KR20170114599A - Smart cruise control system and method for controlling thereof - Google Patents

Abstract

The present invention relates to a smart cruise control (SCC) system for a vehicle and a control method thereof, and more particularly, to a smart cruise control By adjusting the set headway level variably, the SCC control is performed by the adjusted headway step in the situation where the other vehicle running on the side is cut-in, and unnecessary braking by the cut-in vehicle Thereby reducing the situation and improving the performance of the SCC system.

Description

TECHNICAL FIELD [0001] The present invention relates to a smart cruise control system and a control method thereof,

The embodiments relate to a Smart Cruise Control system of a vehicle and a method of controlling the same.

2. Description of the Related Art [0002] As the demand for the performance of a vehicle increases along with a demand for convenience and safety of a driver, a system in the vehicle based on information acquired from a sensor mounted on the vehicle, DAS: Driver Assist System) has been continuously studied and developed and applied to vehicles.

As one of such driver assistance systems (DAS), a Smart Cruise Control (SCC) system for controlling a vehicle to travel at a certain distance from a preceding vehicle has been widely applied to vehicles.

The Smart Cruise Control (SCC) system measures the distance from the preceding vehicle through a sensor mounted on the vehicle, and controls the deceleration and acceleration of the vehicle based on the vehicle speed and the measured distance, .

At this time, the smart cruise control (SCC) system can control the deceleration and acceleration of the vehicle based on the headway time set in the vehicle.

Here, the headway time means a time required for the vehicle to collide with the preceding vehicle in consideration of the speed of the vehicle and the distance from the preceding vehicle.

That is, when it is judged based on the current speed of the vehicle and the distance to the preceding vehicle, it is controlled so that the vehicle decelerates when a collision with the preceding vehicle is expected in the set headway time, You can control to keep the current speed.

A Smart Cruise Control (SCC) system based on the headway time is a system in which a cut-in vehicle is instantaneously operated when a vehicle running in a side lane of the vehicle is cut-in toward the front of the vehicle So that the deceleration control is performed.

However, a cut-in vehicle entering from a side lane generally travels at a speed higher than a predetermined speed for traveling ahead of the vehicle, so that when a cut-in vehicle is detected even though there is no possibility of collision The deceleration control is performed so that an unnecessary braking situation frequently occurs.

As the frequency of unnecessary braking is increased, the driving performance by the Smart Cruise Control (SCC) system is reduced, and the driver of the vehicle controlled by the Smart Cruise Control (SCC) system becomes inconvenient and uneasy exist.

It is an object of the present embodiments to provide a smart cruise control (SCC) system capable of reducing unnecessary braking occurrence frequency by variably adjusting a headway time set in a vehicle controlled by a smart cruise control (SCC) System.

It is an object of the embodiments of the present invention to provide a smart cruise control (SCC) system that prevents a risk of collision that may be caused by variably adjusting a headway time set in a vehicle.

One embodiment includes a relative speed calculation unit for calculating a relative speed of another vehicle with respect to a running vehicle when another vehicle running on the side of the vehicle being driven is detected, A headway adjusting unit for comparing the relative speed of the other vehicle with a threshold value and adjusting a headway step set according to a result of comparison, and a preliminary braking unit for performing a preliminary braking when the headway step set by the headway adjusting unit is adjusted to the highest level A smart cruise control (SCC) system including a braking control unit can be provided.

In such a smart cruise control (SCC) system, the headway adjustment unit adjusts the set headway level upward if the relative speed of the other vehicle is greater than or equal to the threshold value, Step can be maintained.

Alternatively, in a state in which the headway stage is composed of N stages and threshold values are (N-1), the headway adjustment section sequentially sets the relative speeds of the other vehicles from the smallest value among the (N-1) And adjust the set headway level.

At this time, if the relative speed of the other vehicle is equal to or greater than the Kth threshold value among (N-1) threshold values, the headway adjustment unit adjusts the set headway step by K steps or sets the set headway step to (K + 1) th stage.

Another embodiment is a method of calculating a relative speed of another vehicle, the method comprising: calculating a relative speed of another vehicle running on the side of the vehicle under running; comparing the relative speed of the other vehicle with one or more thresholds; (SCC) system control method comprising the steps of: adjusting a headway step set in a running vehicle according to a comparison result of a headway step, and performing a preliminary braking if the adjusted headway step corresponds to the highest step Can be provided.

According to the embodiments, the smart cruise control (SCC) can be performed by variably adjusting the headway time set in the vehicle in accordance with the relative speed with the cut-in vehicle entering into the forward direction of the running vehicle, It is possible to reduce the frequency of an unnecessary braking situation caused by a cut-in vehicle in a vehicle controlled by the vehicle.

According to the present embodiments, when the headway time is adjusted, preliminary braking is performed on the basis of the adjusted headway time, so that it is possible to change the headway time The risk of collision can be prevented.

1 is a diagram for explaining an example of a headway step set in a smart cruise control (SCC) system according to the present embodiments.
FIG. 2 is a diagram illustrating an example of the relationship between each headway step and headway time in a smart cruise control (SCC) system according to the present embodiments.
FIG. 3 is a diagram illustrating a configuration of a smart cruise control (SCC) system according to the present embodiments.
FIGS. 4 and 5 are views showing an example of a manner in which a smart cruise control (SCC) system according to the present embodiments adjusts the headway steps variably.
FIG. 6 is a diagram illustrating an example of a situation in which a smart cruise control (SCC) system according to the present embodiments adjusts a headway phase.
FIG. 7 is a diagram illustrating an example of a manner in which a smart cruise control (SCC) system according to the present embodiments performs preliminary braking.
8 is a diagram showing an example of a situation in which a smart cruise control (SCC) system according to the present embodiments performs a preliminary braking operation.
FIG. 9 is a flowchart illustrating a method of controlling a Smart Cruise Control (SCC) system according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the components from other components, and the terms do not limit the nature, order, order, or number of the components. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; intervening "or that each component may be" connected, "" coupled, "or " connected" through other components.

1 and 2 illustrate a headway step set in a smart cruise control (SCC) system (hereinafter referred to as " SCC system ") according to the present embodiment, The number of headway steps is not limited to four.

The SCC system according to the present embodiments determines the possibility of collision with the preceding vehicle in accordance with the set headway step among the four steps of the headway step, and controls the deceleration and acceleration of the vehicle.

Referring to FIG. 1, the headway step set in the SCC system according to the present embodiment includes four steps, and 101 denotes a headway time corresponding to the first step when the headway step is set to the first step. And 102 denotes a region where a preceding vehicle in which a collision is expected is located in a headway time corresponding to the second stage when the headway stage is set to the second stage .

Reference numeral 103 denotes a region where a preceding vehicle in which a collision is expected to occur in a headway time corresponding to the third step is positioned, and 104 denotes a region in which the headway step is set to four steps In this case, the headway time corresponding to step 4 indicates the area in which the preceding vehicle is expected to collide.

That is, when the headway step is set to the first step, the headway time is set to be the longest, and when the headway time is set to the fourth step, the headway time is set to be the shortest.

FIG. 2 shows an example of a headway time that is set for each headway step. Referring to FIG. 2, if the headway step is one step, the headway time is set to 2 seconds , And the headway time may be set to 1.5 seconds, 1 second, and 0.5 seconds, respectively, when the headway steps are 2, 3, and 4, respectively.

When the headway step is set to the first step and the preceding vehicle is running in the area 101 when the vehicle is traveling, the vehicle travels for 2 seconds, which is the headway time corresponding to the first step at the current speed It is judged that it will collide with the preceding vehicle.

Accordingly, when a preceding vehicle located in the area 101 is detected, the braking of the vehicle is controlled to allow the vehicle to decelerate to travel.

Further, even when a preceding vehicle located in the area of 102, 103, or 104 is sensed, it is determined that the collision will occur within 2 seconds of the headway time corresponding to the first step, so that the vehicle is controlled to decelerate .

When the vehicle travels ahead of the area of 101, the current speed of the vehicle can be maintained or the vehicle can be controlled to accelerate.

Likewise, when the headway step is set to the two-step travel, if the preceding vehicle is located in the area of 102, or is located in the area of 103 or 104, the headway time preceding the headway time The collision with the vehicle is expected so that the vehicle can be decelerated to travel.

At this time, there may occur a situation in which another vehicle traveling on the side of the running vehicle cuts in front of the vehicle controlled by the SCC system.

In the case where a cut-in vehicle enters the front of the vehicle controlled by the SCC system, the cut-in vehicle generally travels at a constant speed or more. Therefore, the area that is the criterion for deceleration travel by the SCC system It is possible to pass through some of the regions 101 to 104 and to exit forward.

Therefore, in this case, it is detected that the cut-in vehicle is temporarily located in the area 101 although the collision between the vehicle controlled by the SCC system and the cut-in vehicle is not expected. The SCC system controls the braking of the vehicle so that the vehicle is decelerating.

This unnecessary braking situation can reduce the performance of the SCC system and make the driver of the vehicle controlled by the SCC system feel uncomfortable and uneasy.

The embodiments of the present invention provide an SCC system that adjusts the headway phase variably according to the driving situation and controls the deceleration and acceleration so as to eliminate such a problem and at the same time prevent the risk of collision.

3 shows a configuration of an SCC system 300 for variably adjusting headway steps according to the present embodiments.

Referring to FIG. 3, the SCC system 300 according to the present embodiment includes a relative speed calculation unit 310 that calculates a relative speed of a vehicle traveling on a side, based on information obtained from a sensor mounted on the vehicle, A headway adjustment unit 320 that adjusts a headway step set in the vehicle based on the calculated relative speed, and a preliminary braking control unit 330 that performs preliminary braking according to the adjusted headway step.

The relative speed calculation unit 310 detects a vehicle traveling on the side of the vehicle from a sensor mounted on the vehicle and calculates the relative speed of the sensed vehicle.

The relative speed calculating unit 310 detects the vehicle traveling on the side through the radar 10 or the ultrasonic sensor 20 mounted on the vehicle and calculates the relative speed of the sensed vehicle when the vehicle traveling on the side is detected can do.

Alternatively, speed information of a vehicle traveling on the side may be received through inter-vehicle communication using the communication module 30, and the relative speed may be calculated using the received speed information.

When the vehicle running on the side of the vehicle controlled by the SCC system 300 is sensed and the relative speed of the sensed vehicle is calculated, the relative speed calculating unit 310 calculates the relative speed based on the calculated relative speed to the headway adjuster 320 .

The headway adjustment section 320 can adjust the headway step set in the vehicle controlled by the SCC system 300 according to the relative speed of the vehicle traveling on the side when receiving the relative speed of the vehicle traveling on the side of the vehicle .

For example, it is checked whether the relative speed of the vehicle traveling on the side of the vehicle controlled by the SCC system 300 is equal to or greater than a preset threshold value. If the relative speed of the vehicle traveling on the side is equal to or greater than a predetermined threshold value The set headway level can be adjusted upward.

If the relative speed of the vehicle traveling on the side is smaller than the predetermined threshold value, the running of the vehicle can be controlled while maintaining the currently set headway level.

That is, if the relative speed of the vehicle traveling on the side is greater than or equal to a predetermined speed, it can be expected that the vehicle will overtake the vehicle controlled by the SCC system 300, and the situation in which the vehicle overtakes and cut- have.

In this case, when the SCC control is performed while maintaining the current headway level, an unnecessary braking situation may occur due to a cut-in of the side vehicle. Therefore, Cut-In) detection is not performed.

For example, a braking situation may occur when the headway step is set to the first step and the side vehicle is cut-in to the front side of the running vehicle and is temporarily located in the area 101. [

However, in the case where the headway step set to the first step is adjusted to the second step according to the relative speed of the side vehicle, if the side vehicle travels forward through the area 101, the side vehicle is not positioned in the area 102 to 104 So that an unnecessary braking situation does not occur.

In comparing the relative speed of the side vehicle with a predetermined threshold value, the headway adjustment unit 320 may compare a plurality of sequentially set threshold values with the relative speed of the side vehicle and adjust the set headway level.

For example, when the headway stage is composed of four stages and three preset threshold values exist, the headway adjustment section 320 adjusts the headway weight from the first threshold value as the smallest threshold value to the third threshold value as the largest threshold value Can be sequentially compared with the relative speed of the side vehicle.

If the relative speed of the side vehicle is equal to or greater than the first threshold value and less than the second threshold value, the headway adjustment section 320 adjusts the headway step by one level, and if the relative speed of the side vehicle is equal to or greater than the second threshold value If the relative speed of the side vehicle is equal to or greater than the third threshold value, the headway step can be adjusted up by three steps.

That is, as the relative speed of the side vehicle increases, the possibility of collision due to the cut-in of the side vehicle is lowered. Therefore, the headway level is adjusted upward to reduce the headway time, Do not perform unnecessary braking by Cut-In.

Alternatively, the headway adjustment unit 320 may configure the threshold value to (N-1) when N headway steps exist and may adjust the headway step according to the section including the relative speed of the side vehicle.

For example, if the relative speed of the side vehicle is greater than the Kth threshold value of the (N-1) threshold values and smaller than the (K + 1) th threshold value, the headway stage may be set to the (K + 1) .

If the relative speed of the side vehicle is equal to or greater than the first threshold value and smaller than the second threshold value, the headway step is adjusted to two levels. If the relative speed of the side vehicle is equal to or greater than the second threshold value and smaller than the third threshold value, If the relative speed of the side vehicle is equal to or greater than the third threshold value, the headway step may be adjusted to four levels.

That is, depending on the driving situation, the headway step may be set to the second step, the third step, or the fourth step instead of the first step, so that the headway step is not simply adjusted upward, It may be adjusted to a suitable headway level.

In this case, when the headway level set in the vehicle is adjusted according to the relative speed of the side vehicle, unnecessary braking situations can be avoided when the headway level is adjusted to the high level 3 or 4, but the headway time ) May be short and dangerous situations may arise.

Thus, the SCC system 300 according to the present embodiments controls the pre-fill of the vehicle in accordance with the adjusted headway steps, so as to be able to prepare for a dangerous situation in the adjustment of the headway steps.

The preliminary braking control unit 330 confirms the headway level adjusted by the headway adjustment unit 320 and determines whether to perform the preliminary braking according to the adjusted headway level.

For example, if the headway level is adjusted by the headway adjustment unit 320 and the headway time is adjusted to the shortest level, the preliminary braking control unit 330 may perform the preliminary braking .

The preliminary braking means that the braking pressure of the vehicle is kept at a value slightly larger than zero, thereby reducing the time required to reach the braking pressure necessary for braking in the braking situation of the vehicle.

Accordingly, according to the embodiments, the headway step set for the vehicle controlled by the SCC system 300 can be variably adjusted in accordance with the relative speed of the side vehicle, so that the unnecessary braking situation at the cut-in of the side vehicle is reduced If the adjusted headway step is equal to or more than a predetermined level, preliminary braking is performed to prevent a dangerous situation.

4 and 5 show an example of a method of adjusting headway steps in the headway adjustment unit 320 of the SCC system 300 according to the present embodiments.

4 shows a case in which the headway adjustment unit 320 raises the headway step by a predetermined step according to the relative speed of the side vehicle.

Referring to FIG. 4, the headway adjustment unit 320 adjusts the set headway step by one step if the relative speed of the side vehicle is equal to or greater than the first threshold value and smaller than the second threshold value. If the relative speed of the side vehicle is equal to or greater than the second threshold value and less than the third threshold value, the headway step is adjusted upward by two steps, and if the relative speed of the side vehicle is equal to or greater than the third threshold value, .

In other words, as the relative speed of the side vehicle is higher, the possibility of collision in the cut-in situation of the side vehicle is lower. Therefore, the number of the upwardly adjusted headway steps is increased according to the relative speed of the side vehicle.

5 shows a case where the headway adjustment unit 320 sets the headway step according to the section including the relative speed of the side vehicle.

Referring to FIG. 5, the headway adjustment unit 320 adjusts the set headway step to two levels when the relative speed of the side vehicle is equal to or greater than the first threshold value and smaller than the second threshold value. If the relative speed of the side vehicle is equal to or greater than the second threshold value and smaller than the third threshold value, the set headway level is adjusted to three levels, and if the relative speed of the side vehicle is equal to or greater than the third threshold value, Step.

That is, the headway step is not always set to the first step but may be set differently according to the driving situation. Therefore, the headway step is set according to the section including the relative speed of the side vehicle.

At this time, the first threshold value among the threshold values shown in FIGS. 4 and 5 may be set to a value less than or equal to 0, and the second threshold value and the third threshold value may be set to a value greater than zero.

In the case where the relative speed of the side vehicle is less than 0 but equal to or higher than a constant relative speed, the headway level is adjusted to detect the side vehicle having a predetermined relative speed or higher, .

FIG. 6 shows an example of a situation in which unnecessary braking does not occur by adjusting the headway level by the headway adjustment unit 320 of the SCC system 300 according to the present embodiments.

Referring to FIG. 6, when the vehicle, which is controlled by the SCC system 300 and whose headway level is set to one level, senses the side vehicle, the relative speed of the side vehicle is calculated.

Then, the headway step is adjusted by comparing the relative speed of the side vehicle with a predetermined threshold value.

6 shows a situation in which the headway step is adjusted from one step to three steps according to the result of comparison between the relative speed of the side vehicle and a predetermined threshold value.

At this time, even if the side vehicle is cut-in toward the front of the vehicle controlled by the SCC system 300 and temporarily located in the area 101, since the headway step is adjusted in three steps, the SCC system 300 It is not judged that there is a possibility of collision with a cut-in vehicle.

Therefore, the SCC system 300 does not perform unnecessary braking, so that the vehicle controlled by the SCC system 300 can continue to run at the current speed without decelerating.

FIGS. 7 and 8 show an example of the manner and manner in which the preliminary braking control unit 330 of the SCC system 300 according to the present embodiments performs preliminary braking based on the adjusted headway steps.

Referring to FIG. 7, the preliminary braking control unit 330 performs preliminary braking when the headway level adjusted by the headway adjustment unit 320 corresponds to the fourth highest level.

If the preliminary braking is performed, the braking pressure of the vehicle can be maintained at a value slightly larger than 0, and the time (t) for reaching the braking pressure necessary for braking in the braking situation can be reduced.

Therefore, in order to reduce the unnecessary braking situation due to the cut-in of the side vehicle, the headway step adjusted by the relative speed of the side vehicle may have a short headway time In the case of the step, preliminary braking is performed.

FIG. 8 shows an example of a situation in which the preliminary braking is performed. According to the result of comparison between the relative speed of the side vehicle and a predetermined threshold value, the headway level of the vehicle is adjusted in four steps with the shortest headway time .

Since the headway step is adjusted in four steps by the relative speed of the side vehicle, the SCC system 300 performs the preliminary braking.

Therefore, even if the side vehicle suddenly decelerates after cutting-in at a high relative speed, the preliminary braking is performed, so that the vehicle controlled by the SCC system 300 collides with the cut-in vehicle .

9 shows a process of a control method of the SCC system 300 according to the present embodiments.

9, the SCC system 300 according to the present embodiment detects a vehicle traveling on the side of the vehicle through a sensor or a vehicle mounted on the vehicle (S900) (S901).

The SCC system 300 compares the relative speed of the vehicle traveling on the side with the first threshold value (S902), and maintains the currently set headway step if the relative speed of the side vehicle is less than the first threshold (S903) .

If the relative speed of the side vehicle is greater than or equal to the first threshold value, the relative speed of the side vehicle is compared with the second threshold value (S904). If the relative speed of the side vehicle is less than the second threshold value, (Step S905).

If the relative speed of the side vehicle is equal to or greater than the second threshold value, the relative speed of the side vehicle is compared with the third threshold value (S906). If the relative speed of the side vehicle is less than the third threshold value, (S907). If it is greater than or equal to the third threshold value, the headway level is adjusted by three steps (S908).

At this time, it is checked whether the adjusted headway step corresponds to the fourth step with the shortest headway time (S909). If the headway step has been adjusted to the fourth step, preliminary braking is performed (S910) If possible, prepare for the risk situation.

Therefore, according to the embodiments, when the side vehicle is detected by the vehicle controlled by the SCC system 300, the relative speed of the side vehicle is measured and the headway phase is variably adjusted according to the relative speed of the side vehicle.

In this way, when a vehicle having a cut-in possibility from the side of the vehicle to the front is cut-in, the cut-in vehicle is controlled by performing the SCC control according to the adjusted headway step So that the SCC control can be performed stably without performing unnecessary braking.

In addition, when the headway time corresponding to the headway step adjusted by the relative speed of the side vehicle is short, the preliminary braking is performed, so that a reduction in the number of cut- It is also possible to prepare for the dangerous situation caused by the inside or the like.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. The embodiments of the present invention are not intended to limit the scope of the present invention but to limit the scope of the present invention.

300: Smart Cruise Control (SCC) system
310: relative speed calculating unit 320: headway adjusting unit
330: preliminary braking control unit 10: radar
20: ultrasonic sensor 30: communication module

Claims (12)

A relative speed calculation unit for calculating a relative speed of the other vehicle with respect to the traveling vehicle when another vehicle running on the side of the traveling vehicle is sensed; And
A headway adjustment unit for comparing the relative speed of the other vehicle with a threshold value and adjusting the set headway step according to a comparison result if the headway step set in the running vehicle is not the highest step,
The Smart Cruise Control System includes:
The method according to claim 1,
The headway adjustment unit includes:
And adjusts the set headway step if the relative speed of the other vehicle is equal to or greater than the threshold value and maintains the set headway step if the relative speed of the other vehicle is less than the threshold value.
The method according to claim 1,
The headway adjustment unit includes:
(N-1) threshold values sequentially from a smaller value among the (N-1) threshold values in a state where the headway step is composed of N steps and the threshold value is (N-1) Smart Cruise control system that adjusts the set headway steps.
The method of claim 3,
The headway adjustment unit includes:
And if the relative speed of the other vehicle is equal to or greater than a Kth threshold value among the (N-1) threshold values, the set headway step is adjusted upward by K steps.
The method of claim 3,
The headway adjustment unit includes:
And adjusts the set headway step to a (K + 1) th step if the relative speed of the other vehicle is equal to or greater than a Kth threshold value among the (N-1) threshold values.
The method of claim 3,
Wherein the first threshold value of the (N-1) threshold values is set to a value less than or equal to zero and the remaining threshold value is set to a value greater than zero.
The method according to claim 1,
The headway adjustment unit includes:
And adjusts the adjusted headway step according to the change of the relative speed of the other vehicle.
The method according to claim 1,
And a preliminary braking control unit for performing preliminary braking when the set headway level is adjusted to the highest level by the headway adjusting unit.
Calculating a relative speed of another vehicle traveling on the side of the vehicle under travel;
Comparing the relative speed of the other vehicle with one or more thresholds;
Adjusting a headway step set in the running vehicle according to a result of comparison between the relative speed of the other vehicle and the one or more threshold values; And
If the adjusted headway step corresponds to the highest step, performing preliminary braking
And a control unit for controlling the smart cruise control system.
10. The method of claim 9,
Wherein comparing the relative speed of the other vehicle with the one or more thresholds comprises:
(N-1) thresholds from a smaller one of the (N-1) threshold values to a relative speed of the other vehicle in a state in which the headway step includes N steps and the threshold value is (N-1) Method of controlling the system.
11. The method of claim 10,
The step of adjusting the headway step set for the running vehicle includes:
And if the relative speed of the other vehicle is equal to or greater than a Kth threshold value among the (N-1) threshold values, the set headway step is adjusted upward by K steps.
11. The method of claim 10,
The step of adjusting the headway step set for the running vehicle includes:
(K + 1) th step if the relative speed of the other vehicle is equal to or greater than a Kth threshold value among the (N-1) threshold values.

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