JPH10115518A - Distance-measuring apparatus and vehicle using the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely measure a distance to an object whether the distance is short or long. SOLUTION: A distance-measuring apparatus consists of an observation system 10 having two pairs of observation parts 10P, 10Q, operating processing parts 11P, 11Q set for each observation part, and a switching controlling part 9 for switching the operating processing parts. The observation parts 10P, 10Q include a pair of photodetecting lenses and a pair of photodetectors and are provided as a field angle-changing means 15 with cylindrical lenses 16P, 16Q of different curvatures so as to enlarge a view field. A vertical angle of field of the observation part 10P, 10Q is se to be large or small by the cylindrical lens 16P, 16Q.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device used for measuring a distance to an object, and a vehicle such as an automobile equipped with the distance measuring device (hereinafter simply referred to as "vehicle"). About.

[0002]

2. Description of the Related Art In recent years, in order to improve the running safety of a vehicle, a distance measuring device for measuring a distance to a preceding vehicle, a following vehicle, and an obstacle around the vehicle is mounted inside or outside the vehicle. It has been proposed to control the traveling of a vehicle while keeping the distance to surrounding vehicles and obstacles constant, based on the measurement results obtained by the distance measuring device.

FIG. 25 shows the configuration of a conventional distance measuring device. A pair of left and right light receiving lenses 1a and 1b and a pair of right and left light receiving devices 2a and 2 corresponding to the respective light receiving lenses 1a and 1b are shown.
The observation system 3 is constituted by b. Each light receiving lens 1a, 1b
Are arranged at a predetermined distance D so that the optical axes are parallel to each other. A PD array is used for each of the light receivers 2a and 2b, and a plurality of pixels 4 are arranged in a row. In the figure,
A and B indicate the horizontal visual fields of the left and right optical systems. When an object enters a visual field range C where the visual fields A and B overlap, the distance to the object can be measured.

When an object exists within the visual field range C, the light receiving lenses 1a and 1b form images of the object on the light receivers 2a and 2b, respectively. Each light receiver 2a, 2b
Detects the light intensity distribution of each image. This distance measuring device has an arithmetic processing unit (not shown) for calculating a distance, and the arithmetic processing unit uses a phase difference correlation method based on a shift amount of the light intensity distribution of the two images. Calculate the distance to.

FIG. 26 is a view for explaining the principle of distance measurement.
Now, the deviation amounts of the light intensity distributions of the respective images detected by the respective light receivers 2a and 2b are x ₁ and x ₂ , the distance between the light receiving lenses 1a and 1b and the light receivers 2a and 2b is F, and the distance between the light receiving lenses 1a and 1b. Is the distance D, the distance L to the object 5 is obtained by the following equation.

[0006]

(Equation 1)

If the number of effective pixels of each of the light receivers 2a and 2b is n and the pixel pitch is p, the effective length S of each of the light receivers 2a and 2b and the viewing angle θ (hereinafter referred to as “horizontal”) defining the view range C The viewing angles are given by the following formulas. When the object 5 exists in the field of view C, a contrast image is formed on each of the light receivers 2a and 2b. Can be measured.

[0008]

(Equation 2)

[0009]

(Equation 3)

[0010]

On the other hand, the photodetectors 2a, 2
The viewing angle in a direction perpendicular to the direction in which b are arranged (hereinafter referred to as “vertical viewing angle”) is determined by the size of each of the light receivers 2a and 2b,
Although determined by the relationship with the light receiving lenses 1a and 1b, this vertical viewing angle cannot usually be made wide. For example, when the vertical size of the light receivers 2a and 2b is 200 μm and the distance F between each of the light receivers 2a and 2b and each of the light receiving lenses 1a and 1b is 20 mm, the vertical viewing angle is about 0.6 degrees.

When the vertical viewing angle is small, each of the light receivers 2a, 2a
b, it is not possible to form a contrasted image, or even if a contrasted image can be formed, the contrasted image may deviate from the light receivers 2a and 2b due to pitching of the own vehicle. You need to spread it.

When measuring the distance to a close object,
If the vertical viewing angle is narrow, the object detection range will be narrow,
In some cases, an image with contrast cannot be obtained and the distance cannot be measured. In particular, when measuring the inter-vehicle distance to a vehicle in front, for a vehicle having a large trunk portion, an image with contrast cannot be obtained at a small vertical viewing angle. Therefore, it is desirable that the vertical viewing angle be wide at a short distance. When measuring the inter-vehicle distance from a preceding vehicle using a license plate present in all vehicles as an object, since the height at which the number plate is installed varies depending on the vehicle, a vertical field of view of 10 degrees or more at a short distance of 1 to 2 m. Need corners.

On the other hand, when the distance from the vehicle in front is long, if the vertical viewing angle is wide, the proportion of the object image other than the image of the vehicle in front, specifically, the image of the road, the sky, the background in front, etc. occupies. Since the image becomes large, the image has a small contrast, and it is difficult to identify and recognize the preceding vehicle. Therefore, when measuring the distance to a distant object, it is necessary to narrow the vertical viewing angle. Assuming that it is desirable that the target object occupies at least half of the viewing range in the height direction in order to perform distance measurement with high accuracy, if the height of the preceding vehicle traveling 30 m ahead is 1.4 m, In order to measure the inter-vehicle distance to the preceding vehicle, the vertical viewing angle is desirably 5 degrees or less. As is clear from the above, there is no optimum vertical viewing angle for any of the distance to the object, whether it is a short distance or a long distance.

The present invention has been made in view of the above problems, and is capable of reliably measuring a distance even if the distance to an object is a short distance or a long distance. It is intended to provide a device. Another object of the present invention is to provide a vehicle in which safe driving is greatly improved by using the above distance measuring device.

[0015]

SUMMARY OF THE INVENTION A distance measuring apparatus according to the present invention comprises an observation system including a pair of image forming means and a pair of light receiving means for respectively detecting a light intensity distribution of an image obtained by each image forming means. An arithmetic processing unit that calculates the distance to the object from the deviation amount of the light intensity distribution detected by each light receiving unit of the observation system. Viewing angle changing means for changing the viewing angle in the vertical direction.

In the distance measuring apparatus according to the present invention, the observation system includes a pair of image forming means and a pair of light receiving means for respectively detecting a light intensity distribution of an image obtained by each image forming means. It includes two sets of observation units, and the viewing angle changing means changes the viewing angle by arranging different types of cylindrical lenses on the optical path of each observation unit and enabling one of the observation units. It is constituted so that it may be.

In the distance measuring apparatus according to the third aspect of the present invention, the observation system includes a pair of image forming means and a pair of light receiving means for respectively detecting a light intensity distribution of an image obtained by each image forming means. The viewing angle changing means is configured to change the viewing angle by selectively disposing different types of cylindrical lenses on the optical path of the observation system.

In the distance measuring apparatus according to a fourth aspect of the present invention, the viewing angle changing means changes the viewing angle in accordance with a distance to an object in the field of view.

In the distance measuring apparatus according to a fifth aspect of the present invention, the viewing angle changing means sets a wide viewing angle if the distance to the target in the field of view is short, and if the distance is long, the viewing angle changing means sets the viewing angle. The viewing angle is set to be narrow.

In the distance measuring apparatus according to a sixth aspect of the present invention, when the measured value of the distance when the viewing angle is set wide by the viewing angle changing means is equal to or larger than the set value, Processed so as not to use the measured values.

The vehicle according to the invention of claim 7 is the vehicle according to claim 1.
The distance measuring device described in any one of the above-described items 6 to 6 is mounted indoors or outdoors.

[0022]

After the vertical viewing angle is set by the viewing angle changing means, an image of the object is formed on the pair of light receiving means by the pair of imaging means of the observation system. The light intensity distributions are respectively detected, and the arithmetic processing unit calculates the distance to the target from the shift amount of the light intensity distribution of each image.

In the distance measuring device according to the second aspect, the distance is measured by one of the two effective observation units including cylindrical lenses of different types, which is made effective.

In the distance measuring device according to the third aspect, one of the different types of cylindrical lenses is applied to the observation system to measure the distance.

In the distance measuring device according to the fourth aspect, the viewing angle is set according to the distance to the object in the field of view, so that the distance to the object is short or long. A reliable distance measurement is performed.

In the distance measuring device according to the fifth aspect, when the distance to the object is short, the viewing angle is set wide,
An image with contrast is obtained. When the distance to the object is long, the viewing angle is set to be narrow, so that the ratio of the object image other than the object occupies a small area, and an image with high contrast is obtained.

According to the distance measuring device of the present invention, by setting a wide viewing angle, even if an object other than the object located farther from the object is observed and the distance is measured, the measured value is set to the set value. Since the above is rejected, the measured value is not erroneously recognized as the distance to the object.

In the vehicle according to the seventh aspect, the distance measuring device according to any one of the first to sixth aspects is installed indoors or outdoors. The running of the vehicle is controlled while keeping the distance to the obstacle constant, and the safe driving performance is improved.

[0029]

1 and 2 show the configuration of a distance measuring apparatus according to an embodiment of the present invention. FIG. 1 is a diagram of the distance measuring device viewed from the side, and FIG. 2 is a diagram of the distance measuring device viewed from above. The distance measuring device in the illustrated example includes two sets of observing units 10P and 10P for observing the object 5 vertically.
Observation system 10 having Q, operation processing units 11P and 11Q provided for observation units 10P and 10Q for calculating distance L to object 5, and switching control unit for switching operation processing units 11P and 11Q. 9.

Each observation unit 10P, 10Q of the observation system 10
Are a pair of left and right light receiving lenses 13a, 13 as imaging means.
3b, and a pair of left and right photodetectors 14a and 14b each composed of a PD array as light receiving means.
Three mirrors 6, 7, and 8 for increasing the measurable distance are arranged in front of the light receiving lenses 13a and 13b of each of the observation units 10P and 10Q to increase the distance between the lenses.

Of the three mirrors 6, 7, 8, left and right mirrors 6, 7 reflect the light from the object 5 to the mirror 8 at the center, and mirror 8 at the center.
Reflect the light from the mirrors 6 and 7 at the left and right positions, respectively, and respectively
a, 13b.

The light receiving lenses 13a and 13b in each of the observation sections 10P and 10Q are integrally fixed to the same frame 20 at a predetermined distance so that the optical axes become parallel. Behind,
With the light receivers 14a and 14b positioned respectively,
The image of is formed. Each of the light receivers 14a and 14b is for detecting the light intensity distribution of each image, and includes a plurality of pixels 16 arranged in a horizontal row.

Each of the arithmetic processing units 11P and 11Q in each of the observation units 10P and 10Q uses the phase difference correlation method to calculate the difference between the light intensity distribution of the image detected by each of the photodetectors 14a and 14b. The distance L is calculated. Observation system 1 mentioned above
0 is provided with a viewing angle changing means 15 for changing the viewing angle in a direction perpendicular to the direction in which the light receiving lenses 13a and 13b are arranged, that is, the vertical viewing angle.

The viewing angle changing means 15 of this embodiment comprises the switching control unit 9 and cylindrical lenses 16P and 16Q provided for the observation units 10P and 10Q. Each of the cylindrical lenses 16P and 16Q is provided with a corresponding one of the observation units 10P and 10Q in order to widen the visual fields P and Q in the vertical direction.
By using the cylindrical lenses 16P and 16Q that are arranged on the optical path of Q and have different curvatures, the vertical viewing angle of one observation unit 10P (hereinafter, referred to as “first observation unit 10P”) is θ _P ( for example theta _P = 4 °), the vertical viewing angle theta _Q (e.g. theta _Q = 10 degrees) of the other observation section 10Q (hereinafter referred to as "the second observation portion 10Q"), set respectively. In the illustrated example, each of the cylindrical lenses 16P and 16Q is disposed at a position in front of the mirrors 6, 7, and 8. However, the present invention is not limited to this.
a, 13b and the photodetectors 14a, 14b.

The directions of the visual fields P and Q of the first and second observation units 10P and 10Q are different from each other by setting the positional relationship between the light receiving lenses 13a and 13b and the light receivers 14a and 14b individually. Can be set to FIGS. 3 and 4 show the directions of the visual fields P and Q of the observation units 10P and 10Q when the distance measurement device is installed at a relatively high position of the vehicle, for example, behind a room mirror. When the installation position of the distance measuring device is high, the trunk portion 31 of the forward vehicle 30
In order to measure the distance to the first distance, the first observation unit 10P for long distance measurement sets the direction of the visual field P at an angle α slightly downward (for example, α = 2 degrees) with respect to the horizontal direction, The second observation unit 10Q for measurement sets the direction of the visual field Q to a further downward angle β (for example, β = 8 degrees). When the distance measuring device is installed at a low position of the vehicle, for example, at a front grill, the fields of view P, Q of the observation units 10P, 10Q are set.
May be set substantially horizontally.

The switching control unit 9 switches the arithmetic processing units 11P and 11Q of the observation units 10P and 10Q in accordance with the distance L to the object 5 in the visual field, and the distance to the object 5 is long. If so, the first observation unit 10P is enabled to set a narrow vertical viewing angle θ _P , and if the distance to the object is short, the second observation unit 10Q is enabled to enable a wide vertical viewing angle Set to θ _Q.

If the horizontal viewing angle is 15 degrees and the width of an ordinary passenger car is about 1.8 m, the entire width of the ordinary passenger car falls within the field of view when the distance from the preceding vehicle is about 7 m. . If the entire vehicle width is always within the field of view, an image with a constant contrast can be obtained even if the vertical viewing angle is narrow. On the other hand, considering that the distance measuring device is mounted on the rear side of the rearview mirror and the direction of the visual field is inclined downward by 8 degrees, the distance to the ground that is within the visual field when there is no preceding vehicle is about 9 m.

In the above case, the observation unit 10P for the long distance and the observation unit 10Q for the short distance may be switched, for example, at a distance of 8 m from the preceding vehicle. That is, if the measured value of the distance by the second observation unit 10Q for short distance is 8 m or more, the measurement output is not adopted and the first observation unit 10P for long distance is switched. By doing so, it is possible to avoid erroneously outputting the distance to the white line or the character on the road. Similarly, if the measured value of the distance by the first observation unit 10P for the long distance is smaller than 8 m, the measurement output is not adopted, and the second observation unit 10Q for the short distance is switched. It is possible to catch the object.

FIG. 5 shows steps 1 to 9 (steps are indicated by "ST" in the figure) of the switching control procedure by the switching control section 9 based on the above principle. In ST1 of FIG. 5, the switching control unit 9 checks the output of the arithmetic processing unit 11Q of the second observation unit 10Q for short distance. If the arithmetic processing unit 11Q outputs the measured value of the distance, the determination in ST2 is “YES”, and the switching control unit 9 determines whether the output is smaller than 8 m in the next ST3. If 8
If it is smaller than m, the determination in ST3 is “YES”,
The output of the arithmetic processing unit 11Q of the second observation unit 10Q is adopted as a distance measurement value (ST4).

If the determination in ST3 is "NO" or the determination in ST2 is "NO", the switching control unit 9
Checks the output of the arithmetic processing unit 11P of the first long-distance observation unit 10P in ST5. If the processing unit 11P
Output the measured value of the distance, the determination in ST6 is “Y
ES ", the switching control unit 9 determines whether or not the return output is 8 m or more in the next ST7. If the determination in ST6 is" NO ", the switching control unit 9 outputs an error message. (ST8).

If the switching control section 9 determines in the step ST7 that the output of the arithmetic processing section 11P is 8 m or more, the determination in the step ST7 is "YES" and the first observation section 1
The output of the arithmetic processing unit 11P of 0P is adopted as the measured value of the distance (ST9), and if the determination of ST7 is "NO", S is determined.
Returning to T1, the switching control unit 9 sets the second observation unit 1 for short distance.
The output of the arithmetic processing unit 11Q of 0Q is checked.

In order to prevent chattering and the like at the time of switching by the switching control unit 9, the distance determined by ST3 is 1 m.
If it is less than 7 m, for example,
There is no problem if the observation unit 10Q is switched to the first observation unit 10P. In addition, as long as an image with contrast is obtained as a result of observation by the first observation unit 10P for long distance, the distance can be measured.
If the arithmetic processing unit 11P of the first observation unit 10P outputs a measured value of the distance, the output is adopted,
If the output is stopped, or if it is determined that an image with contrast cannot be obtained, the switching to the second observation unit 10Q for a short distance may be performed.

FIG. 6 shows a procedure of switching control by the switching control unit 9 based on the above principle. In ST1 of FIG. 6, the photodetector 14 in the first observation unit 10P for a long distance is used.
arithmetic processing unit 11P for at least one of a and 14b
Checks the image signal and determines whether an image with contrast is obtained (ST2). If an image with contrast is obtained, the determination in ST2 is “YES”, and in this case, the arithmetic processing unit 11P of the first observation unit 10P can output the measured value of the distance. The control unit 9 employs the output of the arithmetic processing unit 11P of the first observation unit 10P as a distance measurement value (ST
3).

If the determination in ST2 is "NO", ST2
3, the photodetector 14 in the second observation unit 10Q for a short distance
arithmetic processing unit 11Q for at least one of a and 14b
Checks the image signal and determines whether an image with contrast is obtained (ST5). If an image with contrast is obtained, the determination in ST5 is “YES”. In this case, the arithmetic processing unit 11Q of the second observation unit 10Q can output a measured value of the distance. It is determined whether the output is smaller than 8 m (ST7). If it is smaller than 8 m, the determination in ST7 is “YES”, and the arithmetic processing unit 1 of the second observation unit 10Q
The output of 1Q is adopted as a measured value of the distance (ST8).
If it is determined in ST5 that an image with contrast has not been obtained, the switching control unit 9 outputs an error message in ST6, and if it is determined in ST7 that the distance is 8 m or longer, the determination in ST7 is performed. Is "NO", the process returns to ST1, and the switching control unit 9 checks the image signal of at least one of the photodetectors 14a and 14b for the first observation unit 10P for long distance.

FIG. 7 shows the light intensity distribution of the object image obtained by the photodetectors 14a and 14b.
7 shows the light intensity distribution of a contrasted image, and FIG.
(2) and (3) show the light intensity distribution of an image without contrast, respectively. When the differentiation processing is performed on the contrast image shown in FIG. 7A, a differentiated waveform having an inflection point is obtained as shown in FIG.
Differentiating the image without contrast
As shown in FIG. 7 (2) '(3)', a differential waveform having no inflection point is obtained. Utilizing this, the arithmetic processing unit 11 performs processing on the image on one or both of the light receivers 14a and 14b.
Differential processing is performed at P and 11Q. If an inflection point exists, it is determined that a contrasted image has been obtained. If no inflection point exists, a contrasted image can be obtained. Judge that you have not.

In the embodiment shown in FIG. 6, the second observation unit 1
When it is determined that the output of the arithmetic processing unit 11Q of 0Q is smaller than 8 m, the output of the arithmetic processing unit 11Q of the second observation unit 10Q is adopted as the measured value of the distance (ST8).
Arithmetic processing unit 11 of first and second observation units 10P and 10Q
Of the outputs of P and 11Q, the smaller one may be used, or the average value of both may be calculated and the calculated value may be used.

FIG. 8 shows the configuration of a distance measuring device according to another embodiment of the present invention. FIG. 8 is a diagram of the distance measuring device viewed from the side. The distance measuring device in the illustrated example includes an observation system 10 for observing an object and a distance L to the object.
And a viewing angle changing means 15 for changing the vertical viewing angle of the observation system 10.

The observation system 10 includes a pair of light receiving lenses 13a and 13b as image forming means and a pair of light receivers 14a and 14b formed of a PD array as light receiving means, and is provided at a position in front of the light receiving lenses 13a and 13b. 1, a reflection optical system 40 composed of three mirrors is arranged.

Each of the light receiving lenses 13a, 13b is arranged at a predetermined distance so that the optical axes become parallel.
The light receivers 14a and 14b are located behind the light receiving lenses 13a and 13b, respectively, to form an image of the object 5. The arithmetic processing unit 11 calculates the distance to the target using the phase difference correlation method from the shift amount of the light intensity distribution of the image detected by each of the light receivers 14a and 14b.

The viewing angle changing means 15 includes a switching control unit 9.
A pair of cylindrical lenses 16P and 16Q for expanding the vertical visual field, and a cylindrical lens 16
A switching mechanism 42 for moving a frame 41 on which P and 16Q are integrally fixed up and down to position one of the cylindrical lenses in the optical path of the observation system 10. The cylindrical lenses 16P and 16Q having different curvatures are used. One of the cylindrical lenses 16P has a vertical viewing angle of, for example, 4 degrees, and the other has a vertical viewing angle of, for example, 10 degrees. .

The switching mechanism 42 includes a motor 17 as a drive source, a transmission mechanism 18 that converts the forward / reverse rotation of the motor 17 into a reciprocating linear motion and transmits the reciprocating linear motion to the frame 41. And a drive control unit 19 that controls the forward / reverse rotation of the motor 17 based on the above. The transmission mechanism 18 includes a pinion 21 mounted on a motor shaft of the motor 17 and a rack 2 mounted on the frame 41.
2 can be configured. The pinion 21 and the rack 22 are engaged with each other, and the forward / reverse rotation of the motor 17 is converted into a reciprocating linear motion by the pinion 21 and the rack 22 and transmitted to the frame 41, whereby the reflection optical system 40
Of any one of the cylindrical lenses 16P and 16
Position Q.

The transmission mechanism 18 is not limited to the configuration in which the two cylindrical lenses 16P and 16Q are reciprocated integrally as in this embodiment, and the two cylindrical lenses 16P and 16Q are individually configured as individual mechanisms. May be configured to reciprocate. The transmission mechanism 18
May be constituted by a mechanism other than the rack 22 and the pinion 21, for example, directly by a voice coil motor.
May be driven. Further, instead of moving the cylindrical lenses 16P and 16Q, a method of moving the light receiving lenses 13a and 13b may be used. In this case, the direction of the entire field of view is also changed. The light receiving lenses 13a, 13b and the light receivers 14a, 14b are directed horizontally downward when the long distance cylindrical lens 16P is used, and further downward when the short distance cylindrical lens 16Q is used. Adjust the relative positional relationship.

FIG. 9 shows an embodiment in which a galvanomirror 50 is used as the switching mechanism 42. In the example shown,
The galvanomirror 50 is disposed between the long and short distance cylindrical lenses 16P and 16Q and the optical system 40. By changing the inclination of the galvanomirror 50, One of the cylindrical lenses 16P and 16Q is positioned on the optical path.
According to the configuration of this embodiment, the depth of the distance measuring device can be reduced and the thickness can be reduced. Therefore, when the distance measuring device is mounted on the rear side of the rearview mirror, the mounting becomes easy and the appearance is not impaired.

The distance measuring apparatus according to the present invention is suitable for use in realizing safe driving of vehicles such as automobiles.
Of course, it can be used for other purposes. FIG. 10 shows a vehicle 60 equipped with the distance measuring device of the present invention. In the vehicle 60 in the illustrated example, the distance measuring device is attached to the back of the room mirror.
Alternatively, it may be mounted on the upper surface of the dashboard, or may be mounted on a bumper or front grill if it is outdoors. As described above, the distance measuring device is attached to the front of the vehicle to monitor the front of the vehicle. If it is attached to the rear or side of the vehicle, the rear or side of the vehicle can be monitored.

FIG. 11 shows the driver's seat in the passenger compartment.
On the instrument panel 61 on the front of the driver's seat, in addition to the speedometer 62 and the tachometer 63, a distance indicator 64 for displaying the distance to a detected object such as a preceding vehicle is arranged. Since the distance indicator 64 displays the distance to the detected object in front in real time, the driver can maintain a safe inter-vehicle distance without relying on intuition, and can reduce illusions and driving fatigue. It is possible to prevent the occurrence of an accident due to an excessively short inter-vehicle distance.

The distance measuring apparatus according to the present invention can be used not only for the inter-vehicle distance display system shown in FIGS. 10 and 11, but also for use in a rear-end collision prevention system. FIG. 12 shows a vehicle 65 equipped with a rear-end collision prevention system, and FIG. 13 shows a configuration example of the rear-end collision prevention system. In the vehicle 65 of FIG. 12, a distance measuring device 66 is attached to the back of a room mirror in the room, and a field of view is set on the ground in front of the vehicle 65. Although not shown, an alarm device such as an alarm buzzer for notifying a danger is provided at an appropriate position in the driver's seat.

As shown in FIG. 13, in this rear-end collision prevention system, a distance measurement device 66, a speed sensor 68, an alarm 69, and a brake 70 Are connected respectively. The control unit 67 reports the distance between the vehicle and the preceding vehicle from the distance measuring device 66 and the own vehicle 6 from the speed sensor 68.
5 are input, and the control unit 67
Determines the degree of danger based on the inter-vehicle distance and the traveling speed, and if it is determined to be dangerous, activates the alarm 69 to notify the driver, and forcibly operates the brake 70 to cause the danger. Work around.

FIG. 14 shows a danger determining method by the control unit 67. In the figure, the horizontal axis represents the traveling speed of the vehicle 65 monitored by the speed sensor 68, and the vertical axis represents the inter-vehicle distance to the preceding vehicle monitored by the distance measuring device 66. In FIG. 14, C1 indicates an allowable area, C2 indicates a low-risk area, and C3 indicates a high-risk area. The boundaries of these areas are determined as a function of the traveling speed of the vehicle 65 and the distance between the host vehicle and the preceding vehicle. The rear-end collision prevention system does not operate in the allowable area C1, but when the vehicle enters the low-risk area C2, the alarm 69 first operates to notify the driver of danger. Further, when the vehicle enters the high-risk area C3, the brake 70 is automatically operated to forcibly decelerate or stop the vehicle 65.
Therefore, it is possible to prevent a rear-end collision accident due to the driver's carelessness or falling asleep.

FIG. 15 shows the flow of control by the control section 67. In the figure, each step is indicated by ST. When the distance between the vehicle and the preceding vehicle is measured by the distance measuring device 66 in ST1 of FIG. 5, the control unit 67 calculates the measured distance between the vehicles and the traveling speed of the own vehicle 65 detected by the speed sensor 68. Take in and judge the degree of danger,
It is determined in which area in FIG. 14 the vehicle 65 is located (S
T2). First, in ST3, it is determined whether or not the vehicle 65 is in danger based on whether or not the vehicle is in the allowable area C1, and if it is in the allowable area C1, the determination of "is dangerous" in ST3 is "NO". The control unit 67 continues to monitor the degree of danger. If the vehicle 65 is not in the allowable area C1, the determination of "is dangerous" in ST3 is "YES", and in the next ST4, the vehicle is in the low-risk area C2 or in the high-risk area C3. Judge. If it is within the low-risk area C2, the determination in ST4 is "YES", and the control section 67 activates the alarm 69 (ST5). If it is in the high-risk area C3, the determination in ST4 is “NO”, and the control unit 67 operates the brake 70 (ST4).
6).

In the above rear-end collision prevention system, the danger area is set to the low-level danger area C2 for operating the alarm 69.
And a high danger area 70 for operating the brake 70
The high-risk area 70 is further divided into two parts. In the lower-risk area, the brake 70 is weakly actuated to decelerate the vehicle 65, and in the higher-risk area, the brake is reduced. The vehicle 65 may be suddenly stopped by strongly operating 70.

The distance measuring apparatus of the present invention can be used in a vehicle visibility assist system shown in FIGS. 16 to 19 in addition to the above-described rear-end collision prevention system. This view assist system is for assisting the view at the time of lane change or back parking. FIG. 16 shows a vehicle 71 equipped with the view assist system, and FIG. 17 shows a configuration of the view assist system. , Respectively. The vehicle 71 shown in FIG. 16 includes left and right side mirrors 72, 72 and a bumper 73 at the rear of the vehicle.
A distance measuring device 66 is attached to each of the left and right sides of the vehicle 71 to set the field of view behind the vehicle 71 and the rear of both sides.

As shown in FIG. 17, this view assisting system includes a plurality of distance measuring devices 66, speed sensors 68, and alarms 69 as input / output devices in a view assisting control unit 74 which is a control main body. Are connected respectively. The distance from the distance measuring device 66 to the object to be detected behind, the traveling speed of the own vehicle 71 from the speed sensor 68, and the back lamp control signal and the turn signal Control signal is input. The control unit 74 determines the degree of danger at the time of lane change or back parking based on these inputs, and if determined to be dangerous, activates the alarm 69 to notify the driver.

FIG. 18 shows the flow of control by the control unit 74 when changing lanes. In ST1 of FIG.
The control unit 74 is on standby for transmission of the turn signal control signal. If the driver blinks either the left or right turn signal to change lanes, the control unit 74 takes in the turn signal control signal to the control unit 74, and returns to ST1. The determination is “YES”, and the control unit 74 determines whether the distance measuring device 6
6 and the speed sensor 68 are activated (ST2). When the distance to the vehicle behind is measured by the distance measuring device 66, the control unit 74 determines the risk of the lane change by taking in the measured distance and the traveling speed of the own vehicle detected by the speed sensor 68. (ST3). The risk of lane change is a function of the distance to the detected object and the traveling speed of the host vehicle. As a result, when the controller 74 determines that there is no danger, the determination in ST4 is “NO”, and the controller 74 continues to monitor the degree of danger. If the controller 74 determines that there is danger, the determination in ST4 is "YES", and the controller 74 activates the alarm 69 to notify the driver of danger (ST5). The driver waits without changing lanes until the alarm stops, thereby preventing an accident due to changing lanes. Note that a display may be provided instead of the alarm 69 to visually alert the danger of changing lanes.

FIG. 19 shows the flow of control by the control unit 74 during back parking. In ST1 of the figure, the control unit 74 is on standby for transmission of a back lamp control signal, and if the driver performs a driving operation to reverse the vehicle and the back lamp blinks, the control unit 74 outputs the back lamp control signal. The control unit 74 takes in the data, and the determination in ST1 is “YES”, and the control unit 74 activates the distance measuring device 66 and the speed sensor 68 at the rear of the vehicle (ST2). When the distance measuring device 66 measures the distance to the detected object behind (for example, a parked vehicle, a wall, a person, or the like), the control unit 74 determines the measured distance and the own vehicle detected by the speed sensor 68. The traveling speed of the vehicle is taken into account to determine the risk of back parking (ST3). The risk of back parking is a function of the distance to the detected object and the traveling speed of the host vehicle. As a result, when the controller 74 determines that there is no danger, the determination in ST4 is “NO”, and the controller 74 continues to monitor the degree of danger. If the controller 74 determines that there is danger, the determination in ST4 is “YES”, and
The control unit 74 activates the alarm 69 to notify the driver of danger (ST5). As a result, the driver can immediately perform the brake operation to stop the backward movement of the vehicle, and can prevent a rear-end collision with an obstacle or a person. It should be noted that the alarm may be issued not only to the inside of the vehicle but also to the outside of the vehicle.

FIG. 20 shows an example of the configuration of an automatic vehicle follow-up control system using the distance measuring device of the present invention. This automatic following control system is for semi-automatically following the own vehicle to the preceding vehicle while maintaining a substantially constant inter-vehicle distance from the preceding vehicle.
In addition, as input / output devices, a distance measuring device 66, a speed sensor 68, an accelerator control unit 76, and a brake control unit 77
Is connected. The distance measuring device 66 is attached, for example, to the back of a room mirror, and has a visual field set forward. The control unit 75 includes a distance measuring device 66
From the vehicle, and the traveling speed of the own vehicle from the speed sensor 68, respectively. The control unit 75 controls the accelerator control unit 76 and the brake in accordance with the inter-vehicle distance and the traveling speed. The operation of the control unit 77 is controlled.

FIG. 21 shows a judgment method for the automatic following by the control unit 75. In the figure, the horizontal axis is the traveling speed of the own vehicle monitored by the speed sensor 68, and the vertical axis is the inter-vehicle distance to the preceding vehicle monitored by the distance measuring device 66. In FIG. 21, X is an ideal curve indicating the relationship between the inter-vehicle distance to the preceding vehicle and the running speed of the host vehicle in the case of performing automatic following, and the ideal area E1 is set along the ideal curve X. The ideal region E1 is a region where the inter-vehicle distance is wider or narrower than an ideal inter-vehicle distance, and is allowed. In the ideal region E1, the vehicle is left to the driver. Of the areas inside and outside the ideal area E1, E2 is an area in which the inter-vehicle distance with the preceding vehicle is too wide, and the excessively wide adjustment is required. On the other hand, E3 is an area in which the inter-vehicle distance with the preceding vehicle is too small, and it is necessary to adjust the excessively small distance. The control unit 75 captures the inter-vehicle distance to the preceding vehicle from the distance measuring device 66 and the traveling speed of the own vehicle from the speed sensor 68, and determines in which region in FIG. 21 the own vehicle is located. If it is out of the ideal region E1,
The operation of the accelerator control unit 76 and the brake control unit 77 is controlled so that the vehicle follows the vehicle while maintaining a safe and optimal inter-vehicle distance.

FIG. 22 shows a flow of control for automatic following by the control section 75. When the distance between the vehicle and the vehicle in front is measured by the distance measuring device 66 in ST1 of the figure, the control unit 75 determines the measured distance between the vehicle and the speed sensor 6
Then, the state of the host vehicle with respect to the preceding vehicle is compared with the ideal state to determine the running speed of the host vehicle detected by step 8 (ST2, 3). When the control unit 75 determines that the vehicle is in the ideal state, that is, in the ideal area E1,
The determination in ST3 is “YES”, and the control unit 75 leaves the driving of the vehicle to the driver without outputting a control signal to the accelerator control unit 76 or the brake control unit 77, and continuously changes the state of the own vehicle with respect to the preceding vehicle. Keep monitoring. When the control unit 75 determines that the host vehicle is not in the ideal state, ST3
Is "NO", and then the control unit 75 determines which of the areas E2 and E3 in FIG. 21 includes the state of the own vehicle (ST4). If the state of the own vehicle is in the area E
2, the inter-vehicle distance with the preceding vehicle is too wide, and it is necessary to adjust the excessively wide distance.
Outputs a control signal to the accelerator control unit 76 to increase the accelerator opening and shorten the inter-vehicle distance with the preceding vehicle (ST5).
If the state of the own vehicle is included in the area E3, the inter-vehicle distance with the preceding vehicle is too small, and it is necessary to adjust the too small distance.
To increase the inter-vehicle distance with the preceding vehicle by outputting a control signal to reduce the accelerator opening or outputting a control signal to the brake control unit 77 to perform a braking operation (ST6).

FIG. 23 shows an example of the configuration of a vehicle driving support system in a traffic jam using the distance measuring apparatus of the present invention. In a traffic jam, the driver cannot predict when the preceding vehicle will start, so it is necessary to constantly pay attention to the preceding vehicle and immediately start the own vehicle as soon as the preceding vehicle starts to close the gap. For this reason, during traffic congestion, the driver's nerves become extremely tired, causing annoyance. This driving support system is intended to ease the driver's nerves during a traffic jam. The driving support control unit 78, which is the main control unit, has a distance measuring device 66, a speed sensor 68, and an input / output device. An alarm 69 is connected. The distance measuring device 66 is attached, for example, to the back of a room mirror, and has a field of view set forward. The control unit 78 receives the inter-vehicle distance from the preceding vehicle from the distance measuring device 66 and the traveling speed of the own vehicle from the speed sensor 68, respectively. If the distance between vehicles is more than a certain distance when is zero,
The alarm 69 is operated to notify the driver.

FIG. 24 shows the flow of control for driving support by the control unit 78. In ST1 of the figure, the control unit 78 takes in the traveling speed of the own vehicle detected by the speed sensor 68, and determines whether or not it is zero.
That is, it is determined whether the own vehicle is stopped. If the traveling speed of the own vehicle is not zero, the determination in ST1 is "N
O ", and the driving support system is not activated.
If the traveling speed of the own vehicle is zero, the control unit 78
Determines that the vehicle is stopped due to traffic congestion,
Captures the inter-vehicle distance with the preceding vehicle measured by the distance measuring device 66, and determines whether the inter-vehicle distance is equal to or greater than a predetermined value determined in consideration of an appropriate inter-vehicle distance during traffic congestion (ST2, 3). . If the inter-vehicle distance is smaller than the predetermined value, the determination in ST3 is "NO", and the running speed and the inter-vehicle distance to the preceding vehicle are continuously monitored. If the inter-vehicle distance is equal to or more than the predetermined value, the determination in ST3 is “YES”, and the control unit 78 activates the alarm 69 to urge the driver to reduce the inter-vehicle distance. As a result, the driver does not need to constantly pay attention to the start of the vehicle ahead, and it is possible to prevent the driver from being irritated during a traffic jam.

[0070]

According to the present invention, as described above, the observation system is provided with the viewing angle changing means for changing the viewing angle in the vertical direction. Therefore, even if the distance to the object is short, the distance is long. Even so, an optimal viewing angle can be set for distance measurement, and the distance to the object can be reliably measured.

According to the second aspect of the invention, the viewing angle can be easily changed only by making one of the two observation units effective, so that the number of types of parts is not increased. The viewing angle can be easily switched. In addition, since a simple part such as a cylindrical lens is used for changing the viewing angle, the configuration of the distance measuring device can be simplified.

According to the third aspect of the present invention, the viewing angle can be easily changed only by selectively using different types of cylindrical lenses for the observation system, so that a small distance measuring device can be realized.

According to the fourth and fifth aspects of the present invention, the viewing angle is changed depending on whether the distance to the object is a short distance or a long distance. Distance measurements are possible.

According to the sixth aspect of the present invention, even if an object other than the object enters the field of view, the measured value of the distance equal to or larger than the set value is not adopted by widening the viewing angle for the short distance measurement. Therefore, erroneous recognition can be prevented.

According to the seventh aspect of the present invention, since the distance measuring device according to any one of the first to sixth aspects is mounted inside or outside the vehicle, the distance between the surrounding vehicle and obstacles is kept constant. Driving can be controlled and safe driving performance can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of a distance measuring device according to the present invention as viewed from a side.

FIG. 2 is an explanatory diagram showing the configuration of the embodiment of FIG. 1 as viewed from above.

FIG. 3 is an explanatory diagram showing a direction of a visual field of a distance measuring device.

FIG. 4 is an explanatory diagram showing a direction of a visual field of a visual field measuring device.

FIG. 5 is a flowchart illustrating a procedure of switching control by a switching control unit.

FIG. 6 is a flowchart showing a procedure of another method of switching control.

FIG. 7 is an explanatory diagram showing a light intensity distribution of an object image.

FIG. 8 is an explanatory diagram showing the configuration of another embodiment of the distance measuring device as viewed from the side.

FIG. 9 is an explanatory diagram showing a configuration of an embodiment in which another switching mechanism is used, as viewed from a side.

FIG. 10 is a side view showing a vehicle equipped with the distance measuring device.

FIG. 11 is a front view of an instrument panel in a driver's seat.

FIG. 12 is a side view showing a vehicle equipped with the rear-end collision prevention system.

FIG. 13 is a block diagram illustrating a configuration example of a rear-end collision prevention system.

FIG. 14 is an explanatory diagram showing a danger determination method.

FIG. 15 is a flowchart showing a flow of control by the control unit.

FIG. 16 is a plan view of a vehicle equipped with the view assist system.

FIG. 17 is a block diagram illustrating a configuration example of a view assisting system.

FIG. 18 is a flowchart showing a flow of control by the control unit when changing lanes.

FIG. 19 is a flowchart showing a flow of control by the control unit at the time of back parking.

FIG. 20 is a block diagram illustrating a configuration example of a vehicle automatic tracking control system using a distance measuring device.

FIG. 21 is an explanatory diagram showing a determination method for automatic tracking by the control unit.

FIG. 22 is a flowchart showing a flow of control for automatic tracking by the control unit.

FIG. 23 is a block diagram illustrating a configuration example of a driving support system for a vehicle using the distance measuring device.

FIG. 24 is a flowchart showing a flow of control for driving support by the control unit.

FIG. 25 is an explanatory diagram showing a configuration of a conventional distance measuring device.

FIG. 26 is an explanatory diagram showing the principle of distance measurement.

[Explanation of symbols]

 Reference Signs List 10 Observation system 11 Arithmetic processing unit 13a, 13b Light receiving lens 14a, 14b Light receiver 15 Viewing angle changing means 16a, 16b Cylindrical lens 66 Distance measuring device

Claims (7)

[Claims] 1. An observation system including a pair of image forming means, a pair of light receiving means for respectively detecting a light intensity distribution of an image obtained by each image forming means, and detection is performed by each light receiving means of the observation system. An arithmetic processing unit for calculating a distance from the light intensity distribution to a target object from the shift amount of the light intensity distribution, wherein the observation system changes a viewing angle in a direction perpendicular to a direction in which light receiving means are arranged. Angle measuring device provided with a viewing angle changing means for the user. 2. The observation system includes two observation units each including a pair of imaging units and a pair of light receiving units that respectively detect a light intensity distribution of an image obtained by each of the imaging units. The viewing angle changing means is configured to change the viewing angle by arranging different types of cylindrical lenses on the optical path of each observation unit and activating one of the observation units. The distance measuring device described. 3. The observation system includes: a pair of imaging units; and a pair of light receiving units for respectively detecting a light intensity distribution of an image obtained by each of the imaging units. 2. The distance measuring apparatus according to claim 1, wherein a viewing angle is changed by selectively disposing different types of cylindrical lenses on an optical path of the system. 4. The view angle changing means changes the view angle according to a distance to an object in a view.
A distance measuring device according to any one of the above. 5. The view angle changing means sets a wide view angle if the distance to the object in the view is short, and sets a narrow view angle if the distance is long. 4. The distance measuring device according to 4. 6. The arithmetic processing unit performs processing so as not to use the measured value when a measured value of the distance when the viewing angle is set wide by the viewing angle changing unit is equal to or larger than a set value. The distance measuring device according to claim 1. 7. A vehicle comprising the distance measuring device according to claim 1 mounted indoors or outdoors.