阅读说明：本技术 车辆用警报系统 (Vehicle alarm system ) 是由 吉田优己 于 2019-05-16 设计创作，主要内容包括：提供一种能够减少让驾驶者感到烦躁的警报的车辆用警报系统。车辆用警报系统(1)具备：判定警报部(52),设定从车辆(2)向前方延伸的右警报线(61)及左警报线(62),判定在规定时间以内物体是否与右警报线(61)或者左警报线(62)交叉,并且在判定为在规定时间以内物体与该警报线交叉的情况下使警报装置工作；以及距离检测部(53),检测车辆(2)和在车辆(2)的前方停止的其他车辆之间的距离d。在距离d为规定值以下的情况下,与距离d大于规定值的情况相比,判定警报部(52)执行抑制警报装置的工作的警报抑制控制。(Provided is a vehicle warning system capable of reducing a warning that makes a driver feel annoyed. A vehicle alarm system (1) is provided with: a determination alarm unit (52) that sets a right alarm line (61) and a left alarm line (62) that extend forward from the vehicle (2), determines whether an object intersects the right alarm line (61) or the left alarm line (62) within a predetermined time, and activates the alarm device if it is determined that the object intersects the alarm line within the predetermined time; and a distance detection unit (53) that detects the distance d between the vehicle (2) and another vehicle that has stopped in front of the vehicle (2). When the distance d is equal to or less than a predetermined value, the determination alarm unit (52) executes alarm suppression control for suppressing the operation of the alarm device, as compared with when the distance d is greater than the predetermined value.)

1. A vehicle alarm system is provided with:

An object detection unit that detects an object present around the vehicle;

A determination alarm unit that sets an alarm line extending forward from the vehicle, determines whether or not the object intersects the alarm line within a predetermined time, and activates an alarm device when it is determined that the object intersects the alarm line within the predetermined time; and

A distance detection unit that detects a distance between the vehicle and another vehicle in front of the vehicle,

When the distance is equal to or less than a predetermined value, the determination alarm unit executes alarm suppression control for suppressing the operation of the alarm device, as compared with a case where the distance is greater than the predetermined value.

2. The warning system for a vehicle as claimed in claim 1,

The alarm device comprises a1 st alarm device and a2 nd alarm device,

When the distance is greater than the predetermined value, the judgment alarm unit activates the 1 st alarm device and the 2 nd alarm device,

When the distance is equal to or less than the predetermined value, the 2 nd alarm device is operated as the alarm suppression control without operating the 1 st alarm device.

3. The warning system for a vehicle as claimed in claim 2,

The above-mentioned 1 st alarm device gives an alarm by sound,

The 2 nd alarm device gives an alarm by displaying.

4. The warning system for a vehicle according to any one of claims 1 to 3,

When the distance is the 1 st distance, the judgment warning unit sets the length of the warning line to the 1 st length,

When the distance is a2 nd distance smaller than the 1 st distance, the determination alarm unit sets the length of the alarm line to a2 nd length shorter than the 1 st length as the alarm suppression control.

Technical Field

the present invention relates to a vehicle alarm system, and more particularly to a vehicle alarm system that issues an alarm when an object approaches.

Background

Systems are proposed for issuing an alarm when an object is in proximity. For example, patent literature 1 proposes a system for determining the possibility of collision between an object and a vehicle based on the distance between the object and the vehicle present on the side of the vehicle and the relative speed of the object. In the case where it is determined that an object is likely to collide with the vehicle, the system issues an alarm to the driver of the vehicle.

The system described in patent document 1 acquires a stoppable distance (i.e., a distance that an object moves until it stops) of each object existing around a vehicle. The system operates the warning device in a case where the stoppable distance of the object is larger than the distance from the object to the vehicle. Such a system is effective in that the driver's attention can be directed to an object that is difficult for the driver to see, and the driver is encouraged to perform driving for collision avoidance.

Patent document 1: japanese patent laid-open No. 2012-160103

The system described in patent document 1 is configured to, when an object in the vicinity of a vehicle satisfies a physical condition relating to a collision, recognize that the object may collide with the vehicle, and issue an alarm. However, such systems may unnecessarily sound an alarm in the event that physical conditions do not accurately reflect the actual likelihood of a collision. That is, even if the possibility of an object colliding with the vehicle is actually low, the system issues an alarm, and may be annoying to the driver.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object thereof is to provide a vehicle warning system capable of reducing a warning that a driver feels annoyed.

In order to solve the above problem, the present invention is a vehicle alarm system including: an object detection unit that detects an object present around the vehicle; a determination alarm unit that sets an alarm line extending forward from the vehicle, determines whether or not an object intersects the alarm line within a predetermined time, and activates the alarm device when it is determined that the object intersects the alarm line within the predetermined time; and a distance detection unit that detects a distance between the vehicle and another vehicle in front of the vehicle, and determines that the alarm unit executes alarm suppression control for suppressing operation of the alarm device when the distance is equal to or less than a predetermined value, as compared to when the distance is greater than the predetermined value.

For example, consider a case where there is another vehicle in front of the lane on which the vehicle is traveling, and the other vehicle is stopping based on a stop signal emitted by a traffic light. In this case, the vehicle stops with a gap provided between the vehicle and another vehicle. The vehicle does not start as long as the stop signal is not released and the other vehicles do not start. In this way, when the vehicle is stopped, the possibility that an object existing around the vehicle collides with the vehicle is lower than that in the case where the vehicle can be started.

Here, according to the above configuration, the distance detecting unit detects the distance between the vehicle and another vehicle in front of the vehicle, and when the distance is equal to or less than a predetermined value, alarm suppression control for suppressing the operation of the alarm device is executed as compared with a case where the distance is greater than the predetermined value. As a result, when the possibility of collision between the object and the vehicle is high, the driver is strongly alerted by the alarm, and when the possibility of collision between the object and the vehicle is low, the alarm that makes the driver feel annoyed can be reduced.

In the present invention, it is preferable that the alarm device includes a1 st alarm device and a2 nd alarm device, and the determination alarm section activates the 1 st alarm device and the 2 nd alarm device when the distance is greater than the predetermined value, and activates the 2 nd alarm device as the alarm suppression control without activating the 1 st alarm device when the distance is equal to or less than the predetermined value.

According to this configuration, when the distance between the vehicle and the other vehicle is equal to or less than the predetermined value (that is, when the possibility of collision between the object and the vehicle is relatively low), the determination alarm unit does not operate the 1 st alarm device, and can reduce the number of alarms that cause the driver to feel annoyed.

In the present invention, it is preferable that the 1 st alarm device issues an alarm by sound, and the 2 nd alarm device issues an alarm by display.

Compared to a display-based alert, a sound-based alert is more likely to be irritating to the driver. According to the above configuration, when the distance between the vehicle and another vehicle is equal to or less than the predetermined value (that is, when the possibility of collision between the object and the vehicle is relatively low), the warning by sound is not generated, and the warning that the driver feels annoyed can be reduced.

In the present invention, it is preferable that the determination alarm unit sets the length of the alarm line to 1 st length when the distance is 1 st distance, and sets the length of the alarm line to 2 nd length shorter than the 1 st length as the alarm suppression control when the distance is 2 nd distance smaller than the 1 st distance.

According to this configuration, when the distance between the vehicle and the other vehicle is the 2 nd distance, the warning line is shorter than when the distance is the 1 st distance. Thus, when the distance is relatively small, it is difficult to determine that the object intersects the alarm line within the predetermined time period, as compared with the case where the distance is relatively large. As a result, when the distance is relatively small, the determination warning unit can suppress the operation of the warning device and reduce the warning that the driver feels annoyed, as compared with the case where the distance is relatively large.

The invention has the following effects:

According to the present invention, it is possible to provide a vehicle warning system capable of reducing a warning that makes a driver feel annoyed.

Drawings

Fig. 1 is a block diagram showing a vehicle alarm system according to embodiment 1.

Fig. 2 is an explanatory diagram of collision determination of the vehicle alarm system of fig. 1.

Fig. 3 is an explanatory diagram of collision determination on a crosswalk.

Fig. 4 is a flowchart showing a process executed by the ECU of fig. 1.

Fig. 5 is a flowchart showing a process executed by the ECU of fig. 1.

Fig. 6 is a flowchart showing processing executed by the ECU of the vehicle alarm system according to embodiment 2.

Fig. 7 is a flowchart showing processing executed by the ECU of the vehicle alarm system according to embodiment 2.

Description of symbols:

1. 10 a warning system for a vehicle (warning system); 2, vehicles; 41 speaker (1 st alarm device); 42 display (2 nd alarm device); 51 an object detection unit; 52 a determination alarm part; 53 distance detection part; 61 right alarm line (alarm line); 62 left alarm line (alarm line)

Detailed Description

The embodiments are described below with reference to the drawings. For convenience of explanation, the same components are denoted by the same reference numerals in the drawings, and redundant explanation is omitted.

[ embodiment 1 ]

First, the configuration of a vehicle alarm system 1 (hereinafter referred to as "alarm system 1") according to embodiment 1 will be described with reference to fig. 1. Fig. 1 is a block diagram showing an alarm system 1.

The warning system 1 is mounted on a vehicle, and is a system for alerting a driver of the vehicle to a warning. In the present specification, a vehicle equipped with the alarm system 1 is referred to as a "vehicle 2". The warning system for a vehicle according to the present invention is not limited to 4-wheel vehicles, and may be mounted on a traveling body such as 2-wheel vehicles.

In the present specification, the direction in which the vehicle 2 moves forward is referred to as "front", and the direction in which the vehicle moves backward is referred to as "rear". The left direction when the vehicle 2 is heading in the forward direction is referred to as "left", and the right direction is referred to as "right".

The alarm system 1 includes: a side radar 31, an exterior camera 32, a navigation device 33, and a speed sensor 34. The alarm system 1 further includes: a speaker 41, a display 42, and an ECU (Electronic Control Unit) 5.

The side radar 31 is used for detecting an object existing outside the vehicle 2, detecting the speed of the object, and detecting the distance from an alarm line to the object, which will be described later. Examples of the detectable object include another vehicle, a road fixed structure, a pedestrian, and the like. The "other vehicle" includes not only 4-wheel vehicles but also traveling bodies such as 2-wheel vehicles and bicycles. As will be described later, the side radar 31 performs the above detection with respect to an object existing in a detection area provided on the side of the vehicle 2. The side radar 31 is, for example, a millimeter-wave radar (having a frequency of 76GHz to 77GHz), and includes antennas corresponding to the right and left sides of the vehicle 2. The antenna may be a transmitting/receiving antenna, or may be composed of a transmitting antenna and a receiving antenna separately. The side radar 31 transmits a side stationary wave to a side of the vehicle 2 with respect to the antenna, and receives a reflected wave reflected by an object. The side radar 31 transmits a signal corresponding to the received reflected wave to the ECU 5.

The front radar 32 is provided, for example, in the front of the vehicle 2. The front radar 32 is used for detection of an object existing in front of the vehicle 2, detection of the speed of the object, and detection of the distance from the vehicle 2 to the object. Examples of the detectable object include another vehicle, a fixed structure on the road, a pedestrian, and the like. The front radar 32 transmits the measurement wave to the front of the vehicle 2 with respect to the antenna, and receives the reflected wave reflected by the object. The front radar 32 transmits a signal corresponding to the received reflected wave to the ECU 5.

The exterior camera 32 captures an image of a range including detection areas of the side radar 31 and the front radar 32, and acquires image information. The exterior camera 32 is, for example, an image sensor, and is provided in an interior mirror, not shown, of the vehicle 2. The vehicle exterior camera 32 transmits a signal corresponding to the acquired image information to the ECU 5.

The speed sensor 34 detects the speed of the vehicle 2. The speed sensor 34 detects the speed of the vehicle 2 based on the rotation speed of wheels, not shown, of the vehicle 2, the rotation speed of the engine, and the like, and transmits a signal corresponding to the speed to the ECU 5.

The speaker 41 and the display 42 are examples of the alarm device of the present invention. In particular, the speaker 41 is an example of the 1 st alarm device of the present invention, and the display 42 is an example of the 2 nd alarm device of the present invention. The speaker 41 operates based on the received control signal, and issues an alarm by outputting a warning sound or voice. The display 42 is, for example, a liquid crystal panel, operates based on a received control signal, and displays a picture, a character, or the like to issue an alarm.

The ECU5 is a control device that controls the apparatus by transmitting and receiving signals. A part or the whole of the ECU5 is constituted by an analog circuit or as a digital processor. The ECU5 has: an object detection unit 51, a determination alarm unit 52, and a traffic signal detection unit 53.

In addition, fig. 1 shows the respective functions of the ECU5 as functional blocks. However, the software module incorporated in the analog circuit or digital processor of the ECU5 is not necessarily divided as shown in fig. 1. That is, each of the functional blocks shown in fig. 1 may be further divided, or a single functional block may have functions of a plurality of functional blocks. The internal configuration of the ECU5 may be appropriately changed by those skilled in the art as long as the processing described later can be executed.

The object detection unit 51 detects a moving direction of an object existing outside the vehicle 2, a distance from the alarm line to the object, a relative speed of the object with respect to the alarm line, and a relative acceleration of the object with respect to the alarm line. Specifically, the object detection unit 51 performs a predetermined operation based on the signal received from the side radar 31, and performs detection based on the operation result.

The determination alarm portion 52 sets an alarm line. The warning line is a virtual line arranged in the vicinity of the vehicle 2 and used for collision determination. Details of the alarm line are left to be described later.

Further, the determination alarm portion 52 performs collision determination. In the collision determination, it is determined whether or not an object existing outside the vehicle 2 within a predetermined time period determined in advance intersects with the alarm line. Details of the collision determination are left to be described later.

The determination alarm portion 52 also transmits a control signal to the speaker 41 or the display 42 based on the result of the collision determination. Specifically, when it is determined that there is a possibility of collision between the object and the vehicle 2, the determination alarm unit 52 transmits a control signal to operate the speaker 41 or the display 42.

The distance detection unit 53 detects a distance between the vehicle 2 and another vehicle stopped in front of the vehicle 2. Specifically, the distance detection unit 53 performs a predetermined calculation based on a signal received from the front radar 32 or the vehicle exterior camera 33, and performs detection based on the calculation result.

Next, collision determination of the alarm system 1 will be described with reference to fig. 2. Fig. 2 is an explanatory diagram of collision determination of the alarm system 1.

When the vehicle 2 is stopped or traveling at a relatively low speed (for example, 10km/h or less), the determination alarm unit of the ECU5 (see fig. 1) sets the right alarm line 61 and the left alarm line 62 as shown in fig. 2. The right alarm line 61 and the left alarm line 62 are invisible imaginary lines. The right alarm line 61 is set at a position separated by a predetermined distance (for example, 1m or less) to the right from the right end of the vehicle 2, and the left alarm line 62 is set at a position separated by a predetermined distance (for example, 1m or less) to the left from the left end of the vehicle 2. That is, the distance between the right alarm line 61 and the left alarm line 62 is larger than the width of the vehicle 2.

The right alarm line 61 and the left alarm line 62 extend forward of the vehicle 2 with the base line BL as a base end. The reference line BL is a virtual line that is set back from the front end of the vehicle 2 by a predetermined distance (for example, 2 m). The right alarm line 61 and the left alarm line 62 extend in a straight line along the front-rear direction of the vehicle 2 and are substantially parallel to each other.

The object detector 51 (see fig. 1) of the ECU5 sets a detection area a1 to the right of the right alarm line 61 and a detection area a2 to the left of the left alarm line 62. The detection area a1 extends rightward from the right alarm line 61 by a predetermined distance and is set in a range of approximately 135 ° with respect to the right alarm line 61. The detection area a2 extends a prescribed distance to the left from the left alarm line 62, and is set within a range of approximately 135 ° with respect to the left alarm line 62. The object detection unit 51 detects objects present in the detection areas a1, a2 based on signals received from the side radar 31.

when a virtual line L ₉₁ along the moving direction of the other vehicle 91 intersects the right alarm line 61, the determination alarm unit 52 (see fig. 1) of the ECU5 calculates the time to collision margin of the other vehicle 91 with respect to the right alarm line 61 based on the information detected by the object detection unit 51, TTC (time to collision), which is generally defined as L ₀ the distance between the objects, and V ₀ the relative speed of which is represented by the following equation f1, the relative speed V ₀ of the object is in the positive direction in which the object approaches the alarm line, and equation f1 is derived from the motion equation under the condition that the object performs the equal-speed motion.

[ number 1 ]

The determination alarm unit 52 determines whether or not the other vehicle 91 crosses the right alarm line 61 within a predetermined time period based on the calculated TTC. Specifically, when TTC is equal to or less than a predetermined threshold value (for example, 2 seconds), the determination alarm unit 52 determines that the other vehicle 91 will intersect the right alarm line 61 within a predetermined time (for example, within 2 seconds). In this case, there is a possibility that the other vehicle 91 collides with the vehicle 2.

In this manner, the warning system 1 determines whether or not an object present on the right side of the vehicle 2 is likely to collide with the vehicle 2, with reference to the right warning line 61. Similarly, the warning system 1 determines whether or not an object present on the left side of the vehicle 2 is likely to collide with the vehicle 2, with reference to the left warning line 62.

The determination alarm portion 52 may set the lengths of the right alarm line 61 and the left alarm line 62 to L1 (for example, 7 m). L1 is an example of the 1 st length of the present invention. The determination alarm unit 52 may set the lengths of the right alarm line 61 and the left alarm line 62 to L2 (e.g., 5m) shorter than L1 (i.e., L2 < L1). L2 is an example of the 2 nd length of the present invention.

The collision determination is described, for example, in a case where another vehicle 92 or 93 exists in the detection area a2 and the other vehicle 92 or 93 approaches the left alarm line 62, and the length of the left alarm line 62 is set to L1, both virtual lines L ₉₂ and L ₉₃ along the moving direction of the other vehicle 92 or 93 intersect the left alarm line 62, and therefore the determination alarm unit 52 determines a collision with the other vehicle 92 or 93.

On the other hand, when the length of the left alarm line 62 is set to L2, the virtual line L ₉₃ along the moving direction of the other vehicle 93 does not intersect the left alarm line 62, and therefore the determination alarm unit 52 does not perform collision determination with the other vehicle 93, but only performs collision determination with the other vehicle 92, that is, the determination alarm unit 52 does not operate the speaker 41 and the display 42 (see fig. 1) when the other vehicle 93 approaches.

The warning system 1 configured as described above functions particularly effectively in an environment where a blind spot is present for the driver of the vehicle 2. Examples of the environment in which the driver has a blind spot include an environment in which a wall is present around the driving lane and an environment in which another vehicle is present around the vehicle 2 while the vehicle is parked. That is, when there is a possibility that an object approaching from a blind spot collides with the vehicle 2, at least one of the speaker 41 and the display 42 issues an alarm to make the driver aware of the presence of the object and to prompt driving for avoiding the collision.

next, collision determination on the crosswalk will be described with reference to fig. 3. Fig. 3 is an explanatory diagram of collision determination on the crosswalk 84.

As described in fig. 3, a case is considered in which another vehicle 95 is present in front of the lane 80 on which the vehicle 2 travels. When the vehicle 2 approaches another vehicle 95 from behind and the speed of the vehicle 2 is relatively low, the warning system 1 sets the right warning line 61 and the left warning line 62. When the crosswalk 84 intersecting the lane 80 is provided and the other vehicle 95 stops before the stop line 84a, the vehicle 2 stops with the other vehicle 95 with a clearance CL provided therebetween.

in this case, an object such as a pedestrian or a 2-wheel vehicle approaches the vehicle 2 so as to pass through the clearance CL, and a virtual line along the moving direction may intersect with the right warning line 61 or the left warning line 62. The alarm system 1 calculates the TTC associated with the object. When the TTC is equal to or less than the threshold value, the warning system 1 determines that there is a possibility that the object crosses the right warning line 61 or the left warning line 62 within a predetermined time, that is, determines that the object may collide with the vehicle 2, and issues a warning to the driver of the vehicle 2.

However, such proximity of the object to the vehicle 2 is not caused by the driving of the driver of the vehicle 2, and does not necessarily increase the possibility of the object colliding with the vehicle 2. The vehicle 2 cannot start unless the other vehicle 95 starts after the pedestrian has passed the crosswalk 84 or the stop signal from the traffic light not shown is released. In this case, even if the warning system 1 issues a warning about an object, the driver of the vehicle 2 cannot avoid a collision, and may feel annoyed. Here, when the distance d between the vehicle 2 and the other vehicle 95 is equal to or less than a predetermined value, the alarm system 1 executes alarm suppression control for suppressing the operation of the alarm device, as compared with a case where the distance d is greater than the predetermined value.

Next, the alarm suppression control will be described with reference to fig. 4 and 5. Fig. 4 and 5 are flowcharts showing processing executed by the ECU5 (see fig. 1). This process is repeatedly executed at a predetermined cycle. For the sake of convenience of explanation, the processing performed by each functional block of ECU5 will be described in detail as ECU 5.

first, the ECU5 determines whether the speed v of the vehicle 2 is within a range of 0km/h or more and 10km/h or less in step S10 shown in fig. 4. The ECU5 detects the speed v of the vehicle 2 based on a signal received from the speed sensor 34 (see fig. 1). If it is determined that the speed v is within the range (S10: YES), the ECU5 proceeds to step S11.

In step S11, ECU5 sets right alarm line 61 and left alarm line 62 (see fig. 2). Here, the ECU5 sets the lengths of both the right alarm line 61 and the left alarm line 62 to be constant L1. After the setting of the right alarm line 61 and the left alarm line 62 is completed, the ECU5 proceeds to step S12.

In step S12, the ECU5 determines whether or not there is an object (hereinafter simply referred to as "intersecting object") intersecting the right alarm line 61 or the left alarm line 62 along a virtual line in the moving direction in the detection area a1 or the detection area a2 (see fig. 2). The ECU5 makes this determination based on a signal received from the side radar 31 (see fig. 1). If it is determined that there is an intersecting object (S12: YES), the ECU5 proceeds to step S13.

In step S13, the ECU5 calculates the TTC associated with the intersecting object. The ECU5 calculates the distance from the right alarm line 61 or the left alarm line 62 to the crossing object and the velocity (i.e., relative velocity) of the crossing object with respect to the alarm line based on the signal received from the side radar 31. Further, the ECU5 calculates TTC based on the aforementioned equation f 1. When a plurality of intersecting objects are detected, the ECU5 calculates TTC for each intersecting object. After the calculation of the TTC is completed, the ECU5 proceeds to step S14.

In step S14, the ECU5 determines whether the TTC calculated in step S13 is 2 seconds or less. If it is determined that the TTC is 2 seconds or less (S14: YES), the ECU5 proceeds to step S15.

In step S15, the ECU5 determines whether the TTC calculated in step S13 is greater than 1 second. When the TTC is more than 1 second, the necessity of an alarm is low. If it is determined that TTC is greater than 1 second (S15: YES), ECU5 proceeds to step S16.

In step S16, ECU5 activates display 42 (see fig. 1). Specifically, the ECU5 sends a control signal to the display 42, and the display 42 displays an indication that an object outside the vehicle 2 is likely to collide with the vehicle 2 based on the control signal. After the alarm is displayed on the display 42, the ECU5 ends the process. That is, since the necessity of warning is low when the TTC is 2 seconds or less (yes in S14) but more than 1 second (yes in S15), the ECU5 does not operate the speaker 41 (see fig. 1) and operates the display 42 to give a warning to the driver of the vehicle 2.

On the other hand, when the TTC is 1 second or less, the necessity of an alarm is high. If it is not determined in step S15 that the TTC calculated in step S13 is greater than 1 second (S15: no), ECU5 proceeds to step S17.

In step S17, the ECU5 determines whether the speed v of the vehicle 2 is 0 km/h. That is, the ECU5 determines whether the vehicle 2 is stopping. When the vehicle 2 is stopped, the necessity of warning is low as compared with the case where the vehicle 2 is running. Therefore, if it is determined that the speed v of the vehicle 2 is 0km/h (S17: YES), the ECU5 proceeds to step S16. As described above, in step S16, ECU5 causes display 42 to display an alarm, and then ends the process. That is, when the TTC is 1 second or less (no in S15) but the vehicle 2 is stopped (yes in S17), the ECU5 operates the display 42 without operating the speaker 41 to give an alarm to the driver of the vehicle 2.

On the other hand, in step S17, if it is not determined that the speed v of the vehicle 2 is 0km/h (S17: NO), that is, if the vehicle 2 is not stopped, the ECU5 proceeds to step S18.

In the case where the vehicle 2 is not stopped, the necessity of an alarm is higher than in the case where the vehicle 2 is stopping. The ECU5 determines in step S18 whether an alarm of the speaker 41 is required. Referring to fig. 5, the processing when the ECU5 determines this necessity will be described.

In step S30 shown in fig. 5, the ECU5 determines whether there is another vehicle stopping ahead of the lane on which the vehicle 2 is traveling. The ECU5 makes this determination based on the signal received from the front radar 32 (see fig. 1). If it is determined that there is a stopped vehicle in front of the vehicle 2 (yes at S30), the ECU5 proceeds to step S31.

In step S31, ECU5 determines whether or not distance d (see fig. 3) between vehicle 2 and another vehicle is 3m or less. Here, "3 m" is an example of the predetermined value of the present invention. The ECU5 makes this determination based on a signal received from the front radar 32 or the vehicle exterior camera 33 (see fig. 1). If the distance d is 3m or less, the vehicle 2 is likely to stop. If it is determined that distance d is 3m or less (S31: YES), ECU5 proceeds to step S32. In step S32, the ECU5 determines that the warning of the speaker 41 is not required.

On the other hand, if it is not determined in step S30 that there is another vehicle stopped ahead of vehicle 2 (no in S30), or if it is not determined in step S31 that distance d between vehicle 2 and another vehicle is 3m or less (no in S31), ECU5 proceeds to step S33. In step S33, the ECU5 determines that an alarm of the speaker 41 is required.

The process performed by the ECU5 is described again with reference to fig. 4. If it is determined in step S18 that the alarm of the speaker 41 is not necessary (S18: yes), the ECU5 proceeds to step S16.

In step S16, the ECU5 operates the display 42. Specifically, the ECU5 sends a control signal to the display 42, and the display 42 displays the meaning of the possibility that an object outside the vehicle 2 may collide with the vehicle 2 based on the control signal. After causing the display 42 to display the alarm, the ECU5 ends the process. That is, when the TTC is 1 second or less (S15: No) but the distance d between the vehicle 2 and another vehicle is 3m or less, the ECU5 does not operate the speaker 41 but operates the display 42.

In contrast, if it is not determined in step S18 that the alarm of the speaker 41 is not necessary (no in S18), the ECU5 proceeds to step S19.

When the TTC is 1 second or less (S15: no) and the distance d between the vehicle 2 and another vehicle is greater than 3m, the necessity of an alarm is relatively high. In this case, the ECU5 operates the display 42 to display an alarm in step S19, and operates the speaker 41 to emit an alarm based on a warning sound or voice in step S20.

In embodiment 1, when the distance d is 3m or less and when the distance d is greater than 3m, the operation of the speaker 41 is suppressed, and this control is referred to as "alarm suppression control".

If it is not determined in step S10 that the speed v of the vehicle 2 is within the predetermined range (no in S10), if it is not determined in step S12 that there is a crossing object (no in S12), or if it is not determined in step S14 that the TTC is 2 seconds or less (no in S14), the ECU5 deactivates both the display 42 and the speaker 41, and ends the process.

[ Effect ]

The warning system 1 passes the distance d between the vehicle 2 and another vehicle in front of the vehicle 2 by the distance detection section 53. Further, when the distance d is 3m or less, the alarm system 1 executes alarm suppression control for suppressing the operation of the alarm device, as compared with the case where the distance d is greater than 3 m. As a result, when the possibility of collision of the object with the vehicle 2 is relatively high, the driver is strongly alerted by the warning, while when the possibility of collision of the object with the vehicle 2 is relatively low, the warning that the driver feels annoyed can be reduced.

The alarm device has a speaker 41 as a1 st alarm device and a display 42 as a2 nd alarm device. When the distance d is greater than 3m, it is determined that the alarm unit 52 operates the speaker 41 and the display 42. When the distance d is 3m or less, the determination alarm unit 52 operates the display 42 instead of the speaker 41 as the alarm suppression control.

According to this configuration, when the distance d between the vehicle 2 and another vehicle is 3m or less (that is, when the possibility of collision of an object with the vehicle 2 is relatively low), it is determined that the warning unit 52 does not operate the speaker 41, and it is possible to reduce the warning that the driver feels annoyed.

The speaker 41 as the 1 st alarm device issues an alarm by sound. The display 42 as the 2 nd alarm means issues an alarm by displaying.

Compared to a display-based alert, a sound-based alert is more likely to be irritating to the driver. According to the above configuration, when the distance d between the vehicle 2 and another vehicle is 3m or less (that is, when the possibility of collision of an object with the vehicle 2 is relatively low), the warning by sound is not generated, and the warning that the driver feels annoyed can be reduced.

embodiment 1 shows a mode in which the operation of the speaker 41 is suppressed among the speaker 41 and the display 42. However, the suppression of the operation of the alarm device of the present invention is not limited thereto. For example, the suppression of the operation of the warning device may change the magnitude of the sound, the style of the sound, the color of the display, the content of the display, and the like, to reduce the annoyance of the driver. The warning device may vibrate a steering wheel or a seat of the vehicle, and may give a warning to the driver by the vibration. In this case, the magnitude of the vibration, the pattern of the vibration, and the like can be changed to suppress the operation of the warning device, thereby reducing the annoyance of the driver.

[ 2 nd embodiment ]

Next, a vehicle alarm system 10 (hereinafter referred to as "alarm system 10". refer to fig. 1) according to embodiment 2 will be described with reference to fig. 6 and 7. Fig. 6 and 7 are flowcharts showing processing executed by ECU5 of warning system 10 according to embodiment 2.

The warning system 10 according to embodiment 2 is a system that warns the driver of the vehicle 2 to promote his/her attention, as in embodiment 1 described above. The alarm system 10 is different from embodiment 1 in setting of alarm lines and calculation of TTC, but has substantially the same configuration as that of embodiment 1 shown in fig. 1. The same reference numerals are used for the same portions as those of embodiment 1 in the configuration and control of the alarm system 10, and the description thereof is omitted as appropriate.

The ECU5 determines in step S50 shown in fig. 6 whether the speed v of the vehicle 2 is within a range of 0km/h or more and 10km/h or less. The ECU5 detects the speed v of the vehicle 2 based on a signal received from the speed sensor 34 (see fig. 1). If it is determined that the speed v is within the range (S50: YES), the ECU5 proceeds to step S51.

In step S51, the ECU5 sets an alarm line. Referring to fig. 7, the processing when the ECU5 sets the warning line will be described.

In step S70 shown in fig. 7, the ECU5 determines whether there is another vehicle that is stopped ahead of the lane on which the vehicle 2 is traveling. The ECU5 makes this determination based on the signal received from the front radar 32 (see fig. 1). If it is determined that there is a stopped vehicle ahead of the vehicle 2 (yes in S70), the ECU5 proceeds to step S71.

In step S71, ECU5 determines whether or not distance d (see fig. 3) between vehicle 2 and another vehicle is 5m or less. Here, "5 m" is an example of the predetermined value of the present invention. The ECU5 makes this determination based on a signal received from the front radar 32 or the vehicle exterior camera 33 (see fig. 1). If it is not determined that distance d is 5m or less (S71: YES), ECU5 proceeds to step S72. In step S72, the ECU5 sets the lengths of the right alarm line 61 and the left alarm line 62 to L2 (see fig. 2).

On the other hand, if it is not determined in step S70 that there is another vehicle stopped ahead of vehicle 2 (no in S70), or if it is not determined in step S71 that distance d is 5m or less (no in S71), ECU5 proceeds to step S73. In step S73, the ECU5 sets the lengths of the right alarm line 61 and the left alarm line 62 to L1 (see fig. 2).

in embodiment 2, when the distance d is relatively small as described above, the determination warning unit 52 of the ECU5 sets the lengths of the right warning line 61 and the left warning line 62 to L2, and this control is referred to as "warning suppression control".

Referring again to fig. 6, the processing performed by the ECU5 will be described. After the setting of the right and left alarm lines 61, 62 is ended in step S51, the ECU5 proceeds to step S52.

In step S52, the ECU5 determines whether or not there is an object (hereinafter simply referred to as "intersecting object") intersecting the right alarm line 61 or the left alarm line 62 along a virtual line in the moving direction in the detection area a1 or the detection area a2 (see fig. 2). The ECU5 makes this determination based on a signal received from the side radar 31 (see fig. 1). If it is determined that there is an intersecting object (S52: YES), the ECU5 proceeds to step S53.

In step S53, the ECU5 calculates the TTC associated with the intersecting object. The ECU5 calculates the distance from the right alarm line 61 or the left alarm line 62 to the crossing object and the velocity (i.e., relative velocity) of the crossing object with respect to the alarm line based on the signal received from the side radar 31. Unlike embodiment 1, the ECU5 always calculates TTC based on the aforementioned equation f 1. That is, the ECU5 does not calculate TTC based on equation f 2. When a plurality of intersecting objects are detected, the ECU5 calculates the TTC for each intersecting object. After the calculation of the TTC is completed, the ECU5 proceeds to step S54.

In step S54, the ECU5 determines whether the TTC calculated in step S53 is 2 seconds or less. If it is determined that the TTC is 2 seconds or less (S54: YES), the ECU5 proceeds to step S55.

In step S55, the ECU5 determines whether the TTC calculated in step S53 is greater than 1 second. When the TTC is greater than 1 second, the necessity of an alarm is relatively low. If it is determined that TTC is greater than 1 second (S55: YES), ECU5 proceeds to step S56.

In step S56, ECU5 activates display 42 (see fig. 1). Specifically, the ECU5 sends a control signal to the display 42, and the display 42 displays an indication that an object outside the vehicle 2 is likely to collide with the vehicle 2 based on the control signal. After the alarm is displayed on the display 42, the ECU5 ends the process. That is, since the necessity of a warning is relatively low when the TTC is 2 seconds or less (yes in S54) but more than 1 second (yes in S55), the ECU5 operates the display 42 without operating the speaker 41 (see fig. 1) to give a warning to the driver of the vehicle 2.

on the other hand, when the TTC is 1 second or less, the necessity of an alarm is relatively high. If it is not determined in step S55 that the TTC calculated in step S53 is greater than 1 second (S55: no), ECU5 proceeds to step S57.

in step S57, the ECU5 determines whether the speed v of the vehicle 2 is 0 km/h. That is, the ECU5 determines whether the vehicle 2 is stopped. When the vehicle 2 is stopped, the necessity of warning is low as compared with the case where the vehicle 2 is running. Therefore, if it is determined that the speed v of the vehicle 2 is 0km/h (S57: YES), the ECU5 proceeds to step S56. As described above, in step S56, ECU5 causes display 42 to display an alarm, and then ends the process. That is, when the TTC is 1 second or less (no in S55) but the vehicle 2 is stopped (yes in S57), the ECU5 operates the display 42 without operating the speaker 41 to give an alarm to the driver of the vehicle 2.

On the other hand, in step S57, if it is not determined that the speed v of the vehicle 2 is 0km/h (S57: NO), that is, if the vehicle 2 is not stopped, the ECU5 proceeds to step S58.

When the vehicle 2 is not stopped, the necessity of warning is high as compared with the case where the vehicle 2 is stopped. The ECU5 operates the display 42 to display an alarm in step S58, and operates the speaker 41 to emit an alarm based on a warning sound or voice in step S59. That is, if the TTC is 1 second or less (no in S55) and the vehicle 2 is not stopped (no in S57), the ECU5 operates the display 42 and the speaker 41 to strongly alarm the driver of the vehicle 2.

If it is not determined in step S50 that the speed v of the vehicle 2 is within the predetermined range (no in S50), if it is not determined in step S52 that there is a crossing object (no in S52), or if it is not determined in step S54 that the TTC is 2 seconds or less (no in S54), the ECU5 deactivates both the display 42 and the speaker 41 and ends the processing.

[ Effect ]

When the distance d is greater than 5m, the determination alarm unit 52 sets the lengths of the right alarm line 61 and the left alarm line 62 to L1. When the distance d is 5m or less, the determination alarm unit 52 sets the lengths of the right alarm line 61 and the left alarm line 62 to L2 smaller than L1 as the alarm suppression control.

According to this configuration, when the distance d between the vehicle 2 and another vehicle is relatively small, the right alarm line 61 and the left alarm line 62 are shorter than when the distance d is relatively large. Thus, when the distance d is relatively small, it is difficult to determine that the object intersects the right alarm line 61 or the left alarm line 62 within the predetermined time period or longer, as compared with the case where the distance d is relatively large. As a result, when the distance d is relatively small, the determination warning unit 52 can reduce the warning that the driver feels annoyed by suppressing the operation of the warning device as compared with the case where the distance d is relatively large.

In embodiment 2, the lengths of the right alarm line 61 and the left alarm line 62 are changed in two stages with 5m as a threshold value. However, the change in the length of the alarm line of the present invention is not limited thereto. For example, the length of the warning line may vary in proportion to the distance between the vehicle and the other vehicle, or may be increased in stages with an increase in the distance between the vehicle and the other vehicle.