Patent Description:
Safety related to vehicles is becoming increasingly important over time, and features that assist in ensuring safety are becoming a crucial decision factor in purchasing a vehicle.

As a feature related to vehicle safety, an automatic emergency braking function is being considered to prevent vehicle collisions. <CIT> discloses the content thereof, which pertains to a system in which a subject vehicle positioned at the rearmost calculates the following collision risk levels: <NUM>) a collision risk level between the subject vehicle and a preceding vehicle; <NUM>) a collision risk level between two preceding vehicles in front of the subject vehicle; and <NUM>) a collision risk level between the subject vehicle and a following vehicle behind the subject vehicle. Subsequently, the subject vehicle dynamically adjusts the timing of alerts and the timing of braking for chain collision avoidance by comparing each collision risk level with a reference collision risk level. Then, the subject vehicle provides alerts and applies braking. That is, the system is designed to prevent chain collision accidents during high-speed driving.

The present disclosure aims to propose safety features to prevent rear-end chain collisions and mitigate the impact force during collisions.

Korean Patent No. <NUM>-<NUM>
<CIT> discloses a method for influencing the direction of travel of a vehicle in order to lower the risk of accidents in driving situations in which the driver reacts incorrectly. In the document it is described that the driving operation is monitored in reference to the occurrence of an event due to which the travel direction of the vehicle changes, deviating from the travel direction specified at the steering wheel, and when such an event is detected that an automatic intervention in the driving operation be performed whereby the vehicle is moved back approximately into the original direction of travel in which it was moving before the event occurred. <CIT> discloses a vehicle control apparatus including a contact detector, an attitude stabilization processor, and a steering intention determining unit. In the document it is described that the contact detector is configured to detect a contact of a vehicle with an object, the attitude stabilization processor is configured to execute an attitude stabilization control that generates a yaw moment at a vehicle body on the basis of a deviation between a target yaw rate and an actual yaw rate, the steering intention determining unit is configured to determine a presence of a driver's intention to perform steering, the attitude stabilization processor is configured to stop the generation of the yaw moment by the attitude stabilization control or reduce the yaw moment to be generated by the attitude stabilization control, in a case where the steering intention determining unit determines that the driver's intention to perform the steering is absent after the detection of the contact by the contact detector.

Accordingly, the present invention is directed to a method and apparatus for collision avoidance or impact force reduction that substantially obviates one or more problems due to limitations and disadvantages of the related art.

Based on the background described above, the present invention aims to provide a vehicle control method for avoiding collisions with following vehicles or reducing the impact force in the event of a collision.

The present invention aims to provide a vehicle control method for preventing secondary collisions even in the event of a collision with a following vehicle.

It will be appreciated by persons skilled in the art that the objects that could be achieved with the present invention are not limited to what has been particularly described hereinabove and other objects will be more clearly understood from the following detailed description.

According to the present invention, collision avoidance or impact force reduction during collisions may be achieved.

In addition, it is possible to prevent secondary collisions with other vehicles after an initial collision with a following vehicle.

The effects that are achievable by the present invention are not limited to what has been particularly described hereinabove and other advantages not described herein will be more clearly understood by persons skilled in the art from the following description.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that the present invention may be easily realized by those skilled in the art. However, the present invention may be achieved in various different forms and is not limited to the embodiments described herein. In the drawings, parts that are not related to a description of the present invention are omitted to clearly explain the present invention and similar reference numbers will be used throughout this specification to refer to similar parts.

In the specification, when a part "includes" an element, it means that the part may further include another element rather than excluding another element unless otherwise mentioned.

<FIG> is an overall block diagram of an autonomous driving control system to which an autonomous driving apparatus according to any one of embodiments of the present invention is applicable. <FIG> is a diagram illustrating an example in which an autonomous driving apparatus according to any one of embodiments of the present invention is applied to a vehicle.

First, a structure and function of an autonomous driving control system (e.g., an autonomous driving vehicle) to which an autonomous driving apparatus according to the present embodiments is applicable will be described with reference to <FIG> and <FIG>.

As illustrated in <FIG>, an autonomous driving vehicle <NUM> may be implemented based on an autonomous driving integrated controller <NUM> that transmits and receives data necessary for autonomous driving control of a vehicle through a driving information input interface <NUM>, a traveling information input interface <NUM>, an occupant output interface <NUM>, and a vehicle control output interface <NUM>. However, the autonomous driving integrated controller <NUM> may also be referred to herein as a controller, a processor, or, simply, a controller.

The autonomous driving integrated controller <NUM> may obtain, through the driving information input interface <NUM>, driving information based on manipulation of an occupant for a user input unit <NUM> in an autonomous driving mode or manual driving mode of a vehicle. As illustrated in <FIG>, the user input unit <NUM> may include a driving mode switch <NUM> and a control panel <NUM> (e.g., a navigation terminal mounted on the vehicle or a smartphone or tablet computer owned by the occupant). Accordingly, driving information may include driving mode information and navigation information of a vehicle.

For example, a driving mode (i.e., an autonomous driving mode/manual driving mode or a sports mode/eco mode/safety mode/normal mode) of the vehicle determined by manipulation of the occupant for the driving mode switch <NUM> may be transmitted to the autonomous driving integrated controller <NUM> through the driving information input interface <NUM> as the driving information.

Furthermore, navigation information, such as the destination of the occupant input through the control panel <NUM> and a path up to the destination (e.g., the shortest path or preference path, selected by the occupant, among candidate paths up to the destination), may be transmitted to the autonomous driving integrated controller <NUM> through the driving information input interface <NUM> as the driving information.

The control panel <NUM> may be implemented as a touchscreen panel that provides a user interface (UI) through which the occupant inputs or modifies information for autonomous driving control of the vehicle. In this case, the driving mode switch <NUM> may be implemented as touch buttons on the control panel <NUM>.

In addition, the autonomous driving integrated controller <NUM> may obtain traveling information indicative of a driving state of the vehicle through the traveling information input interface <NUM>. The traveling information may include a steering angle formed when the occupant manipulates a steering wheel, an accelerator pedal stroke or brake pedal stroke formed when the occupant depresses an accelerator pedal or brake pedal, and various types of information indicative of driving states and behaviors of the vehicle, such as a vehicle speed, acceleration, a yaw, a pitch, and a roll formed in the vehicle. The traveling information may be detected by a traveling information detection unit <NUM>, including a steering angle sensor <NUM>, an accelerator position sensor (APS)/pedal travel sensor (PTS) <NUM>, a vehicle speed sensor <NUM>, an acceleration sensor <NUM>, and a yaw/pitch/roll sensor <NUM>, as illustrated in <FIG>.

Furthermore, the traveling information of the vehicle may include location information of the vehicle. The location information of the vehicle may be obtained through a global positioning system (GPS) receiver <NUM> applied to the vehicle. Such traveling information may be transmitted to the autonomous driving integrated controller <NUM> through the traveling information input interface <NUM> and may be used to control the driving of the vehicle in the autonomous driving mode or manual driving mode of the vehicle.

The autonomous driving integrated controller <NUM> may transmit driving state information provided to the occupant to an output unit <NUM> through the occupant output interface <NUM> in the autonomous driving mode or manual driving mode of the vehicle. That is, the autonomous driving integrated controller <NUM> transmits the driving state information of the vehicle to the output unit <NUM> so that the occupant may check the autonomous driving state or manual driving state of the vehicle based on the driving state information output through the output unit <NUM>. The driving state information may include various types of information indicative of driving states of the vehicle, such as a current driving mode, transmission range, and speed of the vehicle.

If it is determined that it is necessary to warn a driver in the autonomous driving mode or manual driving mode of the vehicle along with the above driving state information, the autonomous driving integrated controller <NUM> transmits warning information to the output unit <NUM> through the occupant output interface <NUM> so that the output unit <NUM> may output a warning to the driver. In order to output such driving state information and warning information acoustically and visually, the output unit <NUM> may include a speaker <NUM> and a display <NUM> as illustrated in <FIG>. In this case, the display <NUM> may be implemented as the same device as the control panel <NUM> or may be implemented as an independent device separated from the control panel <NUM>.

Furthermore, the autonomous driving integrated controller <NUM> may transmit control information for driving control of the vehicle to a lower control system <NUM>, applied to the vehicle, through the vehicle control output interface <NUM> in the autonomous driving mode or manual driving mode of the vehicle. As illustrated in <FIG>, the lower control system <NUM> for driving control of the vehicle may include an engine control system <NUM>, a braking control system <NUM>, and a steering control system <NUM>. The autonomous driving integrated controller <NUM> may transmit engine control information, braking control information, and steering control information, as the control information, to the respective lower control systems <NUM>, <NUM>, and <NUM> through the vehicle control output interface <NUM>. Accordingly, the engine control system <NUM> may control the speed and acceleration of the vehicle by increasing or decreasing fuel supplied to an engine. The braking control system <NUM> may control the braking of the vehicle by controlling braking power of the vehicle. The steering control system <NUM> may control the steering of the vehicle through a steering device (e.g., motor driven power steering (MDPS) system) applied to the vehicle.

As described above, the autonomous driving integrated controller <NUM> according to the present embodiment may obtain the driving information based on manipulation of the driver and the traveling information indicative of the driving state of the vehicle through the driving information input interface <NUM> and the traveling information input interface <NUM>, respectively, and transmit the driving state information and the warning information, generated based on an autonomous driving algorithm, to the output unit <NUM> through the occupant output interface <NUM>. In addition, the autonomous driving integrated controller <NUM> may transmit the control information generated based on the autonomous driving algorithm to the lower control system <NUM> through the vehicle control output interface <NUM> so that driving control of the vehicle is performed.

In order to guarantee stable autonomous driving of the vehicle, it is necessary to continuously monitor the driving state of the vehicle by accurately measuring a driving environment of the vehicle and to control driving based on the measured driving environment. To this end, as illustrated in <FIG>, the autonomous driving apparatus according to the present embodiment may include a sensor unit <NUM> for detecting a nearby object of the vehicle, such as a nearby vehicle, pedestrian, road, or fixed facility (e.g., a signal light, a signpost, a traffic sign, or a construction fence).

The sensor unit <NUM> may include one or more of a LiDAR sensor <NUM>, a radar sensor <NUM>, or a camera sensor <NUM>, in order to detect a nearby object outside the vehicle, as illustrated in <FIG>.

The LiDAR sensor <NUM> may transmit a laser signal to the periphery of the vehicle and detect a nearby object outside the vehicle by receiving a signal reflected and returning from a corresponding object. The LiDAR sensor <NUM> may detect a nearby object located within the ranges of a preset distance, a preset vertical field of view, and a preset horizontal field of view, which are predefined depending on specifications thereof. The LiDAR sensor <NUM> may include a front LiDAR sensor <NUM>, a top LiDAR sensor <NUM>, and a rear LiDAR sensor <NUM> installed at the front, top, and rear of the vehicle, respectively, but the installation location of each LiDAR sensor and the number of LiDAR sensors installed are not limited to a specific embodiment. A threshold for determining the validity of a laser signal reflected and returning from a corresponding object may be previously stored in a memory (not illustrated) of the autonomous driving integrated controller <NUM>. The autonomous driving integrated controller <NUM> may determine a location (including a distance to a corresponding object), speed, and moving direction of the corresponding object using a method of measuring time taken for a laser signal, transmitted through the LiDAR sensor <NUM>, to be reflected and returning from the corresponding object.

The radar sensor <NUM> may radiate electromagnetic waves around the vehicle and detect a nearby object outside the vehicle by receiving a signal reflected and returning from a corresponding object. The radar sensor <NUM> may detect a nearby object within the ranges of a preset distance, a preset vertical field of view, and a preset horizontal field of view, which are predefined depending on specifications thereof. The radar sensor <NUM> may include a front radar sensor <NUM>, a left radar sensor <NUM>, a right radar sensor <NUM>, and a rear radar sensor <NUM> installed at the front, left, right, and rear of the vehicle, respectively, but the installation location of each radar sensor and the number of radar sensors installed are not limited to a specific embodiment. The autonomous driving integrated controller <NUM> may determine a location (including a distance to a corresponding object), speed, and moving direction of the corresponding object using a method of analyzing power of electromagnetic waves transmitted and received through the radar sensor <NUM>.

The camera sensor <NUM> may detect a nearby object outside the vehicle by photographing the periphery of the vehicle and detect a nearby object within the ranges of a preset distance, a preset vertical field of view, and a preset horizontal field of view, which are predefined depending on specifications thereof.

The camera sensor <NUM> may include a front camera sensor <NUM>, a left camera sensor <NUM>, a right camera sensor <NUM>, and a rear camera sensor <NUM> installed at the front, left, right, and rear of the vehicle, respectively, but the installation location of each camera sensor and the number of camera sensors installed are not limited to a specific embodiment. The autonomous driving integrated controller <NUM> may determine a location (including a distance to a corresponding object), speed, and moving direction of the corresponding object by applying predefined image processing to an image captured by the camera sensor <NUM>.

In addition, an internal camera sensor <NUM> for capturing the inside of the vehicle may be mounted at a predetermined location (e.g., rear view mirror) within the vehicle. The autonomous driving integrated controller <NUM> may monitor a behavior and state of the occupant based on an image captured by the internal camera sensor <NUM> and output guidance or a warning to the occupant through the output unit <NUM>.

As illustrated in <FIG>, the sensor unit <NUM> may further include an ultrasonic sensor <NUM> in addition to the LiDAR sensor <NUM>, the radar sensor <NUM>, and the camera sensor <NUM> and further adopt various types of sensors for detecting a nearby object of the vehicle along with the sensors.

<FIG> illustrates an example in which, in order to aid in understanding the present embodiment, the front LiDAR sensor <NUM> or the front radar sensor <NUM> is installed at the front of the vehicle, the rear LiDAR sensor <NUM> or the rear radar sensor <NUM> is installed at the rear of the vehicle, and the front camera sensor <NUM>, the left camera sensor <NUM>, the right camera sensor <NUM>, and the rear camera sensor <NUM> are installed at the front, left, right, and rear of the vehicle, respectively. However, as described above, the installation location of each sensor and the number of sensors installed are not limited to a specific embodiment.

Furthermore, in order to determine a state of the occupant within the vehicle, the sensor unit <NUM> may further include a bio sensor for detecting bio signals (e.g., heart rate, electrocardiogram, respiration, blood pressure, body temperature, electroencephalogram, photoplethysmography (or pulse wave), and blood sugar) of the occupant. The bio sensor may include a heart rate sensor, an electrocardiogram sensor, a respiration sensor, a blood pressure sensor, a body temperature sensor, an electroencephalogram sensor, a photoplethysmography sensor, and a blood sugar sensor.

Finally, the sensor unit <NUM> additionally includes a microphone <NUM> having an internal microphone <NUM> and an external microphone <NUM> used for different purposes.

The internal microphone <NUM> may be used, for example, to analyze the voice of the occupant in the autonomous driving vehicle <NUM> based on AI or to immediately respond to a direct voice command of the occupant.

In contrast, the external microphone <NUM> may be used, for example, to appropriately respond to safe driving by analyzing various sounds generated from the outside of the autonomous driving vehicle <NUM> using various analysis tools such as deep learning.

For reference, the symbols illustrated in <FIG> may perform the same or similar functions as those illustrated in <FIG>. <FIG> illustrates in more detail a relative positional relationship of each component (based on the interior of the autonomous driving vehicle <NUM>) as compared with <FIG>.

In this document, a vehicle control method for preventing rear-end collisions will be described. In addition to the vehicle control method for preventing rear-end collisions, a vehicle control method for mitigating the impact force during rear-end collisions will be described as well.

The proposed technology aims not only to prevent rear-end collision accidents that are difficult for drivers to respond to but also to enhance driver survival rates or reduce the extent of injuries through impact mitigation control when avoiding accidents becomes impossible.

The proposed technology may be broadly categorized into providing warnings for rear-end collisions in advance and mitigating the impact force during rear-end collisions.

<FIG> illustrates a vehicle control device <NUM> according to the present invention.

The sensor unit <NUM> may include the radar sensor <NUM> or the ultrasonic sensor <NUM>. The sensor unit <NUM> may detect forward and following vehicles of a subject vehicle and detect the distance, relative velocity, and acceleration between the subject vehicle and the forward or following vehicle. The types of sensors are not limited to the radar sensor <NUM> or the ultrasonic sensor <NUM>. In addition, the sensor unit <NUM> may detect collisions with the forward or following vehicle.

The controller <NUM> includes a recognizer <NUM> and a determiner <NUM>. The recognizer <NUM> may determine the presence or absence of a forward or following vehicleand calculate the position, velocity, acceleration, etc. of the forward or following vehicle, based on sensor values detected by the sensor unit <NUM>. In addition, the recognizer <NUM> may predict the travel path of the forward or following vehicle and compute the distance, relative velocity, and relative acceleration between the subject vehicle and the forward or following vehicle. The determiner <NUM> may assess a potential collision with the forward or following vehicle based on the results computed by the recognizer <NUM>. In addition, the determiner <NUM> may calculate a time to collision (TTC) (i.e., expected collision time) or an enhanced TTC (ETTC) with the following vehicle. Furthermore, the determiner <NUM> may calculate vehicle acceleration, deceleration, or steering control values necessary for collision avoidance or impact force reduction during collisions.

The controller <NUM> may control the sensor unit <NUM>, recognizer <NUM>, or determiner <NUM>. In addition, the controller <NUM> may perform vehicle control such as acceleration/deceleration and steering using the output of the sensor unit <NUM>, recognizer <NUM>, or determiner <NUM>, such as sensor values or calculation results.

The recognizer <NUM> and determiner <NUM> are described as separate components in <FIG>, but the recognizer <NUM> and determiner <NUM> may be integrated into the controller <NUM>.

The vehicle control device <NUM> is installed in the subject vehicle <NUM> and performs the proposed vehicle control. However, for the sake of simplicity in the following descriptions, the subject vehicle <NUM> is described as the entity that executes the proposed vehicle control.

<FIG> illustrates a flowchart of a vehicle control method according to the present invention.

The subject vehicle <NUM> may detect vehicle(s) traveling in front or behind (S410). When driving on a multi-lane road, the subject vehicle <NUM> may detect not only forward or following vehicles located in the same lane but forward or following vehicles located in neighboring lanes.

The subject vehicle <NUM> may compare the TTC or ETTC (hereinafter referred to as "expected collision time") for a following vehicle with a predetermined collision warning reference value (S420). If the expected collision time is greater than the collision warning reference value, the subject vehicle <NUM> may return to the initial process of detecting forward or following vehicles. If the expected collision time is less than the collision warning reference value, the subject vehicle <NUM> may compare the expected collision time for the following vehicle with a predetermined collision control reference value (S430).

If the expected collision time is greater than the collision control reference value, the subject vehicle <NUM> may perform a collision warning (S440). The collision warning includes outputting a warning sound or a warning message through the speaker <NUM> or display <NUM> of the subject vehicle <NUM>. Additionally, the collision warning may include auditory signals such as the horn or visual signals such as flashing the brakes on the subject vehicle <NUM> to enable the driver of a following vehicle <NUM> to perceive the possibility of a collision.

If the expected collision time is less than the collision control reference value, the subject vehicle <NUM> may perform vehicle control depending on the presence of a forward vehicle in front of the subject vehicle (S450).

If there is a forward vehicle, the subject vehicle <NUM> may execute first control for collision avoidance or impact force reduction (S460). The first control may include acceleration control of the subject vehicle <NUM>. Further details regarding the first control will be described with reference to <FIG>.

If there is no forward vehicle, the subject vehicle <NUM> may execute second control for collision avoidance or impact force reduction (S470). The second control may include acceleration control of the subject vehicle <NUM>. Further details regarding the second control will be described with reference to <FIG>.

After executing the first control or second control, the subject vehicle <NUM> may determine whether a collision occurs with the following vehicle (S480). If the subject vehicle <NUM> collides with the following vehicle, the subject vehicle <NUM> may perform third control for preventing secondary collisions (S490). Further details regarding the third control will be described with reference to <FIG>. In <FIG>, the left side of each vehicle (vehicles <NUM>, <NUM>, and <NUM>) corresponds to the front side of the vehicle.

<FIG> is a diagram for explaining the first control.

In <FIG>, the subject vehicle <NUM> is traveling between the forward vehicle <NUM> and the following vehicle <NUM>. It is assumed that the expected collision time is less than the collision control reference value and the forward vehicle <NUM> is present as described above in <FIG>.

In <FIG>, ao and vo denote the acceleration and velocity of the subject vehicle <NUM>, respectively, sfront denote the distance between the subject vehicle <NUM> and the forward vehicle <NUM>, and arear and vrear denote the acceleration and velocity of the following vehicle <NUM>, respectively.

To prevent a collision with the following vehicle <NUM> or reduce the impact force with the following vehicle <NUM>, it may be most desirable to control the acceleration of the subject vehicle <NUM>. However, as shown in <FIG>, when the forward vehicle <NUM> is present, controlling the acceleration of the subject vehicle <NUM> may cause a collision with the forward vehicle <NUM>. Therefore, it is necessary to adjust the timing of acceleration control, unlike a case where there is no forward vehicle. The distance between the subject vehicle <NUM> and forward vehicle <NUM> may be expressed as follows: <MAT>.

In the above equation, Gtarget denotes the target acceleration of the subject vehicle <NUM>. Tcalc denotes the expected collision time between the subject vehicle <NUM> and the forward vehicle <NUM>.

Assuming that Tcollision is a reference value (timing) for acceleration control when there is no forward vehicle, a reference value (timing) (Tcrash_with_frontOBJ) for acceleration control when there is a forward vehicle may be expressed as follows.

For example, when Tcollision and Tcalc are calculated as follows: Tcollision = <NUM> (seconds) and Tcalc = <NUM> (seconds), the timing of controlling the acceleration of the subject vehicle <NUM> is <NUM> (seconds), which means that the acceleration control of the subject vehicle <NUM> is performed at the moment when the expected collision time becomes two seconds. In other words, compared to a case where there is no forward vehicle, the timing of acceleration control is delayed by one second.

Selecting the minimum value between the expected collision time (Tcalc) for the forward vehicle <NUM> and the reference value (Tcollision) for acceleration control is meaningful when the subject vehicle <NUM> and the forward vehicle <NUM> are within a predetermined distance at the time of acceleration control. The reason for this is that the target acceleration of the subject vehicle <NUM> depends on vehicle performance and is subject to certain constraints. Therefore, if the subject vehicle <NUM> and the forward vehicle <NUM> are relatively far apart, Tcalc is expected to be greater than the reference value (Tcollision) for acceleration control. Consequently, the reference value (Tcrash_with_frontOBJ) for acceleration control when there is a forward vehicle may be selected as the reference value (Tcollision) for acceleration control. In other words, when the distance between the forward vehicle <NUM> and the subject vehicle <NUM> is greater than the predetermined distance at the time of acceleration control, even if the forward vehicle <NUM> is present, the timing of acceleration control may be determined to be the same when there is no forward vehicle. This is consistent with the second control, which will be described.

Furthermore, control to warn or avoid a collision with the forward vehicle <NUM> may be performed based on the driving assistance features of the subject vehicle <NUM>. However, this will not be discussed in this specification.

<FIG> is a diagram for explaining the second control.

In <FIG>, the subject vehicle <NUM> is traveling between the forward vehicle <NUM> and the following vehicle <NUM>. It is assumed that the expected collision time is less than the collision control reference value and there is no forward vehicle as described above in <FIG>. The parameters shown in <FIG> are the same as the parameters of <FIG>.

The subject vehicle <NUM> may perform acceleration control based on a predetermined target acceleration (Gtarget). Assuming that the velocity of the following vehicle <NUM> is constant, the change in relative velocity between the subject vehicle <NUM> and following vehicle <NUM> until the point of collision is Gtarget * T, where T denotes the time from the timing of acceleration control to the collision. Considering that the subject vehicle <NUM> is configured to be controlled only when the expected collision time is less than the collision control reference value (Tcollision), the following may be satisfied: T = expected collision time. Alternatively, the expected collision time and the collision control reference value (Tcollision) may be considered almost the same. Regardless of whether T is set to the expected collision time or the collision control reference value, there may not be significant differences in the value of T.

The change in impact force is proportional to the change in velocity. For instance, it is assumed that the following vehicle <NUM> is traveling at a speed of <NUM> kph and the subject vehicle <NUM> is traveling at a speed of <NUM> kph. Assuming that Gtarget = <NUM>/s<NUM> because the maximum acceleration of a typical vehicle is about <NUM>/s<NUM> and a collision occurs after the expected collision time (<NUM> seconds), the change in impact force is calculated as follows: {<NUM> - (<NUM> + <NUM> * <NUM> * <NUM>)} / (<NUM> - <NUM>) * <NUM> = <NUM>%.

As an alternative or complementary function for the first or second control described above, the subject vehicle <NUM> may execute the following control if the expected collision time is less than the collision control reference value.

The subject vehicle <NUM> may transmit control signals in advance to the airbag system or seat headrest control system, thereby preventing airbag malfunction or enabling the occupants within the subject vehicle <NUM> to protect their own bodies during collisions.

Furthermore, if the radar sensor <NUM> is mounted on the rear side of the subject vehicle <NUM>, the subject vehicle <NUM> may transmit interference signals to the following vehicle <NUM>, thereby creating an environment where the following vehicle <NUM> is capable of performing braking control as a driving assistance function such as emergency braking.

When the subject vehicle <NUM> is capable of detecting surrounding vehicles on lanes adjacent to its travel lane (S410), the subject vehicle <NUM> may perform the following control. When there is a safe space for lane change in an adjacent lane, the subject vehicle <NUM> may perform lane change control. In this case, the subject vehicle <NUM> may execute the lane change control in consideration of the position or direction of the following vehicle <NUM>.

<FIG> are diagrams for explaining the third control. The third control is conducted under the assumption of a collision between the following vehicle <NUM> and the subject vehicle <NUM>. Specifically, the collision with the following vehicle <NUM> may result in a turning force (Minput) on the subject vehicle <NUM>. The turning force may cause abrupt turns of the subject vehicle <NUM>, leading to lane departure or even rollover. To prevent secondary collisions or accidents resulting therefrom, control for mitigating the turning force of the subject vehicle <NUM>, that is, the third control will be described.

In <FIG>, Pcenter denotes the center of gravity of the subject vehicle <NUM>, Prear_center denotes the center of gravity of the following vehicle <NUM>, Mcenter denotes the weight of the following vehicle <NUM>, and Minput denotes the turning force exerted by the following vehicle <NUM> on the subject vehicle <NUM>.

<FIG> illustrates that the following vehicle <NUM> is travelling at a certain angle to the travelling direction of the subject vehicle <NUM>. However, even if the following vehicle <NUM> is travelling in the same direction or parallel to the subject vehicle <NUM>, there may be a turning force. Thus, the proposed technique is not limited solely to the illustrated scenario.

<FIG> is a diagram for explaining steering control of the subject vehicle <NUM> due to the turning force. Referring to <FIG>, the subject vehicle <NUM> is oriented at an angle of θ<NUM> before colliding with the following vehicle <NUM>. However, after the collision, the subject vehicle <NUM> is oriented at an angle of θ<NUM> due to the turning force. The steering control of the subject vehicle <NUM> may be applied to enable the subject vehicle <NUM> to keep the same travelling direction as before the collision as much as possible, that is, to allow the subject vehicle <NUM> to maintain its lane.

The subject vehicle <NUM> may be configured to store its orientation angle periodically or aperiodically, thereby enabling retrieval of the orientation angle before the collision. The amount of rotation of the subject vehicle <NUM> due to the collision is computed by a yaw rate sensor, and the steering control controls the subject vehicle <NUM> to recover the orientation angle immediately before the collision. To rapidly recover the orientation angle, the target orientation angle, that is, the orientation angle before the collision, may be set greater than the actual value by a predetermined offset. In this case, a steering angle may be calculated by analyzing the difference between the current orientation angle and the orientation angle before the collision.

<FIG> is a diagram for explaining braking control of the subject vehicle <NUM> due to the turning force. Referring to <FIG>, the subject vehicle <NUM> is oriented at an angle of θ<NUM> before colliding with the following vehicle <NUM>. However, after the collision, the subject vehicle <NUM> is oriented at an angle of θ<NUM> due to the turning force. The braking control of the subject vehicle <NUM> may be applied to enable the subject vehicle <NUM> to keep the same travelling direction as before the collision as much as possible, that is, to allow the subject vehicle <NUM> to maintain its lane. Similarly to how braking is used in the Electronic Stability Program (ESP) for vehicle attitude control, braking pressure is used as a means to regulate vehicle behaviors.

The braking control shown in <FIG> may be applied separately or independently. Alternatively, the braking control may be applied as an auxiliary means when the subject vehicle <NUM> fails to restore its target orientation angle after performing the steering control shown in <FIG> or when there is no change in the rotation after performing the steering control. For example, even after executing the steering control shown in <FIG>, the subject vehicle <NUM> may perform the braking control in the following cases: when the yaw value or yaw rate value is close to zero (or if the yaw value or yaw rate value is less than a threshold), or when the direction of the yaw rate value is the same as the direction of the turning force.

In the state shown in <FIG>, the subject vehicle <NUM> rotates counterclockwise due to the turning force, and accordingly, to recover the orientation angle before the collision, the subject vehicle <NUM> needs to rotate clockwise. Therefore, the braking control may apply a braking pressure only to the right rear wheel of the subject vehicle <NUM>. In other words, the braking control may be implemented as differential braking control capable of applying a braking pressure to any one of the multiple wheels of the vehicle.

The braking control of the subject vehicle <NUM> may be terminated if the yaw rate value exceeds a predetermined threshold in a direction in which the subject vehicle <NUM> is controlled (i.e., the direction opposite to the turning force).

The braking pressure used for differential braking control may be selected from a set of predetermined values and applied. The braking pressure applied for the braking control may be proportional to the magnitude of the difference between the orientation angle before the collision and the current orientation angle of the subject vehicle <NUM>.

The braking control described above with reference to <FIG> may be expressed using conditional statements as follows:
<MAT>.

Regarding the conditions for executing the above-described braking control, the yaw value and the yaw rate value are expressed by the condition "or". In other words, if either the yaw value or the yaw rate value satisfies the conditions, the braking control may be executed. However, for more exclusive vehicle control, the condition "and" may be used instead of using the condition "or", thereby configuring the braking control to be executed only when both conditions are satisfied.

<FIG> is a diagram for explaining acceleration control of the subject vehicle <NUM> due to the turning force. Referring to <FIG>, the subject vehicle <NUM> is oriented at an angle of θ<NUM> before colliding with the following vehicle <NUM>. However, after the collision, the subject vehicle <NUM> is oriented at an angle of θ<NUM> due to the turning force. The acceleration control of the subject vehicle <NUM> may be applied to enable the subject vehicle <NUM> to keep the same travelling direction as before the collision as much as possible, that is, to allow the subject vehicle <NUM> to maintain its lane.

The acceleration control shown in <FIG> may be applied separately or independently. Alternatively, the acceleration control may be applied as an auxiliary means when the subject vehicle <NUM> fails to restore its target orientation angle after performing the control shown in <FIG> or when there is no change in the rotation after performing the control. For example, even after executing the control shown in <FIG>, the subject vehicle <NUM> may perform the acceleration control in the following cases: when the yaw value, the yaw rate value, or the variation in the yaw rate value is close to zero or when the direction of the yaw rate value is the same as the direction of the turning force.

In the state shown in <FIG>, the subject vehicle <NUM> rotates counterclockwise due to the turning force, and accordingly, to recover the orientation angle before the collision, the subject vehicle <NUM> needs to rotate clockwise. Therefore, the acceleration control may be applied only to the left wheel of the subject vehicle <NUM>. In other words, the acceleration control may be implemented as differential acceleration control capable of applying power to any one of the multiple wheels of the vehicle.

The acceleration control of the subject vehicle <NUM> may be terminated if the variation in the yaw rate value exceeds a predetermined threshold.

The acceleration used for differential acceleration control may be selected from a set of predetermined values and applied. The acceleration applied for the acceleration control may be proportional to the magnitude of the difference between the orientation angle before the collision and the current orientation angle of the subject vehicle <NUM>.

The acceleration control described above with reference to <FIG> may be expressed using conditional statements as follows:
<MAT>.

Regarding the conditions for executing the above-described acceleration control, the yaw value, the yaw rate value, and the variation in the yaw rate value are expressed by the condition "and". In other words, if all of the yaw value, the yaw rate value, and the variation in the yaw rate value satisfy the conditions, the acceleration control may be executed.

The steering, braking, or acceleration control may recover the target orientation angle more rapidly if the subject vehicle <NUM> is capable of obtaining the driving information on the following vehicle <NUM> or the vehicle state of the following vehicle <NUM>. In other words, if the driving information or vehicle state of the following vehicle <NUM> is received through communication, the corresponding information may be used to configure a threshold for each of the yaw value, the yaw rate value, and the variation in the yaw rate value and select the braking pressure or acceleration.

Hereinabove, it has been described that the subject vehicle performs vehicle control, but the terms "subject vehicle" and components thereof are merely names, and thus, the scope of the present invention is not limited thereto.

In other words, the proposed technology may be implemented under other names rather than "vehicle" or "system. " Furthermore, the methods or approaches described above may be carried out by software for vehicle control or code readable by computers, machines, devices, and so on.

In another aspect of the present invention, the operations of the proposed technology described above may be provided as code capable of being implemented, performed, or executed by a "computer" (as a comprehensive concept including a system-on-chip (SoC), a processor, a microprocessor, etc.), a computer-readable storage medium that stores or includes the code, a computer program product that stores or includes the code, and so on. Accordingly, the scope of the present invention may extend to the code, the computer-readable storage medium that stores or includes the code, or the computer program product that stores or includes the code.

Claim 1:
A vehicle control method for collision avoidance or impact force reduction, the method comprising:
initiating (S490) control including steering control, differential braking control, or differential acceleration control of a subject vehicle depending on a yaw rate value after a collision with a following vehicle behind the subject vehicle; and
stopping the control depending on the yaw rate value after execution of the control,
wherein the differential braking control is performed based on that criteria based on the yaw rate value are not satisfied after the steering control of the subject vehicle,
characterized in that
the differential acceleration control is performed based on that the criteria based on the yaw rate value are not satisfied after the differential braking control of the subject vehicle.