JP7703004B2 - Lane change decision system and method, and non-transitory computer - Google Patents

Description

The present invention relates to a system and method for determining minimum risk, and a non-transitory computer-readable medium, and to a system and method for determining minimum risk for lane changing, and a non-transitory computer-readable medium.

In recent years, autonomous vehicles have been developing rapidly, and the Society of Automotive Engineers (SAE International) and the National Highway Traffic Safety Administration (NHTSA) have divided autonomous vehicles into five levels based on the degree of driver assistance and automation. Here, a level 3 autonomous vehicle indicates that the autonomous driving system has the ability to recognize the environment, but the driver can intervene appropriately.

To improve the safety of autonomous driving, the United Nations World Forum for Harmonization of Vehicle Regulations has issued UN R157 as a compliance standard for level 3 autonomous vehicles, which aims to require autonomous vehicles to have a mechanism for transferring driving rights and minimizing risk when an emergency occurs in the autonomous vehicle (e.g., system failure) or when the autonomous driving does not meet the activation standard. Conventional technologies lack the ability to perform minimum risk decisions in the process of lane changing, so how to make autonomous vehicles lane changing meet the provisions of UN R157 has become a goal of efforts by relevant parties.

To solve the above problems, the present invention provides a system and method for determining minimum risk for lane changing, and a non-transitory computer-readable medium, and the system architecture, method, and steps enable a self-driving vehicle to perform minimum risk determination during the process of lane changing.

According to one embodiment of the present invention, a minimum risk determination system for lane change is provided, the minimum risk determination system being provided in a vehicle and including at least one processor, the at least one processor including: an extrinsic risk interval calculation module for calculating a collision time with a forward object at a current position at any one of a plurality of time points after the vehicle enters a lane change decision, calculating a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the collision time, and calculating an extrinsic risk interval based on the greater of the lateral acceleration and the maximum normal lateral acceleration and the lateral distance at which the vehicle changes lanes to the target lane; and a system failure determination module for determining whether a system of the vehicle has failed at any one time point and whether a lateral module of a backup system of the vehicle is effective. and an autonomous driving activation condition confirmation module for confirming whether the autonomous driving activation condition is met based on whether the state of the vehicle driver at any point in time is available; and determining whether an exogenous risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk have occurred in the vehicle, determining that an exogenous risk has occurred when the system is in a normal state and the relative vertical distance between the vehicle and a forward object at a certain point in time is equal to or less than the exogenous risk interval, determining that a system failure risk has occurred when the system has failed at a certain point in time but the lateral module of the backup system is active, determining that an autonomous driving activation condition has occurred when the system is normal and the relative vertical distance at a certain point in time is greater than the exogenous risk interval but the autonomous driving activation condition is not met. a lateral component calculation unit that calculates an emergency lateral acceleration of the vehicle by calculating a lane change time for the vehicle to change lanes to the target lane at the certain time point when any of the exogenous risk, the system failure risk, and the risk of the automatic driving activation condition not being satisfied, and calculates a lateral component of the vehicle with the emergency lateral acceleration or the normal lateral acceleration; a drivable space calculation unit that calculates a drivable space in the target lane at the certain time point when any of the exogenous risk, the system failure risk, and the risk of the automatic driving activation condition not being satisfied, with a lateral distance, a lateral component, and a rear object speed of a rear object in the target lane; and a decision execution unit that performs a minimum risk decision when any of the risk of exogenous risk, the risk of system failure, and the risk of not satisfying the autonomous driving start conditions occurs, and performs a decision execution unit that performs a minimum risk decision when any of the risk of exogenous risk, the risk of system failure, and the risk of not satisfying the autonomous driving start conditions occurs, and performs a lane change with the lateral component to enter the drivable space or decelerates to a standstill, and performs a lane change with the lateral component to enter the drivable space or moves the vehicle along the original trajectory of the lane change decision to another time point for at least a certain period of time when the autonomous driving start conditions are not satisfied persistently.

This allows the system to determine whether an exogenous risk, a system failure risk, or a risk of not satisfying the autonomous driving activation conditions has occurred by calculating the exogenous risk interval and detecting whether the system has failed and whether the autonomous driving activation conditions are satisfied, and it allows lane changes to comply with the provisions of UN R157 and improves safety by calculating the drivable space and performing a minimum risk decision.

According to the above embodiment of the minimum risk determination system for lane change, the exogenous risk interval calculation module:
,,
and
where _Tc is the time to impact, _Dr is the relative longitudinal distance between the vehicle and the forward object, _vh is the own vehicle speed of the vehicle, _vt is the forward object speed of the forward object, _ay is the lateral acceleration of the vehicle calculated at the time to impact, _ayrgmax is the maximum normal lateral acceleration, _aymax is the greater of the lateral acceleration and the maximum normal lateral acceleration, _Dy is the lateral distance, _vx is the longitudinal component of the own vehicle speed, and _DF is the extrinsic risk interval.

According to the above embodiment of the minimum risk determination system for lane changing, when the judgment unit judges that an exogenous risk or a system failure risk occurs at a certain time, the lateral component calculation unit:
and
where T _Lc is the lane change time, L is the length of the vehicle, t _{ISO limit} is the legal no lane crossing time, and a _y ^E is the emergency lateral acceleration.

According to the lane-changing minimum risk determination system of the above embodiment, if there are no obstacles in the drivable space at a certain point in time and the emergency lateral acceleration is equal to or less than the upper limit of emergency lateral acceleration set by regulations, the vehicle can change lanes and enter the drivable space, and if not, the vehicle will decelerate until it stops.

According to the above embodiment of the minimum risk determination system for lane change, when the judgment unit determines that a risk of non-satisfaction of the autonomous driving activation conditions has occurred at a certain point in time, the lateral component calculation unit can calculate the lateral component at the normal lateral acceleration.

According to the lane change minimization risk determination system of the above embodiment, if an obstacle is present in the drivable space, the vehicle can wait until the obstacle moves away before entering the drivable space with normal lateral acceleration.

According to the above embodiment of the minimum risk determination system for lane changing, the vehicle will change lanes to the right one after another into drivable spaces on the shoulder of the road and slow down until it comes to a stop.

According to the above embodiment of the minimum risk decision system for lane change, when the judgment unit determines at a certain point in time that a risk of non-satisfaction of the autonomous driving activation conditions has occurred, the decision execution unit can issue a warning within at least the above-mentioned certain period of time.

According to another embodiment of the present invention, a method for determining minimum risk of lane change is provided, comprising: an extrinsic risk interval calculation step of causing an extrinsic risk interval calculation module of at least one processor to calculate a collision time with a forward object at a current position at any one of a plurality of time points after the vehicle enters into a lane change decision, calculate a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the collision time, and calculate an extrinsic risk interval based on the greater of the lateral acceleration and the maximum normal lateral acceleration and the lateral distance at which the vehicle changes lanes to the target lane; a system failure determination step of causing a system failure determination module of the at least one processor to determine whether a system of the vehicle has failed at any point in time and whether a lateral module of the vehicle's backup system is effective; and an automatic driving start condition determination step for causing the automatic driving start condition confirmation module to confirm whether the automatic driving start condition is satisfied based on whether the state of the vehicle driver at any time is available; and a judgment unit of the at least one processor to judge whether an exogenous risk, a system failure risk, and an automatic driving start condition non-satisfaction risk have occurred in the vehicle, and to determine that an exogenous risk has occurred if the system is in a normal state and the relative vertical distance between the vehicle and a forward object at a certain time is less than or equal to the exogenous risk interval, to determine that a system failure risk has occurred if the system has failed at a certain time but the lateral module of the backup system is effective, and to determine that an automatic driving start condition is not satisfied if the system is normal and the relative vertical distance at a certain time is greater than the exogenous risk interval, a risk determination step of determining that a risk of unsatisfied autonomous driving activation conditions has occurred; a lateral component calculation step of causing a lateral component calculation unit of the at least one processor to calculate an emergency lateral acceleration of the vehicle by calculating a lane change time for the vehicle to change lanes to a target lane at the certain time point when any of an exogenous risk, a system failure risk, and a risk of unsatisfied autonomous driving activation conditions has occurred, and to calculate a lateral component of the vehicle with the emergency lateral acceleration or a normal lateral acceleration; and a drivable space calculation module of the at least one processor to calculate a drivable space at the certain time point with a lateral distance, a lateral component, and a rear object speed of a rear object in the target lane when any of an exogenous risk, a system failure risk, and a risk of unsatisfied autonomous driving activation conditions has occurred. and a minimum risk decision execution step of causing the decision execution unit of the at least one processor to make a minimum risk decision when any of an exogenous risk, a system failure risk, and a risk of not satisfying an automatic driving start condition occurs, causing the vehicle to change lanes with a lateral component to enter the drivable space or to decelerate to a standstill when an exogenous risk or a system failure risk occurs, and causing the vehicle to change lanes with a lateral component to enter the drivable space or to move to another time point along the original trajectory of the lane change decision for at least a certain period of time when a risk of not satisfying an automatic driving start condition occurs, and causing the target lane, the lateral component of the lane change, and the drivable space at the other time point to be reconfirmed if the automatic driving start condition is persistently not satisfied.

According to the above embodiment of the lane change minimum risk determination method, the extrinsic risk interval calculation module:
,,
and
where _Tc is the time to impact, _Dr is the relative longitudinal distance between the vehicle and the forward object, _vh is the own vehicle speed of the vehicle, _vt is the forward object speed of the forward object, _ay is the lateral acceleration of the vehicle calculated at the time to impact, _ayrgmax is the maximum normal lateral acceleration, _aymax is the greater of the lateral acceleration and the maximum normal lateral acceleration, _Dy is the lateral distance, _vx is the longitudinal component of the own vehicle speed, and _DF is the extrinsic risk interval.

According to the lane change minimum risk determination method of the above embodiment, when the judgment unit determines that an exogenous risk or a system failure risk occurs at a certain time, the lateral component calculation unit:
and
where T _Lc is the lane change time, L is the length of the vehicle, t _{ISO limit} is the legal no lane crossing time, and a _y ^E is the emergency lateral acceleration.

According to the above-described embodiment of the method for determining the minimum risk of lane changing, if there are no obstacles in the drivable space at a certain point in time and the emergency lateral acceleration is equal to or less than the upper limit of emergency lateral acceleration set by regulations, the vehicle can change lanes and enter the drivable space, and if the opposite is true, the vehicle will decelerate until it stops.

According to the method for determining the minimum risk of lane change in the above-mentioned embodiment, when the judgment unit determines that a risk of not satisfying the autonomous driving activation conditions has occurred at a certain point in time, the lateral component calculation unit can calculate the lateral component at the normal lateral acceleration.

According to the lane change minimization risk determination method of the above embodiment, if there is an obstacle in the drivable space, the vehicle can wait until the obstacle moves away before entering the drivable space with normal lateral acceleration.

According to the method for determining the minimum risk of lane changing in the above embodiment, the vehicle changes lanes to the right one after another into drivable spaces on the shoulder of the road and decelerates until it comes to a stop.

According to the method for determining the minimum risk of lane change in the above-mentioned embodiment, when the judgment unit determines at a certain point in time that a risk of non-satisfaction of the autonomous driving start conditions has occurred, the decision execution unit can issue a warning within at least the above-mentioned certain period of time.

According to another embodiment of the present invention, a non-transitory computer readable medium is provided, storing a computer program for causing at least one processor to: calculate a time to impact with a forward object at a current position at any one of a plurality of time points after the vehicle enters a lane change decision; calculate a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the time of impact; calculate an extrinsic risk interval based on the greater of the lateral acceleration and the maximum normal lateral acceleration and the lateral distance at which the vehicle changes lanes to the target lane; determine whether a system of the vehicle has failed at any one time point and whether a lateral module of a backup system of the vehicle is enabled; and ... Based on whether the state of the vehicle at any time is available, confirm whether the autonomous driving activation condition is satisfied, and judge whether an exogenous risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk have occurred in the vehicle. If the system is in a normal state and the relative vertical distance between the vehicle and the forward object at a certain time is less than or equal to the exogenous risk interval, it is judged that an exogenous risk has occurred. If the system has failed at a certain time but the lateral module of the backup system is effective, it is judged that a system failure risk has occurred. If the system is normal and the relative vertical distance at a certain time is greater than the exogenous risk interval but the autonomous driving activation condition is satisfied, it is judged that an exogenous risk has occurred. If the condition is not satisfied, it is determined that a risk of not satisfying the autonomous driving activation condition has occurred; if any of the exogenous risk, the system failure risk, and the risk of not satisfying the autonomous driving activation condition has occurred, an emergency lateral acceleration of the vehicle is calculated by calculating a lane change time for the vehicle to change lanes to the target lane at the certain time point, and a lateral component of the vehicle is calculated with the emergency lateral acceleration or the normal lateral acceleration; if any of the exogenous risk, the system failure risk, and the risk of not satisfying the autonomous driving activation condition has occurred, a drivable space at the certain time point is calculated with the lateral distance, the lateral component, and the rear object speed of the rear object in the target lane; If either the risk of system failure or the risk of not satisfying the autonomous driving activation conditions occurs, a minimum risk decision is made; if an exogenous risk or a risk of system failure occurs, the vehicle is caused to change lanes using the lateral component to enter the drivable space or is decelerated to a standstill; if a risk of not satisfying the autonomous driving activation conditions occurs, the vehicle is caused to change lanes using the lateral component to enter the drivable space or is moved to another point in time according to the original trajectory of the lane change decision for at least a certain period of time; and if the autonomous driving activation conditions are not persistently satisfied, the target lane, the lateral component of the lane change, and the drivable space at the other point in time are reconfirmed.

FIG. 1 is a system block diagram illustrating a minimum risk determination system for lane changing according to one embodiment of the present invention. FIG. 2 is a schematic diagram of the lane change minimum risk determination system according to the embodiment of FIG. 1 installed in a vehicle and applied to a road; 4 is a block flow diagram illustrating a method for determining a minimum risk of lane changing according to another embodiment of the present invention. 4 is a first detailed flowchart illustrating a method for determining a minimum risk of lane changing according to the embodiment of FIG. 3; 4 is a second detailed flowchart illustrating the method for determining a minimum risk of lane changing according to the embodiment of FIG. 3 . 4 is a third detailed flowchart illustrating the method for determining a minimum risk of lane changing according to the embodiment of FIG. 3 . 4 is a fourth detailed flowchart illustrating the method for determining a minimum risk of lane changing according to the embodiment of FIG. 3 .

In the following, in order to disclose and clearly explain several embodiments of the present invention in the drawings, numerous practical details are described in the following description. However, those skilled in the art should understand that in other embodiments of the present invention, these practical details are not required and are not intended to limit the present invention. In addition, in order to simplify the drawings, certain conventional structures and elements are simply and diagrammatically shown in the drawings, and overlapping elements may be indicated by the same or similar numbers.

The terms first, second, and third in the text are used merely to describe different elements or components, and do not place any restrictions on the elements/components themselves; therefore, the first element/component can be read as the second element/component, and the combinations of elements/components/mechanisms/modules in the text are not ordinary or conventional combinations generally known in this field, and whether the combination relationships can be easily completed by a person skilled in the art cannot be determined based on whether the elements/components/mechanisms/modules themselves are conventional.

Please refer to Figures 1 and 2. Figure 1 is a system block diagram showing a minimum risk determination system for lane change 1000 according to one embodiment of the present invention, and Figure 2 is a schematic diagram of the minimum risk determination system for lane change 1000 according to the embodiment of Figure 1 installed in a vehicle CH and applied to a road. The minimum risk determination system for lane change 1000 is provided in the vehicle CH, and the minimum risk determination system for lane change 1000 includes at least one processor 1100. The at least one processor 1100 includes an exogenous risk interval calculation module 1110, a system failure judgment module 1120, an automatic driving start condition confirmation module 1130, and a determination module 1140.

The extrinsic risk interval calculation module 1110 calculates the collision time with the forward object CT at the current position at any one of a plurality of time points after the vehicle CH enters the lane change decision, calculates the lateral acceleration at which the vehicle CH changes lanes from the current position to the target lane at the collision time, and calculates the extrinsic risk interval D _F by the larger of the lateral acceleration and the maximum normal lateral acceleration and the lateral distance D _y at which the vehicle CH changes lanes to the target lane. The system failure determination module 1120 determines whether the system of the vehicle CH has failed at any one time point and whether the lateral module of the backup system of the vehicle CH is valid. The automatic driving activation condition confirmation module 1130 checks whether the automatic driving activation condition is met based on whether the driver's state of the vehicle CH at any one time point is available.

The determination module 1140 includes a judgment unit 1141, a lateral component calculation unit 1142, a drivable space calculation unit 1143, and a decision execution unit 1144. The judgment unit 1141 judges whether an exogenous risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk occur in the vehicle CH, and judges that an exogenous risk has occurred when the relative vertical distance D _r between the vehicle CH and the forward object CT at the certain time is less than or equal to the exogenous risk interval D _F (i.e. D _F ≧D _r ) if the system is in a normal state, judges that an exogenous risk has occurred when the system has failed at a certain time but the lateral module of the backup system is valid, and judges that an autonomous driving activation condition non-satisfaction risk has occurred when the system is normal and the relative vertical distance D _r at the certain time is greater than the exogenous risk interval D _F (i.e. D _r >D _F ) but the autonomous driving activation condition is not satisfied.

The lateral component calculation unit 1142 calculates the emergency lateral acceleration of the vehicle CH by calculating the lane change time for the vehicle CH to change lanes to a target lane at a certain point in time when any of the exogenous risk, the system failure risk, and the risk of non-satisfaction of the automatic driving activation conditions occurs, and calculates the lateral component v _y of the vehicle CH with the emergency lateral acceleration or the normal lateral acceleration.

When any of exogenous risk, system failure risk, and risk of non-satisfaction of automatic driving activation conditions occurs, the drivable space calculation unit 1143 calculates the drivable space S1 at a certain point in time using the lateral distance D _y , the lateral component v _y , and the rear object speed v _r of the rear object CR in the target lane.

The decision execution unit 1144 makes a minimum risk decision when any of an exogenous risk, a system failure risk, and a risk of not satisfying the autonomous driving activation conditions occurs, and when an exogenous risk or a system failure risk occurs, causes the vehicle CH to change lanes with a lateral component v _y to enter the drivable space S1, or to decelerate to a standstill, and when a risk of not satisfying the autonomous driving activation conditions occurs, causes the vehicle CH to change lanes with a lateral component v _y to enter the drivable space S1, or to move to another point in time according to the original trajectory of the lane change decision for at least a certain period of time, and if the autonomous driving activation conditions are persistently not satisfied, re-checks the target lane, the lateral component v _y of the lane change, and the drivable space S1 at the said other point in time.

Thus, by calculating the exogenous risk interval D _F and detecting whether the system has failed and whether the autonomous driving activation conditions have been satisfied, it is possible to determine whether an exogenous risk, a system failure risk, or a risk of not satisfying the autonomous driving activation conditions has occurred, and by calculating the drivable space S1 and performing a minimum risk determination, the lane change satisfies the provisions of UN R157, thereby improving safety. Details of the lane change minimum risk determination system 1000 will be described in detail below.

At least one processor 1100 of the lane change minimum risk determination system 1000 is installed in the vehicle CH. Specifically, the number of processors 1100 is two, one processor 1100 has a control program for the system (main system), and the other processor 1100 has a control program for the backup system. The processor 1100 may be, for example, a central processor (CPU), a digital signal processor (DSP), a microprocessor (MPU), a microcontroller (MCU), etc., and the processor 1100 can be programmed to achieve a specific function. In this embodiment, each processor 1100 is divided into an exogenous risk interval calculation module 1110, a system fault judgment module 1120, an automatic driving start condition confirmation module 1130, and a decision module 1140 after being programmed, and different program parts in the decision module 1140 may also be divided into a judgment unit 1141, a lateral component calculation unit 1142, a drivable space calculation unit 1143, and a decision execution unit 1144. In addition to the above functions, the processor 1100 can also be programmed to achieve general control and image processing functions of the vehicle CH, but is not limited thereto. In one embodiment, the main system may include multiple on-vehicle mechanisms, such as braking mechanisms and steering mechanisms, which can be operated via the main system's control program to achieve vehicle operation, and the backup system's control program can control these mechanisms, or there are two sets of the same mechanism, one set controlled by the main system and one set controlled by the backup system.

The minimum risk determination system 1000 for lane change may include a driver state detection device 1200 and a sensing module 1300. The sensing module 1300 may include a plurality of cameras for detecting the external environment of the vehicle CH, and may capture the current environment through the cameras, thereby calculating information such as the relative longitudinal distance D _r between the vehicle CH and the forward object CT, the forward object speed v _t of the forward object CT, the current position of the vehicle CH in the lane L1, and the lane line, and the sensing module 1300 may include a radar for detecting obstacles near the vehicle CH, and is not limited to the above. The driver state detection device 1200 detects the state of the driver's eyes, posture, seat belt, etc., and the automatic driving start condition confirmation module 1130 is used to determine whether the automatic driving start condition is met. In this embodiment, the automatic driving start condition may be, for example, the PALS state machine of ISO21202, UNR79, or Taiwan VACC 47-2 standard.

The extrinsic risk interval calculation module 1110 calculates:
,,
and
can be calculated, where _Tc is the collision time, _Dr is the relative longitudinal distance between the vehicle CH and the forward object CT, _vh is the own vehicle speed of the vehicle CH, _vt is the forward object speed of the forward object CT, _ay is the lateral acceleration of the vehicle CH calculated at the collision time, _ayrgmax is the maximum normal lateral acceleration, _aymax is the larger of the lateral acceleration and the maximum normal lateral acceleration, _Dy is the lateral distance, _vx is the longitudinal component of the own vehicle speed, and _Df is the extrinsic risk interval. It is particularly important to note that in a general state, the position the vehicle is trying to reach is located on the center line of the target lane, so the lateral distance is the distance between the vehicle center and the center line of the target lane.

As shown in Figures 1 and 2, when the vehicle CH is in an automatic driving state, the system determines whether to change lanes based on the road conditions of the current lane (e.g., lane L1) in which the vehicle CH is located and the adjacent lane (e.g., lane L2). After the system makes a lane change decision, the vehicle CH starts automatic lane change. During the lane change process, the exogenous risk interval calculation module 1110 constantly detects the vehicle speed _vh of the vehicle CH, the relative longitudinal distance _Dr between the vehicle CH and the forward object CT, and the forward object speed _vt of the forward object CT, and thus:
The impact time (i.e., _Tc ) is obtained by calculating the lateral acceleration of the vehicle CH at the impact time, which can then be compared with the maximum normal lateral acceleration prescribed by the regulations.
By calculating the above, the larger of the lateral acceleration and the maximum normal lateral acceleration is obtained, and in terms of time and space,
By calculating the above, the extrinsic risk interval D _F is obtained, and if any object including the forward object CT is within the extrinsic risk interval D _F , if the vehicle CH continues to travel in the manner (e.g., the speed) originally planned by the system, there is a possibility of a collision risk occurring, so the route needs to be changed to improve the travel safety. In this way, the lateral component v _y and the drivable space S1 can be calculated, and a new trajectory can be planned.

When the judgment unit 1141 determines that an exogenous risk or a system failure risk occurs at a certain time, the horizontal component calculation unit 1142:
and
where T _Lc is the lane change time, L is the length of the vehicle CH, t _{ISO limit} is the lane crossing prohibition time according to regulations, and a _y ^E is the emergency lateral acceleration. After the drivable space S1 is determined, the vehicle CH can be prepared to start moving laterally into the drivable space S1. Since the vehicle CH also moves forward longitudinally when moving laterally, the lane change time must take into account the difference between the relative longitudinal distance D _r between the vehicle CH and the forward object CT and the length L of the vehicle CH, and the relationship between the vehicle speed v _h and the forward object speed v _t , and it is necessary to consider entering the drivable space S1 within half the collision time, and it is necessary to consider the lane crossing prohibition time according to regulations limited by the regulations of each country.
The maximum one among them is taken as the lane change time according to the above, and is used as the basis for calculating the emergency lateral acceleration. Then, the lateral component v _y is calculated based on the emergency lateral acceleration. At this time, the vehicle CH needs to move laterally at a high speed due to the high probability of occurrence of the risk, so as to avoid the occurrence of a collision. In addition, the lateral component calculation unit 1142 can further calculate the steering angle corresponding to this lateral component v _y .

In addition, when the judgment unit 1141 determines that a risk of not satisfying the automatic driving start condition has occurred at a certain point in time, the horizontal component calculation unit 1142 similarly
However, the lateral component v _y can be calculated using a general normal lateral acceleration. In this case, when the autonomous driving activation condition is not satisfied, only driving is disabled, indicating that the system is normal and there is no exogenous risk, so the vehicle CH may change lanes using the normal lateral acceleration.

When planning the drivable space S1, the drivable space calculation unit 1143 refers to the rear object speed _vr of the rear object CR to calculate the front longitudinal extension distance D _NLF of the vehicle CH (particularly the head of the vehicle CH) and the rear longitudinal extension distance D _NLR of the vehicle CH (particularly the tail of the vehicle CH) in the drivable space S1. As a result, based on the length of the vehicle CH, the lateral component v _y and longitudinal component v _x of the vehicle CH, the rear object speed _vr , and the lateral distance D _y between the vehicle CH and the target lane,
Calculate the front longitudinal extension distance D _NLF , and
The rear longitudinal extension distance D _NLR can be calculated by: In one embodiment, if the travelable space is in a lane or a shoulder, the width of the travelable space may be the width of the lane or the width of the shoulder. If the shoulder is not included, the outer boundary (the boundary far from the vehicle) of the travelable space is a curb, and the width of the travelable space is the vehicle width or is fixed at 3.5 meters, in which case the center line of the target lane is half the vehicle width on the inside of the curb or 1.75 meters on the inside of the curb, but is not limited thereto. In the present invention, the target lane refers to an adjacent lane or a space in which adjacent vehicles can travel, and is not limited to a lane with lane markings.

As shown in Fig. 2, if the vehicle CH starts to change lanes from lane L1 to lane L2, and the forward object CT suddenly decelerates or brakes at a certain time, and the current position of the vehicle CH is again on lane L1, the relative longitudinal distance D _r at this time is less than or equal to the exogenous risk interval D _F , the judgment unit 1141 judges that an exogenous risk has occurred, and calculates the lateral component v _y by calculating the emergency lateral acceleration at this time, and calculates the drivable space S1 on the lane L2 adjacent to the lane L1. If the decision execution unit 1144 judges that there is no obstacle in the drivable space S1 on the lane L2 at this time, and the emergency lateral acceleration is less than or equal to the upper limit of the emergency lateral acceleration set by the law, it can notify the steering mechanism that the vehicle CH will change lanes and enter the drivable space S1 on the lane L2, and conversely, notify the brake mechanism that the vehicle CH will decelerate until it stops. Specifically, if the emergency lateral acceleration is equal to or less than the upper emergency lateral acceleration limit (e.g., 4 meters/second squared) set by the regulations, the vehicle enters the drivable space S1 on the lane L2 with the lateral component v _y and steering angle calculated by the emergency lateral acceleration, which indicates that the emergency lateral acceleration is safe and permitted by regulations. If the emergency lateral acceleration is greater than the upper emergency lateral acceleration limit set by the regulations, the vehicle enters the drivable space S1 on the lane L2, which indicates that the emergency lateral acceleration is unsafe, and the vehicle does not change lanes, and directly decelerates until it stops. Also, if there is an obstacle in the drivable space S1 on the lane L2, which indicates that there is a possibility of collision when entering the drivable space S1, the vehicle cannot change lanes, and directly decelerates until it stops. It should be noted that, since the lateral control of the system is active, the vehicle CH's body returns to the positive direction once before decelerating to a stop, and then decelerates to a stop, and at this time, there is a possibility of collision, so the deceleration can be set to 4 meters/second squared.

Furthermore, the vehicle CH can change lanes to the right one after another into the drivable space S1 on the shoulder L3, and decelerate until it stops. In detail, when the vehicle CH moves from lane L1 to lane L2, i.e., into the drivable space S1 on lane L2, it can move to the right onto the shoulder L3, that is, the target lane at this point is the shoulder L3, and at this time, the drivable space S1 on the shoulder L3 and the emergency lateral acceleration are recalculated to cause the vehicle CH to change lanes to the shoulder L3. As shown in FIG. 2, after the lane of the vehicle CH is changed into the drivable space S1 on the shoulder L3, it can decelerate until it stops. Since the shoulder L3 is relatively safe, the deceleration at this time may be less than the square of 4 meters/second, for example, from the square of 1 meter/second to the square of 3 meters/second.

In another hypothetical case, the vehicle CH starts to change lanes from the lane L1 to the lane L2, the system fails but the lateral module of the backup system is effective, at this time, the judgment unit 1141 judges that the system failure risk occurs, calculates the lateral component v _y by calculating the emergency lateral acceleration at this time, and calculates the drivable space S1 on the lane L2 adjacent to the lane L1. If there is no obstacle in the drivable space S1 at this time and the emergency lateral acceleration is below the emergency lateral acceleration upper limit set by the law, the vehicle can change lanes to enter the drivable space S1 on the lane L2, or conversely, decelerate until it stops. It should be noted that the minimum risk determination when the system failure risk occurs is similar to the minimum risk determination when the exogenous risk occurs, and when the system failure risk occurs, the processor 1100 including the backup system control program may perform related calculations.

In a further hypothetical case, the vehicle CH starts to change lanes from the lane L1 to the lane L2, and at some point the driver becomes unconscious due to the driver, and the driver state detection device 1200 detects the driver's eyes and then notifies the automatic driving start condition confirmation module 1130 of the driver abnormality, and then the automatic driving start condition confirmation module 1130 confirms that the automatic driving start condition is not satisfied. If the system is normal at this time and no exogenous risk occurs, the judgment unit 1141 determines that the risk of automatic driving start condition not being satisfied has occurred. In the minimum risk determination, the drivable space S1 on the lane L2 at this time can be calculated. At this time, there is no obstacle in the drivable space S1 on the lane L2, and the lane can be changed to enter the drivable space S1 with the lateral component v _y calculated with the normal lateral acceleration, and if there is an obstacle in the drivable space S2 on the lane L1 at this time, after the obstacle leaves, the lane can be changed to enter the drivable space S1 on the lane L2 with the lateral component v _y calculated with the normal lateral acceleration. At this time, since the system is normal, the vehicle CH can turn back and wait for the obstacle to leave before it can enter the drivable space S1 on the lane L2. After entering the drivable space S1 on the lane L2, the drivable space S1 on the shoulder L3 is calculated, and the lane is changed with the lateral component v _y calculated by the normal lateral acceleration, that is, the vehicle CH can change lanes one after another to the right and into the drivable space S1 on the shoulder L3, and finally decelerate until it stops.

In another minimum risk decision, when the judgment unit 1141 determines that the risk of unsatisfaction of the autonomous driving activation conditions has occurred, it moves to the aforementioned another time point according to the original trajectory of the lane change decision for at least a certain time, and then checks whether the autonomous driving activation conditions are not met persistently. In detail, the original trajectory refers to the steering angle, speed, acceleration, etc. of changing lanes from lane L1 to lane L2 in the lane change decision, and since the system is normal and there is no exogenous risk, the decision execution unit 1144 can issue a warning within the aforementioned at least a certain time, for example, for 10 seconds. Within 10 seconds, the movement of the original trajectory may be completed, that is, the vehicle CH has changed lanes from lane L1 to lane L2. At this time, whether the autonomous driving activation conditions are not met persistently indicates that the driver does not have the ability to react, and should stop on the side of the road to avoid the occurrence of a danger. Therefore, the current position of the vehicle CH at the aforementioned different time point is the lane L2, the target lane is the shoulder L3, and the drivable space S1 on the shoulder L3 can be calculated, and the vehicle decelerates until it stops, and the deceleration can be less than 3 meters/second squared. It is particularly important to note that while the embodiment of FIG. 2 is an example in which the shoulder L3 is added to the two lanes L1 and L2, in other embodiments having multiple lanes, the drivable space is one in which the vehicle can move to the shoulder or into the curb one after the other to the right.

Please refer to FIG. 3. FIG. 3 is a block flowchart showing a method 2000 for determining minimum risk of lane change according to another embodiment of the present invention. The method 2000 for determining minimum risk of lane change includes a step 2100 for calculating an exogenous risk interval, a step 2200 for judging a system fault, a step 2300 for judging an automatic driving start condition, a step 2400 for judging a risk, a step 2500 for calculating a lateral component, a step 2600 for calculating a drivable space, and a step 2700 for proceeding with a minimum risk determination. The details of the minimum risk determination system 1000 for lane change will be described below with reference to the method 2000 for determining minimum risk of lane change in FIG. 1 and FIG. 2.

In the extrinsic risk interval calculation step 2100, the extrinsic risk interval calculation module 1110 of at least one processor 1100 calculates the collision time with the forward object CT at the current position at any one of multiple time points after the vehicle CH enters the lane change decision, calculates the lateral acceleration at which the vehicle CH changes lanes from the current position to the target lane at the collision time, and calculates the extrinsic risk interval D _F based on the greater of the lateral acceleration and the maximum normal lateral acceleration and the lateral distance D _y at which the vehicle CH changes lanes to the target lane.

In the system failure determination step 2200, the system failure determination module 1120 of the at least one processor 1100 determines whether a system of the vehicle CH has failed at any time and whether the lateral module of the backup system of the vehicle CH is enabled.

In the autonomous driving start condition determination step 2300, the autonomous driving start condition confirmation module 1130 of the at least one processor 1100 determines whether the state of the driver of the vehicle CH at any point in time is available and checks whether the autonomous driving start condition is met.

In the risk judgment step 2400, the judgment unit 1141 of the at least one processor 1100 judges whether the exogenous risk of the vehicle CH, the system failure risk, and the risk of not satisfying the automatic driving activation conditions have occurred. When the system is in a normal state, if the relative vertical distance D _r between the vehicle CH and the forward object CT at a certain point in time is less than the exogenous risk interval D _F (i.e., D _F ≧ D _r ), it determines that an exogenous risk has occurred; when the system has failed at a certain point in time but the lateral module of the backup system is effective, it determines that a system failure risk has occurred; when the system is normal and the relative vertical distance D _r at a certain point in time is greater than the exogenous risk interval D _F (i.e., D _r > D _F ), but the automatic driving activation conditions are not satisfied, it determines that a risk of the automatic driving activation conditions has occurred.

In the lateral component calculation step 2500, the lateral component calculation unit 1142 of the at least one processor 1100 calculates the emergency lateral acceleration of the vehicle CH by calculating the lane change time for the vehicle CH to change lanes to the target space at the certain point in time when any of an exogenous risk, a system failure risk, and a risk of non-satisfaction of the autonomous driving activation conditions occurs, and calculates the lateral component v _y of the vehicle CH at the emergency lateral acceleration or the normal lateral acceleration.

In the drivable space calculation step 2600, the drivable space calculation unit 1143 of the at least one processor 1100 calculates the drivable space S1 at the certain point in time when any of exogenous risk, system failure risk, and risk of non-satisfaction of automatic driving activation conditions occurs, using the lateral distance D _y , lateral component v _y , and rear object speed v _r of the rear object CR in the target lane.

In the minimum risk determination proceeding step 2700, the decision execution unit 1144 of the at least one processor 1100 performs a minimum risk determination when any of an exogenous risk, a system failure risk, and a risk of not satisfying an autonomous driving activation condition occurs. When an exogenous risk or a system failure risk occurs, the vehicle CH is caused to change lanes with a lateral component v _y to enter the drivable space S1 or to decelerate to a standstill, and when a risk of not satisfying an autonomous driving activation condition occurs, the vehicle CH is caused to change lanes with a lateral component v _y to enter the drivable space S1 or to move to another time point according to the original trajectory of the lane change decision for at least a certain period of time, and if the autonomous driving activation condition is not persistently satisfied, the target lane at the other time point, the lateral component v _y of the lane change, and the drivable space S1 are confirmed.

Please refer to FIG. 4. FIG. 4 is a first detailed flowchart showing the lane change minimization risk determination method 2000 according to the embodiment of FIG. 3. First, in step S01, the system (i.e., the main system of the automatic driving) operates normally, and in step S02, it is confirmed whether the driver intervenes, that is, whether the driver intervenes and operates the vehicle CH by himself. If so, it proceeds to step S03, and the driving right is returned to the driver; if not, it proceeds to step S04, and it is confirmed whether to enter into lane change determination, that is, the system determines whether to change lanes according to the current road conditions. If not, it returns to step S01, and the system continues to operate; if so, it proceeds to step S05, and it is determined whether the system has failed.

If the system failure judgment module 1120 determines in step S05 that the system has failed, it proceeds to step S06, where it further checks whether the backup system has failed. If so, it proceeds to step S09, where it decelerates until the vehicle CH stops, and if not, it proceeds to step S07, where it is checked by the system failure judgment module 1120 whether the lateral module of the backup system has failed. If the lateral module has failed, it proceeds to step S09, where it decelerates until the vehicle CH stops, and if the lateral module is valid, it proceeds to step S08, where it is determined by the judgment unit 1141 that a system failure risk has occurred in the vehicle CH.

If the system failure judgment module 1120 judges in step S05 that the confirmation system is normal and not faulty, it proceeds to step S10, and calculates the exogenous risk interval D _F by the exogenous risk interval calculation module 1110. The calculation method of the exogenous risk interval D _F is the same as above, so it will not be described again. Then, it proceeds to step S11, and the judgment unit 1141 compares whether the relative vertical distance D _r between the vehicle CH and the forward object CT is less than the exogenous risk interval D _F (i.e., whether D _F ≧D _r is satisfied). If so, it proceeds to step S12, and the judgment unit 1141 judges that an exogenous risk has occurred in the vehicle CH; if not, it proceeds to step S13, and the automatic driving start condition confirmation module 1130 judges whether the driver is available. If the driver is available, it returns to step S01, and the system continues to operate; if the driver is not available, it proceeds to step S14, and the judgment unit 1141 judges that an automatic driving start condition unsatisfied risk has occurred in the vehicle CH.

Please refer to Fig. 5, and also refer to Fig. 1 and Fig. 2. Fig. 5 is a second detailed flow chart showing the method 2000 for determining the minimum risk of lane change according to the embodiment of Fig. 3. If it is determined in step S08 that a system failure risk has occurred, or if it is determined in step S12 that an exogenous risk has occurred, it can proceed to step S15, in which the lateral component calculation unit 1142 calculates the emergency lateral acceleration and the lateral component v _y , and proceeds to step S16, in which the drivable space calculation unit 1143 calculates the drivable space S1, for example, when the vehicle CH is on the lane L1, the drivable space S1 on the lane L2 is calculated.

When a system failure risk or an exogenous risk occurs, if there is no obstacle in the drivable space S1 and the emergency lateral acceleration is equal to or less than the upper emergency lateral acceleration limit set by the regulations, the vehicle can change lanes to enter the drivable space S1, or conversely, decelerate until it stops. For this reason, in step S17, it is possible to check whether there is an obstacle in the drivable space S1 on the lane L2, and if there is, proceed to step S21 to decelerate until the lane L1 stops, or conversely, proceed to step S18 to further check whether the calculated emergency lateral acceleration is consistent with the norm, that is, whether the emergency lateral acceleration is equal to or less than the upper emergency lateral acceleration limit set by the regulations. If yes, proceed to step S19 to enter the drivable space S1 on the lane L2 based on the calculated steering angle and lateral component v _y . Conversely, proceed to step S21 to decelerate until the lane L1 stops. After entering the drivable space S1 on the lane L2, it is determined whether the drivable space S1 at this time is on the shoulder (e.g., shoulder L3) or an adjacent curb. In step S20, if it is determined that the lane L2 is not the shoulder L3 or an adjacent curb, the process returns to steps S15 and S16, where the lateral component v _y and the next drivable space S1, for example the drivable space S1 on the shoulder L3, are calculated again, and steps S17, S18, S19, and S20 are sequentially performed. At this time, in order to determine that the position where the drivable space S1 is located is the shoulder L3, the process proceeds to step S21, where the vehicle decelerates until it stops.

Please refer to Fig. 6, and also refer to Fig. 1 and Fig. 2. Fig. 6 is a third detailed flowchart showing the method 2000 for determining the minimum risk of lane change according to the embodiment of Fig. 3. After determining that the risk of not satisfying the automatic driving start condition occurs in step S14, the method can proceed to step S22, where the lateral component calculation unit 1142 calculates the lateral component v _y with the normal lateral acceleration, and then proceeds to step S23, where the drivable space calculation unit 1143 calculates the drivable space S1, for example, the drivable space S1 on the lane L2. Then, proceed to step S24, where it is confirmed whether there is an obstacle in the drivable space S1 on the lane L2, and if there is, proceed to step S26 to wait in the lane L1, at this time, it returns to the forward direction and continues to wait, and then it returns to steps S22 and S23 to update the drivable space S1 on the lane L2 again with the current position and related data of the vehicle CH, and then proceeds to step S24 to confirm whether there is an obstacle in the drivable space S1 on the lane L2. If there is no obstacle, the process proceeds to step S25, where the vehicle changes lanes and enters the drivable space S1 on lane L2. Steps S27 and S28 are similar to steps S20 and S21, and will not be described again.

Please refer to FIG. 7 and also to FIG. 1 and FIG. 2. FIG. 7 is a fourth detailed flowchart showing the method 2000 for determining the minimum risk of lane change according to the embodiment of FIG. 3. In another way, after determining that the risk of unsatisfying the automatic driving start condition occurs in step S14, the process can proceed to step S29, where the process first issues a warning and maintains the original trajectory, i.e., the original trajectory of changing lanes from lane L1 to lane L2. Then, the process proceeds to step S30 to check whether the driver is available. If so, it indicates that the driver may be asleep and has been awakened by receiving the warning, and the process can proceed to step S32, where the driver restarts the system. If not, the process proceeds to step S31, where the lateral component calculation unit 1142 calculates the lateral component v _y with the normal lateral acceleration, and the process proceeds to step S33 to calculate the drivable space S1 on the road shoulder L3. Steps S33, S34, S35, S36, S37, and S38 are similar to steps S23 to S28, and will not be described again.

A further embodiment of the present invention is a non-transitory computer readable medium having a computer program stored thereon to cause at least one processor to: calculate a time to impact with a forward object at a current position at any one of a plurality of time points after the vehicle enters a lane change decision; calculate a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the time of impact; calculate an extrinsic risk interval based on the greater of the lateral acceleration and the maximum normal lateral acceleration and the lateral distance at which the vehicle changes lanes to the target lane; determine whether a system of the vehicle has failed at any one time point and whether a lateral module of a backup system of the vehicle is enabled; and determine whether a driver of the vehicle has a fault at any one time point. Based on whether the state at any time is available, confirm whether the autonomous driving activation condition is satisfied, and judge whether an exogenous risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk have occurred in the vehicle. If the system is in a normal state and the relative vertical distance between the vehicle and the forward object at a certain time is less than or equal to the exogenous risk interval, it is judged that an exogenous risk has occurred. If the system has failed at a certain time but the lateral module of the backup system is effective, it is judged that a system failure risk has occurred. If the system is normal and the relative vertical distance at a certain time is greater than the exogenous risk interval, but the autonomous driving activation condition is not satisfied. If the vehicle does not reach the target lane, the vehicle control device determines that a risk of not satisfying the autonomous driving activation conditions has occurred; if any of the exogenous risk, the system failure risk, and the risk of not satisfying the autonomous driving activation conditions has occurred, the vehicle control device calculates an emergency lateral acceleration of the vehicle by calculating a lane change time for the vehicle to change lanes to the target lane at the certain time point, and calculates a lateral component of the vehicle with the emergency lateral acceleration or the normal lateral acceleration; if any of the exogenous risk, the system failure risk, and the risk of not satisfying the autonomous driving activation conditions has occurred, the vehicle control device calculates a drivable space at the certain time point with the lateral distance, the lateral component, and the rear object speed of the rear object in the target lane; If either the risk of system failure or the risk of not satisfying the autonomous driving activation conditions occurs, a minimum risk decision is made; if an exogenous risk or a risk of system failure occurs, the vehicle is caused to change lanes using the lateral component to enter the drivable space or is decelerated to a standstill; if a risk of not satisfying the autonomous driving activation conditions occurs, the vehicle is caused to change lanes using the lateral component to enter the drivable space or is moved to another point in time according to the original trajectory of the lane change decision for at least a certain period of time; and if the autonomous driving activation conditions are not persistently satisfied, the target lane, the lateral component of the lane change, and the drivable space at the other point in time are reconfirmed.

The non-transitory computer-readable medium may be any data storage hardware unit, such as a memory device, that can store data and subsequently be read by a computer device. The non-transitory computer-readable medium may be a hard drive, a network attached storage device (NAS), a read-only memory (ROM), a random access memory (RAM), a read-only memory disk (CD-ROM), a recordable CD (CD-R), a rewritable optical disk (CD-RW), a magnetic tape, and other optical or non-optical storage hardware units. This allows the reading and execution of a computer program stored on the non-transitory computer-readable medium.

Although the present invention has been disclosed by way of the above-mentioned embodiment, this does not limit the present invention, and anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is determined by the content specified in the claims.

1000 Lane change minimum risk determination system 1100 Processor 1110 Exogenous risk interval calculation module 1120 System failure judgment module 1130 Automatic driving start condition confirmation module 1140 Determination module 1141 Judgment unit 1142 Lateral component calculation unit 1143 Driveable space calculation unit 1144 Decision execution unit 1200 Driver state detection device 1300 Sensing module 2000 Lane change minimum risk determination method 2100 Exogenous risk interval calculation step 2200 System failure judgment step 2300 Automatic driving start condition judgment step 2400 Risk judgment step 2500 Lateral component calculation step 2600 Driveable space calculation step 2700 Minimum risk determination progress step CH Vehicle CT Forward object CR Rear object D _F Exogenous risk interval D _NLF forward longitudinal extension distance D _NLR rear longitudinal extension distance D _r Relative longitudinal distance D _y Lateral distance L1, L2 Lane L3 Shoulder S1 Drivable space S01, S02, S03, S04, S05, S06, S07, S08, S09, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38 Step v _h Vehicle speed v _r Rear object speed v _t Front object speed v _x Longitudinal component v _y Lateral component

Claims (17)

A lane change decision system provided in a vehicle, the lane change decision system comprising at least one processor,
The at least one processor
an extrinsic risk interval calculation module that calculates a collision time between the vehicle at a current position and a forward object at one of a plurality of time points when the vehicle is about to change lanes after the at least one processor determines a lane change decision, calculates a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the collision time, and calculates an extrinsic risk interval with a larger of the lateral acceleration and a maximum normal lateral acceleration and a lateral distance at which the vehicle changes lanes to the target lane;
a system failure determination module that determines whether a system of the vehicle has failed at any one of the plurality of time points and whether a lateral control module of a backup system of the vehicle is enabled;
an autonomous driving activation condition confirmation module that confirms whether an autonomous driving activation condition is satisfied based on whether a driver of the vehicle is available at any one of the plurality of time points;
a judgment unit for judging whether an exogenous risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk have occurred in the vehicle, and for determining that the exogenous risk has occurred if the relative longitudinal distance between the vehicle and the forward object at one of the plurality of time points is equal to or less than the exogenous risk interval when the system is in a normal state, and for determining that the system failure risk has occurred if the system has failed but the lateral control module of the backup system is effective at one of the plurality of time points ; and for determining that the system failure risk has occurred if the system is normal and the relative longitudinal distance is greater than the exogenous risk interval at one of the plurality of time points, the autonomous driving activation condition confirmation module for confirming whether the autonomous driving activation condition is satisfied based on whether the driver of the vehicle is available, and for determining that the autonomous driving activation condition non-satisfaction risk has occurred if the autonomous driving activation condition is not satisfied;
a lateral velocity vector calculation unit that calculates an emergency lateral acceleration of the vehicle by calculating a lane change time at one of the plurality of time points for the vehicle to change lanes to the target lane when it is determined that any one of the exogenous risk, the system failure risk, and the risk of unsatisfaction of the autonomous driving activation condition has occurred, and calculates a lateral velocity vector of the vehicle using the emergency lateral acceleration or normal lateral acceleration;
a drivable space calculation unit that, when it is determined that any one of the exogenous risk, the system failure risk, and the autonomous driving activation condition non-satisfaction risk has occurred, calculates a drivable space in the target lane at the one time point among the plurality of time points based on the lateral distance, the lateral velocity vector , and a rear object speed of a rear object in the target lane;
A decision making unit that makes a decision when it is determined that any one of the exogenous risk, the system failure risk, and the automatic driving start condition non-satisfaction risk has occurred,
When it is determined that the exogenous risk or the system failure risk has occurred, the vehicle is caused to change lanes at the lateral speed vector and enter the drivable space, or is decelerated until it comes to a standstill; and when it is determined that the risk of unsatisfaction of the autonomous driving activation condition has occurred, the vehicle is caused to change lanes at the lateral speed vector and enter the drivable space, or is caused to move the vehicle along an original trajectory in accordance with the lane change decision, for at least a period until a time point other than the one time point among the multiple time points, and if the autonomous driving activation condition continues to be unsatisfied , the target lane, the lateral speed vector for lane change, and the drivable space at the time point other than the one time point among the multiple time points are reconfirmed .
A decision making unit;
A decision module including:
A lane change decision system comprising: The extrinsic risk interval calculation module includes:

and
2. The lane change decision system of claim 1, further comprising: a y = α γ α γ = α γ α _γ , where _Tc is the collision time, _Dr is the relative longitudinal distance between the vehicle and the forward object, _vh is the host vehicle speed of the vehicle, vt is the forward object speed of the forward object, _ay is the lateral acceleration of the vehicle calculated at the collision time, _ayrgmax is the maximum normal lateral acceleration, _aymax is the greater of the lateral acceleration and the maximum normal lateral acceleration, _Dy is the lateral distance, _vx is the longitudinal vector of the host vehicle speed, and _DF is the extrinsic risk interval . When the judgment unit determines that the exogenous risk or the system failure risk occurs at the one time point among the plurality of time points , the lateral velocity vector calculation unit:
and
3. The lane change decision system according to claim 2, further comprising: a t _{ISO limit} = t _Lc (t Lc )/a y E (t y ^E )=t Lc (t Lc )/a _y E ( t y E ... 4. The lane change determination system according to claim 3, wherein if there is no obstacle in the drivable space at one of the multiple points in time and the emergency lateral acceleration is equal to or less than an upper limit of the emergency lateral acceleration, the vehicle changes lanes to enter the drivable space, and if not, the vehicle decelerates until it stops. The lane change decision system of claim 2, wherein when the judgment unit determines that the risk of non-satisfaction of the automatic driving activation condition has occurred at one of the multiple time points , the lateral velocity vector calculation unit calculates the lateral velocity vector using the normal lateral acceleration. The lane change determination system according to claim 5 , wherein when an obstacle is present in the drivable space, the vehicle waits until the obstacle moves away before entering the drivable space at the normal lateral acceleration. The lane change determination system according to claim 4 or 6, wherein the vehicle gradually moves to the right until it enters the drivable space on the shoulder of the lane , and then decelerates until it stops. The lane change decision system according to claim 1 , wherein when the judgment unit determines that a risk of non-satisfaction of the autonomous driving activation condition has occurred at the one of the plurality of time points , the decision execution unit issues a warning within the period . A lane change decision method, comprising:
an extrinsic risk interval calculation step of causing an extrinsic risk interval calculation module of at least one processor to calculate, after the at least one processor determines a lane change decision, a collision time between the vehicle at a current position and a forward object at one of a plurality of time points when the vehicle is about to change lanes , calculate a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the collision time, and calculate an extrinsic risk interval with the greater of the lateral acceleration and a maximum normal lateral acceleration and a lateral distance at which the vehicle changes lanes to the target lane;
a system fault determination step of causing a system fault determination module of the at least one processor to determine whether a system of the vehicle has failed at any one of the plurality of time points and whether a lateral control module of a backup system of the vehicle is enabled;
an autonomous driving start condition determination step of causing an autonomous driving start condition confirmation module of the at least one processor to confirm whether an autonomous driving start condition is satisfied based on whether a driver of the vehicle is available at any one of the plurality of time points;
a risk determination step of causing a judgment unit of the at least one processor to determine whether an exogenous risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk have occurred in the vehicle, and if the system is in a normal state and the relative longitudinal distance between the vehicle and the forward object is equal to or less than the exogenous risk interval at one of the multiple time points , determine that the exogenous risk has occurred, and if the system has failed but the lateral control module of the backup system is effective at one of the multiple time points, determine that the system failure risk has occurred, and if the system is normal and the relative longitudinal distance is greater than the exogenous risk interval at one of the multiple time points, the autonomous driving activation condition confirmation module checks whether the autonomous driving activation condition is satisfied based on whether the driver of the vehicle is available, and if the autonomous driving activation condition is not satisfied, determine that the autonomous driving activation condition non-satisfaction risk has occurred;
a lateral velocity vector calculation step of calculating an emergency lateral acceleration of the vehicle by calculating a lane change time at one of the plurality of time points for the vehicle to change lanes to the target lane, when the lateral velocity vector calculation unit of the at least one processor determines that any of the exogenous risk, the system failure risk, and the risk of unsatisfaction of the autonomous driving activation condition has occurred, and calculating a lateral velocity vector of the vehicle using the emergency lateral acceleration or normal lateral acceleration;
a drivable space calculation step of calculating a drivable space in the target lane at the one time point among the plurality of time points based on the lateral distance, the lateral velocity vector, and a rear object velocity of a rear object in the target lane when the drivable space calculation module of the at least one processor determines that any one of the exogenous risk, the system failure risk , and the autonomous driving activation condition non-satisfaction risk has occurred;
A decision execution step of causing a decision execution unit of the at least one processor to make a decision when it is determined that any one of the exogenous risk, the system failure risk , and the risk of unsatisfaction of the automatic driving start condition has occurred,
a decision execution step of, when it is determined that the exogenous risk or the system failure risk has occurred, changing lanes of the vehicle at the lateral speed vector to enter the drivable space or decelerating until stationary; and, when it is determined that the risk of unsatisfaction of the autonomous driving activation condition has occurred, changing lanes of the vehicle at the lateral speed vector to enter the drivable space or moving the vehicle along an original trajectory in accordance with the lane change decision for at least a period until a time point other than the one time point among the multiple time points, and if the state in which the autonomous driving activation condition is not satisfied continues , reconfirming the target lane, the lateral speed vector for lane change, and the drivable space at the time point other than the one time point among the multiple time points ;
A lane change decision method comprising: The extrinsic risk interval calculation module includes:
and
10. The lane change decision method of claim 9, further comprising the steps of: calculating a time to collision, _Tc being the time to collision, _Dr being the relative longitudinal distance between the vehicle and the forward object, _vh being the vehicle speed of the vehicle, _vt being the forward object speed of the forward object, _ay being the lateral acceleration of the vehicle calculated at the time to collision, _ayrgmax being the maximum normal lateral acceleration, _aymax being the greater of the lateral acceleration and the maximum normal lateral acceleration, _Dy being the lateral distance, _vx being the longitudinal vector of the vehicle speed, and _DF being the extrinsic risk interval . When the judgment unit determines that the exogenous risk or the system failure risk occurs at the one time point among the plurality of time points , the lateral velocity vector calculation unit:
and
11. The lane change decision method according to claim 10, further comprising the steps of: calculating a lane change time T _Lc , L being the length of the vehicle, t _{ISO limit} being the lane crossing prohibition time, and a _y ^E being the emergency lateral acceleration . 12. The lane change determination method according to claim 11, wherein if there is no obstacle in the drivable space at one of the multiple points in time and the emergency lateral acceleration is equal to or less than an upper limit of the emergency lateral acceleration, the vehicle changes lanes to enter the drivable space, and if not, the vehicle decelerates until it stops. The lane change decision method according to claim 10, wherein when the judgment unit determines that the risk of non-satisfaction of the automatic driving activation condition has occurred at one of the multiple time points , the lateral velocity vector calculation unit calculates the lateral velocity vector using the normal lateral acceleration. The lane change determination method according to claim 13, wherein, when an obstacle is present in the drivable space, the vehicle waits until the obstacle moves away before entering the drivable space at the normal lateral acceleration. The method for determining whether to change lanes according to claim 12 or 14, wherein the vehicle gradually moves to the right until it enters the drivable space on the shoulder of the lane , and then decelerates until it comes to a stop. The lane change decision method according to claim 9 , wherein when the judgment unit determines that a risk of non-satisfaction of the autonomous driving activation condition has occurred at the one of the plurality of time points , the decision execution unit issues a warning within the period . A non-transitory computer-readable medium storing a computer program for at least one processor, the medium comprising:
After the at least one processor determines a lane change decision, if the vehicle is about to change lanes, calculating a collision time between the vehicle at a current position and a forward object at one of a plurality of time points, calculating a lateral acceleration at which the vehicle changes lanes from the current position to a target lane at the collision time, and calculating an extrinsic risk interval with the greater of the lateral acceleration and a maximum normal lateral acceleration and a lateral distance at which the vehicle changes lanes to the target lane;
determining whether a system of the vehicle has failed at any one of the plurality of times and whether a lateral control module of a backup system of the vehicle is enabled;
determining whether an automatic driving activation condition is satisfied based on whether a driver of the vehicle is available at any one of the plurality of time points ;
determining whether an extrinsic risk, a system failure risk, and an autonomous driving activation condition non-satisfaction risk have occurred in the vehicle, determining that the extrinsic risk has occurred if the relative longitudinal distance between the vehicle and the forward object is equal to or less than the extrinsic risk interval at one of the plurality of time points when the system is in a normal state, and determining that the system failure risk has occurred if the system has failed but the lateral control module of the backup system is effective at one of the plurality of time points; and if the system is normal and the relative longitudinal distance is greater than the extrinsic risk interval at one of the plurality of time points, checking whether the autonomous driving activation condition is satisfied based on whether the driver of the vehicle is available, and determining that the autonomous driving activation condition non-satisfaction risk has occurred if the autonomous driving activation condition is not satisfied;
When it is determined that any one of the exogenous risk, the system failure risk, and the risk of unsatisfaction of the autonomous driving activation condition has occurred, an emergency lateral acceleration of the vehicle is calculated by calculating a lane change time at one of the multiple time points for the vehicle to change lanes to the target lane, and a lateral velocity vector of the vehicle is calculated using the emergency lateral acceleration or normal lateral acceleration;
When it is determined that any one of the exogenous risk, the system failure risk, and the risk of unsatisfaction of the autonomous driving activation condition has occurred, a drivable space in the target lane at the one time point among the plurality of time points is calculated based on the lateral distance, the lateral velocity vector , and a rear object velocity of a rear object in the target lane;
When it is determined that any one of the exogenous risk, the system failure risk, and the automatic driving start condition non-satisfaction risk has occurred , a decision is made;
When it is determined that the exogenous risk or the system failure risk has occurred, the vehicle is caused to change lanes at the lateral speed vector and enter the drivable space, or is decelerated until it comes to a standstill; and when it is determined that the risk of unsatisfaction of the autonomous driving activation condition has occurred, the vehicle is caused to change lanes at the lateral speed vector and enter the drivable space, or is caused to move the vehicle along an original trajectory in accordance with the lane change decision, for at least a period until a time point other than the one time point among the multiple time points, and if the state in which the autonomous driving activation condition is not satisfied continues , reconfirming the target lane, the lateral speed vector for lane change, and the drivable space at the time point other than the one time point among the multiple time points;
A non-transitory computer-readable medium for causing the computer to execute