JPH1114754A - Object detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an object detector which requires no light-intercepting means for dirtiness discrimination of a translucent member separately from a light-intercepting means for object detection. SOLUTION: An object detector O irradiates a laser beam to an area to be detected through a translucent member 18 from an irradiating means 11, and intercepts a reflected laser beam from an object by a light-intercepting means 13 for object detection through the translucent member 18. A reference object is detected based on the light-intercepting output of the light-intercepting means 13 for object detection, and the dirtiness of the translucent member 18 is discriminated based on a relation between a distance and intercepting amount in the detected reference object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of projecting light onto a predetermined area, detecting the presence of the object by reflected light from the object by the projection, and detecting the distance to the detected object and the detected object. The present invention relates to an object detection device for measuring the direction of existence of an object.

[0002]

2. Description of the Related Art As a conventional object detecting device, a light projecting means and a light receiving means are housed in a housing, and light is transmitted and received through a light transmitting member (such as glass or plastic) provided in the housing. Things are known. In such an object detection device, if the translucent member is contaminated, the object may not be detected accurately.

Therefore, for example, Japanese Patent Application Laid-Open No. 5-256947
As disclosed in Japanese Unexamined Patent Application Publication No. H11-264, there has been proposed an apparatus provided with a function of judging dirt on a light transmitting member. As shown in FIG. 11, this device includes a light projecting unit 91, an object detecting light receiving unit 92, a dirt determining light receiving unit 93, and an arithmetic circuit 94, and a housing provided with a translucent member (front window) 95. 96. The light projecting unit 91 projects light through the light transmitting member 95 in accordance with a signal from the arithmetic circuit 94. The object detection light receiving means 92 receives light from the outside via the translucent member 95, and the arithmetic circuit 94 determines the object detection based on the received light signal. On the other hand, the dirt determining light receiving means 93 receives the light reflected by the translucent member 95, and the arithmetic circuit 94 determines the dirt on the translucent member 95 based on the level of the received light.

[0004]

However, this device is
In order to determine the contamination of the translucent member 95, a light receiving unit 93 different from that for object detection is further required. Therefore, (1) an increase in the volume of the apparatus due to the provision of the dirt determination light receiving means, (2) an increase in cost due to an increase in the number of components, and (3) a design for making it difficult to optically arrange the dirt determination light receiving means There is a problem of cost increase.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention does not require a separate light receiving means different from the object detecting means, and transmits light with an output from the object detecting light receiving means. This is to determine the contamination of the member.

According to the present invention, a reference object specified in advance is detected based on a light receiving output from a light receiving means for detecting an object, and data relating to a distance to the detected reference object is derived. Data on the amount of light received as light from the object is derived. Then, the stain on the translucent member is determined based on the relationship between the data on the distance and the data on the amount of received light in the detected reference object.

The reference object has a predetermined reflectance, and the amount of light reflected from the reference object has a predetermined relationship depending on the distance to the reference object. Therefore, when the translucent member is not contaminated, the amount of light received by the light receiving unit as reflected light from the reference object and the distance to the reference object are:
The above predetermined relationship is satisfied. On the other hand, if the translucent member is dirty, the reflected light from the reference object is reflected or absorbed due to the stain on the window. Than the amount of received light. As a result, if the translucent member is dirty,
The amount of light received by the light receiving means as reflected light from the reference object and the distance to the reference object do not satisfy the above-described predetermined relationship.

That is, according to the configuration of the present invention, the reference object is detected by the light receiving output of the light detecting means for detecting the object, and the data on the distance and the data on the amount of received light in the reference object are derived. Then, it is determined whether or not the relationship between the data on the distance and the data on the amount of received light in the reference object satisfies the predetermined relationship.
Then, based on the result of the determination, it is determined whether the translucent member is dirty.

In the above arrangement, a plurality of reference objects are detected, and a stain on the translucent member is determined based on a relationship between the data relating to the distance and the data relating to the amount of received light in the plurality of detected reference objects. You may. According to this configuration, a plurality of reference objects are detected, and data relating to the distance and data relating to the amount of received light in the plurality of reference objects are derived. Then, it is determined whether or not the relationship between the data on the distance and the data on the received light amount for each of the plurality of reference objects satisfies the predetermined relationship. Then, based on these determination results, it is determined whether the translucent member is dirty.

Further, in the above configuration, a signal for judging that it is raining may be inputted, and when the signal is inputted, the dirt judgment may not be performed. The signal for determining that it is raining may be, for example, a signal from a sensor that directly detects that it is raining, or indicating that a wiper attached to the vehicle is operating. It may be a signal.
According to this configuration, when it is raining, the dirt determination is not performed.

Further, in the above configuration, a signal for determining that fog is generated may be input, and when the signal is input, the dirt determination may not be performed. The signal for determining that fog is occurring may be, for example, a signal from a sensor that directly detects that fog is occurring, or that a fog lamp attached to the vehicle is lit. May be a signal indicating According to this configuration, when fog is occurring, the dirt determination is not performed.

Further, in the above configuration, it may be possible to notify when it is determined that the translucent member is dirty.
The notification can be performed using, for example, a lamp or a buzzer. According to this configuration, it is notified that the translucent member is dirty.

In the above configuration, a reflector provided on the vehicle may be detected as a reference object. It is obligatory to mount two reflectors on the left and right behind all vehicles, and the distance between the two reflectors is about 2 m. Also, the size of those reflectors is almost the same in all vehicles. Further, since these reflectors have retroreflective characteristics, they all have the same reflectance. These reflectors move as the vehicle travels.

According to this configuration, for example, two objects existing at the same distance with an interval of about 2 m are determined to be the reflectors attached to the vehicle, and are detected as the reference objects. . Alternatively, for example, two objects moving at the same speed are determined to be the reflectors attached to the vehicle, and are detected as reference objects. Then, it is determined whether or not the relationship between the data on the distance and the data on the amount of received light satisfies a predetermined relationship with respect to the reflector attached to the vehicle detected as the reference object. Then, based on the result of the determination, it is determined whether the translucent member is dirty.

In the above configuration, a reflector installed on the road may be detected as a reference object. For example, in the case of an expressway, these roadside reflectors are installed at predetermined distances over the entire area of the road. In the case of a general road, these roadside reflectors are installed at predetermined distances at places where there is a large amount of traffic and at junctions / branches / curves.
Since these roadside reflectors have retroreflective characteristics, they all have the same reflectance.

According to this configuration, for example, reflectors that are regularly arranged at predetermined intervals are determined to be reflectors installed on the roadside, and are detected as reference objects. Then, it is determined whether or not the relationship between the data on the distance and the data on the amount of received light satisfies a predetermined relationship with respect to the reflector installed on the roadside detected as the reference object. Then, based on the result of the determination, it is determined whether the translucent member is dirty.

[0017]

Embodiments of the present invention will be described below.

First, a safe driving system using the object detection device of the present invention for detecting a preceding vehicle will be described. FIG.
FIG. 2 is a block diagram showing a configuration of a safe driving system. The safe driving system S is mounted on a vehicle, detects and displays an inter-vehicle distance to a preceding vehicle, and issues an alarm based on the relationship between the vehicle speed and the inter-vehicle distance. The safety traveling system S includes a safety control controller 21, an object detection device O, a vehicle speed sensor 22, and an inter-vehicle distance display unit 2.
3 and an alarm unit 24.

The object detecting device O emits laser light, receives laser light reflected by the object, and detects the object based on the output of the received light. A vehicle speed sensor 22 is connected to the object detection device O, and a vehicle speed signal indicating the traveling speed of the own vehicle is input. Then, the object detection device O detects the inter-vehicle distance to the preceding vehicle and the preceding vehicle based on the received light output of the laser light and the vehicle speed signal, and outputs the inter-vehicle distance signal to the safety control controller 21. I have. The object detection device O is connected to the wiper 31, and receives an operation signal indicating that the wiper 31 is operating. The object detection device O is connected to the fog lamp 32 and receives an operation signal indicating that the fog lamp 32 is operating.

[0020] The safety control controller 21 controls the following distance display unit 2 based on the following distance signal from the object detection device O.
3, the distance between vehicles to the preceding vehicle is displayed. Further, based on the vehicle speed signal from the vehicle speed sensor 22 and the inter-vehicle distance signal from the object detection device O, if the inter-vehicle distance becomes too short, an alarm is issued by the alarm unit 24.

As described above, the safe driving system S detects and displays the inter-vehicle distance to the preceding vehicle and issues an alarm based on the relationship between the vehicle speed and the inter-vehicle distance.

Next, the object detection device O will be described.
FIG. 2 is a diagram illustrating a configuration of the object detection device O. The object detecting device O includes a light projecting unit 11, a light projecting direction detecting unit 12,
It includes a light receiving unit 13, a control unit 14, an object detection unit 15, a dirt determination unit 16, a housing 17, a translucent member 18, and a notification unit 19.

The housing 17 includes a light emitting means 11, a light emitting direction detecting unit 12, a light receiving means 13, a control unit 14, and an object detecting unit 15
And a stain determination unit 16 are accommodated. And the housing 1
A light-transmitting member 18 such as glass or plastic is provided on the front surface of the light-receiving unit 7.
Numeral 3 is configured to emit and receive light via the translucent member 18. The notification unit 19 is provided outside the housing 17 and notifies that the translucent member 18 is dirty by lighting a lamp.

The light projecting means 11 comprises a light emission control section 11-1, a light emission section 11-2, and a light sweep section 11-3, and receives a start signal from the control section 14 to detect a laser beam. The light is swept and projected onto the target area U.

The light emission control unit 11-1 receives a start signal from the control unit 14, outputs a pulse signal to the light emission unit 11-2, and controls the light emission of the light emission unit 11-2.

The light emitting section 11-2 receives a pulse signal from the light emission control section 11-1 and emits a pulse laser beam.
The configuration is, as shown in FIG.
-2a and a collimating lens 11-2b. The laser diode 11-2a includes an emission control unit 11-
The laser light is driven by a pulse signal from 1 and emits a pulse of laser light. Then, the emitted pulse laser light is emitted from the light emitting unit 11-2 through the collimator lens 11-2b. This pulsed laser light is converted into a light having a substantially parallel thin shape by the function of the collimating lens and emitted.

The light sweep section 11-3 sweeps and emits the pulsed laser light emitted from the light emitting section 11-2 to the detection target area U (see FIG. 4) via the light transmitting member 18. The configuration is, as shown in FIG. 3, a rotating mirror 11-3a,
Motor 11-3b and cylindrical lens 11-3c
And The rotating mirror 11-3a is a motor 11
-3b, the cycle θ = 0.1 s and the angle θ _U
= 0.2 rad. The pulse laser light emitted from the light emitting unit 11-2 is
After being reflected by the rotating mirror 11-3a, the light is emitted from the light sweeping unit 11-3 through the cylindrical lens 11-3c. Then, the pulsed laser light emitted from the light sweep unit 11-3 is emitted via the light transmitting member 18 in a direction determined by the rotation angle of the rotation mirror 11-3a. This pulsed laser light is applied to the cylindrical lens 11
By the action of -3c, the light is converted into a fan-shaped light having a spread angle φ _U = 0.05 rad and emitted (see FIG. 4).

The control unit 14 outputs a start signal to T during a rotation period T = 0.1 s of the rotation mirror 11-3a.
Output twice.

Therefore, the light projecting means 11 emits 80 pulse laser beams in 0.1 seconds. Then, these pulsed laser beams are swept and projected in the range of the angle θ _U = 0.2 rad by the function of the rotating mirror 11-3a.

FIG. 4 is a diagram showing a state in which laser light is projected on the detection target area U. As described above, the light projecting unit 11 projects the pulsed laser light to the detection target region U via the translucent member 18. The pulsed laser light is supplied to a collimating lens 11-2b and a cylindrical lens 11-b.
3c, the divergence angle φ in the θ direction is thin in the θ direction.
It becomes fan-shaped light having _U = 0.05 rad. And
This fan-shaped pulse laser beam is transmitted to the rotating mirror 11-3a.
During the rotation period of T = 0.1 s, 80 light is emitted, and 0.025 r in the θ direction by the action of the rotation mirror 11-3a.
Light is sequentially emitted at ad intervals. That is, the light emitting means 1
1 is a range of an angle θ _U = 0.2 rad in the θ direction,
One sweep light emission is performed by the emitted pulse laser light.

Returning to FIG. 2, the light projecting direction detecting section 12 detects the turning angle of the turning mirror 11-3a, and inputs the angle detection signal to the control section 14. The control unit 14 determines the projection direction θ of the pulsed laser light based on the angle detection signal from the projection direction detection unit 12.

The light receiving means 13 comprises a light receiving section 13-1 and a light receiving signal processing section 13-2. Light receiving unit 13
“−1” receives light from the detection target area U via the translucent member 18, converts the light into an electric signal corresponding to the amount of received light, and outputs the signal as a light reception signal.

The light receiving signal processing section 13-2 includes a light receiving section 13-
The light receiving amount e received by the light receiving unit 13-1 is detected from the light receiving signal from the light receiving unit 1. If the received light amount e exceeds the threshold value, an object detection signal corresponding to the received light amount e is output as the reflected laser light from some object, and the received light amount e does not exceed the threshold value. In such a case, the object detection signal is not output as the noise light (background light).

The control unit 14 measures the time Δt from the time when the start signal is output to the light emitting means 11 to the time when the object detection signal is input from the light receiving means 13, and r = (Δt Calculation of (light speed) / 2 is performed to calculate the distance r to the starting point q of the reflected laser light. Control unit 1
No. 4 sets the projection direction of the pulse laser light to the direction θ of the starting point q of the reflected laser light. Further, the control unit 14 includes the light receiving unit 13
The light receiving amount e received by the light receiving means 13 is calculated from the object detection signal from the CPU. Then, the control unit 14 calculates starting point data q (r, θ, e) relating to the starting point q of the reflected laser light,
The data is transmitted to the object detection unit 15.

When no object detection signal is obtained from the light receiving means 13 (ie, when the reflected laser light is not received), the distance r to the starting point q of the reflected laser light is set to ∞. The projection direction of the pulsed laser light at that time is defined as the direction θ of the starting point q of the reflected laser light. Further, the value of the received light amount e is set to 0.

The object detector 15 receives the starting point data q (r, θ, e) from the controller 14 and a vehicle speed signal from a vehicle speed sensor 21 connected to the object detector O. Then, the object detection unit 15 determines that 80
Pieces of origin data q _n (r, θ, e) (n = 1, 2,...,
80) is stored.

The object detecting section 15 calculates the starting point data q _n (r, θ, e) and the vehicle speed signal based on these 80 data.
A preceding vehicle in the detection target area U is detected, an inter-vehicle distance to the preceding vehicle is calculated, and the value is output to the control unit 14. In addition, the object detection unit 15 detects the reflector installed on the road side as a first-type reference object based on the 80 pieces of the starting point data q _n (r, θ, e) and the vehicle speed signal, and provides the reflector to the vehicle. The detected reflector is detected as a second type reference object. Then, the distance R to the reference object, the direction in which the reference object exists Θ, and the received light amount E from the reference object are calculated, and these values are output to the control unit 14 as reference object data P (R, Θ, E). I do.

The control unit 14 outputs the value of the inter-vehicle distance to the preceding vehicle obtained from the object detection unit 15 to the safety control controller 20 to which the object detection device O is connected. Also, the reference object data P (R, Θ, E) obtained from the object detection unit 15
Is output to the stain determination unit 16.

The dirt determining section 16 is a section for determining dirt on the translucent member 18 based on the relationship between the distance R of the reference object and the amount of received light E. As shown in FIG. And a reference table for the received light amount E.
A curve C in the table of FIG. 5 indicates a threshold value of the light reception amount E set depending on the distance R. This curve C
The lower area is an area where it is determined that the light-transmitting member 18 may be dirty.

The dirt determining section 16 determines the dirt on the translucent member 18 by comparing the distance R and the received light amount E of the three reference objects detected within 15 minutes with the table. That is, the dirt determination unit 16 compares the distance R and the received light amount E with the comparison data Zm (R, R) for the three pieces of reference object data P (R, Θ, E) acquired within 15 minutes.
E) (m = 1, 2, 3). Then, the three comparison data Z _m (R, E) are compared with the above table, and if all of them are in the area below the curve C, it is determined that the translucent member 18 is dirty.

Then, the stain judging section 16 sets the light transmitting member 1
When it is determined that 8 is dirty, a stain detection signal is output to the control unit 14.

The control unit 14 outputs a notification signal to the notification unit 19 in response to the detection signal from the contamination determination unit 16. The notification unit 19 notifies that the translucent member 18 is dirty by turning on the lamp in response to the notification signal.

The object detection device O is mounted on the vehicle as a part of the safe driving system S as described above, and sweeps and emits a laser beam toward a detection target area U in front of the host vehicle. Then, it detects a preceding vehicle traveling ahead of the host vehicle, calculates the inter-vehicle distance to the preceding vehicle, and outputs a signal to the safety control controller 21. Further, the reference object is detected, and the stain on the translucent member 18 is determined based on the distance R to the reference object and the received light amount E from the reference object.

Next, the flow of operation processing in the object detection device O will be described.

First, referring to the flowchart of FIG.
The flow of the object detection process will be described. First, S301
In, the value of n is set to “n = 0”. The value of n represents the number of times the pulsed laser light is projected. S3
In 02, the value of n is increased by "+1", and in S303, the pulsed laser light is emitted from the light emitting means 11 via the light transmitting member 18.

In S 304, the light from the detection target area U is received by the light receiving means 13 via the translucent member 18. In S305, the control unit 14 calculates starting data q _n (r, θ, e) relating to the starting q of the reflected laser light. In S306, the object detecting unit 15 calculates the starting data q _n (r, θ). , E) are stored. And S307
Then, it is determined whether or not the value of n has reached 80 (that is, whether or not one sweep projection onto the detection target area U has been completed).

If No in step S307, that is, if the value of n is less than 80, one sweep light emission is not completed yet, and the flow returns to step S302 to increment the value of n by "+1".
In step 3, the next pulse laser is emitted. Thereafter, the same processing is repeated, and n = 1, 2, 2
80 starting point data qn (r, r,
θ, e) are stored.

In step S307, if Yes, that is, if the value of n reaches 80, one sweep light emission is completed, and the flow proceeds to object detection determination in step S308 and subsequent steps.

Here, a specific example of the object detection in the one sweep light projection will be described with reference to FIGS. 7, 8 and 9. FIG. FIG. 7 is a diagram illustrating a specific situation in which an object is detected by the object detection device O. _Ao is a vehicle running at a speed of about 80 km / h, and is equipped with an object detection device O. A _1, A _2, A ₃ is another vehicle, traveling at about the same speed 80 km / h with the vehicle A _o. Two reflectors a on the left and right are mounted at the rear of all vehicles at an interval of about 2 m. _{B 1, B 2, ...,} B 8 is a the installed reflector roadside. These roadside reflectors B
Are installed at predetermined intervals. Since the reflector a provided on the vehicle and the reflector B provided on the road side are constituted by retroreflective plates,
Have the same reflectivity. C ₁ is a road sign.

The vehicle A _o object detecting device O mounted on
Is configured to sweep projecting optical pulse laser light in front of the detection target area U of the own vehicle A _o, for receiving the reflected laser beam from the detection target area U. In the situation shown in FIG.
₁ and vehicle A ₂ , and roadside reflectors B ₂ , B ₃ , B
₄ , B _5, and the road sign C ₁ are present in the detection target area U, and therefore, reflected laser light from them is received. Then, based on the received light output of the reflected laser light, the control unit 14 causes the starting point data q _n (r, θ,
e) is calculated, and the starting point data qn (r, θ, e) is stored in the object detection unit 15.

FIG. 8 is a view showing 80 pieces of starting point data qn (r, θ, e) in one sweep projection light stored in the object detecting section 15 in the situation shown in FIG. The horizontal axis indicates the number of projections n (corresponding to the projection direction θ), and the vertical axis indicates the distance r to the starting point qn. That is, FIG.
7 shows the distribution of the detection distance r of the starting point qn detected by one sweep projection light in the situation shown in FIG. Q ₁ ,
Q ₂ and Q ₃ are roadside reflectors B ₂ , B ₃ and B, respectively.
₄ is supported. Q ₄ and Q ₅ are vehicles A ₁ ,
Which corresponds to A _2. Q ₆ is the roadside reflector B
₅ corresponds, Q ₇ corresponds to the road sign C _1.

FIG. 9 is a view showing 80 pieces of starting point data qn (r, θ, e) in one sweep light projection stored in the object detecting section 15 in the situation shown in FIG. The horizontal axis indicates the number of light projections n (corresponding to the light projection direction θ), and the vertical axis indicates the amount of received light e with respect to the starting point qn. That is,
FIG. 9 shows the distribution of the received light amount e with respect to the starting point qn received by one sweep projection light in the situation shown in FIG. Q ₁ , Q ₂ , and Q ₃ are each a roadside reflector B
It corresponds to _{2, 3,} B _4. Q _4, Q ₅ corresponds to the vehicle A _1, A _2, respectively. In Q ₄ and Q _5, the two sharp peaks Q ₄ 1 and Q ₄ 2 and Q ₅ 1 and Q ₅ 2 exists is because two reflectors a is provided at the rear of the vehicle. Also, Q ₆ corresponds to the roadside reflector B _5, Q ₇ corresponds to the road sign C _1.

Further, based on the data at the time of the previous sweep and the vehicle speed signal obtained from the vehicle speed sensor 22, Q _i (i =
, 7) are calculated. That is,
For the Q ₄ and Q _5, it is calculated that is moving at a speed of about 80 km / h, with respect to the _{Q 1, Q 2, Q 3} , Q 6, Q 7, not moving (stationary) Is calculated.

Returning to FIG. 6, first, in S308, one of the 80 pieces of starting point data q _n stored in the object detecting unit 15 in which data having substantially the same distance r is continuous is one reflecting object. Extracted as Q _i . That is, FIG.
_{In, Q 1, Q 2, ...} , Q 7 are respectively extracted as one reflecting object Q _i.

Next, in S309, from the reflecting object Q _i, relates roadside reflector are extracted. Here, those that exist regularly at substantially equal distance intervals and have a moving speed of 0 are extracted as those relating to the roadside reflector. That is, Q ₁ and Q in FIG.
_2, Q ₃ is extracted as the data relating to road reflector. And the Q that is closest to them
₁ is extracted as a first type reference object.

Then, in S310, data on the reference object is calculated. That is, with respect to the plurality of pieces of origin data q _n (r, θ, e) corresponding to Q ₁ , the average value of the distances r of the pieces of origin data q _n (r, θ, e) is calculated as the distance R to the reference object. , Their origin data qn
The center value of the direction θ of (r, θ, e) is calculated as the direction 存在 of the reference object. Also, their origin data qn
The sum of the received light amount e of (r, θ, e) is calculated as the received light amount E of the reference object. Then, these calculated values are sent to the control unit 14 as reference object data P (R, Θ, E).

In step S311, a reflection object Qi is extracted from the reflection object Qi. Here, Qi has two peaks in the received light amount distribution and the interval between the peaks is 1.2 m to 2.5 m.
Or at a moving speed of Qi of 50 to 120
km / h is determined as a vehicle. That is,
In Figure 9, Q ₄ and Q ₅ is determined as the vehicle. Then, portions of the two peaks present in their received light amount distribution, i.e., Q ₄₁ and Q _42, and data of Q ₅₁ and Q ₅₂ is extracted as the data relating to the reflector provided in the vehicle. And Q which is the peak part on the left side
₄₁ and Q ₅₁ are respectively extracted as a second type of reference object.

Then, in S312, data relating to these reference objects is calculated. That is, for a plurality of pieces of origin data q _n (r, θ, e) corresponding to Q ₄₁ , the average value of the distances r of the pieces of origin data q _n (r, θ, e) is calculated as the distance R to the reference object. , Their origin data q _n
The center value of the direction θ of (r, θ, e) is calculated as the direction 存在 of the reference object. Also, their origin data q _n
The sum of the received light amount e of (r, θ, e) is calculated as the received light amount E of the reference object. Then, these calculated values are sent to the control unit 14 as reference object data P (R, Θ, E). Also, for multiple origins data q _n corresponding to Q ₅ 1, similarly, the distance R and the direction Θ and the received light amount E is calculated, these calculated values are the reference object data P (R,
Θ, E) are sent to the control unit 14.

[0059] In S313, from among the reflecting object Q _i, relates preceding vehicle is extracted. Here, S
Of the data extracted as the vehicle in 310, data existing on the traveling line of the own vehicle is extracted as the preceding vehicle. That is, with respect to the directions in which the two peak portions (corresponding to the reflectors) exist in the data extracted as vehicles, one is smaller than θ _c (θ _c is the center value of θ _u ) and the other is θ
It is determined that a vehicle larger than _c is a preceding vehicle existing on the traveling line of the own vehicle. That is, in FIG. 9, Q ₄ are extracted as the data relating to the preceding vehicle.

In S314, the following distance to the preceding vehicle is calculated. That is, with respect to the plurality of pieces of origin data q _n (r, θ, e) corresponding to Q ₄ , the average value of the distance r of the pieces of origin data q _n (r, θ, e) is taken as the inter-vehicle distance to the preceding vehicle, The value is sent to the control unit 14.

In step S315, the inter-vehicle distance to the preceding vehicle is output from the control unit 14 to the safety control controller. Then, returning to S301, the value of n is set to 0 and the next 1
The first sweep light emission is started, and the same operation is repeated thereafter.

Next, the flow of the stain determination process will be described with reference to the flowchart of FIG. First, S4
01, the value of the number m of comparison data Z _m (R, E) is changed to “m
= 0 ”, and in S402, the comparison object data Z _m (R,
Clear E).

In S403, reference object data P (R, Θ, E) is obtained from the control unit 14.

In S404, it is determined whether the wiper 31 is operating. No, that is, when the wiper 31 is not operating, the process proceeds to S405, and the fog lamp 3
It is determined whether 2 is lit. N in S405
If o, that is, if the fog lamp 32 is not turned on, the process proceeds to S406, and it is determined whether the reference object detected in the current sweep is the same as the reference object detected in the previous sweep. If No in S406, that is, if the reference object is a newly detected reference object in the current sweep, the process proceeds to S407, and the value of the number m of data is incremented by "+1".

In S408, it is determined whether the reference object data P (R, Θ, E) acquired from the control unit 14 is related to the first type reference object or the second type reference object. If it is related to the second type of reference object, in S409, the reference object data P (R, Θ,
The light receiving amount E of E) is converted (for example, 5 times). This is because the first-type reference object and the second-type reference object have different sizes, so that even if they are at the same distance R, the amount of received light E is different. It is. More specifically, the size of the reflector mounted on the vehicle as the second type reference object is about 1/5 of the size of the roadside reflector as the first type reference object. Is multiplied by 5 to adjust the criterion for dirt determination. Then, in S410, the reference object data P (R,
The values of the distance R and the received light amount E at (Θ, E) are stored as the _m-th comparison data Z _m (R, E).

In S411, it is determined whether or not the value of the number m of comparison data is 1. Yes, that is, m = 1
In the case of, since the first reference object is detected in the current sweep and stored as the _first comparison data Z ₁ (R, E), the process proceeds to S412 and the timer is started. Then, returning to S403, the next reference object data P (R, Θ,
E). If No in S411, that is, m ≠ 1, since the first reference object has already been detected and stored as the first comparison data Z1 (R, E) in the sweeps up to this time, the process proceeds to S413. It is determined whether the value of the number m of data is three.

If No in S413, that is, if m ≠ 3, the third reference object has not been detected yet, and the third comparison data Z ₃ (R, E) has not been stored.
Proceeding to S414, it is determined whether the timer is less than 15 minutes. Also, in the case of Yes in S404, S405, and S406, the process proceeds to S414, and it is determined whether the timer is less than 15 minutes. In the case of Yes in S414, the process returns to S403 to acquire the next data. If No in S414, the timer is cleared in S415 and the process returns to S401.

If Yes in S413, that is, if m = 3, the third reference object is detected in the current sweep, and the third comparison data Z ₃ (R, E) is stored. , S416. In S416, the three comparison data Z _m (R, E) (m = 1, 2, 3) are output to the stain determination unit 16
(See FIG. 5). S
At 416, first, the first comparison data Z ₁ (R, E)
It is determined whether or not the relationship between the distance R and the received light amount E is within an appropriate range. In S417, the second comparison data Z
₂ The relationship between the distance R and the received light amount E at (R, E) is S4
At 18, it is determined whether the relationship between the distance R and the received light amount E in the _third comparison data Z ₃ (R, E) is within an appropriate range.

If No in all of S416, S417, and S418, that is, three comparison data Z _m (R,
If all of E) are out of the appropriate range, it is determined in S419 that "dirty". Then, in S420, dirt notification is performed. This dirt notification continues to be notified until the next "no dirt" determination is made. Then, the timer is cleared in S421, and the process returns to S401.

In the case of Yes in any of S416, S417, and S418, that is, three comparison data Zm
If any one of (R, E) is within the appropriate range, it is determined in S422 that "no contamination". Then, the timer is cleared in S423, and the process returns to S401.

As described above, the object detection device O
A reference object is detected based on the light receiving output of the light receiving means 13 for object detection (inter-vehicle distance detection), and contamination of the translucent member 18 is determined based on the relationship between the distance R and the received light amount E at the detected reference object. Make a decision.

In the embodiment described above, it is determined that the wiper 31 is operating when it is raining, and when a signal indicating that the wiper 31 is operating is input, the I try not to make a decision. However, it is determined that it is raining.
For example, a signal from a rain sensor that directly detects that it is raining may be used in addition to the signal indicating that is operating.

In the above-described embodiment, when the fog lamp 32 is lit, it is determined that fog is occurring, and when a signal indicating that the fog lamp 32 is lit is input, Dirt judgment is not performed. However, the determination that fog is occurring can also be made by using a signal from a fog sensor that directly detects that fog is occurring, for example, in addition to the signal indicating that the fog lamp 32 is turned on. Good.

In the above-described embodiment, the notification of dirt is performed by the notification unit 19 of the object detection device O.
This dirt notification may be performed via the safety control controller 20.

[0075]

As described above, according to the object detecting apparatus of the first aspect, the reference object is detected by the light receiving means for detecting the object, and the reference object is detected based on the relationship between the distance and the amount of received light in the reference object. Thus, since the dirt on the translucent member is determined, there is no need for a light receiving unit for dirt determination that is different from that for object detection. Therefore, it is possible to obtain the effects of reducing the volume of the apparatus, reducing the number of parts, and reducing the cost and design cost, while having the function of determining contamination of the translucent member in the related art.

Further, according to the object detecting device of the present invention, since the dirt judgment is performed based on a plurality of reference objects,
Even if one surface of the detected reference object happens to be dirty and the amount of received light does not satisfy the predetermined relationship depending on the distance, it is determined that the translucent member is dirty. Never. Therefore, it is possible to prevent erroneous determination of dirt determination due to a decrease in the amount of received light due to dirt on one surface of the reference object, and to perform more accurate dirt determination.

According to the third aspect of the present invention, the dirt determination is not performed when it is raining. Therefore, the dirt determination based on a decrease in the amount of received light due to the rain is reduced. An erroneous determination can be prevented, and a more accurate dirt determination can be performed.

Further, according to the object detecting device of the present invention, when fog is generated, no dirt judgment is performed, and therefore, the fog is generated due to a decrease in the amount of received light due to fog. Misjudgment of judgment can be prevented, and more accurate dirt judgment can be performed.

Further, according to the object detecting device of the fifth aspect, since it is possible to know that the translucent member is dirty, it is possible to take an appropriate measure such as wiping the window. The object detection performance of the object detection device can always be maintained in an appropriate state.

According to the object detecting device of the present invention, since the reflector provided on the vehicle, which is an existing object, is detected as the reference object, the specific object for performing the dirt determination is bothersome. There is no need to manufacture or install.

According to the object detecting device of the present invention, since the reflector provided on the road, which is an existing object, is detected as the reference object, the specific object for performing the dirt determination is bothersome. There is no need to manufacture or install.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a safe driving system using an object detection device of the present invention.

FIG. 2 is a block diagram illustrating a configuration of an object detection device according to the present invention.

FIG. 3 is a diagram illustrating a configuration of a light projecting unit of the object detection device of the present invention.

FIG. 4 is a diagram showing a state of light projection of the object detection device of the present invention.

FIG. 5 is a diagram showing a reference table relating to the distance of a reference object and the amount of received light.

FIG. 6 is a flowchart illustrating a flow of an object detection process of the object detection device.

FIG. 7 is a diagram illustrating a specific situation in which an object is detected by the object detection device.

FIG. 8 is a diagram illustrating a distribution of a detection distance with respect to a light projection direction, which is detected by the object detection device.

FIG. 9 is a diagram illustrating a distribution of a received light amount in a light projection direction detected by the object detection device.

FIG. 10 is a flowchart illustrating a flow of a stain determination process of the object detection device.

FIG. 11 is a diagram illustrating a configuration of a conventional object detection device.

[Explanation of symbols]

 O Object detection device S Safe driving system U Detection target area 11 Light emitting means 11-1 Light emission control unit 11-2 Light emission unit 11-3 Light sweep unit 12 Light emission direction detection unit 13 Light receiving means (for object detection) 13-1 Light receiving unit 13-2 Light receiving signal processing unit 14 Control unit 15 Object detection unit 16 Dirt determination unit 17 Housing 18 Translucent member 19 Notification unit 21 Safety control controller 22 Vehicle speed sensor 23 Inter-vehicle distance display unit 24 Alarm unit 31 Wiper 32 Fog lamp Reference Signs List 91 Projecting means 92 Object detecting light receiving means 93 Dirt judging light receiving means 94 Arithmetic circuit 95 Translucent member 96 Housing

Claims (7)

[Claims] 1. A light projecting means for projecting light to a detection target area via a light transmitting member, and a light receiving means for receiving light from the detection target area via the light transmitting member. An object detection device configured to detect at least the presence or absence of an object based on a light reception output of the light receiving unit, wherein a reference object specified in advance is detected based on a light reception output of the light reception unit, and up to the detected reference object. A determination as to whether the light-transmitting member is dirty based on a relationship between data on the distance and data on the amount of light received by the light-receiving unit as light from the detected reference object. Detection device. 2. A method of detecting a plurality of said reference objects, wherein data on a distance to the reference object in the plurality of detected reference objects and data on an amount of light received by the light receiving means as light from the reference object. Based on the relationship
The object detection device according to claim 1, wherein a stain on the light-transmitting member is determined. 3. A signal for determining that it is raining is input, and when the signal is input, the dirt determination is not performed. 3. The object detection device according to any one of 1 and 2. 4. A signal for determining that fog is occurring is input, and when the signal is input, the dirt determination is not performed. Item 3. The object detection device according to any one of Items 1 and 2. 5. The object detection device according to claim 1, wherein a notification is issued when it is determined that the translucent member is dirty. 6. The object detection device according to claim 1, wherein a reflector attached to a vehicle is detected as the specified reference object. 7. The object detection device according to claim 1, wherein a reflector installed on a road side is detected as the pre-specified reference object.