Driving support device and driving support method

Abstract

To provide a driving support device for shortening a time until learning of a deceleration position is completed.SOLUTION: A driving support device performs deceleration control to automatically decelerate a vehicle when the vehicle arrives at a deceleration position where a driver performs a deceleration operation. When it is determined that the deceleration operation is performed due to a deceleration requiring object which is arranged in front of the deceleration position and also requires the deceleration of the vehicle, based on an environment in front of the vehicle when the driver performs the deceleration operation, the driving support device adds a greater score to a learning score of the deceleration position compared with a score when it is determined that the deceleration operation is not performed due to the deceleration requiring object, and performs the deceleration control when the learning score of the deceleration position at which the vehicle arrives is equal to or more than a threshold.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a driving assistance device and a driving assistance method that execute deceleration control to automatically decelerate a vehicle when the vehicle reaches a deceleration position where a deceleration operation has been performed. [Background technology]

[0002] The driving assistance device described in Patent Document 1 (hereinafter referred to as the "conventional device") creates map information by associating a change in the driver's operation with location information at the time when the change in operation occurred. Then, when the vehicle arrives at the "position indicated by the location information at the time when the change in operation occurred," the control gain is changed according to the type of operation performed by the driver. For example, if the change in operation is "brake ON," the conventional device reduces the acceleration gain of the driving force control device and increases the braking gain of the braking control device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-103570 A Summary of the Invention

[0004] The conventional device does not determine whether the deceleration operation performed by the driver is a deceleration operation that needs to be performed every time the vehicle passes that location in the future, or a one-time deceleration operation. It is not preferable for the vehicle to automatically decelerate at a location where a one-time deceleration operation has been performed. In order to prevent the conventional device from learning a location where a one-time deceleration operation has been performed as a "deceleration location where deceleration control is executed", a history of a predetermined number of deceleration operations is required. Therefore, when the vehicle travels along a new route, it is necessary to travel along that route many times until the learning of the deceleration locations for that route is completed.

[0005] The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a driving assistance device that can shorten the time until the learning of the deceleration position is completed.

[0006] When the vehicle reaches the deceleration position where the driver performed a deceleration operation (step 315 ``Yes''), the driving assistance device of the present invention (hereinafter referred to as ``the device of the present invention'') executes deceleration control to automatically decelerate the vehicle (step 425). The driving assistance device includes: When it is determined based on the environment in front of the vehicle when the driver performs the deceleration operation that the deceleration operation is performed due to a deceleration request object that is provided in front of the deceleration position and that requires the vehicle to decelerate (step 220 "Yes"), a score greater than a score when it is determined that the deceleration operation is not performed due to the deceleration request object is added to the learning score of the deceleration position (step 240); When the learning score of the deceleration position reached by the vehicle is equal to or greater than the threshold value ("Yes" at step 320), the deceleration control is executed (step 425).

[0007] If a deceleration operation is performed when there is a deceleration request such as a stop line, a stop sign, a red light, or a curved road ahead of the vehicle, there is a high possibility that a deceleration operation will be performed every time the vehicle passes that position in the future. According to the device of the present invention, if it is determined that the deceleration operation was performed due to a deceleration request based on the environment ahead of the vehicle when the driver performed the deceleration operation, a larger score is added to the learning score of the deceleration position than if it was not. Deceleration control is performed when the learning score of the deceleration position reached by the vehicle is equal to or greater than a threshold value. This reduces the possibility that deceleration control will be erroneously performed at a deceleration position where a one-time deceleration operation has been performed, while shortening the time until the learning of the deceleration position is completed. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention. [Diagram 2] 2 is a flowchart of a deceleration position data learning routine executed by a CPU of the ECU shown in FIG. 1 . [Diagram 3] 2 is a flowchart of a start / end determination routine executed by a CPU of the ECU shown in FIG. 1 . [Figure 4] 2 is a flowchart of a deceleration control routine executed by a CPU of the ECU shown in FIG. 1. [Diagram 5] FIG. 2 is a schematic system configuration diagram of a driving assistance system according to a first modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] As shown in FIG. 1, a driving assistance device 10 according to this embodiment (hereinafter referred to as "the device 10") is applied to a vehicle VA, and includes the components shown in FIG.

[0010] The ECU 20 executes deceleration control, which is a type of automatic driving. In the deceleration control, the ECU 20 automatically decelerates the vehicle VA.

[0011] In this specification, "ECU 20" is an electronic control device having a microcomputer as a main part. The ECU 20 is also called a control unit, a controller, and a computer. The microcomputer includes a CPU (processor), a ROM, a RAM, an interface, and the like. The functions realized by the ECU 20 may be realized by multiple ECUs.

[0012] The camera 22 captures an image of the scenery ahead of the vehicle VA to obtain image data. The ECU 20 obtains the image data from the camera 22.

[0013] The millimeter-wave radar 24 transmits millimeter waves ahead of the vehicle VA. The millimeter-wave radar 24 receives the transmitted millimeter waves reflected by an object, thereby identifying the "position of the object relative to the vehicle VA." The ECU 20 acquires radar object information including the position of the object relative to the vehicle VA from the millimeter-wave radar 24.

[0014] The GNSS receiver 26 receives signals from a plurality of artificial satellites, and determines the current position (latitude and longitude) of the vehicle VA based on the received signals.

[0015] The vehicle speed sensor 28 detects the vehicle speed Vs. The acceleration sensor 30 detects the acceleration G in the longitudinal direction of the vehicle VA. The accelerator operation amount sensor 32 detects the operation amount AP of an accelerator pedal (not shown) of the vehicle VA. The brake operation amount sensor 34 detects the operation amount BP of a brake pedal (not shown) of the vehicle VA (brake operation amount). The ECU 20 obtains the detection values ​​of these sensors.

[0016] The power train actuator 40 changes the driving force generated by a drive device (for example, an internal combustion engine and / or an electric motor) of the vehicle VA. The brake actuator 42 controls the braking force applied to the vehicle VA.

[0017] The storage device 44 has a non-volatile storage area. A deceleration position data storage unit 44a is provided in this storage area. The deceleration position data storage unit 44a stores deceleration position data. In the deceleration position data, a deceleration position indicating the position of the vehicle VA when the driver performs a deceleration operation is registered in association with a learning score S.

[0018] (Overview of operation) When the driver performs a deceleration operation, the device 10 stores the position of the vehicle VA at the time of the deceleration operation (deceleration position) and the learning score S in the deceleration position data. When the vehicle VA reaches the deceleration position, the device 10 executes deceleration control if the learning score S of the deceleration position is equal to or greater than the threshold value Sth, and does not execute deceleration control if the learning score S is less than the threshold value Sth.

[0019] The device 10 judges whether or not there is a deceleration request object based on image data and radar object information when the driver performs a deceleration operation. The deceleration request object is an object that is located in front of the vehicle VA and that requests the vehicle VA to decelerate. For example, the deceleration request object is a stop line, a stop sign, a red light, a curved road, etc.

[0020] When a deceleration request exists, the device 10 determines that the deceleration operation was performed due to the deceleration request, and when a deceleration request does not exist, the device 10 determines that the deceleration operation was performed without being due to the deceleration request. In this case, when a deceleration operation was performed without being due to a deceleration request, the device 10 adds a score (Snor or Spre) to the learning score S of the deceleration position, and when a deceleration operation was performed due to a deceleration request, the device 10 adds a score Sreq to the learning score S of the deceleration position. This score Sreq is set to a value larger than the score (Snor or Spre).

[0021] When a deceleration operation is performed due to a deceleration request, there is a high possibility that the driver will need to perform a deceleration operation every time the vehicle passes that deceleration position. According to the present device 10, when a deceleration operation is performed due to a deceleration request, a larger score is added to the learning score S of the deceleration position than when the deceleration operation is performed without being due to a deceleration request. This reduces the possibility that deceleration control will be performed at the deceleration position where a temporary deceleration operation has been performed, while shortening the time until the learning of the deceleration position is completed.

[0022] (Specific operation) The CPU of the ECU 20 executes the routines shown in the flowcharts of FIGS. 2 to 4 every time a predetermined time elapses.

[0023] <Deceleration position data learning routine> When an appropriate time arrives, the CPU starts the process from step 200 in FIG. 2, and in step 205, the CPU determines, based on the detection value from the brake operation amount sensor 34, whether or not a deceleration operation has been performed.

[0024] If a deceleration operation has not been performed, the CPU determines "No" in step 205, and the process proceeds to step 295, where the CPU temporarily ends this routine. On the other hand, if a deceleration operation has been performed, the CPU determines "Yes" in step 205, and executes steps 210 and 215 in this order.

[0025] Step 210: The CPU acquires the current position of the vehicle VA from the GNSS receiver 26. Step 215: The CPU determines whether or not there is a preceding vehicle based on the image data and the radar object information. A preceding vehicle is a vehicle traveling ahead of the vehicle VA.

[0026] If there is no preceding vehicle, the CPU determines "No" in step 215, and the process proceeds to step 220. In step 220, the CPU determines whether or not there is a deceleration request based on the image data.

[0027] More specifically, the CPU extracts white lines from the image data and determines whether or not a stop line and a curved road exist based on the extracted white lines. Furthermore, the CPU determines that a stop sign exists when the image data contains an image having a similarity to a pre-registered image of a stop sign that is equal to or greater than a threshold. Similarly, the CPU determines that a red light exists when the image data contains an image having a similarity to a pre-registered image of a red light that is equal to or greater than a threshold.

[0028] The CPU may determine whether or not there is a deceleration requirement based on map data instead of image data. The map data includes the locations of stop lines, stop signs, red lights, and curved roads. Specifically, when the CPU determines, by referring to the map data, that any of a stop line, a stop sign, a red light, and a curved road exists within a predetermined distance ahead of the current position of the vehicle VA, it determines that there is a deceleration requirement.

[0029] If there is no deceleration request, the CPU determines “No” in step 220 and executes steps 225 and 230 . Step 225: The CPU sets a new learning score S to a value obtained by adding the normal score Snor to the learning score S of the current position. If there is no record in the deceleration position data in which the current position is registered as the deceleration position in the deceleration position data, the CPU adds a new record to the deceleration position data and sets the normal score Snor as the new learning score S. Step 230: The CPU registers a new learning score S in the learning score S of the record in which the deceleration position of the deceleration position data corresponds to the current position. Thereafter, the process proceeds to step 295, where the CPU temporarily ends this routine.

[0030] When the CPU determines that a preceding vehicle is present when the CPU proceeds to step 215 , the CPU determines “Yes” in step 215 and executes step 235 . Step 235: The CPU adds the preceding vehicle score Spre to the learning score S of the current position and sets the result as a new learning score S. The preceding vehicle score Spre is set to a value smaller than the normal score Snor. Thereafter, the CPU executes step 230, and the process proceeds to step 295, where the CPU temporarily ends this routine.

[0031] If a deceleration request exists when the CPU proceeds to step 220, the CPU determines "Yes" in step 220 and executes step 240. Step 240: The CPU adds the deceleration request score Sreq to the learning score S of the current position and sets the result as a new learning score S. The deceleration request score Sreq is set to a value larger than the normal score Snor. Thereafter, the CPU executes step 240, and the process proceeds to step 295, where the CPU temporarily ends this routine.

[0032] <Start / End Judgment Routine> When an appropriate time arrives, the CPU starts the process from step 300 in FIG. 3, and in step 305, the CPU determines whether the value of the execution flag Xexe is "0". The value of the execution flag Xexe is set to "1" when deceleration control starts, and is set to "0" when deceleration control ends. In the initial routine, the value of the execution flag Xon is set to "0". The initial routine is executed by the CPU when an ignition key switch (not shown) of the vehicle VA is changed from the OFF position to the ON position.

[0033] If the value of the execution flag Xexe is “0”, the CPU determines “Yes” in step 305 and executes steps 310 and 315 . Step 310: The CPU acquires the current position of the vehicle VA from the GNSS receiver 26. Step 315: The CPU determines, based on the current position, whether or not the vehicle VA has reached any of the deceleration positions registered in the deceleration position data.

[0034] If the vehicle VA has not reached any of the deceleration positions, the CPU determines "No" in step 315. After that, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0035] If the vehicle VA has reached any deceleration position, the CPU determines "Yes" in step 315, and the process proceeds to step 320. In step 320, the CPU refers to the deceleration position data and determines whether the learning score S of the deceleration position reached by the vehicle VA is equal to or greater than the threshold value Sth.

[0036] If the learning score S is less than the threshold value Sth, the CPU determines "No" in step 320. After that, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0037] If the learning score S is equal to or greater than the threshold value Sth, the CPU determines "Yes" in step 320, and the process proceeds to step 325. In this case, the condition for starting deceleration control is met. In step 325, the CPU sets the value of the execution flag Xexe to "1". After that, the process proceeds to step 395, and the CPU temporarily ends this routine.

[0038] If the value of the execution flag Xexe is "1" when the process proceeds to step 305, the CPU determines "No" in step 305, and the process proceeds to step 330. In step 330, the CPU determines whether the accelerator operation amount AP is equal to or greater than the threshold accelerator operation amount APth.

[0039] If the accelerator operation amount AP is less than the threshold accelerator operation amount APth, the CPU determines "No" in step 330, and the process proceeds to step 335. In step 335, the CPU determines whether the brake operation amount BP is equal to or greater than the threshold brake operation amount BPth.

[0040] If the brake operation amount BP is less than the threshold brake operation amount BPth, the CPU determines "No" in step 335, and the process proceeds to step 340. In step 340, the CPU determines whether the travel distance TD traveled by the vehicle VA from the time when the start condition is satisfied is equal to or greater than the threshold distance TDth.

[0041] If the traveled distance TD is less than the threshold distance TDth, the CPU makes a "No" determination in step 340, and the process proceeds to step 395, where the CPU temporarily ends this routine.

[0042] If the accelerator operation amount AP is equal to or greater than the threshold accelerator operation amount APth (step 330 "Yes"), if the brake operation amount BP is equal to or greater than the threshold brake operation amount BPth (step 335 "Yes"), or if the traveled distance TD is equal to or greater than the threshold distance TDth (step 340 "Yes"), the end condition is met. In this case, the process proceeds to step 345, where the CPU sets the value of the execution flag Xexe to "0". After that, the process proceeds to step 395, where the CPU temporarily ends this routine.

[0043] <Deceleration control routine> When an appropriate time arrives, the CPU starts the process from step 400 in FIG. 4, and in step 405, the CPU determines whether the value of the execution flag Xexe is "1" or not.

[0044] If the value of the execution flag Xexe is "0", the CPU determines "No" in step 405. After that, the process proceeds to step 495, and the CPU temporarily ends this routine.

[0045] If the value of the execution flag Xexe is "1", the CPU determines "Yes" in step 405, and the process proceeds to step 410. In step 410, the CPU determines whether the vehicle speed Vs is greater than the target vehicle speed Vtgt. Note that the target vehicle speed Vtgt is preset to a predetermined value.

[0046] If the vehicle speed Vs is greater than the target vehicle speed Vtgt, the CPU determines “Yes” in step 410 and executes steps 415 and 420 . Step 415: The CPU and the ECU 20 obtain the target acceleration Gtgt by using the formula (1). Gtgt = α(Vtgt-Vs) Equation (1) α is a weighting coefficient, which is set to a predetermined value greater than 0 and equal to or less than 1. If the vehicle speed Vs is greater than the target vehicle speed Vtgt, the process proceeds to step 415, where the target acceleration Gtgt is acquired, so that the target acceleration Gtgt becomes a negative value (in other words, the target acceleration Gtgt becomes a deceleration).

[0047] Step 420: The CPU determines whether or not the magnitude (|Gtgt|) of the target acceleration Gtgt is greater than a predetermined upper limit acceleration Glmt (a predetermined positive value).

[0048] If the magnitude (|Gtgt|) of the target acceleration Gtgt is equal to or less than the upper limit acceleration Glmt, the CPU determines "No" in step 420, and the process proceeds to step 425. In step 425, the CPU controls the power train actuator 40 and the brake actuator 42 so that the acceleration G coincides with the target acceleration Gtgt. Thereafter, the process proceeds to step 495, and the CPU temporarily ends this routine.

[0049] If the magnitude (|Gtgt|) of the target acceleration Gtgt is greater than the upper limit acceleration Glmt, the CPU determines "Yes" in step 420 and the process proceeds to step 430. In step 430, the CPU sets the negative upper limit acceleration Glmt to the target acceleration Gtgt. After that, the process proceeds to step 425.

[0050] According to this embodiment, when a deceleration operation is performed and there is a deceleration request object in front of the vehicle VA, a larger deceleration request object score Sreq is added than when there is no deceleration request object. This reduces the possibility that deceleration control is executed at the deceleration position where a temporary deceleration operation is performed, and shortens the time until the learning of the deceleration position is completed.

[0051] <First Modification> In this modification, an exercise support system will be described. The exercise support system includes vehicles VA1 to VAn and a storage server 50. Hereinafter, when there is no need to distinguish between the vehicles VA1 to VAn, they will be referred to as vehicles VA. The vehicles VA and the storage server 50 are connected via a network NW.

[0052] The vehicle VA includes the components shown in FIG. 1. Furthermore, the storage device 44 of the vehicle VA includes a temporary storage unit 44b. In this modification, the vehicle VA stores deceleration position data including the deceleration position where the deceleration operation was performed and the learning score in the temporary storage unit 44b instead of the deceleration position data storage unit 44a every time a deceleration operation is performed. When a predetermined transmission condition is met, the vehicle VA transmits the deceleration position data stored in the temporary storage unit 44b to the storage server 50 and erases the deceleration position data stored in the temporary storage unit 44b. As an example, the transmission condition is met when the ignition key switch is changed from the on position to the off position.

[0053] The storage server 50 includes a CPU, a ROM, a RAM, an interface (I / F), and a storage device 52. The storage device 52 has a deceleration position data storage unit 52a for storing the deceleration position data transmitted by the vehicle VA.

[0054] When a predetermined acquisition condition is met, the vehicle VA transmits an acquisition request to the storage server 50 to acquire deceleration position data within a predetermined range from the current position of the vehicle VA. The acquisition request includes information regarding the current position of the vehicle VA. For example, the acquisition condition is met when the ignition key switch is changed from the OFF position to the ON position, and when the number of deceleration positions within a predetermined range from the current position of the vehicle VA stored in the deceleration position data storage unit 44a is equal to or less than a predetermined number.

[0055] When the storage server 50 receives the acquisition request, it selects deceleration position data whose learning score S is equal to or greater than the threshold value Sth from among the deceleration position data within a predetermined range from the current position of the vehicle VA. Then, the storage server 50 transmits the selected deceleration position data to the "vehicle VA that transmitted the acquisition request." When the vehicle VA receives the deceleration position data from the storage server 50, it stores the received deceleration position data in the received deceleration position data storage unit 44a.

[0056] When the storage server 50 receives an acquisition request, the storage server 50 may transmit deceleration position data within a predetermined range from the current position of the vehicle VA to the vehicle VA without determining whether the learning score S is equal to or greater than the threshold value Sth. In this case, when the vehicle VA reaches the deceleration position, the driving assistance device 10 of the vehicle VA executes deceleration control if the learning score S of the deceleration position is equal to or greater than the threshold value Sth, and does not execute deceleration control if the learning score S of the deceleration position is less than the threshold value Sth.

[0057] According to this modification, since the deceleration position data of a plurality of vehicles VA is stored in the storage server 50, the time required to complete learning of the deceleration position can be further shortened.

[0058] 5 shows an example in which a plurality of vehicles (learning vehicles) transmit deceleration position data to the storage server 50, but the number of learning vehicles may be one. A vehicle that is not a learning vehicle (i.e., a vehicle that does not transmit deceleration position data to the storage server 50) may obtain deceleration position data from the storage server 50 and perform deceleration control.

[0059] <Second Modification> When a deceleration request object is present when a deceleration operation is performed, the ECU 20 according to this modification adds a score Sreq corresponding to the type of the deceleration request object. When the deceleration request object is a stop line, a stop sign, or a curved road, the ECU 20 adds a first score Sreq1 to the learning score S. When the deceleration request object is a red light, the ECU 20 adds a second score Sreq2 to the learning score S.

[0060] The first score Sreq1 and the second score Sreq2 are preset to values ​​greater than the normal score Snor. Furthermore, the second score Sreq2 is preset to a value smaller than the first score Sreq1. This is because the vehicle VA does not need to stop when the traffic light is showing green, whereas the vehicle VA must decelerate when traveling around a stop line, a stop sign, or a curved road.

[0061] <Third Modification> The ECU 20 according to this modification example performs deceleration control so that the vehicle VA decelerates more strongly (largely) as the learning score S of the deceleration point where the vehicle VA arrives is larger. In detail, the ECU 20 reduces the target vehicle speed Vtgt as the learning score S is larger. Note that the ECU 20 may increase the upper limit acceleration Glmt as the learning score S is larger.

[0062] The target acceleration Gtgt may be a fixed value. In this case, the ECU 20 sets the target acceleration Gtgt (<0) to a smaller value as the learning score S increases.

[0063] The present device 10 is applicable to vehicles such as internal combustion engine vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles. [Explanation of symbols]

[0064] 10... driving assistance device, 20... ECU, 34... brake operation amount sensor, 40... power train actuator, 42... brake actuator, 44a... deceleration position data storage unit.

Claims

1. A driving assistance device that executes deceleration control to automatically decelerate a vehicle when the vehicle reaches a deceleration position where a driver performs a deceleration operation, The driving assistance device includes: When it is determined based on the environment in front of the vehicle when the driver performs the deceleration operation that the deceleration operation is performed due to a deceleration request object that is provided in front of the deceleration position and that requires the vehicle to decelerate, a score greater than a score when it is determined that the deceleration operation is not performed due to the deceleration request object is added to the learning score of the deceleration position; When the learning score of the deceleration position reached by the vehicle is equal to or greater than a threshold, the deceleration control is executed. A driving assistance device configured as above.

2. The driving assistance device according to claim 1, The driving assistance device includes: determining whether the deceleration operation is caused by a preceding vehicle traveling in front of the vehicle based on an environment in front of the vehicle; when it is determined that the deceleration operation is caused by the preceding vehicle, a smaller score is added to the learning score of the deceleration position than when it is determined that the deceleration operation is caused by neither the deceleration request object nor the preceding vehicle. A driving assistance device configured as above.

3. The driving assistance device according to claim 1, The driving assistance device is configured to, when a learning score of the deceleration position is equal to or greater than the threshold value, decelerate the vehicle more strongly in the deceleration control as the learning score is larger. Driving assistance device.

4. A driving assistance method for causing a learning vehicle including at least one of a first vehicle and a second vehicle to execute deceleration control for automatically decelerating the first vehicle when the first vehicle reaches a deceleration position where a driver of the learning vehicle performs a deceleration operation, comprising: The driving assistance method includes: adding a larger score to the learning score of the deceleration position when it is determined based on the environment in front of the learning vehicle when the driver performs the deceleration operation that the deceleration operation is performed due to a deceleration request object that is provided in front of the deceleration position and that requires the learning vehicle to decelerate, compared with a case where it is determined that the deceleration operation is not performed due to the deceleration request object; When a learning score of a deceleration position reached by the first vehicle is equal to or greater than a threshold, causing the first vehicle to execute the deceleration control; A driving assistance method comprising:

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