Driving assistance devices

Abstract

To provide a driving support system that can execute driving support control with high accuracy, even if the device cannot obtain an object distance using a recognition method with high distance accuracy.SOLUTION: The driving support system is provided with a sensor configured to obtain sensor information which can identify an object distance from a vehicle up to a target object, and a controller that executes driving support control using, as a control distance, a first distance representing the object distance obtained from the sensor information using a first recognition method. The first recognition method has characteristics that as a time required for obtaining the first distance becomes longer, reliability on recognition of the target object becomes higher. The controller is configured to use, as the control distance, an extrapolation distance representing the object distance estimated based on the already obtained first distance and a vehicle speed, when the first distance cannot be obtained and when the time required for obtaining the first distance is above a predetermined threshold time.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device that executes driving assistance control based on the distance between a vehicle and a target object. [Background technology]

[0002] Conventionally, driving assistance devices that perform driving assistance control based on the distance between a vehicle and a target object have been known. For example, a driving assistance device described in Patent Document 1 (hereinafter referred to as the "conventional device") identifies a target object based on the detection result of an external sensor (e.g., a camera), and determines whether a deceleration assistance start condition is met based on the distance (object distance) between the vehicle and the target object. If the deceleration assistance start condition is met, the conventional device executes deceleration assistance control as driving assistance control. In detail, the conventional device calculates a detection reliability that indicates the likelihood of the target object, and the higher the detection reliability, the greater the assistance amount of the deceleration assistance control. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-88289 Summary of the Invention

[0004] In the conventional device, when the detection reliability changes from a high state to a low state, the deceleration assist control is likely to be performed on an object other than the target object, and the driver is likely to find the deceleration assist control performed on an object other than the target object annoying.

[0005] The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a driving assistance device that can reduce the possibility that the driver will feel annoyed by the driving assistance control by reducing the possibility that the driving assistance control will be performed on an object that is not a target object.

[0006] The driving assistance device of the present invention (hereinafter referred to as "the device of the present invention") a sensor (22) for acquiring sensor information capable of identifying a distance between a vehicle and an object; a controller (20) that adopts a first distance representing a distance between the vehicle and a predetermined target object, which is acquired by applying a first recognition method to the sensor information, as a control distance, and executes predetermined driving assistance control based on the control distance; the first recognition method has a characteristic that the longer the acquisition time of the first distance, the higher the recognition reliability of the target object; If the controller is unable to acquire the first distance (step 425 "No"), and if the acquisition time is equal to or longer than a predetermined threshold time (step 455 "Yes"), the controller is configured to adopt the previously acquired distance representing the first distance already acquired and the extrapolated distance representing the object distance estimated based on the vehicle speed as the control distance (steps 460, 465).

[0007] The first recognition method has a characteristic that the longer the acquisition time of the first distance, the higher the recognition reliability of the target object. According to the device of the present invention, if the acquisition time is equal to or greater than a threshold time when the first distance cannot be acquired, the extrapolated distance is adopted as the control distance. That is, if the recognition reliability of the target object is equal to or greater than a predetermined reliability (i.e., if there is a low possibility of misrecognizing an object that is not the target object as the target object), the extrapolated distance is adopted as the control distance. Therefore, since the extrapolated distance of an object that is likely to be the target object is adopted as the control distance, the possibility of driving assistance control being performed for an object that is not the target object can be reduced, and the possibility that the driver will find the driving assistance control annoying can be reduced. If the extrapolated distance is adopted as the control distance when the acquisition time is less than the threshold time, the extrapolated distance of an object that is not the target object will likely continue to be adopted as the control distance, and the possibility of driving assistance control being performed for an object that is not the target object will increase. [Brief explanation of the drawings]

[0008] [Figure 1]1 is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an explanatory diagram of the operation of the driving assistance device. [Figure 3] 4 is a flowchart of a program executed by a CPU of a driving assistance ECU. [Figure 4] 4 is a flowchart of a program executed by a CPU of a driving assistance ECU. [Figure 5] 10 is a flowchart of a program executed by a CPU of a driving assistance ECU according to a first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] A driving assistance device (the assistance device 10) according to an embodiment of the present invention is applied to a vehicle VA, and includes the components shown in FIG.

[0010] The driving assistance ECU is an ECU that executes driving assistance control, and will be referred to as "ECU 20" hereinafter.

[0011] In this specification, an "ECU" is an electronic control unit that includes a microcomputer as its main component. The ECU is also called a controller. The microcomputer includes a CPU (processor), ROM, RAM, an interface, etc. The ECU 20 and some or all of the multiple ECUs described below may be integrated into a single ECU.

[0012] The camera 22 captures an image of the area ahead of the vehicle VA every time a predetermined time period elapses, acquires image data, and transmits the image data to the ECU 20. The image data may be referred to as "sensor information."

[0013] The vehicle speed sensor 24 detects the speed (vehicle speed Vs) of the vehicle VA. The acceleration sensor 26 detects the acceleration G of the vehicle VA. The ECU 20 receives the detection values ​​from these sensors 24 and 26.

[0014] The power management ECU 30 is connected to and controls the power train actuator 32. The power train actuator 32 changes the driving force generated by a drive device (for example, an internal combustion engine and / or an electric motor) of the vehicle VA.

[0015] The brake ECU 40 is connected to the brake actuator 42 and controls the brake actuator 42. The brake actuator 42 controls the braking force applied to the vehicle VA.

[0016] The display ECU 50 is connected to the display device 52, and displays an attention-calling screen on the display device 52 (see a fourth modified example described later).

[0017] The CGW (control gateway) ECU 60 controls the transmission and reception of data between the above-mentioned plurality of ECUs via the first communication line C1 and the second communication line C2.

[0018] (Activated) The operation of the ECU 20 of the assistance device 10 will be described with reference to FIG. The ECU 20 executes deceleration support control as driving support control. The deceleration support control is a control for decelerating the vehicle VA to stop the vehicle VA a predetermined distance Dp before the target object TO. Such deceleration support control is a type of automatic driving. As an example, the target object TO is a traffic light (stationary object) displaying a stop signal (i.e., displaying red or yellow).

[0019] The ECU 20 starts deceleration assist control when it determines that the start condition is met based on the image data acquired from the camera 22. The start condition is met when a target object TO is detected but a preceding vehicle is not detected. The preceding vehicle is a vehicle traveling in the same lane as the vehicle VA and located within a predetermined distance ahead of the vehicle VA.

[0020] In the deceleration assist control, the ECU 20 obtains the target vehicle speed Vtgt by applying a "control distance Dc indicating the distance from the vehicle VA to the target object TO" to a target vehicle speed lookup table MapV(Dc). The target vehicle speed lookup table MapV(Dc) is stored in the ROM of the ECU 20. When the vehicle speed Vs is greater than the target vehicle speed Vtgt, the ECU 20 obtains the target acceleration Gtgt based on the following equation (1) and transmits the target acceleration Gtgt to the power management ECU 30 and the brake ECU 40. Gtgt=Ga(Vtgt-Vs) (1) "Ga" in equation (1) is a predetermined gain.

[0021] The ECU 20 recognizes the target object TO by applying a first recognition method and a second recognition method to the image data, and acquires a first distance D1 and a second distance D2 to the target object TO, respectively. The distance accuracy of the second recognition method is lower than that of the first recognition method. For example, in the first recognition method, the ECU 20 extracts feature points of the target object TO from image data captured at different locations and acquires the first distance D1 to the target object TO based on corresponding feature points in the image data. For example, SfM (Structure from Motion) is used as the first recognition method. In such a first recognition method, the number of feature points is small when the acquisition time of the first distance D1 is short. Therefore, when the acquisition time of the first distance D1 is short, there is a higher possibility that an object that is not the target object will be mistakenly recognized as the target object compared to when the acquisition time of the first distance D1 is long. In other words, the first recognition method has a characteristic that the reliability of the target object recognition increases as the acquisition time of the first distance D1 increases.

[0022] In the second recognition method, the ECU 20 extracts the target object TO by using pattern matching on the image data, and obtains a second distance D2 to the target object TO based on the size of the target object TO in the image data.

[0023] When the ECU 20 has acquired the first distance D1, the ECU 20 uses the first distance D1 as the control distance Dc. When the ECU 20 is no longer able to acquire the first distance D1, the ECU 20 determines whether the acquisition time T1, which indicates the time during which the first distance D1 was acquired, is equal to or greater than a predetermined threshold time T1th. The threshold time T1th is set to a value such that the recognition reliability of the target object in the first recognition method is equal to or greater than a predetermined value.

[0024] (1) When the acquisition time T1 is equal to or greater than the threshold time T1th The ECU 20 estimates an object distance representing the distance to the target object TO based on the already acquired first distance D1 (sometimes referred to as the "previously acquired distance") and the vehicle speed Vs. The object distance estimated in this manner is sometimes referred to as the "extrapolated distance Dex." Specifically, the ECU 20 acquires the extrapolated distance Dex by subtracting the "traveled distance Ds of the vehicle VA" from the last acquired first distance D1. The traveled distance Ds is obtained by multiplying the time elapsed since the last acquisition of the first distance D1 by the vehicle speed Vs. The ECU 20 adopts the extrapolated distance Dex as the control distance Dc.

[0025] (2) When the acquisition time T1 is less than the threshold time T1th The ECU 20 determines whether the first approach / separation state matches the second approach / separation state. The ECU 20 determines a first approach / departure state indicating whether the target object TO recognized using the second recognition method is approaching or moving away from the vehicle VA based on the traveling direction of the vehicle VA. The ECU 20 determines the traveling direction of the vehicle VA based on the shift position detected by a shift position sensor (not shown) and the steering angle of the vehicle detected by a steering angle sensor (not shown). The ECU 20 determines a second approach / departure state indicating whether the target object TO is approaching or moving away from the vehicle VA based on the second distance D2.

[0026] (2A) When the first approach / separation state and the second approach / separation state coincide with each other The ECU 20 employs the second distance D2 as the control distance Dc.

[0027] (2B) When the first approach / separation state and the second approach / separation state do not match The ECU 20 uses the extrapolated distance Dex as the control distance Dc.

[0028] In the case of (1) above, when the recognition reliability of the target object in the first recognition method is equal to or greater than a predetermined value, the extrapolated distance Dex is estimated, and this extrapolated distance Dex is adopted as the control distance Dc. This reduces the possibility that the extrapolated distance Dex of an object that is not the target object continues to be estimated and adopted as the control distance Dc, resulting in the deceleration assist control being continuously executed for an object that is not the target object.

[0029] In the case of (2A) above, the first approaching / separating state and the second approaching / separating state are the same, so the distance accuracy of the second distance D2 is relatively high. Therefore, the second distance D2 is adopted as the control distance Dc. In the case of (2B) above, the first approaching / separating state and the second approaching / separating state are not the same, so the distance accuracy of the second distance D2 is relatively low. In this case, the extrapolated distance Dex estimated based on the first distance D1 is adopted as the control distance Dc.

[0030] The CPU of the ECU 20 executes the routine shown in the flowcharts of FIGS. 3 and 4 every time a predetermined time elapses.

[0031] <Start / End Judgment> Therefore, when the appropriate time arrives, the CPU begins processing at step 300 in FIG.

[0032] Step 305 : The CPU acquires image data from the camera 22 . Step 310: The CPU determines whether the value of the execution flag Xexe is “0” or not. The value of the execution flag Xexe is set to "1" when deceleration assist control starts, and is set to "0" when deceleration assist control ends. The value of the execution flag Xexe is also set to "0" in the initial routine. The initial routine is a routine executed by the CPU when the ignition key switch (not shown) of the vehicle VA is changed from the off position to the on position.

[0033] If the value of the execution flag Xexe is "0", the CPU proceeds to step 315 and determines whether or not the target object TO has been detected from the image data. As an example, the CPU detects the target object TO using pattern matching.

[0034] If the target object TO has not been detected from the image data, the CPU proceeds to step 395 and temporarily ends this routine. If the target object TO has been detected from the image data, the CPU proceeds to step 320 and determines whether a preceding vehicle has been detected based on the image data. As an example, the CPU detects a preceding vehicle using pattern matching.

[0035] If a preceding vehicle is detected, the CPU proceeds to step 395 and terminates this routine. If a preceding vehicle is not detected, the CPU sets the value of the execution flag Xexe to "1" in step 325, proceeds to step 395, and terminates this routine.

[0036] If the value of the execution flag Xexe is "1" in step 310, the CPU determines in step 330 whether the vehicle speed Vs is "0 km / h" (that is, whether the vehicle VA has stopped).

[0037] If the vehicle speed Vs is "0 km / h", the CPU sets the value of the execution flag Xexe to "0" in step 335, proceeds to step 395, and temporarily ends this routine. If the vehicle speed Vs is not "0 km / h", the CPU determines in step 340 whether or not the target object TO has been detected from the image data.

[0038] If the target object TO has not been detected, the CPU sets the value of the execution flag Xexe to "0" in step 335, proceeds to step 395, and temporarily ends this routine. If the target object TO has been detected, the CPU determines in step 345 whether a preceding vehicle has been detected from the image data.

[0039] If a preceding vehicle is detected, the CPU sets the value of the execution flag Xexe to "0" in step 335, proceeds to step 395, and temporarily ends this routine. If a preceding vehicle is not detected, the CPU determines whether an accelerator override has been performed in step 350. The CPU determines that an accelerator override has been performed if the amount of operation of the accelerator pedal (not shown) is equal to or greater than a threshold amount.

[0040] If an accelerator override has been performed, the CPU sets the value of the execution flag Xexe to "0" in step 335, and then proceeds to step 395 to temporarily end this routine. If an accelerator override has not been performed, the CPU proceeds to step 395 to temporarily end this routine.

[0041] <Deceleration support control> Therefore, when an appropriate time arrives, the CPU starts the process from step 400 in FIG. 4, and determines in step 405 whether the value of the execution flag Xexe is "1".

[0042] If the value of the execution flag Xexe is "0", the CPU proceeds to step 495 and temporarily ends this routine. If the value of the execution flag Xexe is "1", the CPU executes steps 410 to 425.

[0043] Step 410 : The CPU acquires image data from the camera 22 . Step 415: The CPU obtains a first distance D1 by applying a first recognition method to the image data. Step 420: The CPU obtains a second distance D2 by applying a second recognition method to the image data. Step 425: The CPU determines whether or not the first distance D1 was obtained in step 415. For example, if the number of feature points of the target object TO is equal to or less than a threshold when the first recognition method is applied to the image data, the CPU determines that the first distance D1 cannot be obtained.

[0044] If the first distance D1 has been acquired, the CPU determines in step 427 whether or not the first distance D1 was acquired the previous time this routine was executed. If the first distance D1 was not acquired last time, the CPU sets the first timer TM1 to "0" in step 429 and executes steps 430 to 450. On the other hand, if the first distance D1 was acquired last time, the CPU executes steps 430 to 443.

[0045] Step 430: The value of the first timer TM1 is incremented by "1," and the value of the second timer TM2 is set to "0." The first timer TM1 is a timer for counting the acquisition time T1, and the second timer TM2 is a timer for counting the time that has elapsed since the first distance D1 could no longer be acquired.

[0046] Step 435: The CPU sets the first distance D1 to the control distance Dc. Step 440: The CPU obtains the target vehicle speed Vtgt by applying the control distance Dc to the target vehicle speed lookup table MapV(Dc). The target vehicle speed lookup table MapV(Dc) defines the relationship between the control distance Dc and the target vehicle speed Vtgt. In detail, as shown in Fig. 2, the target vehicle speed lookup table MapV(Dc) defines the above relationship so that the target vehicle speed Vtgt decreases as the control distance Dc becomes shorter, and when the control distance Dc is "Dp", the target vehicle speed Vtgt is "0 km / h".

[0047] Step 443: The CPU determines whether the vehicle speed Vs is greater than the target vehicle speed Vtgt.

[0048] If the vehicle speed Vs is equal to or lower than the target vehicle speed Vtgt, the CPU proceeds to step 495 and temporarily ends this routine.

[0049] If the vehicle speed Vs is greater than the target vehicle speed Vtgt, the CPU executes step 445 and step 450 in this order. In step 445, the CPU obtains the target acceleration Gtgt by applying the target vehicle speed Vtgt and the vehicle speed Vs to the above equation (1). Step 450: The CPU transmits the target acceleration Gtgt to the power management ECU 30 and the brake ECU 40. When the power management ECU 30 and the brake ECU 40 receive the target acceleration Gtgt, they respectively control the power train actuator 32 and the brake actuator 42 so that the acceleration G coincides with the target acceleration Gtgt.

[0050] Thereafter, the CPU proceeds to step 495 and temporarily ends this routine.

[0051] If the first distance D1 has not been acquired when the CPU proceeds to step 425, the CPU determines whether the first timer TM1 is equal to or greater than the first threshold value TM1th in step 455. The first threshold value TM1th is set so that when the first timer TM1 reaches the first threshold value TM1th, the acquired time T1 becomes the threshold time T1th.

[0052] If the first timer TM1 is equal to or greater than the first threshold value TM1th, the CPU executes steps 460 to 470.

[0053] Step 460: The CPU obtains the extrapolated distance Dex. Step 465: The CPU sets the extrapolation distance Dex to the control distance Dc. Step 470: The CPU determines whether the second timer TM2 is equal to or greater than the second threshold value TM2th.

[0054] If the second timer TM2 is less than the second threshold value TM2th, the CPU increments the second timer TM2 by "1" in step 475 and proceeds to step 440. On the other hand, if the second timer TM2 is equal to or greater than the second threshold value TM2th, the CPU sets the first timer TM1 to "0" in step 480 and proceeds to step 440. If the time during which the first distance D1 cannot be acquired exceeds a predetermined time, the extrapolated distance Dex is estimated based on an older first distance D1, and the distance accuracy of the extrapolated distance Dex decreases. Therefore, if the time during which the first distance D1 cannot be acquired exceeds the predetermined time, the first timer TM1 is set to "0," thereby preventing the extrapolated distance Dex, with reduced distance accuracy, from being set as the control distance Dc.

[0055] When the CPU proceeds to step 455, if the first timer TM1 is less than the first threshold value TM1th, the CPU proceeds to step 485 and determines whether the first approach / separation state and the second approach / separation state match.

[0056] If the first approach / separation state and the second approach / separation state match, the CPU sets the second distance D2 as the control distance Dc in step 490 and proceeds to step 470.

[0057] On the other hand, if the first approaching / separating state and the second approaching / separating state do not match, the CPU proceeds to step 460.

[0058] As explained above, in the above embodiment, even if the first distance D1 can no longer be acquired, the extrapolated distance Dex is adopted as the control distance Dc if the acquisition time T1 is greater than or equal to the threshold time T1th, thereby preventing the distance of an object that is not the target object from continuing to be adopted as the control distance Dc.

[0059] (First Modification) The CPU according to the first modification executes a routine shown by a flowchart in Fig. 5 instead of the routine shown by the flowchart in Fig. 4. In the routine shown in Fig. 5, the CPU executes steps 505 and 510 instead of steps 485 and 490 in Fig. 4.

[0060] If the CPU determines "No" in step 455 of FIG. Step 505: The CPU obtains the weighting factor α by applying the first timer TM1 to the weighting factor lookup table Mapα(TM1). The weighting factor lookup table Mapα(TM1) defines the relationship between the weighting factor α and the first timer TM1. Specifically, as shown in Fig. 5, the weighting factor lookup table Mapα(TM1) defines the weighting factor α so that the weighting factor α increases as the first timer TM1 increases, such that the weighting factor α is "0.0" when the first timer TM1 is "0" and "1.0" when the first timer TM1 is at the threshold value TM1th.

[0061] Step 510: The CPU sets the control distance Dc to a value obtained by applying the extrapolated distance Dex, the second distance D2, and the weighting coefficient α to equation (2). Dc=α*Dex+(1-α)D2...Equation (2)

[0062] According to equation (2), the larger the value of the first timer TM1 (i.e., the longer the acquisition time T1), the larger the weight (α) of the extrapolated distance Dex and the smaller the weight (1-α) of the second distance D2. Since the longer the acquisition time T1, the higher the distance accuracy of the extrapolated distance Dex, the larger the weight of the extrapolated distance Dex and the smaller the weight of the second distance D2.

[0063] (Second Modification) 5, if the CPU determines that the first distance D1 cannot be obtained ("No" in step 425), it may execute steps 505 and 510 without executing step 455. The weighting coefficient lookup table Mapα(TM1) of this modification defines the relationship between the weighting coefficient α and the first timer TM1 so that the weighting coefficient α is "1.0" if the first timer TM1 is equal to or greater than the threshold value TM1th. If the first timer TM1 is equal to or greater than the threshold value TM1th, the weighting coefficient α is set to "1.0," and the extrapolated distance Dex is set to the control distance Dc.

[0064] (Third Modification) When the CPU switches from a state in which it cannot acquire the first distance D1 to a state in which it can acquire the first distance D1, it may prohibit the use of the first distance D1 as the control distance Dc until a predetermined time has elapsed from the time of the switch. In this case, the CPU uses the extrapolated distance Dex as the control distance Dc if the acquisition time T1 is equal to or greater than the threshold time T1th. Furthermore, when the acquisition time T1 is less than the threshold time T1th, the CPU uses the second distance D2 as the control distance Dc if the first approach / separation state and the second approach / separation state match, and uses the extrapolated distance Dex as the control distance Dc if the first approach / separation state and the second approach / separation state do not match. Note that the first and second modifications can also be applied to this modification.

[0065] (Fourth Modification) The driving assistance control is not limited to deceleration assistance control. For example, the driving assistance control may be attention calling control. In the attention calling control, when the control distance Dc becomes equal to or shorter than the threshold distance Dcth, the driving assistance ECU 20 causes the display device 52 to display an attention calling screen for calling the driver's attention to the target object TO. Note that the driving assistance ECU 20 may increase the attention calling level of the attention calling screen as the control distance Dc becomes shorter.

[0066] (Fifth Modification) The target object TO is not limited to a traffic light, but may be, for example, a stop line on the lane in which the vehicle VA is traveling, or a preceding vehicle.

[0067] (Sixth Modification) The area photographed by the camera 22 is not limited to the area in front of the vehicle VA. The camera 22 may photograph the area in front, to the left, to the right, and / or behind the vehicle VA.

[0068] (Seventh Modification) The assistance device 10 may include a sensor such as a millimeter wave radar instead of the camera 22.

[0069] (Eighth Modification) The support device 10 can be mounted on vehicles such as an engine vehicle, a hybrid vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid electric vehicle (PHEV: Plug-in Hybrid Electric Vehicle), a fuel cell electric vehicle (FCEV: Fuel Cell Electric Vehicle), and an electric vehicle (BEV: Battery Electric Vehicle). [Explanation of symbols]

[0070] 10...driving assistance device, 20...driving assistance ECU, 22...millimeter wave radar, 30...power management ECU, 32...power train actuator, 40...brake ECU, 42...brake actuator.

Claims

1. a sensor for acquiring sensor information capable of identifying a distance between a vehicle and an object; a controller that adopts a first distance representing a distance between the vehicle and a predetermined target object, which is acquired by applying a first recognition method to the sensor information, as a control distance, and executes predetermined driving assistance control based on the control distance; the first recognition method has a characteristic that the longer the acquisition time of the first distance, the higher the recognition reliability of the target object; A driving assistance device in which the controller is configured to, when it becomes unable to acquire the first distance, adopt as the control distance a previously acquired distance representing the first distance already acquired and an extrapolated distance representing an object distance estimated based on the vehicle speed if the acquisition time is equal to or longer than a predetermined threshold time.

2. The driving assistance device according to claim 1, A driving assistance device configured such that, when the controller is unable to acquire the first distance and the acquisition time is less than the threshold time, if a first approach / departure state indicating whether the target object is approaching or moving away, recognized by applying a second recognition method to the sensor information, the second recognition method being determined based on the vehicle's traveling direction and having lower distance accuracy than the first recognition method, coincides with a second approach / departure state indicating whether the target object is approaching or moving away, determined based on a second distance indicating the distance between the vehicle and the target object obtained using the second recognition method on the sensor information.

3. The driving assistance device according to claim 1, A driving assistance device configured such that, when the controller is unable to acquire the first distance and the acquisition time is less than the threshold time, if a first approach / departure state indicating whether the target object is approaching or moving away, recognized by applying a second recognition method to the sensor information, the second recognition method being determined based on the vehicle's traveling direction and having lower distance accuracy than the first recognition method, does not match a second approach / departure state indicating whether the target object is approaching or moving away, determined based on a second distance indicating the distance between the vehicle and the target object obtained using the second recognition method on the sensor information.

4. The driving assistance device according to claim 1, The controller when the first distance cannot be acquired and the acquisition time is less than the threshold time, determining the control distance based on the extrapolated distance and a second distance representing the distance between the vehicle and the target object acquired by applying a second recognition method to the sensor information, the second recognition method having a lower distance accuracy than the first recognition method; the longer the acquisition time, the greater the weight of the extrapolated distance and the smaller the weight of the second distance; A driving assistance device configured as follows.

5. The driving assistance device according to any one of claims 1 to 4, The controller is configured to control a traveling state of the vehicle based on the control distance so that the vehicle stops a predetermined distance before the target object.

Images