Method and system for generating lane changing trajectory of vehicle

Abstract

A method and system for generating a lane change trajectory of a vehicle are disclosed, wherein a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention comprises: a lane change function execution step for executing a lane change function of the vehicle; a collision risk calculation step for calculating a collision risk with surrounding vehicles; and a lane change trajectory generation step for generating a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change changes according to the collision risk.

Description

Technology Field

[0001] The present invention relates to a method and system for generating a lane change trajectory of a vehicle. More specifically, the invention relates to a method and system for generating a lane change trajectory of a vehicle that enables the vehicle to generate an optimal lane change trajectory by adapting to the surrounding environment when changing lanes. Background Technology

[0002] In vehicles, Driver Assistance Systems (ADAS) provide support to the driver while driving for the driver's convenience. Among these, the lane change function provides a driver assistance method that safely assists in lane changes when the vehicle intends to change lanes.

[0003] In this regard, situations requiring lane changes arise at highway on / off ramps and other locations, and the need for lane-changing functions is increasing to reach desired destinations in such driving environments. In particular, frequent lane-changing attempts are becoming necessary in environments with high uncertainty, such as those with heavy traffic and low driving speeds.

[0004] In performing such lane change assistance functions, it is necessary to comply with the standards of international regulations regarding Automatically Commended Steering Functions (ACSF). According to the international ACSF regulations regarding lane changes (ACSF C), a lane change must be completed within a certain time (e.g., 10 seconds) in response to the driver's command.

[0005] In order to meet these standards, according to conventional technology, it was common to generate a lane change path by making the lateral velocity at the start of the lane change and the lateral velocity at the end of the lane change the same.

[0006] In this regard, referring to FIG. 1, in a conventional lane change function, as shown in FIG. 1 (a), for example, when a lane change is completed at a lateral distance of 4m, it has a symmetrical shape with respect to a point where the lateral travel distance over time is 2m, and as shown in FIG. 1 (b), the lateral velocity of the vehicle (v y ) is controlled to have the same lateral velocity at the start and end of the lane change.

[0007] That is, the lane change trajectory formed according to the conventional lane change assist method has a graph that is point-symmetric with respect to the midpoint of the lane change in terms of the lateral travel distance (y) over time (see FIG. 1 (a)), and the lateral velocity (v) over time y In the case of ), the graph becomes symmetrical with respect to the midpoint of the lane change (see Fig. 1 (b)). In addition, the lateral acceleration of the vehicle over time (a y In the case of ), the graph becomes point-symmetric with respect to the midpoint of the lane change (see (c) in Fig. 1).

[0008] According to such conventional lane change trajectory generation methods, if the initial lateral velocity is set low, the time required to change lanes becomes long, which not only causes inconvenience to the driver but also may violate the standards of international regulations requiring the lane change to be completed within a specified time.

[0009] In addition, if the initial lateral speed is set high to comply with the lane change time, a high lateral speed is required to return to the original lane in the event of a failed lane change due to the risk of collision with other vehicles traveling in adjacent lanes, making the lane change trajectory unsafe. Furthermore, there is a problem in that the risk of collision with other vehicles may increase as the vehicle encroaches on the adjacent lane when the collision risk is perceived.

[0010] Therefore, regarding the lane change assistance function of a vehicle, there is a need for a lane change trajectory generation method and system that can facilitate rapid lane changes while ensuring safety even in the event of a lane change failure. The problem to be solved

[0011] The present invention aims to solve the problems of the aforementioned prior art, and aims to provide a lane change trajectory generation method and a lane change trajectory generation system that generate a different lane change trajectory based on the risk of collision with surrounding vehicles when changing driving lanes.

[0012] In addition, the present invention aims to provide a lane change trajectory generation method and a lane change trajectory generation system that can improve driving convenience for the driver while complying with the standards of international regulations regarding lane changes.

[0013] However, the technical problems that the embodiments of the present invention aim to solve are not limited to the technical problems described above, and other technical problems may exist. means of solving the problem

[0014] As a technical means for achieving the above-mentioned technical problem, a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention is characterized by comprising: a lane change function execution step for executing a lane change function of the vehicle; a collision risk calculation step for calculating a collision risk with surrounding vehicles; and a lane change trajectory generation step for generating a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change changes according to the collision risk.

[0015] Additionally, the lane change trajectory generation step further includes a collision risk determination step for determining whether the collision risk exceeds a predetermined first threshold value, and if the collision risk exceeds the first threshold value, the lane change trajectory can be generated such that the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity.

[0016] In addition, when the collision risk is below the first threshold value, the lane change trajectory can be generated such that the lateral velocity of the vehicle at the start of the lane change is greater than the predetermined lateral velocity.

[0017] In addition, the lane change trajectory can be generated such that, from the start point of the lane change to the completion point, the graph of the vehicle's lateral velocity according to time before the intermediate point of the lane change is asymmetric to the graph of the vehicle's lateral velocity according to time after the intermediate point.

[0018] In addition, in the lane change trajectory generation step, the lane change trajectory can be generated based on a spline curve using two fifth-order polynomials.

[0019] In addition, after the lane change trajectory generation step, a vehicle control step for controlling the vehicle to drive along the generated lane change trajectory may be further included.

[0020] In addition, the lane change function execution step is performed by operating a lane change button unit installed on the vehicle, and the lane change trajectory can be generated so that the vehicle moves continuously in the lateral direction without stopping from the time of operation of the lane change button unit until the time when the lane change is completed.

[0021] In addition, the lane change trajectory generation step can generate the lane change trajectory such that the lane change is completed within a first predetermined time from the time of operation of the lane change button part.

[0022] In addition, the lane change trajectory generation step may generate the lane change trajectory such that the vehicle overlaps with one side lane of an adjacent lane within a second predetermined time from the time of operation of the lane change button part, and the lane change is completed within a third predetermined time from the time when the overlap with the one side lane begins.

[0023] Additionally, after the vehicle control step, the method may further include a collision risk recalculation step for recalculating the collision risk with surrounding vehicles; a lane return trajectory generation step for comparing the recalculated collision risk with a predetermined second threshold value and, if the collision risk exceeds the second threshold value, generating a return trajectory of the vehicle; and a vehicle return control step for controlling the vehicle to return to an existing lane according to the generated lane return trajectory.

[0024] A lane change trajectory generation system for a vehicle according to one embodiment of the present invention comprises: a sensor unit for detecting the surroundings of the vehicle; a vehicle information detection unit for detecting body information of the vehicle; a lane change button unit for executing a lane change function of the vehicle; and a control unit for generating a lane change trajectory of the vehicle and controlling the vehicle, wherein the control unit calculates the collision risk between the vehicle and surrounding vehicles when the lane change button unit is activated, and generates a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change changes according to the collision risk.

[0025] In addition, the control unit can determine whether the collision risk exceeds a predetermined first threshold value, and if the collision risk exceeds the first threshold value, generate the lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity.

[0026] In addition, the control unit can generate the lane change trajectory such that when the collision risk is below the first threshold value, the lateral velocity of the vehicle at the start of the lane change becomes greater than the predetermined lateral velocity.

[0027] In addition, the sensor unit may include at least one of a front camera, a front radar, and a corner radar mounted on the vehicle.

[0028] In addition, the surrounding vehicle is a vehicle approaching from the rear side of an adjacent lane to the lane in which the vehicle is traveling, and the control unit can calculate the collision risk between the vehicle and the surrounding vehicle from the information obtained by the sensor unit and the vehicle information detection unit.

[0029] In addition, the control unit can generate the lane change trajectory so that the lane change is completed within a first predetermined time from the time of operation of the lane change button unit.

[0030] Additionally, the system further includes an acceleration device, a braking device, and a steering device, and the control unit can control the vehicle according to a lane change trajectory generated by controlling at least one of the acceleration device, the braking device, and the steering device.

[0031] A method for generating a lane change trajectory of a vehicle according to another embodiment of the present invention is characterized by comprising: a lane change function execution step for executing a lane change function of the vehicle; a collision risk calculation step for calculating a collision risk with surrounding vehicles; and a lane change trajectory generation step for generating a lane change trajectory such that the heading angle of the vehicle at the start of the lane change changes according to the collision risk.

[0032] Additionally, the lane change trajectory generation step further includes a collision risk determination step for determining whether the collision risk exceeds a predetermined first threshold value, and if the collision risk exceeds the first threshold value, the lane change trajectory can be generated such that the heading angle of the vehicle at the start of the lane change becomes smaller than a predetermined heading angle.

[0033] In addition, when the collision risk is below the first threshold value, the lane change trajectory can be generated such that the heading angle of the vehicle at the start of the lane change becomes larger than the predetermined heading angle.

[0034] The means for solving the problem described above are merely exemplary and should not be interpreted as intended to limit the present invention. In addition to the exemplary embodiments described above, additional embodiments may exist in the drawings and the detailed description of the invention. Effects of the invention

[0035] According to the means for solving the problem of the present invention described above, a lane change trajectory generation method and a lane change trajectory generation system can be provided, which allow the lane change to be performed with an optimal trajectory by varying the lane change trajectory according to the risk of collision with surrounding vehicles when executing a lane change function.

[0036] In addition, according to the present invention, a lane change trajectory generation method and a lane change trajectory generation system can be provided that can promote driver safety and driving convenience while complying with the standards of international regulations regarding lane change functions.

[0037] However, the effects obtainable from this invention are not limited to those described above, and other effects may exist. Brief explanation of the drawing

[0038] Figures 1 (a) to (c) are graphs showing data on the lane change trajectory of a vehicle in a lane change assist function according to the prior art. FIG. 2 is a control flowchart of a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention. FIG. 3 is a control flowchart showing the lane change trajectory generation step in more detail in a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention. FIG. 4 is a control flowchart of a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention, showing a case where the vehicle returns to the original lane according to the driving risk during a lane change. FIGS. 5(a) and (b) are drawings showing the trajectory of a vehicle changing lanes according to driving risk in a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention. FIGS. 6 (a) to (c) are graphs showing the changes in the lateral travel distance, lateral velocity, and lateral acceleration of a vehicle over time when changing lanes according to the lane change trajectory generation method of the present invention. FIG. 7 is a graph illustrating a method of generating a trajectory using a spline in a lane change trajectory generation method according to one embodiment of the present invention. FIG. 8 is a control flowchart of a method for generating a lane change trajectory of a vehicle according to another embodiment of the present invention. FIG. 9 is a control configuration diagram schematically showing the configuration of a lane change trajectory generation system of a vehicle according to an embodiment of the present invention. Specific details for implementing the invention

[0039] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0040] Throughout this specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected," but also cases where they are "electrically connected" or "indirectly connected" with other elements interposed between them.

[0041] Throughout the entire specification, when a component is described as being located "on," "on top," "on top," "under," "on bottom," or "on bottom" of another component, this includes not only cases where the component is in contact with the other component but also cases where another component exists between the two components.

[0042] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0043] The present invention relates to a lane change trajectory generation method and system that generate an optimal lane change trajectory by adapting to the surrounding environment in which a vehicle is driving.

[0044] FIG. 2 is a control flowchart of a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention, and FIG. 3 is a control flowchart showing a lane change trajectory generation step more specifically in a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention.

[0045] First, referring to FIG. 2 of the present invention, a lane change trajectory generation method (S100) according to one embodiment of the present invention may include a lane change function execution step (S110) that executes a lane change function to cause a vehicle to change lanes.

[0046] This lane change function may be a function to assist the vehicle in changing lanes based on the driver's intention to change lanes, and may be executed, for example, by the driver operating a lane change button installed in the vehicle.

[0047] Next, a lane change trajectory generation method according to one embodiment of the present invention may include a collision risk calculation step (S120) for calculating the collision risk between a driving vehicle and surrounding vehicles.

[0048] Here, 'surrounding vehicle' may refer to a vehicle traveling in an adjacent lane where the driving vehicle intends to change lanes. More specifically, the surrounding vehicle may refer to a vehicle approaching from the rear side of the driving lane that has a possibility of colliding with the driving vehicle when the driving vehicle changes lanes.

[0049] That is, calculating the collision risk in the collision risk calculation step (S120) is intended to generate a lane change trajectory by reflecting the calculated collision risk when the driving vehicle changes lanes, as there may be a risk of collision with a vehicle approaching from the rear side when the driving vehicle changes lanes to an adjacent lane.

[0050] Specifically, the collision risk between a driving vehicle and surrounding vehicles can be calculated based on the Time to Collision (TTC) between the driving vehicle and surrounding vehicles. Alternatively, the collision risk may be calculated based on a probabilistic collision risk model based on Responsibility-Sensitive Safety (RSS). However, this is not limited to these methods, and other methods may be used as long as they can calculate the collision risk between surrounding vehicles and the driving vehicle.

[0051] Next, a lane change trajectory generation step (S130) may be performed to generate a lane change trajectory such that the lateral velocity at the start of the lane change changes according to the calculated collision risk. That is, in the lane change trajectory generation step (S130), based on the collision risk between surrounding vehicles and the driving vehicle, the lateral velocity at the start of the lane change in the lane change trajectory may be different in cases where the collision risk is high and cases where the collision risk is low.

[0052] Referring to FIG. 3, the lane change trajectory generation step (S130) can be examined in more detail. First, a collision risk determination step (S131) ​​can be performed to determine whether the calculated collision risk exceeds a predetermined first threshold value.

[0053] Here, the first threshold value may be a value that can be arbitrarily set. For example, when calculating the collision risk using a probabilistic collision risk model, the collision risk may be set to 10% as the first threshold value.

[0054] Meanwhile, in the collision risk judgment step (S131), if the collision risk with surrounding vehicles exceeds a predetermined first threshold value ('Yes' in S131), a lane change trajectory can be generated such that the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity (S132).

[0055] On the other hand, if the risk of collision with surrounding vehicles does not exceed a predetermined first threshold value ('No' in S131), a lane change trajectory can be generated such that the lateral velocity of the vehicle at the start of the lane change becomes greater than the predetermined lateral velocity (S133).

[0056] Here, 'a predetermined lateral velocity' may be the lateral velocity of the vehicle at the start of the lane change (initial lane change) in a lane change trajectory such that the graph regarding the lateral distance traveled and lateral velocity (or lateral acceleration) over time from the start of the lane change to the completion of the lane change when the lane change function is executed is symmetric (point symmetry or line symmetry).

[0057] In contrast, as in the embodiment of the present invention, a lane change trajectory in which the lateral velocity of the vehicle at the start of the lane change becomes greater than a predetermined lateral velocity and a lane change trajectory in which the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity may be a lane change trajectory in which the graph regarding the lateral distance traveled and lateral velocity (or lateral acceleration) over time from the start of the lane change to the completion is asymmetrical.

[0058] The lane change trajectory generated according to the embodiment of the present invention will be examined in more detail in the description of FIGS. 5 and FIGS. 6.

[0059] After a lane change trajectory is generated in the lane change trajectory generation step (S130), a vehicle control step (S140) for controlling the vehicle to drive according to the generated lane change trajectory may be performed.

[0060] As described above, according to an embodiment of the present invention, when a moving vehicle intends to change lanes, a lane change trajectory can be generated in which the lateral velocity at the start of the lane change is varied based on the risk of collision with surrounding vehicles.

[0061] Accordingly, when the risk of collision with surrounding vehicles is relatively low (when the collision risk is below the first threshold), the lateral speed at the start of the lane change can be increased to quickly enter the adjacent lane, thereby improving the driver's driving responsiveness and maneuverability.

[0062] In addition, when the risk of collision with surrounding vehicles is relatively high (when the collision risk exceeds the first threshold), the lateral velocity at the start of the lane change is reduced to delay entry into the adjacent lane, thereby extending the exposure of the lane change intention to surrounding vehicles (increasing the time for surrounding vehicles to recognize the illuminated turn signal of the moving vehicle), thereby enabling a safe lane change.

[0063] Meanwhile, while the vehicle is driving to change lanes according to the lane change trajectory generated in the lane change trajectory generation step (S130), the risk of collision may increase as surrounding vehicles in the rear side increase their speed. In this case, if the lane change continues, it may result in a collision with surrounding vehicles, so a situation may arise where the vehicle must stop the lane change and return to the original lane.

[0064] FIG. 4 is a control flowchart of a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention, showing a case where the vehicle returns to the original lane according to the driving risk during a lane change.

[0065] Specifically, after a vehicle control step (S140) is performed to control the vehicle according to the lane change trajectory generated in the lane change trajectory generation step (S130), a step (S150) to determine whether the risk of collision with surrounding vehicles exceeds a second threshold value may be performed.

[0066] Here, the second threshold value may be greater than the first threshold value. That is, if the first threshold value is exceeded, a lane change trajectory is generated to reduce the lateral velocity, and if the second threshold value, which is larger than the first, is exceeded, it is determined that there is a high risk of collision if the vehicle continues driving along the generated lane change trajectory, and the vehicle is controlled to return to the original lane. Meanwhile, the second threshold value may be an arbitrary value, just like the first threshold value; for example, when calculating the collision risk using a probabilistic collision risk model, the collision risk may be set to 30% as the second threshold value.

[0067] If the risk of collision with surrounding vehicles exceeds a second threshold ('Yes' in S150), a lane north trajectory generation step (S160) for generating a lane return trajectory is performed, and a step (S170) for controlling the vehicle according to the generated return trajectory may be performed.

[0068] Meanwhile, if the risk of collision with surrounding vehicles does not exceed the second threshold ('No' in S150), the vehicle may be controlled to change lanes according to the previously generated lane change trajectory (S140).

[0069] In this regard, according to the prior art, a lane change trajectory in the form of a symmetric graph is generated regardless of the risk of collision with surrounding vehicles. Therefore, when a vehicle needs to return to its original lane due to the risk of collision with surrounding vehicles, the lane return trajectory is generated unstably due to the sudden change of direction, which may cause discomfort to the driver. Additionally, there is a problem in that the vehicle may have already entered an adjacent lane at the time of determining whether to return to its original lane, which may further increase the risk of collision with surrounding vehicles.

[0070] In contrast, according to the lane change trajectory generation method (S100') of one embodiment of the present invention, when there is a risk of collision with surrounding vehicles (i.e., when the collision risk level exceeds a first threshold), the lateral velocity at the start of the lane change is made smaller than a predetermined lateral velocity (the lateral velocity of the vehicle according to the symmetric graph), so that when the collision risk level increases during the lane change (when the collision risk level exceeds a second threshold) and the vehicle must return to the original lane, the return trajectory can be generated as a safer trajectory. In addition, since the initial lateral velocity is reduced so that entry into the adjacent lane is performed relatively late, the vehicle's return control can be performed before entering the adjacent lane, thereby reducing the risk of collision with surrounding vehicles, and thus the effect of reducing the risk of collision with surrounding vehicles can also be achieved.

[0071] FIGS. 5(a) and (b) are drawings showing the trajectory of a vehicle changing lanes according to driving risk in a method for generating a lane change trajectory of a vehicle according to one embodiment of the present invention.

[0072] In FIG. 5, when a driver performs a lane change function to change lanes while the vehicle (1) is driving, it is determined whether the risk of collision with surrounding vehicles exceeds a predetermined first threshold value.

[0073] As shown in FIG. 5 (a), when the risk of collision with surrounding vehicles does not exceed a predetermined first threshold value, such as when there are no surrounding vehicles, the vehicle (1) can generate a lane change trajectory (A) having an initial lateral velocity greater than the lateral velocity (a predetermined lateral velocity) at the start of the lane change in the lane change trajectory (P) where the graph of the data regarding the lane change trajectory is set to be symmetrical.

[0074] Meanwhile, as shown in FIG. 5(b), when a surrounding vehicle (2) traveling in an adjacent lane where the vehicle (1) intends to change lanes is located within a predetermined distance of the rear side of the vehicle (1), the risk of collision with the surrounding vehicle (2) may exceed a first threshold value, and in this case, the vehicle (1) may generate a lane change trajectory (B) having an initial lateral velocity (a predetermined lateral velocity) that is smaller than the lateral velocity at the start of the lane change in the lane change trajectory (P) in which the graph of the data regarding the lane change trajectory is set to be symmetrical.

[0075] Meanwhile, in FIG. 5(b), when the risk of collision exceeds a second threshold value as surrounding vehicles (2) accelerate while the vehicle (1) is driving along the lane change trajectory (B), a lane return trajectory (R) can be generated to return to the original lane. In this case, since the initial entry speed is smaller than that of the original lane change trajectory (P) according to the B trajectory, it is possible to generate a gentle return trajectory, thereby improving driver safety and driving convenience.

[0076] FIGS. 6 (a) to (c) are graphs showing the changes in the lateral travel distance, lateral velocity, and lateral acceleration of a vehicle over time when changing lanes according to the lane change trajectory generation method of the present invention.

[0077] In the embodiment of FIG. 6, when following the lane change trajectory generated by the lane change trajectory generation method according to the embodiment of the present invention, the lane change is set to be completed when the lateral distance is 4m, and the lane change is exemplified as being completed within 8 seconds (a first predetermined time) from the start of the lane change. However, the present invention is not limited thereto, and the total lateral distance traveled from the start of the lane change to the completion of the lane change and the total lane change time may be set differently if the regulations regarding lane change functions (ACSF) are satisfied.

[0078] Meanwhile, in FIG. 6, the graph drawn with a dotted line represents a conventional lane change trajectory (Trajectory P) in which the graph regarding data during lane change is set to be symmetrical, and the graph drawn with a solid line represents a lane change trajectory (Trajectory A) in which the initial lateral velocity is set high when the collision risk is below a first threshold value in an embodiment of the present invention. In addition, the graph drawn with a dashed line represents a lane change trajectory (Trajectory B) in which the initial lateral velocity is set low when the collision risk is greater than the first threshold value in an embodiment of the present invention.

[0079] Referring to the graph of the lateral travel distance (y) over time with reference to FIG. 6(a), in the lane change trajectory generation method according to the embodiment of the present invention, when the collision risk is below the first threshold value, the midpoint of the lane change (lateral travel distance 2m point) can be passed after approximately 3 seconds (second predetermined time). That is, entry into an adjacent lane (where part of the driving vehicle overlaps with one side of the adjacent lane) can be performed after approximately 3 seconds.

[0080] On the other hand, when the collision risk exceeds the first threshold, the second predetermined time may be approximately 5 seconds. That is, the midpoint of the lane change (a point with a lateral travel distance of 2m) may be passed after approximately 5 seconds have elapsed. In this way, when the collision risk is relatively high, entry into the adjacent lane (where part of the moving vehicle overlaps with one side of the adjacent lane) may be performed at a relatively late time from the start of the lane change.

[0081] Fig. 6(b) shows the lateral velocity (v) from the start to the completion of the lane change. yThis is a graph showing data regarding ). As shown in Fig. 6(b), in the case of the graph of lateral velocity data (trajectory A) when the collision risk is below the first threshold, a lane change trajectory with a relatively large lateral velocity at the beginning of the lane change can be generated. On the other hand, after reaching the maximum lateral velocity, a graph in which the lateral velocity gradually decreases can be formed.

[0082] In the case of the graph (trajectory B) where the collision risk is greater than the first threshold, a lane change trajectory is generated in which the lateral velocity at the beginning of the lane change is relatively small, so it may take longer to reach the maximum lateral velocity. Meanwhile, after reaching the maximum lateral velocity, a graph in which the lateral velocity decreases relatively rapidly may be formed.

[0083] Fig. 6(c) shows the lateral acceleration of the vehicle (a) from the start to the completion of the lane change. y [Regarding the case of [the case of [the case of] and

[0084] As shown in the embodiments of FIG. 6 (a) to (c), the lane change trajectory generated according to the embodiment of the present invention, from the start point of the lane change to the completion point, may have a shape asymmetric to the graph of the vehicle's lateral travel distance, lateral velocity, or lateral acceleration according to time prior to the intermediate point of the lane change (the 4-second point of the graph) with respect to the intermediate point of the lane change.

[0085] Meanwhile, in the embodiment of FIG. 6, the second predetermined time (from the start of lane change to the start of entry into the adjacent lane) is exemplified as 3 seconds and 5 seconds depending on the collision risk, but is not limited thereto, and the second predetermined time in trajectory A and trajectory B can be set differently as long as the condition is satisfied that the time of entry into the adjacent lane is earlier than in trajectory P for trajectory A, and the time of entry into the adjacent lane is later than in trajectory P for trajectory B.

[0086] In addition, the time from the point of entry into an adjacent lane to the point of completion of the lane change can be set as a third predetermined time. That is, the first predetermined time (the time from the start of the lane change to the completion of the lane change) can be the sum of the second predetermined time and the third predetermined time.

[0087] In the embodiment of FIG. 6, since the first predetermined time is 8 seconds, the third predetermined time may be 5 seconds when following trajectory A (when the second predetermined time is 3 seconds), and the third predetermined time may be 3 seconds when following trajectory B (when the second predetermined time is 5 seconds).

[0088] Meanwhile, the embodiment of FIG. 6 illustrates that the first predetermined time is 8 seconds, but if the regulations regarding lane change functions are satisfied (e.g., completing the lane change within 10 seconds), it may be set differently. Meanwhile, in accordance with the standards of the regulations regarding lane change functions, the second predetermined time in the embodiment of the present invention may be in the range of approximately 3 to 5 seconds, and the third predetermined time may be within approximately 5 seconds.

[0089] FIG. 7 is a graph illustrating a method of generating a trajectory using a spline in a lane change trajectory generation method according to one embodiment of the present invention.

[0090] Referring to FIG. 7, the lane change trajectory according to the present invention may be a spline curve-based trajectory. For example, the lane change trajectory of the present invention may be based on a spline curve calculated by two fifth-order polynomials.

[0091] Referring more specifically to Fig. 7, the point at which the midpoint of the lateral travel distance (the entry point into the adjacent lane) is reached ...and the point at which the lane change ends It can be set as follows. In addition, the lateral velocity of the vehicle at the point where it reaches the midpoint of the lateral travel distance is It can be represented as. , and is a tuning parameter, for example, in the embodiment of FIG. 6 is 8 seconds, 3 seconds (when the initial lateral velocity is high according to trajectory A) or 5 seconds (when the initial lateral velocity is low according to trajectory B), It exemplifies that it is 0.937 m / s.

[0092] Here, the point of reaching the midpoint (the point of entry into the adjacent lane) The trajectory up to , from The trajectory up to (the point where the lane change ends) If so, each trajectory can be represented by the following two equations.

[0093]

[0094]

[0095] Here, spline boundary conditions can be the following 8 boundary conditions.

[0096] (1)... (Starting point horizontal position)

[0097] (2)... (Lateral velocity at start)

[0098] (3)... (Lateral acceleration at the start)

[0099] (4)... (Horizontal position at end point)

[0100] (5)... (Lateral velocity at the end point)

[0101] (6)... (Lateral acceleration at the end point)

[0102] (7)... (Lateral position at the point of reaching the midpoint)

[0103] (8)... (Lateral velocity at the point of reaching the midpoint)

[0104] Also, the time of reaching the midpoint ( The spline continuity conditions in ) can be the following four continuity conditions.

[0105] (i)... (Continuity of lateral position at the point of reaching the midpoint)

[0106] (ii)... (Continuous lateral velocity at the point of reaching the midpoint)

[0107] (iii)... (Continuous lateral acceleration at the point of reaching the midpoint)

[0108] (iv)... (Continuous side jerk at the point of reaching the midpoint)

[0109] Using the above equations, 12 systems of equations regarding boundary and continuity conditions can be formed for the lane change start time, the time of reaching the midpoint (the time of entry into the adjacent lane), and the lane change end time (conditions (1) to (8) regarding spline boundary conditions and conditions (i) to (iv) regarding spline continuity conditions). Meanwhile, at the time of reaching the midpoint ( The trajectory up to ) , from The trajectory up to In the two equations regarding , there are 12 constants (unknowns) (c 0,1 , c 1,1 , c 2,1 , c 3,1 , c 4,1 , c 5,1 , c 0,2 , c 1,2 , c 2,2 , c 3,2 , c 4,2 , c 5,2 Since it includes ), two fifth-degree polynomials can be obtained by solving 12 systems of equations.

[0110] A lane change trajectory according to an embodiment of the present invention can be generated by the spline curve calculated by the two fifth-order polynomials obtained in this way.

[0111] Meanwhile, when a lane change trajectory is generated by a conventional method such as a sine wave, as shown in the conventional technology of FIG. 1, the graphs of the vehicle's lateral travel distance, lateral velocity, and lateral acceleration over time are formed symmetrically around the midpoint.

[0112] In contrast, when generating a lane change trajectory based on a spline curve as in the embodiment of the present invention, an asymmetric graph for each data can be generated, and a lane change trajectory can be generated that allows the vehicle's lateral movement from the start to the completion of the lane change to be continuous while completing the lane change within a predetermined time in compliance with international regulations.

[0113] In other words, by generating an asymmetric lane change trajectory based on the risk of collision with surrounding vehicles while complying with international standards regarding lane change functions, a significant effect can be achieved that improves the driver's driving responsiveness and maneuverability and also increases driving convenience.

[0114] FIG. 8 is a control flowchart of a method for generating a lane change trajectory of a vehicle according to another embodiment of the present invention.

[0115] In the lane change trajectory generation method (S200) according to the embodiment of FIG. 8, the lane change function execution step (S210) and the collision risk calculation step (S220) can be performed substantially the same as in the preceding embodiment. On the other hand, the embodiment of FIG. 8 differs from the preceding embodiment in the step (S230) of generating a lane change trajectory based on the collision risk.

[0116] Specifically, according to the embodiment of FIG. 8, it is determined whether the collision risk exceeds a predetermined first threshold value (S231), and if it exceeds the first threshold value ('Yes' in S231), a lane change trajectory can be generated such that the heading angle of the vehicle at the start of the lane change becomes smaller than a predetermined heading angle (S232). On the other hand, if the collision risk does not exceed the first threshold value ('No' in S231), a lane change trajectory can be generated such that the heading angle of the vehicle at the start of the lane change becomes larger than a predetermined heading angle (S233).

[0117] Here, the predetermined heading angle may be the initial heading angle in a lane change trajectory having a graph of lateral displacement, lateral velocity, or lateral acceleration over time in a symmetrical form, as seen in the previous embodiment.

[0118] After the lane change trajectory is generated as described above, a vehicle control step (S240) for controlling the driving of the vehicle according to the generated lane change trajectory may be performed.

[0119] In the embodiments of FIGS. 2 to 4, a lane change trajectory is generated by controlling the vehicle's lateral speed to increase or decrease, based on the premise that the vehicle's longitudinal speed (straight-direction speed) is constant; however, in the embodiment of FIG. 8, a lane change trajectory is generated by controlling both the longitudinal speed and the lateral speed together to increase or decrease the vehicle's heading angle.

[0120] According to the embodiment of FIG. 8, by determining whether the collision risk exceeds a first threshold value, the initial heading angle of the vehicle is made larger than a predetermined heading angle or smaller than a predetermined heading angle according to the collision risk to generate a lane change trajectory, and the vehicle can be controlled according to the generated lane change trajectory.

[0121] By controlling in this way, the driving convenience of the driver when executing the lane change function can be enhanced, and the driving responsiveness and operability during lane changes can be improved.

[0122] FIG. 9 is a control configuration diagram schematically showing the configuration of a lane change trajectory generation system of a vehicle according to an embodiment of the present invention.

[0123] Referring to FIG. 9, a lane change trajectory generation system (100) according to one embodiment of the present invention may include a sensor unit (110) for detecting the surroundings of a vehicle, a vehicle information detection unit (120) for detecting vehicle body information, a lane change button unit (130) for executing a lane change function of a vehicle, and a control unit (140) for generating a lane change trajectory of a vehicle and controlling the vehicle.

[0124] The sensor unit (110) may include at least one of a front camera (10), a front radar (20), and a plurality of corner radars (30) installed on the vehicle. For example, a rear-side vehicle in an adjacent lane can be detected by the corner radar (30).

[0125] Meanwhile, the sensors included in the sensor unit (110) are not limited to those mentioned above, and the sensor unit (110) may further include other types of sensors for detecting the surroundings of the vehicle, such as lidar sensors, ultrasonic sensors, etc.

[0126] The vehicle information detection unit (120) can detect information about the vehicle, such as the speed and steering angle of the vehicle. For example, the control unit (140) can calculate the risk of collision between the vehicle and surrounding vehicles based on the information detected by the sensor unit (110) and the information detected by the vehicle information detection unit (120).

[0127] The lane change button section (130) may be installed inside the vehicle, and the driver may execute the lane change function of the vehicle by operating the lane change button section (130). The lane change button section (130) may be, for example, in the form of a protruding button, but is not limited thereto and may be in a form that can be touched on a display.

[0128] The control unit (140) can calculate the risk of collision between the driving vehicle and surrounding vehicles when the lane change button unit (130) is activated, and generate a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change changes according to the calculated risk of collision.

[0129] More specifically, the control unit (140) determines whether the collision risk exceeds a predetermined first threshold value, and if the collision risk exceeds the first threshold value, it can generate a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity. On the other hand, if the collision risk is less than or equal to the first threshold value, the control unit (140) can generate a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change becomes larger than a predetermined lateral velocity.

[0130] Additionally, the control unit (140) can generate a lane change trajectory such that the lane change is completed within a first predetermined time from the time the lane change button unit (130) is operated. Additionally, it can generate a lane change trajectory such that entry into an adjacent lane begins within a second predetermined time from the time the lane change button (130) is operated, and the lane change is completed within a third predetermined time from the time entry into the adjacent lane begins.

[0131] As the method by which the control unit (140) generates a lane change trajectory based on the collision risk has been explained in detail above, the specific explanation thereof will be omitted here.

[0132] Additionally, a lane change trajectory generation system (100) according to one embodiment of the present invention may further include an acceleration device (150) for accelerating a vehicle, a brake device (160) for decelerating or braking a vehicle, a steering device (170) for controlling the driving direction of a vehicle, and a display device (180) for displaying the driving status of a vehicle, etc.

[0133] Accordingly, by transmitting a control signal of the control unit (140) to the acceleration device (150), the brake device (160), or the steering device (170), the driver's driving can be assisted to perform a lane change function through acceleration, deceleration, or steering control of the vehicle.

[0134] In addition, the status of the driver assistance system regarding the lane change function can be displayed through the display device (180), or a warning to the driver can be displayed when there is a risk of collision with surrounding vehicles. Alternatively, the generated lane change trajectory can be displayed on the display to provide convenience to the driver.

[0135] According to the embodiments of the present invention as described above, when executing a lane change function that assists the driver's driving, convenience and driving stability can be provided to the driver by generating an optimal lane change trajectory by adapting to the surrounding environment.

[0136] In addition, according to the lane change trajectory generation method and lane change trajectory generation system of the embodiment of the present invention, driving responsiveness and maneuverability can be improved by increasing the entry speed when the risk of collision with surrounding vehicles is low, and driving convenience can be further increased by reducing lateral movement when canceling a lane change by reducing the lateral speed when the risk of collision with surrounding vehicles is high (situation with high uncertainty).

[0137] Furthermore, according to the lane change trajectory generation method and lane change trajectory generation system of the embodiment of the present invention, when a surrounding vehicle is approaching, a trajectory with a slow entry speed into an adjacent lane is generated, thereby allowing the intention to change lanes to be exposed to surrounding vehicles for a longer period of time. Additionally, by confirming the approach speed of surrounding vehicles for a long period of time, the intention of surrounding vehicles to yield can be clearly identified, thereby providing an effect that helps in determining whether to continue the lane change.

[0138] In addition, according to an embodiment of the present invention, by controlling the longitudinal angle and lateral velocity together in generating a lane change trajectory that creates a lane change trajectory with a different heading angle of the vehicle, the effect of being able to respond more flexibly to surrounding conditions and smoothly perform the lane change function can also be achieved.

[0139] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0140] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0141] 1: Vehicle 2: Nearby vehicles 10: Front camera 20: Forward radar 30: Corner Radar 100: Lane Change Trajectory Generation System 110: Sensor section 120: Vehicle information detection unit 130: Lane change button section 140: Control unit 150: Acceleration device 160: Brake device 170: Steering system 180: Display device

Claims

Claim 1 A method for generating a lane change trajectory of a vehicle, comprising: a lane change function execution step for executing a lane change function of the vehicle; a collision risk calculation step for calculating a collision risk with surrounding vehicles; and a lane change trajectory generation step for generating a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change changes according to the collision risk, wherein the lane change trajectory is generated such that, from the start point of the lane change to the completion point, the graph of the lateral velocity of the vehicle according to time before the intermediate point of the lane change is asymmetrical to the graph of the lateral velocity of the vehicle according to time after the intermediate point. Claim 2 A method for generating a lane change trajectory according to claim 1, wherein the lane change trajectory generation step further includes a collision risk determination step for determining whether the collision risk exceeds a predetermined first threshold value, and when the collision risk exceeds the first threshold value, the lane change trajectory is generated such that the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity. Claim 3 A method for generating a lane change trajectory according to claim 2, characterized in that when the collision risk is below the first threshold value, the lane change trajectory is generated such that the lateral velocity of the vehicle at the start of the lane change becomes greater than the predetermined lateral velocity. Claim 4 delete Claim 5 A method for generating a lane change trajectory according to claim 1, wherein, in the lane change trajectory generation step, the lane change trajectory is generated based on a spline curve using two fifth-order polynomials. Claim 6 A lane change trajectory generation method according to any one of claims 1 to 3 and 5, further comprising a vehicle control step for controlling a vehicle to drive along the generated lane change trajectory after the lane change trajectory generation step. Claim 7 A method for generating a lane change trajectory according to any one of claims 1 to 3 and 5, wherein the step of executing the lane change function is performed by operating a lane change button unit installed on the vehicle, and the lane change trajectory is generated such that the vehicle moves continuously in the lateral direction without stopping from the time of operation of the lane change button unit until the time when the lane change is completed. Claim 8 A method for generating a lane change trajectory according to claim 7, wherein the lane change trajectory generation step generates the lane change trajectory such that the lane change is completed within a first predetermined time from the time of operation of the lane change button part. Claim 9 A method for generating a lane change trajectory according to claim 8, wherein the lane change trajectory generating step generates the lane change trajectory such that the vehicle overlaps with one side lane of an adjacent lane within a second predetermined time from the time of operation of the lane change button part, and the lane change is completed within a third predetermined time from the time when the overlap with the one side lane begins. Claim 10 A lane change trajectory generation method according to claim 6, further comprising: a collision risk recalculation step for recalculating the collision risk with surrounding vehicles after the vehicle control step; a lane return trajectory generation step for generating a return trajectory of the vehicle when the recalculated collision risk is compared with a predetermined second threshold value and the collision risk exceeds the second threshold value; and a vehicle return control step for controlling the vehicle to return to an existing lane according to the generated lane return trajectory. Claim 11 A lane change trajectory generation system for a vehicle comprises: a sensor unit for detecting the surroundings of the vehicle; a vehicle information detection unit for detecting body information of the vehicle; a lane change button unit for executing a lane change function of the vehicle; and a control unit for generating a lane change trajectory of the vehicle and controlling the vehicle, wherein when the lane change button unit is activated, the control unit calculates the collision risk between the vehicle and surrounding vehicles and generates a lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change changes according to the collision risk, wherein the control unit generates the lane change trajectory such that, from the start point of the lane change to the completion point, the graph of the lateral velocity of the vehicle according to time prior to the intermediate point of the lane change is asymmetrical to the graph of the lateral velocity of the vehicle according to time after the intermediate point. Claim 12 A lane change trajectory generation system according to claim 11, wherein the control unit determines whether the collision risk exceeds a predetermined first threshold value, and if the collision risk exceeds the first threshold value, generates the lane change trajectory such that the lateral velocity of the vehicle at the start of the lane change becomes smaller than a predetermined lateral velocity. Claim 13 A lane change trajectory generation system according to claim 12, wherein the control unit generates the lane change trajectory such that when the collision risk is below the first threshold value, the lateral velocity of the vehicle at the start of the lane change becomes greater than the predetermined lateral velocity. Claim 14 A lane change trajectory generating system according to any one of claims 11 to 13, wherein the sensor unit comprises at least one of a front camera, a front radar, and a corner radar mounted on the vehicle. Claim 15 A lane change trajectory generation system according to any one of claims 11 to 13, wherein the surrounding vehicle is a vehicle approaching from the rear side of an adjacent lane of the lane in which the vehicle is traveling, and the control unit calculates the collision risk between the vehicle and the surrounding vehicle from information obtained by the sensor unit and the vehicle information detection unit. Claim 16 A lane change trajectory generation system according to any one of claims 11 to 13, wherein the control unit generates the lane change trajectory such that the lane change is completed within a first predetermined time from the time of operation of the lane change button unit. Claim 17 A lane change trajectory generating system according to any one of claims 11 to 13, further comprising an acceleration device, a braking device, and a steering device, wherein the control unit controls the vehicle according to a lane change trajectory generated by controlling at least one of the acceleration device, the braking device, and the steering device. Claim 18 delete Claim 19 delete Claim 20 delete

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