JP2000187799A - Obstacle detector for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an obstacle detector which gives an alarm in the case of the existence of an obstacle with which it is truly necessary to avoid collision. SOLUTION: A shift position sensor 1 which discriminates whether a vehicle will go forward or backward, a steering angle sensor 2 which discriminates the going direction of the vehicle, a vehicle speed sensor 3 which discriminates the running speed of the vehicle, a course discrimination means 4 which predicts the course of the vehicle in accordance with signals from the shift position sensor 1, the steering angle sensor 2, and the vehicle speed sensor 3, an obstacle position detection means 5 which can detect the positions of obstacles existing around the vehicle, and a collision discrimination means 6 which discriminates a dangerous area of a high possibility of collision in the case of the existence of obstacles and a safe area of a low possibility of collision in spite of the existence of obstacles in accordance with signals from the course discrimination means 4 and the obstacle position detection means 5 and outputs a collision detection signal in the case that obstacles exist in the dangerous area are provided.

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 a vehicle that allows an occupant to recognize an obstacle approaching a vehicle in advance.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a collision with an obstacle when operating a vehicle, an alarm device for generating an alarm sound when an obstacle at a predetermined distance from the vehicle is detected is provided. There is a warning that is issued when approaching. Sounding devices such as buzzers are mainly used as alarms.
In some cases, the occupant is notified of the distance between the obstacle and the vehicle by changing the sound of the sounding device according to the distance between the vehicle and the obstacle.

[0003]

However, in the vehicle obstacle detecting device having the above-described structure, it is determined whether or not an alarm is issued only from the distance between the vehicle and the obstacle. Therefore, when an obstacle is present near the vehicle, there is a problem that an alarm is issued even though the vehicle has no danger of collision. For example, even if the obstacle is a moving object and the obstacle only passes by the side of the vehicle and there is no possibility of contact at all, an alarm is generated if the distance between the obstacle and the moving object is within a predetermined range. was there.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a vehicle obstacle that generates an alarm when there is an obstacle that truly needs to avoid collision. An object detection device is provided.

[0005]

According to the first aspect of the present invention,
A shift position sensor that determines whether the vehicle moves forward or backward, a steering angle sensor that determines the traveling direction of the vehicle, a vehicle speed sensor that determines the traveling speed of the vehicle, a shift position sensor, a steering angle sensor, and a vehicle speed sensor Path determination means for predicting the path of the vehicle based on the signal of the vehicle, obstacle position detection means capable of detecting the position of an obstacle present around the vehicle, and an obstacle based on signals from the path determination means and the obstacle position detection means. Collision determining means for determining a dangerous area where there is a possibility of collision if there is an obstacle, and a safety area where there is a low possibility of collision even if an obstacle exists, and outputting a collision detection signal when there is an obstacle in the dangerous area Is provided.

According to a second aspect of the present invention, in the vehicle obstacle detecting device according to the first aspect, the collision determining means predicts a locus of movement of the obstacle and locates the obstacle in a dangerous area. Also, when it is determined that the obstacle is moving from the danger area to the safety area, the collision detection signal is not output.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle obstacle detecting device according to an embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a schematic configuration diagram of the vehicle obstacle detection device. FIG. 2 is a layout diagram of a two-dimensional ultrasonic sensor installed in a vehicle. FIG. 3 is an explanatory diagram showing a method of predicting a course and determining a collision in relation to the vehicle obstacle detection device. FIG.
FIG. 6 is another explanatory diagram showing a method of predicting a course and determining a collision in relation to a vehicle obstacle detection device. FIG. 5 is another explanatory diagram showing a method of predicting a course and determining a collision in relation to the vehicle obstacle detection device. FIG. 6 is an explanatory diagram for explaining parameters for displaying the positional relationship between the obstacle position detecting means and the obstacle. FIG. 7 is an explanatory diagram showing a process in which the obstacle position detecting means detects an obstacle. FIG. 8 is an explanatory diagram showing another process in which the obstacle position detecting means detects an obstacle. FIG. 9 is a time chart showing the timing of the transmission / reception signal of the obstacle position detecting means. FIG. 10 is a time chart showing the timing of the shaping signal of the transmission / reception signal of the obstacle position detecting means. FIG.
FIG. 4 is an explanatory diagram for explaining a method for predicting movement of a plurality of obstacles.

As shown in FIG. 1, a vehicle obstacle detecting device according to the present embodiment includes a shift position sensor 1 for determining whether the vehicle is moving forward or backward, and a steering angle for determining the traveling direction of the vehicle. The vehicle includes a sensor 2 and a vehicle speed sensor 3 that determines the traveling speed of the vehicle. A course determination unit 4 predicts the course of the vehicle based on signals from the shift position sensor 1, the steering angle sensor 2, and the vehicle speed sensor 3. In addition, the vehicle obstacle detection device includes a two-dimensional ultrasonic sensor 5 corresponding to obstacle position detection means capable of detecting the position of an obstacle existing around the vehicle.
And a danger area where there is a possibility of collision if an obstacle is present, and a safety area where the possibility of collision is low even if an obstacle is present, based on signals from the course determination means 4 and the two-dimensional ultrasonic sensor 5, When an obstacle exists in the danger area, a collision determination unit 6 that outputs a collision detection signal is provided. Further, it has a display 7 such as a liquid crystal display for displaying the position of a safety area, a danger area, an obstacle or the like, and a buzzer 8 corresponding to a sounding device driven upon receiving a collision detection signal. The above-described vehicle obstacle detection device detects an obstacle that is likely to collide with the vehicle and outputs a collision detection signal to notify the occupant of the fact. In addition,
In the present embodiment, an ultrasonic wave is used as the obstacle position detecting means. However, an obstacle may be detected using a laser or a microwave. Also,
Since the shift position sensor 1 makes it possible to determine whether the vehicle is going forward or backward, it is preferable to use only the two-dimensional ultrasonic sensor 5 mounted in front of the vehicle when going forward. By using only the two-dimensional ultrasonic sensor 5 attached to the rear when it is going to retreat,
The power consumption may be reduced. Further, when the vehicle is neither going forward nor backward, the collision detection signal may not be output regardless of the presence or absence of an obstacle, so that unnecessary sounding may not be performed.

As shown in FIG. 2, the two-dimensional ultrasonic sensor 5 is embedded at four locations in a bumper provided in front of the vehicle (front side), and similarly to a bumper provided in the rear side (rear side) of the vehicle. It is embedded in four places. The mounting position and the number of the two-dimensional ultrasonic sensors 5 are not limited to these.

The display 7 is, as shown in FIGS.
Based on signals from the route determination means 4 and the two-dimensional ultrasonic sensor 5, an image of the danger area, the safety area, and the vehicle is generated, and if an obstacle exists in the area, the position is displayed. . Here, the safety area is an area where there is no possibility of collision even if there is an obstacle at that position from the direction of travel of the vehicle, and the danger area is a collision if there is an obstacle at that position from the direction of travel of the vehicle. This indicates an area in which the possibility of occurrence is high.

The safety area and the danger area are determined by the following procedure. First, the course determination means 4 calculates a predicted course of the vehicle assuming that the steering angle and the vehicle speed are maintained as they are from the steering angle and the vehicle speed that determine the traveling direction of the vehicle. Then, an area through which the vehicle passes when the vehicle moves on the predicted course is defined as a danger area, and the other area is defined as a safety area. For example, as shown in FIG. 3, when the vehicle is about to make a right turn, the trajectory drawn by the front left side of the vehicle as the vehicle travels is defined as a boundary line, the area on the left side is defined as a safety area, and the area on the right side is defined as a hazard It is an area. In addition, considering that an inner wheel difference occurs due to the length of the vehicle, the right side of the vehicle is defined as a trajectory drawn by the rear right side of the vehicle as the vehicle advances, and an area on the right side thereof is defined as a safety area. . The area outside the area that can be detected by the two-dimensional ultrasonic sensor 5 is regarded as a safe area.
Furthermore, in the vehicle obstacle detection device according to the present embodiment, in consideration of the extremely high possibility of collision with an obstacle in a region near the vehicle, a range of a predetermined distance from the vehicle is It is a danger area regardless of the predicted course.

According to the setting of the area determined by the above-described procedure, for example, when an obstacle exists in the dangerous area, the possibility that the vehicle collides with the obstacle is extremely high. Output and the buzzer 8 sounds. Thus, the occupant can easily determine that an obstacle having a high possibility of collision exists around the vehicle.
Needless to say, the above-described determination of the predicted course of the vehicle and the setting of the area are updated at predetermined intervals, but generally, the higher the vehicle speed, the higher the possibility of collision with an obstacle. Therefore, if the speed of the vehicle is high, it may be updated frequently.

The positional relationship between the two-dimensional ultrasonic sensor 5 and the obstacle is expressed using parameters shown in FIG. That is, H is a plane of the two-dimensional ultrasonic sensor 5 and an opening surface on which an opening for transmitting / receiving ultrasonic waves is formed in the two-dimensional ultrasonic sensor 5. V is a normal line of the two-dimensional ultrasonic sensor 5, passes through a substantially center O of an opening for transmitting / receiving ultrasonic waves in the two-dimensional ultrasonic sensor 5, and is perpendicular to ultrasonic sensors 5 a and 5 b described later. Construct a bisector. L is the distance from the approximate center O of the opening to the obstacle. φ is the angle between the normal V and the obstacle.

As shown in FIGS. 7 and 8, the two-dimensional ultrasonic sensor 5 includes an ultrasonic sensor 5a for both transmitting and receiving, an ultrasonic sensor 5b for receiving only, and a driving circuit for driving them. (Not shown), and the positional relationship of the obstacle is specified by the following method.

The ultrasonic sensors 5a and 5b are arranged on the same plane with a distance Ls therebetween. Ultrasonic sensor 5
As shown in FIG. 9, a transmission signal (pulse waveform) is applied to a, and while the transmission signal is at a high level (FIG. 9 (a)).
9) generate ultrasonic waves (see FIG. 9).
(B)). The transmitted signal goes low (Fig. 9
(Refer to FIG. 9A.) Since it takes time until the vibration of the ultrasonic transducer constituting the ultrasonic sensor 5a stops, a reverberation phenomenon occurs and the ultrasonic signal is continuously emitted for a while (FIG. 9B). reference).

FIG. 9D shows the reception signal of the ultrasonic sensor 5b, in which the signal on the left is the ultrasonic sensor 5a.
The waveform on the right side shows a reflected wave from an obstacle. 9 (b) and 9 (d) show the envelope of the vibration waveform (about 40 KHz) of the ultrasonic vibrator, and when the amplitude is higher than a certain level, the received signal becomes low. The waveforms shown in FIGS. 9 (c) and 9 (d) are shaped so as to be at the high level when the level is below a certain level.
The two-dimensional ultrasonic sensors 5a and 5b detect falling of the shaped signals a and b from the high level to the low level, thereby recognizing that the received signal is a reflected wave. .

When the ultrasonic wave radiated from the ultrasonic sensor 5a hits a nearby object and is reflected, FIG. 9 (b) and FIG.
As shown in (d), reflected waves are observed at the ultrasonic sensors 5a and 5b. Since ultrasonic waves move in the air at the speed of sound c (about 340 m / s), the distance to a nearby object can be calculated by measuring the time from the start of transmission of ultrasonic waves to the reception of reflected waves. Become.

The time during which the reflected waves are received by the ultrasonic sensors 5a and 5b varies depending on the position of a nearby object because the ultrasonic sensors 5a and 5b are arranged apart from each other. For example, if the near object is located closer to the ultrasonic sensor 5a than the normal V on which the ultrasonic sensors 5a and 5b are arranged, the ultrasonic sensor 5a receives the reflected wave first (ta
<Tb) (see FIG. 10 (c)), if located on the ultrasonic sensor 5b side, the ultrasonic sensor 5b receives the reflected wave first (tb <ta) (see FIG. 10 (d)). That is, as shown in FIGS. 5 and 6, by measuring the time ta and tb from when the ultrasonic wave is transmitted from the ultrasonic sensor 5a to when the ultrasonic sensors 5a and 5b receive the reflected wave, the method is performed. The angle φ between the line V and the nearby object and the distance L from the approximate center O of the opening to the obstacle can be calculated.

However, due to the reverberation of the ultrasonic sensor 5a,
The reflected wave cannot be received for a while after transmitting the ultrasonic wave. Therefore, for example, as shown in FIG. 10B, depending on the detection timing of the reflected wave, if the obstacle is present within the reverberation time, the reflected wave is observed only by the ultrasonic sensor 5b. In this case, the angle φ is not calculated, and only the information of the distance L is obtained, so that the angle is approximated to be 0.

As described above, the distance L to the nearby object and the angle φ are obtained by the two-dimensional ultrasonic sensor 5. An obstacle existing around the vehicle is detected from information obtained from all the two-dimensional ultrasonic sensors 5 attached to the vehicle by the above procedure.

When there are a plurality of obstacles, the same method as described above is applied. As shown in FIG. 11, when there are two obstacles, the reflected waves a1, b1 and reflected waves a1, b1 from the first obstacle are displayed. Time ta from when the reflected waves a2 and b2 from the second obstacle are detected and when the ultrasonic sensors 5a and 5b receive the reflected waves.
1, the distance L1 from tb1 to the first obstacle and the angle φ1
Is calculated, and the distance L1 and the angle φ1 from the times ta2 and tb2 until the ultrasonic sensors 5a and 5b receive the reflected waves to the second obstacle are calculated.

The collision judging means 6 operates at a constant interval (for example, 1
Every 00 ms), the distance L and the angle φ from each two-dimensional ultrasonic sensor 5 are read to determine the presence or absence of an obstacle. If an obstacle exists, the distance L and the angle φ for three times thereafter are stored for each obstacle, and it is examined whether or not the extension of the obstacle reaches the vehicle. When the extension line reaches the vehicle, the collision detection signal is output on the assumption that the vehicle is likely to come into contact with the obstacle. For example, as shown in FIG. 4, when the extension line does not reach the vehicle, the collision detection signal is not output because the possibility of collision is low even if there is an obstacle in the dangerous area. However, since the direction of travel of the obstacle may suddenly change, the obstacle detection device for a vehicle according to the present embodiment requires the obstacle existing in the danger area once having no possibility of collision. Even after that, the distance L to the obstacle and the angle φ are continuously stored, and the collision is determined.

A case where there are a plurality of obstacles as shown in FIG. 5 will be described. The obstacle detected at the obstacle detection point 1 is a wall existing on the left side of the vehicle, and the obstacle detected at the obstacle detection point 2 is an obstacle existing in front of the vehicle. Since the vehicle is running parallel to the wall, an obstacle is always detected at the same point on the left side of the vehicle, but time elapses (here, from t1 to t3).
No warning is issued for this obstacle because the vehicle does not approach the vehicle. On the other hand, the obstacle detected at the obstacle detection point 2 approaches the vehicle over time,
Since the extension has also reached the vehicle, a collision detection signal is output at time t3.

As shown in FIG. 3, even if the obstacle is in the safety area, the distance L and the angle φ are monitored, and if the extension of the obstacle reaches the vehicle, the obstacle moves to the danger area. By outputting a collision detection signal immediately when the vehicle enters, the danger of collision may be notified to the occupant as soon as possible.

In the vehicle obstacle detection device according to the present embodiment, there is an obstacle that is highly likely to collide due to the relative position change of the obstacle over time and the predicted course of the vehicle. It is possible to output the collision detection signal only at the time, to sound the buzzer 8 or to display the fact on the display 7. If the alarm sound is changed or the display on the screen is changed according to the degree of danger at the time of the alarm, the occupant can be more clearly notified of the danger of collision.

[0026]

As described above, according to the first aspect of the present invention, the shift position sensor for determining whether the vehicle is moving forward or backward, the steering angle sensor for determining the traveling direction of the vehicle, and the vehicle. Speed sensor that determines the traveling speed of the vehicle, route determination means that predicts the route of the vehicle based on signals from a shift position sensor, a steering angle sensor, and a vehicle speed sensor, and an obstacle that can detect the position of an obstacle present around the vehicle. Based on the signals from the object position detecting means, the path determining means and the obstacle position detecting means, a danger area where there is a possibility of collision if an obstacle is present, and a safety area where the possibility of collision is low even if an obstacle is present are determined. However, when an obstacle is present in the danger area, the vehicle is provided with a collision determination unit that outputs a collision detection signal, so that there is a high possibility of collision based on the predicted course of the vehicle and the positional relationship with the obstacle. Since it is possible to detect an object, truly an effect that it is possible to provide a vehicle obstacle detection device for generating an alarm if there is an obstacle there is a need for a collision avoidance.

According to a second aspect of the present invention, in the vehicle obstacle detecting device according to the first aspect, the collision judging means predicts a trajectory of the movement of the obstacle and finds the obstacle in the danger area. Even if it is determined that an obstacle is moving from the danger area to the safety area, the collision detection signal is not output, so that even if the obstacle is in the danger area, a warning is given for an obstacle that is unlikely to collide. Therefore, it is possible to reduce the useless output of the collision detection signal.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle obstacle detection device.

FIG. 2 is a layout diagram of a two-dimensional ultrasonic sensor installed in a vehicle.

FIG. 3 is an explanatory diagram illustrating a method of predicting a course and determining a collision in the vehicle obstacle detection device.

FIG. 4 is another explanatory diagram showing a method of predicting a course and determining a collision in relation to the vehicle obstacle detection device.

FIG. 5 is another explanatory diagram showing a method of predicting a course and determining a collision in the vehicle obstacle detection device.

FIG. 6 is an explanatory diagram illustrating parameters for displaying a positional relationship between an obstacle position detection unit and an obstacle.

FIG. 7 is an explanatory diagram showing a process in which an obstacle position detection unit detects an obstacle.

FIG. 8 is an explanatory diagram showing another process in which the obstacle position detecting means detects an obstacle.

FIG. 9 is a time chart showing the timing of a transmission / reception signal of the obstacle position detection means.

FIG. 10 is a time chart showing the timing of the shaping signal of the transmission / reception signal of the obstacle position detection means.

FIG. 11 is an explanatory diagram for explaining a method of performing movement prediction of a plurality of obstacles.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shift position sensor 2 Steering angle sensor 3 Vehicle speed sensor 4 Course determination means 5 Two-dimensional ultrasonic sensor (obstacle position detection means) 6 Collision determination means 7 Display 8 Buzzer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C086 AA54 BA22 CA21 CA22 CA25 CB28 DA01 DA08 FA02 FA18 5H180 AA01 CC03 CC11 CC12 LL01 LL02 LL07 LL08

Claims (2)

[Claims] A shift position sensor for determining whether the vehicle moves forward or backward, a steering angle sensor for determining a traveling direction of the vehicle, a vehicle speed sensor for determining a traveling speed of the vehicle,
Path determination means for predicting the path of the vehicle based on signals from a shift position sensor, a steering angle sensor, and a vehicle speed sensor; obstacle position detection means capable of detecting a position of an obstacle present around the vehicle; If there is an obstacle based on a signal from the obstacle position detecting means, a danger area where a collision is likely to occur and a safety area where a collision is unlikely even if an obstacle is present are determined, and the obstacle is present in the danger area. And a collision judging means for outputting a collision detection signal in a case. 2. The collision judging means predicts a trajectory of movement of an obstacle, and even if the obstacle is in a dangerous area,
The vehicle obstacle detection device according to claim 1, wherein a collision detection signal is not output when it is determined that the obstacle is moving from the danger area to the safety area.