JPH0261799A - Device for controlling distance between cars - Google Patents

Abstract

PURPOSE:To secure safety by executing braking with a control means when a distance to a front obstacle goes smaller than a first value, canceling the braking with its own car and obtaining a condition, in which departure can be executed, when the distance between cars goes to be a second value, which is greater than the first value, after its own car is once stopped in case the front obstacle is a preceding car. CONSTITUTION:An output from a means 1 to measure the distance between the cars is received in a processing circuit 2 and a distance R between the cars is computed and obtained. Next, a target vehicle speed V1 and a warning distance RAL are calculated and obtained. When its own car is just traveling and the distance R between the cars is < the warning distance RAL, the braking is executed by a braking means 4. At such a time, the target vehicle speed V1 is made to be zero and the opening of a throttle valve is made to be zero by a throttle valve driving means 5. When its own car is just stopped, the preceding vehicle departs and the distance R between the cars goes to be >= the second value, a braking condition by the braking means 4 is canceled and departure operation is executed according to the target vehicle speed V1. When the distance R between the cars is < the second value, the braking condition is kept by the braking means 4.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an inter-vehicle distance control device.

In the present specification, the term "vehicle distance" refers to the distance between an obstacle in front of the vehicle in the direction of travel, such as a vehicle traveling ahead and a guardrail stationary in front.

In the following explanation, the vehicle in front will be referred to as the preceding vehicle, and the following vehicle-to-vehicle distance control! A car equipped with l device is sometimes referred to as own car.

BACKGROUND OF THE INVENTION Conventionally, automobiles equipped with a constant speed driving device are often combined with an inter-vehicle distance control device (1g) in order to safely reduce the distance from obstacles in front, such as a preceding vehicle. A typical conventional technology for an inter-vehicle distance control device is disclosed in Japanese Patent Application Laid-open No. 1986-10.
2335. This conventional technology is configured to automatically apply brakes when the vehicle in front is within a safe distance of 11 in a situation where engine braking alone cannot provide sufficient braking force, such as on a long downhill slope. has been done.

Problem to be Solved by the Invention In the inter-vehicle distance control device having such a configuration, when the preceding vehicle does not stop, its own weight stops accordingly, and when the preceding vehicle starts moving, the following vehicle immediately follows. The dead weight causes it to start. If the preceding vehicle starts and decelerates for some reason, the braking force of the vehicle that started is applied f? If the vehicle is delayed, there is a risk of rear-end collision, which is dangerous.

The purpose of this system is to establish a distance control system that ensures safety even when encountering a large number of obstacles in front, such as a preceding vehicle. +31! The equipment is to be provided.

The method for solving the problem is as follows: 1. A distance measuring means for measuring the distance between the Ml-7J and an obstacle, a braking means, and a means for stopping the vehicle. In response to the output of the distance measuring means, when the distance between the vehicle and the object in front reaches a predetermined first value T,
The braking means performs braking, the vehicle stop detection means detects the stop of the vehicle, and then the distance becomes the first value and the second value determined by T above. Vli3, which releases the brake and makes the vehicle ready to start
An inter-vehicle distance system characterized by f-hand r2 and hand money 2:.

(According to the present invention), when the inter-vehicle distance measured by the distance 1 (by the measuring means), for example, from the preceding vehicle, becomes less than the predetermined value 1, the control ( 1 means is a braking means (4- Therefore, braking is performed. Therefore, when the preceding vehicle stops and the own vehicle is moved and stops), the leading weight and f) vehicle distance are, for example, When the weight of the vehicle stops as shown in the first value 6: (/'), the stopped state is detected by the vehicle stop detection means (-), and the vehicle in front starts moving! ,・In some cases, after the preceding vehicle has started, the distance between vehicles must be determined in advance to be greater than or equal to the value 1.1) of Nii.
Only when the value of -) is reached, the control stage 214 releases the braking of the vehicle. Then, it was ready to start.

After the distance between the vehicle and the vehicle in front becomes large enough, your army will be able to take off.

Therefore, even if an unexpected situation occurs, such as when the vehicle in front of the vehicle starts and decelerates for some reason, the vehicle in front of the vehicle and the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the driver and the vehicle in front of the vehicle in front of the vehicle in front of the vehicle in front of the driver and the vehicle in front of the vehicle in front of the vehicle, and J
) The distance is a sufficiently large value (g), so that even if the own vehicle's J/M1/IY is delayed, there will be no rear-end collision and safety is ensured.

Embodiment 1 Column 1 [1] is a block diagram of an embodiment of the present invention. A vehicle driven by an internal combustion engine has an inter-vehicle distance, it, 11, which measures the inter-vehicle distance R between the obstacles in front.
11 hands R21 is provided, and the signal indicating this inter-vehicle distance is
It is realized by a computer (eg, 20 computers) and is applied to a processing circuit 2 which is a control means. Manako, 1) The car is equipped with a heavy speed detector 3 that measures the vehicle speed.
A signal representing this vehicle speed is input to the processing circuit 2. Also, in the circuit 2, there is an output signal from a stop detector 8 which detects the stopped state of the vehicle. The stop state may be detected by detecting the vehicle speed detected by the vehicle speed or the vehicle speed being zero. (or release the driving state and release the braking (Set of internal combustion engine))
The throttle valve is driven by the throttle valve driving means 5.

The second throttle valve driving means 5 may include one for driving the throttle valve using the intake pressure of the internal combustion engine or using a motor. The throttle valve driving means 5 is controlled by a signal from the processing circuit 2.The braking means 4 also performs the braking operation by operating a foot pedal 0 operated by the driver. The throttle valve drive stage 5 can also change the opening degree of the throttle valve by operating the throttle pedal 7 with the operating sound.The processing circuit 2 has the following equation: The indicated target vehicle speed ■1 is calculated.

V1=v+K (R-Ra> -(1) Here, one-dimensional ζt is the time change rate of vehicle 3!!■ and inter-vehicle distance f4 R, that is, the phase k (velocity dR) between the preceding obstacle and own vehicle. ,
'd t- and the predetermined distance depending on 1-t6(l
R Ra-fl(v, -) -<2)d
Fig. 2 is a graph showing the relationship between the predetermined inter-vehicle distance gF(a) which depends on the vehicle speed V and the relative speed dR/dj.Line 8 shows the relationship between the phase t4th speed dR/(,!t Line 9 shows the characteristic when is a small value v2, and line 9 shows the characteristic (7) when the relative velocity dR/dt is a large value v1.

3rd (2I is vehicle speed v tom vs. 4 Jt d R/
dt,! :, c, :, (This is a graph that does not show the renal range pHRAL determined by fZ. Line 10 shows the characteristics when the relative velocity ct R,' d t is small, and line 11 shows the relative distance. The characteristic when dR/dt is large is shown.The characteristic indicated by reference numeral 12 in FIG. When the vehicle speed decreases (-) and decelerates, the vehicle speed V reaches zero and then stops as it follows the sequence of ■→■.

If distance RAt, has a value of 1-11. When the automatic east starts moving J', the warning distance RhL is set to the value L2, as shown by the red light ■.
y), and then trace the progress of reference i■-■.

Such IF reporting distances R and AL are used in the operation fj performed with reference to FIGS. 6 and 7 (2ff) in the description.

9r! ! The throttle speed n2 controls the throttle valve driving means as described above so that the opening degree θ of the throttle valve F becomes a value expressed by the above-mentioned first equation ζ, which corresponds to the target vehicle speed V1. is calculated.

The opening degree θ of the throttle valve corresponding to the target vehicle speed V1 is determined by a function representing the characteristics shown in FIG.

Referring to No. 1, reference station 1-3 in FIG. 6 (1) indicates the speed of the preceding vehicle, which is an obstacle ahead, and sanmeikari j4 indicates the speed of own troops. When the speed of the traveling vehicle decreases at time t1, due to the delay in the operation of the inter-vehicle distance #iυItH device shown in FIG.

4 after which the speed of the mouth wheel is decreased at time L2? The inter-vehicle distance #R with the vehicle is as shown in Section 6 II (2). This inter-vehicle distance mystery Y7 reaches the predetermined first value at time [-3] and reaches one satisfaction. 1: Processing circuit 2
The beam 1 moving means 4 is driven and braking is performed as shown in Figure J (3).

It is assumed that the preceding vehicle has stopped at time t4.

In response, the vehicle stops at time t54:.

At time t6, the preceding vehicle starts moving. At this time, the own weight is
Ruru remains stopped. At time t7 when the inter-vehicle distance R reaches a predetermined second value of 2 or more, the braking state by the braking means 4 is released, and the braking state by the throttle valve driving means 5 is stopped.
), the throttle valve is driven and the pilot wheel starts moving. After the preceding vehicle is running at a constant speed after time t8, the preceding vehicle f) travels at a speed that matches the speed of the preceding vehicle f).

In the state where the brake is being applied by the braking means 1 from time t3 to time t17, the processing circuit 2 is operated by the throttle valve driving means 5.
Therefore, the opening degree of the 1-1 Hel valve is set to the minimum value, for example, zero.

7th [:! Look at U, 9F! ! The operation of the logic circuit 2 will be further explained. In step nl, the output from the inter-vehicle distance measuring means 1 is received in the processing circuit 2, and the inter-vehicle distance 1 is
iiiR is calculated and obtained. At the step port 2, the output from the heavy speed detector 3 is received by the logic circuit 2, and the vehicle speed V is calculated and determined. In step n3, the following distance R
time rate of change, i.e. the relative distance from the front obstacle dR
/' (l t is calculated and obtained. In step r+ 4, the target vehicle speed ■1 is calculated and obtained based on the above-mentioned formula 1. In step 5, the alarm distance RA shown in FIG.
Calculate L by Jt.

Next, in step r16, the stop detector 8 determines whether the vehicle is at a standstill, that is, whether the vehicle speed V is zero. If the own vehicle is running, the process moves to step n7, and it is determined whether the inter-vehicle distance giR is equal to the warning distance RAL. The inter-vehicle distance R is the warning distance w1. When it is equal to or higher than RAL, the process moves to Stella'γn8, and without performing braking by the braking means 4, the throttle valve opening degree θ corresponding to the target vehicle speed ■1 is determined in step rr9. In step rrlQ, the throttle valve is driven by the throttle valve driving means 5 to achieve this throttle valve opening degree θ.

In step rI7, the inter-vehicle distance i? [j[R is alarm distance 1
−(□, if it is determined that it is less than step 1
Moving on to step 2, braking by the braking means 1 is performed. At step r113, the eyesight 3! E
V ] is set to zero, thereby setting the throttle valve opening θ to zero in step n9, and the throttle valve driving means 5 drives the throttle valve opening θ to zero.

If it is determined in step 56 that the own vehicle is stopped, the process moves to step r111, where it is determined whether the inter-vehicle distance R is less than the predetermined second value 2. For example, when the preceding vehicle starts and the inter-vehicle distance itR becomes the second value 2 or more, the process moves to step rr8, where the braking condition by the braking means 4 is released, and the starting operation follows the target vehicle speed V1. When the inter-vehicle distance R is less than the second 1L2 in step n11, step n
At step 12, the braking condition is maintained by the braking means 4.

When the inter-vehicle distance 1liiR measured by the inter-vehicle distance measuring means 1 becomes less than the predetermined first value 1 due to a decrease in the speed of the preceding vehicle, the braking means 4 is activated,
When the stop detector 8 detects that the own troops have stopped, the braking means 4 starts braking (
Since t is released and the vehicle is ready to start,
During braking operation and when the braking operation is released, the inter-vehicle distance fll
A so-called hysteresis can be added to the value of R, so that even if an unexpected situation occurs, such as the vehicle in front coming to a standstill immediately after the vehicle starts, and the braking action of the vehicle is delayed,
The inter-vehicle distance R is a sufficiently large value, so that accidents such as rear-end collisions can be prevented and safety can be improved.

Effects of the Invention As described above, according to the present invention, when the distance to the front obstacle becomes less than a predetermined first value, braking is performed by the braking means, and if the front obstacle is, for example, a preceding vehicle. One time, after the own vehicle had stopped, if the distance between the vehicles reached a predetermined second value that was greater than the first value, the own army would be able to release the brakes and take off, so for example, Is the car in front starting straight away? Even if an unexpected situation occurs, such as when a concubine slows down, the risk of rear-end collision is prevented and safety is improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of an embodiment of the present invention.
311Z is a graph showing the relationship between vehicle speed V and alarm distance RAL, FIG. 4 is a graph showing the line 12 shown in 30, and FIG. 5 is a graph showing the throttle valve depending on target vehicle speed 1. Graph showing the relationship with opening degree θ, No. 6
The figure is a timing chart for explaining the operation when a preceding vehicle is present, and FIG. 7 is a flowchart for explaining the operation of the processing circuit 2. 1... Inter-vehicle distance measuring means, 2... Processing circuit, 3...
・Vehicle speed detector, 4... Braking means, 5... Throttle valve drive means, 8... Stop detector Agent Patent attorney Number of strokes Keiichi 1st figure 1

Claims (1)

[Scope of Claims] Distance measuring means for measuring the distance to a front obstacle; braking means; vehicle stop detection means for detecting that the vehicle has stopped; responsive to the output of the distance measuring means; When the distance to the obstacle in front becomes less than a predetermined first value, the braking means performs braking, the vehicle stop detection means detects the stop of the vehicle, and then, An inter-vehicle distance control device comprising: control means for releasing the brake and making the vehicle ready to start when the distance reaches a predetermined second value that is greater than or equal to the first value.