JP3229447B2 - Obstacle detection 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 obstacle detecting apparatus for detecting the position of an obstacle using a radar.

2. Description of the Related Art In a vehicle, for example, an automobile, the position of an obstacle in front is known for automatic driving or for alerting a driver to the front. In order to detect the position, especially the direction, of the obstacle, it has been proposed to use a scanning type radar.
Da is very expensive.

For this reason, as shown in JP-A-62-81588, a plurality of light receiving means of a radar are provided so that their light receiving ranges partially overlap, and the number of the light receiving means is larger than the number of the plurality of light receiving means. There has been proposed one in which a number of detection areas can be set. More specifically, for example, two left and right light receiving means are provided, and a left detection area only by the left light reception means, a left detection area only by the right light reception means, and a common area detected by both the left and right detection means There has been proposed an apparatus which can set three areas such that the obstacle can be roughly classified into any of the three areas.

[0004]

However, the circuit disclosed in the above publication is considerably inexpensive as compared with the scan type radar, but a circuit system for processing the received light signal to determine the position of the obstacle. Is required to be provided in correspondence with the plurality of light receiving means, so that the cost is not sufficiently satisfactory.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an obstacle detection system capable of simplifying the configuration of a circuit system for processing a received signal to determine the position of an obstacle on the premise of having a plurality of receiving means. It is to provide a device.

[0006]

To achieve the above object, the present invention has the following configuration as a first configuration. That is, as described in claim 1 of the claims,

An obstacle detecting device for detecting an obstacle in a traveling direction of a vehicle, comprising: transmitting means for transmitting a detection signal in the traveling direction of the vehicle; and transmitting a detection signal transmitted from the transmitting means. Two receiving means for detecting and receiving areas set so as to partially overlap each other, and an amplifying means which is provided in common to the two receiving means and amplifies a received signal received by the receiving means. Means, position determining means for determining the position data of an obstacle based on the reception signal amplified by the amplifying means, and selectively connecting one of the two receiving means to the amplifying means. Switching means for switching, switching control means for controlling the switching of the switching means in synchronization with the transmission of the detection signal from the transmitting means, driving means for changing the orientation of the two receiving means, One of the drive control means for controlling said drive means so as to be detected by the receiving means, a configuration equipped with.

In order to achieve the above object, the present invention has the following configuration as a second configuration. That is, as described in claim 2 of the claims,

An obstacle detecting device for detecting an obstacle in a traveling direction of an automobile, comprising: transmitting means for transmitting a detection signal in the traveling direction of the automobile; and transmitting the detection signal transmitted from the transmitting means. Two receiving means for detecting and receiving areas set to partially overlap each other, and two amplifying means provided corresponding to the two receiving means, for amplifying a received signal received by the receiving means Means, position determining means shared by the two receiving means and two amplifiers, and determining position data of an obstacle based on the received signal amplified by the amplifying means; Switching means for selectively switching the connection between any one of the amplifying means and the position determining means; switching control means for controlling switching of the switching means in synchronization with transmission of a detection signal from the transmitting means; Two A driving means for changing the orientation of the signal means, it is constituted an obstacle and a driving control means for controlling said drive means so as to be detected by the two receiving means.

Preferred embodiments based on the first configuration are as described in claims 3 and 4 in the claims.

A preferred embodiment based on the second configuration is as described in claims 3 and 4 of the claims.

[0012]

According to the present invention, the following effects can be obtained.

According to the configuration described in claim 1, the amplifying unit and the position determining unit are common to a plurality of receiving units, and an extremely inexpensive circuit configuration can be achieved. In addition, it is preferable to detect an obstacle with both receiving means while minimizing the number of receiving means as much as possible.

According to the second aspect of the present invention, a plurality of amplifying means must be provided in correspondence with the plurality of receiving means. Since it is good, an inexpensive circuit configuration can be obtained. In addition, it is preferable to detect an obstacle with both receiving means while minimizing the number of receiving means as much as possible.

According to the configuration described in claim 3, it is possible to determine whether an obstacle is detected by a simple method of comparing the reception level with a predetermined value.

The configuration as described in claim 4 is preferable for more accurately detecting the direction of an obstacle.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 4 , R is a light-emitting / light-receiving unit provided at a front part and a left-right intermediate part of an automobile, and the light-emitting / light-receiving unit R has an axis O extending substantially vertically. It has a turntable 1 rotatable about the center. On the turntable 1, one laser light emitting means 2 and two light receiving means PD1, P
D2 is fixed. Laser light is emitted from the light emitting means 2 at predetermined intervals, and the emitted laser light passes through the lens 5, collides with the obstacle B in front, and is reflected.
The reflected laser is received by the light receiving means PD1 or PD2 through the honeycomb filter 6 or 7.

The light receiving range of the light receiving means PD1 is indicated by A1, the light receiving range of the light receiving means PD2 is indicated by A2, and the range in which both light receiving means PD1 and PD2 can receive light, that is, the overlapping area is indicated by A3. As described above, the area A1 is a detection area mainly including the right front part of the vehicle, the area A2 is a detection area mainly including the left front part of the car, and the area A3 is a detection area.
Is a detection area mainly in front of the center of the vehicle. FIG.
Then, the obstacle B is located in the area A2. At this time, the light receiving levels of the light receiving means PD1 and PD2 are large as shown in FIG. The level is smaller than the predetermined level α (it may be zero).

The turntable 1 has an obstacle B in the area A3.
, That is, the left and right light receiving means PD1 and PD
2 are driven so that the respective light receiving levels are equal to or higher than a predetermined level α, and the state after the driving is shown in FIG.
FIG. 4 shows the light receiving levels of the left and right light receiving means PD1 and PS2 when the obstacle B is in the area A3. When the obstacle B is extremely far, the obstacle B
Is located at the predetermined level α even when the
However, at this time, the obstacle B is regarded as an obstacle that is not a problem.

The driving means for driving the turntable 1 comprises:
Although not shown in FIGS. 1 and 3, the servo motor is provided with a servo motor and a potentiometer using a servo mechanism, and the rotary position of the servo motor, that is, the turntable 1 is provided. Is measured by a potentiometer, and the measured rotational position is determined as the direction in which the obstacle B exists.

FIGS. 5 and 6 show a drive control system of the light emitting / receiving unit R and position data of the obstacle B (distance data and direction data in the embodiment).
And a control system for obtaining the data. In FIG. 5, S1 is an amplifier, S2 is a flip-flop, S3
Is a time measurement circuit, and S4 is a distance calculation circuit. Also, S
A control circuit 5 includes a direction detection circuit S6 and a changeover switch control circuit S7. The above means S1 to S4 and S
Reference numeral 6 is used in common for the two light receiving means PD1 and PD2, and only one is provided for each. Also,
A driving means including a servo mechanism for rotating the turntable 1 described above is shown by S8.

Two light receiving means PD1, PD2 and an amplifier S
A switch S9 is provided between the switch S1 and the switch S1. The changeover switch S9 includes a common contact 10 always connected to the amplifier S1 and a changeover contact 11 connected to the light receiving means PD1.
And a switching contact 12 connected to the light receiving means PD2. The common contact 10 is selectively connected to one of the switching contacts 11 and 12. Further, a signal from the sensor S10 for detecting the operation direction of the steering wheel is input to the changeover switch control circuit S7.

The operation of each of the means S1 to S9 will be described separately for the following cases (1) to (3). (1) Control mode 1 Now, when the obstacle B is in the area A3 and both light receiving means PD
Consider a case in which both PD1 and PD2 detect a light receiving level equal to or higher than a predetermined level α. At this time, the changeover switch S9
Is switched between the switching contacts 11 and 12 alternately at each light emission start timing from the light emitting means 2 as shown in FIG.

The light emission start timing from the light emission means 2 is S
On the other hand, a light receiving signal (a voltage value in the embodiment) received by the light receiving means (the light receiving means PD1 in the case shown in FIG. 5) is amplified by S1 and then input to S2. In S2, a light emission start signal is output at the time of input from the light emitting means 2, and
A light receiving signal is output at the time of input from S1. At S3, a time difference between the light emitting signal from S2 and the light receiving signal is measured,
The distance to the obstacle B is calculated in S4 based on the measurement result in S3.

The direction detecting circuit S6 receives the light emission start timing from the light emitting means 2 and receives a signal indicating the switching state of the changeover switch S9 from S7. This S7
Is a state indicating that the changeover switch S9 is alternately switched in the control mode 1, that is, a state where the obstacle B is located in the area A3. At this time,
In S6, the direction of the obstacle B is determined based on the driving position data (rotational position data of the turntable 1) from the driving means S8.

(2) Control Mode 2 When the obstacle B is not in the area A3 and the light receiving level of one of the light receiving means, for example, PD1, is equal to or higher than the predetermined level α, the obstacle B is located in the area A3. Thus, the driving of the driving means S8 is controlled (the clockwise rotation driving in FIG. 1). At this time, the changeover switch S9 performs a changeover control that gives priority to the changeover contact 12 corresponding to the light receiving means PD2 so that the light receiving means having a low light receiving level, for example, the PD2 detects the obstacle B earlier. This preferential switching control is performed, for example, by selecting the switching contact 12 for the PD 2 multiple times (for example, twice) continuously, selecting the switching contact 11 once, and then repeating the switching contact 12 again multiple times. This is performed by continuously performing a switching state for selection. Of course, when the switching contact 11 side is preferentially switched, the selection mode is the reverse of the above case.

When the light receiving levels of the two light receiving means PD1 and PD2 each become equal to or higher than a predetermined level α by the rotation driving of the turntable 1 by the driving means S8, the driving is stopped at this position and the above-described operation is performed. Thus, the direction of the obstacle B is determined in S6 according to the driving position at this time. The distance data is determined when the obstacle B is in the area A1 or A2, but the distance data may be determined only when the obstacle B is in the area A3. (3) Control mode 3 If the light receiving levels of both the light receiving means PD1 and PD2 are not equal to or higher than the predetermined level α, in principle, the turntable 1 is used.
Is set to the neutral position. Then, the switching control of the changeover switch S9 is performed so that the light receiving means located in the steering wheel operating direction detected in S10 has priority. That is, during cornering, preferential switching control of the changeover switch S9 is performed so that an obstacle in the turning direction in which the steering wheel is operated is detected quickly.

Description of FIG . 7 The above- described control mode is shown in a flowchart of FIG. Hereinafter, this flowchart will be described. In the following description, P indicates a step. First, at P1, it is determined whether or not the light receiving level of the light receiving means PD1 is equal to or higher than a predetermined value α. If the determination in P1 is YES, in P2, it is determined whether the light receiving level of the light receiving means PD2 is equal to or higher than a predetermined value α. If the determination in P2 is YES,
This is when the obstacle B is in the area A3. In this case, P
In FIG. 3, the changeover switch S9 is set to P as shown in FIG.
In a state where D1 and PD2 are alternately selected, at P4, position data (distance and direction) relating to the obstacle B is set.
Is determined. It should be noted that the distance data is expressed by the left and right light receiving means P.
It is preferable to set the average value of the values obtained by D1 and PD2.

If the determination in P2 is NO, in P5, the turntable 1 is driven to rotate toward the light receiving means PD1, that is, clockwise in FIG. 1, so that the light receiving means PD2 detects an obstacle. Driven. Thereafter, at P6, the changeover switch S9 is controlled so that the light receiving means PD2 side (switching contact 12 side) has priority. Also, P
If the determination in Step 1 is NO, in P7, the light receiving means PD
It is determined whether or not the light receiving level 2 is equal to or higher than a predetermined value α. If the determination in P7 is YES, in P8,
The turntable 1 is driven to rotate toward the light receiving means PD2, that is, counterclockwise in FIG. 1, and is driven by the light receiving means PD1 in a direction to detect an obstacle. Thereafter, at P9,
The changeover switch S9 is connected to the light receiving means PD1 side (the changeover contact 11
Side) is controlled so as to give priority. This P5-P
The control 9 is a control for causing the obstacle B to be located in the central area A3.

If the determination in P7 is NO, in P10, the table 1 is driven to be at the center neutral position. Thereafter, in P11, it is determined whether or not the handle has been operated toward the light receiving means PD1. If the determination in P11 is YES, the process proceeds to P9, and the area A mainly detects the direction in which the steering wheel is operated.
The process shifts to P9 to give priority to the obstacle detection in Step 1. P1
If the determination in 1 is NO, in P12, it is determined whether or not the steering wheel is operated toward the light receiving means PD2. If the determination in P12 is YES, the process shifts to P6 in order to give priority to obstacle detection in the direction in which the steering wheel is operated. P1
If the determination in step 2 is NO, the setting state at P10, that is, the turntable 1 remains at the neutral position.

FIGS . 8 and 9 show another embodiment of the present invention. The same components as those of the above embodiment are designated by the same reference numerals and the description thereof is omitted. I do. First, in the example of FIG.
Only the light receiving means PD2 and PD2 are used in common for the two light receiving means PD2. On the other hand, a circuit for determining the position data of the obstacle based on the output of the amplifier S1 (corresponding to S2 to S4 and S6 in FIG. 5) comprises A circuit X1 for PD1 and a circuit X2 for the other light receiving means PD2 are provided exclusively.

In the example of FIG. 9, each means S2 to S shown in FIG.
4. The position determining circuit corresponding to S6 includes two light receiving means P
While configured as a common circuit Y1 for D1 and PD2,
Amplifiers S1-1 and S1-2 are connected to respective light receiving means PD1 and PD
2 is provided exclusively.

Although the embodiment has been described, three or more light receiving means may be provided. In addition, the direction of the obstacle may be determined by roughly classifying the number of areas, such as the areas A1, A2, and A3, which are set to be larger than the number of light receiving means. Is the driving means S8
May not be separately provided. Further, as the detection signal, an ultrasonic wave or the like can be used instead of a laser (light). Further, the receiving ranges of the plurality of receiving means may be set so as not to overlap each other.

[Brief description of the drawings]

FIG. 1 is a diagram showing a light emitting / receiving unit and a detection area.

FIG. 2 is a diagram showing a light receiving level of each light receiving unit in the case shown in FIG.

FIG. 3 is a diagram when the light-emitting / light-receiving unit is rotated from the state of FIG. 1 so that an obstacle is located in a central overlapping light-receiving range.

FIG. 4 is a view showing a light receiving level of each light receiving means in the case shown in FIG. 3;

FIG. 5 is a diagram showing an example of a control system according to the present invention.

FIG. 6 is a diagram illustrating a switching state of a changeover switch when an obstacle is located in a central overlapping light receiving range.

FIG. 7 is a flowchart showing control contents of the control system shown in FIG. 5;

FIG. 8 is a main part system diagram showing another embodiment of the present invention.

FIG. 9 is a main part system diagram showing still another embodiment of the present invention.

[Explanation of symbols]

 R: Light emitting / receiving unit 1: Turntable 2: Light emitting means PD1, PD2: Light receiving means S1: Amplifier S1-1: Amplifier S1-2: Amplifier S2 to S4: Distance data determination circuit S6: Direction determination Circuit S7: Switching control means S8: Driving means S9: Changeover switch X1, X2: Position determination circuit Y1: Position determination circuit

Continuation of front page (56) References JP-A-4-148883 (JP, A) JP-A-5-134041 (JP, A) JP-A-5-150045 (JP, A) JP-A-4-249706 (JP) JP-A-5-126956 (JP, A) JP-A-2-143187 (JP, A) JP-A-5-87922 (JP, A) (58) Fields studied (Int. Cl. ⁷ , DB G01S 7/48-7/50 G01S 17/00-17/88

Claims (4)

(57) [Claims] 1. An obstacle detecting device for detecting an obstacle in a traveling direction of an automobile, comprising: transmitting means for transmitting a detection signal in the traveling direction of the automobile; and detecting means transmitted from the transmitting means. While detecting the signal,
Two receiving means whose receiving ranges are set so as to partially overlap each other; provided in common to the two receiving means, respectively;
Amplifying means for amplifying a received signal received by the receiving means;
Position determining means for determining the position data of an obstacle based on the received signal amplified by the amplifying means; and switching for selectively switching the connection between any one of the two receiving means and the amplifying means. Means, switching control means for controlling the switching of the switching means in synchronization with the transmission of the detection signal from the transmission means, driving means for changing the direction of the two receiving means, And a drive control means for controlling the drive means so as to be detected by the means. 2. An obstacle detecting device for detecting an obstacle in a traveling direction of an automobile, comprising: transmitting means for transmitting a detection signal in the traveling direction of the automobile; and detecting means transmitted from the transmitting means. While detecting the signal,
Two receiving units whose receiving ranges are set to partially overlap each other; two amplifying units provided corresponding to the two receiving units, for amplifying a received signal received by the receiving unit; A position determining unit that is used in common for the two receiving units and the two amplifiers, and that determines position data of an obstacle based on the received signal amplified by the amplifying unit; Switching means for selectively switching the connection between one of the position determining means and the position determining means; switching control means for controlling switching of the switching means in synchronization with transmission of a detection signal from the transmitting means; and two receiving means An obstacle detection device comprising: a driving unit that changes the direction of the vehicle; and a driving control unit that controls the driving unit so that an obstacle is detected by the two receiving units. 3. An apparatus according to claim 1 or claim 2, the reception level received by the two receiving means when the predetermined value or more, respectively, are the two receiving means is detecting an obstacle An obstacle detection device, characterized in that: 4. Oite to claim 3, wherein the position de - data determination means, the obstacle on the basis of the driving position of the drive means receiving level at the time of the predetermined value or more each of the two receiving means Determine the direction,
An obstacle detection device, characterized in that: