Vehicle control device

Abstract

To provide a vehicle control device that, when there are a preceding vehicle and a leading vehicle ahead of the preceding vehicle, increases the possibility of appropriately executing vehicle control in response to the deceleration of the leading vehicle even if the preceding vehicle is delayed in deceleration when the leading vehicle decelerates, and can reduce the possibility of executing unnecessary vehicle control.SOLUTION: A vehicle control device executes vehicle control for reducing the risk of collision when a collision condition is satisfied that the risk of collision with an object is a threshold or higher. When both a following condition that a preceding vehicle is following a leading vehicle ahead of the preceding vehicle and a trajectory condition that an own vehicle and the preceding vehicle are traveling on the trajectory of the leading vehicle ahead of the preceding vehicle are satisfied, the vehicle control device determines whether the collision condition is satisfied by using a first index value that represents the risk of collision of the leading vehicle. When at least either the following condition or the trajectory condition is not satisfied, the vehicle control device determines whether the collision condition is satisfied by using a second index value that represents the risk of collision of the preceding vehicle.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that executes vehicle control to reduce a collision risk when a collision condition is met in which the risk of collision with an object is equal to or greater than a threshold value. [Background technology]

[0002] Conventionally, there have been known vehicle control devices that execute vehicle control (such as issuing an alert to the driver and controlling deceleration) to reduce the risk of collision when the risk of collision with an object becomes high. For example, a vehicle control device described in Patent Document 1 (hereinafter referred to as the "conventional device") determines whether or not both of the following conditions 1 and 2 are met when there are a preceding vehicle and a vehicle ahead of the preceding vehicle. Condition 1: The distance between the preceding vehicle and the vehicle ahead of it is less than a threshold value. Condition 2: The value obtained by subtracting the speed of the vehicle before the preceding vehicle from the speed of the preceding vehicle is equal to or greater than a threshold value.

[0003] When both Condition 1 and Condition 2 are met, the distance between the preceding vehicle and the vehicle ahead is close, and there is a high possibility that the preceding vehicle will suddenly approach the vehicle ahead. In this case, the conventional device increases the brake oil pressure in advance to prepare for braking. This allows for responsive brake control even when the preceding vehicle suddenly brakes due to the presence of the vehicle ahead. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-106588 Summary of the Invention

[0005] If the vehicle ahead of ...

[0006] The present invention has been made to address the above-mentioned problems, and an object of the present invention is to provide a vehicle control device that, when there are a vehicle ahead and a preceding vehicle, increases the likelihood that appropriate vehicle control will be performed in response to the deceleration of the preceding vehicle, even if the preceding vehicle is slow to decelerate when the preceding vehicle decelerates, and reduces the likelihood that unnecessary vehicle control will be performed.

[0007] The vehicle control device of the present invention (hereinafter referred to as "the device of the present invention") executes vehicle control to reduce the collision risk (step 340) when a collision condition is met in which the risk of collision with an object is greater than or equal to a threshold value (step 335 "Yes", step 365 "Yes"). The vehicle control device includes: If both the following condition, that a preceding vehicle ahead of the host vehicle is following a second preceding vehicle ahead of the preceding vehicle, and the trajectory condition, that the host vehicle and the preceding vehicle are traveling along a second preceding vehicle trajectory that represents the trajectory traveled by the second preceding vehicle, are met (step 325 "Yes"), a first index value (second preceding vehicle TTC) that represents the collision risk of the second preceding vehicle is used to determine whether the collision condition is met (step 365), If at least one of the following condition and the trajectory condition is not satisfied (step 325 "No"), a second index value (preceding vehicle TTC) representing the collision risk of the preceding vehicle is used to determine whether the collision condition is satisfied (step 335). It is structured as follows.

[0008] When both the following condition and the trajectory condition are satisfied, the device of the present invention determines whether to execute vehicle control using a first index value representing the collision risk of the second-leading vehicle. When both the following condition and the trajectory condition are satisfied, if the second-leading vehicle decelerates, there is a high possibility that the preceding vehicle will decelerate without changing lanes. In other words, there is a high possibility that the deceleration of the second-leading vehicle will be propagated to the preceding vehicle. Therefore, the device of the present invention can reduce the possibility of executing unnecessary vehicle control because the preceding vehicle has changed lanes when the second-leading vehicle decelerates. Furthermore, the device of the present invention can increase the possibility of executing appropriate vehicle control even if the preceding vehicle decelerates later when the second-leading vehicle decelerates. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a vehicle control device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an explanatory diagram of the distance relationship between the subject vehicle, a preceding vehicle, and a vehicle ahead of the preceding vehicle; [Figure 3] 2 is a flowchart of a vehicle control routine executed by a CPU of the ECU shown in FIG. 1. [Figure 4] 2 is a flowchart of a follow-up condition determination subroutine executed by a CPU of the ECU shown in FIG. 1. [Figure 5] 2 is a flowchart of a trajectory condition determination subroutine executed by a CPU of the ECU shown in FIG. 1. [Figure 6] 3 is an explanatory diagram of the lateral distance, deviation angle, and lateral speed of the host vehicle and the preceding vehicle; DETAILED DESCRIPTION OF THE INVENTION

[0010] As shown in FIG. 1, a vehicle control device according to this embodiment (hereinafter referred to as "the device 10") is applied to a host vehicle VA, and includes the components shown in FIG.

[0011] The ECU 20 executes vehicle control to reduce the risk of collision with an object, such as deceleration control to decelerate the host vehicle VA.

[0012] In this specification, "ECU 20" refers to an electronic control device that includes a microcomputer as its main component. The ECU 20 is also referred to as a control unit, a controller, and a computer. The microcomputer includes a CPU (processor), a ROM, a RAM, an interface, and the like. The functions realized by the ECU 20 may be realized by multiple ECUs.

[0013] The camera 22 acquires image data by capturing images of the scenery ahead of the host vehicle VA. The camera 22 acquires camera object information and white line information based on the image data. The camera object information includes the positions of objects located ahead of the host vehicle VA relative to the host vehicle VA. The white line information includes the positions of white lines on the road on which the host vehicle VA is traveling relative to the host vehicle VA. The camera 22 transmits the camera object information and white line information to the ECU 20.

[0014] The millimeter-wave radar 24 transmits millimeter waves ahead of the host vehicle VA and receives waves reflected by an object, thereby acquiring radar object information including the “position of the object with respect to the host vehicle VA” and the “relative speed Vr of the object with respect to the host vehicle VA.” The millimeter-wave radar 24 transmits the radar object information to the ECU 20.

[0015] The millimeter-wave radar 24 is disposed in a position (for example, near the license plate at the front end of the host vehicle VA) where part of the light emitted by the millimeter-wave radar 24 passes under the preceding vehicle VB and is reflected by the second preceding vehicle VC traveling ahead of the preceding vehicle VB. This allows the millimeter-wave radar 24 to detect the second preceding vehicle VC.

[0016] The preceding vehicle VB is a vehicle located ahead of the host vehicle VA, traveling in the same direction as the host vehicle VA, and closest to the host vehicle VA. The ECU 20 detects the preceding vehicle VB based on camera object information, radar object information, and lidar object information (described later). The second preceding vehicle VC is located ahead of the preceding vehicle VB, travels in the same direction as the host vehicle VA, and is closest to the preceding vehicle VB. The ECU 20 detects the second preceding vehicle VC based on radar object information.

[0017] The lidar 25 emits light ahead of the vehicle VA and receives light reflected by an object, thereby acquiring lidar object information including the position of the object relative to the vehicle VA and the relative speed Vr of the object relative to the vehicle VA. The lidar 25 transmits the lidar object information to the ECU 20. The lidar 25 is disposed above the millimeter-wave radar 24.

[0018] The vehicle speed sensor detects the vehicle speed Vs that indicates the speed of the host vehicle VA. The ECU 20 acquires the detected value of the vehicle speed sensor .

[0019] The power train actuator 32 changes the driving force generated by a drive device (e.g., an internal combustion engine and / or an electric motor) of the host vehicle VA. The brake actuator 34 controls the braking force applied to the wheels of the host vehicle VA. The display device 36 displays a warning screen, which will be described later. The speaker 38 emits a warning sound.

[0020] (Overview of operation) The ECU 20 identifies the preceding vehicle VB and the vehicle VC ahead of the preceding vehicle VB based on the camera object information, radar object information, and lidar object information. When the preceding vehicle VB and the vehicle VC ahead of the preceding vehicle VB are present, the ECU 20 typically performs vehicle control when a collision condition is met in which the TTC of the preceding vehicle VB (hereinafter referred to as "preceding vehicle TTC") is equal to or less than a threshold time Tth. TTC stands for Time To Collision and represents the time it takes for an object to collide with the host vehicle VA. The ECU 20 obtains the TTC by dividing the distance between the host vehicle VA and the object by the relative speed Vr of the object. The ECU 20 obtains the preceding vehicle TTC by dividing the inter-vehicle distance Dx1 (see FIG. 2) between the host vehicle VA and the preceding vehicle VB by the relative speed Vr of the preceding vehicle VB. The TTC can also be expressed as an index value representing the risk of collision with an object. The shorter the TTC, the higher the collision risk. When the preceding vehicle TTC becomes equal to or shorter than the threshold time Tth, the collision risk between the preceding vehicle VB and the host vehicle VA becomes equal to or greater than the threshold.

[0021] However, if the preceding vehicle VB is slow to decelerate when the vehicle VC ahead of the preceding vehicle decelerates, the preceding vehicle VB is likely to suddenly decelerate because it will decelerate only after approaching the vehicle VC ahead of the preceding vehicle. In this case, if vehicle control is initiated when the preceding vehicle TTC becomes equal to or shorter than the threshold time Tth, the timing of the initiation of vehicle control will be late.

[0022] In this embodiment, when a preceding vehicle VB and a second preceding vehicle VC are present and both the following following condition and trajectory condition are met, the ECU 20 determines that the collision condition is met when the TTC of the second preceding vehicle VC (hereinafter referred to as "second preceding vehicle TTC") becomes equal to or less than the threshold time Tth, and executes vehicle control. The acquisition of the second preceding vehicle TTC will be described later. The second preceding vehicle TTC may be referred to as the "first index value," and the preceding vehicle TTC may be referred to as the "second index value."

[0023] The following condition and the trajectory condition are met when there is a high possibility that the deceleration of the second-preceding vehicle VC will propagate to the preceding vehicle VB. Specifically, the following condition is met when the preceding vehicle VB is following the second-preceding vehicle VC. The trajectory condition is met when the preceding vehicle VB is traveling along the second-preceding vehicle trajectory TR (see Figures 2 and 6) that represents the trajectory traveled by the second-preceding vehicle VC. When the following condition and the trajectory condition are met, even if the second-preceding vehicle VC decelerates, there is a high possibility that the preceding vehicle VB will continue to follow the second-preceding vehicle VC and travel along the second-preceding vehicle trajectory TR without changing lanes. In other words, there is a high possibility that the deceleration of the second-preceding vehicle VC will propagate to the preceding vehicle VB.

[0024] With reference to FIG. 2, the acquisition of the TTC for the vehicle before the preceding one will be described. ECU20 obtains the subtraction value (Dx2-Lp-Dmin) obtained by subtracting the "length Lp of the preceding vehicle and minimum inter-vehicle distance Dmin" from the "inter-vehicle distance Dx2 between the rear end of the preceding vehicle VC and the front end of the host vehicle VA."

[0025] The preceding vehicle length Lp is preset to a value representing the length of the preceding vehicle VB. The minimum inter-vehicle distance Dmin is preset to a value representing the minimum inter-vehicle distance when the preceding vehicle VB is following the second preceding vehicle VC. It is desirable that the minimum inter-vehicle distance Dmin be set based on statistical information of general drivers. The subtraction value represents the inter-vehicle distance between the second preceding vehicle VC and the host vehicle VA when it is assumed that the preceding vehicle VB does not exist.

[0026] The ECU 20 obtains the second preceding vehicle TTC by dividing the subtracted value by the "relative speed Vr of the second preceding vehicle VC with respect to the host vehicle VA." When both the following condition and the trajectory condition are satisfied, the ECU 20 determines that the collision condition is satisfied if the second preceding vehicle TTC is equal to or shorter than the threshold time Tth, and performs the vehicle control.

[0027] Even if the deceleration of the preceding vehicle VB is delayed when the second-preceding vehicle VC decelerates, the second-preceding vehicle TTC decreases from the point when the second-preceding vehicle VC decelerates. This allows the vehicle control to be executed at an appropriate timing even if the deceleration of the preceding vehicle VB is delayed when the second-preceding vehicle VC decelerates. Furthermore, when both the following condition and the trajectory condition are met, the preceding vehicle VB is unlikely to change lanes, so there is a high possibility that the deceleration of the second-preceding vehicle VC will be propagated to the preceding vehicle VB. In this embodiment, when both the following condition and the trajectory are met, it is determined whether the second-preceding vehicle TTC is equal to or less than the threshold time Tth, thereby reducing the possibility of unnecessary vehicle control being executed when the preceding vehicle VB changes lanes.

[0028] (Specific operation) <Vehicle control routine> The CPU of the ECU 20 executes the routine shown in the flowchart of FIG. 3 every time a predetermined time period elapses. When the appropriate time arrives, the CPU starts processing at step 300 in FIG.

[0029] Step 305: The CPU acquires camera object information, white line information, radar object information, and Lidar object information as "environment information related to the surrounding environment of the host vehicle VA." Step 310: The CPU determines whether the establishment flag Xsat is "0". The establishment flag Xsat is set to "1" when both the following condition and the trajectory condition are established. The establishment flag Xsat is set to "0" when at least one of the following condition and the trajectory condition is not established. The establishment flag Xsat is set to "0" in the initialization routine. The initialization routine is executed by the CPU when the ignition key switch (not shown) of the host vehicle VA is changed from the OFF position to the ON position.

[0030] If the establishment flag Xsat is "0", the CPU determines "Yes" in step 310 and executes steps 315 to 325.

[0031] Step 315: The CPU executes a follow-up condition determination subroutine to determine whether the follow-up condition is met. The follow-up condition determination subroutine will be described in detail later. Step 320: The CPU executes a path condition determination subroutine to determine whether the path condition is met. The path condition determination subroutine will be described in detail later. Step 325: The CPU determines whether or not both the following condition and the trajectory condition are met.

[0032] If at least one of the following condition and the trajectory condition is not met, the CPU determines "No" in step 325 and executes steps 330 and 335.

[0033] Step 330: The CPU acquires the TTC of the preceding vehicle. Step 335: The CPU determines whether the preceding vehicle TTC is equal to or less than the threshold time Tth.

[0034] If the TTC of the preceding vehicle is longer than the threshold time Tth, the CPU determines that the collision condition is not met. In this case, the CPU determines "No" in step 335, and the process proceeds to step 395, where the CPU temporarily ends this routine.

[0035] If the preceding vehicle TTC is equal to or shorter than the threshold time Tth, the CPU determines that a collision condition is met. In this case, the CPU determines "Yes" in step 335, and the process proceeds to step 340. In step 340, the CPU executes vehicle control. Specifically, the CPU controls the powertrain actuator 32 and the brake actuator 34 so that the acceleration Ga of the host vehicle VA coincides with a predetermined negative target acceleration. Thereafter, the process proceeds to step 395, where the CPU temporarily terminates this routine.

[0036] When the process proceeds to step 325, if both the following condition and the trajectory condition are met, the CPU determines "Yes" in step 325 and executes steps 345 and 350.

[0037] Step 345: The CPU sets the establishment flag Xsat to “1”. Step 350: The CPU determines whether the vehicle ahead of the vehicle VC has suddenly decelerated. Specifically, the CPU obtains the acceleration Gc of the second-preceding vehicle VC by time-differentiating the relative speed Vr of the second-preceding vehicle VC. The acceleration Gc takes a positive value when the second-preceding vehicle VC moves away from the host vehicle VA, and takes a negative value when the second-preceding vehicle VC approaches the host vehicle VA. If the acceleration Gc is equal to or less than a threshold acceleration Gth set to a predetermined negative value, the CPU determines that the second-preceding vehicle VC has suddenly decelerated.

[0038] If the vehicle VC ahead of the vehicle VC has suddenly decelerated, the CPU determines "Yes" in step 350 and executes steps 355 to 365.

[0039] Step 355: The CPU executes the warning control. In detail, the CPU causes the display device 36 to display a warning screen to notify the driver that the vehicle VC before ahead has suddenly decelerated. Furthermore, the CPU causes the speaker 38 to emit a predetermined warning sound.

[0040] Step 360: The CPU acquires the TTC of the vehicle before the preceding one. Step 365: The CPU determines whether the TTC of the vehicle before the preceding vehicle is equal to or less than the threshold time Tth.

[0041] If the TTC of the vehicle before preceding is longer than the threshold time Tth, the CPU determines "No" in step 365, and the process proceeds to step 395, where the CPU temporarily ends this routine.

[0042] If the TTC of the vehicle before preceding is equal to or less than the threshold time Tth, the CPU determines "Yes" in step 365 and executes vehicle control in step 340. Thereafter, the process proceeds to step 395, where the CPU temporarily ends this routine.

[0043] If the establishment flag Xsat is "1" when the process proceeds to step 310, the CPU determines "No" in step 310, and the process proceeds to step 370. In step 370, the CPU determines whether or not a preceding vehicle VB exists. If a preceding vehicle VB exists, the CPU determines "Yes" in step 370, and the process proceeds to step 375. In step 375, the CPU determines whether or not a preceding vehicle VC exists. If a preceding vehicle VC exists, the CPU determines "Yes" in step 375, and the process proceeds to step 350.

[0044] If the preceding vehicle VB is not present when the process proceeds to step 370, the CPU determines "No" in step 370, and the process proceeds to step 380. In step 380, the CPU sets the establishment flag Xsat to "0." Thereafter, the process proceeds to step 330.

[0045] If there is no preceding vehicle VC when the process proceeds to step 375 , the CPU determines “No” in step 375 and the process proceeds to step 380 .

[0046] <Follow-up condition determination subroutine> When the CPU proceeds to step 315 in Fig. 3, it starts the process from step 400 in Fig. 4 and proceeds to step 405. In step 405, the CPU determines whether the second-preceding vehicle VC and the preceding vehicle VB are traveling in the current lane SL (see Fig. 2). The current lane SL is the lane (traveling area) in which the current vehicle VA is traveling.

[0047] If the second-preceding vehicle VC and the preceding vehicle VB are traveling in the same lane SL, the CPU determines "Yes" in step 405, and the process proceeds to step 410. In step 410, the CPU determines whether the inter-vehicle distance Dx3 (see FIG. 2) between the rear end of the second-preceding vehicle VC and the preceding vehicle VB is equal to or less than a predetermined threshold distance Dth.

[0048] If the inter-vehicle distance Dx3 is equal to or less than the threshold distance Dth, the CPU determines "Yes" in step 410, and the process proceeds to step 415. In step 415, the CPU determines that the following condition is met. Thereafter, the CPU proceeds to step 495, where it temporarily ends this routine, and then proceeds to step 320 shown in FIG. 3.

[0049] On the other hand, if the inter-vehicle distance Dx3 is longer than the threshold distance Dth, the CPU determines "No" in step 410 and proceeds to step 420. In step 420, the CPU determines whether the inter-vehicle time Tv is equal to or less than the threshold time Tvth. The inter-vehicle time Tv is the time it takes for the preceding vehicle VB to travel the inter-vehicle distance Dx3, and is obtained by dividing the inter-vehicle distance Dx3 by the "speed Vvb of the preceding vehicle VB." The speed Vvb is obtained based on the relative speed Vr of the preceding vehicle VB with respect to the host vehicle VA and the vehicle speed Vs of the host vehicle VA.

[0050] If the time headway Tv is equal to or less than the threshold time Tvth, the CPU determines "Yes" in step 420, and the process proceeds to step 415. As a result, the CPU determines that the following condition is met.

[0051] On the other hand, if the inter-vehicle time Tv is longer than the threshold time Tvth, the CPU determines "No" in step 420, and the process proceeds to step 425. In step 425, the CPU determines that the following condition is not met. Thereafter, the CPU proceeds to step 495, where it temporarily ends this routine, and proceeds to step 320 shown in FIG. 3.

[0052] When the process proceeds to step 405, if at least one of the second-preceding vehicle VC and the preceding vehicle VB is not traveling in the current lane SL, the CPU determines "No" in step 405, and the process proceeds to step 425. As a result, the CPU determines that the following condition is not met.

[0053] <Trajectory condition determination subroutine> When the process proceeds to step 320 in FIG. 3, the CPU starts the process from step 500 in FIG. Step 505: The CPU acquires the locus TR of the second preceding vehicle based on the history of the position of the second preceding vehicle VC relative to the host vehicle VA.

[0054] Step 510: The CPU acquires the lateral distance Dya (see FIG. 6), the deflection angle θa (see FIG. 6), and the lateral speed Vya (see FIG. 6) of the host vehicle VA based on the trajectory TR of the vehicle before preceding. The lateral distance Dya represents the lateral distance between the host vehicle VA and the trajectory of the vehicle before the preceding vehicle TR. In the example shown in FIG. The deflection angle θa represents the angle between the longitudinal axis of the host vehicle VA and the trajectory TR of the vehicle before preceding it. In the example shown in FIG. The lateral velocity Vya represents the velocity of the host vehicle VA in the lateral direction relative to the trajectory TR of the vehicle ahead of the host vehicle VA.

[0055] Step 515: The CPU determines whether or not a state in which all of the following conditions A1 to A3 are satisfied continues for a threshold time or longer. Condition A1: The lateral distance Dya is equal to or less than the threshold lateral distance Dyth. Condition A2: The magnitude of the deflection angle θa is equal to or smaller than the threshold angle θth. Condition A3: The magnitude of the lateral velocity Vya is equal to or less than the threshold lateral velocity Vyth.

[0056] If the state in which all of the conditions A1 to A3 are satisfied continues for the threshold time or longer, the CPU determines "Yes" in step 515 and executes steps 520 and 525.

[0057] Step 520: The CPU acquires the lateral distance Dyb (see FIG. 6), the deflection angle θb (see FIG. 6), and the lateral speed Vyb (see FIG. 6) of the preceding vehicle VB based on the trajectory TR of the preceding vehicle. Regarding the lateral distance Dyb, the deflection angle θb, and the lateral speed Vyb, "host vehicle VA" in the above description of the lateral distance Dya, the deflection angle θa, and the lateral speed Vya should be read as "preceding vehicle VB."

[0058] Step 525: The CPU determines whether or not a state in which all of the following conditions B1 to B3 are satisfied continues for a threshold time or longer. Condition B1: The lateral distance Dyb is equal to or less than the threshold lateral distance Dyth. Condition B2: The magnitude of the deflection angle θb is equal to or smaller than the threshold angle θth. Condition B3: The magnitude of the lateral velocity Vyb is equal to or less than the threshold lateral velocity Vyth.

[0059] If the state in which all of conditions B1 to B3 are satisfied continues for the threshold time or longer, the CPU determines "Yes" in step 525, and the process proceeds to step 530. In step 530, the CPU determines that the trajectory condition is satisfied. Thereafter, the CPU proceeds to step 595, where it temporarily ends this routine, and proceeds to step 325 shown in FIG. 3.

[0060] When the process proceeds to step 515, if the state in which all of conditions A1 to A3 are satisfied has not continued for the threshold time or longer, the CPU determines "No" in step 515, and the process proceeds to step 535. In step 535, the CPU determines that the trajectory condition is not satisfied. Thereafter, the CPU proceeds to step 595 to temporarily end this routine, and proceeds to step 325 shown in FIG. 3.

[0061] When the process proceeds to step 525, if the state in which all of conditions B1 to B3 are satisfied has not continued for the threshold time or longer, the CPU determines "No" in step 525, and the process proceeds to step 535. As a result, the CPU determines that the trajectory condition is not satisfied.

[0062] As described above, according to this embodiment, it is possible to increase the possibility of appropriately executing vehicle control even if the preceding vehicle slows down later when the vehicle ahead of it slows down, and it is also possible to reduce the possibility of executing unnecessary vehicle control.

[0063] (Variation) In the above embodiment, the CPU uses the TTC as the index value of the collision risk, but other values ​​may be used. For example, the CPU may use the "distance Dx between the object and the host vehicle VA" as the index value. The CPU performs vehicle control when the distance Dx is equal to or less than the threshold distance Dxth.

[0064] In the above embodiment, the millimeter-wave radar 24 detects the second-preceding vehicle VC, but this is not limiting. For example, the camera 22 may be disposed on the roof of the host vehicle VA, and the camera 22 may detect the second-preceding vehicle VC. Furthermore, the lidar 25 may be disposed in the same position as the millimeter-wave radar 24 in the above embodiment, and the lidar 25 may detect the second-preceding vehicle VC. Furthermore, the sensors that detect objects are not limited to the camera 22, the millimeter-wave radar 24, and the lidar 25.

[0065] The vehicle control may be a control to change the steering angle of the steered wheels of the host vehicle VA so as to avoid a collision with an object, or may be a warning control to notify the driver of a collision risk.

[0066] The device 10 is applicable to vehicles such as engine vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles, and is also applicable to autonomous vehicles. [Explanation of symbols]

[0067] 10...vehicle control device, 22...camera, 24...millimeter wave radar, 25...lidar, 32...power train actuator, 34...brake actuator.

Claims

1. A vehicle control device that executes vehicle control to reduce a collision risk when a collision condition is established in which a collision risk with an object is equal to or greater than a threshold, The vehicle control device includes: if both a following condition that a preceding vehicle in front of the host vehicle is following a second preceding vehicle in front of the preceding vehicle and a trajectory condition that the host vehicle and the preceding vehicle are traveling on a second preceding vehicle trajectory that represents a trajectory traveled by the second preceding vehicle are satisfied, determine whether or not the collision condition is satisfied using a first index value that represents a collision risk with the second preceding vehicle; if at least one of the following condition and the trajectory condition is not satisfied, a second index value representing a collision risk of the preceding vehicle is used to determine whether the collision condition is satisfied. A vehicle control device configured as above.

2. 2. The vehicle control device according to claim 1, The vehicle control device is configured to determine that the following condition is met when the preceding vehicle is traveling in the same lane as the second preceding vehicle, and the inter-vehicle distance between the second preceding vehicle and the preceding vehicle is less than a threshold distance or the inter-vehicle time required for the preceding vehicle to travel the inter-vehicle distance is less than a threshold time.

3. 2. The vehicle control device according to claim 1, The vehicle control device includes: a first condition that the lateral distance of the preceding vehicle relative to the locus of the second preceding vehicle is equal to or less than a threshold lateral distance, the lateral speed of the preceding vehicle is equal to or less than a threshold lateral speed, and the deflection angle of the preceding vehicle relative to the locus of the second preceding vehicle is equal to or less than a threshold angle; and a second condition that a lateral distance of the host vehicle with respect to the locus of the second preceding vehicle is equal to or less than a threshold lateral distance, a lateral speed of the host vehicle is equal to or less than a threshold lateral speed, and a deviation angle of the host vehicle with respect to the locus of the second preceding vehicle is equal to or less than a threshold angle; and determining that the trajectory condition is met when both of the above conditions are met.

4. 2. The vehicle control device according to claim 1, The vehicle control device includes: When both the following condition and the trajectory condition are satisfied, a sum of a vehicle length value representing the length of the preceding vehicle and a minimum inter-vehicle distance value representing the minimum inter-vehicle distance when the preceding vehicle is following the second preceding vehicle is subtracted from the inter-vehicle distance between the subject vehicle and the second preceding vehicle, and the resulting subtraction value is divided by the relative speed of the second preceding vehicle with respect to the subject vehicle, and the resulting value is used as the first index value; When at least one of the following condition and the trajectory condition is not satisfied, a value obtained by dividing the inter-vehicle distance between the host vehicle and the preceding vehicle by the relative speed of the preceding vehicle with respect to the host vehicle is used as the second index value. A vehicle control device configured as above.

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