Vehicle control device and program

Abstract

To provide a vehicle control device capable of reducing a collision possibility by appropriately selecting, depending on a collision object, whether to perform simultaneously a first control to reduce the collision possibility and a second control to control a steering angle so as to suppress a deviation of a vehicle from a travel area fixed by a boundary or perform only the first control.SOLUTION: A vehicle control device performs a first control when a collision possibility between a vehicle and a target satisfies a predetermined collision condition, and can perform a second control. The vehicle control device determines whether a collision object being the target satisfying the collision condition satisfies a predetermined prohibition condition, so as to prohibit the performance of the second control when the collision object satisfies the prohibition condition, and to permit the performance of the second control when the collision object does not satisfy the prohibition condition.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle control device capable of executing first control to reduce the possibility of collision when the possibility of collision between a vehicle and an object satisfies a predetermined collision condition, and executing second control to control the steering angle of the vehicle so as to suppress the vehicle from deviating from a traveling region, and a program capable of causing a computer mounted on the vehicle to execute deceleration control and deviation suppression control.

Background Art

[0002] Conventionally, there is known a vehicle control device that executes "deceleration control for decelerating the vehicle to reduce the possibility of collision" as first control and can execute deviation suppression control as second control. For example, the vehicle control device described in Patent Document 1 (hereinafter referred to as the "conventional device") executes deceleration control (first control) when a collision condition is satisfied, and executes deviation suppression control (second control) when a deviation condition is satisfied. The collision condition is satisfied when there is a high possibility that the vehicle and the object will collide. The deviation condition is satisfied when there is a high possibility that the vehicle will deviate from the traveling region or when the vehicle has deviated from the traveling region.

[0003] When the collision condition is satisfied, the conventional device determines whether or not the steering direction of the steering angle by the deviation suppression control is the same as the collision avoidance direction for avoiding a collision with an object (hereinafter referred to as the "collision target") that satisfies the collision condition. When the steering direction and the collision avoidance direction are different, the conventional device stops the execution of the deviation suppression control and executes the deceleration control, and when the steering direction and the collision avoidance direction are the same, the conventional device simultaneously executes the deviation suppression control and the deceleration control.

[0004] The reason for stopping the execution of the deviation suppression control when the steering direction and the collision avoidance direction are different is to prevent the vehicle from traveling in the direction of colliding with the collision target. Thereby, it is possible to suppress the occurrence of a situation in which the collision avoidance effect is reduced due to the deviation suppression control.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-94955 [Overview of the Initiative]

[0006] If the object to be hit is "a target located outside the boundary of the driving area and capable of autonomous movement (e.g., pedestrians and motorcycles)," the object may move inward to avoid a collision with the vehicle. Conventional systems may determine that the steering direction and the collision avoidance direction are the same in such cases, potentially executing both departure prevention control and deceleration control simultaneously. If departure prevention control is executed in such a case, both the vehicle and the object to be hit will move in the same direction (i.e., inward to the driving area), potentially increasing the likelihood of a collision.

[0007] On the other hand, for stationary targets such as guardrails, simultaneously executing lane departure prevention control and deceleration control can reduce the likelihood of a collision.

[0008] The present invention was made to address the aforementioned problems. Specifically, it aims to provide a vehicle control device that can reduce the likelihood of collision by appropriately selecting whether to simultaneously execute deceleration control (first control) and departure prevention control (second control) or to execute only deceleration control (first control) depending on the object of collision.

[0009] The vehicle control device of the present invention (hereinafter also referred to as the "device of the present invention") is In a vehicle control device (step 450) that performs a first control to reduce the likelihood of collision between a vehicle and a target when the likelihood of collision between the vehicle and a target meets predetermined collision conditions (step 320 "Yes") (step 325), and performs a second control to control the steering angle of the vehicle so as to prevent the vehicle from deviating from a driving area defined by a boundary, The aforementioned vehicle control device is The collision target that satisfies the aforementioned collision conditions is determined to have met the predetermined prohibition conditions (step 330), If the collision target satisfies the prohibition condition (step 330 "Yes"), the execution of the second control is prohibited (steps 335, 435, and 445). If the collision target does not meet the prohibition conditions (step 330 "No"), the execution of the second control is permitted (steps 340, 435, and 445). It is structured in this way.

[0010] Whether the execution of the second control (deviation suppression control) increases the likelihood of a collision, or whether the execution of the second control reduces the likelihood of a collision, depends on the object being hit. According to the device of the present invention, if the object being hit meets the prohibition conditions, the execution of the second control is prohibited and only the first control (deceleration control) is executed. If the object being hit does not meet the prohibition conditions, the first and second controls can be executed simultaneously. This makes it possible to appropriately select whether to execute the first and second controls simultaneously or only the first control depending on the object being hit, thereby reducing the possibility of increasing the likelihood of a collision by executing the second control and increasing the possibility of reducing the likelihood of a collision by executing the second control. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic system configuration diagram of a vehicle control device according to an embodiment of the present invention. [Figure 2] This is an explanatory diagram illustrating the general operation of a vehicle control device according to an embodiment of the present invention. [Figure 3] Figure 1 is a flowchart showing the deceleration control routine executed by the CPU of the vehicle control ECU. [Figure 4] Figure 1 is a flowchart showing the lane departure prevention control routine executed by the CPU of the vehicle control ECU. [Modes for carrying out the invention]

[0012] As shown in Figure 1, the vehicle control device according to this embodiment (hereinafter referred to as "this device 10") is applied to a vehicle VA and comprises the components shown in Figure 1.

[0013] The vehicle control ECU20 is an ECU capable of performing deceleration control and lane departure prevention control, and will be referred to as "ECU20" below.

[0014] Deceleration control is a control system that decelerates the vehicle VA to reduce the likelihood of collision with a target when the possibility of collision between the vehicle VA and the target meets predetermined collision conditions, regardless of the driver's braking operation. Deviation prevention control is a control system that controls the steering angle θ of the vehicle VA to prevent the vehicle VA from deviating from the driving area TA (see Figure 2). In some cases, deceleration control is referred to as "first control" and deviation prevention control as "second control".

[0015] In this specification, "ECU" refers to an electronic control unit comprising a microcomputer as its main component. An ECU is also referred to as a controller or computer. The microcomputer includes a CPU (processor), ROM, RAM, and an interface (I / F), etc. The CPU implements various functions by executing instructions (routines) stored in memory (ROM). At least one function implemented by ECU 20 may be implemented by multiple ECUs.

[0016] Camera 22 acquires image data by photographing the scenery in front of the vehicle VA. Based on the image data, Camera 22 acquires camera target information and boundary information. The camera target information includes the position of the target located in front of the vehicle VA relative to the vehicle VA. The boundary information includes the position of the boundary BL that defines the driving area TA relative to the vehicle VA. Examples of boundary BL include white lines on the road, guardrails, curbs, and walls. Camera 22 transmits the image data, camera target information, and white line information to the ECU 20.

[0017] The millimeter-wave radar 24 transmits millimeter waves forward of the vehicle VA, and receives the reflected waves of the transmitted millimeter waves reflected by the target, thereby obtaining radar target information including "the position of the target with respect to the vehicle VA" and "the relative speed Vr of the target with respect to the vehicle VA". The millimeter-wave radar 24 transmits the radar target information to the ECU 20.

[0018] The vehicle speed sensor 26 detects the vehicle speed Vs representing the speed of the vehicle VA. The acceleration sensor 28 detects the acceleration G in the longitudinal axis direction of the vehicle VA. In the present embodiment, the acceleration G has a positive value when the vehicle VA accelerates and a negative value when the vehicle VA decelerates. The steering angle sensor 29 detects the steering angle θ of the steering wheels of the vehicle VA. The yaw rate sensor 30 detects the yaw rate Yr of the vehicle VA. The ECU 20 acquires the detection values of these sensors 26 to 30.

[0019] The power train actuator 32 changes the driving force generated by the drive device (e.g., internal combustion engine and / or electric motor) of the vehicle VA. The brake actuator 34 controls the braking force applied to the wheels of the vehicle VA. The steering motor 36 is incorporated in the steering mechanism 38. The steering mechanism 38 is a mechanism for steering the steering wheels in response to the operation of the steering wheel. The steering motor 36 generates an assist torque for assisting the operation of the steering wheel in response to an instruction from the ECU 20, and generates an automatic steering torque for changing the steering angle θ of the steering wheels in the steering mechanism 38.

[0020] (Deceleration control) The ECU 20 acquires the TTC (Time To Collision) representing the time required until the vehicle VA collides with the target as "a collision index value representing the possibility of collision". Specifically, the ECU 20 acquires the TTC by dividing the distance D between the vehicle VA and the target by the relative speed Vr. The smaller the TTC, the higher the possibility of collision.

[0021] When the minimum TTC is less than or equal to the threshold time Tth, the ECU 20 determines that the collision condition is satisfied and executes deceleration control to avoid or suppress a collision with a collision target, which is an object having the minimum TTC. In the deceleration control, the ECU 20 decelerates the vehicle VA by controlling the power train actuator 32 and the brake actuator 34 so that the acceleration G matches a preset target acceleration Gtgt having a predetermined negative value.

[0022] (Deviation suppression control) Based on the boundary information, the ECU 20 identifies a right boundary RBL (see FIG. 2) that defines the right end of the travel region TA in which the vehicle VA travels and a left boundary LBL (see FIG. 2) that defines the left end of the travel region TL. The right boundary RBL and the left boundary LBL are referred to as the "boundary BL" when there is no need to distinguish between them.

[0023] The ECU 20 sets start reference lines Lsth (right start reference line RLsth and left start reference line LLsth) at positions separated from the boundary BL by a predetermined distance in a direction orthogonal to the boundary BL (see FIG. 2). In the example shown in FIG. 2, the start reference line Lsth is set inside the boundary BL, but it may be set outside the boundary BL. The ECU 20 sets an end reference line Leth (not shown) inside each start reference line Lsth.

[0024] When any of the following Condition 1 and Condition 2 is satisfied, the ECU 20 determines that the deviation condition is satisfied and executes deviation suppression control. Condition 1: The predicted travel route PR of the vehicle VA intersects the start reference line Lsth, and the distance D between the start reference line Lsth where the predicted travel route PR intersects and the vehicle VA is less than or equal to the threshold distance Dth. Condition 2: The vehicle VA has deviated from the start reference line Lsth. Note that the ECU 20 identifies the predicted travel route PR from the current position of the vehicle VA to a predetermined distance ahead based on the vehicle speed Vs and the yaw rate Yr.

[0025] In deviation suppression control, the ECU 20 controls the steering motor 36 so that the steering angle θ matches the "target steering angle θtgt for suppressing the vehicle VA from deviating from the driving area TR".

[0026] The ECU20 terminates the deviation suppression control when the termination condition is met, which is that the vehicle VA is now located inside the termination reference line Leth.

[0027] (Summary of operation) This section will explain the general operation of the ECU 20 of this device 10. The ECU20 determines whether a collision target that meets the collision conditions also meets the prohibition conditions. If the collision target meets the prohibition conditions, the ECU20 prohibits the execution of the departure prevention control; if the collision target does not meet the prohibition conditions, the ECU20 permits the execution of the departure prevention control.

[0028] The ECU20 determines that a collision target meets the prohibition conditions if the collision target is located outside the boundary BL and is a specific movable target. Pedestrians PD (see Figure 2) and motorcycles, etc., are pre-set as specific targets.

[0029] If the collision target is located outside the boundary BL and is a movable target, as shown in Figure 2, the collision target may move inside the boundary BL to avoid a collision with the vehicle VA. If departure suppression control is executed in such a case, both the vehicle VA and the collision target will move in the same direction, potentially increasing the likelihood of a collision. Since the prohibition condition is met when the collision target is located outside the boundary BL and is a movable target, the ECU 20 prohibits the execution of departure suppression control.

[0030] On the other hand, if the object to be hit is an immovable target (e.g., a guardrail or wall), the likelihood of a collision is reduced if lane departure prevention control is performed compared to if lane departure prevention control is not performed. Since the prohibition condition is not met when the object to be hit is an immovable target, the ECU20 permits the execution of lane departure prevention control.

[0031] According to this embodiment, it is possible to appropriately select whether to execute departure suppression control and deceleration control simultaneously or deceleration control only depending on the collision target, thereby reducing the possibility of increasing the likelihood of collision by executing departure suppression control and increasing the possibility of reducing the likelihood of collision by executing departure suppression control.

[0032] (Specific operation) <Deceleration control routine> The CPU of ECU20 executes the deceleration control routine shown in the flowchart in Figure 3 at predetermined intervals.

[0033] Therefore, at a predetermined timing, the CPU starts processing from step 300 in Figure 3 and executes steps 305 and 310.

[0034] Step 305: The CPU acquires camera target information from camera 22 and radar target information from millimeter-wave radar 24. Step 310: The CPU determines, based on the predicted path PR of the vehicle VA, whether or not there is a target that could potentially collide with the vehicle VA.

[0035] If there is a target that could potentially collide with the vehicle VA, the CPU determines "Yes" in step 310 and executes steps 315 and 320.

[0036] Step 315: The CPU obtains the TTC of a target that could potentially collide with the vehicle VA. Step 320: The CPU determines whether the minimum TTC is less than or equal to the threshold time Tth.

[0037] If the minimum TTC is less than or equal to the threshold time Tth, the CPU determines that the collision condition is met. In this case, the CPU determines "Yes" in step 320 and executes steps 325 and 330.

[0038] Step 325: The CPU performs deceleration control. That is, the CPU controls the powertrain actuator 32 and the brake actuator 34 so that the acceleration G matches the target acceleration Gtgt. Step 330: The CPU determines whether the object that satisfies the collision conditions is located outside the boundary BL and is a movable target. The CPU identifies the position of the boundary BL relative to the vehicle VA based on boundary information, and determines whether the position of the collision target, identified based on camera object information and radar object information, is outside the boundary BL. Furthermore, as an example, the CPU determines whether the object to be hit is a specific target based on image data. Specifically, an image of the "specific target" is pre-stored as a template image in a memory device (not shown), and the CPU determines whether the object to be hit is a specific target by comparing the image of the object to be hit with the template image. As another example, the CPU determines whether an object to be hit is a specific target based on the reflection intensity of the reflected waves from millimeter-wave radar 24, because the reflection intensity differs for each type of target.

[0039] If the object to be hit is located outside the boundary BL and is a movable target, the CPU determines that the object to be hit has met the prohibition condition. In this case, the CPU determines "Yes" in step 330 and proceeds to step 335. In step 335, the CPU sets the value of the prohibition flag Xkns to "1". After that, the CPU proceeds to step 395 and terminates this routine.

[0040] The value of the prohibition flag Xkns is set to "1" to prohibit the execution of lane departure suppression control, and to "0" to allow the execution of lane departure suppression control. Note that the value of the prohibition flag Xkns is set to "0" in the initial routine. The initial routine is executed by the CPU when the ignition key switch (not shown in the diagram) of the vehicle VA is changed from the off position to the on position.

[0041] If there are no targets that could be hit when the CPU proceeds to step 310, the CPU determines "No" in step 310 and proceeds to step 340. In step 340, the CPU sets the value of the forbidden flag Xkns to "0". After that, the CPU proceeds to step 395 and terminates this routine.

[0042] If the minimum TTC is greater than the threshold time Tth when the CPU proceeds to step 320, the CPU determines "No" in step 320 and proceeds to step 340. If the collision target does not satisfy the prohibition condition when the CPU proceeds to step 330, the CPU determines "No" in step 330 and proceeds to step 340.

[0043] <Deviation Suppression Control Routine> The CPU executes the deviation suppression control routine, as shown in the flowchart in Figure 4, at predetermined intervals.

[0044] Therefore, at a predetermined timing, the CPU starts processing from step 400 in Figure 4 and executes steps 405 to 420.

[0045] Step 405: The CPU obtains boundary information from camera 22. Step 410: The CPU identifies the boundary BL based on the boundary information. Step 415: The CPU sets the start reference line Lsth and the end reference line Leth. Step 420: The CPU determines whether the value of the execution flag Xexe is "0".

[0046] The execution flag Xexe is set to "1" when deviation suppression control begins and to "0" when deviation suppression control ends. The execution flag Xexe is initially set to "0" during the initial routine.

[0047] If the value of the execution flag Xexe is "0", the CPU determines "Yes" in step 420 and proceeds to step 425. In step 425, the CPU determines whether the condition (Condition 1) is met, which states that the predicted path PR intersects the starting reference line Lsth and the above distance D is less than or equal to the threshold distance Dth.

[0048] If the above condition (Condition 1) is not met, the CPU determines "No" in step 425 and proceeds to step 430. In step 430, the CPU determines whether or not the vehicle VA has deviated from the starting reference line Lsth.

[0049] If the vehicle VA does not deviate from the starting reference line Lsth, the CPU determines "No" in step 430 and proceeds to step 495 to terminate this routine.

[0050] If the above condition (condition 1) is met when the CPU proceeds to step 425, the CPU determines "Yes" in step 425 and proceeds to step 435. In step 435, the CPU determines whether the value of the forbidden flag Xkns is "0".

[0051] If the value of the prohibition flag Xkns is "0", the CPU determines "Yes" in step 435 and proceeds to step 440. In step 440, the CPU sets the value of the execution flag Xexe to "1". After that, the CPU proceeds to step 495 and terminates this routine.

[0052] On the other hand, if the value of the prohibition flag Xkns is "1", the CPU determines "No" in step 435 and proceeds to step 495 to terminate this routine. In this case, although the deviation condition is met, the value of the prohibition flag Xkns is set to "1" because the collision target satisfies the prohibition condition, and therefore the value of the execution flag Xexe is not set to "1".

[0053] If the vehicle VA deviates from the reference line Lth when the CPU proceeds to step 430, the CPU determines "Yes" in step 430 and proceeds to step 435.

[0054] If the value of the execution flag Xexe is "1" when the CPU proceeds to step 420, the CPU determines "No" in step 420 and proceeds to step 445. In step 445, the CPU determines whether the value of the prohibition flag Xkns is "0".

[0055] If the value of the forbidden flag Xkns is "0", the CPU determines "Yes" in step 445 and proceeds to steps 450 and 455.

[0056] Step 450: The CPU performs deviation suppression control. That is, the CPU controls the steering motor 36 so that the steering angle θ matches the target steering angle θtgt. Step 455: The CPU determines whether the vehicle VA is located inside the end reference line Leth.

[0057] If vehicle VA is located outside the termination reference line Leth, the CPU determines that the termination condition is not met. In this case, the CPU determines "No" in step 455 and proceeds to step 495 to terminate this routine.

[0058] If the value of the prohibition flag Xkns is "1" when the CPU proceeds to step 445, the CPU determines "No" in step 445 and proceeds to step 460. In step 460, the CPU sets the value of the execution flag Xexe to "0". After that, the CPU proceeds to step 495 and terminates this routine. In this case, when the deviation condition was met, the collision target did not satisfy the prohibition condition, so deviation suppression control was initially started, but after the collision target satisfied the prohibition condition, the deviation suppression control was terminated.

[0059] If, when the CPU proceeds to step 455, vehicle VA is located inside the termination reference line Leth, the CPU determines that the termination condition has been met. In this case, the CPU determines "Yes" in step 455 and sets the value of the execution flag Xexe to "0" in step 460. After that, the CPU proceeds to step 495 and terminates this routine.

[0060] As explained above, if the object to be hit meets the prohibition conditions, the execution of the departure prevention control is prohibited, and if the object to be hit does not meet the prohibition conditions, the execution of the departure prevention control is permitted. This allows for an appropriate selection of whether to execute departure prevention control and deceleration control simultaneously or deceleration control only, depending on the object to be hit. This reduces the possibility of increasing the likelihood of a collision by executing departure prevention control, and increases the possibility of reducing the likelihood of a collision by executing departure prevention control.

[0061] The present invention is not limited to the embodiments described above, and various modifications of the present invention can be adopted. In the above embodiments, the ECU 20 may determine that the prohibition condition is met if the collision target is a specific movable object, regardless of whether the collision target is located outside the boundary BL. This also allows for an appropriate selection of whether to execute departure suppression control and deceleration control simultaneously or deceleration control only, depending on the collision target.

[0062] As in the embodiment described above, determining that the prohibition condition is met when the collision target is located outside the boundary BL and the collision target is a movable target increases the likelihood that the collision target will move in the same direction as the steering direction caused by the departure suppression control (inside the driving area TR) in order to avoid a collision with the vehicle VA. Therefore, the possibility of mistakenly prohibiting the execution of the departure suppression control can be reduced.

[0063] Furthermore, the ECU20 may determine that the prohibition condition has been met if the collision target is located outside the starting reference line Lsth and the collision target is a movable object.

[0064] In the above embodiment, the ECU 20 performed deceleration control as a first control to reduce the probability of collision when collision conditions were met, but it is not limited to this. For example, the ECU 20 may perform warning control as a first control to reduce the probability of collision when collision conditions were met. Warning control is a control to inform the driver that there is a high probability of collision with an object. For example, the ECU 20 may display a warning screen on a display mounted on the vehicle VA indicating to the driver that there is a high probability of collision with an object, or it may emit a predetermined warning sound from a speaker mounted on the vehicle VA.

[0065] Furthermore, the ECU20 may perform deceleration control and warning control as first controls.

[0066] In the above embodiment, the ECU20 used TTC as a "collision index value representing the likelihood of collision," but the distance between the vehicle VA and the target may also be used as the collision index value.

[0067] Camera 22 may be a stereo camera or a monocular camera. Millimeter-wave radar 24 may be a remote sensing device capable of detecting objects by transmitting a wireless medium other than millimeter waves and receiving the reflected wireless medium. Furthermore, if the position of the object relative to the vehicle VA can be accurately determined based on the camera object information, the device 10 does not need to be equipped with millimeter-wave radar 24.

[0068] The device 10 is applicable to vehicles such as engine-powered vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles. Furthermore, the device 10 is also applicable to autonomous vehicles. Moreover, the present invention can also be considered as a non-temporary storage medium on which a program for realizing the functions of the device 10 is stored and which is readable by a computer. [Explanation of symbols]

[0069] 10...Driving assistance system, 20...Vehicle control ECU, 22...Camera, 24...Millimeter-wave radar, 32...Powertrain actuator, 34...Brake actuator, 36...Steering motor.

Claims

1. A vehicle control device capable of executing a first control to reduce the possibility of collision when the possibility of collision between a vehicle and a target satisfies predetermined collision conditions, and a second control to control the steering angle of the vehicle to prevent the vehicle from deviating from a driving area defined by a boundary, The aforementioned vehicle control device is It is determined whether the target object that satisfies the aforementioned collision conditions satisfies the predetermined prohibition conditions. If the collision target satisfies the prohibition conditions, the execution of the second control is prohibited. If the collision target does not satisfy the prohibition conditions, the execution of the second control is permitted. It is configured in such a way, Furthermore, the vehicle control device is configured to determine that the collision target satisfies the prohibition condition if the collision target is a specific movable object and is located outside the boundary. Vehicle control device.

2. In the vehicle control device according to Claim 1, The vehicle control device is configured to pre-set pedestrians or motorcycles as the specific targets. Vehicle control device.

3. A program that causes a computer mounted on a vehicle to execute a first control to reduce the possibility of collision between the vehicle and a target when the possibility of collision between the vehicle and a target satisfies predetermined collision conditions, and causes the computer to execute a second control to control the steering angle of the vehicle so as to prevent the vehicle from deviating from a driving area defined by a boundary, The aforementioned program, The first step is to determine whether the target object that satisfies the aforementioned collision conditions satisfies predetermined prohibition conditions, If the collision target satisfies the prohibition conditions, the second step is to prohibit the execution of the second control, If the collision target does not satisfy the prohibition conditions, the third step is to allow the execution of the second control, and to have the computer execute In the first step, if the object to be hit is a specific movable target and is located outside the boundary, the computer is made to determine that the object to be hit has met the prohibition conditions. program.

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