JP3525727B2 - Travel control device for vehicles with inter-vehicle distance alarm - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for a vehicle having an inter-vehicle distance warning device, which is a combination of an inter-vehicle distance control device and an inter-vehicle distance warning device. 2. Description of the Related Art Some automobiles (vehicles) are equipped with an inter-vehicle distance warning device. The inter-vehicle distance warning device, for example, issues a warning when the inter-vehicle distance to a preceding vehicle in a traffic flow is equal to or less than a predetermined warning distance, and calls the driver's attention or calls for a braking operation. On the other hand, automobiles are equipped with a vehicle speed control device (running control device) called an auto cruise device in order to reduce the burden of the driver's driving operation. Recent vehicle speed control systems not only maintain their own vehicle speed at the set vehicle speed, but also use an inter-vehicle control device to maintain a safe target inter-vehicle distance (safe inter-vehicle distance) with the preceding vehicle when there is a preceding vehicle. Control of the own vehicle speed is performed. In recent years, in order to enhance safety, it has been considered to combine such an inter-vehicle distance control device with the inter-vehicle distance control device. By the way, the target inter-vehicle distance is maintained when the inter-vehicle distance from the preceding vehicle is shorter than the target inter-vehicle distance (safety inter-vehicle distance), and the reduction gear of the own vehicle (generally using an engine brake, an auxiliary brake, and a downshift). Is operated to decelerate the own vehicle, and if the inter-vehicle distance becomes longer than the target inter-vehicle distance, the control is performed by controlling the governor of the engine of the own vehicle to the output increasing side. However, the inter-vehicle distance warning device is set so as to issue an alarm only when the inter-vehicle distance becomes equal to or less than a predetermined warning distance. During this time, the following distance warning device may unnecessarily issue a following distance warning because the following distance between the preceding vehicle and the preceding vehicle is less than or equal to the predetermined warning distance. That is, despite the fact that the danger is sufficiently avoided by the deceleration operation of the headway distance control device, the headway distance warning device issues an unnecessary warning. Therefore,
In Japanese Patent Application Laid-Open No. Hei 8-216728, when traveling while maintaining the target inter-vehicle distance, the timing of the inter-vehicle distance warning is delayed as compared with the normal traveling, and when traveling following the preceding vehicle, an unnecessary warning is issued. There has been proposed a travel control device that suppresses generation from the device. [0007] By the way, automobiles are required to have safety. However, the traveling control device uniformly delays the timing of issuing an alarm, so that the margin time given to the driver is shortened accordingly. In addition, since the brake operation is performed from the easy drive state provided by the inter-vehicle control, the start of the operation tends to be delayed, and there is a possibility that the emergency brake operation cannot be performed in time. [0008] Therefore, there is a demand for an inter-vehicle distance alarm that can both eliminate useless alarms and ensure safety. In addition, in consideration of safety, not only the inter-vehicle distance alarm but also an alarm in consideration of the characteristics of the reduction gear of the inter-vehicle control device is desired. That is, the reduction gear used in the headway control device generally uses the engine brake, the auxiliary brake, and the downshift as described above.
In each case, the deceleration ability is relatively small. For this reason, the speed reducer can exhibit sufficient control performance in maintaining the target inter-vehicle distance if the relative speed with respect to the preceding vehicle is small, but the braking force tends to be insufficient when the relative speed is large. There is a characteristic that the control performance tends to be insufficient. Therefore, it is desired to provide an inter-vehicle distance warning in consideration of the characteristics of the inter-vehicle control device. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an inter-vehicle distance alarm that can perform an inter-vehicle distance alarm that does not cause useless alarms and that provides high safety in accordance with the characteristics of the inter-vehicle distance device. An object of the present invention is to provide a travel control device for a vehicle with the device. [0011] Means for Solving the Problems] running controller for the distance warning system with a vehicle as claimed in claim 1 in order to achieve the above object, the decelerating operation of the vehicle distance between the host vehicle and the preceding vehicle There vehicle controller and union to keep <br/> target inter-vehicle distance, the vehicle and the preceding
Warning distance determined according to the relative speed of the approaching vehicle
The distance warning equipment for issuing an alarm and more shortened, sufficiently danger is avoided by the reduction operation according to the headway distance control system
In the region where the relative speed is lower,
Who at the time of the operation is shorter alarm distance than when, in the inter-vehicle control device
In areas where the relative speed is so high that danger is not sufficiently avoided by the deceleration operation , the system operates more than when the headway control system is not operating.
By setting the warning distance to be set longer at the time, when the relative speed with the preceding vehicle is small when the following distance is maintained, and when the deceleration operation of the following distance control device is sufficiently avoided, the warning distance is set to be shorter. The warning distance prevents the inter-vehicle distance warning from being issued. At the start of maintaining the following distance, when the relative speed with respect to the preceding vehicle is high and the control of maintaining the following distance cannot be performed sufficiently with the deceleration ability of the following distance control device, the brake operation is performed by the long warning distance. An inter-vehicle distance warning is issued at an early stage so that the driver can quickly recognize that a brake operation is required. This eliminates useless inter-vehicle warnings without delaying the alarm timing, and enables effective inter-vehicle alarms in consideration of the characteristics of the inter-vehicle control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in FIGS. In FIG. 1, reference numeral 1 denotes an automobile (vehicle) equipped with, for example, a diesel engine 2 for traveling, and reference numeral 3 denotes a vehicle speed control apparatus (travel control apparatus) called an auto cruise apparatus installed in the automobile 1. The vehicle speed control device 3 has, for example, a cruise control unit 4 (for example, composed of a microcomputer, hereinafter simply referred to as the control unit 4) connected to the governor control unit 2a of the diesel engine 2. . The control unit 4 includes a laser radar unit 5 that detects a position of the preceding vehicle X by capturing a laser beam reflected from a reflector (not shown) of the preceding vehicle X as an inter-vehicle distance detecting device mounted on the vehicle, and a vehicle speed. A sensor 6 and a set vehicle speed input unit 7 are connected, and the output of the laser radar unit 5
Is detected, the vehicle speed of the vehicle 1 is detected from the output of the vehicle speed sensor 6, and the set vehicle speed (Cools vehicle speed) for performing auto cruise is detected from the output of the set vehicle speed input unit 7. is there. The control unit 4 is connected to, for example, an on / off switch 4a (means for switching the operation / non-operation of the headway distance control device) for turning on / off the auto cruise, and an auxiliary brake 8 (corresponding to a speed reduction device) for decelerating the own vehicle speed. is there. The control unit 4 incorporates a constant speed control unit 9a / inter-vehicle distance control unit 9b (corresponding to an inter-vehicle distance control device) which operates according to the ON of the ON / OFF switch 4a and the setting of the set vehicle speed input unit 7. The governor control unit 2a is controlled according to the vehicle speed detected by the vehicle speed sensor 6.
/ A function to control the auxiliary brake 8 to maintain the own vehicle speed at a set vehicle speed (Cools vehicle speed). The inter-vehicle control unit 9b controls the governor control unit 2a / auxiliary brake 8 according to the inter-vehicle information detected by the laser radar unit 5 to control the preceding vehicle X.
It has a function to keep the inter-vehicle distance with the target inter-vehicle distance. These functions are switched according to the presence or absence of the preceding vehicle X. That is, for example, the control unit 4 has a function of detecting whether or not the preceding vehicle X is present in the own vehicle traveling lane based on the output of the laser radar unit 5.
A function to keep the inter-vehicle distance at the target inter-vehicle distance when the vehicle is detected in the traveling lane, and a function to keep the vehicle speed at the set vehicle speed when the preceding vehicle X does not exist in the traveling lane. The constant speed control or the inter-vehicle distance control is performed in accordance with the control. The control unit 4 is connected to an alarm device 10 (corresponding to an inter-vehicle distance alarm device) which issues an alarm when the inter-vehicle distance from the preceding vehicle X is less than a predetermined alarm distance. Under the control of the control unit 4, the brake operation can be performed in any of the cruise running in which the constant speed control unit 9a / the headway control unit 9b operates and the normal running in which the control units 9a and 9b are not operating. When a situation is required, the alarm 10 issues an inter-vehicle distance alarm to the driver. That is, the control unit 4 includes:
For example, as shown in FIG. 2, when the vehicle speed control device 3 is not operated (when the inter-vehicle distance holding is not operated), for example, at each initial speed of the own vehicle, the primary safety warning distance Ds1 is set.
Distance maps a to e are set for obtaining (alarm distance that calls attention of the driver, inter-vehicle distance having a margin including determination time before brake operation is performed: equivalent to a predetermined alarm distance). Specifically, the distance maps a to e are obtained by obtaining the primary safety warning distance Ds1 according to the secondary safety warning distance Ds2 on the assumption that the vehicle 1 does not need to collide with the preceding vehicle X. It is. The secondary safety warning distance Ds2 in the distance maps a to e is a warning distance for which there is no determination time and a brake operation is required immediately. [0019] Here, the secondary safety alarm distance D _S 2 _{is, D S 2 = Vf · Td} + Vf 2 / 2αf -Va 2 / 2αa
In which in accordance with the primary safety warning distance Ds1 is calculated from the given equation consisting Ds1 = D s 2 + Vf · Tx. Vf is the own vehicle speed, Va is the preceding vehicle speed, Td is the idle running time, Tx is the judgment time, αf is the own vehicle deceleration, and αa is the preceding vehicle deceleration. In addition, the control unit 4 includes FIG.
As shown in FIG. 3, during the operation of the vehicle speed control device 3 (when the inter-vehicle distance is activated), for example, at each initial speed of each vehicle, the primary safety alarm distance Ds3 (the alarm distance that calls the driver's attention, Distance maps A to E are set for obtaining an inter-vehicle distance having a margin including a determination time before the operation is performed (corresponding to a predetermined warning distance). Specifically, in the distance maps A to E, the setting of the warning distance of the primary safety warning distance Ds3 is compared with the primary safety warning distance DS1 of the distance maps a to e, and the relative speed (approaching to the preceding vehicle X) is set. In this case, a map is used in which a region having a small relative speed (with respect to the direction) is short and a region having a relatively high relative speed is long. With this change, the primary safety alarm distance Ds3 becomes
It is short in a region where danger is sufficiently avoided by the deceleration operation of the auxiliary brake 8, and is long in a region where it is difficult to control the inter-vehicle distance maintenance in the deceleration operation of the auxiliary brake 8. Note that the region of the minimum relative speed is a region where the deceleration by the auxiliary brake 8 is sufficiently exerted, so that the setting is made so that the primary alarm is not issued. Such distance maps a to e / distance map A
, The secondary warning distance DS2 is combined with the primary warning distance DS1 / DS3 to form a warning distance map suitable for both the vehicle-to-vehicle distance keeping cruise and when the vehicle-to-vehicle distance is not used.
FIG. 4 shows the entire system of the alarm generation distance when the own vehicle speed becomes 80 km / h. When the constant speed control unit 9a / inter-vehicle control unit 9b is not operated, the control unit 4 determines the inter-vehicle distance detected by the laser radar unit 5 from the primary maps obtained by the distance maps a to e shown in FIG. When the distance falls below the warning distance DS1, the primary alarm is issued from the warning device 10, and when the constant speed control unit 9a / inter-vehicle control unit 9b operates, the primary alarm distance DS3 obtained by the inter-vehicle distance obtained by the distance maps A to E shown in FIG. A setting is made to issue a primary alarm from the alarm device 10 when the vehicle speed falls below the threshold, and an inter-vehicle distance alarm suitable for each characteristic of cruise traveling / non-cruise traveling is performed. In addition, in all the secondary warnings, the following distance warning is performed according to the same warning distance DS2. (However, if the warning distance of the primary warning is smaller than the warning distance of the secondary warning, the warning distance of the secondary warning is set. The inter-vehicle distance warning is given priority.) Such distance maps a to e / distance map A
The control of the inter-vehicle distance warning by E is shown in the flowchart of FIG. Next, the flowchart of FIG. 5 will be described. It is assumed that, for example, the host vehicle 1 is traveling following the preceding vehicle X in the traveling lane of the highway. At this time, the on / off switch 4a is turned off,
Assuming that there is no input from the set vehicle speed input unit 7, the control unit 4 does not operate the constant speed control unit 9a / inter-vehicle control unit 9b (deactivates), and uses the output of the laser radar unit 4 to output The inter-vehicle distance with the car X is monitored. That is, while the host vehicle 1 is traveling, the control unit 4 detects the host vehicle speed from the output of the vehicle speed sensor 6 and uses the output of the laser radar unit 5 to determine the distance between the host vehicle 1 and the preceding vehicle X. The relative speed (with respect to the approaching direction to the preceding vehicle X) is calculated, and the primary warning distance Ds1 is obtained from the primary warning distance map (when the inter-vehicle distance keeping cruise is not used) shown in FIG. At this time, when the own vehicle 1 approaches the preceding vehicle X running ahead and the actual inter-vehicle distance D detected by the laser radar unit 4 becomes smaller than the primary warning distance Ds1, the steps 1 to 5 are repeated. S2 (actual headway distance D is secondary warning distance D _S 2 smaller than determines whether), step S3 (whether in distance control decision), in step S4 (actual headway distance D
Is smaller than the primary alarm distance Ds1 ), the process proceeds to step S5, where the alarm 10 emits a primary alarm sound (for example, an intermittent sound), and the inter-vehicle distance is insufficient for the driver. Notify that. When the driver receives the notification and operates the brake to recover the inter-vehicle distance, the alarm is released. Even if the primary warning is issued, if the vehicle 1 further approaches the preceding vehicle X and enters the secondary warning distance DS2, the process proceeds from step S2 to step S6, and the secondary warning sound (e.g. For example, a continuous sound is emitted. On the other hand, while the own vehicle 1 is traveling, for example, in a traveling lane on a highway, a set vehicle speed (cruise vehicle speed) is input from the setting input unit 7, and the on / off switch 4a is turned on. At this time, if the preceding vehicle X does not exist in the detection range of the laser radar unit 5, the control unit 4 determines that there is no preceding vehicle X, and controls the constant speed control unit 9a, that is, maintains the set vehicle speed (cruise vehicle speed). The governor control unit 2a and the auxiliary brake 8 are controlled as described above. That is, the own vehicle 1 cruises while maintaining the set cruise vehicle speed without stepping on the accelerator pedal / brake pedal. During this cruise traveling, it is assumed that a preceding vehicle X traveling at a lower speed than the set vehicle speed (cruise vehicle speed) exists in the same traveling lane. Then, the own vehicle 1 approaches the preceding vehicle X due to the speed difference. When the preceding vehicle X reaches the detection range of the laser radar unit 4 and the control unit 4 recognizes the presence of the preceding vehicle X from the output of the laser radar unit 4, the control is switched to the control of the following distance control unit 9b, and the following distance control is started. You. At this time, if the primary warning distance DS1 is obtained from the primary warning distance map shown in FIG. 2, since the deceleration ability of the following distance control is not taken into consideration, the primary warning distance DS1 is also used during the deceleration control when danger is sufficiently avoided. Regardless, the distance between the preceding vehicle X and the host vehicle 1 that shrinks while recovering the target inter-vehicle distance is captured, and FIG.
The useless primary alarm is output from the alarm device 10 as seen in the area of the small relative speed in the vertical line portion surrounded by the one-dot chain line in the middle (when the vehicle speed is 80 km / h). According to the present invention, it is determined whether or not the actual inter-vehicle distance D is smaller than the primary alarm distance DS3 by using the primary alarm distance DS3 in consideration of the inter-vehicle holding control as in step S7. That is, of the primary warning distance DS3, the warning distance in the region where the relative speed with respect to the preceding vehicle X is small is the primary warning distance D3 as shown in the output range of the primary warning distance DS3 in FIG.
Shorter than S1. Therefore, during the headway holding control, the auxiliary brake 8
The useless primary alarm is suppressed from being generated in a region that is sufficiently avoided by the operation (region where the relative speed with respect to the preceding vehicle X is low). During the headway control, for example, the preceding vehicle X
Begins to decelerate, the inter-vehicle distance from the preceding vehicle X decreases, and when the brake operation is required, the actual inter-vehicle distance D
Becomes less than or equal to the primary alarm distance Ds3, and proceeds to step S5.
The primary alarm sound (for example, intermittent sound: inter-vehicle distance alarm) is issued from the alarm device 10 to notify the driver that the inter-vehicle distance is insufficient, so that the brake operation does not tend to be delayed. For example, when the preceding vehicle X reaches the detection range of the laser radar unit 4 (at the start of maintaining the inter-vehicle distance), the relative speed with respect to the preceding vehicle X is large, and the inter-vehicle control unit 9b
It is assumed that the deceleration ability (auxiliary brake 8) cannot control the inter-vehicle distance. That is, the auxiliary brake 8 used for decelerating the following distance control exerts sufficient control performance to maintain the following distance if the relative speed with respect to the preceding vehicle X is small, When the speed is high, there is a characteristic that the braking force tends to be insufficient and the control performance tends to be insufficient. Therefore, in the case of an inter-vehicle control relying on the auxiliary brake 8, the situation in which a large relative speed occurs with the preceding vehicle X is taken into consideration in consideration of the characteristics of the auxiliary brake 8 in FIG. If the primary warning is issued at the primary warning distance DS1 of the primary warning distance map, there is a possibility that the brake operation may not be in time. According to the present invention, of the warning distance of the primary warning distance DS3, the region where the relative speed with respect to the preceding vehicle X is large is the primary warning distance DS1 as apparent from the output range of the primary warning distance DS3 in FIG. Much longer than in. With the long primary alarm distance DS3, the alarm 10 emits a primary alarm sound early so that the brake operation can be performed in time. As a result, a primary alarm is issued at an appropriate time, and the driver is made aware early that the brake operation is required. By setting the inter-vehicle distance for activating the primary alarm in accordance with the characteristics of the inter-vehicle control device (constant speed control unit 9a / inter-vehicle control unit 9b) using the auxiliary brake 8 together, the braking operation is delayed. It is possible to eliminate wasteful inter-vehicle warnings and further improve safety without causing a tendency to tend. In the embodiment, an auxiliary brake is taken as an example of the speed reducer used in the headway control device. However, the present invention is not limited to this, and an engine brake, a downshift or the like may be used. As described above, according to the first aspect of the present invention, when the relative speed with respect to the preceding vehicle is small and danger is sufficiently avoided by the deceleration operation of the headway distance control device, the distance is short. By setting the warning distance, useless warning of the distance between vehicles can be suppressed.When the relative speed with the preceding vehicle is too large to control the distance between vehicles with the deceleration ability of the distance control system, the longer warning distance is used. Thus, an early inter-vehicle distance warning can be issued so that the brake operation can be performed in time. Therefore, it is possible to achieve both the elimination of useless alarms and the further improvement of safety without causing the brake operation to tend to be delayed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a configuration of a travel control device of a vehicle with an inter-vehicle distance warning device according to a first embodiment of the present invention. FIG. 2 is a map for obtaining a primary warning distance of the following distance warning device used when the following distance device is not operated. FIG. 3 is a map for obtaining a primary warning distance used for an inter-vehicle distance warning device when the inter-vehicle distance device is activated. FIG. 4 is a map for obtaining the entire alarm generation distance when the vehicle speed is 80 km / h. FIG. 5 is a flowchart for performing a primary alarm according to the characteristics of the following distance control device. [Description of Signs] 1... Own vehicle 3... Vehicle speed control device (running control device) 4... Control unit 8… auxiliary brake 9 b… inter-vehicle control unit (inter-vehicle control device) 10. car.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI G08B 21/00 G08B 21/00 H (58) Field surveyed (Int.Cl. ⁷ , DB name) G08G 1/16 B60K 31/00 B60R 21 / 00 B60T 7/12

Claims (1)

(57) Patent Claims 1. A deceleration operates the inter-vehicle distance between the host vehicle and the preceding vehicle
The inter-vehicle control device that keeps the target inter-vehicle distance more and the inter-vehicle distance between the preceding vehicle and the preceding vehicle
An inter-vehicle distance alarm device that issues an alarm when the distance becomes shorter than an alarm distance determined according to speed , wherein the inter-vehicle distance alarm device is decelerated by the inter-vehicle control device.
The relative speed is so high that the danger is sufficiently avoided by the operation.
In a small area, it operates from the time when the headway control device is not operating.
It said alarm distance towards the time is short, due to the vehicle control device
In a region where the relative speed is so large that the danger is not sufficiently avoided by the deceleration operation, it is better than when the inter-vehicle distance control device is not operated.
A travel control device for a vehicle with an inter-vehicle distance warning device, wherein the warning distance is set longer when the vehicle is operated .