JPH11352229A - Rear monitor system for use in vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly decide whether or not an object is an approaching object, even if the object is is a state juts out of the detection range of a rear sensor. SOLUTION: This rear monitor system identifies objects present in the rear and sideways of a vehicle by an object identification means 6, on the basis of positional information on wave reflection points detected by a rear sensor 2 and a side sensor 20. At this time, when the object which is decided on the basis of detection information of the side sensor 20 at the present control cycle is decided by an identification deciding means 6C to be equal to the object decided on the basis of detection information by the rear sensor 2 at a previous control cycle, deciding means 7, 8 decide the object identified on the basis of the detection information by the side sensor 20 to be an approaching object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a moving object present behind a host vehicle in a vehicle such as an automobile.
The present invention relates to a rear monitor system for a vehicle.

[0002]

2. Description of the Related Art Conventionally, there has been known a rear monitor system for a vehicle which detects the presence of a moving object approaching from behind the host vehicle of a vehicle and alerts a driver.
In such a vehicle rear monitor system, a laser radar,
Position information of an object present behind the host vehicle is acquired by a rear sensor such as an ultrasonic sensor, and a relative speed of the object with respect to the host vehicle is calculated based on the position information. Then, it is determined whether or not the object is approaching the own vehicle based on the sign of the relative speed.

In other words, a detection wave such as a laser or an ultrasonic wave is output toward the rear of the host vehicle, and a reflected wave which responds to each detection wave is captured, whereby the position of the wave reflection point behind the host vehicle is detected. Can be detected. Then, the object is identified as a set of a plurality of wave reflection points, and the relative speed of the identified object with respect to the own vehicle is calculated,
If the relative speed is positive, it can be determined that such an object is approaching.

[0004] Based on such a determination result, the driver of the host vehicle is informed that an object (usually an automobile) is approaching from behind by a visual display such as an alarm lamp or an alarm buzzer, or an audio display. You can be notified by display.

[0005]

Since the purpose of the vehicle rear monitor system is to detect an object approaching from the rear of the host vehicle as described above, the detection range of the rear sensor is generally the rear of the host vehicle. Is limited to a certain range. For example, as shown in FIGS.
If provided with the rear sensor 102 to the end portion of the vehicle 101, the detection range A _B is the largest vehicle rear 18
The range is 0 degrees.

[0006] As shown in FIG. 11 (a), when an object 103 is present within the detection range A _B, the detection range A
The own vehicle 101 of the object 103 based on the change in the position in _B
Can be determined to determine whether the object 103 is an approaching object. That is, in the case shown in FIG. 11A, the detection surface of the object 103 is the front surface and the side surface, and the detection data in the width direction and the detection data in the length direction of the object 103 can be obtained. In addition, it is possible to clearly recognize the shape of the object 103, and thereby it is possible to accurately grasp the change in the position of the object 103.

[0007] However, as shown in FIG. 11 (b), inconvenience occurs when the front portion of the object 103 is protruded from the detection range A _B. That is, as shown in FIG. 11 (b), when an object 103 protrudes forward from the front edge of the detection range A _B, since from the rear sensor 102 is not visible only a part of the side surface of the object 103, the object 103 Neither the detection data in the width direction nor the detection data in the length direction necessary for specifying the length of the object can be obtained. For this reason, the shape of the object 103 cannot be specified sufficiently. In particular, when the relative speed is low, the position change cannot be accurately grasped, and it cannot be determined whether the object 103 is an approaching object.

[0008] Further, as shown in FIG.
When front portion 03 is in a position protruding from the detection range A _B, just often object 103 enters the blind spot for the driver, is detected and an alarm therefor precise approaching object by the rear monitoring system for a vehicle Especially required.
Therefore, if it is not possible to determine whether or not the object 103 is an approaching object as described above, not only the effect of the rear monitor system will be reduced, but also the driver will feel uncomfortable and uneasy.

Therefore, even in a situation in which an object protrudes beyond the detection range of the rear sensor, a change in the position of the object is accurately detected, and it is possible to accurately determine whether or not the object is an approaching object. Is desired. Here, as a technique for detecting the relative speed of an object moving to the side of the host vehicle, there is a technique disclosed in Japanese Patent Application Laid-Open No. 8-114444. According to this technique, two sensors are arranged in parallel in the front-rear direction of the side surface of the vehicle, and the relative speed of the object is calculated based on the reaction delay time of the two sensors when the object moves to the side of the own vehicle. It has become.

However, since this technique is intended only to detect the relative speed of an object running in parallel with the host vehicle, the relative speed is calculated while constantly monitoring an object approaching from behind. It is not possible to determine whether or not it is an approaching object. Even if the rear sensor is simply replaced with a rear sensor, if it is not possible to determine whether the object detected by the rear sensor and the object detected by the front sensor are the same object, it is determined whether the object is an approaching object. Cannot be determined accurately.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and accurately determines whether or not an object is an approaching object even in a situation in which the object protrudes forward from a detection range of a rear sensor. It is an object of the present invention to provide a vehicular rear monitor system capable of performing the following.

[0012]

Therefore, in the vehicle rear monitor system of the present invention, a plurality of detection waves are output from the rear of the host vehicle to different regions by the rear sensor, and each detection wave is output. The position of the wave reflection point behind the host vehicle is detected by capturing the reflected wave that responds to the vehicle, and the side sensor outputs the detection wave from the side of the host vehicle to generate the reflected wave that responds to the detection wave. By detecting the position of the wave reflection point on the side of the own vehicle by capturing the information, based on the wave reflection point position information detected by the rear sensor and the side sensor, the object identification means determines the position of the wave reflection point behind the own vehicle and the side of the own vehicle. Identify objects that exist on the side.

At this time, the object identified based on the detection information of the side sensor in the current control cycle is identified by the identification determining means as the same object as the object identified based on the detection information of the rear sensor in the previous control cycle. If it is determined that there is, the determining means determines the identified object as an approaching object based on the detection information of the side sensor. Thus, even for an object existing in front of the detection range of the rear sensor, it is reliably determined whether or not the object is an approaching object.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a vehicle rear monitor system according to an embodiment of the present invention; FIG. As shown in FIG. 2, the vehicle rear monitor system includes a laser radar 2 as a rear sensor for detecting an object present behind the host vehicle at a predetermined position of the vehicle 1 (for example, above the trunk lid). . The laser radar 2 rotates within a predetermined cycle T (for example, 100 msec / rotation), and data, that is, laser light transmitted from the transmission unit of the laser radar 2 is reflected by an object at every predetermined rotation angle θ and received. The response time until returning to the section is obtained, and the position of the wave reflection point is detected. Here, it is assumed that the laser radar 2 rotates right by 180 degrees from the right side of the vehicle to the left side, and acquires data for each rotation angle from 0 degrees to 180 degrees. For example, if θ = 1 degree, 0 degree, 1 degree, 2 degrees, etc.
At 180 degrees, 181 data are acquired in one cycle.

At predetermined positions on both left and right sides of the vehicle 1, there are provided ultrasonic sensors 20 as side sensors for detecting an object present on the side of the vehicle. Here, the ultrasonic sensor 20 is arranged at 90 degrees to the traveling direction, that is, right beside, and the ultrasonic wave is reflected from the wave reflection point by the response time until the emitted ultrasonic wave is reflected back to the object. The position can be detected. FIG. 3 shows the laser radar 2 and the ultrasonic sensor 2 in the vehicle rear monitor system.
FIG. 4 is a diagram showing a detection range of 0, where the laser radar 2 is a 180-degree range from the right side to the left side of the vehicle behind the own vehicle 1, and is a fixed range (rear direction) limited in both the width direction and the front-rear direction. sensor detection area) and performs the detection in a _B. The reason why the limit the detection range of the laser radar 2 is to eliminate the information of the object far no influence on the running of the vehicle 1, from the rear sensor detection area A _B out of the object Even when a reflected wave is received, it is not regarded as detection data.

On the other hand, the ultrasonic sensor 20 does not perform detection over a wide range unlike the laser radar 2,
The detection is performed in a narrow range in only one direction to which the ultrasonic sensor 20 is directed. However, the directivity of the ultrasonic wave is not as high as that of the laser and is within a certain range (about 15
), The detection ranges (side sensor detection areas) A _R and _AL also have a certain spread. Also, the installation position of the ultrasonic sensor 20, the rear sensor detection area A _B and the side sensor detection area A _R, and the A _L is set so as not to interfere.

The detection data obtained by the laser radar 2 and the ultrasonic sensor 20 respectively correspond to the control EC inside the vehicle 1.
The data is input to U10. The instrument panel inside the vehicle 1 is provided with an alarm lamp 11 and an alarm buzzer 12, which are turned on or emit an alarm sound according to the output of the control ECU 10. Control E
The configuration of the CU 10 will be described.
As shown in FIG. 1, a laser radar communication unit 3, a laser radar control unit 4, a data conversion unit 5, an ultrasonic sensor communication unit 21, an input data processing unit 22, an object recognition selection unit (object identification unit) 6, It comprises a relative speed calculation section 7, an alarm determination section 8, and an output processing section 9. The relative speed calculation unit 7 and the alarm determination unit 8 constitute a determination unit.

The laser radar communication unit 3 includes a control ECU 10
Is an interface when communicating with the laser radar 2, and the laser radar control unit 4 has a function of controlling the scan cycle and timing of the laser radar 2,
The laser radar 2 is controlled via the laser radar communication unit 3 so as to acquire data at the above-described predetermined period T and the predetermined rotation angle θ. Then, the detection data acquired by the laser radar 2 is input to the data conversion unit 5 via the laser radar communication unit 3.

The data converter 5 calculates the distance between the own vehicle and the detection point based on the detection data obtained by the laser radar 2, that is, the response time, and further calculates the relative distance to the own vehicle based on the calculated distance and the rotation angle. The position is calculated and the position of a detection point (wave reflection point) is plotted on a map represented by XY coordinates (hereinafter referred to as an XY map). Then, the detected point information plotted on the XY map is input to the object recognition selecting unit 6.

On the other hand, the ultrasonic sensor communication unit 21
The interface when the CU 10 communicates with the ultrasonic sensor 20. The detection data acquired by the ultrasonic sensor 20, that is, the response time of the ultrasonic wave between the host vehicle and the detected object is determined by the ultrasonic sensor communication. The data is input to the input data processing unit 22 via the unit 21. Then, the input data processing unit 22
Calculates the distance (wave reflection point position) between the host vehicle and the detection point based on the detection data acquired by the ultrasonic sensor 20. Also, the input data processing unit 22 includes:
An output signal from a wheel speed sensor 13 used in an ABS (anti-lock brake system) is also input as vehicle speed information. The distance information of the detection point and the vehicle speed information of the own vehicle are input to the object recognition selecting unit 6.

In the object recognition selecting section 6, relative speed calculating section 7, and alarm determining section 8, a data converting section 5, an input data processing section 2
Based on the detection point information respectively input from step 2, an approaching object present behind or on the side of the vehicle is recognized, and an alarm determination as to whether or not to issue an alarm is performed. The rear monitor system for a vehicle has two alarm determination modes having different processing contents according to detected detection point information.
First, the first warning determination mode is not the detection point is obtained on the side sensor detection area A _R, A _L, is a determination mode when only the detection point behind the sensor detection area A _B was obtained.

In the first alarm determination mode, first, the object recognition selecting unit 6 detects the position behind the vehicle based on the detection point information of the laser radar 2 displayed on the XY map input from the data conversion unit 5. Recognize the approaching object that exists in. More specifically, the object recognition selecting unit 6 sets a group of detection points on the XY map by using a group setting unit 6A as a functional element. The group setting by the group setting unit 6A is such that a continuous detection point group among a plurality of detection points plotted on the XY map, that is, each detection point is obtained as continuous data and the distance between the detection points is constant. If there is a group of detected points that fall within the distance, they are regarded as belonging to the same group and are grouped.

For example, as shown in FIG. 4A, detection points _{pn to pn + 5} are acquired by the laser radar 2, while
It is assumed that no detection data was obtained by the ultrasonic sensor 20. In this case, since the detection points _{pn to pn + 5} are continuous data and the distance between the detection points is also within a certain distance, the same group G _{1 as} shown in FIG. , That is, they are regarded as the same object and are grouped.

[0024] Thus, when the detected object is recognized as the detection point groups G _1, then the object recognition selection section 6
As shown in FIG. 3 (c), present in the traveling direction of the host is a vehicle from the rear end is set to a predetermined distance mode switching area A _C in an object specified rear sensor detection area A _B Is determined. If the object is present in this mode switching area A _C, there is a case where the front portion of the object can not cause detectable only side portions only go out the rear sensor detection area A _B. In this case, in the identification determination based on the shape of the object specified from the distribution of the detection points described below, it is determined that the detection point detected in the current control cycle and the detection point detected in the previous control cycle belong to different objects. As a result, there is a possibility that no alarm is issued despite the fact that the alarm is issued. Therefore, if the object is present in the mode switching area A _C, is of the switching to a second alarm determination mode will be described later.

The mode switching area A _C has a predetermined range set in advance on the XY map. If a part of the detection points belonging to the detection point group is located in the alarm area, the detection point is set to the detection point. Group is mode switching area A
It is determined that the vehicle has entered _C. For example, in the example shown in FIG. 4 (c), although not located both mode switching area A _C of the detection point p _n ~p _n + _5, the detection point p _n ~p
If located in any even one mode switching area A _C of the _{n + 5,} it determines that the object corresponding to the detection point group G ₁ is present in the mode switching area A _C.

[0026] Here, when the object corresponding to the detection point group G ₁ is is determined not to exist in the mode switching area A _C, the process based on the first warning determination mode is continued, the object recognition Selection The unit 6 performs an identification determination (first identification determination) with the object detected in the previous control cycle by an identification determining unit (identification determining unit) 6C as a functional element. In the first identification determination, the relative speed of the object, which is a criterion for determining whether the object is an approaching object or not, is calculated based on a change in the position of the object in the current control cycle with respect to the position of the object in the previous control cycle. The precondition is that the object detected in and the object detected in the current control cycle are the same object. Therefore, a first identification determination is performed to determine this identity.

This first identification judgment is performed as follows. Figure 4 (b), the case where the mode switching area A _C detection point outside the p _n ~p _n + ₅ is acquired in the current control cycle, these detection points p _n ~p _n + ₅ is the detection point both the front portion and side portion of the object corresponding to the group G ₁ is believed to have been detected. Accordingly, as shown in FIG. 4C, the minimum frame S _{1 including} all the detection points _{pn to pn + 5.}
By setting, it is possible to identify the shape of the object corresponding to the detection point group G _1.

Therefore, the identification judging unit 6C sets the frame S ₁
Is compared with the shape of the frame S ₁ ′ set in the detection point group G ₁ ′ obtained in the previous control cycle, and the position change amount between the detection point group G ₁ and the detection point group G ₁ ′ is calculated. . And the change amount of both shapes, that is, the width W and the length L is equal to or less than a predetermined change amount, and
If the position change amount below the predetermined change amount, it is determined that the same object is a detection point group G ₁ 'and the detection point group G _1, a predetermined one of the variation or change in position of the shape amount In the above case, it is determined that the object is another object.

When the object recognition selecting section 6 determines that the detection point group G ₁ detected in the current control cycle is the same object as the detection point group G ₁ ′ detected in the previous control cycle, the detection point group G ₁ Is selected as a target of the relative speed calculation processing. The relative speed calculation unit 7 calculates the relative speed of the processing target selected by the object recognition selection unit 6 based on the movement amount of the detection point group on the XY map.

That is, since the position of the detection point on the XY map is updated every scan cycle T of the laser radar 2, the position of the detection point group in the previous cycle and the position of the detection point group in the current cycle are compared. The amount of movement of the detection point group during T is determined as the relative speed. In case of FIG. 4 (c), by dividing the position change amount of the detection point group G ₁ from the detection point groups G ₁ 'in period T, calculates a relative speed of the object corresponding to the detection point group G ₁ I do.

As described above, based on the first alarm determination mode,
By the processing, the detection point group G₁Relative of the object corresponding to
When the speed is calculated, the alarm determination means 8 calculates the relative speed.
A warning is issued based on the magnitude of the relative speed calculated by the unit 7.
It is determined whether or not to do so. That is,
If the relative speed is greater than 0, the detection point group G ₁
It is determined that a moving object corresponding to is approaching the own vehicle,
If the relative speed is 0 or less, the detection point group G₁Equivalent to
Moving objects are running parallel to or away from your vehicle
It is determined that there is. And when approaching your vehicle
If it is determined, an alarm signal will be output to the output processing unit 9.
Swelling.

Next, the second alarm judgment mode is a side alarm
Detection area A_ROr A_LWhen a detection point is acquired within
Is the determination mode. This side sensor detection area A_Ror
Is A _LInside is just a blind spot for the driver
Therefore, whether there is an approaching object in this area is
Important, more important than the first alarm determination mode
Is a high determination mode.

In the second alarm determination mode, the object recognition selecting section 6 inputs the detection point information of the laser radar 2 represented on the XY map inputted from the data conversion section 5 from the input data processing section 22. The detected point information of the ultrasonic sensor 20 is added, and the detected point information is integrated to recognize an approaching object existing behind or beside the host vehicle. In this case, the following two patterns exist as patterns of the obtained detection point information.

First, as a first pattern, FIG.
(A), the detection point p _o laterally sensor detection area A _R is obtained, the case where the detection point p _q ~p _q + ₂ rearward sensor detection area A in _B is obtained. Here, whether or not the detection point p _o belongs to the detection point p _q ~p _q + ₂ of the same object becomes a problem. In this case, there is no continuity in the data because it was detected by a different sensor from the detection point p _q ~p _q + ₂ and the detection point p _o. However, the same object may sometimes be present straddling the rear sensor detection area A _B and the side sensor detection area A _R. Therefore,
The group setting unit 6A detects the detection points p _{q to} p
It is determined whether _{q + 2} and the detection point _po belong to the same object.

First, the group setting section 6A sets the detection point p_o
And detection point p_q~ P_{q + 2}Of the vehicle traveling direction
Starting point p_qDistance on the XY map (corresponding to the following distance)
E) is calculated. Then, the calculated distance e and the own vehicle
Calculate the inter-vehicle time t (t = e / v) from the vehicle speed v,
t₀Compare with This threshold t₀Is running at the same speed
When there are two vehicles, and the vehicle ahead stops suddenly
The minimum vehicle required for the vehicle behind to stop following
If two vehicles are running,
Normally, this threshold value t₀Keep more time between cars
It is thought that it is running. Therefore, group setting
The determining unit 6A determines that the calculated inter-vehicle time t is equal to the threshold value t. ₀If more than
Is the detection point p_oAnd detection point p_q~ P_{q + 2}Belongs to another object
Conversely, the inter-vehicle time t becomes the threshold t₀Smaller than
In this case, as shown in FIG.
_TwoAnd group them together.

Thus, the laser radar 2, the ultrasonic sensor
20 are detected point groups G_TwoAs
When the object is recognized, the object recognition selecting unit 6
G _TwoIs the detection point group detected in the previous control cycle.
G_Two'Is determined. But the group
G_TwoDetection point p that defines_O, P_q~ P_{q + 2}Is the side of the object
It is highly likely that only the detection points corresponding to the
The defined shape has no thickness in the width direction. Therefore, the first
Detection point in the same way as the identification judgment in the alarm judgment mode
p_O, P_q~ P_{q + 2}For the previous control cycle
Detection point group G obtained in the period_Two′ And shape
Even so, there is a high possibility that they are not determined to be the same object.

Therefore, in the case of the second alarm judgment mode, the identification judging section (identification judging means) 6C sets the detection point group G ₂
When calculates only the position change amount between been detected point groups G ₂ 'obtained in the previous control cycle. However, in this case, the position of the tip portion of the object corresponding to the detection point group G ₂ is because it is not known, the position change amount of the entire detection point groups G ₂ to calculate the amount of change d in the position of the rear end portion .

[0038] Then, the calculated position change amount d is compared with a threshold value d ₀ position change amount, when the position change amount d is the threshold value d ₀ or less, the detection point group G ₂ and the detection point in the previous control cycle It is determined that the group G ₂ ′ is the same object. Note that the threshold value d ₀ is the maximum distance that the object in the normal running state can move during the cycle T. When it is determined that the detection point group G ₂ and the detection point group G ₂ ′ in the previous control cycle are the same object, an alarm determination unit (determination means) 8
Is a moving object corresponding to the detection point group G ₂ is adapted to determined to be approaching the own vehicle, and outputs a warning signal to the output processing unit 9.

Further, in the first alarm determination mode described above, even if the object corresponding to the detection point group G ₁ is is determined that the present mode switching area A _C, corresponding to the detection point group G ₁ is likely the front portion of the object is protruding outside the rear sensor detection area a _B. For this reason,
In the same manner as above, only the position change amount d with respect to the detection point group G ₁ ′ acquired in the previous control cycle is calculated, and the identification judgment is performed based on the position change amount, and an alarm is issued. It is determined whether or not to emit.

On the other hand, as shown in FIG. 6A, only the detection point _po may be obtained by the ultrasonic sensor 20 as a second detection point acquisition pattern. In this case, the object recognition selecting unit 6 recognizes the detection point _po as one object. Then, when the detection point group G ₃ ′ has been acquired in the previous control cycle as shown in FIG. 6B, the identity between the acquired detection point group G ₃ ′ and the detection point _po is determined. .

The identification of the detection point p _o and the detection point group G ₃ ′ cannot be determined by the shape specified from the distribution of the detection points, similarly to the first pattern. _This is performed only by the positional relationship between _o and the detection point group G ₃ ′. That is, the identification judgment unit 6C calculates the position change between the detection point group G ₃ 'and the detection point p _o, and inputs to the alarm determination unit 8. However, here, the detection point _po is regarded as a detection point near the rear end of the object, and is compared with the position of the rear end of the detection point group G ₃ ′ in the previous control cycle to calculate the position change amount d. And
The calculated position change amount d is compared with a position change amount threshold value d _0, and when the position change amount d is equal to or smaller than the threshold value d ₀ , the detection point _po and the detection point group G ₃ ′ in the previous control cycle are different. It is determined that they are the same object.

When it is determined that the detection point _po and the detection point group G ₃ ′ in the previous control cycle are the same object, the alarm determination unit 8 determines that the moving object corresponding to the detection point _po approaches the own vehicle. And outputs an alarm signal to the output processing unit 9. Thus, in each case of the first alarm determination mode and the second alarm determination mode, an alarm determination is performed. When an alarm signal is input from the alarm determination unit 8 to the output processing unit 9, the output processing unit 9 sets the alarm buzzer. 1
2, an alarm sound is generated, and an alarm lamp 11 provided in the instrument panel is turned on.
The alarm buzzer 12 emits an alarm sound only for the first few seconds,
Thereafter, only the warning lamp 11 is turned on.

Further, as shown in FIG.
As for, LED lamps 11L and 11R are provided on the left and right sides of the symbol 15 indicating the host vehicle, respectively, so that it can be grasped from which side of the host vehicle the moving object is approaching. The approach direction of the moving object is determined by referring to the Y coordinate value of the detection point group corresponding to the moving object on the XY map.

Since the rear monitor system for a vehicle according to one embodiment of the present invention is configured as described above, for example, it approaches from the rear of the host vehicle in a control flow as shown in FIGS. 8, 9, and 10. The moving object that moves is detected. First, as shown in FIG. 8, when starting the control, all data such as the position of a detection point (wave reflection point) on the XY map is initialized (step S100). This processing is performed only for the first time, and thereafter, steps S200 to S7
00 will be repeated.

Step S200 is for performing the control after step S300 at a fixed period T (here, 100 msec). A timer (not shown) is counted, and when the timer value reaches 100 msec, the process proceeds to step S300. Transition. The timer value is cleared at the same time as counting 100 msec, and counting up to 100 msec is started again.

In step S200, the fixed period T (1
(00 msec), the laser radar control unit 4 rotates the laser radar 2 from 0 degrees to 180 degrees, and acquires data on an object located behind at every predetermined rotation angle θ (step S300). Further, data on an object existing on the side of the own vehicle is acquired by the ultrasonic sensor 20 (step S400).

Then, based on the detection data acquired by the laser radar 2 and the ultrasonic sensor 20, it is determined whether or not to issue an alarm for an object existing behind or on the side (step S500). In this determination, first, as shown in FIG.
Calculates the relative position of the detection point with respect to the own vehicle based on the distance between the own vehicle and the detection point obtained from the respective detection data obtained in and the rotation angle θ of the laser radar 2, and calculates the position of the detection point on the XY map Plotting is performed (step S510).

In the input data processing unit 22,
The detection data obtained by the ultrasonic sensor 20 is filtered, and the distance between the vehicle and the detection point, which is obtained from the effective detection data, is calculated. At this time, when valid detection data is obtained by the ultrasonic sensor 20, the alarm determination mode is set to the second alarm determination mode, and when valid detection data is not obtained, the first alarm determination mode is set. (Step S520).

In the object recognition selecting section 6, first, in the group setting section 6A, when there are continuous detection points among a plurality of detection points plotted on the XY map, they are determined to belong to the same group. The grouping is performed on the assumption (step S530). When the grouping of the detection points is completed, it is determined whether or not this detection point group exists in the mode switching area. If it is within the mode switching area, the mode is switched to the second alarm determination mode (step S540).

Next, in the identification judging section 6C, the identification of the grouped detection points with the detection point group acquired in the previous control cycle is performed (step S55).
0). When the alarm judgment mode is the first alarm judgment mode,
First, a minimum frame including all the detection points of the detection point group acquired in the current control cycle is set, and the shape of the object is specified. Then, the shape of the set frame is compared with the shape of the frame corresponding to the object detected in the previous control cycle, and the amount of change in the position is calculated. If the amount of change in the shape and the amount of change in the position of the two are not more than the predetermined amount of change, it is determined that the object detected in the current control cycle is the same as the object detected in the previous control cycle.

On the other hand, when the alarm judgment mode is the second alarm judgment mode, processing is performed according to the flow shown in FIG. That is, when an object is detected by the laser radar 2 in the previous control cycle (step S551) and an object is detected by the ultrasonic sensor 20 in the current control cycle (step S552), the laser radar 2
If an object is also detected (step S55)
3) First, the distance e between the detection point detected by the laser radar 2 and the detection point detected by the ultrasonic sensor 20 in the current control cycle is calculated (step S554). Then, the inter-vehicle time t is calculated from the calculated distance e and the vehicle speed v of the own vehicle (step S555).

At this time, the calculated inter-vehicle time t is equal to the threshold value t _0.
If it is smaller than (Step S556), it is determined that the detection point detected by the laser radar 2 and the detection point detected by the ultrasonic sensor 20 in the current control cycle are the same object,
Set as one detection point group (step S55)
8). Then, it calculates the position change amount d with respect to the object detected in the previous control cycle of the detection point group (step S559), is compared with a threshold value d ₀ (step S56
1). If the calculated position change amount d is smaller than the threshold value d ₀ , the laser radar 2 and the ultrasonic sensor 2
It is determined that the object detected by 0 and the object detected by the laser radar 2 in the previous control cycle are the same object (step S562).

If no object is detected by the laser radar 2 in the current control cycle (step S553), the detection point detected by the ultrasonic sensor 20 in the current control cycle is determined with respect to the object detected in the previous control cycle. The position change amount d is calculated (step S560), and the threshold value d is calculated.
Compare with ₀ (step S561). When the calculated position change amount d is smaller than the threshold value d _0, the object detected by the ultrasonic sensor 20 in the current control cycle and the object detected by the laser radar 2 in the previous control cycle are determined to be the same object. (Step S562).

Based on the determination as to whether there are any other detected objects (step S563), the above-described identification determination processing is performed for all the detected objects detected by the laser radar 2 and the ultrasonic sensor 20. When it is determined that the object detected by the identification determination is the same as the object detected in the previous control cycle, and the alarm determination mode is the first alarm determination mode, the relative speed calculation unit 7 determines in the previous cycle. The position of the detected object is compared with the position of the detected object in the current cycle, and the moving amount of the detected object during the cycle T is calculated to calculate the relative speed with respect to the own vehicle (step S570).

When the alarm determination mode is set to the first alarm determination mode, if the relative speed calculated by the relative speed calculation unit 7 is greater than 0, the alarm determination unit 8 determines that the detected object is in its own right. It is determined that a warning is issued as if the vehicle is approaching. When the second alarm determination mode is set, if the object detected in the current control cycle is determined to be the same as the object detected in the previous control cycle in step S562, the detected object approaches the own vehicle. It is determined that an alarm is to be issued assuming that a warning has been issued (step S580).

When the alarm judging unit 8 judges that an alarm is to be issued, the alarm lamp 11 provided in the instrument panel is turned on (step S600), and at the same time, an alarm sound is generated from the alarm buzzer 12 (step S700). As described above, according to the vehicle rear monitor system, the laser radar 2 that detects an object existing behind the host vehicle and the ultrasonic sensor 20 that detects an object existing on the side of the host vehicle are provided. , objects can be detected by even if the ultrasonic sensor 20 located in front of the rear sensor detection area a _B is the detection range of the laser radar 2, only the detection information of the laser radar 2 is approaching the detection object Even if it is not possible to determine whether the object is an object, the ultrasonic sensor 20 is determined by determining the identity between the object identified by the detection information of the ultrasonic sensor 20 and the object identified by the detection information of the laser radar 2 in the previous control cycle. There is an advantage that it is possible to reliably determine whether or not the object detected in is an approaching object. This makes it easy for drivers to be blind spots,
In addition, it is possible to reliably perform a warning determination regarding an approaching object existing diagonally rearward of the host vehicle, which requires the most attention, and does not give the driver a feeling of anxiety.

Further, the vehicle rear monitor system is constructed by simply adding a side sensor such as an ultrasonic sensor to a conventional vehicle rear monitor system having a rear sensor for detecting an object behind the host vehicle. Therefore, there is also an advantage that the above effects can be obtained without increasing the cost. Note that the present invention is not limited to the above-described embodiment, and can be implemented with various modifications without departing from the gist of the present invention. For example, as a side sensor, a detection wave is output. Any device that can detect the position of the wave reflection point on the side of the vehicle by capturing the reflected wave that responds to the lever detection wave may be used. In addition to the ultrasonic sensor as in the present embodiment, a laser radar may be used. And the like, and it is also possible to install a plurality of detectors without being limited to one on the left and right as in the present embodiment. Similarly, as the rear sensor, various detecting means such as an ultrasonic sensor can be used in addition to the laser radar as in the present embodiment.

In addition to the exclusion of the stationary object from the calculation of the relative speed, the stationary object may be excluded from the determination of the approaching object.

[0059]

As described above in detail, according to the vehicle rear monitor system of the present invention, a rear sensor for detecting an object existing behind the host vehicle and a side sensor for detecting an object existing on the side of the host vehicle. Since it has a side sensor, even if the object is located ahead of the detection range of the rear sensor, it can be detected by the side sensor, and only the detection information of the rear sensor determines whether the detected object is an approaching object. Even if it is impossible to determine whether the object detected by the side sensor approaches the object detected by the side sensor by determining the identity between the object identified by the detection information of the side sensor and the object identified by the detection information of the rear sensor in the previous control cycle. It is possible to reliably determine whether the object is an object.

This makes it possible for the driver to easily make a blind spot, and to make an alarm determination regarding an approaching object that is most observable at an obliquely rear side position of the own vehicle. It does not give a feeling.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a vehicle rear monitor system as one embodiment of the present invention.

FIG. 2 is a diagram showing an example of an arrangement on a vehicle of a vehicle rear monitor system as one embodiment of the present invention and a scan range of a rear sensor.

FIG. 3 is a schematic diagram showing detection ranges of a rear sensor and a side sensor according to the vehicle rear monitor system as one embodiment of the present invention.

FIG. 4 is an explanatory diagram for describing a process of recognizing a rear object according to the vehicle rear monitor system as one embodiment of the present invention, in which recognition processes are performed in the order of (a) to (c).

FIG. 5 is an explanatory diagram for explaining a rear object identification determination process according to the vehicle rear monitor system as one embodiment of the present invention, in which determination is performed in the order of (a) and (b).

FIG. 6 is an explanatory diagram for explaining a rear object identification determination process according to the vehicle rear monitor system as one embodiment of the present invention, in which determination is performed in the order of (a) and (b).

FIG. 7 is a diagram showing an example of an arrangement of an alarm lamp according to the vehicle rear monitor system as one embodiment of the present invention.

FIG. 8 is a flowchart illustrating an overall flow of an approaching object detection process of the rear monitor system for a vehicle according to an embodiment of the present invention.

FIG. 9 is a flowchart illustrating a flow of a process of determining whether or not the vehicle is an approaching object in the vehicle rear monitor system according to the embodiment of the present invention;

FIG. 10 is a flowchart illustrating a flow of an identification determination process of the vehicular rear monitor system as one embodiment of the present invention.

11 (a) and 11 (b) are schematic diagrams for explaining a problem with a conventional vehicle rear monitor system.

[Explanation of symbols]

 Reference Signs List 2 laser radar (rear sensor) 6 object recognition selection unit (object identification unit) 6A group setting unit 6B shape specification unit 6C identification determination unit (identification determination unit) 7 relative speed calculation unit constituting determination unit 8 configures determination unit Alarm determination unit 10 ECU 11 Alarm lamp 12 Alarm buzzer 20 Ultrasonic sensor (side sensor)

Claims (1)

[Claims] 1. A rear part for detecting a position of a wave reflection point behind a host vehicle by outputting a plurality of detection waves toward different regions from behind the host vehicle and capturing reflected waves responding to the detection waves. A side sensor for detecting a wave reflection point position on the side of the own vehicle by outputting a detection wave from the side of the own vehicle and capturing a reflected wave responding to the detection wave, and the rear sensor; And object identification means for identifying an object behind and on the side of the own vehicle based on the wave reflection point position information detected by the side sensor, and an object identified based on the detection information of the side sensor Determination means for determining whether or not the object is an approaching object, wherein the object identification means determines whether the object identified based on the detection information of the rear sensor is the same as the object identified based on the detection information of the side sensor. Identification to determine gender Determination means, wherein the identification means is identified based on the detection information of the side sensor in the current control cycle and the object identified based on the detection information of the rear sensor in the previous control cycle. A rear monitor system for a vehicle, characterized in that, when it is determined that the same object is the same object, the object is determined to be an approaching object.