KR100559385B1 - Method of judging a driving in self-lane for preceding vehicle - Google Patents

Abstract

Disclosed is a method for determining own lane driving of a preceding vehicle. The disclosed vehicle lane determination method of the preceding vehicle includes the steps of: (a) driving a radar installed in front of the own vehicle to obtain data of the preceding vehicle; (b) analyzing the data and determining whether the same data is received in two consecutive frames; (c) arithmetically calculating angle data when the condition of step (b) is satisfied; (d) determining whether the data calculated in step (c) is in a data area in which the preceding vehicle is traveling in the same lane as the host vehicle; (e) calculating a safety distance when the condition of step (d) is satisfied; (f) determining whether the safety distance obtained in step (e) is greater than the inter-vehicle distance; (g) generating an alarm when the condition of step (f) is satisfied.

According to the present invention, it is possible to prevent the risk of collision with the preceding vehicle, and in particular, there is an advantage of alerting the user by an alarm due to the proximity of the front vehicle when driving at night or lowering attention.

Radar, Car Distance, Safety Distance

Description

Method of judging own lane driving of preceding vehicle {METHOD OF JUDGING A DRIVING IN SELF-LANE FOR PRECEDING VEHICLE}

1 is a schematic flowchart showing sequentially the method of determining the own lane driving of a preceding vehicle according to the present invention.

2 is a view schematically showing the configuration of a system applied to the own lane driving determination method of a preceding vehicle according to the present invention.

Figure 3 is a view showing for explaining the distance detection principle by the radar.

4, 5, 6, and 8 are views showing received signal pattern data when a preceding vehicle travels in the same lane as a host vehicle using radar according to an embodiment of the present invention.

7 is a diagram illustrating an algorithm according to the present invention.

9 is a diagram illustrating an algorithm for calculating a safety clearance distance.

<Description of the symbols for the main parts of the drawings>

11.radar

12. Sensor detector

13. Signal Processor

14. Alarm system

The present invention relates to a method for determining the own lane driving of a preceding vehicle, and more particularly, to determine whether the preceding vehicle is the own lane driving vehicle or the driving vehicle of another lane, and determines the own lane driving of the preceding vehicle to prevent an alarm malfunction. It is about a method.

Due to the quantitative increase in the number of vehicles, congestion is increasing in each section of the road, and there is a risk of contact accidents if the driver does not maintain a constant distance from the preceding vehicle. Accordingly, the driver can prevent the accident by operating the brake and the accelerator appropriately according to the situation while maintaining a constant distance from the preceding vehicle.

However, if the driver is fatigued by repeating the above motions for a long time, it is likely that an accident will occur by causing a decrease in mental concentration.

In order to solve the above problems, an automatic driving distance maintenance system is disclosed in Korean Utility Model Application No. 94-9594.

The mileage automatic maintenance system calculates the distance by the radar installed in front of the vehicle with the auto switch, the mileage automatic maintenance button set to on, in order to maintain the distance from the vehicle in front of the set safety distance. By comparing the calculated distance with the set safety distance, the brake and accelerator are operated automatically to maintain the safety distance.

In addition, when the increase rate of the increase in the front vehicle increases during the autonomous driving, the driver generates an alarm sound, which causes the driver to operate manually.

As described above, in the case of the automatic mileage maintenance system using the radar, it is possible to recognize the preceding vehicle, but there is a problem in that the recognized vehicle travels the own lane and cannot determine whether there is a real danger.

The present invention has been made to solve the above problems, and provides a method for determining the own lane driving of the preceding vehicle to determine whether the preceding vehicle is the own lane driving vehicle or the driving vehicle of another lane to prevent the risk of collision. The purpose is.

In order to achieve the above object, the method of determining a vehicle lane of a preceding vehicle according to the present invention includes the steps of: (a) driving a radar installed in front of the vehicle to obtain data of a preceding vehicle; (b) analyzing the data and determining whether the same data is received in two consecutive frames; (c) calculating angle data as an arithmetic mean value when the condition of step (b) is satisfied; (d) determining whether the data calculated in step (c) is in a data area in which the preceding vehicle is traveling in the same lane as the host vehicle; (e) calculating a safety distance when the condition of step (d) is satisfied; (f) determining whether the safety distance obtained in step (e) is greater than the inter-vehicle distance; (g) generating an alarm when the condition of step (f) is satisfied, wherein the data of the preceding vehicle in step (a) is -10 degrees to +10 by the radar. It is characterized in that it is obtained by the received angle signal between the degrees.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic flowchart showing sequentially a method for determining own lane driving of a preceding vehicle according to the present invention.

Referring to the drawings, the method of determining the own lane driving of a preceding vehicle according to the present invention is performed by driving a radar (sensor) (for example, mm wave module) 11 installed in front of the own vehicle, as shown in FIG. Signals are sent to a sensor detector (e.g., mm wave sensor detector) 12 installed at the rear of the vehicle and processed by the mm wave signal processor (e.g., DSP) 13 to obtain data (steps 110, 120).

As an example, the principle of the radar 11 will be described.

In contrast to conventional electrical signals that flow on copper wires and block electrical flow with rubber sheaths, a new signal transmission method that flows electrical signals through dielectric lines such as plastic and prevents the flow of electricity by metal cladding. Lines are inserted to prevent transmission waves flowing along the dielectric.

And the operation principle thereof is outlined as follows.

First, as shown in FIG. 3, the 77 GHz mm wave generated by the radar 11 mounted at the front of the vehicle is reflected to the preceding vehicle or the stationary object in front of the vehicle, and the reflected wave is detected at the radar receiver. Then, the detected signal is read out from the reflector through frequency analysis through a Fast Fourier Transform (FFT).

And the speed detection calculates the relative speed V by the formula [fd = 2V.cos ￠ .77GHz / beam] by the Doppler effect.

Subsequently, the data acquired in step 120 is analyzed, and it is determined whether the same data is received continuously in two frames from the analyzed data.

When the condition of step 130 is satisfied, that is, when the same data is received in two consecutive frames, the angle data as described later is calculated as an arithmetic mean value (step 150).

Subsequently, it is determined whether the data calculated by the arithmetic mean value in the step 150 is in the data area in which the preceding vehicle is in the same lane as the host vehicle described later (step 160).

When the condition of step 160 is satisfied, that is, when there is a preceding vehicle in the same lane as the host vehicle as described below, the safety distance is calculated.

In addition, it is determined whether the safety distance obtained in step 170 is greater than the inter-vehicle distance.

When the condition of the step 180 is satisfied, that is, when the current inter-vehicle distance is smaller than the safety distance, for example, an alarm is generated through the alarm system 14 as shown in FIG. 2 (step 190).

In step 190, the alarm calculates the risk from the danger information of the own vehicle, for example, the own vehicle speed, the brake signal, and the distance between the preceding vehicle, and the safety distance varies according to the speed of the own vehicle and the preceding vehicle in order to properly perform the alarm. Therefore, it is roughly classified into a primary alarm and a secondary alarm.

The above-mentioned first alarm generates a warning sound, for example, beeping when a caution is required because there is a danger of collision between the own vehicle and the preceding vehicle, and this warning sound is generated at about 5 second intervals. When the brake signal is input, a warning sound is stopped when it is determined that the driver recognizes the brake signal.

In addition, the second alarm generates a warning sound when braking is required because there is a danger of collision with the preceding vehicle, and the warning sound continues to be generated until a safety distance from the preceding vehicle is secured.

On the other hand, the data of the vehicle in the step 120 is obtained by the angle signal received between -10 degrees to +10 degrees by the radar 11.

More specifically, FIG. 4 is a view illustrating a received signal pattern when the preceding vehicle travels in the left lane about 65m ahead using the radar 11.

4 is an example of signal analysis reflected by the radar 11 when the preceding vehicle travels at a relative speed of 20 km in the left lane ahead of the 65m ahead. At this time, the reflected signal is represented by similar relative speed and power value over -0.9˚ ~ -5.3˚.

Such a signal pattern is recognized as a vehicle upon continuous reception of at least two frames A that are not one-time. At this time, whether or not the vehicle is in the same lane as the observation vehicle is used by calculating an arithmetic mean value of angle data observed from two or more.

The arithmetic mean of the above-mentioned angle data is -3.1 degrees, and data of 65 meters ahead of -3.1 degrees belongs to the area X in FIG. With reference to this area, it is determined that this is a left lane vehicle and does not alert. That is, excluded from the alarm logic.

On the contrary, in FIG. 6, the signal pattern is shown when the preceding vehicle travels in the same lane about 65m ahead using the radar.

That is, FIG. 6 is an example of signal analysis reflected by the radar when the preceding vehicle is driven at a relative speed of 20 km in the left lane in front of 65 m in front, and the reflected signal has a similar relative speed and similar power over 1.3 ° to -3.1 °. Appear by value

Such a signal pattern is recognized as a vehicle when continuous reception of at least two frames (B) is not one-time. At this time, whether or not the vehicle is in the same lane as the observation vehicle is used by calculating an arithmetic mean value of the angle data observed in two or more.

The arithmetic mean of the above-mentioned angle data is -0.9 degrees, and this data of 65 m ahead of -0.9 degrees belongs to the above-mentioned area Y of FIG. Therefore, it is determined that this is a traveling lane vehicle, and an alarm is generated. That is, it is included in the alarm logic and the alarm logic is activated.

In the own lane driving determination method of the preceding vehicle having the configuration as described above, the trend of the development of a safety device for improving the safety of the current vehicle driving is an accident in the existing passive concept that minimizes the damage of the driver after the accident. It is developing as an active safety device to prevent the accident.

There is a possibility of a collision due to a vehicle or other stationary object in front of the vehicle while driving, but even if the driver does not detect it, an alarm is issued within an appropriate time to induce an immediate response of the driver, thereby preventing a collision accident. By controlling the driving of the vehicle in consideration of the distance to the rotatable object, the relative speed and the position, an intelligent vehicle for proactive accident prevention can be developed.

This will be described in more detail.

The method of determining the own lane driving of the preceding vehicle according to the present invention is to determine whether the preceding vehicle is the own lane driving vehicle, the left and right lane driving vehicle, and to prevent the malfunction of the alarm, and to the radar 11 attached to the front of the vehicle. As described above, the received signal has 38 angular signals between -10 ° and + 10 °.

However, there may be an error in the angle information due to the slight left and right movement of the steering wheel, rather than driving only the electrostatic direction without the movement of the steering wheel (steering wheel).

As a result, the left or right lane driving vehicle is recognized as the own lane driving vehicle and a false alarm occurs. In this case, reception characteristics of the signals reflected by the actual vehicle are as follows.

For example, when the reflection reception signal group is numbered 1 by the own lane as shown in FIG. 7, the signal distribution received according to the distance is equal to the ellipse 1 of FIG.

If the reflected reception signal group is 2 by the left lane, the signal distribution according to the distance is the same as the ellipse 2 of FIG.

In addition, if the reflected reception signal group is 3 by the right lane, the signal distribution according to the distance is the same as the ellipse 3 of FIG. 8.

8 is a schematic diagram showing the angular distribution of reflected signals. At this time, the angle of the center point of the received signals in this distribution is obtained in consideration of the distortion or movement of the vehicle.

As described above, when it is determined to exist in the region Y of FIG. 5 using the angle of the center thus obtained, it is recognized as a collision danger alarm object, and when it is determined to be within a safety distance, the alarm logic is operated.

On the other hand, a description will be given of the safety distance, that is, the safety clearance distance calculation algorithm in step 170.

In the figure as shown in FIG. 9,

D: inter-vehicle distance when t = 0,

Df: distance between stops,

D1: distance traveled until the vehicle brakes and stops,

D2: distance traveled until the preceding vehicle is braked to stop,

T1: time taken for the vehicle to brake and stop,

T2: time taken for the preceding vehicle to brake and stop,

A1: acceleration of the host vehicle (acceleration +, deceleration-),

A2: acceleration of the preceding vehicle (acceleration +, deceleration-),

TB: princess time,

V1: Own vehicle speed at t = 0,

V2: Preceding car speed when t = 0,

D1 = V1TB + V1T1 + (1/2) A1T1²,

D2 = V2T2 + (1/2) A2T2²,

Df = D-D1 + D2 = D-V1TB-V1T1-(1/2) A1T1² + V2T2 + (1/2) A2T2²

The condition that collision between the host vehicle and the preceding vehicle does not occur is set to Df? 0?

In addition, D is obtained using two equations, T1 = -V1 / A1 and T2 = -V2 / A2.

Thus D = V1TB + V1 (-V1 / A1) + (1/2) A1 (-V1 / A1) ²

-V2 (-V2 / A2)-(1/2) A2 (-V2 / A2) ²

         = V1TB + V2² / 2A2-V1² / 2A1

         = V1TB + (V1-V2) ² / V1 + V2² / 2A2- V1² / 2A1 (Km) [Human Factor Consideration]

For example, TB = 1Sec, A1 = 90000 Km / H², A2 = 85000 Km / H²,

When setting relative speed R = V1-V2,

It can be calculated as D = (10/36) V1 + 10R² / 36V1 + V1² / 180 to V2² / 170 (m).

Therefore, the alarm algorithm compares the measured distance between the safe inter-vehicle distance and the preceding car, and generates an alarm sound through, for example, a speaker when it is determined that the measured distance?

As described above, the method for determining the own lane driving of the preceding vehicle according to the present invention has the following effects.                     

It is possible to determine whether the preceding vehicle is the own lane driving vehicle or the driving vehicle of another lane, calculate the safety distance between vehicles when the preceding vehicle is in the own lane, and if there is a collision risk, alert the collision.

Therefore, it is possible to prevent a driver's drowsiness while driving or inadvertent other traffic accidents, and in particular, it is possible to call attention to an alarm due to the proximity of the front vehicle when driving at night or lowering attention.

And it is possible to warn of danger when it is impossible to secure the visibility due to pollution and unlit lighting of the preceding vehicle.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments are possible. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (4)

(a) driving a radar installed in front of the host vehicle to obtain data of a preceding vehicle; (b) analyzing the data and determining whether the same data is received in two consecutive frames; (c) calculating angle data as an arithmetic mean value when the condition of step (b) is satisfied; (d) determining whether the data calculated in step (c) is in a data area in which the preceding vehicle is traveling in the same lane as the host vehicle; (e) calculating a safety distance when the condition of step (d) is satisfied; (f) determining whether the safety distance obtained in step (e) is greater than the inter-vehicle distance; (g) generating an alarm if the condition of step (f) is satisfied; At this time, the data of the preceding vehicle in the step (a) is obtained by the radar by the angular signal received from -10 degrees to +10 degrees, the own lane driving determination method of the preceding vehicle. delete The method of claim 1, In the step (g), the alarm is divided into a first alarm and a second alarm according to the degree of risk, The first alarm is generated when there is a risk of collision between the host vehicle and the preceding vehicle and requires attention, and a warning sound is generated at about 5 second intervals. The second alarm is generated when braking is required because there is a risk of collision with the preceding vehicle, and a warning sound is generated until a safety distance from the preceding vehicle is secured. . The method of claim 3, The first alarm, the vehicle lane determination method of the preceding vehicle, characterized in that to stop the warning sound when it is determined that the driver recognizes when the brake signal is input.

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