Vehicle alarm system

Abstract

To properly output an alarm so as to mitigate discomfort given to a driver.SOLUTION: An alarm system for a vehicle in accordance with the present invention includes an alarm control unit that outputs an alarm when a collision prediction time for an own vehicle and an object of collision is equal to or smaller than a predetermined collision prediction time threshold. When the object of collision does not decelerate and a braking operation of the own vehicle is recognized, the alarm control unit prohibits output of an alarm. Alternatively, when the deceleration of the own vehicle is equal to or larger than a predetermined deceleration threshold, the alarm control unit inhibits output of the alarm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle alarm device that is configured to output an alarm in accordance with a collision prediction time associated with a collision of a host vehicle with a collision object. [Background technology]

[0002] Vehicles such as automobiles may be equipped with a vehicle warning device that outputs a warning to prompt the driver to apply the brakes when the possibility of the vehicle colliding with a collision object located in front of the vehicle (hereinafter, referred to as "collision possibility" as necessary) increases. Typically, the collision possibility is determined based on the collision prediction time (hereinafter, referred to as "TTC" as necessary). The TTC is a value obtained by dividing the relative distance between the vehicle and the collision object by the relative speed between the vehicle and the collision object.

[0003] Furthermore, when comparing the relative distance between the vehicle and the vehicle ahead of it, i.e., the vehicle distance, in countries around the world, the vehicle distance tends to vary depending on the traffic conditions and national characteristics of each country. For example, the vehicle distance in India tends to be smaller than that in Japan. Therefore, if a vehicle alarm device designed for Japan is used in India, the vehicle alarm device may output an excessive alarm. Such an excessive alarm may cause discomfort to the driver. Furthermore, regardless of differences between countries, it is also important to prevent the vehicle alarm device from outputting unnecessary alarms. Therefore, it is required for the vehicle alarm device to suppress excessive alarms from causing discomfort to the driver.

[0004] An example of a vehicle warning device that can meet such a demand is a driving support device having a first sensor that detects an obstacle in front of the vehicle, a second sensor that detects the driver's intention to brake the vehicle, an alarm that generates an alarm, and a controller, in which the controller is configured to predict whether the vehicle will collide with the obstacle detected by the first sensor, the controller is also configured to determine whether the driver's braking operation has been predicted based on the intention to brake the vehicle detected by the second sensor, and the controller is further configured to activate the alarm to issue an alarm when it is determined that the vehicle will collide with the obstacle and the driver's braking operation is not predicted, and to prohibit the issuance of an alarm when it is determined that the vehicle will collide with the obstacle and the driver's braking operation is predicted (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-045569 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a configuration that simply prohibits the output of an alarm when the driver's brake operation is predicted, as in the above example of a vehicle alarm device, there is a risk that an alarm will not be output in a situation where the driver predicts a collision between the vehicle and a collision object by his / her own senses and senses the risk of a collision. In this case, the driver may feel uneasy, which is also a factor that causes discomfort to the driver.

[0007] In view of this situation, it is desirable for a vehicle alarm device to appropriately output an alarm so as to reduce discomfort felt by the driver. [Means for solving the problem]

[0008] In order to solve the problem, a vehicle warning device according to one embodiment includes a collision information acquisition unit configured to be able to acquire a relative distance between a host vehicle and a collision object located in a traveling direction of the host vehicle, a relative speed between the host vehicle and the collision object, and a collision prediction time based on the relative distance and the relative speed, an alarm control unit configured to be able to execute alarm output control that outputs an alarm when an acquired value of the collision prediction time acquired by the collision information acquisition unit is equal to or less than a predetermined collision prediction time threshold, and a brake operation recognition unit configured to be able to recognize a brake operation by a driver of the host vehicle, and further includes an object deceleration determination unit configured to be able to determine whether or not the collision object is decelerating based on the acquired value of the relative speed acquired by the collision information acquisition unit, and the alarm control unit executes alarm prohibition control that prohibits output of the alarm by the alarm output control when the acquired value of the collision prediction time is equal to or less than the predetermined collision prediction time threshold, the object deceleration determination unit determines that the collision object is not decelerating, and the brake operation recognition unit recognizes the brake operation. After determining that The object deceleration determination unit determines that the collision object is decelerating. and the brake operation recognition unit recognizes the brake operation. When the above-mentioned alarm output control is performed, the alarm output control is performed.

[0009] In order to solve the problem, a vehicle warning device according to another embodiment is a vehicle warning device including a collision information acquisition unit configured to be able to acquire a relative distance between a host vehicle and a collision object located in a traveling direction of the host vehicle, a relative speed between the host vehicle and the collision object, and a collision prediction time based on the relative distance and the relative speed, an alarm control unit configured to be able to execute alarm output control that outputs an alarm when an acquired value of the collision prediction time acquired by the collision information acquisition unit is equal to or less than a predetermined collision prediction time threshold, and a host vehicle deceleration acquisition unit configured to be able to acquire a deceleration of the host vehicle, and further includes a host vehicle deceleration determination unit that determines whether or not the acquired value of the deceleration acquired by the host vehicle deceleration acquisition unit is equal to or greater than a predetermined deceleration threshold, and the alarm control unit: the acquired collision prediction time is equal to or less than the predetermined collision prediction time threshold, When the host vehicle deceleration determination unit determines that the acquired value of the deceleration is equal to or greater than a predetermined deceleration threshold value, The alarm output control Executes alarm inhibition control to inhibit output of the alarm and when the host vehicle deceleration determination unit determines that the acquired value of the collision prediction time is equal to or less than the predetermined collision prediction time threshold and that the acquired value of the deceleration is less than the predetermined deceleration threshold, the host vehicle deceleration determination unit executes the warning output control. It is configured to: Effect of the Invention

[0010] In the vehicle alarm device according to one aspect, an alarm can be appropriately output so as to reduce discomfort felt by the driver. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a configuration diagram of a vehicle including a vehicle alarm device according to a first embodiment. [Diagram 2] FIG. 2 is a plan view that illustrates a schematic diagram of the host vehicle according to the first embodiment and another vehicle that is a collision object. [Diagram 3] FIG. 3 is a graph showing the relationship between the acquired value of the number of brake operations while a specific driver is driving and the acquired value of the relative distance between the host vehicle and another vehicle in the vehicle alarm device according to the first embodiment. [Figure 4] FIG. 4 is a flowchart showing an example of a control method for the vehicle alarm device according to the first embodiment. [Diagram 5] FIG. 5 is a configuration diagram of a vehicle including a vehicle alarm device according to the second embodiment. [Figure 6] FIG. 6 is a graph showing the relationship between the acquired value of the predicted collision time between the host vehicle and another vehicle during AEB control and the acquired value of the host vehicle deceleration in the vehicle warning device according to the second embodiment. [Figure 7] FIG. 7 is a flowchart showing an example of a control method for the vehicle alarm device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The vehicle alarm device according to the first and second embodiments will be described together with the vehicle in which it is mounted. In each embodiment, the vehicle in which the vehicle alarm device (hereinafter, simply referred to as "alarm device" as necessary) is mounted is an automobile. However, such a vehicle is not limited to an automobile.

[0013] "First embodiment" A vehicle alarm device and a vehicle according to a first embodiment will be described.

[0014] "Outline of vehicle warning device and vehicle" 1 to 3, the vehicle alarm device 20 and vehicle 10 according to this embodiment are generally configured as follows. With reference to Fig. 1 and Fig. 2, the vehicle alarm device 20 has a collision information acquisition unit 21. The collision information acquisition unit 21 is capable of acquiring collision information related to a collision predicted between the vehicle 10, i.e., the host vehicle 10, and a collision object P located in the traveling direction of the host vehicle 10.

[0015] As shown in Fig. 2, in many cases, the collision object P is a vehicle P other than the host vehicle 10, i.e., another vehicle P. In many cases, the traveling direction side of the host vehicle 10 is the front side of the host vehicle 10 (indicated by a one-sided arrow F). However, the collision object may be a moving object other than a vehicle. In many cases, the traveling direction side of the host vehicle may be the rear side of the host vehicle.

[0016] 1 and 2, the collision information includes the relative distance (m) between the host vehicle 10 and the other vehicle P. The collision information includes the relative speed (m / sec) between the host vehicle 10 and the other vehicle P. The collision information includes these relative distances and a collision prediction time (hereinafter, referred to as "TTC" as necessary) (sec) based on the relative distances. Therefore, the collision information acquisition unit 21 can acquire an acquired value A of the relative distance, an acquired value B of the relative speed, and an acquired value C of the TTC.

[0017] The warning device 20 has a warning control unit 22. The warning control unit 22 is capable of executing warning output control for outputting a warning when an acquired value C of the TTC acquired by the collision information acquisition unit 21 is equal to or smaller than a predetermined TTC threshold value C1. The warning device 20 has a brake operation recognition unit 23. The brake operation recognition unit 23 is capable of recognizing a brake operation by a driver (not shown) of the host vehicle 10.

[0018] The warning device 20 has an object deceleration determination unit 24. The object deceleration determination unit 24 is capable of determining whether or not the other vehicle P is decelerating, based on the relative speed acquisition value B acquired by the collision information acquisition unit 21. The warning control unit 22 executes warning prohibition control for prohibiting output of a warning when the object deceleration determination unit 24 determines that the other vehicle P is not decelerating and the brake operation recognition unit 23 recognizes a brake operation.

[0019] Further, the vehicle alarm device 20 and the vehicle 10 according to the present embodiment can be configured as follows. Referring to Figs. 1 to 3, the vehicle alarm device 20 has a brake operation count acquisition unit 25. The brake operation count acquisition unit 25 is capable of acquiring the brake operation count (times) of the driver of the vehicle 10. The alarm control unit 22 executes alarm prohibition control for prohibiting the output of an alarm when the acquisition value A of the relative distance acquired by the collision information acquisition unit 21 is equal to or greater than a predetermined relative distance threshold A1. The relative distance threshold A1 is changed based on the relationship between the acquisition value A of the relative distance and the acquisition value D of the brake operation count acquired by the brake operation count acquisition unit 25. In Fig. 3, the horizontal axis A indicates the acquisition value (m) of the relative distance, and the vertical axis D indicates the acquisition value (times) of the brake operation count. In Fig. 3, as an example, the characteristic of the relative distance-brake operation count when a specific driver is driving is indicated by a solid line J.

[0020] "Vehicle Details" 1, the vehicle 10 can be configured in detail as follows. The vehicle 10 has an object detection device 11. The object detection device 11 is capable of detecting the presence of a collision object P, in particular, another vehicle P. The object detection device 11 is also capable of detecting the relative distance from the host vehicle 10 to the collision object P. The object detection device 11 includes a sonar sensor. However, the object detection device may include a camera, a millimeter wave radar, an infrared laser radar, a LiDAR (Light Detection and Ranging), or the like, instead of or in addition to the sonar sensor.

[0021] The vehicle 10 typically has four wheels 12. The vehicle 10 rotates at a rotational speed (sec -1 However, the vehicle may have a vehicle speed sensor capable of detecting the traveling speed of the host vehicle instead of or in addition to the wheel speed sensor.

[0022] The vehicle 10 has a sound output device 14 that can output the above-mentioned warning by sound information such as a buzzer sound, voice, etc. For example, the sound output device 14 can include a speaker. The vehicle 10 also has a display output device 15 that can output the warning by visual information such as characters, figures, illustrations, light, etc. For example, the display output device 15 can be a display having a liquid crystal panel, an organic EL (electroluminescence) panel, etc., an instrument panel, a lamp, etc.

[0023] The vehicle 10 has a brake device 16 used for braking. The brake device 16 has brakes 16a capable of braking each wheel 12. The brake device 16 has a hydraulic unit 16b capable of adjusting the braking force of each brake 16a. The brake device 16 has a brake pedal 16c that allows the hydraulic unit 16b to be operated to adjust the braking force of each brake 16a. The brake device 16 has a hydraulic pressure sensor 16d that can detect the operation of the brake pedal 16c by the driver. However, the brake device may have a stroke sensor instead of or in addition to the hydraulic pressure sensor.

[0024] "Details of vehicle alarm system" 1 to 3, the vehicle alarm device 20 according to this embodiment can be configured in detail as follows. The vehicle alarm device 20 is configured to include electronic components such as a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an input interface, an output interface, and an electric circuit in which such electronic components are arranged. The ROM stores a program for performing the functions of the alarm device 20 together with various control constants, various maps, and the like. Therefore, when the CPU executes the program stored in the ROM, the alarm device 20 can perform the functions. However, the automatic parking device is not limited to this.

[0025] 1 and 2, the collision information acquisition unit 21 of the warning device 20 can be a collision damage mitigation brake unit (hereinafter, referred to as an "AEB unit" as necessary) 21. The AEB unit 21 directly or indirectly controls the brake device 16 to execute AEB control when there is a possibility that the host vehicle 10 will collide with a collision object P.

[0026] The collision information acquisition unit 21 is capable of acquiring a detection value of the relative distance detected by the object detection device 11. The collision information acquisition unit 21 is capable of acquiring a detection value of the wheel speed detected by the wheel speed sensor 13. The collision information acquisition unit 21 calculates the vehicle speed (m / sec, km / h) of the host vehicle 10 based on the acquired value of the wheel speed, thereby acquiring the vehicle speed of the host vehicle 10. However, the collision information acquisition unit can also acquire the detection value of the vehicle speed detected by the vehicle speed sensor.

[0027] The collision information acquisition unit 21 calculates the relative speed between the host vehicle 10 and the collision object P based on the acquired vehicle speed value E of the host vehicle 10 and the acquired relative distance value A, thereby acquiring the relative speed. The collision information acquisition unit 21 calculates the TTC based on the following (Equation 1) related to the acquired relative distance value A and the acquired relative speed value B, thereby acquiring the TTC. That is, the acquired TTC value C is obtained by the following (Equation 1).

[0028] C = A / B (Formula 1)

[0029] The warning device 20 includes a TTC determining unit 26. The TTC determining unit 26 determines whether or not the acquired value C of the TTC acquired by the collision information acquiring unit 21 is equal to or less than a predetermined TTC threshold value C1.

[0030] The warning device 20 has a host vehicle speed determination unit 27. The host vehicle speed determination unit 27 determines whether or not the acquired value E of the host vehicle 10 acquired by the collision information acquisition unit 21 is equal to or less than a vehicle speed threshold E1. For example, the vehicle speed threshold E1 may be in the range of about 20 km / h to about 30 km / h. However, the vehicle speed threshold is not limited to this.

[0031] The warning device 20 includes a relative distance determination unit 28. The relative distance determination unit 28 determines whether or not an acquired value A of the relative distance acquired by the collision information acquisition unit 21 is equal to or greater than a predetermined relative distance threshold A1.

[0032] The brake operation recognizing unit 23 is capable of determining whether or not the operation of the brake pedal 16c by the driver has been recognized. Specifically, the brake operation recognizing unit 23 is capable of determining whether or not the operation of the brake pedal 16c by the driver has been detected by the hydraulic pressure sensor 16d of the braking device 16. When the operation of the brake pedal 16c is detected by the hydraulic pressure sensor 16d of the braking device 16, the brake operation recognizing unit 23 recognizes the brake operation by the driver.

[0033] The object deceleration determination unit 24 can determine whether the collision object P is decelerating based on the acquired value E of the vehicle speed of the host vehicle 10 and the acquired value B of the relative speed acquired by the collision information acquisition unit 21. For example, the object deceleration determination unit 24 can determine that the collision object P is decelerating when the acquired value B of the relative speed decreases and the acquired value E of the vehicle speed of the host vehicle 10 is approximately constant or decreases. For example, the object deceleration determination unit 24 can determine that the collision object P is not decelerating when the acquired value B of the relative speed increases. For example, the object deceleration determination unit 24 can determine that the collision object P is not decelerating when the acquired value B of the relative speed decreases and the acquired value E of the vehicle speed of the host vehicle 10 increases.

[0034] The braking count acquisition unit 25 is capable of storing the recognition of the braking operations by the braking operation recognition unit 23. The braking count acquisition unit 25 accumulates the recognition of the braking operations thus stored, thereby acquiring the number of braking operations. The warning device 20 has a relative distance threshold changing unit 29 that changes the relative distance threshold A1 based on the relationship between the acquired value A of the relative distance and the acquired value D of the braking operation number acquired by the braking count acquisition unit 25.

[0035] 3, for example, as a first case, the relative distance threshold change unit 29 can set the relative distance threshold A1 to a small value when the acquired value D of the number of brake operations is large even if the acquired value A of the relative distance is small. In this first case, even if the vehicle 10 approaches the collision object P, it becomes difficult to output an alarm.

[0036] On the other hand, for example, in a second case, the relative distance threshold change unit 29 can set the relative distance threshold A1 to be larger than in the first case when the acquired value D of the number of brake operations is small even if the acquired value A of the relative distance is large compared to the first case. In this second case, an alarm is more likely to be output even if the vehicle 10 is farther away from the collision object P than in the first case.

[0037] "Method for controlling vehicle alarm device" An example of a control method for the vehicle alarm device 20 according to this embodiment will be described with reference to Fig. 4. First, it is determined whether the acquired TTC value C is equal to or smaller than a predetermined TTC threshold value C1 (step S1). If the acquired TTC value C is greater than the predetermined TTC threshold value C1 (NO), the vehicle 10 performs normal driving (step S2).

[0038] If the acquired TTC value C is equal to or less than the predetermined TTC threshold C1 (YES), it is determined whether the acquired vehicle speed value E of the vehicle 10 is equal to or less than the vehicle speed threshold E1 (step S3). If the acquired vehicle speed value E of the vehicle 10 is greater than the vehicle speed threshold E1 (NO), an alarm is output (step S4).

[0039] If the acquired vehicle speed E of the vehicle 10 is equal to or less than the vehicle speed threshold E1 (YES), it is determined whether or not the operation of the brake pedal 16c by the driver has been recognized (step S5). If the operation of the brake pedal 16c by the driver has not been recognized (NO), an alarm is output (step S4).

[0040] If the operation of the brake pedal 16c by the driver is recognized (YES), it is determined whether or not the collision object P is decelerating (step S6). If the collision object P is decelerating (YES), a warning is output (step S4). If the collision object P is not decelerating (NO), the output of the warning is prohibited (step S7).

[0041] As described above, the vehicle warning device 20 according to this embodiment includes a collision information acquisition unit 21 configured to be able to acquire the relative distance between the host vehicle 10 and a collision object P located in the traveling direction of the host vehicle 10, the relative speed between the host vehicle 10 and the collision object P, and a collision prediction time based on the relative distance and the relative speed, a warning control unit 22 configured to be able to execute warning output control that outputs a warning when an acquired value C of the collision prediction time acquired by the collision information acquisition unit 21 is equal to or smaller than a predetermined collision prediction time threshold C1, and a warning control unit 23 configured to execute a warning output control that outputs a warning when the host vehicle 10 is in a collision with the collision object P. The vehicle warning device 20 is equipped with a brake operation recognition unit 23 configured to be able to recognize the brake operation of the driver of the vehicle (10), and an object deceleration determination unit 24 configured to be able to determine whether or not the collision object P is decelerating based on the acquisition value B of the relative speed acquired by the collision information acquisition unit 21, and the warning control unit 22 is configured to execute warning prohibition control that prohibits the output of the warning when the object deceleration determination unit 24 determines that the collision object P is not decelerating and the brake operation recognition unit 23 recognizes the brake operation.

[0042] Generally, even if the brake operation of the vehicle is not performed, if the collision object does not decelerate, the relative distance between the vehicle and the collision object is almost never shortened. In such a case, the driver hardly ever predicts the collision between the vehicle and the collision object by his / her own senses and perceives the risk of collision, so there is no risk that the driver will feel uneasy because a warning is not output.

[0043] In contrast, in the vehicle alarm device 20 according to the present embodiment, when the vehicle 10 is not braking and the collision object P is not decelerating as described above, an alarm is prohibited from being output, and when the relative distance between the vehicle 10 and the collision object P is likely to decrease, an alarm is output to encourage the driver to apply a stronger brake. This makes it possible to prevent an excessive alarm from causing discomfort to the driver, and also to prevent the driver from feeling uneasy due to the absence of an alarm. Therefore, an alarm can be appropriately output to reduce discomfort to the driver.

[0044] The vehicle warning device 20 in this embodiment is equipped with a braking count acquisition unit 25 configured to acquire the number of brake operations by the driver of the vehicle 10, and the warning control unit 22 is configured to be able to execute warning prohibition control that prohibits the output of the warning when the acquired value A of the relative distance acquired by the collision information acquisition unit 21 is equal to or greater than a predetermined relative distance threshold A1, and the relative distance threshold A1 is configured to be changed based on the relationship between the acquired value A of the relative distance and the acquired value D of the brake operation number acquired by the braking count acquisition unit 25.

[0045] In such a vehicle alarm device 20, whether or not to output an alarm is determined based on the relative distance between the vehicle 10 and the collision object P, taking into account the characteristics of the driver's braking operation, so that the alarm can be output more appropriately so as to appropriately reduce the discomfort caused to the driver.

[0046] "Second embodiment" A vehicle alarm device and a vehicle according to the second embodiment will be described.

[0047] "Outline of vehicle warning device and vehicle" 5 and 6, the vehicle alarm device 40 and the vehicle 30 according to this embodiment are generally configured as follows. Referring to Fig. 5, the vehicle alarm device 40 has a collision information acquisition unit 41. The collision information acquisition unit 41 is generally configured similarly to the collision information acquisition unit 21 of the first embodiment.

[0048] The vehicle warning device 40 has a warning control unit 42. The warning control unit 42 is capable of executing warning output control in the same manner as the warning control unit 22 of the first embodiment. The warning device 40 has a host vehicle deceleration acquisition unit 43. The host vehicle deceleration acquisition unit 43 acquires the deceleration (m / s 2 ) can be obtained.

[0049] 5 and 6, the warning device 40 has a host vehicle deceleration determination unit 44. The host vehicle deceleration determination unit 44 determines whether the acquired deceleration value F acquired by the host vehicle deceleration acquisition unit 43 is equal to or greater than a predetermined deceleration threshold value F1. The warning control unit 42 executes warning prohibition control to prohibit the output of a warning when the host vehicle deceleration determination unit 44 determines that the acquired deceleration value F is equal to or greater than the predetermined deceleration threshold value F1. In FIG. 6, the horizontal axis C indicates the acquired TTC value (sec), and the vertical axis F indicates the acquired deceleration value (m / s 2 In FIG. 6, the TTC-deceleration characteristic during AEB control is shown by a solid line K.

[0050] Furthermore, the vehicle warning device 40 and the vehicle 30 according to this embodiment can be generally configured as follows: In the vehicle warning device 40, the deceleration threshold value F1 is set to increase as the acquired TTC value C decreases.

[0051] The warning device 40 has a braking count acquisition unit 45. The braking count acquisition unit 45 is generally configured similarly to the braking count acquisition unit 25 of the first embodiment. The warning control unit 42, like the warning control unit 22 of the first embodiment, executes warning prohibition control for prohibiting output of a warning when the acquisition value A of the relative distance acquired by the collision information acquisition unit 41 is equal to or greater than a predetermined relative distance threshold A1. Like the warning device 20 of the first embodiment, the relative distance threshold A1 is changed based on the relationship between the acquisition value A of the relative distance and the acquisition value D of the number of brake operations acquired by the braking count acquisition unit 45.

[0052] "Vehicle Details" 5, the vehicle 30 according to this embodiment can be configured in detail as follows. The vehicle 30 according to this embodiment has an object detection device 31, wheels 32, wheel speed sensors 33, sound output device 34, display output device 35, and brake device 36, which are configured similarly to the object detection device 11, wheels 12, wheel speed sensors 13, sound output device 14, display output device 15, and brake device 16 of the first embodiment, respectively. Furthermore, the brake device 36 according to this embodiment has a brake 36a, a hydraulic pressure unit 36b, a brake pedal 36c, and a hydraulic pressure sensor 36d, which are configured similarly to the brake 16a, hydraulic pressure unit 16b, brake pedal 16c, and hydraulic pressure sensor 16d of the first embodiment, respectively.

[0053] "Details of vehicle alarm system" 5 and 6, the vehicle alarm device 40 according to this embodiment can be configured in detail as follows. The vehicle alarm device 40 is configured to include the above-mentioned electronic components and electric circuits, similar to the vehicle alarm device 20 according to the first embodiment.

[0054] 5, the collision information acquisition unit 41 is configured in a manner similar to the collision information acquisition unit 21 according to the first embodiment in detail. The warning device 40 has a TTC determination unit 46. The TTC determination unit 46 according to this embodiment is configured in a manner similar to the TTC determination unit 26 according to the first embodiment in detail. The warning device 40 has a host vehicle speed determination unit 47. The host vehicle speed determination unit 47 according to this embodiment is configured in a manner similar to the host vehicle speed determination unit 27 according to the first embodiment.

[0055] The warning device 40 has a relative distance determination unit 48. The relative distance determination unit 48 according to this embodiment is configured similarly to the relative distance determination unit 28 according to the first embodiment. The warning device 40 has a relative distance threshold changing unit 49. The relative distance threshold changing unit 49 according to this embodiment is configured similarly to the relative distance threshold changing unit 29 according to the first embodiment.

[0056] Furthermore, the host vehicle deceleration acquisition unit 43 of the warning device 40 calculates the deceleration of the host vehicle 30 based on the acquired value E of the host vehicle 30 acquired by the collision information acquisition unit 41, thereby acquiring the deceleration of the host vehicle 30. The host vehicle deceleration determination unit 44 increases the deceleration threshold value F1 in accordance with the decrease in the acquired value C of the collision prediction time.

[0057] "Method for controlling vehicle alarm device" An example of a control method for the vehicle alarm device 40 according to this embodiment will be described with reference to Fig. 7. First, it is determined whether the acquired TTC value C is equal to or smaller than a predetermined TTC threshold value C1 (step S11). If the acquired TTC value C is greater than the predetermined TTC threshold value C1 (NO), the vehicle 30 performs normal driving (step S12).

[0058] If the acquired TTC value C is equal to or less than the predetermined TTC threshold C1 (YES), it is determined whether the acquired vehicle speed value E of the host vehicle 30 is equal to or less than the vehicle speed threshold E1 (step S13). If the acquired vehicle speed value E of the host vehicle 30 is greater than the vehicle speed threshold E1 (NO), an alarm is output (step S14).

[0059] If the acquired vehicle speed value E of the host vehicle 30 is equal to or less than the vehicle speed threshold E1 (YES), it is determined whether the acquired deceleration value F is equal to or greater than a predetermined deceleration threshold F1 (step S15). If the acquired deceleration value F is less than the predetermined deceleration threshold F1 (NO), an alarm is output (step S4). If the acquired deceleration value F is equal to or greater than the predetermined deceleration threshold F1 (YES), output of the alarm is prohibited (step S16).

[0060] As described above, the vehicle warning device 40 according to this embodiment includes a collision information acquisition unit 41 configured to acquire the relative distance between the host vehicle 30 and a collision object P located in the traveling direction of the host vehicle 30, the relative speed between the host vehicle 30 and the collision object P, and a collision prediction time based on the relative distance and the relative speed, a warning control unit 42 configured to execute warning output control that outputs a warning when the acquired value C of the collision prediction time acquired by the collision information acquisition unit 41 is equal to or less than a predetermined collision prediction time threshold C1, and a host vehicle deceleration acquisition unit 43 configured to acquire the deceleration of the host vehicle 30. The vehicle warning device 40 includes a host vehicle deceleration determination unit 44 that determines whether the acquired value F of the deceleration acquired by the host vehicle deceleration acquisition unit 43 is equal to or greater than a predetermined deceleration threshold F1, and the warning control unit 42 is configured to execute warning prohibition control that prohibits the output of the warning when the host vehicle deceleration determination unit 44 determines that the acquired value F of the deceleration is equal to or greater than the predetermined deceleration threshold F1.

[0061] Generally, when the vehicle is decelerating suddenly, the driver is actively trying to stop the vehicle by his / her own will in most cases, so the relative distance between the vehicle and the collision object is almost never shortened. In such a case, the driver hardly ever predicts a collision between the vehicle and the collision object by his / her own senses, and hardly ever senses the risk of a collision, so there is no risk that the driver will feel uneasy because a warning is not output.

[0062] In contrast, in the vehicle alarm device 40 according to the present embodiment, when the vehicle 30 is decelerating rapidly, the output of an alarm is prohibited, and when the relative distance between the vehicle 30 and the collision object P is likely to decrease, an alarm is output to prompt the driver to apply stronger brakes. This makes it possible to prevent an excessive alarm from causing discomfort to the driver, and also to prevent the driver from feeling uneasy due to the absence of an alarm. Therefore, an alarm can be appropriately output to reduce discomfort to the driver.

[0063] In the vehicle warning device 40 according to this embodiment, the deceleration threshold value F1 is set to increase as the acquired value C of the collision prediction time decreases.

[0064] Generally, as the collision prediction time increases, the collision possibility decreases, and as the collision prediction time decreases, the collision possibility increases. In contrast, in the vehicle alarm device 40 according to this embodiment, the deceleration threshold F1 decreases when the collision possibility decreases, so that excessive alarm output can be suppressed, and the deceleration threshold F1 increases when the collision possibility increases, so that an alarm can be reliably output in a situation where the driver predicts a collision between the vehicle 30 and the collision object P by his / her own senses and senses the risk of a collision. Therefore, an alarm can be appropriately output so as to reduce discomfort to the driver.

[0065] According to the vehicle alarm device 40 of this embodiment, alarm prohibition control can be executed according to the relative distance, as in the first embodiment. Therefore, the vehicle alarm device 40 of this embodiment can provide an effect based on the alarm prohibition control according to the relative distance, as in the first embodiment.

[0066] Although the embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiment, and the present invention can be modified and changed based on the technical concept thereof. [Explanation of symbols]

[0067] 10…Vehicle, own vehicle 20... vehicle warning device, 21... collision information acquisition unit, collision damage mitigation brake unit, AEB unit, 22... warning control unit, 23... brake operation recognition unit, 24... object deceleration determination unit, 25... braking count acquisition unit 30…Vehicle, own vehicle 40... Vehicle warning device, 41... Collision information acquisition unit, collision damage mitigation brake unit, AEB unit, 42... Warning control unit, 43... Vehicle deceleration acquisition unit, 44... Vehicle deceleration determination unit, 45... Braking count acquisition unit A...obtained value of relative distance, horizontal axis, B...obtained value of relative speed, C...obtained value of predicted collision time, obtained value of TTC, horizontal axis, C1...predicted collision time threshold, TTC threshold, D...obtained value of number of brake operations, vertical axis, E...obtained value of vehicle speed, E1...vehicle speed threshold, F...obtained value of deceleration, vertical axis, F1...deceleration threshold P: Collision object, other vehicle

Claims

1. a collision information acquisition unit configured to be able to acquire a relative distance between a host vehicle and a collision object located in a traveling direction of the host vehicle, a relative speed between the host vehicle and the collision object, and a collision prediction time based on the relative distance and the relative speed; a warning control unit configured to execute warning output control for outputting a warning when an acquired value of the collision prediction time acquired by the collision information acquisition unit is equal to or less than a predetermined collision prediction time threshold; a brake operation recognition unit configured to recognize a brake operation by a driver of the vehicle; A vehicle alarm device comprising: an object deceleration determination unit configured to determine whether or not the object being hit is decelerating based on the acquired value of the relative velocity acquired by the collision information acquisition unit, The alarm control unit is when the acquired value of the collision prediction time is equal to or less than the predetermined collision prediction time threshold, the object deceleration determination unit determines that the collision object is not decelerating, and the brake operation recognition unit recognizes the brake operation, executes an alarm prohibition control that prohibits output of the alarm by the alarm output control, A vehicle warning device configured to execute the warning output control when, after determining that the acquired value of the collision prediction time is equal to or less than the predetermined collision prediction time threshold, the object deceleration determination unit determines that the collision object is decelerating and the brake operation recognition unit recognizes the brake operation.

2. a collision information acquisition unit configured to be able to acquire a relative distance between a host vehicle and a collision object located in a traveling direction of the host vehicle, a relative speed between the host vehicle and the collision object, and a collision prediction time based on the relative distance and the relative speed; a warning control unit configured to execute warning output control for outputting a warning when an acquired value of the collision prediction time acquired by the collision information acquisition unit is equal to or less than a predetermined collision prediction time threshold; a host vehicle deceleration acquisition unit configured to acquire the deceleration of the host vehicle; A vehicle alarm device comprising: a host vehicle deceleration determination unit that determines whether or not the acquired value of the deceleration acquired by the host vehicle deceleration acquisition unit is equal to or greater than a predetermined deceleration threshold value, The alarm control unit is When the host vehicle deceleration determination unit determines that the acquired value of the collision prediction time is equal to or less than the predetermined collision prediction time threshold and that the acquired value of the deceleration is equal to or greater than a predetermined deceleration threshold, the host vehicle deceleration determination unit executes an alarm prohibition control for prohibiting output of the alarm by the alarm output control, A vehicle warning device configured to execute the warning output control when the vehicle deceleration determination unit determines that the acquired value of the collision prediction time is equal to or less than the predetermined collision prediction time threshold and that the acquired value of the deceleration is less than the predetermined deceleration threshold.

3. 3. The vehicle warning device according to claim 2, wherein the deceleration threshold is set to increase as the acquired value of the collision prediction time decreases.

4. A braking frequency acquisition unit configured to acquire a braking frequency of a driver of the vehicle, the warning control unit is configured to execute warning prohibition control for prohibiting output of the warning when an acquired value of the relative distance acquired by the collision information acquisition unit is equal to or greater than a predetermined relative distance threshold, The vehicle warning device according to any one of claims 1 to 3, wherein the relative distance threshold is changed based on a relationship between the acquired value of the relative distance and the acquired value of the number of brake operations acquired by the braking number acquisition unit.

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