Vehicle driving assistance system, vehicle driving assistance method, and vehicle driving assistance program

Abstract

The present invention provides a vehicle driving assistance device that can perform intermittent driving control in accordance with the operator's desire to reduce the vehicle's energy consumption during driving. [Solution] The vehicle driving support device 10 performs intermittent driving control to allow the vehicle 100 to drive autonomously. Intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. Intermittent vehicle speed control is a control that autonomously alternates between power control and coasting control so that the vehicle's speed remains within a predetermined range. Intermittent inter-vehicle distance control is a control that autonomously alternates between power control and coasting control so that the distance between the vehicle and the preceding vehicle 200 remains within a predetermined range. The level of driving support for the vehicle through intermittent driving control is set by the operator of the vehicle. When the driving support level is set to the first level, the vehicle driving support device sets the predetermined range to a wider range compared to when the driving support level is set to a second level which is lower than the first level.

Description

Technical Field

[0001] The present invention relates to a vehicle driving support device, a vehicle driving support method, and a vehicle driving support program.

Background Art

[0002] A vehicle driving support device is known that executes, as intermittent travel control, intermittent vehicle speed control that causes the host vehicle to travel by autonomously and alternately repeating power running of the host vehicle and coasting of the host vehicle such that the travel speed of the host vehicle falls within a predetermined speed range (see, for example, Patent Document 1). By executing the intermittent travel control, the travel energy consumption can be reduced. Note that the travel energy consumption is the amount of energy consumed by the drive device of the host vehicle to generate the driving force for causing the host vehicle to travel.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of Invention

[0004] Meanwhile, there is a vehicle driving support device that allows an operator of the host vehicle to set the driving support level by the intermittent travel control. Here, when the driving support level is high, the operator of the host vehicle desires to significantly reduce the travel energy consumption. On the other hand, when the driving support level is low, the operator of the host vehicle does not desire to significantly reduce the travel energy consumption. Therefore, when the driving support level is settable by the operator of the host vehicle, it is desired that the intermittent travel control be executed so as to meet the wish of the operator of the host vehicle regarding the reduction of the travel energy consumption.

[0005] An object of the present invention is to provide a vehicle driving support device, a vehicle driving support method, and a vehicle driving support program that can execute the intermittent travel control so as to meet the wish of the operator of the host vehicle regarding the reduction of travel energy consumption.

[0006] The vehicle driving support system according to the present invention includes a control device that performs intermittent driving control, which autonomously drives the vehicle, as a driving support control. The intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. The intermittent vehicle speed control is a control that drives the vehicle by autonomously alternating between power control, which powers the vehicle, and coasting control, which coasts the vehicle, so that the vehicle's speed remains within a predetermined speed range when there is no preceding vehicle. The intermittent inter-vehicle distance control is a control that drives the vehicle by autonomously alternating between power control and coasting control, so that the distance between the vehicle and the preceding vehicle remains within a predetermined distance range when there is a preceding vehicle. The level of driving support for the vehicle provided by the intermittent driving control is set by the operator of the vehicle. Furthermore, when the driving assistance level is set to a first level, the control device is configured to set the predetermined speed range and the predetermined distance range to a wider range compared to when the driving assistance level is set to a second level which is lower than the first level.

[0007] When intermittent driving control is in operation, a wider predetermined speed range tends to result in a greater reduction in driving energy consumption. Similarly, when intermittent driving control is in operation, a wider predetermined distance range tends to result in a greater reduction in driving energy consumption. On the other hand, when the driver assistance level is set to a high level, the operator of the vehicle desires a significant reduction in driving energy consumption.

[0008] According to the vehicle driving assistance device of the present invention, when the driving assistance level is set to a high level (i.e., the first level), the predetermined speed range and predetermined distance range are set to a wider range compared to when the driving assistance level is set to a low level (i.e., the second level). Therefore, intermittent driving control can be performed in accordance with the driver's desire to reduce the driving energy consumption.

[0009] Furthermore, in the vehicle driving support device according to the present invention, the control device may be configured to limit the acceleration of the vehicle to a range that is below the upper limit acceleration and above the lower limit acceleration when the intermittent driving control is executed. In this case, the control device may be configured to set the upper limit acceleration to a smaller value and the lower limit acceleration to a larger value when the driving support level is set to the second level, compared to when the driving support level is set to the first level.

[0010] When the driver assistance level is set to a low level, the driver of the vehicle wants the vehicle's speed to not change significantly.

[0011] According to the vehicle driving assistance device of the present invention, when the driving assistance level is set to a low level (i.e., the second level), the upper limit acceleration is set to a smaller value and the lower limit acceleration is set to a larger value compared to when the driving assistance level is set to a high level (i.e., the first level). As a result, large changes in the vehicle's speed are suppressed. Therefore, intermittent driving control can be performed in accordance with the wishes of the vehicle's operator.

[0012] Furthermore, the vehicle driving assistance method according to the present invention is a method of performing intermittent driving control, which autonomously drives the vehicle, as a driving assistance control. The intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. The intermittent vehicle speed control is a control that drives the vehicle by autonomously alternating between power control, which powers the vehicle, and coasting control, which coasts the vehicle, so that the vehicle's speed remains within a predetermined speed range when there is no preceding vehicle. The intermittent inter-vehicle distance control is a control that drives the vehicle by autonomously alternating between power control and coasting control, so that the distance between the vehicle and the preceding vehicle remains within a predetermined distance range when there is a preceding vehicle. The level of driving assistance for the vehicle provided by the intermittent driving control is set by the operator of the vehicle. Furthermore, the vehicle driving assistance method according to the present invention includes a step of setting the predetermined speed range and the predetermined distance range to a wider range when the driving assistance level is set to a first level compared to when the driving assistance level is set to a second level which is lower than the first level.

[0013] According to the vehicle driving assistance method of the present invention, for the same reasons as described above, intermittent driving control can be performed in accordance with the operator's desire to reduce the amount of energy consumed while driving.

[0014] Furthermore, the vehicle driving support program according to the present invention is a program that executes intermittent driving control, which autonomously drives the vehicle, as a driving support control. The intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. The intermittent vehicle speed control is a control that drives the vehicle by autonomously alternating between power control, which powers the vehicle, and coasting control, which coasts the vehicle, so that the vehicle's speed remains within a predetermined speed range when there is no preceding vehicle. The intermittent inter-vehicle distance control is a control that drives the vehicle by autonomously alternating between power control and coasting control, so that the distance between the vehicle and the preceding vehicle remains within a predetermined distance range when there is a preceding vehicle. The level of driving support for the vehicle provided by the intermittent driving control is set by the operator of the vehicle. Furthermore, the vehicle driving assistance program according to the present invention is configured such that when the driving assistance level is set to a first level, the predetermined speed range and the predetermined distance range are set to a wider range compared to when the driving assistance level is set to a second level which is lower than the first level.

[0015] According to the vehicle driving support program of the present invention, for the same reasons as described above, intermittent driving control can be performed in accordance with the operator's desire to reduce driving energy consumption.

[0016] The components of the present invention are not limited to the embodiments described below with reference to the drawings. Other objects, features, and incidental advantages of the present invention will be readily apparent from the description of the embodiments. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a diagram showing a vehicle driving assistance device according to an embodiment of the present invention. [Figure 2] Figure 2 shows a scenario where a preceding vehicle is present. [Figure 3]Figure 3 is a flowchart showing the routine executed by a vehicle driving assistance device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0018] Hereinafter, with reference to the drawings, a vehicle driving support device, a vehicle driving support method, and a vehicle driving support program according to embodiments of the present invention will be described.

[0019] Figure 1 shows a vehicle driving support device 10 according to an embodiment of the present invention. The vehicle driving support device 10 is installed in the vehicle 100. Hereinafter, the vehicle driving support device 10 will be described using the case where the operator or user of the vehicle 100 is the driver of the vehicle 100 (i.e., a person who is in the vehicle 100 and drives the vehicle 100) as an example. However, the operator or user of the vehicle 100 may also be a remote operator of the vehicle 100 (i.e., a person who does not ride in the vehicle 100 and drives the vehicle 100 remotely). In the following description, the driver of the vehicle 100 may be simply referred to as "driver".

[0020] As shown in Figure 1, the vehicle driving assistance system 10 includes an ECU (Electronic Control Unit) 90 as a control device. The ECU 90 mainly consists of a microcomputer. The microcomputer includes a CPU, a computer-readable storage medium, and an interface, etc. The storage medium is ROM, RAM, and non-volatile memory, etc. The CPU realizes various functions by executing instructions, programs, or routines stored in the storage medium. In particular, in this example, the vehicle driving assistance system 10 stores programs that realize the various controls that the vehicle driving assistance system 10 performs in the storage medium.

[0021] In this example, the vehicle driver assistance system 10 is equipped with only one ECU 90. However, the vehicle driver assistance system 10 may be equipped with multiple ECUs, and each ECU may be configured to perform the functions of the vehicle driver assistance system 10 described below.

[0022] Further, the vehicle driving support device 10 may be configured to be capable of updating (upgrading) a program stored in a storage medium via wireless communication (for example, Internet communication) with an external device.

[0023] Further, the vehicle driving support device 10 can be applied not only to a vehicle that travels by manual driving by an operator, but also to a vehicle that travels by automated driving.

[0024] As shown in Figure 1, a host vehicle 100 is equipped with a drive device 20, a braking device 30, and a driving force transmission device 40.

[0025] The drive device 20 is a device that generates driving force to be applied to the host vehicle 100 (in particular, drive wheels of the host vehicle 100). In the present example, the drive device 20 includes an internal combustion engine 21 and an electric motor 22. The drive device 20 is electrically connected to an ECU 90. The vehicle driving support device 10 can control the driving force applied to the host vehicle 100 by controlling the operation of the drive device 20 (that is, the internal combustion engine 21 and the electric motor 22).

[0026] The braking device 30 is a device that applies braking force to the host vehicle 100 (in particular, wheels of the host vehicle 100). In the present example, the braking device 30 includes a hydraulic brake device 31. The braking device 30 is electrically connected to the ECU 90. The vehicle driving support device 10 can control the braking force applied to the host vehicle 100 by controlling the operation of the braking device 30 (more specifically, the operation of the hydraulic brake device 31).

[0027] The driving force transmission device 40 is a device that transmits the driving force output from the drive device 20 to the drive wheels of the host vehicle 100. The driving force transmission device 40 is, for example, a transmission. The driving force transmission device 40 is electrically connected to the ECU 90.

[0028] The vehicle driving support system 10 can establish a power transmission path and transmit the power output from the drive unit 20 to the drive wheels of the vehicle 100 by controlling the operation of the power transmission device 40. The power transmission path is the path that transmits power from the drive unit 20 to the drive wheels of the vehicle 100. On the other hand, the vehicle driving support system 10 can also block the power transmission path by controlling the operation of the power transmission device 40, preventing power from being transmitted from the drive unit 20 to the drive wheels of the vehicle 100.

[0029] Furthermore, the vehicle 100 is equipped with a driver assistance control unit 51, an intermittent driving control unit 52, a support level setting control unit 53, a vehicle speed detection device 60, and a surrounding information acquisition device 70.

[0030] The driver assistance control unit 51 is a device operated by the driver. By operating the driver assistance control unit 51, the driver can request the execution or cessation of the driver assistance control described later. The driver assistance control unit 51 is electrically connected to the ECU 90.

[0031] The vehicle driver assistance system 10 determines that the execution of driver assistance control has been requested if the driver assistance control device 51 is operated when driver assistance control is not being performed. On the other hand, the vehicle driver assistance system 10 determines that the stopping of driver assistance control has been requested if the driver assistance control device 51 is operated when driver assistance control is being performed.

[0032] The intermittent driving control device 52 is also a device operated by the driver. By operating the intermittent driving control device 52, the driver can request the execution or cessation of the intermittent driving control described later. The intermittent driving control device 52 is electrically connected to the ECU 90.

[0033] The vehicle driving support system 10 determines that intermittent driving control has been requested when the intermittent driving control operator 52 is operated while intermittent driving control is not being performed. On the other hand, the vehicle driving support system 10 determines that the intermittent driving control has been requested to be stopped and that the steady-state driving control, described later, has been requested when the intermittent driving control operator 52 is operated while intermittent driving control is being performed.

[0034] The support level setting control device 53 is also a device operated by the driver. The driver can set the driver assistance level L by operating the support level setting control device 53.

[0035] In this example, three levels of driver assistance L are available: strong assistance level Ls, medium assistance level Lm, and weak assistance level Lw.

[0036] When a strong support level Ls is set as the driver assistance level L, a significant reduction in driving energy consumption is required compared to when a medium support level Lm is set as the driver assistance level L.

[0037] Furthermore, when a medium support level Lm is set as the driver assistance level L, it is required to significantly reduce the amount of energy consumed while driving compared to when a weak support level Lw is set as the driver assistance level L.

[0038] Thus, the driving assistance level L represents the degree to which the amount of energy consumed during driving is reduced by intermittent driving control. The amount of energy consumed during driving is the amount of energy consumed by the drive unit 20 of the vehicle 100 in order to generate the driving force necessary to move the vehicle 100.

[0039] The support level setting device 53 is electrically connected to the ECU 90. The vehicle driving support system 10 acquires the driving support level L set by the operation of the support level setting device 53. As will be described later, the vehicle driving support system 10 changes the control parameters of the intermittent driving control according to the set driving support level L.

[0040] Thus, in this example, the driver assistance level L for the vehicle 100 through intermittent driving control is set by the driver of the vehicle 100.

[0041] The vehicle speed detection device 60 is a device for detecting the vehicle speed V. The vehicle speed V is the travel speed of the vehicle 100. The vehicle speed detection device 60 is equipped with, for example, wheel speed sensors provided on each wheel of the vehicle 100. The vehicle speed detection device 60 is electrically connected to the ECU 90. The vehicle driving support system 10 acquires the vehicle speed V using the vehicle speed detection device 60.

[0042] The surrounding information acquisition device 70 is a device for detecting information about the surroundings of the vehicle 100. In this example, the surrounding information acquisition device 70 is equipped with a plurality of electromagnetic wave sensors 71 and a plurality of image sensors 72.

[0043] The electromagnetic wave sensor 71 is electrically connected to the ECU 90. The electromagnetic wave sensor 71 is, for example, a radar sensor such as a millimeter-wave radar. The vehicle driving support system 10 acquires information (target information IO) related to targets present around its own vehicle 100 as surrounding information IS using the electromagnetic wave sensor 71. In particular, the target information IO includes information about the preceding vehicle 200.

[0044] As shown in Figure 2, the preceding vehicle 200 is another vehicle traveling in the vehicle's own lane LN1 and located within a predetermined distance Dp ahead of the vehicle 100. The vehicle's own lane LN1 is the lane in which the vehicle 100 is traveling.

[0045] The image sensor 72 is electrically connected to the ECU 90. The image sensor 72 is, for example, a camera sensor. The vehicle driving assistance system 10 acquires image information ICs related to the surroundings of its own vehicle 100 as surrounding information IS using the image sensor 72. In particular, the image information ICs include information about the preceding vehicle 200.

[0046] <Operation of vehicle driver assistance system> Next, the operation of the vehicle driving assistance system 10 will be explained.

[0047] The vehicle driving support system 10 executes the routine shown in Figure 3 at predetermined time intervals, and when predetermined conditions are met, it performs driving support control. Driving support control is a control that allows the vehicle 100 to drive autonomously. Driving support control includes steady-state driving control and intermittent driving control.

[0048] Steady-state driving control includes steady-state vehicle speed control and steady-state inter-vehicle distance control.

[0049] As shown in Figure 2, the vehicle driving support system 10 performs steady-state inter-vehicle distance control as steady-state driving control when a preceding vehicle 200 is present. On the other hand, when a preceding vehicle 200 is not present, the vehicle driving support system 10 performs steady-state vehicle speed control as steady-state driving control. The vehicle driving support system 10 detects the preceding vehicle 200 based on surrounding information IS.

[0050] Steady-state speed control is a control system that allows the vehicle 100 to move autonomously by controlling the operation of the drive unit 20 and the braking unit 30 so that the vehicle speed V is maintained at a set vehicle speed Vset. The set vehicle speed Vset is set by the driver.

[0051] Thus, steady-state speed control is a control method that causes the vehicle 100 to travel by autonomously accelerating and decelerating so that its own vehicle speed V is maintained at a predetermined speed (i.e., set vehicle speed Vset) when there is no preceding vehicle 200.

[0052] On the other hand, steady-state inter-vehicle distance control is a control system that allows the vehicle 100 to drive autonomously by controlling the operation of the drive unit 20 and the braking unit 30 so that the inter-vehicle distance D is maintained at a set inter-vehicle distance Dset. The inter-vehicle distance D is the distance between the vehicle 100 and the preceding vehicle 200. The vehicle driving support system 10 acquires the inter-vehicle distance D based on surrounding information IS. The set inter-vehicle distance Dset is set by the driver.

[0053] Thus, steady-state inter-vehicle distance control is a control method that causes the vehicle 100 to travel by autonomously accelerating and decelerating so that the inter-vehicle distance D is maintained at a predetermined inter-vehicle distance (i.e., set inter-vehicle distance Dset) when a preceding vehicle 200 is present.

[0054] Furthermore, intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control.

[0055] Intermittent driving control includes power control and coasting control. Intermittent driving control is a control system that allows the vehicle 100 to move autonomously by alternately switching between power control and coasting control.

[0056] Power control is a control that powers the vehicle 100. In particular, in this example, power control is a control that powers the vehicle 100 so that it accelerates. When power control is performed, the vehicle driving support device 10 powers the vehicle 100 by applying driving force from the drive unit 20 to the vehicle 100. Optimal power control may also be used as the power control. Optimal power control is a control that powers the vehicle 100 by applying driving force from the drive unit 20 to the vehicle 100 while controlling the operation of the drive unit 20 to maximize the driving energy efficiency. Driving energy efficiency is the energy efficiency when the drive unit 20 generates driving force.

[0057] Coasting control is a control method that allows the vehicle 100 to coast. When coasting control is performed, the vehicle driving support device 10 allows the vehicle 100 to coast by stopping the supply of driving force from the drive unit 20 to the vehicle 100. In this example, when coasting control is performed, the vehicle driving support device 10 stops the supply of driving force from the drive unit 20 to the vehicle 100 by disconnecting the driving force transmission path. As described above, the driving force transmission path is the path through which driving force is supplied from the drive unit 20 to the vehicle 100. The vehicle driving support device 10 disconnects the driving force transmission path by controlling the operation of the driving force transmission device 40. In this example, when coasting control is performed, the operation of the internal combustion engine 21 is stopped.

[0058] As shown in Figure 2, the vehicle driving support system 10 performs intermittent distance control as intermittent driving control when there is a preceding vehicle 200. On the other hand, when there is no preceding vehicle 200, the vehicle driving support system 10 performs intermittent speed control as intermittent driving control.

[0059] Intermittent speed control is a control method that allows the vehicle 100 to move autonomously by repeatedly alternating between power control and coasting control so that the vehicle speed V is maintained within the target vehicle speed range RVtgt. Therefore, when performing intermittent speed control, the vehicle driving support device 10 alternately switches between power control and coasting control so that the vehicle speed V stays within a predetermined range (i.e., the target vehicle speed range RVtgt).

[0060] When the vehicle driving support device 10 is performing intermittent speed control, if the vehicle speed V increases due to the execution of power control and reaches the upper limit speed Vmax, it terminates power control and starts coasting control. The upper limit speed Vmax is the upper limit of the target vehicle speed range RVtgt. In this example, the set vehicle speed Vset is set as the upper limit speed Vmax (Vmax = Vset).

[0061] On the other hand, when the vehicle driving support device 10 is performing intermittent vehicle speed control, if the vehicle speed V decreases due to the execution of coasting control and reaches the lower limit speed Vmin, it terminates coasting control and starts power control. The lower limit speed Vmin is the lower limit of the target vehicle speed range RVtgt. In this example, the lower limit speed Vmin is the value obtained by subtracting the target vehicle speed control width WVtgt from the set vehicle speed Vset (Vmin = Vset - WVtgt).

[0062] Thus, intermittent speed control is a control method that drives the vehicle 100 by autonomously and repeatedly alternating between power control and coasting control so that the vehicle speed V remains within a predetermined speed range (i.e., target speed range RVtgt) when there is no preceding vehicle 200.

[0063] Furthermore, intermittent inter-vehicle distance control is a control method that autonomously drives the vehicle 100 by repeatedly and alternately executing power control and coasting control so that the inter-vehicle distance D is maintained within the target inter-vehicle distance range RDtgt. Therefore, when executing intermittent inter-vehicle distance control, the vehicle driving support device 10 alternately switches between power control and coasting control so that the inter-vehicle distance D falls within a predetermined range (i.e., the target inter-vehicle distance range RDtgt).

[0064] When the vehicle driving support device 10 is performing intermittent inter-vehicle distance control, if the inter-vehicle distance D is shortened by the execution of power control and reaches the lower limit inter-vehicle distance Dmin, it terminates power control and starts coasting control. The lower limit inter-vehicle distance Dmin is the lower limit of the target inter-vehicle distance range RDtgt. In this example, the set inter-vehicle distance Dset is set as the lower limit inter-vehicle distance Dmin (Dmin = Dset).

[0065] On the other hand, when the vehicle driving support device 10 is performing intermittent inter-vehicle distance control, if the inter-vehicle distance D increases due to the execution of coasting control and reaches the upper limit inter-vehicle distance Dmax, it terminates coasting control and starts power control. The upper limit inter-vehicle distance Dmax is the upper limit of the target inter-vehicle distance range RDtgt. In this example, the upper limit inter-vehicle distance Dmax is the value obtained by adding the target inter-vehicle distance control width WDtgt to the lower limit inter-vehicle distance Dmin (Dmax = Dmin + WDtgt).

[0066] Thus, intermittent inter-vehicle distance control is a control method that causes the vehicle 100 to move by autonomously and repeatedly alternating between power control and coasting control so that the inter-vehicle distance D remains within a predetermined distance range (i.e., the target inter-vehicle distance range RDtgt) when a preceding vehicle 200 is present.

[0067] Furthermore, when power control is being performed, if the vehicle speed V reaches the upper limit speed Vmax before the inter-vehicle distance D reaches the lower limit inter-vehicle distance Dmin, the vehicle driving support device 10 stops power control and performs upper limit speed maintenance control, which controls the acceleration and deceleration of the vehicle 100 so that the vehicle speed V is maintained at the upper limit speed Vmax.

[0068] When a predetermined timing occurs, the vehicle driving support system 10 starts processing from step S300 of the routine shown in Figure 3. Then, the vehicle driving support system 10 proceeds to step S305 and determines whether the driving support request condition C1 is met. The driving support request condition C1 is met when the execution of driving support control is requested. On the other hand, the driving support request condition C1 is not met when the stopping of driving support control is requested.

[0069] If the driver assistance request condition C1 is not met, the vehicle driver assistance system 10 determines "No" in step S305, proceeds directly to step S395, and terminates the processing of this routine. On the other hand, if the driver assistance request condition C1 is met, the vehicle driver assistance system 10 determines "Yes" in step S305, proceeds to step S310, and determines whether the intermittent driving request condition C2 is met. The intermittent driving request condition C2 is met when the execution of intermittent driving control is requested. On the other hand, the intermittent driving request condition C2 is not met when the stopping of intermittent driving control is requested.

[0070] If the intermittent driving requirement condition C2 is not met, the vehicle driving support system 10 determines "No" in step S310 and proceeds to step S340 to execute steady-state driving control. In this case, if there is a preceding vehicle 200, the vehicle driving support system 10 executes steady-state inter-vehicle distance control as steady-state driving control. On the other hand, if there is no preceding vehicle 200, the vehicle driving support system 10 executes steady-state vehicle speed control as steady-state driving control.

[0071] Next, the vehicle driving support system 10 proceeds to step S395 and terminates the processing of this routine.

[0072] On the other hand, if the intermittent driving requirement condition C2 is met, the vehicle driving support device 10 determines "Yes" in step S310, proceeds to step S315, and obtains driving support level L.

[0073] Next, the vehicle driving support device 10 proceeds to step S320 to set the target control range Rtgt.

[0074] Specifically, when the driver operates the support level setting device 53 to set the driving support level L to the strong support level Ls, the vehicle driving support system 10 sets the target vehicle speed control width WVtgt and the target inter-vehicle distance control width WDtgt to the expanded vehicle speed control width WVl and the expanded inter-vehicle distance control width WDl, respectively. As a result, the lower limit speed Vmin and the upper limit inter-vehicle distance Dmax are set to the low speed Vl and the long inter-vehicle distance Dl, respectively.

[0075] On the other hand, if the driver operates the support level setting device 53 to set the driving support level L to the medium support level Lm, the vehicle driving support device 10 sets the target vehicle speed control width WVtgt and the target inter-vehicle distance control width WDtgt to the standard vehicle speed control width WVb and the standard inter-vehicle distance control width WDb, respectively. As a result, the lower limit speed Vmin and the upper limit inter-vehicle distance Dmax are set to the standard speed Vb and the standard inter-vehicle distance Db, respectively.

[0076] Furthermore, when the driver operates the support level setting control 53 to set the driving support level L to the weak support level Lw, the vehicle driving support device 10 sets the target vehicle speed control width WVtgt and the target inter-vehicle distance control width WDtgt to the reduced vehicle speed control width WVs and the reduced inter-vehicle distance control width WDs, respectively. As a result, the lower limit speed Vmin and the upper limit inter-vehicle distance Dmax are set to the high speed Vh and the short inter-vehicle distance Ds, respectively.

[0077] Here, low speed Vl is a speed lower than standard speed Vb. High speed Vh is a speed higher than standard speed Vb. Long following distance Dl is a distance longer than standard following distance Db. Short following distance Ds is a distance shorter than standard following distance Db.

[0078] As a result, the target vehicle speed range RVtgt is set to a wider range when the strong support level Ls is set as the driver assistance level L than when the medium support level Lm is set as the driver assistance level L. Also, the target vehicle speed range RVtgt is set to a wider range when the medium support level Lm is set as the driver assistance level L than when the weak support level Lw is set as the driver assistance level L.

[0079] Similarly, the target inter-vehicle distance range RDtgt is set to a wider range when the strong support level Ls is set as the driver assistance level L than when the medium support level Lm is set as the driver assistance level L. Also, the target inter-vehicle distance range RDtgt is set to a wider range when the medium support level Lm is set as the driver assistance level L than when the weak support level Lw is set as the driver assistance level L.

[0080] Thus, when the driving assistance level L of the vehicle driving assistance system 10 is set to the first level (for example, strong assistance level Ls), the predetermined speed range (i.e., target vehicle speed range RVtgt) and predetermined distance range (i.e., target inter-vehicle distance range RDtgt) are set to a wider range compared to when the driving assistance level L is set to the second level which is lower than the first level (for example, medium assistance level Lm or weak assistance level Lw).

[0081] Next, the vehicle driving support system 10 proceeds to step S325 and executes intermittent driving control. At this time, if there is a preceding vehicle 200, the vehicle driving support system 10 executes intermittent distance control as intermittent driving control. On the other hand, if there is no preceding vehicle 200, the vehicle driving support system 10 executes intermittent vehicle speed control as intermittent driving control.

[0082] Next, the vehicle driving support system 10 proceeds to step S395 and terminates the processing of this routine.

[0083] The above describes the operation of the vehicle driving assistance device 10.

[0084] When intermittent driving control is in operation, a wider target vehicle speed range (RVtgt) tends to result in a greater reduction in driving energy consumption. Similarly, when intermittent driving control is in operation, a wider target inter-vehicle distance range (RDtgt) tends to result in a greater reduction in driving energy consumption. On the other hand, when the driver assistance level L is set to a high level, the driver of vehicle 100 desires a significant reduction in driving energy consumption.

[0085] According to the vehicle driving assistance system 10, when the driving assistance level L is set to a high level (for example, strong assistance level Ls), the target vehicle speed range RVtgt and the target inter-vehicle distance range RDtgt are set to a wider range compared to when the driving assistance level L is set to a low level (for example, medium assistance level Lm or weak assistance level Lw). Therefore, intermittent driving control can be performed in accordance with the driver's desire to reduce the driving energy consumption of the vehicle 100.

[0086] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention.

[0087] For example, there exists an appropriate acceleration for the vehicle 100 depending on the gradient of the road on which the vehicle 100 is traveling. Therefore, the vehicle driving support system 10 may be configured to set a target acceleration ARtgt and perform intermittent driving control so that the acceleration of the vehicle 100 is maintained at the target acceleration ARtgt. In this case, the vehicle driving support system 10 sets, for example, an appropriate acceleration according to the gradient of the road on which the vehicle 100 is traveling as the target acceleration ARtgt.

[0088] In particular, from the standpoint of minimizing energy consumption during driving, there is an appropriate acceleration for the vehicle 100 depending on the gradient of the road on which the vehicle 100 is traveling. Therefore, the vehicle driving support system 10 may be configured to set a target acceleration ARtgt and to perform power control so that the acceleration of the vehicle 100 is maintained at the target acceleration ARtgt. In this case as well, the vehicle driving support system 10 sets, for example, an appropriate acceleration according to the gradient of the road on which the vehicle 100 is traveling as the target acceleration ARtgt.

[0089] Furthermore, the vehicle driving support device 10 may be configured to limit the target acceleration ARtgt to less than or equal to the upper limit acceleration ARU, and to limit the target acceleration ARtgt to more than or equal to the lower limit acceleration ARL, when intermittent driving control is performed. In other words, the vehicle driving support device 10 may be configured to limit the acceleration of its own vehicle 100 to less than or equal to the upper limit acceleration ARU and more than or equal to the lower limit acceleration ARL, when intermittent driving control is performed.

[0090] In this case, if the target acceleration ARtgt is greater than the upper limit acceleration ARU, the vehicle driving support system 10 sets the upper limit acceleration ARU as the target acceleration ARtgt. On the other hand, if the target acceleration ARtgt is less than the lower limit acceleration ARL, the vehicle driving support system 10 sets the lower limit acceleration ARL as the target acceleration ARtgt. This prevents the acceleration of the vehicle 100 from becoming excessively large or excessively small.

[0091] Furthermore, in step S320, the vehicle driving support device 10 may be configured to set the target control range Rtgt, as well as the upper limit acceleration ARU and the lower limit acceleration ARL according to the driving support level L.

[0092] In this case, if the driver operates the support level setting device 53 to set the driving support level L to the strong support level Ls, the vehicle driving support system 10 sets the expanded upper acceleration ARUl and expanded lower acceleration ARLl as the upper and lower acceleration ARUl, respectively. The expanded upper acceleration ARUl is set to a value greater than the standard upper acceleration ARUb. Also, the expanded lower acceleration ARLl is set to a value less than the standard lower acceleration ARLb.

[0093] On the other hand, if the driver operates the support level setting device 53 to set the driving support level L to the medium support level Lm, the vehicle driving support device 10 sets the standard upper limit acceleration ARUb and standard lower limit acceleration ARLb as the upper limit acceleration ARU and lower limit acceleration ARL, respectively.

[0094] Furthermore, when the driver operates the support level setting device 53 to set the driving support level L to the weak support level Lw, the vehicle driving support system 10 sets the reduced upper acceleration ARUs and reduced lower acceleration ARLs as the upper and lower acceleration ARUs, respectively. The reduced upper acceleration ARUs is set to a value smaller than the standard upper acceleration ARUb. Also, the reduced lower acceleration ARLs is set to a value larger than the standard lower acceleration ARLb.

[0095] In other words, the vehicle driving support system 10 may be configured to set the upper limit acceleration ARU to a smaller value and the lower limit acceleration ARL to a larger value when the driving support level L is set to the second level (for example, weak support level Lw), compared to when the driving support level L is set to the first level (for example, medium support level Lm or strong support level Ls).

[0096] When the driver assistance level L is set to a low level, the driver of vehicle 100 wants the vehicle speed V to not change significantly.

[0097] According to the vehicle driving assistance system 10, when the driving assistance level L is set to a low level (for example, weak assistance level Lw), the upper limit acceleration ARU is set to a smaller value and the lower limit acceleration ARL is set to a larger value compared to when the driving assistance level L is set to a high level (for example, medium assistance level Lm or strong assistance level Ls). As a result, large changes in the vehicle speed V are suppressed. Therefore, intermittent driving control can be performed in accordance with the wishes of the driver of the vehicle 100. [Explanation of Symbols]

[0098] 10...Vehicle driving assistance system, 52...Intermittent driving control device, 53...Assistance level setting control device, 60...Vehicle speed detection device, 70...Surrounding information acquisition device, 90...ECU, 100...Own vehicle, 200...Preceding vehicle

Claims

1. A vehicle driving assistance system equipped with a control device that performs intermittent driving control to autonomously drive the vehicle as a driving assistance control, The aforementioned intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. The aforementioned intermittent vehicle speed control is a control method that autonomously alternates between power control, which powers the vehicle, and coasting control, which allows the vehicle to coast, so that the vehicle's speed remains within a predetermined speed range when no vehicle is present in front of it, thereby driving the vehicle. The intermittent inter-vehicle distance control is a control method that causes the vehicle to move by autonomously and repeatedly performing the power control and coasting control alternately so that the distance between the vehicle and the preceding vehicle remains within a predetermined distance range when the preceding vehicle is present. The level of driver assistance provided to the vehicle by the intermittent driving control is set by the operator of the vehicle. In a vehicle driving assistance system, The control device is configured such that when the driving assistance level is set to a first level, the predetermined speed range and the predetermined distance range are set to a wider range compared to when the driving assistance level is set to a second level which is lower than the first level. Vehicle driving assistance system.

2. In the vehicle driving support device according to claim 1, The control device is configured to limit the acceleration of the vehicle to a range between the upper limit acceleration and the lower limit acceleration when the intermittent driving control is performed. The control device is configured such that when the driving assistance level is set to the second level, it sets the upper limit acceleration to a smaller value and the lower limit acceleration to a larger value compared to when the driving assistance level is set to the first level. Vehicle driving assistance system.

3. A vehicle driving assistance method that performs intermittent driving control to autonomously drive the vehicle as a driving assistance control, The aforementioned intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. The aforementioned intermittent vehicle speed control is a control method that autonomously alternates between power control, which powers the vehicle, and coasting control, which allows the vehicle to coast, so that the vehicle's speed remains within a predetermined speed range when no vehicle is present in front of it, thereby driving the vehicle. The intermittent inter-vehicle distance control is a control method that causes the vehicle to move by autonomously and repeatedly performing the power control and coasting control alternately so that the distance between the vehicle and the preceding vehicle remains within a predetermined distance range when the preceding vehicle is present. The level of driver assistance provided to the vehicle by the intermittent driving control is set by the operator of the vehicle. In vehicle driving assistance methods, When the driving assistance level is set to a first level, the process includes setting the predetermined speed range and the predetermined distance range to a wider range compared to when the driving assistance level is set to a second level which is lower than the first level. Vehicle driving assistance methods.

4. A vehicle driving assistance program that performs intermittent driving control to autonomously drive the vehicle as a driving assistance control, The aforementioned intermittent driving control includes intermittent vehicle speed control and intermittent inter-vehicle distance control. The aforementioned intermittent vehicle speed control is a control method that autonomously alternates between power control, which powers the vehicle, and coasting control, which allows the vehicle to coast, so that the vehicle's speed remains within a predetermined speed range when no vehicle is present in front of it, thereby driving the vehicle. The intermittent inter-vehicle distance control is a control method that causes the vehicle to move by autonomously and repeatedly performing the power control and coasting control alternately so that the distance between the vehicle and the preceding vehicle remains within a predetermined distance range when the preceding vehicle is present. The level of driver assistance provided to the vehicle by the intermittent driving control is set by the operator of the vehicle. In the vehicle driving assistance program, When the driving assistance level is set to the first level, the predetermined speed range and the predetermined distance range are configured to be set to a wider range compared to when the driving assistance level is set to the second level, which is lower than the first level. Vehicle driving assistance program.

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