JPS5880800A - Car-to-car distance controller for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automobile inter-vehicle distance control device that uses a road surface condition sensor to set an appropriate inter-vehicle distance depending on whether or not the road surface is dry.

A conventional inter-vehicle distance control device, as shown in Fig. 1, detects the distance and relative speed to the preceding vehicle using a distance sensor 1 using a microwave radar or a sensor, and then sets the distance and relative speed by the driver or a microcomputer. Accordingly, an accelerator 5 and a brake 6 are controlled by a command from a microcomputer 3 through a control device 4 so as to maintain a preset inter-vehicle distance constant according to vehicle speed information from a vehicle speed sensor 2.

The appropriate following distance varies depending on the road surface condition.

In general, the stopping distance is different between dry and wet or icy roads, and when the road is wet, the stopping distance is significantly longer than when the road is dry, so it is important to keep a wide following distance. No. However, the conventional inter-vehicle distance control device as shown in FIG. 1 cannot perform control according to road surface conditions.

This invention was made to eliminate the above-mentioned conventional drawbacks, and uses a road surface condition sensor to determine the condition of the road surface.
It is an object of the present invention to provide an inter-vehicle distance control device for an automobile that can set the inter-vehicle distance to an appropriate value by setting the inter-vehicle distance according to the vehicle speed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an automobile inter-vehicle distance control device of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram showing the configuration of one embodiment. In this Figure 2, 1.
In addition to the distance sensor 1 and the vehicle speed sensor 2, a wheel direction sensor 10 that detects the direction the wheels are facing and a road surface condition sensor 11 that detects the road surface condition are newly added.
Information from the distance sensor 11, vehicle speed sensor 2, wheel direction sensor 10, and road surface condition sensor 11 is input to the microcomputer 3, which calculates an appropriate inter-vehicle distance according to the vehicle speed, steady running speed, and running speed when curved. The accelerator 5 and brake 6 are controlled through the control device 4.

The distance sensor 1 provides the inter-vehicle distance and relative speed, but if the vehicle speed is high, the inter-vehicle distance must be widened. The required following distance also varies depending on whether the road surface is dry or wet. Therefore, the present invention is characterized in that when setting the inter-vehicle distance, an appropriate inter-vehicle distance N1 is set based on the vehicle speed and the output of the road surface condition sensor.

FIG. 3 is a block diagram showing the configuration of a specific embodiment of the road surface condition sensor 11. In the embodiment shown in FIG. The basic elements of the resistor 20, the emitter element control device 21, the optical system 22 for forming a complete beam, the light receiving element system 23 that receives the scattered light on the road surface 26, the light receiving element 24 that detects the origin, and the emitted light It is comprised of a comparison/determination device 25 that compares the intensity of the received light with the original intensity of the received light to determine the condition of the road surface 26.

The operation of this road surface condition sensor is such that the light emitted from the light emitting element 20 passes through the entire light emitting optical system 22, hits the road surface 26, and is scattered. If the road surface is currently dry, the light will be diffusely reflected almost completely, and the scattered light will be emitted isotropically, passing through the entire light-receiving optical system 23 and being captured by the light-receiving element 24. Therefore, the deviation can be determined by comparing the output level of the light receiving element 24 with a predetermined reference level created for the emission intensity using the comparison/judgment device 25.

Assuming that the reference level value is lower than the output level of all light receiving elements 24, a comparison will be made with a case where the road surface 26 is wet. When the road surface is wet or icy, the road surface 26 has a near-mirror reflection. Therefore, the light that hits the road surface is almost completely reflected, so the source that returns to the light emitting side becomes extremely weak. Therefore, the output level from the light receiving element 24 becomes lower than the reference level. In this way, it can be determined that the road surface 26 is dry if the output from the comparison/determination device is positive, and that it is wet if the output is negative.

Next, the operation of the automobile inter-vehicle distance control device of the present invention will be explained. Now, if the following distance and constant speed driving device are set while the preceding vehicle and the vehicle in question are traveling at a certain speed with a certain distance between them, the vehicle speed at that time will be memorized and the following distance will be optimized.

For example, if the speed of the car in question is 60km/h and the appropriate following distance is 30m, if the following distance is shorter than 30m when the car following distance control device is set, the speed will gradually increase. , while increasing the following distance,
The vehicle starts running at a constant speed of 60KII/H, and when the inter-vehicle distance is 30 m, it becomes a constant speed running state of 601B/H.

On the other hand, if the distance between vehicles when set is longer than 30m, the vehicle will continue to drive at a constant speed and the distance between vehicles will not decrease.

If the vehicle in front increases its speed while driving at a constant speed with an appropriate following distance, the vehicle will continue to travel at a constant speed, although the following distance will increase. Conversely, if the preceding vehicle decelerates, control is performed to maintain an appropriate inter-vehicle distance at the new vehicle speed.

If it starts to rain and the road surface condition changes while the vehicle is running, the appropriate inter-vehicle distance is corrected based on the output of the road surface condition sensor 11, and the vehicle is controlled to widen the inter-vehicle distance and drive at a constant speed.

In addition, at curves, guardrails and objects on the roadside are detected, the vehicle speed is reduced, and the wheel direction sensor 1
Microcomputer 3 calculates the output of 0, the vehicle speed, and the radius of multiple rotations.
The system calculates the speed and controls the vehicle to the appropriate speed.

As described above, according to the vehicle distance control device of the present invention, the outputs of the distance sensor, wheel direction sensor, and road surface condition sensor are processed by a microcomputer to operate the accelerator and brake. Therefore, it is possible to automatically maintain an appropriate inter-vehicle distance and vehicle speed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional automobile inter-vehicle distance control device, FIG. 2 is a block diagram showing the structure of an embodiment of the automobile inter-vehicle distance control device of the present invention, and FIG. FIG. 3 is a block diagram showing the configuration of a road surface condition sensor in the automobile inter-vehicle distance control device shown in FIG. 2; DESCRIPTION OF SYMBOLS 1... Distance sensor, 2... Vehicle speed sensor, 3... Microcomputer, 4... Control device, 5... Accelerator, 6... Brake, 10... Wheel direction sensor,
11... Road surface condition sensor, 20... Light emitting element, 21
・-・Light-emitting element control device, 22...Gengen Science, 23
. . . Light receiving optical system, 24 . . . Light receiving element, 25 . Agent Shin Kuzuno - Figure 1

Claims (4)

[Claims] (1) A distance sensor that detects the distance and relative speed to the preceding vehicle, a vehicle speed sensor that obtains speed information, a wheel direction sensor that detects the direction of the wheels, a road surface condition sensor that detects the road surface condition, the above distance sensor, and vehicle speed sensor , a microcomputer that calculates the entire appropriate inter-vehicle distance based on the outputs of a wheel direction sensor and a road surface condition sensor, and a control device that controls the inter-vehicle distance and vehicle speed by controlling the brake and accelerator based on the calculation results of this microcomputer. Inter-vehicle distance control device. (2) When there is an interruption between the vehicle in front and the vehicle in front, the distance between the two vehicles is increased at a predetermined rate according to the vehicle speed, and control is performed so that the distance between the two vehicles reaches the predetermined distance before the interruption in a predetermined time. An automobile inter-vehicle distance control device according to claim 1. (3) Inter-vehicle distance control for automobiles according to claim 1, which is characterized in that when the preceding vehicle is at a position where the preceding vehicle is at a predetermined inter-vehicle distance, the vehicle is controlled to travel at a constant speed at a preset speed. Device. (4) Distance at object 1 existing on the roadside at the curve,
Claims characterized in that the vehicle is controlled to a predetermined vehicle speed set by a microcomputer based on information on relative speed, positional relationship, vehicle speed sensor, wheel direction sensor, road surface condition sensor, etc. The inter-vehicle distance control device for automobiles according to item 1.