JP2648309B2 - Vehicle control system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an inter-vehicle control device which is suitably implemented in an automobile having a constant speed running function.

2. Description of the Related Art Conventionally, in a vehicle having a constant speed traveling function, when a preceding vehicle is slower than a set vehicle speed, the inter-vehicle distance is measured using a radar or the like to prevent the inter-vehicle distance from shortening, and the traveling is measured. A configuration is used in which the vehicle travels following the vehicle while maintaining a predetermined safety interval corresponding to the speed. In this case, when there is no preceding vehicle, the vehicle is accelerated to the original set vehicle speed.

Problems to be Solved by the Invention The causes of losing the leading vehicle are considered to be due to a curve or a case where the leading vehicle deviates from the road due to a turn or the like.
However, in the above-mentioned prior art, when a preceding car is lost,
Since the acceleration operation is performed up to the set vehicle speed, if the preceding vehicle is lost due to the curve, the vehicle enters the curve while accelerating despite the presence of the preceding vehicle, which is dangerous. Also, if it is detected that the vehicle has entered the curve regardless of the presence or absence of the preceding vehicle, the speed at the time of entering the curve is maintained until the vehicle exits the curve. Even then, the acceleration operation is performed only after the vehicle completely escapes from the curve, and agile driving cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an inter-vehicle control device for an automobile in which safety is improved and agile driving can be performed.

Means for solving the problems The present invention relates to a distance detecting means for detecting a distance to an object in front of a vehicle body, a road condition detecting means for detecting a road condition such as a curve, and a driving means for driving and driving the vehicle body. In response to the output from the distance detecting means, if the object is detected, the driving means controls the driving means so that the distance to the object is not less than a predetermined value, and performs the following travel, A control means for controlling the driving means so that the vehicle body has a preset vehicle speed so that the vehicle body travels at a constant speed when the object is not detected; In response to the output from the vehicle, when the object is no longer detected during the following travel, means for holding the running speed at that time for a predetermined period W1 from that time, and when the object is no longer detected. During the period W1, when a curve is not detected by the road condition detecting unit, a unit that performs control by the control unit after the lapse of the period W1, and during the period W1 from the time when the object is no longer detected. Means for running when the curve is detected by the road condition detecting means until the curve is no longer detected at the held traveling speed.

According to the present invention, the presence or absence of an object, for example, a preceding vehicle traveling ahead of the own vehicle is detected, and if a curve is not detected within a predetermined time from the time when the preceding vehicle is lost, the preceding vehicle moves rightward on the road. It is conceivable that the vehicle deviated from the road for the reason of turning left or changing lanes, etc., and the predetermined time for detecting the presence or absence of a curve holds the vehicle speed at the time of losing the vehicle ahead, but after the predetermined time has elapsed It is not necessary to maintain the vehicle speed, so if an object is detected, the distance to the object should not be less than a predetermined value. Normal control for controlling the vehicle speed is performed. If a curve is detected within a predetermined time from the point in time when the vehicle in front is lost, it is assumed that the vehicle in front has lost the vehicle in front because the vehicle has traveled on the curve, and the vehicle is not seen until the vehicle exits the curve from the point in time when it is lost. The vehicle speed at the time of the loss is maintained.

That is, the vehicle speed is maintained for a predetermined time from the time when the front vehicle is lost, and only when a curve is detected during that time, the front vehicle has entered the curve and the front vehicle has been lost,
Keeping the vehicle speed until the end of the curve, otherwise, the vehicle in front was returned to normal control as if it had actually disappeared from before the vehicle, so even before the vehicle enters the curve Even when the preceding vehicle enters a curve and disappears from the field of view, it is assumed that the preceding vehicle has disappeared, the vehicle speed is increased, and the inter-vehicle distance between the own vehicle and the preceding vehicle is not undesirably reduced.

Embodiment FIG. 1 is a block diagram of an inter-vehicle distance control device 1 according to one embodiment of the present invention. The inter-vehicle detector 2, which is a distance detecting means, emits, for example, a pulse-modulated millimeter wave of about 20 to 50 GHz, receives the reflected wave, and utilizes the Topura effect,
The relative speed with respect to the preceding vehicle is detected from the frequency difference between the emitted wave and the reflected wave, and the distance D1 to the preceding vehicle is detected from the time transmission between the emitted wave and the reflected wave. To the vehicle speed setting switch 4, a set vehicle speed V2 which is a target when performing the constant speed traveling control is input. Further, a steering angle detector 5 is provided to detect a road condition such as a curve, and it is detected that the vehicle is traveling on a curve by the turning angle of the steering wheel.
The vehicle speed V1 is detected by a vehicle speed detector 6. Information from each of these detectors and the switches 2, 4, 5, and 6 is given to a processing circuit 3, for example, the throttle valve opening is controlled. Thus, the internal combustion engine 7 as the driving means is controlled, and constant speed traveling control and inter-vehicle distance control are performed.

FIG. 2 and FIG. 3 are diagrams for explaining the headway control operation. As shown in FIG. 2A, in a state where the constant speed traveling control is performed at the speed V2 set by the vehicle speed setting switch 4, the set vehicle speed V2 of the own vehicle 11 is the When the vehicle speed is higher than the vehicle speed of the vehicle 12, the inter-vehicle distance D1 detected by the inter-vehicle detector 2 is reduced, and the safety inter-vehicle distance predetermined by the vehicle speed V1 detected by the vehicle speed detector 6 is reduced. When it becomes equal to, the processing circuit 3 interrupts the constant speed traveling control and performs the normal headway control for traveling following the preceding vehicle 12. In this way, the following travel is performed such that the inter-vehicle distance D1 does not become less than the safe inter-vehicle distance.

In the state where the vehicle is following, the preceding vehicle 12 turns to the side road 13 as shown in FIG. 2 (2), for example, and the preceding vehicle 12 is not detected by the following distance detector 2. And a period W1 required for the vehicle 11 to travel from a point A of the vehicle 11 at that time to a point B in the vicinity where the preceding vehicle 12 has been lost, for example, a predetermined period of about 3 seconds. By following control that maintains the speed V1 corresponding to the following distance D1 at the time when the driver 12 loses sight of 12, the vehicle continuously follows the vehicle in a pseudo manner. Note that since the period W1 does not require much accuracy, the predetermined period may be employed as described above.However, the period W1 is based on the inter-vehicle distance D1 when the preceding vehicle 12 is lost and the speed V1 at that time. The time corresponding to W1 may be obtained, and the period W1 may be set to the inter-vehicle distance D1. In any case, it is preferable that the period W1 has some allowance.

A curve is not detected by the steering angle detector 5 in a state where a period W1 has elapsed since the time when the preceding vehicle 12 was lost, that is, in a state where the vehicle reached the point B indicated by the temporary line 11a in FIG. At that time, that is, when the vehicle is traveling in the straight section M2, the processing circuit 3 determines that the preceding vehicle 12 has not deviated from the curve but deviates to the side road 13 and shifts to the constant speed traveling control, and performs the acceleration operation to the set vehicle speed V2. . As shown in FIG. 2 (3) during such acceleration operation, even if the vehicle enters the curve section M3, the acceleration operation is continued until the set vehicle speed V2 is reached, so that agile driving can be performed.

In addition, as shown in FIG. 2 (1), while the vehicle is following, the preceding vehicle 12 changes lanes, or as shown in FIG. 3 (1), the preceding vehicle 12 Curve section M3
When the vehicle enters the vehicle and disappears from the detection area of the headway detector 2 indicated by the reference numeral 14, the vehicle speed holding control for holding the vehicle speed V1 at that time for a period W1 from the time when the preceding vehicle 12 is lost is pseudo. Follow-up running is performed. During this period W1, when the steering angle detector 5 detects that the vehicle has entered the curve section M3 as shown in FIG. 3 (2), the preceding vehicle 12 is lost due to the curve, that is, It can be determined that the preceding vehicle 12 is present, and such follow-up running is continued until the steering angle detector 5 stops detecting a curve, that is, until the vehicle exits the curve section M3. Thus, even if the vehicle enters the curve section M3 immediately after losing sight of the preceding vehicle 12, acceleration for constant-speed traveling control is not performed, and accordingly, as shown in FIG. It is possible to safely travel on the curve section M3 without the distance D1 being undesirably reduced.

FIG. 4 is a flow chart showing the algorithm of the headway control operation as described above. At step n1, it is determined whether or not the vehicle is following, that is, whether or not there is a preceding vehicle 12, and if not, the process proceeds to step n1.
Moving to n2, it is determined whether or not the vehicle has been following the vehicle at the time before the period W1 from the present time.If not, that is, when the following traveling has not been performed from the time before the period W1 to the current time, the process proceeds to step n3. The constant speed traveling control is performed at the set vehicle speed V2.

When it is determined in step n1 that the vehicle is following the vehicle, that is, when the vehicle is in the state shown in FIG. 2A, the process proceeds to step n4, and the speed corresponds to the speed V1 detected by the vehicle speed detector 6. Normal inter-vehicle control is performed to achieve the safe inter-vehicle distance D1.

In step n2, when it is determined that the vehicle is following the road before the period W1, the process proceeds to step n5, and it is determined whether the vehicle is currently traveling in the curve section M3. Curve section M3
When the vehicle is not traveling, that is, when the vehicle is in the state shown in FIG. 2 (2), the process proceeds to step n6, in which the headway control by the speed V1 corresponding to the headway distance D1 at the time when the preceding vehicle 12 is lost is performed. Follow-up running is performed.

In step n5, when it is determined that the vehicle is traveling on the curve section M3, that is, when the vehicle is in the state shown in FIG. 3 (2), the process proceeds to step n7, and the vehicle speed holding control based on the speed V1 is performed. The follow-up running is continued, and the time before the period W1 in step n8 is set as if the follow-up running.

FIG. 5 is a flowchart showing a specific processing procedure of the algorithm shown in FIG. The inter-vehicle distance D1 is detected by the inter-vehicle detector 2 at step m1, and the vehicle speed V1 is detected by the vehicle speed detector 6 at step m2.

At step m3, it is determined whether or not the inter-vehicle distance D1 is infinite, that is, whether or not the vehicle is currently following the vehicle, and if so, that is, if the vehicle is not following the vehicle, the process proceeds to step m4 to set the time. The flag to represent is 1
Is only subtracted. The content of this flag corresponds to the time from when the preceding vehicle 12 is lost to when the control is switched to the constant speed traveling control.

At step m5, it is determined whether or not the content of this flag is greater than 0. If not, that is, if the content of the flag is less than 0, it is determined that the vehicle has not followed the vehicle before the period W1. Judgment proceeds to step m6, and constant speed traveling control is performed at the set vehicle speed V2.
Resets the contents of the flag to 0, and returns to step m1.

In step m5, when the content of the flag exceeds 0, the process proceeds to step m8, where it is determined by the steering angle detector 5 whether or not the vehicle is traveling on the curve section M3. When the vehicle is in the middle, the process proceeds to step m9, where the following control is performed with the speed V1 corresponding to the following distance D1, and the process returns to step m1.

In step m8, when the steering angle detector 5 detects that the vehicle is traveling on the curve section M3, it can be determined that the preceding vehicle 12 exists as described above. The vehicle speed holding control is performed, and in step m11, the content of the flag becomes 0 while the car is running.
The flag is set to a predetermined time period W1 of, for example, about 3 seconds so as not to shift the constant speed traveling control by step m6 even when
And returns to step m1.

If it is determined in step m3 that the vehicle is following the vehicle, the flow proceeds to step m12, and the following distance control is continued. In step m13, the content of the flag is incremented by 1, and the continuation time of the following running is counted. In step m14,
It is determined whether or not the content of the flag has exceeded the period W1. If so, at step m15, the period W1 is substituted for the flag and the process returns to step m1. If the content of the flag is less than or equal to the period W1 in step m14, the flow directly returns to step m1.

In the above-described embodiment, the inter-vehicle detector 2 performs detection using radio waves. However, as another embodiment of the present invention, for example, a laser beam or an ultrasonic wave may be used. The object detected by the inter-vehicle detector 2 may be a vehicle stopped at the shoulder of a road or an obstacle. Further, although the steering angle detector 5 is used for detecting the road condition, as shown in FIG.
Since the inter-vehicle distance D1 changes suddenly, it may be configured to detect a curve, or by utilizing the fact that the reflected wave from the side wall 15 of the curve section M3 is unstable compared to the reflected wave of the preceding vehicle 12. Thus, a curve may be detected.

Effects As described above, according to the present invention, the vehicle speed is maintained for a predetermined time from the point in time when the preceding vehicle is lost, and only when a curve is detected during that time, the preceding vehicle has entered the curve and the preceding vehicle has been seen. Assuming that the car has lost, keep the vehicle speed until the end of the curve, otherwise return to normal control as if the car ahead was actually gone from before the car, so even if the car Even if the preceding vehicle enters a curve before entering the road and disappears from view, it is assumed that the preceding vehicle has disappeared, the vehicle speed is increased, and the inter-vehicle distance between the own vehicle and the preceding vehicle is not undesirably reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an inter-vehicle distance control device 1 according to one embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining an inter-vehicle distance control operation, and FIG. 4 is a flowchart showing an algorithm of the inter-vehicle distance control operation. FIG. 5 is a flowchart showing a specific processing procedure of the algorithm shown in FIG. Reference Signs List 1 inter-vehicle control device, 2 inter-vehicle detector, 3 processing circuit, 4 vehicle speed setting switch, 5 steering angle detector, 6
…… vehicle speed detector, 7 …… internal combustion engine, 11 …… own car, 12 ……
Car ahead, 13 ... side road, D1 ... distance between cars, M2 ... straight section, M3 ... curve section

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-43009 (JP, A) JP-A-64-52531 (JP, A)

Claims (1)

(57) [Claims] 1. A distance detecting means for detecting a distance from an object in front of a vehicle body, a road condition detecting means for detecting a road condition such as a curve, a driving means for driving and driving the vehicle body, and In response to the output of, if the object is detected, the driving means controls the driving means so that the distance to the object does not become a predetermined value or less, and performs the following travel,
When the object is not detected, the vehicle-to-vehicle control apparatus further includes control means for controlling the driving means so that the vehicle body has a preset vehicle speed and performing constant-speed traveling. In response to the output from the means, when the object is no longer detected during the following running, means for holding the running speed at that time for a predetermined period W1 from that time, and the object is no longer detected. When a curve is not detected by the road condition detecting means during the period W1 from the time point, a means for performing control by the control means after the lapse of the time period W1, and during the time period W1 from the time when the object is no longer detected. Means for running when the curve is detected by the road condition detection means until the curve is no longer detected at the held traveling speed. That vehicle-to-vehicle control device.