JP2017188066A - Autonomous mobile body system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an autonomous mobile body system capable of keeping reliability of a plurality of mobile bodies at the high level in whole.SOLUTION: An autonomous mobile body system 110 comprises: sensor information acquisition means 141, which includes a plurality of mobile bodies 100 autonomously moving to a target place by measuring a self position with use of a sensor 103 and controlling movement means 101, for acquiring sensor information; position estimation means 142 for estimating a self position on the basis of the sensor information; reliability calculation means 143 for calculating reliability of the self position; mobile body information communication means 148 for transmitting holding information held by themselves between the mobile bodies 100; position reliability recording means 144 for recording the reliability and the self position, and an identifier for identifying a mobile body in association with each other; reliability recovery mobile body selection means 147 for selecting a mobile body which is caused to carry out reliability recovery action; and reliability recovery action control means 145 for controlling the movement means 101 to move the selected mobile body 100 to a position with high reliability.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a moving body system including a plurality of moving bodies that autonomously move to a target place by measuring a self-position with a sensor and controlling moving means.

  2. Description of the Related Art Conventionally, there has been proposed a moving body that autonomously moves to a target location while grasping its own position with various sensors. If such a moving body fails to acquire its own position, it cannot reach a preset location and cannot perform a desired work.

  For example, Patent Document 1 discloses an autonomous flying robot that moves autonomously while acquiring its own position using map information including obstacles such as buildings stored in advance and measurement results obtained by sensors. . If the surrounding environment changes greatly due to the appearance of a large obstacle such as a truck, and the self-position cannot be acquired, the autonomous flying robot will acquire the self-position again by increasing the flight altitude. It is intended to perform the desired work.

  Further, as in Patent Document 2, a plurality of moving bodies exchange information about their own positions by communication, and the relative position between the moving body and the moving body that can accurately acquire the absolute self-position using a satellite or the like. A technique has also been proposed in which a mobile body that acquires a self-position based on the positional relationship is assigned a role, and even a mobile body that cannot directly acquire an absolute self-position can perform work based on the absolute self-position.

JP 2014-149622 A JP 2006-300700 A

  However, the self-position re-acquisition technique described in Patent Document 1 cannot be applied to a moving body that travels on the ground, and if there are bridges or electric wires in the sky, the altitude is increased. It can be difficult.

  On the other hand, in the technique described in Patent Document 2, when there are a plurality of moving bodies and a wide area, a plurality of dedicated machines for obtaining the absolute position are also required. In the case where necessary work is performed such as inefficiency of providing a dedicated machine that does not perform work from within the body, it is considered difficult to improve the work efficiency of the entire mobile body.

  Moreover, even if these technologies are combined, it is difficult to efficiently operate the entirety of the plurality of moving objects.

  This invention is made | formed in view of the said subject, and provides the autonomous mobile body system which can operate a some mobile body efficiently.

  In order to achieve the above object, an autonomous mobile system according to the present invention includes an autonomous mobile system including a plurality of mobile bodies that autonomously move to a target location by measuring a self-position with a sensor and controlling a moving means. A sensor information acquisition unit that acquires sensor information relating to a self-position including a relative positional relationship with another moving body from the sensor; and a self-position is estimated based on the sensor information acquired by the sensor information acquisition unit. Position estimation means, reliability calculation means for calculating the reliability of the self-position estimated by the position estimation means, mobile information communication means for transmitting retained information held by itself between the mobile bodies, and the reliability Position reliability recording means for recording the reliability calculated by the degree calculation means, the self-position estimated by the position estimation means, and an identifier for identifying the moving object; and position reliability A reliability recovery mobile object selection means for selecting a mobile object that causes a reliability recovery action based on information recorded by the recording means, and a position of the mobile object selected by the reliability recovery mobile object selection means with a high reliability. And a reliability recovery action control means for controlling the moving means to move to the position.

  According to the present invention, a moving body that moves to a position where a self-position can be acquired with high reliability is selected from a plurality of moving bodies, and the result is shared among the moving bodies, so that the entire group of moving bodies is stable. It can move autonomously while grasping its own position with high reliability. This makes it possible to efficiently operate a plurality of moving objects.

FIG. 1 is a perspective view showing one appearance of a moving body provided in the self-supporting moving body system according to the first embodiment. FIG. 2 is a block diagram illustrating a part of a functional unit included in a control unit of each mobile unit included in the self-supporting mobile system according to Embodiment 1 together with a part of the mechanism unit. FIG. 3 is a diagram visually illustrating an example of data stored in the storage unit. FIG. 4 is a flowchart showing the flow of processing of the reliability recovery moving body selection means. FIG. 5 is a perspective view three-dimensionally showing the positional distribution of reliability when the self-position is the center. FIG. 6 is a block diagram illustrating a functional unit of a moving body included in the autonomous mobile body system according to the second embodiment. FIG. 7 is a perspective view showing an autonomous mobile system that performs bridge inspection work. FIG. 8 is a block diagram illustrating a functional unit of a moving body included in an autonomous mobile system according to another aspect.

  Next, an embodiment of an autonomous mobile body system according to the present invention will be described with reference to the drawings. The following embodiment is merely an example of the moving body according to the present invention. Therefore, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the highest concept of the present invention are not necessarily required to achieve the object of the present invention. It will be described as constituting a preferred form.

  In addition, the drawings are schematic diagrams in which emphasis, omission, and ratio adjustment are appropriately performed to show the present invention, and may differ from actual shapes, positional relationships, and ratios.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described using an autonomous flying body, a so-called drone, as an example of the moving body 100 included in the autonomous moving body system 110.

  FIG. 1 is a perspective view showing one appearance of a moving body provided in the self-supporting moving body system according to the present embodiment.

  FIG. 2 is a block diagram showing a part of a functional unit included in a control unit of each mobile unit included in the self-supporting mobile system according to the present embodiment together with a part of the mechanism unit.

  As shown in these drawings, the moving body 100 includes a plurality of rotors 111 (propellers) as a moving unit 101, a plurality of motors 112 that individually drive the rotors 111, and a sensor 103 for acquiring a self-position. And a control device 104 that acquires signals from the sensor 103 and controls the motor 112 to control autonomous movement.

  The drone type moving body 100 including a plurality of rotors 111 controls the movement and posture of the moving body 100 in various directions (for example, front, back, left, right, up and down) by individually controlling the rotation speed of each rotor 111. Adjustments can be made. In the case of the present embodiment, the control device 104 also acquires information based on the control state of the rotational speed of the rotor 111 as sensor information from the moving unit 101 and uses it as one piece of information for estimating the self position.

  The sensor 103 is not particularly limited as long as it is a device that can acquire information for estimating its own position by measurement. Specifically, as the sensor 103, an inertial measurement device (IMU: Internal Measurement Unit), a pressure gauge (altimeter), and a flow meter (anemometer) that detect angles and speeds in three axes and acceleration in three axes. A GPS (Global Positioning System) receiver, a LRF (Laser Range Finder), a depth camera, and the like can be exemplified. The sensor 103 includes a sensor that can acquire information related to the relative positional relationship between the self-position and the position of the other moving body 100 as sensor information. For example, relative position information that is a relative positional relationship of another moving body 100 present around the moving body 100 may be acquired as sensor information by LRF.

  In addition, the moving body 100 is equipped with one or a plurality of types of sensors 103 out of a plurality of types of sensors 103. In addition, the sensor 103 to be equipped is appropriately selected depending on the type of the moving body 100, the purpose of movement, and the movement location.

  As shown in FIG. 2, the control device 104 is a device that controls the moving means 101 based on information acquired from the sensor 103 or another moving body 100 to move the moving body 100, such as a storage unit 140. The computer includes a so-called CPU that performs various processes by executing programs stored in the computer. The control device 104 includes, as processing units executed by a program, a sensor information acquisition unit 141, a position estimation unit 142, a mobile body information communication unit 148, a reliability calculation unit 143, a position reliability recording unit 144, Reliability recovery moving body selection means 147 and reliability recovery action control means 145 are provided.

  In the case of the present embodiment, the control device 104 is provided for each moving body 100, and the moving body 100 moves autonomously by the control device 104 and is relative to other moving bodies 100. It moves while grasping the relationship.

  The storage unit 140 is an information storage device such as a ROM (Read Only Memory) or a HDD (Hard Disk Drive), and stores a program corresponding to each processing unit, a self-location, and the like. The storage unit 140 also stores location information of the destination, map information indicating a route, an obstacle, and the like.

  The sensor information acquisition unit 141 is a processing unit that acquires a signal measured by the sensor 103 as sensor information used for self-position estimation. The sensor information acquisition unit 141 also acquires information obtained from the moving unit 101, for example, control information such as the number of rotations of each of the plurality of rotors 111 as sensor information. Moreover, the relative positional relationship with the other mobile body 100 is also acquired as sensor information.

  The position estimation unit 142 is based on at least one of the sensor information and the relationship between the sensor information and the self-position of the other mobile object 100 acquired from the other mobile object 100. Is a processing unit for estimating. In the case of the present embodiment, the position estimation unit 142 calculates a measurement position that is a result of actual measurement by the sensor 103 based on a plurality of pieces of sensor information. Next, the position estimation unit 142 performs a process of estimating a self-position by integrating a plurality of measurement positions. On the other hand, the self position of the other mobile object 100 acquired from the other mobile object 100 is acquired, and the measurement position is calculated from the sensor information indicating the relative position information with respect to the other mobile object 100, and the measurement position Are also integrated to estimate the self-position.

The method for estimating the self position is not particularly limited. For example, the measurement position calculated based on the signal received from the GPS satellite, the measurement position calculated based on the sensor information from the inertial measurement device, and the like. The self position may be estimated by a Kalman filter. The measurement position calculated by comparing the sensor information from the depth camera and the map information stored in the storage unit 140, the measurement position calculated based on the sensor information from the inertial measurement device, and the like are SLAM. (Simultaneous Localization And
Mapping may also be estimated.

  When a Kalman filter is employed as the position estimating means 142, the self position is expressed as a normal distribution. The dispersion of the normal distribution increases according to the elapsed time and the amount of movement since the last observation of the absolute position, and decreases when the absolute position is observed. That is, the reliability decreases according to the elapsed time and the amount of movement since the last observation of the absolute position, and increases (recovers) by observing the absolute position. The absolute position is observed by GPS positioning or by observing a landmark whose position is known.

  The reliability calculation means 143 is a processing unit that calculates the reliability of the self position based on the reliability of the sensor 103 itself to be measured, the reliability that decreases with time, the error of the sensor information used when the self position is estimated, and the like. It is. In the case of the present embodiment, the reliability calculation unit 143 positions the self-position created based on the measurement position indicating the relative positional relationship with the other mobile object 100 and the self-position of the other mobile object 100. When the estimation unit 142 estimates, the reliability of the other mobile unit 100 obtained from the other mobile unit 100 via the mobile unit information communication unit 148 is also integrated to calculate the reliability level.

  As a reliability calculation method performed by the reliability calculation unit 143, for example, a method (for example, a normal distribution) used when the position estimation unit 142 estimates the self-position and a reciprocal of variance is calculated as the reliability. Can be displayed.

  The mobile object information communication means 148 is an apparatus that transmits the information held by itself between the mobile objects 100 included in the autonomous mobile system 110.

  Here, the holding information includes the self position, the reliability of the self position, the absolute position of the other moving body 100, the reliability of the absolute value, the relative positional relationship between the self position and the other moving body 100, and the Information such as the reliability of the relative positional relationship. Further, the holding information may be sensor information acquired by the sensor information acquisition unit 141 as long as it is information held by itself, or may be a signal from the sensor 103 itself.

  Specifically, for example, the following combinations can be listed as the holding information transmitted mutually by the mobile information communication unit 148. (1) Self-position and its reliability, (2) Absolute position and reliability of other mobile unit 100, (3) Relative position of self-position and other mobile unit 100, and respective reliability. In the case of the present embodiment, mobile body information communication means 148 transmits and receives signals in order to share holding information including its own position and its reliability between mobile bodies 100 by wireless communication.

  The position reliability recording unit 144 is a processing unit that links the self position (coordinates) estimated by the position estimation unit 142 and the reliability calculated by the reliability calculation unit 143 and records them in the storage unit 140. In the case of the present embodiment, as shown in FIG. 3, the position reliability recording unit 144 associates time information with the associated self-position and reliability and records them in the storage unit 140. Furthermore, the time, the self position (coordinates), and the reliability transmitted from the other mobile unit 100 are associated with the identifier (id) and recorded in the storage unit 140. Here, the time information is information indicating the time when the self-position is estimated by the position estimation unit 142, for example. In FIG. 3, information about time and coordinates other than the reliability is described with identification symbols for distinguishing from each other, and these have no specific meaning. Therefore, the same coordinates may be indicated even with different identification symbols.

  The reliability recovery moving body selection unit 147 is a processing unit that selects a mobile body that causes a reliability recovery action based on information recorded by the position reliability recording unit 144. In the case of the present embodiment, each mobile body 100 included in the autonomous mobile body system 110 includes a reliability recovery mobile body selection unit 147, and when the mobile body 100 of itself satisfies a predetermined condition, It is selected as the moving body 100 for recovering the overall reliability of the autonomous moving body system 110.

  FIG. 4 is a flowchart showing the flow of processing of the reliability recovery moving body selection means.

  As shown in the figure, the reliability recovery mobile body selection means 147 determines whether or not the reliability of the entire autonomous mobile system satisfies a predetermined condition (S101). The overall reliability is evaluated based on the reliability of each mobile unit 100 stored in the storage unit 140. When the reliability of the entire moving body does not satisfy the predetermined condition (S101: N), normal work is maintained. Here, the normal work is, for example, work for moving the moving body 100 to a target position or work for inspection at the target position.

  Examples (patterns) of specific determination methods when the overall reliability satisfies a predetermined condition are listed below.

  1-1. The reliability recovery moving body selection means 147 reads the reliability of its own moving body 100 and the reliability of other moving bodies 100 from the storage unit 140, performs statistical processing, and calculates the variance at each time. When the calculated variance is equal to or greater than the first threshold and the state continues for the first threshold time, the process proceeds to the process of selecting the moving body 100 to be recovered (S103).

  In such a case, it is determined that the reliability of the entire moving body 100 cannot be improved uniformly only by observing the positional relationship among the plurality of moving bodies 100 and sharing the observation result by communication. .

  1-2. The reliability recovery moving body selection means 147 is such that the difference between the minimum value and the maximum value of the reliability of the entire moving body 100 is not less than the first threshold value, and the state continues continuously for the first threshold time, The process proceeds to the process of selecting the moving body 100 to be recovered (S103).

  In such a case as well, the reliability of the entire moving body 100 cannot be improved uniformly only by observing the positional relationship between the plurality of moving bodies 100 and sharing the observation result by communication. It is judged as a state.

  1-3. The reliability recovery moving body selection unit 147 statistically processes the reliability of the entire moving body 100, and at least one of the obtained maximum value, average value, and median value is lower than the second threshold value. In this case, the process proceeds to selecting the moving body 100 to be recovered (S103).

  In such a case, it is determined that the reliability of the entire moving body 100 does not increase even if the relative positions of the moving bodies 100 are measured and communicated with each other.

  1-4. The reliability recovery moving body selection means 147 statistically processes the reliability of the entire moving body 100 and obtains at least one of the obtained maximum value, average value, and median value first. If the difference is greater than or equal to the third threshold value compared to the type value, it is determined that the overall reliability has dropped sharply, and the mobile body 100 to be recovered is selected (S103).

  In such a case, it is determined that the plurality of moving bodies 100 are losing sight of their positions due to a disturbance such as a gust of wind.

  Next, based on the information recorded by the position reliability recording means 144, a moving body that causes the reliability recovery action is selected (S103).

  Below, the example (pattern) of the selection conditions at the time of selecting the mobile body 100 which raises reliability recovery action is enumerated below. In the case of the present embodiment, since each moving body 100 includes the reliability recovery moving body selecting means 147, it is individually determined whether or not the following selection conditions are satisfied, and it is determined that the conditions are satisfied. In the case (S103: Y), the reliability recovery behavior (S104) is autonomously executed. On the other hand, if it is determined that the condition is not satisfied (S103: N), the normal operation is maintained.

  2-1. The reliability recovery moving body selection unit 147 selects the moving body 100 to be recovered based on the reliability. For example, the moving body 100 having the lowest reliability is selected as the moving body 100 that performs the recovery action. The condition is that the variance of the reliability of the entire mobile object 100 is equal to or greater than the first threshold, and the state continues for the first threshold time, or the reliability of the entire mobile object 100 is the minimum value. This is effective when the difference between the maximum values is equal to or greater than the first threshold and the state continues for the first threshold time.

  In the case of the present embodiment, the latest reliability of the other mobile unit 100 obtained by the mobile information communication unit 148 is compared with the latest reliability of its own, and the reliability must be lower than its own reliability. If so, the recovery action is started autonomously (S104).

  2-2. The reliability recovery moving body selection unit 147 selects the moving body 100 to be recovered based on the remaining battery level of the battery that supplies the moving power included in the moving body 100. For example, the moving body 100 having the largest remaining battery capacity is selected as the moving body 100 to be recovered. This condition is effective when at least one of the maximum value, the average value, and the median value of the reliability of the entire moving body 100 is less than the second threshold value. In particular, since the remaining amount of battery of each moving body 100 can be made uniform, it is possible to perform a long-time operation as the entire moving body 100.

  In the case of the present embodiment, the mobile body information communication means 148 communicates and shares information indicating the remaining battery level in addition to its own position and reliability, and each mobile body 100 is connected to another mobile body. The latest battery remaining amount of 100 is compared with the latest battery remaining amount of the self, and if there is no battery remaining amount higher than the own battery remaining amount, the recovery action is started autonomously (S104).

  2-3. The reliability recovery moving body selection unit 147 selects the moving body 100 to be recovered based on the reliability. For example, the mobile body 100 having the highest reliability is selected as the mobile body 100 that performs the recovery action. This condition is effective when at least one of the maximum value, the average value, and the median value of the reliability of the entire moving body 100 is less than the second threshold value.

  In the case of the present embodiment, the mobile information communication unit 148 compares the latest reliability of the other mobile unit 100 obtained by the mobile information communication unit 148 with the latest reliability of its own, and the self-trust If there is no reliability higher than the degree, recovery action is started autonomously (S104).

  2-4. The reliability recovery moving body selection unit 147 selects the moving body 100 that is closest to the region having the high reliability as the moving body 100 that performs the recovery action. This condition is effective when at least one of the maximum value, the average value, and the median value of the reliability of the entire moving body 100 is less than the second threshold value. In this case, the amount of energy spent for reliability recovery can be suppressed, and the time required for reliability recovery can be shortened.

  In the case of the present embodiment, each moving body 100 aggregates the reliability of all the moving bodies 100 from the storage unit 140 and searches for a region with the highest reliability. Then, the Euclidean distance between the coordinate of the region with the highest reliability and the latest self-position of the other mobile object 100 is calculated, and the Euclidean distance between the coordinate of the region with the highest reliability and the self-position is compared. If there is no distance shorter than the self distance, the recovery action is started autonomously (S104).

  Next, examples (patterns) of specific control techniques for recovering the reliability of the moving body 100 selected by the reliability recovery moving body selecting means 147 are listed below.

  The reliability recovery action control unit 145 is a moving unit that moves the mobile unit 100 selected by the reliability recovery mobile unit selection unit 147 to a position with high reliability based on the information recorded by the position reliability recording unit 144. 101 is a processing unit for controlling 101.

  3-1. Based on the reliability recorded in the storage unit 140, the reliability recovery behavior control unit 145 moves the moving unit 101 so as to sequentially move following the self-position recorded in the storage unit 140 until the reliability reaches a predetermined threshold or more. Is controlled (S104).

  This will be specifically described based on the data shown in FIG. As a premise, the current time is 6, the threshold is 0.8, and the identifier indicating the selected mobile object 100 is 1001. The reliability recovery action control means 145 follows the coordinates of G (reliability 0.3) → F (reliability 0.5) → E (reliability 0.6) → D (reliability 0.8). The moving body 101 is moved by controlling the moving means 101. That is, the path that has reached the coordinates whose reliability is equal to or higher than the threshold is returned to the selected moving body 100.

  As described above, the self-position is estimated again at the coordinate position with high reliability, and the other mobile body 100 estimates the self-position again using the mobile body 100, thereby improving the reliability of the entire mobile body 100. Can do.

  Such a recovery action is effective when the moving body 100 is moving in the first space, or when reliability is drastically reduced due to a sudden wind or the like.

  3-2. The reliability recovery action control unit 145 controls the moving unit 101 so that the reliability stored in the storage unit 140 moves to a position that is equal to or greater than a predetermined threshold and is closest to the current self position.

  Specifically, as shown in FIG. 5, when the reliability satisfies a predetermined condition (current time 6), the self-position of the selected moving body 100 is the center, and its surroundings (up / down, front / back, left / right). Based on the information stored in the storage unit 140, the coordinates (for example, A, C, D) having a reliability equal to or greater than the first threshold (0.8). Extract. Further, the Euclidean distance between each coordinate and the current self-position is calculated, and the moving unit 100 is moved to the coordinate d by controlling the moving means 101 so as to move linearly to the coordinate having the smallest Euclidean distance (for example, D). Let

  As described above, the coordinate position with high reliability can be reached in a short time, and the self-position can be estimated again with the coordinate and the action for performing the normal work can be shifted in a short time.

  Such a recovery action is effective when the moving body 100 is performing an inspection operation or the like within a narrow range.

  3-3. The reliability recovery behavior control means 145 controls the movement means 101 so that the past reliability of the selected moving object is equal to or greater than a predetermined threshold value and moves to a position associated with time information closest to the current time. .

  This will be specifically described based on the data shown in FIG. As a premise, the current time is 6 and the predetermined threshold is 0.8. In the ID of 1001, the reliability recovery action control means 145 is 6 (reliability 0.3) → 5 (reliability 0.5) → 4 (reliability 0.6) → 3 (reliability 0.8). Going back in time, the reliability is checked, and the moving unit 101 is moved to the coordinate D by controlling the moving means 101 so as to move linearly to the coordinate whose reliability is equal to or greater than the threshold, that is, the coordinate (D).

  As described above, the coordinate position with high reliability can be reached in a short time, and the self-position can be estimated again with the coordinate and the action for performing the normal work can be shifted in a short time.

  Such a recovery action is effective when the moving body 100 is moving in a wide space with few obstacles.

(Embodiment 2)
Next, another embodiment of the autonomous mobile body system 110 will be described. In addition, the same code | symbol may be attached | subjected to what has the effect | action and function similar to the said Embodiment 1, and the same shape, mechanism, and structure (part) may be abbreviate | omitted. In the following description, differences from the first embodiment will be mainly described, and description of the same contents may be omitted.

  FIG. 6 is a block diagram showing a functional unit of the control means provided in each moving body of the autonomous moving body system according to the present embodiment.

  The autonomous mobile system 110 according to the present embodiment includes, as the mobile body 100, a master mobile body 100M that includes the reliability recovery mobile body selection means 147 in the control device 104, and a slave mobile body that acts according to instructions from the master mobile body 100M. 100S.

  The master mobile unit 100M collects the self-location and reliability of all the mobile units 100 by the mobile unit information communication unit 148. Then, the reliability recovery mobile object selection means 147 provided in the master mobile object 100M selects the mobile object 100 whose reliability is to be recovered in the same manner as in the first embodiment or based on the following determination.

  Examples (patterns) of selection conditions when selecting a moving body 100 that causes a reliability recovery action different from that of the first embodiment are listed below.

  2-5. The reliability recovery mobile object selection means 147 selects at least one mobile object 100 to be recovered from the mobile objects 100 existing in the region where the mobile objects 100 with low reliability are concentrated. The master mobile unit 100M transmits information indicating the selection to the mobile unit 100 selected using the mobile unit information communication unit 148. The condition is that the variance of the reliability of the entire mobile object 100 is equal to or greater than the first threshold, and the state continues for the first threshold time, or the reliability of the entire mobile object 100 is the minimum value. This is effective when the difference between the maximum values is equal to or greater than the first threshold and the state continues for the first threshold time.

  In the case of the present embodiment, the coordinates associated with the reliability below a predetermined threshold are extracted from the latest reliability of all the mobile bodies 100 collected by the mobile body information communication means 148 and the coordinates of the self-position, A region having the largest number of coordinates included in a predetermined unit region is identified as a region where the mobile objects 100 having low reliability are concentrated. Then, an arbitrary one is selected from the plurality of moving bodies 100 existing at the coordinates included in the specified area, and information indicating that is transmitted by the moving body information communication means 148. In addition, when the master mobile body 100M is selected, transmission is not necessary.

  2-6. The reliability recovery moving body selection means 147 selects the moving body 100 in the area where the moving body 100 is concentrated as the moving body 100 that causes the recovery action. The master mobile unit 100M transmits information indicating the selection to the mobile unit 100 selected using the mobile unit information communication unit 148. This condition is effective when at least one of the maximum value, the average value, and the median value of the reliability of the entire moving body 100 is less than the second threshold value.

  In the case of the present embodiment, from the latest self-position coordinates of all the moving bodies 100 collected by the moving body information communication means 148, the area having the largest number of the coordinates included in a predetermined unit area is selected. Is identified as the area where the Then, an arbitrary one is selected from the plurality of moving bodies 100 existing at the coordinates included in the specified area, and information indicating that is transmitted by the moving body information communication means 148.

  As described above, the processing load on the control device 104 of the slave moving body 100S is reduced by consolidating the evaluation of the reliability of the entire moving body 100 and the selection of the moving body 100 to be restored to the master moving body 100M. Is possible.

  Next, a specific example of the autonomous mobile system 110 will be described.

  FIG. 7 is a perspective view showing an autonomous mobile system that performs bridge inspection work.

  As shown in the figure, in this embodiment, the moving body 100 is a drone, and the self-supporting moving body system 110 includes a plurality of drone-type moving bodies 100. In addition, the work performed by the autonomous mobile system 110 is an inspection of the lower surface of the bridge 200, and each mobile body 100 takes an image of the lower surface of the bridge 200 by using an inspection camera mounted on the upper surface of each mobile body 100. Work. In addition, the detection of the crack of a structural member, etc. are performed based on the image imaged by the moving body 100 and the imaged position.

  Each moving body 100 performs work while estimating its own position using the Kalman filter based on sensor information from the sensors 103 such as IMU and GPS, the relative positional relationship of the moving body 100, and the like. . As such work proceeds, the reliability of the autonomous mobile system 110 as a whole decreases. For example, when the dispersion of the reliability of the self position of the entire mobile unit 100 is more than the first threshold and exceeds the first threshold time, the mobile units 100 communicate with each other by the mobile unit information communication unit 148. For example, the moving body 100 closest to the region having high reliability (in the present embodiment, the moving body 100 with id: 1002) is selected.

  The reliability recovery behavior control means 145 of the selected moving body 100 moves so as to move to a region where the reliability is high based on the information stored in the storage unit 140, for example, a region where a signal from the GPS satellite 210 can be received. The means 101 is controlled.

  The moving body 100 that has moved under the control of the moving means 101 recovers the reliability of its own position, returns to the initial position where the recovery action has been executed, and takes an image of the bridge 200 again.

  On the other hand, by transmitting the new self-position and reliability to the other mobile body 100, the reliability of the other mobile body 100 can be improved, and the reliability of the entire self-supporting mobile system 110 can be improved. It becomes.

  As described above, according to the self-supporting mobile system 110, it is possible to perform work efficiently while maintaining a high reliability of the entire system.

  The present invention is not limited to the above embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning of the words described in the claims. It is.

  For example, the master mobile unit 100M has been described as performing normal work similar to the slave mobile unit 100S, but the master mobile unit 100M may perform only management of the slave mobile unit 100S without performing normal work. .

  As shown in FIG. 8, the autonomous mobile system 110 includes a communication unit 149 that can communicate with the mobile unit information communication unit 148, a position reliability recording unit 144, and a reliability recovery mobile unit selection unit 147. The fixed device 100B that does not move may be provided. In this case, all the mobile units 100 become slave mobile units 100S, and the fixed device 100B acquires the self-position and its reliability from the slave mobile unit 100S by communication, and restores the reliability based on these information. The mobile unit 100S is selected, and information indicating that fact is transmitted to the selected slave mobile unit 100S. In this case, the slave mobile unit 100S may not include the position reliability recording unit 144, the storage unit 140, and the like.

  Further, the fixed device 100B aggregates sensor information from the sensor information acquisition unit 141 of each mobile unit 100 via the mobile unit information communication unit 148, and the fixed unit 100B estimates the position of the entire mobile unit 100 and the reliability thereof. The reliability recovery moving body selection unit 147 included in the fixed device 100B may start selecting the moving body 100 that performs the recovery action based on the reliability.

  Moreover, although the autonomous flying body which can move freely in the three-dimensional direction as the moving body 100, ie, the so-called drone capable of flying in the air, is exemplified in the above embodiment, the moving body 100 is not limited to this. As the mobile body 100, for example, an autonomous traveling vehicle traveling on the ground, an autonomous ship navigating the water surface, and the like can be listed.

  The sensor 103 is not particularly limited as long as it can measure information that contributes to the estimation of the self-position, and includes all sensors other than those already listed.

  In addition, although all the processing units are realized by one control device 104, each processing may be shared by a plurality of control units, and information may be exchanged by mutual communication.

  The condition for ending the recovery action may be ended when the self-position and the reliability are sequentially calculated even during the recovery action and the obtained reliability exceeds a predetermined value. Further, the process may be terminated when the destination and the self-position match.

  In addition, after the reliability is recovered, it may return to the point where the recovery action is started, or it may be directed directly from the position where the reliability is recovered to the destination.

  The present invention can be used for autonomously moving vehicles, trains, ships, aircraft, vacuum cleaners, and the like.

DESCRIPTION OF SYMBOLS 100 Mobile body 100B Fixed apparatus 100M Master mobile body 100S Slave mobile body 101 Movement means 103 Sensor 104 Control apparatus 110 Autonomous mobile body system 111 Rotor 112 Motor 140 Storage part 141 Sensor information acquisition means 142 Position estimation means 143 Reliability calculation means 144 Position Reliability recording means 145 Reliability recovery action control means 147 Reliability recovery moving body selection means 148 Mobile information communication means

Claims (11)

An autonomous mobile system comprising a plurality of mobile bodies that autonomously move to a target location by measuring a self-position with a sensor and controlling a moving means,
Sensor information acquisition means for acquiring sensor information relating to a self-position including a relative positional relationship with another moving body from the sensor;
Position estimation means for estimating a self-position based on the sensor information acquired by the sensor information acquisition means;
Reliability calculation means for calculating the reliability of the self-position estimated by the position estimation means;
Mobile information communication means for transmitting the information held by itself between the mobiles;
Position reliability recording means for recording the reliability calculated by the reliability calculation means, the self-position estimated by the position estimation means, and an identifier for identifying a moving object;
A reliability recovery moving body selection means for selecting a moving body that causes a reliability recovery action based on information recorded by the position reliability recording means;
An autonomous mobile system comprising: reliability recovery behavior control means for controlling the movement means so as to move the mobile body selected by the reliability recovery mobile body selection means to a position with high reliability. The autonomous mobile body according to claim 1, wherein the reliability recovery mobile body selection unit starts selection of the mobile body to perform recovery action based on a statistic calculated from the reliability of self-positions of the plurality of mobile bodies. system. The statistic is the total variance or the difference between the minimum and maximum values, and the total variance or the state where the difference between the minimum and maximum values is greater than or equal to the first threshold lasts beyond the first threshold time. The autonomous mobile body system according to claim 2, wherein, when the mobile body is selected, the mobile body to be recovered is selected. The statistics are the maximum value, the average value, and the median value of the overall confidence level, and at least one of the maximum value, the average value, and the median value of the overall confidence level rapidly decreases. The autonomous mobile body system according to claim 2, wherein the mobile body to be recovered is selected. The statistic is a maximum value, an average value, and a median value of the overall confidence level, and at least one of the maximum value, the average value, and the median value of the overall confidence level has a second threshold value. The autonomous mobile body system according to claim 2, wherein when it falls below, the mobile body to be recovered is selected.   The autonomous mobile body system according to any one of claims 1 to 5, wherein the reliability recovery mobile body selection unit selects the mobile body to be recovered based on reliability. The said reliability recovery mobile body selection means selects as the said mobile body to which the said mobile body in the area | region where the said mobile body with low reliability concentrates is made to make recovery action. Autonomous mobile system. The autonomous mobile body system according to any one of claims 1 to 5, wherein the reliability recovery mobile body selection unit selects the mobile body to be recovered based on a remaining battery level. The autonomous mobile body system according to any one of claims 1 to 5, wherein the reliability recovery mobile body selection unit selects the mobile body that is closest to an area with high reliability as the mobile body that performs recovery behavior. The autonomous mobile body according to any one of claims 1 to 5, wherein the reliability recovery mobile body selection unit selects the mobile body in the area where the mobile body is concentrated as the mobile body that causes the mobile body to recover. system. The autonomous mobile body system according to any one of claims 1 to 10, wherein the reliability recovery behavior control means controls the movement means based on information recorded by the position reliability recording means.

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