehicle departure notification will be issued if the preceding vehicle has made an early departure.

[0073] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention. For example, the notification device DS can be applied to an autonomous vehicle in a state where the driving mode has transitioned from autonomous driving to manual driving.

[0074] Furthermore, the notification device DS may be configured to calculate the notification permission determination value P based on a plurality of index values ​​for the preceding vehicle, namely, "any combination of any two or more of W, T, θ, N, and A." That is, the notification device DS may be configured to calculate the notification permission determination value P based only on at least two or more of the first to fifth determination element values. [Explanation of symbols]

[0075] 10...driving assistance ECU, 21...forward radar device, 22L...left front side radar device, 22R...right front side radar device, 24...forward camera device, 25L...left camera device, 25R...right camera device, 50...alarm ECU, 51...display, 52...sound generating device.

Claims

1. an information acquisition device that acquires information about a preceding vehicle that is stopped immediately in front of the host vehicle; a controller that, when detecting that the preceding vehicle has started moving based on the information, issues a preceding vehicle departure notification to notify the driver of the host vehicle that the preceding vehicle has started moving; In a departure notification device equipped with The controller calculating a determination value that is correlated with the possibility that the preceding vehicle has made an early departure based on a plurality of index values ​​for the preceding vehicle obtained from the information; and determining whether to issue the preceding vehicle departure notification based on a comparison result between the determination value and a predetermined permission threshold value. Departure notification device.

2. The vehicle start notification device according to claim 1, The controller The controller is configured to use, as the plurality of index values, at least two or more of: a size (W) of the preceding vehicle; a recognition time (T) which is a time during which the controller continues to recognize the preceding vehicle from the time the preceding vehicle stops; a magnitude (θ) of the traveling angle of the preceding vehicle relative to the host vehicle; a speed fluctuation correlation value (N) which is correlated with the degree of fluctuation in the speed of the preceding vehicle after the preceding vehicle starts moving; and an acceleration correlation value (A) which is correlated with the acceleration of the preceding vehicle when the preceding vehicle starts moving. Departure notification device.

3. 3. The vehicle start notification device according to claim 2, The controller repeatedly calculating the determination value so that the determination value decreases as the likelihood that the preceding vehicle has made the early start increases; The preceding vehicle departure notification is not performed until the determination value is equal to or greater than the permission threshold, and the preceding vehicle departure notification is performed when the determination value is equal to or greater than the permission threshold. Departure notification device.

4. 4. The vehicle start notification device according to claim 3, The controller When the determination value becomes smaller than a predetermined prohibition threshold which is smaller than the permission threshold, the preceding vehicle departure notification is prohibited for the preceding vehicle whose determination value is smaller than the prohibition threshold. Departure notification device.

5. acquiring information about a preceding vehicle that is stopped immediately in front of the host vehicle; a step of notifying a driver of the host vehicle of the departure of the preceding vehicle when it is detected that the preceding vehicle has started based on the information; A departure notification method including: The step of notifying the preceding vehicle of departure includes: calculating a determination value correlating with a possibility that the preceding vehicle has made an early departure based on a plurality of index values ​​for the preceding vehicle obtained from the information; determining whether to issue the notification based on a comparison result between the determination value and a predetermined permission threshold; A departure notification method including:

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