JPH08240658A - Radar apparatus - Google Patents

Abstract

PURPOSE: To correctly grasp a road condition under which an own vehicle is run and to optimally control the detection method of a radar apparatus according to the grasped road condition. CONSTITUTION: A radar apparatus by which a distance up to a front target and a relative speed are detected is provided with an own-vehicle-position recognition means 9 which detects the position of an own vehicle on a road, with a road-condition judgment means 10 by which a road condition under which the own vehicle is run is judged on the basis of data by the own-vehicle-position recognition means 9 and with a detection-method control means 11 by which the detection method of the radar apparatus is controlled on the basis of a judged result by the road-condition judgment means. On the basis of map data by the own-vehicle-position recognition means 9, the road-condition judgment means 10 judges the road condition under which the own vehicle is run. The detection-method control means 11 controls the detection method of the radar apparatus regarding the direction of a radar beam, a maximum detection distance, the width of the radar beam and the like when a road condition at the front is recognized, and a required target can be recognized properly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radar device for determining a distance and a relative speed with respect to a front target, which is mounted on a car and is located in front of the own car. And used to measure the relative speed between the vehicle and itself.

[0002]

2. Description of the Related Art A configuration example of a conventional radar device is shown in FIG. In the radar apparatus of FIG. 12, the signal analysis unit 2 analyzes the signal detected by the radar sensor 1, and the distance / relative speed calculation unit 3 calculates the distance / relative speed with respect to the vehicle ahead. Further, based on signals from the vehicle sensor 4 such as a steering sensor, a yaw rate sensor, and a vehicle speed sensor, the vehicle signal analysis means 5 determines the road condition on which the vehicle is traveling and calculates the traveling speed of the vehicle. . The beam steering means 6 changes the direction of the radar beam for searching the target.

The alarm output means 8 determines the degree of danger of the vehicle based on the above calculation / judgment results and outputs an alarm if necessary, and the vehicle control means 7 adjusts the accelerator opening. Control the vehicle.

[0004]

However, the above-mentioned conventional radar device cannot accurately grasp the road condition on which the vehicle is traveling. For example, as shown in FIG. 13, when the own vehicle 21 is traveling on a straight road and is approaching a curve entrance, the vehicle sensor (yaw rate sensor, steering sensor) of the own vehicle is used even if the road condition ahead is a curve. The situation judged from the signal is a straight road.

Therefore, in the conventional radar device, problems such as losing sight of the forward vehicle 22 and recognizing the wall 23 on the curved road side as a target and issuing a false alarm occur. It is an object of the present invention to accurately grasp a road condition on which a vehicle travels in a radar device, and to optimize a detection method of the radar device according to the grasped road condition.

[0006]

In order to achieve the above object, the present invention provides a vehicle position recognizing means for detecting the position of a vehicle on a road in a radar device for detecting a distance and a relative speed to a front target. And a road condition judging means for judging the road condition on which the own vehicle is traveling based on the data of the own vehicle position recognizing means, and a detecting method controlling means for controlling the detecting method of the radar device based on the judgment result of the road condition judging means. And.

The detection method of the radar device controlled by the detection method control means is as follows:
There are maximum detection distance and radar beam width.

[0008]

The road condition judging means judges, based on the data of the own vehicle position recognizing means, the road condition on which the own vehicle is traveling, for example, that the entrance or exit of a curve is approaching or an intersection is approaching. To do. This makes it possible to determine that the vehicle is traveling on a straight road but there is a curve ahead.

When the road condition judging means recognizes the road condition ahead, the detecting method controlling means controls the detecting method of the radar device such as the direction of the radar beam, the maximum detection distance, the radar beam width, and the like, so that a necessary target is detected. Be able to recognize properly.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of the radar device of the present invention.
In FIG. 1, reference numeral 1 denotes a radar sensor, which emits a radar beam in front of the vehicle and outputs a signal based on the radar beam reflected from the target. Reference numeral 2 is a signal analyzing means for analyzing the output signal of the radar sensor 1. Reference numeral 3 is a distance / relative speed calculation means, which calculates the distance / relative speed with respect to the target based on the analysis result of the signal analysis means 2.

A vehicle sensor 4 is a steering sensor,
It includes a yaw rate sensor and a vehicle speed sensor. Reference numeral 5 denotes a vehicle signal analyzing means, which determines the road condition on which the vehicle is traveling and calculates the traveling speed of the vehicle based on the signal from the vehicle sensor 4. Reference numeral 9 is a vehicle position recognition means, for example, GP
The navigation system using S (Grobal Positioning system) recognizes the position of the vehicle on the map. Also,
The vehicle position recognition means 9 has map data.
The own vehicle position recognizing means 9 is not limited to GPS, and other navigation systems can be used.

Reference numeral 10 is a road condition judging means for judging the road condition on which the own vehicle is traveling based on the output of the own vehicle position recognizing means 9. This road condition judging means 10 recognizes the running condition of the own vehicle and the road condition in front of it from the position of the own vehicle on the map recognized by the own vehicle position recognizing means 9 and the map data possessed by the own vehicle position recognizing means 9. To do. As a concrete method for recognizing the road condition from this map data, for example, Japanese Patent Publication No. 6-727
The technique described in Japanese Patent Publication No. 82 can be used.

Detecting method control means 11 controls the radar beam width radiated forward by the radar sensor 1 based on the road condition judged by the road condition judging means 10 and operates the beam steering means 6 to operate the radar beam. Control the direction of
Alternatively, the maximum detection distance used for the calculation of the distance / relative speed calculation means 3 is changed. Note that the present embodiment is different from the above-described conventional example in FIG. 12 in that the vehicle position recognizing means 9 and the road condition determining means 10 are provided. For others, a general radar device can be used.

The operation of the radar device configured as described above will be described. In addition, each example in the following description,
Each can be used alone, or can be used in an appropriate combination.

[Embodiment 1] A first embodiment of the present invention will be described. As shown in FIG. 2, when the host vehicle 21 approaches the curve entrance and becomes a curve ahead, depending on the radius R of the curve, the radar beam 2 of the radar device
6 will reach the outside of the curve, that is, the lane of the own vehicle.

In the first embodiment, the maximum detection distance of the radar device is changed according to the road condition, and when the front is a curve, the maximum detection distance is set to the curve range cut distance Rc1 and is farther than that. Target outside your lane,
For example, the roadside wall 23 is not detected. Further, when the host vehicle 21 approaches the exit of the curve and becomes a straight road ahead, the maximum detection distance is returned to the original long distance to ensure the detection of the target.

The specific operation will be described with reference to the flowchart of FIG. In step S11, the road condition judging means 10 judges the road condition in front of the own vehicle based on the map position of the own vehicle recognized by the own vehicle position recognizing means 9 and the map data. In step S12, it is determined whether or not the front of the vehicle is a curve based on the determination by the road condition determination means 10. If the vehicle is a curve, the process proceeds to step S13.
If it is not a curve, the process proceeds to step S15.

If the front is a curve, step S13
Then, the distance between the host vehicle and the road side of the front curve (FIG. 2) is calculated from the data on the front curve, and this is set as the curve range cut distance Rc1. Then step S14
Then, the curve range cut distance Rc1 is set to the maximum detection distance Rmax of the radar device. Accordingly, when the front of the vehicle is a curve, the maximum detection distance of the radar device is limited to within the vehicle lane.

If the front of the vehicle is not a curve, the maximum detection distance Rmax is set to RL1 in step S15. This distance RL1 is an originally long distance necessary for searching a target on a straight road. In step S16, the set maximum detection distance Rmax is compared with the distance Rn to the target. When there are a plurality of targets, the distance / relative speed calculation means 3 calculates the distance for each target. The subscript n means that it is the n-th target counted from the side closer to the vehicle. In step S16, if Rmax> Rn for each target, the process proceeds to step S17, and if not, the process proceeds to step S18.

If the n-th target is within the maximum detection distance, the target is determined to be a vehicle ahead in step S17. If the nth target is farther than the maximum detection distance, that target is ignored in step S18. Thereafter, the alarm output means 8 judges the degree of danger of the own vehicle based on the above-described calculation / judgment result and outputs an alarm if necessary, and the vehicle control means 7 adjusts the accelerator opening degree or the like. Vehicle control.

According to the example described above, when the front side is a curve, the maximum detection distance is set to the front side of the road side of the curve, so that the road side wall outside the curve is not detected as a target. . Further, since the road condition judging means 10 can judge whether the front is a curve or a straight road based on the map data, the road condition ahead can be accurately judged and the maximum detection distance is set to an optimum value. it can.

That is, when approaching the entrance of a curve, even if the vehicle is on a straight road and the front is a curve, the maximum detection distance can be set to a value according to the curve, resulting in a false alarm,
Erroneous control can be prevented. Also, when approaching the exit of a curve, even if the vehicle is traveling on a curve, if the road ahead is a straight road, the maximum detection distance can be returned to the value used on a straight road, ensuring safety. You can

[Second Embodiment] A second embodiment of the present invention will be described. In the above-described first embodiment, the direction of the radar beam is fixed, and the maximum detection distance of the radar device is changed according to road conditions. On the other hand, in the second embodiment, as shown in FIG. 4, the beam steer means is operated according to the road condition to direct the radar beam 26 in the optimum direction to search the target 22.

The specific operation will be described with reference to the flowchart of FIG. In step S21, the road condition determination means 10 determines the road condition in front of the own vehicle, and in step S22, it is determined whether or not the front of the own vehicle is a curve based on the determination. When it is determined in step S22 that the front of the vehicle is a curve, the process proceeds to step S23, and the beam steering by the beam steering means 6 is started. If it is determined that the front is not a curve, the process proceeds to step S24, and the beam steer operation by the beam steer means 6 is terminated.

The beam steering operation in step S23 will be described with reference to FIG. When the radar beam is capturing the target 22 ahead, the distance Ra to the target 22 is calculated, and the beam steer angle θ that can be effectively covered by the distance Ra in the curve of the radius R is calculated. Then, the beam steering means 6 changes the direction of the radar beam to the angle θ. When the front target 22 is not captured, the distance Ra uses a tentatively determined value, and the beam steer angle θ is calculated from the tentatively determined distance Ra and the radius R of the curve.

The calculation and control of the beam steer angle θ is continued while it is determined that the curve is ahead. And
When it is determined that the host vehicle is approaching the curve exit and the front is not a curve, the beam steer angle θ is returned to 0 in step S24.

[Third Embodiment] A third embodiment of the present invention will be described. If the front of the vehicle is a curve as shown in FIG. 6, the radar apparatus may detect the target 22 on the oncoming lane 25 because the radar beam 26 may reach not only the own lane 24 but also the oncoming lane 25. , Will give a false alarm. In the present embodiment, when the road condition determining means 10 determines that the front of the vehicle is a curve, the target ahead of the vehicle is ignored, and unnecessary calculation and determination are performed. I try not to do it.

The specific operation will be described with reference to FIG. In step S31, the road condition judging means 9 judges the road condition in front of the own vehicle. In step S32, as shown in FIG. 6, based on the road condition in front of the own vehicle, the minimum distance R within the own lane 24 in the range detected by the radar device.
Calculate L2.

In step S33, the minimum distance RL2 is compared with the distance Rn to each target 22. This distance Rn is the same as that described in step S16 of FIG. 2 of the first embodiment. In step S33, if RL2> Rn for each target, the process proceeds to step S34, and if not, the process proceeds to step S35. Distance Rn
The n-th target inside (that is, inside the own lane 24) is determined to be a forward vehicle in step S34, and the distance Rn
At a greater distance (for example, within the diagonal line 25)
The nth target is ignored in step S35.

Thereafter, the alarm output means 8 judges the degree of danger of the own vehicle based on the above calculation / judgment results and outputs an alarm if necessary, and the vehicle control means 7 adjusts the accelerator opening degree. Vehicle control. According to the example described above, there is the vehicle 22 or the like in front of the own vehicle, which is the radar beam 2
Even if it is within the range that 6 detects, if it is not within the own lane 24, it is ignored, so that false alarms and useless calculations are prevented.

[Embodiment 4] A fourth embodiment of the present invention will be described. As shown in FIG. 8, when the front of the own vehicle 21 is a curve and the detection direction of the radar device is kept in the direction 27 on the straight road, the target 22 traveling along the curve is It becomes out of 26 and cannot be detected. In the fourth embodiment, when the front of the own vehicle 21 is a curve, the beam steering means 6 is operated to control the direction of the radar beam 26 to search for a target.

The operation will be described below with reference to the flowcharts of FIGS. 9 and 10. Step S41 of FIG.
Then, the road condition judging means 10 judges the road condition in front of the own vehicle, and in step S42, it is judged whether or not the front of the own vehicle is a curve. If it is determined in step S42 that the front of the vehicle is a curve, the process proceeds to step S43 to start the target search, and if it is determined not to be a curve, the process proceeds to step S44 to end the target search.

Details of the target search in steps S43 and S44 are shown in FIG. In step S51, the radius R of the curve ahead is calculated based on the map data of the vehicle position recognizing means 9. In step S52, the beam steer means 6 sets the radar beam to the beam steer angle θ (i). The beam steering angle θ (i) is a plurality of angles set with respect to the front direction 27 of the vehicle 21, as shown in FIG. 8, and is numbered sequentially from left (or right). ing. The number (i) is set according to the contents of the counter (i).

In step S53, the range cut distance R
Calculate c. This range cut distance Rc is a function f1 based on the shape of the curve based on the map data of the vehicle position recognizing means 9 and the beam steer angle θ (i). Step S
At 54, the radar beam width W is calculated. The radar beam width W is a function f2 based on the curve shape and the beam steer angle θ (i). For example, the beam steering angle θ in FIG.
In (1), the radar beam width is widened, and in the beam steer angle (i), the radar beam width is narrowed so that targets other than the own lane are not detected.

In step S55, the distance to the target and the relative speed are calculated. At this time, the maximum detection distance of the radar device is set to the range cut distance Rc, and calculation is not performed for targets that are not within the range cut distance Rc. In step S56, it is determined whether or not there is a target based on the calculation result in step S55. Here, if it is determined that the target is present, the operation is ended, and if it is determined that the target is not present, the process proceeds to step S57.

In step S57, the value of the counter i is set to 1
Is added, and the process returns to step S52. In step S52, the beam steering angle of the beam steering means 6 is counted by the counter i.
The next beam steer angle is set based on the value of. After that, steps S52 to S57 until the target is recognized.
The beam steering means 6 sequentially changes the beam steering angle θ to search for a target.
When the target is recognized or the search for all the beam steer angles θ (i) is completed, the operation is ended through step S56. With the above operation, when the front of the vehicle is a curve, the target is searched by the beam steer.

If it is determined in step S42 in FIG. 9 that the front of the vehicle is not a curve, then in step S44
After finishing the target search in FIG. 10, the beam steer angle,
Return the maximum detection distance and radar beam width to the values when traveling on a straight road. In the example described above, when it is determined that the front of the vehicle is a curve, the beam steer angle, the maximum detection distance, and the radar beam width are all controlled, but these are used independently. It can also be combined appropriately.

[Embodiment 5] A fifth embodiment of the present invention will be described. At the intersection, the range in which the target in front of the own vehicle is present is wider than in the normal driving lane.
In this embodiment, when the vehicle approaches the intersection, the radar beam width is expanded to widen the target detection range.

The operation will be described below with reference to the flowchart of FIG. In step S61, the road condition judging means 9 judges the road condition in front of the vehicle. In step S62, based on the data of the vehicle position recognition means 9,
It is determined whether or not the front of the vehicle is an intersection. If the intersection is ahead, the process proceeds to step S63, and if it is not the intersection, the process proceeds to step S64.

In step S63, the radar beam width is expanded. This makes it possible to detect a wide range of targets at intersections. In step S64,
Return the radar beam width to the normal value.

[0041]

According to the present invention, in the radar device,
You can accurately understand the road conditions on which your vehicle is traveling,
The detection method of the radar device can be controlled to the optimum one according to the grasped road condition.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a radar device of the present invention.

FIG. 2 is a diagram showing a road condition for explaining a first operation example of the radar device of FIG.

FIG. 3 is a flowchart showing a first operation example of the radar device of FIG.

FIG. 4 is a diagram showing a road condition for explaining a second operation example of the radar device of FIG. 1.

5 is a flowchart showing a second operation example of the radar device of FIG.

FIG. 6 is a diagram showing a road condition for explaining a third operation example of the radar device of FIG. 1.

7 is a flowchart showing a third operation example of the radar device of FIG.

8 is a diagram showing a road condition for explaining a fourth operation example of the radar device of FIG. 1. FIG.

9 is a flowchart showing a fourth operation example of the radar device of FIG.

10 is a flowchart showing an operation example of target search in FIG.

11 is a flowchart showing a fifth operation example of the radar device in FIG.

FIG. 12 is a block diagram showing a configuration example of a conventional radar device.

FIG. 13 is a diagram showing a road condition for explaining the operation of FIG. 12;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Radar sensor 2 ... Signal analysis means 3 ... Distance / relative speed calculation means 4 ... Vehicle sensor 5 ... Vehicle signal analysis means 6 ... Beam steering means 7 ... Vehicle control means 8 ... Warning output means 9 ... Own vehicle position recognition means 10 ... Road condition judging means 11 ... Detection method controlling means 21 ... Own vehicle 22 ... Forward vehicle 23 ... Wall 24 ... Own lane 25 ... Oncoming lane 26 ... Radar beam

Claims (14)

[Claims] 1. A radar apparatus for detecting a distance and a relative speed to a front target, a vehicle position recognizing means for detecting a position of a vehicle on a road, and a vehicle based on data of the vehicle position recognizing means. A radar device comprising: a road condition judging means for judging a road condition on which the vehicle travels; and a detection method controlling device for controlling a detecting method of the radar device based on a judgment result of the road condition judging means. 2. The radar device comprises beam steer means for changing the direction of the radar beam, and the detection method control means operates the beam steer means to control the direction of the radar beam. The radar device according to claim 1. 3. The detection method control means changes the maximum detection distance of the radar device.
The described radar device. 4. The radar device according to claim 1, wherein the detection method control means controls a radar beam width of the radar device. 5. The detection method control means changes the maximum detection distance of the radar device according to the radius of the curve when the road condition determination means recognizes that the vehicle ahead is a curve. The radar device according to claim 3. 6. The detection method control means, when the road condition determination means recognizes that the front of the vehicle is not a curve, returns the maximum detection distance of the radar device to a value used on a straight road. The radar device according to claim 5. 7. The detection method control means, when the vehicle position recognition means recognizes that the front of the vehicle is the entrance of the curve, operates the beam steering means to change the direction of the radar beam to the direction of the curve. The radar device according to claim 2, wherein the radar device is controlled according to a radius. 8. The detection method control means, when the road condition determination means recognizes that the front of the vehicle is not a curve, operates the beam steer means to return the direction of the radar beam to a state on a straight road. The radar device according to claim 7, wherein 9. The radar device according to claim 3, wherein the detection method control means sets the maximum detection distance of the radar device within a range included in the own lane. 10. The detection method control means, when the road condition determination means recognizes that the front of the vehicle is a curve, operates the beam steer means to cause the radar device to move within a curve ahead. The radar device according to claim 2, wherein a certain target is searched. 11. The radar device according to claim 10, wherein the detection method control means changes the maximum detection distance of the radar device at the same time. 12. The radar apparatus according to claim 4, wherein the detection method control means widens the radar beam width when the road condition determination means recognizes that the front of the vehicle is an intersection. . 13. The detection method control means narrows the radar beam width and operates the beam steer means when the road condition determination means recognizes that the front of the vehicle is a curve. 3. The radar device according to claim 2, wherein the radar device is caused to search for a target within the curve. 14. The radar device according to claim 13, wherein the detection method control means changes the maximum detection distance at the same time.