JPH0986312A - Vehicle obstacle detection device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To accurately detect the position of an obstacle using a plurality of radars. SOLUTION: Three ultrasonic radars 11R to 13R are provided at the right rear end of the vehicle for detecting obstacles on the right rear side.
Is installed. The detection area of the radar 11R is set to 11ZR, and the detection area of the radar 112R is set to 12ZR.
The detection area of the radar 13R is set to 13ZR, and the detection areas of the radars are set to be different and close to each other.
The frequencies used by the radars 11R to 13R are set to be different from each other. When the detection wave transmitted from a certain radar, for example, 11R, is received by another radar, for example, 12R, it is determined that the detection wave is wraparound, and the operating frequency of each radar is It is made large (directivity is strengthened).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle obstacle detection device for detecting obstacles around a vehicle.

[0002]

2. Description of the Related Art In recent vehicles, there is a tendency that the number of radars, for example, ultrasonic radars, which detect obstacles around the vehicle is increasing (for example, Japanese Patent Laid-Open Publication No. Sho. 6
No. 2-80575).

[0003]

It has been desired to detect in more detail the position where an obstacle exists, that is, the position around the vehicle. Therefore, it is considered that a plurality of radars are provided and the detection areas are different from each other. In this case, the detection areas are close to each other.

However, if the detection areas are close to each other, so-called wraparound, which causes interference between the radars, is likely to occur. That is, a situation where a detection wave transmitted by a certain radar is detected by another radar, and it is erroneously recognized that an obstacle exists in the detection area corresponding to the detected radar. It tends to occur. Such wraparound causes the detected wave to be largely deflected and reflected by the uneven portion of the obstacle (for example, the wheel arch portion or the side mirror of the following vehicle), or the detected wave itself with respect to the traveling vehicle. Caused by relative displacement. Such wraparound is particularly likely to occur when an ultrasonic radar having a slow detection wave velocity is used.

The present invention has been made in consideration of the above circumstances, and is based on the premise that a plurality of radars are used to detect the position of an obstacle in more detail. It is an object of the present invention to provide an obstacle detection device for a vehicle that can prevent a situation in which the position of an object is erroneously recognized.

In order to achieve the above object, the first aspect of the present invention is to use different frequencies between the radars corresponding to the adjacent detection areas. Specifically, the configuration is as described in claim 1 or claim 7 in the claims.

In order to achieve the above object, the present invention has a second configuration in which the directivity of a detection wave is enhanced when a wraparound occurs. Specifically, the configuration is as described in claim 4 or claim 8 in the claims.

[0007]

According to the invention described in claim 1, since the frequencies used by the radars corresponding to the adjacent detection areas are set to be different from each other, that is, the radars are located in a certain predetermined detection area. Since the obstacle is set to be detected only by the radar corresponding to the predetermined detection area, an obstacle that may be mistaken for an obstacle located in a certain detection area to be in the adjacent detection area. It is possible to prevent misidentification of the position.

With the structure as described in claim 2, erroneous position recognition of the obstacle is surely prevented by ignoring the detection waves of frequencies other than the corresponding frequency.

With the structure as described in claim 3, the detection area of each radar is clearly set as an area where the detection wave transmitting direction and the detection wave receiving direction overlap each other, and the detection area is set. It is preferable for the setting of and the prevention of misidentification of the position of the obstacle.

According to the invention described in claim 4, when the wraparound occurs, the directivity of the detection wave is strengthened to prevent the wraparound, thereby preventing misidentification of the position of the obstacle.

With the structure as described in claim 5, the directivity of the detected wave can be enhanced by a simple method of increasing the frequency.

By adopting the structure as described in claim 6, a concrete method for judging whether or not the wraparound has occurred is provided.

According to the invention described in claim 7, in the rear side region of the vehicle, which is likely to be a blind spot by the driver, the effect corresponding to claim 1 is obtained, and the position of the obstacle such as the following vehicle is accurately determined. It will be preferable to know.

According to the invention described in claim 8, in the rear side area of the vehicle, which is likely to be a blind spot by the driver, the effect corresponding to claim 4 is obtained, and the position of the obstacle such as the following vehicle is accurately determined. It will be preferable to know.

According to the invention described in claim 9, both the effects corresponding to claims 1 and 4 are obtained, and it is preferable in order to more surely prevent the misidentification of the position of the obstacle.

With the structure as described in claim 10, the ultrasonic radar is used while using the inexpensive ultrasonic radar.
It is possible to prevent misidentification of the position of an obstacle due to a wraparound that tends to cause a problem. Of course, since the ultrasonic radar is fixedly set, that is, not movable like a scan type, it is preferable for inexpensive implementation.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, a plurality of ultrasonic radars 11 (three in the embodiment) are provided at the right rear end of the vehicle 1.
R, 12R, and 13R are arranged. Similarly, vehicle 1
A plurality (three in the embodiment) of ultrasonic type radars 11L, 12L, 13L are also arranged at the left rear end of the. In addition,
The left and right radars are set to be bilaterally symmetric, including the detection area thereof.
The description will focus on the das 11R to 13R.

As shown in FIG. 2, each of the radars 11R to 13R is a transmitter 14 as a transmitting means for transmitting a detection wave.
And a receiver 15 as a receiving means for receiving the detection wave. The detection area of each of the radars 11R to 13R is set as an area in which the detection wave transmission direction from the transmitter 14 and the detection wave reception direction from the receiver 15 overlap each other when the vehicle 1 is stopped. It

The frequencies of the detection waves of the radars 11R to 13R are set to be a predetermined frequency for each radar as will be described later, but when a predetermined basic frequency is used as a reference, The detection areas of the radars 11R to 13R are set to be different from each other. That is, each radar 11R-1
Although the detection area by 3R is set to the rear side on the right side of the vehicle as a whole, the detection area 11ZR of the radar 11R is set to the right side area, and the radar 1
The detection area 13ZR of 3R is set to the right rear, and the radar 12R
The detection region 12ZR is set as a region between 11ZR and 13ZR. In addition, the left-side radars 11L to 1
3L detection area is 11ZL (corresponding to 11ZR), 12
It is designated as ZL (corresponding to 12ZR) or 13ZL (corresponding to 13ZR).

In FIG. 2, U is a control unit constructed by using a microcomputer mounted on the vehicle 1. With this control unit U,
The obstacle detection control by the das 11R to 13R (11L to 13L) is performed. A signal from a vehicle speed sensor S1 as a vehicle speed detecting means is input to the control unit U.
Further, the control unit U is adapted to output to an alarm device 22 including a display 21 and a buzzer described later. In FIG. 2, the left radar 11L to
13L is omitted.

The control of obstacle detection by the control unit U will be described with reference to the flowcharts shown in FIGS. In the following description, Q indicates a step. First, in Q0 of FIG. 3, it is determined whether or not the distance L to the obstacle measured last time is smaller than the predetermined distance LB. If YES in the determination of Q0, in Q1,
It is determined whether or not the current vehicle speed V is lower than the predetermined vehicle speed VB. If NO in the determination of Q0 or NO in the determination of Q1, in Q3, each of the radars 11R to 13
The transmission frequencies ft1 to ft3 of R are all set as the same basic frequency fa1. After that, in Q4, the wraparound flag is reset to 0. When the wraparound flag is 1, it indicates that the wraparound is occurring.

When the determination in Q1 is YES, it is determined in Q2 whether the wraparound flag is 1 or not. When the determination in Q2 is NO, that is, when the wraparound does not occur, in Q5, the transmission frequency ft1 of the radar 11R is set to the basic frequency fa1 and the radar 12
The transmission frequency ft2 of R is set to the frequency fb1, and the radar 1
The transmission frequency ft3 of 1R is set to the frequency fc1 (each frequency fal, fb1 and fc1 are different from each other,
In the embodiment, fa1 <fb1 <fc1).

When the determination in Q2 is YES, that is, when wraparound occurs, the transmission frequency ft1 of the radar 11R is set to frequency fa2, and the transmission frequency ft2 of the radar 12R is set to frequency fb2. The transmission frequency ft3 of the radar 11R is set to the frequency fc2 (fa2 and fb2
And fc2 are different from each other, and in the embodiment, fa1 <
fa2, fb1 <fb2, fc1 <fc2). In this way, when the wraparound occurs, the transmission frequency is increased and the directivity of the detection wave is strengthened, as compared with when the wraparound does not occur. By increasing the directivity of the detection wave, each of the detection regions 11ZR to 13ZR becomes narrower, and the wraparound is less likely to occur.

In the processing of Q3 and Q4, if the distance to the obstacle is large, it is not necessary to accurately detect the position of the obstacle, and when the vehicle speed is high, the accuracy of the position of the obstacle is higher than that of the obstacle. Also gives priority to the detection of the existence of the obstacle itself.
The transmission frequencies of R to 13R are all set to the same small frequency.

After Q4, Q5 or Q6, Q7
The processing of Q12 is performed, but this processing is performed by each radar 11
R to 13R are simultaneously performed. That is, the detection wave is transmitted from the radar in Q7, and the timer is reset to zero in Q8 (counting the transmission timing of the detection wave). After Q8, in Q9, it is determined whether or not the count value of the timer is equal to or larger than the predetermined value TB. Initially, the determination in Q9 is NO, and in this case, in Q10, it is determined whether or not the transmitted detection wave is received by the receiver 15. If NO in this Q10 determination,
After the timer counts up in Q11, Q9
Return to.

When the determination in Q10 is YES, the distance L to the obstacle is calculated according to the count value of the timer. Further, when the determination in Q9 is YES, the obstacle is not detected and the detection wave is not received. At this time, the distance L is calculated in Q12, and the calculated distance L at this time is , Q0 is a constant distance sufficiently larger than the predetermined distance LB. The distance L at Q0 is Q1
The smallest one of the distances L calculated for each of the radars 11R to 13R is used.

After Q12, it is judged by the processing of Q21 to Q23 in FIG. 4 whether or not the wraparound has occurred. That is, the reception frequency fr1 of the radar 11R substantially matches the transmission frequency ft1 of the radar 11R, and the reception frequency fr2 of the radar 12R almost equals the transmission frequency ft2 of the radar 12R. That they match, and that the reception frequency fr3 of the radar 13R is the same as that of the radar 1
When all the conditions that the transmission frequency ft3 of 3R substantially matches are satisfied, it is determined that the wraparound has not occurred, and the wraparound flag is reset to 0 in Q24. When all the above conditions are not satisfied, it is determined that the wraparound has occurred, and the wraparound flag is set to 1 in Q25. After Q24 or Q25, Q2 respectively
In step 6, the driver is notified of the obstacle.

The processing contents in Q26 are as follows, for example. That is, the display 2 provided at a position where the driver can easily see it, such as an instrument panel.
1 and the rear part of the vehicle 1 together with the detection areas 11ZR to 13Z.
R (same for 11ZL to 13ZL) is displayed. Then, when there is no obstacle in the detection area (including the case where the calculated distance L in Q12 is larger than the predetermined distance), the display of the detection area is displayed in, for example, colorless or green. If there is an obstacle in the detection area but the distance to the obstacle is larger than a certain distance, only the detection area in which the obstacle exists is displayed in orange, for example. When an obstacle is present in the detection area and the distance to the obstacle is small, only the detection area in which the obstacle is present is displayed, for example, in red, and the alarm 22 composed of a buzzer is activated. .

Although the embodiment has been described above, the present invention is not limited to this and includes, for example, the following cases. The receiver 15 of the radar is generally structured to detect frequencies within a certain range. Therefore, in order to detect only a predetermined frequency, the detection wave received by the receiver 15 is separately provided. It suffices to filter out only predetermined frequencies. That is, even if the receiver 15 receives a detection wave in a frequency band having a relatively wide width, only the predetermined frequency can be extracted, so that the detection waves other than the predetermined frequency can be virtually ignored.

When changing the transmission frequency even with the same radar, the filter (pass frequency) for processing the received detection wave may be changed according to the change of the transmission frequency. In addition, before filtering the received detection wave, it is possible to know whether or not the detection wave of the frequency transmitted from another radar is received by checking which frequency of the detection wave is being received. It is possible (judging can be determined).

The transmission frequency and the reception frequency may be different for each of the radars 11R to 13R (11L to 13L) without detecting the wraparound. Also,
The use frequency may be different only between two radars corresponding to the adjacent detection areas in which the wraparound is a particular problem (for example, in FIG. 1, the detection area 11ZR is used).
And 13ZR radars 11R and 13R have the same use frequency, and the detection region 12ZR radar 12R is used.
Only the used frequency of 11R and 13R should be made different.

It is also possible to increase the directivity by increasing the operating frequency of each radar only when wraparound occurs without changing the operating frequency between the radars. Further, the frequency change for strengthening the directivity is not limited to the two-step type, and it is also possible to change it in a plurality of steps such as the three-step type (the frequency is increased stepwise until the wraparound does not occur. Go).

In order to determine whether or not the wraparound has occurred, the detection waves of a plurality of radars are transmitted at different times, and the radar receiving the transmitted detection waves has a predetermined radar. It can also be done by checking whether or not it is Da. That is, for example, when the radar 12R receives a detection wave transmitted by the radar 11R within a predetermined time, it is considered that wraparound has occurred. Such a wraparound determination method can be applied when the same frequency is used among a plurality of radars. Further, when the transmission frequency is different among a plurality of radars, the received detection wave is subjected to frequency analysis in the state before being filtered as described above (the filter is a predetermined frequency corresponding to a certain radar). It is possible to determine that the wraparound has occurred when the frequencies of other radars are included, so that only the frequency is passed.

The detection area detected by a plurality of radars can be set appropriately such as the rear side of the side mirror 5 (see FIG. 1). In addition, always right radar 11R ~
Instead of operating 13R and the left radars 11L to 13L, it is possible to operate only the radar for the pointing direction when the direction indicator 6 (see FIG. 1) is operated.

Each step shown in FIG. 3 and FIG. 4 can be the function expression with the name of the means. Of course, the ROM and RAM provided in the control unit U can be expressed as a storage means. Further, the object of the present invention is not limited to the explicitly described contents, and implicitly includes those corresponding to the effects, advantages or preferable contents of the invention.

[Brief description of drawings]

FIG. 1 is a top view showing a vehicle to which the present invention is applied together with a radar detection area.

FIG. 2 is a diagram showing a control system of the present invention.

FIG. 3 is a flowchart showing a control example of the present invention.

FIG. 4 is a flowchart showing a control example of the present invention.

[Explanation of symbols]

 1: Vehicle 11R to 13R: Radar 11L to 13L: Radar 11ZR to 13ZR: Detection area 11ZL to 13ZL: Detection area 14: Transmitter 15: Receiver U: Control unit

Claims (10)

[Claims] 1. An obstacle detection apparatus for a vehicle, comprising a plurality of radars, wherein the detection areas of the respective radars are set to be different areas that are close to each other. -The vehicle obstacle detection device is characterized in that the frequencies used by the antennas are set to be different from each other. 2. The radar according to claim 1, wherein when the radar detects a detection wave having a frequency other than the frequency used, the radar is set to ignore the detected detection wave. Vehicle obstacle detection device. 3. The obstacle detection device for a vehicle according to claim 1, wherein the transmission frequency and the reception frequency are set to be different for each radar. 4. An obstacle detection device for a vehicle, comprising a plurality of radars, wherein the detection areas of the respective radars are set to be different areas that are close to each other. It is set so that the directivity of the detection wave of the radar is strengthened when a wraparound state in which the detection wave transmitted from a certain radar is being received by another radar is detected. Characteristic vehicle obstacle detection device. 5. The vehicle obstacle detection device according to claim 4, wherein the frequency of the detection wave transmitted from the radar is changed to a high frequency when the wraparound is detected. 6. The radar according to claim 4, wherein the detection waves are transmitted from the plurality of radars at different times, and the radar receiving the transmitted detection waves is a predetermined radar. An obstacle detection device for a vehicle, which is set so as to detect whether or not the vehicle is in the wraparound state by checking whether or not the obstacle is detected. 7. A plurality of radars are provided, and the detection areas of the respective radars are set so as to be different areas close to each other on the rear side of the vehicle, and the operating frequencies of the plurality of radars are set. The obstacle detection device for a vehicle, wherein the obstacle detection devices are set to be different from each other. 8. A plurality of radars are provided, and the detection areas of the respective radars are set so as to be different areas that are close to each other on the rear side of the vehicle. -It is set so that the directivity of the detection wave of each radar is strengthened when the wraparound state in which the detection wave transmitted from the radar is being received by another radar is detected. An obstacle detection device for a vehicle. 9. An obstacle detection device for a vehicle, comprising a plurality of radars, wherein the detection areas of the respective radars are set to be different areas that are close to each other. Are set to be different from each other, and when the detection wave received by a certain radar among the plurality of radars has a frequency deviated from the frequency used by the radar,
The frequency used by each radar is changed to be large,
An obstacle detection device for a vehicle characterized by the above. 10. The radar according to any one of claims 1 to 9, wherein the radar is an ultrasonic radar, and a transmitting direction and a receiving direction of a detection wave are fixedly set. An obstacle detection device for a vehicle characterized by the above.