JPH06282798A - Target searching device and alarm device and automatic tracking device using the same - Google Patents

Abstract

PURPOSE:To improve the target identifying capability when a moving body is turning maneuver in regard of a target searching device which identifies a target positioned on the of the moving body. CONSTITUTION:A target catching means 1 is provided to catch a target 5 by searching the periphery of a moving body 4 and obtains a relative position P of the target 5 for the body 4, together with a circle orbit estimating means 2 which estimates a circle orbit C of the body 4 in a turning maneuver of the body 4, and a control means 3 which decides whether the target 5 is positioned on the circle orbit C or not based on the relative position P of the target 5 obtained by the means 1 and the estimated circle orbit estimated by the means 2 C and then identifies the target 5 positioned on the travelling lane of the body 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a target search device for identifying a target located on the course of a vehicle. More specifically, the present invention relates to a target search device that searches the vicinity of a vehicle by using a radar or the like, captures a target, and identifies a target located on the course of the vehicle from the captured targets. The present invention is particularly applicable to, but is not limited to, an alarm device that warns of an abnormal approach of an obstacle in front of the vehicle, and an automatic tracking device that automatically tracks a vehicle traveling in front of the host vehicle.

[0002]

2. Description of the Related Art For example, in the field of motoronics, there is an increasing interest in measures for preventing traffic accidents and measures for reducing the burden on the driver. The alarm device that has been installed in a vehicle in recent years has been developed from such a background, and is a device that detects an abnormal approach of an obstacle in front of the vehicle and issues a warning to the driver. .

In such an alarm device, a laser radar mainly using laser light in the infrared region is used to capture an obstacle in front of the vehicle. When an obstacle is captured in front of the vehicle, the distance to the obstacle is compared with the safety distance, and if there is an obstacle within the safety distance, a warning is issued.

Although such an alarm device is effective in preventing a traffic accident, on the other hand, with the spread of the device, the alarm sounds only by passing a vehicle traveling in an oncoming lane. There are quite a few false alarms, such as an alarm sounding only when a vehicle passes the passing lane.

Therefore, in the conventional warning device, if the direction of the captured target is relatively small,
That is, such a false alarm is reduced by determining that the target is on the same lane as the own vehicle, and setting the target as a warning target, and excluding the target other than the target from the warning target.

[0006]

The problems in the conventional target search will be described by taking the above alarm device as an example. Figure 9
FIG. 6 is a diagram illustrating a problem in a conventional target search. Now, it is assumed that vehicles 100a and 100b are traveling in front of the host vehicle 101 as shown in FIG. Then, it is assumed that the safety distance is L _S.

A warning is issued to the vehicle 100a because the distance is within the safety distance L _S. On the other hand, vehicle 100b
However, even if the distance L ₁ is within the safety distance L _S , no warning is issued. This is because, in the conventional target search, whether or not the target is located on the course of the vehicle is identified based on the direction of the captured target as described above.

That is, in this example, since the angle of the vehicle 100a seen from the own vehicle 101 is extremely small, the vehicle 100a
Is determined to be on the same lane as own vehicle 101 and is a warning target, but the vehicle seen from own vehicle 101
Because the angle θ ₁ of 100b is relatively large, it is determined that the vehicle 100b is located on a different lane than the host vehicle 101, and is excluded from the warning target. And vehicle 100b
Since the vehicle is actually traveling in a different lane, in the situation shown in Figure (a), the conventional target search functions effectively and there is no problem.

Next, it is assumed that the host vehicle 101 is traveling behind the vehicle 100a and is approaching a curve as shown in FIG. Then, it is assumed that the angle of the vehicle 100a viewed from the own vehicle 101 at that time is θ ₁ and the distance thereof is L ₁ . In such a case, no warning is given to the vehicle 100a even though the distance is within the safety distance L _S.

The reason is that the own vehicle 101 in FIG.
The relative positional relationship between the vehicle and the vehicle 100a is
This is because the relative positional relationship between 101 and the vehicle 100b is the same. However, in this case, the vehicle 100a is actually the own vehicle 10
Since you are traveling in the same lane as 1 and the safety distance between vehicles is not maintained, you need to sound an alarm to warn.

Nevertheless, in the conventional target search,
It is determined that the vehicle 100a is a warning target, as described above.
It is when the angle θ ₁ becomes relatively small. for that reason,
In such a curve, the warning cannot be issued until the own vehicle 101 and the vehicle 100a come close to each other. As a result, the conventional target search rather acts so as to suppress the necessary warnings and is accompanied by a driving risk, and therefore improvement is strongly desired.

It is also assumed that there is a signboard 102 directly in front of the host vehicle 101. In such a case, a warning is issued to the signboard 102. The reason is that the own vehicle 10 in FIG.
This is because the relative positional relationship between 1 and the signboard 102 is the same as the relative positional relationship between the host vehicle 101 and the vehicle 100a in FIG. However, it is inconvenient if a warning is issued every time there is a curve, not only for a signboard but also for a house or a wall around the road.

As described above, in the conventional target search, when the vehicle such as the vehicle makes a turning motion such as the curve running, the ability to identify the target located on the course of the vehicle is deteriorated. There is a problem. Therefore, in the above-described alarm device to which the conventional target search is applied, there is a problem that an erroneous alarm is generated when traveling on a curve.

The technical problem of the present invention is to improve the target discriminating ability at the time of the turning motion of the operating body in the target searching apparatus for identifying the target located on the course of the operating body, focusing on such a problem. It is in. Then, the target searching device is applied to an alarm device, an automatic tracking device, etc. to eliminate false alarms, false tracking, etc., to reduce the burden on the driver and surely prevent traffic accidents.

[0015]

FIG. 1A is a block diagram for explaining the basic principle of the present invention. The target search device according to claim 1 searches the periphery of the moving body 4 to capture the target 5,
The target capturing means 1 for obtaining the relative position P of the target 5 with respect to the operating body 4, the circular trajectory estimating means 2 for estimating the circular trajectory C of the operating body 4 in the turning motion of the operating body 4, and the target capturing means 1 are obtained. The relative position P of the target 5 and the circular orbit estimating means 2
Based on the circular orbit C of the operating body 4 estimated by
Is located on the circular orbit C and identifies the target located on the course of the operating body 4.

The target searching apparatus according to a second aspect is the moving body 4 estimated by the circular orbit estimating means 2 in the configuration according to the first aspect.
The target capturing means 1 is controlled based on the circular trajectory C of
It has means for increasing the ratio of searching the turning direction of the running body 4.

An alarm device according to a third aspect of the present invention has the target searching device according to the first or second aspect, and based on the target identification result of the target searching device, an obstacle located on the lane in which the host vehicle is traveling. It has a means to selectively make only the object a warning target.

An automatic tracking device according to claim 4 has the target searching device according to claim 1 or 2, and travels on the lane in which the vehicle is traveling based on the target identification result of the target searching device. It has a means for selectively tracking only the vehicle.

[0019]

In the conventional target searching apparatus, as described above, the target located on the path of the vehicle is identified only by determining whether the direction of the captured target is close to the direction directly in front of the vehicle. In other words, in other words, in the past, the course of the vehicle was estimated by a linear trajectory, and it was determined whether the captured target was on the estimated linear trajectory, and the target located on the route of the vehicle was identified. It can be said that it was doing.

In the turning motion of the operating body, it is closer to the actual path of the operating body than estimating the straight line trajectory when estimating the circular orbit. Incidentally, if a vehicle is taken as an example of the operating body, the curve as described above can be approximated by a part of the circumference, so that the estimation of the circular trajectory is extremely effective and almost coincides with the actual course of the vehicle.

The target searching apparatus according to claim 1 includes a target capturing means 1 for obtaining the relative position P of the target 5 and a circular trajectory estimating means 2 for estimating a circular trajectory C of the operating body 4 in the turning motion of the operating body 4.
Based on the relative position P of the target 5 and the estimated circular orbit C, the target 5 has the estimated circular orbit C of the moving body 4.
Since the control means 3 for determining whether or not the vehicle can be located above is provided, the ability to identify the target located on the path of the operating body 4 is improved as compared with the related art for the above reason.

The target searching apparatus according to claim 2 has means for increasing the ratio of searching the turning direction of the operating body 4 based on the estimated circular trajectory C when the operating body 4 makes a turning motion. Therefore, in the traveling direction of the moving body 4 which is important in the target search, the chances of capturing the target increase, and in the traveling direction other than the traveling direction which is not so important in the target search,
Inevitably the rate of capture is low.

As a result, the target 5 which is highly likely to be on the route of the operating body 4 is intensively identified, while the targets which are obviously not on the route of the operating body 4 are identified one by one. Since the processing to be performed can be omitted, the processing capacity such as the calculation required for the target search can be small.

If the required processing capacity is reduced, the processing capacity of the remaining capacity can be applied to another processing, and the processing capacity of the remaining capacity is deleted, for example, a circuit element with a slow operation speed. It is possible to reduce the size of the device and to reduce the cost by using, and by simplifying the heat dissipation mechanism.

Since the alarm device according to claim 3 has the target searching device according to claims 1 and 2, even if the vehicle travels on a curve, the target on the course of the vehicle, that is, the vehicle is traveling. It is possible to accurately identify the target on the moving lane.
Then, since only the targets thus identified are selected as warning targets, no false alarm is issued in the curve, unlike the conventional case.

According to the automatic tracking device of claim 4,
Even if the vehicle travels on a curve, it is possible to accurately identify the target on the route of the own vehicle, that is, the target on the lane in which the own vehicle is traveling, because the target searching device is included. . Then, since only the target thus identified is selected and set as the tracking target, it is possible to accurately track only the preceding vehicle on the lane in which the host vehicle is traveling.

As a result, there is no fear of false recognition tracking such as tracking a vehicle overtaking in the overtaking lane, so the driver can use the automatic tracking with confidence.
The burden on the driver is reduced, and at the same time, accidents such as rear-end collisions can be reliably prevented.

[0028]

EXAMPLES Next, examples of practical use of the target searching apparatus according to the present invention will be described. Figure 2
FIG. 6 is a diagram illustrating a specific method of estimating a circular trajectory of a moving body and a specific method of identifying a target on the estimated circular trajectory.

Now, it is assumed that the operating body 6 is turning, and at a certain moment, the operating body 6 is moving at a velocity vector V as shown in FIG. In that case, it is preferable that the estimated trajectory of the operating body 6 is a circle passing through the operating body 6 and having a tangent line in the direction of the velocity vector V at the position of the operating body 6.

It can be interpreted that the direction of the velocity vector V coincides with the direction directly in front of the moving body 6, so that it is practically sufficient. Will be located in. Therefore, if only the radius R of the circular orbit is determined by the method described later, the circular orbit C ₁ satisfying the above condition is uniquely determined.

Here, it is assumed that the target 7 is on the estimated circular orbit C ₁ . If the target 7 is captured by the radar, the relative position of the target 7 obtained is the angle θ and the distance L. At this time, in principle, L = 2Rsin θ (Equation 1) holds. Therefore, if all the captured targets are collated with the left side and the right side of Expression 1 having a certain width, it is possible to identify whether or not each target is located on the estimated circular orbit.

Next, a method for obtaining the radius of the circular orbit will be described. FIG. 3 is a block diagram illustrating a configuration example for obtaining the radius of the circular orbit, that is, the radius of gyration of the moving body. In the same figure (a), the traveling direction control means 10
The control value φ _{sf in} the traveling direction of the vehicle and the speed V _{sf of the} vehicle output by the speed sensor 11 are input to the calculating means 12a. The output φ _sf of the traveling direction control means 10 is, for example, the steering operation angle of the vehicle.

According to such a configuration, the speed V _sf of the moving body, the control value φ _{sf in the} traveling direction, and the radius of gyration of the moving body, which are obtained in the steering test of the moving body to which the present apparatus is applied, etc. It is possible to obtain the above radius of gyration by incorporating the above relation into the calculating means 12a. Of course, the relationship obtained by simulation, physical theory, or the like may be incorporated in the arithmetic means 12a without depending on the test.

In FIG. 3B, the rotational angular velocity ω _sf of the moving body output by the gyro sensor 13 and the velocity V _sf of the moving body output by the speed sensor 11 are input to the calculating means 12b. According to such a configuration, the radius of gyration can be obtained by calculating V _sf / ω _sf by the calculating means 12b.

Next, a target searching method suitable for the present invention will be described. A radar is suitable for searching for a target in the present invention. Particularly when applied to a vehicle, a laser radar using laser light in the infrared region is suitable.
FIG. 4 is a diagram for explaining the scanning control of the radar beam suitable for the present invention.

FIG. 3A shows a so-called multi-beam system, in which the radar beam scans from S ₁ to S _{n in the} same direction in each direction when the vehicle 21 is not turning. Has been fired, so that. Then, when the running body 21 starts to turn, in order to search the circular orbit C ₂ obtained by the above method more densely, the ratio of scanning from S _A to S _{B is set} to be smaller than the ratio of scanning in other directions. Also increase.

Further, FIG. 6B shows a so-called scanning method, and when the operating body 21 is not turning,
The radar beam sweeps between θ _all so that the scanning rate in each direction is the same. Then, when the running body 21 starts to turn, in order to search the circular orbit C ₂ obtained by the above method more densely, the ratio of sweeping between θ _p is
Use more than the rate of sweeping in the other direction.

Since such a scanning control increases the ratio of searching for the traveling direction of the moving body 21 and decreases the ratio of searching for other directions, the chances of capturing the target located on the traveling route increase, and obviously Opportunities to capture targets that are not on the path are reduced. Therefore, it is unlikely that you will miss a target located on the path, and the time to search for a target that is clearly not on the path is shortened one by one.
The required processing power is reduced.

As described above, if the required processing capacity is reduced, it is possible to use a lower-cost element having a slower operation speed, and it is also possible to allocate the remaining processing speed to another processing. Become. Further, a distributed processing circuit used for speeding up, for example, a plurality of DSPs (Digital Signals)
It is also possible to reduce some such as Processor).

Further, the number of used elements is reduced due to the reduction of a part of the distributed processing circuit, and the elements with slow operation speed are
In general, since power consumption and heat generation are small, it is also possible to simplify the heat dissipation mechanism or reduce the power supply capacity to reduce the size and weight of the device.

In addition, in the alarm device mounted on the vehicle as described above, S ₁ to S _n shown in FIG.
As described above, or if the vehicle is always searched in the same ratio as in the case of θ _all shown in FIG. 7B, a large amount of processing capacity is difficult to realize.
Therefore, in the present situation, such a scanning control is used to realize an alarm device mounted on a vehicle.
It is extremely effective to reduce the required processing capacity.

Next, an alarm device to which the present invention is applied will be described. FIG. 5 is a block diagram illustrating a configuration example of an alarm device mounted on a vehicle, and is an example configuration of a device that issues an alarm to an obstacle within a safe distance in front of the vehicle. In this example, the DSP 31, ROM 32, and RAM 33 constitute the control means.

When the target 42 is captured by the radar device 36, the captured distance L _T , azimuth θ _T , and relative velocity V _T of the target 42 are output to the DSP 31 via the I / O port 34a. . On the other hand, the radar device 36 scans in the I / O port 34
It is controlled by the DSP 31 via a.

When the vehicle makes a turning motion, the gyro device 38
Output is digitized by the A / D converter 37, and the rotational angular velocity ω _{S of the} vehicle is transferred to the DSP via the I / O port 34b.
It is output to 31. In addition, the vehicle speed V _S is determined by the I / O port
It is output from the vehicle speed detection device 39 to the DSP 31 via 34c. And the alarm is sent to the DSP via the I / O port 34d.
When the alarm device 40 is controlled by 31, it is sounded.

FIG. 6 is a flow chart for explaining an example of control performed by the DSP 31. Whether or not the vehicle is making a turning motion is determined by the angular velocity ω _S as in steps H50 and H51. In the radar scanning, during the period when the vehicle is traveling straight, as in step H52, normal scanning, that is,
The front of the vehicle is controlled to scan at the same rate. Then, when the vehicle approaches a curve and makes a turning motion, it is controlled so as to increase the ratio of intensive scanning, that is, the direction of the curve, as in steps H53, H54, and H55.

When such radar scanning control is performed, the ratio of scanning in the opposite direction of the curve is inevitably reduced when the vehicle approaches the curve, so that the vehicle clearly travels in the opposite direction of the curve. For the obstacles not on the lane, the frequency of performing the processing such as steps H56, H57, H58, and H59 is reduced, and thus the processing capacity required for the present apparatus is reduced.

Supplementation of the target is performed as in steps H56 and H57, and it is determined in steps H58 and H59 whether the supplemented target is on the traveling lane of the host vehicle. If the supplemented target is on the lane of the host vehicle, the distance to the target is compared with the safety distance as in step H60, and if the safety distance is not maintained,
An alarm is sounded, as in step H61.

In this way, since the present device only targets obstacles on the driving lane of the own vehicle even in a curve, unlike in the prior art, no false alarm is issued even in a curve. Then, an alarm is issued to an obstacle approaching the host vehicle without a false alarm, which is useful for preventing a traffic accident.

Next, an automatic tracking device to which the present invention is applied will be described. FIG. 7 is a block diagram illustrating a configuration example of an automatic tracking device mounted on a vehicle, which is a configuration example of a device that automatically maintains a safe inter-vehicle distance. Also in this device,
The portion of A30 including the DSP31 is the same as the portion of A30 shown in FIG.

With this arrangement, in the present apparatus, the acceleration controller 70 is controlled by the DSP 31 via the I / O port 34e, and the vehicle speed is controlled by the DSP 31. Of course, release that control,
The speed of the vehicle can also be changed by the accelerator.

FIG. 8 is a flow chart illustrating an example of control performed by the DSP 31. Steps H80, H81,
The radar scanning control shown in H82, H83, H84, and H85, and the target search shown in steps H86, H87, H88, and H89 are as described with reference to FIG.

If the preceding vehicle traveling on the lane of travel of the host vehicle is supplemented, the relative speed with respect to the preceding vehicle is judged as in step H90, and if the inter-vehicle distance is shrinking, step H92 If the vehicle-to-vehicle distance is increasing, the vehicle-to-vehicle distance is kept constant by accelerating as in step H91.

As described above, the present apparatus targets only the preceding vehicle on the traveling lane of the host vehicle even in a curve, so that false tracking does not occur. Further, since the vehicle-to-vehicle distance can be automatically kept constant without misidentification tracking, the burden on the driver is reduced, which is useful for preventing accidents such as a rear-end collision.

[0054]

As described above, the target searching apparatus according to the first aspect of the invention is configured to estimate the circular orbit of the moving body in the turning motion of the moving body. It has become possible to estimate a trajectory that is closer to the actual course of the vehicle, and the ability to identify targets located on the course of the vehicle has improved.

As described above, the target searching apparatus according to the second aspect estimates the circular orbit of the operating body in the turning motion of the operating body, and determines the ratio of searching the turning direction of the operating body based on the estimated circular orbit. Since it is configured to increase, unlike in the past, the chances of target acquisition in the traveling direction of the operating body, which is important for target searching, increased, and the ability to identify the target located on the route of the operating body improved. .

Along with this, the rate of searching in a direction other than the traveling direction of the operating body, which is not so important in the target search, is reduced, and the processing capacity required for the target search is reduced. Has become smaller and lighter and has reduced costs. Since the required processing capacity has decreased, an alarm device or the like, which was difficult to realize at present, could be easily realized.

As described above, the alarm device according to claim 3 has the target searching device according to claims 1 and 2, and selects only a target on the lane in which the host vehicle is traveling as a warning target. Therefore, it becomes possible to accurately identify the target on the lane on which the vehicle is traveling even on a curve, and unlike the conventional case, no false alarm is issued on the curve.

As described above, the automatic tracking device according to claim 4 has the target searching device according to claims 1 and 2, and selects only the target on the lane in which the host vehicle is traveling as a tracking target. Because of the configuration, it is now possible to accurately track a vehicle in front of the lane in which the vehicle is traveling without misidentifying tracking. Further, since there is no false tracking, the driver can use the automatic tracking with peace of mind, the burden on the driver is reduced, and at the same time, the accident such as a rear-end collision can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram and a sketch showing the basic principle of the present invention.

FIG. 2 is a diagram for explaining the operation of a circular orbit estimation means and a control means.

FIG. 3 is a block diagram illustrating a configuration example of a circular trajectory estimation means.

FIG. 4 is a diagram illustrating target scanning control suitable for the present invention.

FIG. 5 is a block diagram illustrating a configuration example of an alarm device for an obstacle.

FIG. 6 is a flowchart illustrating an example of control in the alarm device.

FIG. 7 is a block diagram illustrating a configuration example of an automatic tracking device.

FIG. 8 is a flowchart illustrating an example of control in the automatic tracking device.

FIG. 9 is a diagram illustrating a problem in a conventional target search.

[Explanation of symbols]

 1 target capturing means 2 circular orbit estimating means 3 control means 4 moving body 5 target

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G05D 1/02 J 9323-3H G08B 21/00 9177-5G

Claims (4)

[Claims] 1. A target capturing means (1) for searching a periphery of a vehicle (4) to capture a target (5) and obtaining a relative position (P) of the target (5) to the vehicle (4), Circular orbit of the operating body (4) in the turning motion of the operating body (4)
The relative position (P) of the circular orbit estimation means (2) for estimating (C) and the target (5) obtained by the target capturing means (1)
And whether the target (5) is located on the circular orbit (C) based on the circular orbit (C) of the moving body (4) estimated by the circular orbit estimation means (2). A target searching device comprising: a control unit (3) for making a determination and identifying a target located on the course of the operating body (4). 2. The target searching apparatus according to claim 1, wherein the circular orbit (C) of the moving body (4) estimated by the circular orbit estimating means (2).
A target searching apparatus comprising means for controlling the target capturing means (1) so as to increase the rate of searching the turning direction of the operating body (4) based on the above. 3. An alarm device for warning abnormal approach of an obstacle in front of a vehicle, comprising the target searching device according to claim 1 or 2, and based on a target identification result of the target searching device.
An alarm device comprising means for selectively warning only obstacles located on the lane in which the host vehicle is traveling. 4. An automatic tracking device for automatically tracking a vehicle traveling in front of the own vehicle, comprising the target searching device according to claim 1 or 2, and based on a target identification result of the target searching device. An automatic tracking device comprising means for selectively targeting only a vehicle traveling on a lane on which the vehicle is traveling.