Vehicle driving assistance system

Abstract

The present invention provides a vehicle driving assistance device that allows the vehicle to move autonomously by alternately coasting and accelerating, while minimizing inconvenience to drivers of surrounding vehicles. [Solution] The vehicle driving support device 10 performs driving support control to drive the vehicle 100 by autonomously performing coasting and powering alternately. When the inter-vehicle distance, which is the distance between the vehicle and surrounding vehicles present around the vehicle, is less than or equal to a predetermined inter-vehicle distance, and the vehicle is powered based on the required acceleration, if the acceleration of the vehicle is less than a predetermined lower limit acceleration, the vehicle driving support device powers the vehicle so that the acceleration of the vehicle becomes equal to or greater than the predetermined lower limit acceleration.

Description

Technical Field

[0001] The present invention relates to a vehicle driving support device.

Background Art

[0002] There is known a vehicle driving support device that executes driving support control for driving the host vehicle by alternately and autonomously performing coasting and power running of the host vehicle. According to the above driving support control, coasting and power running of the host vehicle are alternately performed so that the running speed of the host vehicle repeatedly moves up and down within a predetermined speed range. However, when such driving support control is executed when there is a following vehicle, it may cause annoyance to the driver of the following vehicle. Therefore, there is also known a vehicle driving support device that narrows the above predetermined speed range when there is a following vehicle (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] However, even if the above predetermined speed range is narrowed, if the acceleration of the host vehicle is too small, it may cause annoyance to the driver of the following vehicle.

[0005] An object of the present invention is to provide a vehicle driving support device capable of driving the host vehicle by alternately and autonomously performing coasting and power running of the host vehicle while suppressing annoyance to the drivers of surrounding vehicles including the following vehicle.

[0006] The vehicle driving support device according to the present invention includes a control device that performs driving support control to drive the vehicle by autonomously performing alternating coasting and powering of the vehicle. The control device is configured to power the vehicle based on a required acceleration when the distance between the vehicle and surrounding vehicles present in the vicinity of the vehicle is greater than a predetermined distance. Furthermore, the control device is configured to continue powering the vehicle based on a predetermined lower limit acceleration when the acceleration of the vehicle is greater than or equal to a predetermined lower limit acceleration when the distance between the vehicle and surrounding vehicles is less than or equal to the predetermined distance. Furthermore, the control device is configured to power the vehicle so that the acceleration of the vehicle becomes greater than or equal to the predetermined lower limit acceleration when the acceleration of the vehicle is less than or equal to the predetermined lower limit acceleration when the acceleration of the vehicle is greater than or equal to the predetermined lower limit acceleration when the distance between the vehicle and surrounding vehicles is less than or equal to the predetermined distance.

[0007] According to the present invention, when surrounding vehicles are near the vehicle, the acceleration of the vehicle is maintained at least above a predetermined lower limit acceleration. Therefore, the inconvenience caused to drivers of surrounding vehicles due to the low acceleration of the vehicle is suppressed. Accordingly, the vehicle can be driven by autonomously alternating between coasting and powering, while suppressing the inconvenience caused to drivers of surrounding vehicles.

[0008] Furthermore, in the vehicle driving support device according to the present invention, the surrounding vehicle distance is, for example, the distance between the vehicle and a following vehicle that is located behind the vehicle and traveling in the same lane as the vehicle.

[0009] According to the present invention, in particular, the vehicle can be driven by autonomously alternating between coasting and accelerating, while suppressing any inconvenience caused to the driver of a following vehicle.

[0010] Furthermore, in the vehicle driving support device according to the present invention, the driving support control is, for example, when there is no preceding vehicle present in front of the vehicle and traveling in the same lane as the vehicle, the vehicle starts coasting when the vehicle's speed reaches a predetermined upper limit speed due to the vehicle's acceleration, and starts acceleration when the vehicle's speed reaches a predetermined lower limit speed due to the vehicle's coasting. Furthermore, the driving support control is, for example, when there is a preceding vehicle, the vehicle starts coasting when the distance between the vehicle and the preceding vehicle, which is the distance between the vehicle and the preceding vehicle, reaches a predetermined lower limit distance due to the vehicle's acceleration, and starts acceleration when the vehicle's distance between the vehicle and the preceding vehicle reaches a predetermined upper limit distance due to the vehicle's coasting.

[0011] According to the present invention, whether the driving assistance control is based on the vehicle's own speed or the driving assistance control is based on the distance to the preceding vehicle, the vehicle can be driven by autonomously alternating between coasting and accelerating, while suppressing any inconvenience caused to the drivers of surrounding vehicles.

[0012] 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]

[0013] [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 is a flowchart showing the routine executed by a vehicle driving assistance device according to an embodiment of the present invention. [Figure 3] Figure 3 shows the surrounding vehicles. [Modes for carrying out the invention]

[0014] Hereinafter, a vehicle driving support device according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows a vehicle driving support device 10 according to an embodiment of the present invention. The vehicle driving support device 10 is mounted on the vehicle 100. Hereinafter, the vehicle driving support device 10 will be described using the case where the operator 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 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).

[0015] As shown in Figure 1, the vehicle driving assistance system 10 is equipped with 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.

[0016] In this example, the vehicle driving assistance system 10 is equipped with only one ECU 90, but it may also be equipped with multiple ECUs, and the functions of the vehicle driving assistance system 10 described below may be divided among the ECUs.

[0017] Furthermore, the vehicle driving assistance device 10 may be configured to update the program stored in the storage medium via wireless communication with an external device (for example, internet communication).

[0018] Furthermore, the vehicle driving assistance system 10 is applicable not only to vehicles driven by manual operation by an operator, but also to vehicles driven by both manual and automated driving.

[0019] As shown in FIG. 1, the host vehicle 100 is equipped with a drive device 20, a braking device 30, a driving support operator 40, a vehicle speed detection device 50, a longitudinal acceleration sensor 60, a road gradient sensor 70, and a surrounding information detection device 80.

[0020] The drive device 20 is a device that generates a driving force applied to the host vehicle 100 (particularly, the drive wheels of the host vehicle 100). In this example, the drive device 20 includes an internal combustion engine 21 and a motor 22. The drive device 20 is electrically connected to the 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 (i.e., the internal combustion engine 21 and the motor 22).

[0021] The braking device 30 is a device that applies a braking force to the host vehicle 100 (particularly, the wheels of the host vehicle 100). The braking device 30 is, for example, a hydraulic braking device. 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.

[0022] The driving support operator 40 is a device that is operated by the driver of the host vehicle 100 to request the execution of the optimal fuel consumption control described later or to request its stop. The driving support operator 40 is electrically connected to the ECU 90. In this example, when the driving support operator 40 is operated when the optimal fuel consumption control is not being executed, the vehicle driving support device 10 determines that the execution of the optimal fuel consumption control is requested. On the other hand, when the driving support operator 40 is operated when the optimal fuel consumption control is being executed, the vehicle driving support device 10 determines that the stop of the optimal fuel consumption control is requested.

[0023] The vehicle speed detection device 50 is a device for detecting the host vehicle speed V. The host vehicle speed V is the traveling speed of the host vehicle 100. The vehicle speed detection device 50 includes, for example, wheel speed sensors provided on each wheel of the host vehicle 100. The vehicle speed detection device 50 is electrically connected to the ECU 90. The vehicle driving support device 10 acquires the host vehicle speed V by the vehicle speed detection device 50.

[0024] The longitudinal acceleration sensor 60 is a sensor for detecting the longitudinal acceleration Gx. The longitudinal acceleration Gx is the acceleration in the front-rear direction of the host vehicle 100. The longitudinal acceleration sensor 60 is electrically connected to the ECU 90. The vehicle driving support device 10 acquires the longitudinal acceleration Gx by means of the longitudinal acceleration sensor 60.

[0025] The road gradient sensor 70 is a sensor for detecting the road gradient Grod. The road gradient Grod is the gradient of the road on which the host vehicle 100 is currently traveling. The road gradient sensor 70 is electrically connected to the ECU 90. The vehicle driving support device 10 acquires the road gradient Grod by means of the road gradient sensor 70.

[0026] The surrounding information detection device 80 is a device for detecting information on the surroundings of the host vehicle 100. In this example, the surrounding information detection device 80 includes a plurality of electromagnetic wave sensors 81 and a plurality of image sensors 82. The electromagnetic wave sensors 81 and the image sensors 82 are electrically connected to the ECU 90. The electromagnetic wave sensor 81 is, for example, a radar sensor such as a millimeter-wave radar. The vehicle driving support device 10 acquires information on an object existing around the host vehicle 100 as surrounding information IS by means of the electromagnetic wave sensor 81. Also, the image sensor 82 is, for example, a camera sensor. The vehicle driving support device 10 acquires image information regarding the surroundings of the host vehicle 100 as surrounding information IS by means of the image sensor 82.

[0027] Next, the operation of the vehicle driving support device 10 will be described. When a predetermined condition is satisfied, the vehicle driving support device 10 is configured to execute fuel consumption optimal control as driving support control. The fuel consumption optimal control is control for driving the host vehicle 100 by alternately and autonomously performing coasting and power running of the host vehicle 100.

[0028] The vehicle driving support system 10 executes the routine shown in Figure 2 at predetermined time intervals, and when predetermined conditions are met, it performs optimal fuel efficiency control. Therefore, when the predetermined timing arrives, the vehicle driving support system 10 starts processing from step S200 of the routine shown in Figure 2. Then, the vehicle driving support system 10 proceeds to step S205 and determines whether or not execution condition C1 has been met. Execution condition C1 is met when the execution of optimal fuel efficiency control is requested.

[0029] If the vehicle driving support system 10 determines "Yes" in step S205, it proceeds to step S210 to determine whether the normal driving support condition C2 is met. The normal driving support condition C2 is met when the distance between surrounding vehicles Dsrd is less than or equal to the predetermined coasting prohibition distance Dfbd.

[0030] As shown in Figure 3, the distance between surrounding vehicles Dsrd is the distance between the vehicle 100 and the surrounding vehicle 200. In this example, the surrounding vehicle 200 is the following vehicle 201 and the parallel vehicle 202. As shown in Figure 3, the following vehicle 201 is another vehicle that is located behind the vehicle 100, within a predetermined distance, and traveling in the same lane LN1 as the vehicle 100. On the other hand, as shown in Figure 3, the parallel vehicle 202 is another vehicle that is located within a predetermined distance in the longitudinal direction of the vehicle 100 and traveling in lane LN2 adjacent to lane LN1 in which the vehicle 100 is traveling.

[0031] Furthermore, the coasting prohibition distance Dfbd is set to an appropriate distance that is estimated to prevent any inconvenience to the drivers of surrounding vehicles 200, even when power is applied based on the required acceleration Greq, as described later.

[0032] Furthermore, the vehicle driving support system 10 detects surrounding vehicles 200 based on surrounding information IS. In addition, the vehicle driving support system 10 acquires the distance between surrounding vehicles Dsrd based on surrounding information IS.

[0033] If the vehicle driving support system 10 determines "No" in step S210, it executes fuel-efficient control. In this case, the vehicle driving support system 10 proceeds to step S215 to determine whether the vehicle 100 is coasting under fuel-efficient control. In other words, the vehicle driving support system 10 determines whether coasting control is being executed.

[0034] Coasting control is a control included in fuel efficiency optimization control. Coasting control is a control that allows the vehicle 100 to coast by disconnecting the connection between the drive unit 20 and the drive wheels of the vehicle 100, thereby reducing the driving force supplied from the drive unit 20 to the vehicle 100 to zero.

[0035] If the vehicle driving support device 10 determines "Yes" in step S215, it proceeds to step S220 to determine whether or not the powering condition C3 is met. The powering condition C3 is met when the vehicle speed V reaches a predetermined lower limit speed Vlwr when there is no preceding vehicle 300. The powering condition C3 is also met when the distance Dfwd between vehicles reaches a predetermined upper limit distance Dupr when there is a preceding vehicle 300.

[0036] As shown in Figure 3, the preceding vehicle 300 is another vehicle that is located in front of the own vehicle 100, within a predetermined distance, and traveling in the same lane LN1 as the own vehicle 100. The distance between the preceding vehicle Dfwd is the distance between the preceding vehicle 300 and the own vehicle 100 in the longitudinal direction of the own vehicle 100. The vehicle driving support system 10 detects the preceding vehicle 300 based on the surrounding information IS. The vehicle driving support system 10 also acquires the distance between the preceding vehicle Dfwd based on the surrounding information IS.

[0037] Furthermore, the lower limit speed Vlwr is set to a value that is a predetermined speed less than the set vehicle speed Vset. Furthermore, the upper limit following distance Dupr is set to a value that is a predetermined distance greater than the set following distance Dset. The set vehicle speed Vset is the vehicle speed set by the driver of vehicle 100. Furthermore, the set following distance Dset is the following distance set by the driver of vehicle 100.

[0038] If the vehicle driving support system 10 determines "Yes" in step S220, it proceeds to step S225 and starts powering the vehicle 100 based on the requested acceleration Greq. In other words, the vehicle driving support system 10 starts power control based on the requested acceleration Greq.

[0039] Power control is a control included in fuel efficiency optimization control. Power control is a control that provides driving force from the drive unit 20 to the vehicle 100 to power the vehicle 100. In particular, power control is an optimal power control that provides driving force from the drive unit 20 to the vehicle 100 to power the vehicle 100 while operating the drive unit 20 with optimal energy efficiency.

[0040] Furthermore, power control based on the required acceleration Greq is performed as follows. First, the required acceleration Greq is obtained based on the current vehicle speed V. In this case, the required acceleration Greq is the acceleration preset according to the vehicle speed V. Alternatively, the required acceleration Greq is obtained based on the current vehicle speed V and the current road gradient Grod. In this case, the required acceleration Greq is the acceleration preset according to the vehicle speed V and the road gradient Grod. Next, the driving force that can achieve the acceleration of the vehicle 100 corresponding to the required acceleration Greq is calculated and obtained as the required driving force Freq. Then, the operation of the drive unit 20 is controlled so that the obtained required driving force Freq is output from the drive unit 20.

[0041] Next, the vehicle driving assistance device 10 proceeds to step S295 and terminates the processing of this routine. From this point onward, the result will be "No" in step S215.

[0042] On the other hand, if the vehicle driving support system 10 determines "No" in step S220, it proceeds to step S230 and continues coasting of its own vehicle 100 with optimal fuel consumption control. Next, the vehicle driving support system 10 proceeds to step S295 and terminates the processing of this routine.

[0043] Furthermore, if the vehicle driving support device 10 determines "No" in step S215, it proceeds to step S235 to determine whether coasting condition C4 is met. Coasting condition C4 is met when the vehicle speed V reaches a predetermined upper limit speed Vupr when there is no preceding vehicle 300. Also, coasting condition C4 is met when the distance between preceding vehicles Dfwd reaches a predetermined lower limit distance Dlwr when there is a preceding vehicle 300.

[0044] In this example, the upper speed limit Vupr is set to the set vehicle speed Vset. Also, the lower limit following distance Dlwr is set to the set following distance Dset.

[0045] If the vehicle driving support system 10 determines "Yes" in step S235, it proceeds to step S240 and starts coasting of its own vehicle 100 with fuel-efficient control. That is, the vehicle driving support system 10 starts coasting control. Next, the vehicle driving support system 10 proceeds to step S295 and terminates the processing of this routine.

[0046] On the other hand, if the vehicle driving support system 10 determines "No" in step S235, it proceeds to step S245 to obtain the longitudinal acceleration Gx. Next, the vehicle driving support system 10 proceeds to step S250 to determine whether the lower limit condition C5 is met. The lower limit condition C5 is met when the distance between surrounding vehicles Dsrd is less than or equal to a predetermined distance between vehicles (i.e., the control switching distance Dswc) and the longitudinal acceleration Gx is less than a predetermined lower limit acceleration Glwr.

[0047] In this example, the control switching distance Dswc is set to a distance longer than the coasting prohibition distance Dfbd. Also, the lower limit acceleration Glwr is set to an appropriate acceleration that is estimated to prevent the drivers of surrounding vehicles 200 from feeling bothered by the low acceleration of the vehicle 100.

[0048] If the vehicle driving support system 10 determines "Yes" in step S250, it proceeds to step S255 and continues to power the vehicle 100 using fuel-efficient optimal control so that the acceleration of the vehicle 100 becomes the lower limit acceleration Glwr. In this case, the vehicle driving support system 10 may be configured to continue powering the vehicle 100 using fuel-efficient optimal control so that the acceleration of the vehicle 100 is equal to or greater than the lower limit acceleration Glwr. Next, the vehicle driving support system 10 proceeds to step S295 and terminates the processing of this routine.

[0049] On the other hand, if the vehicle driving support system 10 determines "No" in step S250, it proceeds to step S260 and continues powering based on the requested acceleration Greq through fuel-efficient control. Next, the vehicle driving support system 10 proceeds to step S295 and terminates the processing of this routine.

[0050] Furthermore, if the vehicle driving support system 10 determines "No" in step S210, it proceeds to step S265 and performs normal driving support. That is, the vehicle driving support system 10 performs normal driving support control as driving support control. Next, the vehicle driving support system 10 proceeds to step S295 and terminates the processing of this routine.

[0051] The normal driving support control is a control that autonomously controls the operation of the drive unit 20 and the braking unit 30 to maintain the vehicle speed V at a set vehicle speed Vset when there is no preceding vehicle 300, thereby driving the vehicle 100. On the other hand, the normal driving support control is a control that autonomously controls the operation of the drive unit 20 and the braking unit 30 to maintain the distance Dfwd between vehicles Dfwd at a set distance Dset when there is a preceding vehicle 300, thereby driving the vehicle 100.

[0052] Furthermore, if the vehicle driving assistance device 10 determines "No" in step S205, it proceeds directly to step S295 and terminates the processing of this routine.

[0053] The above describes the operation of the vehicle driving support system 10. According to the vehicle driving support system 10, when a surrounding vehicle 200 is near the vehicle 100, the acceleration of the vehicle 100 is maintained at or above the lower limit acceleration Glwr. Therefore, the possibility of the driver of the surrounding vehicle 200 feeling annoyed due to the low acceleration of the vehicle 100 is suppressed. Thus, the vehicle 100 can be driven by autonomously alternating between coasting and powering, while suppressing the annoyance of the driver of the surrounding vehicle 200.

[0054] 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.

[0055] For example, in order to further reduce the impact on surrounding vehicles 200 due to a slow vehicle speed V, the vehicle driving support device 10 may be configured as follows. That is, the vehicle driving support device 10 may be configured to narrow the vehicle speed control range and perform optimal fuel efficiency control from the time of execution of step S255 until "No" is determined in step S250. Here, the vehicle speed control range is the range with the upper limit speed Vupr as the upper limit and the lower limit speed Vlwr as the lower limit. In this case, the vehicle driving support device 10 narrows the vehicle speed control range by increasing the lower limit speed Vlwr without changing the upper limit speed Vupr, for example.

[0056] Alternatively, the vehicle driving support device 10 may be configured to perform fuel-efficient control by narrowing the inter-vehicle distance control range from the time of step S255 until it determines "No" in step S250. Here, the inter-vehicle distance control range is a range with the upper limit inter-vehicle distance Dupr as the upper limit and the lower limit inter-vehicle distance Dlwr as the lower limit. In this case, the vehicle driving support device 10 narrows the vehicle speed control range by, for example, reducing the upper limit inter-vehicle distance Dupr without changing the lower limit inter-vehicle distance Dlwr.

[0057] Alternatively, in order to further improve fuel efficiency by extending the period during which the vehicle 100 coasts, the vehicle driving support device 10 may be configured as follows. That is, the vehicle driving support device 10 may be configured to widen the vehicle speed control range and perform fuel efficiency optimal control from the time of execution of step S255 until "No" is determined in step S250. In this case, the vehicle driving support device 10 widens the vehicle speed control range by, for example, reducing the lower limit speed Vlwr without changing the upper limit speed Vupr. However, in this case, it is preferable that the control switching distance Dswc is set to a larger value than the control switching distance Dswc in the example described above.

[0058] Alternatively, the vehicle driving support device 10 may be configured to widen the inter-vehicle distance control range and perform fuel-efficient control after the execution of step S255. In this case, the vehicle driving support device 10 widens the inter-vehicle distance control range by, for example, increasing the upper limit inter-vehicle distance Dupr without changing the lower limit inter-vehicle distance Dlwr. However, even in this case, it is preferable that the control switching distance Dswc is set to a larger value than the control switching distance Dswc in the example described above.

[0059] 10...Vehicle driving assistance system, 20...Drive system, 90...ECU, 100...Own vehicle, 200...Surrounding vehicles, 201...Following vehicle, 202...Vehicle running alongside, 300...Leading vehicle

Claims

1. A vehicle driving assistance system equipped with a control device that performs driving assistance control to drive the vehicle by autonomously performing coasting and powering alternately, The control device is When the aforementioned driving assistance control is executed, if the distance between the vehicle and surrounding vehicles is greater than a predetermined distance, the vehicle will be powered based on the required acceleration, which is the acceleration of the vehicle. When the aforementioned driving assistance control is executed, if the distance between surrounding vehicles is less than or equal to the predetermined distance between vehicles, and the vehicle's acceleration is greater than or equal to a predetermined lower limit acceleration when the vehicle's acceleration is applied based on the requested acceleration, the vehicle's acceleration based on the requested acceleration is continued. When the aforementioned driving assistance control is executed, if the distance between surrounding vehicles is less than or equal to the predetermined distance between vehicles, and the acceleration of the vehicle is reduced to less than the predetermined lower limit acceleration when the vehicle is powered based on the requested acceleration, the vehicle will be powered so that the acceleration of the vehicle becomes equal to or greater than the predetermined lower limit acceleration. It is structured in such a way. Vehicle driving assistance system.

2. In the vehicle driving support device according to claim 1, The aforementioned distance between surrounding vehicles is the distance between the vehicle itself and a following vehicle that is located behind the vehicle and traveling in the same lane as the vehicle itself. Vehicle driving assistance system.

3. In the vehicle driving support device according to claim 1 or claim 2, The aforementioned driver assistance control is, If there is no preceding vehicle located in front of the vehicle and traveling in the same lane, the vehicle will begin coasting when its speed reaches a predetermined upper limit due to its acceleration, and will begin acceleration when its speed reaches a predetermined lower limit due to its coasting. If a preceding vehicle exists, when the distance between the vehicle and the preceding vehicle, which is the distance between the vehicle and the preceding vehicle, reaches a predetermined lower limit due to the vehicle's acceleration, the vehicle begins to coast, and when the distance between the vehicle and the preceding vehicle reaches a predetermined upper limit due to the vehicle's coasting, the vehicle begins to accelerate. It is control. Vehicle driving assistance system.

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