COLLISION AVOIDANCE CONTROL SYSTEM AND PROCEDURES

Abstract

Collision avoidance control system (100) comprising: a GPS receiver (110) configured to receive position information of a vehicle (A, 210); a navigation system (120) in which map information is stored; a control unit (140) configured to receive the position information of the vehicle (A, 210) from the GPS receiver (110) and the map information from the navigation system (120); and a sensor unit (130) configured to detect at least one target vehicle (B, 220, 222) that is near a roundabout (230), and to obtain driving information about the target vehicle (B, 220, 222), including a distance to the target vehicle (B, 220, 222), a position of the target vehicle (B, 220, 222) and / or a speed of the target vehicle (B, 220, 222), and a forward vision image information of the vehicle (A, 210), wherein the control unit (140) is configured toto calculate an estimated collision point (260) based on the map information, the position information of the vehicle (A, 210) and the driving information about the target vehicle (B, 220, 222), to determine a collision risk based on an absolute value of a difference between a first arrival time (TA) of the vehicle (A, 210) at the calculated estimated collision point (260) and a second arrival time (TB) of the target vehicle (B, 220, 222) at the calculated estimated collision point (260) and to adjust a speed of the vehicle (A, 210) in response to the determined collision risk, wherein the control unit (140) is configured to: derive a plurality of characteristic points with reference to corresponding corners (1, 2, 3, 4) of the target vehicle (B, 220, 222) from the image information obtained by means of the sensor unit (130). extract; extract at least one interpolation point (5, 6) by linear interpolation with reference to the corners,to calculate the points arranged in the steering direction of the target vehicle (B, 220, 222) when the total length of the target vehicle (B, 220, 222) is greater than a predetermined length; and to calculate a plurality of second arrival times (TB_1, TB_2, TB_3, TB_4, TB_5, TB_6) that require the extracted plurality of characteristic points and the calculated minimum interpolation point (5, 6) to reach the estimated collision point (260).

Description

Field of invention The present invention relates to a collision avoidance control system and method, and more specifically to a collision avoidance control system and method that prevents a collision when a vehicle is driven through a roundabout. Discussion of the related technology Recently, safety devices have been developed and installed in vehicles to prevent various types of accidents that can occur while driving. Examples of these safety devices include a frontal collision warning system, which warns of the risk of a collision between the vehicle and a vehicle ahead, and an intersection collision avoidance system, which predicts a collision between vehicles at an intersection. Specifically, the intersection collision avoidance system calculates a vehicle's trajectory, estimates the time to cross the intersection, and transmits the calculated trajectory and estimated time to other vehicles via a vehicle-to-everything (V2X) network, thereby predicting the possibility of a collision and providing a warning. However, in a roundabout, other vehicles approach the vehicle laterally from an area to the side and in front of the vehicle. Therefore, a roundabout collision avoidance system requires a collision detection method that differs from that of a conventional frontal collision warning system. Furthermore, since there are no traffic lights in a roundabout, a collision cannot be avoided simply by predicting and warning of an impending collision. Additionally, the conventional intersection collision avoidance system is only capable of being used in pre-configured spaces or areas, and there remains a risk of collision with other vehicles that do not support inter-vehicle communication among a multitude of vehicles crossing the intersection. It is also limited in its ability to consider vehicles that...driving in a roundabout. From DE 10 2017 122 969 A1, a collision avoidance control system is known which comprises: a GPS receiver configured to receive position information of a vehicle; a navigation system in which map information is stored; a control unit configured to receive the vehicle's position information from the GPS receiver and the map information from the navigation system; and a sensor unit configured to detect at least one target vehicle that is near a roundabout and to obtain driving information about the target vehicle, including a distance to the target vehicle, a position of the target vehicle and / or a speed of the target vehicle, and a forward-looking image of the vehicle, wherein the control unit is configured to calculate an estimated collision point based on the map information.The system calculates the vehicle's position information and the driving information about the target vehicle, determines a collision risk based on an absolute value of the difference between the vehicle's first arrival time at the calculated estimated collision point and the target vehicle's second arrival time at the same point, and adjusts the vehicle's speed in response to the determined collision risk. Further collision avoidance control systems are known from DE 10 2015 217 107 A1, DE 10 2015 205 133 A1, and EP 3 001 272 A1. SHORT DESCRIPTION Accordingly, the present invention relates to a collision avoidance control system and method that essentially avoid one or more problems arising from the limitations and disadvantages of the related technology. It is an object of the present invention to provide a system and method for avoiding a collision when a vehicle enters or drives through a roundabout by determining a collision risk between the vehicle and other vehicles, independent of support for a V2X network function, and by establishing a different driving strategy for the vehicle based on the determined collision risk. Additional advantages, functions, and features of the invention are partly described further below and partly become obvious to those skilled in the art upon studying the following or can be learned from practicing the invention. The functions and other advantages of the invention can be realized and maintained by means of the structure that is presented in particular in the written description and the claims thereto, as well as in the attached drawings. To achieve these tasks and other advantages, and in accordance with the purpose of the invention as set forth and described in detail herein, the invention provides a collision avoidance control system according to claim 1, a collision avoidance control method according to claim 9, and a non-volatile, computer-readable storage medium according to claim 16. Further developments are the subject of the dependent claims. According to the invention, a collision avoidance control system comprises: a global positioning system (GPS) receiver configured to receive position information from a vehicle; a navigation system in which map information is stored; and a control unit configured to receive the vehicle's position information and the map information from the GPS receiver and the navigation system, respectively.and a sensor unit configured to detect at least one target vehicle positioned near a roundabout and to obtain driving information about the target vehicle, including a distance to the target vehicle, a position of the target vehicle and / or a speed of the target vehicle, and / or a preview image information of the (own) vehicle, wherein the control unit is configured to: extract a plurality of characteristic points with reference to corresponding corners of the target vehicle from the image information obtained by means of the sensor unit; calculate at least one interpolation point by linear interpolation with reference to the corners arranged in the steering direction of the target vehicle if the total length of the target vehicle is greater than a predetermined length;and to calculate a plurality of second arrival times that require the extracted plurality of characteristic points and the calculated at least one interpolation point to reach the estimated collision point. Additionally, the control unit can be trained to calculate an estimated collision point based on map information, the vehicle's position information, and driving information about the target vehicle, to determine a collision risk based on an absolute value of the difference between a first arrival time of the vehicle at the calculated estimated collision point and a second arrival time of the target vehicle at the calculated estimated collision point, and to adjust the vehicle's speed in response to the determined collision risk. The control unit can also be trained to estimate a route of the vehicle and a route of the target vehicle based on map information and to calculate the estimated collision point using a point where the route of the vehicle and the route of the target vehicle meet. The collision risk can be determined based on the minimum absolute value of the difference between the second and first arrival times. The control unit can be trained, when the target vehicle is driving through the roundabout, to determine whether the roundabout is ahead of the vehicle by applying the position information received via the GPS receiver at predetermined time intervals to the map information extracted by the navigation system. The control unit can be configured to determine the collision risk when the vehicle is in an area separated from a roundabout entry boundary line by a predetermined distance. The control unit can be configured to allow the vehicle to enter the roundabout if the minimum value is greater than a predetermined first reference value. The control unit can also be configured to prevent the vehicle from entering the roundabout if the minimum value is less than the first reference value. The control unit can be configured to decelerate or brake the vehicle already in the roundabout when it is expected to enter the roundabout, if the minimum value is less than a predefined second reference value. The second reference value can be less than the first reference value, which is a criterion used to determine the collision risk when the vehicle enters the roundabout. It should be understood that both the preceding general description and the following detailed description of the present invention are exemplary and illustrative, and are intended to provide a further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and which are incorporated into and form part of this application, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, Fig. 1 shows a block diagram schematically illustrating the configuration of a collision avoidance control system according to an exemplary embodiment of the present invention; Fig. 2 shows a view showing a situation before a vehicle enters a roundabout, in accordance with an exemplary embodiment of the present invention; Fig. 3 shows a view showing a method for calculating an estimated collision point in accordance with an exemplary embodiment of the present invention; Fig.Figure 4A shows a method for determining a collision risk in accordance with an exemplary embodiment of the present invention; Figure 4B shows a method for calculating an interpolation point of a target vehicle of a predetermined size or more in accordance with an exemplary embodiment of the present invention; Figure 5 shows a situation after a vehicle has entered a roundabout in accordance with an exemplary embodiment of the present invention; and Figure 6 shows a flowchart illustrating a collision avoidance control method according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION It is to be understood that the term "vehicle" or "vehicle-related" or other similar terms as used herein include motor vehicles in general, such as passenger automobiles including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft and the like, and including hybrid vehicles, electric vehicles, internal combustion engine vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other vehicles powered by alternative fuels (for example, fuels derived from raw materials other than oil). Although the exemplary embodiment is described as using a plurality of units that perform the exemplary method, it should be understood that the exemplary method can also be executed by one or more modules. Furthermore, it should be understood that the term controller / control unit refers to a hardware device comprising a memory and a processor. The memory is configured to store the modules, and the processor is specifically configured to execute the modules in order to perform the one or more methods that are further described below. Furthermore, the control logic of the present disclosure can be implemented as a non-volatile, computer-readable medium on a computer-readable medium containing executable program instructions that are executed by a processor, control unit, or similar device. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash memory, smart cards, and optical data storage devices. The computer-readable recording medium can also be distributed in a network coupled with computer systems, such that the computer-readable medium is stored and executed in a distributed manner, for example, by means of a telematics server or a controller area network (CAN). The terminology used herein serves the purpose of describing certain embodiments and is not intended to limit the disclosure. As used herein, the singular forms "a," "an," "one," "the," "the," and "that" are to be understood as including the plural forms unless the context clearly indicates otherwise. Furthermore, the terms "have" and / or "having" when used in this description are to be understood as specifying the presence of a named feature, number, step, process, element, and / or other component, but not excluding the presence or addition of one or more further features, numbers, steps, processes, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of the one or more accordingly listed items. Exemplary embodiments are described in detail below with reference to the accompanying drawings. While the disclosure is directed to various modifications and alternative forms, specific exemplary embodiments are shown as examples in the drawings and are explained in detail in the description. However, the disclosure should not be interpreted as being limited to the exemplary embodiments described herein; rather, the disclosure is intended to cover all modifications and alternatives that fall within the scope of the exemplary embodiments, the invention being defined by the claims. It should be understood that, although the terms "first," "second," etc., may be used herein to describe different elements, these elements should not be interpreted as being limited by these terms. These terms are generally used to distinguish one element from another. Furthermore, terms specifically defined with regard to the design and function of the exemplary embodiments are used only to describe the embodiments; they do not define the scope of the exemplary embodiments. The terminology used herein serves only to describe certain embodiments and is not intended to limit the exemplary embodiments of the invention. Unless otherwise defined, all terms used herein that include technical or scientific expressions have the same meaning as those normally preferred by those skilled in the art. Terms such as those defined in ordinary dictionaries should be interpreted as having the same meaning as terms used in the context of the relevant technology and should not be interpreted as having an ideal or excessively formal meaning unless clearly defined in the description. A collision avoidance control system for a vehicle driving through a roundabout is described below according to an exemplary embodiment of the present invention with reference to the accompanying drawings. Fig. 1 is a block diagram schematically showing the configuration of a collision avoidance control system for driving through a roundabout according to an exemplary embodiment of the present invention. As shown in Fig. 1, a collision avoidance control system 100 according to an exemplary embodiment can comprise a global positioning system (GPS) receiver 110, a navigation system 120, a sensor unit 130, a control unit 140, and a driving unit 150. The control unit 140 can be configured to operate other components of the system 100. In particular, the GPS receiver 110 can be configured to receive a navigation message from at least one GPS satellite positioned above the Earth in order to obtain the position information of a vehicle. The current position coordinates of a vehicle can be determined by measuring the delay time of radio waves transmitted by the GPS satellite. The navigation system 120 can include a database containing map information relating to a nationwide map and route guidance data associated with that map information. The map information can include road information (for example, curves, bumps, adjacent buildings, school zones, number of lanes, speed limits, gradients, accident hotspots, traffic lights, one-way streets, etc.).), route guidance data, road deviation information and intersection information (for example, the type of intersection and possible turning directions depending on the type of intersection). The sensor unit 130 may comprise: a camera 132 configured to detect an object in front of the vehicle by acquiring and processing image information of the object using an optical system; a radio receiver and spread sensor (radar) 134 configured to detect the distance to an object, as well as its speed and angle, using an electromagnetic wave; and a light detector and spread sensor (lidar) 136 configured to monitor a blind spot that cannot be monitored by the radar sensor using light. The sensor unit 130 may be configured to detect a target vehicle positioned within a predetermined area FR in front of the vehicle using at least one of the sensors 132, 134, or 136 described above, and to acquire image information and driving information about the target vehicle. The control unit 140 can be configured to receive the vehicle's position information, map information, and image information, or driving information about the target vehicle, from the GPS receiver 110, the navigation system 120, or the sensor unit 130 via a Controller Area Network (CAN) communication. The control unit 140 can then be configured to calculate an estimated collision point between the vehicle and the target vehicle in the roundabout based on the received vehicle position information, map information, image information, and / or driving information about the target vehicle. Additionally, the control unit 140 can be configured to determine a collision risk based on the difference between the arrival time of the vehicle at the calculated estimated collision point and the arrival time of the target vehicle at the same point, and to develop a driving strategy for the vehicle (for example, a driving control to prevent a collision with the target vehicle when entering, driving through, or exiting the roundabout) based on the determined collision risk. The driving unit 150 can include devices such as a motor, a throttle valve, a transmission, a brake, and similar components that influence the vehicle's speed. These devices can be operated accordingly based on the driving strategy developed by the control unit 140. The operation of the control unit in situations where the vehicle enters, passes through, and exits the roundabout is described in greater detail below with reference to Figures 2, 3, 4 to 5. Figure 2 shows a view of the situation before the vehicle enters the roundabout, in accordance with an exemplary embodiment of the present invention. Referring to Figure 2, the control unit 140 can be configured to determine whether the roundabout 230 is present in front of (or within the path of) the vehicle (A) 210. In one example, the control unit 140 can be configured to determine the presence or absence of the roundabout 230 in front of its own or the vehicle 210 in question by applying the current position information of its own vehicle 210, which is received via the GPS receiver 110 at predetermined time intervals, to the map information extracted by the navigation system 120. In another example, the control unit 140 can be configured to determine, upon detecting a given traffic sign 240, that the roundabout 230 is on the route of its own vehicle 210, based on the forward-looking image information of its own vehicle 210, which is periodically received by the sensor unit 130. In response to the determination that the roundabout 230 is located in front of the vehicle 210, the control unit 140, in order to determine the collision risk between the vehicle 210 and the target vehicle (B) 220, can be configured to determine whether the vehicle 210 is currently located in a predefined area 250 immediately in front of an entry boundary line or a stop line STOP_LINE of the roundabout 230. In particular, the predefined area 250 can be an area that is separated from the entry boundary line STOP_LINE of the roundabout 230 by a predefined distance that is equal to or greater than a first distance Lmin and equal to or less than a second distance Lmax.The first distance Lmin can be a minimum edge distance to ensure a safety distance, and the second distance Lmax can be a distance calculated based on the average time required by the control unit 140 to determine a collision risk and develop a driving strategy, and based on the speed of the vehicle 210. The second distance Lmax can also be set taking into account the overall length of the vehicle 210. However, the present invention is not limited to this. If the distance Lstop between the current position of the own vehicle 210 and the entry boundary line STOP_LINE of the roundabout 230 is less than the first distance Lmin, the braking distance of the own vehicle 210 may be greater than the distance Lstopda between them. In particular, the own vehicle 210 may be allowed to enter the roundabout 230. If the distance Lstop between the current position of the own vehicle 210 and the entry boundary line STOP_LINE of the roundabout 230 is greater than the second distance Lmax, a pre-developed logic for determining a collision risk between the own vehicle 210 and the target vehicle 220 cannot be executed. The control unit 140 can be configured to reduce the speed of the own vehicle 210 to a predetermined level or less when the distance Lstop between the current position of the own vehicle 210 and the entry boundary line STOP_LINE of the roundabout 230 is within the specified range 250 between the first distance Lmin and the second distance Lmax, and the sensor unit 130 can be configured to detect at least one target vehicle 220 which is driving through the roundabout 230 within a specified range FR in front of the own vehicle 210, by means of at least one of the sensors 132, 134 136. The logic for determining the collision risk between the own vehicle 210 and the target vehicle 220 can be explained below. With reference to Fig. 3, a method for calculating an estimated collision point is described below, which is needed to determine the collision risk between the own vehicle 210 and the target vehicle 220. Fig. 3 is a view showing the method for calculating an estimated collision point in accordance with an exemplary embodiment of the present invention. Referring to Fig. 3, the control unit 140 can be configured to estimate the route of the own vehicle 210 and the route of the target vehicle 220 based on the map information and to calculate an estimated collision point 260 using a point where the route of the own vehicle 210 and the route of the target vehicle meet. In particular, the route of the vehicle 210 can be estimated based on the position information (e.g., the position coordinates) received by the GPS receiver 110 at predefined time intervals. The direction of travel of the vehicle 210 can be calculated based on the change in the vehicle's steering coordinates per unit of time, which is contained in the position information, and the route of the vehicle 210 can be estimated by applying the calculated direction of travel to the map information. Additionally, the route of the target vehicle 220 can be estimated based on the driving information about the target vehicle 220, which is periodically received by the radar sensor 134 and / or the lidar sensor 136 of the sensor unit 130. In particular, the direction of travel of the target vehicle 220 can be calculated based on changes in distance to the target vehicle 220 per unit of time, angles to the target vehicle 220, etc., which are contained in the driving information, and the route of the target vehicle 220 can be estimated by applying or assigning the calculated direction of travel to the map information. As shown in Fig. 3, the control unit 41 can be configured to calculate the estimated collision point 260 using a point where the estimated route of the own vehicle 210 and the estimated route of the target vehicle 220 meet, or at a point where an imaginary line extending from the route of the own vehicle 210 and an imaginary line extending from the route of the target vehicle 220 meet (for example, cross). The control unit 41 can be configured to determine a collision risk when the estimated collision point 260 is calculated by calculating a first arrival time of the own vehicle 210 at the estimated collision point 260 and a second arrival time of the target vehicle 220 at the estimated collision point 260. To calculate the first arrival time of the own vehicle 210 and the second arrival time of the target vehicle 220, the speeds of the own vehicle 210 and the target vehicle 220, or the lengths of their routes to the estimated collision point 260, are required. This is described in greater detail with reference to Figures 4A and 4B. Fig. 4A is a view showing a method for determining a collision risk according to an exemplary embodiment of the present invention, and Fig. 4B is a view showing a method for calculating an interpolation point of a target vehicle having a predetermined size or more, in accordance with an exemplary embodiment of the present invention. The speed VA of the own vehicle 210 can be calculated using the position information received from the GPS receiver 110, for example, via the change in position per unit of time. Alternatively, the speed VA can be obtained using a speed sensor (not shown) located in the own vehicle 210. The speed VB of the target vehicle 220, as shown in Fig. 4A, can be calculated by correcting a speed VH of the target vehicle 220 obtained from the sensor unit 130, based on the local coordinate system of the own vehicle 210. Since roundabout 230 has a specific radius of curvature, and the target vehicle 220 travels along the route influenced by the radius of curvature of roundabout 230, the value of the Y-vector component of the target vehicle 220's speed VH, obtained from sensor unit 130, can change continuously. Accordingly, to correct for this changing Y-vector component, it may be necessary to calculate the vehicle's speed VB by projecting the target vehicle 220's speed VH, obtained from sensor unit 130, onto the route associated with the map information. In particular, the control unit 140 can be configured to place a value of the position coordinate of its own vehicle 210 at the origin (0, 0) of an XY coordinate system; to decompose the velocity VH of the target vehicle 220, obtained from the sensor unit 130, into an X-vector component and a Y-vector component VX and VY; and to determine the driving speed VB by projecting the vectors onto the route associated with the map information. The vector of the corrected driving speed VB can have the same direction as a tangent to the route. Additionally, the control unit 140 can be configured to calculate a route distance to the estimated collision point 260 and to calculate an arrival time using a ratio of route distance to vehicle speed. A first arrival time TA of the own vehicle 210 can be calculated using a ratio of the route distance LA from the current position to the estimated collision point 260 to the vehicle speed VA of the own vehicle 210. The first arrival time TA can be expressed using the following equation 1. A second arrival time TB of the target vehicle 220 can be calculated by extracting a plurality of characteristic points with reference to corresponding corners of the target vehicle 220. Referring to Fig. 4A, the control unit 140 can be configured to extract the characteristic features 270 with reference to the corresponding corners 1, 2, 3 and 4 of the target vehicle 220 from the image information obtained by means of the sensor unit 130 and to calculate route distances LB_1, LB_2, LB_3 and LB_4 from the corresponding extracted characteristic points 270 to the estimated collision point 260. Accordingly, the second arrival time TB of the target vehicle 220 can comprise a plurality of second arrival time values ​​TB_1, TB_2, TB_3 and TB_4, which are calculated using the ratio of the route distances LB_1, LB_2, LB_3 and LB_4, from the corresponding characteristic points 270 to the estimated collision point 260, to the speed VB of the target vehicle 220. The second arrival time values ​​TB_1, TB_2, TB_3 and TB_4 can be expressed using the following equation 2. Furthermore, as shown in Fig. 4B, if the overall length of the target vehicle 222 is greater than a predetermined length, for example in the case of a bus, a truck, or the like, at least one interpolation point 5 and 6 can be set in addition to the characteristic points 272 with reference to the corresponding corners 1, 2, 3, and 4 of the target vehicle 222. In the case of a long vehicle, such as a bus, a truck, or the like, if a collision risk between the user's own vehicle 210 and the long vehicle is determined by extracting only the characteristic points 272 with reference to the four corners of the long vehicle, the possibility of a collision with the central section of the long vehicle cannot be ruled out.For example, the own vehicle 210 can recognize the front corners 1 and 4 of the target vehicle 222 as a preceding vehicle and can recognize the rear corners 2 and 3 of the target vehicle 222 as a following vehicle. Accordingly, the own vehicle 210 can collide with a section of the target vehicle 222 that corresponds to an area between the front corners 1 and 4 of the target vehicle 222 and its rear corners 2 and 3. Therefore, the control unit 140 can be configured to additionally set at least one interpolation point 5 and 6 based on the size or overall length of the target vehicle 222. In particular, the interpolation point 5 or 6 can be determined by linear interpolation by applying a predefined weighting value to the positional coordinates between the corners arranged in the steering direction of the target vehicle 222, for example, between the front corners 1 or 4 and the rear corners 2 or 3. As an example, with reference to Fig. 4B, Table 280 is shown, in which the position coordinates of the interpolation points 5 and 6, calculated by linear interpolation using a weighting value of 0.5, are entered. However, this is merely an illustration. The weighting value can be set in a range from 0 to 1 based on the size of the target vehicle 222. Furthermore, the control unit 140 can be configured to additionally calculate a route distance LB_5 or LB_6 from the at least one interpolation point 5 or 6 to the estimated collision point 260, or a second arrival time TB_5 or TB_6, in order to determine a collision risk with the at least one interpolation point 5 or 6. Referring to Fig. 4A, when the first arrival time TA of the own vehicle 210 and the second arrival times TB_1, TB_2, TB_3 and TB_4 of the target vehicle 220 are calculated, the control unit 140 can be configured to determine a collision risk based on absolute values ​​of differences between the first arrival time and each of the second arrival times. In particular, it is possible to determine collision risks of the own vehicle 210 with each of the corners 1, 2, 3 and 4 of the target vehicle 220 using absolute values ​​|TG| (hereinafter referred to as the "arrival time gap") of differences between the first arrival time TA and each of the second arrival times TB_1, TB_2, TB_3 and TB_4. The arrival time gaps |TGAB_1|, |TGAB_2|, |TGAB_3| and |TGAB_4| The position of the own vehicle 210 with reference to each of the corners 1, 2, 3 or 4 of the target vehicle 220 can be expressed using the following equation 3. The collision risk of the own vehicle 210 with respect to corners 1, 2, 3, and 4 of the target vehicle 220 can vary based on the size of the corresponding arrival time gaps |TG|. For example, the probability of a collision between the own vehicle 210 and the target vehicle 220 is greater the smaller the arrival time gap |TG|. Conversely, the larger the arrival time gap |TG|, the lower the probability of a collision between the own vehicle 210 and the target vehicle 220. Therefore, the control unit 140 can be trained to calculate a collision risk based on the minimum value |TGAB| of the arrival time gaps of its own vehicle 210 with respect to the corresponding corners 1, 2, 3 and 4 of the target vehicle 220. The minimum value |TGAB| of the arrival time gaps can be expressed using the following equation 4. Furthermore, the control unit 140 can be configured to determine whether the own vehicle 210 should be allowed to enter the roundabout 230 by comparing the minimum value |TGAB| of the arrival time gaps of the own vehicle 210 with respect to the corresponding corners 1, 2, 3, 4 of the target vehicle 220 with a predefined first reference value Tth_1. For example, the control unit 140 can be configured to allow the own vehicle 210 to enter the roundabout 230 if the calculated minimum value |TGAB| is greater than the first reference value Tth_1 (|TGAB|>Tth_1). The control unit 140 can be configured to prevent the own vehicle 210 from entering the roundabout 230 if the calculated minimum value |TGAB| smaller than the first reference value Tth_1 (|TGAB| < Tth_1), by operating the vehicle in a manner that avoids entering the roundabout. In particular, the control unit 140 can be configured to determine, when the control unit 140 prevents the vehicle 210 from entering the roundabout 230, whether the vehicle 210 should slow down or stop by comparing the minimum value |TGAB| with a predefined second reference value Tth_2, which differs from the first reference value Tth_1. For example, the control unit 140 can be configured to generate a braking command if the minimum value |TGAB| is less than the first reference value Tth_1 and greater than the second reference value Tth_2 (Tth_1 > |TGAB| > Tth_2). The control unit 140 can be configured to generate a stop command if the minimum value |TGAB| is less than the second reference value Tth_2 (Tth_1 > |TGAB| > Tth_2). The driving unit 150 can therefore be trained to perform a braking maneuver in response to the control command. As described above, the control unit 140 can be trained to develop a different driving strategy for the vehicle (for example, a driving control to avoid a collision with a target vehicle when the vehicle enters the roundabout) based on the determined collision risk. Alternatively, the control unit 140 can be trained to determine whether the own vehicle 210 should be allowed to enter the roundabout 230, based on a result strategy developed taking into account traffic rules that indicate which vehicle traveling through the roundabout 230 has priority. However, the control unit 140 can be trained, with regard to alleviating a traffic jam, to allow the own vehicle 210 to enter the roundabout even if the target vehicle 220 has priority, if the probability of a collision is extremely low. For example, the control unit 140 can be configured to determine the minimum values ​​of the second arrival times TB_1, TB_2, TB_3, and TB_4 when the target vehicle 220 is a vehicle driving through the roundabout 230. The control unit can be configured to generate a stop control command if the calculated minimum value is less than a predefined third reference value Tth_3. The control unit 41 can be configured to allow its own vehicle 210 to enter the roundabout (for example, not to interrupt any vehicle operations to steer the vehicle away from the roundabout) if the calculated minimum value is greater than the third reference value Tth_3. The following describes, with reference to Fig. 5, a method for determining a collision risk and developing a driving strategy when the driving state of the vehicle 210, shown in Figs. 2 and 3, changes after the vehicle 210 has entered the roundabout 230 (for example, a transition from an anticipatory roundabout entry strategy to a roundabout transit strategy). Fig. 5 is a view showing the situation after the vehicle has entered the roundabout, in accordance with an exemplary embodiment of the present invention. The sensor unit 130 can be configured to detect at least one target vehicle (C) 510 that is expected to enter the roundabout 230 within a predetermined area FR in front of the own vehicle (A) 210 (for example, within a predetermined distance in front of the own vehicle), using at least one of the sensors 132, 134, 136. The control unit can be configured, in response to the detection of the at least one target vehicle (C) 510 that is expected to enter the roundabout 230, to determine a collision risk between the own vehicle 210 and the target vehicle 510 and to adjust the speed of the own vehicle 210 in response to the determined collision risk. In particular, the determination of the collision risk can be implemented in the same way as described above with reference to Figures 3 and 4A to 4B. In other words, an estimated collision point 260 can be determined based on the position information of the own vehicle 210 and the driving information of the target vehicle 510, and the collision risk can be determined based on an absolute value of the difference between a first arrival time of the own vehicle 210 at the calculated estimated collision point 260 and a second arrival time of the target vehicle 510 at the calculated estimated collision point 260. The control unit 140 can be configured to determine whether to slow down or brake its own vehicle 210, which is driving through the roundabout 230, by comparing the minimum value |TGAC| of the arrival time gap of its own vehicle 210 with respect to the corresponding corners (not shown) of the target vehicle 510 with a predefined fourth reference value Tth_4. The control unit 140 can be configured, for example, if the calculated minimum value |TGAC| is greater than the fourth reference value Tth_4 (|TGAC| > Tth_4), to prevent its own vehicle 210 from slowing down or braking at the roundabout 230. The control unit 140 can be configured if the calculated minimum value |TGAC| smaller than the fourth reference value Tth_4ist (|TGAC| > Tth_4), to generate a control command to slow down or brake the own vehicle 210, which is driving through the roundabout 230. The fourth reference value Tth_4 can be smaller than the first reference value Tth_1, which is a criterion used to determine a collision risk when the vehicle 210 enters the roundabout. Specifically, the vehicle 210 has priority in accordance with traffic regulations when its driving state changes from an anticipated entry into the roundabout to a state of traversing the roundabout.The control unit 140 can be configured to adjust the speed of its own vehicle 210 when the target vehicle 510 enters the roundabout 230 within the specified area in front of its own vehicle 210, while the control unit 140 is performing the deceleration or braking control of its own vehicle 210 due to the high probability of collision, so that its own vehicle 210 follows the target vehicle 510 while maintaining a specified distance to the target vehicle 510. As described above, the control unit 140 can be configured to develop different driving strategies for a vehicle (for example, a driving control strategy to avoid a collision with a target vehicle when the vehicle is driving through a roundabout) based on the determined collision risk. If the intention is for the own vehicle 210 to exit the roundabout 230, the driving strategy can vary based on the road on which the own vehicle 210 is driving. For example, the vehicle 210 can be trained to generate an exit route from the roundabout and leave the roundabout by driving along the exit route when the vehicle 210 is driving in an exit lane of the roundabout 230. If the vehicle 210 is not driving in the exit lane of the roundabout 230, the vehicle 210 can move onto the exit lane at a predetermined distance from the exit boundary line of the roundabout 230 and then leave the roundabout 230. A collision avoidance control method according to an exemplary embodiment of the present invention is described below with reference to Fig. 6. Fig. 6 is a flowchart illustrating a collision avoidance control method according to an exemplary embodiment of the present invention. As shown in Fig. 6, the collision avoidance control method according to an exemplary embodiment of the present invention can be divided into a method in a situation before the vehicle enters the roundabout (S610) and a method in a situation after the vehicle enters the roundabout (S620). First, the collision avoidance control procedure is described for the situation before the vehicle enters the roundabout (S610). The control unit 140 can be configured to determine the presence or absence of the roundabout 230 in front of the vehicle 210 (S611) by applying the current position information of the vehicle 210, which is received by the GPS receiver 110 at predefined time intervals, to the map information extracted by the navigation system 120 (for example, the received position information is compared with the extracted map information). In response to the determination that the roundabout 230 is in front of the vehicle 210, the control unit 140 can be configured to calculate a remaining distance Lstop between the current position of the vehicle 210 and the entry boundary line STOP_LINE of the roundabout 230 (S612). The control unit 140 can be configured to subsequently determine whether the remaining distance Lstop lies within a predetermined area 250, which is spaced from the entry boundary line STOP_LINE of the roundabout 230 by a distance equal to or greater than a first distance Lmin and equal to or less than a second distance Lmax (S613). The first distance Lmin can be a minimum edge distance to ensure a safety distance, and the second distance Lmax can be a distance calculated based on an average time required by the control unit 140 to determine a collision risk and develop a driving strategy, and based on the speed of the vehicle 210. The second distance Lmax can additionally be set based on the overall length of the vehicle 210. However, the present invention is not limited to this. The control unit 140 can be configured to reduce the speed of its own vehicle 210 to a predetermined level or less if the remaining distance Lstop is within the specified range 250 (JA in S613), and the sensor unit 130 can be configured to detect, by means of at least one of the sensors 132, 134, 136, whether at least one target vehicle 220 is driving through the roundabout 230 within a specified range FR in front of its own vehicle 210 (S614). The control unit 140 can be configured to allow the own vehicle 210 to enter the roundabout 230 if the remaining distance Lstop is less than the initial distance Lminist (NO in S613) or if no target vehicle is detected (NO in S614) (S618). However, the control unit 41 can be configured to calculate an estimated collision point 260 if at least one target vehicle 220 is detected (YES in S614) using a point where the route of the own vehicle 210 and the route of the target vehicle 220 meet or intersect, and can be configured to calculate an arrival time gap value |TG|, which is an absolute value of the difference between a first arrival time of the own vehicle 210 at the estimated collision point 260 and a second arrival time of the target vehicle 220 at the estimated collision point 260 (S615). The control unit 140 can be configured to determine whether it permits the own vehicle 210 to enter the roundabout 230 by comparing the calculated arrival time gap |TG| with a first reference value Tth_1 (S616). The control unit 140 can be configured to prevent the own vehicle 210 from entering the roundabout 230 and generate a braking or stop control command (S617) if the calculated arrival time gap |TG| is smaller than the first reference value Tth_1 (|TG| < Tth_1) (NO in S616). The control unit 140 can be configured to permit the own vehicle 210 to enter the roundabout 230 (S618) if the calculated arrival time gap |TG| is smaller than the first reference value Tth_1 (|TG| > Tth_1) (YES in S616). The following describes the collision avoidance control procedure in the situation after the vehicle has entered the roundabout (S620). The sensor unit 130 can be configured to detect whether at least one target vehicle 510 is expected to enter the roundabout 230 within a predefined area FR in front of the vehicle 210, using at least one of the sensors 132, 134, or 136 (S621). If no target vehicle is detected (NO in S621), the vehicle 210 can proceed continuously through the roundabout 230 (S625). The control unit 41 can be configured, when at least one target vehicle 510 is detected (JA in S621), to calculate an estimated collision point using a point where the route of the own vehicle 210 and the route of the target vehicle 510 meet, and can be configured to calculate an arrival time gap |TG| which is an absolute value of a difference between a first arrival time of the own vehicle 210 at the estimated collision point and a second arrival time of the target vehicle 510 at the estimated collision point (S622). The control unit 140 can be configured to subsequently determine whether to slow down or brake its own vehicle 210, which is driving through the roundabout 230, by comparing the calculated arrival time gap |TG| with a fourth reference value Tth_4 (S623). The control unit 140 can be configured to generate a control command to slow down or brake its own vehicle 210, which is driving through the roundabout 230, if the calculated arrival time gap |TG| is less than the fourth reference value Tth_4 (|TG| < Tth_4) (NO in S623) (S624). The control unit 140 can be configured to generate a control command to slow down or brake its own vehicle 210, which is driving through the roundabout 230, if the calculated arrival time gap |TG| greater than the fourth reference value Tth_4ist (|TG| > Tth_4) (JA in S623), to prevent the own vehicle 210 from slowing down or braking in the roundabout 230 (S625).The control unit 140 can be trained to subsequently determine whether the own vehicle 210 has left the roundabout 230 (626). If the vehicle 210 has not left the roundabout 230 (NO in S626), the procedure can be continued in step S621, in which the sensor unit 130 detects whether at least one target vehicle 510 is expected to enter the roundabout 230 within a predetermined area FR in front of the vehicle 210. If the vehicle 210 has left the roundabout 230 (YES in S626), the collision avoidance control procedure for driving through a roundabout according to an exemplary embodiment of the present invention can be terminated. The collision avoidance control method according to an exemplary embodiment described above can be programmed to run on a computer and can be stored on a non-volatile, computer-readable storage medium. Examples of non-volatile, computer-readable storage media include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices. The non-volatile, computer-readable storage medium can also be distributed across a network-connected computer system, so that the computer-readable code is stored and executed in a distributed manner. Furthermore, functional programs, code, and code segments for carrying out the procedure described above can be easily constructed by programmers experienced in this field, to whom this disclosure is addressed. Although only a limited number of exemplary embodiments have been described above, various other exemplary embodiments are possible. The technical content of the exemplary embodiments described above can be combined in various ways, provided they are not incompatible with each other, and thus implemented in new embodiments. The collision avoidance control system and procedure according to the exemplary embodiments described above can be applied not only to a roundabout, but also to a general intersection where there is no traffic light, where the traffic light flickers abnormally, or where a left turn is permitted. As is evident from the preceding description, the present invention provides a system and a method for avoiding collisions when a vehicle enters or passes through a roundabout by determining a collision risk between the vehicle and other vehicles, independent of the support of a V2X network function. Additionally, it may be possible to effectively prevent vehicle collisions at a roundabout and improve traffic flow by establishing different driving strategies for the vehicle based on the determined collision risk. Experts in this field will appreciate that the effects achieved by means of the present invention are not limited to those specifically described above, and other effects of the present invention are better understood from the preceding detailed description. Those skilled in the art will appreciate that the present invention can be carried out in other specific ways than those described herein without departing from the spirit and essential characteristics of the present invention. The preceding exemplary embodiments are therefore designed to be illustrative and non-limiting in all aspects. The scope of the present invention should be determined by the attached claims and their legal equivalents, and not by the preceding description, and any modifications that fall within the scope and equivalence of the attached claims are intended to be included therein.

Claims

Collision avoidance control system (100) comprising: a GPS receiver (110) configured to receive position information of a vehicle (A, 210); a navigation system (120) in which map information is stored; a control unit (140) configured to receive the position information of the vehicle (A, 210) from the GPS receiver (110) and the map information from the navigation system (120); and a sensor unit (130) configured to detect at least one target vehicle (B, 220, 222) that is near a roundabout (230), and to obtain driving information about the target vehicle (B, 220, 222), including a distance to the target vehicle (B, 220, 222), a position of the target vehicle (B, 220, 222) and / or a speed of the target vehicle (B, 220, 222), and a forward vision image information of the vehicle (A, 210), wherein the control unit (140) is configured toto calculate an estimated collision point (260) based on the map information, the position information of the vehicle (A, 210) and the driving information about the target vehicle (B, 220, 222), to determine a collision risk based on an absolute value of a difference between a first arrival time (TA) of the vehicle (A, 210) at the calculated estimated collision point (260) and a second arrival time (TB) of the target vehicle (B, 220, 222) at the calculated estimated collision point (260) and to adjust a speed of the vehicle (A, 210) in response to the determined collision risk, wherein the control unit (140) is configured to: derive a plurality of characteristic points with reference to corresponding corners (1, 2, 3, 4) of the target vehicle (B, 220, 222) from the image information obtained by means of the sensor unit (130). extract; extract at least one interpolation point (5, 6) by linear interpolation with reference to the corners,to calculate the points arranged in the steering direction of the target vehicle (B, 220, 222) when the total length of the target vehicle (B, 220, 222) is greater than a predetermined length; and to calculate a plurality of second arrival times (TB_1, TB_2, TB_3, TB_4, TB_5, TB_6) that require the extracted plurality of characteristic points and the calculated minimum interpolation point (5, 6) to reach the estimated collision point (260). Collision avoidance control system (100) according to claim 1, wherein the control unit (140) is configured to: estimate a route of the vehicle (A, 210) and a route of the target vehicle (B, 220, 222) based on the map information; and calculate the estimated collision point (260) using a point where the route of the vehicle (A, 210) and the route of the target vehicle (B, 220, 222) meet. Collision avoidance control system (100) according to one of claims 1 or 2, wherein the collision risk is determined based on a minimum value (|TGAB|) of absolute values ​​of differences between the second arrival times (TB_1, TB_2, TB_3, TB_4, TB_5, TB_6) and the first arrival time (TA). Collision avoidance control system (100) according to claim 3, wherein the control unit (140) is configured to determine, when the target vehicle (B, 220, 222) is driving through the roundabout (230): whether the roundabout (230) is in front of the vehicle (A, 210) by comparing the position information received by the GPS receiver (110) at predetermined time intervals with the map information extracted by the navigation system (120). Collision avoidance control system (100) according to claim 4, wherein the control unit (140) is configured to determine the collision risk when the vehicle (A, 210) is located in an area that is separated from an entry boundary line (STOP_LINE) of the roundabout (230) by a predetermined distance. Collision avoidance control system (100) according to one of claims 4 or 5, wherein the control unit (140) is configured to allow the vehicle (A, 210) to enter the roundabout (230) when the minimum value (|TGAB|) is greater than a predetermined first reference value (Tth_1). Collision avoidance control system (100) according to one of claims 4 to 6, wherein the control unit (140) is configured to prevent the vehicle (A, 210) from entering the roundabout (230) when the minimum value (|TGAB|) is less than a predetermined first reference value (Tth_1). Collision avoidance control system (100) according to one of claims 3 to 6, wherein the control unit (140) is configured to slow down or brake the vehicle (A, 210) traveling through the roundabout (230) when the target vehicle (B, 220, 222) is expected to enter the roundabout (230), if the minimum value (|TGAB|) is less than a predetermined second reference value (Tth_2), and wherein the second reference value (Tth_2) is less than a first reference value (Tth_1), the first reference value (Tth_1) being a criterion used to determine the collision risk when the vehicle (A, 210) enters the roundabout (230). Collision avoidance control method comprising: Receiving map information and position information of a vehicle (A, 210) by means of a control unit (140); Detecting at least one target vehicle (B, 220, 222) located near a roundabout (230) and receiving driving information about the target vehicle (B, 220, 222), including a distance to the target vehicle (B, 220, 222), a position of the target vehicle (B, 220, 222) and / or a speed of the target vehicle (B, 220, 222), and of forward image information of the vehicle (A, 210) using at least one sensor (132, 134, 136) arranged in the vehicle (A, 210) by means of the control unit (140); Calculating an estimated collision point (260) based on the map information, the Position information of the vehicle (A, 210) and driving information about the target vehicle (B, 220, 222), by means of the control unit (140);Determining a collision risk based on an absolute value of a difference between a first arrival time (TA) of the vehicle (A, 210) at the calculated estimated collision point (260) and a second arrival time (TB) of the target vehicle (B, 220, 222) at the calculated estimated collision point (260); and adjusting a speed of the vehicle (A, 210) in response to the determined collision risk, by means of the control unit (140); wherein determining the collision risk comprises: extracting a plurality of characteristic points with reference to corresponding corners (1, 2, 3, 4) of the target vehicle (B, 220, 222) from the image information obtained from the sensor (132, 134, 136), by means of the control unit (140);Calculate at least one interpolation point (5, 6) by linear interpolation with reference to the corners arranged in the steering direction of the target vehicle (222), if the target vehicle (B, 220, 222) has a total length greater than a predetermined length, using the control unit (140); and calculate a plurality of second arrival times (TB_1, TB_2, TB_3, TB_4, TB_5, TB_6) that require the extracted plurality of characteristic points and the calculated at least one interpolation point (5, 6) to reach the estimated collision point (260). Collision avoidance control method according to claim 9, wherein the calculation of the estimated collision point (260) comprises: estimating a route of the vehicle (A, 210) and a route of the target vehicle (B, 220, 222) based on the map information by means of the control unit (140); and calculating the estimated collision point (260) using a point where the route of the vehicle (A, 210) and the route of the target vehicle (B, 220, 222) meet, by means of the control unit (140). Collision avoidance control method according to claim 9 or 10, wherein the determination of the collision risk comprises: determining the collision risk based on a minimum value (|TGAB|) of the absolute values ​​of the differences between the second arrival times (TB_1, TB_2, TB_3, TB_4, TB_5, TB_6) and the first arrival time (TA), by means of the control unit (140). Collision avoidance control method according to claim 11, further comprising: Determining by means of the control unit (140) whether the roundabout (230) is in front of the vehicle (A, 210) when the target vehicle (B, 220, 222) is driving through the roundabout (230), by comparing the position information received at specified time intervals with the map information. Collision avoidance control method according to claim 12, wherein the determination of the collision risk further comprises: determining the collision risk by means of the control unit (140) when the vehicle (A, 210) is in an area that is separated from an entry boundary line (STOP_LINE) of the roundabout (230) by a predetermined distance. Collision avoidance control method according to claim 12, wherein the adjustment of the speed of the vehicle (A, 210) comprises: allowing the vehicle (A, 210) by means of the control unit (140) to enter the roundabout (230) when the minimum value (|TGAB|) is greater than a predetermined first reference value (Tth_1). Collision avoidance control method according to one of claims 12 or 13, wherein, when the target vehicle (B, 220, 222) is expected to enter the roundabout (230), the adjustment of the speed of the vehicle (A, 210) comprises: slowing down or braking the vehicle (A, 210) traveling through the roundabout (230) by means of the control unit (140) when the minimum value (|TGAB|) is less than a predetermined second reference value (Tth_2), and wherein the second reference value (Tth_2) is less than a first reference value (Tth_1), the first reference value (Tth_1) being a criterion used to determine the collision risk when the vehicle (A, 210) enters the roundabout (230). Non-volatile, computer-readable storage medium on which a program is stored that causes a computer to execute the collision avoidance control procedure according to any one of claims 9 to 15.

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