Vehicle driving support device

Abstract

To provide a vehicle driving support device capable of suppressing a driver of an adjacent vehicle from feeling troublesomeness due to repeated coasting and powering of an own vehicle.SOLUTION: The vehicle driving support device 10 executes automatic traveling control for causing the own vehicle 100 to travel while repeating powering and coasting of the own vehicle 100. When the coasting stop condition is satisfied while the host vehicle is coasting, the vehicle driving assistance device stops the coasting of the host vehicle. The coast stop condition is a condition that the neighboring vehicle 300 is present in the coast stop area. The adjacent vehicle is another vehicle traveling in an adjacent lane adjacent to the lane in which the host vehicle is traveling in the same direction as the traveling direction of the host vehicle. The coasting stop area includes an area of the adjacent lane directly beside the own vehicle, and is composed of an area of the adjacent lane within a first distance from the own vehicle in the forward direction and an area of the adjacent lane within a second distance from the own vehicle in the rearward direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle driving assistance device. [Background technology]

[0002] BACKGROUND ART A vehicle driving assistance device is known that includes a control device that executes automatic driving control to make the host vehicle travel by repeatedly powering and coasting the host vehicle (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-134925 Summary of the Invention

[0004] When automatic cruise control is being executed to cause the host vehicle to travel while repeatedly powering and coasting, if another vehicle (adjacent vehicle) traveling in an adjacent lane is present near the host vehicle, a situation may occur in which the adjacent vehicle overtakes the host vehicle while the host vehicle is coasting, and then the host vehicle begins powering immediately thereafter, causing the host vehicle to overtake the adjacent vehicle. If such a situation occurs repeatedly, it may be annoyed to the driver of the adjacent vehicle.

[0005] An object of the present invention is to provide a vehicle driving assistance device that can prevent the driver of an adjacent vehicle from feeling annoyed due to the vehicle's repeated coasting and powering.

[0006] A vehicle driving assistance device according to the present invention includes a control device that executes automatic driving control for causing a host vehicle to travel while repeatedly powering and coasting. The control device is configured to stop coasting of the host vehicle if a coasting stop condition is met while the host vehicle is coasting. The coasting stop condition is a condition in which an adjacent vehicle is present in a coasting stop area. The adjacent vehicle is another vehicle traveling in an adjacent lane next to the lane in which the host vehicle is traveling in the same direction as the host vehicle. The coasting stop area includes an area of ​​the adjacent lane directly to the side of the host vehicle, and is composed of an area of ​​the adjacent lane within a first distance ahead of the host vehicle and an area of ​​the adjacent lane within a second distance behind the host vehicle.

[0007] When automatic cruise control is being executed, if there is an adjacent vehicle near the host vehicle, a situation may occur in which the adjacent vehicle overtakes the host vehicle while the host vehicle is coasting, and then the host vehicle starts powering immediately thereafter, causing the host vehicle to overtake the adjacent vehicle. If such a situation occurs repeatedly, it may cause annoyance to the driver of the adjacent vehicle.

[0008] According to the vehicle driving assistance device of the present invention, when automatic cruise control is being executed, if an adjacent vehicle is present near the host vehicle (i.e., if a coasting cancellation condition is met), coasting of the host vehicle is stopped. This makes it possible to avoid the occurrence of the situation described above. This makes it possible to prevent the driver of the adjacent vehicle from feeling annoyed by repeated coasting and powering of the host vehicle.

[0009] In the vehicle driving assistance device according to the present invention, the coasting cancellation condition may be a condition that the adjacent vehicle is present in the coasting cancellation area and the traveling speed of the adjacent vehicle is within a coasting cancellation speed range.

[0010] This makes it possible to determine whether or not to stop coasting of the vehicle while taking into consideration the traveling speed of the adjacent vehicle.

[0011] In the vehicle driving assistance device according to the present invention, the control device may be configured to set upper and lower limit values ​​for the traveling speed of the host vehicle when the automatic traveling control is being executed, to stop powering the host vehicle and start coasting the host vehicle when the traveling speed of the host vehicle increases and reaches the upper limit value while powering the host vehicle when the automatic traveling control is being executed, and to stop coasting the host vehicle and start coasting the host vehicle when the traveling speed of the host vehicle decreases and reaches the lower limit value while coasting the host vehicle. In this case, the cancellation speed range may be a range from the upper limit value to the lower limit value.

[0012] According to this, coasting control can be stopped only when there is a relatively high possibility that the driver of an adjacent vehicle will feel annoyed by the first automatic driving control repeatedly coasting and powering the vehicle.

[0013] In the vehicle driving assistance device according to the present invention, the control device may be configured to not switch the driving state of the host vehicle from the powered state to the coasting state if a switch prohibition condition is satisfied when a switch condition for switching the driving state of the host vehicle from the powered state to the coasting state is satisfied. In this case, the switch prohibition condition may be a condition that the adjacent vehicle is present in a switch prohibition area. In this case, the switch prohibition area includes the adjacent lane area directly to the side of the host vehicle, and is composed of the adjacent lane area within a third distance forward from the host vehicle that is longer than the first distance, and the adjacent lane area within a fourth distance rearward from the host vehicle that is longer than the second distance.

[0014] When automatic cruise control is being executed, an adjacent vehicle may not be in the coasting cancellation zone, but may be near the coasting cancellation zone. In this case, the adjacent vehicle may enter the coasting cancellation zone immediately after the host vehicle starts coasting. If the adjacent vehicle enters the coasting cancellation zone, the host vehicle will stop coasting and start powering. This will actually increase the amount of energy consumed to drive the host vehicle.

[0015] According to the vehicle driving assistance device of the present invention, when automatic driving control is being executed, if the adjacent vehicle is not in the coasting cancellation area but is near the coasting cancellation area (i.e., if the switching prohibition condition is met), coasting of the host vehicle is not started. Therefore, the amount of energy consumed to drive the host vehicle can be kept small.

[0016] Furthermore, in the vehicle driving assistance device according to the present invention, the control device may be configured to set upper and lower limit values ​​for the traveling speed of the host vehicle when the automatic traveling control is being executed and there is no preceding vehicle, and to stop powering the host vehicle and start coasting the host vehicle when the traveling speed of the host vehicle increases and reaches the upper limit value while the host vehicle is powering and there is no preceding vehicle when the automatic traveling control is being executed and there is no preceding vehicle, and to stop coasting the host vehicle and start coasting the host vehicle when the traveling speed of the host vehicle decreases and reaches the lower limit value while the host vehicle is coasting. In this case, the switching prohibition condition may be a condition that the preceding vehicle is not present and the adjacent vehicle is present in the switching prohibition area and the adjacent vehicle is an adjacent vehicle traveling in front of the host vehicle and the traveling speed of the adjacent vehicle is slower than the average value of the upper limit value and the lower limit value, or that the preceding vehicle is not present and the adjacent vehicle is present in the switching prohibition area and the adjacent vehicle is an adjacent vehicle traveling behind the host vehicle and the traveling speed of the adjacent vehicle is faster than the average value.

[0017] This makes it possible to prohibit switching of the driving control for the vehicle from powering control to coasting control only when there is a relatively high possibility that the adjacent vehicle will enter the coasting suspension area within a relatively short time after the driving control for the vehicle is switched from powering control to coasting control.

[0018] The components of the present invention are not limited to the embodiments of the present invention described below with reference to the drawings. Other objects, features, and attendant advantages of the present invention will be easily understood from the description of the embodiments of the present invention. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram showing a vehicle driving assistance device according to an embodiment of the present invention. [Figure 2] FIG. 2 shows a scene in which a preceding vehicle is present. [Figure 3] FIG. 3 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention. [Figure 6] FIG. 6 is a diagram showing a coasting stop region. [Figure 7] FIG. 7 is a diagram showing a switching prohibition area. [Figure 8] FIG. 8 is a diagram showing the rear area after coasting has stopped. [Figure 9] FIG. 9 is a diagram showing the switching prohibition rear area. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a vehicle driving assistance device, a vehicle driving assistance method, and a vehicle driving assistance program according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows a vehicle driving assistance device 10 according to an embodiment of the present invention.

[0021] The vehicle driving assistance device 10 is mounted on the host vehicle 100. Hereinafter, the vehicle driving assistance device 10 will be described using as an example a case where the operator of the host vehicle 100 is a person who gets into the host vehicle 100 and drives the host vehicle 100 (i.e., the driver of the host vehicle 100). However, the operator of the host vehicle 100 may also be a person who drives the host vehicle 100 remotely without getting into the host vehicle 100 (i.e., a remote operator of the host vehicle 100). The present invention is also applicable to vehicles that run by automatic driving without requiring driving by a driver or a remote operator.

[0022] As shown in FIG. 1, the vehicle driving assistance device 10 includes an ECU (electronic control unit) 90 as a control device. The ECU 90 includes a microcomputer as a main component. The microcomputer includes a CPU, a computer-readable storage medium such as a ROM, a RAM, and a non-volatile memory, as well as an interface. The CPU executes instructions, programs, or routines stored in the storage medium to realize various functions. In particular, in this example, the vehicle driving assistance device 10 stores programs in the storage medium that realize various controls executed by the vehicle driving assistance device 10.

[0023] In this example, the vehicle driving assistance device 10 includes only one ECU 90. However, the vehicle driving assistance device 10 may be configured to include multiple ECUs, with each ECU performing a respective function of the vehicle driving assistance device 10 described below. Furthermore, the vehicle driving assistance device 10 may be configured to be able to update a program stored in a storage medium via wireless communication with an external device (for example, via the Internet).

[0024] The host vehicle 100 is equipped with a power unit 20, a braking unit 30, a host vehicle speed detection unit 40, and a surrounding information detection unit 50.

[0025] The power unit 20 is a device that generates driving force to be applied to the host vehicle 100 (particularly, the drive wheels of the host vehicle 100). In this example, the power unit 20 includes an internal combustion engine 21 and an electric motor 22. The power unit 20 is electrically connected to the ECU 90. The vehicle driving assistance device 10 can control the driving force to be applied to the host vehicle 100 by controlling the operation of 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 (particularly, the wheels of the host vehicle 100). In this example, the braking device 30 is equipped with a hydraulic brake device 31. The braking device 30 is electrically connected to the ECU 90. The vehicle driving assistance device 10 can control the braking force applied to the host vehicle 100 by controlling the operation of the hydraulic brake device 31.

[0027] The host vehicle speed detection device 40 is a device that detects the traveling speed of the host vehicle 100. The host vehicle speed detection device 40 is, for example, a wheel speed sensor provided on each wheel of the host vehicle 100. The host vehicle speed detection device 40 is electrically connected to the ECU 90. The vehicle driving assistance device 10 acquires the traveling speed of the host vehicle 100 as the host vehicle speed Vego using the host vehicle speed detection device 40.

[0028] The surrounding information detection device 50 is a device that detects information about the surroundings of the host vehicle 100. In this example, the surrounding information detection device 50 includes an electromagnetic wave sensor 51 and an image sensor 52. The surrounding information detection device 50 is electrically connected to the ECU 90. The electromagnetic wave sensor 51 is, for example, a radar sensor such as a millimeter wave radar. The vehicle driving assistance device 10 acquires information about objects present in the surroundings of the host vehicle 100 as surrounding information IS using the electromagnetic wave sensor 51. Furthermore, the image sensor 52 is, for example, a camera sensor. The vehicle driving assistance device 10 acquires image information about the surroundings of the host vehicle 100 as surrounding information IS using the image sensor 52.

[0029] 2, when a preceding vehicle 200 is present, the vehicle driving assistance device 10 acquires the distance between the preceding vehicle 200 and the host vehicle 100 as the preceding vehicle distance Dfw based on the surrounding information IS. The preceding vehicle 200 is another vehicle traveling in the host vehicle lane LN_O immediately before the host vehicle 100, and is another vehicle present in the region of the host vehicle lane LN_O within a predetermined distance Dfw_th from the host vehicle 100.

[0030] <Operation of vehicle driving assistance device> Next, we will explain the operation of the vehicle driving assistance device 10. The vehicle driving assistance device 10 is configured to execute automatic driving control in response to a request from the driver of the vehicle 100. The automatic driving control includes a first automatic driving control and a second automatic driving control.

[0031] When the driver requests the execution of the first automatic driving control, the vehicle driving assistance device 10 starts the first automatic driving control. The first automatic driving control includes a first vehicle speed control and a second inter-vehicle distance control.

[0032] The first vehicle speed control is one type of automatic cruise control that causes the host vehicle 100 to travel while repeatedly powering and coasting the host vehicle 100. In this example, the first vehicle speed control causes the host vehicle 100 to travel while alternately repeating powering control and coasting control so that the host vehicle speed Vego is maintained at a speed within a predetermined vehicle speed range RV. More specifically, the first vehicle speed control stops the powering control and starts coasting control when the host vehicle speed Vego increases during powering control and reaches an upper limit of the predetermined vehicle speed range RV (upper limit vehicle speed Vmax), and stops the coasting control and starts powering control when the host vehicle speed Vego decreases during coasting control and reaches a lower limit of the predetermined vehicle speed range RV (lower limit vehicle speed Vmin). The first vehicle speed control is executed when execution of the first automatic cruise control is requested and no preceding vehicle 200 is present.

[0033] The first inter-vehicle distance control is also one of the automatic travel controls that causes the host vehicle 100 to travel while repeatedly powering and coasting. In this example, the first inter-vehicle distance control causes the host vehicle 100 to travel while alternately repeating powering control and coasting control so that the preceding vehicle distance Dfw is maintained within a predetermined inter-vehicle distance range RD. More specifically, the first inter-vehicle distance control stops powering control and starts coasting control when the preceding vehicle distance Dfw decreases during powering control and reaches the lower limit of the predetermined inter-vehicle distance range RD (lower limit inter-vehicle distance Dmin), and stops coasting control and starts powering control when the preceding vehicle distance Dfw increases during coasting control and reaches the upper limit of the predetermined inter-vehicle distance range RD (upper limit inter-vehicle distance Dmax). The first inter-vehicle distance control is executed when execution of the first automatic travel control is requested and a preceding vehicle 200 is present.

[0034] Furthermore, when an upper limit vehicle speed Vmax and a lower limit vehicle speed Vmin are set as described below even when a preceding vehicle 200 is present, the first inter-vehicle distance control may be configured to stop powering control and start coasting control if the preceding vehicle distance Dfw becomes smaller during powering control and the host vehicle speed Vego reaches the upper limit vehicle speed Vmax before the preceding vehicle distance Dfw reaches the lower limit vehicle speed Dmin, and to stop coasting control and start powering control if the preceding vehicle distance Dfw becomes larger during coasting control and the host vehicle speed Vego reaches the lower limit vehicle speed Vmin before the preceding vehicle distance Dmax is reached.

[0035] On the other hand, when the driver requests the execution of the second automatic driving control, the vehicle driving assistance device 10 starts the second automatic driving control. The second automatic driving control includes a second vehicle speed control and a second inter-vehicle distance control.

[0036] The second vehicle speed control is a control for maintaining the host vehicle speed Vego at the set vehicle speed Vset when there is no preceding vehicle 200. Therefore, the second vehicle speed control is a so-called constant speed cruise control. The set vehicle speed Vset is a speed set by the driver as a target value for the host vehicle speed Vego in the automatic cruise control.

[0037] The second inter-vehicle distance control is a control for maintaining the preceding vehicle distance Dfw at the set inter-vehicle distance Dset when the preceding vehicle 200 is present. Therefore, the second inter-vehicle distance control is a so-called follow-up cruise control. The set inter-vehicle distance Dset is a distance set by the driver as a target value for the preceding vehicle distance Dfw in the automatic cruise control.

[0038] The vehicle driving assistance device 10 sets an upper limit inter-vehicle distance Dmax and a lower limit inter-vehicle distance Dmin, and sets an upper limit vehicle speed Vmax and a lower limit vehicle speed Vmin, in accordance with conditions that are established while the first automatic driving control is being executed, by executing the routine shown in Fig. 3 at predetermined time intervals. Furthermore, the vehicle driving assistance device 10 selectively executes powering control and coasting control, cancels coasting control, or prohibits switching of the driving control for the host vehicle 100 from powering control to coasting control, in accordance with conditions that are established while the first automatic driving control is being executed, by executing the routine shown in Fig. 4 at predetermined time intervals.

[0039] 3, the vehicle driving assistance device 10 starts the process from step S300, and then proceeds to step S305 to determine whether the first automatic driving control is being executed. If the determination in step S305 is "No," the vehicle driving assistance device 10 proceeds directly to step S395 and temporarily ends the process of this routine.

[0040] On the other hand, if the determination in step S305 is "Yes," the vehicle driving assistance device 10 proceeds to step S310 and determines whether or not there is a preceding vehicle 200. The vehicle driving assistance device 10 determines whether or not there is a preceding vehicle 200 based on the surrounding information IS.

[0041] If the determination in step S310 is "Yes," the vehicle driving assistance device 10 proceeds to step S315, where it acquires the target inter-vehicle distance Dfw_tgt and the target inter-vehicle distance width Wd.

[0042] The target inter-vehicle distance Dfw_tgt may be a distance equal to the set inter-vehicle distance Dset, but in this example, it is a distance obtained by subtracting a predetermined distance ΔD from the set inter-vehicle distance Dset (Dfw_tgt=Dset-ΔD). The predetermined distance ΔD may be a constant distance or a distance corresponding to the set inter-vehicle distance Dset. Furthermore, the target inter-vehicle distance width Wd determines the range within which the preceding inter-vehicle distance Dfw is controlled when the first inter-vehicle distance control is executed. The target inter-vehicle distance width Wd may be a constant value or a value corresponding to the set inter-vehicle distance Dset.

[0043] Next, the vehicle driving assistance device 10 proceeds to step S320 to set the upper limit inter-vehicle distance Dmax and the lower limit inter-vehicle distance Dmin. Next, the vehicle driving assistance device 10 proceeds to step S395 to temporarily end the processing of this routine.

[0044] In this example, the lower limit inter-vehicle distance Dmin is the target inter-vehicle distance Dfw_tgt (Dmin=Dfw_tgt), and the upper limit inter-vehicle distance Dmax is the target inter-vehicle distance Dfw_tgt plus the target inter-vehicle distance width Wd (Dmax=Dfw_tgt+Wd).

[0045] In step S320, the vehicle driving assistance device 10 may be configured to set an upper limit vehicle speed Vmax and a lower limit vehicle speed Vmin in addition to setting the upper limit vehicle distance Dmax and the lower limit vehicle distance Dmin. In this case, the upper limit vehicle speed Vmax is the target vehicle speed Vtgt (Vmax = Vtgt). The lower limit vehicle speed Vmin is the speed obtained by subtracting the target vehicle speed width Wv from the target vehicle speed Vtgt (Vmin = Vtgt - Wv).

[0046] On the other hand, if the determination in step S310 is "No," the vehicle driving assistance device 10 proceeds to step S315, where it acquires the target vehicle speed Vtgt and the target vehicle speed range Wv.

[0047] The target vehicle speed Vtgt may be equal to the set vehicle speed Vset, but in this example, it is the set vehicle speed Vset minus a predetermined speed ΔV (Vtgt=Vset−ΔV). The predetermined speed ΔV may be a constant speed or a speed corresponding to the set vehicle speed Vset. The target vehicle speed range Wv determines the range within which the host vehicle speed Vego is controlled when the first vehicle speed control is executed. The target vehicle speed range Wv may be a constant value or a value corresponding to the set vehicle speed Vset.

[0048] Next, the vehicle driving assistance system 10 proceeds to step S330 to set the upper limit vehicle speed Vmax and the lower limit vehicle speed Vmin. Next, the vehicle driving assistance system 10 proceeds to step S395 to temporarily end the processing of this routine.

[0049] In this example, the upper limit vehicle speed Vmax is the target vehicle speed Vtgt (Vmax=Vtgt), and the lower limit vehicle speed Vmin is the target vehicle speed Vtgt minus the target vehicle speed width Wv (Vmin=Vtgt-Wv).

[0050] 4, the vehicle driving assistance device 10 starts the process from step S400, and proceeds to step S405 to determine whether the first automatic driving control is being executed. If the determination in step S405 is "No," the vehicle driving assistance device 10 proceeds directly to step S495 and temporarily ends the process of this routine.

[0051] On the other hand, if the vehicle driving assistance device 10 determines "Yes" in step S405, the process proceeds to step S410, where it determines whether coasting control is being executed. If the vehicle driving assistance device 10 determines "Yes" in step S410, the process proceeds to step S415, where it determines whether coasting termination condition C1 is satisfied.

[0052] The coasting cancellation condition C1 is a condition for determining whether or not to cancel coasting control, and in this example, is a condition that an adjacent vehicle 300 is present in the coasting cancellation area AS. Here, as shown in FIG. 6, the adjacent vehicle 300 is another vehicle traveling in the adjacent lane LN_N in the same direction as the traveling direction of the host vehicle 100. The adjacent lane LN_N is a lane adjacent to the host lane LN_O. The host lane LN_O is the lane in which the host vehicle 100 is traveling.

[0053] In addition, the coasting stop area AS includes the area of ​​the adjacent lane LN_N directly to the side of the host vehicle 100, and consists of the area of ​​the adjacent lane LN_N within a first distance D1 forward from the host vehicle 100 (particularly, the front end of the host vehicle 100) and the area of ​​the adjacent lane LN_N within a second distance D2 rearward from the host vehicle 100 (particularly, the front end of the host vehicle 100).

[0054] In this example, the first distance D1 is the first basic distance D11 plus the first stopping distance D12 (D1 = D11 + D12). In this example, the first basic distance D11 is set to a constant distance. The first stopping distance D12 is set according to the host vehicle speed Vego, the upper limit vehicle speed Vmax, the acceleration Gego, and the preceding adjacent vehicle speed Vnext_fw, and is calculated, for example, by the following formula 1. The acceleration Gego is the acceleration of the host vehicle 100 when the host vehicle 100 is traveling under powering control, or when the host vehicle 100 is traveling under coasting control and the acceleration Gego of the host vehicle 100 is a positive value. The preceding adjacent vehicle speed Vnext_fw is the traveling speed of the adjacent vehicle 300 traveling ahead of the host vehicle 100.

[0055] D12=((Vmax-Vego) / Gego)·((Vego+Vmax) / 2-Vnext_fw) …(1)

[0056] In this example, the second distance D2 is the second basic distance D21 plus the second stopping distance D22 (D2 = D21 + D22). In this example, the second basic distance D21 is set to a fixed distance. The second stopping distance D22 is set according to the host vehicle speed Vego, the upper limit vehicle speed Vmax, the acceleration Gego, and the following adjacent vehicle speed Vnext_rw, and is calculated, for example, using the following equation 2. The following adjacent vehicle speed Vnext_rw is the traveling speed of the adjacent vehicle 300 traveling behind the host vehicle 100.

[0057] D22=((Vmax-Vego) / Gego)·(Vnext_rw-(Vego+Vmax) / 2) …(2)

[0058] The first distance D1 and the second distance D2 may be equal to each other or may be different from each other.

[0059] In this example, in addition to the coasting cancellation area AS, a switching prohibition area AF is also set. As shown in Fig. 7 , the switching prohibition area AF includes the area of ​​the adjacent lane LN_N directly beside the host vehicle 100, and is made up of the area of ​​the adjacent lane LN_N within a third distance D3 forward from the host vehicle 100 (particularly, the front end of the host vehicle 100), which is longer than the first distance D1, and the area of ​​the adjacent lane LN_N within a fourth distance D4 rearward from the host vehicle 100 (particularly, the front end of the host vehicle 100), which is longer than the second distance D2.

[0060] In this example, the third distance D3 is the first distance D1 plus a third prohibited distance D31 (D3 = D1 + D31). The third prohibited distance D31 is set according to the upper limit vehicle speed Vmax, the lower limit vehicle speed Vmin, the adjacent vehicle speed ahead Vnext_fw, and the minimum coasting time Tmin, and is calculated, for example, by the following formula 3. Note that the minimum coasting time Tmin is the shortest period of time for which coasting control is desired to continue when the travel control for the host vehicle 100 is switched from powering control to coasting control, from the viewpoint of minimizing the amount of energy consumed to travel the host vehicle 100 as much as possible.

[0061] D31=-(Vnext_fw-(Vmax+Vmin) / 2)·Tmin …(3)

[0062] When the adjacent forward vehicle speed Vnext_fw is equal to or greater than the average host vehicle speed Vego_ave, the third prohibited distance D31 calculated by equation 3 becomes a value equal to or less than zero, but in this case, the third prohibited distance D31 is set to 0. The average host vehicle speed Vego_ave represents the host vehicle speed Vego while the host vehicle 100 is traveling under coasting control, and is the average value of the upper limit vehicle speed Vmax and the lower limit vehicle speed Vmin (Vego_ave=(Vmax+Vmin) / 2).

[0063] In this example, the fourth distance D4 is the second distance D2 plus a fourth prohibited distance D41 (D4=D2+D41). The fourth prohibited distance D41 is set according to the upper limit vehicle speed Vmax, the lower limit vehicle speed Vmin, the adjacent vehicle speed Vnext_rw behind, and the minimum coasting time Tmin, and is calculated, for example, by the following formula 4.

[0064] D41=(Vnext_rw-(Vmax+Vmin) / 2)·Tmin …(4)

[0065] When the following adjacent vehicle speed Vnext_rw is equal to or less than the average host vehicle speed Vego_ave, the fourth prohibited distance D41 calculated by equation 4 is equal to or less than zero. In this case, the fourth prohibited distance D41 is set to zero.

[0066] Furthermore, the third distance D3 and the fourth distance D4 may be equal to each other or may be different from each other.

[0067] Alternatively, the coasting cancellation condition C1 may be a condition that the adjacent vehicle 300 is present in the coasting cancellation area AS and that the traveling speed of the adjacent vehicle 300 is within the coasting cancellation speed range RS. In this case, the cancellation speed range RS is, for example, a range with an upper limit vehicle speed Vmax as its upper limit and a lower limit vehicle speed Vmin as its lower limit. In other words, the cancellation speed range RS is the range from the upper limit vehicle speed Vmax to the lower limit vehicle speed Vmin. When the coasting cancellation condition C1 is set in this manner, the coasting control can be cancelled only when there is a relatively high possibility that the driver of the adjacent vehicle 300 will be annoyed by the first automatic cruise control repeatedly coasting and powering the host vehicle 100.

[0068] Furthermore, the coasting suspension area AS may include a coasting suspension rear area ASR. As shown in Fig. 8, the coasting suspension rear area ASR is an area of ​​the host vehicle 100's lane LN_O that is within a fifth distance D5 rearward from the host vehicle 100 (particularly, the front end of the host vehicle 100). In this case, the coasting suspension condition C1 is a condition that an adjacent vehicle 300 or a following vehicle 400 is present in the coasting suspension area AS. The following vehicle 400 is another vehicle traveling on the host vehicle lane LN_O immediately behind the host vehicle 100, and is present in an area of ​​the host vehicle lane LN_O that is within a predetermined distance Drw_th from the host vehicle 100.

[0069] In this example, the fifth distance D5 is the fifth basic distance D51 plus the fifth stopping distance D52 (D5 = D51 + D52). In this example, the fifth basic distance D51 is set to a fixed distance. The fifth stopping distance D52 is set according to the host vehicle speed Vego, the upper limit vehicle speed Vmax, the acceleration Gego, and the following vehicle speed Vrw, and is calculated, for example, by the following formula 5. The following vehicle speed Vrw is the traveling speed of the following vehicle 400.

[0070] D52=((Vmax-Vego) / Gego)·(Vrw-(Vego+Vmax) / 2) …(5)

[0071] The fifth distance D5 may be equal to or different from the second distance D2.

[0072] The switching prohibited area AF may also include a switching prohibited rear area AFR, which is an area of ​​the own lane LN_O that is within a sixth distance D6, which is longer than the fifth distance D5, rearward from the own vehicle 100 (particularly the front end of the own vehicle 100), as shown in FIG.

[0073] In this example, the sixth distance D6 is the fifth distance D5 plus a sixth prohibited distance D61 (D6 = D5 + D61). The sixth prohibited distance D61 is set according to the following vehicle speed Vrw, upper limit vehicle speed Vmax, lower limit vehicle speed Vmin, and minimum coasting time Tmin, and is calculated, for example, by the following formula 6.

[0074] D61=(Vrw-(Vmax+Vmin) / 2)·Tmin …(6)

[0075] When the following vehicle speed Vrw is equal to or less than the average host vehicle speed Vego_ave, the sixth prohibition distance D61 calculated by equation 6 is a value equal to or less than zero, and in this case, the sixth prohibition distance D61 is set to zero.

[0076] Furthermore, the sixth distance D6 may be equal to or different from the fourth distance D4.

[0077] Furthermore, the vehicle driving assistance device 10 determines whether or not a coasting stop condition C1 is met based on the surrounding information IS.

[0078] If the vehicle driving assistance device 10 determines "Yes" in step S415, the process proceeds to step S420 and stops the coasting control. Next, the vehicle driving assistance device 10 proceeds to step S425 and starts the second automatic driving control. Next, the vehicle driving assistance device 10 proceeds to step S495 and temporarily ends the processing of this routine.

[0079] In this way, the vehicle driving assistance device 10 is configured to stop the coasting of the host vehicle 100 if the coasting stop condition C1 is met while the host vehicle 100 is coasting.

[0080] When the second automatic driving control is started in step S425, the vehicle driving assistance device 10 continues the second automatic driving control unless the driver requests the execution of the first automatic driving control again.

[0081] On the other hand, if the determination in step S415 is "No," the vehicle driving assistance device 10 proceeds to step S430 and determines whether or not the switching condition C2 is satisfied.

[0082] The switching condition C2 in step S430 is a condition that, when the first inter-vehicle distance control is being executed, the distance Dfw between the preceding vehicle increases and reaches the upper limit inter-vehicle distance Dmax, and when the first vehicle speed control is being executed, the host vehicle speed Vego decreases and reaches the lower limit vehicle speed Vmin. Note that, in step S430, the vehicle driving assistance device 10 determines whether the switching condition C2 is satisfied based on the surrounding information IS.

[0083] If the determination in step S430 is "Yes," the vehicle driving assistance device 10 proceeds to step S435, where it stops the coasting control and starts the powering control. That is, the vehicle driving assistance device 10 switches the driving control for the host vehicle 100 from the coasting control to the powering control. Next, the vehicle driving assistance device 10 proceeds to step S495, where it temporarily ends the processing of this routine.

[0084] On the other hand, if the determination in step S430 is "No," the vehicle driving assistance device 10 proceeds to step S440, where the coasting control continues. Next, the vehicle driving assistance device 10 proceeds to step S495, where the processing of this routine is temporarily ended.

[0085] If the vehicle driving assistance device 10 determines "No" in step S410, the process proceeds to step S505 of the routine shown in Fig. 5, where it determines whether or not the switching condition C2 is satisfied. The switching condition C2 in step S505 is a condition that, if the first inter-vehicle distance control is being executed, the distance Dfw between the preceding vehicles has shortened to reach the lower limit inter-vehicle distance Dmin, and a condition that, if the first vehicle speed control is being executed, the host vehicle speed Vego has increased to reach the upper limit vehicle speed Vmax. In step S505, the vehicle driving assistance device 10 determines whether or not the switching condition C2 is satisfied based on the surrounding information IS.

[0086] If the determination in step S505 is "Yes," the vehicle driving assistance device 10 proceeds to step S510 and determines whether or not the switching prohibition condition C3 is satisfied.

[0087] The switching prohibition condition C3 is a condition for determining whether or not the driving control for the host vehicle 100 is to be switched from powering control to coasting control, and in this example, is a condition that the adjacent vehicle 300 is present in the switching prohibition area AF.

[0088] In addition, the switching prohibition condition C3 may be a condition in which the adjacent vehicle 300 is present in the switching prohibition area AF, the adjacent vehicle 300 is traveling in front of the host vehicle 100, and the traveling speed of the adjacent vehicle 300 (forward adjacent vehicle speed Vnext_fw) is slower than the average host vehicle speed Vego_ave, or a condition in which the adjacent vehicle 300 is present in the switching prohibition area AF, the adjacent vehicle 300 is traveling behind the host vehicle 100, and the traveling speed of the adjacent vehicle 300 (rear adjacent vehicle speed Vnext_rw) is faster than the average host vehicle speed Vego_ave.

[0089] When the switching prohibition condition C3 is set in this manner, the switching of the driving control for the vehicle 100 from powering control to coasting control can be prohibited only when there is a relatively high possibility that the adjacent vehicle 300 will enter the coasting suspension area AS within a relatively short period of time after the driving control for the vehicle 100 is switched from powering control to coasting control.

[0090] The vehicle driving assistance device 10 determines whether or not the switching prohibition condition C3 is satisfied based on the surrounding information IS.

[0091] If the vehicle driving assistance device 10 determines "Yes" in step S510, the vehicle driving assistance device 10 proceeds to step S515 and stops the first automatic driving control. That is, the vehicle driving assistance device 10 prohibits switching of the driving control for the host vehicle 100 from powering control to coasting control. Next, the vehicle driving assistance device 10 proceeds to step S520 and starts the second automatic driving control. Next, the vehicle driving assistance device 10 proceeds to step S595 and temporarily ends the processing of this routine.

[0092] In this way, when the switching condition C2 for switching the driving state of the vehicle 100 from a state in which the vehicle 100 is powered to a state in which the vehicle 100 is coasting is satisfied, if the switching prohibition condition C3 is satisfied, the vehicle driving assistance device 10 is configured not to switch the driving state of the vehicle 100 from a state in which the vehicle 100 is powered to a state in which the vehicle 100 is coasting.

[0093] When the second automatic driving control is started in step S520, the vehicle driving assistance device 10 continues the second automatic driving control unless the driver requests the execution of the first automatic driving control again.

[0094] On the other hand, if the vehicle driving assistance device 10 determines "No" in step S510, the process proceeds to step S525, where the powering control is stopped and coasting control is started. That is, the vehicle driving assistance device 10 switches the driving control for the host vehicle 100 from powering control to coasting control. Next, the vehicle driving assistance device 10 proceeds to step S595, where the process of this routine is temporarily ended.

[0095] If the determination in step S505 is "No," the vehicle driving assistance device 10 proceeds to step S535, where the powering control continues. Next, the vehicle driving assistance device 10 proceeds to step S595, where the processing of this routine ends.

[0096] The operation of the vehicle driving assistance device 10 is as described above.

[0097] In this way, unless the coasting stop condition C1 and the switching prohibition condition C3 are satisfied, the vehicle driving assistance device 10 is configured to set an upper limit (upper limit vehicle speed Vmax) and a lower limit (lower limit vehicle speed Vmin) for the driving speed of the vehicle 100 when the automatic driving control is being executed and there is no preceding vehicle 200, and when the automatic driving control is being executed and there is no preceding vehicle 200, when the driving speed of the vehicle 100 increases while the vehicle 100 is powered and reaches the upper limit (upper limit vehicle speed Vmax), stop the powering of the vehicle 100 and start coasting the vehicle 100, and when the driving speed of the vehicle 100 decreases while the vehicle 100 is coasting and reaches the lower limit (lower limit vehicle speed Vmin), stop the coasting of the vehicle 100 and start coasting the vehicle 100.

[0098] Furthermore, unless the coasting stop condition C1 and the switching prohibition condition C3 are satisfied, the vehicle driving assistance device 10 is configured to set an upper limit value (upper limit inter-vehicle distance Dmax) and a lower limit value (lower limit inter-vehicle distance Dmin) for the preceding vehicle distance Dfw when the preceding vehicle 200 is present during execution of the automatic driving control, and when the preceding vehicle 200 is present during execution of the automatic driving control, when the preceding vehicle distance Dfw shortens while the host vehicle 100 is powered and reaches the lower limit value (lower limit inter-vehicle distance Dmin), stop powering of the host vehicle 100 and start coasting of the host vehicle 100, and when the preceding vehicle distance Dfw lengthens while the host vehicle 100 is coasting and reaches the upper limit value (upper limit inter-vehicle distance Dmax), stop coasting of the host vehicle 100 and start coasting of the host vehicle 100.

[0099] Furthermore, the vehicle driving assistance device 10 can prevent the driver of the adjacent vehicle 300 from feeling annoyed by the host vehicle 100 repeatedly coasting and powering.

[0100] That is, when the first automatic cruise control is being executed, if an adjacent vehicle 300 is present near the host vehicle 100, there is a possibility that the adjacent vehicle 300 will overtake the host vehicle 100 while the host vehicle 100 is coasting, and immediately thereafter the host vehicle 100 will start powering, causing the host vehicle 100 to overtake the adjacent vehicle 300. If such an event occurs repeatedly, there is a possibility that the driver of the adjacent vehicle 300 will feel annoyed.

[0101] According to the vehicle driving assistance device 10, when the first automatic cruise control is being executed, if an adjacent vehicle 300 is present near the host vehicle 100 (i.e., if the coasting cancellation condition C1 is met), coasting of the host vehicle 100 is stopped. This makes it possible to avoid the situation described above. This makes it possible to prevent the driver of the adjacent vehicle 300 from feeling annoyed by repeated coasting and powering of the host vehicle 100.

[0102] Furthermore, the vehicle driving assistance device 10 can keep the amount of energy consumed to drive the host vehicle 100 to a minimum.

[0103] That is, when the first automatic traveling control is being executed, the adjacent vehicle 300 may not be in the coasting cancellation area AS but may be near the coasting cancellation area AS. In this case, there is a possibility that the adjacent vehicle 300 will enter the coasting cancellation area AS immediately after the host vehicle 100 starts coasting. Then, when the adjacent vehicle 300 enters the coasting cancellation area AS, the host vehicle 100 will stop coasting and start powering. As a result, the amount of energy consumed to travel the host vehicle 100 will increase instead.

[0104] According to the vehicle driving assistance device 10, when the first automatic driving control is being executed, if the adjacent vehicle 300 is not in the coasting suspension area AS but is near the coasting suspension area AS (i.e., if the switching prohibition condition C3 is satisfied), coasting of the host vehicle 100 is not started. This makes it possible to keep the amount of energy consumed to drive the host vehicle 100 small.

[0105] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. [Explanation of symbols]

[0106] 10...vehicle driving assistance device, 20...power unit, 30...braking device, 40...own vehicle speed detection device, 50...surrounding information detection device, 90...ECU, 100...own vehicle, 200...preceding vehicle, 300...adjacent vehicle, 400...following vehicle

Claims

1. A vehicle driving assistance device including a control device that performs automatic driving control to drive a host vehicle while repeatedly powering and coasting the host vehicle, the control device is configured to stop coasting of the host vehicle when a coasting stop condition is met while the host vehicle is coasting, The coasting cancellation condition is a condition that an adjacent vehicle is present in a coasting cancellation area, The adjacent vehicle is another vehicle traveling in an adjacent lane next to the lane in which the host vehicle is traveling in the same direction as the host vehicle, the coasting-stop region includes a region of the adjacent lane directly beside the host vehicle, and is composed of a region of the adjacent lane within a first distance ahead of the host vehicle and a region of the adjacent lane within a second distance behind the host vehicle; Vehicle driving assistance device.

2. The vehicle driving assistance device according to claim 1, the coasting cancellation condition is a condition that the adjacent vehicle is present in the coasting cancellation area and the traveling speed of the adjacent vehicle is within a coasting cancellation speed range; Vehicle driving assistance device.

3. 3. The vehicle driving assistance device according to claim 2, The control device When the automatic driving control is executed, an upper limit value and a lower limit value of a driving speed of the host vehicle are set; During execution of the automatic travel control, when the traveling speed of the host vehicle increases while the host vehicle is being powered and reaches the upper limit value, the powering of the host vehicle is stopped and coasting of the host vehicle is started, and when the traveling speed of the host vehicle decreases while the host vehicle is coasting and reaches the lower limit value, the coasting of the host vehicle is stopped and coasting of the host vehicle is started. It is structured as follows: The stop speed range is from the upper limit value to the lower limit value. Vehicle driving assistance device.

4. The vehicle driving assistance device according to claim 1, the control device is configured to not switch the running state of the host vehicle from the powered state to the coasting state if a switching prohibition condition is satisfied when a switching condition for switching the running state of the host vehicle from the powered state to the coasting state is satisfied, the switching prohibition condition is a condition that the adjacent vehicle is present in a switching prohibition area, the switching prohibition area includes an area of ​​the adjacent lane directly to the side of the host vehicle, and is composed of an area of ​​the adjacent lane within a third distance forward from the host vehicle that is longer than the first distance, and an area of ​​the adjacent lane within a fourth distance rearward from the host vehicle that is longer than the second distance; Vehicle driving assistance device.

5. 5. The vehicle driving assistance device according to claim 4, The control device When the automatic driving control is being executed, if there is no preceding vehicle, an upper limit value and a lower limit value of the driving speed of the subject vehicle are set; When the automatic driving control is being executed, if the preceding vehicle does not exist, when the traveling speed of the host vehicle increases while the host vehicle is being powered and reaches the upper limit value, the powering of the host vehicle is stopped and coasting of the host vehicle is started, and when the traveling speed of the host vehicle decreases while the host vehicle is coasting and reaches the lower limit value, the coasting of the host vehicle is stopped and coasting of the host vehicle is started. It is structured as follows: The switching prohibition condition is a condition that the preceding vehicle does not exist, the adjacent vehicle exists in the switching prohibition area, the adjacent vehicle is an adjacent vehicle traveling ahead of the host vehicle, and the traveling speed of the adjacent vehicle is slower than the average value of the upper limit value and the lower limit value, or the preceding vehicle does not exist, the adjacent vehicle exists in the switching prohibition area, the adjacent vehicle is an adjacent vehicle traveling behind the host vehicle, and the traveling speed of the adjacent vehicle is faster than the average value. Vehicle driving assistance device.

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