JP5159369B2 - Search and monitoring method with multiple robots - Google Patents

Description

  In the present invention, when a building such as a building or an urban area is occupied by, for example, an anti-social force (hereinafter referred to as “threat object”), a search by a plurality of robots that search or monitor a threat object by a plurality of robots It relates to a monitoring method.

  In recent years, the problem of worsening security, with terrorism as a representative example, has become increasingly serious and worse, both domestically and internationally. Terrorism tends to be thought of as a far-off issue, but there are various large and small problems in the country, such as the criminal cramming and the invasion of elementary and junior high schools from the subway sarin incident, and it needs to be considered as a familiar issue . In such cases, not only the direct victims, but also police officers, guards, and station staff who tried to help were sacrificed.

  On the other hand, the robot technology that has been used in limited places such as factories is used as a technology to safely and efficiently perform disaster relief and dangerous work at the time of disaster, and it is familiar to support the declining birthrate and aging society. It is expected to be used as a technology, and in recent years, research and development from various aspects has been accelerated.

  For this reason, as an application example of the robot technology, it is conceivable to search and monitor the above-described threat object that occupies a building such as a building or an urban area with a robot. As a result, it is possible to search and monitor the threat object safely, and to take measures with low risk and high efficiency. Therefore, there is a high possibility that the secondary damage as described above can be reduced.

  A security company has already developed a security robot, but it is designed to detect and report abnormalities through a route specified in advance, and automatically take appropriate actions according to the situation. It hasn't been done yet. In the event of an emergency, it is necessary to continue monitoring the threat object, and when the threat object escapes during monitoring, it is necessary to act so that it can be re-searched immediately. Of course, since the threat object refuses to search and monitor by the robot, it is possible to perform a destructive action on the robot. In particular, if the sensor function of the robot is destroyed, information from the site where the threat object exists will be lost.

  For this reason, in such a case, it is necessary to make another robot promptly go to the site, but there is a high possibility that no threat object already exists when the site arrives. Therefore, there is a tracking robot system that continues to move in the direction in which the threat object exists in cooperation with a plurality of robots (see, for example, Patent Document 1), but this alone is insufficient.

JP 2005-173968 A

  The present invention has been made in view of the above-described points, and a plurality of threat objects can be searched for more effectively by utilizing event information such as a destructive action or escape to a robot caused by a threat object. The purpose is to obtain a search monitoring method by a robot.

The search monitoring method using a plurality of robots according to the present invention can be any one of a search space having a plurality of branch points, with a threat object whose movement speed can be assumed in advance by a plurality of robots incorporating a communication function and a computer . In the search and monitoring method by a plurality of robots for searching and monitoring the object existing in the plurality of robots, as a step executed by the computer incorporated in each of the plurality of robots, the own position and the sensor that the sensor has are periodically provided. The monitoring range and the detection information including the detection result are distributed to the other robot, thereby exchanging information with the other robot, and when the object is out of the monitoring range of the sensor during the monitoring, or When the object escapes, or the monitoring function by the sensor is broken by the object. If the event corresponding to the case where it is received as the detection information of the occurrence in another robot, by assuming the traveling speed of the threat objects, the other robots at the time when the event occurred comprising calculating a possible presence of a range of the object from the monitoring range spread over time, and setting a destination robot so as to move reduces the possible presence of a range of objects, the object The step of calculating a range of possibility of existence obtains the range of possibility of existence that spreads with time as a tree structure having the plurality of branch points in the search space as nodes, and branches offspring for each node The step of calculating the total number as the degree of diffusion and setting the destination includes determining that the robot has elapsed with time based on the calculated degree of diffusion. Based on the information exchange with other robots, each robot autonomously sets the first point with the largest degree of diffusion after each boundary point as the destination. If it is determined that the robot can reach the point with the highest degree of diffusion earlier than other robots, the first point is maintained as the target value setting, and any of the other robots performs the diffusion. If it is determined that the point with the highest degree can be reached earlier than itself, the second point with the second highest degree of diffusion is reset as the destination, until the destination does not overlap with the other robot. The resetting process is repeated .

  According to the present invention, the event information is used to specify the range of the possibility of existence of the target object when the event occurs, and the destination where the robot moves to reduce the range of the possibility of existence of the target object. By setting, the object can be searched more effectively.

  In addition to the usual patrol work by a plurality of robots, the present invention utilizes event information such as a destructive action or escape to a robot caused by a threat object when a threat object exists. In particular, when such an event occurs, the range of the possibility of the presence of the threat object is specified, and the movement speed of the threat object is assumed to spread over time. Calculate the range.

  And if the sensor function of any robot is destroyed, or if the moving function is destroyed and escaped to a threat object, other robots simply go to the site where such an event occurred. Rather than selecting a route that can be reached, the movement is made by preferentially selecting a point where the spread of the range of possibility of the threat target can be stopped, and this action prevents the threat target from being escaped and Improve detection accuracy.

  In addition, since such robot behavior requires responsiveness, the behavior after waiting for an instruction from a supervisor or the like is too slow, and the present invention automates this behavioral logic to provide the responsiveness. It is for realizing.

  Regarding robot behavior design, a typical method is to make it possible to reach an area where there is a high possibility that a threat target exists in a short time, or to prevent a threat target from being missed. A method of ambushing in places where things pass reliably can be considered.

  However, with the former method, there is a possibility that the threat object can be detected quickly, but there is also a possibility that it will be missed. Further, the latter method is not missed, but is inefficient due to unnecessary waiting time.

  The present invention is a compromise between both methods, and each robot selects a route that is most likely not to miss the threat object from the current state, and reduces the range of the possibility of the presence of the threat object. The robots act to improve the detection efficiency of threat objects.

Embodiment 1 FIG.
FIG. 1 shows an operation example assuming application of the present invention. In this example, FIG. 1A is a floor plan showing the situation of the site occupied by a threatened object such as a trespasser or a terrorist (viewing the building floor plan from above). (B) shows the command post observing the situation of the threat object on the site based on the sensing information obtained from the robot thrown into the site. Here, a triangle mark indicates a threat object 1 such as a terrorist or an illegal intruder, a circle mark is a search monitoring robot (hereinafter simply referred to as “robot”) 2, It shows the direction viewed by its own sensor 3. Each search monitoring robot 2 has a communication function and a computer built therein so as to be communicable with other search monitoring robots 2 and the command post 4, and the command post 4 also has a communication function and a computer built therein.

  In the example shown in FIG. 1, the map of the site is assumed to be known. In the command post 4, the “?” Portion in the figure, that is, the range outside the monitoring (detection) range of the robot 2 is eliminated. As described above, first, a search work instruction is sent to each robot 2, and the search work by the robot 2 is started. Each robot 2 periodically distributes its position and detection information to other robots 2 and command post 4. In addition, each robot 2 autonomously performs a search activity, and selects a movement location in cooperation so that the search locations do not overlap between the robots. When each robot 2 detects the threat object 1, monitoring is performed while maintaining an appropriate distance so as not to be found from the threat object 1 and to prevent harm.

  As one example of operation, each robot 2 is pre-programmed with basic actions, and in most situations, it performs a mission to search and monitor the threat object 1 in an autonomous and cooperative manner. Depending on the order, an operation mode of acting based on an instruction from the command post 4 can be considered. This is because in order to take quick action according to the situation, it is necessary to automate up to a certain level. At the same time, not only the situation in the field but also action judgment from a macro viewpoint. This is because it may be necessary.

  FIG. 2 illustrates a mechanism when each robot 2 performs autonomous / distributed behavior. Each robot 2 searches for the threat object 1 based on the initially set route (search mode). Further, when the threat object 1 is searched, a monitoring action is taken (monitoring mode). However, when the threat object 1 escapes or is lost, the search mode is entered again. On the other hand, information on the environment side includes invariant information (static information) and information that varies depending on the situation (dynamic information). In the above example, since the target space (map) is known, this information corresponds to static information. However, if the map is unknown, the robot creates a map while searching, The “target space” information is dynamic information. The action of the threat object 1 is naturally positioned in the dynamic information, but the range of the possibility of existence of the threat object 1 described later also corresponds to this. In particular, the dynamic information depends on the behavior of the robot 2.

  FIG. 3 illustrates the range of the possibility of the presence of the threat object 1 in the present invention, taking as an example the case where the robot 2 is unexpectedly destroyed by the threat object 1. In the following examples including this example, the description will be made using a space having only a passage without a room in order to simplify the description.

  For example, as shown in FIG. 3A, when the robot 2A is suddenly destroyed by the threat object 1, the threat object 1 is within the range where the robot 2A can be aimed at and the detection area of the robot 2A. It would have existed outside. Assuming that each robot 2 appearing in this example has the ability to sufficiently detect the inside of the target space with respect to the detection direction, the range of possible existence of the threat object 1 at the time when the event occurs is shown in FIG. This is the range shown in 3 (a). Furthermore, by assuming the moving speed of the threat object 1, it is possible to calculate the range of the possibility of existence of the threat object 1 that spreads with time as shown in FIG. The basic concept of the present invention is that each robot 2 moves so as to stop this diffusion, thereby improving the detection accuracy of the threat object 1. For this reason, if the robots 2B to 2E take an action as shown in FIG. 3B, for example, the diffusion of the range can be prevented. Then, any of the robots 2B to 2E should be able to detect the threat object 1.

  Here, for example, if it is known that the threat object 1 is a human being, it is assumed that the actual position of the threat object 1 exceeds the range if it is assumed that 100 meters is moved in 10 seconds. Absent.

  FIG. 4 shows a calculation example of the range of possible existence of the threat object 1 and an action selection example of the robot 2 based on the present invention. In the space shown in FIG. 4A, when the robot 2A is unexpectedly destroyed by the threat object 1, the situation of the possibility of existence of the threat object 1 that spreads over time is shown in FIG. It can be expressed by a tree structure shown in 4 (b). Here, a node indicated by □ indicates a branch point on the map, and a dotted line portion indicates a portion to be merged by diffusion of the existence possibility range. The value shown next to the node indicates the total number of branches of the descendant of the node. Similarly, the robot 2B, which has detected this event due to communication disconnection or the like, calculates each arrival time from its own position and speed at that point in time to the range of possibility of existence of the threat object 1 that spreads with time. Can do. In this example, x, y, and z in the figure correspond to the respective arrival points and time points. In this example, it is assumed that the sensor 3 of the robot 2B can detect only the vicinity (for example, within the triangular range shown).

  The concept of the present invention is to improve the search accuracy of the threat object 1 and not to miss the threat object 1. If the robot 2B takes the point x as the destination, the robot 2B approaches the event occurrence range at the earliest time. However, the selection of the point y can prevent the range of the possibility of existence of the threat object 1 from spreading. In the present invention, this point y is selected, and the destination of each robot 2 is derived by calculating a branch of the range of possibility of existence of the threat object 1 shown in FIG. 4 (b). is there.

  FIG. 5 shows an example in which the behavior of each robot 2 and the behavior determination between the robots 2 are coordinated. FIG. 5A is a flowchart showing the behavior of each robot 2. When the presence of the threat object 1 is not known in the target space, each robot 2 performs a patrol work in accordance with normal search behavior, that is, a patrol program set in advance, or the threat object When a similar new event occurs when the robot 2 is moving to some destination (step S1) due to an event such as escape of 1 or destruction of the robot 2 (step S1) Step S2) (re) calculates the destination. In this calculation, first, the degree of diffusion with the passage of time within the range of the possibility of existence of the threat object 1 relating to the new event is calculated (step S3). This degree of diffusion indicates the total number of subsequent branches at each branch point shown in FIG.

  Based on this result, each boundary point of the range in which the robot 2 diffuses over time is obtained, and the degree of diffusion after the point at each point is sorted and examined. Then, the point having the largest diffusion degree is set as the destination of the robot 2. If the destination is already moving toward the destination, a point with the highest degree of diffusion including the degree of diffusion at the destination is set as a new destination (step S4).

  Next, information is exchanged and adjusted between the robots 2 so that the destinations do not overlap. FIG. 5B shows an example in which the two robots 2 cooperate to prevent the destinations from overlapping. Here, as shown in FIG. 5 (c), a1 and a1 ′ are points of the same branch, and are obtained by increasing the number of dashes (′) in order of distance from the route (source of the event). is there. In the example of FIG. 5B, since the point a1 is selected with the highest priority for both the robots 2A and 2B, the robot 2A that can reach a point closer to the route is assigned to the point a1. This is because, after reaching the point, it moves to a higher branch point so as to reduce the range of the possibility of existence, and it is more effective to select a point that can reach the point earlier. Thus, the robot 2B selects the next candidate b1 as the destination at that time (step S5). This is a simple method for adjusting the destinations so that they do not overlap, but it is also conceivable that the destinations of the respective robots 2 are set so that the range becomes smaller overall.

  If the robot 2 is monitoring the threat object 1, it is assumed that the threat object 1 is basically monitored even if a new event occurs.

  Further, if the above-described cooperative processing is performed by all the robots 2, overhead such as communication increases, so that it may be performed only between neighboring robots 2 based on the received power. This is because the robots 2 in the vicinity are likely to select the same destination, and there is a possibility that a large effect can be exhibited with a small overhead.

  In addition, it is conceivable that the processing of FIG. 5A is calculated at one place such as the command post 4 or the main robot 2. In addition, it is conceivable that each robot 2 calculates the process independently, but in this case, all the actions of the other robots 2 must be calculated. However, in the latter method, high robustness as a system can be realized even when the robot 2 is broken or broken.

  FIG. 6 shows a calculation example of the range of possibility of existence of the threat object 1 when the map of the target space is unknown. As shown in FIG. 6A, even if the target space is unknown at first, the location searched by the robot 2 is known. In this way, while creating a map of the target space and searching for the threat object 1, as shown in FIG. 6A, the robot 2 is unexpectedly destroyed by the threat object 1. In this case, the range of the possibility of existence of the threat object 1 is calculated by the above-described method for the already known space, but the unknown part may actually be the space shown in FIG. 6B. It is conceivable to calculate the range as a free space where no obstacles exist. In this way, assuming that the unknown space at that time is a free space and calculating the range of the possibility of existence of the threat object 1 that spreads over time, the range will actually spread further. There is no problem because there is no problem.

  In the above embodiment, the threat object is described. However, the present invention is not limited to the threat object, and can be applied to other objects.

It is the figure which showed the example of operation assumed application of this invention. It is the figure which showed the mechanism in case each robot 2 shown in FIG. 1 carries out autonomous and distributed action. It is a figure explaining the range of the possibility of existence of threat object 1 in this invention, taking as an example the case where robot 2 is destroyed by threat object 1 unexpectedly. It is the figure which showed the calculation example of the range of the possibility of the threat target 1, and the action selection example of the robot 2 based on this invention. It is a figure which shows the example in the case of determining the action of each robot 2, and action between the robots 2 in cooperation. It is the figure which showed the example of calculation of the range of the possibility of presence of the threat target object 1 when the map of object space is unknown.

Explanation of symbols

  1 threat object, 2 robot, 3 sensor, 4 command post.

Claims (1)

A plurality of robots that search for and monitor the target object existing in any of search spaces having a plurality of branch points by using a threat target object whose movement speed can be assumed in advance by a plurality of robots incorporating a communication function and a computer. In the search monitoring method by
As steps executed by the computer incorporated in each of the plurality of robots,
Periodically exchanging information with other robots by distributing to the other robots its position and the detection information including the monitoring range and detection result by the sensor that it has,
An event corresponding to a case where the object is out of the monitoring range of the sensor during monitoring, the object escapes, or a monitoring function by the sensor is destroyed by the object is detected by another robot. when that occurred it has been received as the detection information, by assuming the traveling speed of the object, the possible presence of the object from the monitoring range spread over time of the other robot at the time when the event occurred Calculating a range of
Setting a destination for the robot to move to reduce the range of possible existence of the object ,
The step of calculating the range of possibility of existence of the object is obtained as a tree structure having the plurality of branch points in the search space as nodes, with the range of possibility of existence expanding with time. Calculate the total number of descendant branches for
In the step of setting the destination, each boundary point in a range where the robot diffuses over time is obtained based on the calculated degree of diffusion, and the first point having the largest degree of diffusion after each boundary point is determined as each robot. Is autonomously set as the destination and, based on information exchange with other robots, determines that it can reach the point with the highest degree of diffusion earlier than other robots, If the first point is maintained as the setting of the target value, and it is determined that any of the other robots can reach the point with the highest degree of diffusion earlier than itself, the second largest degree of diffusion is the second. reconfigure the point as the destination, to the other robots and destination do not overlap, the search monitoring by multiple robots and repeating the process of the resetting Law.

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