JPH08268191A - Inter-vehicle distance warning device - Google Patents

Abstract

PURPOSE: To eliminate a useless warning, by outputting an alarm respectively, when the inter-vehicle distance is made in a caution inter vehicle distance or a dangerous inter-vehicle distance, and outputting no caution alarm when it is in a caution inter- vehicle distance, but outputting a dangerous alarm when it is in a dangerous inter- vehicle distance, even after the brake operation is released. CONSTITUTION: A controller 4 reads the relative speed from a radar device 1 and the car speed from a car speed sensor 2, to a safety inter-vehicle distance calculator 41, and also reads the actual inter-vehicle distance and the relative speed from the rader 1 commonly to an emergency deciding member 43 and a target tracing deciding member 44. A waiting condition deciding member 45 receives the signals to the deciding members 43 and 44, a warning unit 5, and a brake pedal switch 3. When the actual inter-vehicle distance detected by the radar 1 is made within the caution inter-vehicle distance at first, a caution alarm is outputted by a warning unit 5 by a warning controller 42. The warning controller 42 memorizes that, and even though the vehicle leaves from a target, and after that, approaches to the target, it outputs n caution alarm in the caution inter-vehicle distance, but when the vehicle approaches to the dangerous inter-vehicle distance further, it outputs a dangerous alarm.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-vehicle distance warning device, and more particularly to an inter-vehicle distance warning device which issues an alarm when the inter-vehicle distance from a vehicle ahead becomes a safe inter-vehicle distance or less.

[0001]

2. Description of the Related Art Conventionally, many devices have been proposed for issuing an alarm according to an inter-vehicle distance, and FIG. 5 shows an example of a well-known inter-vehicle distance alarm device. 1 is a radar device, 2 is a vehicle speed sensor, 3 is a brake pedal switch (or flasher switch), 4
Reference numeral 0 is a controller that receives the output signals of the radar device 1, the vehicle speed sensor 2, and the brake pedal switch 3 and controls the alarm device 5.

FIG. 6 is a flow chart showing the control operation of the controller 40. The operation of FIG. 5 will be described with reference to FIG. 6. First, the controller 40 is an actual vehicle detected by the radar device 1. Of distance and relative speed,
The relative speed is input and the vehicle speed signal from the vehicle speed sensor 2 is input, and the safe inter-vehicle distance calculation unit 41 calculates the safe inter-vehicle distance (step S21).

The safe inter-vehicle distance in this case is shown in FIG.
And, as shown in Fig. 4 (1), the distance between attention vehicles (attention area)
And the dangerous inter-vehicle distance (danger area) are included in the calculation.

In this way, when the warning inter-vehicle distance or the dangerous inter-vehicle distance calculated by the calculation unit 41 is given to the alarm control unit 42, it is compared with the actual inter-vehicle distance from the radar device 1.

First, in the alarm control unit 42, the caution inter-vehicle distance is compared with the actual inter-vehicle distance (step S22). When the actual inter-vehicle distance is larger than the caution inter-vehicle distance, the alarm control unit 42 does not activate the alarm device 5 ( Step S27).

However, when the actual inter-vehicle distance becomes equal to or less than the caution inter-vehicle distance, as shown in FIGS. 3 (1) and 4 (1), a caution alarm is first issued at point A, but before that, the brake operation is performed. Whether or not it is performed is determined by the output signal from the brake pedal switch 3 (step S23).

As a result, the brake pedal switch 3 is turned off.
When it becomes N and it is found that the brake pedal is depressed, the alarm device 5 does not operate (step S2).
When it is determined in 7) that the brake pedal switch 3 is OFF and the brake pedal is not depressed, it is further determined whether the actual inter-vehicle distance is less than or equal to the dangerous inter-vehicle distance (step S24).

As a result, when the actual inter-vehicle distance is larger than the dangerous inter-vehicle distance, it is assumed that the vehicle exists at the point B shown in FIGS. 3 (1) and 4 (1).
A control signal is sent so as to issue a caution alarm to (step S26). This caution alarm has a relatively low alarm volume, for example.

When it is determined in step S24 that the actual inter-vehicle distance has become equal to or less than the dangerous inter-vehicle distance, it is assumed that the vehicle is located at the point C or the point D shown in FIGS. 3 (1) and 4 (1). The alarm control unit 42 sends a control signal to the alarm device 5 so as to issue a danger alarm indicating a danger (step S25). This danger warning is, for example, a warning signal having a louder volume than the above caution warning.

Thus, in the prior art,
When the vehicle enters the caution inter-vehicle distance area, an alarm corresponding to this is issued, and when the vehicle enters the dangerous inter-vehicle distance area,
In addition to issuing another alarm, if a brake operation (or direction instruction operation) is performed at such a cautionary or dangerous vehicle distance, the alarm operation is interrupted and the brake operation (or direction instruction operation) is performed. When it disappears, the alarm is output again.

[0011]

In the conventional vehicle-to-vehicle distance warning device as described above, the vehicle is not always in the approaching state when the vehicle actually travels on the road, and as shown in FIG.
After approaching the dangerous inter-vehicle distance from the point, by performing the brake operation, the inter-vehicle distance is expanded by a certain distance to reach point B. If the brake operation is released at this point, the caution alarm will be output again.

Further, as shown in FIG. 4 (1), after passing through the caution area from point A and reaching point D in the danger area, a brake operation is performed to return to the caution inter-vehicle distance, and again at point B. When approaching, a caution warning will be output even at this point.

Therefore, in general running, the approaching → brake operation → cruising is often repeated, and therefore, there are many cases where the operator moves back and forth to the caution or danger area or stays within the area.

That is, even if the driver recognizes the warning alarm once and outputs the caution warning when he / she performs the brake operation, the warning is repeated more than necessary regardless of whether the warning warning is recognized or not. However, there was a problem that it became an unreliable unpleasant alarm.

Therefore, it is an object of the present invention to eliminate an unnecessary alarm recognized by a driver in an inter-vehicle distance warning device which issues an alarm when the inter-vehicle distance to a vehicle ahead becomes a safe inter-vehicle distance or less. .

[0016]

In order to achieve the above object, an inter-vehicle distance warning device according to the present invention includes an obstacle detection means for detecting an actual inter-vehicle distance and a relative speed, a vehicle speed detection means, and a brake operation detection. Means, an alarm means, and a distance between the caution vehicle and the dangerous vehicle distance from the relative speed and the vehicle speed,
When the actual inter-vehicle distance first falls within the caution inter-vehicle distance or the dangerous inter-vehicle distance, respectively, a caution warning or a danger warning is output from the warning means for a certain period of time, and the fact that each warning is issued is stored. Even when the brake operation is released, the caution alarm is not output if the distance between the caution vehicles is still after the caution warning or the danger warning, and then the actual vehicle distance becomes within the dangerous vehicle distance. And a controller for outputting the danger warning again from the warning means.

Further, when the controller detects that the vehicle ahead is approaching abruptly from the actual vehicle-to-vehicle distance and the change amount and average value of the relative speed, the actual vehicle-to-vehicle distance is the caution vehicle-to-vehicle distance or the vehicle-to-vehicle distance. The warning warning or the danger warning can be output from the warning means whenever the distance is within the dangerous distance.

Further, when the controller detects a target change or a lost target by processing the actual vehicle-to-vehicle distance and the relative speed in time series, the actual vehicle-to-vehicle distance is the target vehicle-to-vehicle distance or the target vehicle-to-vehicle distance. An alarm can always be output from the alarm means if the distance is within the dangerous inter-vehicle distance.

Instead of the above-mentioned brake operation detecting means, it is possible to use means for detecting a direction instruction operation of the vehicle or means for detecting ON / OFF of the accelerator.

[0020]

In the present invention, the controller calculates the caution inter-vehicle distance and the dangerous inter-vehicle distance based on the relative speed detected by the obstacle detection means and the vehicle speed detected by the vehicle speed detection means.

When the actual inter-vehicle distance detected by the obstacle detecting means is within the inter-vehicle distance for the first time, the caution alarm a is given for a certain time at the point A shown in FIGS. 3 (1) and 4 (1). Only output from the alarm device.

The state in which the alarm is output in this way is stored, and thereafter, as shown in FIG. 3 (1), the brake operation, the direction instruction operation, or the accelerator O is performed within the vehicle distance.
Even if FF is performed, the target is separated, and then the target is approached, the warning alarm a is once issued at point A,
At point B, the warning means does not output a caution warning.

Further, from the point B to the dangerous vehicle distance C
When the vehicle approaches the point, the danger alarm c is output for a certain period of time as if the vehicle ahead was the target.

Also, as shown in FIG. 4 (1), when the vehicle travels from point A of the cautionary inter-vehicle distance to point D of the dangerous inter-vehicle distance, the danger alarm d is issued as in the case of FIG. 3 (1). Output.

After that, when the driver performs the brake operation or the direction instruction operation, the controller which detects the brake operation or the direction instruction operation by the brake operation detection means or the direction instruction operation detection means, at the point B where the brake operation or the direction instruction operation is released. As in the case of FIG. 3A, the caution alarm is not output from the alarm means.

As in the same figure, when the point B further approaches the point E which is the distance between dangerous vehicles, the warning means is controlled so as to issue the danger warning e to the preceding vehicle.

When the controller detects a state in which the vehicle ahead is approaching rapidly from the above-described change amount and average value of the actual vehicle-to-vehicle distance and the relative speed, as described above, within the vehicle-to-vehicle distance as described above. The alarm means can be controlled so as to always output the caution alarm instead of suppressing the caution alarm. Further, by processing the actual inter-vehicle distance and the relative speed in time series, the target change or the lost target is performed. When it is detected that the actual inter-vehicle distance is within the caution inter-vehicle distance or the dangerous inter-vehicle distance, the alarm means can be controlled to always output an alarm.

[0028]

1 shows an embodiment of an inter-vehicle distance warning device according to the present invention. In this embodiment, a radar device 1, a vehicle speed sensor 2 and a brake pedal are provided as in the conventional example shown in FIG. Each output signal from the switch (or flasher switch) 3 is input to the controller 4, and the controller 4
Controls the alarm device 5.

Further, in the controller 4, as in the conventional example of FIG. 5, the safe inter-vehicle distance calculating section 41 and the alarm control section 4 are provided.
2 and inputting the actual inter-vehicle distance and the relative speed from the radar device 1 to determine the emergency state of the vehicle, and the same inputting the actual inter-vehicle distance and the relative speed of the radar device 1. The target tracking determination unit 44 for tracking the target, the output signals of the determination units 43 and 44, and the control signal to the alarm device 5 from the alarm control unit 42, the alarm control unit 42 outputs an alarm signal to the alarm device 5. Is provided in relation to the brake pedal switch 3 and a standby state determination unit 45 that gives a control signal for determining whether or not to output.

The operation of the inter-vehicle distance warning device according to the present invention will be described with reference to the operation flow shown in FIG. 2 and FIGS.
The operation will be described below with reference to the operation explanatory diagram shown in FIG.

First, the controller 4 performs initial setting including resetting of each flag and alarm output status described below (step S1).

Next, the controller 4 reads the relative speed from the radar device 1 and the vehicle speed from the vehicle speed sensor 2 into the safe inter-vehicle distance calculation section 41, and the radar is shared by the emergency state determination section 43 and the target tracking determination section 44. The actual inter-vehicle distance and the relative speed from the device 1 are read (step S2).

Further, the controller 4 reads the actual inter-vehicle distance from the radar device 1 and the brake operation signal from the brake pedal switch 3 into the alarm controller 42 (step S).
3).

Next, the controller 4 processes the actual inter-vehicle distance and the relative speed in time series on the basis of the actual inter-vehicle distance and the relative speed from the radar device 1 in the target tracking determination section 44, and the target of alarm (front vehicle). It is tracked and determined whether or not (step S4).

In this way, it is determined whether or not the target for which the target tracking determination has been performed has been changed or lost target (step S5). As a result, when it is found that the target has been changed or there is no lost target, the emergency state is set. The determination unit 43 determines a sudden change in the traveling state such as a sudden braking of the preceding vehicle from the change amount and the average value of the actual inter-vehicle distance and the relative speed from the radar device 1, and if the sudden change occurs, the state is flagged as an emergency state. Is set ("1") (step S6).

Next, the standby state determination unit 45 receives the output signals of the determination units 43 and 44, the output signal for the alarm device 5, and the signal for the brake pedal switch 3 to execute the following processing.

That is, first, when it is found that the caution alarm or the danger alarm is output based on the "alarm output status" stored in step S16 described later, it is determined that the standby state is established and the standby state flag is established. Is set (step S7).

Then, it is determined whether the standby state is set or not by setting the standby state flag (step S8).

As a result, when the standby state flag is cleared ("0"), the process proceeds to step S11.

On the other hand, when it is found that the standby state flag is set, it is determined whether or not the standby reset condition is satisfied (step S9).

The standby reset condition is satisfied when the emergency state flag is set, or when the actual inter-vehicle distance is more than the safe inter-vehicle distance (step S11) by a set distance or more. It is a thing.

As a result, when it is found that the standby reset condition is satisfied, the standby state flag is cleared (step S10).

Further, the safe inter-vehicle distance is calculated based on the relative speed and the vehicle speed fetched in step S2 (step S11). In this case, the safe inter-vehicle distance includes both the caution inter-vehicle distance (caution area) and the dangerous inter-vehicle distance (danger area) shown in FIGS. 3 and 4, as described in the conventional example of FIG.

Next, the controller 4 shifts to the control of the alarm control unit 42, and if the brake operation signal from the brake pedal switch 3 is read, it sets the alarm output suppression flag. A flasher switch indicating a direction indicating operation may be used instead of the brake pedal switch.

Further, the alarm control unit 42 compares the caution inter-vehicle distance and the dangerous inter-vehicle distance calculated in step S11 with the actual inter-vehicle distance from the radar device 1 to determine which of safety, caution, and danger states. It is determined and these pieces of information are set (step S13).

Then, in step S14, the alarm control unit 42, as shown in FIGS. 3 (2) and 4 (2), the judgment result of the alarm judgment (step S13) and the standby state judgment (step S7). The alarm device 5 is controlled so as to generate an alarm output corresponding to each of the standby state flags (step S15).

After that, the current alarm output status is stored as one of safety, caution, and danger (step S16).

When the target is changed or lost in step S5, both the emergency state flag and the standby state flag are released (step S17).

In this way, the alarm determination (step S1
3 (1) and FIG. 4 (2) are shown together when the alarm is output (steps S14 and S15) based on 3) and the standby state flag (step S7).

That is, when the vehicle stays within the distance between cautions as shown in FIG. 3A, as shown in FIG. 2B, no alarm is output up to the point A, but the point A approaches. At this point, the warning alarm a is output only for a certain period of time, assuming that this is within the first distance between warning vehicles.

After that, as a result of performing the brake operation within the distance between caution vehicles, when the vehicle reaches the point B, the warning judgment is "warning warning", but the standby state flag is "1". The caution alarm is not output, and the danger alarm c is output only when the point C of the dangerous inter-vehicle distance is reached thereafter.

Further, in the case where the vehicle makes a round trip within the cautionary inter-vehicle distance and the dangerous inter-vehicle distance shown in FIG.
As shown in, first, the warning alarm a is generated at point A, and D
At this point, the danger alarm d is output for a certain period of time, but as a result of performing the brake operation after this, as in the case of FIG.
When the inter-vehicle distance is extended to the point, the warning judgment is "caution warning", but the standby state flag is "1".
Even in this case, the caution alarm is not output, and the danger alarm e is output again when the dangerous vehicle distance E is approached again.

As described above, when it is determined by the emergency state determination (step S6) that the vehicle is in the emergency state, the standby state flag is cleared in step S10 via the above step S9. Is careful, as long as you do not operate the brakes,
An alarm is always output as an "emergency condition".

[0054]

As described above, according to the inter-vehicle distance warning device of the present invention, when the actual inter-vehicle distance falls within the caution inter-vehicle distance or the dangerous inter-vehicle distance for the first time, the caution warning or the danger warning is generated for a predetermined time, respectively. This warning state is stored and the warning alarm is not issued again even if the vehicle comes and goes within the distance between vehicles, so the warning is repeated unnecessarily. It becomes possible to eliminate the unpleasant alarm for the driver.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an inter-vehicle distance warning device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the controller in the inter-vehicle distance warning device according to the present invention.

FIG. 3 is a diagram for explaining an alarm situation when the vehicle stays within a cautionary inter-vehicle distance in the inter-vehicle distance warning devices according to the present invention and the conventional example.

FIG. 4 is a diagram for explaining an alarm situation when the vehicle reciprocates within the caution inter-vehicle distance and the dangerous inter-vehicle distance in the inter-vehicle distance warning devices according to the present invention and the conventional example.

FIG. 5 is a block diagram showing a configuration example of an inter-vehicle distance warning device according to a conventional example.

6 is a flow chart diagram for explaining the operation of the conventional example of FIG.

[Explanation of symbols]

 1 radar device (obstacle warning means) 2 vehicle speed sensor (vehicle speed detection means) 3 brake pedal switch (brake operation detection means) 4 controller 5 alarm device 41 safe inter-vehicle distance calculation unit 42 alarm control unit 43 emergency state determination unit 44 target tracking Part 45 Standby state determination part In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (5)

[Claims] 1. An obstacle detection means for detecting an actual inter-vehicle distance and a relative speed, a vehicle speed detection means, a brake operation detection means, an alarm means, and a caution inter-vehicle distance and a dangerous inter-vehicle distance from the relative speed and the vehicle speed. However, when the actual inter-vehicle distance falls within the caution inter-vehicle distance or the dangerous inter-vehicle distance for the first time, a caution warning or a danger warning is output from the warning means for a certain period of time, and it is stored that each warning is issued. , Even when the brake operation is released, if the warning distance is still within the caution vehicle distance after the caution warning or the danger warning, the caution warning is not output, and then the actual vehicle distance becomes within the dangerous vehicle distance. An inter-vehicle distance warning device, comprising: a controller that outputs the danger warning again from the warning means. 2. The controller detects that the actual inter-vehicle distance is the approaching inter-vehicle distance, or the attention inter-vehicle distance or 2. The inter-vehicle distance warning device according to claim 1, wherein the warning warning or the danger warning is output from the warning means whenever the distance is within the dangerous distance. 3. When the controller detects a target change or a lost target by processing the actual inter-vehicle distance and the relative speed in time series, the actual inter-vehicle distance is the attention inter-vehicle distance or the lost inter-vehicle distance. The inter-vehicle distance warning device according to claim 1 or 2, wherein an alarm is always output from the warning means if the distance is within the dangerous inter-vehicle distance. 4. The inter-vehicle distance warning device according to any one of claims 1 to 3, wherein a means for detecting a direction indicating operation of the vehicle is used in place of the brake operation detecting means. 5. An inter-vehicle distance warning device according to claim 1, wherein a means for detecting ON / OFF of an accelerator is used in place of the brake operation detecting means.