Vehicle control device, vehicle control method and vehicle control computer program

Abstract

To provide a vehicle control device capable of controlling vehicle movement in a way that does not cause a driver to feel anxious, even when an operation assistance mode is applied in conjunction with a high-response mode.SOLUTION: A vehicle control device comprises: a change rate setting section 33 which sets a lower upper limit value for an acceleration change rate, when an own vehicle 10 is controlled in an operation support mode, based on an inter-vehicle distance between a preceding vehicle and the own vehicle 10, compared to the upper limit value when a driver manually controls the own vehicle 10 in the case where the own vehicle 10 is being controlled in a high-response mode with higher acceleration responsiveness than a normal travel mode; and a control section 34 which controls the movement of the own vehicle 10 so that the acceleration change rate becomes equal to or lower than the set upper limit value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a computer program for vehicle control. [Background technology]

[0002] There are vehicles that allow the driver to select one of a plurality of driving modes that differ in the response of the vehicle to acceleration and deceleration. For such vehicles, a technology has been proposed for selecting a driving mode to be applied to the vehicle in relation to driving assistance control (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-28560 Summary of the Invention [Problem to be solved by the invention]

[0004] A driving mode of a vehicle, such as a sports mode, which has a higher response to acceleration than a normal driving mode (hereinafter referred to as a high-response mode), may be set together with a driving assistance mode that controls the driving of the host vehicle according to the distance between the host vehicle and a preceding vehicle. In such a case, the vehicle may repeatedly accelerate and decelerate suddenly in a traffic jam, which may make the driver feel uneasy.

[0005] Therefore, an object of the present invention is to provide a vehicle control device that can control the vehicle's driving so as not to make the driver feel uneasy, even when a driving assistance mode is applied and a high-response mode is set. [Means for solving the problem]

[0006] A vehicle control device according to one embodiment has a rate of change setting unit that sets an upper limit value of the rate of change of acceleration when a driving assistance mode that controls the driving of the host vehicle according to the distance between the host vehicle and a preceding vehicle is applied, lower than the upper limit value when the driver of the host vehicle manually controls the driving, when the driving of the host vehicle is controlled according to a high-response mode that has higher acceleration responsiveness than a normal driving mode, and a control unit that controls the driving of the host vehicle so that the rate of change of acceleration is below the set upper limit value.

[0007] In one embodiment, the vehicle control device further includes a mode setting unit that stops application of the high-response mode while the driving assistance mode is applied.

[0008] In one embodiment, the vehicle control device further has a detection unit that detects congestion around the vehicle, and the change rate setting unit sets the upper limit value of the rate of change of acceleration when congestion is detected to be smaller than the upper limit value of the rate of change of acceleration when congestion is not detected.

[0009] In one embodiment, the change rate setting unit reduces the upper limit value of the change rate of acceleration as the speed of the host vehicle decreases.

[0010] In another embodiment, a vehicle control device has a notification processing unit that notifies the driver of the vehicle that the high response mode is set via a notification device provided in the vehicle when the vehicle's driving is controlled according to a high response mode that has a higher acceleration response than a normal driving mode, and a driving assistance mode that controls the vehicle's driving according to the distance between the vehicle and a preceding vehicle is additionally applied.

[0011] In one embodiment, the vehicle control device further has a detection unit that detects traffic congestion around the vehicle, and the notification processing unit notifies the driver that the high response mode is set after the traffic congestion is detected and before the vehicle begins to decelerate.

[0012] A vehicle control method according to yet another embodiment includes, when the driving of the host vehicle is controlled according to a high-response mode that has higher acceleration responsiveness than a normal driving mode, setting an upper limit value for the rate of change of acceleration when a driving assistance mode that controls the driving of the host vehicle according to the distance between the host vehicle and a preceding vehicle is applied to be lower than the upper limit value when the driver of the host vehicle manually controls the driving, and controlling the driving of the host vehicle so that the rate of change of acceleration is equal to or lower than the set upper limit value.

[0013] In yet another embodiment, a computer program for vehicle control includes instructions to cause a processor mounted on the host vehicle to execute the following when the host vehicle's driving is controlled according to a high-response mode that has higher acceleration responsiveness than a normal driving mode: when a driving assistance mode is applied that controls the driving of the host vehicle according to the distance between the host vehicle and a preceding vehicle, the upper limit value of the rate of change of acceleration is set lower than the upper limit value when the driver of the host vehicle manually controls the driving; and the host vehicle's driving is controlled so that the rate of change of acceleration is below the set upper limit value. [Effects of the Invention]

[0014] The vehicle control device according to the present disclosure has the effect of being able to control the vehicle's driving so as not to make the driver feel uneasy, even when the driving assistance mode is applied and the high response mode is set. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic configuration diagram of a vehicle in which a vehicle control device is implemented; [Figure 2] 2 is a functional block diagram of a processor of an electronic control unit related to vehicle control processing according to the first embodiment. FIG. [Figure 3] 4A and 4B are diagrams illustrating an outline of acceleration / deceleration control according to a driving assistance mode when a high response mode is set according to the first embodiment. [Figure 4] 4 is an operational flowchart of a vehicle control process according to the first embodiment. [Figure 5]FIG. 10 is a functional block diagram of a processor of an electronic control unit related to vehicle control processing according to a second embodiment. [Figure 6] 10 is an operational flowchart of a vehicle control process according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] A vehicle control device, a vehicle control method executed on the vehicle control device, and a computer program for vehicle control will be described below with reference to the drawings. The vehicle control device is capable of selecting and setting one of a plurality of driving modes with different acceleration responsiveness. Furthermore, the vehicle control device can assist the driver of the host vehicle by applying a driving assistance mode that controls the driving of the host vehicle according to the distance between the host vehicle and a preceding vehicle traveling ahead of the host vehicle. In particular, the vehicle control device sets a driving mode (hereinafter referred to as a high-response mode) with higher acceleration responsiveness than a normal driving mode, and sets an upper limit value for the amount of change in acceleration per unit time (hereinafter referred to as the rate of change in acceleration) when the driving assistance mode is applied lower than the upper limit value when the driver manually controls the driving. Alternatively, when the high-response mode is set and the driving assistance mode is additionally applied, the vehicle control device notifies the driver that the high-response mode is being applied.

[0017] 1 is a schematic diagram of a vehicle in which a vehicle control device is implemented. A vehicle 10 is an example of a host vehicle, and includes an external sensor 11, a notification device 12, and an electronic control unit (ECU) 13.

[0018] The vehicle 10 allows selection of a plurality of driving modes that differ in acceleration response when the accelerator opening is changed. The plurality of driving modes includes a normal driving mode and a high-response mode that has higher acceleration response than the normal driving mode. The plurality of driving modes may also include a plurality of high-response modes that differ from each other in acceleration response. These high-response modes are called, for example, a sport mode or a power mode. The high-response mode in the following description may refer to any of the plurality of high-response modes. The plurality of driving modes may further include one or more driving modes (hereinafter referred to as low fuel consumption modes) that have lower acceleration response than the normal driving mode but good fuel economy.

[0019] Furthermore, not only acceleration responsiveness but also deceleration responsiveness may differ depending on the driving mode. Therefore, the high-response mode may be set to have not only acceleration responsiveness but also deceleration responsiveness higher than the normal driving mode. Similarly, the fuel-efficient mode may be set to have not only acceleration responsiveness but also deceleration responsiveness lower than the normal driving mode. In the following description, both acceleration responsiveness and deceleration responsiveness differ depending on the driving mode. Furthermore, acceleration responsiveness and deceleration responsiveness are collectively referred to as acceleration / deceleration responsiveness. Note that if the deceleration responsiveness is the same for each driving mode but differs depending on the driving mode, the following description regarding acceleration / deceleration responsiveness and the rate of change of acceleration / deceleration should be understood to refer to acceleration responsiveness and the rate of change of acceleration. Furthermore, hereinafter, control related to acceleration or deceleration according to the driving mode applied to the vehicle 10 is simply referred to as acceleration / deceleration control.

[0020] The external sensor 11 is a sensor that generates an external sensor signal that indicates the situation around the vehicle 10, and is, for example, a camera that is installed so as to be able to capture images of the area around the vehicle 10, or a distance measurement sensor such as a LiDAR or a radar. The vehicle 10 may be provided with a plurality of external sensors 11 with different detectable ranges or types. Each time the external sensor 11 generates an external sensor signal, the external sensor 11 outputs the generated external sensor signal to the ECU 13.

[0021] The notification device 12 is an example of a notification unit and is provided in the passenger compartment of the vehicle 10. The notification device 12 has, for example, at least one of a speaker, a light source, a vibrator, or a display device. When the notification device 12 receives a notification signal representing a predetermined notification to the driver from the ECU 13, the notification device 12 notifies the driver by sound from the speaker, light emission from the light source, vibration of the vibrator, or display of a message on the display device. When the notification device 12 has two or more types of devices, the notification may be given to the driver via each of the two or more types of devices.

[0022] The ECU 13 is an example of a vehicle control device, and executes acceleration / deceleration control of the vehicle 10 according to a set driving mode among a plurality of driving modes. Furthermore, when a driving assistance mode is applied, the ECU 13 executes driving assistance control for the driver of the vehicle 10.

[0023] The ECU 13 includes a communication interface 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 may be configured as separate circuits, or may be integrated into a single integrated circuit.

[0024] The communication interface 21 has an interface circuit for connecting the ECU 13 to other devices. The communication interface 21 passes signals from the outside-vehicle sensors 11 to the processor 23. Furthermore, the communication interface 21 outputs a control signal for a powertrain (not shown) received from the processor 23 to the powertrain. Furthermore, the communication interface 21 outputs a notification signal received from the processor 23 to the notification device 12.

[0025] The memory 22 is an example of a storage unit and includes a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in the vehicle control process executed by the processor 23 or generated during the vehicle control process.

[0026] The processor 23 includes one or more central processing units (CPUs) and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logic unit, a numerical calculation unit, or a graphics processing unit. The processor 23 executes vehicle control processing for the vehicle 10.

[0027] (First embodiment) Hereinafter, a description will be given of the vehicle control process by the processor 23 in the first embodiment. In this embodiment, when the high response mode is set as the driving mode, the processor 23 sets the upper limit value of the rate of change of acceleration / deceleration when the driving assistance mode is applied to be lower than the upper limit value when the driver is driving manually.

[0028] 2 is a functional block diagram of the processor 23 related to vehicle control processing according to the first embodiment. The processor 23 has a mode setting unit 31, a detection unit 32, a change rate setting unit 33, and a control unit 34. Each of these units included in the processor 23 is a functional module realized by, for example, a computer program running on the processor 23. Alternatively, each of these units may be a dedicated arithmetic circuit provided in the processor 23.

[0029] The mode setting unit 31 sets a driving mode to be applied to the acceleration / deceleration control of the vehicle 10 from among a plurality of driving modes with different acceleration / deceleration responsiveness.

[0030] The mode setting unit 31 sets a driving mode specified by an operation signal from an operating device (not shown) provided in the passenger compartment of the vehicle 10 as a driving mode to be applied to acceleration / deceleration control of the vehicle 10. Then, every time the driving mode to be applied to the vehicle 10 is changed via operation of the operating device, the mode setting unit 31 notifies the change rate setting unit 33 and the control unit 34 of the changed driving mode.

[0031] Furthermore, when an operation to apply the driving assistance mode is performed via the operating device, the mode setting unit 31 notifies the change rate setting unit 33 and the control unit 34 that the driving assistance mode is being applied. Similarly, when an operation to cancel the application of the driving assistance mode is performed via the operating device, the mode setting unit 31 notifies the change rate setting unit 33 and the control unit 34 that the application of the driving assistance mode has been canceled.

[0032] The detection unit 32 detects congestion around the vehicle 10. To this end, the detection unit 32 detects other vehicles by inputting the exterior sensor signals, which are obtained by the exterior sensors 11 and indicate the conditions of the area around the vehicle 10, into a classifier that has been trained in advance to detect other vehicles traveling around the vehicle 10. Such a classifier can be a classifier based on a so-called deep neural network (DNN) having a convolutional neural network (CNN) type architecture or an attention mechanism.

[0033] The detection unit 32 determines whether there is a traffic jam around the vehicle 10 based on the detected speed of the other vehicle. To this end, the detection unit 32 tracks the other vehicle detected from each of a plurality of external sensor signals obtained in time series over the most recent predetermined period, thereby determining the change in relative position between the other vehicle and the vehicle 10, and estimates the speed of the other vehicle based on the change in relative position and the speed of the vehicle 10.

[0034] When the external sensor 11 is a camera installed to capture images of the surroundings of the vehicle 10 and the external sensor signal is an image, the position of the bottom edge of the area on the image that includes the detected other vehicle (hereinafter referred to as the object area) is assumed to represent the position where the other vehicle is in contact with the road surface. Furthermore, the position on the image has a one-to-one correspondence with the orientation as seen from the camera that generated the image. Therefore, the detection unit 32 can estimate the distance from the camera 2 to the other vehicle and the orientation from the vehicle 10 to the other vehicle by referring to the position of the bottom edge of the object area on the image and parameters such as the installation height, shooting direction, and angle of view of the camera that is the external sensor 11.

[0035] Furthermore, if the external sensor 11 is a distance measurement sensor, the detection unit 32 may estimate the distance measured in the direction corresponding to the other vehicle detected in the external sensor signal as the distance between the vehicle 10 and the other vehicle.

[0036] The detection unit 32 performs the above processing on each of the multiple exterior sensor signals obtained in time series over the most recent predetermined period, thereby estimating the relative position of other vehicles with respect to the vehicle 10 at the time each exterior sensor signal was generated. Furthermore, the detection unit 32 determines a change in the relative position of other vehicles with respect to the vehicle 10 from the relative positions of the other vehicles with respect to the vehicle 10 at the time each of the exterior sensor signals arranged in time series over the most recent predetermined period was generated, and estimates the relative speed of the surrounding vehicles with respect to the vehicle 10 based on the change in relative position.

[0037] If multiple other vehicles are detected, the detection unit 32 may track each of the other vehicles across multiple external sensor signals obtained in time series by applying a predetermined tracking method such as KLT tracking. Then, the detection unit 32 may estimate the relative position and relative speed of each other vehicle with respect to the vehicle 10 for each other vehicle being tracked.

[0038] The detection unit 32 determines that a traffic jam has occurred when the estimated average speed of other vehicles continues to be slower than a predetermined reference speed by at least a congestion determination threshold for at least a predetermined period of time (for example, several seconds to 10 seconds). The reference speed may be, for example, the speed limit or legal speed for the road section on which the vehicle 10 is traveling, or a speed set via an operating device provided in the cabin of the vehicle 10. The detection unit 32 may identify the road section on which the vehicle 10 is traveling and the speed limit or legal speed for that road section by referring to map information and the current position of the vehicle 10. The map information is stored in advance in the memory 22. The current position of the vehicle 10 may be determined by a satellite positioning system receiver, such as a GPS receiver, mounted on the vehicle 10.

[0039] The detection unit 32 notifies the change rate setting unit 33 of the determination result as to whether or not the vehicle 10 is in a traffic jam.

[0040] The change rate setting unit 33 sets an upper limit value of the change rate of acceleration / deceleration (hereinafter, sometimes referred to as the upper limit change rate) depending on the set driving mode and whether or not a driving assistance mode is applied. In this embodiment, when the set driving mode is the high-response mode, the change rate setting unit 33 sets the upper limit change rate so that the upper limit change rate when the driving assistance mode is set is lower than the upper limit change rate when the driving assistance mode is not applied, i.e., when the driver is manually controlling the driving. For example, the upper limit change rate when the driving assistance mode is applied and the high-response mode is set is set to 0.6 to 0.8 times the upper limit change rate when the driving assistance mode is not applied and the high-response mode is set. This prevents sudden acceleration and deceleration during driving control in accordance with the driving assistance mode. Therefore, even when the driving assistance mode is applied and the high-response mode is set, the driver is prevented from feeling uneasy about driving the vehicle 10.

[0041] Furthermore, when the driving assistance mode is applied and the high response mode is set, the change rate setting unit 33 may set the upper limit change rate when the detection unit 32 detects congestion around the vehicle 10 to be even lower than the upper limit change rate when congestion is not detected. This allows the vehicle 10 to accelerate or decelerate more slowly when the speed of the vehicle 10 is slow, thereby further reducing the driver's anxiety about the driving of the vehicle 10.

[0042] If the set driving mode is a driving mode other than the high-response mode, the change rate setting unit 33 sets an upper limit change rate corresponding to that driving mode, i.e., an upper limit change rate that is lower than the upper limit change rate when the high-response mode is set, regardless of whether the driving assistance mode is applied or not.

[0043] The change rate setting unit 33 notifies the control unit 34 of the set upper limit change rate.

[0044] When the driving assistance mode is not applied, the control unit 34 refers to a map corresponding to the selected driving mode from among maps prepared in advance for each driving mode, which represent the relationship between the accelerator pedal position, the engine or motor rotation speed included in the powertrain, and the target torque. Based on the referenced map, the control unit 34 sets the target torque according to the accelerator pedal position corresponding to the driver's accelerator pedal depression amount, and generates a control signal for the powertrain according to the set target torque. The control unit 34 generates the control signal so that the rate of change of the acceleration / deceleration until the acceleration / deceleration corresponding to the target torque is equal to or less than the upper limit rate of change for the selected driving mode. The control unit 34 then outputs the generated control signal to the powertrain. The control unit 34 may control the powertrain according to feedback control such as PID control. Furthermore, the control unit 34 controls a brake device (not shown) according to the driver's brake pedal depression amount.

[0045] Furthermore, while the driving assistance mode is being applied, the control unit 34 controls the powertrain so that the vehicle 10 travels at a set target vehicle speed. Furthermore, the control unit 34 controls the powertrain so that the inter-vehicle distance between the vehicle 10 and a preceding vehicle traveling ahead of the vehicle 10 in the vehicle's own lane is maintained at a predetermined distance or greater. To this end, the control unit 34 detects other vehicles traveling around the vehicle 10 by performing processing similar to that described for the detection unit 32. Furthermore, the control unit 34 detects lane lines by inputting an image generated by a camera, which is an example of the external sensor 11, into a classifier that has been trained in advance to detect lane lines. The control unit 34 then determines, as the own lane area representing the vehicle's own lane, the other vehicle whose bottom edge of the object area in the image is included in the own lane area and which is closest to the bottom of the image. Alternatively, the control unit 34 may identify, as the preceding vehicle, one of the detected other vehicles that is located in a direction corresponding to the traveling direction of the vehicle 10. The control unit 34 may then estimate the distance to the preceding vehicle by performing the same processing as that described for the detection unit 32. Alternatively, the control unit 34 may receive the detection result of the other vehicle from the detection unit 32 to identify the preceding vehicle, and may also receive from the detection unit 32 the estimated result of the distance to the identified preceding vehicle.

[0046] If the estimated distance to the preceding vehicle (hereinafter sometimes simply referred to as the inter-vehicle distance) is less than a predetermined distance, the control unit 34 sets the target acceleration / deceleration and the rate of change of acceleration / deceleration so as to decelerate the vehicle 10. In this case, the control unit 34 sets the target acceleration / deceleration in accordance with the set driving mode so that the deceleration increases as the inter-vehicle distance to the preceding vehicle becomes shorter or the relative speed of the vehicle 10 with respect to the preceding vehicle becomes faster. On the other hand, if the estimated inter-vehicle distance to the preceding vehicle is equal to or greater than the predetermined distance, the control unit 34 sets the target acceleration / deceleration in accordance with the set driving mode so that the speed of the vehicle 10 approaches the target vehicle speed. However, if the speed of the preceding vehicle is slower than the target vehicle speed, the control unit 34 sets the target acceleration / deceleration in accordance with the set driving mode so that the inter-vehicle distance becomes the predetermined distance and the relative speed between the vehicle 10 and the preceding vehicle becomes zero. To this end, the control unit 34 sets the target acceleration / deceleration based on, for example, a relational expression corresponding to the set driving mode, among relational expressions between the inter-vehicle distance, the relative speed, and the target acceleration / deceleration, which are predefined for each driving mode. Furthermore, the control unit 34 sets the rate of change of the acceleration / deceleration in accordance with the set driving mode. However, if the set driving mode is the high-response mode, the control unit 34 sets the rate of change of the acceleration / deceleration so that it is equal to or less than the upper limit rate of change set by the rate-of-change setting unit 33. The control unit 34 then calculates a target torque corresponding to the set target acceleration / deceleration, and outputs a control signal corresponding to the target torque and the rate of change of the acceleration / deceleration to the powertrain. Furthermore, when decelerating the vehicle 10, for example, the control unit 34 generates a control signal for a brake device of the vehicle 10 according to the set target acceleration / deceleration and the rate of change of the acceleration / deceleration, and outputs the generated control signal to the brake device.

[0047] Even when the driving assistance mode is applied, if the driver depresses the accelerator pedal or the brake pedal by a predetermined amount or more, the control unit 34 may control the powertrain in accordance with the driving operation by the driver. In this case, if the high response mode is set, the control unit 34 may apply the upper limit change rate during manual driving by the driver as the upper limit change rate.

[0048] FIG. 3 is a diagram illustrating an overview of acceleration / deceleration control according to the driving assistance mode when the high-response mode is set according to the first embodiment. In FIG. 3, the horizontal axis represents elapsed time. In the top chart, graph 300 represents the change over time in the setting state of the high-response mode. In the second chart from the top, graph 301 represents the change over time in the inter-vehicle distance between vehicle 10 and a preceding vehicle according to this embodiment, and graph 311 represents the change over time in the inter-vehicle distance when the upper limit change rate is set to the value ULM during manual driving by the driver as a comparative example. In the third chart from the top, graph 302 represents the change over time in the speed of vehicle 10 according to this embodiment, and graph 311 represents the change over time in the speed of vehicle 10 when the upper limit change rate is set to the value ULM during manual driving by the driver as a comparative example. Finally, in the bottom chart, graph 303 represents the change over time in the acceleration / deceleration of vehicle 10 according to this embodiment, and graph 311 represents the change over time in the acceleration / deceleration of vehicle 10 when the upper limit change rate is set to the value ULM during manual driving by the driver as a comparative example.

[0049] In this embodiment, when the driving assistance mode is applied while the high-response mode is set, the upper limit change rate ULS of acceleration / deceleration is set to a value lower than the upper limit change rate ULM during manual driving by the driver. Therefore, as shown in graphs 303 and 313, the change in acceleration / deceleration of the vehicle 10 according to this embodiment is more gradual than the change in acceleration / deceleration of the vehicle 10 according to the comparative example. As a result, as shown in graphs 301 and 311, the change in the inter-vehicle distance between the vehicle 10 according to this embodiment and the preceding vehicle is smaller than the change in the inter-vehicle distance between the vehicle 10 according to the comparative example. Similarly, as shown in graphs 302 and 312, the change in the speed of the vehicle 10 according to this embodiment is smaller than the change in the speed of the vehicle 10 according to the comparative example. In this way, since sudden acceleration and deceleration are suppressed in this embodiment, changes in the speed of the vehicle 10 and changes in the inter-vehicle distance between the vehicle 10 and the preceding vehicle are also suppressed. As a result, even if the driving of the vehicle 10 is controlled according to both the high-response mode and the driving assistance mode, the driver's anxiety is suppressed.

[0050] FIG. 4 is an operational flowchart of the vehicle control process according to the first embodiment.

[0051] The change rate setting unit 33 refers to the notification from the mode setting unit 31 and determines whether or not the high-response mode is set as the driving mode to be applied to the vehicle 10 (step S101). If the high-response mode is not set (step S101-No), the change rate setting unit 33 sets an upper limit change rate according to the set driving mode (step S102).

[0052] If the high response mode is set (step S101—Yes), the change rate setting unit 33 refers to the notification from the mode setting unit 31 and determines whether or not the driving assistance mode is applied to the vehicle 10 (step S103). If the driving assistance mode is not applied (step S103—No), the change rate setting unit 33 sets a first upper limit change rate that is higher than when the other driving modes are set (step S104). On the other hand, if the driving assistance mode is applied (step S103—Yes), the change rate setting unit 33 determines whether or not congestion around the vehicle 10 is detected by the detection unit 32 (step S105). If congestion around the vehicle 10 is not detected (step S105—No), the change rate setting unit 33 sets a second upper limit change rate that is lower than the first upper limit change rate (step S106). On the other hand, if congestion around the vehicle 10 is detected (step S105-Yes), the change rate setting unit 33 sets a third upper limit change rate that is even lower than the second upper limit change rate (step S107). Note that the second upper limit change rate and the third upper limit change rate are preferably higher than the upper limit change rates when the other driving modes are set.

[0053] Once the upper limit change rate is set, the control unit 34 sets the target acceleration / deceleration and the change rate of acceleration / deceleration that is equal to or less than the upper limit change rate in accordance with the set driving mode, the accelerator operation by the driver or the distance to the preceding vehicle and the target vehicle speed, and controls the driving of the vehicle 10 in accordance with the set target acceleration / deceleration and the change rate of acceleration / deceleration (step S108).

[0054] As described above, when the vehicle driving is controlled according to the high-response mode, this vehicle control device sets the upper limit change rate of acceleration / deceleration when the driving assistance mode is applied to be lower than the upper limit change rate when the driver manually controls the driving. Therefore, this vehicle control device can suppress sudden acceleration and deceleration when the vehicle driving is controlled according to both the driving assistance mode and the high-response mode. As a result, this vehicle control device can prevent the driver from feeling uneasy when the vehicle driving is controlled according to both the driving assistance mode and the high-response mode.

[0055] According to a modified example, when the high-response mode is set, if an operation to apply the driving assistance mode is performed via an operating device and the driving assistance mode is applied to the vehicle 10, the mode setting unit 31 may stop applying the high-response mode. At that time, the mode setting unit 31 may change the driving mode that is set while the driving assistance mode is applied from the high-response mode to the normal driving mode or the fuel-efficient mode. This further suppresses sudden acceleration and deceleration in the driving control of the vehicle 10 when the driving assistance mode is applied.

[0056] According to another modification, when the driving assistance mode is applied, the change rate setting unit 33 may lower the upper limit change rate as the speed of the vehicle 10 measured by a vehicle speed sensor (not shown) provided in the vehicle 10 decreases. As a result, the vehicle 10 accelerates and decelerates more slowly as the speed of the vehicle 10 decreases, making the driver less likely to feel uneasy when the driving assistance mode is applied.

[0057] According to yet another modification, the change rate setting unit 33 may set the upper limit change rate based on the set driving mode and whether or not the driving assistance mode is applied, regardless of whether or not congestion is detected around the vehicle 10. In this case, the processing of the detection unit 32 may be omitted. This reduces the calculation load on the processor 23.

[0058] (Second embodiment) Next, a second embodiment will be described. In the second embodiment, when the driving assistance mode is additionally applied while the high response mode is set, the vehicle control device notifies the driver that the high response mode is set. The following describes the differences from the first embodiment.

[0059] 5 is a functional block diagram of the processor 23 related to vehicle control processing according to the second embodiment. The processor 23 has a mode setting unit 31, a change rate setting unit 33, a control unit 34, and a notification processing unit 35. Each of these units included in the processor 23 is a functional module realized by, for example, a computer program running on the processor 23. Alternatively, each of these units may be a dedicated arithmetic circuit provided in the processor 23.

[0060] When the high-response mode is set and the mode setting unit 31 receives an operation signal indicating that an operation to apply the driving assistance mode has been performed from an operating device, the mode setting unit 31 notifies the notification processing unit 35 that the high-response mode is being set and that the driving assistance mode has been additionally applied.

[0061] When the notification processing unit 35 is notified by the mode setting unit 31 that the driving assistance mode has been additionally applied while the high response mode is set, the notification processing unit 35 generates a notification signal indicating that the high response mode is set and outputs the notification signal to the notification device 12. As a result, the notification processing unit 35 notifies the driver via the notification device 12 that the high response mode is set. At this time, the notification processing unit 35 causes a speaker of the notification device 12 to output a sound indicating that the high response mode is set. Alternatively, the notification processing unit 35 causes a display device of the notification device 12 to display a message or an icon indicating that the high response mode is set. Alternatively, the notification processing unit 35 turns on or blinks a light source of the notification device 12 that corresponds to the high response mode. As a result, the driver is notified that the high response mode is set, and therefore, even if sudden acceleration or deceleration occurs as a result of the traveling of the vehicle 10 being controlled according to the driving assistance mode and the high response mode, the driver's anxiety is suppressed.

[0062] In this embodiment, even when the high-response mode is set, the change rate setting unit 33 may set the same upper limit change rate regardless of whether the driving assistance mode is applied. Then, as in the first embodiment, the control unit 34 sets the target acceleration / deceleration and the change rate of the acceleration / deceleration in accordance with the accelerator pedal position or the target vehicle speed and the inter-vehicle distance between the preceding vehicle and the vehicle 10. However, in this embodiment, the control unit 34 only needs to set the change rate of the acceleration / deceleration to be equal to or lower than the upper limit change rate according to the set driving mode, regardless of whether the driving assistance mode is applied. Then, the control unit 34 outputs control signals according to the set target acceleration / deceleration and the change rate of the acceleration / deceleration to the powertrain and, if necessary, to the brake device.

[0063] 6 is an operation flowchart of the vehicle control device according to the second embodiment. While the high response mode is turned on, the processor 23 executes the vehicle control device in accordance with the following operation flowchart.

[0064] The mode setting unit 31 determines whether or not an operation signal for applying the driving assistance mode has been received from the operating device (step S201). If an operation signal for applying the driving assistance mode has not been received (step S201-No), the control unit 34 controls the traveling of the vehicle 10 in accordance with the high response mode and the driving operation by the driver (step S202).

[0065] On the other hand, if the mode setting unit 31 receives an operation signal to apply the driving assistance mode (step S201-Yes), the notification processing unit 35 notifies the driver via the notification device 12 that the high response mode is being set (step S203). Then, the control unit 34 controls the traveling of the vehicle 10 in accordance with both the high response mode and the driving assistance mode (step S204).

[0066] As described above, when the driving assistance mode is started while the high-response mode is set, the vehicle control device notifies the driver that the high-response mode is set. Therefore, even if sudden acceleration and deceleration occur due to driving control in accordance with the driving assistance mode and the high-response mode, the driver's anxiety is suppressed.

[0067] According to a modification, in the second embodiment, the processor 23 may also include the detection unit 32, as in the first embodiment. In this case, the detection unit 32 preferably detects other vehicles traveling ahead of the vehicle 10 based on a portion of the exterior sensor signal that represents an area ahead of the vehicle 10. For example, if the exterior sensor 11 includes a camera that captures an area ahead of the vehicle 10, the detection unit 32 detects other vehicles traveling ahead of the vehicle 10 by inputting an image generated by the camera to a classifier. The detection unit 32 may then detect congestion based on other vehicles traveling ahead of the vehicle 10, as in the first embodiment. This allows the detection unit 32 to detect congestion ahead of the vehicle 10 before the vehicle 10 catches up with the end of the congestion. When the detection unit 32 detects congestion, it notifies the notification processing unit 35 of the detection. When the mode setting unit 31 notifies the notification processing unit 35 that the driving assistance mode will be applied while the high response mode is set and the detection unit 32 notifies the notification processing unit 35 that a traffic jam has been detected, the notification processing unit 35 notifies the driver via the notification device 12 that the high response mode is set, before the vehicle 10 starts to decelerate in the driving assistance mode. This prevents the driver from feeling uneasy even if the vehicle 10 suddenly decelerates due to driving control in accordance with the driving assistance mode and the high response mode when the vehicle 10 catches up with the end of the traffic jam.

[0068] The processor 23 may execute both the vehicle control process according to the first embodiment or its modified example and the vehicle control process according to the second embodiment or its modified example. That is, the processor 23 may execute the processes of the mode setting unit 31, the detection unit 32, the change rate setting unit 33, the control unit 34, and the notification processing unit 35. That is, when the driving assistance mode is applied while the high-response mode is set, the processor 23 may notify the driver via the notification device 12 that the high-response mode is set, and may set the upper limit change rate of acceleration / deceleration to a value lower than that during manual driving by the driver. In this case, the processor 23 may lower the upper limit change rate as the speed of the vehicle 10 decreases, or may further lower the upper limit change rate when there is congestion around the vehicle 10. Furthermore, when the driving assistance mode is applied while the high-response mode is set, the processor 23 may notify the driver via the notification device 12 that the high-response mode is set, as well as suggesting a change to the normal driving mode or the fuel-efficient driving mode. Then, when an operation signal indicating that an operation to approve the proposal has been performed is received from the operating device, the processor 23 may change the driving mode to be set to the normal driving mode or the fuel-efficient mode.

[0069] A computer program that realizes the functions of the processor 23 of the ECU 13 according to each of the above embodiments or variations may be provided in a form recorded on a computer-readable portable recording medium such as a semiconductor memory, a magnetic recording medium or an optical recording medium. [Explanation of symbols]

[0070] 10 vehicle, 11 outside sensor, 12 notification device, 13 electronic control unit (ECU, vehicle control unit), 21 communication interface, 22 memory, 23 processor, 31 mode setting unit, 32 detection unit, 33 change rate setting unit, 34 control unit, 35 notification processing unit

Claims

1. a change rate setting unit that sets an upper limit value of a change rate of acceleration when a driving assistance mode that controls the driving of the host vehicle in accordance with a vehicle-to-vehicle distance between a preceding vehicle and the host vehicle is applied, in a case where the driving of the host vehicle is controlled according to a high response mode that has a higher acceleration response than a normal driving mode, to be lower than the upper limit value when the driver of the host vehicle manually controls the driving; a control unit that controls the traveling of the host vehicle so that the rate of change of the acceleration is equal to or less than the set upper limit value; A vehicle control device having the above.

2. The vehicle control device according to claim 1 , further comprising a mode setting unit that stops application of the high-response mode while the driving assistance mode is being applied.

3. a detection unit that detects congestion around the vehicle; The vehicle control device according to claim 1 , wherein the change rate setting unit sets the upper limit value when the congestion is detected to be smaller than the upper limit value when the congestion is not detected.

4. The vehicle control device according to claim 1 , wherein the change rate setting unit reduces the upper limit value as the speed of the host vehicle decreases.

5. a notification processing unit that notifies a driver of the host vehicle that the high response mode is set via a notification device provided in the host vehicle when a driving assistance mode that controls the driving of the host vehicle in accordance with a vehicle-to-vehicle distance between the host vehicle and a preceding vehicle is additionally applied in a state where the host vehicle is being controlled in accordance with a high response mode that has a higher acceleration response than a normal driving mode; A vehicle control device having the above.

6. a detection unit that detects congestion around the vehicle; The vehicle control device according to claim 5 , wherein the notification processing unit notifies the driver that the high response mode is set before the host vehicle starts to decelerate after the congestion is detected.

7. When the driving of the host vehicle is controlled in accordance with a high response mode in which the acceleration response is higher than in a normal driving mode, an upper limit value of the rate of change of acceleration when a driving assistance mode is applied in which the driving of the host vehicle is controlled in accordance with the inter-vehicle distance between the host vehicle and a preceding vehicle is set to be lower than the upper limit value when the driver of the host vehicle manually controls the driving; controlling the running of the host vehicle so that the rate of change of the acceleration is equal to or less than the set upper limit value; A vehicle control method comprising:

8. When the driving of the host vehicle is controlled in accordance with a high response mode in which the acceleration response is higher than in a normal driving mode, an upper limit value of the rate of change of acceleration when a driving assistance mode is applied in which the driving of the host vehicle is controlled in accordance with the inter-vehicle distance between the host vehicle and a preceding vehicle is set to be lower than the upper limit value when the driver of the host vehicle manually controls the driving; controlling the running of the host vehicle so that the rate of change of the acceleration is equal to or less than the set upper limit value; A computer program for vehicle control that causes a processor mounted on the vehicle to execute the above.

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