Method for collision avoidance of autonomous mobile robit using v2v communication in facing situation and apparatus and system for the same

Abstract

According to the present invention, a collision prevention method for an autonomous mobile robot using V2V communication performed in a mobile robot comprises: a step of collecting movement information related to the position and speed of a guest mobile robot from each of a plurality of guest mobile robots located nearby using V2V (Vehicle-to-Vehicle Communication); a step of determining a collision situation based on the movement information of the guest mobile robot and the movement information of the mobile robot itself; a step of determining a speed reduction ratio of the mobile robot or the guest mobile robot to prepare for a collision situation; and a step of performing driving, deceleration, or stopping control of the mobile robot by applying the determined speed reduction ratio. The step of determining a collision situation includes a step of determining whether the path directions of the mobile robot and the guest mobile robot are opposite to each other and the two paths are on the same line, thereby forming a facing situation. The V2V communication utilizes a broadcast communication method.

Description

Technology Field

[0001] The present invention relates to a method for preventing collisions of autonomous mobile robots using Vehicle-to-Vehicle Communication (V2V) in a face-to-face situation, and to an apparatus and system for the same. More specifically, the invention relates to a method, apparatus, and system for preventing collisions between mobile robots and controlling their movements using V2V communication in an environment where multiple autonomous mobile robots are moving. Background Technology

[0003] V2V communication refers to wireless communication between vehicles. Recently, as autonomous driving functions have been installed in automobiles, active research and development are being conducted to prevent collisions between vehicles by using terminals equipped with V2V wireless communication technology to continuously transmit and receive data wirelessly with surrounding vehicles and identify the speed and location of other vehicles. Furthermore, as logistics automation expands, the demand for autonomous guided vehicles (AGVs) is growing, and research and development on the movement control of mobile robots in such work environments is being carried out.

[0004] Conventionally, research and development on collision avoidance has been conducted by using V2V terminals to receive data such as vehicle speed and location information and predict the path of other vehicles. Additionally, development and research are underway to prevent collisions by detecting objects and decelerating or stopping using sensor devices such as depth cameras and LiDAR on mobile robots. Furthermore, control systems, such as central control centers, and control methods are being developed to prevent traffic collisions involving multiple mobile robots.

[0005] However, conventional collision avoidance technologies using such sensors focus on detecting objects, making it impossible to handle blind spots. Furthermore, there is a problem in that it is difficult to manage collisions in the event of sensor errors or failures. Additionally, if traffic control collision avoidance commands are not properly transmitted from the control system or if an error occurs in the control system, collision avoidance by the mobile robot becomes impossible.

[0006] Therefore, to solve the above problems, a new method and device are required that can receive mobile robot data, such as the robot's position path, in real time via V2V wireless communication and utilize that information in real time to implement collision prevention. Prior art literature

[0008] Republic of Korea Registered Patent No. 10-1716047 The problem to be solved

[0009] The present invention aims to provide a method and device for preventing collisions that may occur during the movement of multiple autonomous guided vehicles (AGVs) or autonomous mobile robots (AMRs) in industrial sites.

[0010] In addition, the present invention aims to provide a method for preventing collisions and controlling the speed of an autonomous mobile robot using V2V communication, and a device for the same, in order to resolve the issue of collisions caused by malfunctions and blind spots during object recognition via sensors such as cameras and LiDAR when there is an error in the control of a central control system performing traffic control or when the system does not operate normally.

[0011] In addition, the present invention aims to provide a method and device that enable each mobile robot to independently and autonomously control movement, such as deceleration and stopping, by utilizing data analysis through V2V communication between multiple mobile robots, thereby preventing collisions.

[0012] In addition, the present invention aims to provide a method, device, and system for more effectively preventing collisions of autonomous mobile robots by classifying crossing situations, following situations, and facing situations in an environment where multiple mobile robots are driving, and deriving a deceleration ratio value for each situation.

[0013] The problems to be solved by the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by a person skilled in the art from the description below. means of solving the problem

[0015] According to one embodiment of the present invention, a collision prevention method for an autonomous mobile robot using V2V communication performed in a mobile robot comprises: a step of collecting movement information related to the position and speed of a guest mobile robot from each of a plurality of guest mobile robots located in the vicinity using V2V (Vehicle-to-Vehicle Communication); a step of determining a collision situation based on the movement information of the guest mobile robot and the movement information of the mobile robot itself; a step of determining a speed reduction ratio of the mobile robot or the guest mobile robot to prepare for the collision situation; and a step of performing driving, deceleration, or stopping control of the mobile robot by applying the determined speed reduction ratio, wherein the step of determining a collision situation includes a step of determining whether the path directions of the mobile robot and the guest mobile robot are opposite to each other and the two paths are on the same line in a facing situation, and wherein the V2V communication utilizes a broadcast communication method.

[0016] Additionally, the step of determining whether the above-mentioned situation is facing each other may include the step of determining the identity and directionality of the predetermined paths of the mobile robot itself and the guest mobile robot.

[0017] Additionally, if it is determined in the step of determining whether the situation is facing, a step for processing the facing situation is further included, and the step for processing the facing situation may include: a step of aligning a plurality of guest mobile robots determined to be facing based on the distance between the current position of the mobile robot and the position of each of the plurality of guest mobile robots determined to be facing; and a step of determining a speed reduction ratio of the mobile robot or the guest mobile robot to prevent a collision with the guest mobile robot located closest to the current position of the mobile robot among the plurality of guest mobile robots determined to be facing.

[0018] Additionally, the step of determining the speed reduction ratio of the mobile robot or the guest mobile robot involves reducing the speed of at least one of the mobile robots and the guest mobile robot when the distance between the mobile robot and the nearest guest mobile robot is greater than the stopping distance of the mobile robot or the guest mobile robot and less than the starting distance for deceleration, and the starting distance for deceleration may be the value obtained by adding a predetermined margin distance to the stopping distance of the mobile robot or the guest mobile robot.

[0019] Additionally, the step of determining the speed reduction ratio of the mobile robot or the guest mobile robot may set the speed of the mobile robot and the guest mobile robot to 0 if the distance between the mobile robot and the nearest guest mobile robot is smaller than the stopping distance of the mobile robot or the guest mobile robot.

[0020] Additionally, the step for handling the above-mentioned facing situation may include determining a final target point within the same path among the paths of the mobile robot and the guest mobile robot when the path of the mobile robot or the guest mobile robot includes a driving path that changes the direction of movement, and treating it as not being a facing situation when the final target points within the same path of the mobile robot and the guest mobile robot do not meet each other.

[0021] Additionally, the method further includes the step of receiving object information related to the length and width information of a guest mobile robot from each of a plurality of guest mobile robots located in the vicinity using the V2V communication, and the step of determining the collision situation can determine whether a collision has occurred based on the movement information and the object information.

[0022] According to another embodiment of the present invention, a mobile robot for preventing collisions of an autonomous mobile robot using V2V communication comprises: a data collection processing unit configured to collect movement information related to the position and speed of a guest mobile robot from each of a plurality of guest mobile robots located in the vicinity using a V2V (Vehicle-to-Vehicle Communication) communication unit; a situation determination processing unit configured to determine a collision situation based on the movement information of the guest mobile robot and the movement information of the mobile robot itself; and a speed control unit configured to determine a speed deceleration ratio of the mobile robot or the guest mobile robot to prepare for the collision situation and to perform driving, deceleration, or stopping control of the mobile robot by applying the determined speed deceleration ratio, wherein the situation determination processing unit is configured to determine whether there is a facing situation in which the directions of the paths of the mobile robot and the guest mobile robot are opposite to each other and both paths are on the same line, and the V2V communication utilizes a broadcast communication method. Effects of the invention

[0024] According to the present invention, a method and device for preventing collisions that may occur when multiple unmanned transport devices (AGVs) or autonomous mobile robots (AMRs) move in an industrial site can be provided.

[0025] In addition, according to the present invention, a method and device for preventing collisions and controlling the speed of an autonomous mobile robot using V2V communication can be provided to resolve the issue of collisions occurring due to malfunctions and blind spots during object recognition through sensors such as cameras and LiDAR when there is an error in the control of a central control system performing traffic control or when the system does not operate normally.

[0026] In addition, according to the present invention, a method and device can be provided that allow each mobile robot to independently and autonomously control movement such as deceleration and stopping by utilizing data analysis through V2V communication between multiple mobile robots to prevent collisions.

[0027] In addition, according to the present invention, a method, device, and system for more effectively preventing collisions of autonomous mobile robots can be provided by classifying crossing situations, following situations, and facing situations in an environment where multiple mobile robots are driving, and deriving a deceleration ratio value for each situation.

[0028] In addition, according to the present invention, by preventing collisions of mobile robots in a work environment, losses due to production interruptions caused by collisions, as well as hardware replacement costs and time, can be reduced.

[0029] The effects of the present invention are not limited to those mentioned above, and other unmentioned technical effects will be clearly understood by a person skilled in the art from the description below. Brief explanation of the drawing

[0031] FIG. 1 is an exemplary diagram illustrating the configuration of a collision avoidance system for an autonomous mobile robot according to one embodiment of the present invention. FIGS. 2a and 2b are flowcharts illustrating a collision prevention method for an autonomous mobile robot according to an embodiment of the present invention. FIG. 3 is a block diagram illustrating the configuration of an autonomous mobile robot according to one embodiment of the present invention. FIGS. 4a to 4d are illustrative diagrams for explaining a method of avoiding a collision in a crossing situation according to an embodiment of the present invention. FIG. 5 is an illustrative diagram for explaining a method of avoiding a collision in a following situation according to an embodiment of the present invention. FIG. 6 is an illustrative diagram for explaining a method of avoiding a collision in a facing situation according to one embodiment of the present invention. FIGS. 7a and 7b are illustrative diagrams for explaining a method of avoiding a collision in an avoidance situation according to an embodiment of the present invention. Specific details for implementing the invention

[0032] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the embodiments of the present invention in the drawings, parts unrelated to the explanation have been omitted.

[0033] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions may include plural expressions unless the context clearly indicates otherwise.

[0034] In this specification, terms such as “comprising,” “having,” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0035] Furthermore, the components shown in the embodiments of the present invention are illustrated independently to represent different characteristic functions and do not imply that each component consists of separate hardware or a single software unit. That is, for convenience of explanation, each component is described as a separate component, and at least two of the components may be combined to form a single component, or a single component may be divided into multiple components to perform a function. Such integrated and separated embodiments of each component are also included within the scope of the present invention as long as they do not deviate from the essence of the invention.

[0036] In addition, the following embodiments are provided to explain more clearly to those with average knowledge in the industry, and the shapes and sizes of the elements in the drawings may be exaggerated for clearer explanation.

[0037] Hereinafter, a preferred embodiment according to the present invention will be described with reference to the attached drawings.

[0039] FIG. 1 is an exemplary diagram illustrating the configuration of a collision avoidance system for an autonomous mobile robot according to one embodiment of the present invention.

[0040] Referring to FIG. 1, the mobile robot (100) is a robot device capable of moving autonomously and may be an Autonomous Guided Vehicle (AGV) or an Autonomous Mobile Robot (AMR). The mobile robot (100) may include a V2V communication unit (110) for communication with other mobile robots.

[0041] The guest mobile robot (200) is an autonomous mobile robot that moves while located in the vicinity of the mobile robot (100), and may include the same components as the mobile robot (100), including a V2V communication unit (210). There are multiple guest mobile robots (200), and the mobile robot (100) and the multiple guest mobile robots (200) can wirelessly transmit and receive data through the V2V communication unit, and may be configured so that all mobile robots located in the vicinity, that is, within the communication range, transmit and receive data using a broadcast communication method.

[0042] For example, a guest mobile robot (200) can transmit data, such as its own movement information or object attribute information, in a broadcast manner through a V2V communication unit (210), and a mobile robot (100) located within a communication range with the guest mobile robot (200) can receive the data transmitted by the guest mobile robot (200) through a V2V communication unit (110). Similarly, a mobile robot (100) can transmit data in a broadcast manner through a V2V communication unit (110), and a plurality of guest mobile robots (200) located within a communication range can receive the data transmitted by the mobile robot (100) through a V2V communication unit (210).

[0043] Additionally, the mobile robot (100) and the guest mobile robot (200) may be of the DD (Dual Drive) type, which moves straight and turns with two motors and two drive axes, or the QD (Quad Drive) type, which moves straight, turns, runs along the longitudinal path, runs along the lateral path, and runs along the meandering path with two motors and four drive axes, and may have various other types of movement methods.

[0044] The present invention relates to a method and apparatus for preventing collisions between robots and controlling movement, wherein a plurality of mobile robots, namely a mobile robot (100) and a plurality of guest mobile robots (200), each independently communicate with a V2V terminal to recognize surrounding mobile robots and transmit and receive data necessary for collision prevention. A specific method for preventing collisions will be described later with reference to FIG. 2, and a specific configuration of the mobile robot (100) will be described later with reference to FIG. 3.

[0046] FIGS. 2a and 2b are flowcharts illustrating a collision prevention method for an autonomous mobile robot according to an embodiment of the present invention.

[0047] First, referring to FIG. 2a, a mobile robot (100) can receive data from a plurality of guest mobile robots (200) located nearby and filter the necessary data (S210). Here, the data transmitted and received by the mobile robots may include data related to movement information such as the position, timestamp, and speed of the mobile robot, and data related to object attribute information such as the length, width, and type of the mobile robot. The mobile robot (100) can filter only the data of the guest mobile robots necessary for collision avoidance processing among the data received from the plurality of guest mobile robots (200).

[0048] The mobile robot (100) can perform data analysis to perform collision prevention logic using its own data and data received from multiple guest mobile robots (200). (S220) At this time, the mobile robot (100) can calculate and predict information regarding relative position and relative speed at each time using its own position information and speed information, the position information and speed information of the guest mobile robots (200), etc.

[0049] The mobile robot (100) can classify and determine the collision situation for each guest mobile robot (200) as one of the following through such data analysis: a crossing situation, a following situation, or a facing situation (S230). Here, the crossing situation is a situation where the movement directions of the two robots intersect each other, the following situation is a situation where the movement directions of the two robots match so that one robot follows the preceding robot, and the facing situation means a situation where the movement directions of the two robots are opposite to each other and both paths are on the same line. The mobile robot (100) can classify and determine which type of collision situation each guest mobile robot (200) in the vicinity is in.

[0050] Depending on the judgment of each situation, handling operations such as cross situation processing, following situation processing, and facing situation processing can be performed to prepare for collision situations (S240). At this time, if it is determined to be a cross situation, logic to handle the cross situation is executed, if it is determined to be a following situation, logic to handle the following situation is executed, and if it is determined to be a facing situation, logic to handle the facing situation is executed. A more specific explanation of this will be provided with reference to FIG. 2b.

[0051] Based on the deceleration ratio or speed ratio derived in each collision situation, the maximum speed of the mobile robot (100) or guest mobile robot (200) can be determined to limit the maximum speed and perform speed control accordingly (S250). Here, the deceleration ratio is a ratio that reduces the maximum speed currently set for the mobile robot; for example, if the set maximum speed is 20 m / s and a deceleration ratio of 60% is applied, the maximum speed is determined to be 8 m / s. Additionally, if there are multiple deceleration ratios derived in each collision situation, the maximum value among them can be applied to determine the minimum value among the maximum speeds determined according to each collision situation. Furthermore, the target for speed control may be either the mobile robot (100) or the guest mobile robot (200), or both if necessary, and the target robot for deceleration or stop control can be determined based on a priority that considers the mobile robot's work distance, work priority, type of robot, etc. Additionally, the maximum driving speed of each mobile robot can be set to a designated speed determined by the control system.

[0052] Referring to FIG. 2b, in the collision situation determination step (S230), the intersection situation determination step (S231) may determine whether the predetermined paths of each mobile robot intersect (a), determine whether they are parallel (b), determine the error between the predetermined path of the mobile robot and the current position (c), and extract the intersection point (d). At this time, in the subsequent intersection situation processing step (S241), the intersection points of each guest mobile robot (200) classified as an intersection situation may be extracted and sorted to find the closest intersection point (a), find the closest intersecting mobile robot corresponding thereto (b), determine whether the self or the corresponding mobile robot should drive, decelerate, or stop (c), and output the deceleration ratio accordingly (d).

[0053] Next, in the collision situation determination step (S230), the following situation determination step (S232) may determine the sameness and same direction of the predetermined path of each mobile robot (a), determine whether to follow a curve (b), and extract a following point (c), wherein the following point may be the position value of the mobile robot being followed. At this time, in the following following situation processing step (S242), the following points of each guest mobile robot (200) classified as being in a following situation may be extracted and sorted to find the closest following point (a), find the closest following mobile robot (b), determine whether to drive, decelerate, or stop of itself or the corresponding mobile robot (c), and output the deceleration ratio accordingly (d).

[0054] Next, in the collision situation judgment step (S230), the facing situation judgment step (S233) determines the sameness and opposite direction of the predetermined path of each mobile robot (a) and extracts the facing point, where the facing point may be the current position value of each mobile robot. Then, in the following facing situation processing step (S243), the facing points of each guest mobile robot (200) classified as facing situations are extracted and sorted to find the closest tracking point (a), find the closest facing mobile robot (b), determine whether to drive, decelerate, or stop of itself or the corresponding mobile robot (c), and output the deceleration ratio accordingly (d).

[0055] At this time, in the maximum speed determination and speed control step (S250), the highest value among the speed reduction ratios for each judgment derived through each situation judgment step (S230) and situation processing step (S240) can be selected, and the maximum speed of the mobile robot can be reduced or stopped by applying the minimum value among the maximum speed values ​​derived for each situation.

[0057] FIG. 3 is a block diagram illustrating the configuration of an autonomous mobile robot according to one embodiment of the present invention.

[0058] The mobile robot (100) may include a V2V (Vehicle-to-Vehicle) communication unit (110) for communication with other mobile robots, and may be configured to support various wireless communications such as WAVE (Wireless Access in Vehicular Environments), DSRC (Dedicated Short-Range Communications), WiFi, or wireless LAN-based communication, or cellular-based 4G, 5G communication in which the communication network is configured in a cellular manner. The mobile robot (100) may be configured to transmit and receive data with all mobile robots located nearby, that is, within the communication range, using a broadcast communication method through the V2V communication unit.

[0059] Additionally, the mobile robot (100) may include a central processing unit (CPU), an application processor (AP), etc., and may include internal memory capable of storing commands or data related to at least one other component, or may communicate with a memory unit within the device or, if necessary, with external memory to access necessary information.

[0060] Additionally, the mobile robot (100) may include a data collection processing unit (120), a situation judgment processing unit (130), a speed control unit (140), and an avoidance path setting unit (150), and these components may include a program or program module that can be executed by one or more processors. This program or program module may be configured in the form of an operating system, an application program, or a program, and may be physically stored on various types of widely used storage devices. Such a program or program module may include one or more routines, subroutines, programs, objects, components, instructions, data structures, and various forms for performing specific tasks or executing specific data types, but is not limited to these forms.

[0061] The data collection processing unit (120) may be configured to collect movement information related to the position and speed of the guest mobile robots and object attribute information related to the length, width, type, etc. of the guest mobile robots from each of the multiple guest mobile robots (200) located nearby, and to filter the necessary data.

[0062] The situation judgment processing unit (130) may be configured to determine a collision situation based on the movement information of the guest mobile robot and the movement information of the mobile robot itself, and to perform a processing process for each collision situation. At this time, the collision may be determined by additionally considering object attribute information in the movement information of the mobile robot. As shown in FIG. 2b, the situation judgment processing unit (130) may classify and determine the collision situation into a crossing situation, a following situation, and a facing situation, and derive a deceleration ratio or speed ratio value for each collision situation.

[0063] Additionally, the situation judgment processing unit (130) is configured to determine whether there is a crossover situation, and when the crossover situation is determined, it can be configured to determine whether the mobile robot itself and the guest mobile robot's predetermined paths intersect and are parallel, determine the error between the position of the guest mobile robot and the predetermined path of the guest mobile robot, and generate an intersection point between the paths of the mobile robot itself and the guest mobile robot. At this time, the situation judgment processing unit (130) is also configured to process the crossover situation, and when processing the crossover situation, it can be configured to list a plurality of guest mobile robots determined to be in a crossover situation based on the distance between the current position of the mobile robot and the intersection point generated for each of the plurality of guest mobile robots determined to be in a crossover situation, and to determine the speed reduction ratio of the mobile robot or the guest mobile robot using the guest mobile robot corresponding to the intersection point closest to the current position of the mobile robot and the Estimated Time of Arrival from the mobile robot's current position to the intersection point to prevent a collision with the guest mobile robot among the plurality of guest mobile robots determined to be in a crossover situation. In addition, when a mobile robot arrives at the nearest intersection, to prevent a collision with the guest mobile robot corresponding to the second nearest intersection among the intersections generated for each of the multiple guest mobile robots determined to be in an intersection situation, the speed reduction ratio of the mobile robot or the guest mobile robot can be determined using the estimated arrival time from the current position of the mobile robot to the intersection and the guest mobile robot corresponding to the second nearest intersection, and thus, collisions with the guest mobile robots corresponding to the intersection can be prevented sequentially.Additionally, when the situation judgment processing unit (130) determines whether there is an intersection with each guest mobile robot, it can make a situation judgment by considering the width and length information of the mobile robot (100) and the guest mobile robot (200) even when no direct intersection point occurs on the path of the mobile robot (100) and the guest mobile robot (200), and can prevent collisions by configuring to generate an arbitrary intersection point.

[0064] Additionally, when determining whether there is an intersection with each guest mobile robot, the situation judgment processing unit (130) may be configured to generate an arbitrary intersection point formed by extending the straight driving path before or after the curved driving path and converting the curved path into a straight path when the path of the mobile robot (100) or the guest mobile robot (200) includes a curved driving path that changes the direction of movement.

[0065] Additionally, the situation judgment processing unit (130) is configured to determine whether a following situation exists, and when a following situation is determined, it may be configured to determine the identity and same directionality of the predetermined paths of the mobile robot itself and the guest mobile robot. At this time, the situation judgment processing unit (130) is also configured to process the following situation, and when processing the following situation, it may be configured to align the multiple guest mobile robots determined to be in a following situation based on the distance between the current position of the mobile robot and the position of each of the multiple guest mobile robots determined to be in a following situation, and to determine the speed reduction ratio of the mobile robot itself to prevent collision with the guest mobile robot located closest to the current position of the mobile robot among the multiple guest mobile robots determined to be in a following situation, that is, those moving ahead. At this time, when determining the speed reduction ratio of the mobile robot, the distance between the guest mobile robot located closest to the current position of the mobile robot and the mobile robot may be continuously calculated, and if the distance between the guest mobile robot located closest to the current position of the mobile robot and the mobile robot is less than or equal to a predetermined standard, the speed reduction ratio of the mobile robot may be determined. Additionally, when determining the speed deceleration ratio of the mobile robot, if the distance between the mobile robot and the guest mobile robot is greater than the stopping distance of the mobile robot following from behind and less than the deceleration start distance, the speed of the mobile robot following from behind may be configured to be decelerated, where the deceleration start distance may be the value obtained by adding a predetermined margin distance to the distance between the mobile robot and the guest mobile robot. Additionally, when determining the speed deceleration ratio of the mobile robot, if the speed of the mobile robot following from behind among the mobile robot or the guest mobile robot is faster than the speed of the mobile robot leading from behind, the speed of the mobile robot following from behind may be configured to be decelerated to be equal to the speed of the mobile robot leading from behind.Additionally, when processing a tracking situation, the situation judgment processing unit (130) may be configured to set a curved tracking area extended by a preset distance from the curved section when the path of the mobile robot (100) or the guest mobile robot (200) that is following from behind includes a curved driving path that changes the direction of movement, and to set a deceleration ratio or speed ratio for deceleration or stop control of the mobile robot following from behind when the mobile robot that is leading is located within the curved tracking area.

[0066] Additionally, the situation judgment processing unit (130) is configured to determine whether there is a facing situation, and when a facing situation is determined, it may be configured to determine the identity and opposite direction of the predetermined paths of the mobile robot itself and the guest mobile robot. At this time, the situation judgment processing unit (130) is also configured to process the facing situation, and when processing the facing situation, it may be configured to align the multiple guest mobile robots determined to be in a facing situation based on the distance between the current mobile robot's position and each of the multiple guest mobile robots determined to be in a facing situation, and to determine the speed reduction ratio of the mobile robot or the guest mobile robot to prevent a collision with the guest mobile robot located closest to the current mobile robot's position among the multiple guest mobile robots determined to be in a facing situation. When determining the speed reduction ratio of the mobile robot, the situation judgment processing unit (130) is configured to reduce the speed of at least one of the mobile robots and the guest mobile robot if the distance between the mobile robot and the guest mobile robot closest to it is greater than the stopping distance of the mobile robot or the guest mobile robot and less than the starting distance for deceleration, and the starting distance for deceleration may be the value obtained by adding a predetermined margin distance to the stopping distance of the mobile robot or the guest mobile robot. Additionally, when determining the speed reduction ratio of the mobile robot, the situation judgment processing unit (130) may set the speed of the mobile robot and the guest mobile robot to 0 if the distance between the mobile robot and the guest mobile robot closest to it is less than the stopping distance of the mobile robot or the guest mobile robot.Additionally, when processing a facing situation, the situation judgment processing unit (130) may be configured to determine a final target point within the same path among the paths of the mobile robot (100) and the guest mobile robot (200) when the path of the mobile robot (100) or the guest mobile robot (200) includes a driving path that changes the direction of movement, and to process it as not being a facing situation if the final target points within the same path of the mobile robot and the guest mobile robot do not meet each other.

[0067] The speed control unit (140) may be configured to determine the speed deceleration ratio of the mobile robot (100) or guest mobile robot (200) to prepare for a collision situation, and to perform driving, deceleration, or stopping control of the mobile robot by applying the determined speed deceleration ratio. Here, the highest value among the deceleration ratios derived according to each situation judgment, or the lowest value among the speed ratios, may be selected to control the speed of the mobile robot or stop it. That is, the highest value among the multiple speed deceleration ratios derived for each situation judgment in the situation judgment processing unit (130) may be selected to decelerate or stop the maximum speed of the mobile robot by applying the minimum value among the maximum speed values ​​derived in each situation.

[0069] The avoidance path setting unit (150) may be configured to determine whether an error has occurred in the guest mobile robot when the leading guest mobile robot or the facing guest mobile robot is stopped due to an operation error, and to generate an avoidance path for the mobile robot if it is determined that there is an error in the guest mobile robot. At this time, the situation judgment processing unit (130) may be configured to determine the collision situation between the avoidance path of the mobile robot generated by the avoidance path setting unit (150) and another guest mobile robot, and to determine the collision situation between the avoidance path of the mobile robot and another guest mobile robot. At this time, it may determine whether the path directions of the mobile robot and the other guest mobile robot are opposite to each other and whether the two paths are in a facing situation where they are on the same line, and if it is determined that they are in a facing situation, the timing of avoiding a collision with another mobile robot when changing to the avoidance path can be adjusted by setting the movement of the mobile robot so that the mobile robot re-enters the normal path through the avoidance path after one of the mobile robots, either the mobile robot or the other guest mobile robot, is temporarily stopped.

[0071] FIGS. 4a and 4b are illustrative diagrams for explaining a method of avoiding a collision in a crossing situation according to an embodiment of the present invention.

[0072] First, as shown in FIG. 2b, to determine whether there is an intersection situation where the movement directions of the mobile robot (R1) and the guest mobile robots (C1, C2, C3) intersect each other, the paths of the two robots are intersected, an intersection point is extracted, a parallel determination is made, and the error of the mobile robots from the path is performed, and the mobile robots in the intersection situation can be determined and classified. At this time, when determining whether there is an intersection of paths for each mobile robot, the intersection status and the intersection point can be extracted by considering the final target point.

[0073] Referring to FIG. 4a, among the multiple guest mobile robots (C1, C2, C3) classified as crossing situations, the extracted intersection point and the mobile mobile robot can be arranged and sorted in order of proximity, and the speed can be controlled to decelerate or stop by making a collision avoidance judgment from the first guest mobile robot (C2) that is closest among the sorted guest mobile robots.

[0074] The collision avoidance judgment can basically be configured to determine deceleration, stop, or driving by selecting priorities among each mobile robot based on the Estimated Time of Arrival (ETA) from the current position to the intersection, and also to make a judgment by considering the work distance, work priority, and type of mobile robot depending on other situations.

[0075] In addition, assuming that no collision occurs with the first guest mobile robot (C2), when passing the first intersection, the robot can decelerate or stop to prevent a collision with a number of aligned guest mobile robots in advance at the next intersection, and thus, collisions with the next guest mobile robot at the intersection can be prevented sequentially.

[0076] Referring to Fig. 4b, even when the movement paths of both robots are not orthogonal as in Fig. 4a, the intersection point of the paths of the mobile robot (R1) and the guest mobile robot (C1) can be extracted and collisions can be prevented.

[0077] Referring to FIG. 4c, situations (c-3), (c-4), and (c-5) represent examples of situations where two mobile robots do not form paths that directly intersect each other, but are judged to be intersecting. As in (c-3) and (c-4), if the width between the paths of the two mobile robots is sufficiently far, there is no overlapping part when the two robots drive, so they can proceed without collision. At this time, the presence of a collision can be determined by using the width of the mobile robot's path together with object attribute information or footprint information, such as the length or width information of each mobile robot. Meanwhile, in the case of (c-5), if the width between the paths of the two mobile robots is narrow and the width between the paths is smaller than the width length of the mobile robot, the two paths are judged to overlap. At this time, the vertical path of the mobile robot (R1) is extended by a certain distance calculated based on the width or length information of the mobile robot to create an intersection point with the path of the guest mobile robot (C1), and at the intersection point, a collision avoidance judgment is made to decelerate or stop.

[0078] Referring to FIG. 4d, just as an intersection point is created between the path of the mobile robot (R1) and the guest mobile robot (C1) when the mobile robot (R1) travels in a straight line in (c-6), when the mobile robot (R1) travels in a curve in (c-7), an arbitrary intersection point is created by extending the straight path before or after the curve travel and converting the curve path into a straight path, thereby allowing for deceleration and stopping by performing collision avoidance judgment in the same way as in (c-6).

[0079] Next, referring to (c-8), the mobile robot (R1) has a path that performs two C-turns. Since the mobile robot (R1) is designed to travel in a curved path, no intersection point is created with respect to the actual path of the guest mobile robots (C1, C2). Therefore, by extending the straight path before or after the curved path to convert the curved path into a straight path, an arbitrary virtual target point is created. Based on the intersection point created based on this virtual target point, a collision avoidance judgment can be made for the guest mobile robots (C1, C2) to decelerate or stop. Additionally, the guest mobile robots (C1, C2) can also receive information about the mobile robot (R1) and make a collision avoidance judgment in the same way based on the same intersection point information.

[0080] In these situations, when the guest mobile robot is stopped near an intersection, it can be determined whether it can pass without collision by considering object attribute information such as the length or width information of the guest mobile robot.

[0082] FIG. 5 is an illustrative diagram for explaining a method of avoiding a collision in a following situation according to an embodiment of the present invention.

[0083] First, in order to determine whether the mobile robot (R1) is following the guest mobile robot (F1), the paths of the two mobile robots are identical, directions are identical, and a curve-following area is created when the preceding robot travels on a curve, and by extracting the following point, the robot being followed can be determined and classified.

[0084] In the following situation, the collision avoidance judgment is performed by first listing and sorting the guest mobile robots classified as being in the following situation in order of proximity between the extracted following point and the mobile robot (R1), and then performing a collision avoidance judgment with the first guest mobile robot (F1) that is closest among the sorted guest mobile robots. The following point used in this judgment method is the position value of the guest mobile robot that the mobile mobile robot is following. Through this position value, the distance between the mobile robot (R1) and the guest mobile robot (F1) can be continuously calculated to perform a judgment of deceleration or stopping. For example, if the distance between the mobile robot and the guest mobile robot located closest to the mobile robot's position is less than or equal to a predetermined standard, for example, less than or equal to the stopping distance, the mobile robot (R1) can be stopped. At this time, the stopping distance can be set using a preset default value or a distance value transmitted by the control system.

[0085] In addition, the method for determining deceleration here may be to decelerate when the position of the mobile robot is greater than the stopping distance and less than or equal to the deceleration start distance. In this case, the deceleration start distance may be the value obtained by adding a predetermined margin distance to the distance between the two mobile robots. (a) Furthermore, for example, the speed deceleration ratio may be set to select the highest deceleration ratio between the value obtained by subtracting the actual distance from the tracking point from the stopping distance in real time and dividing it by the deceleration interval distance, and the ratio obtained by dividing the current guest mobile robot's speed by the current mobile robot's speed. Additionally, the maximum speed specified for the path along which the current mobile robot and the guest mobile robot are proceeding may be calculated in the same manner, and the highest value selected by comparing it with the previously calculated smaller value may be reflected. Here, the deceleration interval distance is the value obtained by subtracting the stopping distance from the deceleration start distance, and for example, the method for determining the final speed deceleration ratio applied is as follows.

[0086] (Example of determining speed reduction ratio)

[0087] Speed ​​reduction ratio 1 : (Actual distance - Stopping distance) / Deceleration section distance

[0088] Speed ​​Deceleration Ratio 2: Real-time Guest Robot Speed ​​ / Real-time Mobile Robot Speed

[0089] Speed ​​Deceleration Ratio 3 : Guest Robot's Set Path Speed ​​ / Robot's Set Path Speed

[0090] Speed ​​reduction ratio 4 : Maximum reduction ratio = 1.0

[0091] The maximum value of the speed reduction ratio among the speed reduction ratios 1, 2, and 3 derived above can be determined, and the maximum value is set so as not to exceed the preset speed reduction ratio 4 (maximum reduction ratio). If the maximum value of the speed reduction ratio is greater than the maximum reduction ratio, the maximum reduction ratio can be adopted as the speed reduction ratio.

[0092] Now, referring to (d-1) in FIG. 5, in a basic following situation, when the speed of the guest mobile robot (F1) is slower than that of the mobile robot (R1), the mobile robot (R1) can be decelerated at the same speed as the guest mobile robot (F1) in the deceleration section to move at a constant speed, and also, when the mobile robot (F1) is stopped, the following mobile robot (R1) can be controlled to stop when it is closer than the stopping distance.

[0093] In addition, referring to (d-2) in FIG. 5, there is a situation where the paths of the mobile robot (R1) and the guest mobile robot (F1) are different but their footprints overlap. At this time, the width information of the mobile robot (R1) and the guest mobile robot (F1) is checked to determine if the footprints overlap, and if they overlap, a collision avoidance judgment is performed to control deceleration, constant speed driving, and stopping actions.

[0094] In addition, referring to (d-3) in FIG. 5, the direction of travel of the mobile robot (R1) and the guest mobile robot (F1) is the same, but the two paths do not overlap and are separated. At this time, if the distance between the target point of the mobile robot (R1) and the position of the guest mobile robot (F1) is such that there is no collision when the mobile robot (R1) moves, the mobile robot (R1) is controlled to continue moving as is; otherwise, the mobile robot (R1) can perform a collision avoidance judgment to control deceleration, constant speed driving, and stopping actions.

[0095] Additionally, referring to (d-4) in FIG. 5, the mobile robot (R1) is driving along a curved path, and the guest mobile robot (F1) is located behind where the curved path has ended. At this time, regarding the path of the mobile robot (R1), a curve-following area (510) is set for a predetermined distance from the curved section, and if the guest mobile robot (F1) ahead is within the curve-following area (510), deceleration, constant speed driving, and stopping actions can be controlled. Also, if the guest mobile robot (F1) crosses in at the point where the curved section ends, and the guest mobile robot (F1) is in the curve-following area (510) at this time, the mobile robot (R1) can make a collision avoidance judgment and decelerate or stop in other situations.

[0097] FIG. 6 is an illustrative diagram for explaining a method of avoiding a collision in a facing situation according to one embodiment of the present invention.

[0098] First, in order to determine whether the mobile robot (R1) and the guest mobile robot (F1) are in a facing situation where they are following each other while driving, the robots in a facing situation can be determined and classified by extracting the sameness of the paths, the sameness of the directions, and the facing points of the two mobile robots.

[0099] In the face-to-face situation, the collision avoidance judgment is made by sorting the guest mobile robots listed for the face-to-face situation in order of proximity to the mobile robot (R1), and the distance to prevent collision is based on the distance transmitted by the control system, and can be set as a parameter in case the distance is incorrect. In addition, the deceleration start distance can be set as the value obtained by adding a predetermined margin distance to the stopping distance.

[0100] Among the collision avoidance judgment conditions, deceleration control can be set to operate between the deceleration start distance and the stopping distance from the extracted opposing point, and can be set to stop if the distance from the mobile robot (R1) to the opposing point becomes closer than the predetermined stopping distance.

[0101] Referring to (e-1) in Fig. 6, a general facing situation can be observed. In this situation, the mobile robot (R1) is moving toward the guest mobile robot (A1), and the guest mobile robot (A1) is moving toward the mobile robot (R1), and they are moving toward each other facing each other. In this facing situation, a collision avoidance judgment can be made to decelerate or stop.

[0102] In addition, referring to (e-2) in FIG. 6, the paths of the two mobile robots are facing each other on different lines rather than on the same line. Also, it can be seen that the footprints of the two mobile robots overlap. At this time, the width information of the mobile robot (R1) and the guest mobile robot (A1) is checked to see if the footprints overlap, and if they overlap, a collision avoidance judgment is performed to control deceleration and stopping actions.

[0103] Additionally, referring to (e-3) and (e-4) of FIG. 6, there is an exception where the mobile robot (R1) or the guest mobile robot (A1) changes its direction of movement to dock out while the two mobile robots are facing each other. In this case, since the target points of the mobile robot (R1) and the guest mobile robot (A1) do not overlap and thus do not interfere with each other, and since there is no need for them to stop under conditions where their footprints do not overlap, this case can be treated as an exception rather than a situation where they are facing each other, allowing the robots to continue driving without unnecessary movements.

[0105] FIGS. 7a and 7b are illustrative diagrams for explaining a method of avoiding a collision in an avoidance situation according to an embodiment of the present invention.

[0106] If some mobile robots stop due to errors or other issues during operation, it may be necessary to move around the stopped mobile robots to ensure the smooth operation of other mobile robots. In this case, if the leading guest mobile robot (A1) in the following situation is stopped, it is determined whether an error has occurred in the guest mobile robot (A1). If it is determined that there is an error in the guest mobile robot (A1), an avoidance path for the mobile robot (R1) can be generated to move around the guest mobile robot (A1). At this time, the system may be configured to determine a collision situation between the avoidance path (720) of the mobile robot (A1) and another guest mobile robot (A2). The collision situation determination based on the avoidance path is determined by determining whether the path directions of the mobile robot (R1) and the other guest mobile robot (A2) are opposite and whether the two paths are facing each other on the same line. If it is determined that they are facing each other, the movement of the mobile robot (R1) is set so that after the temporary stop of either the mobile robot (R1) or the other guest mobile robot (A2), the mobile robot (R1) passes through the avoidance path (720) and re-enters the normal path (720), thereby allowing the two mobile robots to pass through the avoidance path without collision.

[0107] Referring to (f-1) in FIG. 7a, in a following situation, the leading guest mobile robot (A1) is stopped because an error occurred while it was moving, and the mobile robot (R1) is moving forward following the guest mobile robot (A1). In addition, another guest mobile robot (A2) is moving in the opposite direction toward it.

[0108] Referring to (f-2) in FIG. 7a, the mobile robot (R1) can determine whether it can avoid the guest mobile robot (A1) by using a collision avoidance determination method for the following situation, stopping at a certain distance behind the guest mobile robot (A1), and then checking whether the guest mobile robot (A1) stopped due to an error. At this time, the mobile robot (R1) determines the collision situation based on the avoidance path (720) to determine whether it can pass the avoidance path (720) and return to the original normal path (710). At this time, it calculates the distance to another guest mobile robot (A2) coming from the opposite direction and checks the footprint. If the distance between the two paths is such that a space for avoidance is secured, it determines that the mobile robot (R1) and the other guest mobile robot (A2) are not facing each other, as in (f-3), and proceeds with the avoidance.

[0109] Referring to FIG. 7b, if it is determined that the footprints of two mobile robots overlap based on the width of the mobile robot and the length between the two paths, then it is determined that they are in a confrontational situation by comparing the path of another guest mobile robot (A2) based on the avoidance path (720), and thus the collision between the two mobile robots can be determined. When the mobile robot (R1) performs avoidance driving, the path of the mobile robot (R1) at this time is not the normal path (710) it originally had, but rather the newly set avoidance path (720). For example, as in (f-4), the mobile robot (R1) can be set to stop until the guest mobile robot (A2) passes, and then proceed through the avoidance path (720) after the guest mobile robot (A2) passes the side of the mobile robot (R1). Additionally, if it is determined that there is a risk of collision between the two mobile robots as in (f-5), the guest mobile robot (A2) may be stopped first, and after the mobile robot (R1) completes the avoidance drive through the avoidance path (720) and enters the normal path (710), the guest mobile robot (A2) may be set to drive again.

[0110] Additionally, when the guest mobile robot (A2), which is in a facing situation as in (f-5), receives that the guest mobile robot (A1) is in an error state and the mobile robot (R1) is in an avoidance state, the guest mobile robot (A2) can gradually decelerate and stop first, leaving a margin of distance for the mobile robot (R1) to avoid. After the mobile robot (R1) completes the avoidance drive through the avoidance path (720) and enters the normal path (710), the guest mobile robot (A2) can be set to drive again.

[0112] The various embodiments described herein may be implemented by hardware, middleware, microcode, software, and / or combinations thereof. For example, the various embodiments may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions presented herein, or combinations thereof.

[0113] Additionally, for example, various embodiments may be stored or encoded on a computer-readable medium containing instructions. Instructions stored or encoded on a computer-readable medium may enable a programmable processor or another processor to perform a method, for example, when the instructions are executed. A computer-readable medium includes both a computer storage medium and a communication medium including any medium that facilitates the transfer of a computer program from one place to another. A storage medium may be any available medium accessible by a computer. For example, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage media, magnetic disc storage media or other magnetic storage devices, or any other medium that can be used to transport or store desired program code in the form of instructions or data structures accessible by a computer.

[0114] Such hardware, software, firmware, etc., may be implemented within the same device or in individual devices to support the various operations and functions described in this specification. Additionally, components, units, modules, components, etc., described as “parts” in this invention may be implemented together or individually as separate but interoperable logic devices. Descriptions of different features for modules, units, etc., are intended to highlight different functional embodiments and do not necessarily imply that they must be realized by individual hardware or software components. Rather, functions associated with one or more modules or units may be performed by individual hardware or software components or integrated within common or individual hardware or software components.

[0115] Furthermore, although operations are depicted in a specific order in the drawings, it should not be understood that these operations must be performed in the specific order depicted or in a sequential order to achieve the desired result, or that all depicted operations must be performed. In any environment, multitasking and parallel processing may be advantageous. Moreover, the distinction between the various components in the above-described embodiments should not be understood as requiring such distinction in all embodiments, and it should be understood that the described components may generally be integrated together into a single software product or packaged into multiple software products.

[0116] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0118] 100: Mobile robot 110: V2V Communication Unit 120: Data Collection and Processing Unit 130: Situation judgment processing unit 140: Speed ​​control unit 150: Evasion Path Setting Section 200: Guest Mobile Robot

Claims

Claim 1 A method for preventing collisions in an autonomous mobile robot using V2V communication performed in a mobile robot, comprising: a step of collecting movement information related to the position and speed of a guest mobile robot from each of a plurality of guest mobile robots located in the vicinity using V2V (Vehicle-to-Vehicle Communication); a step of determining a collision situation based on the movement information of the guest mobile robots and the movement information of the mobile robot itself; and a step of determining a speed reduction ratio of the mobile robot or the guest mobile robot to prepare for the collision situation. The method includes a step of performing driving, deceleration, or stopping control of the mobile robot by applying the speed deceleration ratio determined above, wherein the step of determining the collision situation includes a step of determining whether the path directions of the mobile robot and the guest mobile robot are opposite to each other and the two paths are on the same line, and the V2V communication uses a broadcast communication method, and the step of determining whether the situation is facing includes a step of determining the identity and directionality of the predetermined paths of the mobile robot itself and the guest mobile robot, and if the situation is determined to be facing in the step of determining whether the situation is facing, the method further includes a step for processing the facing situation, and the step for processing the facing situation includes a step of aligning a plurality of guest mobile robots determined to be facing based on the distance between the current position of the mobile robot and the position of each of the plurality of guest mobile robots determined to be facing. A method for preventing collisions of an autonomous mobile robot, comprising the step of determining a speed reduction ratio of the mobile robot or the guest mobile robot to prevent collisions with the guest mobile robot located closest to the current position of the mobile robot among a plurality of guest mobile robots determined to be in a facing situation. Claim 2 delete Claim 3 delete Claim 4 A method for preventing collisions of an autonomous mobile robot, wherein, in claim 1, the step of determining the speed reduction ratio of the mobile robot or the guest mobile robot is to reduce the speed of at least one of the mobile robots and the guest mobile robot when the distance between the mobile robot and the nearest guest mobile robot is greater than the stopping distance of the mobile robot or the guest mobile robot and less than the starting distance for deceleration, and the starting distance for deceleration is the value obtained by adding a predetermined margin distance to the stopping distance of the mobile robot or the guest mobile robot. Claim 5 A method for preventing collisions of an autonomous mobile robot, wherein, in claim 1, the step of determining the speed reduction ratio of the mobile robot or the guest mobile robot is to set the speed of the mobile robot and the guest mobile robot to 0 when the distance between the mobile robot and the nearest guest mobile robot is smaller than the stopping distance of the mobile robot or the guest mobile robot. Claim 6 A method for preventing collisions of an autonomous mobile robot, wherein, in claim 1, the step for handling the facing situation comprises: determining a final target point within the same path among the paths of the mobile robot and the guest mobile robot when the path of the mobile robot or the guest mobile robot includes a driving path that changes the direction of movement; and treating the situation as not being a facing situation when the final target points within the same path of the mobile robot and the guest mobile robot do not meet each other. Claim 7 A method for preventing collisions of an autonomous mobile robot, wherein, in claim 1, the method further comprises the step of receiving object information related to the length and width information of a guest mobile robot from each of a plurality of guest mobile robots located in the vicinity using the V2V communication, and the step of determining a collision situation is to determine whether a collision has occurred based on the movement information and the object information. Claim 8 A mobile robot for preventing collisions of an autonomous mobile robot using V2V communication, comprising: a data collection processing unit configured to collect movement information related to the position and speed of a guest mobile robot from each of a plurality of guest mobile robots located in the vicinity using a V2V (Vehicle-to-Vehicle Communication) communication unit; and a situation judgment processing unit configured to determine a collision situation based on the movement information of the guest mobile robots and the movement information of the mobile robot itself. The system includes a speed control unit configured to determine a speed deceleration ratio of the mobile robot or the guest mobile robot to prepare for the collision situation, and to perform driving, deceleration, or stopping control of the mobile robot by applying the determined speed deceleration ratio; the situation determination processing unit is configured to determine whether there is a facing situation where the path directions of the mobile robot and the guest mobile robot are opposite to each other and both paths are on the same line; the V2V communication uses a broadcast communication method; the situation determination processing unit is configured to determine the identity and directionality of the predetermined paths of the mobile robot itself and the guest mobile robot when determining whether there is a facing situation; the situation determination processing unit is configured to process the facing situation when it is determined to be a facing situation; when processing the facing situation, the system aligns the plurality of guest mobile robots determined to be in a facing situation based on the distance between the current position of the mobile robot and the position of each of the plurality of guest mobile robots determined to be in a facing situation, and with the guest mobile robot located closest to the current position of the mobile robot among the plurality of guest mobile robots determined to be in a facing situation A mobile robot configured to determine the speed reduction ratio of the mobile robot or the guest mobile robot to prevent collisions.

Images