Method, system, and mobile robot for generating environment map

Abstract

The present invention provides a method, a system and a mobile robot for generating an environment map which make it possible to generate a wide and accurate environment map at low cost and in a short time. This method according to one embodiment of the present invention is a method for generating an environment map by controlling a movable first mobile robot provided with a first detection means for detecting an environment and generating first environment information, and a movable second mobile robot provided with a second detection means for detecting an environment and generating second environment information, said method involving: a step in which the first mobile robot moves; a step in which a first detection means of the moving first mobile robot detects the environment to generate first environment information; a step in which the second mobile robot moves so as to follow the first mobile robot; a step in which the second detection means of the moving second mobile robot detects the environment to generate second environment information; and a step in which the environment map is generated on the basis of the first environment information and the second environment information.

Description

Method, system and mobile robot for generating an environmental map

[0001] The present invention relates to a method, a system, and a mobile robot for generating an environmental map.

[0002] In order for a mobile robot to move autonomously in an environment where humans and other machines exist, it is necessary for the mobile robot itself to correctly recognize its own position, posture, and surrounding environment. A conventional method for such recognition is Simultaneous Localization and Mapping (SLAM), which creates a map of the environment while simultaneously estimating its own position.

[0003] For example, Patent Document 1 discloses a robot system that evaluates the reliability of multiple estimators that perform self-position estimation based on the outputs of multiple different sensors, and integrates the self-position estimation information from the multiple estimators according to the reliability.

[0004] JP 2012-248032 A

[0005] However, there are limitations to the range that sensors can detect and the number of sensors that can be installed, and as a result, occlusion due to the complex shape of the environment can cause missing areas on the constructed map. Reflective surfaces in the environment can also cause missing or incorrect areas on the constructed map. While these issues can be addressed by repeatedly moving and sensing using a mobile robot or by editing the map, both of these solutions require significant time and cost.

[0006] Therefore, the present invention provides a method, a system, and a mobile robot for generating an environmental map that can generate a wide-area, highly accurate environmental map at low cost and in a short time.

[0007] A method according to one aspect of the present invention is a method for generating an environmental map by controlling a first mobile robot equipped with a first detection means for detecting the environment and generating first environmental information, and a second mobile robot equipped with a second detection means for detecting the environment and generating second environmental information, the method including the steps of: moving the first mobile robot; generating first environmental information by the first detection means of the moving first mobile robot detecting the environment; moving the second mobile robot to follow the first mobile robot; generating second environmental information by the second detection means of the moving second mobile robot detecting the environment; and generating an environmental map based on the first environmental information and the second environmental information.

[0008] According to this aspect, an environmental map is generated based on first environmental information generated by detecting the environment using a first detection means provided on a first mobile robot that moves within the environment, and second environmental information generated by detecting the environment using a second detection means provided on a second mobile robot that moves within the environment so as to follow the first mobile robot, making it possible to generate an extensive and highly accurate environmental map at low cost in a short period of time.

[0009] In the above aspect, the step of the second mobile robot moving to follow the first mobile robot may include the steps of acquiring route information regarding the route traveled by the first mobile robot, generating a route plan for the second mobile robot to move based on the route information, and moving the second mobile robot based on the route plan.

[0010] According to this aspect, the second mobile robot moves to follow the first mobile robot based on a route plan generated based on route information regarding the route traveled by the first mobile robot, thereby improving the accuracy with which the second mobile robot follows the first mobile robot and improving the completeness of the environmental map.

[0011] In the above aspect, in the step of acquiring route information regarding the route traveled by the first mobile robot, the second mobile robot may acquire the route information, and in the step of generating a route plan for the second mobile robot to move based on the route information, the second mobile robot may generate the route plan.

[0012] According to this aspect, the second mobile robot acquires a path plan generated based on route information regarding the route traveled by the first mobile robot, and then generates a path plan for the second mobile robot to move based on this, making it possible to move the second mobile robot to follow the first mobile robot at low cost and in a short time.

[0013] In the above aspect, in the step of generating an environmental map based on the first environmental information and the second environmental information, the second mobile robot may acquire the first environmental information from the first mobile robot, the second mobile robot may acquire the second environmental information from the second detection means, and the second mobile robot may generate an environmental map based on the acquired first environmental information and second environmental information.

[0014] According to this aspect, the second mobile robot generates an environmental map based on the first environmental information obtained from the first mobile robot and the second environmental information obtained from the second detection means, making it possible to generate an environmental map at low cost and in a short period of time.

[0015] In the above aspect, in the step of generating an environmental map based on the first environmental information and the second environmental information, the first mobile robot may acquire the second environmental information from the second mobile robot, the first mobile robot may acquire the first environmental information from the first detection means, and the first mobile robot may generate the environmental map based on the acquired first environmental information and second environmental information.

[0016] According to this aspect, the first mobile robot generates an environmental map based on the first environmental information acquired from the first detection means and the second environmental information acquired from the second mobile robot, making it possible to generate an environmental map at low cost and in a short period of time.

[0017] In the above aspect, the step of acquiring route information regarding the route traveled by the first mobile robot may include a step in which the server acquires the route information, and the step of generating a route plan for the second mobile robot to travel based on the route information may include a step in which the server generates the route plan, and further, the server transmits the route plan to the second mobile robot.

[0018] According to this aspect, the server acquires a route plan generated based on route information regarding the route traveled by the first mobile robot, and then generates a route plan for the second mobile robot based on this, making it possible to move the second mobile robot to follow the first mobile robot at low cost and in a short time.

[0019] In the above aspect, in the step of generating an environmental map based on the first environmental information and the second environmental information, the server may acquire the first environmental information from the first mobile robot, the server may acquire the second environmental information from the second mobile robot, and the server may generate the environmental map based on the acquired first environmental information and second environmental information.

[0020] According to this aspect, the server generates an environmental map based on the first environmental information obtained from the first mobile robot and the second environmental information obtained from the second mobile robot, making it possible to generate an environmental map at low cost and in a short time.

[0021] In the above aspect, the step of causing the second mobile robot to move to follow the first mobile robot may include a step of obtaining position information indicating the position of the first mobile robot by detecting the first mobile robot using a third detection means provided on the second mobile robot, a step of generating a path plan for movement of the second mobile robot based on the position information, and a step of causing the second mobile robot to move based on the path plan.

[0022] According to this aspect, a path plan for the movement of the second mobile robot is generated based on the position information of the first mobile robot obtained when the third detection means provided on the second mobile robot detects the first mobile robot, making it possible to easily generate the path plan.

[0023] In the above aspect, in the step in which the second mobile robot moves to follow the first mobile robot, the second mobile robot may move so that the orientation of the second detection means relative to the direction of movement of the second mobile robot is different from the orientation of the first detection means relative to the direction of movement of the first mobile robot.

[0024] According to this aspect, since the orientation of the first detection means provided on the first mobile robot is different from the orientation of the second detection means provided on the second mobile robot, the range of the first environmental information is different from the range of the second environmental information, and the degree to which the first environmental information and the second environmental information complement each other in the environmental map is increased.

[0025] In the above aspect, in the step in which the second mobile robot moves to follow the first mobile robot, the second mobile robot may move so that the orientation of the second detection means relative to the direction of movement of the second mobile robot is opposite to the orientation of the first detection means relative to the direction of movement of the first mobile robot.

[0026] According to this aspect, since the orientation of the first detection means provided on the first mobile robot and the orientation of the second detection means provided on the second mobile robot are opposite directions, the range of the first environmental information and the range of the second environmental information become different, and the degree to which the first environmental information and the second environmental information complement each other in the environmental map increases.

[0027] A system according to one aspect of the present invention comprises a first mobile robot equipped with a first detection means for detecting the environment and generating first environmental information, a second mobile robot equipped with a second detection means for detecting the environment and generating second environmental information, a first movement control unit that controls the first mobile robot to move, a first detection control unit that controls the first detection means of the moving first mobile robot to detect the environment and generate the first environmental information, a second movement control unit that controls the second mobile robot to move to follow the first mobile robot, a second detection control unit that controls the second detection means of the moving second mobile robot to detect the environment and generate second environmental information, and an environmental map generation unit that generates an environmental map based on the first environmental information and the second environmental information.

[0028] According to this aspect, an environmental map is generated based on first environmental information generated by detecting the environment using a first detection means provided on a first mobile robot that moves within the environment, and second environmental information generated by detecting the environment using a second detection means provided on a second mobile robot that moves within the environment so as to follow the first mobile robot, making it possible to generate a highly accurate environmental map at low cost in a short period of time.

[0029] A mobile robot according to one aspect of the present invention is a mobile robot provided with a detection means for detecting the environment and generating environmental information, a movement control unit that controls the mobile robot to move so as to follow another mobile robot, the other mobile robot being provided with another detection means for detecting the environment and generating other environmental information and configured to be mobile, a movement control unit that controls the detection means of the moving mobile robot to generate environmental information, and a supply unit that supplies the generated environmental information to an environmental map generation unit that generates an environmental map based on the environmental information and the other environmental information.

[0030] According to this aspect, an environmental map is generated based on other environmental information generated by another detection means provided on another mobile robot moving within the environment detecting the environment, and on environmental information generated by a detection means provided on a mobile robot moving within the environment so as to follow the other mobile robot, thereby making it possible to generate a highly accurate environmental map at low cost in a short time.

[0031] According to the present invention, it is possible to provide a method, a system, and a mobile robot for generating an environmental map that can generate an extensive and highly accurate environmental map at low cost and in a short time.

[0032] 1 is a diagram for explaining an overview of an environment map generating system 1 according to the present embodiment. FIG. 1 is a schematic diagram showing an example of the functional configuration of the environment map generating system 1 according to the first embodiment. FIG. 2 is a diagram showing an example of an operation flow showing operation processing performed by the environment map generating system 1 according to the first embodiment. FIG. 3 is a diagram showing an example of map information ML. FIG. 4 is a diagram showing an example of map information MF. FIG. 5 is a diagram showing an example of composite map information MA. FIG. 6 is a schematic diagram showing an example of the functional configuration of an environment map generating system 2 according to a second embodiment. FIG. 7 is a diagram showing an example of an operation flow showing operation processing performed by the environment map generating system 2 according to the second embodiment. FIG. 8 is a schematic diagram showing an example of the functional configuration of an environment map generating system 3 according to a third embodiment. FIG. 9 is a diagram showing an example of an operation flow showing operation processing performed by the environment map generating system 3 according to the third embodiment. FIG. 10 is a schematic diagram showing an example of the functional configuration of an environment map generating system 4 according to a fourth embodiment. FIG. 11 is a diagram showing an example of an operation flow showing operation processing performed by the environment map generating system 4 according to the fourth embodiment.

[0033] A preferred embodiment of the present invention will be described with reference to the accompanying drawings (in each drawing, the same reference numerals denote the same or similar configurations).

[0034] (1) First Embodiment (1-1) Overview Fig. 1 is a diagram for explaining an overview of an environmental map generation system 1 according to this embodiment. The environmental map generation system includes, for example, a first mobile robot 10 and a second mobile robot 20. The environmental map generation system 1 controls the first mobile robot 10 and the second mobile robot 20 to generate an environmental map.

[0035] Both the first mobile robot 10 and the second mobile robot 20 are so-called self-propelled robots that move by autonomously running on a floor surface. In Fig. 1, the running surface (movement surface) is shown as a surface approximately parallel to the XY plane defined by the X-axis and the Y-axis. Note that the term "self-propelled" does not necessarily mean a robot that runs completely autonomously, but may also mean a robot that runs by being remotely controlled by an external device such as a remote controller.

[0036] The first mobile robot 10 is configured to be mobile and is provided with an external sensor 11 for detecting the environment and generating map information ML (an example of "first environment information"). In FIG. 1 , the movement direction of the first mobile robot 10 is represented by a solid line DL, and the orientation of the external sensor 11 is represented by a dotted line SL. The external sensor 11 is configured to detect, for example, the environment in a predetermined first range direction relative to the external sensor 11. FIG. 1 shows, as an example of the first range, a first range 11R of approximately 270 degrees centered on the orientation SL of the external sensor 11. Note that the angle of the first range 11R is not limited to approximately 270 degrees and may be any value. The external sensor 11 is configured to detect the environment in the direction of the first range 11R. As the first mobile robot 10 moves within the environment, the external sensor 11 detects the environment in the direction of the first range 11R, and map information ML is generated based on the detection results.

[0037] The second mobile robot 20 is configured to be mobile and is provided with an external sensor 21 for detecting the environment and generating map information MF (an example of "second environment information"). In FIG. 1 , the movement direction of the second mobile robot 20 is represented by a solid line DF, and the orientation of the external sensor 21 is represented by a dotted line SF. The external sensor 21 is configured to detect, for example, the environment in a predetermined second range direction relative to the external sensor 21. FIG. 1 shows, as an example of the second range, a second range 21R of approximately 270 degrees centered on the orientation SF of the external sensor 21. Note that the angle of the second range 21R is not limited to approximately 270 degrees and may be any value. The external sensor 21 is configured to detect the environment in the direction of the second range 21R. As the second mobile robot 20 moves through the environment following the first mobile robot 10, the external sensor 21 detects the environment in the direction of the second range 21R, and map information MF is generated based on the detection results.

[0038] The environmental map generating system 1 generates composite map information MA (an example of an "environment map") based on the map information ML and the map information MF. In the environmental map generating system 1, for example, the second mobile robot 20 acquires the map information ML from the first mobile robot 10 and generates the composite map information MA by combining this with the map information MF generated based on the detection results of the external sensor 21.

[0039] In this way, in the environmental map generation system, the first mobile robot 10 moves within the environment, and the second mobile robot 20 moves within the environment so as to follow the first mobile robot 10. Then, composite map information MA is generated based on map information ML generated by the external sensor 11 provided on the first mobile robot 10 and map information MF generated by the external sensor 21 provided on the second mobile robot 20. This makes it possible to generate an extensive and highly accurate environmental map at low cost and in a short time.

[0040] In this disclosure, the posture information, route information, and map information may be simply referred to as "posture," "route," and "map," respectively.

[0041] (1-2) Configuration Fig. 2 is a schematic diagram showing an example of the functional configuration of the environmental map generating system 1 according to the first embodiment. The first mobile robot 10 and the second mobile robot 20 are connected to each other via a communication network N such as Wi-Fi (registered trademark) or Bluetooth (registered trademark) so as to be able to send and receive information to and from each other.

[0042] In the environmental map generating system 1 according to the first embodiment, the second mobile robot 20 acquires the route information TL of the first mobile robot 10 and then generates a route plan for the second mobile robot 20 so that the second mobile robot 20 follows the first mobile robot 10. Also, in the environmental map generating system 1 according to the first embodiment, the second mobile robot 20 acquires the map information ML and the map information MF and then generates composite map information MA based on these.

[0043] (1-2-1) Configuration of the First Mobile Robot 10 The first mobile robot 10 has an external sensor 11 , an internal sensor 12 , a communication unit 13 , a running unit 14 , and a control unit 15 .

[0044] The external sensor 11 detects information about the environment surrounding the first mobile robot 10. The external sensor 11 detects, for example, information about the position of the surrounding environment, two-dimensional or three-dimensional shape, color, and material. The external sensor 11 may be composed of sensors such as a laser range finder (LRF), a laser imaging detection and ranging (LIDAR), a camera, a depth camera, a stereo camera, a sonar, or a radar, or a combination of all of these. Note that the number and locations of the external sensors 11 possessed by the first mobile robot 10 are not particularly limited. The external sensors 11 may be disposed at any position, such as the front, rear, or side of the first mobile robot 10. The external sensor 11 is, for example, arranged to face a predetermined direction SL relative to the first mobile robot 10 and is configured to detect the environment in the direction of a predetermined first range 11R relative to the external sensor 11 (see FIG. 1 ).

[0045] The internal sensor 12 is a sensor that detects information regarding the position and posture of the first mobile robot 10. The internal sensor 12 is configured to be able to detect at least one absolute value of each of the three directional components (e.g., the X-axis component, the Y-axis component, and the Z-axis component of an X-Y-Z Cartesian coordinate system) of the travel distance, velocity, acceleration, angular velocity, and posture of the first mobile robot 10. The internal sensor 12 may be configured by, for example, an acceleration sensor, an angular velocity sensor, an encoder, a geomagnetic sensor, an air / water pressure sensor, a torque sensor, or a combination of these sensors.

[0046] The communication unit 13 is a wireless communication module (also referred to as a communication circuit) that enables the first mobile robot 10 to communicate wirelessly with other devices such as the second mobile robot 20 via the communication network N. There are no particular limitations on the communication standard used for communication, but it may be, for example, Wi-Fi (registered trademark) or Bluetooth (registered trademark).

[0047] The running unit 14 is a means for running (moving) the first mobile robot 10 and may include, for example, at least one wheel and an actuator that powers the wheel. The actuator drives, for example, the wheel based on a control command from the running control unit 151b, thereby moving the first mobile robot 10.

[0048] The control device 15 is a computer including a CPU (Central Processing Unit), a storage device (such as a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), or an SSD (Solid State Drive)), and various interfaces. The control device 15 includes a control unit 151 and a storage unit 152. Some or all of the functional units of the control unit 151 described below may be realized by executing a predetermined program stored in the storage device. Alternatively, some or all of the functional units of the control unit 151 may be realized by hardware such as a custom IC.

[0049] The control unit 151 includes a sensor control unit 151a, a driving control unit 151b, a map information generation and self-position estimation unit 151c, and a transmission / reception unit 151d.

[0050] The sensor control unit 151a controls the external sensor 11 and the internal sensor 12 and generates detection results of each sensor. For example, the sensor control unit 151a constitutes a first detection means together with the external sensor 11 and generates map information ML based on a detection signal supplied from the external sensor 11. The sensor control unit 151a may control the external sensor 11. For example, the sensor control unit 151a may control the orientation SL of the external sensor 11 and / or the size of the first range 11R.

[0051] The driving control unit 151b generates a path plan for the first mobile robot 10 and controls the driving unit 14 based on the path plan to move the first mobile robot 10. The method for generating the path plan is not particularly limited. For example, the driving control unit 151b may generate the path plan using map information ML stored in the memory unit 152 and information on the self-position of the first mobile robot 10 estimated by the map generation / self-position estimation unit 151c. The driving control unit 151b may also generate the path plan based on a set operation mode. The operation mode may be any operation mode, such as a "free mode" for random movement, a "map generation mode" for expanding the map generation range, or a "destination specification mode" for moving to a specified location. The driving control unit 151b generates control signals based on the generated path plan and supplies them to actuators of the driving unit 14 to drive wheels and other components to move the first mobile robot 10.

[0052] The map generation / self-location estimation unit 151c acquires at least one of the absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and attitude of the first mobile robot 10 obtained from the internal sensor 12. The map generation / self-location estimation unit 151c also acquires information about the surrounding environment of the first mobile robot 10 from the external sensor 11. The map generation / self-location estimation unit 151c then estimates the self-location of the first mobile robot 10 and generates map information from the acquired information by filtering. The filtering process can be implemented using any of the following methods: a Kalman filter, an extended Kalman filter, an unsent Kalman filter, a particle filter, and a Rao-Blackwellized particle filter.

[0053] Posture information PL and path information TL are generated by estimating the self-position. Map information ML is generated by generating map information. Here, the posture information PL may include the position (coordinates) and orientation of the first mobile robot 10. The path information TL may include information indicating the path traveled by the first mobile robot 10. The map information ML may include information on the map of the environment.

[0054] The map generation and self-position estimation unit 151c stores the generated posture information PL, route information TL, and map information ML in the storage unit 152. If the corresponding posture information PL, route information TL, and map information ML already exist, the map information stored in the storage unit 152 is used together with the updated map information, and the updated map information is stored in the storage unit 152.

[0055] The transmitter / receiver 151d transmits and receives information to and from other devices such as the second mobile robot 20 via the communication unit 13 and the communication network N. The transmitter / receiver 151d may transmit, for example, posture information PL, route information TL, and / or map information ML to the second mobile robot 20.

[0056] The storage unit 152 stores various programs and various data for controlling the first mobile robot 10. The storage unit stores, for example, the posture information PL, the route information TL, and / or the map information ML generated by the map generation / self-position estimation unit 151c or the like.

[0057] (1-2-2) Configuration of the Second Mobile Robot 20 The second mobile robot 20 has an external sensor 21 , an internal sensor 22 , a communication unit 23 , a running unit 24 , and a control device 25 .

[0058] The external sensor 21 detects information about the surrounding environment of the second mobile robot 20. The external sensor 21 detects, for example, information about the position of the surrounding environment, two-dimensional or three-dimensional shape, color, and material. The external sensor 21 may be composed of, for example, a laser range finder (LRF), a laser imaging detection and ranging (LIDAR), a camera, a depth camera, a stereo camera, a sonar, a radar, or any combination of these sensors. Note that the number and locations of the external sensors 21 possessed by the second mobile robot 20 are not particularly limited. The external sensor 21 may be disposed at any position, such as the front, rear, or side of the second mobile robot 20. The external sensor 21 is, for example, disposed so as to face a predetermined direction SF relative to the second mobile robot 20 and is configured to detect the environment in the direction of a predetermined second range 21R relative to the external sensor 21 (see FIG. 1 ).

[0059] The internal sensor 22 is a sensor that detects information regarding the position and posture of the second mobile robot 20. The internal sensor 22 is configured to be able to detect at least one absolute value of each of the three directional components (e.g., the X-axis component, the Y-axis component, and the Z-axis component of an X-Y-Z Cartesian coordinate system) of the movement distance, velocity, acceleration, angular velocity, and posture of the second mobile robot 20. The internal sensor 22 may be configured by, for example, an acceleration sensor, an angular velocity sensor, an encoder, a geomagnetic sensor, an air / water pressure sensor, a torque sensor, or a combination of these sensors.

[0060] The communication unit 23 is a wireless communication module (also referred to as a communication circuit) that enables the second mobile robot 20 to communicate wirelessly with other devices such as the first mobile robot 10 via the communication network N. The communication standard used for communication is not particularly limited, but may be, for example, Wi-Fi (registered trademark) or Bluetooth (registered trademark).

[0061] The running unit 24 is a means for running (moving) the second mobile robot 20, and may include, for example, at least one wheel and an actuator that powers the wheel. The actuator drives, for example, the wheel based on a control command from the running control unit 251b, thereby moving the second mobile robot 20.

[0062] The control device 25 is a computer including a CPU (Central Processing Unit), a storage device (such as a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), or an SSD (Solid State Drive)), and various interfaces. The control device 25 includes a control unit 251 and a storage unit 252. Some or all of the functional units of the control unit 251 described below may be realized by executing a predetermined program stored in the storage device. Alternatively, some or all of the functional units of the control unit 251 may be realized by hardware such as a custom IC.

[0063] The control unit 251 includes a sensor control unit 251a, a driving control unit 251b, a map information generation and self-position estimation unit 251c, a transmission / reception unit 251d, and a map information synthesis unit 251e.

[0064] The sensor control unit 251a controls the external sensor 21 and the internal sensor 22 and acquires the detection results of each sensor. For example, the sensor control unit 251a constitutes a second detection means together with the external sensor 21 and generates map information MF based on the detection signal supplied from the external sensor 21. The sensor control unit 251a may control the external sensor 21. For example, the sensor control unit 251a may control the orientation SF of the external sensor 21 and / or the size of the second range 21R. In particular, when the second mobile robot 20 moves to follow the first mobile robot 10, the sensor control unit 251a may control the orientation SF of the external sensor 21 and / or the size of the second range 21R so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment.

[0065] The traveling control unit 251b generates a path plan for the second mobile robot 20 and controls the traveling unit 24 based on the path plan to move the second mobile robot 20. In particular, the traveling control unit 251b moves the second mobile robot 20 so as to follow the first mobile robot 10. To this end, the traveling control unit 251b acquires, for example, path information TL regarding the path traveled by the first mobile robot 10, and generates a path plan for the second mobile robot 20 based at least on the path information TL. Note that the path plan may also be generated based on map information MF stored in the memory unit 252 and information on the self-position of the second mobile robot 20 estimated by the map generation / self-position estimation unit 251c.

[0066] Here, following the first mobile robot 10 is not limited to following a path that completely matches the path traveled by the first mobile robot 10, but may also include moving along a path that is within a range that is a predetermined distance from the path traveled by the first mobile robot 10. The predetermined distance may be stored, for example, as a predetermined value in the storage unit 252 or the like. The value may be set, for example, depending on the mode of the first mobile robot 10 and the mode of the second mobile robot 20. Furthermore, the traveling control unit 251b may calculate and update the predetermined distance depending on the detection results of the external sensor 21 and the internal sensor 22.

[0067] The driving control unit 251b may move the second mobile robot 20 so that the second range 21R in which the external sensor 21 possessed by the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 possessed by the first mobile robot 10 detects the environment.

[0068] For example, if the size of the first range 11R of the external sensor 11 and the size of the second range 21R of the external sensor 21 are equal, the travel control unit 251b may move the second mobile robot 20 so that the orientation of the external sensor 21 relative to the movement direction of the second mobile robot 20 is different from the orientation of the external sensor 11 relative to the movement direction of the first mobile robot 10. For example, in FIG. 1 , the movement direction of the first mobile robot 10 is represented by a solid arrow DL, the orientation of the external sensor 21 is represented by a dotted arrow SL, the movement direction of the second mobile robot 20 is represented by a solid arrow DF, and the orientation of the external sensor 21 is represented by a dotted arrow SF. As shown in FIG. 1 , the angle between the movement direction DL of the first mobile robot 10 and the orientation SL of the external sensor 11 is approximately 0 degrees. Also, as shown in FIG. 1 , the angle between the movement direction DF of the second mobile robot 20 and the orientation SF of the external sensor 21 is approximately 180 degrees. Therefore, the orientation of the external sensor 21 relative to the direction of movement of the second mobile robot 20 is different from the orientation of the external sensor 11 relative to the direction of movement of the first mobile robot 10 .

[0069] As described above, in the environmental map generating system 1 according to this embodiment, the second mobile robot 20 can move so as to follow the first mobile robot 10. Therefore, the direction of movement DF of the second mobile robot 20 when passing through an arbitrary position can be substantially equal to the direction of movement DL of the first mobile robot 10 when passing through the position. In this case, as described above, the second mobile robot 20 moves so that the orientation of the external sensor 21 relative to the direction of movement of the second mobile robot 20 is different from the orientation of the external sensor 11 relative to the direction of movement of the first mobile robot 10. As a result, the orientations of the external sensor 11 provided on the first mobile robot 10 and the external sensor 21 provided on the second mobile robot 20 when passing through an arbitrary position differ from each other, and the second range R21 of the external sensor 21 includes a range that is not included in the first range R11 of the external sensor 11. Therefore, the map information ML and map information MF that form the basis of the composite map information MA can complement each other in terms of the range of the image capture area, etc.

[0070] The travel control unit 251b of the second mobile robot 20 may move the second mobile robot 20 so that the difference between the angle between the movement direction DL of the first mobile robot 10 and the orientation SL of the external sensor 11 and the angle between the movement direction DF of the second mobile robot 20 and the orientation SF of the external sensor 21 becomes a predetermined value. The predetermined value may be any value, such as any value between 0 and 45 degrees, 45 degrees, any value between 45 and 90 degrees, 90 degrees, or any value between 90 and 180 degrees. The travel control unit 251b may also change the predetermined value based on various parameters. For example, the travel control unit 251b may change the predetermined value depending on a mode set by the user (e.g., a mode related to the accuracy of the generated environmental map). Furthermore, for example, the driving control unit 251b may change the specified value depending on the generated / acquired data (e.g., posture information PF, route information TF, map information MF, posture information PL, route information TL, map information ML, composite map information MA).

[0071] Also, for example, if the size of the second range 21R of the external sensor 21 is smaller than the size of the first range 11R of the external sensor 11, the travel control unit 251b may move the second mobile robot so that the second range 21R includes a range that is not included in the first range 11R.

[0072] For example, if the size of the second range 21R is larger than the size of the first range 11R, the second range 21R includes a range that is not included in the first range 11R, regardless of the orientation SF of the external sensor 21, and therefore the travel control unit 251b may move the second mobile robot arbitrarily.

[0073] The map generation / self-position estimation unit 251c acquires at least one of the absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and attitude of the second mobile robot 20 obtained from the internal sensor 22. The map generation / self-position estimation unit 251c also acquires information about the surrounding environment of the second mobile robot 20 from the external sensor 21. The map generation / self-position estimation unit 251c then estimates the self-position of the second mobile robot 20 and generates map information from the acquired information by filtering processing. The filtering processing can be implemented by any of the following methods: a Kalman filter, an extended Kalman filter, an unsent Kalman filter, a particle filter, and a Rao-Blackwellized particle filter.

[0074] Posture information PF and path information TF are generated by estimating the self-position. Map information MF is generated by generating map information. Here, the posture information PF may include the position (coordinates) and orientation of the second mobile robot 20. The path information TF may include information indicating the path traveled by the second mobile robot 20. The map information MF may include information on a map of the environment.

[0075] The map generation / self-location estimation unit 251c stores the generated attitude information PF, route information TF, and map information MF in the storage unit 252. If the corresponding attitude information PF, route information TF, and map information MF already exist, the map information stored in the storage unit 252 is also used to update the map information, and the updated information is stored in the storage unit 252. The map generation / self-location estimation unit 251c, as an example of a supply unit, supplies the map information MF to the map information synthesis unit 251e.

[0076] The transmitter / receiver 251d transmits and receives information to and from other devices such as the first mobile robot 10 via the communication unit 23 and the communication network N. The transmitter / receiver 251d may receive, for example, posture information PL, route information TL, and / or map information ML from the first mobile robot 10.

[0077] The map information synthesis unit 251e generates composite map information MA based on the map information ML and the map information MF. The map information synthesis unit 251e generates the composite map information MA by, for example, synthesizing the map information ML and the map information MF. The synthesis of the map information ML and the map information MF may use a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. Note that, in generating the composite map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. Also, in generating the composite map information MA, the route information TL and the route information TF may be converted into the same coordinate system.

[0078] The memory unit 252 stores various programs and various data for controlling the second mobile robot 20. The memory unit 252 stores, for example, posture information PF, path information TF, and / or map information MF generated by the map generation / self-position estimation unit 251c, etc. The memory unit 252 stores, for example, posture information PL, path information TL, and / or map information ML received from the first mobile robot 10. The memory unit 252 stores, for example, synthesized map information MA generated by the map information synthesis unit 251e, etc.

[0079] (1-3) Operation Processing Fig. 3 is a diagram showing an example of an operation flow showing the operation processing executed by the environmental map generating system 1 according to the first embodiment. The operation flow includes an operation flow showing the operation processing executed by the first mobile robot 10 and an operation flow showing the operation processing executed by the second mobile robot 20.

[0080] (1-3-1) Operation Processing of the First Mobile Robot 10 First, the operation processing executed by the first mobile robot 10 will be described.

[0081] First, in step S111, the internal sensor 12 acquires information about the position and posture of the first mobile robot 10. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the first mobile robot 10.

[0082] Next, in step S112, the external sensor 11 acquires information about the surrounding environment of the first mobile robot 10. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0083] Next, in step S113, the map generation / self-position estimation unit 151c generates map information and estimates the self-position of the first mobile robot 10 using the information acquired by the external sensor 11 and the information acquired by the internal sensor 12. As a result, posture information PL, path information TL, and map information ML of the first mobile robot 10 are generated.

[0084] The posture information PL, the path information TL, and the map information ML will be described with reference to FIG. 4 . FIG. 4 shows the map information ML when the first mobile robot 10 moves along the path TL to the position PL while detecting walls W1, W2, and W3 with the external sensor 11. In FIG. 4 , the walls W1, W2, and W3 detected by the external sensor 11 and the path TL are indicated by solid lines. As shown in FIG. 4 , when the external sensor 11 detects the wall W1, a defect d1 occurs due to the angle of the external sensor 11. Furthermore, the wall W3 has protrusions S1 and S2. As shown in FIG. 4 , when the external sensor 11 detects the wall W3, a defect d2 occurs due to light reflection by the protrusion S2.

[0085] Next, in step S114 , the transmitter / receiver 151 d transmits the generated posture information PL, route information TL, and map information ML of the first mobile robot 10 to the second mobile robot 20 .

[0086] Next, in step S115, the traveling control unit 151b generates a route plan for the first mobile robot 10. The traveling control unit 151b may generate the route plan using, for example, the map information ML stored in the memory unit 152 and information on the self-position of the first mobile robot 10 estimated by the map generation / self-position estimation unit 151c.

[0087] Next, in step S116, the traveling control unit 151b controls the traveling unit 14 based on the path plan generated in step S115 to move the first mobile robot 10. Thereafter, steps S111 to S116 are repeated until a predetermined termination condition is satisfied.

[0088] (1-3-2) Operation Processing of the Second Mobile Robot 20 Next, the operation processing executed by the second mobile robot 20 will be described.

[0089] First, in step S121, the internal sensor 22 acquires information about the position and posture of the second mobile robot 20. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the second mobile robot 20.

[0090] Next, in step S122, the external sensor 21 acquires information about the surrounding environment of the second mobile robot 20. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0091] Next, in step S123, the map generation / self-position estimation unit 251c generates map information and estimates the self-position of the second mobile robot 20 using the information acquired by the external sensor 21 and the information acquired by the internal sensor 22. As a result, posture information PF, path information TF, and map information MF of the second mobile robot 20 are generated.

[0092] The posture information PF, path information TF, and map information MF will be described with reference to FIG. 5 . FIG. 5 shows the map information MF when the second mobile robot 20 moves along the path TF to the position PF while detecting walls W1, W2, and W3 with the external sensor 21. In FIG. 5 , the walls W1, W2, and W3 detected by the external sensor 21 and the path TF are indicated by dotted lines. At this time, as indicated by reference character c1 in FIG. 5 , it is assumed that no loss occurs in the detection of wall W1 by the external sensor 21 due to the angle of the external sensor 21. Also, at this time, it is assumed that no loss occurs in the detection of wall W3 by the external sensor 21 due to light reflection, as indicated by reference character c2 in FIG. 5 .

[0093] Next, in step S124, the transmitter / receiver 251d receives the posture information PL, the route information TL, and the map information ML of the first mobile robot 10 transmitted from the first mobile robot 10 in step S114.

[0094] Next, in step S125, the map information synthesis unit 251e generates composite map information MA based on the map information ML generated by the first mobile robot 10 and the map information MF generated by the second mobile robot 20. The map information ML and the map information MF may be synthesized using a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. In generating the composite map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. In generating the composite map information MA, the path information TL and the path information TF may be converted into the same coordinate system.

[0095] FIG. 6 shows the composite map information MA. The walls W1, W2, and W3 detected by the external sensor 11 and the route TL are indicated by solid lines. The walls W1, W2, and W3 detected by the external sensor 21 and the route TF are indicated by dotted lines. As shown in FIG. 6 , in the composite map information MA, the walls W1, W2, and W3 detected by the external sensor 11 and the walls W1, W2, and W3 detected by the external sensor 21 are arranged so as to coincide with or be close to each other. As described above, in the detection of the wall W1 by the external sensor 11, a defect d1 occurred due to the angle of the external sensor 11 ( FIG. 4 ), whereas in the detection of the wall W1 by the external sensor 21, no defect occurred due to the angle of the external sensor 21 ( FIG. 5 ). Regarding the defect portion, as indicated by reference symbol c1 in FIG. 6 , in the composite map information MA, the defect d1 in the detection of the wall W1 by the external sensor 11 is complemented by the detection of the wall W1 by the external sensor 21. As described above, in the detection of wall W3 by external sensor 11, a defect d2 occurred due to the reflection of light by protrusion S2 ( FIG. 4 ), whereas in the detection of wall W3 by external sensor 21, no defect occurred due to the angle of external sensor 21 ( FIG. 5 ). Regarding the defect portion, as shown by reference symbol c2 in FIG. 6 , in the composite map information MA, the defect d2 in the detection of wall W1 by external sensor 11 is complemented by the detection of wall W1 by external sensor 21.

[0096] Next, in step S126, the traveling control unit 251b generates a path plan for the second mobile robot 20. In particular, the traveling control unit 251b generates a path plan for moving the second mobile robot 20 so as to follow the first mobile robot 10, based on the path information TL of the first mobile robot 10 acquired in step S124.

[0097] Next, in step S127, the travel control unit 251b controls the travel unit 24 based on the path plan generated in step S126 to move the second mobile robot 20. At this time, the travel control unit 251b may move the second mobile robot 20 so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Furthermore, at this time, the sensor control unit 251a may control the orientation SF of the external sensor 21 and / or the size of the second range 21R when the second mobile robot 20 moves to follow the first mobile robot 10 so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Thereafter, steps S121 to S127 are repeated until a predetermined termination condition is met.

[0098] (2) Second Embodiment (2-1) Configuration Figure 7 is a schematic diagram showing an example of the functional configuration of an environment map generation system 2 according to the second embodiment. Below, the differences between the environment map generation system 2 according to the second embodiment and the environment map generation system 2 according to the first embodiment will be described, and descriptions of the same parts as those in the environment map generation system 1 according to the first embodiment will be omitted as appropriate. In the environment map generation system 1 according to the second embodiment, the first mobile robot 10 acquires map information ML and map information MF, and then generates composite map information MA based on these.

[0099] (2-1-1) Configuration of the First Mobile Robot 10 The transmitter / receiver 151d may receive, for example, posture information PF, path information TF, and / or map information MF from the second mobile robot 20.

[0100] The first mobile robot 10 has a map information synthesis unit 151e. The map information synthesis unit 151e generates composite map information MA based on the map information ML and the map information MF. The map information synthesis unit 151e generates the composite map information MA by, for example, synthesizing the map information ML and the map information MF. The synthesis of the map information ML and the map information MF may use a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. In generating the composite map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. In generating the composite map information MA, the path information TL and the path information TF may be converted into the same coordinate system.

[0101] The storage unit 152 stores, for example, the posture information PL, the route information TL, and / or the map information ML generated by the map generation / self-position estimation unit 151c, etc. The storage unit 152 stores, for example, the posture information PF, the route information TF, and / or the map information MF received from the second mobile robot 20. The storage unit 152 stores, for example, the composite map information MA generated by the map information synthesis unit 151e, etc.

[0102] (2-2) Operation Processing Fig. 8 is a diagram showing an example of an operation flow showing an operation processing executed by the environmental map generating system 2 according to the second embodiment. The operation flow includes an operation flow showing an operation processing executed by the first mobile robot 10 and an operation flow showing an operation processing executed by the second mobile robot 20.

[0103] (2-2-1) Operation Processing of the First Mobile Robot 10 First, the operation processing executed by the first mobile robot 10 will be described.

[0104] First, in step S211, the internal sensor 12 acquires information about the position and posture of the first mobile robot 10. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the first mobile robot 10.

[0105] Next, in step S212, the external sensor 11 acquires information about the surrounding environment of the first mobile robot 10. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0106] Next, in step S213, the map generation / self-location estimation unit 151c generates map information and estimates the self-location of the first mobile robot 10 using the information acquired by the external sensor 11 and the information acquired by the internal sensor 12. As a result, for example, posture information PL, path information TL, and map information ML of the first mobile robot 10 are generated as shown in FIG.

[0107] Next, in step S214, the transmitter / receiver 151d receives the posture information PF, path information TF, and map information MF of the second mobile robot 20 transmitted from the second mobile robot 20 in step S224. The transmitter / receiver 151d also transmits the generated path information TL of the first mobile robot 10 to the second mobile robot 20.

[0108] Next, in step S215, the map information synthesis unit 151e generates composite map information MA based on the map information ML generated by the first mobile robot 10 and the map information MF generated by the second mobile robot 20. The map information ML and the map information MF may be synthesized using a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. In generating the composite map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. In generating the composite map information MA, the path information TL and the path information TF may be converted into the same coordinate system. As a result, for example, composite map information MA as shown in FIG. 6 is generated.

[0109] Next, in step S216, the traveling control unit 151b generates a route plan for the first mobile robot 10. The traveling control unit 151b may generate the route plan using, for example, the map information ML stored in the memory unit 152 and information on the self-position of the first mobile robot 10 estimated by the map generation / self-position estimation unit 151c.

[0110] Next, in step S217, the traveling control unit 151b controls the traveling unit 14 based on the path plan generated in step S216 to move the first mobile robot 10. Thereafter, steps S211 to S217 are repeated until a predetermined termination condition is met.

[0111] (2-2-2) Operation Processing of the Second Mobile Robot 20 Next, the operation processing executed by the second mobile robot 20 will be described.

[0112] First, in step S221, the internal sensor 22 acquires information about the position and posture of the second mobile robot 20. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the second mobile robot 20.

[0113] Next, in step S222, the external sensor 21 acquires information about the surrounding environment of the second mobile robot 20. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0114] Next, in step S223, the map generation / self-position estimation unit 251c generates map information and estimates the self-position of the second mobile robot 20 using the information acquired by the external sensor 21 and the information acquired by the internal sensor 22. As a result, for example, posture information PL, route information TL, and map information ML of the second mobile robot 20 are generated as shown in FIG.

[0115] Next, in step S224, the transmitter / receiver 251d transmits the generated posture information PF, path information TF, and map information MF of the second mobile robot 20 to the first mobile robot 10. The transmitter / receiver 251d also receives the path information TL of the first mobile robot 10 transmitted from the first mobile robot 10 in step S214.

[0116] Next, in step S225, the traveling control unit 251b generates a path plan for the second mobile robot 20. In particular, the traveling control unit 251b generates a path plan for moving the second mobile robot 20 so as to follow the first mobile robot 10, based on the path information TL of the first mobile robot 10 acquired in step S224.

[0117] Next, in step S226, the travel control unit 251b controls the travel unit 24 based on the path plan generated in step S225 to move the second mobile robot 20. At this time, the travel control unit 251b may move the second mobile robot 20 so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Furthermore, at this time, the sensor control unit 251a may control the orientation SF of the external sensor 21 and / or the size of the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment when the second mobile robot 20 moves to follow the first mobile robot 10, so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Thereafter, steps S221 to S226 are repeated until a predetermined termination condition is met.

[0118] (3) Third Embodiment (3-1) Configuration Fig. 9 is a schematic diagram showing an example of the functional configuration of an environment map generation system 3 according to the third embodiment. Below, the differences between the environment map generation system 3 according to the third embodiment and the environment map generation system 1 according to the first embodiment will be described, and descriptions of the same parts as those of the environment map generation system 1 according to the first embodiment will be omitted as appropriate.

[0119] The environmental map generating system 3 according to the third embodiment includes a server 30 in addition to the first mobile robot 10 and the second mobile robot 20. The server 30 is connected to the first mobile robot 10 and the second mobile robot 20 via a communication network N so as to be able to send and receive information to and from the first mobile robot 10 and the second mobile robot 20. In the environmental map generating system 3 according to the third embodiment, the server acquires path information TL of the first mobile robot 10 from the first mobile robot 10, generates a path plan for the second mobile robot 20 so that the second mobile robot 20 follows the first mobile robot 10, and transmits the path plan to the second mobile robot 20. In addition, in the environmental map generating system 3 according to the third embodiment, the second mobile robot 20 acquires map information ML from the first mobile robot 10 and map information MF from the second mobile robot 20, and generates composite map information MA based on these.

[0120] (3-1-1) Configuration of Server 30 The server 30 is a computer including a CPU (Central Processing Unit), a storage device (composed of a storage device such as a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), or an SSD (Solid State Drive)), and various interfaces. The server 30 includes a communication unit 31, a control unit 32, and a storage unit 33. Some or all of the functional units of the control unit 32 described below may be realized by executing a predetermined program stored in the storage device. Alternatively, some or all of the functional units of the control unit 32 may be realized by hardware such as a custom IC.

[0121] The communication unit 31 is a wireless communication module (also referred to as a communication circuit) that enables the server 30 to communicate wirelessly with other devices such as the first mobile robot 10 and the second mobile robot 20 via the communication network N. There are no particular limitations on the communication standard used for communication, but it may be, for example, Wi-Fi (registered trademark) or Bluetooth (registered trademark).

[0122] The control unit 32 includes a transmission / reception unit 32a, a map information synthesis unit 32b, and a route plan generation unit 32c.

[0123] The transmitter / receiver 32a transmits and receives information to and from other devices such as the first mobile robot 10 and the second mobile robot 20 via the communication unit 31 and the communication network N. The transmitter / receiver 32a may receive, for example, posture information PL, path information TL, and / or map information ML from the first mobile robot 10. The transmitter / receiver 32a may receive, for example, posture information PF, path information TF, and / or map information MF from the second mobile robot 20. The transmitter / receiver may transmit, for example, a path plan generated by the path plan generator 32c to the second mobile robot 20.

[0124] The map information synthesis unit 32b generates the synthetic map information MA by, for example, synthesizing the map information ML and the map information MF. The synthesis of the map information ML and the map information MF may use a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. In generating the synthetic map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. In generating the synthetic map information MA, the route information TL and the route information TF may be converted into the same coordinate system.

[0125] The path plan generating unit 32c generates a path plan for the second mobile robot 20. In particular, the path plan generating unit 32c generates a path plan that causes the second mobile robot 20 to move so as to follow the first mobile robot 10. For this purpose, the path plan generating unit 32c generates a path plan for the second mobile robot 20 based at least on, for example, path information TL related to the path traveled by the first mobile robot 10. The method for generating a path plan by the path plan generating unit 32c may be similar to the method for generating a path plan by the traveling control unit 251b of the second mobile robot 20 in the environmental map generating system 1 according to the first embodiment.

[0126] The storage unit 33 stores, for example, the posture information PL, the path information TL, and / or the map information ML received from the first mobile robot 10. The storage unit 33 stores, for example, the posture information PF, the path information TF, and / or the map information MF received from the second mobile robot 20. The storage unit 33 stores, for example, the composite map information MA generated by the map information synthesis unit 32b or the like.

[0127] 10 is a diagram showing an example of an operation flow showing the operation processing executed by the environmental map generating system 3 according to the third embodiment. The operation flow includes an operation flow showing the operation processing executed by the first mobile robot 10, an operation flow showing the operation processing executed by the second mobile robot 20, and an operation flow showing the operation processing executed by the server 30.

[0128] (3-2-1) Operation Processing of the First Mobile Robot 10 First, the operation processing executed by the first mobile robot 10 will be described.

[0129] First, in step S311, the internal sensor 12 acquires information about the position and posture of the first mobile robot 10. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the first mobile robot 10.

[0130] Next, in step S312, the external sensor 11 acquires information about the surrounding environment of the first mobile robot 10. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0131] Next, in step S313, the map generation / self-position estimation unit 151c generates map information and estimates the self-position of the first mobile robot 10 using the information acquired by the external sensor 11 and the information acquired by the internal sensor 12. As a result, for example, posture information PL, route information TL, and map information ML of the first mobile robot 10 are generated as shown in FIG.

[0132] Next, in step S314, the transmitter / receiver 151d transmits the generated posture information PL of the first mobile robot 10, the route information TL, and the map information ML to the server 30.

[0133] Next, in step S315, the traveling control unit 151b generates a route plan for the first mobile robot 10. The traveling control unit 151b may generate the route plan using, for example, the map information ML stored in the memory unit 152 and information on the self-position of the first mobile robot 10 estimated by the map generation / self-position estimation unit 151c.

[0134] Next, in step S316, the travel control unit 151b1 controls the travel unit 14 based on the path plan generated in step S315 to move the first mobile robot 10. At this time, the travel control unit 251b may move the second mobile robot 20 so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Furthermore, at this time, the sensor control unit 251a may control the orientation SF of the external sensor 21 and / or the size of the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment, when the second mobile robot 20 moves to follow the first mobile robot 10, so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Thereafter, steps S311 to S316 are repeated until a predetermined termination condition is met.

[0135] (3-2-2) Second Mobile Robot 20 Next, the operation process executed by the second mobile robot 20 will be described.

[0136] First, in step S321, the internal sensor 22 acquires information about the position and posture of the second mobile robot 20. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the second mobile robot 20.

[0137] Next, in step S322, the external sensor 21 acquires information about the surrounding environment of the second mobile robot 20. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0138] Next, in step S323, the map generation / self-position estimation unit 251c generates map information and estimates the self-position of the second mobile robot 20 using the information acquired by the external sensor 21 and the information acquired by the internal sensor 22. As a result, for example, posture information PL, route information TL, and map information ML of the second mobile robot 20 are generated as shown in FIG.

[0139] Next, in step S324, the transmitter / receiver 251d transmits the generated posture information PF of the second mobile robot 20, the path information TF, and the map information MF to the server.

[0140] Next, in step S325, the transmitter / receiver 251d receives the path plan (path plan for moving the second mobile robot 20 so as to follow the first mobile robot 10) transmitted from the server in step S332.

[0141] Next, in step S326, the traveling control unit 251b controls the traveling unit 24 based on the path plan acquired in step S325 to move the second mobile robot 20. Thereafter, steps S321 to S326 are repeated until a predetermined termination condition is satisfied.

[0142] (3-2-3) Operational Processing of Server 30 Next, the operational processing executed by the server 30 will be described.

[0143] First, in step S331, the transmitter / receiver 32a receives the posture information PL, path information TL, and map information ML of the first mobile robot 10 transmitted from the first mobile robot 10 in step S314. The transmitter / receiver 32a also receives the posture information PF, path information TF, and map information MF of the second mobile robot 20 transmitted from the second mobile robot 20 in step S324.

[0144] Next, in step S332, the path plan generating unit 32c generates a path plan for the second mobile robot 20. In particular, the path plan generating unit 32c generates a path plan for moving the second mobile robot 20 so as to follow the first mobile robot 10, based on the path information TL of the first mobile robot 10 acquired from the first mobile robot 10 in step S314. Then, the transmitting / receiving unit 32a transmits the path plan generated by the path plan generating unit 32c to the second mobile robot 20.

[0145] Next, in step S333, the map information synthesis unit 32b generates composite map information MA based on the map information ML generated by the first mobile robot 10 and the map information MF generated by the second mobile robot 20. The map information ML and the map information MF may be synthesized using a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. In generating the composite map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. In generating the composite map information MA, the path information TL and the path information TF may be converted into the same coordinate system. As a result, composite map information MA such as that shown in FIG. 6 is generated. Steps S331 to S333 are then repeated until a predetermined termination condition is met.

[0146] (4) Fourth Embodiment (4-1) Configuration Fig. 11 is a schematic diagram showing an example of the functional configuration of an environment map generation system 4 according to the fourth embodiment. Below, the differences between the environment map generation system 4 according to the fourth embodiment and the environment map generation system according to the third embodiment will be described, and descriptions of the same parts as those of the environment map generation system according to the third embodiment will be omitted as appropriate.

[0147] In the environmental map generating system 4 according to the fourth embodiment, the second mobile robot 20 has a second external sensor 26. In the environmental map generating system 4 according to the fourth embodiment, the second mobile robot 20 detects the first mobile robot 10 using the second external sensor 26, and generates position information indicating the position of the first mobile robot 10 based on the detection result. Then, the second mobile robot 20 generates a path plan for movement of the second mobile robot 20 based on the position information indicating the position of the first mobile robot 10, and moves based on the path plan.

[0148] (4-1-1) First Mobile Robot 10 The second mobile robot 20 has a second external sensor 26. The second external sensor 26 is a sensor that detects information about the surrounding environment of the second mobile robot 20. The second external sensor 26 detects, for example, information about the position of the surrounding environment, two-dimensional or three-dimensional shape, color, and material. The second external sensor 26 may be composed of sensors such as an LRF (Laser Range Finder), a LIDAR (Laser Imaging Detection and Ranging), a camera, a depth camera, a stereo camera, sonar, or RADAR, or a combination of all of these. Note that the number and locations of the second external sensors 26 included in the second mobile robot 20 are not particularly limited. The second external sensor 26 may be located at any position, such as the front, rear, or side of the second mobile robot 20.

[0149] The sensor control unit 251a of the second mobile robot 20 constitutes a third detection means together with the second external sensor 26, and generates a detection result of the second external sensor 26 detecting the first mobile robot 10 based on a detection signal supplied from the second external sensor 26. The sensor control unit 251a may generate the detection result of the first mobile robot 10, for example, by performing feature analysis on the detection signal supplied from the second external sensor 26. The detection result may include, for example, position information of the first mobile robot 10, the distance to the first mobile robot 10, the direction of the first mobile robot 10, etc. Note that the sensor control unit 251a may further use position information (self-position) of the second mobile robot 20 in calculating the detection result of the first mobile robot 10.

[0150] The travel control unit 251b of the second mobile robot 20 generates a path plan for the second mobile robot 20 to move so as to follow the first mobile robot 10, based on the detection result of the first mobile robot 10. The method for generating the path plan is not particularly limited, but may be, for example, PID (Proportional Integral-Differential) control or Pure-Pursuit control.

[0151] When generating a path plan for the second mobile robot 20, the traveling control unit 251b may generate a path plan such that the angle between the orientation of the second external sensor 26 and the orientation of the second mobile robot 20 is less than a predetermined threshold. The traveling control unit 251b may also change the predetermined threshold based on various parameters. For example, the traveling control unit 251b may change the predetermined threshold depending on a mode set by the user (such as a mode related to the accuracy of the generated environmental map). The traveling control unit 251b may also change the predetermined threshold depending on generated / acquired data (e.g., posture information PF, path information TF, map information MF, posture information PL, path information TL, map information ML, and composite map information MA).

[0152] 12 is a diagram showing an example of an operation flow showing the operation processing executed by the environmental map generating system 4 according to the fourth embodiment. The operation flow includes an operation flow showing the operation processing executed by the first mobile robot 10, an operation flow showing the operation processing executed by the second mobile robot 20, and an operation flow showing the operation processing executed by the server 30.

[0153] (4-2-1) Operation processing of the first mobile robot 10 The operation processing performed by the first mobile robot 10 is similar to the operation processing by the first mobile robot 10 of the environmental map generation system according to the third embodiment (FIG. 10), and therefore will not be described here.

[0154] (4-2-2) Operation Processing of the Second Mobile Robot 20 Next, the operation processing executed by the second mobile robot 20 will be described.

[0155] First, in step S421, the internal sensor 22 acquires information about the position and posture of the second mobile robot 20. Here, the acquired information may include, for example, absolute values ​​of the three directional components of the travel distance, velocity, acceleration, angular velocity, and posture of the second mobile robot 20.

[0156] Next, in step S422, the external sensor 11 acquires information about the surrounding environment of the second mobile robot 20. The acquired information includes information about the position of the surrounding environment, and information about the two-dimensional or three-dimensional shape, color, and material.

[0157] Next, in step S423, the map generation / self-position estimation unit 251c generates map information and estimates the self-position of the second mobile robot 20 using the information acquired by the external sensor 11 and the information acquired by the internal sensor 22. As a result, posture information PF, path information TF, and map information MF of the second mobile robot 20 are generated, for example, as shown in FIG.

[0158] Next, in step S424, the transmitter / receiver 251d transmits the generated posture information PF of the second mobile robot 20, the path information TF, and the map information MF to the server.

[0159] Next, in step S425, the second external sensor 26 acquires information about the surrounding environment of the second mobile robot 20. Then, the sensor control unit 251a generates a detection result of the first mobile robot 10 based on the detection signal supplied from the second external sensor 26.

[0160] Next, in step S426 , the traveling control unit 251 b generates a path plan for the second mobile robot 20 to move so as to follow the first mobile robot 10 based on the detection result of the first mobile robot 10 .

[0161] Next, in step S427, the travel control unit 251b controls the travel unit 24 based on the path plan generated in step S426 to move the second mobile robot 20. At this time, the travel control unit 251b may move the second mobile robot 20 so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Furthermore, at this time, the sensor control unit 251a may control the orientation SF of the external sensor 21 and / or the size of the second range 21R when the second mobile robot 20 moves to follow the first mobile robot 10 so that the second range 21R in which the external sensor 21 of the second mobile robot 20 detects the environment includes a range that is not included in the first range 11R in which the external sensor 11 of the first mobile robot 10 detects the environment. Thereafter, steps S421 to S427 are repeated until a predetermined termination condition is met.

[0162] (4-2-3) Operational Processing of the Server Next, the operational processing executed by the server 30 will be described.

[0163] First, in step S431, the transmitter / receiver 32a receives the posture information PL, path information TL, and map information ML of the first mobile robot 10 transmitted from the first mobile robot 10 in step S414. The transmitter / receiver 32a also receives the posture information PF, path information TF, and map information MF of the second mobile robot 20 transmitted from the second mobile robot 20 in step S424.

[0164] Next, in step S432, the map information synthesis unit 32b generates composite map information MA based on the map information ML generated by the first mobile robot 10 and the map information MF generated by the second mobile robot 20. The map information ML and the map information MF may be synthesized using a known point cloud matching technique, such as the Iterative Closest Point (ICP) algorithm. In generating the composite map information MA, the orientation information PL and the orientation information PF may be converted into the same coordinate system. In generating the composite map information MA, the path information TL and the path information TF may be converted into the same coordinate system. As a result, composite map information MA such as that shown in FIG. 6 is generated. Steps S431 to S432 are then repeated until a predetermined termination condition is met.

[0165] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined with each other.

[0166] 1, 2, 3, 4...Environmental map generation system, 10...First mobile robot, 11...External sensor, 12...Internal sensor, 13...Communication unit, 14...Travel unit, 15...Control device, 151...Control unit, 152...Memory unit, 151a...Sensor control unit, 151b...Travel control unit, 151c...Map information generation / self-position estimation unit, 151d...Transmitting / receiving unit, 151e...Map information synthesis unit, 21...External sensor, 22...Internal sensor, 23...Communication unit, 24...traveling unit, 25...control device, 251...control unit, 252...storage unit, 251a...sensor control unit, 251b...traveling control unit, 251c...map information generation / self-position estimation unit, 251d...transmission / reception unit, 251e...map information synthesis unit, 26...second external sensor, 30...server, 31...communication unit, 32...control unit, 33...storage unit, 32...control unit, 32a...transmission / reception unit, 32b...map information synthesis unit, 32c...route plan generation unit

Claims

1. A method for generating an environmental map by controlling a first mobile robot provided with a first detection means for detecting the environment and generating first environmental information, and a second mobile robot provided with a second detection means for detecting the environment and generating second environmental information, the method comprising the steps of: moving the first mobile robot; generating first environmental information by the first detection means of the moving first mobile robot detecting the environment; moving the second mobile robot to follow the first mobile robot; generating second environmental information by the second detection means of the moving second mobile robot detecting the environment; and generating an environmental map based on the first environmental information and the second environmental information.

2. The method of claim 1, wherein the first sensing means is configured to generate the first environmental information by sensing an environment in a first range of directions relative to the first sensing means, and the second sensing means is configured to generate the second environmental information by sensing an environment in a second range of directions relative to the second sensing means.

3. The method according to claim 2, wherein in the step of generating second environmental information, the second range includes a range not included in the first range.

4. The method according to claim 1, wherein the step of the second moving robot moving to follow the first moving robot includes the steps of: acquiring route information regarding the route traveled by the first moving robot; generating a route plan for the movement of the second moving robot based on the route information; and moving the second moving robot based on the route plan.

5. The method according to claim 4, wherein in the step of acquiring route information regarding the route traveled by the first mobile robot, the second mobile robot acquires the route information, and in the step of generating a route plan for the movement of the second mobile robot based on the route information, the second mobile robot generates the route plan.

6. The method according to claim 1, wherein in the step of generating an environmental map based on the first environmental information and the second environmental information, the second mobile robot acquires the first environmental information from the first mobile robot, the second mobile robot acquires the second environmental information from the second detection means, and the second mobile robot generates the environmental map based on the acquired first environmental information and second environmental information.

7. The method according to claim 1, wherein in the step of generating an environmental map based on the first environmental information and the second environmental information, the first mobile robot acquires the second environmental information from the second mobile robot, the first mobile robot acquires the first environmental information from the first detection means, and the first mobile robot generates the environmental map based on the acquired first environmental information and second environmental information.

8. The method according to claim 4, further comprising the steps of: in the step of acquiring route information regarding the route traveled by the first moving robot, a server acquires the route information; in the step of generating a route plan for the movement of the second moving robot based on the route information, the server generates the route plan; and further comprising the step of the server transmitting the route plan to the second moving robot.

9. The method according to claim 1, wherein in the step of generating an environmental map based on the first environmental information and the second environmental information, the server acquires the first environmental information from the first mobile robot, the server acquires the second environmental information from the second mobile robot, and the server generates the environmental map based on the acquired first environmental information and second environmental information.

10. The method according to claim 1, wherein the step of the second moving robot moving to follow the first moving robot includes: a step of a third detection means provided on the second moving robot detecting the first moving robot; a step of generating a path plan for the movement of the second moving robot based on the detection result by the third detection means; and a step of the second moving robot moving based on the path plan.

11. The method of claim 10, wherein the detection result includes position information indicating a position of the first mobile robot.

12. A system comprising: a first mobile robot provided with a first detection means for detecting an environment and generating first environmental information; a second mobile robot provided with a second detection means for detecting an environment and generating second environmental information; a first movement control unit that controls the first mobile robot to move; a first detection control unit that controls the first detection means of the moving first mobile robot to detect the environment and generate first environmental information; a second movement control unit that controls the second mobile robot to move to follow the first mobile robot; a second detection control unit that controls the second detection means of the moving second mobile robot to detect the environment and generate second environmental information; and an environmental map generation unit that generates an environmental map based on the first environmental information and the second environmental information.

13. A mobile robot provided with a detection means for detecting an environment and generating environmental information, a movement control unit that controls the mobile robot to move so as to follow another mobile robot, the other mobile robot being provided with another detection means for detecting the environment and generating other environmental information and configured to be mobile, a detection control unit that controls the detection means of the moving mobile robot to generate the environmental information, and a supply unit that supplies the generated environmental information to an environmental map generation unit that generates an environmental map based on the environmental information and the other environmental information.

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