Patent Description:
An autonomous vehicle employs an advanced driver assistance system (ADAS) to free a driver from simple work, such as steering wheel and pedal manipulation during driving, and prevent accidents caused by a driver's carelessness. Therefore, people's interest therein is currently increasing.

The advanced driver assistance system includes a highway driving assist (HDA) function of assisting a vehicle to travel along the center of a driving lane, and lane following assist (KFA) and lane keeping assist (LKA) functions of assisting a vehicle not to deviate from the lines of a driving lane. When such functions are performed, a vehicle may recognize the lines of a driving lane, in which the vehicle is currently driving, by using a front camera included in the vehicle, and perform steering control along the recognized lines of the driving lane. Therefore, steering control performed by these kinds of assistance functions requires precise recognition of lines.

However, when steering control is performed using only curvature information of a line of a driving lane, this may be problematic in that lines are mis-recognized due to diversity of a driving road environment in which a vehicle is driving, and steering is mis-controlled. For example, if there is a stretch diverged or expanded from a driving lane in which a vehicle is driving, when the vehicle enters the stretch, the vehicle mis-recognizes a line of the diverged or expanded stretch as a line of the driving lane, and thus steering to the stretch may be performed.

The foregoing described as the background is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art already known to those skilled in the art.

<CIT> discloses a lane keep control apparatus. In the document the apparatus is described to include a first calculator, wherein the first calculator includes a first determiner, a second determiner, a third determiner, and a second calculator, wherein the first determiner is configured to determine whether a preceding vehicle travels on a traveling lane of an own vehicle, the second determiner is configured to determine whether a blinker of the preceding vehicle blinks, the third determiner is configured to determine whether widening of one or both of lane lines is present, and the second calculator is configured to set, on a condition that the blinker of the preceding vehicle is determined as blinking and the widening is determined as being present, a target traveling course on the basis of one of the lane lines positioned on opposite side of the other of the lane lines that is positioned on a side on which the blinker of the preceding vehicle is determined as blinking.

<CIT> discloses that lane feature data is processed to compute a feed-forward lane curvature of a left lane boundary and a right lane boundary, a look-ahead lane width and a near lane width are computed based on left and right lane boundaries, a lane width increase is computed to detect a lane split or lane merge based on differences between increasing lane widths, a side of the vehicle on which the lane split or merge occurred is identified or determined, the lane boundary on the side on which the lane split or merged occurred is ignored, and a single-sided lane centering calculation is performed based on the non-ignored lane boundary.

The present invention has been made to solve such a problem, and is to provide a vehicle control system and method by which whether the lane width of a lane in which a vehicle is driving increases is determined, and driving of the vehicle is controlled on the basis of the determination.

The technical subjects pursued in the present invention may not be limited to the above-mentioned technical subjects, and other technical subjects which are not mentioned may be clearly understood, through the following descriptions, by those skilled in the art to which the present invention pertains.

According to a vehicle control system and method of the present invention, even when the lane width of a driving lane, in which a vehicle is driving, increases, a line positioned opposite to a side at which the lane width increases is recognized and driving of the vehicle is controlled, thereby preventing mis-controlling of lane following assist (LFA), lane keeping assist (LKA), and highway driving assist (HDA) functions which serve as transverse control in an advanced driver assistance system.

Advantageous effects obtainable from the present invention may not be limited to the above-mentioned effects, and other effects which are not mentioned may be clearly understood, through the following descriptions, by those skilled in the art to which the present invention pertains.

Terms including an ordinal number such as "first", "second", or the like may be used to describe various elements, but the elements are not limited to the terms. The above terms are used only for the purpose of distinguishing one element from another element.

In the case where an element is referred to as being "connected" or "coupled" to any other element, it should be understood that another element may be provided therebetween, as well as that the element may be directly connected or coupled to the other element. In contrast, in the case where an element is "directly connected" or "directly coupled" to any other element, it should be understood that no other element is present therebetween.

A singular expression may include a plural expression unless they are definitely different in a context.

As used herein, the expression "include" or "have" are intended to specify the existence of mentioned features, numbers, steps, operations, elements, components, or combinations thereof, and should be construed as not precluding the possible existence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, and the same or similar elements are given the same and similar reference numerals, so duplicate descriptions thereof will be omitted.

A unit or a control unit included in the name "control unit" is merely a term widely used for naming a controller configured to control a specific function of a vehicle, but does not mean a generic function unit. For example, the controller may include a communication device configured to communicate with a sensor or another control unit, a memory configured to store an operation system, a logic command, or input/output information, and at least one processor configured to perform determination, calculation, decision or the like which are required for responsible function controlling.

First, referring to <FIG>, a configuration of a vehicle control system according to an embodiment of the present invention is described.

<FIG> is a block diagram illustrating a configuration of a vehicle control system according to an embodiment of the present invention.

Referring to <FIG>, a vehicle control system according to an embodiment of the present invention may include a camera <NUM> and a controller <NUM>. <FIG> shows mainly elements related to an embodiment of the present invention, and thus it is obvious that fewer or more elements may be included when a real vehicle control system is implemented.

Hereinafter, each element will be described.

The camera <NUM> is an image capturing device mounted at a vehicle, and may be at least one camera among a front camera, a side camera, and a rear camera according to the position in which the camera is mounted. The camera <NUM> according to an embodiment of the present invention is assumed as a front camera mounted at a front of the vehicle. The camera <NUM> may be mounted at the front of the vehicle to capture an image of the foreground of the vehicle. In addition, multiple cameras <NUM> may be arranged at the front of the vehicle, and an image of the foreground of the vehicle may be captured by means of the multiple cameras. The camera <NUM> may collect image information obtained by capturing an image of the foreground of the vehicle, and provide the collected information to the controller <NUM>.

The controller <NUM> may recognize at least one piece of information among traffic information and road information, the traffic and roads of which are positioned ahead of the vehicle, based on the image information obtained by the camera <NUM>. For example, the controller <NUM> may recognize a driving lane ahead of the vehicle, in which the vehicle is driving. Thereafter, the controller <NUM> may control driving of the vehicle, based on information on the recognized driving lane. An aspect of the present invention is to, even in a case of occurrence of a change, such as increasing of the lane width of a driving lane in which a vehicle is driving, keep controlling the vehicle to travel in the current driving lane. Therefore, the controller <NUM> may determine an expected lane width of the driving lane over time, determine whether a real lane width of the driving lane increases at a time point at which the determined expected lane width increases, and when it is determined that the real lane width increases, control driving, based on information on a line, among both lines of the driving lane, positioned in an opposite direction of a direction in which the lane width increases. To this end, the controller <NUM> may include a determination unit <NUM>, an information generation unit <NUM>, and a driving control unit <NUM>. Hereinafter, each element will be described.

The determination unit <NUM> may recognize a driving lane in image information provided from the camera <NUM>, and determine an expected lane width of the driving lane, based on information related to the recognized driving lane. Specifically, the determination unit <NUM> may determine an expected lane width of the driving lane, based on a longitudinal distance of the vehicle and at least one piece of information among an offset, a heading angle, a curvature, and a curvature derivative value of a line of the driving lane in information related to the recognized driving lane.

For example, the determination unit <NUM> may determine an expected lane width through a line equation, based on a longitudinal distance of the vehicle and an offset, a heading angle, a curvature, and a curvature derivative value of a line of the driving lane. The determination unit <NUM> may determine an expected lane width through a line equation as Equation <NUM> below.

In Equation <NUM>, X may denote a longitudinal distance of the vehicle, and Y may denote the distance from the vehicle to the left line or the right line. α may indicate an offset of the line, β may indicate a heading angle, γ may indicate the curvature of the line, δ may indicate the curvature derivative value of the line. In addition, the determination unit <NUM> may apply the curvature and the curvature derivative value of the line in consideration of a correction factor.

The determination unit <NUM> may determine an expected lane width over time through the described line equation, based on information related to a driving lane. That is, the determination unit <NUM> may determine an expected lane width that is expected over time with respect to a current location of the vehicle. For example, the expected lane width may be a value obtained by adding the distance from the vehicle to the left line and the distance from the vehicle to the right line, which are determined through Equation <NUM> described above, respectively.

As time passes, an offset, a heading angle, a curvature, and a curvature derivative value of a line of a driving lane in which the vehicle is driving and the longitudinal distance of the vehicle may change. Therefore, the expected lane width may be determined based on an offset, a heading angle, a curvature, and a curvature derivative value of a line, and the longitudinal distance of the vehicle which are obtained in consideration of a change over time. For example, an offset, a heading angle, a curvature, and a curvature derivative value of a driving lane line which are obtained in consideration of a change over time may be determined through Equation <NUM> below.

Here, αk, βk, γk, and δk may denote an offset, a heading angle, a curvature, and a curvature derivative value of a line at a random time of k seconds, and αk+<NUM>, βk+<NUM>, γk+<NUM>, and δk+<NUM> may denote an offset, a heading angle, a curvature, and a curvature derivative value of a line at a random time of (k+<NUM>) seconds. ΔX, ΔY, and Δθ may be determined through Equation <NUM> below.

Here, ΔX may denote the longitudinal displacement of the vehicle for ΔT, ΔY may denote the transverse displacement of the vehicle for ΔT, and Δθ may denote the angle displacement in yaw of the pose of the vehicle for ΔT.

Therefore, the determination unit <NUM> may determine an expected lane width of a driving lane in which the vehicle is driving, over time through line equations including Equations <NUM> to <NUM>. However, this is an example, and it is obvious that a method of determining an expected lane width of a driving lane is not limited to the method described above. For example, when an expected lane width of a driving lane is determined, information other than the above information of a line may be used, and the expected lane width may be determined through methods other than the line equations described above.

Furthermore, the determination unit <NUM> may determine whether there is a time point at which a determined expected lane width increases, and when there is a time point at which the expected lane width increases, may determine a real lane width of the driving lane at the time point at which the expected lane width increases. If it is determined using only an expected lane width that the lane width of a driving lane in which the vehicle is driving increases, when line mis-recognition using the camera <NUM> occurs, the expected lane width may be incorrectly determined as increasing. Therefore, in order to prevent this problem, the determination unit <NUM> may determine a real lane width when an expected lane width increases, to determine whether the real lane width also increases. For example, the determination unit <NUM> may determine a real lane width when an expected lane width increases, and determine whether the determined real lane width increases within a pre-configured reference time from a time point at which the expected lane width increases.

As another example, the determination unit <NUM> may identify, in data of an expected lane width determined over time, a time interval in which the expected lane width increases, and determine an increased amount of the expected lane width in the time interval. Thereafter, the determination unit <NUM> may determine a changed amount of a real lane width of the driving lane in the time interval, and determine whether the real lane width increases, based on the changed amount of the real lane width and a changed amount of the expected lane width.

When it is determined that the real lane width also increases at a time point at which the expected lane width increases, the determination unit <NUM> may determine that the vehicle has entered a stretch in which the driving lane in which the vehicle is driving expands. For example, when it is determined that an expected lane width and a real lane width increases, the determination unit <NUM> may determine that the vehicle has entered a stretch in which there is at least one lane among a diverged lane and an expanded lane of the driving lane in which the vehicle is driving.

In addition, when it is determined that the real lane width also increases at a time point at which the expected lane width increases, the determination unit <NUM> may determine whether the driving lane in which the vehicle is driving is the outermost lane. When it is determined that the real lane width increases, the determination unit <NUM> may collect at least one piece of information among information on both lines of the driving lane, and information relating to existence or absence of a road edge with respect to both sides of the driving lane. Thereafter, the determination unit <NUM> may determine whether the driving lane in which the vehicle is driving is the outermost lane, by using the collected at least one piece of information. For example, the determination unit <NUM> may collect information relating to existence or absence of a road edge with respect to both sides of the driving lane, and when a road edge exists at one side among both sides of the driving lane, may determine that the driving lane in which the vehicle is currently driving is the outermost lane. In addition, the determination unit <NUM> may collect lane information including the shapes and colors of both lines of the driving lane, and when one line of both lines of the driving lane is a line configured by a single unbroken line indicating lane change being impossible, a line configured by double lines, or a line configured by a yellow unbroken line, may determine that the driving lane in which the vehicle is currently driving is the outermost lane.

When the driving lane in which the vehicle is driving is the outermost lane, the determination unit <NUM> may determine that the vehicle has entered a stretch in which there is at least one lane among a diverged lane and an expanded lane of the driving lane.

Meanwhile, when the driving lane is a single one-way lane, road edges may exist at both sides of the driving lane, or both lines of the driving lane may be lines indicating lane change being impossible. Accordingly, the determination unit <NUM> may make mis-determination when determining whether a lane is the outermost lane. Therefore, when the driving lane is a single one-way lane, the determination unit <NUM> may determine which side, among both sides of the driving lane, to which an expected lane width and a real lane width increase more, based on the driving lane. Thereafter, the determination unit <NUM> may determine that at least one lane among a diverged lane and an expanded lane exists at a side to which the expected lane width and the real lane width increase more, and determine that the vehicle has entered a stretch in which there is at least one lane among the diverged lane and the expanded lane of the driving lane.

When it is determined that the vehicle has entered a stretch in which there is at least one lane among the diverged lane and the expanded lane of the driving lane, the determination unit <NUM> may transfer a result of the determination to the information generation unit <NUM>.

When it is determined that the vehicle has entered the stretch, the information generation unit <NUM> may generate driving control information of the vehicle, based on information of a line, among both lines of the driving lane, existing opposite to a side at which there is at least one lane among the diverged lane and the expanded lane. For example, the information generation unit <NUM> may generate driving control information of the vehicle, based on at least one piece of information among the offset, a heading angle, a curvature, and a curvature derivative value of a line, among both lines of the driving lane, existing opposite to a side at which there is at least one lane among the diverged lane and the expanded lane. However, this is an example, and it is obvious that various information other than the above information may be used to generate driving control information of a vehicle.

The information generation unit <NUM> may output the generated driving control information of the vehicle to the driving control unit <NUM>. When the information generation unit <NUM> outputs the generated driving control information, the driving control information of the vehicle generated by the information generation unit <NUM> may differ from driving control information of the vehicle based on information of a driving lane line previously recognized by the camera <NUM>, and this difference may make control of vehicle driving unstable. Therefore, before outputting the generated driving control information of the vehicle, the information generation unit <NUM> may reflect, on the driving control information, a correction value considering a change rate of the driving control information and then output the driving control information. For example, the correction value may be a value configured by considering an upper limit value of a change rate of driving control information in order to prevent a rapid change between existing driving control information and generated driving control information. However, this is an example, and it is obvious that the invention is not necessarily limited thereto.

The driving control unit <NUM> may control driving of the vehicle, based on driving control information of the vehicle output from the information generation unit <NUM>. For example, the driving control unit <NUM> may control a steering device included in the vehicle, based on the output driving control information, such that the vehicle does not travel to the side at which there is at least one lane among the diverged lane and the expanded lane, and travels in the driving lane where the vehicle is originally driving.

Meanwhile, in implementation of the controller <NUM> according to an embodiment of the present invention, the controller <NUM> may be implemented as one function of an advanced driver assistance system (ADAS) controller controlling an ADAS. However, this is an example, and the invention is not necessarily limited thereto. For example, the controller <NUM> may be implemented as a separate controller different from the ADAS controller, or may be implemented such that the functions thereof are disposed into two or more different controllers.

Hereinafter, a vehicle to which a vehicle control system described above has been applied will be described with reference to <FIG>.

<FIG> is a diagram illustrating control of a vehicle having entered a stretch in which a lane width increases, according to an embodiment of the present invention.

Referring to <FIG>, a vehicle is illustrated as moving in an X direction along a current driving lane. The vehicle illustrated in <FIG> may include a vehicle control system described with reference to <FIG>.

While the vehicle is driving in the driving lane, when the vehicle reaches point A, the vehicle may determine an expected lane width over time. Thereafter, if it is determined that the expected lane width increases at point B, when the vehicle reaches point B during driving, the vehicle may determine whether a real lane width increases.

If the real lane width increases when the vehicle reaches point B, the vehicle may collect information on both lines of the driving lane in which the vehicle is driving, and information relating to existence or absence of a road edge with respect to both sides of the driving lane. When a line (RL) positioned at the right side among both sides of the driving lane in which the vehicle is driving is determined as an unbroken line indicating lane change being impossible, or when a road edge exists at the right side among both sides of the driving lane, the vehicle may determine that the driving lane in which the vehicle is currently driving is the outermost lane.

When the expected lane width and the real lane width increase at point B, and the driving lane in which the vehicle is driving is the outermost lane, the vehicle may determine that the vehicle has entered a stretch of the driving lane in which there is at least one lane among a diverged lane and an expanded lane. <FIG> is used to describe an example in which a diverged lane exists, but the same application to an expanded lane is obviously possible.

When a diverged lane exists at the right side in the driving lane of the vehicle, the diverged lane may be mis-recognized as the existing driving lane, and thus driving of the vehicle may be wrongly controlled. Therefore, when a diverged lane exists, the vehicle may control driving thereof, based on information of a line LL existing opposite to the line RL, among both lines of the driving lane, at which the diverged lane exists. In other words, when the vehicle enters a stretch in which a diverged lane exists, the vehicle may recognize a line LL, which faces, in a horizontal direction (Y direction), the line RL, among both lines of the driving lane, at which the diverged lane exists, and control driving of the vehicle, based on information of the line LL. If the vehicle passes point C, the vehicle becomes out of the stretch in which the diverged lane exists in the driving lane, and thus the vehicle may perform a previous driving control scheme again.

That is, while driving the driving lane, when the vehicle enters a stretch (stretch between point B and point C) in which a diverged lane exists, the vehicle may only recognize, rather than the line RL connecting to the diverged lane, only the line LL which is opposite to the line RL and faces same in the horizontal direction, and control driving of the vehicle, based on information of the line LL. Therefore, even when the vehicle enters a stretch in which a diverged lane exists, a line of the diverged lane is not mis-recognized and a line of a driving lane in the vehicle is driving is recognized, whereby malfunction of vehicle driving control can be prevented and driving stability of the vehicle can be improved.

Hereinafter, a vehicle control method according to an embodiment will be described with reference to <FIG>, based on a configuration of a vehicle control system described above with reference to <FIG>.

<FIG> is a flowchart of a vehicle control method according to an embodiment of the present invention.

Referring to <FIG>, an image of the foreground of a vehicle may be captured by means of the camera <NUM> included in the vehicle, and the controller <NUM> may recognize a driving lane in which the vehicle is currently driving, based on image information obtained by the camera <NUM> (operation S310), and may determine an expected lane width of the driving lane, based on recognized information (operation S320).

In determination of the expected lane width, when there is a time point at which the expected lane width increases (Yes of operation S330), the controller <NUM> may determine a real lane width at the time point at which the expected lane width increases (operation S340). When the real lane width increases at the time point at which the expected lane width increases (Yes of operation S350), the controller <NUM> may determine, based on whether the driving lane in which the vehicle is driving is the outermost lane, whether the vehicle has entered a stretch in which there is at least one lane among a diverged lane and an expanded lane (operation S360).

If the real lane width does not increase at the time point at which the expected lane width increases (No of operation S350), the controller <NUM> may defer a process of determining whether the vehicle has entered the stretch in which there is at least one lane among the diverged lane and the expanded lane. In addition, even though the real lane width increases at the time point at which the expected lane width increases (Yes of operation S350), when the driving lane in which the vehicle is driving is not the outermost lane, or recognition of both lines of the driving lane fails, the controller <NUM> may determine that the vehicle has not entered the stretch in which there is at least one lane among the diverged lane and the expanded lane (No of operation S360).

When the vehicle has entered the stretch in which there is at least one lane among the diverged lane and the expanded lane (Yes of operation S360), the controller <NUM> may recognize a line, among both lines of the driving lane, existing opposite to a side at which there is at least one lane among the diverged lane and the expanded lane. The controller <NUM> may generate driving control information of the vehicle, based on information of the recognized line (operation S370). The controller <NUM> may control driving of the vehicle, based on the generated driving control information, while driving in the stretch in which there is at least one lane among the diverged lane and the expanded lane (operation S380).

Thereafter, the controller <NUM> may determine whether the vehicle is out of the stretch in which there is at least one lane among the diverged lane and the expanded lane (operation S390). For example, the controller <NUM> may periodically measure a lane width, and when the lane width has been reduced to be similar to the lane width before the vehicle enters the stretch in which there is at least one lane among the diverged lane and the expanded lane, may determine that the vehicle is out of the stretch in which there is at least one lane among the diverged lane and the expanded lane (Yes of operation S390), and terminate control. In addition, when a longitudinal driving distance of the vehicle exceeds a pre-configured reference distance, the controller <NUM> may determine that the vehicle is out of the stretch in which there is at least one lane among the diverged lane and the expanded lane (Yes of operation S390). The controller <NUM> may perform corresponding control again, based on the driving lane recognized by the camera <NUM>, or may terminate control.

Meanwhile, when the vehicle is still driving in the corresponding stretch without being out of the stretch in which there is at least one lane among the diverged lane and the expanded lane (No of operation S390), the controller <NUM> may continuously perform control based on control information of the vehicle.

As described above, according to the present invention, even when the lane width of a driving lane in which a vehicle is driving increases, a line positioned opposite to a side at which the lane width increases is recognized and driving of the vehicle is controlled, whereby vehicle driving mis-control caused by lane width increment can be prevented, and stability of vehicle driving control can be ensured.

Claim 1:
A vehicle control method comprising:
recognizing (S310), by a controller, a driving lane ahead of a vehicle by utilizing a camera included in the vehicle, and determining (S320), by the controller, an expected lane width of the driving lane over time;
determining (S350), by the controller, whether a real lane width of the driving lane increases at a time point at which the determined expected lane width increases; and
controlling (S380) driving, by the controller and in response to the determination that the real lane width is increasing, based on information on a line, wherein the line is one among two lines of the driving lane and positioned opposite a side of the driving lane in which the lane width increases.