Autonomous driving control apparatus and method for determining lane change and timing thereof based on analysis for shapes and links of forward road

An autonomous driving control apparatus and method are provided to automatically determine whether a lane change is required by considering shapes of forward roads, a link relationship between the roads, a speed limit, the number of lanes, road characteristics (e.g., a crossroad, a crosswalk, an interchange, a junction, a speed bump, a dead-end, etc.), and the like which are recognized from a detailed map. The method also effectively determines a timing of the lane change when the lane change is required for a driver to more conveniently, stably, and efficiently arrive at a destination using an autonomous driving.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims the benefit of priority to Korean Patent Application No. 10-2015-0112340, filed on Aug. 10, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to an autonomous driving control apparatus and method, and more particularly, to an autonomous driving control apparatus and method for determining a lane change and a timing thereof based on shapes of forward roads, a link relationship between the roads, and the like recognized from a detailed map for autonomous driving.

BACKGROUND

Today, due to an increase in use of electric vehicles support to conveniently arrive at a destination while minimizing a manual driving by the aid of an autonomous driving apparatus has been increasingly researched and developed. To implement a more convenient and stable autonomous driving, performance of the autonomous driving apparatus has improved. However, there is a need for an autonomous driving apparatus for solving a limitation of the autonomous driving apparatus according to the related art and more effectively assisting the driving of the driver. The autonomous driving apparatus is related to the technologies such as Adaptive (responsive) Cruise Control System (ACCS), Forward Vehicle Collision Avoidance System (FVCAS), Side and Backward Vehicle Collision Avoidance System (SBVCAS) and Lane Departure Warning System (LDWS), etc.

SUMMARY

The present disclosure provides an autonomous driving control apparatus and method capable of automatically determining whether a lane change is required and effectively determining a timing of the lane change when the lane change is required, based on shapes of forward roads, a link relationship between the road, a speed limit, the number of lanes, road characteristics (e.g., crossroads, crosswalks, interchanges, junctions, speed bumps, dead-ends), and the like, detected using a detailed map, to support a more convenient, stable, and efficiently arrival at a destination by the aid of autonomous driving.

According to an exemplary embodiment of the present disclosure, an autonomous driving control method of a vehicle may include: generating a path plan from a current position of the vehicle toward a destination with reference to a map database while driving the vehicle; determining a farthest segment among the segments for each of the lanes from the current position of the vehicle to a predetermined target segment on the path plan as a local goal point; determining whether a lane change is required to arrive at the local goal point and determining a direction of the lane change based on the determination of whether the lane change is required; and determining a lane change completion segment among the segments for each of the lanes up to the target segment and determining a segment position before a distance for the lane change from an end of the lane change completion segment as a timing position for the lane change.

The path plan may include information regarding a shape of a road, a link relationship between the segments linking between road separation nodes, a speed limit of the vehicle, the number of lanes, or events (e.g., road characteristics). The target segment may include a segment which is spaced apart from the current position of the vehicle in a forward direction by a predetermined distance, a farthest segment that corresponds to when a summation of the number of segments forward from the current position of the vehicle becomes a predetermined number, or a farthest segment that corresponds to when a summation of the number of events forward from the current position of the vehicle becomes the predetermined number.

In the determination of the direction of the lane change, the direction of the lane change in a left direction or a right direction may be determined based on whether the vehicle arrives at the local goal point by a straight driving after performing the lane change in the left or right direction. In addition, in the determination of the segment position as the timing position for the lane change, a segment before segments having a road characteristic including a crossroad, a crosswalk, an interchange, a junction, a speed bump, or a dead-end may be determined as the lane change completion segment.

When the segment before the distance for the lane change has a road curvature of a predetermined threshold value or greater, when the number of lanes is one, for a crossroad, or during a traffic jam state due to an excessive traffic volume within a corresponding segment, in the determination of the segment position as the timing position for the lane change, a segment immediately before or after the corresponding segment may be determined as the timing position for the lane change.

In the determination of the segment position as the timing position for the lane change, when the distance (K) for the lane change is greater than a distance (Devent) from the current position of the vehicle to the end of the lane change completion segment, a segment position before the distance for the lane change may be determined as the timing position for the lane change. In addition, in the determination of the segment position as the timing position for the lane change, a minimum distance (Dmin_require=Dlc+Ddec) necessary for the lane change may be calculated by calculating a distance (Dlc) in which the vehicle is moved during a process of performing the lane change and a deceleration distance (Ddec), and a preset distance (Dmargin) of stability of the lane change may be reflected to calculate the distance for the lane change (K=Dmin_require+Dmargin).

In the determination of the segment position as the timing position for the lane change, the following Equation may be used,
Dlc=v(t1*p+t2*(p−1))   Equation

wherein v is a speed of the vehicle, t1is a time necessary for the lane change, and t2is a preset time for stability between the lane change and a next lane change when the number of execution times (p) of the lane change is two or more.

According to another exemplary embodiment of the present disclosure, an autonomous driving control apparatus of a vehicle may include: a path generator configured to generate a path plan from a current position of the vehicle toward a destination with reference to a map database while the vehicle is being driven; a segment/local goal point determiner configured to determine a farthest segment among the segments for each lane from the current position of the vehicle to a predetermined target segment on the path plan as a local goal point; a lane change/direction determiner configured to determine whether a lane change is required to arrive at (e.g., to reach) the local goal point and determine a direction of the lane change based on the determination of whether the lane change is required; and a lane change timing determiner configured to determine a lane change completion segment the segments for each lane up to the target segment and determine a segment position before a distance for the lane change from an end of the lane change completion segment as a timing position for the lane change. Each of the above modules or units may be executed by a centralized controller configured to generally operate the autonomous driving control apparatus.

The path plan may include information regarding a shape of a road, a link relationship between the segments linking between road separation nodes, a speed limit of the vehicle, the number of lanes, or road characteristics. The target segment may include a segment which is spaced apart from the current position of the vehicle in a forward direction by a predetermined distance, a farthest segment that corresponds to when a summation of the number of segments forward from the current position of the vehicle becomes a predetermined number, or a farthest segment that corresponds to when a summation of the number of events forward from the current position of the vehicle becomes the predetermined number.

The lane change/direction determiner may be configured to determine a direction of the lane change in a left direction or a right direction based on whether the vehicle arrives at the local goal point by driving after performing the lane change in the left or right direction. The lane change timing determiner may be configured to determine a segment before segments having an event including a crossroad, a crosswalk, an interchange, a junction, a speed bump, or a dead-end, as the lane change completion segment.

When the segment before the distance for the lane change has a road curvature of a predetermined threshold value or greater, when the number of lanes is one for a crossroad, or for a traffic jam state due to an excessive traffic volume within a corresponding segment, the lane change timing determiner may be configured to determine a segment immediately before or after the corresponding segment as the timing position for the lane change.

When the distance (K) for the lane change is greater than a distance (Devent) from the current position of the vehicle to the end of the lane change completion segment, the lane change timing determiner may be configured to determine a segment position before the distance for the lane change, as the timing position for the lane change. In particular, the lane change timing determiner may be configured to calculate the distance for the lane change (K=Dmin_require+Dmargin) by calculating a distance (Dlc) in which the vehicle is moved during a process of performing the lane change and a deceleration distance (Ddec) to calculate a minimum distance (Dmin_require=Dlc+Ddec) necessary for the lane change, and reflecting a preset distance (Dmargin) for stability of the lane change.

The lane change timing determiner may calculate the following Equation,
Dlc=v*(t1*p+t2*(p−1))   Equation

wherein v is a speed of the vehicle, t1is a time necessary for the lane change, and t2is a preset time for stability between the lane change and a next lane change when the number of execution times (p) of the lane change is two or more.

DETAILED DESCRIPTION

Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings. Here, like reference numerals denote like elements in the respective drawings. In addition, a detailed description of functions and/or configurations which are already known will be omitted. The contents disclosed below mainly describe portions necessary to understand operations according to various exemplary embodiments and a description of elements which may obscure the gist of the description will be omitted. In addition, some components shown in the drawings may be exaggerated, omitted or schematically illustrated. The size of each component does not exactly reflect its real size and accordingly, the contents described in this specification are not limited by relative sizes or intervals of the components illustrated in the respective drawings.

FIG. 1is a block diagram of an autonomous driving control apparatus100according to an exemplary embodiment of the present disclosure. An operation of the autonomous driving control apparatus100according to an exemplary embodiment of the present disclosure will be described with reference toFIG. 2.

Referring toFIG. 1, the autonomous driving control apparatus100according to an exemplary embodiment of the present disclosure may include a controller110, a map database (DB)120, a path generator130, a segment/local goal point determiner140, a lane change/direction determiner150, a lane change timing determiner160, and a lane changer170. The respective components of the autonomous driving control apparatus100as described above may be determined by hardware such as a semiconductor processor, software such as an application program, or a combination thereof. The controller110may be configured to generally operate the other components of the autonomous driving control apparatus100as described above. In some cases, the controller110may also be implemented to include all or a portion of other components of the autonomous driving control apparatus100to perform functions thereof.

The map DB120may be configured to store detailed map information having a collection of segments as basic information for an autonomous driving with regard to a road and traffic situation of each region (see S110ofFIG. 2). The segments may be configured in a form of a function (e.g., a cubic or higher-order function) representing shapes of roads to be displayed on a display apparatus. For example, one road may include one segment or more than two segments, the respective segments may be linked to each other to configure an overall map, and information regarding a link relationship may also be included and stored in the map DB120.

In other words, the map DB120may be configured to the detailed map information regarding the shapes of the roads, a link relationship between the segments (e.g., the roads linking between separation nodes of the roads such as the crossroads, interchanges, junctions, and the like), a speed limit of a vehicle, the number of lanes, events or road characteristics (e.g., the crossroads, crosswalks, the interchanges, the junctions, speed bumps, dead-ends, and the like), and the like, with regard to the road and traffic situation of each region based on the segments as described above. In addition to traffic related data as described above, the map DB120may be configured to store information regarding a polygon, a polyline a text, etc., related to a background of the map and information regarding facilities, directions (or bearings), etc., to indicate a basic map. In some cases, the map DB120may further be configured to store safety related data including information regarding a current/prediction traffic situation (e.g., traffic congestion, etc.), information regarding an accident related traffic situation, information regarding a position, a type, etc., related to safe driving zones (e.g., a game reserve, a construction region, etc.), and the like.

The path generator130may be configured to perform a navigation function of generating a corresponding path plan for arriving at (e.g., reaching) a destination from a current position during the autonomous driving of the vehicle with reference to the map DB120(see S120ofFIG. 2). The path generator120may further be configured to generate a path plan including information regarding the shapes of the roads, the link relationship between the segments (e.g., the roads linking between separation nodes of the roads such as the crossroads, the interchanges, the junctions, and the like), the speed limit of the vehicle, the number of lanes, the road characteristics (e.g., the crossroads, the crosswalks, the interchanges, the junctions, the speed bumps, the dead-ends, and the like), and the like, on a path between the current position and the destination.

The segment/local goal point determiner140may be configured to determine all of the segments for each lane from the current position of the vehicle to a target segment from the path plan generated as described above, and determine (or set) a farthest segment(s) among the segments for each lane as a local goal point(s) (S130). For example, as in an example ofFIG. 3, when a self-vehicle500(e.g., autonomous vehicle) is driving on a segment3and all of the segments for each lane from a current position of the self vehicle500to the target segment form a segment link relationship in a form of six trees, a segment26and a segment27may be set as the local goal points.

Particularly, the target segment may be determined as (1) a corresponding segment(s) which is spaced apart from the current position of the vehicle in a forward direction by a predetermined distance (e.g., N (real number) meters), (2) a farthest segment that corresponds to when a summation of the number of segments forward from the current position of the vehicle becomes a predermined number (e.g., M (natural number)), (3) a farthest segment that corresponds to when a summation of the number of events (e.g., the crossroads, the crosswalks, the interchanges, the junctions, the speed bumps, the dead-ends, and the like) forward from the current position of the vehicle becomes the predetermined number (e.g., M (natural number)), or the like.

The segment/local goal point determiner140may be configured to determine all of the segments up to the above-mentioned target segment for each lane and set the farthest segment among all of the segments for each lane as the local goal point(s). Further, the lane change/direction determiner150may be configured to determine whether a lane change from a current road is required to arrive at the local goal point from the current position of the vehicle during the autonomous driving of the vehicle, and determine which direction to change the lane among a fight direction or a left direction from the current road, in response to determining that the lane change is required (S140).

When the vehicle is being continuously driven substantially straight on a road on which the vehicle is currently positioned, the lane change/direction determiner150may be configured to determine whether the vehicle may arrive at the local goal point, determine that the lane needs to be maintained when the vehicle may arrive at the local goal point, and determine that the lane change is required when the vehicle may not arrive at the local goal point. As in the example ofFIG. 3, since the road on which the self vehicle500is currently positioned may be a three-lane road, which is the segment3included in a tree3, the self vehicle500may not arrive at the segments26and27, which are the local goal points, straightly from the current road (e.g., turns may be required to reach the local goal points). Therefore, the lane change/direction determiner150may be configured to determine that the lane change is required.

In addition, in response to determining that the lane change is required as described above, the lane change/direction determiner150may be configured to determine a direction of a lane change in any one of the right direction and the left direction from the current road. When the vehicle is currently driving in the leftmost lane, the lane change/direction determiner150may be configured to determine the land change in the right direction and when the vehicle is currently in the rightmost lane, the lane change/direction determiner150may be configured to determine the lane change in the left lane.

When the vehicle is not on the above-mentioned one lane (the leftmost lane) or the rightmost lane, the lane change/direction determiner150may be configured to determine whether the vehicle may arrive at the local goal point when the vehicle is continuously driven in substantially straight (e.g., without turns) in a left road or a right road of the current road of the vehicle to determine whether the lane is changed in which direction of the right direction and the left direction. For example, as in the example ofFIG. 3, for the self vehicle500to arrive at the local goal point, that is, the segment26or27from the road on which the self vehicle500is currently positioned, the lane change/direction determiner150may be configured to determine the lane change in the right direction.

In particular, in response to determining that the lane changes of the number of p (natural number) times (e.g., two or more times) in the left road or the right road of the current road of the vehicle are required, the lane change/direction determiner150may also be configured to determine that the lane changes of the number of p times in the corresponding direction once sequentially by the following method are required.

Furthermore, the lane change timing determiner160may be configured to determine a lane change timing by synthetically reflecting information regarding a plurality of parameters such as a speed limit of a vehicle for each of the segments, a maximum curvature for each of the segments determined based on a road shape, the number of lanes for each of the segments, the number of times (p times) of lane changes in the corresponding direction, actual driving speed of the vehicle based on a current traffic situation (e.g., average speed during a time between a current and a predetermined prior time, etc.), a time t1necessary to change the lane for each of the actual driving speeds of the vehicle, and the like, in the path plan as described above (S150).

For example, the lane change timing determiner160may be configured to determine a lane change completion segment (e.g., a segment before the segment having the road characteristics such as the crossroads, the crosswalks, the interchanges, the junctions, the speed bumps, the dead-ends, and the like) that the lane change needs to be completed, among all of the segments for each lane up to a target segment, and when a distance (K=Dmin_require+Dmargin) calculated to change the lane as described below is greater than a distance (Devent) from the current position of the vehicle to an end of the corresponding lane change completion segment, the lane change timing determiner160may be configured to determine a segment position(s) before the distance (K=Dmin_require+Dmargin) calculated to change the lane from the end of the corresponding lane change completion segment, as a timing position for the lane change.

However, the lane change is impossible or difficult to execute at the timing position for the lane change (e.g., the segment position before the distance for the lane change) as described below, the lane change may be performed at a segment before or after the corresponding segment. For example, the lane change timing determiner160may be configured to determine a segment immediately before or after a corresponding position (segment) as the timing position for starting the lane change, (1) when a road curvature is greater than a predetermined threshold value, (2) when the number of lanes is one, (3) for the crossroad, (4) in the case of a traffic jam state due to an excessive volume of traffic within the corresponding segment, and the like.

The lane change timing determiner160may be configured to calculate a minimum distance (Dmin_require=Dlc+Ddec) necessary for the lane change as expressed in Equation 3 by calculating a distance (Dlc) in which the vehicle is moved during a process of performing the lane change, according to Equation 1 below and calculating a deceleration distance (Ddec) of cases (e.g., a left turn, a right tutu, a stop, a passage of the speed bump, etc.) in which deceleration of the vehicle is required before the local goal point, according to Equation 2 below, and may be configured to calculate a distance (K=Dmin_require+Dmargin) for the lane change to be compared with a distance (Devent) up to the end of the lane change completion segment by summing the minimum distance (Dmin_require) and a preset distance (Dmargin) for stability of the lane change.

Where v denotes speed of the vehicle without deceleration, t1denotes a time necessary for the lane change, t2denotes a preset time for stability between the lane change and a next lane change in the case in which the number of execution times (p) of lane change is two or more, vcurrentdenotes current speed at the time of starting deceleration, vlastdenotes final speed at the time of deceleration, and a denotes deceleration.

As the lane change timing determiner160determines the timing position (segment) for starting the lane change, the lane changer170may be configured to generate a control signal to trigger the change the lane in the corresponding direction from the corresponding position (segment) by sensing forward and backward vehicles of a current lane and a lane to be changed (e.g., surrounding vehicles) using a radar, an infrared sensor, or the like, and a vehicle control system such as an electronic control unit (ECU) of the vehicle may be configured to perform the lane change based on the corresponding control signal.

FIG. 4illustrates an example of a detailed map illustrating a lane changing method performed between the current position of the vehicle and a forward local goal point, according to a control of the autonomous driving control apparatus100according to the exemplary embodiment of the present disclosure.

In particular,FIG. 4illustrates a case in which the self vehicle500having the autonomous driving control apparatus100is driven on a segment immediately before entering a crossroad600. When the autonomous driving control apparatus100sets two segments700as the forward local goal points as illustrated inFIG. 4and the self-vehicle500is driven while maintaining a current driving lane, the self-vehicle500may not arrive at the local goal point700due to the dead-end segment. Therefore, the autonomous driving control apparatus100may be configured to perform a control to execute a left lane change. As described above, the autonomous driving control apparatus100may be configured to determine a segment800of the timing position for starting the lane change, and since the calculated corresponding segment800may be a segment having one lane, the autonomous driving control apparatus100may be configured to perform the lane change on a segment having a plurality of lanes such as a segment immediately after the segment800.

FIG. 5illustrates an example of a detailed map illustrating a lane changing method performed between a position of the vehicle of which a lane is changed and a forward new local goal point, according to a control of the autonomous driving control apparatus100according to the exemplary embodiment of the present disclosure.

As illustrated inFIG. 5, after the self vehicle500having the autonomous driving control apparatus100performs the left lane change as illustrated inFIG. 4, the autonomous driving control apparatus100may again be configured to detect a new local goal point on the path plan. Since the self-vehicle500arrives at the crossroad while continuously driving after performing the lane change in a left lane direction, but does not arrive at a local goal point900while being driven substantially straight (e.g., without turns), the autonomous driving control apparatus100may be configured to determine a lane change necessity, as described above. Since a right turn is required at the crossroad from the current position of the self-vehicle500to reach the local goal point900, the autonomous driving control apparatus100may be configured to determine and execute a right lane change. Additionally, since the interchange is present after turning to the right at the crossroad and the corresponding lane disappears after the interchange, the autonomous driving control apparatus100may be configured to determine and execute a left lane change necessity.

FIG. 6is an illustrative diagram illustrating a lane changing method in a link relationship of segments having a form of three trees between a current position (segment1) of a vehicle on a path plan and a local goal point (segment17), according to an exemplary embodiment of the present disclosure.

In particular, it may be assumed that a length of each segment is about 100 meters, and a speed limit and a driving speed of the self vehicle500on a current traffic flow is about 80 kph (kilometers per hour). In addition, in the link relationship of the segments as illustrated inFIG. 6, the autonomous driving control apparatus100mounted within the self-vehicle500may be configured to set a segment17as the local goal point at the current position (segment1) of the vehicle. For the self vehicle500to arrive at the segment17from the current position (segment1) of the vehicle, the self-vehicle500may be configured to execute two lane changes in the right direction, and the two lane changes may be completed up to a segment12before segments13and14(or segment15) corresponding to the road characteristics such as the dead-end, and the like. In other words, it may be assumed that the distance (Devent) from the current position of the vehicle to an end of the corresponding lane change completion segment (segment11) (or segment10/12) is about 400 meters ((Devent)=400 meters), the driving speed of the self-vehicle500is about 80 kph, the number of times (p times) of lane changes is two, the time t1necessary for the lane change for each of the actual driving speeds of the vehicle is about 5 seconds at about 80 kph, the preset time t2for stability between the lane change and the next lane change is about 5 seconds.

Therefore, according to Equations 1 to 3, the distance (Dlc) in which the vehicle is moved during a process of performing the lane change may be about 333 meters ((Dlc)=2 times*5 sec/times*80 KPH+1 times*5 sec/times*80 KPH=333 meters). In addition, when the cases (e.g., a left turn, a right turn, a stop, a passage of the speed bump, etc.) in which deceleration of the vehicle is required does not occur, deceleration may be unnecessary. Therefore, if it may be assumed that the deceleration distance (Ddec) is about zero and the preset distance (Dmargin) for stability of the lane change is about 100 meters, the distance (K=Dmin_require+Dmargin) for the lane change is about 433 meters ((K=Dmin_require±Dmargin)=Dlc+Ddec+Dmargin=333+0+100=433 meters), which is greater than Devent.

Therefore, the autonomous driving control vehicle100may be configured to determine a segment before the segments13and14(or segment15) corresponding to the road characteristics such as the dead-end, and the like, that is, a segment position before the distance (K=Dmin_require+Dmargin)=433 meters) calculated to perform the lane change from an end of the lane change completion segment (segment10/11/12), as the timing position for starting the lane change, and in the example ofFIG. 6, since the self-vehicle500is on a point before 433 meters from the road characteristic, the autonomous driving control apparatus100may be configured to start the lane change at a current segment.

FIG. 7is another illustrative diagram illustrating a lane changing method in a link relationship of segments having a form of three trees between a current position (segment1) of a vehicle on a path plan and a local goal point (segment17), according to an exemplary embodiment of the present disclosure.

Particularly, when it may be assumed that a length of each of all of the segments is about 100 meters, and a speed limit and a driving speed of the self vehicle500on a current traffic flow is about 80 kph (kilometers per hour), a segment16corresponds to a zone in which the self vehicle500turns to the right at the crossroad, and it may be assumed that suitable speed of the vehicle in this zone is about 20 kph. In addition, in the link relationship of the segments as illustrated inFIG. 7, the autonomous driving control apparatus100mounted within the self-vehicle500may be configured to set the segment17as the local goal point at the current position (segment1) of the vehicle. For the self vehicle500to arrive at the segment17from the current position (segment1) of the vehicle, the self-vehicle500may be configured to execute two lane changes in the right direction, and the two lane changes may be completed up to a segment12before a segment15(or segments13and14).

In other words, it may be assumed that the distance (Devent) from the current position of the vehicle to an end of the corresponding lane change completion segment (segment11) (or segment10/12) is about 400 meters ((Devent)=400 meter), the current driving speed of the self-vehicle500is about 80 kph, the number of times (p times) of lane changes is two, the time t1necessary for the lane change for each of actual driving speeds of the vehicle is about 5 seconds at about 80 kph, the preset time t2for stability between the lane change and the next lane change is about 5 seconds.

Therefore, according to Equations 1 to 3, the distance (Dlc) in which the vehicle is moved during a process of performing the lane change may be about 333 meters ((Dlc)=2 times*5 sec/times*80 KPH+1 times*5 sec/times*80KPH=333 meters). In addition, when the cases (e.g., a left turn, a right turn, a stop, a passage of the speed bump, etc.) in which deceleration of the vehicle is required occurs and it may be assumed that deceleration (a) is −0.2 m/sec2(a=−0.2 m/sec2), since vcurrent=80 KPH and vlast=20 KPH, the deceleration distance (Ddec) is 35 (see Equation 2).

In addition, when it is assumed that the preset distance (Dmargin) for stability of the lane change is about 100 meters, the distance (K=Dmin_require+Dmargin) for the lane change may be about 468 meters ((K=Dmin_require+Dmargin)=Dlc+Ddec+Dmargin=333+35+100=468 meters), which is greater than Devent. Therefore, the autonomous driving control vehicle100may be configured to determine a segment before the segments13and14(or segment15) corresponding to the road characteristics such as the dead-end, and the like, that is, a segment position before the distance (K=Dmin_require+Dmargin)=468 meters) calculated to perform the lane change from an end of the lane change completion segment (segment10/11/12), as the timing position for starting the lane change, and in the example ofFIG. 7, since the self vehicle500is on a point before 468 meters from the event, the autonomous driving control apparatus100may be configured to start the lane change at a current segment.

FIG. 8is still another illustrative diagram illustrating a lane changing method in the case in which crossroads7,8, and9are present between a current position (segment1) of a vehicle on a path plan and a local goal point (segment17), according to an exemplary embodiment of the present disclosure.

In particular, it may be assumed that a length of each of all of the segments is about 200 meters, and a speed limit and a driving speed of the self vehicle500on a current traffic flow is about 80 kph (kilometers per hour). In addition, in the link relationship of the segments as illustrated inFIG. 8, the autonomous driving control apparatus100mounted within the self-vehicle500may be configured to set the segment17as the local goal point at the current position (segment1) of the vehicle. It may be assumed that the segments7,8, and9are the crossroads. For the self vehicle500to arrive at the segment17from the current position (segment1) of the vehicle, the self-vehicle500may be configured to execute two lane changes in the right direction, and the two lane changes may be completed up to a segment12before segments13and14(or segment15) corresponding to the road characteristics such as the dead-end, and the like.

In other words, it may be assumed that the distance (Devent) from the current position of the vehicle to an end of the corresponding lane change completion segment (segment11) (or segment10/12) is about 800 meters ((Devent)=800 meter), the driving speed of the self-vehicle500is about 80 kph, the number of times (p times) of lane changes is two, the time t1necessary for the lane change for each of the actual driving speeds of the vehicle is about 5 seconds at about 80 kph, the preset time t2for stability between the lane change and the next lane change is about 5 seconds.

Therefore, according to Equations 1 to 3, the distance (Dlc) in which the vehicle is moved during a process of performing the lane change may be about 333 meters ((Dlc)=2 times*5 sec/times*80 KPH+1 times*5 sec/times*80 KPH=333 meters). In addition, when the cases (e.g., a left turn, a right turn, a stop, a passage of the speed bump, etc.) in which deceleration of the vehicle is required does not occur, deceleration may be unnecessary. Therefore, when it is assumed that the deceleration distance (Ddec) is about zero and the preset distance (Dmargin) for stability of the lane change is about 100 meters, the distance (K=Dmin_+Dmargin) for the lane change may be 433 meters ((K=Dmin_require+Dmargin)=Dlc+Ddec+Dmargin=333+0+100=433meters), which is less than Devent.

Accordingly, the autonomous driving control vehicle100may be configured to determine a segment before the segments13and14(or segment15) corresponding to the road characteristics such as the dead-end, and the like, that is, a segment position before the distance (K=Dmin_+Dmargin)=433 meters) calculated to perform the lane change from an end of the lane change completion segment (segment10/11/12), as the timing position for starting the lane change. In the example ofFIG. 8, the autonomous driving control apparatus100may be configured to start the lane change after a zone of a segment4in which the self vehicle500is on a point before 433 meters from the event. However, since a lane marking is not present within the crossroad, the lane change may not be performed, and since the segments7,8, and9are within the crossroad, the lane change may be performed at a segment10immediately after the segments7,8, and9(or a segment4immediately before the segments7,8, and9).

As described above, according to the exemplary embodiments of the present disclosure, the autonomous driving control apparatus100may be configured automatically determine whether the lane change is required and effectively determine the timing of the lane change when the lane change is required, based on the shapes of the forward roads, the link relationship between the roads, the speed limit, the number of lane, the road characteristics (e.g., the crossroads, the crosswalks, the interchanges, the junctions, the speed bumps, the dead-ends, etc.), and the like, recognized from the detailed map while assisting the autonomous driving of the vehicle, thereby making it possible to support the driver to more conveniently, stably, and efficiently arrive at the destination by the aid of the autonomous driving.

Hereinabove, although the present disclosure is described by specific matters such as concrete components, and the like, exemplary embodiments, and drawings, they are provided merely for assisting in the entire understanding of the present disclosure. Therefore, the present disclosure is not limited to the exemplary embodiments. Various modifications and changes may be made by those skilled in the art to which the present disclosure pertains from this description. Therefore, the spirit of the present disclosure should not be limited to the above-described exemplary embodiments, and the following claims as well as all technical spirits modified equally or equivalently to the claims should be interpreted to fall within the scopes and spirits of the disclosure.