Vehicle control device and program

Abstract

To properly perform vehicle deceleration control based on map information.SOLUTION: The ECU10 uses the map information from the navigation device 40 to execute deceleration control for decelerating the own vehicle according to the road situation ahead of the own vehicle in the traveling direction. The ECU10 includes an accelerator operation determination unit configured to determine that an accelerator operation is performed by a driver of the own-vehicle under a situation in which the deceleration control is being executed, and a deceleration control unit configured to cancel the deceleration control based on traveling information of at least one of the own-vehicle and other vehicles traveling in the same direction as the own-vehicle around the own-vehicle when it is determined that the deceleration control is being executed and the accelerator operation is performed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The disclosure in this specification relates to a vehicle control device and a program. [Background technology]

[0002] As a vehicle control for assisting a vehicle's driving, a technology is known in which a vehicle follows a preceding vehicle traveling ahead of the vehicle. Another technology is known in which the vehicle's position is determined using a global positioning system (GPS) or the like, and deceleration control of the vehicle is performed based on the vehicle's position and map information. For example, when the map information indicates that the road ahead of the vehicle is a curved road or an intersection entrance, the brakes are automatically applied to perform deceleration control without the driver's brake operation.

[0003] In addition, in the technology described in Patent Document 1, for example, when entering a curve, deceleration control of the vehicle is performed based on information on the curve curvature and gradient included in map information. Also, if the driver operates the accelerator during deceleration control, the deceleration control is stopped at that point. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-147506 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-described configuration in which deceleration control is stopped by the driver's accelerator operation, it is possible that the deceleration control will be stopped unintentionally if the driver mistakenly operates the accelerator while deceleration control is being performed. In this case, there is a concern that unnecessary acceleration of the vehicle will occur as a result of the deceleration control being stopped. On the other hand, if an error occurs in the map information, it is possible that unnecessary deceleration control will be performed. In this case, there is thought to be room for technical improvement in order to appropriately stop deceleration control while reflecting the driver's intention.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a vehicle control device and a program that can appropriately perform vehicle deceleration control based on map information. [Means for solving the problem]

[0007] A vehicle control device according to the present disclosure is capable of executing deceleration control for decelerating a host vehicle in accordance with road conditions ahead in the traveling direction of the host vehicle using map information. The vehicle control device includes an accelerator operation determination unit that determines whether an accelerator operation has been performed by the driver of the host vehicle while deceleration control is being executed, and a deceleration control unit that cancels the deceleration control when deceleration control is being executed and it is determined that an accelerator operation has been performed, based on travel information of at least one of the host vehicle and other vehicles traveling in the same direction around the host vehicle.

[0008] When map information indicates that the road ahead of the host vehicle is a curved road, a T-junction, a roundabout, or the like, the host vehicle is decelerated by deceleration control. Furthermore, when deceleration control is being performed based on map information, the deceleration control is canceled based on the accelerator operation by the driver of the host vehicle. However, if the accelerator operation is erroneous, there is a concern that the vehicle may accelerate unintentionally immediately after the deceleration control is canceled. In this regard, the above configuration cancels the deceleration control based on travel information of at least one of the host vehicle and other vehicles traveling in the same direction as the host vehicle around the host vehicle when deceleration control is being performed based on map information and it is determined that the driver has operated the accelerator. In this case, the travel information of at least one of the host vehicle and other vehicles traveling in the same direction as the host vehicle around the host vehicle makes it possible to determine whether the accelerator operation was erroneous during deceleration control based on map information or whether deceleration control was performed based on erroneous map information. This makes it possible to correctly determine whether the driver's accelerator operation is valid or invalid, and then appropriately cancel the deceleration control. As a result, vehicle deceleration control based on map information can be performed appropriately. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram showing an overview of a vehicle driving assistance system. [Figure 2] FIG. 2 is a diagram showing an example of a driving scene of the host vehicle; [Figure 3] 4 is a time chart for explaining deceleration control. [Figure 4] 4 is a time chart for explaining deceleration control. [Figure 5] 4 is a flowchart showing a procedure for deceleration control. [Figure 6] 10 is a flowchart showing a processing procedure for deceleration control in the second embodiment. [Figure 7] FIG. 2 is a diagram showing an example of a driving scene of the host vehicle; [Figure 8] 10 is a flowchart showing a processing procedure for deceleration control in a third embodiment. [Figure 9] FIG. 2 is a diagram showing an example of a driving scene of the host vehicle; [Figure 10] 10 is a flowchart showing the procedure of a threshold setting process in the fourth embodiment. [Figure 11] FIG. 10 is a diagram showing the relationship between the host vehicle acceleration and a reduction correction value K. [Figure 12] 10 is a flowchart showing the procedure of a threshold setting process. [Figure 13] 10 is a flowchart showing the procedure of a threshold setting process. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) Hereinafter, a vehicle control device according to an embodiment of the present disclosure will be described with reference to the drawings. In this embodiment, a driving assistance system is configured to provide driving assistance to a vehicle such as a passenger car, a truck, or a bus.

[0011] 1, the driving assistance system according to this embodiment includes an ECU 10 (Electronic Control Unit) as a vehicle control device, sensors 20, controlled devices 30, and a navigation device 40. The sensors 20 include a camera 21, a radar device 22, a speed sensor 23, and an accelerator sensor 24. The controlled devices 30 include an accelerator device 31 and a brake device 32.

[0012] The camera 21 is, for example, a monocular camera. The cameras 21 are attached, for example, to the front end, rear end, and both left and right sides of the vehicle, and capture images of the surroundings of the vehicle. Each camera 21 transmits the captured images to the ECU 10 at a predetermined interval. The camera 21 may also be a stereo camera.

[0013] The radar device 22 is a distance measuring device that transmits high-frequency signals in the millimeter wave band. The radar devices 22 are mounted, for example, at the front end, rear end, and left and right sides of the vehicle, and measure the distance to objects around the vehicle. Specifically, the radar device 22 transmits probe waves at a predetermined cycle and receives reflected waves using multiple antennas. The radar device 22 measures the distance to the object based on the transmission time of the probe waves and the reception time of the reflected waves. The radar device 22 also calculates the direction of the object based on the phase difference between the reflected waves received by the multiple antennas. By calculating the distance to the object and the direction of the object, the relative position of the object with respect to the vehicle can be identified.

[0014] The speed sensor 23 is a sensor that detects the traveling speed of the vehicle. For example, a wheel speed sensor that detects the rotation speed of the wheels can be used as the speed sensor 23. The accelerator sensor 24 is a sensor that detects the accelerator operation by the driver of the vehicle. For example, when the amount of depression of the accelerator pedal reaches a predetermined amount or more, the accelerator sensor 24 outputs an electric signal indicating that the accelerator has been operated. The accelerator sensor 24 may also be a sensor that detects the magnitude of the accelerator operation amount.

[0015] The ECU 10 is an electronic control unit equipped with a well-known microcomputer including a CPU, ROM, RAM, flash memory, etc. The microcomputer provides various calculation functions. The functions provided by the microcomputer can be provided by software recorded in a physical memory device and a computer executing the software, the software alone, the hardware alone, or a combination thereof. The microcomputer executes programs stored, for example, in a non-transitory tangible storage medium serving as a storage unit provided within the microcomputer. The programs include, for example, programs related to object recognition processing for recognizing objects around the vehicle and processing for avoiding collisions with objects around the vehicle or mitigating damage in the event of a collision. Execution of the programs results in the execution of a method corresponding to the programs. The storage unit is, for example, a non-volatile memory. The programs stored in the storage unit can be updated, for example, via a network such as the Internet.

[0016] The ECU 10 acquires object detection information from the camera 21 and the radar device 22, respectively, and recognizes objects around the vehicle based on this information. Specifically, the ECU 10 calculates the relative position and presence area of ​​the object as image information based on the distance to the object and the direction of the object calculated from the camera image, and calculates the relative position and presence area of ​​the object as radar information based on the distance to the object and the direction of the object included in the distance information acquired from the radar device 22. The ECU 10 then recognizes the object by fusing this image information with the radar information. In this embodiment, the object is recognized based on whether the presence area of ​​the object included in the image information overlaps with the presence area of ​​the object included in the radar information. However, in this embodiment, any object recognition method may be used. For example, it is also possible to recognize an object based on only the object detection information from the camera 21 or only the object detection information from the radar device 22 out of the object detection information from the camera 21 and the radar device 22.

[0017] The ECU 10 executes adaptive cruise control (ACC) as a cruise assist control for the host vehicle. Specifically, the ECU 10 executes constant-speed cruise control of the host vehicle at a target speed set by the driver, and also executes follow-up control to make the host vehicle follow the preceding vehicle while maintaining a predetermined target inter-vehicle distance when a preceding vehicle traveling ahead of the host vehicle is present. In this case, the ECU 10 searches for a preceding vehicle to be followed ahead of the host vehicle in the traveling direction while executing ACC control. If no preceding vehicle is present, the ECU 10 controls the host vehicle to travel at a constant speed at a target speed. If a preceding vehicle is present, the ECU 10 controls the host vehicle to travel while maintaining the inter-vehicle distance from the preceding vehicle at the target inter-vehicle distance. In this case, the ECU 10 executes speed control by adjusting the driving force and braking force of the host vehicle using the controlled device 30 to control the speed of the host vehicle.

[0018] In this embodiment, the vehicle is equipped with an accelerator device 31 and a brake device 32 as controlled devices 30. The accelerator device 31 is an engine or a motor as a vehicle power source, and when the driver operates the accelerator, a driving force is applied to the vehicle in response to a control command from the ECU 10. The brake device 32 is provided on each wheel of the vehicle, and when the driver operates the brake, a braking force is applied to the vehicle in response to a control command from the ECU 10.

[0019] The ACC control can be turned on and off by the driver. For example, when the driver turns on a set switch, the ECU 10 executes the ACC control. Also, when a predetermined release condition is met, such as when the driver turns off the set switch, the ACC control by the ECU 10 is stopped.

[0020] In this embodiment, the ACC control is configured to execute deceleration control to decelerate the host vehicle based on map information acquired from the navigation device 40. That is, the ECU 10 executes deceleration control to decelerate the host vehicle using the map information in accordance with road conditions ahead in the traveling direction of the host vehicle. In this case, the navigation device 40 acquires host vehicle position information, which is information on the current position of the host vehicle, and map information. The host vehicle position information is acquired by a vehicle position sensor using, for example, GPS or GNSS (Global Navigation Satellite System).

[0021] The map information includes information on roads that vehicles can travel on, as well as information on road configuration, information on stopping positions on the road, information on traffic lights, and information on traffic priority when multiple roads intersect. The information on road configuration includes information on whether the road configuration is a curved road, a T-junction, a roundabout, or a toll gate. Curved roads, T-junctions, roundabouts, and toll gates are road configurations that require a vehicle to slow down if they exist in the vehicle's direction of travel, and deceleration targets in these road configurations are also referred to as deceleration landmarks. Other information on road configuration may include information on intersections with speed limit signs, STOP signs, and YIELD signs (yield signs).

[0022] The ECU 10 acquires vehicle position information and map information from the navigation device 40, and based on the vehicle position information and map information, executes deceleration control of the host vehicle in a section immediately before the host vehicle reaches a deceleration landmark such as an intersection stop position. At this time, the brake device 32 applies braking depending on the position to the deceleration landmark, etc., and the host vehicle is decelerated. Vehicle deceleration by deceleration control is performed with priority over speed control by constant speed cruise control or tracking control. Note that intersections that correspond to deceleration landmarks are assumed to be intersections without traffic lights where a priority road and a non-priority road intersect in a T-shape or a cross, and which the host vehicle passes through when entering the priority road from the non-priority road.

[0023] Incidentally, when the driver of the vehicle operates the accelerator while deceleration control is being executed based on map information, it is conceivable that the accelerator operation is regarded as the driver's intention to accelerate, and the deceleration control is canceled. However, if the accelerator is operated erroneously and the deceleration control is canceled as a result of the accelerator operation, there is a concern that the vehicle may accelerate unintentionally immediately after the deceleration control is canceled. On the other hand, it is conceivable that an error has occurred in the map information, and if deceleration control is being executed based on the incorrect map information, it is desirable that the deceleration control be canceled by the driver's accelerator operation. For example, if the map information used by the navigation device 40 is old information (unupdated information) or if temporary road repairs or the like are being performed, deceleration control may be executed based on the incorrect map information.

[0024] Therefore, in this embodiment, when deceleration control is being performed based on map information, the deceleration control is canceled based on the travel information of at least one of the host vehicle and other vehicles traveling in the same direction around the host vehicle. In this case, it becomes possible to determine whether the accelerator operation was performed erroneously during deceleration control or whether deceleration control was performed based on erroneous map information, and it is correctly determined whether the driver's accelerator operation is valid or invalid.

[0025] FIG. 2 is a diagram showing an example of a driving scene of the host vehicle CA. In FIG. 2, a T-junction is shown as an intersection without traffic lights where a priority road R1 and a non-priority road R2 intersect, and the host vehicle CA is driving toward the T-junction on the non-priority road R2. A position before the T-junction, i.e., the entrance to the intersection, is a vehicle stopping position ahead of the host vehicle CA in the traveling direction. Also, on the non-priority road R2, a preceding vehicle CB is driving ahead of the host vehicle CA as another vehicle. Note that a similar driving scene can be expected at a cross intersection rather than a T-junction, as long as it is an intersection without traffic lights where the priority road R1 and the non-priority road R2 intersect.

[0026] In the driving scene shown in Fig. 2, when ACC control is being performed on the host vehicle CA, the host vehicle speed is controlled so as to maintain the inter-vehicle distance D1 between the host vehicle CA and the preceding vehicle CB at a target inter-vehicle distance. When the preceding vehicle CB is not present, the host vehicle speed is controlled to a predetermined target speed.

[0027] Furthermore, the host vehicle CA determines from the map information that a T-junction is ahead of the host vehicle, and performs deceleration control in a predetermined section before the T-junction. In this case, the deceleration of the host vehicle CA is controlled based on, for example, the distance from the host vehicle CA to the T-junction. As a result, the host vehicle speed gradually decreases as the host vehicle approaches the T-junction.

[0028] Consider a scenario in which the driver of the host vehicle CA operates the accelerator while deceleration control is being executed. Here, if a T-junction is actually present ahead of the host vehicle CA in the direction of travel, as shown in FIG. 2, the driver may have erroneously operated the accelerator, and it is undesirable to cancel the deceleration control. However, on the other hand, there may be a case in which, although map information indicates that a T-junction is present ahead of the host vehicle CA in the direction of travel, the map information is incorrect and the T-junction does not actually exist, i.e., it is not necessary for the host vehicle CA to decelerate. In this case, it is undesirable for the driver's intention to accelerate, which is reflected in the accelerator operation, not being reflected.

[0029] When the vehicle speed decreases due to deceleration control, if the driver intends to accelerate, the driver will actually operate the accelerator so as to increase the vehicle speed. In this case, the ACC system compares a target acceleration set based on the driver's accelerator operation amount with a target acceleration set based on the positional relationship with the preceding vehicle, etc., and if the former target acceleration (the target acceleration requested by the driver) is larger on the positive side, the vehicle CA is accelerated based on the target acceleration requested by the driver. Therefore, the vehicle speed returns to the vehicle speed before deceleration or to a value close to that speed. Therefore, in this embodiment, a speed return parameter indicating the state of the increase and return of the vehicle speed after the start of accelerator operation is acquired during deceleration control, and the deceleration control is canceled based on the speed return parameter.

[0030] The following describes the configuration related to deceleration control in the ECU 10. In Fig. 1, the ECU 10 includes an ACC control unit 11, an accelerator operation determination unit 12, a parameter acquisition unit 13, and a deceleration control unit 14. As described above, the ACC control unit 11 executes constant speed cruise control based on a target speed, follow-up control for a preceding vehicle, and deceleration control based on map information.

[0031] The accelerator operation determination unit 12 determines whether the driver of the host vehicle has operated the accelerator pedal while deceleration control is being executed based on map information. The presence or absence of the accelerator operation is determined based on the detection signal of the accelerator sensor 24.

[0032] The parameter acquisition unit 13 acquires a speed recovery parameter that indicates the state of the increase and recovery of the host vehicle speed after the start of the accelerator operation under the condition that deceleration control is being executed based on the map information. The speed recovery parameter corresponds to the traveling information of the host vehicle, such as the host vehicle speed.

[0033] In a situation where deceleration control is being executed based on map information, the deceleration control unit 14 cancels the deceleration control based on the vehicle speed (speed return parameter) acquired by the parameter acquisition unit 13. Specifically, the deceleration control unit 14 compares the vehicle speed with a predetermined threshold value TH1, and cancels the deceleration control based on the result.

[0034] The deceleration control in this embodiment will be described in more detail below. Here, a control mode will be described in which it is determined whether or not to cancel the deceleration control based on the host vehicle speed as a speed recovery parameter. FIG. 3 is a time chart showing a state in which the map information is correct and the deceleration control is being properly performed, and FIG. 4 is a time chart showing a state in which the map information is incorrect and the deceleration control is not being properly performed. In FIGS. 3 and 4, the target speed is indicated by a dashed line in the charts showing the host vehicle speed.

[0035] In Fig. 3, before timing t1, the traveling of the host vehicle is controlled by ACC control, and the host vehicle is traveling at a target speed. In other words, the host vehicle speed and the target speed are approximately the same. At timing t1, deceleration control is started based on the host vehicle position and map information. As a result, the host vehicle speed gradually decreases after timing t1.

[0036] Thereafter, at timing t2, the driver of the host vehicle operates the accelerator, causing the host vehicle speed to begin to increase. At this time, because the accelerator is operated in a relatively short period (the period from t2 to t3), the increase in the host vehicle speed is not so great, and the host vehicle speed remains below the threshold value TH1 for determining whether the host vehicle speed has returned to normal. Therefore, deceleration control continues. In this case, because the map information is correct, even if the driver erroneously operates the accelerator temporarily, the accelerator operation is invalidated, and deceleration control continues.

[0037] The threshold value TH1 is a speed threshold for determining whether the host vehicle speed has returned to the target speed in response to accelerator operation when the host vehicle speed has decreased after the start of deceleration control. The target speed is a target value of the host vehicle speed determined before timing t1. Specifically, the threshold value TH1 may be a speed threshold obtained by multiplying the target speed by a reduction correction value K (K≦1). In other words, the threshold value TH1 is "target speed × K." The threshold value TH1 may be, for example, approximately 80% of the target speed. In this case, the reduction correction value K is a value of approximately 0.8. The threshold value TH1 may also be a speed obtained by subtracting a predetermined value α from the target speed (TH1=target speed−α). In this case, the predetermined value α may be approximately several km / h (for example, 5 km / h). The threshold value TH1 may be the same as the target speed or a value slightly smaller than the target speed.

[0038] After timing t3, as the accelerator operation is released, the vehicle speed decreases again due to deceleration control.

[0039] On the other hand, in Fig. 4, the host vehicle is traveling at a target speed under ACC control before timing t11, as in Fig. 3. After timing t11, the host vehicle speed gradually decreases as deceleration control based on map information begins.

[0040] Thereafter, at timing t12, the driver of the host vehicle operates the accelerator, and the host vehicle speed begins to increase. At this time, the driver intends to accelerate and operates the accelerator for a relatively long period of time, so the host vehicle speed increases to the threshold value TH1. In this case, in order to prioritize the driver's accelerator operation (intention to accelerate), the deceleration control is canceled at timing t13 when the host vehicle speed reaches the threshold value TH1. From timing t13 onwards, the host vehicle speed is controlled in the state before the deceleration control was started, i.e., in the constant speed cruise control state.

[0041] Note that the vehicle speed is approximately equal to the target speed immediately before the start of deceleration control. Therefore, it is possible to configure the threshold value TH1 to be set based on the vehicle speed immediately before the start of deceleration control. In this case, the threshold value TH1 is determined as "the vehicle speed immediately before the start of deceleration control × K."

[0042] 5 is a flowchart showing the procedure for deceleration control that is executed based on map information. This process is repeatedly executed at a predetermined interval by the ECU 10. This process is performed on the assumption that ACC control is being performed on the host vehicle.

[0043] In FIG. 5, in step S101, the host vehicle position information and map information are acquired from the navigation device 40. In step S102, it is determined whether deceleration control is currently being executed, i.e., whether the host vehicle is being decelerated by deceleration control. If deceleration control is not currently being executed, the process proceeds to step S103. In step S103, the host vehicle position information and map information acquired from the navigation device 40 are used to determine whether a deceleration landmark that is a deceleration target exists ahead of the host vehicle in the traveling direction. Specifically, it is determined whether a deceleration landmark such as a T-junction or a roundabout exists ahead of the host vehicle. If no deceleration landmark exists ahead of the host vehicle in the traveling direction, the process ends temporarily. If a deceleration landmark exists ahead of the host vehicle in the traveling direction, the process proceeds to step S104. In step S104, deceleration control of the host vehicle is started. After the deceleration control is started, the host vehicle speed is decelerated based on the distance between the host vehicle position and the deceleration landmark.

[0044] On the other hand, after deceleration control has started, a positive result is obtained in step S102 and the process proceeds to step S105. In step S105, it is determined whether it is time to end deceleration control. For example, if the host vehicle has reached a deceleration landmark, the process proceeds to step S110 and ends deceleration control. If the host vehicle has not reached a deceleration landmark, the process proceeds to step S106.

[0045] In step S106, it is determined whether or not the driver of the host vehicle has operated the accelerator pedal. At this time, whether or not the accelerator pedal has been operated is determined based on the detection signal from the accelerator sensor 24. If the accelerator pedal has not been operated, the process ends, and if the accelerator pedal has been operated, the process proceeds to the subsequent step S107.

[0046] In step S107, the host vehicle speed is acquired, and in the following step S108, a threshold value TH1 is set. The host vehicle speed is a speed calculated from the detection signal of the speed sensor 23. In step S108, the threshold value TH1 is set by multiplying the target speed of the host vehicle by the reduction correction value K.

[0047] Thereafter, in step S109, it is determined whether the host vehicle speed is greater than the threshold value TH1. If the host vehicle speed is not greater than the threshold value TH1, this process ends. In this case, deceleration control continues. If the host vehicle speed is greater than the threshold value TH1, the process proceeds to the following step S110. In step S110, deceleration control ends.

[0048] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0049] When deceleration control is being performed based on map information and it is determined that the driver has operated the accelerator pedal, the deceleration control is canceled based on the vehicle's travel information. In this case, the vehicle's travel information makes it possible to determine whether the accelerator pedal was erroneously operated during deceleration control based on map information, or whether deceleration control was performed based on incorrect map information. This makes it possible to properly cancel deceleration control after correctly determining whether the driver's accelerator operation is valid or invalid. As a result, vehicle deceleration control based on map information can be properly performed.

[0050] When the vehicle speed decreases due to deceleration control, if the driver intends to accelerate, the actual vehicle speed will increase in response to accelerator operation, and will return to the vehicle speed before deceleration or close to that speed. In consideration of this, a speed return parameter indicating the state of the increase and return of the vehicle speed after the start of accelerator operation during deceleration control is acquired, and deceleration control is canceled based on the speed return parameter. Specifically, when deceleration control is being executed, deceleration control is canceled based on the vehicle speed being greater than a threshold value TH1 set based on the target speed. This makes it possible to execute appropriate deceleration control while reflecting the driver's intention.

[0051] Another embodiment, which is a partial modification of the first embodiment, will be described below, focusing on the differences from the first embodiment.

[0052] (Second embodiment) In this embodiment, if the driver operates the accelerator after deceleration control has started, the deceleration control is canceled based on the vehicle speed and the distance between the vehicle and the preceding vehicle.

[0053] Specifically, in FIG. 1, the parameter acquisition unit 13 acquires the host vehicle speed and the inter-vehicle distance between the host vehicle and the preceding vehicle as speed recovery parameters during execution of deceleration control.

[0054] During execution of deceleration control, the deceleration control unit 14 cancels the deceleration control when the speed of the host vehicle is greater than a threshold value TH2 set based on the speed of the preceding vehicle and the inter-vehicle distance from the preceding vehicle is smaller than a target inter-vehicle distance. The preceding vehicle speed may be calculated from the host vehicle speed and the relative speed between the host vehicle and the preceding vehicle. Alternatively, the preceding vehicle speed may be speed information of the preceding vehicle obtained through vehicle-to-vehicle communication between the host vehicle and the preceding vehicle, or speed information of the preceding vehicle obtained through road-to-vehicle communication with a road-side device.

[0055] The threshold value TH2 is a speed threshold for determining whether the host vehicle speed has returned to near the speed of the preceding vehicle in response to accelerator operation when the host vehicle speed has decreased after the start of deceleration control. Specifically, the threshold value TH2 is preferably a speed threshold obtained by multiplying the preceding vehicle speed by a reduction correction value K (K≦1). In other words, the threshold value TH2 is "preceding vehicle speed × K." The threshold value TH2 may be, for example, approximately 80% of the preceding vehicle speed. In this case, the reduction correction value K is a value of approximately 0.8. The threshold value TH2 may also be a speed obtained by subtracting a predetermined value α from the preceding vehicle speed (TH2=preceding vehicle speed−α). In this case, the predetermined value α may be approximately several km / h (for example, 5 km / h). The threshold value TH2 may be the same as the preceding vehicle speed or a value slightly smaller than that.

[0056] 6 is a flowchart showing the procedure for deceleration control in this embodiment. This process is repeatedly executed at a predetermined interval by the ECU 10. This process is performed on the assumption that ACC control is being performed on the host vehicle.

[0057] In FIG. 6, steps S201 to S206 are the same processes as steps S101 to S106 in FIG. 5. Here, steps S201 to S206 will be briefly described. After acquiring host vehicle position information and map information from navigation device 40 (step S201), if it is determined that deceleration control is not currently being executed (NO in step S202), it is determined whether or not a deceleration landmark exists ahead of the host vehicle (step S203). If a deceleration landmark exists ahead of the host vehicle (step S204), deceleration control of the host vehicle is initiated. After deceleration control has been initiated, if it is not time to end deceleration control, it is determined whether or not the driver of the host vehicle has operated the accelerator (steps S205 and S206). If the accelerator is being operated, the process proceeds to the subsequent step S207.

[0058] In step S207, it is determined whether or not there is a preceding vehicle to be followed ahead in the direction of travel of the host vehicle. If there is no preceding vehicle, the process proceeds to step S208. If the process proceeds to step S208, a process is executed to determine whether to continue or cancel deceleration control based on a comparison between the host vehicle speed and a threshold value TH1 (a speed threshold value set based on the target speed). This process corresponds to steps S107 to S110 in FIG. 5, and a description thereof will be omitted here.

[0059] If a preceding vehicle is present, the process proceeds to step S209. In step S209, the host vehicle speed, the distance between the host vehicle and the preceding vehicle, and the preceding vehicle speed are acquired, and in the following step S210, a threshold value TH2 is set based on the preceding vehicle speed. At this time, the threshold value TH2 is set by multiplying the current preceding vehicle speed by a reduction correction value K.

[0060] Then, in step S211, it is determined whether the vehicle speed is greater than a threshold value TH2, and in the following step S212, it is determined whether the inter-vehicle distance to the preceding vehicle is also smaller than the target inter-vehicle distance. If either step S211 or S212 is negative, this process ends. In this case, deceleration control continues. If both steps S211 and S212 are positive, the process proceeds to the following step S213. In step S213, deceleration control ends.

[0061] In this embodiment, when the deceleration control is being executed, the deceleration control is cancelled if the speed of the host vehicle is greater than a threshold value TH2 set based on the speed of the preceding vehicle and the distance to the preceding vehicle is smaller than the target distance, thereby enabling the execution of appropriate deceleration control while reflecting the driver's intention.

[0062] As a modification of this embodiment, the following configuration can also be adopted. That is, when the driver operates the accelerator after the start of deceleration control, it is also possible to configure the deceleration control to be canceled only when the speed of the host vehicle becomes greater than the threshold value TH2 set based on the speed of the preceding vehicle (step S211) or when the inter-vehicle distance to the preceding vehicle becomes smaller than the target inter-vehicle distance (step S212). In this case, the processing of step S212 in FIG. 6 is omitted.

[0063] When deceleration control is initiated based on map information, if the map information is correct, the host vehicle speed will decrease due to the deceleration control, and the preceding vehicle speed will also decrease. In this case, since both the host vehicle speed and the preceding vehicle speed decrease, it is unlikely that there will be a difference between these speeds. Therefore, even if the map information is correct, i.e., even if the deceleration control is being properly executed, the host vehicle speed may exceed the threshold value TH2 in step S209, resulting in the deceleration control being canceled in step S211. However, after the deceleration control is canceled, the host vehicle will decelerate to match the preceding vehicle through follow-up control for the preceding vehicle. Therefore, it is believed that no substantial problems will occur in the running of the host vehicle.

[0064] (Third embodiment) When deceleration control is being performed in the host vehicle based on map information, if the map information is incorrect, the preceding vehicle traveling ahead of the host vehicle will exhibit behavior that is contrary to the deceleration of the host vehicle. Therefore, in this embodiment, during deceleration control, other vehicle behavior parameters that indicate behavior of the preceding vehicle that is contrary to the deceleration of the host vehicle are acquired, and the deceleration control is canceled based on the other vehicle behavior parameters.

[0065] 1, the parameter acquisition unit 13 acquires another vehicle behavior parameter indicating a behavior of a preceding vehicle ahead of the host vehicle that is contrary to the deceleration of the host vehicle when deceleration control is being executed based on map information. The other vehicle behavior parameter corresponds to driving information of the preceding vehicle, such as the speed of the preceding vehicle.

[0066] The deceleration control unit 14 cancels the deceleration control based on the preceding vehicle speed (other vehicle behavior parameter) acquired by the parameter acquisition unit 13 under the condition that deceleration control is being executed based on map information.

[0067] Specifically, the deceleration control unit 14 compares the speed of the preceding vehicle with a threshold value TH3 set based on the target speed of the constant speed cruise control, and cancels the deceleration control based on the result. In other words, if the map information is incorrect while the deceleration control is being executed, the host vehicle will be decelerated, but the preceding vehicle will not be decelerated (see FIG. 4). In this case, the deceleration control unit 14 cancels the deceleration control based on the fact that the speed of the preceding vehicle is greater than the threshold value TH3 set based on the target speed of the host vehicle.

[0068] The threshold value TH3 is preferably a value obtained by adding a predetermined value β to the target speed (TH3 = target speed + β). The predetermined value β is preferably, for example, 0 to several km / h. The threshold value TH3 may also be a speed threshold value obtained by multiplying the target speed by a correction value K2 (K2 ≥ 1). The threshold value TH3 is preferably the same as the target speed or a value slightly larger than the target speed. If the speed of the preceding vehicle is larger than the threshold value TH3, this means that the speed of the preceding vehicle is not decreasing during deceleration control, i.e., the preceding vehicle is not decelerating.

[0069] Furthermore, if the map information is incorrect during deceleration control, the preceding vehicle will continue to travel without slowing down even when it reaches the vicinity of a deceleration landmark ahead in the direction of travel. This driving scene is shown in Figure 7. Note that Figure 7 shows a state in which the map incorrectly recognizes that a cross road R12 intersects with the road R11 on which the host vehicle CA is traveling. In this case, deceleration control is performed using the intersection of roads R11 and R12 as the deceleration landmark. In Figure 7, the inter-vehicle distance between the host vehicle CA and the preceding vehicle CB is D1, and the distance from the host vehicle CA to the intersection (deceleration landmark) on the map is D2.

[0070] During execution of deceleration control, the deceleration control unit 14 cancels the deceleration control when the preceding vehicle CB is within a predetermined distance of the position of a deceleration landmark ahead in the traveling direction in the map information, but the preceding vehicle CB is not decelerating. The preceding vehicle CB being within the predetermined distance of the position of the deceleration landmark in the map information means that the inter-vehicle distance D1 is longer than the distance D2 to the deceleration landmark minus a predetermined value ΔD, i.e., "D1>D2-ΔD." The predetermined value ΔD is, for example, approximately 0 to several meters.

[0071] As described above, it is preferable to determine whether the preceding vehicle CB is not decelerating by comparing the preceding vehicle speed with the threshold value TH3. Alternatively, it may be determined that the preceding vehicle CB is not decelerating if the rate of decrease in the preceding vehicle speed per unit time (deceleration of the preceding vehicle) is less than a predetermined value. In this case, the preceding vehicle speed and deceleration are other vehicle behavior parameters. Furthermore, the preceding vehicle speed and deceleration correspond to preceding vehicle deceleration information that indicates whether the preceding vehicle is decelerating.

[0072] The other vehicle behavior parameter (preceding vehicle deceleration information) may be information indicating that the preceding vehicle CB is not braking (depressing the brake pedal). The information indicating that the brake is not being operated may be based on, for example, the brake lights of the preceding vehicle CB not being illuminated or on preceding vehicle braking information acquired through vehicle-to-vehicle communication or the like.

[0073] 8 is a flowchart showing the procedure for deceleration control in this embodiment. This process is repeatedly executed at a predetermined interval by the ECU 10. This process is performed on the assumption that ACC control is being performed on the host vehicle.

[0074] In FIG. 8, steps S301 to S306 are the same processes as steps S101 to S106 in FIG. 5. Here, steps S301 to S306 will be briefly described. After acquiring vehicle position information and map information from navigation device 40 (step S301), if it is determined that deceleration control is not currently being executed (NO in step S302), it is determined whether or not a deceleration landmark exists ahead of the vehicle (step S303). If a deceleration landmark exists ahead of the vehicle (step S302), deceleration control of the vehicle is initiated (step S304). After deceleration control has been initiated, if it is not time to end deceleration control, it is determined whether or not the driver of the vehicle has operated the accelerator (steps S305 and S306). If the accelerator is being operated, the process proceeds to the subsequent step S307.

[0075] In step S307, it is determined whether or not there is a preceding vehicle to be followed ahead in the direction of travel of the host vehicle. If there is no preceding vehicle, the process proceeds to step S308. If the process proceeds to step S308, a process is executed to determine whether to continue or cancel deceleration control based on the host vehicle speed. This process corresponds to steps S107 to S110 in FIG. 5, and a description thereof will be omitted here.

[0076] If a preceding vehicle is present, the process proceeds to step S309. In step S309, the preceding speed is acquired, and in the following step S310, the inter-vehicle distance D1 between the host vehicle and the preceding vehicle and the distance D2 from the host vehicle to a deceleration landmark on the map are acquired. Then, in step S311, it is determined whether the inter-vehicle distance D1 is longer than the distance D2 to the deceleration landmark minus a predetermined value ΔD (whether D1 > D2 - ΔD), and in the following step S312, it is determined whether the preceding vehicle speed is greater than a threshold TH3 set based on the target speed of the host vehicle. Note that step S312 corresponds to the process of determining whether the preceding vehicle is not decelerating.

[0077] If either step S311 or S312 is negative, this process ends. In this case, deceleration control continues. If both steps S311 and S312 are positive, the process proceeds to the following step S313. In step S313, deceleration control ends.

[0078] It is also possible to omit the processing of steps S310 and S311. In this case, after the deceleration control is started, if the driver of the host vehicle operates the accelerator and there is a preceding vehicle ahead in the traveling direction of the host vehicle, and if the speed of the preceding vehicle is greater than threshold value TH3 (if step S312 is YES), the deceleration control is ended (step S313).

[0079] On a road on which a host vehicle is traveling, other vehicles may be present in front, behind, to the left, or to the right of the host vehicle. Other vehicles are other vehicles traveling around the host vehicle in the same direction as the host vehicle. For example, in FIG. 9, a host vehicle CA is traveling in its own lane L1 on a road having two adjacent lanes L1 and L2 traveling in the same direction. Furthermore, in the host vehicle lane L1, a leading vehicle CB is traveling in front of the host vehicle CA, a following vehicle CC is traveling behind the host vehicle CA, and a lateral vehicle CD is traveling near the host vehicle CA in the adjacent lane L2.

[0080] In this case, the other vehicle behavior parameters may indicate the traveling state of the preceding vehicle CB, the side vehicle CD, or the following vehicle CC. In other words, if deceleration control is performed based on incorrect map information, not only the preceding vehicle CB but also the side vehicle CD and the following vehicle CC may exhibit behavior that is contrary to the deceleration of the host vehicle CA.

[0081] Therefore, if a side vehicle CD is present during deceleration control of the host vehicle CA, the ECU 10 may acquire the traveling speed, etc. of the side vehicle CD as another vehicle behavior parameter, and cancel the deceleration control based on the traveling speed, etc. of the side vehicle CD. The method for canceling the deceleration control based on the traveling speed, etc. of the side vehicle CD may be similar to the method for canceling the deceleration control based on the traveling speed, etc. of the preceding vehicle CB described above.

[0082] Furthermore, if a following vehicle CC is present during deceleration control of the host vehicle CA, the ECU 10 may acquire the traveling speed, etc. of the following vehicle CC as another vehicle behavior parameter, and cancel the deceleration control based on the traveling speed, etc. of the following vehicle CC. In this case, if the following vehicle CC does not recognize a deceleration landmark ahead in the traveling direction despite the deceleration control being executed in the host vehicle CA, the deceleration control is canceled.

[0083] Specifically, as a control for the following vehicle CC, when the speed of the host vehicle is slower than the speed of the following vehicle and the relative speed between the host vehicle CA and the following vehicle CC (host vehicle speed - following vehicle speed) is less than a predetermined value during deceleration control, the deceleration control may be canceled. Alternatively, when the inter-vehicle distance between the host vehicle CA and the following vehicle CC is smaller than a predetermined value during deceleration control, the deceleration control may be canceled.

[0084] As shown in Fig. 9, during deceleration control, if a rear vehicle CE traveling behind the host vehicle in adjacent lane L2 changes lanes from adjacent lane L2 to host lane L1 and moves to a position immediately behind the host vehicle in host lane L1, the deceleration control may be canceled. Alternatively, during deceleration control, if the rear vehicle CE changes lanes and moves to a position immediately behind the host vehicle in host lane L1 when there is no following vehicle CC, the deceleration control may be canceled. Furthermore, if the rear vehicle CE activates its turn signal to indicate its intention to move to a position immediately behind the host vehicle in host lane L1, the deceleration control may be canceled.

[0085] In addition, in a configuration in which deceleration control is canceled based on the travel information of the following vehicle CC, it may be determined whether or not to cancel deceleration control depending on the type of deceleration landmark. For example, if the deceleration landmark ahead of the host vehicle is a YIELD sign (a deceleration target with a relatively low deceleration requirement), the deceleration control may be canceled, and if the deceleration landmark ahead of the host vehicle is a T-junction intersection, a roundabout, or the like other than a YIELD sign, the deceleration control may not be canceled.

[0086] According to the present embodiment described above in detail, the following effects can be obtained.

[0087] When deceleration control is performed on a host vehicle based on map information, if the map information is incorrect, other vehicles around the host vehicle will behave in a manner that contradicts the host vehicle's deceleration. In consideration of this, during deceleration control, other vehicle behavior parameters that indicate behavior that contradicts the host vehicle's deceleration, for example, of a preceding vehicle, are acquired, and deceleration control is canceled based on the other vehicle behavior parameters. This makes it possible to reflect the driver's intentions and execute appropriate deceleration control while properly determining whether the map information is correct.

[0088] If the map information is incorrect during deceleration control, the host vehicle will decelerate but the preceding vehicle will not. In this case, the speed of the preceding vehicle will be greater than the threshold value TH3 set based on the target speed of the host vehicle, so the deceleration control can be properly canceled.

[0089] If the map information is incorrect during deceleration control, the preceding vehicle will continue traveling without decelerating even when it reaches a deceleration landmark ahead of it in the direction of travel. In other words, if the preceding vehicle does not decelerate even when it approaches within a predetermined distance of the deceleration landmark ahead of it in the direction of travel, it is highly likely that the deceleration landmark on the map is incorrect. In this case, the deceleration control can be appropriately canceled based on the fact that the preceding vehicle is near the deceleration landmark ahead of it in the direction of travel in the map information and that the preceding vehicle is not decelerating.

[0090] (Fourth embodiment) In this embodiment, after the deceleration control is started, the deceleration control is cancelled based on the result of comparing the vehicle speed, which is a speed recovery parameter, with the threshold value TH1 (see, for example, the flowchart in FIG. 5), and the threshold value TH1 is variably set. In this embodiment, the ECU 10 corresponds to the threshold value setting unit.

[0091] During deceleration control, the driver's intention to accelerate can be determined based on the acceleration of the host vehicle (host vehicle acceleration) that occurs when the driver operates the accelerator. In this case, the higher the host vehicle acceleration, the higher the probability that the map information used for deceleration control is incorrect. Taking this into consideration, the threshold value TH1 is variably set based on the host vehicle acceleration.

[0092] 10 is a flowchart showing the procedure of the threshold setting process. This process is repeatedly executed at a predetermined interval by the ECU 10. This process is executed during deceleration control, and more specifically, it is preferably executed in step S108 in the flowchart of FIG. 5.

[0093] 10, in step S401, the host vehicle speed is acquired, and in the following step S402, the host vehicle acceleration is calculated by differential calculation of the host vehicle speed. In step S403, a reduction correction value K is set based on the host vehicle acceleration, and a threshold value TH1 is set based on the reduction correction value K and the target speed.

[0094] Fig. 11 is a diagram showing the relationship between the host vehicle acceleration and the reduction correction value K. In Fig. 11, the reduction correction value K is a value equal to or less than 1, and the greater the host vehicle acceleration, the smaller the value becomes. The threshold value TH1 is a speed threshold value obtained by multiplying the target speed by the reduction correction value K, and the smaller the reduction correction value K, the smaller the value of the threshold value TH1 becomes. A small value for the threshold value TH1 means that the deceleration control is more likely to be canceled after the deceleration control has started.

[0095] 11, the reduction correction value K may be variably set in multiple stages (for example, two or more stages) according to the host vehicle acceleration. Also, the reduction correction value K may be selectively set between 1 and a value less than 1 according to the host vehicle acceleration.

[0096] According to this embodiment, the threshold value TH1 for canceling the deceleration control is variably set based on the acceleration of the host vehicle, thereby improving the accuracy of canceling the deceleration control.

[0097] (Another example of the fourth embodiment) During deceleration control, if another vehicle traveling around the host vehicle exhibits behavior contrary to the deceleration of the host vehicle, the probability that the map information used for the deceleration control is incorrect increases. Therefore, it is preferable that the deceleration control be easily canceled when the other vehicle exhibits behavior contrary to the deceleration of the host vehicle. In consideration of this, the threshold value TH1 may be variably set so that the deceleration control is more easily canceled when it is determined based on the other vehicle behavior parameters that the deceleration control should be canceled than when it is not determined based on the other vehicle behavior parameters that the deceleration control should be canceled. This improves the accuracy of canceling the deceleration control.

[0098] Furthermore, when it is determined based on the other vehicle behavior parameters that deceleration control should be canceled around the host vehicle, the reliability of determining that the map information is erroneous may differ depending on whether the other vehicle, whose other vehicle behavior parameters have been acquired, is located in the front, rear, left, or right direction relative to the host vehicle, or depending on how many other vehicles there are from which other vehicle behavior parameters have been acquired. In consideration of this, when it is determined based on the other vehicle behavior parameters that deceleration control should be canceled, the threshold value TH1 may be variably set based on whether the other vehicle, whose other vehicle behavior parameters have been acquired, is located in the front, rear, left, or right direction relative to the host vehicle, or depending on how many other vehicles there are.

[0099] 12 is a flowchart showing the procedure of the threshold setting process. This process is repeatedly executed at a predetermined interval by the ECU 10. This process is executed during deceleration control, and more specifically, it is preferably executed in step S108 in the flowchart of FIG.

[0100] 12, in step S501, another vehicle behavior parameter indicating behavior contrary to the deceleration of the host vehicle is acquired for another vehicle traveling in a position in front, behind, or to the left or right of the host vehicle. The other vehicle behavior parameter is, for example, the traveling speed of the other vehicle. Then, in step S502, it is determined whether or not deceleration control should be canceled based on the other vehicle behavior parameter acquired in step S501. At this time, another vehicle behavior parameter of at least one vehicle traveling around the host vehicle is acquired, and if it is not determined that deceleration control should be canceled based on the other vehicle behavior parameter, the process proceeds to step S503, and if it is determined that deceleration control should be canceled, the process proceeds to step S504.

[0101] In step S503, the threshold value TH1 is set to a relatively large value, and in step S504, the threshold value TH1 is set to a relatively small value. In this case, in step S504, the threshold value TH1 is set so that when it is determined based on the other vehicle behavior parameters that the deceleration control should be canceled, the deceleration control is more likely to be canceled than when it is not determined based on the other vehicle behavior parameters that the deceleration control should be canceled. Note that in steps S503 and S504, the reduction correction value K may be set in the range of 0.5 to 1, for example. In this case, in step S503, the reduction correction value K may be set to 1, and in step S504, the reduction correction value K may be set to a value less than 1.

[0102] In step S504, when it is determined that the deceleration control should be canceled based on the other vehicle behavior parameters, the threshold value TH1 may be set based on whether the other vehicle from which the other vehicle behavior parameters have been acquired is located in front of, behind, or to the left or right of the host vehicle. In this case, it is considered that the reliability of determining that the map information is incorrect based on the other vehicle behavior parameters is higher for a preceding vehicle located in front of the host vehicle than for a lateral vehicle on the left or right side or a following vehicle. Therefore, when it is determined that the deceleration control should be canceled based on the other vehicle behavior parameters, if the other vehicle from which the other vehicle behavior parameters have been acquired is a preceding vehicle, the threshold value TH1 is set to a relatively small value (a value that makes it easier to cancel the deceleration control), and if the other vehicle from which the other vehicle behavior parameters have been acquired is a vehicle other than the preceding vehicle, the threshold value TH1 is set to a relatively large value (a value that makes it harder to cancel the deceleration control).

[0103] In addition, when a determination that deceleration control should be canceled based on the other-vehicle behavior parameters of the preceding vehicle and a determination that deceleration control should be canceled based on the other-vehicle behavior parameters of a vehicle other than the preceding vehicle occur simultaneously, the former determination result may be prioritized. Furthermore, the threshold value TH1 may be different for a case where it is determined that deceleration control should be canceled based on the other-vehicle behavior parameters of the left and right side vehicles and a case where it is determined that deceleration control should be canceled based on the other-vehicle behavior parameters of the following vehicle. For example, the threshold value TH1 is set smaller in the former case (side vehicle) than in the latter case (following vehicle).

[0104] Alternatively, in step S504, when it is determined that deceleration control should be canceled based on the other vehicle behavior parameters, the threshold value TH1 may be set based on the number of other vehicles for which other vehicle behavior parameters have been acquired. In this case, when it is determined that deceleration control should be canceled based on the other vehicle behavior parameters, the greater the number of other vehicles for which this determination has been made, the higher the reliability of determining that the map information is incorrect based on the other vehicle behavior parameters. Therefore, when it is determined that deceleration control should be canceled based on the other vehicle behavior parameters, if the number of other vehicles for which other vehicle behavior parameters have been acquired is large (e.g., two or more), the threshold value TH1 is set to a smaller value than when it is small (e.g., one).

[0105] The degree of the deceleration request for the host vehicle varies depending on the type of deceleration landmark ahead of the host vehicle in the traveling direction. In consideration of this, the threshold value TH1 may be variably set based on the type of deceleration landmark ahead of the host vehicle in the traveling direction. This increases the reliability of canceling the deceleration control.

[0106] 13 is a flowchart showing the procedure of the threshold setting process. This process is repeatedly executed at a predetermined interval by the ECU 10. This process is executed during deceleration control, and more specifically, it is preferably executed in step S108 in the flowchart of FIG.

[0107] 13, in step S601, a deceleration landmark ahead of the vehicle in the traveling direction is recognized based on map information, and in the following step S602, it is determined whether the deceleration landmark recognized in step S601 is a YIELD sign. At this time, if the deceleration landmark ahead of the vehicle is not a YIELD sign but a deceleration landmark such as a T-junction or roundabout that requires a higher deceleration, the process proceeds to step S603, and if the deceleration landmark ahead of the vehicle is a YIELD sign, the process proceeds to step S604.

[0108] In step S603, threshold value TH1 is set to a relatively large value, and in step S604, threshold value TH1 is set to a relatively small value. In this case, in step S603, threshold value TH1 that makes it relatively difficult to cancel deceleration control is set, and in step S604, threshold value TH1 that makes it relatively easy to cancel deceleration control is set. Note that in steps S603 and S604, reduction correction value K may be set in the range of 0.5 to 1, for example. In this case, in step S603, reduction correction value K may be set to 1, and in step S604, reduction correction value K may be set to a value less than 1.

[0109] (Other embodiments) The above embodiment may be modified as follows, for example.

[0110] When deceleration control is being performed based on map information and it is determined that the driver has operated the accelerator, the deceleration control may be canceled using the following method.

[0111] When the deceleration control is being executed and it is determined that the driver has operated the accelerator, the deceleration control may be cancelled if the duration of the accelerator operation of the host vehicle exceeds a predetermined time. In this case, the duration of the accelerator operation corresponds to the vehicle's travel information and speed return parameter.

[0112] When the deceleration control is being executed and it is determined that the driver has operated the accelerator, the deceleration control may be canceled on the condition that the target speed of the constant speed cruise control has been changed to an increasing speed by the operation of the driver, etc. In this case, the information that the target speed has been changed to an increasing speed corresponds to the driving information of the host vehicle.

[0113] When deceleration control is being executed and it is determined that the driver has operated the accelerator, the deceleration control may be canceled on the condition that the road is a straight road on the map and the steering angle caused by the driver's steering operation is equal to or greater than a predetermined value. In this case, a driving scene in which the steering angle caused by the driver's steering operation is equal to or greater than a predetermined value is considered to indicate that the driver is intentionally attempting to change lanes or turn, and the deceleration control can be appropriately canceled in that driving scene. In this case, the steering angle corresponds to the driving information of the host vehicle.

[0114] When the deceleration control is being executed and it is determined that the driver has operated the accelerator, the deceleration control may be canceled on the condition that the driver of the host vehicle operates a turn signal. In this case, the operation of the turn signal is one of the driver's expressions of intent regarding vehicle driving, and the cancellation of the deceleration control allows the vehicle to be driven as desired by the driver. In this case, the operation information of the turn signal corresponds to the driving information of the host vehicle.

[0115] Note that driving situations in which the driver operates the turn signal may include a situation in which the driver intends to change lanes or a situation in which the driver intends to turn right or left. In this case, in a situation in which the driver intends to change lanes, the deceleration control may interfere with the driver's intended driving, and therefore the deceleration control may be canceled in response to the operation of the turn signal. On the other hand, in a situation in which the driver intends to turn right or left, particularly in a situation in which the driver intends to turn right or left in a direction that matches the future driving route of the vehicle (for example, the driving guidance route of the navigation device 40), the deceleration control does not necessarily interfere with the driver's intended driving, and therefore the deceleration control may not be canceled even if the turn signal is operated.

[0116] If it is determined that the driver has operated the accelerator while deceleration control is in progress, the deceleration control may be canceled if the preceding vehicle has changed lanes or made a right or left turn and become absent immediately before the accelerator operation, i.e., if the preceding vehicle has changed from a state where it is present to a state where it is absent. Alternatively, if it is determined that the driver has operated the accelerator while deceleration control is in progress, the deceleration control may be canceled if the preceding vehicle has flashed either the left or right turn signal lamp immediately before the accelerator operation.

[0117] When the preceding vehicle is no longer present due to a lane change or a right or left turn, or when the preceding vehicle is flashing either its left or right turn signal, a space is created in front of the host vehicle that can be entered by accelerating the host vehicle. Therefore, it is considered that the driver's accelerator operation is intended to accelerate the host vehicle. In this case, the deceleration control is canceled, and the vehicle can be driven in the manner desired by the driver.

[0118] When map information indicates that the road ahead of the vehicle is a curve, and the vehicle is decelerated before the curve by deceleration control, the deceleration control may be canceled if the vehicle speed is greater than the target speed for traveling on the curve. The target speed for traveling on the curve may be set according to the curvature of the curve. Here, when deceleration control is being performed using the curve as a deceleration landmark, if the vehicle speed is greater than the target speed for traveling on the curve, the map information may be considered to be incorrect, and the deceleration control may be appropriately canceled.

[0119] If the deceleration control is canceled (forced to terminate) due to a speed recovery parameter or another vehicle behavior parameter after the deceleration control has started, the ECU 10 may store and retain in a storage unit the map information that served as the basis for the execution of the deceleration control, i.e., the deceleration landmarks on the map. In other words, the deceleration landmarks on the map that are erroneous information may be stored and retained as driving history. Then, the ECU 10 may be configured not to execute the deceleration control for the deceleration landmarks that are erroneous information from the next time the host vehicle is driven.

[0120] The control device and method described herein may be implemented by a special-purpose computer configured with a processor and memory programmed to perform one or more functions embodied in a computer program. Alternatively, the control device and method described herein may be implemented by a special-purpose computer configured with a processor comprising one or more dedicated hardware logic circuits. Alternatively, the control device and method described herein may be implemented by one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. [Explanation of symbols]

[0121] 10...ECU, 20...sensors, 30...controlled device, 40...navigation device

Claims

1. A vehicle control device (10) that can execute deceleration control to decelerate a vehicle in accordance with road conditions ahead in a traveling direction of the vehicle using map information, an accelerator operation determination unit that determines whether an accelerator operation has been performed by the driver of the host vehicle while the deceleration control is being executed; a deceleration control unit that, when the deceleration control is being executed and it is determined that the accelerator operation has been performed, cancels the deceleration control based on travel information of at least one of the host vehicle and another vehicle traveling in the same direction as the host vehicle around the host vehicle; A vehicle control device comprising:

2. a parameter acquisition unit that acquires, under a condition in which the deceleration control is being executed, a speed recovery parameter that indicates a state of an increase and recovery of the traveling speed of the host vehicle after the accelerator operation is started, The vehicle control device according to claim 1 , wherein the deceleration control unit uses the speed recovery parameter as the traveling information and cancels the deceleration control based on a comparison between the speed recovery parameter and a predetermined threshold value.

3. A vehicle control device that can execute a constant speed traveling control for traveling the host vehicle at a predetermined target speed in addition to the deceleration control, the parameter acquisition unit acquires a traveling speed of the host vehicle as the speed recovery parameter; 3. The vehicle control device according to claim 2, wherein the deceleration control unit cancels the deceleration control when the traveling speed of the host vehicle is greater than the threshold value set based on either the target speed or the traveling speed of a preceding vehicle traveling ahead of the host vehicle during execution of the deceleration control.

4. a vehicle control device that can execute, in addition to the deceleration control, a following control that causes the host vehicle to follow a preceding vehicle traveling ahead of the host vehicle while maintaining a predetermined target inter-vehicle distance, the parameter acquisition unit acquires, as the speed recovery parameters, a traveling speed of the host vehicle and a vehicle-to-vehicle distance between the host vehicle and the preceding vehicle; 3. The vehicle control device according to claim 2, wherein the deceleration control unit cancels the deceleration control when the traveling speed of the host vehicle is greater than the threshold value set based on the traveling speed of the preceding vehicle and the inter-vehicle distance is smaller than the target inter-vehicle distance during execution of the deceleration control.

5. 5. The vehicle control device according to claim 2, further comprising a threshold setting unit that variably sets the threshold based on acceleration of the host vehicle that occurs in conjunction with the accelerator operation during execution of the deceleration control.

6. the parameter acquisition unit acquires, during the execution of the deceleration control, in addition to the speed return parameter, another vehicle behavior parameter that indicates behavior contrary to the deceleration of the host vehicle, for another vehicle traveling in a position that is either in front of, behind, or to the left or right of the host vehicle; the deceleration control unit is capable of determining whether or not the deceleration control should be canceled based on the other vehicle behavior parameter, 5. The vehicle control device according to claim 2, further comprising a threshold setting unit that variably sets the threshold so that the deceleration control is more likely to be canceled when it is determined that the deceleration control should be canceled based on the other vehicle behavior parameters, compared to when it is not determined that the deceleration control should be canceled based on the other vehicle behavior parameters.

7. the parameter acquisition unit acquires, during the execution of the deceleration control, in addition to the speed return parameter, another vehicle behavior parameter that indicates behavior contrary to the deceleration of the host vehicle, for another vehicle traveling in a position that is either in front of, behind, or to the left or right of the host vehicle; the deceleration control unit is capable of determining whether or not the deceleration control should be canceled based on the other vehicle behavior parameter, 5. The vehicle control device according to claim 2, further comprising a threshold setting unit that variably sets the threshold when it is determined that the deceleration control should be canceled based on the other vehicle behavior parameters, based on whether the other vehicle from which the other vehicle behavior parameters have been acquired is located in front of, behind, or on the left or right of the host vehicle, or based on how many other vehicles there are.

8. 5. The vehicle control device according to claim 2, further comprising a threshold setting unit that variably sets the threshold based on a type of deceleration landmark ahead in the traveling direction in the map information.

9. a parameter acquisition unit that acquires another vehicle behavior parameters that indicate behavior contrary to the deceleration of the host vehicle, the another vehicle traveling at a position in front of, behind, on the left of, or on the right of the host vehicle under a condition in which the deceleration control is being executed, The vehicle control device according to claim 1 , wherein the deceleration control unit cancels the deceleration control based on the other vehicle behavior parameter as the traveling information.

10. A vehicle control device that can execute a constant speed traveling control for traveling the host vehicle at a predetermined target speed in addition to the deceleration control, the parameter acquisition unit acquires, as the other vehicle behavior parameter, a traveling speed of a preceding vehicle traveling ahead of the host vehicle; 10. The vehicle control device according to claim 9, wherein the deceleration control unit cancels the deceleration control when the traveling speed of the preceding vehicle is greater than a threshold value set based on the target speed during execution of the deceleration control.

11. the parameter acquisition unit acquires preceding vehicle deceleration information indicating whether a preceding vehicle traveling ahead of the host vehicle is decelerating as the other vehicle behavior parameter; 10. The vehicle control device according to claim 9, wherein the deceleration control unit cancels the deceleration control when the preceding vehicle approaches within a predetermined distance from a position of a deceleration landmark ahead in the direction of travel in the map information and the preceding vehicle deceleration information indicates that the preceding vehicle is not decelerating.

12. A program capable of executing deceleration control to decelerate a vehicle in accordance with road conditions ahead in a traveling direction of the vehicle by using map information, On the computer, an accelerator operation determination process for determining whether an accelerator operation has been performed by the driver of the host vehicle while the deceleration control is being executed; a deceleration control process for canceling the deceleration control when the deceleration control is being executed and it is determined that the accelerator operation has been performed, based on travel information of at least one of the host vehicle and another vehicle traveling in the same direction as the host vehicle around the host vehicle; A program that executes the following.

Images