JPH08276806A - Preceding vehicle starting cautioning device - Google Patents

Abstract

PURPOSE: To detect automatically stopping of own vehicle and starting of a preceding vehicle in the case of a preceding vehicle starting cautioning device which cautions that a preceding vehicle at a stop has started while as own vehicle is standing in series with the preceding vehicle. CONSTITUTION: An inter-vehicle distance detection means 1 detects an inter- vehicle distance from a preceding vehicle. A relative-speed computation means 22 computes a relative speed from the inter-vehicle distance. An own vehicle stopping detection means 23 detects an own vehicle's stopping based on the relative speed and the inter-vehicle distance. The inter-vehicle distance at the time when the own vehicle stopping is detected is set as a reference inter-vehicle distance. A starting determination means 24, comparing a present inter-vehicle distance with the reference inter-vehicle distance, determines that the preceding vehicle has started when the present inter-vehicle distance becomes greater than the reference inter-vehicle distance by a predetermined value. A cautioning means 3 issues a caution to a driver according to the preceding vehicle's starting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a device which is used by being mounted on an automobile and which automatically warns that a preceding vehicle that has been stopped has started when its own vehicle is stopped following the preceding vehicle. It is about.

[0002]

2. Description of the Related Art A driver of an automobile may take actions other than driving by utilizing a temporary stoppage time such as traffic jam on the road or waiting for a signal. During such an action, even if the preceding vehicle starts, the driver may not notice it. On the other hand, there is a vehicle front confirmation device that automatically detects the preceding vehicle when it starts to warn the driver (Japanese Patent Laid-Open No. 64-57188). In order to use this front confirmation device, the driver operates the set switch when the host vehicle is behind the stopped preceding vehicle.
By this operation, the front confirmation device detects the inter-vehicle distance when the vehicle is stopped by the inter-vehicle distance detection sensor, and sets this as the reference inter-vehicle distance. Then, the inter-vehicle distance is sequentially measured, and when the inter-vehicle distance becomes larger than the reference inter-vehicle distance, it is determined that the preceding vehicle has started and issues a warning.

[0003]

In the above conventional device, the driver has to perform a troublesome switch operation every time the vehicle is stopped. Further, since it is necessary to provide a set switch, the cost of the device becomes high. The present invention
When the own vehicle is stopped following the preceding vehicle, the preceding vehicle start warning device that warns that the stopped preceding vehicle has started automatically indicates that the own vehicle has stopped and that the preceding vehicle has started. The purpose of this is to eliminate the need for operation by the driver and to omit the parts for operation by enabling the detection.

[0004]

In order to achieve the above object, the present invention provides a means for detecting an inter-vehicle distance to a preceding vehicle and a relative speed calculation for calculating a relative speed between the preceding vehicle and the own vehicle from the inter-vehicle distance. Means, a vehicle stop detection means for detecting a stop of the own vehicle based on the relative speed and the vehicle-to-vehicle distance, and an inter-vehicle distance and a current inter-vehicle distance when the own-vehicle stop detecting means detects the stop of the own vehicle. The leading vehicle start warning device is constituted by the starting determination means for determining whether or not the preceding vehicle has started by comparison and the warning means for issuing a warning according to the output from the starting determination means.

[0005]

The relative speed calculation means calculates the relative speed between the preceding vehicle and the own vehicle from the inter-vehicle distance. The own vehicle stop detection means detects the stop of the own vehicle based on the relative speed and the inter-vehicle distance.
The inter-vehicle distance when the own-vehicle stop detection means detects the stop of the own vehicle is set as the reference inter-vehicle distance. The start determination means compares the sequentially input inter-vehicle distance with the reference inter-vehicle distance, and determines that the preceding vehicle has started when the inter-vehicle distance is greater than the reference inter-vehicle distance by a predetermined value or more.

The warning means issues a warning to the driver when the preceding vehicle starts. From this warning, the driver knows that the preceding vehicle has started and can immediately start driving.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a preceding vehicle start warning device. The preceding vehicle start warning device includes an inter-vehicle distance detection device 1, a processing unit 2 that processes the signal, and a warning device 3 that issues a warning to the driver according to the processing result. Processing unit 2
Is a memory 21, a relative speed calculation unit 22, a vehicle stop detection unit 2
3 and a start determination unit 24.

The data output from the inter-vehicle distance detection device 1 is input to the memory 21, the vehicle stop detection unit 23, and the start determination unit 24. The memory 21 stores the past n times of data of the inter-vehicle distance detected by the inter-vehicle distance detecting device 1. Note that n
Is a value determined in advance in consideration of the sampling frequency and responsiveness of the inter-vehicle distance detecting device 1. Memory 21
Performs a FILO process that erases one old data each time new data is input.

The relative speed calculation unit 22 retrieves the past n inter-vehicle distance data from the memory 21, calculates the relative speed between the preceding vehicle and the own vehicle, and outputs the calculated relative speed to the vehicle stop detection unit 23. This calculation process is performed when the vehicle stop detection unit 23 does not detect that the vehicle is stopped, that is, when it is determined that the vehicle is traveling. The vehicle stop detection unit 23 detects that the host vehicle is stopped based on the relative speed input from the relative speed calculation unit 22 and the current inter-vehicle distance input from the inter-vehicle distance detection device 1. When it is detected that the host vehicle is stopped, the inter-vehicle distance when the vehicle is stopped is set to the reference inter-vehicle distance, and the start determination unit 24 is made to determine the start. When it is not detected that the own vehicle is stopped, the relative speed calculation unit 22 calculates the relative speed.

When the vehicle stop detector 23 detects that the own vehicle is stopped, the start determination unit 24 detects the inter-vehicle distance.
The current inter-vehicle distance input from is compared with the reference inter-vehicle distance, and when the current inter-vehicle distance exceeds the reference inter-vehicle distance by a predetermined value or more, it is determined that the preceding vehicle has started. Warning device 3
When the start determination unit 24 determines that the preceding vehicle has started,
Warn the driver. Although various means can be adopted as the warning means, it is effective to issue a sound warning to the driver who performs an unspecified action other than driving.

Next, the operation of the preceding vehicle start warning device of FIG. 1 will be described with reference to the flowchart of FIG. The process of FIG. 2 starts when the ignition is turned on. In step 101, three threshold values Δ, σsh, and Dsh described below are initialized. Δ is the threshold value for incremental distance. When the preceding vehicle is separated from the reference inter-vehicle distance Ds by Δ or more, the start determination unit 24 determines that the preceding vehicle has started.

Σsh is a threshold value of the variance value. The variance σn calculated by the relative speed calculator 22 is σs
One of the conditions is that the value is equal to or less than h.
Detects that your vehicle is stopped. Dsh is a threshold value of the inter-vehicle distance. The vehicle stop detection unit 23 detects that the own vehicle is stopped, on the condition that the vehicle-to-vehicle distance D detected by the vehicle-to-vehicle distance detection device 1 is Dsh or more.

In step 102, four variables Flag, Ds, Dp [n] and σn described below are reset (0.
Substitute). Flag is a flag indicating whether or not the host vehicle is stopped, where 1 means stopped and 0 means running. D is
This is a variable for substituting the inter-vehicle distance detected by the inter-vehicle distance detection device 1.

Ds is a variable for substituting the inter-vehicle distance when the vehicle is stopped, and this is the reference inter-vehicle distance for starting determination.
Dp [n] is a variable that represents the past n inter-vehicle distance measurement values stored in the memory 21. σn is a variable for substituting the variance calculated by the relative speed calculation unit 22 using the past n inter-vehicle distance measurement values Dp [n].

In step 103, the inter-vehicle distance detecting device 1 measures the distance to the preceding vehicle and sets this as the inter-vehicle distance D. In step 104, the vehicle stop detection unit 23 sets Flag = 1.
Is determined. If it is determined that the host vehicle is already stopped, Flag = 1, and the routine proceeds to steps 109 to 110 for detecting the start of the preceding vehicle. If Flag = 0, the stopped vehicle is detected. To the routine of steps 105 to 108.

In step 105, the relative speed calculation unit 22
However, the past n inter-vehicle distance measurement values Dp from the memory 21
[N] is taken out and the variance σn of the inter-vehicle distance is calculated. In step 106, the vehicle stop detection unit 23 determines that the inter-vehicle distance variance σ
Compare n with the threshold value σsh. σn ≦ σ
In the case of sh, it is considered that the relative speed between the preceding vehicle and the own vehicle is 0, and the routine proceeds to step 107. If σn> σsh, it is considered that the vehicle is running because the inter-vehicle distance has changed, and the process returns to step 103.

In step 107, the vehicle stop detection unit 23 compares the inter-vehicle distance D with the threshold value Dsh. D
If> Dsh, the relative speed σn is 0, but the inter-vehicle distance is relatively large, so it is determined that the host vehicle is traveling following the preceding vehicle, and the process returns to step 103. If D ≦ Dsh, the inter-vehicle distance to the preceding vehicle is short. Therefore, the preceding vehicle and the own vehicle are stopped together with the fact that the relative speed with the preceding vehicle is determined to be 0 in step 106 described above. It is determined that there is, and the process proceeds to step 108.

At step 108, the vehicle stop detection unit 23 determines that the F
1 is set to lag, and the inter-vehicle distance D detected by the inter-vehicle distance detecting device 1 is set to the reference inter-vehicle distance Ds. Then, the process returns to step 103. Returning to step 103, the inter-vehicle distance detecting device 1 measures the distance to the preceding vehicle and newly sets this as the inter-vehicle distance D. Further, in step 104, the vehicle stop detection unit 23 determines whether Flag = 1. Here, if the vehicle is traveling and Flag = 0, the routine again proceeds to the routine of steps 105 to 108 for detecting that the vehicle is stopped. On the other hand, if it is detected by the routine of steps 105 to 108 that the vehicle is stopped, F
Since lag = 1, the process proceeds to step 109.

In step 109, the starting determination unit 24 determines whether the inter-vehicle distance D detected by the inter-vehicle distance detecting device 1 is more than the increment Δ from the reference inter-vehicle distance Ds (D ≧ Ds + Δ). If the inter-vehicle distance D is not far, it is determined that the preceding vehicle has not started, and the process returns to step 103. If the inter-vehicle distance D is long, it is determined that the preceding vehicle has started, and the process proceeds to step 110.

In step 110, the warning device 3 warns the driver that the preceding vehicle has started. afterwards,
Returning to step 102, the same processing as described above is repeated. In the process of FIG. 2, the order of steps whose processing result does not depend on the processing order can be changed. For example, step 107 can be located before step 105 or 106.

Through the above processing, the preceding vehicle start warning device automatically detects that the own vehicle has stopped behind the preceding vehicle and automatically sets the reference inter-vehicle distance. After that, when the preceding vehicle starts, the driver is warned accordingly. Therefore, the driver will be warned by a sound etc. when the preceding vehicle starts, even if the driver is engaged in activities other than driving, such as traffic jams on the road, waiting for traffic lights, etc.
You can start driving immediately.

Further, according to the preceding vehicle start warning device, the driver does not need to operate the set switch every time the vehicle stops, so that the convenient preceding vehicle start warning device can be obtained. . Furthermore, the processing unit 2
Since the processing can be performed only on the basis of the data of the inter-vehicle distance D from the position detector 1, it is not necessary to provide a set switch or a means for picking up a vehicle speed signal. Therefore, a device that is easy to install and low in cost can be obtained.

[0023]

According to the present invention, when the own vehicle is stopped following the preceding vehicle, the preceding vehicle start warning device warns that the preceding vehicle that has been stopped has started. And that the preceding vehicle has started can be automatically detected, and the driver's operation is unnecessary and the parts for the operation can be omitted.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of a preceding vehicle start warning device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the apparatus shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Position detector 2 ... Processing part 3 ... Warning device 21 ... Memory 22 ... Relative speed calculation part 23 ... Stop detection part 24 ... Start determination part

Claims (1)

[Claims] 1. A means for detecting an inter-vehicle distance from a preceding vehicle,
Relative speed calculation means for calculating a relative speed between the preceding vehicle and the own vehicle from the inter-vehicle distance, own vehicle stop detection means for detecting stop of the own vehicle based on the relative speed and the inter-vehicle distance, and the own vehicle By comparing the inter-vehicle distance when the vehicle stop detecting means detects the stop of the own vehicle and the current inter-vehicle distance, a start determination means for determining whether or not the preceding vehicle has started, and a start determination means from the start determination means A preceding vehicle start warning device, comprising: warning means for issuing a warning according to an output.