JPS59119418A - Inter-car distance control device - Google Patents

Abstract

PURPOSE:To control automatically an inter-car distance to a preceding car to a safe distance by controlling driving force and braking force of a car basing on a function determined by the inter-car distance and a car speed. CONSTITUTION:Each detecting signal of an accelerator detecting part 100 being an accelerator sensor, a car speed detecting part 200 being a car speed sensor and an inter-car distance detecting part 300 being an inter-car distance sensor is supplied to a microcomputer 1. The microcomputer 1 controls a servo-system 400 for a driving force of a car and a servo-system 500 of a damping hydraulic pressure, in accordance with magnitude of an accelerator signal from the sensor 100 in a prescribed area, basing on a function determined by an inter-car distance signal from the sensor 300 and a car speed signal from the sensor 200. By controlling in this way, an inter-car distance to a preceding car can be controlled automatically to a safe distance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inter-vehicle distance control device that automatically corrects an inter-vehicle distance between vehicles such as automobiles to a safe range.

Conventionally, this type of device generally performs feedback control of the inter-vehicle distance according to the traveling speed (vehicle speed) of the vehicle. Therefore, for example, when driving to overtake a vehicle in front, the feedback is temporarily canceled. Additionally, there are problems such as erroneous judgments such as sudden changes in the distance between vehicles when the vehicle in front leaves the detection area or enters the detection area on a curved road, etc., resulting in unnecessary acceleration or deceleration. There is.

The present invention has been developed in view of the above-mentioned problems, and it automatically controls the distance between the vehicle in front and the vehicle in front to a safe distance during normal vehicle driving, and also automatically controls the distance between the vehicle and the preceding vehicle to a safe distance. The purpose is to smoothly perform acceleration or deceleration according to the intention of deceleration or deceleration outside the range of the above-mentioned automatic control during deceleration operation.

To this end, in the present invention, the vehicle is moved according to the magnitude of the accelerator signal from the accelerator sensor within a predetermined area based on a function determined by an inter-vehicle distance signal indicating the inter-vehicle distance to the preceding vehicle from the inter-vehicle distance sensor and a vehicle speed signal from the vehicle speed sensor. The structure includes a control means for controlling a combination of propulsive force and braking force.

Below, the present invention will be described with reference to embodiments shown in the drawings.

In the overall configuration diagram of FIG. 1, numeral 1 is a microcomputer which mainly includes a CPU, RAMXROM, etc. (Hereinafter, referred to as a microcomputer.) A block 100 is an accelerator detection section that includes a potentiometer 102 and a D/A converter 103 that operate in conjunction with an accelerator 101, and transmits the amount of accelerator depression to the microcomputer 1. Block 200 includes an electromagnetic pickup 201 and an interface circuit 202
This is a vehicle speed detection section that detects vehicle speed information.

Block 300 is an inter-vehicle distance detection unit consisting of a TV left camera 01 and 302 using two CCD image pickup devices.

Next, the flock 400 is a servo system that controls the engine throttle opening, and includes a control circuit 401 and a servo motor 4.
02. It is composed of a potentiometer 403 for detecting a throttle angle, and controls the throttle opening degree by feedback control according to a throttle angle signal from the microcomputer 1. Similarly, a block 500 is a servo system that controls braking oil pressure, including a control circuit 501, a hydraulic actuator 502,
It is composed of a hydraulic pressure sensor 503.

Next, the operation of the above configuration will be explained. Figure 2 (A)
, (B) is a control flowchart.

After the necessary initial settings, the microcomputer 1 repeatedly executes the main routine (FIG. 2(A)) at regular intervals (50 ms). The interrupt routine (FIG. 2(B)) is executed at fixed time intervals (about 5 ms). Next, I will explain the main routine. The main routine uses the inter-vehicle distance and vehicle speed S as a function of throttle opening and auxiliary brake pressure (corresponding to parameter P) with respect to accelerator depression amount.
Establish.

Then, check whether or not to control the following distance,
If not controlled, return as P-0.

If the inter-vehicle distance control is ON, first, in step 1003, the image signal from block 300 is processed to calculate the inter-vehicle distance to the preceding vehicle traveling in front. Next, the process proceeds to step 1004, where the vehicle speed signal from block 200 is processed to obtain the vehicle speed S. From this inter-vehicle distance MD and vehicle speed S, Figure 3 (bl
Parameter PL=F (D, S) is set in step 10 from the pattern stored in 30M of microcomputer 1 shown in
A new parameter P (-F (Pl
)).

ΔmaX in the above equation is the parameter P from O to maX
(maximum) is set so that the minimum time is about 1 second, and the rate of change of the parameter P over time is limited.

Next, the interrupt routine shown in FIG. 2(B) will be explained. This interrupt routine determines the accelerator depression amount and Fig. 2 (A
) From the parameter P value calculated by the main routine, the throttle opening or auxiliary brake pressure is calculated and output to each control block. That is, step 20
At step 01, the amount of accelerator depression is manually controlled from block 100. Next, from the accelerator depression amount A and the parameter P, the throttle index is set in step 20 according to the characteristics shown in Fig. 3 (a).
02, and depending on its positive and negative polarity, step 200j,
At 2005, the throttle opening or brake pressure is calculated and output to each corresponding control block 400, 500.

By carrying out the above control, for example, when the vehicle is traveling with a constant amount of accelerator depression and the distance between the vehicle and the preceding vehicle is decreasing, the variable make P is adjusted according to the characteristics shown in Fig. 3(b). The value increases, and therefore, Fig. 3(a)
Due to this characteristic, the throttle opening is reduced, and furthermore, auxiliary brake pressure is applied to decelerate the vehicle. In this way, Figure 3 (al
The following distance will be automatically maintained at a safe distance within the range of throttle opening and brake pressure from P-0 to max.

By adopting the above configuration and control method, the following advantages can be obtained.

(Since the driver can change the throttle opening to the maximum by operating the accelerator even under distance control, sufficient driving performance can be obtained even if the driver misjudges the distance between vehicles when overtaking, accelerating, or turning corners.) I can do it.

(b) Inter-vehicle distance control area (Fig. 3 Fal OkuP≦ma
x), the brake pressure is controlled with a single operation of the accelerator, making it easier to drive in traffic jams than with conventional vehicles (especially torque converter vehicles).

(C) By limiting the rate of change over time of the parameter P that determines the accelerator characteristics, inter-vehicle distance control can be performed without disturbing the driver's sense of accelerator operation and acceleration/deceleration of the vehicle.

(There is no need to cancel the dl inter-vehicle distance feedback loop even in the case of overtaking acceleration, etc., and the control loop can be simplified.

In the above-described embodiments, an imaging device using a CCD element is used as the inter-vehicle distance sensor, but a microwave radar or the like may also be used. Furthermore, various other types of detection means for detecting the amount of accelerator depression and vehicle speed may be used. Furthermore, although the blocks 400 and 500 are servo systems with a minor feed bank, they can also be directly controlled by the microcomputer 1.

In addition, the amount of change with respect to the amount of accelerator depression is shown in Figure 3 (
Although the throttle angle and auxiliary brake pressure are made to correspond as shown in a), it is also possible to make this correspondence the propulsion force and braking force of the vehicle, and in this case, it can be applied to electric vehicles and the like.

As described above, according to the present invention, the propulsive force and braking force of the vehicle are controlled in combination according to the accelerator signal within a predetermined area based on a function determined by the inter-vehicle distance and the vehicle speed. The combination of these controls makes it possible to automatically control the distance between the vehicle in front and the vehicle in front to a safe distance.Furthermore, it is possible to automatically control the following distance to a safe distance from the preceding vehicle, and furthermore, it is possible to automatically control the following distance to a safe distance. When performing a deceleration operation, the driver can deviate from the automatic control and adjust the acceleration and deceleration according to the driver's will, which has the excellent effect of preventing interference with the automatic control.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram of the device of the present invention, Figures 2 (A) and (B)
) is a flowchart showing the control calculation, and Figure 3 (Tsukasa,
fb) is a characteristic diagram used to explain the operation of the present invention. DESCRIPTION OF SYMBOLS 1... A microcomputer forming a control means, 100... An accelerator detection section often forming an accelerator sensor, 200... A vehicle speed detection section forming a vehicle speed sensor, 300... An inter-vehicle distance detection section forming an inter-vehicle distance sensor, 400.・Servo system for propulsion,
500...Brake oil pressure servo system. Representative Patent Attorney Takashi Okabe Figure 2 (A3 (El) Figure 3 (a)

Claims (1)

[Scope of Claims] An inter-vehicle distance sensor that detects the inter-vehicle distance to the preceding vehicle; a vehicle speed sensor that detects the traveling speed; an accelerator sensor that detects the accelerator operation amount of the vehicle; and an inter-vehicle distance detected by the inter-vehicle distance sensor. control means for controlling the propulsive force and braking force of the vehicle in accordance with the magnitude of the accelerator signal from the accelerator sensor within a predetermined area, based on a function determined by the signal of the vehicle and the signal of the vehicle speed detected by the vehicle speed sensor. An inter-vehicle distance control device characterized by: