JP5157803B2 - Autonomous mobile device - Google Patents

Description

  The present invention relates to an autonomous mobile device having an environment map creation function, a route planning function, and an autonomous movement function.

Conventionally, an autonomous mobile device that moves autonomously in the surrounding environment is known. In order for an autonomous mobile device to move autonomously in the surrounding environment, an environment map that represents areas where objects (hereinafter also referred to as “obstacles”) in the moving space exist and areas that do not exist is required. . Various methods have been devised for obtaining such an environment map. Recently, SLAM (Simultaneous Localization and Mapping) is a technique for performing self-location estimation and environment map creation in real time while moving. Attention has been paid. Here, Patent Document 1 discloses a mobile robot that uses SLAM and generates a topographic map (environmental map) using topographic data obtained as a result of distance measurement by a laser range finder (or camera). .
JP 7-129238 A

However, the following problems have been pointed out in the method of creating an environmental map using SLAM.
1. An inconsistency may occur in the created environmental map due to accumulation of measurement errors. In particular, when creating a circular environment map, the start portion and the end portion may not match (so-called circular route problem).
2. When the layout of a part of the moving area is changed, it is necessary to recreate the entire environment map.

  The present invention has been made to solve the above-described problems, can solve inconsistencies in the environmental map due to accumulation of measurement errors, and can flexibly cope with partial layout changes of moving areas. An object of the present invention is to provide an autonomous mobile device capable of performing the above.

  An autonomous mobile device according to the present invention includes an acquisition unit that acquires position information of an object existing in the surroundings, and a plurality of partial maps that constitute an environment map of a movement region based on the position information of the object acquired by the acquisition unit A creation means for creating a plurality of partial maps by the creation means, a setting means for setting a connection point for connecting the plurality of partial maps, and a connection point set by the setting means, A selection means for selecting a connection point for each of the partial maps to be connected, and a connection means for determining a connection relationship between the connection points of the partial maps selected by the selection means.

  According to the autonomous mobile device according to the present invention, a plurality of independent partial maps are created, and connection points are set when the partial map is created. And the connection point which connects partial maps is selected and the connection relation between connection points is defined. Therefore, since the accumulation of errors can be suppressed by dividing the environment map of the entire mobile environment into independent partial maps, inconsistencies in the environment map due to the accumulation of errors can be eliminated. Further, since each partial map has a connection relationship between connection points included in the partial map, it is possible to move to a different partial map according to this connection relationship. In addition, since the environment map of the entire moving environment is managed by dividing it into partial maps, if there is a partial layout change in the moving area, only the partial map with the changed layout is recreated and recreated. It is possible to replace only the partial map. Therefore, it is possible to flexibly cope with a partial layout change of the moving area.

  An autonomous mobile device according to the present invention includes an extraction unit that extracts and thins a movable area for each of a plurality of partial maps created by the creation unit, and is thinned by the extraction unit for each of the plurality of partial maps. The topological map creating means for searching for branch points in the movable area and creating a topological map representing the connection relation of the branch points, and the topological map for each partial map created by the topological map creating means are selected by the selecting means. Search means for connecting the selected connection points and searching for the shortest path in the connected topological map; and dividing means for dividing the shortest path searched by the search means into a topological map for each of the plurality of partial maps; For each partial map divided by the dividing means, it is planned to plan a movement route that connects the connection points included in the topological map. Characterized in that it comprises a means.

  According to the autonomous mobile device of the present invention, for each partial map, the connection relationship between the branch points of the thinned movable area is expressed by the topological map, and the topological map created for each partial map is connected. As a result, the entire moving area is represented by a single topological map. Here, the topological map is a map having only the distance between the branch points connected to the connection relation of the branch points as information (that is, having no coordinate information). Not affected by distortion. Then, after the shortest route search is executed using the connected topological maps, the topological map is again divided for each partial map, and the movement route is planned according to the searched shortest route. As a result, it is possible to plan the shortest movement route across a plurality of partial maps.

  The autonomous mobile device according to the present invention includes a moving means for moving the own device, and a control means for controlling the moving means so as to move autonomously along a moving route planned for each of a plurality of partial maps by the planning means. When moving from a moving partial map to a different partial map, the partial map used for movement is changed to the partial map of the destination based on the connection relationship between the connecting points of the partial maps determined by the connecting means. And switching means for switching.

  According to the autonomous mobile device according to the present invention, when moving autonomously along a movement route extending over a plurality of partial maps, when moving from a moving partial map to a different partial map, based on the connection relationship between the partial maps. The partial map is switched. Therefore, it becomes possible to autonomously move to a destination (goal point) across a plurality of partial maps.

  In the autonomous mobile device according to the present invention, when the switching unit moves to a different partial map, it is preferable to switch the coordinate system to be used from the coordinate system of the moving partial map to the coordinate system of the destination partial map. .

  In this case, when moving to a different partial map, the coordinate system is switched from the coordinate system of the moving partial map to the coordinate system of the destination partial map. Therefore, it is possible to move from the moving partial map to the destination partial map.

  According to the present invention, it is possible to eliminate inconsistencies in the environmental map due to accumulation of measurement errors, and to flexibly cope with partial layout changes in the moving area.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, the configuration of the autonomous mobile device 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the autonomous mobile device 1.

  The autonomous mobile device 1 includes an environment map creation function for creating an environment map composed of a plurality of partial maps, a route planning function for planning a travel route that spans a plurality of partial maps, and a travel route that spans the plurality of partial maps. It has an autonomous movement function to move. More specifically, the autonomous mobile device 1 uses the SLAM to map an environment map of a moving area (a grid indicating an area where an obstacle exists and an area where an obstacle does not exist) when the self-machine is guided according to a remote operation by a user. Multiple partial maps that make up a map), and when it is guided to reach a connection point between partial maps (hereinafter referred to as a “connection point”, specified by the user) It has a function of registering as a position coordinate of a connection point on a map (a mode for executing this function is referred to as “installation mode”). In addition, the autonomous mobile device 1 extracts a movable area for each of the created partial maps, connects them using a topological map, performs a shortest path search on the topological map, and then divides the partial map again. It has a function to plan each movement route. Furthermore, the autonomous mobile device 1 has a function of autonomously moving across a plurality of partial maps from a start point to a goal point along a planned movement route (a mode in which this function is executed is referred to as a “transport mode”) ).

  Therefore, the autonomous mobile device 1 is a distance between the main body 10 provided with the electric motor 12 and the omni wheel 13 driven by the electric motor 12 at a lower portion thereof and an object (for example, a wall or an obstacle) existing in the surroundings. And a joystick 21 for guiding the autonomous mobile device 1 and registering a connection point. In addition, the autonomous mobile device 1 includes an electronic control device 30 that manages the creation of a plurality of partial maps (environmental maps), the planning of a travel route across the plurality of partial maps, and the autonomous movement along the travel route in an integrated manner. I have. Hereinafter, each component will be described in detail.

  The main body 10 is, for example, a metal frame formed in a substantially bottomed cylindrical shape, and the above-described laser range finder 20 and the electronic control device 30 are attached to the main body 10. The shape of the main body 10 is not limited to a substantially bottomed cylindrical shape. Four electric motors 12 are arranged in a cross shape and attached to the lower portion of the main body 10. Omni wheels 13 are attached to the drive shafts 12A of the four electric motors 12, respectively. That is, the four omni wheels 13 are mounted on the same circumference at intervals of 90 ° along the circumferential direction.

  The omni wheel 13 is provided so as to be rotatable around two wheels 14 that rotate about the drive shaft 12A of the electric motor 12 and an axis that is orthogonal to the drive shaft 12A of the electric motor 12 on the outer periphery of each wheel 14. Further, the wheel has six free rollers 15 and is movable in all directions. The two wheels 14 are attached with a phase shifted by 30 °. Due to such a configuration, when the electric motor 12 is driven and the wheel 14 rotates, the six free rollers 15 rotate together with the wheel 14. On the other hand, when the grounded free roller 15 rotates, the omni wheel 13 can also move in a direction parallel to the rotation axis of the wheel 14. For this reason, the autonomous mobile device 1 is moved in any direction (omnidirectional) by independently controlling the four electric motors 12 and individually adjusting the rotational direction and rotational speed of the four omni wheels 13. be able to. That is, the electric motor 12 and the omni wheel 13 function as moving means described in the claims.

  An encoder 16 that detects the rotation angle (that is, the drive amount or the rotation amount) of the drive shaft 12A is attached to the drive shaft 12A of each of the four electric motors 12. Each encoder 16 is connected to the electronic control unit 30, and outputs the detected rotation angle of each electric motor 12 to the electronic control unit 30. The electronic control unit 30 calculates the movement amount of the autonomous mobile device 1 from the input rotation angle of each electric motor 12.

  The laser range finder 20 is attached to the front part of the autonomous mobile device 1 so as to face the front direction (front) of the own device. The laser range finder 20 emits a laser (detection wave) and reflects the emitted laser with a rotating mirror, thereby scanning the periphery of the autonomous mobile device 1 in a fan shape with a central angle of 240 ° in the horizontal direction. The laser range finder 20 detects, for example, a laser reflected and returned by an object such as a wall or an obstacle, and detects a detection angle of the laser (reflected wave) and returns after being reflected by the object. By measuring the time (propagation time) until it comes, the angle and distance from the object are detected. That is, the laser range finder 20 functions as an acquisition unit described in the claims. The laser range finder 20 is connected to the electronic control device 30, and outputs distance information and angle information with respect to the detected surrounding object to the electronic control device 30.

  The joystick 21 is an input device for guiding and moving the autonomous mobile device 1 according to a user's remote operation. The joystick 21 is connected to a bar-shaped lever 22 that indicates a direction for guiding the autonomous mobile device 1 and a partial map. And a setting switch 23 for registering points. The user can guide the autonomous mobile device 1 by operating the lever 22 of the joystick 21 to instruct the autonomous mobile device 1 in the moving direction. Further, when the user reaches the connection point of the partial map while guiding the autonomous mobile device 1, the user can register the self position at that time as the position coordinates of the connection point by pressing the setting switch 23. it can. That is, the setting switch 23 constituting the joystick 21 functions as a setting unit described in the claims. The joystick 21 is connected to the electronic control unit 30 and outputs a guidance control (direction instruction) signal and a connection point registration signal to the electronic control unit 30.

  The touch screen 24 includes an input unit configured by a display unit 25 including a liquid crystal display (LCD) and the like, and an operation input unit 26 including a touch panel that detects a user's touch operation (input) on the display unit 25. Device. For example, when registering a connection point and selecting a connection point, the display unit 25 displays a partial map including the connection point, coordinate information of the connection point, and the like. Further, the display unit 25 displays various switches and the like for accepting an operation from a user who selects a connection point, a start point / goal point, and the like. Here, an example of the connection point selection screen displayed on the display unit 25 is shown in FIG. In the screen shown in FIG. 2, the coordinate information of the selected connection point, the connection relationship of the connection points, and the like are displayed.

  The operation input unit 26 is provided so as to cover the display screen of the display unit 25, and two-dimensional coordinates (XY coordinates) are virtually arranged on the surface thereof. The operation input unit 26 receives a selection operation from the user, and outputs coordinate information corresponding to the touch position when the user performs a touch operation. For example, pressure, capacitance, infrared rays, and ultrasonic waves are used for detecting the touch position. The operation input unit 26 determines the operation content of the user based on the display position of various switches and the coordinate information indicating the touch position of the user. Then, the operation input unit 26 outputs the determined operation content to the electronic control device 30. Here, when performing a route plan, the user can select a connection point for connecting partial maps, or set a start point / goal point, etc. by operating the operation input unit 26. That is, the operation input unit 26 functions as selection means described in the claims.

  The electronic control device 30 integrally controls the autonomous mobile device 1. The electronic control unit 30 includes a microprocessor that performs calculations, a ROM that stores a program for causing the microprocessor to execute each process, a RAM that temporarily stores various data such as calculation results, and a storage content thereof Backup RAM or the like. The electronic control unit 30 also includes a laser range finder 20, a joystick 21, an interface circuit that electrically connects the touch screen 24 and the microprocessor, a driver circuit that drives the electric motor 12, and the like.

  By executing the installation mode, the electronic control unit 30 creates an environment map of a moving area composed of a plurality of partial maps using SLAM, and registers the position coordinates of the connection points on the partial map. In addition, the electronic control unit 30 plans a movement route that spans a plurality of partial maps. Furthermore, the electronic control unit 30 controls the electric motor 12 so as to autonomously move across a plurality of partial maps from the start point to the goal point along the planned movement route by executing the transfer mode. Therefore, the electronic control device 30 includes a local map creation unit 31, a self-position estimation unit 32, a partial map creation unit 33, a storage unit 34, a route plan unit 35, a travel control unit 36, a sensor information acquisition unit 37, and obstacle avoidance control. A portion 38, a connecting portion 44, a switching portion 45, and the like. Each of these units is constructed by a combination of the hardware and software described above.

  The local map creation unit 31 uses the laser range finder 20 as the origin based on distance information and angle information (corresponding to position information described in claims) with surrounding objects read from the laser range finder 20. A local map around the own device (within the detectable range of the laser range finder 20) is created.

  The self-position estimation unit 32 collates the local map with the partial map in consideration of the movement amount of the own machine calculated according to the rotation angle of each electric motor 12 read from the encoder 16, and based on the result. To estimate the self-position. Further, when a connection point registration signal is input from the joystick 21 (setting switch 23), the self-position estimation unit 32 registers the self-position at that time in the storage unit 34 as the position coordinates of the connection point on the environment map. .

  The partial map creation unit 33 creates a plurality of partial maps constituting the environmental map of the movement area using SLAM during guided movement (when the installation mode is executed). That is, the partial map creation unit 33 functions as creation means described in the claims. More specifically, first, the partial map creation unit 33 obtains a local map from the local map creation unit 31 and obtains a self-position from the self-position estimation unit 32. Next, the partial map creation unit 33 performs coordinate conversion of the local map with the laser range finder 20 as the origin from the coordinate system with the laser range finder 20 as the origin to the coordinate system of the partial map according to its own position, Project a local map onto a partial map. Then, the partial map creation unit 33 repeatedly executes this process while the autonomous mobile device 1 is guided and moved, and sequentially adds the local map to the partial map. Create a map. Similarly, the partial map creation unit 33 sequentially creates a plurality of corresponding partial maps for each of a plurality of areas forming the movement area, thereby generating a plurality of partial maps covering the entire range of the movement area. create. When only the layout of a part of the moving area is changed, only the partial map of the area where the layout is changed may be created.

  The connection unit 44 determines a connection relationship between connection points of the partial map selected by the operation input unit 26 (that is, which connection point is connected to which connection point) based on a user operation. That is, the connecting portion 44 functions as connecting means described in the claims. Here, FIG. 3 shows an example of the partial map connected at the connection point. In the example shown in FIG. 3, the annular moving area is composed of four partial maps I to IV. In addition, one end of the partial map I and one end of the partial map II, and the other end of the partial map I and one end of the partial map IV are connected at a connection point, and the other end of the partial map II and one end of the partial map III, And the other end of the partial map IV and the other end of the partial map III are connected. Further, FIG. 4 shows an environment map in which the above-described partial map III is replaced in accordance with the layout change of the movement area. In the example shown in FIG. 4, the partial map III shown in FIG. 3 is replaced with the partial map III '. Thus, when the layout of a part of the moving area (here, the area of the partial map III) is changed, only the partial map of the area where the layout is changed is replaced and the connection relation is updated. This can be dealt with.

  The storage unit 34 is composed of, for example, the backup RAM described above, and stores a plurality of partial maps created by the partial map creation unit 33. In addition, the storage unit 34 has a storage area for storing the position coordinates of the connection points, connection information indicating the connection relationship of the connection points, movement route information planned by the route planning unit 35 described later, and the like. This information is also stored.

  The route plan unit 35 plans a travel route that crosses a plurality of partial maps created by the partial map creation unit 33. More specifically, the route planning unit 35 extracts a movable area for each of the created partial maps, thins the connected regions, connects them using a topological map, and performs a shortest route search on the topological map. Divide again and plan the movement route for each partial map. For this purpose, the route planning unit 35 includes a movable region extracting unit 39, a topological map creating unit 40, a shortest route searching unit 41, a dividing unit 42, and a planning unit 43.

  For each partial map, the movable area extraction unit 39 creates an extended obstacle area by expanding the outline of the obstacle area included in the partial map by using the Minkowski sum and by expanding the outline of the obstacle area. The area excluding the obstacle area is extracted as a movable area that can move without contacting the obstacle. Next, the movable area extracting unit 39 thins the extracted movable area using the thinning method of Hilitch. That is, the movable area extraction unit 39 functions as an extraction unit described in the claims.

  The topological map creation unit 40 searches for branch points (nodes) in the movable area thinned by the movable area extraction unit 39 for each of the plurality of partial maps, and creates a topological map representing the connection relation of the branch points. . That is, the topological map creation unit 40 functions as a topological map creation unit described in the claims. Here, the topological map is a map having only the distance between the branch points connected to the connection relation of the branch points as information (that is, having no coordinate information).

  The shortest path search unit 41 connects the topological maps of the partial maps created by the topological map creation unit 40 at connection points, and uses the A * algorithm (A star algorithm) on the connected topological maps. The shortest path connecting the start point and the goal point is searched. That is, the shortest path search unit 41 functions as search means described in the claims.

  The dividing unit 42 divides the shortest route searched by the shortest route searching unit 41 into a topological map for each of a plurality of partial maps. That is, the dividing unit 42 functions as a dividing unit described in the claims. In addition, the planning unit 43 plans a movement route that connects the connection points on the topological map for each partial map divided by the dividing unit 42. That is, the planning unit 43 functions as a planning unit described in the claims.

  The traveling control unit 36 drives the electric motor 12 so that the autonomous mobile device 1 moves (guides) in accordance with a guidance control (direction instruction) signal input from the joystick 21 (lever 22) when the installation mode is executed. On the other hand, the traveling control unit 36 causes the electric motor 12 to move autonomously to the goal point along a planned movement route across a plurality of partial maps while avoiding obstacles when the conveyance mode is executed. Control. That is, the traveling control unit 36 functions as a control unit described in the claims.

  Here, in the present embodiment, the virtual potential method is employed as a control method for autonomously moving the aircraft to the goal point along the movement path while avoiding an obstacle when the transfer mode is executed. This virtual potential method creates and superimposes a virtual attractive potential field for the goal point and a virtual repulsive potential field for the obstacle to be avoided, thereby avoiding contact with the obstacle. The way to head. More specifically, the traveling control unit 36 first calculates a virtual attractive force for heading to the goal point based on the self position. On the other hand, the obstacle avoidance control unit 38 calculates a virtual repulsive force for avoiding the obstacle based on the self position, the moving speed, and the position and speed of the obstacle. Subsequently, the traveling control unit 36 calculates a virtual force vector by vector combining the obtained virtual attractive force and the virtual repulsive force. Then, the traveling control unit 36 drives the electric motor 12 (omni wheel 13) according to the obtained virtual force vector, thereby controlling the traveling of the aircraft so as to move to the goal point while avoiding the obstacle. To do.

  In addition, when moving from a moving partial map to a different partial map, the switching unit 45 switches the partial map used for movement based on the connection relationship between the connection points of the partial maps determined by the connection unit 44. . More specifically, when switching to a different partial map, the switching unit 45 changes the coordinate system to be used from the coordinate system of the moving partial map to the coordinate system of the destination partial map ( Switching is performed using the coordinate transformation matrix shown in 2). That is, the switching unit 45 functions as switching means described in the claims. Thereby, the autonomous mobile device 1 can move autonomously across a plurality of partial maps.

  Next, operation | movement of the autonomous mobile apparatus 1 is demonstrated using FIGS. FIG. 6 is a flowchart showing a processing procedure of partial map creation processing (installation mode) by the autonomous mobile device 1. FIG. 7 is a flowchart showing a processing procedure of route planning processing by the autonomous mobile device 1. FIG. 8 is a flowchart showing a processing procedure of autonomous movement processing (transport mode) by the autonomous mobile device 1. Each process shown in FIGS. 6 to 8 is mainly performed by the electronic control unit 30 and is activated and executed by an operation from the user.

  First, the processing procedure of the partial map creation process (installation mode) shown in FIG. 6 will be described. In addition, before starting a partial map creation process, it is preferable to exclude the movable object placed on the guidance route as advance preparation. Further, when the environment map is created while guiding the autonomous mobile device 1, it is preferable that the moving body does not enter the detection range of the laser range finder 20.

  In step S100, when a partial map creation start instruction is received from the user, the autonomous mobile device 1 is guided to start moving. In subsequent step S102, a partial map is created using SLAM. In addition, since the creation method of a partial map is as above-mentioned, detailed description is abbreviate | omitted here.

  Subsequently, in step S104, the autonomous mobile device 1 is guided and moved in accordance with a guidance control (direction instruction) signal (ie, user operation) input from the joystick 21 (lever 22).

  Next, in step S106, it is determined whether or not a connection point registration signal has been input from the joystick 21 (setting switch 23). Here, when the connection point registration signal is input, in step S108, the self position of the point is registered as the position coordinate of the connection point on the partial map. On the other hand, when the connection point registration signal is not input, the process proceeds to step S110.

  In step S110, creation of all necessary partial maps is completed, and it is determined whether or not a partial map creation termination instruction from the user has been accepted. If the partial map creation end instruction is not accepted, the process proceeds to step S102, and the above-described steps S102 to S108 are repeatedly executed until a partial map creation end instruction is accepted. A partial map of is created. On the other hand, when all the partial maps have been created and a partial map creation end instruction has been received, the partial map creation process (installation mode) ends.

  Next, the process procedure of the route planning process shown in FIG. 7 will be described. First, in step S200, the partial map created by the partial map creation process described above is read (see FIG. 9), and for each partial map, the contour of the obstacle area included in the partial map is the radius of the own aircraft. Only an extended obstacle area is generated.

  In the subsequent step S202, the area excluding the extended obstacle area generated in step S200 from the partial map is extracted as a movable area that can move without contacting the obstacle. Subsequently, in step S204, thinning processing of the extracted movable area is performed (see FIG. 10).

  Next, in step S206, a branch point (node) search of the thinned movable area is performed for each partial map (see FIG. 11). Subsequently, in step S208, for each partial map, a topological map representing the connection relation of the branch points searched in step S206 and the distance between the connected branch points is created (see FIG. 12). Next, in step S210, the topological maps for each partial map created in step S208 are connected at the selected connection point (see FIG. 13).

In the following step S212, the starting point and the goal point given by the user are used as the base points, and for example, using the A * algorithm, it is determined which branch point on the topological map passes through the minimum cost (shortest route) ( (See FIG. 14). Subsequently, in step S214, the shortest path searched in step S212 is divided again into a topological map for each partial map (see FIG. 15). In step S216, for each partial map divided in step S214, a movement route and a subgoal connecting the connection points included in the topological map are determined, and route information represented by a subgoal point sequence (coordinate sequence) is acquired. (See FIG. 16).

  Next, the processing procedure of the autonomous movement process (transport mode) shown in FIG. 8 will be described. First, in step S300, self-position estimation is performed. That is, the local map and the partial map are collated in consideration of the movement amount of the own machine calculated according to the rotation angle of each electric motor 12 read from the encoder 16, and the self position is estimated based on the result. Is done.

  Subsequently, in step S302, autonomous movement control is executed, and while crossing the partial map to the goal point along the movement route for each partial map planned in the route planning process described above, avoiding obstacles. The electric motor 12 is controlled to move autonomously. As described above, in the present embodiment, the virtual potential method is employed as a control method for moving the aircraft to the goal point along the movement path while avoiding the obstacle. Since the virtual potential method is as described above, detailed description thereof is omitted here.

  In the subsequent step S304, a determination is made as to whether or not the vicinity of the connection point of the partial map, that is, the partial map switching area has been reached. More specifically, a circle having a predetermined radius centered on the own aircraft (for example, a distance that is specifically 2 m and preferably determined from the effective range of sensing) and a predetermined center centered on the connection point are described. Switching between partial maps depending on whether or not they overlap with a circle with a radius (for example, a distance of 2 m, which is preferably a distance that can be switched back enough from the maximum speed output during driving). It is determined whether or not the area has been reached. Here, if the partial map switching area has not been reached (that is, if the circles do not overlap), the process proceeds to step S308. On the other hand, when the switching area of the partial map has been reached (that is, when the circles overlap), the process proceeds to step S306.

  In step S306, the coordinate system to be used is switched from the coordinate system of the moving partial map to the coordinate system of the destination partial map by the above-described coordinate transformation matrix (see equation (2) in FIG. 5). As a result, the partial map to be used is switched. Thereafter, the process proceeds to step S308. In addition, in order to run smoothly, when the movement control of the autonomous mobile device 1 is performed with the target sequentially set based on a plurality of subgoals ahead of the current position as a target, the subgoal points near the connection point An overlap section is set for both the moving partial map and the destination partial map, and a boundary line is set near the connection point while driving, and the map is displayed when the aircraft crosses the boundary line. Is switched.

  In step S308, a determination is made as to whether or not the aircraft has arrived at the goal point across a plurality of partial maps. If the aircraft has not arrived at the goal point, the process proceeds to step S300, and the above-described steps S300 to S306 are repeatedly executed until the aircraft arrives at the goal point. On the other hand, when the aircraft arrives at the goal point, the autonomous movement process (conveyance mode) ends.

  According to the present embodiment, a plurality of independent partial maps are created, and connection points are set when the partial map is created. And the connection point which connects partial maps is selected and the connection relation between connection points is defined. Therefore, since the accumulation of errors can be suppressed by dividing the environment map of the entire mobile environment into independent partial maps, it is possible to eliminate inconsistencies in the environment map due to the accumulation of errors. Further, since each partial map has a connection relationship between connection points included in the partial map, it is possible to move to a different partial map according to this connection relationship.

  Furthermore, according to the present embodiment, since the environment map of the entire moving environment is divided and managed, only the partial map whose layout has been changed when the partial layout of the moving area is changed. It is possible to replace only the recreated partial map. Therefore, it is possible to flexibly cope with a partial layout change of the moving area.

  According to the present embodiment, for each partial map, the connection relationship between the branch points (nodes) of the thinned movable area is expressed by the topological map, and the topological map created for each partial map is connected. As a result, the entire moving area is represented by a single topological map. Here, the topological map is a map having only the distance between the branch points connected to the connection relation of the branch points as information (that is, having no coordinate information). Not affected by distortion. Then, after the shortest route search is executed using the connected topological maps, the topological map is again divided for each partial map, and the movement route is planned according to the searched shortest route. As a result, it is possible to plan the shortest movement route across a plurality of partial maps.

  According to this embodiment, when moving autonomously along a movement route that spans a plurality of partial maps, when moving from a moving partial map to a different partial map, based on the connection relationship between the partial maps, The map is switched. Therefore, it becomes possible to autonomously move to a destination (goal point) across a plurality of partial maps.

  According to this embodiment, when moving to a different partial map, the coordinate system is switched from the coordinate system of the moving partial map to the coordinate system of the destination partial map. Therefore, it is possible to move from the moving partial map to the destination partial map.

  In the above-described embodiment, when planning a movement route, the connection point set by the user is used as it is. However, the connection point optimization unit (linkage) that optimizes the position of the connection point set by the autonomous mobile device 1 A point optimizing means may be further provided. In this case, a connection point optimization process (step S205) described below is executed between step S204 and step S206 described above. Here, the optimization process of a connection point is demonstrated, referring FIG. In FIG. 17, “A” is a connection point prepared in advance by user input, “B” is an optimized connection point, “S” is a start point, “G” is a goal point, and “L1” is A temporary movement route passing through the connection point A, “L2” represents an optimum movement route, “R1 to R8” represent region lines of each map, and “P1 to P4” represent region lines of overlapping regions.

In step S205, a connection point B is obtained according to the following procedure.
(1) The partial map 2 is converted into the coordinate system of the partial map 1, and a temporary map of the partial map 1 + the partial map 2 is prepared.
(2) A temporary movement route L1 passing through the connection point A is calculated on the temporary map.
(3) The optimum route L2 is determined by an optimization method (a known method or a linearization method or a smoothing method described in Japanese Patent Application No. 2008-231519, for example).
(4) A connection point is replaced with an overlapping area between the partial map 1 and the partial map 2 on the optimum route L2, and this is set as a connection point B.

Here, the determination algorithm of the connection point B is demonstrated in detail. The connection point B starts at the intersection Bs between the optimum path L2 and the area line R6, and ends at the intersection Be between the optimum path L2 and the area line R4, and repeats the following procedure between the intersection Bs and the intersection Be in steps of a predetermined step. Is determined by
(5) As a n-th step, a straight line that passes through the connection point candidate B (n) and is parallel to the region line R1 is drawn, and the intersection of this straight line and each of the region lines R1 to R8 is obtained. Is obtained, and the value of the minimum line segment among these line segments is held.
(6) The above processing (5) is performed on the region lines R2 to R8, and the smallest value h (n) is held among the eight minimum values.
(7) The process proceeds to the (n + 1) th step, the processes (5) and (6) are performed on the next connection point candidate B (n + 1), and the minimum value h (n + 1) of the line segment is held.
(8) Compare h (n) and h (n + 1), rewrite the larger one to h (n + 1) and hold.
(9) By repeating the processes (5) to (8) at predetermined steps from Bs to Be, points B (n) that are generally separated from each of the region lines P1 to P4 of the overlapping region are calculated. This is the new connection point B. Through the above processing, the (optimized) connection point B on the optimum route L2 that is generally separated from each of the region lines P1 to P4 of the overlapping region can be obtained. Note that after the connection point is replaced, the above-described processing from step S206 is executed using the optimized connection point.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, the joystick 21 is used as an input device for remotely operating the autonomous mobile device 1, but it is only necessary to be able to guide the autonomous mobile device 1 and register a connection point. A remote controller or the like may be used.

  In the above-described embodiment, a partial map is created (setting and selection of connection points) based on the user's operation. However, the partial map may be automatically created. For example, when creating a partial map, for example, the movement distance of the autonomous mobile device, the area of the partial map, and / or sensor input (for example, when a marker placed near a connection point is detected by a camera) is automatically triggered Alternatively, the following new partial map may be created. Here, thresholds such as the movement distance of the autonomous mobile device and the area of the partial map for triggering can be determined according to the degree of accumulated error at the time of map creation of the sensor system of the autonomous mobile device. . When automatically creating the next new partial map, the current position and orientation in the existing partial map and the position and orientation of the origin in the new partial map are set as connection points, and the two points are selected as a set. Can be used for map switching.

  In the above embodiment, the touch screen 24 in which the display unit 25 and the operation input unit 26 are integrated is used. However, a normal display may be used as the display unit, and a keyboard, a mouse, or the like may be used as the operation input unit. .

  In the above-described embodiment, the distance to the obstacle is measured using the laser range finder 20, but instead of or in addition to the laser range finder, for example, a stereo camera, an ultrasonic sensor, or the like may be used.

  In the said embodiment, although the omni wheel 13 which can move to all directions was employ | adopted as a wheel, it is good also as a structure which uses a normal wheel (a steering wheel and a drive wheel).

It is a block diagram which shows the structure of the autonomous mobile apparatus which concerns on embodiment. It is a figure which shows an example of the selection screen of a connection point. It is a figure which shows an example of a partial map. It is a figure for demonstrating replacement of the partial map at the time of layout change. It is a figure which shows the coordinate transformation matrix of a partial map. It is a flowchart which shows the process sequence of the partial map creation process (installation mode) by the autonomous mobile device which concerns on embodiment. It is a flowchart which shows the process sequence of the route planning process by the autonomous mobile apparatus which concerns on embodiment. It is a flowchart which shows the process sequence of the autonomous movement process (conveyance mode) by the autonomous mobile device which concerns on embodiment. It is a figure which shows an example of the environmental map divided | segmented into the partial map. It is a figure which shows the partial map where the thinning of the movable area | region was performed. It is a figure which shows the partial map in which the node (branch point) search was performed. It is a figure which shows the divided topological map. It is a figure which shows the connected topological map. It is a figure which shows the topological map in which the shortest path | route search was performed. It is a figure which shows the topological map divided | segmented again. It is a figure which shows the partial map where the movement path | route was planned. It is a figure for demonstrating optimization of a connection point.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Autonomous mobile device 10 Main body 12 Electric motor 13 Omni wheel 14 Wheel 15 Free roller 16 Encoder 20 Laser range finder 21 Joystick 22 Lever 23 Setting switch 24 Touch screen 25 Display part 26 Operation input part 30 Electronic control unit 31 Local map creation part 32 Self-position estimation unit 33 Partial map creation unit 34 Storage unit 35 Route planning unit 36 Travel control unit 37 Sensor information acquisition unit 38 Obstacle avoidance control unit 39 Movable region extraction unit 40 Topological map creation unit 41 Shortest path search unit 42 Dividing unit 43 Planning Department 44 Connection Department 45 Switching Department

Claims (4)

An acquisition means for acquiring position information of an object existing around;
Creating means for creating a plurality of partial maps constituting the environmental map of the moving region based on the position information of the object obtained by the obtaining means;
Setting means for setting connection points for connecting the plurality of partial maps when the plurality of partial maps are created by the creation means;
A selection means for selecting a connection point of each of the partial maps connected to each other from the connection points set by the setting means;
An autonomous mobile device comprising: a coupling unit that determines a coupling relationship between coupling points of the partial map selected by the selection unit. For each of the plurality of partial maps created by the creating means, extracting means for extracting and thinning a movable area;
For each of the plurality of partial maps, a topological map creating unit that searches for a branch point of the movable area thinned by the extracting unit and creates a topological map that represents a connection relation of the branch point;
Search means for connecting the topological map for each partial map created by the topological map creating means at the connecting point selected by the selecting means, and searching for the shortest path in the connected topological map;
A dividing unit that divides the shortest path searched by the searching unit into a topological map for each of the plurality of partial maps;
The autonomous mobile device according to claim 1, further comprising: planning means for planning a movement route that connects connection points included in the topological map for each partial map divided by the dividing means. Moving means for moving the aircraft;
Control means for controlling the moving means so as to move autonomously along the movement route planned for each of the plurality of partial maps by the planning means;
When switching from a moving partial map to a different partial map, switching to switch the partial map used for the movement to the partial map to be migrated based on the connection relationship between the connection points of the partial maps determined by the connecting means. The autonomous mobile device according to claim 2, further comprising: means. The said switching means switches the coordinate system to be used from the coordinate system of the moving partial map to the coordinate system of the transfer destination partial map when moving to a different partial map. Autonomous mobile device.

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