JP2601685B2 - Overtaking warning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Equipped with a radar device that can detect obstacles ahead in the direction of travel, the status of the vehicle ahead immediately before starting to overtake and the status of oncoming vehicles after entering the overtaking system are automatically determined. If it is determined that there is no room for safe overtaking, a warning is issued to alert the driver.

[Industrial applications]

The present invention relates to an overtaking warning device for a vehicle equipped with a radar device.

[Conventional technology]

A vehicle traveling in the same direction in front of the own vehicle (forward vehicle)
When overtaking, the distance and speed to the oncoming vehicle are usually estimated based on the driver's experience. However, it is difficult to accurately grasp the actual distance and speed by experience,
Occasionally, an overtaking may occur, including the risk of a collision with an oncoming vehicle.

[Problems to be solved by the invention]

The safety of overtaking depends on the accuracy of grasping the vehicle speed of the preceding vehicle, the vehicle speed of the oncoming vehicle, the separation distance, and the like. In the present invention, this is actually measured by mounting a radar device, and based on the result, an overtaking that cannot be afforded is issued to a driver by giving an alarm and giving up.

[Means for solving the problem]

FIG. 1 is a block diagram of the present invention, wherein 1 is a radar device for detecting an obstacle (a forward vehicle, an oncoming vehicle, a fixed object) ahead in the traveling direction;
2 calculates the distance to the obstacle from the output and the relative speed of the obstacle from the time change of the distance, and calculates the speed of the obstacle (= own vehicle speed + relative speed) in consideration of the own vehicle speed. This is a processing device that determines the risk of collision with an oncoming vehicle when the vehicle tries to pass the preceding vehicle.

The processing device 2 has two types. (A) shows the distance to the obstacle calculated by the distance detection unit 21 as a relative speed detection unit 22;
And calculates the relative speed of the obstacle from the time change. In this method, the determination unit 23 detects the speed of the obstacle by adding the relative speed of the obstacle and the vehicle speed.

On the other hand, (b) inputs the own vehicle speed to the speed detecting unit 24, and calculates the speed of the obstacle by adding the own vehicle speed to the obtained relative speed of the obstacle. Therefore, the speed of the obstacle can be directly input to the determination unit 23.

In any of the methods, the determination unit 23 performs a determination process on passing safety while grasping the distance to the obstacle, the speed of the obstacle, and the speed of the own vehicle.

[Action]

FIG. 2 is an explanatory diagram of the operation. If overtaking is started in the state, the processing device 2 determines that the speed V _{1 of the} immediately preceding vehicle is ahead.
The distance between the vehicle and the own vehicle is stored. Thereafter, the vehicle is When turned overtaking state, constantly monitors the distance between the oncoming vehicle speed V ₂ and the vehicle. Then, it is determined whether or not the own vehicle can safely enter the front vehicle before meeting the oncoming vehicle. If it is determined that there is not enough room, an alarm is issued.

〔Example〕

FIG. 3 is a block diagram showing one embodiment of the present invention, which employs the system shown in FIG. 1 (a). In the input of the determination unit 23 of this example, in addition to the vehicle speed sensor C for detecting the own vehicle speed, a blinker switch and a steering sensor S for confirming the overtaking start and end, and a gear position sensor G necessary for estimating the acceleration. There is each output of.

Hereinafter, the operation will be described with reference to FIG. 4 and FIG. Step S1 in FIG. 5 is a process for calculating the separation distance between the obstacle in front of the traveling direction and the own vehicle, which can be grasped by the radar device 1, from the reflection time of the radar. This is a process for calculating the relative speed V of the obstacle. By adding the own vehicle speed Vs obtained in step S3 to the relative speed V, the speed of the obstacle is obtained. Step S4 is a process for determining whether the speed of the obstacle is negative, zero or positive, and whether the fixed object is a preceding vehicle from the oncoming vehicle.

Overtaking involves a lane change, so if it can be detected that the distance to the obstacle has suddenly changed from the preceding vehicle to the oncoming vehicle, the start time can be determined. However, in order to ensure this determination, a blinker ON is preliminary determined in step S5, and a lane change is detected from a change in the steering angle in step S6. The change in the steering angle due to the lane change has a pattern of straight-ahead → non-straight-ahead → straight-ahead. After changing lanes, the overtaking acceleration Gv is estimated in step S7.

Next, in step S8, the time T ₁ required to pass the preceding vehicle
Is calculated. FIG. 4 (a) is an explanatory diagram of this. Vehicle speed V ₁ of the preceding vehicle stores the value immediately before the change speed. This is obtained by adding the time change V = Δl ₁ / Δt of the distance l _{1 to} the preceding vehicle as the relative speed of the preceding vehicle, and adding this to the own vehicle speed Vs.

V ₁ = Vs + V However, when Δl ₁ is positive, V is positive (own vehicle speed <forward vehicle speed),
When Δl ₁ is negative, V is negative (own vehicle speed> forward vehicle speed).

Since overtaking is implemented in Vs ≧ V _1, when the Vs <V ₁ Vs
= Distance which the vehicle is traveling and during time t ₁ until the V ₁
seeking l _2, those obtained by adding l ₂ at a distance l ₁ of overtaking immediately before the inter-vehicle L ₁ of the front wheel.

L ₁ = l ₁ + l ₂ time t ₁ is acceleration estimated from gear position and vehicle speed
It can be calculated by using Gv.

The distance l ₂ is Can be calculated.

Thus it is possible to determine the entry position L by adding the distance L ₂ in consideration of entering vehicle distance with the vehicle ahead of the vehicle flow (e.g. 25 m) to headway L ₁ obtained in the.

L = L ₁ + L _{2 The} overtaking time T ₁ is calculated by the following equation using the L and the acceleration Gv.

On the other hand, there is no need to consider the distance l ₂ If Vs ≧ V ₁ in overtaking the beginning, may be handled as L ₁ = l _1.

Figure 4 (b) is an explanatory view of time to meet the oncoming vehicle in step S9 (collision time) T _2. The relative velocity V ₂ of the oncoming vehicle is calculated as the sum of the per unit time changes in S ₂ in the distance due to the change S ₁ and oncoming distance by the vehicle.

The oncoming vehicle speed can be obtained by adding the vehicle Vs to the oncoming vehicle speed, so that V ₂ = V + Vs (where V is negative).

The previous velocity V _2n-1 of the oncoming vehicle and calculates the oncoming vehicle acceleration G ₂ from the current velocity V _2n.

The relative acceleration G is obtained by adding the acceleration Gv of the own vehicle to this.

G = Gv + G _{2 The} collision time T ₂ is the time when the distance traveled at the relative speed V and the relative acceleration G is equal to the remaining distance S. In a relationship. Therefore, the collision time T ₂ are determined by the following equation.

Time T ₁ obtained in step S8 is complete their successfully overtaking if Mijikakare from the obtained time T ₂ in step S9, provided 3 seconds to the margin time T in order to increase safety, in step S10 When it is determined that T ₂ −T ₁ ≦ T, an alarm is issued by a buzzer or the like.

〔The invention's effect〕

As described above, according to the present invention, the safety of overtaking can be confirmed without depending on the driver's feeling, and when it is determined that there is danger, a warning is issued and the overtaking can be abandoned.

[Brief description of the drawings]

 1 is a block diagram of the present invention, FIG. 2 is an explanatory diagram of the operation of the present invention, FIG. 3 is a block diagram of an embodiment of the present invention, FIG. 4 is an explanatory diagram of time determination, FIG. 6 is a flowchart showing the operation of the first embodiment.

Claims (1)

(57) [Claims] 1. A radar device for detecting an obstacle ahead in the traveling direction is mounted, a separation distance between the obstacle and the own vehicle is measured, and a relative speed of the obstacle is calculated by a processing device to start overtaking. Memorize the relative speed and separation distance of the immediately preceding vehicle, and always measure the relative speed, separation distance and own vehicle speed of the oncoming vehicle after overtaking, and go ahead of the preceding vehicle before meeting the oncoming vehicle An overtaking warning device characterized in that a warning is issued when it is determined that there is no room.