Driving support device

Abstract

To provide a driving support device which can improve convenience of brake auto hold control.SOLUTION: A driving support device 10 of the present disclosure performs a brake auto hold control of maintaining brake force by holding brake fluid pressure P in a halting state of a vehicle 1, and simultaneously releasing the brake force through a start operation. The driving support device 10 includes: a detector 11 which detects a position of the vehicle 1 and a travel direction; and a controller 12 which performs the brake auto hold control based on the brake fluid pressure P and information detected by the detector 11. The controller 12 starts the brake auto hold control when the vehicle 1 is positioned in front of a cross point or a cross walk and when the brake liquid pressure P is a first threshold value P1 or more, or starts the brake auto hold control when the vehicle 1 is moving backward in a parking area and when the brake fluid pressure P is a second threshold value P2 or more which is higher than the first threshold value P1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a driving assistance device that performs brake auto hold control.

Background Art

[0002] In the field of vehicle driving assistance control, when a vehicle in motion approaches a traffic signal, control is known that applies an auxiliary braking force to the braking force by a braking operation. Also known is control that increases the assist braking force when the vehicle is parked compared to the assist braking force during normal driving, making it easier to avoid collisions with obstacles in a parking lot. Further, brake auto hold control is known that holds the braking force until an accelerator operation is detected when the braking operation is released after the vehicle has stopped (see Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] When brake auto hold control is performed when parking the vehicle in reverse, the vehicle easily enters a stopped and held state, and an accelerator operation is required to release that state, thus hindering a smooth parking operation. In response to such a problem, it is conceivable to make it difficult for the vehicle to enter a stopped and held state by setting the start condition of the brake auto hold control more strictly. However, in this case, for example, it also becomes difficult for the brake auto hold control to start even when the vehicle stops while waiting for a normal traffic signal, resulting in a decrease in the convenience of the control.

[0005] One of the objectives of the present invention is to provide a driving support device that was devised in view of the above problems and can improve the convenience of brake auto-hold control. Note that, not limited to this objective, any operational effects derived from each configuration shown in the "Mode for Carrying Out the Invention" described later and not achievable with conventional technologies are also regarded as other objectives of the present invention.

Means for Solving the Problems

[0006] The disclosed driving support device can be realized as the following disclosed modes (application examples) and solves at least some of the above problems. Each mode after Mode 2 is an additionally and optionally selectable mode and is an omissible mode. Each mode after Mode 2 does not disclose any mode or configuration that is essential for the present invention.

[0007] Mode 1. The disclosed driving support device is a driving support device that implements brake auto-hold control to maintain braking force by holding brake hydraulic pressure in a stopped state of the vehicle and releases the braking force by a start operation. This driving support device includes a detection unit that detects the position and traveling direction of the vehicle, and a control unit that implements the brake auto-hold control based on the brake hydraulic pressure and the information detected by the detection unit. When the vehicle is located in front of an intersection or a crosswalk, the control unit starts the brake auto-hold control if the brake hydraulic pressure is equal to or higher than a first threshold value. When the vehicle is reversing in a parking lot, the control unit starts the brake auto-hold control if the brake hydraulic pressure is equal to or higher than a second threshold value that is higher than the first threshold value.

[0008] Mode 2. In the above Mode 1, it is preferable that the control unit starts the brake auto-hold control if the brake hydraulic pressure is equal to or higher than the second threshold value when the vehicle is about to drive out of the parking lot onto an external road. Aspect 3. In the aspect including the above Aspect 1, it is preferable that the detection unit detects a pedestrian in front of the vehicle. The control unit preferably starts the brake auto-hold control when the vehicle is positioned in front of the intersection or the crosswalk and there is a pedestrian in front of the vehicle, and if the brake hydraulic pressure is equal to or higher than a third threshold value lower than the first threshold value.

[0009] Aspect 4. In the aspect including the above Aspect 1, it is preferable that the detection unit detects the presence or absence of a traffic signal at the intersection or the crosswalk. The control unit preferably starts the brake auto-hold control when the vehicle is positioned in front of the intersection or the crosswalk and there is no traffic signal, and if the brake hydraulic pressure is equal to or higher than a third threshold value lower than the first threshold value.

Advantages of the Invention

[0010] According to the disclosed driving support device, the convenience of the brake auto-hold control can be improved by making the start condition of the brake auto-hold control during reverse in the parking lot stricter.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0012] The disclosed driving assistance device is applicable to a vehicle equipped with a Brake Auto Hold (BAH) function. The Brake Auto Hold function is a function that maintains braking force by holding brake hydraulic pressure in a stopped state of the vehicle and releases the braking force by a start operation. Control for operating the Brake Auto Hold function or releasing its operating state is called Brake Auto Hold control. The type of brake device is not limited, and for example, it may be a disc brake device or a drum brake device.

Embodiment

[0013] [1. Device Configuration] FIG. 1 is a block diagram showing the configuration of a vehicle 1 to which a driving assistance device 10 according to an embodiment is applied. In this vehicle 1, a master cylinder 3 that generates a brake hydraulic pressure P corresponding to the depression amount of a brake pedal 2 is provided. A brake booster for amplifying the stepping force input to the brake pedal 2, for example, is provided between the master cylinder 3 and the brake pedal 2. The brake hydraulic pressure P generated by the master cylinder 3 is transmitted to the brake device of the wheels via a hydraulic circuit 4.

[0014] In the vehicle 1 shown in FIG. 1, a disc brake device is provided for the front wheels and a drum brake device is provided for the rear wheels. The hydraulic circuit 4 is connected to a brake caliper 5 of the disc brake device and a wheel cylinder 6 of the drum brake device. Further, a valve 7 capable of opening and closing operations is interposed in the hydraulic circuit 4 to temporarily hold the brake hydraulic pressure P. The Brake Auto Hold control is realized by opening and closing the valve 7.

[0015] When the valve 7 is opened, the operation of a general braking device is realized. That is, a braking force corresponding to the depression amount of the brake pedal 2 is generated at each wheel, and when the depression of the brake pedal 2 stops, the braking force at each wheel disappears. On the other hand, while the valve 7 is closed, the brake hydraulic pressure P in the hydraulic circuit 4 is maintained. As a result, the brake hydraulic pressure P transmitted to the braking device (brake caliper 5, wheel cylinder 6) is maintained, and the braking force at each wheel is maintained even when the depression of the brake pedal 2 stops.

[0016] The opening and closing state of the valve 7 is controlled by the driving support device 10. The driving support device 10 is a computer that determines the start condition and end condition of the brake auto hold control and controls the opening and closing state of the valve 7. Inside the driving support device 10, a processor (central processing unit), a memory (main memory), a storage device (storage), an interface device, etc. are built in. The content of the control (control program) implemented by the driving support device 10 is stored in the memory and the storage device, and the content is appropriately read by the processor and executed.

[0017] A brake hydraulic pressure sensor 13, a BAH switch 14, a positioning device 15, a select lever sensor 16, a vehicle speed sensor 17, and a radar device 18 are connected to the driving support device 10. The brake hydraulic pressure sensor 13 detects the brake hydraulic pressure P generated by the master cylinder 3. The BAH switch 14 is an on-off switch operated by the occupant of the vehicle 1. When the BAH switch 14 is operated to the on position, the brake auto hold control is enabled. When the BAH switch 14 is operated to the off position, the brake auto hold control is disabled.

[0018] The positioning device 15 is a device that measures the position of the vehicle 1. For example, it measures the position of the vehicle 1 based on GNSS (Global Navigation Satellite System). Further, the positioning device 15 is provided so as to be able to refer to map information, and also has a function of specifying the position of the vehicle 1 in light of the map information. The select lever sensor 16 is a sensor that detects the operating position of the select lever related to the setting of the gear stage of the transmission. Here, the transmission mentioned here may be an automatic transmission or a manual transmission.

[0019] In this embodiment, the information detected by the select lever sensor 16 is used to grasp the traveling direction of the vehicle 1. For example, when the operating position is the R position, it can be determined that the traveling direction of the vehicle 1 is the reverse direction (the vehicle 1 is about to move in the reverse direction). Also, when the operating position is a driving position such as the D position or the first gear or second gear, it can be determined that the traveling direction of the vehicle 1 is the forward direction (the vehicle 1 is about to move in the forward direction).

[0020] The vehicle speed sensor 17 is a sensor that detects the vehicle speed V (the traveling speed of the vehicle 1). The brake auto hold control is implemented at least during the following creep driving when the vehicle speed V is a predetermined vehicle speed V TH as follows. The radar device 18 is a sensor that irradiates electromagnetic waves in front of the vehicle and detects the presence of objects, other vehicles, pedestrians, etc. in front of the vehicle based on the reflected waves. Note that a control configuration may be adopted in which an in-vehicle camera is used instead of the radar device 18 to detect the presence of objects, other vehicles, pedestrians, etc. in front of the vehicle. The information detected by the above various devices and sensors is transmitted to the driving support device 10. The driving support device 10 implements brake auto hold control based on this information.

[0021] [2. Driving Support Device] The driving support device 10 includes a detection unit 11 and a control unit 12 as elements for implementing brake auto hold control. These elements are for the sake of conveniently classifying and showing the functions of the driving support device 10. These elements may be described as independent programs for realizing the functions of each element. Alternatively, a plurality of elements may be combined and described as one composite program.

[0022] The detection unit 11 has a function of detecting the position and traveling direction of the vehicle 1. The detection unit 11 detects the position and traveling direction of the vehicle 1 based on the detection information of, for example, the positioning device 15 and the select lever sensor 16. By comparing the position of the vehicle 1 detected here with the map information, for example, it is grasped that the vehicle 1 is located in front of an intersection or a crosswalk (that there is an intersection or a crosswalk in front of the vehicle 1), or that it is located within a parking lot. The intersections referred to here include not only crossroads but also five-way intersections, three-way intersections, T-shaped roads, etc. Further, the intersections and crosswalks referred to here include those with traffic lights and those without traffic lights.

[0023] In addition, the detection unit 11 also has a function of detecting a pedestrian in front of the vehicle 1. The detection unit 11 detects a pedestrian existing in front of the vehicle 1 based on the detection information of the radar device 18 when, for example, there is an intersection or a crosswalk in front of the vehicle 1. Further, the detection unit 11 also has a function of detecting the presence or absence of a traffic light at the intersection or crosswalk when there is an intersection or a crosswalk in front of the vehicle 1. The detection unit 11 detects the presence or absence of a traffic light based on the detection information of the radar device 18 and the map information when, for example, there is an intersection or a crosswalk in front of the vehicle 1.

[0024] The control unit 12 has a function of performing brake auto-hold control based on the brake hydraulic pressure P detected by the brake hydraulic pressure sensor 13 and the information detected by the detection unit 11. When determining the start condition of the brake auto-hold control, the control unit 12 determines the success or failure of the start condition with reference to at least the brake hydraulic pressure P, the position of the vehicle 1, and the traveling direction. Preferably, in addition to these pieces of information, the control unit 12 refers to the presence or absence of pedestrians and traffic lights in front of the vehicle 1.

[0025] When the vehicle 1 is located in front of a normal intersection with a traffic light or a crosswalk, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than the first threshold value P1. On the other hand, when the vehicle 1 is reversing in a parking lot, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than the second threshold value P2, which is higher than the first threshold value P1. That is, in a situation where the vehicle 1 is trying to park while reversing in a parking lot, the start condition of the brake auto-hold control is stricter (less likely to be satisfied) than in normal times. This prevents the brake auto-hold control from being started unintentionally during parking operation and the vehicle 1 from stopping. Also, it eliminates the annoyance of being required to perform an accelerator operation to end the brake auto-hold control.

[0026] When the vehicle 1 is about to drive out of the parking lot onto an external road, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than the second threshold value P2. That is, even in a situation where the vehicle 1 is about to merge from the parking lot onto an external road, the start condition of the brake auto-hold control is strict (less likely to be satisfied). This suppresses the start of the brake auto-hold control near the exit of the parking lot.

[0027] When the vehicle 1 is located in front of an intersection or a crosswalk and there is a pedestrian in front of the vehicle 1, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than a third threshold value P3 which is lower than the first threshold value P1. That is, in a situation where a pedestrian is crossing the intersection or crosswalk in front of the vehicle 1, the start condition of the brake auto-hold control is relaxed (more likely to be satisfied) compared with the case where there is no pedestrian. Thereby, the brake auto-hold control is more surely started in front of the pedestrian.

[0028] When the vehicle 1 is located in front of an intersection or a crosswalk and there is no traffic signal at the intersection or crosswalk, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than a third threshold value P3 which is lower than the first threshold value P1. That is, when there is no traffic signal at the intersection or crosswalk in front of the vehicle 1, the start condition of the brake auto-hold control is relaxed (more likely to be satisfied) compared with the case where there is a traffic signal. Thereby, the brake auto-hold control is more surely started at an intersection or crosswalk without a traffic signal where the driver should consciously stop temporarily.

[0029] Note that the end condition of the brake auto-hold control is set to be satisfied when a start operation is performed. Specific examples of the end condition include that the accelerator pedal is depressed, the depression amount of the accelerator pedal becomes equal to or more than a predetermined amount, the depression time of the accelerator pedal becomes equal to or more than a predetermined time, and the like. When the end condition is satisfied during the execution of the brake auto-hold control, the control unit 12 ends the brake auto-hold control.

[0030] FIG. 2 is a diagram summarizing the start conditions of the brake auto-hold control with respect to the brake hydraulic pressure P. The brake auto-hold control starts when the BAH switch 14 is operated to the on position and the vehicle speed V is TH under the premise of the following creeping driving, if the brake hydraulic pressure P is equal to or higher than a threshold value P TH The threshold value P TH is changed according to the situation. The threshold value P THThe higher it is, the less likely the brake auto hold control is to start, and the threshold value P TH The lower it is, the more likely the brake auto hold control is to start.

[0031] When the brake hydraulic pressure P is equal to or higher than the first threshold value P1, the brake auto hold control is started during a normal signal waiting stop. Specifically, the normal signal waiting stop here means "when there is an intersection or a crosswalk in front of the vehicle 1 that is about to stop, and there is a traffic signal, and there are no pedestrians". In addition, even when the vehicle 1 tries to stop at a position where there is no intersection or crosswalk in front, the brake auto hold control may be started when the brake hydraulic pressure P is equal to or higher than the first threshold value P1.

[0032] When the brake hydraulic pressure P is equal to or higher than the second threshold value P2 (where P2 > P1), the brake auto hold control is started when the vehicle 1 is backing into a parking space or merging. Specifically, the backing into a parking space here means "when the vehicle 1 is in a parking lot and is trying to reverse". Specifically, the merging here means "when the vehicle 1 is in a parking lot and is trying to drive out onto a road outside the parking lot".

[0033] When the brake hydraulic pressure P is equal to or higher than the third threshold value P3 (where P1 > P3), the brake auto hold control is started when pedestrians are crossing or when stopping at a place without a signal. Specifically, the pedestrians crossing here means "when there is an intersection or a crosswalk in front of the vehicle 1 that is about to stop and there are pedestrians". Also, specifically, the stopping at a place without a signal here means "when there is an intersection or a crosswalk in front of the vehicle 1 that is about to stop and there is no traffic signal".

[0034] The start condition related to the third threshold value P3 can be omitted. When the start condition related to the third threshold value P3 is omitted, the start condition related to the first threshold value P1 may be set to be satisfied when "an intersection or a crosswalk exists in front of the vehicle 1 that is about to stop temporarily" regardless of the presence or absence of pedestrians or traffic signals. Also, the start condition related to the first threshold value P1 may be set to be satisfied when "it is neither the time of reverse parking nor the time of merging" regardless of the presence or absence of intersections or crosswalks.

[0035] The difference between the first threshold value P1 and the second threshold value P2 may be made to coincide with the difference between the first threshold value P1 and the third threshold value P3. For example, when the first threshold value P1 is α [bar] and the second threshold value P2 is α + β [bar], the third threshold value P3 may be α - β [bar].

[0036] [3. Flowchart] Figure 3 is a flowchart for determining the start condition of the brake auto-hold control. The control of this flowchart is repeatedly executed at a predetermined cycle in the driving support device 10 when the main power supply of the vehicle 1 is turned on and the brake auto-hold control has not been started.

[0037] In step A1, it is determined whether the BAH switch 14 is operated to the on position. If this condition is satisfied, the process proceeds to step A2, and if not, the control for that cycle ends. In step A2, it is determined whether the position of the vehicle 1 measured by the positioning device 15 is within the parking lot. If the vehicle 1 is within the parking lot, the process proceeds to step A3, and if it is outside the parking lot, the process proceeds to step A5.

[0038] In step A3, it is determined whether or not the operation position of the select lever detected by the select lever sensor 16 is the R position. If this condition is satisfied, the process proceeds to step A8; if not, the process proceeds to step A4. In step A4, based on the position and traveling direction of the vehicle 1, it is determined whether or not the vehicle 1 is about to drive out from the parking lot onto an external road. For example, when the position of the vehicle 1 is near the exit of the parking lot and the operation position of the select lever is in the driving position, it is determined that the vehicle 1 is about to drive out from the parking lot onto an external road. When the condition in step A4 is satisfied, the process proceeds to step A8; if not, the process proceeds to step A5.

[0039] In step A5, it is determined whether or not the position of the vehicle 1 is in front of an intersection or a crosswalk. If this condition is satisfied, the process proceeds to step A6; if not, the process proceeds to step A9. In step A6, based on the detection information of the radar device 18, it is determined whether or not there is a pedestrian in front of the vehicle 1. If this condition is satisfied, the process proceeds to step A10; if not, the process proceeds to step A7. In step A7, based on the detection information of the radar device 18, it is determined whether or not there is a traffic signal at the intersection or crosswalk in front of the vehicle 1. If this condition is satisfied, the process proceeds to step A9; if not, the process proceeds to step A10.

[0040] In step A8, the value of the second threshold P2 is substituted into the threshold P TH In step A9, the value of the first threshold P1 is substituted into the threshold P TH In step A10, the value of the third threshold P3 is substituted into the threshold P TH Thereafter, in step A11 following each of steps A8 to A10, it is determined whether or not the brake hydraulic pressure P is equal to or greater than the threshold P TH If this condition is satisfied, the process proceeds to step A12; if not, the control for that cycle ends. In step A12, the vehicle speed V is the predetermined vehicle speed V THIt is determined whether the following conditions are met. If the condition of step A12 is satisfied, the process proceeds to step A13, and the brake auto-hold control is started. If the condition of step A12 is not satisfied, the control for that cycle ends.

[0041] [4. Function, Effect] (1) The above driving support device 10 performs brake auto-hold control that maintains the braking force by holding the brake hydraulic pressure P in the stopped state of the vehicle 1 and releases the braking force by a start operation. This driving support device 10 includes a detection unit 11 that detects the position and traveling direction of the vehicle 1, and a control unit 12 that performs brake auto-hold control based on the brake hydraulic pressure P and the information detected by the detection unit 11.

[0042] When the vehicle 1 is located in front of an intersection or a crosswalk, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than the first threshold value P1. On the other hand, when the vehicle 1 is reversing in a parking lot, the control unit 12 starts the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than the second threshold value P2, which is higher than the first threshold value P1. In this way, by making the start condition of the brake auto-hold control stricter during reversing in the parking lot, it is possible to suppress the unintentional start of the brake auto-hold control in the parking lot, and the release operation becomes unnecessary. Therefore, the convenience of the brake auto-hold control can be improved.

[0043] (2) When the vehicle 1 is about to drive out of the parking lot onto an external road, the above control unit 12 can start the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than the second threshold value P2. Thereby, it is possible to suppress the unintentional start of the brake auto-hold control when merging from the parking lot onto an external road, and the release operation becomes unnecessary. Therefore, the convenience of the brake auto-hold control can be improved.

[0044] (3) The above-mentioned detection unit 11 can detect a pedestrian in front of the vehicle 1. Further, when the vehicle 1 is located in front of an intersection or a crosswalk and there is a pedestrian in front of the vehicle 1, the above-mentioned control unit 12 can start the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than a third threshold value P3 that is lower than the first threshold value P1. Thereby, it is possible to prompt the start of the brake auto-hold control in front of the pedestrian, and the convenience of the brake auto-hold control can be improved.

[0045] (4) The above-mentioned detection unit 11 can detect the presence or absence of a traffic signal at an intersection or a crosswalk. Further, when the vehicle 1 is located in front of an intersection or a crosswalk and there is no traffic signal, the above-mentioned control unit 12 can start the brake auto-hold control if the brake hydraulic pressure P is equal to or higher than a third threshold value P3 that is lower than the first threshold value P1. Thereby, it is possible to prompt the start of the brake auto-hold control at an intersection or a crosswalk without a traffic signal where the driver should consciously stop temporarily, and the convenience of the brake auto-hold control can be improved.

[0046] [5. Others] The above embodiments are merely illustrative, and there is no intention to exclude various modifications and applications of technologies not explicitly stated in this embodiment. Each configuration of this embodiment can be variously modified and implemented without departing from their gist. Further, each configuration of this embodiment can be selected as appropriate or combined as appropriate.

[0047] In the above embodiment, the specific situations where the brake auto-hold control is started when the brake hydraulic pressure P is equal to or higher than the second threshold value P2 are exemplified as when the vehicle 1 is reverse parking or merging, but the merging may be excluded from the control target. That is, the brake auto-hold control may be started when the brake hydraulic pressure P is equal to or higher than the second threshold value P2 only for the case of "when the vehicle 1 exists in a parking lot and is about to reverse". By making the start condition of the brake auto-hold control at least during the reverse parking of the vehicle 1 stricter, the convenience of the brake auto-hold control can be improved.

[0048] In the above-described embodiment, the configuration for detecting the position of the vehicle 1 using the positioning device 15 has been exemplified. However, the position of the vehicle 1 may be detected using other methods. For example, the position of the vehicle 1 may be detected based on the vehicle speed V or the steering angle, or the position of the vehicle 1 may be detected based on the captured image of the in-vehicle camera. Further, when a parking frame exists in the captured image of the in-vehicle camera, it may be determined that the vehicle 1 is located within the parking lot.

Industrial Applicability

[0049] The present invention can be applied to the manufacturing industry of driving assistance devices mounted on vehicles, and can also be applied to the manufacturing industry of vehicles equipped with driving assistance devices.

Explanation of Reference Numerals

[0050] 1 Vehicle 2 Brake Pedal 3 Master Cylinder 4 Hydraulic Circuit 5 Brake Caliper 6 Wheel Cylinder 7 Valve 10 Driving Assistance Device 11 Detection Unit 12 Control Unit 13 Brake Hydraulic Sensor 14 BAH Switch 15 Positioning Device 16 Select Lever Sensor 17 Vehicle Speed Sensor 18 Radar Device P Brake Hydraulic Pressure P1 First Threshold Value P2 Second Threshold Value P3 Third Threshold Value

Claims

1. A driving assistance device that maintains braking force by holding brake hydraulic pressure in a stopped state of a vehicle and releases the braking force by a start operation, and performs brake auto hold control, a detection unit that detects the position and traveling direction of the vehicle, and a control unit that performs the brake auto hold control based on the brake hydraulic pressure and the information detected by the detection unit, wherein the control unit starts the brake auto hold control if the brake hydraulic pressure is equal to or higher than a first threshold when the vehicle is located in front of an intersection or a crosswalk, and starts the brake auto hold control if the brake hydraulic pressure is equal to or higher than a second threshold that is higher than the first threshold when the vehicle is reversing in a parking lot. A driving assistance device characterized by the above.

2. The control unit starts the brake auto hold control if the brake hydraulic pressure is equal to or higher than the second threshold when the vehicle is about to leave the parking lot and enter an external road. The driving assistance device according to claim 1, characterized by the above.

3. The detection unit detects a pedestrian in front of the vehicle, and the control unit starts the brake auto hold control if the brake hydraulic pressure is equal to or higher than a third threshold that is lower than the first threshold when the vehicle is located in front of the intersection or the crosswalk and a pedestrian exists in front of the vehicle. The driving assistance device according to claim 1, characterized by the above.

4. The detection unit detects the presence or absence of a traffic signal at the intersection or the crosswalk, and the control unit starts the brake auto hold control if the brake hydraulic pressure is equal to or higher than a third threshold that is lower than the first threshold when the vehicle is located in front of the intersection or the crosswalk and no traffic signal exists. The driving assistance device according to claim 1, characterized by the above.

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