JP2501517B2 - Inter-vehicle distance alarm device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-vehicle distance warning device for issuing an alarm when the inter-vehicle distance from a preceding vehicle falls within an alarm distance which is previously determined based on relative speed.

[0002]

2. Description of the Related Art An inter-vehicle distance warning device is a device which issues an alarm when the inter-vehicle distance from a preceding vehicle becomes equal to or less than an alarm distance previously obtained corresponding to a traveling vehicle speed. In order to measure the vehicle-to-vehicle distance, a so-called laser radar is used which measures a vehicle-to-vehicle distance by irradiating a laser beam or the like forward and measuring the arrival time of a reflected beam from a preceding vehicle. The warning distance is predetermined according to the traveling vehicle speed. Further, the warning is configured to stop when the driver steps on the brake pedal.

[0003]

In the prior art as described above, the warning distance is set in advance in correspondence with the traveling vehicle speed, but the inter-vehicle distance that the driver feels optimal is different for each driver. There is. Therefore, the determination level at which the vehicle approaches the preceding vehicle and is determined to be dangerous varies depending on the driver.

The alarm is stopped when the brake pedal is depressed. Therefore, even if the driver just stepped on the brake lightly and was not aware of the danger,
Since the alarm is stopped, even if the preceding vehicle is suddenly approached from that state, the alarm is not issued and it is dangerous. Further, even if there is an interruption vehicle while decelerating by depressing the brake pedal, no alarm is issued and it is dangerous.

An object of the present invention is to detect a danger at an optimum level that matches a driver's feeling, and to prevent an undesired alarm from occurring and to reliably generate an alarm when dangerous. It is to provide a distance warning device.

[0006]

According to the present invention, an inter-vehicle distance from a preceding vehicle is measured by a measuring means, and an alarm is generated when the measurement result is equal to or shorter than an alarm distance previously obtained corresponding to a traveling vehicle speed. In the inter-vehicle distance warning device, the following traveling detection means for detecting that the vehicle is following the preceding vehicle provided that the traveling vehicle speed is at least a predetermined value and the relative speed with the preceding vehicle is within a predetermined range. In response to the output of the follow-up running detection means, when it is detected that the follow-up running is being performed, the measured inter-vehicle distance is based on a comparison result between the inter-vehicle distance measured by the measuring means and a reference value. If is larger than the reference value, the alarm distance is greatly corrected,
An inter-vehicle distance warning device, comprising: a correction unit that corrects the alarm distance to a smaller value if the measured inter-vehicle distance is smaller than a reference value.

Further, according to the present invention, the reference value is set larger as time elapses if the measured inter-vehicle distance is larger than the reference value, and is set as time elapses if the measured inter-vehicle distance is smaller than the reference value. The inter-vehicle distance warning device according to claim 1, wherein the inter-vehicle distance warning device is set small. Further, according to the present invention, the inter-vehicle distance warning device measures the inter-vehicle distance with a preceding vehicle by a measuring means, and issues a warning when the measurement result is equal to or less than a predetermined warning distance corresponding to the traveling vehicle speed. A braking detecting means for detecting an operation, and a correcting means responsive to an output of the braking detecting means for correcting the alarm distance to be short when it is detected that a braking operation is being performed. It is an inter-vehicle distance warning device.

[0008]

According to the present invention, the warning is issued when the inter-vehicle distance from the preceding vehicle becomes equal to or shorter than the warning distance previously obtained corresponding to the traveling vehicle speed. The vehicle-to-vehicle distance is measured by a measuring unit such as a so-called laser radar that irradiates a laser beam or the like and measures the arrival time of the reflected beam from the preceding vehicle.

The warning distance is corrected by the correcting means on the basis of the measurement result of the measuring means when the following traveling detecting means detects that the vehicle is following the preceding vehicle. The follow-up running detection means determines whether or not the follow-up running is being performed on condition that the vehicle speed is equal to or higher than a predetermined value and the relative speed with respect to the preceding vehicle is within a predetermined range. According to the present invention, in particular, the correction means includes the inter-vehicle distance LD and the reference value LST measured by the measurement means.
Based on the result of comparison with K, step n1 in FIG. 5 described later.
At 0, the measured inter-vehicle distance LD is the reference value LST.
If it is larger than K, the learning value K in step n13
Is set to a large value, and therefore the warning distance LAR · K is largely corrected in step n15. If the inter-vehicle distance LD measured in step n11 is smaller than the reference value LST · K, the learning value K is set small in the next step n12, and therefore the warning distance LAR · K is corrected small in step n15. The reference value LST · K is set every 5 seconds as shown in step n8 of FIG.
As shown in n13, if the measured inter-vehicle distance LD is larger than the reference value LST · K, it is set to a large value in step n13 with the lapse of time in step n8, and the measured inter-vehicle distance LD Is smaller than the reference value LST · K at step n11, step n1 is performed as time elapses at step n8.
It will be set small in 2.

Therefore, since the warning distance is corrected for each driver so that the driver feels the optimum, it is possible to judge the danger at the optimum level and prevent an undesired warning.

Further, according to the present invention, when the braking detecting means detects that the braking operation is being performed, the driver has already performed the braking operation.
Since the danger avoidance can be promptly taken, the warning distance is corrected by the correction means to be short.

Therefore, the warning distance is corrected to be shorter when the braking operation is being performed than when the braking operation is not being performed. Therefore, it is possible to judge the danger at an optimum level and issue an undesired warning. Even if the braking operation is not performed and the braking operation is performed, the alarm can be surely issued in a dangerous case.

[0013]

1 is a block diagram showing the electrical construction of an embodiment of the present invention. Inter-vehicle distance warning control device (EC
1 is abbreviated as U). The vehicle speed detector D1 detects the traveling vehicle speed of the host vehicle, the inter-vehicle distance detector D3 detects the inter-vehicle distance from the preceding vehicle, and the detection results are used to correspond to the traveling vehicle speed in advance. If it is judged that the actual inter-vehicle distance is too short than the required warning distance and it is dangerous, the buzzer 6
Generate an alarm to alert you to danger. The vehicle speed detector D1 is provided with, for example, a magnet piece that rotates in association with the rotation of a propeller shaft or a speedometer cable, and a change in the magnetic field due to the rotation of the magnet piece is detected by a reed switch or the like provided at a fixed position. Is realized by The inter-vehicle distance detector D3 is realized by, for example, a so-called laser laser that irradiates a laser beam forward and determines the distance based on the arrival time of light reflected by the preceding vehicle. You can also find the speed. The relative speed is positive when approaching the preceding vehicle and negative when leaving the preceding vehicle.

Based on the traveling vehicle speed and the relative speed,
The alarm distance LAR is obtained in advance as shown in FIG. 2, and the graph shown in FIG. 2 is stored in the memory 4 in the ECU 1 as a map. This alarm distance L
An area where the inter-vehicle distance LD is shorter than AR is an alarm generation area.

This alarm generation area differs depending on the learning value K obtained as described later, and the solid line is a standard alarm distance that is set in advance, and this is the case where the learning value K = 1.0. On the other hand, the chain double-dashed line is the alarm distance corrected by multiplying the predetermined alarm distance by the learning value K. For example, if the traveling vehicle speed is 60 km / h and the preceding vehicle is approaching at a relative speed Vd = 20 km / h, the learning value K = 1.0 corresponding to a standard driver.
In this case, the warning is issued when the inter-vehicle distance LD is 50 m or less, but for a driver who prefers a relatively long inter-vehicle distance, for example, the learning value K is set to 1.2, and the warning is issued when the inter-vehicle distance is 60 m or less. That is, in FIG. 2, the relationship indicated by the solid line A is displaced to the two-dot chain line B.

FIG. 3 is a graph for explaining how to obtain the learning value K. The horizontal axis represents the traveling vehicle speed Vs, and the vertical axis represents the inter-vehicle distance LD. The solid line indicates the standard inter-vehicle distance LST that has been obtained in advance, and the broken line indicates the actual inter-vehicle distance LD that the driver has followed. The learning value K is obtained by dividing the actual inter-vehicle distance LD by the standard inter-vehicle distance LST.

In obtaining the learning value K, learning conditions are set. The learning condition is the traveling vehicle speed Vs.
Is 30 km / h or more, brake switch S2
Is off, the throttle fully closed switch S1 is off, and the steering angle θ is -5 °.
Above + 5 °, relative velocity Vd is -3 km /
It is assumed that it is h or more and +3 km / h or less, and that 5 seconds or more have elapsed since the detection of the vehicle ahead. When these conditions are satisfied, it is confirmed that the vehicle is stably following the preceding vehicle, and the learning value K is calculated.

The learning conditions are detected by a vehicle speed detector D1, a steering angle detector D2, an inter-vehicle distance detector D3, a throttle fully closed switch S1, and a brake switch S2.
Through the input interface circuit 2 in the ECU 1, it is input to the processing circuit 3 realized by a microcomputer or the like, and the determination is performed. When the learning condition is satisfied, the processing circuit 3 determines the vehicle speed detector D1 and the inter-vehicle distance detector D3.
Of the learning value K based on the detection result of the above and the standard inter-vehicle distance LST shown in FIG.
Is calculated to obtain. When the inter-vehicle distance LD becomes an alarm area equal to or less than the alarm distance LAR corresponding to the learned value K, the processing circuit 3 sounds the buzzer 6 via the output interface 5.

As another embodiment of the present invention, as shown in FIG. 4, the learning value K is K1, K depending on the traveling vehicle speed Vs.
It may be obtained and stored for each of a plurality of areas such as 2 and K3.

FIG. 5 is a flow chart for explaining the alarm control operation of the embodiment of the present invention as described above.
In step n1, the vehicle speed detector D1 detects the traveling vehicle speed V.
s is detected, and in step n2, an inter-vehicle distance detector D3
The actual inter-vehicle distance LD with the preceding vehicle is detected by.
In step n3, it is determined whether or not the traveling vehicle speed Vs is 30 km / h or more, and if so, the process proceeds to step n4 and it is determined whether or not the brake switch S2 is in the off state. If it is in the off state, that is, if the brake pedal is not depressed, the process proceeds to step n5, and it is determined whether the throttle fully closed switch S1 is in the on state, that is, whether the throttle valve or the fully closed state. When the accelerator pedal is not fully closed, that is, when the accelerator pedal is depressed, the process proceeds to step n6, and the steering angle detector D2 determines whether the steering angle is -5 ° or more and + 5 ° or less. If so, that is, if the vehicle is traveling straight ahead, the process proceeds to step n7.

At step n7, the relative speed Vd is -3k.
It is determined whether or not m / h or more and +3 km / h or less,
If so, the process proceeds to step n8, and it is determined whether or not 5 seconds or more have elapsed since the detection of the vehicle ahead. 5
When more than a second has elapsed, that is, when the vehicle is following stably, the routine proceeds to step n9, where the standard inter-vehicle distance LST corresponding to the traveling vehicle speed Vs obtained in step n1 from the standard inter-vehicle distance map shown in FIG. It is requested by searching. In step n10, it is judged whether or not the actual inter-vehicle distance LD obtained in step n2 is larger than the value obtained by multiplying the standard inter-vehicle distance LST by the learning value K. If it is larger, the process proceeds to step n13 to learn. K is updated by adding 0.01. When the actual inter-vehicle distance LD is not larger than the value obtained by multiplying the standard inter-vehicle distance LST by the learning value K in step n10,
In step n11, it is determined whether or not the inter-vehicle distance LD is less than the standard inter-vehicle distance LST multiplied by the learning value K, and if so, the learning value K is updated by subtracting 0.01. It

In step n11, the standard inter-vehicle distance LS
When the multiplication value of T and the learning value K is equal to the actual inter-vehicle distance LD, and from step n12, n13 to step n
Go to 14. Further, in step n3, the traveling vehicle speed Vs is 30.
When it is less than km / h, when the brake pedal is depressed in step n4, when the throttle valve is fully closed in step n5, and the steering angle is ± in step n6.
If it is not within 5, the relative speed Vd is ± 3 in step n7.
When it is not within km / h, and when 5 seconds have not elapsed since the vehicle was detected forward in Step 8, that is, stable follow-up traveling is not performed, and any one of the learning conditions is not satisfied. Sometimes step n14
Move on to. At step n14, the warning distance LAR is searched for from the warning distance map shown in FIG. 2, and at step n15, it is judged whether or not the value obtained by multiplying the warning distance LAR by the learning value K is larger than the actual inter-vehicle distance LD. When it is larger, the process moves to step n17 and the alarm is turned off, and when it is smaller, the process moves to step n16 and the alarm is turned on.

In this way, the learning value K is obtained in a state where it is confirmed that all the learning conditions are satisfied and the vehicle is following, and the warning distance that the driver feels optimal is the learning value K. Since it is corrected by, the risk is judged at an optimum level, and an undesired alarm is prevented.

Further, in the ECU 1, the alarm distance LAR is changed depending on whether the brake is on or off as shown in FIG. FIG. 6 (1) is a graph showing the warning distance LAR when the brake is off, and FIG. 6 (2) is a graph showing the warning distance LAR when the brake is on. These graphs are stored in the memory 4 as maps. From these graphs, the warning distance LAR is corrected to be shorter when the brake is on than when the brake is off. For example, under the condition that the traveling vehicle speed Vs is 80 km / h and the relative speed is 0 km / h, an alarm is issued when the inter-vehicle distance LD is 20 m or less when the brake is off, but is not issued when the brake distance is 10 m or less. .

FIG. 7 is a flow chart for explaining the alarm control operation of another embodiment of the present invention as described above. At step m1, the traveling vehicle speed Vs is detected, and at step m2, the actual inter-vehicle distance LD is detected. At step m3, it is judged whether or not the brake is on,
If it is in the off state, the process proceeds to step m4, and the alarm distance LAR is obtained by searching from the alarm distance map at the time of brake off shown in FIG. 6 (1). If it is in the on state, the process proceeds to step m5, and FIG. The alarm distance LAR is obtained by searching from the alarm distance map when the brake is turned on, which is shown in FIG. In step m6, it is determined whether or not the warning range, that is, the inter-vehicle distance LD is less than the warning distance LAR, and if so, the warning is turned on in step m7, and if not, the warning is turned off in step n8.

Therefore, when the brake pedal is depressed, the warning distance LAR is corrected to be shorter than when the brake pedal is not depressed, so that the danger is judged at an optimum level and the warning is issued undesirably. Without
Moreover, even if the brake pedal is stepped on, an alarm can be surely generated in the case of danger.

As another embodiment of the present invention, the alarm distance LAR at least when the brake is on or off may be corrected by the learning value K.

[0028]

As described above, according to the present invention, when it is detected that the vehicle is following the preceding vehicle, the driver feels that the driver is optimum for each driver based on the measurement result of the measuring means. To correct the alarm distance. Therefore, the warning that is generated when the distance is equal to or less than the warning distance is generated at the determination level that the driver feels to be optimum, and the warning is prevented from being undesirably generated.

Further, according to the present invention, when it is detected that the braking operation is being performed, the driver can promptly cope with the danger avoidance, so that the warning distance is corrected to be short. Therefore, it is possible to judge the danger at an optimum level, and to certainly generate the alarm without causing the alarm undesirably and when it is dangerous even if the braking operation is performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electrical configuration of an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a traveling vehicle speed Vs and a relative speed Vd and an alarm distance LAR according to an embodiment of the present invention.

FIG. 3 is a graph showing a change in a standard inter-vehicle distance LST for obtaining a learning value K with respect to a traveling vehicle speed Vs.

FIG. 4 shows learning values K1 and K for each predetermined region of traveling vehicle speed Vs.
It is a map diagram in the case of trying to obtain 2, K3.

FIG. 5 is a flowchart for explaining an alarm control operation according to an embodiment of the present invention.

FIG. 6 is a graph showing a relationship between a traveling vehicle speed Vs and a relative speed Vd and an alarm distance LAR according to another embodiment of the present invention.

FIG. 7 is a flow chart for explaining an alarm control operation of another embodiment of the present invention.

[Explanation of symbols] 1 ECU 6 Buzzer D1 Vehicle speed detector D2 Steering angle detector D3 Inter-vehicle distance detector S1 Throttle fully closed switch S2 Brake switch

Claims (3)

(57) [Claims] 1. An inter-vehicle distance warning device for measuring an inter-vehicle distance from a preceding vehicle by a measuring means, and issuing an alarm when the measurement result is equal to or shorter than an alarm distance previously obtained corresponding to a traveling vehicle speed, A follow-up running detection unit that detects that the vehicle is running following the preceding vehicle on condition that the traveling vehicle speed is equal to or higher than a predetermined value and the relative speed with the preceding vehicle is within a predetermined range, and the output of the follow-up running detection unit. When it is detected that the vehicle is following, the warning is issued if the measured inter-vehicle distance is larger than the reference value, based on the result of comparison between the inter-vehicle distance measured by the measuring means and the reference value. An inter-vehicle distance warning device, comprising: a correction unit that corrects the distance to a large extent and corrects the alarm distance to a smaller value if the measured inter-vehicle distance is smaller than a reference value. 2. The reference value is set to be large with the passage of time when the measured inter-vehicle distance is larger than the reference value, and is set to be small with the passage of time when the measured inter-vehicle distance is smaller than the reference value. The inter-vehicle distance warning device according to claim 1, wherein: 3. An inter-vehicle distance warning device that measures an inter-vehicle distance from a preceding vehicle by a measuring means, and issues an alarm when the measurement result is equal to or less than an alarm distance previously obtained corresponding to a traveling vehicle speed, in a braking system. A braking detecting means for detecting an operation, and a correcting means responsive to an output of the braking detecting means for correcting the alarm distance to be short when it is detected that a braking operation is being performed. Inter-vehicle distance warning device.