JPH0528760U - Collision warning device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an obstacle detection device that enables safer driving when traveling on a road where the inter-vehicle distance is regulated. [Configuration] A legal violation determination unit that generates a violation signal when the vehicle speed detected by a vehicle speed sensor exceeds a predetermined reference value and the distance to an obstacle ahead is less than a predetermined reference value Is provided to warn the driver of the violation of laws and regulations with an alarm issued based on the violation signal.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a collision warning device for detecting an obstacle in front of a vehicle and preventing a collision accident from occurring.

[0002]

[Prior Art]

 As a conventional collision warning device, for example, there is one shown in FIG. In the figure, 1 is a distance detection unit that detects a distance between a vehicle and an obstacle using a laser beam emitted from a laser diode (hereinafter, LD), and 2 is a vehicle speed or the like. It is a running state detection unit that detects the running state of the host vehicle.

The reference numeral 3 designates a distance detection command to the distance detection unit 1, and based on the distance information returned in response to the command and the own vehicle speed information detected by the traveling state detection unit 2, obstacles with the own vehicle. Calculates the relative speed with the object to determine whether the obstacle is a stationary object or a moving object, and also sets it according to the individual speed, relative speed, and individual differences in free running time until the driver brakes. This is a signal processing unit that determines the possibility of collision between the host vehicle and an obstacle according to the distance setting.

Reference numeral 4 indicates the distance between the host vehicle and the obstacle based on the information from the signal processing unit 3, and when the signal processing unit 3 determines that there is a possibility of collision with the obstacle. Is an alarm notification unit that issues an alarm.

Next, the operation will be described. The traveling state detection unit 2 includes a vehicle speed sensor 31, and the signal processing unit 3 includes an arithmetic circuit 41 and a distance setting switch 42. The vehicle speed signal of the host vehicle detected by the vehicle speed sensor 31 is sent to the arithmetic circuit 41. When the vehicle speed calculated based on the vehicle speed signal is 35 Km / h or more, the arithmetic circuit 41 informs the distance detecting unit 1 of the distance. Sends a separation detection command signal.

In the distance detecting section 1, the drive signal generating circuit 11 receives the distance detection command signal, and the drive signal generating circuit 11 sends the LD light emission signal shown in FIG. The LD switching driver 12 sends out the signals shown in FIGS. 4B, 4C, and 4D based on the received LD light emission signal (a), and LD-L, LD of the LD array 13 as the light emitting means. -C and LD-R are made to emit light one by one.

The laser beam from the LD-L of the LD array 13 is moved to the front left side of the vehicle, the laser beam from the LD-C is moved to the front side, and the laser beam from the LD-R is moved to the front right side. The laser beam of LD-C is used to detect obstacles ahead, the laser beam of LD-L is to detect an interrupting vehicle from the left lane, and the laser beam of LD-R is to detect an interrupting vehicle from the right lane. Used.

The reflected light from the obstacle is condensed by the light receiving lens 15 and received by the photodiode (hereinafter referred to as PD) 16. This received light signal is sent to the amplification circuit 17, and the amplification circuit 17 amplifies it and outputs the signal of FIG. In this signal, a reflection signal B from an obstacle and a reflection signal A from a short distance road surface are mixed.

The threshold value generation circuit 18 generates a threshold value signal shown in FIG. 4F based on the LD light emission signal (a) output from the drive signal generation circuit 11 and outputs it to the comparator 19. The comparator 19 compares the level of the output signal (e) of the amplifier circuit 17 with the threshold value signal (f) to extract only the reflected signal from the obstacle, and the obstacle shown in FIG. The object detection pulse signal is output.

As shown in FIG. 4H, the counter 20 starts counting the clock pulse signal supplied from the reference pulse generation circuit 21 at the rising edge of the LD light emission signal (a), and the reflected signal from the obstacle is generated. Counting is stopped at the rising edge of the obstacle detection pulse signal (g) based on the above, distance information to the obstacle is obtained from the count-up time and light speed, and the information is sent to the arithmetic circuit 41 of the signal processing unit 3.

Next, a method of determining the possibility of collision in the arithmetic circuit 41 of the signal processing unit 3 will be described with reference to the flowchart shown in FIG. First, when the power is turned on, the process proceeds to the START step, and the CPU, RAM, etc. constituting the arithmetic circuit 41 are initialized. Next, at step ST11, the distance signal indicating the information of the distance R to the obstacle from the counter 20 of the distance detecting unit 1 and the vehicle speed V _f from the vehicle speed sensor 31 of the running state detecting unit 2 are determined every predetermined period. A vehicle speed signal indicating information is taken into the arithmetic circuit 41.

Then, in step ST12, the distance signal R is converted into a display signal and sent to the distance indicator 51 for display. Next, in step ST13, the inter-vehicle distance R is differentiated to calculate the relative speed (d / dt) R between the obstacle such as the preceding vehicle and the own vehicle using a calculation method such as the least squares method, and the preceding vehicle is also calculated. Of the vehicle speed V _a is calculated by the sum of the vehicle speed V _f and the relative speed (d / dt) R.

In this calculation, when (d / dt) R <0, the distance decreases, and it means that the vehicle is approaching an obstacle, and when (d / dt) R> 0, The fact that the distance has increased indicates that there is no change in the distance when (d / dt) R = 0.

In determining the possibility of collision with an obstacle, the initial speed of the host vehicle is V _f (m / sec) and the initial speed of the obstacle (preceding vehicle) is V _a (m / sec). When the deceleration performance and α (m / sec ^2), the difference between the preceding vehicle stopping distance V _a ² / 2α and vehicle stopping distance V _f ² / 2α, set vehicle distance setting switch 42 There was added an empty run distance V _f · T _d by time T _d to follow a braking distance R shown in Equation 1 becomes the reference for judgment.

[0015]

[Equation 1]

[0016] Therefore, by comparing the relative speed (d / dt) R and the vehicle speed V _f first in step ST14, - if the (d / dt) R ≒ V f, i.e. obstacle and road stationary object If it is considered, the process proceeds to step ST15, and since V _a = 0 in the equation 1, the risk of collision is determined according to the driving law according to the following equation 2.

[0017]

[Equation 2]

When Equation 2 is satisfied, there is a danger of collision with an obstacle, and the process proceeds to step ST18 to generate an alarm signal and send it to the alarm notifying unit 4, and the alarm device 52 Issues an alarm to avoid danger.

On the other hand, if the result of determination in step ST14 is that-(d / dt) R≈V _f is not satisfied, the obstacle is the preceding vehicle traveling on the road ahead, and the risk determination should be made in accordance with Equation 1. Is. However, since the calculation accuracy of the relative speed (d / dt) R cannot be accurately obtained, a calculation error may give an erroneous alarm. Therefore, in the case of a leading vehicle in which an obstacle moves, the relative speed is calculated in step ST16. First, it is determined whether (d / dt) R is equal to or higher than a predetermined speed C (m / sec).

As a result, when (d / dt) R ≧ C, the relative speed is high and the vehicle is approaching rapidly. Therefore, the preceding vehicle is regarded as infinitely close to the stopped object, and the process proceeds to step ST15. With the same logic as that of the stop obstacle, the warning output judgment is performed by the discriminant of the equation (2).

[0021] When the determined result at step ST16 is (d / dt) R <C, the relative speed is slow, it is regarded to be in the normal follow-up running at a constant inter-vehicle distance, and the vehicle speed V _f Since the preceding vehicle speed V _a is almost equal, the equation 1 becomes the equation 3 shown below, and in step ST17, the danger of collision is judged by the equation 3 and similarly, when the equation 3 holds, an alarm is issued. Emit.

[0022]

[Equation 3]

[0023]

[Problems to be solved by the device]

 However, in such a conventional collision warning device, the warning is given only to the theoretically calculated dangerous distance, and the distance indicator 51 displays the distance to the preceding vehicle as it is. Since it has been subject to legal regulations such as those found on German highways (autobahns), it is necessary to maintain a vehicle-to-vehicle distance of 50 m or more when the vehicle speed is 50 km / h or more. If the vehicle is not followed, the warning is not always issued, and the driver always pays close attention to the distance indicator 51 to ensure that the distance to the preceding vehicle does not fall below the legally regulated distance. There was a problem that we had to do it.

The present invention has been made in view of such a problem, and an object thereof is to solve the above problems by issuing an alarm when a condition for violation of a legal regulation regarding an inter-vehicle distance is satisfied. I am trying.

[0025]

[Means for Solving the Problems]

 The collision warning device according to the present invention is a law that generates a violation signal when the speed of the vehicle exceeds a predetermined reference value and the distance to an obstacle ahead is less than the predetermined reference value. A violation determination unit is provided.

[0026]

[Action]

 The collision warning device according to the present invention violates legal regulations by issuing an alarm based on a violation signal generated when both the vehicle speed and the distance to an obstacle ahead of the vehicle exceed predetermined reference values. A collision warning device that can automatically warn the driver of this is realized.

[0027]

【Example】

 The invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of the present invention. First, the configuration will be described. Here, reference numerals 1 to 4 and 11 to 21, 31, 41, 42, 51, and 52 are the same as those in the conventional example of FIG. 3, the same configurations are shown, and duplicate description is omitted. ..

In the figure, reference numeral 5 indicates the speed of the own vehicle and the distance to the obstacle ahead, and when the speed of the own vehicle exceeds a predetermined reference value, the obstacle ahead It is a legal violation determination unit that creates a violation signal and sends it to the alarm device 52 of the alarm notification unit 4 when the distance between the distance and is less than a predetermined reference value.

Next, the operation will be described. In the collision warning device according to the present invention, the distance information output from the counter 20 of the distance detection unit 1 is input to the arithmetic circuit 41 of the signal processing unit 3 and also to the distance determination circuit 61 of the legal violation determination unit 5. To be done. The distance determination circuit 61 sets its output to a high level when the received distance information is less than 50 m.

Similarly, the own vehicle speed information detected by the vehicle speed sensor 31 of the traveling state detection unit 2 is also input to the arithmetic circuit 41 of the signal processing unit 3 and also to the vehicle speed determination circuit 62 of the legal violation determination unit 5. Is also entered. The vehicle speed determination circuit 62 sets its output to a high level when the received vehicle speed information is 50 km / h or more.

The outputs of the distance determination circuit 61 and the vehicle speed determination circuit 62 are input to the AND circuit 63 of the legal violation determination unit 5, respectively. Therefore, when the inter-vehicle distance is less than 50 m and the own vehicle speed is 50 km / h or more, the AND circuit 63 outputs a high-level violation signal.

The alarm device 52 of the alarm notifying unit 4 gives an alarm if the violation signal output from the AND circuit 63 becomes high level even if the conventional alarm signal from the arithmetic circuit 41 is not satisfied. Emit.

At this time, if the conventional warning signal from the arithmetic circuit 41 is given (the area indicated by (b) in FIG. 2), a loud alarm indicating a dangerous warning should be issued. If the conventional alarm condition is not satisfied (area indicated by (a) in FIG. 2), a low volume alarm is issued to warn against legal violation.

[0034]

[Effect of the device]

 As described above, according to the present invention, the light beam is emitted from the light emitting means to the front, and the reflected light and the front obstacle between the reflected light and the vehicle speed of the host vehicle detected by the vehicle speed sensor are calculated. In a collision warning device equipped with a signal processing unit that generates an alarm signal based on the distance and relative speed of the vehicle, the speed of the host vehicle detected by the vehicle speed sensor exceeds a predetermined reference value, and the obstacle ahead Since the system is equipped with a legal violation determination unit that creates a violation signal when the distance between the vehicle and the vehicle is less than a predetermined reference value, an alarm is issued when the violation condition is met, and the driver displays the distance indicator. It is possible to obtain the effect that it becomes possible to drive safely without having to pay attention.

[Brief description of drawings]

FIG. 1 is a block diagram showing a collision warning device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a relationship between a vehicle speed and an inter-vehicle distance to be warned in the above embodiment.

FIG. 3 is a block diagram showing a conventional collision warning device.

FIG. 4 is a timing chart showing a time relationship of signals of respective parts in the distance detecting part.

FIG. 5 is a flowchart showing a flow of processing in the arithmetic circuit.

[Explanation of symbols]

 3 Signal Processing Section 5 Legal Violation Judgment Section 13 Light Emitting Means (LD Array) 31 Vehicle Speed Sensor

Claims (1)

[Scope of utility model registration request] 1. A light beam emitted from a light emitting means in the forward direction, and based on the reflected light and the vehicle speed of the host vehicle detected by a vehicle speed sensor, the distance between the obstacle and the front obstacle, and the relative speed. In a collision warning device including a signal processing unit that generates an alarm signal, the speed of the host vehicle detected by the vehicle speed sensor exceeds a predetermined reference value, and the distance to the front obstacle is a predetermined reference value. A collision warning device characterized by comprising a legal violation determination unit that generates a violation signal when the value is less than a value.