JPH05141285A - Traveling control device for vehicle - Google Patents

Abstract

PURPOSE:To carry out follow-up traveling following along the flow of vehicles while automatically controlling the target intervehicle distance, in a traveling control device for a vehicle in which a target car-to-car distance for following up with the preceding vehicle is calculated for carrying out acceleration/ deceleration control, when the target car-to-car distance is improper so that it does not follow up with the flow of vehicles. CONSTITUTION:The detected signals from an intervehicle distance sensor 10 and a vehicle speed sensor 12 are inputted into a microcomputer 18. The microcomputer 18 calculates a target intervehicle distance LT on the basis of the vehicle speed, and carries out vehicle-speed control to satisfy this target intervehicle distance LT. At that time, it is judged whether or not the interruption detected by a sudden change in the intervehicle distance has occurred more than a prescribed times within a prescribed time, and when the interruption frequently occurs, it is judged that the present target intervehicle distance is improper, and the target intervehicle distance is shortened by a prescribed amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle travel control device, and more particularly to a control device that travels following a preceding vehicle while maintaining a substantially constant vehicle-to-vehicle distance.

[0002]

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

In such a traveling control device, a constant speed traveling mode in which the driver cruises the vehicle at a predetermined vehicle speed, and when there is a preceding vehicle, the distance between the preceding vehicle and the preceding vehicle is maintained at a safe distance. However, a follow-up traveling mode or the like that follows the preceding vehicle is set.

In the follow-up running mode, the vehicle speed control is performed so that the current vehicle-to-vehicle distance matches the target vehicle-to-vehicle distance that is predetermined or calculated based on the vehicle speed. However, environmental conditions such as road congestion and weather conditions may occur. The target inter-vehicle distance is not always appropriate because the appropriate inter-vehicle distance changes variously. For example, the inter-vehicle distance may be too large with respect to the traffic volume of the vehicle, and an interrupt from an adjacent lane may occur.

When another vehicle cuts in between the preceding vehicle and the own vehicle in this way, the interrupting vehicle becomes a new preceding vehicle to follow, and the inter-vehicle distance is less than the target inter-vehicle distance. Sudden deceleration occurs and the driver feels uncomfortable.

Therefore, for example, Japanese Patent Laid-Open No. 60-131327.
In the official gazette, when another vehicle interrupts while following,
A configuration has been proposed in which the current own vehicle speed is maintained for a predetermined time, and then acceleration / deceleration control is performed according to the relative speed to the interrupting vehicle.

[0007]

However, while such follow-up running can prevent sudden deceleration or the like at the time of interruption, it is highly likely that another vehicle will interrupt again while the follow-up running is carried out. If the vehicle is interrupted by other vehicles one after another in this way, not only will the vehicle not be able to run as intended, but the distance to the following vehicle will become shorter and There was a problem that the person felt anxious.

The present invention has been made in view of the above-mentioned problems of the prior art. The purpose of the present invention is to set the target inter-vehicle distance to an appropriate inter-vehicle distance along the flow of the vehicle when the target inter-vehicle distance is not appropriate due to road conditions or the like. It is an object of the present invention to provide a vehicle travel control device capable of promptly correcting a target inter-vehicle distance and performing an appropriate follow-up travel along a flow of a vehicle when there is a high possibility that another vehicle will significantly interrupt. ..

[0009]

In order to achieve the above object, the present invention detects an inter-vehicle distance detecting means 1 for detecting an inter-vehicle distance to a preceding vehicle as shown in FIG. 1 and a speed of an own vehicle. A vehicle speed detection means 2, a target inter-vehicle distance calculation means 3 for calculating a target inter-vehicle distance based on the speed of the own vehicle, and a control means 4 for controlling a throttle so that the inter-vehicle distance with a preceding vehicle becomes the target inter-vehicle distance. In the vehicle travel control device including the above, an interrupt detection unit 5 that detects that an interrupt has occurred from the change in the inter-vehicle distance, and a determination unit 6 that determines whether the interrupt has occurred a predetermined number of times or more within a predetermined time.
And a correction unit 7 that shortens and corrects the target inter-vehicle distance when the interruption occurs a predetermined number of times or more within a predetermined time.

[0010]

The vehicle travel control device of the present invention has such a configuration, and when the number of interruptions within the predetermined time is equal to or greater than the predetermined number, the current target inter-vehicle distance is appropriate along the flow of the vehicle. It is determined that the distance is not the inter-vehicle distance, and the correction means 7 shortens and corrects the target inter-vehicle distance to automatically adjust to the appropriate inter-vehicle distance.

[0011]

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

FIG. 2 shows a block diagram of the configuration of this embodiment. Inter-vehicle distance sensor 10 as inter-vehicle distance detecting means
Is provided at the front of the vehicle. This inter-vehicle distance sensor 10
For example, it is possible to use a CCD camera, a radar device, a laser radar device, or the like that captures an image of 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.

A setting SW 14 for setting the vehicle speed during constant speed traveling is provided in the driver's seat, and a follow-up traveling system SW16 is similarly provided in the driver's seat. Then, the signals from these respective sensors and SW are supplied to the microcomputer 18.

The microcomputer 18 has an input / output port, a ROM storing a processing program to be described later, a CPU for performing an operation according to the processing program, a RAM for storing the operation result, and the like. The processing result is stored in the throttle actuator 20 or the brake. Actuator 2
2 (in the present embodiment, the vehicle speed control is basically performed by the throttle control, so the brake actuator is not controlled, but the brake control can be performed if necessary). It is configured to control the traveling and notify the driver that the inter-vehicle distance is inappropriate through the alarm device 26 and the display device 28 provided in the driver's seat.

The processing of the microcomputer 18 will be described in detail below with reference to the flow charts of FIGS. FIG. 3 shows the overall processing process of follow-up running (inter-vehicle distance control) in this embodiment. First, the inter-vehicle distance L0 to the preceding vehicle is detected by the detection signal from the inter-vehicle distance sensor 10.
Is detected (S101) and the relative speed VR with respect to the preceding vehicle is calculated by the rate of change of the inter-vehicle distance L0 within a predetermined time, that is, the time differentiation (S102). Further, the vehicle speed sensor 12
The vehicle speed V0 of the host vehicle is detected by the detection signal from the vehicle, and the target vehicle distance LT is calculated using this vehicle speed V0 (S10).
3). As a function form for calculating the target inter-vehicle distance LT from the vehicle speed V0, a known function form such as LT = V ² /(2×0.7×9.8) can be used.

Then, the target vehicle speed VT = V0 + VR-K based on the vehicle speed V0, the relative speed VR, and the difference between the target vehicle distance and the current vehicle distance so as to match the target vehicle distance LT.
(LT-L) (K: gain) is calculated and throttle control (or transmission control) is performed (S10
6) A feature of the present embodiment is whether or not the calculated target inter-vehicle distance LT is appropriate for the flow of the vehicle (S104), and when it is determined that the target inter-vehicle distance LT is not appropriate, this target inter-vehicle distance LT is set. The microcomputer 18 performs the correction process (S105).

FIG. 4 shows a processing process for determining whether or not the target inter-vehicle distance LT is appropriate. First, it is determined whether or not the preceding vehicle to be followed is being recognized (S201). This determination is made based on whether finite data is supplied from the inter-vehicle distance sensor 10. Next, the inter-vehicle distance Ln n seconds (for example, n = 1) before is read from the inter-vehicle distance data stored in the RAM, and the difference from the current inter-vehicle distance L is calculated. Then, it is determined whether or not this difference Ln-L is equal to or greater than a predetermined distance KL (S202), and if it is equal to or greater than KL, it means that the inter-vehicle distance is rapidly reduced in a short time, and thus it is determined that an interrupt has occurred. Yes (S203).

As described above, the microcomputer 18 detects an interrupt depending on whether or not there is a rapid decrease in the inter-vehicle distance within a predetermined time. To further evaluate the interrupt frequency,
Counts the number of interrupts generated within a predetermined time. That is, the time T at which an interrupt occurs is detected and stored in the RAM (S204), and the flag C indicating the number of interrupts is incremented by 1 (S205). Then, it is judged whether or not the number of interruptions C has reached a predetermined number m (for example, m = 5) (S206), and the time difference Tm between the time Tm when the number of times C has reached m and the first interrupt occurrence time T is −. T is the predetermined time T
It is determined whether it is 0 or more (S207). Predetermined time T0
When frequent interrupts occur such that interrupts occur m times or more, the time difference Tm-T is the predetermined time T0.
The following is obtained, and it is determined that the current target inter-vehicle distance LT is not suitable for not following the flow of the vehicle (S20).
8).

When it is determined that the target inter-vehicle distance LT is inappropriate, the target inter-vehicle distance LT is corrected as described above (S105). Specifically, the calculated target inter-vehicle distance LT is set to a predetermined amount. The target inter-vehicle distance LT is shortened and corrected by reducing ΔLT (S209). Then, the vehicle speed control is performed so that the vehicle-to-vehicle distance matches the new target vehicle-to-vehicle distance that has been shortened (S106), and the vehicle-to-vehicle distance to the interrupting vehicle is shortened and the possibility of being interrupted further is reduced. Follow-up running can be performed (S209).

Even if the target inter-vehicle distance is shortened in S209, if the interrupts still occur m times within the predetermined time, the target inter-vehicle distance is further reduced by ΔLT.

Of course, in addition to automatically correcting the target inter-vehicle distance as described above, it is possible to inform the driver via the alarm device 26 or the display device 28 that the current inter-vehicle distance (target inter-vehicle distance) is inappropriate. You may notify (S20
9).

As described above, in the present embodiment, when the interrupts occur a predetermined number of times or more within the predetermined time, it is determined that the current inter-vehicle distance, that is, the target inter-vehicle distance is inappropriate, and the target inter-vehicle distance is the predetermined amount. By shortening the correction,
It is possible to follow the preceding vehicle without further interruption.

[0023]

As described above, according to the vehicle travel control apparatus of the present invention, the target inter-vehicle distance can be maintained even when inappropriate follow-up travel is performed in which a large number of interruptions occur due to road conditions. Is automatically adjusted, and there is an effect that appropriate follow-up traveling along the flow of the vehicle becomes possible.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of the present invention.

FIG. 2 is a configuration block diagram of an embodiment of the present invention.

FIG. 3 is an overall processing flowchart of the embodiment.

FIG. 4 is a flowchart of target inter-vehicle distance correction according to the embodiment.

[Explanation of Codes] 10 Vehicle Distance Sensor 12 Vehicle Speed Sensor 14 Setting SW 16 System SW 18 Microcomputer 20 Throttle Actuator 22 Brake Actuator

Claims (1)

[Claims] 1. An inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle, a vehicle speed detecting means for detecting a speed of the own vehicle, and a target inter-vehicle distance calculating means for calculating a target inter-vehicle distance based on the speed of the own vehicle. And a control means for controlling the throttle so that the inter-vehicle distance to the preceding vehicle becomes this target inter-vehicle distance, and an interrupt detection for detecting that an interrupt has occurred from the change in the inter-vehicle distance. Means, determining means for determining whether or not the interrupt has occurred a predetermined number of times or more within a predetermined time, and correction means for shortening and correcting the target inter-vehicle distance when the interrupt has occurred a predetermined number of times or more within the predetermined time, A travel control device for a vehicle, comprising: