JP2003081035A - Obstacle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To issue an optimal alarm according to the states of a vehicle such as the turning direction, the car speed, and the advancing direction of the vehicle. SOLUTION: The detection area of an obstacle is changed by changing the sensitivities of multiple sensors 11-14 disposed in the same direction of the vehicle according to the turning direction of the vehicle. Or, the detection area of the obstacle is changed by changing the sensitivity of the sensor disposed in the vehicle according to the car speed. Or, the detection area of the obstacle is changed by changing the sensitivity of each sensor disposed in the front/rear of the vehicle according to the advancing direction of the vehicle. When changing the sensitivity, a threshold determining the level of a reflected signal, the level of a transmission signal, or the determination time from the transmission of the signal to the receiving of the reflected signal is changed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an obstacle detecting device for detecting an obstacle in a vehicle and issuing an alarm.

[0002]

2. Description of the Related Art Generally, in this type of obstacle detection device,
As an obstacle detection sensor, ultrasonic sensors installed at appropriate positions such as bumpers in front of and behind the vehicle transmit ultrasonic burst waves and measure the time until the reflected waves from the obstacles are received. It is configured to issue an alarm when the distance to the corresponding obstacle is shorter than a predetermined distance.

[0003]

However, in the conventional obstacle detection device, an alarm is issued when the distance to the obstacle is shorter than a predetermined distance regardless of the vehicle condition such as the turning direction, the vehicle speed, and the traveling direction of the vehicle. However, there is a problem in that the driver is annoyed by issuing an unnecessary alarm or not issuing a necessary alarm. For example, when the vehicle turns to the left front, an unnecessary alarm is issued even if an obstacle in front of the right that does not collide is detected. Further, when the vehicle speed is high, a distant obstacle cannot be detected, and the alarm cannot catch up with the collision. Furthermore, when an obstacle in a direction other than the traveling direction of the vehicle is detected, an unnecessary alarm is issued.

In view of the above-mentioned problems of the conventional example, it is an object of the present invention to provide an obstacle detecting device capable of issuing an optimum alarm according to the operating state of a vehicle.

[0005]

In order to achieve the above object, the present invention changes an obstacle detection area in accordance with an operating state of a vehicle. With the above configuration, it is possible to issue an optimum alarm according to the operating state of the vehicle.

The present invention also changes the detection area of an obstacle by changing the sensitivity of each of a plurality of sensors arranged in the same direction of the vehicle in accordance with the turning direction of the vehicle, or is arranged in the vehicle. By changing the sensitivity of the sensor according to the vehicle speed, the obstacle detection area can be changed, and by changing the sensitivity of the individual sensors arranged in front of and behind the vehicle according to the traveling direction of the vehicle, obstacles can be detected. Change the area. Also, when changing the sensitivity, change the threshold for determining the level of the reflected signal, change the level of the transmitted signal,
Change the judgment time from the signal transmission to the reflected signal reception. With the above configuration, it is possible to issue an optimum alarm according to the turning direction, the vehicle speed, and the traveling direction of the vehicle.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION <First Embodiment> An embodiment of the present invention will be described below with reference to the drawings. 1 is a block diagram showing an embodiment of an obstacle detection device according to the present invention, FIG. 2 is a flow chart for explaining the processing of the microcomputer of FIG. 1, and FIG. 3 is a detection area of the obstacle detection device of FIG. It is an explanatory view shown.

In FIG. 1, ultrasonic sensors 11, 12, 13, and 14 which are obstacle detection sensors are installed at appropriate obstacle detection positions such as front and rear bumpers of a vehicle, and a control controller 9 which is a central control unit. Lines 31 and 3 respectively
It is star-connected via 2, 33, and 34. In this example, the sensors 11, 12, 13, and 14 will be described as being attached to the left corner, front left (closer to the center), right front (closer to the center), and right corner of the front bumper (which may be the rear).

In the control controller 9, the sensor driving voltage variable power supply 1 generates a voltage of a level according to the voltage raising / lowering signal 23 from the microcomputer 3, and the transmitting circuit 2 is the microcomputer 3.
An ultrasonic burst wave (for example, 10 pulses of a rectangular wave of 40 kHz) corresponding to the burst-shaped ultrasonic wave ON signal 28 from is generated. Then, the ultrasonic burst wave of the transmission circuit 2 is superimposed on the output voltage of the sensor driving voltage variable power source 1, and the ultrasonic sensor driving signal 2 having a level according to the voltage rising / falling signal 23
4, the ultrasonic sensor drive signal 24 is sent to the sensor 11 by the analog switch (SW) 8 and the switching signal 22.
It is selectively applied to one of 12, 13, and 14.

The sensors 11, 12, 13, 14 generate ultrasonic burst waves by the ultrasonic sensor drive signal 24, and if there is an obstacle, receive the reflected wave after a lapse of time corresponding to the distance. Reflected signal 31 obtained by receiving this reflected wave
To 34 are sent to the controller 9 for control and are analog SW
It is applied to the comparator 4 through the amplifier 8, the amplifier 7, the low-pass filter 6, and the half-wave rectifier 5. The comparator 4 compares the level of this reflected signal with the threshold value 21 which is the D / A output voltage from the microcomputer 3, and outputs an obstacle detection signal 29 to the microcomputer 3 when the reflected signal> the threshold value 21. .

The microcomputer 3 issues an alarm when the time from the ultrasonic wave ON signal 28 to the obstacle detection signal 29 (= distance to the obstacle) is within a predetermined time. For the alarm, the detection position is displayed and the indicator / buzzer for the alarm is displayed.
For example, in the range of 20 cm to 50 cm, driving is performed with blinking / intermittent sound, and with 20 cm or less, continuous lighting / continuous sound is driven.

The microcomputer 3 controls the shift position 2 of the vehicle.
When 7 is any one of R, D, 2 and L and the vehicle speed 26 is 10 km / h or less, for example, the obstacle detection process as shown in FIG. 2 is executed. First, the sensor counter S = 1 is set, and the sensor 11 with the counter S = 1 is selected by the analog SW 8 and the switching signal 22 (step S1), and then a constant drive voltage is set by the voltage raising / lowering signal 23 (step S2). -1). Next, the ultrasonic wave is transmitted to the sensor 11 by the ultrasonic wave ON signal 28 (step S3), and then the steering angle 25 of the vehicle is recognized (step S4).

Next, it is determined whether the vehicle is going straight or turning left or right based on the steering angle 25 (step S5), and if the vehicle is going straight, a constant threshold value 21 is set in the comparator 4 (step S6-1). . On the other hand, in the case of turning to the left or right, the threshold value th1 that differs depending on the steering angle 25 of the sensor 11 is set in the comparator 4 (step S6-).
2). At this time, the threshold value th is set in the comparator 4 so as to detect the traveling direction sensitively and the opposite direction insensitively. For example, when the steering is switched to the left, th1 <th2 <t for the left corner sensor 11, the left front sensor 12, the right front sensor 13, and the right corner sensor 14, respectively.
By setting the threshold value th1 such that h3 <th4 in the comparator 4, the detection area as shown in FIG. 3 is set.

Next, the output of the comparator 4 (obstacle detection signal 2
It is determined whether or not 9) is present (step S7). If there is an output, the process proceeds to step S8, and if not, the process proceeds to step S12. In step S8, the time from the ultrasonic wave ON signal 28 to the obstacle detection signal 29 is measured, and then the distance according to the time is calculated (step S9). Next, it is determined whether or not the distance is an alarm distance (step S10). If the distance is an alarm distance, the process proceeds to step S11 to issue an alarm, and then the process proceeds to step S12. If the warning distance is not reached in step S10, the process directly proceeds to step S12. Step S
In 12, the sensor counter S is incremented, and then it is determined whether S = 4 (step S13). If S = 4, the process returns to step S2-1 and the same obstacle detection process is executed for the next sensor. On the other hand, if S = 4, this process ends.

<Second Embodiment> Next, a second embodiment will be described with reference to the flow chart shown in FIG.
The microcomputer 3 indicates that the shift position 27 of the vehicle is R, D,
Either 2 or L and the vehicle speed 26 is, for example, 10 km
In the case of / h or less, the obstacle detection process as shown in FIG. 4 is executed. First, the sensor counter S = 1 is set, the sensor 11 with the counter S = 1 is selected by the analog SW 8 and the switching signal 22 (step S1), and then the steering angle 25 of the vehicle is recognized (step S4).

Next, it is determined whether the vehicle is going straight or turning to the left or right based on the steering angle 25 (step S5). ). On the other hand, in the case of turning left and right, a different drive voltage V1 is set for the sensor 11 according to the steering angle 25 (step S2-
2). At this time, the drive voltage V is set so that the traveling direction is wide and the opposite direction is narrow. For example, when the steering is switched to the left as shown in FIG. 3, V1>V2>V3> V for the left corner sensor 11, the left front sensor 12, the right front sensor 13, and the right corner sensor 14, respectively.
The driving voltage V1 which is 4 is set in the left corner sensor 11.

Next, an ultrasonic wave is transmitted to the sensor 11 by the ultrasonic wave ON signal 28 (step S3), and then a constant threshold value 21 is set in the comparator 4 (step S6-).
1). Next, in step S7 and the subsequent steps, the same obstacle determination processing as in the first embodiment is executed.

<Third Embodiment> Next, a third embodiment will be described with reference to the flow chart shown in FIG.
The microcomputer 3 indicates that the shift position 27 of the vehicle is R, D,
Either 2 or L and the vehicle speed 26 is, for example, 10 km
When / h or less, the obstacle detection process as shown in FIG. 5 is executed. First, the sensor counter S = 1 is set, the sensor 11 with the counter S = 1 is selected by the analog SW 8 and the switching signal 22 (step S1), and then the steering angle 25 of the vehicle is recognized (step S4).

Next, it is determined whether the vehicle is going straight or turning to the left or right based on the steering angle 25 (step S5). If the vehicle is going straight, a certain warning distance Dth is set as a threshold for obstacle determination (step S5). S14-1). On the other hand, in the case of turning left and right, a different warning distance Dth1 is set for the sensor 11 depending on the steering angle 25 (step S14-2). At this time, the alarm distance Dth is set such that the traveling direction is long and the opposite direction is short. For example, when the steering is switched to the left, Dth1>Dth2> for the left corner sensor 11, the left front sensor 12, the right front sensor 13, and the right corner sensor 14, respectively.
An alarm distance Dth1 such that Dth3> Dth4 is set in the left corner sensor 11.

Next, the drive voltage V of a constant voltage is set by the voltage raising / lowering signal 23 (step S2-1), and then the ultrasonic wave is transmitted to the sensor 11 by the ultrasonic wave ON signal 28 (step S3). Then, in step S6-1 and below,
A constant threshold value 21 is set in the comparator 4 and the same obstacle determination processing as in the first and second embodiments is executed. here,
In FIG. 5, for simplification of explanation, the case where different alarm distances Dth are set according to the steering angle 25 has been described, but when the reflection time is not converted into the distance and the determination is made by the reflection time, the obstacle is detected. The reflection time is set as a threshold for judgment.

<Fourth Embodiment> Next, a fourth embodiment will be described with reference to the flow chart shown in FIG.
The microcomputer 3 indicates that the shift position 27 of the vehicle is R, D,
Either 2 or L and the vehicle speed 26 is, for example, 10 km
When / h or less, the obstacle detection process as shown in FIG. 6 is executed. First, the sensor counter S = 1 is set, the sensor 11 with the counter S = 1 is selected by the analog SW 8 and the switching signal 22 (step S1), and then the vehicle speed is recognized (step S15). Next, a different drive voltage V1 is set for the sensor 11 according to the vehicle speed (step S
2-3). At this time, the drive voltage V is increased so that the wider the vehicle speed, the wider the detection.

Then, similarly to the third embodiment (see FIG. 4), ultrasonic waves are transmitted to execute the obstacle determination processing. Also,
As in the second embodiment (see FIG. 2), the threshold value may be set smaller so that the vehicle speed is detected more widely.
The alarm distance Dth (or time) may be set longer as in the fourth embodiment (see FIG. 5) so that the vehicle speed is detected more widely.

<Fifth Embodiment> Next, a fifth embodiment will be described with reference to the flowchart shown in FIG.
The microcomputer 3 indicates that the shift position 27 of the vehicle is R, D,
Either 2 or L and the vehicle speed 26 is, for example, 10 km
When / h or less, the obstacle detection process as shown in FIG. 7 is executed. First, the sensor counter S = 1 is set, the sensor 11 with the counter S = 1 is selected by the analog SW 8 and the switching signal 22 (step S1), and then the shift position 27 is recognized (step S16).

Next, a different drive voltage V1 is set for the sensor 11 according to the shift position 27 (step S2-4). At this time, when the shift position 27 is reverse, the drive voltage V is increased for the sensors 11, 12, 13, and 14 attached to the front bumper as shown in FIG. Although not provided, the drive voltage V is made small for the sensor mounted on the rear bumper to detect it. On the other hand, in the case of forward movement, the drive voltage V is increased for the front sensors 11, 12, 13, 14 to detect it widely, and the drive voltage V is decreased for the rear sensors.

Then, similarly to the third embodiment (see FIG. 4), ultrasonic waves are transmitted to execute the obstacle judging process. Also,
The threshold value may be made smaller as in the second embodiment (see FIG. 2) so that the direction of travel is detected more sensitively.
The alarm distance Dth (or time) may be increased as in the fourth embodiment (see FIG. 5) so that the direction of travel is detected more sensitively.

As described above, according to the present invention, it is possible to issue an optimum alarm according to the operating state of the vehicle such as the turning direction, the vehicle speed and the traveling direction of the vehicle.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an obstacle detection device according to the present invention.

FIG. 2 is a flow chart for explaining the processing of the microcomputer of FIG.

3 is an explanatory diagram showing a detection area of the obstacle detection device of FIG. 1. FIG.

FIG. 4 is a flowchart for explaining processing of a microcomputer of the second embodiment.

FIG. 5 is a flow chart for explaining the processing of the microcomputer of the third embodiment.

FIG. 6 is a flow chart for explaining the processing of the microcomputer of the fourth embodiment.

FIG. 7 is a flow chart for explaining the processing of the microcomputer of the fifth embodiment.

[Explanation of symbols]

1 Sensor drive voltage variable power supply 3 Microcomputer 4 comparator 11-14 sensors

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B60R 21/00 B60R 21/00 626E G08G 1/16 G08G 1/16 C

Claims (7)

[Claims] 1. An obstacle detection device for transmitting a signal and issuing an alarm based on a reflected signal from an obstacle to a vehicle, comprising sensitivity changing means for changing an obstacle detection area according to an operating state of the vehicle. An obstacle detection device characterized by being provided. 2. The sensitivity changing means changes an obstacle detection area by changing individual sensitivities of a plurality of sensors arranged in the same direction of the vehicle according to a turning direction of the vehicle. The obstacle detection device according to claim 1, wherein the obstacle detection device is provided. 3. The sensitivity changing means changes the detection area of an obstacle by changing the sensitivity of a sensor arranged in the vehicle according to the vehicle speed. Obstacle detection device. 4. The sensitivity changing means changes the detection area of an obstacle by changing the sensitivity of individual sensors arranged in front of and behind the vehicle according to the traveling direction of the vehicle. The obstacle detection device according to any one of claims 1 to 3. 5. The sensitivity changing means changes the detection area of the obstacle by changing the sensitivity by changing the threshold value for judging the level of the reflected signal. The obstacle detection device according to any one of 1. 6. The sensitivity changing means changes the detection area of the obstacle by changing the sensitivity by changing the level of the transmission signal. The obstacle detection device described. 7. The sensitivity changing unit changes the detection area of an obstacle by changing the sensitivity by changing the determination time from the signal transmission to the reflection signal reception. 7. The obstacle detection device according to any one of 1 to 6.