JPH08285941A - On-vehicle radar system - Google Patents

Abstract

PURPOSE: To obtain a radar apparatus by which an obstacle can be detected properly by a method wherein a running lane is discriminated on the basis of an image which has been photographed by a photographing means at the front of a vehicle, the sighting of a beam is matched to a point at a constant distance inside the lane and a beam irradiation direction is corrected. CONSTITUTION: A road state at the front is photographed by a camera 22a installed at the front of a vehicle. The state of a curve or the like in a running lane is grasped by an image processing part 22b by making use of a white line as a reference. An angle θ which of formed by a point at a prescribed distance L1 on the lane and by a present running direction is found. In succession, it is judged whether an obstacle exists or not within a prescribed distance L2 which is smaller than the distance L1 . When the obstacle does not exist, it is confirmed by a radar apparatus 1 that the obstacle does not exist within the distance L2 , and the beam irradiation direction of the apparatus 1 is corrected to the angle θ. When the obstacle exists within the distance L2 , the beam irradiation direction is set to 0 deg. (it is returned to an original state). In this manner, the obstacle can be detected always properly irrespective of the road state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle radar device for monitoring the front and the periphery of a vehicle, and more particularly to an on-vehicle radar device capable of changing the irradiation direction of a beam depending on the direction of a traveling lane.

[0002]

2. Description of the Related Art An on-vehicle radar device is provided as an alarm means for preventing a collision by measuring a distance to an obstacle (front vehicle, etc.) and a relative speed by a radar device installed in front of a vehicle. Has been done. FIG. 4 is a diagram showing a configuration of a conventional vehicle-mounted radar device. 5A and 5B are views showing a beam irradiation state of a conventional vehicle-mounted radar device. FIG. 5A is a curve entrance vicinity, FIG. 5B is a curve middle vicinity, and FIG. 5C is a curve exit vicinity. Hereinafter, description will be given with reference to the drawings.

Reference numeral 91 denotes a radar device installed in front of the vehicle, which is a radar 91a for radiating a beam toward the front of the vehicle.
And a steering unit 91b that changes the irradiation direction of the beam, receives the beam reflected by an obstacle (front vehicle, etc.), and measures the distance to the obstacle, the relative speed, and the like from the time difference and frequency shift. . A curve detection unit 95 detects whether or not the vehicle is traveling on a curve based on signals from a steering wheel turning angle detector 95a, a yaw rate sensor (angular velocity sensor) 95b, and the like. A control unit 94 detects an obstacle on the curved lane by instructing the steering unit 91b to change the irradiation direction (angle) of the beam of the radar device 91 based on a signal from the curve detection unit 95. it can.

[0004]

DISCLOSURE OF THE INVENTION Problem to be Solved by the Invention
Curve detection unit 9 such as a yaw rate sensor (angular velocity sensor)
When the irradiation direction of the beam is changed by the signal from the vehicle 5, when the host vehicle 7 is near the middle of the curve of the traveling lane 8 (see FIG. 5 (b)), it is directed toward the front center of the curved traveling lane 8. (Arrow F2) Since the beam is emitted, the radar device 91 functions normally. However, when the vehicle 7 is near the entrance of the curve (see FIG. 5 (a)), the irradiation position of the beam for detecting an obstacle (front vehicle, etc.) must be on the forward traveling lane. However, since the own vehicle 7 has not yet entered the curve, the steering wheel is not turned and the vehicle is in a straight traveling state. Therefore, the beam is emitted in the front direction (arrow F1), and the obstacle on the curved traveling lane 8 cannot be detected. On the contrary, the guardrail of the curved traveling lane 8 is detected as an obstacle. Also,
In the vicinity of the exit of the curve (see FIG. 5 (c)), the irradiation position of the beam for detecting an obstacle (front vehicle, etc.) must be on the straight ahead traveling lane 8, but the own vehicle 7 is still on the curve. Since it is on the top, the handle remains in the off state. Therefore, the beam does not illuminate the front surface but illuminates the direction (arrow F3) corresponding to the curve, and the traveling lane 8 goes straight.
Will detect the guardrail as an obstacle. Further, even if the beam direction is straightened at the exit of the curve, if an obstacle to be detected from the adjacent lane laterally breaks in, there is a secondary problem that the obstacle cannot be detected. In addition, unless this detection range is set appropriately, the obstacle cannot be detected reliably.

The present invention provides an on-vehicle radar device capable of appropriately detecting obstacles by controlling the radar device so that the beam always irradiates toward the front center of the traveling lane regardless of road conditions. To aim.

[0006]

In order to achieve the above object, the present invention provides an on-vehicle radar for controlling the irradiation direction of a beam of a radar device for monitoring the front of the vehicle according to the condition of the traveling lane of the vehicle. In the device, a first lane identification installed in front of the vehicle, for photographing a situation of a traveling lane in a forward direction of the vehicle, and a traveling lane for identifying the traveling lane of the vehicle from an image photographed by the photographing means. Means for adjusting the irradiation direction of the beam by aiming the beam of the radar device at a point at a first predetermined distance in the traveling lane of the vehicle identified by the first lane identification means. It is characterized by having steering means.

In addition, depending on the situation of the traveling lane of the vehicle,
In a vehicle-mounted radar device that controls a beam irradiation direction of a radar device that monitors the front of the vehicle, a second lane identification unit that identifies a traveling lane of the vehicle based on information from the infrastructure provided to the vehicle. Beam steering means for adjusting the irradiation direction of the beam by aiming the beam of the radar device at a point at a first predetermined distance in the traveling lane of the vehicle identified by the second lane identification means, It is characterized by having.

Further, depending on the situation of the traveling lane of the vehicle,
In a vehicle-mounted radar device that controls a beam irradiation direction of a radar device that monitors the front of the vehicle, a third lane identification unit that identifies a traveling lane of the vehicle based on information from a navigation system mounted on the vehicle. Beam steering means for correcting the irradiation direction of the beam by aiming the beam of the radar device at a point at a first predetermined distance in the traveling lane of the vehicle identified by the third lane identification means. It is characterized by having.

The beam steering means includes an obstacle recognizing means for recognizing that there is an obstacle, and when the beam recognizing means determines that there is an obstacle within the second predetermined distance by the obstacle recognizing means. The feature is that the correction of the irradiation direction of the beam is prohibited. The beam steering means includes an obstacle recognition means for recognizing that there is an obstacle, and the beam steering means detects that there is an obstacle within the second predetermined distance by the obstacle recognition means while the irradiation direction of the beam is being corrected. If you decide,
It is characterized in that the correction of the irradiation direction of the beam is stopped and the original state is restored.

The beam steering means is provided with an obstacle recognition means for recognizing that there is an obstacle, and the beam steering means is within a second predetermined distance by the obstacle recognition means after the correction of the irradiation direction of the beam is completed. If you determine that there is an obstacle,
It is characterized in that the irradiation direction of the beam is returned to the original state. Further, the obstacle recognition means is characterized in that it is recognized by the image taken by the imaging means.

Further, the obstacle recognition means is characterized by being recognized by the on-vehicle radar device. Further, the obstacle recognition means is characterized by being recognized by an infrastructure provided to the vehicle. Further, the obstacle recognizing means is recognized by a navigation system mounted on the vehicle.

Further, the first predetermined distance is variable according to the speed of the vehicle. Further, the first predetermined distance is variable according to an inter-vehicle warning distance indicating that the vehicle is too close to the front vehicle. Further, the first predetermined distance is variable according to an inter-vehicle control distance indicating that the relative distance to the preceding vehicle is constant.

Further, the second predetermined distance is variable according to the speed of the vehicle. Further, the second predetermined distance is variable according to an inter-vehicle warning distance indicating that the vehicle is too close to the front vehicle. Further, the second predetermined distance is variable according to an inter-vehicle control distance indicating that the relative distance to the preceding vehicle is constant.

[0014]

The function of the photographing means installed in front of the vehicle is to photograph the situation in front of the vehicle. Then, the first lane recognition means grasps the situation in front of the vehicle lane from the photographed image.
The beam steering means controls the direction of the beam of the radar device so that the beam is aimed at a first predetermined distance ahead of the vehicle lane, so that an obstacle on the traveling lane is always detected even on a curved road. it can.

Further, the second lane recognition means grasps the situation in front of the own vehicle lane by the infrastructure provided to the vehicle. The beam steering means controls the direction of the beam of the radar device so that the beam is aimed at a first predetermined distance ahead of the vehicle lane, so that an obstacle on the traveling lane is always detected even on a curved road. it can. In addition, whether the third lane recognition means is installed in the vehicle or not, the situation in front of the vehicle lane is grasped by the navigation system. The beam steering means controls the direction of the beam of the radar device so that the beam is aimed at a first predetermined distance ahead of the vehicle lane, so that an obstacle on the traveling lane is always detected even on a curved road. it can.

When the obstacle recognition means determines that there is an obstacle within the second predetermined distance, the beam steering means changes the beam direction of the radar device so as to act on the safety side. By prohibiting it, it is possible to deal with lane change vehicles from adjacent lanes. Further, while the beam steering means is changing the beam direction of the radar device, if the obstacle recognition means determines that there is an obstacle within the second predetermined distance, the beam steering means operates so as to act on the safe side. Can stop the change of the beam direction of the radar device and return to the original state, so that it is possible to cope with a lane change vehicle from an adjacent lane.

If the obstacle recognizing means determines that there is an obstacle within the second predetermined distance after the beam steering means changes the beam direction of the radar device, the beam is operated so as to act on the safe side. The steering means returns the beam direction of the radar device to the original state, so that it is possible to cope with a lane change vehicle from an adjacent lane. Further, the obstacle recognition means recognizes that there is an obstacle based on the image taken by the image pickup means.

Further, the radar device recognizes that there is an obstacle based on the time difference between the irradiation beam and the reflected beam. Further, the obstacle recognition means recognizes that there is an obstacle based on the information from the infrastructure provided to the vehicle. Further, the obstacle recognition means recognizes that there is an obstacle based on the current position information and the road map information from the navigation system mounted on the vehicle.

Further, by varying the first predetermined distance according to the speed of the vehicle, the front vehicle is accurately caught by aiming further at high speed and closer at low speed. . In addition, by varying the first predetermined distance according to the inter-vehicle warning distance, by aiming at an optimal position according to the performance and condition of the own vehicle at that time, based on the distance that does not approach the front vehicle too much. The front car can be accurately captured.

Further, by varying the first predetermined distance by the inter-vehicle control distance, based on the distance at which the relative distance to the preceding vehicle is constant, the optimum position is determined according to the performance and condition of the vehicle at that time. The front vehicle can be accurately captured by focusing on. Further, by changing the second predetermined distance according to the speed of the vehicle, the obstacle can be detected in a farther range at a high speed and in a closer range at a low speed.

Further, by changing the second predetermined distance according to the inter-vehicle warning distance, the obstacle is set within the optimum range according to the performance and condition of the own vehicle at that time, based on the distance that does not approach the front vehicle too much. Can be detected. Further, by changing the second predetermined distance by the inter-vehicle control distance, based on the distance at which the relative distance to the preceding vehicle is constant, obstacles are set in the optimum range according to the performance and condition of the own vehicle at that time. Can be detected.

[0022]

1 is a system configuration diagram of an on-vehicle radar device according to an embodiment of the present invention. 2A and 2B are views showing a beam irradiation state of an on-vehicle radar device according to an embodiment of the present invention. FIG. 2A shows a beam irradiation direction by recognition of a traveling lane, and FIG. 2B shows a relationship between the beam irradiation direction and an obstacle. It is a figure. FIG. 3 is a flowchart showing a method of controlling the beam direction of the on-vehicle radar device according to the embodiment of the present invention. Hereinafter, description will be given with reference to the drawings.

Reference numeral 1 denotes a radar device installed in front of the vehicle, which comprises a radar 1a for irradiating a beam toward the front of the vehicle and a steering section 1b for changing the irradiating direction of the beam.
Receive the beam reflected by an obstacle (front vehicle, etc.),
The distance to the obstacle and the relative speed are measured from the time difference and the frequency shift. Reference numeral 2 denotes a traveling lane recognition unit that recognizes the state of a road or a traveling lane in front of the own vehicle. The camera 22a installed in front of the vehicle photographs the road condition in front of the vehicle, and the image is processed by the image processing unit 22b. An image processing system for grasping the condition (curve, etc.) of the vehicle's running lane based on the white line of the road, a GPS receiver, and a satellite detecting the current position of the vehicle based on the map data 23a G
The PS system 23b is an infrastructure receiver, and is composed of, for example, an infrastructure 24 that receives road condition (curvature radius, etc.) data from a transmitter installed on the road.

Reference numeral 3 denotes an obstacle detection section for detecting an obstacle within a predetermined distance. The camera 22a installed in front of the vehicle photographs the road condition in front of the vehicle, and the image processing section 22b produces the image. Image processing system for processing and grasping obstacles, radar device 1 for irradiating a beam toward the front of the vehicle
Is a radar system that receives a beam reflected from an obstacle (such as a front vehicle) and measures the distance to the obstacle and the relative speed from the time difference and frequency shift.

Reference numeral 4 controls the irradiation angle of the beam of the radar 1a with respect to the steering section 1b of the radar apparatus 1 by the inputs from the lane recognition section 1, the obstacle detection section 3 and the detection section 5 for setting a predetermined distance. , A control unit that recognizes an obstacle based on information from the radar device 1. 5 is a detection unit for setting a predetermined distance, which is a vehicle speedometer 51 for detecting the speed of the vehicle,
In addition to various ECUs (arithmetic units) 52 installed in the vehicle,
Information on the radar device 1, the infrastructure 24, etc. is detected and sent to the control unit 4. In this configuration, the same name and the same reference numeral indicate the same thing and are shared according to the purpose.

Next, the radar steering method will be described.
In the description of the present embodiment, an image processing system including a camera 22a and an image processing unit 22b is used as the lane recognition unit 2, the detection unit 5 for setting a predetermined distance is a predetermined distance and the output of the detection unit is used. Not in. In step S1, the direction in which the road ahead or the traveling lane extends is grasped by image processing, and the process proceeds to step S2. That is, the image processing unit 22b processes the image taken by the camera 22a to grasp whether the road condition in front of the vehicle is a straight condition or a curved condition. For example, there is a method of scanning an image captured by the camera 22a in the horizontal direction and extracting a white line that determines a traveling lane.

In step S2, image processing is performed to calculate how many times (θ) the predetermined distance (L1) on the vehicle traveling lane 61 is from the current traveling direction of the vehicle (direction of arrow O). Go to step S3. That is, a point (point a) on the vehicle traveling lane 61 (lane center portion) and at a predetermined distance (L1) from the image captured by the camera 22a with respect to the front direction (arrow O direction) of the vehicle. The number of times (θ) in the direction (arrow A direction) is calculated (see FIG. 2A).

The predetermined distance (L1) is any one of the following distances and is selected according to the specifications and purpose of the on-vehicle radar.
Detecting a preset fixed distance (in the case of this embodiment), a distance that is variable (far when the speed is fast, close when the speed is slow), and an inter-vehicle distance with the preceding vehicle. Warning distance between vehicles (warning speed,
Variable distance depending on the relative speed with the preceding vehicle, the distance to the preceding vehicle, the braking performance, etc.) The distance between the vehicle and the preceding vehicle is detected and the vehicle speed is controlled to reach the prescribed distance. It is a variable distance or the like depending on the control distance (predetermined by the vehicle speed, the relative speed with respect to the preceding vehicle, the distance between the preceding vehicle, the braking performance, the engine torque, the shift position, the gear ratio, etc.). Information for setting these distances is input to the control unit 4 from the detection unit 5 for setting the predetermined distance.

In step S3, the camera 22a and the image processing unit 22b are used to drive a predetermined distance (L2
) To see if there is an obstacle inside. If there is, go to step S6. If not, the process proceeds to step S4. That is,
Before changing the beam irradiation direction, grasp the surroundings of your vehicle. Then, at this point, the image shows an obstacle 72.
Make sure that is not detected. In addition, a predetermined distance (L
2) is basically obtained by any of the above-mentioned methods of obtaining L1, but it is set to be smaller than the predetermined distance (L1) used for determining the irradiation direction of the beam.

In step S4, the radar device 1 determines whether or not there is an obstacle 72 within a predetermined distance (L2). If there is, move to step S6, and if there is not, step S5
Move on to. In other words, the situation around the vehicle is grasped before changing the irradiation direction of the beam. Then, at this time, it is confirmed that the obstacle 72 is not detected by the radar device 1.

In step S5, the irradiation direction of the beam of the radar device 1 is corrected to θ degrees and the process returns to step S1. That is, it is confirmed by both the image processing unit 22b and the radar device 1 that there is no obstacle within the predetermined distance L2 (the own vehicle traveling lane 61 and the adjacent lane 62). All you have to do is focus on tracking an obstacle (for example, the preceding vehicle). Therefore, the control unit 4 instructs the steering unit 1b of the radar device 1 to correct the irradiation direction of the beam of the radar 1a to θ degrees (direction of arrow A).

In step S6, if there is an obstacle within the predetermined distance (L2) according to the determination in step S3 or step S4, the correction of the irradiation direction of the beam of the radar 1a is completed or is being corrected. This is a processing step for determining whether or not. Therefore, if the correction is completed or is being modified, the process proceeds to step S7. If the modification is not completed or is not being modified, the process returns to step S1. That is, it is determined whether or not the irradiation direction of the beam of the radar 1a is 0 ° ahead of the vehicle.

In step S7, the irradiation direction of the beam of the radar 1a is returned to the original state (0 degree), and the process returns to step S1. That is, since an obstacle has been detected within the predetermined distance (L2), the obstacle 72 that is actually detected is more likely to be tracked than a new obstacle (for example, the preceding vehicle) along the traveling lane 61.
Since it is necessary to give priority to the tracking of the beam, the control unit 4 instructs the radar device 1 to return the beam irradiation direction to the original state (0 degree, that is, the straight traveling direction). This is because the vehicle (obstacle 72) traveling on the adjacent lane 62 may change lanes and enter the vehicle traveling lane 61. Therefore, the vehicle is returned based on the irradiation direction of the beam of the radar device 1. 7
This is for surely monitoring the second item.

In the above explanation, the case where the lane is recognized by the camera 22a of the lane recognizing unit 2 and its image processing unit 22b has been described, but by the GPS system (by the map disk 23a and the GPS 23b) and the infrastructure 24. The same applies when recognizing the driving lane. It is also possible to change the predetermined distance (L1, L2) according to the output of the detection unit 5 for setting the predetermined distance. For example, according to the output of the vehicle speed indicator 51, a predetermined distance (L1, L
2) Depending on the vehicle speed at that time, when the vehicle speed is high, the predetermined distance L1 is increased so as to aim at a further distance, and the predetermined distance L2 is increased so that a wider range of obstacles can be detected.

As described above, in this embodiment, the irradiation direction of the beam is controlled by grasping the condition of the road ahead of the own vehicle, and when there is a vehicle in the vicinity of the own vehicle even in the adjacent lane. It is effective for safe driving because it enables detailed monitoring such as returning the beam irradiation direction in case of an unexpected situation such as interruption.

[0036]

As described above, according to the present invention, the radar device is controlled so that the beam of the radar device always irradiates the center of the traveling lane so that an obstacle can always be detected appropriately regardless of road conditions. Effective for safe driving.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a vehicle-mounted radar device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a beam irradiation state of a vehicle-mounted radar device according to an embodiment of the present invention, in which (a) shows a beam irradiation direction based on recognition of a traveling lane, and (b) shows a relationship between the beam irradiation direction and an obstacle. FIG.

FIG. 3 is a flowchart showing a method of controlling a beam direction of a vehicle-mounted radar device according to an embodiment of the present invention.

FIG. 4 is a system configuration diagram of a conventional vehicle-mounted radar device.

5A and 5B are diagrams showing a beam irradiation state of a conventional vehicle-mounted radar device. FIG. 5A is a curve entrance vicinity, FIG. 5B is a curve middle area, and FIG. 5C is a curve exit area.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Radar device 2 ... Lane recognition unit 3 ... Obstacle recognition unit 4 ... Control unit 5 ... Detection unit for setting a predetermined distance 1a ... Radar 1b ... Steering unit 22a ... camera 22b ... image processing unit

Claims (16)

[Claims] 1. An in-vehicle radar device for controlling the irradiation direction of a beam of a radar device for monitoring the front of the vehicle according to the condition of a traveling lane of the vehicle, wherein the radar device is installed in front of the vehicle and in front of the vehicle. And a first lane identifying means for identifying the traveling lane of the vehicle from the image taken by the image capturing means, and the image capturing means for capturing the situation of the traveling lane in the direction is identified by the first lane identifying means. A vehicle-mounted radar device, comprising beam steering means for adjusting the irradiation direction of the beam of the beam of the radar device by aiming the beam of the beam at the first predetermined distance in the traveling lane of the vehicle. 2. An in-vehicle radar device for controlling the irradiation direction of a beam of a radar device for monitoring the front of the vehicle according to the condition of a traveling lane of the vehicle, wherein the information is provided from infrastructure provided to the vehicle. A second lane identifying means for identifying a traveling lane of the vehicle is provided, and a beam of the radar device is aimed at a point at a first predetermined distance in the traveling lane of the vehicle identified by the second lane identifying means. The vehicle-mounted radar device further comprising beam steering means for correcting the irradiation direction of the beam. 3. An in-vehicle radar device for controlling the irradiation direction of a beam of a radar device for monitoring the front of the vehicle according to the condition of a traveling lane of the vehicle, wherein information from a navigation system mounted on the vehicle is used. A third lane identifying means for identifying a traveling lane of the vehicle is provided, and a beam of the radar device is provided at a point of a first predetermined distance in the traveling lane of the vehicle identified by the third lane identifying means. An on-vehicle radar device, comprising beam steering means for adjusting an aiming direction of the beam. 4. An obstacle recognizing means for recognizing that an obstacle is present is provided, and the beam steering means uses the obstacle recognizing means for the second operation.
The vehicle-mounted radar device according to claim 1, wherein correction of the irradiation direction of the beam is prohibited when it is determined that there is an obstacle within the predetermined distance. 5. An obstacle recognition means for recognizing that there is an obstacle is provided, and the beam steering means is an obstacle within a second predetermined distance by the obstacle recognition means while the irradiation direction of the beam is being corrected. The vehicle-mounted radar device according to any one of claims 1 to 3, wherein when it is determined that there is a beam, the correction of the irradiation direction of the beam is stopped and the beam is returned to the original state. 6. An obstacle recognition means for recognizing that there is an obstacle is provided, and the beam steering means is within a second predetermined distance by the obstacle recognition means after the correction of the irradiation direction of the beam is completed. 4. The in-vehicle radar device according to claim 1, wherein when it is determined that there is an obstacle, the irradiation direction of the beam is returned to the original state. 7. The on-vehicle radar device according to claim 4, wherein the obstacle recognition means is recognized by an image taken by the imaging means. 8. The on-vehicle radar device according to claim 4, wherein the obstacle recognition means is recognized by the on-vehicle radar device. 9. The on-vehicle radar device according to claim 4, wherein the obstacle recognition means is recognized by an infrastructure provided to the vehicle. 10. The on-vehicle radar device according to claim 4, wherein the obstacle recognition means is recognized by a navigation system mounted on the vehicle. 11. The in-vehicle radar device according to claim 1, wherein the first predetermined distance is variable according to the speed of the vehicle. 12. The on-vehicle radar device according to claim 1, wherein the first predetermined distance is variable according to an inter-vehicle warning distance indicating that the vehicle is too close to the front vehicle. 13. The on-vehicle radar according to claim 1, wherein the first predetermined distance is variable according to an inter-vehicle control distance that indicates that the relative distance to the preceding vehicle is constant. apparatus. 14. The in-vehicle radar device according to claim 4, wherein the second predetermined distance is variable according to the speed of the vehicle. 15. The on-vehicle radar device according to claim 4, wherein the second predetermined distance is variable according to an inter-vehicle warning distance indicating that the vehicle is too close to the front vehicle. 16. The on-vehicle radar according to claim 4, wherein the second predetermined distance is variable according to an inter-vehicle control distance indicating that the relative distance to the preceding vehicle is constant. apparatus.