JP2646950B2 - Travel control device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for a vehicle, and more particularly to an improvement in the position identification of a preceding vehicle detected by a radar device.

[0002]

2. Description of the Related Art Conventionally, a travel control device for adjusting the speed of a vehicle has been developed for the purpose of reducing the driving operation of a driver and improving the safety on a highway or the like.

[0003] In such a traveling control device, a constant speed traveling mode in which the driver cruises the vehicle at a preset vehicle speed, or when a preceding vehicle exists, the inter-vehicle distance to the preceding vehicle is maintained at a safe distance. A follow-up running mode for following the preceding vehicle while the vehicle is running is set.

In such a travel control device, it is needless to say how to accurately capture the preceding vehicle. For example, a preceding vehicle traveling in an adjacent lane is erroneously recognized as a preceding vehicle on its own lane. If the control is performed, smooth running cannot be performed. Therefore, it is necessary to accurately grasp on which lane the detected preceding vehicle is located.
For example, Japanese Patent Application Laid-Open No. 3-92436 proposes a configuration in which a preceding vehicle offset by a predetermined amount or more from a forward extension of the own vehicle is determined to be not a preceding vehicle to be followed, and the following control is stopped. Have been.

[0005]

However, in a configuration in which the continuation / stop of the control is determined based on whether or not the vehicle is offset from the forward extension of the own vehicle by a predetermined amount or more, appropriate control may not always be performed. FIGS. 6 and 7 show an example of such a case. First, FIG. 6 shows a case where, on a two-lane road including an overtaking lane and a traveling lane, the own vehicle is traveling leftward on the traveling lane, and the preceding vehicle is traveling near the center on the same traveling lane. Although the preceding vehicle is offset from the forward extension of the own vehicle by a predetermined amount or more, the preceding vehicle is traveling on the same lane as the own vehicle.

On the other hand, FIG. 7 shows a case where the own vehicle is traveling near the center on the traveling lane and the preceding vehicle is traveling near the center on the overtaking lane. In this case, the offset amount is almost the same as in FIG. 6, but the preceding vehicle is traveling on the passing lane, which is an adjacent lane, and it is not appropriate to follow the preceding vehicle.

As described above, depending on the traveling positions of the own vehicle and the preceding vehicle in the lane, the preceding vehicle may correspond to the same lane or the adjacent lane even with the same offset amount. There has been a problem that it is not always possible to reliably determine whether a vehicle is a preceding vehicle to follow.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to accurately determine whether a preceding vehicle detected by a radar device is on its own lane or another lane, and smoothly. It is an object of the present invention to provide a vehicle control device capable of following the vehicle.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, a vehicular cruise control device according to the present invention maintains a predetermined distance between a vehicle and a preceding vehicle and controls the cruise control for the vehicle. A radar device for detecting an inter-vehicle distance and an azimuth with respect to a preceding vehicle (a degree of orthogonal offset with respect to an extension of a center line of the own vehicle), and a detected lane region in which the detected preceding vehicle is determined from a detection range of the radar device. Or first determining means for determining whether the vehicle is located in another lane region; and, when the preceding vehicle is not located in any of the own lane region and the other lane region, a relative speed between the preceding vehicle and the own vehicle. A second determining means for determining in which area the preceding vehicle is located, and a following travel for a preceding vehicle determined to be in the own lane area by the first or second determining means. The other lane area For been preceding vehicle and having a control means for maintaining the vehicle speed.

[0010]

The vehicle traveling control according to the present invention has such a configuration, and identifies whether the preceding vehicle detected by the two-step criterion is the preceding vehicle in the own lane or the preceding vehicle in another lane. .

That is, the inter-vehicle distance and azimuth with respect to the preceding vehicle (degree of orthogonal offset with respect to the extension of the center line of the own vehicle) are detected by the radar device. Based on the inter-vehicle distance and azimuth, it is determined whether the detected preceding vehicle is located in the own lane area or the other lane area determined from the detection range of the radar device. When the azimuth is based on the forward extension of the own vehicle, the azimuth is near zero, that is, the area on the forward extension of the own vehicle is the own lane area, and the distance from the forward extension determined from the distance and the azimuth is The area exceeding the predetermined value is the other lane area. When the detected preceding vehicle corresponds to these regions, it can be reliably determined that the vehicle is ahead of the own lane or the vehicle ahead of another lane.However, in the case of the preceding vehicle indicating the distance and the azimuth between both regions, As described above, it is not always clear on which lane the vehicle is located.

Therefore, the second determining means determines in which area the detected preceding vehicle is located based on the relative speed with respect to the detected preceding vehicle. For example, when the vehicle is traveling on the traveling lane, the average speed is generally lower than that of the vehicle traveling on the passing lane. Therefore, when the speed of the own vehicle with respect to the detected preceding vehicle is low, it can be determined that the detected preceding vehicle is traveling in the adjacent lane. When the vehicle speed is high, it can be determined that the detected preceding vehicle is the preceding vehicle in the adjacent lane. Further, the speed of the own vehicle with respect to the detected preceding vehicle is almost 0,
That is, when the vehicle is traveling at substantially the same speed, it can be determined that the vehicle is traveling on the same lane.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a vehicle travel control device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment. A scanning laser radar device 10 is provided at the front of the vehicle as a radar device. The distance measured by the laser radar varies depending on the weather and the like, but is approximately 100 m in fine weather. Therefore, a vehicle traveling a distance of 100 m ahead of the own vehicle is detected as a preceding vehicle. A vehicle speed sensor 12 that optically detects the rotation speed of the drive shaft of the vehicle is provided as vehicle speed detection means. Further, a steering angle sensor 13 for detecting a steering angle of the vehicle is provided on a steering shaft or the like.

Further, an adjustment lever 14 for setting the vehicle speed at the time of constant-speed running and for adjusting the inter-vehicle distance during the following running is provided in the driver's seat, and is further provided with a system switch and for changing the inter-vehicle distance during the following running (in the present embodiment). A changeover switch 16 (three steps of far / middle / near) is similarly provided in the driver's seat.
Then, signals from these sensors and switches are supplied to the microcomputer 18.

The microcomputer 18 includes an input / output port, a ROM in which a processing program described later is stored, a CPU for performing an operation in accordance with the processing program, a RAM for storing the operation result, and the like. 2
2 as a control signal to control the running of the vehicle, and display the current inter-vehicle distance as appropriate with an alarm / display device 24 provided in the driver's seat, or warn the driver when the inter-vehicle distance becomes unacceptable. It is a configuration to give.

Here, the scanning laser radar device 10
Is a fan-shaped area ahead of the own vehicle, and depending on the positional relationship with the preceding vehicle, not only the preceding vehicle traveling on the own lane but also the preceding vehicle traveling on the adjacent lane may be detected. If the preceding vehicle in the adjacent lane is erroneously recognized as a preceding vehicle to be followed, the vehicle is followed and the vehicle is accelerated or decelerated unnecessarily, so that the vehicle cannot travel smoothly.
Therefore, in the present embodiment, the microcomputer 18
Thus, the following two-stage determination process is performed to determine whether the detected preceding vehicle is the preceding vehicle in the own lane or the preceding vehicle in the other lane. That is, (1) which of the own lane area and the other lane area determined from the detection range of the scanning laser radar 10 corresponds to the detected preceding vehicle (2) If the detected preceding vehicle is not located in any of the areas Then, it is determined in which region the detected preceding vehicle is located based on the relative speed between the detected preceding vehicle and the own vehicle.

FIG. 2 shows an own lane area (A area), and FIGS. 3 and 4 show another lane area (B area). The own lane area is a specific area within the radar detection range, and all the preceding vehicles detected within this area are areas where it is possible to determine the preceding vehicle in the own lane. When the azimuth angle is defined as the reference (origin) of the azimuth angle on the front extension line of the own vehicle, the area where the azimuth angle of the detected preceding vehicle is almost 0 is the own lane area (see FIG. 2).

On the other hand, the other lane region is a specific region within the radar detection range, and all preceding vehicles detected in this region can be determined to be preceding vehicles traveling on other lanes. FIG. 3 shows another lane region when the vehicle is traveling at each of the positions a, b, and c in the lane having the lane width L (the hatched portion in FIG. 3). Regardless of the vehicle traveling in any position on the lane, the condition of the area B for determining the detected preceding vehicle as the preceding vehicle in the other lane is as shown in FIG. This is an area where the distance from the line is equal to or greater than the lane width L. Therefore, the microcomputer 18 calculates the azimuth data θ based on the distance data 1 and the azimuth data θ detected by the scanning laser radar device 10.
Is smaller than or equal to a predetermined value to determine whether or not the vehicle is in the area A.
It is determined whether or not the area is the area B based on whether or not nθ is equal to or greater than the lane width L.

However, there are cases where the detected preceding vehicle does not correspond to either the A region or the B region. In this case, it is not possible to identify whether the detected preceding vehicle is the preceding vehicle in the own lane or the preceding vehicle only by the distance data and the azimuth data.
Then, the process shifts to the determination of the above (2), and it is determined which of the preceding vehicles is based on the relative speed with respect to the detected preceding vehicle. When the preceding vehicle and the own vehicle are traveling on the same lane, there is no large difference in the relative speed, and the own vehicle is traveling on the traveling lane, and the preceding vehicle is traveling on the overtaking lane, or When the own vehicle is traveling in the passing lane and the preceding vehicle is traveling in the traveling lane, there is a great difference in the speed difference. Therefore, it is possible to identify whether the detected preceding vehicle is the preceding vehicle in the own lane or the preceding vehicle in the other lane based on the relative speed.

The microcomputer 18 determines whether the detected preceding vehicle is the preceding vehicle in the own lane or the preceding vehicle in the other lane based on the above principle. If it is determined that the preceding vehicle is the preceding vehicle in the own lane, the microcomputer 18 follows the preceding vehicle. The vehicle travels by controlling the throttle actuator 20. If it is determined that the vehicle is ahead of another lane, the vehicle does not follow the preceding vehicle, and the current vehicle speed is maintained by keeping the throttle opening constant.

FIG. 5 shows a more detailed processing flowchart of the microcomputer 18. First, the magnitude of the steering angle ST detected by the steering angle sensor 13 is compared with a predetermined value ST0 (S100). This determination is a process for determining whether or not the vehicle is traveling on a curved road. If the steering angle ST is larger than a predetermined value ST0, it is determined that the vehicle is traveling on a curved road, and The processing shifts to the determination processing in (S200). A known technique is used to determine a preceding vehicle to be detected on a curved track, based on the steering angle, the vehicle speed, and the azimuth of the radar device. Then, Va and Vb are reset (Va and Vb will be described later).

On the other hand, when the own vehicle is traveling on a straight road, the process proceeds to the area determination processing of the detected preceding vehicle from the distance data and the azimuth data from the radar device 10 described above (S).
100). That is, first, it is determined whether or not the detected preceding vehicle is located in the area A (S120). This determination is made based on whether or not the azimuth angle of the detected preceding vehicle is near zero. When it is determined that the detected preceding vehicle is located in the area E, the detected preceding vehicle is recognized as a preceding vehicle traveling in the same lane as the own lane (S300), and the latest several vehicles (3
The average vehicle speed Va of the detected preceding vehicle located in the area A (from 10 to 10) is calculated. When the vehicle is traveling in the traveling lane, the average vehicle speed Va corresponds to the average vehicle speed in the traveling lane. When the vehicle is traveling in the passing lane,
It corresponds to the average vehicle speed in the passing lane. If the azimuth of the detected preceding vehicle is equal to or larger than the predetermined value, it is determined that the detected preceding vehicle is not in the area A, and then it is determined whether the detected preceding vehicle is located in the area B (S130). This determination is made based on the distance data and the azimuth data of the detected preceding vehicle, as described above, based on whether or not the distance from the front extension line of the own vehicle is equal to or larger than the lane width. When it is determined that the detected preceding vehicle is located in the area B, the detected preceding vehicle is recognized as a preceding vehicle traveling on another lane (S400), and is located in the area B in the same manner as in S310. Then, the average vehicle speed Vb of several detected preceding vehicles is calculated (S410).

On the other hand, depending on the distance data and the azimuth data of the detected preceding vehicle, it may be determined that the vehicle is not located in either the A region or the B region. In this case, first, it is determined whether or not the average vehicle speeds Va and Vb have been determined (S
140). In the state where the above-described processes of S310 to S410 are not performed and the average vehicle speeds Va and Vb are not yet determined, the magnitude comparison between the relative speed Vrr obtained by differentiating the distance data of the detected preceding vehicle and the predetermined value Vrr0 is performed. (S
500). When the own vehicle and the detected preceding vehicle are traveling on the same lane, there is no significant difference in the relative speed.When the own vehicle is traveling in the traveling lane, the detected preceding vehicle is traveling in the passing lane, or the own vehicle is running. When the detected preceding vehicle is traveling in the traveling lane, the relative speed is largely different because the average vehicle speed in the overtaking lane is generally higher than the average vehicle speed in the traveling lane. Therefore, as a result of the magnitude comparison between the relative speed Vrr and the predetermined value Vrr0,
If it is less than the predetermined value, it is determined that the detected preceding vehicle is the preceding vehicle in the own lane (S510), and if it is more than the predetermined value, it is determined that it is the preceding vehicle in the other lane (S520). When the average vehicle speeds Va and Vb are determined, the detected preceding vehicle is determined using the average vehicle speed. As described above, it is possible to determine whether the detected preceding vehicle is the own lane or another lane based on the magnitude of the relative speed with respect to the detected preceding vehicle, but this determination is generally based on the average vehicle speed of the traveling lane and the passing lane. It is assumed that they are different. However, it is well known that the average speed difference between the overtaking lane and the traveling lane changes depending on the road conditions. Therefore, in the process of comparing the relative speed and the predetermined value, the detection of the preceding vehicle is not necessarily performed in all road conditions. Is not always accurate. Therefore, the average vehicle speed V that reflects the actual driving situation
By making a determination using a and Vb, the accuracy of identifying the detected preceding vehicle is further improved. Identification of the detected preceding vehicle using Va and Vb in this embodiment is performed as follows. That is, first, a comparison is made between the average vehicle speed Va in the A region and the average vehicle speed Vb in the B region (S150). V
If a is larger than Vb, that is, if the average vehicle speed in the own lane area is higher than the average vehicle speed in the other lane area, it can be determined that the own vehicle is currently running in the passing lane. And
A comparison is made between the detected vehicle speed Vs calculated from the relative speed Vrr and the host vehicle speed V and the average vehicle speed Vb (S60).
0), if the detected preceding vehicle is slower than the other lane average vehicle speed Vb, it is determined that it is another lane preceding vehicle (S620); otherwise, it is determined that it is the own lane preceding vehicle (S610). If the average vehicle speed Va is lower than the average vehicle speed Vb, it is determined that the own vehicle is traveling in the traveling lane, and the speed Vs of the detected preceding vehicle and the average vehicle speed Vb are compared (S160). ). If the detected preceding vehicle is faster than the average vehicle speed Vb, that is, the average vehicle speed of the overtaking lane, it is determined that the vehicle is ahead of the other lane (S180). Otherwise, it is determined that the vehicle is ahead of the own lane (S170).

As described above, by comparing the average vehicle speed in the own lane area with the average vehicle speed in the other lane area and the speed of the detected preceding vehicle, the detected preceding vehicle is located in the own lane area or in the other lane area. Can be more reliably identified.

As a result of this determination, when the detected preceding vehicle is the preceding vehicle in the own lane (S700), the throttle distance is maintained to maintain the following distance to the detected preceding vehicle at the safe following distance calculated from the own vehicle speed. Following the traveling (inter-vehicle control) is performed by controlling the actuator 20 (S720). On the other hand, if it is determined that the detected preceding vehicle is the preceding vehicle in the other lane, the current vehicle speed is adjusted without following the preceding vehicle. Control for maintaining is performed (S710). Therefore, in the travel control device according to the present embodiment, following a vehicle ahead in another lane, it is possible to prevent a situation in which unnecessary acceleration and deceleration is performed for the driver.
Comfortable and smooth following can be continued.

[0027]

As described above, according to the vehicle travel control device of the present invention, it is possible to determine with high accuracy whether the detected preceding vehicle is the preceding vehicle in the own lane or the preceding vehicle in the other lane. Since the control that follows only the vehicle is performed, comfortable and smooth following travel can be performed without performing unnecessary acceleration / deceleration control for the driver.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an own lane area in the embodiment.

FIG. 3 is an explanatory diagram of another lane area in the embodiment.

FIG. 4 is an explanatory diagram of another lane area in the embodiment.

FIG. 5 is a processing flowchart of a microcomputer in the embodiment.

FIG. 6 is an explanatory diagram showing a relative positional relationship between a host vehicle and a preceding vehicle.

FIG. 7 is an explanatory diagram showing a relative positional relationship between a host vehicle and a preceding vehicle.

[Explanation of symbols]

 Reference Signs List 10 laser radar device 12 vehicle speed sensor 13 steering angle sensor 14 adjustment lever 16 system switch 18 microcomputer 20 throttle actuator 22 brake actuator 24 alarm / display device

Claims (1)

(57) [Claims] 1. A traveling control device for a vehicle that follows a preceding vehicle while maintaining a predetermined inter-vehicle distance with a preceding vehicle, comprising: a radar device that detects an inter-vehicle distance and an azimuth with the preceding vehicle; First determining means for determining whether the vehicle is located in the own lane area or another lane area determined from the detection range of the radar device; and the preceding vehicle is located in any of the own lane area and the other lane area. When the vehicle is not located, a second determination unit that determines in which region the preceding vehicle is located based on a relative speed between the preceding vehicle and the own vehicle, and a first lane region based on the first or second determination unit. Control means for performing follow-up running with respect to the preceding vehicle determined to be and maintaining the own vehicle speed with respect to the preceding vehicle determined to be in the other lane area. Travel control device.