Return assistance device

Abstract

Provided is a retreat assist device capable of reducing the possibility of losing the opportunity of execution of retreat assist control. The reverse assist device includes: a storage device that stores a forward path through which the vehicle passes when the vehicle is moving forward; and a control unit capable of executing retreat assist control for retreating the vehicle along the forward path. The control unit suggests execution of the reverse assist control to a driver of the vehicle when it is determined that a predetermined suggestion condition is satisfied on the basis of the surroundings of the vehicle or a reverse route through which the vehicle passes when the vehicle moves backward, and executes the reverse assist control when the driver agrees the execution of the reverse assist control.

Description

Technical Field

[0001] The present invention relates to a reverse assist device that performs reverse assist control for causing a vehicle to reverse along a forward path when the vehicle is forward. Background Art

[0002] Conventionally, there is known a reverse assist device that can perform reverse assist control to make a vehicle reverse along a forward path. For example, the reverse assist device described in Patent Document 1 (hereinafter referred to as "conventional device") determines whether a reverse travel request signal is input by the driver when the vehicle enters a travel restriction area. The conventional device performs reverse assist control when a reverse travel request signal is input.

[0003] The driving restriction area includes an area where driving is originally restricted (such as a road end (end) and a one-way street) and an area where driving is temporarily restricted due to other obstacles. The reverse driving request signal is input when the driver agrees to execute the reverse assist control.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: U.S. Patent No. 11097733 Summary of the invention

[0007] In the conventional device, if there is no input of the reverse driving request signal, the reverse assist control is not executed. When the driver wishes to execute the reverse assist control, he needs to spontaneously perform the "consent operation for generating the reverse request signal". Even if the reverse assist control can be used, the driver will certainly not perform the consent operation if he is not aware of it. Therefore, the opportunity to execute the reverse assist control may be lost.

[0008] The present invention has been made to address the above-mentioned problems. That is, one object of the present invention is to provide a reverse assist device that can reduce the possibility of losing the opportunity to execute reverse assist control.

[0009] The back-up assist device of the present invention (hereinafter referred to as "the device of the present invention") comprises:

[0010] a storage device (38) storing a forward path traversed by the vehicle as the vehicle advances; and

[0011] a control unit (20) capable of executing reverse assist control for causing the vehicle to reverse along the forward path,

[0012] The control unit is configured as follows:

[0013] When it is determined that a predetermined recommendation condition is satisfied based on the surrounding conditions of the vehicle or the reverse path that the vehicle passes through when the vehicle reverses (“Yes” in step 310 and “Yes” in step 315, “Yes” in step 510, and “Yes” in step 605), the execution of the reverse assist control is recommended to the driver of the vehicle (step 320),

[0014] When the driver agrees to the execution of the reverse assist control (“Yes” in step 325 ), the reverse assist control is executed (step 330 , steps 400 to 495 ).

[0015] According to the device of the present invention, when it is determined that the recommendation condition is satisfied, the execution of the reverse assist control is recommended. Thus, even if the driver is not aware that the reverse assist control is available, the driver can be made aware that the reverse assist control can be executed. Therefore, the loss of the execution opportunity of the reverse assist control can be prevented.

[0016] Furthermore, according to the device of the present invention, it is determined whether the suggestion condition is satisfied based on the surrounding conditions of the vehicle or the backing path. Therefore, it is possible to determine that the suggestion condition is satisfied when the driver is likely to need to perform the backing assist control, thereby reducing the possibility that the driver will be annoyed by the suggestion to perform the backing assist control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic system configuration diagram of a reverse assist device according to an embodiment of the present invention.

[0018] Figure 2 This is a flowchart of a routine executed by the CPU of the ECU of the reverse assist device according to the first embodiment.

[0019] Figure 3 This is a flowchart of a routine executed by the CPU of the ECU of the reverse assist device according to the first embodiment.

[0020] Figure 4 This is a flowchart of a routine executed by the CPU of the ECU of the reverse assist device according to the first embodiment.

[0021] Figure 5 This is a flowchart of a routine executed by the CPU of the ECU of the reverse assist device according to the second embodiment.

[0022] Figure 6 This is a flowchart of a routine executed by the CPU of the ECU of the reverse assist device according to the third embodiment.

[0023] Description of Reference Numerals

[0024] 10 ... reverse assist device, 20 ... ECU, 38 ... storage device, 38 a ... route storage unit, 42 ... transmission system actuator, 44 ... brake actuator, 46 ... steering motor, 60 ... suggestion screen. DETAILED DESCRIPTION

[0025] like Figure 1 As shown, the reverse assist device 10 according to the present embodiment (hereinafter referred to as "the present device 10") is applied to a vehicle VA and includes Figure 1 The components shown.

[0026] The control ECU 20 is an ECU that executes reverse assist control, which is a type of automatic driving. The reverse assist control is a control that causes the vehicle VA to reverse along a forward path that the vehicle VA passes through when it is advancing.

[0027] In this specification, "ECU" is an electronic control device with a microcomputer as its main part. ECU is also called a control unit, a controller, and a computer. A microcomputer includes a CPU (processor), ROM, RAM, and an interface (I / F), etc. The functions implemented by ECU20 can also be implemented by multiple ECUs.

[0028] The plurality of cameras 22A to 22D are respectively a front camera, a left camera, a right camera, and a rear camera. The front camera, the left camera, the right camera, and the rear camera respectively capture the front, left, right, and rear of the vehicle VA to obtain front image data, left image data, right image data, and rear image data. In addition, when there is no need to distinguish between the cameras 22A to 22D, they are referred to as "camera 22". When there is no need to distinguish between the front image data, the left image data, the right image data, and the rear image data, they are referred to as "image data".

[0029] The following describes each sonar included in the present device 10. The sonar transmits ultrasonic waves and receives the ultrasonic waves reflected by an object. The sonar determines the distance to the object based on the time from the transmission to the reception of the ultrasonic waves, and transmits the sonar object information including the distance to the ECU 20.

[0030] The front sonars 24A to 24D are arranged on the front bumper (not shown) of the vehicle VA, the rear sonars 26A to 26D are arranged on the rear bumper (not shown) of the vehicle VA, the left sonars 28A and 28B are arranged on the left side of the vehicle VA, and the right sonars 30A and 30B are arranged on the right side of the vehicle VA.

[0031] The front sonars 24A to 24D obtain the distance to the object in front of the vehicle VA, the rear sonars 26A to 26D obtain the distance to the object behind the vehicle VA, the left sonars 28A and 28B obtain the distance to the object on the left side of the vehicle VA, and the right sonars 30A and 30B obtain the distance to the object on the right side of the vehicle VA.

[0032] The vehicle speed sensor 32 detects the speed of the vehicle VA (vehicle speed Vs). The acceleration sensor 33 detects the acceleration G of the front-rear axial direction of the vehicle VA. The steering angle sensor 34 detects the steering angle θ of the steering wheel (not shown). The gear position sensor 35 detects the position (gear position) of the gear shift lever (not shown) of the vehicle VA. The ECU 20 obtains the detection values ​​of the above sensors. In addition, the gear positions include N gear (neutral position), P gear (parking position), D gear (forward position) and R gear (reverse position). The GNSS receiver 36 receives signals from multiple artificial satellites and determines the current position (latitude and longitude) of the vehicle VA based on the received signals.

[0033] The storage device 38 includes a route storage unit 38a. The route storage unit 38a stores route information related to the route along which the vehicle VA travels while the vehicle VA is traveling.

[0034] The transmission system actuator 42 changes the driving force generated by the driving device (such as an internal combustion engine and / or an electric motor) of the vehicle VA. The brake actuator 44 controls the braking force applied to the vehicle VA. The steering motor 46 is installed in the steering mechanism 48. The steering mechanism 48 is a mechanism for steering the steering wheel according to the operation of the steering wheel. The steering motor 46 causes the steering mechanism 48 to generate an automatic steering torque for changing the steering angle of the steering wheel according to the instruction from the ECU 20. The speed ratio and gear shifting of the transmission 50 are controlled based on the gear position (shift lever position). In addition, the transmission 50 can be any one of a gear transmission and a continuously variable transmission. The display 52 is a touch panel display, which is arranged at a position where the driver in the vehicle cabin can see it. The suggestion screen 60 described later is displayed on the display 52. ​​The speaker 54 is arranged in the vehicle cabin. The speaker 54 emits a suggestion voice message described later.

[0035] <Back assist control>

[0036] When the vehicle speed Vs is less than or equal to the predetermined threshold speed Vsth and the gear position is D, the device 10 obtains the route information related to the route traveled by the vehicle VA and stores the route information in the route storage unit 38a. The route information includes the estimated position, the road surface image, and the GNSS position.

[0037] The estimated position is the current position of the vehicle VA estimated based on the last estimated position. The device 10 estimates the current position of the vehicle VA based on the vehicle speed Vs and the steering angle θ. The road surface image is obtained, for example, from a bird's-eye view image generated based on image data obtained by the camera 22. The GNSS position is the current position of the vehicle VA determined by the GNSS receiver 36.

[0038] The device 10 starts the reverse assist control when it detects that the driver has performed a predetermined consent operation. In the reverse assist control, the device 10 compares the GNSS position obtained at the current time point and the road surface image obtained at the current time point with the GNSS position and road surface image of the forward path information stored in the path storage unit 38a, and determines the current position of the vehicle VA with the forward path as a reference. Then, based on the determined current position and forward path of the vehicle VA, the device 10 obtains the target steering angle θtgt for making the vehicle VA reverse along the forward path. The device 10 controls the steering motor 46 so that the steering angle θ is consistent with the target steering angle θtgt.

[0039] In the reverse assist control, the device 10 obtains a target acceleration Gtgt for making the vehicle speed Vs equal to or less than a predetermined reverse speed Vre. The device 10 controls the powertrain actuator 42 and the brake actuator 44 so that the acceleration G matches the target acceleration Gtgt.

[0040] (Work Summary)

[0041] The device 10 determines whether the advice condition is satisfied based on the surrounding conditions of the vehicle VA or the reverse path of the vehicle VA when the vehicle VA reverses. If the advice condition is satisfied, the device 10 displays an advice screen 60 for suggesting execution of reverse assist control on the display 52 .

[0042] The device 10 determines that the advice condition is satisfied when it determines that the vehicle VA cannot move forward based on the surrounding conditions of the vehicle VA. Specifically, the device 10 determines that the advice condition is satisfied when it determines that the following condition A or condition B is satisfied based on the surrounding conditions of the vehicle VA.

[0043] Condition A: A condition that a road width W indicating the width of a road on which the vehicle VA is traveling is equal to or smaller than a predetermined threshold width Wth, and an oncoming vehicle is detected within a predetermined distance from the vehicle VA.

[0044] Condition B: The road on which the vehicle VA is traveling is at the end of the road (has reached the end) or the vehicle VA is located on a narrow road whose width is such that the vehicle VA cannot travel.

[0045] The device 10 determines that the advice condition is satisfied when it determines that the reverse assist control is executable based on the reverse route. Specifically, the device 10 determines that the advice condition is satisfied when it determines that either of the following conditions C1 and C2 is satisfied based on the reverse route.

[0046] Condition C1: A condition that the retreat time of the vehicle VA along the retreat path, that is, the forward path, is equal to or longer than a predetermined threshold time.

[0047] Condition C2: a condition that the retreat distance of the vehicle VA along the retreat path, that is, the forward path, is equal to or larger than a predetermined threshold distance.

[0048] In addition, the above-mentioned condition A is described in Example 1, the above-mentioned condition B is described in Example 3, and the above-mentioned conditions C1 and C2 are described in Example 2.

[0049] The advice screen 60 includes an advice message 62, an approval button 64, and a rejection button 66. The advice message 62 displays a message advising the driver to perform the back assist control. Figure 1 As shown, the message "Start back-up assist?" is displayed in the advice message 62. The driver touches the approval button 64 to approve the execution of the back-up assist control, and touches the rejection button 66 to reject the execution of the back-up assist control. When the approval button 64 is touched, an approval signal is input to the ECU 20. When the rejection button 66 is touched, a rejection signal is input to the ECU 20.

[0050] The above-mentioned suggestion condition is satisfied when there is a high possibility that the back assist control will be executed. When the suggestion condition is satisfied, the suggestion screen 60 is displayed. Thus, even if the driver is not aware of the situation in which the back assist control can be used, the suggestion screen 60 is displayed, so the possibility of losing the opportunity to execute the back assist control can be reduced.

[0051] The possibility that the advice screen 60 is displayed even in a situation where the reverse assist control cannot be used can be reduced. Thus, the possibility that the driver becomes annoyed by the advice screen 60 can be reduced.

[0052] (Specific work)

[0053] <Example 1>

[0054] The CPU of the ECU 20 executes the Figures 2 to 4 The routine is shown in the flowchart.

[0055] <Forward path storage routine>

[0056] When the appropriate time comes, the CPU Figure 2 The process starts from step 200. The process proceeds to step 205, in which the CPU determines whether the vehicle speed Vs is equal to or lower than a threshold vehicle speed Vsth.

[0057] When the vehicle speed Vs is equal to or lower than the threshold vehicle speed Vsth, the CPU makes a “Yes” determination in step 205 and advances the process to step 210. In step 210, the CPU determines whether the shift position is the D range.

[0058] When the shift position is the D range, the CPU makes a "Yes" determination in step 210, and the process proceeds to step 215. In step 215, the CPU stores the forward route information in the route storage unit 38a. Thereafter, the process proceeds to step 295, and the CPU temporarily terminates this routine.

[0059] When the process proceeds to step 205 and the vehicle speed Vs is greater than the threshold vehicle speed Vsth, the CPU makes a “NO” determination in step 205. Thereafter, the process proceeds to step 295, and the CPU temporarily terminates this routine.

[0060] When the process proceeds to step 210 and the shift position is not the D range, the CPU makes a “NO” determination in step 210 . Thereafter, the process proceeds to step 295 , and the CPU temporarily terminates this routine.

[0061] <Back Assist Suggestion Routine>

[0062] When the appropriate time comes, the CPU Figure 3 The process starts from step 300. The process proceeds to step 305, in which the CPU determines whether the value of the execution flag Xexe is "0".

[0063] The value of the execution flag Xexe is set to "1" when the CPU starts the reverse assist control, and is set to "0" when the CPU ends the reverse assist control. In addition, the value of the execution flag Xexe is set to "0" in the initialization routine. The initialization routine is a routine executed by the CPU when the ignition key switch (not shown) of the vehicle VA is changed from the off position to the on position.

[0064] When the value of the execution flag Xexe is "0", the CPU determines "yes" in step 305. In this case, the process proceeds to step 310, and the CPU determines the road width W based on the front image data, and determines whether the road width W is less than the threshold width Wth. The threshold width Wth is preset to a value indicating the width to which the vehicle VA cannot pass (meet) an oncoming vehicle (for example, a width of about 2 times the width of the vehicle VA).

[0065] When the road width W is equal to or smaller than the threshold width Wth, the CPU makes a “Yes” determination in step 310 and the process proceeds to step 315. In step 315, the CPU determines whether or not there is an oncoming vehicle based on the front image data.

[0066] When there is an oncoming vehicle, the CPU makes a “yes” determination in step 315 , and executes steps 320 and 325 .

[0067] Step 320 : The CPU displays the suggestion screen 60 on the display 52 .

[0068] Step 325 : The CPU determines whether an approval signal is input before a predetermined time elapses from when the advice screen 60 is displayed.

[0069] When the approval signal is input before the predetermined time has elapsed, the CPU makes a “YES” determination at step 325 , and executes steps 330 and 335 .

[0070] Step 330: The CPU sets the value of the execution flag Xexe to "1".

[0071] Step 335: The CPU determines whether the gear position is the R gear.

[0072] When the shift position is not the R range, the CPU makes a "No" determination in step 335 and advances the process to step 340. In step 340, the CPU controls the transmission 50 so that the shift position becomes the R range. Thereafter, the process advances to step 395, and the CPU temporarily terminates this routine.

[0073] On the other hand, when the shift position is the R range, the CPU makes a “YES” determination in step 335 . In this case, the process proceeds to step 395 , and the CPU temporarily terminates this routine.

[0074] When the value of the execution flag Xexe is "1" when the process proceeds to step 305, the CPU makes a "No" determination in step 305. In this case, the process proceeds to step 395, and the CPU temporarily terminates this routine.

[0075] When the process proceeds to step 310 , if the road width W is larger than the threshold width Wth, the CPU makes a “NO” determination in step 310 . In this case, the process proceeds to step 395 , and the CPU temporarily terminates this routine.

[0076] When there is no oncoming vehicle when the process proceeds to step 315, the CPU makes a "No" determination in step 315. In this case, the process proceeds to step 395, and the CPU temporarily terminates this routine.

[0077] When the processing proceeds to step 325 and the approval signal is not input before the predetermined time has passed, the CPU determines "No" in step 325. In this case, the processing proceeds to step 395, and the CPU temporarily ends this routine. Figure 3 The steps 345 and 350 shown are described later.

[0078] <Back assist control routine>

[0079] When the appropriate time comes, the CPU Figure 4 The process starts from step 400. The process proceeds to step 405, in which the CPU determines whether the value of the execution flag Xexe is "1".

[0080] When the value of the execution flag Xexe is "0", the CPU makes a "No" determination in step 405. In this case, the process proceeds to step 495, and the CPU temporarily terminates this routine.

[0081] When the value of the execution flag Xexe is “1”, the CPU makes a “Yes” determination in step 405 , and executes steps 410 to 435 .

[0082] Step 410: The CPU determines the current position of the vehicle VA based on the forward path based on the GNSS position and the road image.

[0083] Step 415: The CPU obtains the target steering angle θtgt for causing the vehicle VA to travel along the forward path based on the determined current position of the vehicle VA.

[0084] Step 420: The CPU obtains the target acceleration Gtgt for making the vehicle speed Vs travel at a speed lower than the reverse speed Vre.

[0085] Step 425: The CPU performs steering control to control the steering motor 46 so that the steering angle θ coincides with the target steering angle θtgt.

[0086] Step 430: The CPU performs acceleration / deceleration (acceleration / deceleration) control to control the powertrain actuator 42 and the brake actuator 44 so that the acceleration G coincides with the target acceleration Gtgt.

[0087] Step 435: The CPU determines whether a predetermined termination condition is met.

[0088] When any one of the following conditions D to F is satisfied, the CPU determines that the end condition is satisfied.

[0089] Condition D: The vehicle VA has reversed all the routes indicated by the route information stored in the route storage unit 38a.

[0090] Condition E: The condition that the steering wheel is operated.

[0091] Condition F: A condition that an end button (not shown) is operated.

[0092] When the end condition is not satisfied, the CPU makes a “NO” determination in step 435 . In this case, the process proceeds to step 495 , and the CPU temporarily ends this routine.

[0093] If the termination condition is satisfied, the CPU determines “Yes” in step 435 . In this case, the process proceeds to step 440 , and the CPU sets the value of the execution flag Xexe to “0.” Thereafter, the process proceeds to step 495 , and the CPU temporarily terminates this routine.

[0094] According to the present embodiment, when it is determined that the vehicle VA cannot pass the oncoming vehicle based on the surrounding conditions of the vehicle VA, it is determined that the suggestion condition is satisfied. In this case, the suggestion screen 60 is displayed. This prevents the opportunity to perform the back-up assist control from being lost, and reduces the possibility that the driver is annoyed by the suggestion to perform the back-up assist control.

[0095] <Example 2>

[0096] The CPU involved in this embodiment replaces Figure 3 The routine shown is executed Figure 5 In addition, regarding Figure 5 The processing shown is Figure 3 and Figure 4 Same treatment as shown, marked with Figure 3 and Figure 4 The processes shown are denoted by the same reference numerals, and description thereof will be omitted.

[0097] When the appropriate time comes, the CPU Figure 5 The process starts from step 500. When the value of the execution flag Xexe is "0" ( Figure 5 If "Yes" is received in step 305 shown in the figure, the process proceeds to step 505. In step 505, the CPU determines whether the gear position is the R position.

[0098] When the gear position is R, the CPU determines "yes" in step 505. Figure 5 In step 410 shown, the current position of the vehicle VA with respect to the forward path is determined.

[0099] After that, the process proceeds to step 510, where the CPU determines whether any one of the above-mentioned conditions C1 and C2 is satisfied. Figure 5When the distance from the current position of the vehicle VA specified in step 410 to the forward path is equal to or smaller than a predetermined distance, it is determined that the vehicle VA is moving backward along the forward path.

[0100] If either of the conditions C1 and C2 is satisfied, the CPU makes a "yes" determination in step 510. In this case, the process does not proceed to step 520. Figure 5 Instead, the process proceeds to step 515 shown in dashed lines. Figure 5 In step 320 shown, the CPU causes the suggestion screen 60 to be displayed on the display 52. Figure 5 Step 515 indicated by a dotted line in FIG. 1 is described later. If an approval signal is input within a predetermined time ( Figure 5 Step 325 shown as "yes"), in Figure 5 In step 330 shown in FIG. 1 , the CPU sets the value of the execution flag Xexe to "1". After that, the process proceeds to step 595, and the CPU temporarily terminates this routine. If no consent signal is input within a predetermined time ( Figure 5 If "No" is received at step 325 shown in the figure, the processing proceeds to step 595, and the CPU temporarily ends this routine.

[0101] In processing forward to Figure 5 In step 305 shown in FIG. 1 , if the value of the execution flag Xexe is "1" ( Figure 5 If the condition C1 and the condition C2 are not satisfied when the process proceeds to step 510 (step 510 "No"), the process proceeds to step 595, and the CPU temporarily terminates the routine.

[0102] According to the present embodiment, when the time for which the vehicle VA has moved backward along the forward path becomes longer than a threshold time or when the distance for which the vehicle VA has moved backward along the forward path becomes longer than a threshold distance, the suggestion screen 60 is displayed. This prevents the opportunity for executing the reverse assist control from being lost, and reduces the possibility that the driver will be annoyed by the suggestion for executing the reverse assist control.

[0103] <Example 3>

[0104] The CPU involved in this embodiment replaces Figure 3 The routine shown is executed Figure 6 In addition, regarding Figure 6 The processing shown is Figure 3 and Figure 5 Same treatment as shown, marked with Figure 3 and Figure 5 The processes shown are denoted by the same reference numerals, and description thereof will be omitted.

[0105] When the appropriate time comes, the CPU Figure 6 The process starts from step 600. When the value of the execution flag Xexe is "0" ( Figure 6 Step 305 shown as “Yes”), when the gear position is R gear ( Figure 6 If the result is “yes” in step 505 shown in the figure, the processing proceeds to step 605.

[0106] In step 605, the CPU determines whether the road on which the vehicle VA is traveling is the end of the road (the road has come to an end) or whether the vehicle VA is located on the above-mentioned narrow road based on the image data and the sonar object information.

[0107] Specifically, when the CPU determines that there is a "structure (e.g., guardrail, wall, etc.) having a predetermined length and not being a vehicle, pedestrian, or two-wheeled vehicle" within a predetermined distance from the front end of the vehicle VA, the CPU determines that the road on which the vehicle VA is traveling is the end of the road (reached the end). In addition, the CPU determines whether the object existing within a predetermined distance from the front end of the vehicle VA is the above-mentioned structure based on the front image data and the sonar object information transmitted from the front sonars 24A to 24D.

[0108] Furthermore, when the CPU determines that the above-mentioned structure exists within a predetermined distance from the left side of the vehicle VA and the above-mentioned structure exists within a predetermined distance from the right side of the vehicle VA, the CPU determines that the vehicle VA is located on a narrow road. In addition, the CPU determines whether the object existing within a predetermined distance from the left side of the vehicle VA is the above-mentioned structure based on the left image data and the sonar object information transmitted from the left sonars 28A and 28B. Similarly, the CPU determines whether the object existing within a predetermined distance from the right side of the vehicle VA is the above-mentioned structure based on the right image data and the sonar object information transmitted from the right sonars 30A and 30B.

[0109] If the road on which the vehicle VA is traveling is a road end or if the vehicle VA is located on a narrow road, the CPU makes a "yes" determination in step 605 and proceeds to step 610. Figure 6 Step 320 is shown. Figure 6 The processing after step 320 shown in FIG. Figure 3 It has been explained in , so the explanation is omitted.

[0110] According to the present embodiment, when it is determined based on the surrounding conditions of the vehicle VA that the vehicle VA has entered a road end or a narrow road, it is determined that the suggestion condition is satisfied. In this case, the suggestion screen 60 is displayed. This can prevent the opportunity to perform the back-up assist control from being lost, and can reduce the possibility that the driver is annoyed by the suggestion to perform the back-up assist control.

[0111] <Combination of Embodiments>

[0112] The above-mentioned embodiments 1 to 3 may be combined. When the above-mentioned embodiments 1 to 3 are combined, for example, the suggestion condition of the embodiment 2 may be satisfied after the suggestion condition of the embodiment 1 or the suggestion condition of the embodiment 3 is satisfied. In this case, the driver may operate the rejection button 66 in the suggestion screen 60 displayed due to the suggestion condition being satisfied first. If the suggestion condition of the embodiment 2 is satisfied after the driver operates the rejection button 66, the suggestion screen 60 is displayed again. If the suggestion screen 60 is displayed again even though the driver clearly refuses the execution of the back-up assist control, the driver may feel annoyed by the suggestion screen 60.

[0113] Therefore, when processing proceeds to Figure 3 Step 325 shown is when no consent signal is input before a predetermined time has passed ( Figure 3 If the decision is "No" in step 325 shown in the figure, the process proceeds to step 345. In step 345, the CPU determines whether a rejection signal is input before a predetermined time has passed since the suggestion screen 60 was displayed.

[0114] If the rejection signal is input before the predetermined time has elapsed, the CPU makes a “Yes” determination in step 345 , and executes step 350 . In step 350 , the CPU sets the value of the rejection flag Xrej to “1.” Thereafter, the process proceeds to step 335 .

[0115] The value of the rejection flag Xrej is set to "1" when a rejection signal is input before a predetermined time has passed since the suggestion screen 60 was displayed, and is set to "0" when a predetermined invalid time has passed since the rejection signal was input. In addition, the invalid time is preferably set to be longer than the predetermined time. The value of the rejection flag Xrej is also set to "0" in the initialization routine.

[0116] If the rejection signal is not input before the predetermined time has elapsed, the CPU makes a “NO” determination in step 345 . Thereafter, the process proceeds to step 395 , and the CPU temporarily terminates this routine.

[0117] Furthermore, when the CPU Figure 5 When a "YES" determination is made in step 510 shown, the process proceeds to step 515. In step 515, the CPU determines whether the value of the reject flag Xrej is "0".

[0118] If the value of the rejection flag Xrej is "0", the CPU makes a "yes" determination in step 515, and the process proceeds to step 516. Figure 5On the other hand, when the value of the rejection flag Xrej is "1", the CPU determines "No" in step 515, and the processing proceeds to step 595, and the CPU temporarily terminates this routine. As a result, when the value of the rejection flag Xrej is "1", the suggestion screen 60 will not be displayed again even if the suggestion condition of the second embodiment is satisfied. Therefore, the possibility of displaying the suggestion screen 60 again after the driver rejects the execution of the back assist control can be reduced, and the possibility of the driver being annoyed by the suggestion screen 60 can be reduced.

[0119] In addition, the CPU Figure 6 When the determination in step 325 shown is "NO", the determination in step 345 described above is performed.

[0120] In the first and third embodiments as well, even if the advice condition is satisfied, when the value of the rejection flag Xrej is "1", the CPU may not display the advice screen 60.

[0121] <Modification>

[0122] The ECU 20 involved in this modification may also change the threshold used in the suggested condition based on the driver's consent or rejection history of the execution of the back-up assist control. Specifically, the ECU 20 changes the threshold so that the suggested condition is more likely to be satisfied as the number of consents increases, and changes the threshold so that the suggested condition is less likely to be satisfied as the number of rejections increases.

[0123] In the suggestion condition (condition A) of the first embodiment, the threshold width Wth is the above-mentioned threshold. The threshold width Wth is set larger as the number of approvals increases, and the threshold width Wth is set smaller as the number of rejections increases.

[0124] In the suggestion condition (condition C) of the second embodiment, the threshold time and the threshold distance are the above-mentioned threshold values. The more times of approval, the smaller the threshold time and the threshold distance are set, and the more times of rejection, the larger the threshold time and the threshold distance are set.

[0125] In the suggestion condition (condition B) of the third embodiment, "the structure exists within a predetermined distance from the vehicle VA" is a condition, and the predetermined distance is the above-mentioned threshold. The greater the number of approvals, the larger the predetermined distance is set, and the greater the number of rejections, the smaller the predetermined distance is set.

[0126] For example, the ECU 20 adds a predetermined first value to the recommendation index value when the approval button 64 is operated before a predetermined time has passed since the recommendation screen 60 was displayed. The ECU 20 subtracts a predetermined second value from the recommendation index value when the rejection button 66 is operated before a predetermined time has passed since the recommendation screen 60 was displayed. The ECU 20 changes the threshold value so that the recommendation condition is more likely to be satisfied as the recommendation index value increases.

[0127] Thus, the display frequency of the advice screen 60 can be adjusted according to whether the driver prefers to execute the reverse assist control.

[0128] In the above embodiment, ECU 20 suggests the backing assist control by displaying the suggestion screen 60 on the display 52, but the present invention is not limited thereto. For example, ECU 20 may also issue a "suggestion voice message for suggesting the backing assist control" from the speaker 54. Furthermore, ECU 20 may also determine whether the driver agrees or rejects the backing assist control by voice recognition.

[0129] In the above embodiment, as a sensor for detecting an object, a sonar that detects an object using ultrasonic waves is exemplified, but any sensor that detects an object using wave motion (for example, electromagnetic waves, sound waves, etc.) may be used.

[0130] The device 10 can be applied to vehicles such as engine vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles.

Claims

1. A back-up assist device, comprising: a storage device that stores a forward path that the vehicle travels as the vehicle moves forward; and a control unit capable of executing reverse assist control for causing the vehicle to reverse along the forward path, The control unit is configured as follows: When it is determined that a predetermined advice condition is satisfied based on the surrounding conditions of the vehicle or the reverse path that the vehicle takes when the vehicle reverses, advising the driver of the vehicle to execute the reverse assist control, The reverse assist control is executed if the driver consents to the execution of the reverse assist control.

2. The back-up assist device according to claim 1, The control unit is configured to determine that the advice condition is satisfied when a time period during which the vehicle reverses along the forward path is greater than a predetermined threshold time period or a distance during which the vehicle reverses along the forward path is greater than a predetermined threshold distance when the reverse assist control is not being executed.

3. The back-up assist device according to claim 1, The control unit is configured to determine that the recommendation condition is met when it is determined based on the surrounding conditions that the width of the road on which the vehicle is traveling is less than a predetermined threshold width and there is an oncoming vehicle coming toward the vehicle, or when it is determined based on the surrounding conditions that the road on which the vehicle is traveling has come to an end or the width of the road is such that the vehicle cannot travel.

4. The back-up assist device according to claim 1, The control unit is configured as follows: determining whether the suggestion condition is satisfied based on the surrounding conditions, and determining whether the suggestion condition is satisfied based on the retreat path, If the driver rejects the execution of the reverse assist control when the execution of the reverse assist control is recommended because the recommendation condition is satisfied based on the surrounding situation, the execution of the reverse assist control is not recommended even if the recommendation condition is satisfied based on the reverse route.

5. The back-up assist device according to claim 1, The control unit is configured to make the suggestion condition more likely to be satisfied as the driver agrees to the execution of the back assist control more times, and to make the suggestion condition less likely to be satisfied as the driver rejects the execution of the back assist control more times.

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