JP2001291199A - Preceding vehicle departure reporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preceding vehicle departure reporting device capable of preventing erroneous alarm when a plurality of pedestrians walk across in front of one's own vehicle by prohibiting the output of alarm for reporting preceding vehicle departure when the reduction rate of a distance from a front obstacle before deciding a stop is larger than a prescribed value. SOLUTION: The device is characterized by providing a distance detecting means S1 for detecting the distance from the front obstacle by emitting a detection wave to the front part of one's own vehicle and receiving the reflection wave of the detection wave from the front obstacle, a stop deciding means S5 for deciding that a self vehicle and the front obstacle are commonly stopped based on the detection result of the detecting means S1, an alarm means S14 for outputting alarm when the increase rate of the distance from the front obstacle becomes within the prescribed range during stop decision by the deciding means S5 and an alarm prohibiting means S18 for prohibiting the alarm output when the reduction rate of the distance from the front obstacle before stop decision is larger than the prescribed value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preceding vehicle start notifying device which executes a preceding vehicle start notifying (preceding vehicle starting alarm) when a preceding vehicle stopped ahead of the own vehicle starts.

[0002]

2. Description of the Related Art Conventionally, as a device for executing a preceding vehicle start notification when a preceding vehicle stopped in front of the own vehicle starts, there is a device described in Japanese Patent Application Laid-Open No. 8-115499, for example. That is, a distance detection unit provided at the forefront of the vehicle and detecting a relative distance from the vehicle (own vehicle) to another vehicle (preceding vehicle) located in front of the vehicle at predetermined time intervals, and a vehicle (own vehicle). A traveling state detection unit provided in the traveling system for detecting the traveling and stopped states, and determines whether or not the relative distance detected by the distance detection unit has changed with time; This is a device configured to determine that a preceding vehicle has started when a vehicle-to-vehicle distance between the vehicle and the vehicle has increased, and to output an alarm (notice of preceding vehicle starting).

According to this conventional device, when the preceding vehicle starts moving, there is an advantage that it is possible to notify the driver (driver) of the preceding vehicle, but there is an advantage that a plurality of pedestrians cross the front of the own vehicle. In such a case, or when another vehicle interrupts between the own vehicle and the preceding vehicle, there is a problem that a false alarm is output.

[0004] For example, when a plurality of pedestrians cross the front of the own vehicle, the distance between the own vehicle and the obstacle in front of the own vehicle becomes narrower and then wider due to a signal from the distance detector. There is a problem in that it is erroneously recognized that the preceding vehicle has started, and the preceding vehicle start notification is executed.

[0005]

SUMMARY OF THE INVENTION According to the present invention, when the rate of decrease in the distance to an obstacle ahead of a vehicle before a stop is determined is greater than a predetermined value, the output of an alarm for notifying the start of the preceding vehicle is prohibited, thereby preventing the own vehicle from outputting. It is an object of the present invention to provide a preceding vehicle start notification device that can prevent a false alarm when a plurality of pedestrians cross in front.

According to the present invention, when the rate of decrease in the distance to the obstacle ahead of the vehicle before the stop is determined is greater than a predetermined value, the rate of decrease in the distance is within the predetermined value (for example, this corresponds to the rate of decrease in the distance of a normally stopped vehicle ahead). By setting the stop determination time to a longer value (when within a predetermined value), it is possible to prevent a false alarm when a plurality of pedestrians cross the front of the own vehicle, and It is an object of the present invention to provide a preceding vehicle start notification device which can notify the start of an interrupted vehicle when another vehicle interrupts ahead of the vehicle.

[0007] Further, the present invention further provides that, when the rate of increase in the distance to the obstacle ahead of the vehicle is outside the predetermined range during the stop determination, when the distance between the host vehicle and the obstacle in front of the vehicle exceeds a predetermined distance, It is an object of the present invention to provide a preceding vehicle start notification device that can reliably output a start notification by outputting an alarm even when the preceding vehicle advances very slowly (slow forward).

The present invention further outputs an alarm when the ratio of non-detection of the distance by the distance detection means exceeds the predetermined ratio because the reflected wave is not received. An object of the present invention is to provide a preceding vehicle start notification device capable of performing start notification.

The present invention further cancels the output of an alarm when the degree of decrease in the distance between the own vehicle and the obstacle ahead is small after the stop determination (see the case of the preceding vehicle retreating slowly).
After the stop determination, when the above-mentioned decrease is sharply reduced (see the crossing of a two-wheeled vehicle), when the rate of distance detection by the distance detecting means after the sharp decrease exceeds a predetermined rate (2% when the vehicle crosses the front of the vehicle). When the two-wheeled vehicle moves in the forward direction and the preceding vehicle also moves in the forward direction, an alarm is output and when the ratio is within a predetermined ratio (two-wheeled vehicles that have crossed in front of the own vehicle have moved away in the forward direction. If there is a preceding vehicle in front of the vehicle), the determination of the start of the obstacle ahead is continued, so that even if the detected inter-vehicle distance greatly changes due to the two-wheeled vehicle crossing the front of the vehicle, an accurate leading It is an object of the present invention to provide a preceding vehicle start notification device capable of executing vehicle start notification.

[0010]

According to the present invention, a preceding vehicle starting and notifying device transmits a detection wave in front of an own vehicle and receives a reflected wave of the detection wave from an obstacle in front of the vehicle, thereby detecting the preceding obstacle. Distance detecting means for detecting a distance between the vehicle and the vehicle, a stop determining means for determining that both the own vehicle and the front obstacle are stopped based on a detection result of the distance detecting means, and a stop by the stop determining means. When the rate of increase of the distance to the front obstacle is within a predetermined range during the judgment, an alarm means for outputting an alarm, and when the rate of decrease of the distance to the front obstacle before the stop judgment is greater than a predetermined value, Alarm prohibiting means for prohibiting output of an alarm.

With the above arrangement, the above-mentioned distance detecting means is
By transmitting a detection wave (see ultrasound, millimeter wave, laser radar, etc.) ahead of the vehicle and receiving a reflected wave of the detection wave from an obstacle ahead (such as a preceding vehicle), the vehicle can recognize the obstacle ahead of the vehicle. The distance between the vehicle and the vehicle is detected, and the above-described stop determination means determines that both the own vehicle and the obstacle ahead are stopped. An alarm is output when the rate of increase in distance with the distance falls within a predetermined range, but the above-mentioned alarm prohibiting means outputs the above-mentioned alarm when the rate of decrease in distance as a forward obstacle before the stop determination is larger than a predetermined value. Ban.

Here, the rate of decrease in distance from the obstacle ahead of the vehicle before the stop determination (the stop determination is executed after the rate of change of the distance with respect to time becomes constant) as shown in FIG. The characteristic G when a plurality of pedestrians cross the front of the own vehicle with respect to the distance reduction rate e of the characteristic E of (agree with the preceding vehicle)
Since the distance reduction rate g becomes large, if a predetermined value of the distance reduction rate is set in advance, the alarm output is prohibited when the distance reduction rate to the obstacle ahead of the vehicle before the stop determination is greater than the predetermined value. This can prevent a false alarm when a plurality of pedestrians cross the front of the own vehicle.

The preceding vehicle start notification device according to the present invention also transmits a detection wave in front of the own vehicle and receives a reflected wave of the detection wave from an obstacle in front of the vehicle, thereby detecting a distance between the vehicle and the preceding obstacle. A stop detecting means for determining that both the own vehicle and the front obstacle are stopped based on a detection result of the distance detecting means. When the rate of increase in the distance to the obstacle falls within a predetermined range, an alarm means that outputs an alarm, and when the rate of decrease in the distance to the front obstacle before the stop determination is greater than a predetermined value, the rate of decrease in the distance is a predetermined value. And a stop determination time changing means for setting the stop determination time to a longer value than when the value is within the value.

With the above arrangement, the above-mentioned distance detecting means is
By transmitting a detection wave (see ultrasound, millimeter wave, laser radar, etc.) ahead of the vehicle and receiving a reflected wave of the detection wave from an obstacle ahead (such as a preceding vehicle), the vehicle can recognize the obstacle ahead of the vehicle. The distance between the vehicle and the vehicle is detected, and the above-described stop determination means determines that both the own vehicle and the obstacle ahead are stopped. When the rate of increase in the distance to the obstacle falls within a predetermined range, an alarm is output. The stop determination time is set to a longer value than when the rate is within a predetermined value.

Here, as shown in FIG. 5, the distance decrease rate with respect to the obstacle in front of the host vehicle before the stop determination is different from the distance decrease rate e of the characteristic E of the normal forward stop vehicle by a plurality of points in front of the own vehicle. The distance reduction rate g of the characteristic G when a pedestrian crosses and the distance reduction rate f of the characteristic F when another vehicle interrupts between the own vehicle and the preceding vehicle increase.

As is clear from the characteristic diagram of FIG. 5, after the forward obstacle approaches the own vehicle and the distance becomes constant (specifically, the rate of change of the distance with respect to time becomes constant), this constant condition is satisfied. The time to maintain is the normal forward stopped vehicle (preceding vehicle)
(See characteristic E) and the case of an interrupted vehicle (see characteristic F) are long, and the case where a plurality of pedestrians cross the front of the own vehicle (see characteristic G) is relatively short. If the distance reduction rate with the car, the interrupted vehicle, and the pedestrian crossing is greater than the predetermined value, the stop determination time is set to a longer value than when the distance reduction rate is within the predetermined value.
If multiple pedestrians cross the front of your vehicle,
This makes it possible to prevent a false alarm by not performing a stop determination, and to determine the stop of the interrupted vehicle by performing a stop determination when another vehicle is interrupted ahead of the own vehicle.

According to one embodiment of the present invention, an alarm is output when the distance increase rate is outside the predetermined range and when the distance between the host vehicle and the front obstacle is longer than a predetermined distance. Is what you do. According to the above configuration, when the preceding vehicle as the obstacle in front of the vehicle advances very slowly, the distance increase rate does not reach the predetermined range, so that the preceding vehicle cannot normally be notified of the start of the preceding vehicle. When the distance between the host vehicle and the obstacle in front is greater than the predetermined distance, an alarm is output when the distance increase rate is out of the predetermined range, so that the preceding vehicle moves forward very slowly (slow forward). Even in such a case, the start notification can be reliably performed.

According to an embodiment of the present invention, when the reflected wave is not received and the ratio of distance detection by the distance detecting means that cannot be detected exceeds a predetermined ratio, an alarm is output. With the above configuration, when the preceding vehicle as an obstacle in front of the vehicle advances very slowly, the reflected wave of the detection wave transmitted by the own vehicle at a certain distance gradually becomes unreceivable, and the ratio of distance detection unrecoverable gradually increases. If this is the case, it will not be possible to report the start of the preceding vehicle, but in such a case (when the ratio of distance detection exceeds the predetermined ratio), an alarm is output, so even when the preceding vehicle moves forward at a very low speed, the transmission notification is securely made. Can be performed.

According to one embodiment of the present invention, the output of the alarm is canceled when the degree of decrease in the distance between the host vehicle and the obstacle ahead is small after the stop determination, and the decrease degree is determined after the stop determination. Is large, the alarm is output when the ratio of distance detection by the distance detecting means after the sudden decrease exceeds a predetermined ratio, and when the ratio is within the predetermined ratio, the start determination of the forward obstacle is continued.

With the above configuration, the alarm prohibiting means can issue an alarm if the degree of decrease in the distance between the host vehicle and the obstacle ahead is small after the stop determination is made (see the case where the preceding vehicle retreats at a very low speed). When the output is canceled and the above-mentioned warning means is judged to be stopped, and the degree of the decrease is large and suddenly decreases (see the case where the two-wheeled vehicle cuts in between the preceding vehicle and the own vehicle), the distance after the sudden decrease When the ratio of distance detection failure by the detection means exceeds a predetermined ratio (see the case where the two-wheeled vehicle crossing the front of the own vehicle moves away in the forward direction and the preceding vehicle also moves away in the forward direction), an alarm is output. When the rate of distance detection failure by the distance detecting means after the sudden decrease is within a predetermined rate (when the two-wheeled vehicle that has crossed the front of the own vehicle has moved away in the forward direction, but there is a preceding vehicle in front of the own vehicle. (See)). It can be. Therefore, even if the detected inter-vehicle distance greatly fluctuates due to the crossing of the motorcycle in front of the own vehicle, it is possible to execute the appropriate preceding vehicle start notification.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a preceding vehicle start notifying device. The preceding vehicle starting notifying device includes an ultrasonic sensor 2 embedded in a front bumper 1 in a host vehicle A (hereinafter simply referred to as host vehicle) in FIG. As shown in FIG. 2, the distance R between the own vehicle A and the preceding vehicle B or another object (front obstacle) ahead of the own vehicle is detected.

That is, the ultrasonic sensor 2 transmits an ultrasonic wave as a detection wave in front of the own vehicle A, and the preceding vehicle B of the ultrasonic wave.
By receiving the reflected wave from the obstacle ahead including
It detects a distance R between the obstacle A ahead and the host vehicle A.

FIG. 3 is a block diagram showing a control circuit of the preceding vehicle start notifying device. The CPU 10 as a control means includes an ultrasonic sensor 2, a vehicle speed sensor 3, a parking brake switch 4, a foot brake switch 5, a gear position. A shift position switch such as a switch; a ROM 8 based on various signal inputs from a power switch 7;
In accordance with the program stored in the RAM, the ultrasonic sensor 2 and a buzzer 9 (including an electronic buzzer) as an example of an alarm (alarm) are driven and controlled, and a RAM (storage means) 11 is stored in a first map shown in FIG. M1 and other necessary data are stored.

In the first map M1 shown in FIG. 4, the horizontal axis represents the distance reduction rate Dbe with respect to the front obstacle before the stop determination, and the vertical axis represents the stop determination time Tstop. When the distance reduction rate Dbe is within a predetermined value D1 corresponding to the distance reduction rate e of the characteristic E (see FIG. 5) of the stopped vehicle (see the preceding vehicle B), and when the distance reduction rate Dbe is larger than the predetermined value D1 (Dbe> D1). Is a map in which the stop determination time Tstop is set to a long value.

In this embodiment, the distance reduction rate Dbe is a predetermined value D
When 1, the stop determination time Tstop is set to 0.1 second, and when the distance reduction rate Dbe is a value D2 larger than the predetermined value D1, the stop determination time Tstop is set to 0.6 second. It is not limited to numerical values.

The predetermined value D1 is larger than the first threshold value x and smaller than the second threshold value y, that is, x <D
1 <y is set. Further, the value D2 is y <D2
Is set to

By the way, the CPU 10 shown in FIG. 3 has a delay time setting unit 12 formed therein,
The longer the time required for the start operation from the stop state according to the operation state at the time of stop of the own vehicle A based on the signal input from 5 and 6, the longer the delay time from the preceding vehicle start detection to the alarm output becomes. The delay time is set as follows.
Instead of the configuration in which the delay time setting unit 12 is formed in the CPU 10, for example, a table TA in which different delay times are set corresponding to the operation state patterns P1 to P6 when the vehicle stops as shown in FIG. The delay time may be stored in the RAM 11 or other storage means in advance, and the delay time may be read from the table TA.

Further, the CPU 10 transmits an ultrasonic wave to the front of the vehicle A using the ultrasonic sensor 2 and receives a reflected wave of the ultrasonic wave from the front obstacle, thereby detecting the front obstacle. Distance detecting means (see step S1 in the flowchart shown in FIG. 7) for detecting the distance R between the vehicle A and the vehicle A and the preceding obstacle are both determined to be stopped based on the detection result of the distance detecting means. Stop determination means (FIG. 7
During the stop determination by the stop determination means, the distance increase rate Ad with respect to the obstacle in front is within a predetermined range β (the creep running characteristic is 0.03 G or more shown by hatching in FIG. 8). When the acceleration characteristic falls within a range of 0.3 G or less, a warning means for outputting a warning (see step S14 in the flowchart shown in FIG. 7) and a distance reduction rate Dbe between the obstacle and the front obstacle before the stop determination are set to a predetermined value D1. When it is larger, the stop determination time changing means for setting the stop determination time Tstop to a longer value (Tstop = 0.6 sec) than when the distance reduction rate Dbe is within the predetermined value D1 (see step S4 in the flowchart shown in FIG. 7). ), And an alarm canceling means for canceling the output of an alarm when the degree of decrease Daf of the distance R between the vehicle A and the obstacle ahead after the stop determination is smaller than a predetermined value Daf1 (the flowchart shown in FIG. 7). Step S
7), and after the stop determination, the decrease degree Daf is set to the predetermined value Daf.
An alarm output unit (see YES determination in step S16 of the flowchart shown in FIG. 7) that outputs an alarm when the ratio of distance detection failure by the distance detection unit after the sudden decrease exceeds the predetermined ratio α when the sudden decrease is greater than 1. When the decrease degree Daf suddenly decreases after the stop determination and is greater than the predetermined value Daf1,
When the ratio of distance detection failure by the distance detecting means after the rapid decrease is within the predetermined ratio α, the determination also serves as the start determination continuation (see the NO determination in step S16 of the flowchart shown in FIG. 7) in which the start determination of the forward obstacle is continued.

In this embodiment, the distance increase rate
When Ad is outside the predetermined range β (see the hatched portion in FIG. 8), the distance R between the vehicle A and the obstacle in front is equal to the predetermined distance R1.
(For example, 4 m) or more, an alarm is output (see YES determination in step S10).

Further, in this embodiment, when the above-mentioned reflected wave is not received and the ratio α in which the distance detecting means cannot detect the distance exceeds a predetermined ratio, an alarm is output (YES in step S11). See Judgment).

The operation of the preceding vehicle start notifying device configured as described above will be described in detail below with reference to the flowchart shown in FIG. The contents of the reference numerals used in the following description are as follows.

R: distance between own vehicle A and the preceding obstacle (including preceding vehicle B) R1: predetermined distance (for example, 4 m) V: vehicle speed Dbe: distance reduction rate with respect to the preceding obstacle before stop determination D1 ... Predetermined value (however, D1 <D2) Tstop... Stop determination time T... Both vehicle stop time Daf... Reduction ratio of distance R between own vehicle and front obstacle after stop determination Daf1... Predetermined value Ad. Medium distance increase rate α: predetermined rate of distance undetectable rate β: predetermined range of distance increase rate Ad.

First, in step S1, the CPU 10 uses the ultrasonic sensor 2 to control the own vehicle A and the preceding vehicle B including a front obstacle.
And the current vehicle speed V (hereinafter simply abbreviated as vehicle speed) is measured by the input from the vehicle speed sensor 3, and the brake signal is input from the switches 4 and 5 in FIG. Execute the process.

The above distance R can be obtained by the following [Equation 1]. [Equation 1] R = Va × t ÷ 2 where Va is a sound speed (340 m / sec) t is an ultrasonic wave, and this ultrasonic wave is reflected by the preceding vehicle B or another object until the reflected wave is received. The time required, in seconds.

Next, in step S2, the CPU 10 obtains the reduction rate Dbe of the distance R before the stop determination and determines which area of the first map M1 in FIG. 4 this distance reduction rate Dbe corresponds to.

Since the distance decrease rate Dbe in the case of a normal forward vehicle (preceding vehicle B) (see reference symbol e in FIG. 5) falls within the range of a predetermined value D1, it is determined that Dbe = D1 and the next step S
Move to 3.

As shown in FIG. 9, the distance reduction rate Dbe when a plurality of pedestrians C and C cross the front of the vehicle A (see g in FIG. 5) is larger than a predetermined value D1, and Dbe = D2. If it is determined, the process proceeds to another step S4.

As shown in FIG. 10, the distance reduction rate Dbe (see reference numeral f in FIG. 5) Dbe becomes larger than the predetermined value D1 when another vehicle J interrupts between the own vehicle A and the preceding vehicle B. = D2
Is determined, and the process proceeds to step S4.

In step S3, the CPU 10 sets the stop determination time Tstep to 0.1 second, while the CPU 10 sets the stop determination time Tstep to 0.1 second.
4, the distance reduction rate Dbe is large,
U10 sets the stop determination time Tstep to 0.6 seconds.

Next, in step S5, the CPU 10 determines whether or not the both vehicle stop time T is equal to or longer than the stop determination time Tstep. Here, the stop of the own vehicle A is determined based on the vehicle speed V = 0, and the stop of the forward obstacle is determined by A = V = 0 and the distance R is constant.
It can be determined by ND logic.

If the preceding obstacle is the preceding vehicle B, Tstop = 0.1 sec, so that T> Tstop is determined based on the relationship with the characteristic E shown in FIG.
Move to

When the preceding obstacle is the interrupting vehicle J (see FIG. 10), Tstop = 0.6 sec.
T> Tstop is determined based on the relationship with the characteristic F shown in
The process proceeds to the next step S6 as in the case of the preceding vehicle B.

On the other hand, if the obstacle in front is a crossing pedestrian C (see FIG. 9), the distance reduction rate Dbe is large, but in step S4, Tstop is set to 0.6 sec.
Is determined as T <Tstop (NO determination) based on the relationship with the characteristic G shown in (1), and the process proceeds to another step S7 for the purpose of preventing the false alarm by the pedestrian C. This step S7
Thus, the CPU 10 prohibits the buzzer 9 from outputting a warning of the preceding vehicle start notification.

In step S6, the CPU 10 determines whether or not the distance R has decreased. When the determination is NO, the process proceeds to the next step S8, and when the determination is YES, the process proceeds to another step S9.

In step S8, the CPU 10 determines whether or not the condition for canceling the preceding vehicle start notification has been satisfied. This determination is based on the fact that the shift lever has been operated to the reverse position, the input of the brake OFF signal, the OR of V> 2 km / h.
It is determined that the condition is satisfied by the logic.

If the determination is YES in step S8, the process proceeds to step S7, whereas if the determination is NO, the process proceeds to the next step S10. In this step S10, C
The PU 10 determines whether or not the distance R has become equal to or greater than a predetermined distance R1 (for example, 4 m) set in advance, and when R <R1 (N
(At the time of O determination), the process proceeds to the next step S11, while R
If> R1 (YES determination), the process skips to step S14.

In step S11 described above, the CPU 10 determines whether or not the undetectable ratio of the front obstacle by the ultrasonic sensor 2 has exceeded a predetermined ratio α. When the determination is NO, the process proceeds to the next step S12, while YES When the determination is made, the process skips to step S14.

In the above-described step S12, the CPU 10 executes a start determination of an obstacle ahead including the preceding vehicle B. This start determination is made based on whether or not the distance increase rate Ad during the stop determination is within a predetermined range β indicated by hatching in FIG. 8. The process proceeds to the next step S13 only when YES is determined, while the NO determination is made. Sometimes, the process returns to the previous step S6.

In step S13 described above, the CPU 10 determines whether or not the delay time set by the delay time setting unit 12 has elapsed, and proceeds to the next step S14 only when YES is determined. In this step S14, the CPU 10
Is activated to output an alarm to notify the occupant that the obstacle ahead including the preceding vehicle B has started.

If it is determined in step S6 that the distance R has decreased after the stop determination, the process proceeds to step S9. In this step S9, the CPU 10 determines whether or not the degree of reduction Daf of the distance R between the vehicle A and the obstacle ahead after the stop determination is greater than a predetermined value Daf1.

When the distance R gradually decreases such that the preceding vehicle B stopped in front of the own vehicle A slowly retreats, Daf <Daf
1 and a negative determination is made in step S9, so that the process proceeds to step S7 for the purpose of canceling the alarm.

However, as shown in FIG. 11, when the distance R such that the two-wheeled vehicle U interrupts and crosses the preceding vehicle B and the own vehicle A decreases sharply, Daf> Daf1, and YES in step S9.
Since the determination is made, the process proceeds to the next step S15.

In the above step S15, the CPU 10
After judging (certifying) that the wheel U interrupted and crossed,
The process moves to the next step S16. This step S16
Then, the CPU Q10 determines whether or not the undetectable ratio has become larger than the predetermined ratio α in order to detect and determine the behavior of the obstacles B and U ahead of the own vehicle A.

That is, when the two-wheeled vehicle U is interrupted between the two vehicles A and B, and when the crossing is completed, the distance increase rate rapidly increases regardless of the presence or absence of the preceding vehicle B located in front of the own vehicle A. At this distance increase rate, it is difficult to accurately detect and determine the behavior of the obstacles B and U ahead of the own vehicle A. Therefore, the obstacles B and U ahead of the own vehicle A are detected and determined based on the undetectable rate. Things.

Thus, the two-wheeled vehicle U crossing the front of the vehicle A
If the vehicle has moved away in the forward direction and the preceding vehicle B has also moved away in the forward direction, the undetectable ratio> α.
A YES determination is made in step S16, the process proceeds to step S14, and a notification output for notifying that the preceding vehicle B has started is executed.

On the other hand, the two-wheeled vehicle U crossing the front of the own vehicle A has moved away in the forward direction, but the preceding vehicle B is ahead of the own vehicle A.
Is present, the undetectable ratio <α, so the determination in step S16 is NO, and the process proceeds to step S12 for the purpose of continuing the start determination of the preceding vehicle B.
By the processing of 2, S13, S14, an alarm is output when the preceding vehicle B starts.

As described above, the preceding vehicle start notification device of the embodiment shown in FIGS. 1 to 11 (an embodiment corresponding to claims 2 to 5).
Transmits an ultrasonic wave in front of the own vehicle A, and receives a reflected wave of the ultrasonic wave from an obstacle ahead (refer to a preceding vehicle B, a pedestrian C, an interrupting vehicle J, and a two-wheeled vehicle U). Distance detecting means (see step S1) for detecting a distance R from the preceding obstacle; and judging that both the vehicle A and the preceding obstacle are stopped based on the detection result of the distance detecting means. An alarm is output when the distance increase rate Ad with respect to the preceding obstacle is within a predetermined range β (see the hatched portion in FIG. 8) during the stop determination by the stop determination means (see step S5) and the stop determination means. Alarm means (see step S14)
When the distance decrease rate Dbe from the front obstacle before the stop determination is larger than the predetermined value D1 (that is, when Dbe = D2), when the distance decrease rate Dbe is within the predetermined value D1 (that is, when Dbe = D1). The stop judgment time Tstop is longer (Tstop = 0.6sec)
(See step S4).

With the above-described configuration, the distance detecting means (see step S1) emits an ultrasonic wave in front of the own vehicle A and receives a reflected wave of the ultrasonic wave from an obstacle ahead (such as the preceding vehicle B). Accordingly, the distance R between the forward obstacle and the own vehicle A is detected, and the above-described stop determination means (see step S5) determines that both the own vehicle A and the forward obstacle are stopped. ,
The warning means (see step S14) determines that the distance increase rate Ad with respect to the obstacle ahead is within the predetermined range β during the stop determination by the stop determination means.
The stop determination time changing means (see step S4) outputs a warning when the distance reduction rate Dbe with the obstacle ahead of the vehicle before the stop determination is greater than a predetermined value D1. Is within the predetermined value D1, the stop determination time T
Set stop to a long value (from 0.1 seconds to 0.1 in this example).
6 seconds).

Here, as shown in FIG. 5, the distance reduction rate with respect to the obstacle ahead of the vehicle before the stop determination is different from the distance reduction rate e of the characteristic E of the normal vehicle stopped ahead (the preceding vehicle B). Car A
When multiple pedestrians C and C cross the front of the road (see FIG. 9)
And the characteristic F when the other vehicle J is interrupted between the own vehicle A and the preceding vehicle B (see FIG. 10).
Has a large distance reduction rate f.

Further, as is clear from the characteristic diagram of FIG. 5, after the forward obstacle approaches the own vehicle A and the distance R becomes constant, the time for maintaining this constant condition is equal to the normal forward stop. The vehicle (preceding vehicle B) (see characteristic E) and the interrupting vehicle J (see characteristic F) are long, and a plurality of pedestrians C, C cross the front of the vehicle A (see characteristic G). So short
If the distance decrease rate Dbe with respect to the preceding obstacle (preceding vehicle B, interrupting vehicle J, pedestrian C, C) before the stop determination is greater than a predetermined value D1 (when Dbe = D2), the distance decrease rate By setting the stop determination time Tstop to a longer value (Tstop = 0.6 sec) than when Dbe is within the predetermined value D1 (Dbe = D1), a plurality of pedestrians C, In the case where C crosses, a stop determination is not performed, thereby preventing a false alarm. In addition, when another vehicle J interrupts ahead of the own vehicle A, a stop determination is performed. The start of the interrupted vehicle J can be notified.

Further, when the increasing rate Ad of the distance R to the front obstacle during the stop determination is outside the predetermined range β (see the hatched portion in FIG. 8), the own vehicle A and the front obstacle are When the distance R between the two has exceeded a predetermined distance R1, an alarm is output. According to this configuration, when the preceding vehicle B as the forward obstacle advances very slowly, the distance increase rate Ad does not reach the predetermined range β, and thus the preceding vehicle cannot be notified of the start of the preceding vehicle. (When the distance increase rate Ad is outside the predetermined range β), when the distance R between the vehicle A and the obstacle in front is equal to or more than the predetermined distance R1.
Since an alarm is output (when YES is determined in step S10), the start notification can be reliably performed even when the preceding vehicle B advances very slowly (slow speed advance).

Further, when the reflected wave is not received and the ratio of distance detection failure by the distance detecting means (see step S1) exceeds a predetermined ratio α (see YES determination in step S11), an alarm is output. is there. With this configuration, when the preceding vehicle B as a forward obstacle advances very slowly, the reflected wave of the ultrasonic wave transmitted by the own vehicle A at a certain distance becomes gradually unreceivable, and the ratio of distance detection failure gradually increases. Therefore, it is impossible to report the start of the preceding vehicle, but in such a case (when the ratio of distance detection exceeds the predetermined ratio α), an alarm is output, so even if the preceding vehicle moves at a Can be notified.

In addition, when the degree of decrease Daf of the distance R between the host vehicle A and the obstacle ahead of the vehicle is smaller than a predetermined value Daf1 after the above-mentioned stop determination (see NO at step S9), the above-mentioned alarm is issued. Is canceled, and when the degree of decrease Daf is sharply reduced after the stop determination (see the YES determination in step S9), the ratio of distance detection impossibility by the distance detecting means (see step S1) after the sharp decrease is equal to the predetermined ratio α. When exceeded
(Refer to YES determination in step S16), output an alarm,
When it is within the predetermined ratio α (see the NO determination in step S16), the start determination of the forward obstacle is continued.

According to this configuration, the warning canceling means (see step S7), when the degree of reduction Daf of the distance R between the host vehicle A and the obstacle ahead is small and the degree of reduction Daf is small after the stop determination (the preceding vehicle B retreats at a very low speed) In such a case, the output of the warning is canceled, and the above-mentioned warning means (see step S14) performs a rapid decrease (the two-wheeled vehicle between the preceding vehicle B and the own vehicle A) when the decrease degree Daf is large after the stop determination. In the case where the two-wheeled vehicle U crossing the front of the own vehicle A moves in the forward direction when the ratio of the distance detection impossible by the distance detecting means after the sudden decrease exceeds the predetermined ratio α And the preceding car B
Also, when the distance is not detected by the distance detecting means after the sudden decrease is within a predetermined ratio α (see FIG. 2).
Although the wheeled vehicle U has moved away in the forward direction, see the case where the preceding vehicle B exists in front of the own vehicle A).
(See the preceding vehicle B). Therefore, even if the detected inter-vehicle distance R greatly changes due to the crossing of the two-wheeled vehicle U in front of the own vehicle A, it is possible to execute accurate preceding vehicle start notification.

FIG. 12 is a flowchart showing another embodiment of the preceding vehicle start notification device. In the flowchart of FIG. 7, step S2 is replaced with step S17 of FIG. 12, and step S4 of FIG. Is changed to return to step S1 after the processing in step S18.

Also in this embodiment, FIGS.
6, 8 to 11 are used. In this case,
The CPU 10 shown in FIG. 3 transmits an ultrasonic wave in front of the own vehicle A, and receives a reflected wave of the ultrasonic wave from an obstacle in front of the host vehicle A to detect a distance R between the host vehicle A and the obstacle in front of the vehicle. Means (see step S1) and stop determination means (see step S5) for determining that both the own vehicle A and the preceding obstacle are stopped based on the detection result of the distance detection means.
Alarm means for outputting an alarm when the distance increase rate Ad with respect to the preceding obstacle falls within a predetermined range β (see the hatched portion in FIG. 8) during the stop determination by the stop determination means (see step S14). And when the distance reduction rate Dbe with respect to the preceding obstacle before the stop determination is larger than a predetermined value D1 (that is, Dbe> D1)
) Also serves as alarm inhibiting means (see step S18) for inhibiting the output of the alarm.

The operation of the preceding vehicle start notifying device configured as described above will be described in detail below with reference to the flowchart shown in FIG. First, in step S1, the CPU 10 uses the ultrasonic sensor 2 to control the vehicle A and the preceding vehicle B including an obstacle ahead.
, The current vehicle speed V is measured based on the input from the vehicle speed sensor 3, and the input processing of the brake signal from each of the switches 4 and 5 in FIG. 3 is executed.

The above distance R can be obtained by the following [Equation 1] as in the previous embodiment. [Equation 1] R = Va × t ÷ 2 where Va is a sound speed (340 m / sec) t is an ultrasonic wave, and this ultrasonic wave is reflected by the preceding vehicle B or another object until the reflected wave is received. The time required, in seconds.

Next, in step S17, the CPU 10 calculates the distance reduction rate Dbe with respect to the obstacle ahead of the vehicle before the stop is determined, and determines whether the calculated distance reduction rate Dbe is a predetermined value D1. At the time (NO determination), the process proceeds to step S18 for the purpose of preventing false alarms by the pedestrians C, C, and when Dbe = D1 (YES determination), the process proceeds to step S3.

In step S18, the distance reduction rate Db
e is larger than the predetermined value D1,
Prohibits the warning output of the preceding vehicle start notification by the buzzer 9 and returns to step S1.

On the other hand, in step S3, corresponding to Dbe = D1, the stop determination time Tstop is set to 0.1 second, and then the process proceeds to step S5. Since the processing contents in steps S5 to S16 are almost the same as those in the previous embodiment, the same reference numerals in FIG. 12 denote the same parts as in FIG. 7, and a detailed description thereof will be omitted.

In short, the preceding vehicle start notifying device of the embodiment shown in FIG. 12 (the embodiment corresponding to the first, third, fourth and fifth aspects) transmits an ultrasonic wave in front of the own vehicle A, and Distance detection means (see step S1) for detecting a distance R from the front obstacle by receiving a reflected wave of the ultrasonic wave from the front obstacle, and detection results of the distance detection means (see step S1) Stop determination means (see step S5) for determining that both the vehicle A and the front obstacle are stopped based on the distance between the vehicle A and the front obstacle during the stop determination by the stop determination means. Warning means for outputting a warning when a value falls within a predetermined range (see a hatched portion in FIG. 8).
(See step S14) and when the distance reduction rate Dbe with respect to the preceding obstacle before the stop determination is larger than a predetermined value D1 (Dbe> D
1) is provided with alarm prohibiting means (see step S18) for prohibiting the output of the alarm.

With this configuration, the above-described distance detecting means (see step S1) transmits an ultrasonic wave in front of the vehicle A,
By receiving a reflected wave of the ultrasonic wave from the front obstacle (such as the preceding vehicle B), the distance R between the front obstacle and the own vehicle A is detected, and the above-described stop determination means (see step S5)
Determines that both the vehicle A and the obstacle ahead are stopped, and the warning means (see step S14) determines that the distance increase rate Ad with respect to the obstacle ahead is within the predetermined range during the stop determination by the stop determination means. An alarm is output when the value is within β (see the hatched portion in FIG. 8).
Means that when the distance reduction rate Dbe as a forward obstacle before the stop determination is larger than a predetermined value D1 (when Dbe> D1), the output of the alarm is prohibited.

That is, as shown in FIG. 5, the distance decrease rate Dbe with respect to the obstacle ahead of the vehicle before the stop determination is different from the distance decrease rate e of the characteristic E of the normal forward stopped vehicle by a plurality of distances ahead of the own vehicle A. When the pedestrians C and C cross each other (see FIG. 9), the distance reduction rate g of the characteristic G increases, and if a predetermined value D1 of the distance reduction rate Dbe is set in advance, the forward obstacle before the stop determination is made. When the distance reduction rate Dbe with the object becomes larger than the predetermined value D1, the alarm output is prohibited, thereby preventing a false alarm when a plurality of pedestrians C and C cross the front of the vehicle A. be able to.

In this embodiment, even when another vehicle J (see FIG. 10) is interrupted in front of the own vehicle A, an alarm prohibition process is performed, and the start notification of the interrupting vehicle J is disabled. In other respects, the operation and effect are almost the same as those of the previous embodiment.

In the correspondence between the configuration of the present invention and the above-described embodiment, the detection wave of the present invention corresponds to the ultrasonic wave of the embodiment. C, the interrupt vehicle J, the two-wheeled vehicle U, the distance detection means corresponds to step S1 controlled by the CPU 10, the stop determination means corresponds to step S5, the alarm means corresponds to step S14, and the alarm The prohibition unit performs step S18.
And the stop determination time changing means corresponds to step S4, but the present invention is not limited to only the configuration of the above-described embodiment.

For example, instead of the ultrasonic wave, another detection wave such as a millimeter wave or a laser radar may be used as the detection wave. Further, as the alarm 9, an electronic sound generating means may be used instead of the buzzer. Further, each step under the control of the CPU 10 constitutes means corresponding to the processing content.

[0078]

According to the present invention, when the rate of decrease in distance from the obstacle ahead of the vehicle before the stop determination is greater than a predetermined value, the output of the warning for informing the start of the preceding vehicle is prohibited, or the stop determination time is set to a longer value. Since the setting is made, there is an effect that a false alarm can be prevented when a plurality of pedestrians cross the front of the own vehicle.

[Brief description of the drawings]

FIG. 1 is a front view of a host vehicle provided with a preceding vehicle start notification device of the present invention.

FIG. 2 is an explanatory diagram showing a distance between a host vehicle and a preceding vehicle.

FIG. 3 is a control circuit block diagram of the preceding vehicle start notification device.

FIG. 4 is an explanatory diagram of a first map stored in a RAM.

FIG. 5 is a characteristic diagram showing a difference in a distance change rate due to a difference in a forward obstacle.

FIG. 6 is an explanatory diagram of a table in which delay times are set according to patterns.

FIG. 7 is a flowchart showing a preceding vehicle start notification process.

FIG. 8 is an explanatory diagram showing a predetermined range of a distance increase rate.

FIG. 9 is an explanatory view of a pedestrian crossing in front of the own vehicle.

FIG. 10 is an explanatory view of another vehicle interrupting in front of the own vehicle.

FIG. 11 is an explanatory diagram of a two-wheeled vehicle that crosses between a preceding vehicle and the host vehicle.

FIG. 12 is a flowchart showing another embodiment of the preceding vehicle start notification process.

[Explanation of symbols]

 A: own vehicle B: preceding vehicle (front obstacle) C: pedestrian (front obstacle) J: interruption vehicle (front obstacle) U: two-wheeled vehicle (front obstacle) S1: distance detection means S4: stop determination Time changing means S5 ... Stop determination means S14 ... Warning means S18 ... Warning prohibition means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60R 21/00 626 B60R 21/00 626B (72) Inventor Takuji Oka 3-1, Fuchu-cho, Fuchu-cho, Aki-gun, Hiroshima Prefecture No. Mazda Co., Ltd. (72) Inventor Tsukasa Harada 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima F-term (reference) 5H180 AA01 CC11 EE02 LL01 LL04 LL07

Claims (5)

[Claims] 1. A distance detecting means for transmitting a detection wave in front of an own vehicle and detecting a distance between the detection object and a front obstacle by receiving a reflection wave of the detection wave from the front obstacle; Stop determination means for determining that both the vehicle and the preceding obstacle are stopped based on the detection result of the distance detection means,
When the rate of increase in the distance to the front obstacle is within a predetermined range during the stop determination by the stop determination means, an alarm means for outputting an alarm, and a rate of decrease in the distance to the front obstacle before the stop determination is predetermined. A preceding vehicle start notification device comprising: an alarm prohibition unit that prohibits the output of the alarm when the value is larger than the value. 2. A distance detecting means for transmitting a detection wave in front of the own vehicle and receiving a reflected wave of the detection wave from an obstacle in front of the own vehicle to detect a distance from the obstacle in front of the vehicle. Stop determination means for determining that both the vehicle and the preceding obstacle are stopped based on the detection result of the distance detection means,
When the rate of increase in the distance to the front obstacle is within a predetermined range during the stop determination by the stop determination means, an alarm means for outputting an alarm, and a rate of decrease in the distance to the front obstacle before the stop determination is predetermined. A preceding vehicle start notification device comprising: a stop determination time changing unit that sets the stop determination time to a longer value when the distance decrease rate is within a predetermined value when the distance reduction rate is within a predetermined value. 3. The alarm according to claim 1, wherein when the distance increase rate is out of the predetermined range, an alarm is output when a distance between the host vehicle and the front obstacle is equal to or longer than a predetermined distance. A preceding vehicle start notification device. 4. The preceding vehicle start notification device according to claim 1, wherein an alarm is output when the ratio of the distance detection means not detecting the reflected wave and the distance detection means cannot detect the distance exceeds a predetermined ratio. 5. The alarm output is canceled when the degree of decrease in the distance between the vehicle and the obstacle ahead of the vehicle is small after the stop determination, and when the decrease is large after the stop determination, the warning is output. 5. The preceding vehicle start according to claim 1, 2, 3 or 4, wherein an alarm is output when a ratio of distance detection impossible by the distance detecting means exceeds a predetermined ratio, and when the ratio is within the predetermined ratio, start determination of a front obstacle is continued. Notification device.