Automatic driving control device and method for vehicle

Abstract

The present disclosure relates to an automatic driving control method for a vehicle, the method comprising: selecting a target object in front of the vehicle based on driving information; generating a speed profile for maintaining a desired distance from the target object; calculating a desired acceleration based on the speed profile and a delay time of the vehicle; and controlling an actuator of the vehicle based on the desired acceleration.

Description

Technical Field

[0001] The present disclosure relates to a control technology for maintaining a distance between vehicles of an autonomous driving vehicle, and more particularly, to an autonomous driving control device and method for a vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Conventional technology for maintaining distance between vehicles is implemented through acceleration feedback control using the relative speed and distance to the preceding vehicle. Specifically, acceleration feedback control measures the relative speed and distance and multiplies the measured values ​​by a predetermined proportional gain, integral gain, and differential gain (hereinafter referred to as "control gain") in a proportional-integral-differential (PID) control format to calculate the required acceleration.

[0004] However, it has been found that conventional techniques for maintaining distance between vehicles are complicated in that control gains need to be set differently depending on the driving environment, and disadvantageous in that control is unstable, for example, when the control gain is not accurately adjusted, it is impossible to ensure that a collision with the preceding vehicle is avoided.

[0005] Furthermore, the control gain is a predetermined arbitrary value for uncertain future conditions, and therefore has limitations in flexibly responding to various driving environments. Summary of the Invention

[0006] The present disclosure relates to an automatic driving control device and method for a vehicle, which applies a longitudinal acceleration and deceleration curve in the form of a curve based on a third-order polynomial and the concept of convergence time to correct the required acceleration calculated according to a conventional technique for maintaining the distance between vehicles, thereby flexibly responding to various driving conditions while ensuring avoidance of collision with a preceding vehicle.

[0007] Technical problems solved by the form are not limited to the above technical problems, and other technical problems not described herein will become apparent to those skilled in the art through the following description.

[0008] In one form of the present disclosure, a method for controlling an autonomous driving of a vehicle includes: a driving environment identifier selecting a target object in front of the vehicle based on driving information; a velocity profile generator generating a velocity profile for maintaining a desired distance between the vehicle and the target object; an acceleration calculator calculating a desired acceleration based on the velocity profile and a delay time of the vehicle; and a vehicle controller controlling an actuator of the vehicle based on the desired acceleration.

[0009] The method may further include: a driving information processor calculating a target speed of the vehicle based on a speed limit of a road on which the vehicle is traveling and a speed and a direction of travel of a target object; and the driving information processor applying a predetermined weight to a predicted time to collision (TTC) between the vehicle and the target object to calculate a target convergence time.

[0010] The speed profile can be divided into acceleration and deceleration intervals and a constant speed interval based on the target convergence time as a boundary.

[0011] Generating the speed profile may include generating a longitudinal acceleration and deceleration profile in the form of a curve based on a third-order polynomial, taking into account a current speed, a target speed, and a target convergence time of the vehicle.

[0012] Generating the speed profile may include determining an initial slope of the longitudinal acceleration and deceleration profile using a speed error between a current speed of the vehicle and a target speed and a distance error between a relative distance to the target object and a desired distance.

[0013] Generating a speed curve may include calculating coefficients of respective orders of a third-order polynomial according to preset constraints, wherein the preset constraints may satisfy the following conditions: the speed at the target convergence time is the target speed, and the speed slope at the target convergence time is zero (0).

[0014] Calculating the required acceleration may include extracting a reaction speed corresponding to the delay time based on the longitudinal acceleration and deceleration curve; and calculating the required acceleration using a vehicle speed change between the reaction speed and a current speed during the delay time.

[0015] Controlling actuators of the vehicle may include maintaining a constant speed of the vehicle according to the target speed after the target convergence time.

[0016] The target convergence time may be variably adjusted according to the driving environment of the vehicle.

[0017] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order that the present disclosure may be better understood, various forms of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0019] Figure 1 is a block diagram illustrating an automatic driving control device for a vehicle in one form of the present disclosure;

[0020] Figure 2A and Figure 2B 1 is a diagram for respectively explaining a method of calculating a required distance, a target speed, and a target convergence time required for generating a speed profile according to one form of the present disclosure;

[0021] Figure 3 (A) and Figure 3 (B) are diagrams for respectively explaining speed curves generated by an automatic driving control device of a vehicle according to another form of the present disclosure;

[0022] Figure 4 is a diagram for explaining a method of calculating required acceleration by an automatic driving control device of a vehicle in another form of the present disclosure;

[0023] Figure 5A 、 Figure 5B 、 Figure 5C and Figure 5D are diagrams each illustrating an example of a longitudinal driving scenario in which a traffic light is recognized by an automatic driving control device of a vehicle according to one form of the present disclosure;

[0024] Figure 6A 、 Figure 6B and Figure 6C are diagrams each illustrating an example of a longitudinal driving scenario in which a preceding vehicle is recognized by an automatic driving control device of a vehicle in another form of the present disclosure; and

[0025] Figure 7 is a flowchart for illustrating an automatic driving control method for a vehicle according to one form of the present disclosure.

[0026] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0027] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0028] Hereinafter, exemplary forms of the present disclosure will be described in detail with reference to the accompanying drawings. However, these forms can be implemented in many different forms, and the present disclosure should not be interpreted as being limited to the forms set forth herein. Therefore, although the present disclosure is susceptible to various modifications and alternative forms, specific forms of the present disclosure are shown by way of example in the accompanying drawings, and the specific forms of the present disclosure will be described in detail herein. However, it should be understood that the present disclosure is not intended to limit the present disclosure to the specific forms disclosed, but on the contrary, the present disclosure will cover all modifications, equivalents, and alternative forms that fall within the ideas and scope of these forms.

[0029] Terms such as "first" and "second" used herein are merely used to describe various components, but these components are not limited by these terms. These terms are used only to distinguish one component from another. In addition, terms defined in consideration of the configuration and operation of the form are for illustrative purposes only and are not intended to limit the scope of the form.

[0030] The terms used in this specification are used to illustrate specific exemplary forms, rather than to limit the present disclosure. Therefore, unless otherwise clearly indicated in the context, the singular expressions in this specification include plural expressions. Moreover, terms such as "comprise" or "comprising" may be interpreted as representing certain features, numbers, steps, operations, constituent elements or combinations thereof, but may not be interpreted as excluding the presence of one or more other features, numbers, steps, operations, constituent elements or combinations thereof, or the possibility of adding one or more other features, numbers, steps, operations, constituent elements or combinations thereof.

[0031] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will be further understood that terms such as those defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an ideal or excessive sense unless expressly defined herein.

[0032] Hereinafter, an automatic driving control apparatus for a vehicle according to one form of the present disclosure will be described with reference to the accompanying drawings.

[0033] Figure 1 is a block diagram illustrating an automatic driving control device for a vehicle according to one form of the present disclosure.

[0034] Reference Figure 1 , the vehicle's automatic driving control device 100 may include a driving environment identifier 110 , a driving information processor 120 , a speed profile generator 130 , an acceleration calculator 140 and a vehicle controller 150 .

[0035] The driving environment identifier 110 may collect driving information of the vehicle through various sensors installed in the vehicle, may identify at least one driving environment of acceleration and deceleration based on the driving information, and may select a target object in front of the vehicle.

[0036] Here, driving information may include information about traffic lights in front of the vehicle, information about the behavior of the target object (stop or move), information about the vehicle's driving path, driving lane, current speed, and the longitudinal relative distance between the vehicle and the target object, etc.

[0037] The target object may include a preceding vehicle that has entered the driving lane or is scheduled to enter the driving lane, a pedestrian, an obstacle, or a virtual object generated at the position of a stop line on the road.

[0038] The various sensors may be implemented as, for example, a global positioning system (GPS) receiver 10, a map database (DB) 20, a navigation device 30, a sensor unit 40, and the like. However, this is exemplary, and at least one of the aforementioned components may be omitted, or other components may be additionally included. For example, information about traffic lights around the vehicle and information about preceding vehicles may also be collected using vehicle-to-everything (V2X) communication.

[0039] The GPS receiver 10 may be a sensor configured to estimate the geographic location of the vehicle, and may receive navigation messages from GPS satellites located above the earth, and may collect the current location (including latitude and longitude) of the vehicle in real time.

[0040] The map database 20 can store precise maps obtained by recording lane-by-lane road information in the form of a database (DB). The precise map can contain digital geographic information, lane information, road surface information, target location information, traffic signals, road signs, and the like, and can include road network data consisting of nodes and links. The map database 20 can be implemented as a storage medium such as a flash memory, a hard disk, a secure digital (SD) card, a random access memory (RAM), a read-only memory (ROM), or a network storage device, and can be automatically updated at predetermined intervals using wireless communication or manually updated by the user.

[0041] Upon receiving a departure point and a destination from a user, the navigation device 30 may search for a driving route of the vehicle in consideration of path cost (shortest distance, shortest time, etc.), and may display the driving route on a precise map to provide a route guidance service.

[0042] The sensor unit 40 may include an image sensor 41 and a distance measurement sensor 42 that sense information about the surrounding environment of the vehicle in real time, and a yaw rate sensor 43 and a speed sensor 44 that measure information about the state of the vehicle.

[0043] The image sensor 41 can collect information about images of the area surrounding the vehicle captured by the optical system, can recognize colors, and can perform image processing (noise removal, adjustment of image quality and color, file compression, etc.) on the information about the image to recognize lanes on the road, traffic lights (including signal forms such as red, yellow, and green), obstacles, etc.

[0044] The distance measurement sensor 42 can measure the distance between the vehicle and the measurement target, and can be implemented as, for example, radar (RADAR), laser radar (LIDAR), etc. RADAR uses electromagnetic waves to measure the distance, direction, relative speed, height, etc. of obstacles located around the vehicle, can identify obstacles at a long distance, and can cope with inclement weather. LIDAR can generate LIDAR data in the form of points from laser pulses reflected after being emitted on the road in front of the vehicle, and has precise resolution, and is therefore mainly used to detect objects around the vehicle.

[0045] The yaw rate sensor 43 can measure the yaw rate of the vehicle that is traveling automatically, and the speed sensor 44 can measure the traveling speed of the vehicle based on an output waveform of the wheel speed of the vehicle obtained in a differential manner.

[0046] The GPS receiver 10, map DB 20, navigation device 30 and sensor unit 40 described above can communicate with the driving environment identifier 110 through a vehicle network (NW) (not shown), and the vehicle network (NW) may include various in-vehicle communications such as controller area network (CAN), CAN with Flexible Data rate (CAN-FD), FlexRay, Media Oriented Systems Transport (MOST) or Time Triggered Ethernet (TT Ethernet).

[0047] The driving environment identifier 110 can use the image sensor 41 to identify information about traffic lights ahead of the vehicle, determine whether the vehicle is stopped at or has passed the stop line, and generate a virtual object for controlling the vehicle's stop. For example, the driving information processor 120 can generate a virtual preceding vehicle at the location of the stop line ahead of the vehicle.

[0048] The driving environment recognizer 110 may map the vehicle onto a driving path using the GPS receiver 10 , the map DB 20 , and the navigation device 30 , and may fuse information output from the sensor unit 40 to select a target object entering or scheduled to enter the driving lane of the vehicle.

[0049] The driving information processor 120 may process the driving information output from the driving environment identifier 110 and may set a predetermined distance (hereinafter referred to as a “required distance”) to be maintained from a target object during control of the vehicle in the longitudinal direction. des , and the required distance d for the vehicle to reach can be calculated des The target speed v des and converges to the target velocity v des The target convergence time consumed is t converge .

[0050] The driving information processor 120 may set the required distance d in consideration of the driver's driving tendency (eg, aggressiveness or defensiveness) and the minimum safe distance from the target object. des In this case, the required distance d des It can be set in advance by the driver or can be set by learning the driver's driving tendency during autonomous driving. des This may be determined by applying the riskiness of the identified target objects (eg, the relative importance of collision risks due to stop lines, pedestrians, and preceding vehicles).

[0051] The driving information processor 120 may consider the speed limit v of the road limit , based on the target object's velocity v target and the direction of travel to calculate the vehicle's target speed v des , and the target speed v can be expressed according to, for example, the following equation 1 des .

[0052] [Equation 1]

[0053] v des =min[v target cosθ,v limit ]

[0054] As shown in the above equation 1, the driving information processor 120 can calculate the speed limit v of the road limit and considering the velocity v of the target object target and the direction of travel to project the speed v onto the vehicle's path target The minimum value of cosθ is taken as the target speed v of the vehicle des Here, θ is the angle of the target object's travel direction relative to the vehicle's travel path.

[0055] The driving information processor 120 may apply a predetermined weight R to the predicted time to collision (TTC) between the vehicle and the target object to calculate a target convergence time t converge , and the target convergence time t can be expressed according to, for example, the following equation 2 converge .

[0056] [Equation 2]

[0057]

[0058] Here, the predetermined weight R can be an adjustment coefficient of the predicted time to collision (TTC), and can be variably adjusted within the range between 0 and 1 in real time (0 < R < 1) in consideration of the characteristics of the vehicle and the behavior of the target object. For example, when the vehicle in front that is attempting to change lanes from the driving lane to a surrounding lane abandons the attempt midway, the driving information processor 120 can decrease the value of R to reduce the target convergence time t converge .

[0059] In this case, the driving information processor 120 can compare the current speed v of the vehicle acquired through the speed sensor 44 ego with the target speed v of the vehicle calculated according to Equation 1 des to determine the predicted time to collision (TTC).

[0060] For example, when the target speed v of the vehicle des is lower than the current speed v ego , the driving information processor 120 can calculate the predicted time to collision (TTC) by the ratio of the longitudinal relative distance d between the vehicle and the target object target to the speed error (or longitudinal relative speed) between the current speed v of the vehicle ego and the target speed v des .

[0061] When the target speed v of the vehicle des is higher than the current speed v ego , the driving information processor 120 can calculate the predicted time to collision (TTC) by the ratio of the speed error between the target speed v and the current speed v of the vehicle des to the maximum acceleration a of the vehicle ego . max

[0062] For ease of understanding, the required distance, target speed, and target convergence time set and calculated by the driving information processor 120 will be described below with reference to FIG. 2

[0063] Figure 2A and Figure 2B are diagrams for explaining a method of calculating the required distance, target speed, and target convergence time for generating a speed curve according to one form of the present disclosure

[0064] Referring to Figure 2A , when red signal information is recognized through the traffic signal in front of the vehicle V1, the driving environment recognizer 110 can generate a virtual object at the position of the stop line 1 on the road, and the driving information processor 120 can consider the virtual object to be in a stopped state

[0065] ​The driving information processor 120 can set the required distance d from the virtual object. des , and the required distance d for vehicle V1 to reach can be calculated based on the behavior of the virtual object des The target speed v des For example, the virtual object is in a stopped state, so the target speed v of vehicle V1 is des Can be set to 0.

[0066] The driving information processor 120 can use the relative distance d between the vehicle V1 and the virtual object collected by the distance measurement sensor 42 to obtain the relative distance d between the vehicle V1 and the virtual object. target and the current speed v of vehicle V1 ego With target speed v des The target convergence time t is calculated by the longitudinal relative velocity between converge .

[0067] Reference Figure 2B , when a preceding vehicle V2 that is scheduled to enter the driving lane ahead of the vehicle V1 is detected, the driving information processor 120 may set a required distance d relative to the preceding vehicle V2. des , and the speed v of the preceding vehicle V2 can be considered target To calculate the target speed v of vehicle V1 des In this case, the velocity v of the preceding vehicle V2 can be considered. target and the speed v projected onto the travel path 3 of the vehicle V1 in the direction 2 target cosθ, and considering the road speed limit v limit To determine the target speed v des Here, θ is the angle of departure of the target object's traveling direction 2 relative to the vehicle's traveling path 3 .

[0068] The driving information processor 120 can use the target speed v of the vehicle V1 des With the current speed v ego The longitudinal relative speed between them and the relative distance d to the preceding vehicle V2 target or the maximum acceleration a of vehicle V1 max To calculate the target convergence time t converge .

[0069] The speed profile generator 130 may generate a speed profile for maintaining a desired distance from the target object. In this case, the target convergence time t may be used as a boundary. converge , the speed curve is divided into acceleration and deceleration intervals and a constant speed interval, and the speed curve generator 130 can consider the current speed v of the vehicle ego 、Target speed v des and target convergence time t converge, generate the longitudinal acceleration and deceleration curves in the form of curves based on third-order polynomials, and refer to Figure 3 (A) to Figure 3 (B) describes this in more detail.

[0070] Figure 3 (A) and Figure 3 (B) is a diagram for explaining a speed curve generated by an automatic driving control device of a vehicle according to another form of the present disclosure.

[0071] Figure 3 (A) shows a longitudinal deceleration curve when the target speed of the vehicle is lower than the current speed. Figure 3 (B) shows the longitudinal acceleration curve when the target speed of the vehicle is higher than the current speed. Here, the x-axis of the speed curve represents time, the y-axis of the speed curve represents speed, and it is assumed that the current speed v of the vehicle ego The corresponding time is 0.

[0072] Refer to it together Figure 3 (A) and Figure 3 (B), the speed curve generator 130 may generate a speed curve including a target convergence time t based on the boundary converge The speed curve of the deceleration (or acceleration) interval and the constant speed interval is shown, and the speed curve can be expressed according to the following equation 3.

[0073] [Equation 3]

[0074]

[0075] As shown in the above equation 3, the speed profile generator 130 can be configured to generate the speed profile at the time of reaching t converge Previously, the acceleration and deceleration motion of the vehicle was controlled according to the longitudinal acceleration and deceleration curves, and the vehicle could be converge After that, the vehicle is controlled to move at a constant speed to follow the target speed v des .

[0076] The speed profile generator 130 may consider the current speed v of the vehicle outputted by the driving information processor 120. ego 、Target speed v des and target convergence time t converge , a longitudinal acceleration and deceleration curve in the form of a curve based on a third-order polynomial is generated. However, this is exemplary, and the scope of the present disclosure is not limited thereto. Therefore, a longitudinal acceleration and deceleration curve based on an n-order polynomial (where n is a natural number equal to or greater than 4) may be generated.

[0077] In this case, the speed profile generator 130 may determine an initial slope C1 of the longitudinal acceleration and deceleration profile and may calculate coefficients C0, C2, and C3 of respective orders of a third-order polynomial according to preset constraints to generate the longitudinal acceleration and deceleration profile.

[0078] The speed profile generator 130 can use the current speed v of the vehicle according to the following equation 4: ego and target speed v des The velocity error between the target object and the desired distance d des and relative distance d target The initial slope C1 is calculated based on the distance error △d between them.

[0079] [Equation 4]

[0080] C1=-K v (v ego -v des )+K d (d target -d des )

[0081] Here, v ego is the current speed of the vehicle, v des is the target speed of the vehicle, d target is the relative distance to the target object, d des is the desired distance to the target object, K v is the speed gain, K d is the distance gain.

[0082] The speed curve generator 130 can generate the speed curve according to the following equation 5: converge The coefficients C0, C2, and C3 of each order of the third-order polynomial are calculated based on the preset constraints at t=0. Here, the preset constraints can satisfy the following conditions: the speed at t=0 is the current speed v of the vehicle. ego , target convergence time t converge The speed at which the vehicle is moving is the target speed v des , and the target convergence time t converge The velocity slope at is 0.

[0083] [Equation 5]

[0084] C0=v(0)=v ego

[0085]

[0086]

[0087] The speed profile generator 130 may calculate a third-order polynomial according to Equation 4 and Equation 5, and may generate a speed profile corresponding to t=0 and t=t based on the third-order polynomial. converge In this case, the target convergence time t can be variably adjusted according to the characteristics of the vehicle and the behavior changes of the target object. converge , therefore, the curves of the longitudinal acceleration and deceleration curves can also be changed.

[0088] The speed curve generator 130 can generate a speed curve that is divided into acceleration and deceleration intervals and a constant speed interval so that the speed of the vehicle is within the target convergence time t converge It converges to a constant velocity at , thus ensuring that collision with the target object is avoided.

[0089] The acceleration calculator 140 may take into account the generated longitudinal acceleration and deceleration profile and the vehicle's delay time t delay To calculate the required acceleration a des Here, the vehicle delay time t delay is the time it takes for the vehicle to actually behave in response to a speed control command applied to the actuator 50 from the vehicle controller 150, which will be described below. For example, the acceleration calculator 140 may measure the time between the time when the speed control command is executed by the vehicle controller 150 and the time when a response is received from at least one wheel included in the vehicle to extract the delay time t delay In addition, the acceleration calculator 140 may also measure the time for supplying driving pressure or braking pressure from the engine control unit (ECU) or brake control unit (BCU) of the actuator 50 to extract the delay time t delay .

[0090] Reference Figure 3 (A) and Figure 3 (B), the acceleration calculator 140 may read the longitudinal acceleration and deceleration curve generated by the speed curve generator 130, and may extract the delay time t with the vehicle based on the longitudinal acceleration and deceleration curve. delay The corresponding reaction rate v delay Here, the reaction rate v delay is the arbitrary speed and delay time t on the curve based on the cubic equation delay The corresponding speed.

[0091] The acceleration calculator 140 can obtain the delay time t according to the following equation 6: delay The current speed v of the vehicle during ego and reaction speed v delayThe vehicle speed change between φ and φ to calculate the required acceleration a for outputting the vehicle speed change to the vehicle controller 150. des .

[0092] [Equation 6]

[0093]

[0094] In this way, the acceleration calculator 140 can take into account the vehicle's delay time t delay , the required acceleration a des The acceleration calculator 140 is set to be smaller than the initial slope C1, so that it can respond to uncertain conditions that may occur in the future to a minimum extent. Therefore, during deceleration or acceleration, the acceleration calculator 140 can quickly respond to changes in the behavior of the target object.

[0095] According to another form, the acceleration calculator 140 may also use multiple points instead of a single point to calculate the required acceleration a. des , which will refer to Figure 4 Provide a description.

[0096] Figure 4 is a diagram for explaining a method of calculating required acceleration by an automatic driving control device of a vehicle according to another form of the present disclosure.

[0097] Figure 4 Another example of a longitudinal deceleration curve is shown in FIG. 1 , and the shape of the curve can be changed according to the coefficients of the respective terms of the third-order polynomial. Figure 3 Compared with the longitudinal deceleration curve shown in (A), Figure 4 In the longitudinal deceleration curve shown, due to the current speed v of the vehicle according to the driving environment ego 、Target speed v des and target convergence time t converge The difference in the initial slope C1 of the deceleration curve and the coefficient of each order term can be calculated, so that curves of different shapes can be formed.

[0098] Reference Figure 4 The acceleration calculator 140 can extract multiple points of the deceleration curve to calculate the required acceleration a according to the following equation 7: des .

[0099] [Equation 7]

[0100]

[0101] Here, t delay_1 is the first delay time of the vehicle, t delay_2 is the second delay time of the vehicle, v delay_1 is the first reaction speed corresponding to the first delay time, vdelay_2 is the second reaction speed corresponding to the second delay time, v ego is the current speed of the vehicle, α and β are the weights of each parameter.

[0102] Thus, the acceleration calculator 140 can use multiple points to set the required acceleration a des , thereby improving the reliability of autonomous driving control for uncertain situations that may occur in the future.

[0103] The vehicle controller 150 may calculate the required acceleration a based on the output from the acceleration calculator 140. des The driving pressure or braking pressure is transmitted to the actuator 50 to control the acceleration or deceleration of the vehicle.

[0104] The actuator 50 may include an engine control unit (ECU) that performs acceleration of the vehicle and a brake control unit (BCU) that performs deceleration, and may receive the required acceleration transmitted from the vehicle controller 150 and may control the engine and brakes of the vehicle.

[0105] In the following, reference will be made to 5A to 5D and Figures 6A to 6C A method of longitudinal control of a vehicle by an autonomous driving control apparatus of the vehicle is described according to one form.

[0106] 5A to 5D 1 and 2 are diagrams each illustrating an example of a longitudinal driving scenario in which a traffic light is recognized by an automatic driving control device of a vehicle in one form of the present disclosure.

[0107] Figure 5A A longitudinal driving scenario showing a situation where a red signal message is recognized at a long distance, Figure 5B Shown according to Figure 5A The speed curve shown is a longitudinal driving scenario in which a green signal message is recognized during deceleration. Figure 5C Shows when generating Figure 5A The speed curve shown is a longitudinal driving scenario in which a red signal message is detected late. Figure 5D Shown according to Figure 5C The speed profile shown is a longitudinal driving scenario for a situation where the vehicle comes to a complete stop.

[0108] Reference Figure 5A When the red signal information is recognized at a long distance, the speed profile generator 130 may generate a speed profile for the vehicle to converge within the target convergence time t converge The target speed of the vehicle is v des The target convergence time t converge is set to 0, and the vehicle delay time t can also be considered delayTo determine the required deceleration a des .

[0109] Reference Figure 5B , when based on Figure 5A The speed curve shown is during vehicle deceleration at time t a When a green signal is recognized, the speed profile generator 130 may use information about the behavior of a new target object in front of the vehicle and the speed limit v of the road. limit To reset the vehicle's target speed v des , and when the target speed v des Higher than the current speed v ego When the target convergence time t converge When it is longer, the acceleration curve can be compensated to reduce the required acceleration a des , when the target convergence time t converge When it is shorter, the acceleration curve can be compensated to increase the required acceleration a des , thereby flexibly responding to behavioral changes of the target object.

[0110] Reference Figure 5C , when judging based on Figure 5A The speed curve shown is during vehicle deceleration at time t b When the vehicle speed is not sufficiently reduced or the red signal information is recognized late, the deceleration curve can be compensated to shorten the target convergence time t converge To increase the required deceleration a des , which can control the autonomous driving to quickly slow the vehicle down.

[0111] Reference Figure 5D When the vehicle needs to stop completely, the speed curve can be the initial slope C1 and the required acceleration a des are all set to 0 and can remain stopped.

[0112] Figures 6A to 6C 1 and 2 are diagrams each illustrating an example of a longitudinal driving scenario in which a preceding vehicle is recognized by an automatic driving control apparatus of a vehicle according to another form of the present disclosure.

[0113] Figure 6A shows the target speed v of the vehicle relative to the preceding vehicle V2 in the driving path des Lower than the current speed v ego And the relative distance d from the preceding vehicle V2 target Less than the required distance d des Longitudinal driving scenario of the situation, Figure 6B shows the target speed v of the vehicle relative to the preceding vehicle V2 in the driving path des With the current speed vego The same or similar relative distance d to the preceding vehicle V2 target Less than the required distance d des Longitudinal driving scenario of the situation, Figure 6C shows the target speed v of the vehicle relative to the preceding vehicle V2 in the driving path des Higher than the current speed v ego And the relative distance d from the preceding vehicle V2 target Greater than the required distance d des Longitudinal driving scenario for the situation.

[0114] Reference Figure 6A When a preceding vehicle V2 traveling in front of the vehicle V1 at a lower speed than the vehicle V1 is identified, the speed profile generator 130 may generate a speed profile that enables the vehicle to converge within the target convergence time t converge decelerate to the target speed v des The vehicle's delay time t can be considered. delay To determine the required deceleration a des , and when the target convergence time t converge When the vehicle V2 is shorter and an immediate collision with the preceding vehicle V2 is expected, the deceleration curve can be compensated to increase the required deceleration a des , thereby avoiding a collision with the preceding vehicle V2.

[0115] Reference Figure 6B When the preceding vehicle V2 is identified as traveling in front of the vehicle V1 at the same speed as the vehicle V1, the speed profile generator 130 may generate a speed profile that temporarily decelerates the vehicle and then accelerates it to a target speed v of the vehicle. des At the target convergence time t converge Converges to the current velocity v ego In this case, the target convergence time t can be increased. converge , and can compensate for the deceleration and acceleration curves to reduce the required deceleration a des , thereby avoiding a collision with the preceding vehicle V2.

[0116] Reference Figure 6C When a preceding vehicle V2 traveling ahead of the vehicle V1 at a higher speed than the vehicle V1 is identified, the speed profile generator 130 may generate a speed profile that enables the vehicle to converge within the target convergence time t converge Accelerate to the target speed v des The acceleration curve of the vehicle can be considered. delay To determine the required deceleration a des , and the target convergence time t can be adjusted converge , to compensate the acceleration curve so that the target convergence time t convergeConverge quickly or slowly to flexibly respond to changes in the behavior of the preceding vehicle V2.

[0117] In the following, reference will be made to Figure 7 A method for controlling an autonomous driving system in accordance with one embodiment of the present invention is described.

[0118] Figure 7 is a flowchart for illustrating an automatic driving control method for a vehicle according to one form of the present disclosure.

[0119] Reference Figure 7 , an automatic driving control method for a vehicle may include: operation S710, selecting a target object in front of the vehicle based on driving information; operation S720, generating a speed curve for maintaining a desired distance from the target object; operation S730, calculating a required acceleration considering the speed curve and a delay time of the vehicle; and operation S740, controlling an actuator of the vehicle to perform acceleration or deceleration based on the required acceleration.

[0120] In operation S710, the autonomous driving control device 100 may recognize information about a traffic light in front of the vehicle through the image sensor 41 to determine whether the vehicle is stopped at or passed the stop line of the road, and may generate a virtual object for controlling the stop. The autonomous driving control device 100 may map the vehicle onto a driving path using the GPS receiver 10, the map DB 20, and the navigation device 30, and may fuse information output from the sensor unit 40 to select a target object (e.g., a preceding vehicle) that has entered or is scheduled to enter the vehicle's driving lane.

[0121] In operation S720, the autonomous driving control device 100 may process the driving information to set a desired distance from the target object and calculate a target speed for the vehicle to reach the desired distance and a target convergence time required to converge to the target speed. This has been described in detail above with reference to FIG. 2 , and thus will not be described again to avoid repetition.

[0122] In operation S720, the automatic driving control device 100 may generate a speed curve including a deceleration (or acceleration) interval and a constant speed interval based on a target convergence time as a boundary, and may generate a longitudinal acceleration and deceleration curve in the form of a curve based on a third-order polynomial taking into account the current speed, target speed, and target convergence time of the vehicle. In this case, the automatic driving control device 100 may determine the initial slope C1 of the longitudinal acceleration and deceleration curve, and may calculate the coefficients C0, C2, and C3 of each order of the third-order polynomial according to preset constraints to generate the longitudinal acceleration and deceleration curve. The above has been referred to Figure 3 This has been described in detail, so in order to avoid duplication, this will not be described again.

[0123] Then, in operation S730, the automatic driving control device 100 can read the longitudinal acceleration and deceleration curve, can extract the reaction speed corresponding to the delay time of the vehicle, and can obtain the vehicle speed change between the reaction speed of the vehicle during the delay time and the current speed to calculate the required acceleration.

[0124] In operation S740, the automatic driving control device 100 may transmit driving pressure or braking pressure based on the required acceleration to the actuator to control acceleration or deceleration of the vehicle.

[0125] Therefore, according to at least one form of the present disclosure, the concept of convergence time can be applied to generate a longitudinal acceleration and deceleration profile in the form of a curve based on a third-order polynomial, thereby ensuring avoidance of a collision with a preceding vehicle.

[0126] In addition, the required acceleration can be calculated taking into account the vehicle's delay time (reactivity) to respond to uncertain driving conditions that may occur in the future, and the convergence time can be adjusted to increase and decrease the required acceleration, thereby flexibly responding to various driving conditions.

[0127] Those skilled in the art will recognize that the effects that can be achieved using the present disclosure are not limited to the effects that have been specifically described above, and other advantages of the present disclosure will be more clearly understood from the detailed description.

[0128] The automatic driving control method of the aforementioned vehicle can be compiled as a program for running in a computer and can be stored in a computer-readable recording medium. Examples of computer-readable recording media include read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, hard disk, floppy disk, flash memory, optical data storage device, etc.

[0129] The computer readable recording medium can also be distributed on computer systems connected via a network so that the computer readable code is stored and executed in a distributed manner. Moreover, programmers in the field of the present disclosure can easily construct functional programs, codes, and code segments for implementing the present disclosure.

[0130] Although some cases related to exemplary forms have been described above, these forms can be changed in various forms. The technical features of the aforementioned forms can be implemented in various forms as long as they are compatible, and new forms can be implemented through these forms.

[0131] Those skilled in the art will appreciate that, without departing from the spirit and features of the present disclosure, the present disclosure can be carried out in other specific ways other than those set forth herein. Therefore, the above forms are to be interpreted in all aspects as illustrative and not restrictive.

Claims

1. A method for controlling an automatic driving of a vehicle, comprising: A driving environment identifier selects a target object in front of the vehicle based on driving information; a driving information processor calculating a target speed of the vehicle based on a speed limit of a road on which the vehicle is traveling and a speed and a traveling direction of the target object; The driving information processor applies a predetermined weight to a predicted time to collision (TTC) between the vehicle and the target object to calculate a target convergence time; A speed profile generator generates a speed profile for maintaining a desired distance between the vehicle and the target object; An acceleration calculator calculates a required acceleration based on the speed profile and a delay time of the vehicle; as well as A vehicle controller controls actuators of the vehicle based on the desired acceleration.

2. The method according to claim 1, wherein Based on the target convergence time, the speed curve is divided into acceleration and deceleration intervals and a constant speed interval.

3. The method according to claim 2, wherein: Generating a speed curve includes: Based on the current speed of the vehicle, the target speed, and the target convergence time, a longitudinal acceleration and deceleration curve in the form of a curve based on a third-order polynomial is generated.

4. The method according to claim 3, wherein: Generating a speed curve includes: An initial slope of the longitudinal acceleration and deceleration curve is determined using a speed error between a current speed of the vehicle and a target speed and a distance error between a relative distance to the target object and a desired distance.

5. The method according to claim 3, wherein: Generating a speed curve includes: Calculate the coefficients of each term of the third-order polynomial according to the preset constraints, The preset constraint conditions include the following conditions: the speed at the target convergence time is the target speed, and the speed slope at the target convergence time is zero, that is, 0.

6. The method according to claim 3, wherein: Calculating the required acceleration involves: extracting a reaction speed corresponding to the delay time based on the longitudinal acceleration and deceleration curve; and The required acceleration is calculated using a change in vehicle speed between the reaction speed and the current speed during the delay time.

7. The method according to claim 1, wherein Control actuators include: After the target convergence time, a constant speed of the vehicle is maintained according to the target speed.

8. The method according to claim 1, wherein The target convergence time is variably adjusted based on a driving environment of the vehicle.

9. A non-transitory computer-readable recording medium having a program recorded thereon, the program being configured to instruct a processor to perform the following operations: The driving environment identifier selects a target object in front of the vehicle based on the driving information; a driving information processor calculating a target speed of the vehicle based on a speed limit of a road on which the vehicle is traveling and a speed and a traveling direction of the target object; The driving information processor applies a predetermined weight to a predicted time to collision (TTC) between the vehicle and the target object to calculate a target convergence time; A speed profile generator generates a speed profile for maintaining a desired distance between the vehicle and the target object; An acceleration calculator calculates a required acceleration based on the speed profile and a delay time of the vehicle; as well as A vehicle controller controls actuators of the vehicle based on the desired acceleration.

10. An automatic driving control device for a vehicle, comprising: a driving environment identifier, which selects a target object in front of the vehicle based on driving information; a driving information processor that calculates a target speed of the vehicle based on a speed limit of a road on which the vehicle is traveling and a speed and a traveling direction of the target object, and applies a predetermined weight to a predicted time to collision (TTC) between the vehicle and the target object to calculate a target convergence time; a speed profile generator for generating a speed profile for maintaining a desired distance between the vehicle and the target object; an acceleration calculator for calculating a required acceleration based on the speed profile and a delay time of the vehicle; as well as A vehicle controller controls actuators of the vehicle based on the desired acceleration.

11. The apparatus according to claim 10, wherein Based on the target convergence time, the speed curve is divided into acceleration and deceleration intervals and a constant speed interval.

12. The apparatus according to claim 11, wherein The speed profile generator generates a longitudinal acceleration and deceleration profile in the form of a curve based on a third-order polynomial based on the current speed of the vehicle, the target speed, and the target convergence time.

13. The apparatus according to claim 12, wherein The speed profile generator determines an initial slope of the longitudinal acceleration and deceleration profile using a speed error between a current speed of the vehicle and a target speed and a distance error between a relative distance to the target object and a desired distance.

14. The apparatus according to claim 12, wherein The speed curve generator calculates the coefficients of each order of the third-order polynomial according to preset constraints, and The preset constraint conditions include the following conditions: the speed at the target convergence time is the target speed, and the speed slope at the target convergence time is zero, that is, 0.

15. The apparatus according to claim 12, wherein The acceleration calculator extracts a reaction speed corresponding to the delay time based on the longitudinal acceleration and deceleration curve, and calculates the required acceleration using a vehicle speed change between the reaction speed and the current speed during the delay time.

16. The apparatus according to claim 10, wherein The vehicle controller maintains a constant speed of the vehicle according to the target speed after the target convergence time.

17. The apparatus according to claim 10, wherein The target convergence time is variably adjusted based on a driving environment of the vehicle.

Images