JPWO2018180175A1 - Moving object, signal processing device, and computer program - Google Patents

Abstract

The moving body (10) of the present disclosure includes a motor (16a to 16d), a driving device (17) for the motor, a sensor (15) that senses surrounding space and outputs sensor data, and A storage device for storing map data, wherein each of the plurality of intermediate maps is generated from sensor data of a surrounding space sensed by a sensor at a time interval, and a storage device (14c); A processing circuit (14a, 14e, 14g) for generating one map from the plurality of intermediate maps. One map includes a plurality of feature points (51) in a distinguishable manner. Each of the plurality of feature points indicates a position where the degree of coincidence among the plurality of intermediate maps is larger than a predetermined value. The processing circuit performs processing for identifying one's own position by comparing one map with sensor data newly output from the sensor.

Description

  The present disclosure relates to a moving object, a signal processing device, and a computer program.

  There is an autonomous mobile robot that moves along a route created on an environmental map. The “environmental map” is a map showing the geometric situation of an entity in space. An autonomous mobile robot measures its surrounding shape using an external sensor such as a laser distance sensor, and geometrically matches the surrounding shape with an environment map to estimate its own current position and posture (identification). I do. As a result, the autonomous mobile robot can move along the route created on the environment map.

  Since the arrangement and shape of objects in space can change, it is necessary to update the environment map so that the actual state of the entity matches the environment map.

  Japanese Patent Laying-Open No. 2012-93811 discloses a technique for updating an environment map. The update of the environment map is a process of matching new measurement data with the shape of the past environment map and overwriting the past environment map with the new measurement data. Since an error included in the shape of the past environmental map affects the accuracy when the new measurement data is adjusted, the updated environmental map may include a new error. Therefore, when the update process is repeated, the error is accumulated, and the accuracy of the environment map may be reduced.

  In Japanese Patent Application Laid-Open No. 2012-93811, an attribute indicating that the shape is invariable is set in an area (invariant area) where the actual shape is invariant on the environment map. The environment map is not updated for the invariant area having the attribute. As a result, no error is accumulated in the invariable area, and accuracy can be maintained for shapes other than the invariable area.

JP 2012-93811 A

  The environment map created by the measurement data reflects the position, size, and the like of the object existing in the space at the time of measurement. If the object is a movable object such as a box, for example, and is moved after the measurement data is obtained, a mismatch occurs between the actual arrangement of the objects in the space and the environment map. However, according to the technology disclosed in Japanese Patent Application Laid-Open No. 2012-93811, the autonomous mobile robot must identify its own position with reference to an existing environment map. In this case, the self-position may be erroneously identified.

  The exemplary embodiment of the present disclosure can accurately identify its own position using a plurality of intermediate maps generated before and after the object moves, even when the object moves. Provide map generation technology.

  The moving body of the present disclosure, in an exemplary embodiment, a motor, a driving device that controls the motor to move the moving body, a sensor that senses surrounding space and outputs sensor data, A storage device for storing data of an intermediate map, wherein each of the plurality of intermediate maps is generated from sensor data of the surrounding space sensed by the sensor at a time interval. And a processing circuit for generating one map from the plurality of intermediate maps stored in the storage device, wherein the one map includes a plurality of feature points so that they can be identified, and the plurality of feature points Includes a processing circuit indicating a position where the degree of coincidence is greater than a predetermined value among the plurality of intermediate maps. The processing circuit performs a process of identifying the self-position by comparing the one map with sensor data newly output from the sensor.

  A mobile system according to an exemplary embodiment of the present invention includes a mobile and a signal processing device. The moving body includes a motor, a driving device that controls the motor to move the moving body, a sensor that senses surrounding space and outputs sensor data, and a storage device that stores data of a plurality of intermediate maps. And a circuit. Each of the plurality of intermediate maps is generated from sensor data of the surrounding space sensed by the sensor at intervals of time. The signal processing device includes a processing circuit that generates one map from a plurality of intermediate maps stored in a storage device of the moving object. The one map includes a plurality of feature points so as to be identifiable, and each of the plurality of feature points is a point where the degree of coincidence between the plurality of intermediate maps is larger than a predetermined value. The control circuit of the moving object performs a process of identifying its own position by comparing one map generated by the processing circuit of the signal processing device with sensor data newly output from the sensor. As a result, the moving body can more accurately identify its own position.

FIG. 1 is a diagram illustrating an exemplary AGV 10 traveling on a passage 1 in a factory. FIG. 2 is a diagram illustrating an outline of an exemplary management system 100 that manages the travel of the AGV 10. FIG. 3 is a diagram showing an example of each target position (▲) set on the traveling route of the AGV 10. FIG. 4A is a diagram illustrating an example of a moving path of the AGV 10 that moves continuously. FIG. 4B is a diagram illustrating an example of a moving route of the AGV 10 that moves continuously. FIG. 4C is a diagram illustrating an example of a moving route of the AGV 10 that moves continuously. FIG. 5 is an external view of an exemplary AGV 10. FIG. 6 is a diagram illustrating a hardware configuration of the AGV 10. FIG. 7 is a diagram showing the AGV 10 that scans the surrounding space using the laser range finder 15 while moving. FIG. 8 is a diagram illustrating the AGV 10 that generates a map while moving. FIG. 9 is a diagram illustrating the AGV 10 that generates a map while moving. FIG. 10 is a diagram illustrating the AGV 10 that generates a map while moving. FIG. 11 is a diagram illustrating the AGV 10 that generates a map while moving. FIG. 12 is a diagram schematically showing the completed intermediate map 30. FIG. 13 is a diagram schematically illustrating a procedure of a general position identification process. FIG. 14 is a diagram schematically illustrating a procedure of a general position identification process. FIG. 15 is a diagram schematically showing a procedure of a general position identification process. FIG. 16 is a diagram illustrating an example in which one or a plurality of obstacles 38 are placed in a part of the space in which the AGV 10 travels. FIG. 17 is a diagram illustrating an example of the sensor data 40 reflecting the position of the obstacle 38. FIG. 18 is a schematic diagram of a comparison process between the reference map 30 and the sensor data 40. FIG. 19 is a diagram illustrating an area 34e including a set 6 of a plurality of points erroneously determined to match as a result of the matching processing. FIG. 20 is a diagram schematically illustrating a procedure of the second process performed by the positioning device 14e. FIG. 21 is a diagram showing one map 50b including feature points and non-feature points so as to be distinguishable. FIG. 22 is a schematic diagram of a comparison process between the map 50a and the sensor data 40. FIG. 23 is a diagram showing points determined to match as a result of the comparison. FIG. 24 is a flowchart illustrating a procedure of a process of generating a new map. FIG. 25 is a diagram showing a hardware configuration of the travel management device 20 and a configuration of the mobile system 60.

  Hereinafter, an example of a moving object according to the present disclosure and a management system including the moving object and a travel management device will be described with reference to the accompanying drawings. In this specification, an automatic guided vehicle will be described as an example of a moving object. The automatic guided vehicle is also called an AGV (Automated Guided Vehicle), and is described as “AGV” in this specification.

  FIG. 1 shows, for example, an AGV 10 traveling on a passage 1 in a factory. FIG. 2 shows an outline of a management system 100 for managing the travel of the AGV 10 according to the present embodiment. In the illustrated example, the AGV 10 has map data and travels while recognizing which position the vehicle is currently traveling. The travel route of the AGV 10 follows a command from the travel management device 20. The AGV 10 moves by driving a plurality of built-in motors and rotating wheels according to a command. The command is sent from the travel management device 20 to the AGV 10 by radio. Communication between the AGV 10 and the travel management device 20 is performed using wireless access points 2a and 2b provided near the ceiling of the factory. Communication conforms to, for example, the Wi-Fi (registered trademark) standard. Although only one AGV 10 is shown in FIG. 1, a plurality of AGVs 10 may travel. The travel of each of the plurality of AGVs 10 may or may not be managed by the travel management device 20.

  The outline of the operation of the AGV 10 and the travel management device 20 included in the management system 100 is as follows.

The AGV 10 describes the position from the n-th position to the (n + 1) -th position which is the target position (hereinafter referred to as “position M _{n + 1} ”) in accordance with a command (n-th command (n: positive integer)) from the travel management device 20. ). The destination position can be determined by the administrator for each AGV 10, for example.

When the AGV 10 reaches the target position M _{n + 1} , the AGV 10 transmits an arrival notification (hereinafter referred to as “notification”) to the travel management device 20. The notification is sent to the travel management device 20 via the wireless access point 2a. In the present embodiment, the AGV 10 identifies its own position by comparing the output of a sensor that senses the surroundings with the map data. Then, it is sufficient to determine whether or not the self-position matches the position _{Mn + 1} .

Upon receiving the notification, the travel management device 20 generates the next command ((n + 1) th command) for moving the AGV ₁₀ from the position M _{n + 1} to the position M _{n + 2} . The (n + 1) th command includes the position coordinates of the position _{Mn + 2} , and may further include numerical values such as an acceleration time and a moving speed during constant speed traveling. The travel management device 20 transmits the (n + 1) th command to the AGV 10.

Upon receiving the (n + 1) th command, the AGV 10 analyzes the (n + 1) th command and performs a preprocessing operation necessary for movement from the position _{Mn + 1} to the position _{Mn + 2} . The pre-processing calculation is, for example, a calculation for determining a rotation speed, a rotation time, and the like of each motor for driving each wheel of the AGV 10.

  FIG. 3 shows an example of each target position (▲) set on the traveling route of the AGV 10. The interval between two adjacent target positions does not have to be a fixed value and can be determined by an administrator.

  The AGV 10 can move in various directions according to a command from the travel management device 20. 4A to 4C show examples of the moving path of the AGV 10 that moves continuously.

FIG. 4A shows a movement route of the AGV 10 when traveling straight. After arriving at the position M _{n + 1} , the AGV 10 can perform a pre-processing operation, operate each motor according to the operation result, and continue linearly to the next position M _{n + 2} .

FIG. 4B shows a moving path of the AGV ₁₀ that turns left at the position M _{n + 1} and moves toward the position M _{n + 2} . After reaching the position M _{n + 1} , the AGV 10 performs a pre-processing operation, and rotates at least one motor located on the right side in the traveling direction according to the operation result. Then, when rotated counterclockwise by the angle θ on the spot, the AGV 10 rotates all the motors at a constant speed toward the position M _{n + 2} and goes straight.

FIG. 4C shows a moving path of the AGV 10 when moving in an arc from the position M _{n + 1} to the position M _{n + 2} . After arriving at the position M _{n + 1} , the AGV 10 performs a pre-processing operation, and increases the rotation speed of the motor on the outer peripheral side relative to the motor on the inner peripheral side according to the operation result. Thereby, the AGV 10 can continue moving along the arcuate path toward the next position _{Mn + 2} .

  FIG. 5 is an external view of an exemplary AGV 10 according to the present embodiment. FIG. 6 shows a hardware configuration of the AGV 10.

  The AGV 10 has four wheels 11a to 11d, a frame 12, a transport table 13, a travel control device 14, and a laser range finder 15. Although FIG. 5 shows the front wheel 11a, the rear wheel 11b, and the rear wheel 11c, the front wheel 11d is not shown because it is hidden behind the frame 12.

  The travel control device 14 is a device that controls the operation of the AGV 10. The travel control device 14 mainly includes a plurality of integrated circuits including a microcomputer (described later), a plurality of electronic components, and a substrate on which the plurality of integrated circuits and the plurality of electronic components are mounted. The travel control device 14 performs the above-described transmission and reception of data with the travel management device 20 and performs preprocessing calculations.

  The laser range finder 15 is an optical device that measures a distance to a target by irradiating, for example, an infrared laser beam 15a to a target and detecting reflected light of the laser beam 15a. In the present embodiment, the laser range finder 15 of the AGV 10 changes the direction of the pulsed laser light in a space of 135 degrees left and right (total 270 degrees) with respect to the front of the AGV 10 while changing the direction every 0.25 degrees. The laser beam 15a is emitted, and the reflected light of each laser beam 15a is detected. This makes it possible to obtain data on the distance to the reflection point in a direction determined by an angle of a total of 1080 steps every 0.25 degrees.

  The position of the object around the AGV can be obtained from the position and orientation of the AGV 10 and the scan result of the laser range finder 15. Generally, the position and posture of a moving object are called a pose. The position and orientation of the moving body in the two-dimensional plane are represented by position coordinates (x, y) in an XY orthogonal coordinate system and an angle θ with respect to the X axis. Hereinafter, the position and posture of the AGV 10, that is, the pose (x, y, θ) may be simply referred to as “position”.

  The positioning device, which will be described later, matches local map data created from the scan result of the laser range finder 15 with environmental map data over a wider range (matching) to thereby determine its own position (x, y, θ) on the environmental map. ) Can be identified.

  In addition, the position of the reflection point viewed from the radiation position of the laser beam 15a can be expressed using polar coordinates determined by the angle and the distance. In this embodiment, the laser range finder 15 outputs sensor data expressed in polar coordinates. However, the laser range finder 15 may convert the position represented by the polar coordinates into rectangular coordinates and output the result.

  Since the structure and operation principle of the laser range finder are known, further detailed description is omitted in this specification. Examples of objects that can be detected by the laser range finder 15 are a person, luggage, a shelf, and a wall.

  The laser range finder 15 is an example of an external sensor for sensing a surrounding space and acquiring sensor data. Other examples of such an external sensor include an image sensor and an ultrasonic sensor.

  In this specification, data output from the sensor is referred to as “sensor data”. The “sensor data” output from the laser range finder 15 is a plurality of sets of vector data including the angle θ and the distance L as one set. The angle θ changes by, for example, 0.25 degrees in a range from -135 degrees to +135 degrees. The angle may be expressed as positive on the right side and negative on the left side with respect to the front of the AGV 10. The distance L is a distance to the object measured for each angle θ. The distance L is obtained by dividing half the difference between the emission time of the infrared laser light 15a and the reception time of the reflected light (that is, the time required for reciprocation of the laser light) by the speed of light.

  Please refer to FIG. FIG. 6 also shows a specific configuration of the travel control device 14 of the AGV 10.

  The AGV 10 includes a travel control device 14, a laser range finder 15, four motors 16a to 16d, and a drive device 17.

  The travel control device 14 includes a microcomputer 14a, a memory 14b, a storage device 14c, a communication circuit 14d, and a positioning device 14e. The microcomputer 14a, the memory 14b, the storage device 14c, the communication circuit 14d, and the positioning device 14e are connected by a communication bus 14f, and can exchange data with each other. The laser range finder 15 is also connected to a communication bus 14f via a communication interface (not shown), and transmits measurement data as a measurement result to the microcomputer 14a, the positioning device 14e, and / or the memory 14b.

  The microcomputer 14a is a control circuit (computer) that performs an operation for controlling the entire AGV 10 including the travel control device 14. Typically, the microcomputer 14a is a semiconductor integrated circuit. The microcomputer 14a controls the driving device 17 by transmitting a PWM (Pulse Width Modulation) signal to the driving device 17 to adjust the current flowing through the motor. As a result, each of the motors 16a to 16d rotates at a desired rotation speed.

  The memory 14b is a volatile storage device that stores a computer program executed by the microcomputer 14a. The memory 14b can also be used as a work memory when the microcomputer 14a and the positioning device 14e perform calculations.

  The storage device 14c is a nonvolatile semiconductor memory device that stores map data. However, the storage device 14c may be a magnetic recording medium typified by a hard disk or an optical recording medium typified by an optical disk, and a head for writing and / or reading data to or from any of the recording media. It may include a device and a control device for the head device. Details of the map data will be described later with reference to FIG.

  The communication circuit 14d is a wireless communication circuit that performs wireless communication conforming to, for example, the Wi-Fi (registered trademark) standard.

  The positioning device 14e receives the sensor data from the laser range finder 15, and reads the map data stored in the storage device 14c. The positioning device 14e performs a process of identifying its own position by comparing the sensor data with the map data. The specific operation of the positioning device 14e will be described later.

  In the present embodiment, the microcomputer 14a and the positioning device 14e are separate components, but this is an example. It may be a single chip circuit or a semiconductor integrated circuit capable of independently performing each operation of the microcomputer 14a and the positioning device 14e. FIG. 6 shows a chip circuit 14g including the microcomputer 14a and the positioning device 14e. In this specification, the microcomputer 14a, the positioning device 14e, and / or the chip circuit 14g may be referred to as a computer or a processing circuit. Hereinafter, an example in which the microcomputer 14a and the positioning device 14e are provided separately and independently will be described.

  The four motors 16a to 16d are attached to four wheels 11a to 11d, respectively, and rotate each wheel. The number of motors is an example. The number may be two or three, or five or more.

  The driving device 17 has motor driving circuits 17a to 17d for adjusting the current flowing through each of the four motors 16a to 16d. Each of the motor drive circuits 17a to 17d is a so-called inverter circuit, and turns on or off a current flowing through each motor according to a PWM signal transmitted from the microcomputer 14a, thereby adjusting a current flowing through the motor.

  Next, an example of a process in which the AGV 10 according to the present disclosure generates one map will be described.

  The process of generating a map can be divided into a first process and a second process. The first process is a process for generating a plurality of intermediate maps. The second process is a process of determining a plurality of feature points from the plurality of intermediate maps and generating one map.

  First, the first process will be described.

  In the present embodiment, the first processing is realized by, for example, a Simultaneous Localization and Mapping (SLAM) technique. The AGV 10 scans the surrounding space by operating the laser range finder 15 while actually traveling in a factory where the AGV 10 is used, and generates a map while estimating its own position. Alternatively, the AGV 10 may travel on a specific route while being controlled by an administrator, and generate a map from the sensor data acquired by the laser range finder 15.

  7 to 11 each show an AGV 10 that generates a map while moving. FIG. 7 shows an AGV 10 that scans a surrounding space using a laser range finder 15. Laser light is emitted at each predetermined step angle, and scanning is performed.

  In each of FIGS. 7 to 11, the position of the reflection point of the laser beam is indicated by using a plurality of points represented by the symbol “•”, such as point 4 in FIG. The positioning device 14e stores the position of the black spot 4 obtained as the vehicle travels, for example, in the memory 14b. By continuing the scan while the AGV 10 runs, the map is gradually completed. 8 to 11, only the scan range is shown for simplicity. The scan range is also an example, and is different from the above example of a total of 270 degrees.

  FIG. 12 schematically shows the completed intermediate map 30. The positioning device 14e stores the data of the intermediate map 30 in the memory 14b or the storage device 14c. The number or density of the black spots shown is an example.

  The AGV 10 travels a plurality of times at intervals of time to generate a plurality of intermediate maps, and stores the intermediate maps in the memory 14b or the storage device 14c. The AGV 10 travels at intervals that can be appropriately determined by those skilled in the art, such as several days, several hours, tens of minutes, and several minutes, and generates a plurality of intermediate maps.

  The reason why the AGV 10 generates the plurality of intermediate maps is that an object that has not been moved (referred to as “fixed object”) and an object that has been moved (referred to as “movable object”) can be distinguished. Reflection points that are co-located over multiple intermediate maps can be considered to represent a fixed object. On the other hand, a reflection point whose position changes between a plurality of intermediate maps means that the existing movable object has been removed or the movable object has been newly placed. In this specification, an object that can be actually moved, but is not moved in the process of generating a plurality of intermediate maps, is also referred to as a “fixed object”. On the other hand, an object, such as a wall, which is generally considered to have few opportunities to be moved, is referred to as a “movable object” if the object has been moved in the process of generating a plurality of intermediate maps.

  In general, if one map shown in FIG. 12 is acquired by using the SLAM technique, and then the map is compared with sensor data obtained by actually traveling, the AGV can identify its own position. it can. Hereinafter, an example of a process of identifying a self-position using one map will be described.

  13 to 15 schematically show the procedure of a general position identification process. The AGV previously acquires a map (hereinafter, referred to as “reference map 30”) corresponding to the intermediate map 30 in FIG. 13 acquired by the SLAM technique. During traveling, the AGV acquires the sensor data 32 shown in FIG. 13 at predetermined time intervals or constantly, and executes processing for identifying its own position.

  First, the AGV sets various regions (for example, regions 34a, 34b, and 34c) whose positions and angles are changed on the reference map 30, and sets a plurality of reflection points included in each of the regions and reflections included in the sensor data 32. Match with point. FIG. 14 shows a point determined as a match (for example, point 5) as a result of the collation with a symbol “■”. If the ratio of the number of matching points is larger than the predetermined reference value, the AGV determines that the sensor data 32 and the plurality of black points in the area 34d match.

  The AGV determines a light emitting position of a laser beam at which each black point included in the area 34d can be obtained, that is, a self position. FIG. 15 shows the identified self-position 36 represented by the symbol “X”.

  According to the above method, the AGV can identify its own position. However, in the above-described method, the AGV cannot always identify the self-position correctly, and may erroneously identify a position different from the actual position as the self-position.

  FIG. 16 shows an example in which one or a plurality of obstacles 38 are placed in a part of the space in which the AGV 10 travels. The sensor data acquired by the AGV differs depending on whether or not the obstacle 38 exists. FIG. 17 shows an example of sensor data 40 reflecting the position of the obstacle 38.

  FIG. 18 is a schematic diagram of a comparison process between the reference map 30 and the sensor data 40. As described in the example of FIG. 13, the AGV sets various areas 34 a, 34 b, 34 c, and the like, and compares the plurality of reflection points included in each of the areas with the sensor data 40.

  FIG. 19 shows an area 34e including a set 6 of a plurality of points erroneously determined to match as a result of the matching processing. When such an erroneous determination is made, the AGV erroneously identifies the position 44 deviating from the actual position 42 as its own position.

  Hereinafter, a method capable of avoiding the erroneous position identification as described above will be described. In the method developed by the inventor, as described above, the first processing is performed a plurality of times to obtain a plurality of intermediate maps, and then the second processing is further performed.

  FIG. 20 schematically illustrates the procedure of the second process performed by the positioning device 14e. In the second process, the positioning device 14e generates one map 50a from the six intermediate maps 30a to 30f acquired at intervals. The number of intermediate maps may be any number as long as it is plural. For example, the number may be two to five, or seven or more.

  Each black point constituting the six intermediate maps 30a to 30f indicates the position of the reflection point of the laser light. The positioning device 14e determines a feature point from the intermediate maps 30a to 30f. In the present embodiment, the “feature point” is a point at which the “matching degree” is relatively high among a plurality of intermediate maps acquired a plurality of times, and more specifically, the matching degree is higher than a predetermined value. It means a large virtual coordinate point. Each virtual coordinate point is one unit for determining whether it is “free space” through which laser light can pass or “occupied space” through which laser light cannot pass. In the present embodiment, an example of the “occupied space” is the surface of the object existing in the space and the inside of the object.

  The "match degree" can be calculated by various methods. For example, when the “matching degree” is represented by the degree of matching with respect to the position of each black point constituting the intermediate maps 30a to 30f, it can be calculated by the following method.

  The positioning device 14e adjusts the angles of the intermediate maps 30a to 30f based on one or a plurality of feature amounts commonly included in the intermediate maps 30a to 30f, and superimposes the intermediate maps 30a to 30f. The “feature amount” is represented by a positional relationship (arrangement) of a plurality of black points indicating a position where a movable object is not considered to be substantially placed, for example, a staircase or a lifting device.

  After determining the angle at which the intermediate maps 30a to 30f overlap, the positioning device 14e determines whether there are four or more intermediate maps having black points at the same position. If there are four or more intermediate maps having a black point at the same position, the black point at that position is reflected as a “feature point” on a newly generated map. On the other hand, if there are less than three intermediate maps having a black point at the same position, the black point at that position is excluded from the “feature points”. Note that “four sheets” is an example of the threshold. The feature points only need to be included in common on at least two intermediate maps, in which case the threshold value is “two”.

  Alternatively, the positioning device 14e sets a virtual coordinate position, determines a black point closest to the coordinate position for each intermediate map, determines a shift amount from the coordinate position, and further calculates a sum of the shift amounts. The positioning device 14e may obtain a difference or a ratio between the obtained sum and a predetermined allowable value as the degree of coincidence. When the degree of coincidence is determined for each virtual coordinate position on the map to be generated, the positioning device 14e can determine a feature point.

  It can be said that the coordinate position determined to be each feature point represents the surface of a fixed object that is commonly present on a plurality of maps. On the other hand, it can be said that a coordinate position that is not determined to be a feature point indicates a position where the surface of the removed movable object exists or a position where the surface of the newly placed movable object exists.

  The positioning device 14e of the AGV 10 generates one map 50a in which the feature points have been determined. As shown in FIG. 20, the map 50a indicates the positions of a plurality of feature points 51, but the position 52 where the feature points 51 do not exist is blank. The map 50a is a map in which only each feature point is identified.

  The expression format of the map 50a is an example. The AGV 10 may generate a map in another expression format. For example, FIG. 21 shows one map 50b including feature points and non-feature points so as to be distinguishable. In the map 50b, a plurality of feature points 51 and a plurality of non-feature points 53 are identifiably shown.

  The map 50b may be generated by another method. After determining the angle at which the intermediate maps 30a to 30f are superimposed, the positioning device 14e determines the ratio at which the black point is commonly present for each position of the intermediate maps 30a to 30f. For example, when a black point is commonly present on three of the six intermediate maps at a certain position, the ratio of the black point at that position is set to 0.5 (= 3/6). For example, each of the plurality of black points 51 shown in FIG. 21 may represent a position with a weight of 0.5 or more, and each of the plurality of X points 53 may represent a position with a weight of less than 0.5. The set ratio indicates the degree to which the ratio is reflected in the calculation at the time of the position identification processing using one finally generated map 50a. At the time of position identification processing using the map 50b, each point is used to determine whether or not each point matches a point acquired as sensor data at a rate corresponding to the value of each rate. That is, the “ratio” represents the “weight” used for the calculation at the time of the position identification processing. A black point having a weight of 1 that is always included in the calculation at the time of position identification processing may be called a “feature point”, and a black point less than 1 may be called a non-feature point. A black point having a weight equal to or greater than a threshold value, for example, 0.6 or more, may be referred to as a “feature point”, and a black point having a weight less than 0.6 may be referred to as a non-feature point. Alternatively, a black point having a weight greater than at least 0 may be referred to as a “feature point”, and a black point having a weight of 0 may be referred to as a non-feature point. A black point having a weight greater than or equal to an arbitrary threshold or greater than the threshold may be referred to as a feature point, and a black point having a weight less than or less than the threshold may be referred to as a non-feature point. Alternatively, a black point to which a weight is set may be called a “feature point”, and a black point to which no weight is set may be called a “non-feature point”.

  The positioning device 14e performs a process of identifying its own position by comparing the sensor data with a plurality of feature points included in the map 50a or 50b. Hereinafter, as an example, a process of comparing the sensor data 40 illustrated in FIG. 17 with the map 50a will be described.

  FIG. 22 is a schematic diagram of a comparison process between the map 50a and the sensor data 40. The positioning device 14e sets various regions 34a, 34b, 34c, and the like, and compares the plurality of feature points included in each region with the sensor data 40 by the method described with reference to FIG.

  FIG. 23 shows a point (for example, point 7) determined to be a match as a result of the comparison with a symbol “■”. The example of FIG. 23 differs from the example of FIG. 19 in that, in the example of FIG. 23, the position (or area) 52 where the feature point 51 does not exist is not used for the matching processing. Since the positioning device 14e performs the matching process using the feature point having a high degree of coincidence and the sensor data, a more reliable matching result can be obtained. As a result, the positioning device 14e can correctly identify the position 42 that actually exists as its own position.

In the matching process, setting a plurality of regions having various possible sizes and angles and comparing the plurality of feature points in each region with the sensor data 40 requires an extremely large amount of calculation. It is not realistic. Therefore, the positioning device 14e limits the range in which the region is set in order to reduce the amount of calculation. AGV10, upon reaching the target position M _n, traveling by receiving the next instruction target position M _{n + 1} should be headed from the running management apparatus 20. Therefore, an area may be set to include the traveling route between the positions _Mn and _{Mn + 1} , and a plurality of features in each area may be compared with the sensor data 40. As a result, the comparison operation can be omitted for an area including a position far away from the current travel route.

  When a process of comparing the map 50b shown in FIG. 21 with the sensor data 40 is performed, a method similar to that of the example of the map 50a can be adopted using only a plurality of feature points 51. Further, a plurality of non-characteristic points 53 may be used. At this time, the positioning device 14e may perform a process of assigning different weights to the feature points 51 and the non-feature points 53 and collating the map 50b with the sensor data 40. For example, the weight of each feature point 51 is made larger than the weight of the non-feature point 53. As a result, if the amount of deviation between the position of each feature point 51 in a certain area and the position of the reflection point included in the sensor data 40 is relatively small, it is determined that the certain feature point 51 and the sensor data of the area match. Can be determined.

  As described above, the AGV 10 generates a new map including feature points representing a fixed object from the plurality of intermediate maps so as to be identifiable. FIG. 24 is a flowchart illustrating a procedure of a process of generating a new map.

  In step S10, the positioning device 14e of the AGV 10 senses the surrounding space while traveling in the factory and acquires a plurality of intermediate maps. In step S11, the positioning device 14e determines a feature point having a degree of coincidence greater than a predetermined value among a plurality of intermediate maps. The method of calculating the degree of coincidence and the method of determining feature points are as described above. In step S12, the positioning device 14e generates a map including the feature points so as to be distinguishable. The map generated in step S12 may be the map 50a shown in FIG. 20 or the map 50b shown in FIG.

  The above processing may be performed by the microcomputer 14a instead of the positioning device 14e, or may be performed by the chip circuit 14g in which the microcomputer 14a and the positioning device 14e are integrated. That is, the above processing may be performed by the “processing circuit”. In the above-described processing, all of the plurality of intermediate maps are used, but not all of them and at least two intermediate maps may be used.

  Hereinafter, a modified example of the above-described embodiment will be described.

(Modification 1)
In the example described above, the positioning device 14e of the AGV 10 generates a plurality of intermediate maps from the sensor data, and further generates one map from the plurality of intermediate maps. However, a process of generating one final map from the sensor data may be performed by an external signal processing device other than the AGV 10, for example, the travel management device 20. A system having the AGV 10 and the signal processing device is referred to as a “map generation system”. Further, a system in which the AGV 10 performs a process of identifying its own position using one map generated from a plurality of intermediate maps is referred to as a “mobile system”.

  Hereinafter, the “travel management device 20” will be exemplified as an external signal processing device.

  The AGV 10 goes around the factory, acquires a group of sensor data required for the intermediate map, and writes the acquired data to, for example, a removable recording medium. The administrator removes the recording medium and causes the travel management device 20 to read the written group of sensor data. Alternatively, the AGV 10 may wirelessly transmit the obtained sensor data to the travel management device 20 every one scan or every several scans while traveling in the factory. After making a round of the factory, the travel management device 20 can acquire a group of sensor data required for the intermediate map. In the present modified example, the intermediate map is created not by the AGV 10 but by the travel management device 20.

  FIG. 25 shows the configuration of the mobile system 60. FIG. 25 also shows a hardware configuration of the travel management device 20. The travel management device 20 includes a CPU 21, a memory 22, a storage device 23, a communication circuit 24, and an image processing circuit 25. The CPU 21, the memory 22, the storage device 23, the communication circuit 24, and the image processing circuit 25 are connected by a communication bus 27 and can exchange data with each other.

  The CPU 21 is a signal processing circuit (computer) that controls the operation of the travel management device 20. Typically, the CPU 21 is a semiconductor integrated circuit.

  The memory 22 is a volatile storage device that stores a computer program executed by the CPU 21. The memory 22 can also be used as a work memory when the CPU 21 performs an operation.

  The storage device 23 stores a group of sensor data received from the AGV 10. The storage device 23 may store data of a plurality of intermediate maps generated from a group of sensor data, or may store data of one map generated from the plurality of intermediate maps. . The storage device 23 may be a nonvolatile semiconductor memory, a magnetic recording medium represented by a hard disk, or an optical recording medium represented by an optical disk.

  Note that the storage device 23 may also store position data indicating each position that can be a destination of the AGV 10 and that is necessary to function as the travel management device 20. The position data can be represented by, for example, coordinates virtually set in a factory by an administrator. Position data is determined by the administrator.

  The communication circuit 24 performs wired communication conforming to, for example, the Ethernet (registered trademark) standard. The communication circuit 24 is connected to the wireless access points 2a and 2b and the like by wire, and can communicate with the AGV 10 via the wireless access points 2a and 2b and the like. The travel management device 20 receives individual data or a group of data of a plurality of intermediate maps from the AGV 10 via the communication circuit 24, and transmits the generated data of one map to the AGV 10.

  Further, the communication circuit 24 receives data of a position to which the AGV 10 should go from the CPU 21 via the bus 27 and transmits the data to the AGV 10. The communication circuit 24 transmits the data (for example, notification) received from the AGV 10 to the CPU 21 and / or the memory 22 via the bus 27.

  The image processing circuit 25 is a circuit that generates video data to be displayed on the external monitor 29. The image processing circuit 25 operates exclusively when the administrator operates the travel management device 20. In this embodiment, further detailed description is omitted. The monitor 29 may be integrated with the travel management device 20. The processing of the image processing circuit 25 may be performed by the CPU 21.

  The CPU 21 or the image processing circuit 25 of the traveling management device 20 reads a group of sensor data with reference to the storage device 23. Each sensor data is, for example, vector data in which the position and orientation of the AGV 10 at the time of acquisition of the sensor data, the angle at which the laser light is emitted, and the distance from the emission point to the reflection point are set. The CPU 21 or the image processing circuit 25 converts each sensor data into a position of a coordinate point on the rectangular coordinates. By converting all sensor data, a plurality of intermediate maps are obtained.

  The CPU 21 or the image processing circuit 25 generates one map from the plurality of intermediate maps. That is, in the process of FIG. 24, the travel management device 20 may perform the above-described steps S11 and S12.

  When one map is generated from a plurality of intermediate maps by the above-described processing, data of the generated map is temporarily stored in the memory 22 or the storage device 23. The generated map data is then transmitted to the AGV 10 that generated the intermediate map data via the access points 2a and 2b via a wireless or removable recording medium or the like. However, the data of the intermediate map may be transmitted to another AGV 10.

  In the above description, the travel management device 20 has generated one map from a group of sensor data. The travel management device 20 is an example. If a signal processing circuit (or a computer), a memory, and a communication circuit corresponding to the CPU 21 are provided, any signal processing device can generate one map from a group of sensor data. In that case, functions and configurations necessary for functioning as the travel management device 20 can be omitted from the signal processing device.

(Modification 2)
Modification 2 is an application of Modification 1.

  For example, in a very large factory, sensing a plurality of times using a sensor while running one AGV 10 requires a lot of trouble and time. Therefore, the entire factory may be divided into a plurality of smaller zones, and an intermediate map may be created using one AGV 10 for each zone. For example, a 150 mx 100 m factory is divided into six zones with 50 mx 50 m as one zone.

  The AGV 10 in each zone acquires a group of sensor data, and causes an external signal processing device other than the AGV 10, for example, the travel management device 20 to acquire the group of sensor data by any of the methods described in the first modification. The travel management device 20 generates a plurality of intermediate maps for each zone by the above-described processing, and further creates one zone map from the plurality of intermediate maps. Then, the travel management device 20 creates an integrated map in which the zone maps are combined into one. By operating a plurality of AGVs 10 in parallel, scanning of the entire factory is completed in substantially the time of sensing one zone, and one integrated map can be obtained.

  The travel management device 20 may transmit the obtained integrated map to all the AGVs 10, or may cut out and transmit only the pertinent zone to the AGV 10 in which the moving zone is determined in advance.

(Modification 3)
In the above-described embodiment, the AGV 10 generates one map from a plurality of intermediate maps. In this modification, the positioning device 14e of the AGV 10 obtains a plurality of intermediate maps, compares the sensor data with the data of each intermediate map, and, for each intermediate map, a plurality of intermediate maps each having a degree of coincidence greater than a predetermined value. Determine feature points. For example, the positioning device 14e collates the sensor data with the data of the first intermediate map, and determines a plurality of first feature points for the first intermediate map. Similarly, the positioning device 14e collates the sensor data with the data of the second intermediate map, and determines a plurality of second feature points for the second intermediate map. Then, the positioning device 14e determines a plurality of feature points (referred to as “common feature points”) that are commonly included in the plurality of first feature points and the plurality of second feature points. The common feature point corresponds to a feature point included in the map 50a or 50b in the above-described embodiment.

  Note that the positioning device 14e may determine, for each position, whether or not the ratio of the number of intermediate maps having feature points to the number of all intermediate maps is greater than or equal to a threshold. As in the above-described embodiment, when the ratio is greater than or equal to the threshold, the positioning device 14e may determine that the position is a common feature point.

  The positioning device 14e identifies its own position using the collation result between the data of the common feature point and the sensor data. The “collation result” may be a result of the collation between the data of the common feature point and the sensor data by the positioning device 14e again, or a result of a process performed before determining the common feature point. It may be.

(Modification 4)
In each of the above-described examples, a map in a two-dimensional space in which the AGV 10 travels is assumed. However, a map in a three-dimensional space may be generated using a laser range finder capable of scanning a space in the height direction.

  The AGV 10 generates a plurality of intermediate maps not only in the plane direction but also in the height direction. Then, by further considering the element in the height direction, a point having a degree of coincidence greater than a predetermined value among the plurality of intermediate maps is determined as a plurality of feature points. If one map including the plurality of feature points so as to be identifiable is used, a process of identifying a self-position using a feature amount in the height direction can be performed.

  The technology of the present disclosure can be widely used in a mobile body that performs a process of identifying its own position, a travel management device that controls the mobile body, and a management system that includes the mobile body and the travel management device.

  2a, 2b wireless access point, 10 automatic guided vehicle (AGV), 14 travel control device, 14a microcomputer, 14b memory, 14c storage device, 14d communication circuit, 14e positioning device, 15 laser range finder, 16a to 16d motor, 17 drive Device, 17a to 17d motor drive circuit, 20 travel management device

Claims (13)

A moving object,
Motor and
A driving device that controls the motor to move the moving body,
A sensor that senses the surrounding space and outputs sensor data,
A storage device that stores data of a plurality of intermediate maps, wherein each of the plurality of intermediate maps is generated from sensor data of the surrounding space sensed by the sensor at an interval. A storage device;
A processing circuit for generating one map from the plurality of intermediate maps stored in the storage device, wherein the one map includes a plurality of feature points so as to be identifiable, and each of the plurality of feature points And a processing circuit that indicates a position where the degree of coincidence is greater than a predetermined value among the plurality of intermediate maps,
The moving body, wherein the processing circuit performs a process of identifying the self-position by comparing the one map with sensor data newly output from the sensor.   The processing circuit calculates a degree of coincidence between at least two intermediate maps of the plurality of intermediate maps, determines the plurality of feature points, and includes the determined plurality of feature points so as to be identifiable. The moving body according to claim 1, wherein the mobile body generates one map.   The moving body according to claim 2, wherein each of the plurality of feature points is determined from sensor data present at a common position on at least two intermediate maps of the plurality of intermediate maps.   The moving body according to claim 2, wherein each of the plurality of feature points indicates that the sensor data is present at a common position on a number of intermediate maps equal to or greater than a threshold value among the plurality of intermediate maps.   The moving body according to claim 3, wherein each of the plurality of feature points represents a position of an object existing in the surrounding space sensed by the sensor.   The processing circuit determines whether or not the sensor data is present, for each position of the plurality of intermediate maps, for the number of the plurality of intermediate maps, for the number of intermediate maps of the intermediate map where the sensor data was present The moving body according to claim 2, wherein the one map having each position at which the ratio of the number of sheets is greater than or equal to or greater than a threshold value as each feature point is generated.   The processing circuit determines whether or not each of the plurality of feature points on the one map matches sensor data newly output from the sensor by using the ratio for each position. The moving object according to claim 5, wherein the determination is made.   The moving body according to claim 3, wherein the storage device of the moving body stores the one map generated by the processing circuit of the signal processing device.   The processing circuit superimposes the plurality of intermediate maps on the basis of a feature amount commonly included in the plurality of intermediate maps, and according to a magnitude of a shift amount between the plurality of maps when the superimposition is performed. The moving object according to claim 1, wherein the degree of coincidence is calculated.   10. The one map generated from the plurality of intermediate maps includes the plurality of feature points and a plurality of non-feature points other than the plurality of feature points in a distinguishable manner. The moving object according to any one of the above. A signal processing device that generates a map referred to by the moving object to identify its own position,
The moving object is
Motor and
A driving device that controls the motor to move the moving body,
A sensor that senses the surrounding space and outputs sensor data,
A storage device that stores data of a plurality of intermediate maps, wherein each of the plurality of intermediate maps is generated from sensor data of the surrounding space sensed by the sensor at an interval. A storage device;
And a control circuit.
The signal processing device,
A processing circuit for generating one map from the plurality of intermediate maps stored in the storage device, wherein a plurality of feature points having a degree of coincidence greater than a predetermined value between the plurality of intermediate maps are determined; A processing circuit for generating one map including a plurality of feature points so that they can be identified;
A storage device for storing the generated one map. A moving object,
Motor and
A driving device that controls the motor to move the moving body,
A sensor that senses the surrounding space and outputs sensor data,
A storage device that stores data of a plurality of intermediate maps, wherein each of the plurality of intermediate maps is generated from sensor data of the surrounding space sensed by the sensor at an interval. A storage device;
And a processing circuit.
The sensor outputs the sensor data during the movement of the moving body,
The processing circuit includes:
The sensor data output from the sensor during the movement is compared with each of the plurality of intermediate maps stored in the storage device, and for each position on each intermediate map, the sensor data and each intermediate map are compared. Determining feature points whose degree of matching with the map is greater than a predetermined value,
Whether the ratio of the number of the intermediate maps determined to have the feature points to the number of the plurality of intermediate maps is greater than or equal to or greater than a threshold is determined by the intermediate map determined to have the feature points. Is determined for each position of
Each position where the ratio is greater than or equal to or greater than a threshold is determined as a common feature point,
A moving object that identifies its own position by using a result of collation with the common feature point and the sensor data. A computer program executed by a computer mounted on a signal processing device that generates a map referred to by a moving object to identify its own position,
The moving object is
Motor and
A driving device that controls the motor to move the moving body,
A sensor that senses the surrounding space and outputs sensor data,
A storage device that stores data of a plurality of intermediate maps, wherein each of the plurality of intermediate maps is generated from sensor data of the surrounding space sensed by the sensor at an interval. And a storage device.
The computer program is stored in the computer,
The data of the plurality of intermediate maps is received from the moving object,
A plurality of feature points whose degree of coincidence is larger than a predetermined value among the plurality of intermediate maps are determined,
By generating one map including the plurality of feature points in a distinguishable manner, the one map is generated from the plurality of intermediate maps,
Causing the moving body to transmit the generated one map so as to be stored in the storage device;
Computer program.

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