JPH1089954A - Distance-measuring apparatus and vehicle using the apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a distance-measuring apparatus by which a distance can be measured surely even when a distance up to an object is a short distance or a long distance. SOLUTION: A distance-measuring apparatus is composed of an observation system 10 and of a computing and processing part 11. The observation system 10 comprises three mirros 12a, 12b, 12c and one pair of light-receiving lenses 13a, 13b as image formation means, and it comprises one pair of photodetectors 14a, 14b. A visual-field-angle change mechanism 15 which is used to change a visual-field angle used to prescribe the visual-field range of the observation system 10 is installed at the observation system 10. When the visual-field-angle change mechanism 15 is operated, the light-receiving lenses 13a, 13b are moved, and the distance between the respective photodetectors 14a, 14b is changed, thereby changing the visual-field angle.

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 the 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. 28 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 is disposed at a predetermined distance D so that the optical axes are parallel. A PD array is used for each of the light receivers 2a and 2b, and a plurality of pixels 4 are arranged in a horizontal 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 target 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 the object.

FIG. 29 is a diagram for explaining the principle of distance measurement.
Now, the shift 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 respective light receiving lenses 1a and 1b. Assuming that the distance between them is D, the distance L to the object 5 is obtained by the following equation.

[0006]

(Equation 1)

Further, assuming that 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 defining the field of view C are given by the following equations. Given by

[0008]

(Equation 2)

[0009]

(Equation 3)

[0010]

When an object 5 exists in the visual field range C, a contrast image is formed on each of the light receivers 2a and 2b in order to measure the distance L to the object 5. However, when the distance to the object 5 is short, an image with contrast cannot be obtained at a small viewing angle θ, and it is difficult to measure the distance.

Particularly, when measuring the distance between the vehicle and the preceding vehicle,
With respect to a vehicle type having a large trunk portion, an image of the vehicle having a contrast cannot be obtained at a small viewing angle θ, and it is difficult to measure a distance at a short distance. For example, when the vehicle in front is an ordinary passenger car and the distance between the vehicles is 2-3 m, it is necessary to set 30 to 30 to completely include the vehicle width of the vehicle within the visual field range C.
A viewing angle θ of about 40 degrees is required.

On the other hand, when the distance to the vehicle ahead is a long distance,
At a large viewing angle θ, objects other than the vehicle in front, specifically, guide rails, pedestrians on the sidewalks, buildings on the side of the road, etc. also enter the viewing range 3, making it difficult to identify and recognize the vehicle in front. is there. For example, when the inter-vehicle distance is 20 to 30 m,
In order to completely include a road having a road lane width of 3.5 m in the viewing range C over the entire width, the viewing angle θ is about 7 to 10 degrees.
is necessary.

[0013] When the vehicle follows the vehicle while maintaining a constant inter-vehicle distance with the preceding vehicle, when the traveling speed of the own vehicle is high, it is considered that the inter-vehicle distance is appropriate and the driver's attention is moderately high. Although it is not necessary to have such a wide view range C, when the traveling speed of the own vehicle is slow, it is considered that there is congestion with a short inter-vehicle distance, and the driver's attention tends to be distracted. C is required.

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 The present invention provides 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. And a calculation processing unit that calculates the distance to the object from the deviation amount of the light intensity distribution detected by each light receiving unit, wherein the observation system has a visual field range in which distance can be measured. A viewing angle changing means for changing the determined viewing angle is provided.

In the distance measuring apparatus according to the second aspect of the present invention,
As the view angle changing means, means for changing the view angle by changing the position of each image forming means with respect to each light receiving means is used.

In the distance measuring apparatus according to the third aspect of the present invention,
The viewing angle changing means changes the viewing angle according to a distance to an object existing in the viewing range.

In the distance measuring apparatus according to the invention of claim 4,
The viewing angle changing means changes the viewing angle according to the contrast of an image obtained by one or both of the imaging means.

In the distance measuring apparatus according to the invention of claim 5,
The viewing angle changing means changes the viewing angle depending on whether a plurality of objects exist in the viewing range.

In the distance measuring apparatus according to the invention of claim 6,
The viewing angle changing means has a setting section for manually setting a viewing range, and changes the viewing angle so as to obtain the viewing range set by the setting section.

In the distance measuring device according to the invention of claim 7,
The viewing angle changing means changes the viewing angle to one of a plurality of viewing angles set in advance in a stepwise manner.

In the distance measuring apparatus according to the invention of claim 8,
The observation system changes the position of each imaging unit with respect to each light receiving unit so that the product of the distance between each imaging unit with respect to each light receiving unit and the distance between the imaging units is constant. And a distance changing means for changing the distance between the imaging means.

According to a ninth aspect of the present invention, there is provided a vehicle equipped with the distance measuring device according to any one of the first to eighth aspects and a speed detecting device for detecting a traveling speed of the own vehicle. The observation system of the measuring device is provided with a viewing angle changing means for changing the viewing angle in accordance with the traveling speed of the vehicle detected by the speed detecting device.

[0024]

The viewing angle is set by the viewing angle changing means so that the object enters the viewing range in which the distance can be measured.
An image of the object is formed on a pair of light receiving means by a pair of image forming means of the observation system. When each light receiving unit detects the light intensity distribution of each image, 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, when the viewing angle changing means changes the position of each imaging means with respect to each light receiving means, the distance between the light receiving means and the imaging means changes, and the viewing angle changes.

In the distance measuring apparatus according to the third aspect, for example, when the distance to the object is short, the viewing angle increases, and when the distance to the object is long, the viewing angle decreases.

In the distance measuring apparatus according to the fourth aspect, for example, if the contrast of the image of the object is not obtained, the viewing angle is changed to a large one.

In the distance measuring apparatus according to the fifth aspect, when a plurality of objects exist in the visual field range, the visual field is changed to a small visual angle,
Make sure that only the target object is within the field of view.

In the distance measuring apparatus according to the sixth aspect, when the setting section is manually operated, the viewing angle changes.

In the distance measuring device according to the seventh aspect, the viewing angle is set stepwise to any one of the plurality of viewing angles.

In the distance measuring device according to the present invention, the product of the distance between each image forming means and the distance between the image forming means with respect to each light receiving means is always constant. Can calculate the distance using the same parameters.

In the vehicle according to the ninth aspect, for example, the viewing angle decreases when the running speed is high, and the viewing angle increases when the running speed is low.

[0033]

FIG. 1 shows the configuration of a distance measuring apparatus according to an embodiment of the present invention. FIG. 1 is a view of the distance measuring device in a plan view. The distance measuring device in the illustrated example includes an observation system 10 for observing the target 5 and a target 5.
And an arithmetic processing unit 11 for calculating a distance L to the distance.

The observation system 10 includes three mirrors 12a, 12b, 12c and a pair of light receiving lenses 1 as imaging means.
3a and 13b, and a pair of photodetectors 14a and 14b composed of a PD array as light receiving means. Further, the observation system 10 is provided with a viewing angle changing mechanism 15 for changing a viewing angle that defines a viewing range of the observation system 10.

The three mirrors 12a, 12b, 12
c is provided to increase the measurement distance. The mirrors 12a and 12b at the left and right positions reflect light from the object 5 and guide it to the mirror 12c at the center, and the mirror 12c at the center is The light from the mirrors 12a and 12b at the left and right positions is reflected respectively to receive the left and right light receiving lenses 13a and
Lead to 13b. Each of the light receiving lenses 13a and 13b is separated from the same frame 2 by a predetermined distance so that the optical axis becomes parallel.
0, and is fixed integrally to each of the light receiving lenses 13a, 13a.
Behind b, the light receivers 14a and 14b are respectively positioned to form an image of the object 5. Each light receiver 14a, 1
4b is for detecting the light intensity distribution of each image, and a plurality of pixels 16 are arranged in a horizontal row.

The arithmetic processing unit 11 includes the respective light receivers 14a,
The distance L to the object 5 is calculated from the shift amount of the light intensity distribution of the image detected in 14b by using the phase difference correlation method.

The viewing angle changing mechanism 15 includes a light receiver 14.
The positions of the light receiving lenses 13a, 13b with respect to the light receiving lenses 14a, 14b and the light receiving lenses 13a, 13a, 1b are changed.
The viewing angle θ is changed by changing the distance F between the lens 3b. In this embodiment, a motor 17 as a driving source is used.
And a transmission mechanism 18 for converting the forward / reverse rotation of the motor 17 into a reciprocating linear motion and transmitting the reciprocal linear movement to the frame 20, and a control unit 19 for controlling the forward / reverse rotation of the motor 17 to constitute a viewing angle changing mechanism 15. You.

The transmission mechanism 18 is, as shown in FIG.
Pinion 21 mounted on the motor shaft of the motor 17
And a rack 22 mounted on the frame 20. The pinion 21 and the rack 22 are engaged with each other, and the forward and reverse rotation of the motor 17 is
And the rack 22 is converted into a reciprocating linear motion to
0, thereby changing the distance F between the light receivers 14a, 14b and the light receiving lenses 13a, 13b.

An aperture stop 23 for increasing the depth of focus is provided at a position behind each of the light receiving lenses 13a and 13b.
Even if the positions of the light receiving lenses 13a and 13b are changed, the images on the light receivers 14a and 14b are not blurred. The aperture stop 23 may be placed in front of each of the light receiving lenses 13a, 13b.
3b may be placed at both the front position and the rear position.

The transmission mechanism 18 is not limited to the structure in which the two light receiving lenses 13a and 13b are reciprocated integrally as in this embodiment, but the two light receiving lenses 13a and 1b.
3b may be reciprocated by the same distance by an individual mechanism. Further, the transmission mechanism 18 may be configured by a mechanism other than the rack 22 and the pinion 21, and the frame 20 may be directly driven by, for example, a voice coil motor.

FIGS. 3A and 3B show the viewing angle changing mechanism 15.
Shows an example of changing the viewing angle θ by the following method. FIG. 3A shows a state in which the viewing angle θ is reduced by moving the light receiving lenses 13a and 13b away from the light receivers 14a and 14b by the viewing angle changing mechanism 15 and increasing the distance F between the two. FIG.
(2) the light receiving lens 13 by the viewing angle changing mechanism 15
This shows a state in which the viewing angle θ is widened by setting the distance F between the light receiving devices 14a and 14b close to the light receiving devices 14a and 14b and setting the distance F between them small.

FIGS. 4 and 5 show a state where the vehicle 30 ahead of the vehicle equipped with the distance measuring device of the present invention is observed. FIG. 4 shows a case where the preceding vehicle 30 is at a short distance, and FIG. 5 shows a case where the preceding vehicle 30 is at a long distance. The vehicle 30 at a short distance in FIG. 4, when narrowing the viewing angle θ is set to a narrow field of view C _1, can not be obtained an image with a contrast, the distance measurement of it is difficult, the viewing angle θ When spread setting a wide field of view C _2, the obtained image with a contrast, distance measurements can be performed.

On the other hand, with respect to the vehicle 30 in the long distance in FIG. 5, when the viewing angle is widened θ set the wide field of view C _2,
Vehicle 31 other than the target vehicle 30 and surrounding buildings 32
Is within the visual field range C ₂ , it is difficult to specify the target vehicle 30 and measure the distance, but the visual angle θ
If you set the narrow field of view C ₁ narrowed, it is possible to capture reliably only vehicle 30 of interest to the field of view C _1, distance measurement is possible.

When the viewing angle θ is changed in accordance with the inter-vehicle distance from the preceding vehicle 30 as described above, the distance between the light receiving lenses 13a and 13b is initially set to a predetermined standard position when the operation of the distance measuring device is started. Measurement is performed, and the viewing angle changing mechanism 15 is driven in accordance with the measurement result to drive each of the light receiving lenses 13a, 13a.
3b may be moved. The viewing angle θ may be changed by moving the light receiving lenses 13a and 13b by a continuous amount in accordance with the measured distance. However, a plurality of viewing angles θ ₁ , θ ₂ and θ ₃ (where θ ₁ > θ _2> θ ₃₎ may be set stepwise, one of the light receiving lens 13a to a position where the viewing angle theta ₁ through? ₃ obtained according to the distance measured,
13b may be moved. For example, if the inter-vehicle distance to the vehicle ahead is 10 m or less, the widest viewing angle θ
Set to ₁ and if it is 20 m or more, the narrowest viewing angle θ ₃
, And if it is 10 to 20 m, an intermediate standard viewing angle θ ₂ is set.

FIG. 6 (1) shows the light intensity distribution of a contrasted image, and FIGS. 6 (2) and (3) show the light intensity distribution of a non-contrast image. When the differentiation processing is performed on the image having the contrast in FIG.
As shown in (1) ′, a differentiated waveform having an inflection point is obtained. However, when the differential processing is performed on the image without contrast shown in FIGS. 6 (2) and (3), FIG. 6 (2) ′ (3) ′ As shown in (1), a differentiated waveform having no inflection point is obtained. Using this,
Differential processing is performed on the image on one or both of the light receivers 14a and 14b by the arithmetic processing unit 11, and if there is no inflection point, the arithmetic processing unit 11 determines that the image has no contrast. Viewing angle changing mechanism 15
Of the light receiving lenses 13a and 13b in a direction in which the viewing angle θ increases, thereby expanding the viewing range.

FIG. 7 shows a light intensity distribution when a plurality of objects enter the visual field range. When such a light intensity distribution is obtained, the arithmetic processing unit 11 sets a plurality of distance data d1, d
2, d3. Using this, the arithmetic processing unit 11
When a plurality of distance data is generated in
Determines that there are multiple objects in the field of view,
A drive command is given to the control unit 19 of the viewing angle changing mechanism 15, and the light receiving lenses 13a and 13b are moved in a direction in which the viewing angle θ decreases.
To reduce the field of view.

FIG. 8 shows a configuration of an embodiment in which the viewing angle θ is controlled to be changed according to the traveling speed of the host vehicle. In this embodiment, the vehicle is equipped with a speed sensor 25,
The speed data detected by the speed sensor 25 is provided to the control unit 19 of the viewing angle conversion mechanism 15. When the running speed of the own vehicle is high, the inter-vehicle distance is appropriately present and the driver's attention is moderately high, so that a wide view range is not required.However, when the running speed of the own vehicle is low, the At the time of congested traffic, the driver's attention tends to be distracted, and a considerably wide field of view is required. The viewing angle conversion mechanism 15 changes the viewing angle θ in accordance with the traveling speed of the host vehicle.
Each of the light receiving lenses 13a and 13b is moved to change the field of view so that the viewing angle θ becomes small, and if the traveling speed is low, the field of view θ becomes large.

In the above embodiment, the viewing angle θ is automatically changed by the viewing angle changing mechanism 15. However, if it is configured as shown in FIG. 9, the viewing angle changing mechanism 15 is manually operated by the driver. The viewing angle θ can be changed by driving at any time. In FIG. 9, a viewing angle manual setting device 26 includes a setting switch 27, a viewing angle input unit 28, and a storage unit 29. The setting switch 27 is set to a desired viewing angle θ by manual operation of the driver.
In this embodiment, a changeover switch for switching the viewing angle θ between three stages of “narrow”, “normal” and “wide” is used. The viewing angle input unit 28 has a configuration such as a numeric keypad for inputting the desired three-stage viewing angle θ, and the input viewing angle θ is stored in the storage unit 29.

The driver sets the desired viewing angle θ by operating the setting switch 27 according to his or her physical condition and the surrounding environment. For example, when the driver is unwell and distracted,
Set the viewing angle θ to “wide”. In addition, when it is desired to reliably catch a vehicle ahead in an urban area where the surrounding environment is complicated, the viewing angle θ is set to “narrow”. Further, when a person or a bicycle is likely to fly out in a residential area or the like, the viewing angle θ is switched to “wide”. The change of the viewing angle θ is not limited to the multi-stage switching method as in this embodiment, but can be performed in an analog manner by using a volume or the like as the setting switch 27.

The light receiving lenses 13a, 13a
When the distance F between the light receiving devices 14a and 14b is set to a plurality of levels (for example, 3 to 5 levels), the viewing angle changing mechanism 15
The control unit 19 sends a signal indicating which stage the distance is set to the arithmetic processing unit 11, and the arithmetic processing unit 11 calculates the distance L to the object by the above equation (1).
Is calculated. In this case, the controller 19 of the viewing angle changing mechanism 15 controls the light receiving lenses 13a and 13b and the light receivers 14a and 14a.
If the measured value of the distance F to b is sent to the arithmetic processing unit 11, the arithmetic processing unit 11 can calculate the distance L to the object with high accuracy.

FIGS. 10 and 11 show the light receiving lens 13.
An embodiment in which the distance calculation is performed from the measured value of the distance F between the light receiving devices 14a and 14b and the light receiving devices 14a and 14b will be described. FIG.
Are light receiving lenses 13a and 13b and light receiving devices 14a and 14b
FIG. 11 shows an embodiment provided with a distance detection mechanism 45 for obtaining an absolute distance between the light receiving lenses 13a and 13b and the light receivers 14a and 14b. It is an example.

In the embodiment shown in FIG. 10, a rotary encoder is used as the change amount detecting mechanism 40. A slit disk 41 is mounted on the motor shaft of the motor 17, and the optical sensor is arranged so as to sandwich the slit disk 41 in the middle. 42 are arranged. Note that, as the change amount detection mechanism 40, a linear encoder may be used instead of the rotary encoder. In the embodiment of FIG. 11, a light emitting element 46 such as an LED is provided on the frame 20 and a position detecting element 47 such as a PSD is mounted on a fixed frame (not shown).
Are provided so as to face the light emitting element 46, thereby constituting the distance detecting mechanism 45.

FIG. 12 shows the configuration of an embodiment for simplifying the distance calculation by the arithmetic processing unit 11. In this embodiment, a distance changing mechanism 50 is provided in the observation system 10, and one mirror 12a is formed so as to be able to reciprocate with respect to the other mirror 12b.
The distance D between the lenses 2b (corresponding to the distance D between the light receiving lenses 1a and 1b in FIG. 29) can be freely changed. The distance changing mechanism 50 has the same configuration as the viewing angle changing mechanism 15, specifically, includes a motor 51 and a transmission mechanism 52. The rack of the transmission mechanism 52 is mounted on the mirror 12a. A pinion that meshes with the rack is mounted on a shaft.

In this embodiment, the viewing angle changing mechanism 15
When the light receiving lenses 13a and 13b are moved to the positions indicated by the broken lines in the figure to change the distance from F to F 'from F to F', the distance is changed by the same amount (F-F '). The mirror 12a is moved to the position shown by the broken line in the figure by the mechanism 50, and the distance to the other mirror 12b is set to D.
From D 'to D', whereby (1)
The value of the parameter (D × F) in the equation is fixed. Therefore, the arithmetic processing unit 11 can always perform the distance calculation using the same parameters. In this embodiment, one mirror 12a is moved, but the present invention is not limited to this.
The other mirror 12b may be moved, or both mirrors 12a and 12b may be moved.

In each of the above embodiments, the light receiving lens 13
Although a single lens is used for each of a and 13b, the use of a so-called zoom lens can prevent out-of-focus with respect to a change in the viewing angle θ, and can improve the accuracy of distance measurement. Note that a zoom lens is usually composed of a plurality of lenses, and when changing the viewing angle θ, each lens moves in a complicated manner, but the lens arrangement for obtaining a certain viewing angle θ is unique. Therefore, the position of each lens with respect to the light receivers 14a and 14b can be associated with the viewing angle θ.

The light receiving lenses for each of the light receivers 14a and 14b are changed by changing the range of use of each of the light receivers 14a and 14b by using light receivers 14a and 14b having sufficiently small pixels and a large number of pixels. 13a, 13b
It is also possible to electronically change the viewing angle θ without changing the position.

The distance measuring apparatus of the present invention is suitable for use in realizing the safe running of a vehicle such as an automobile.
Of course, it can be used for other purposes. FIG. 13 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. 14 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. 13 and 14 but also for a further collision prevention system. FIG. 15 shows a vehicle 65 equipped with a rear-end collision prevention system, and FIG. 16 shows a configuration example of the rear-end collision prevention system. A vehicle 65 shown in FIG. 15 has a distance measuring device 66 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.

In this rear-end collision prevention system, as shown in FIG. 16, a distance measurement device 66, a speed sensor 68, an alarm 69, and a brake 70 are provided as input / output devices to a rear-end collision prevention control section 67, which is a control body. Each is connected. 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. 17 shows a danger determination method by the control section 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. 17, 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 host 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. 18 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 region in FIG. 17 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 rear-end collision prevention system described above, 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 according to the present invention can be used in a vehicle visibility assisting system shown in FIGS. 19 to 22 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. 19 shows a vehicle 71 equipped with the view assist system, and FIG. 20 shows a configuration of the view assist system. , Respectively. 19 includes side mirrors 72, 72 on the left and right sides 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. 20, 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 subject. 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. 21 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. 22 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. 23 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. 24 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. 24, X is an ideal curve indicating the relationship between the inter-vehicle distance to the preceding vehicle and the traveling speed of the host vehicle when 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. 24 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. 25 shows a flow of control for automatic tracking by the control unit 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
8 and the traveling speed of the own vehicle detected, and the state of the own vehicle with respect to the preceding vehicle is compared with the ideal state to determine (ST2). When the control unit 75 determines that the host vehicle is in the ideal state, that is, in the ideal region E1, ST3
Is YES, 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 monitors the state of the own vehicle with respect to the preceding vehicle. Keep doing. When the control unit 75 determines that the own vehicle is not in the ideal state, the determination in ST3 is “NO”, and then the control unit 75 determines whether the own vehicle state is included in any of the regions E2 and E3 in FIG. It is determined whether it has been performed (ST4). If the state of the own vehicle is included in the area E2, the inter-vehicle distance to the preceding vehicle is too wide, and the excessively wide adjustment is necessary. Therefore, the control unit 75 outputs a control signal to the accelerator control unit 76. Then, the accelerator opening is increased to reduce the inter-vehicle distance with the preceding vehicle (ST5). If the state of the own vehicle is included in the region E3, the inter-vehicle distance to the preceding vehicle is too small, and it is necessary to adjust the too small distance. Therefore, the control unit 75 sends a control signal to the accelerator control unit 76. Then, the accelerator opening is reduced, or a control signal is output to the brake control unit 77 to perform a braking operation, thereby increasing the inter-vehicle distance with the preceding vehicle (ST6).

FIG. 26 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. The alarm 79 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. 27 shows a flow of control by the control unit 78 for driving support. 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 79 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.

[0073]

According to the present invention, as described above, the observation system is provided with the viewing angle changing means for changing the viewing angle, so that the distance to the object is short or long. The optimal viewing angle for distance measurement can be set, and the distance to the object can be reliably measured.

According to the second aspect of the present invention, the viewing angle can be easily changed only by moving each imaging means or each light receiving means.

According to the third aspect of the present invention, the viewing angle can be changed depending on whether the distance to the object is short or long.
It is possible to reliably obtain a contrast image of the target object and measure the distance.

According to the fourth aspect of the invention, since the viewing angle is changed according to the contrast of the obtained image, the distance to the object can be reliably measured.

According to the fifth aspect of the present invention, even if a plurality of objects are present in the visual field range, only a target object can be made to enter the visual field range with a small visual angle.

According to the sixth aspect of the invention, since the viewing angle can be manually set, a desired viewing angle can be set according to the situation.

According to the seventh aspect of the present invention, the viewing angle is set to one of the values set in advance in a stepwise manner, so that the distance can be easily calculated.

According to the eighth aspect of the present invention, the parameters for distance calculation are always constant even if the viewing angle is changed, so that the distance calculation can be easily performed.

According to the ninth aspect of the present invention, the view angle changes according to the running speed of the vehicle. Therefore, when the traffic speed is slow, the view angle is increased, so that the driver is likely to be distracted. Power can be supplemented and safe driving can be realized.

[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.

FIG. 2 is an explanatory diagram showing a specific example of a transmission mechanism.

FIG. 3 is an explanatory diagram showing a state in which a viewing angle is changed.

FIG. 4 is an explanatory diagram showing an example of observation of a preceding vehicle.

FIG. 5 is an explanatory diagram showing an example of observation of a preceding vehicle.

FIG. 6 is an explanatory diagram showing a light intensity distribution of an image.

FIG. 7 is an explanatory diagram showing a light intensity distribution when a plurality of objects enter a visual field range.

FIG. 8 is a block diagram illustrating a configuration of an embodiment in which a viewing angle is changed according to a traveling speed of a host vehicle.

FIG. 9 is a block diagram illustrating a configuration of an embodiment in which a viewing angle is manually changed.

FIG. 10 is an explanatory diagram illustrating a configuration of an embodiment including a change amount detection mechanism.

FIG. 11 is an explanatory diagram illustrating a configuration of an embodiment including a distance detection mechanism.

FIG. 12 is an explanatory diagram illustrating a configuration of an embodiment including a distance changing mechanism.

FIG. 13 is a side view showing a vehicle equipped with the distance measuring device.

FIG. 14 is a front view of an instrument panel in a driver's seat.

FIG. 15 is a side view showing a vehicle equipped with a rear-end collision prevention system.

FIG. 16 is a block diagram illustrating a configuration example of a rear-end collision prevention system.

FIG. 17 is an explanatory diagram illustrating a danger determination method.

FIG. 18 is a flowchart illustrating a flow of control by a control unit.

FIG. 19 is a plan view of a vehicle equipped with the view assist system.

FIG. 20 is a block diagram illustrating a configuration example of a view assisting system.

FIG. 21 is a flowchart showing a flow of control by the control unit when changing lanes.

FIG. 22 is a flowchart showing the flow of control by the control unit during back parking.

FIG. 23 is a block diagram illustrating a configuration example of a vehicle automatic following control system using a distance measuring device.

FIG. 24 is an explanatory diagram illustrating a determination method for automatic following by the control unit.

FIG. 25 is a flowchart showing a flow of control for automatic following by the control unit.

FIG. 26 is a block diagram showing a configuration example of a driving support system for a vehicle using the distance measuring device.

FIG. 27 is a flowchart showing a flow of control for driving support by the control unit.

FIG. 28 is an explanatory diagram showing a configuration of a conventional distance measuring device.

FIG. 29 is an explanatory diagram showing the principle of distance measurement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Observation system 11 Arithmetic processing part 13a, 13b Light receiving lens 14a, 14b Light receiver 15 Viewing angle changing mechanism 26 Manual setting device for viewing angle 40 Displacement detecting mechanism 45 Distance detecting mechanism 50 Distance changing mechanism 66 Distance measuring apparatus

Claims (9)

[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 that calculates a distance to the object from the shift amount of the light intensity distribution, wherein the observation system includes a viewing angle for changing a viewing angle that determines a viewing range in which the distance can be measured. A distance measuring device provided with a viewing angle changing means. 2. A distance measuring apparatus according to claim 1, wherein said viewing angle changing means changes said viewing angle by changing a position of each imaging means with respect to each light receiving means. 3. The distance measuring device according to claim 1, wherein the viewing angle changing unit changes the viewing angle according to a distance to an object existing in the viewing range. 4. The distance measuring apparatus according to claim 1, wherein the viewing angle changing unit changes the viewing angle according to the contrast of an image obtained by one or both of the image forming units. 5. The distance measuring apparatus according to claim 1, wherein the viewing angle changing unit changes the viewing angle according to whether a plurality of objects exist in the viewing range. 6. The method according to claim 1, wherein the viewing angle changing means has a setting section for manually setting a viewing range, and changes the viewing angle so as to obtain the viewing range set by the setting section. The distance measuring device described. 7. The distance measuring device according to claim 1, wherein the viewing angle changing means changes the viewing angle to one of a plurality of viewing angles set in advance in a stepwise manner. 8. The observation system according to claim 1, wherein a position of each imaging unit with respect to each light receiving unit is changed such that a product of a distance between each imaging unit with respect to each light receiving unit and a distance between the imaging units is constant. 2. The distance measuring apparatus according to claim 1, further comprising: a viewing angle changing unit for changing the viewing angle; and a distance changing unit for changing a distance between the imaging units. 9. A vehicle equipped with the distance measuring device according to claim 1 and a speed detecting device for detecting a traveling speed of the own vehicle, wherein an observation system of the distance measuring device is provided. A view angle changing means for changing a view angle in accordance with a traveling speed of the own vehicle detected by the speed detection device.