JP2019212196A - Controller and control method - Google Patents

Abstract

To provide a controller and a control method suppressing an increase in frequency in which an autonomous mobile body can no longer move along a predefined route.SOLUTION: A controller includes: a moving distance information acquisition part which acquires moving distance information indicating a distance over which a mobile body including a photographing part and moving along a predefined route has moved; an image acquisition part which acquires image data of an image photographed by the photographing part; a match score acquisition part which, where selection reference images are those which are included in Q-number (where Q is an integer of 5 or larger) of reference images previously photographed before start of the movement by the mobile body and which satisfy first condition, acquires a match score between the M-number (where M is an odd number equal to or greater than 3 and less than Q) of selection reference images and the image acquired by the image acquisition part after the start of the movement by the mobile body; a position information acquisition part which acquires position information indicating the position of the mobile body based on the M-number of selection reference images satisfying second condition and the information indicating the positions at which the selection reference images have been photographed; and a movement control part which causes the mobile body to move until a predetermined position in accordance with the position information.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device and a control method.

  When an autonomous mobile robot moves in a place where GPS cannot be used, such as in a building or behind a building, it is necessary to recognize the surrounding environment and estimate its own position based on the recognized environment (Patent Document 1). reference). As a method for estimating the self position, for example, a method using a laser range scanner has been proposed (see Non-Patent Document 1). In this method, the surrounding shape is scanned with a laser, and the self-position is estimated based on the scan result and information indicating the surrounding shape stored in advance. However, this method has a problem that the laser range scanner is expensive. Therefore, a method for estimating the self-position based on an image taken by the camera has been proposed. In this method, a self-position is estimated by comparing a captured image with a reference image. It has been proposed that autonomous traveling of an autonomous mobile robot by a method of estimating a self-position by comparing a captured image with a reference image can be realized as follows, for example. First, the autonomous mobile robot performs teaching travel in advance and records a route during teaching traveling and an image (hereinafter referred to as “reference image”) taken by the camera during teaching traveling. During autonomous traveling, the autonomous mobile robot compares an image captured by the camera (hereinafter referred to as “input image”) with a reference image recorded in advance, and calculates a difference between the input image and the reference image. The autonomous mobile robot corrects the traveling direction based on the deviation. In this way, the autonomous mobile robot travels along a pre-recorded route.

  When the autonomous mobile robot travels autonomously by this method, it is better that a plurality of reference images are recorded along the route during teaching travel. When there are a plurality of reference images, the autonomous mobile robot can calculate the deviation with high accuracy by selecting a reference image close to its own position from the plurality of reference images during autonomous traveling. In order to increase the accuracy of the deviation calculated by the autonomous mobile robot, a method for selecting the reference image by the autonomous mobile robot during autonomous traveling has also been proposed.

  For example, a method has been proposed in which the degree of matching with a reference image that satisfies a predetermined condition during autonomous traveling is calculated, and a reference image for calculating a deviation is selected based on a change in the degree of matching. However, with this method, if the reference image selected at some point in time of travel is not appropriate, the autonomous mobile robot cannot correctly estimate its own position, and then moves along a pre-recorded route. There was a case where it became impossible.

JP 2014-002638 A

Yoshio Matsumoto, Masayuki Inaba, Hirochika Inoue, "View-Based Approach to Robot Navigation" J. of Robotics Society of Japan, vol.20, No.5, pp. 506-514,2002

  In view of the above circumstances, an object of the present invention is to provide a control device and a control method that suppress an increase in frequency at which an autonomous mobile body cannot move along a predetermined route.

  One aspect of the present invention includes a photographing unit that photographs a subject, and obtains moving distance information that indicates a moving distance information indicating a distance that a moving body moving along a predetermined route moves on the route. An image acquisition unit that acquires image data of an image captured by the imaging unit, and Q images (Q is an integer of 5 or more) captured in advance before the moving body starts to move. The reference images satisfying the first condition among the reference images are selected reference images, and the M (M is an odd number greater than or equal to 3 and less than Q) selected reference images and the images after the start of movement by the moving object. A match score acquisition unit that acquires a match score that is a value indicating a degree of matching with an image acquired by the acquisition unit, and a predetermined condition based on the match score and the movement distance information acquired by the match score acquisition unit. Article 2 As a position information acquisition unit that acquires position information indicating the position of the moving body based on the M selected reference images satisfying the second condition and information indicating a position where the selected reference image is captured. And a movement control unit that moves the moving body to a predetermined position according to the position information in accordance with the position information acquired by the position information acquisition unit.

  One aspect of the present invention is the above-described control device, wherein a distance between a position where the selected reference image is captured and a start point of the route is a reference route start point distance, and the reference route is determined according to the reference route start point distance. When the number given in ascending order from 1 to M in ascending order of the starting point distance is a selected reference image number, when the M is 5 or more, the second condition is that the match score acquired by the match score acquisition unit is the maximum The selected reference image is a reference image whose selected reference image number is from (M−1) / 2 + 2 to M, a condition that the maximum value of the match score is greater than a first value, and When the movement distance indicated by the movement distance information satisfies all the conditions such as the condition that the distance to the reference path starting point at the position where the selected reference image having the selected reference image number of 1 is photographed is shorter. And when the M is 3, the second condition is that the selected reference image having the largest match score is the selected reference image having the selected reference image number of 3, The condition that the maximum value of the match score is larger than the first value, and the movement distance indicated by the movement distance information is the reference path start point distance at the position where the selected reference image with the selected reference image number 1 is taken. It is a condition that all conditions with the condition of shorter than are satisfied.

  One aspect of the present invention is the above-described control device, which is a number assigned to each of the M selected reference images, and includes a position where the selected reference image is captured and a start point of the route. The distance is a reference route start point distance, a number assigned in ascending order from 1 to M in ascending order of the reference route start point distance according to the reference route start point distance is a selected reference image number, and the second condition is the match score The selected reference image having the largest match score acquired by the acquisition unit is a condition that the selected reference image number is (M−1) / 2 + 2 to M and the selected reference image number is M. The reference route start point distance at the position where the selected reference image is photographed is a condition that all the conditions such as the condition that the reference route start point distance is longer than the movement distance information by a second value or more are satisfied.

  One aspect of the present invention is the above-described control device, which is a number assigned to each of the M selected reference images, and includes a position where the selected reference image is captured and a start point of the route. The distance is a reference route start point distance, a number assigned in ascending order from 1 to M in ascending order of the reference route start point distance according to the reference route start point distance is a selected reference image number, and the second condition is the match score And the reference path start point distance at the position where the selected reference image with the selected reference image number M is photographed is a second value greater than the distance indicated by the movement distance information. It is a condition that all the conditions, such as the condition that it is longer than the value of, are satisfied.

  One aspect of the present invention is a number assigned to each of the M selected reference images, and a distance between a position where the selected reference image is captured and the start point of the route is a reference route start point distance, When the reference path number is an ascending order from 1 to M in ascending order of the reference path start point distance according to the reference path start point distance, and the M is 5 or more, the second condition is the match The condition that the selected reference image number of the selected reference image having the maximum score is the selected reference image from (M−1) / 2 + 2 to M, and the maximum value of the match score is twice the first value And when all of the above conditions are satisfied, and when M is 3, the second condition is that the selected reference image having the largest match score has the selected reference image number 3 above selection A condition that an image, the maximum value of the match score is a condition that all the conditions are satisfied with the condition that is greater than twice the first value.

  One aspect of the present invention is the above-described control device, which is a number assigned to each of the M selected reference images, and includes a position where the selected reference image is captured and a start point of the route. The distance is set as a reference path start point distance, a number given in ascending order from 1 to M in ascending order of the reference path start point distance according to the reference path start point distance is set as a selected reference image number, and a first value is set as X. The condition that the selected reference image number of the selected reference image having the largest match score is (M−1) / 2 + 2 to M when M is 5 or more, and the moving distance information Is a condition that all conditions such as a distance longer than the reference path start point distance at the position where the selected reference image with the selected reference image number M is photographed is X / 2 meters or more are satisfied. When M is 3, the second condition is that the selected reference image having the largest match score is the selected reference image having the selected reference image number of 3, and the moving distance information is The distance shown is a condition that all conditions are satisfied, such as the condition that the reference path starting point distance is longer than the reference path starting point distance at the position where the selected reference image with the selected reference image number M is photographed.

  One aspect of the present invention is the above-described control device, which is a number assigned to the Q reference images, and refers to a distance between a position where the reference image is captured and a starting point of the route. As the route start point distance, a number given in ascending order from 1 in ascending order of the reference route start point distance according to the reference route start point distance is used as a reference image number, and the first condition is that the reference image number of the reference image is The condition is 1 to M.

  One aspect of the present invention is the above-described control device, which is a number assigned to the Q reference images, and refers to a distance between a position where the reference image is captured and a starting point of the route. As a route start point distance, a number given in ascending order from 1 in ascending order of the reference route start point distance according to the reference route start point distance is used as a reference image number, and the moving body is controlled to the predetermined position by the control of the movement control unit. It is assumed that the reference image numbers of the M selected reference images for which the match score has been acquired by the match score acquisition unit immediately before moving to are from Z + 1 to Z + M (Z is an integer of 0 or more). The condition is that the reference image number of the selected reference image from which the match score acquisition unit acquires the match score is from Z + 2 to Z + 2 + M.

  One aspect of the present invention is the above-described control device, which is a number assigned to the Q reference images, and refers to a distance between a position where the reference image is captured and a starting point of the route. As a route start point distance, a number given in ascending order from 1 in ascending order of the reference route start point distance according to the reference route start point distance is used as a reference image number, and the moving body is controlled to the predetermined position by the control of the movement control unit. It is assumed that the reference image numbers of the M selected reference images for which the match score has been acquired by the match score acquisition unit immediately before moving to are from Z + 1 to Z + M (Z is an integer of 0 or more). The condition is that the reference image numbers of the selected reference image from which the match score acquisition unit acquires the match score are Z + 1 to Z + (M−1) and Z + (M + 1). A.

  One aspect of the present invention includes a photographing unit that photographs a subject, and obtains moving distance information that indicates a moving distance information indicating a distance that a moving body moving along a predetermined route moves on the route. A step, an image acquisition step of acquiring image data of an image captured by the imaging unit, and Q images (Q is an integer of 5 or more) previously captured before the moving body starts moving The reference images satisfying the first condition among the reference images are selected reference images, and the M (M is an odd number greater than or equal to 3 and less than Q) selected reference images and the images after the start of movement by the moving object. A match score acquisition step of acquiring a match score that is a value indicating a degree of matching with the image acquired in the acquisition step; and the match score acquired in the match score acquisition step Based on a predetermined condition based on the movement distance information as a second condition, the movement based on the M selected reference images satisfying the second condition and information indicating a position where the selected reference image is captured A position information acquisition step for acquiring position information indicating the position of the body, and a movement control for moving the movable body to a predetermined position according to the position information in accordance with the position information acquired in the position information acquisition step And a control method.

  According to the present invention, it is possible to suppress an increase in the frequency at which an autonomous mobile body cannot move along a predetermined route.

The figure which shows the specific system configuration example of the autonomous mobile system 100 of embodiment. The figure which shows the specific example of a function structure of the main-control part 23 in embodiment. The figure which shows the specific example of the reference image relevant information in embodiment. Explanatory drawing explaining the 3rd selection process in embodiment. Explanatory drawing explaining the 4th selection process in embodiment. 6 is a flowchart showing a specific processing flow of reference image determination processing in the embodiment.

FIG. 1 is a diagram illustrating a specific system configuration example of the autonomous mobile system 100 of the embodiment. The autonomous mobile system 100 includes an autonomous mobile body 1 and a control device 2.
The autonomous mobile body 1 includes an imaging unit and a driving unit, and moves autonomously by driving of the driving unit based on an image captured by the imaging unit. The photographing unit may be anything as long as it can photograph an image, for example, a camera. The control device 2 acquires position information indicating the position of the autonomous mobile body 1. The control device 2 controls the operation of the autonomous mobile body 1.

  The autonomous mobile body 1 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a program. The autonomous mobile body 1 functions as a device including the communication unit 11, the imaging unit 12, the drive unit 13, the odometry acquisition sensor 14, and the mobile body main control unit 15 by executing a program.

The communication unit 11 includes a communication interface for connecting the own device to the control device 2. The communication unit 11 communicates with the control device 2 via a communication interface.
The photographing unit 12 photographs a subject and acquires image data of the subject image. The photographing unit 12 may be anything as long as it can photograph a subject, and may be a camera, for example.

  The drive unit 13 moves the autonomous mobile body 1. The drive unit 13 may be anything as long as it can drive the autonomous mobile body 1. The drive unit 13 may be, for example, a wheel or a propeller.

  The odometry acquisition sensor 14 acquires the drive amount of the drive unit 13. The driving amount of the driving unit 13 is a driving amount that can be converted into the moving amount of the autonomous mobile body 1 and may be any value as long as the value indicates the driving amount of the driving unit 13. The drive amount of the drive unit 13 may be, for example, the number of rotations of the wheel when the drive unit 13 includes wheels and the autonomous mobile body 1 moves by the rotation of the wheels. The drive amount of the drive unit 13 may be, for example, the rotation angle of the wheel when the drive unit 13 includes a wheel and the autonomous mobile body 1 moves by the rotation of the wheel. The driving amount of the drive unit 13 may be, for example, the number of rotations of the propeller when the autonomous mobile body 1 includes a propeller and the autonomous mobile body 1 moves by the rotation of the propeller. The odometry acquisition sensor 14 may be an inner angle sensor of a rudder angle sensor, for example.

  The mobile body main control unit 15 controls the operation of each functional unit provided in the autonomous mobile body 1. Each functional unit is specifically a communication unit 11, an imaging unit 12, a drive unit 13, and an odometry acquisition sensor 14. The moving body main control unit 15 controls the operations of the photographing unit 12 and the drive unit 13 under the control of the control device 2 via the communication unit 11.

  The control device 2 includes a CPU, a memory, an auxiliary storage device, and the like connected by a bus, and executes a program. The control device 2 functions as a device including the communication unit 21, the input unit 22, and the main control unit 23 by executing a program.

The communication unit 21 includes a communication interface for connecting the own device to the autonomous mobile body 1. The communication unit 21 communicates with the autonomous mobile body 1 via a communication interface.
The input unit 22 includes an input device such as a mouse, a keyboard, and a touch panel. The input unit 22 may be configured as an interface for connecting these input devices to the own device. The input unit 22 is a user input to the own device and accepts an input of a start instruction that instructs to start moving the autonomous mobile body 1. The input unit 22 outputs the input start instruction to the main control unit 23. When a start instruction is input to the input unit 22, the autonomous mobile body 1 starts moving. Hereinafter, an image photographed by the photographing unit 12 after the time when a start instruction is input to the input unit 22 (hereinafter referred to as “movement start time”) is referred to as a main image. That is, the main image is an image taken by the photographing unit 12 after the movement start time. The reference image is an image taken before the movement start time.
The main control unit 23 controls the operation of each functional unit provided in the control device 2. When acquiring the start instruction, the main control unit 23 starts controlling the movement of the autonomous mobile body 1.

  The control device 2 acquires position information indicating the position of the autonomous mobile body 1 based on the main image acquired by the photographing unit 12 and the reference image stored in advance in the own device.

  The reference image is an image acquired in advance before the autonomous mobile body 1 starts autonomous movement along a route (hereinafter referred to as “reference route”) that is predetermined as a route that the autonomous mobile body 1 should move. is there. The reference image may be any image as long as it is an image acquired every predetermined distance on the reference route. The predetermined distance is, for example, 1 meter. Hereinafter, for the sake of simplicity, the description will be made assuming that the predetermined distance is X meters.

FIG. 2 is a diagram illustrating a specific example of a functional configuration of the main control unit 23 in the embodiment.
The main control unit 23 includes an auxiliary storage device 200, a start instruction acquisition unit 201, a movement distance information acquisition unit 202, an image acquisition unit 203, an obstacle determination unit 204, an obstacle avoidance route acquisition unit 205, an initial reference image selection unit 206, A moving reference image selection unit 207, a match score acquisition unit 208, a determination unit 209, a position information acquisition unit 210, a movement control unit 211, and an end point determination unit 212 are provided.

  The auxiliary storage device 200 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The auxiliary storage device 200 includes image data of a reference image (hereinafter referred to as “reference image data”), reference path information, information about the reference image (hereinafter referred to as “reference image related information”), and an initial reference image described later. Information indicating the reference image selected by the selection unit 206 and information indicating the reference image selected by the moving reference image selection unit 207 described later are stored. The number of reference image data stored in the auxiliary storage device 200 is Q (Q is an integer of 5 or more).

  The reference route information is information indicating a reference route. The reference route information may indicate how the autonomous mobile body 1 should move. The reference route information may indicate a route on which the autonomous mobile body 1 should move, for example, by direction change location information, direction information, and linear movement distance information. The direction change location information indicates start point end point information indicating a start point and an end point of a route, and a position where the autonomous mobile body 1 changes its direction (hereinafter referred to as “direction change position”). The direction information indicates the direction in which the autonomous mobile body 1 faces after the autonomous mobile body 1 changes the direction at the orientation change position. The linear movement distance information indicates the distance that the autonomous mobile body 1 moves without changing its direction.

  The reference image related information includes reference image identifier information, reference image number information, reference image position information indicating a position where the reference image is captured, and reference image capturing direction information. The reference image identifier information indicates an identifier of reference image data. The reference image number information indicates a reference image number that is a number indicating the order between reference images represented by each reference image data stored in the auxiliary storage device 200. Specifically, the reference image number information indicates the order determined based on a predetermined condition regarding the distance on the reference route connecting the position where the reference image was taken and the starting point of the reference route, by the reference image number. Hereinafter, the distance between two points on the reference route is referred to as a reference route distance. Hereinafter, the reference route distance between the start point of the reference route and the position on the reference route is referred to as a reference route start point distance. Hereinafter, the predetermined condition regarding the reference path distance between the position where the reference image is taken and the start point of the reference path is referred to as a reference image number condition.

  The reference image number condition is a condition relating to the order of the reference image represented by each reference image data stored in the auxiliary storage device 200 based on the reference path distance between the position where the reference image is captured and the start point of the reference path. Any condition may be used. The reference image number condition may be, for example, a condition that a reference image taken at a position where the reference path start point distance is shorter is an earlier image. The reference image number condition may be, for example, a condition that the reference image taken at a position where the reference path start point distance is short is later in order. Hereinafter, for the sake of simplicity, it is assumed that the reference image number condition is a condition that a reference image taken at a position where the reference path start point distance is short is an earlier image. That is, hereinafter, for the sake of simplicity, it is assumed that reference image numbers are assigned to each reference image in ascending order from 1 in ascending order of the reference path start point distance.

  The reference image shooting direction information indicates the direction in which the shooting unit 12 is facing when the reference image is shot. The direction in which the photographing unit 12 is facing when the reference image is photographed is a direction of a straight line connecting the photographing unit 12 and the subject when the reference image is photographed.

FIG. 3 is a diagram illustrating a specific example of the reference image related information in the embodiment.
The reference image related information is stored in the auxiliary storage device 200, for example, as a reference image related information table shown in FIG. The reference image related information table D110 has a record for each “reference image number”. Each record has values of “reference image number”, “reference image ID”, “reference image position”, and “reference image shooting direction”. “Reference image number” indicates the reference image number of each reference image stored in the auxiliary storage device 200. “Reference image number” is a specific example of reference image number information. “Reference image ID” represents an identifier of a reference image. “Reference image position” represents the reference path distance between the position where the reference image is taken and the start point of the reference path. “Reference image shooting direction” represents a direction in which the shooting unit 12 faces when the reference image is shot.
For example, the record D111 indicates that the reference path start point distance at the position where the reference image having the identifier “RefIm2” is captured is 1 m. The record D111 indicates that the direction in which the photographing unit 12 is facing when the reference image with the identifier “RefIm2” is directed is 11 degrees north and 9 degrees east. The record D111 indicates that the order of the reference image whose identifier is “RefIm2” is second.

Returning to the description of FIG. The start instruction acquisition unit 201 acquires the start instruction input to the input unit 22.
The movement distance information acquisition unit 202 acquires information indicating the movement distance of the autonomous mobile body 1 (hereinafter referred to as “movement distance information”). Specifically, when the start instruction acquisition unit 201 acquires a start instruction, the movement distance information acquisition unit 202 controls the odometry acquisition sensor 14 to start acquisition of the drive amount. The movement distance information acquisition unit 202 acquires the driving amount acquired by the odometry acquisition sensor 14, and acquires the movement distance information based on the acquired driving amount.

The image acquisition unit 203 acquires image data of the main image captured by the imaging unit 12 of the autonomous mobile body 1. The image acquisition unit 203 acquires the movement distance information acquired by the movement distance information acquisition unit 202. When a predetermined condition based on the acquired travel distance information is satisfied, the image acquisition unit 203 controls the imaging unit 12 included in the autonomous mobile body 1 to cause the imaging unit 12 to image the subject. Image data of a photographed subject image is acquired. The predetermined condition based on the movement distance information may be any condition as long as it is a condition relating to the movement distance of the autonomous mobile body 1. The predetermined condition based on the travel distance information may be, for example, a condition that the travel distance of the autonomous mobile body 1 is 0 (that is, the autonomous mobile body 1 is at the starting point of the reference route).
The movement distance information may be, for example, a condition that the movement distance indicated by the movement distance information is an integral multiple of a predetermined length.

  The obstacle determination unit 204 determines that there is an obstacle on the path of the autonomous mobile body 1 when the image data of the main image acquired by the image acquisition unit 203 satisfies a predetermined condition regarding the obstacle. Hereinafter, the predetermined condition regarding the obstacle is referred to as an obstacle condition. The obstacle condition may be any condition as long as the obstacle determination unit 204 can determine the obstacle based on the image data. The condition under which the obstacle can be determined based on the image data may be, for example, whether or not there is a predetermined shape in the image indicated by the image data. The condition under which an obstacle can be determined based on image data may be a condition based on a luminance edge, for example. A luminance edge is a luminance difference between adjacent pixels in image data. In this case, the obstacle determination unit 204 first applies a predetermined filter to the image data when the luminance edge is larger than a predetermined value, and determines whether there is an obstacle image in the image represented by the image data by a predetermined algorithm. Determine. If there is an obstacle image in the image represented by the image data, then the obstacle determination unit 204 is viewed from the position of the autonomous mobile body 1 when the image represented by the image data is captured based on the image data. The direction of the obstacle and the distance between the autonomous mobile body 1 and the obstacle are acquired. The obstacle determination unit 204 determines whether there is an obstacle on the reference route based on the acquired direction, distance, and reference route. In this way, the obstacle determination unit 204 determines whether there is an obstacle on the path of the autonomous mobile body 1.

The obstacle avoidance route acquisition unit 205 executes an obstacle avoidance route acquisition process when the obstacle determination unit 204 determines that there is an obstacle (hereinafter referred to as “avoidance route”). Get).
In the obstacle avoidance route acquisition process, the method by which the obstacle avoidance route acquisition unit 205 acquires the avoidance route may be any method as long as it can acquire the avoidance route. The method for obtaining the avoidance route may be, for example, an A star search algorithm. The method for obtaining the avoidance route may be, for example, the potential method. The method for acquiring the avoidance route may be, for example, processing for acquiring a predetermined route as a avoidance route.
The obstacle avoidance route acquisition unit 205 changes the route indicated by the reference route information stored in the auxiliary storage device 200 to the avoidance route after calculating the avoidance route by the obstacle avoidance route acquisition process.

  When the image acquisition unit 203 acquires the image data of the main image, the initial reference image selection unit 206 performs the first selection based on the movement distance information after the processing by the obstacle determination unit 204 or the obstacle avoidance route acquisition unit 205. The process or the second selection process is executed. The initial reference image selection unit 206 executes the first selection process when the movement distance information is 0. The initial reference image selection unit 206 selects the reference image data of the reference image satisfying the first selection condition from the reference images represented by the reference image data stored in the auxiliary storage device 200 by executing the first selection process. The first selection condition is a condition that the reference image number is 1 to M (M is an odd number of 3 or more and less than Q). The initial reference image selection unit 206 records the reference image number of the reference image selected by executing the first selection process in the auxiliary storage device 200. Hereinafter, for the sake of simplicity, selecting the reference image data stored in the auxiliary storage device 200 is referred to as selecting a reference image.

  The initial reference image selection unit 206 executes the second selection process when the movement distance information is not zero. The initial reference image selection unit 206 obtains the reference image image data stored in the auxiliary storage device 200 by the execution of the second selection process, and the reference image image data selected by the moving reference image selection unit 207. select.

  The moving reference image selection unit 207 executes processing related to selection of a reference image according to a determination result of the determination unit 209 described later. Specifically, the moving reference image selection unit 207 selects predetermined M reference images according to the determination result of the determination unit 209 from the reference images stored in the auxiliary storage device 200. The processes according to the determination result of the determination unit 209 are two processes, a third selection process and a fourth selection process.

The third selection process is executed by the moving reference image selection unit 207 when the determination result of the determination unit 209 is a determination result that satisfies any one of a first determination condition to a fourth determination condition described later. The moving reference image selection unit 207 selects a reference image that satisfies the second selection condition by executing the third selection process.
The second selection condition is that the reference image number of the reference image selected by the moving reference image selection unit 207 or the initial reference image selection unit 206 immediately before the determination by the determination unit 209 is from Z + 1 to Z + M. Is from Z + 2 to Z + 2 + M.
That is, the moving reference image selection unit 207 selects M reference images with reference image numbers Z + 2 to Z + 2 + M instead of reference images with reference image numbers Z + 1 to Z + M by executing the third selection process. Z is an integer of 0 or more.

The fourth selection process is executed by the moving reference image selection unit 207 when the determination result of the determination unit 209 is a determination result that satisfies a later-described fifth determination condition. The moving reference image selection unit 207 selects a reference image that satisfies the third selection condition by executing the fourth selection process.
The third selection condition is that the reference image number of the reference image selected by the moving reference image selection unit 207 or the initial reference image selection unit 206 immediately before the determination by the determination unit 209 is from Z + 1 to Z + M. Is a condition that Z + 1 to Z + (M−1) and Z + (M + 1).
In other words, the moving reference image selection unit 207 executes the fourth selection process and replaces the reference images with the reference image numbers Z + 1 to Z + M with the reference images with the reference image numbers Z + 1 to Z + (M−1). M reference images with a reference image having an image number Z + (M + 1) are selected.

  The moving reference image selection unit 207 records the selected reference image selected by the third selection process or the fourth selection process in the auxiliary storage device 200.

FIG. 4 is an explanatory diagram illustrating a third selection process in the embodiment.
4A shows a reference image (hereinafter referred to as “selection reference”) selected by the initial reference image selection unit 206 or the movement reference image selection unit 207 before the movement reference image selection unit 207 executes the third selection process. "Image"). In FIG. 4A, the selected reference images are five reference images P + 2 to P + 6 (P is an integer). FIG. 4B shows the selected reference image after the moving reference image selection unit 207 executes the third selection process. In FIG. 4B, the selected reference images are five reference images P + 3 to P + 7.
As described above, the moving reference image selection unit 207 executes the third selection process, so that M reference images with reference image numbers Z + 2 to Z + 2 + M are used instead of reference images with reference image numbers Z + 1 to Z + M. select.

FIG. 5 is an explanatory diagram illustrating a fourth selection process in the embodiment.
FIG. 5A illustrates a selected reference image at a time point before the moving reference image selection unit 207 executes the fourth selection process. In FIG. 5A, the selected reference images are five images of P + 2 to P + 6 (P is an integer). FIG. 5B shows the selected reference image after the moving reference image selection unit 207 executes the fourth selection process. In FIG. 5B, the selected reference images are five reference images of P + 2 to P + 5 reference images and P + 7 reference images.
In this way, the moving reference image selection unit 207 executes the fourth selection process, so that reference image numbers Z + 1 to Z + (M−1) are referenced instead of reference image numbers Z + 1 to Z + M. M reference images of the image and Z + (M + 1) reference images are selected.

  Returning to the description of FIG. The match score acquisition unit 208 calculates a match score between the M reference images selected by the initial reference image selection unit 206 or the moving reference image selection unit 207 and the main image. The match score represents the degree of matching between the reference image and the main image acquired by the image acquisition unit 203.

  Based on the match score calculated by the match score acquisition unit 208 and the movement distance information acquired by the movement distance information acquisition unit 202, the determination unit 209 determines the first determination condition, the second determination condition, the third determination condition, It is determined which of the 4 determination condition, the fifth determination condition, and the sixth determination condition is satisfied. Hereinafter, the process determined by the determination unit 209 is referred to as a determination process.

Hereinafter, for the sake of simplicity, it is assumed that M = 5.
The first determination condition is a condition that all of the following three conditions are satisfied. The first condition is that the selected reference image number of the reference image with the largest match score is 4 or 5. The second condition is a condition that the maximum value of the match score is larger than a predetermined value (hereinafter referred to as “score threshold”). The third condition is a condition that the movement distance indicated by the movement distance information is shorter than the reference route start point distance at the position where the selected reference image having the selected reference image number 1 is taken. The selected reference image number is a number for identifying the five selected reference images selected by the initial reference image selection unit 206 or the moving reference image selection unit 207, and is a number given in order from 1 in ascending order of the reference image number. It is. That is, the selected reference image number is a number assigned to each selected reference image in ascending order from 1 in ascending order of the reference path start point distance. Specifically, when the reference image numbers of the five selected reference images selected by the initial reference image selection unit 206 or the moving reference image selection unit 207 are 4, 5, 6, 7, and 8, each selection reference The selected reference image numbers of the images are 1, 2, 3, 4, and 5.

  The second determination condition is a condition that the following two conditions are all satisfied. The first condition is that the selected reference image number of the selected reference image with the largest match score is 3, 4 or 5. The second condition is that the reference path start point distance at the position where the selected reference image with the selected reference image number 5 is photographed is longer than the moving distance indicated by the moving distance information by a length of X meters or more. X may be any value, for example, X = 1.

  The third determination condition is a condition that the following two conditions are all satisfied. The first condition is that the maximum match score is smaller than the score threshold. The second condition is that the reference path start point distance at the position where the selected reference image with the selected reference image number 5 is photographed is longer than the moving distance indicated by the moving distance information by X meters or more.

  The fourth determination condition is a condition that the following two conditions are all satisfied. The first condition is that the selected reference image number of the selected reference image having the largest match score is 4 or 5. The second condition is that the maximum match score is greater than twice the score threshold.

  The fifth determination condition is a condition that the following two conditions are all satisfied. The first condition is that the selected reference image number of the selected reference image having the largest match score is 4 or 5. The second condition is that the movement distance indicated by the movement distance information is X / 2 meters or more longer than the reference path start point distance at the position where the selected reference image with the selected reference image number 5 is taken.

  The sixth determination condition is a condition that all conditions from the first determination condition to the fifth determination condition are not satisfied.

  The determination unit 209 ends the determination process when the sixth determination condition is satisfied, that is, when all of the first determination condition to the fifth determination condition are not satisfied.

  When the determination process by the determination unit 209 is completed, the position information acquisition unit 210 determines the position of the autonomous mobile body 1 based on the M selected reference images selected by the moving reference image selection unit 207 or the initial reference image selection unit 206. The position information indicating the position is acquired. Specifically, the self-position acquiring unit uses the position information indicating the position of the autonomous mobile body 1 as the position information indicating the position where the selected reference image having the maximum match score is captured among the selected M selected reference images. Get as.

Based on the position information acquired by the position information acquisition unit 210 and the reference route information stored in the auxiliary storage device 200, the movement control unit 211 determines whether the autonomous mobile body 1 moves along the reference route or the route indicated by the avoidance route. The drive unit 13 of the autonomous mobile body 1 is controlled via the communication unit 21 and the communication unit 11 so as to move.
The end point determination unit 212 determines whether the position of the autonomous mobile body 1 is the end point of the designated route based on the movement distance information acquired by the movement distance information acquisition unit 202. When the end point determination unit 212 determines that it is the end point, the autonomous mobile system 100 stops its operation. The end point determination unit 212 may perform determination at any timing. The end point determination unit 212 may determine, for example, at the timing when the movement distance information acquisition unit 202 acquires the movement distance information.

  Hereinafter, a series of processing by the initial reference image selection unit 206, the moving reference image selection unit 207, the match score acquisition unit 208, and the determination unit 209 is referred to as reference image determination processing.

FIG. 6 is a flowchart showing a specific process flow of the reference image determination process in the embodiment.
The initial reference image selection unit 206 executes the first selection process to select five reference images (step S101). The match score acquisition unit 208 calculates a match score for each of the five selected reference images (step S102). The determination unit 209 determines whether or not the first determination condition is satisfied (step S103). In step S103, when the first determination condition is not satisfied, the determination unit 209 determines whether or not the second determination condition is satisfied (step S104). That the first determination condition is not satisfied means that at least one of the three conditions included in the first determination condition is not satisfied. In step S104, when the second determination condition is not satisfied, the determination unit 209 determines whether or not the third determination condition is satisfied (step S105). “The second determination condition is not satisfied” means that at least one of the two conditions included in the second determination condition is not satisfied. In step S105, when the third determination condition is not satisfied, the determination unit 209 determines whether or not the fourth determination condition is satisfied (step S106). That the third determination condition is not satisfied means that at least one of the two conditions included in the third determination condition is not satisfied. In step S106, when the fourth determination condition is not satisfied, the determination unit 209 determines whether or not the fifth determination condition is satisfied (step S107). That the fourth determination condition is not satisfied means that at least one of the two conditions included in the fourth determination condition is not satisfied.
If the fifth determination condition is not satisfied in step S107, the sixth determination condition is satisfied, and the determination unit 209 ends the determination process. (Step S107). That the fifth determination condition is not satisfied means that at least one of the two conditions included in the fifth determination condition is not satisfied.

On the other hand, when the first determination condition is satisfied in step S103, the moving reference image selection unit 207 executes a third selection process (step S108).
On the other hand, when the second determination condition is satisfied in step S104, the moving reference image selection unit 207 executes a third selection process (step S108).
On the other hand, when the third determination condition is satisfied in step S105, the moving reference image selection unit 207 executes a third selection process (step S108).
On the other hand, when the fourth determination condition is satisfied in step S106, the moving reference image selection unit 207 executes a third selection process (step S108).
On the other hand, when the fifth determination condition is satisfied in step S107, the moving reference image selection unit 207 executes a fourth selection process (step S109).

  After step S108 and step S109 are executed, the process of step S102 is executed.

  Since the autonomous mobile system 100 of the embodiment configured as described above includes the reference image selection unit 207 at the time of moving that changes the reference image based on the match score, the position estimated from the movement distance information and the actual position An increase in deviation can be suppressed. Therefore, the autonomous mobile system 100 according to the embodiment configured as described above can suppress an increase in the frequency at which the autonomous mobile body 1 cannot move along a predetermined route.

  Further, in the autonomous mobile system 100 of the embodiment configured as described above, the reference image may be an image acquired at intervals of 1 meter. In such a case, the autonomous mobile system 100 can acquire position information indicating the position of the autonomous mobile body 1 using five reference images acquired at intervals of 1 meter. Generally, when the interval at which the reference image is acquired is shortened, the difference between the base match score and the previous match score is reduced. Therefore, the accuracy of the position of the autonomous mobile body 1 indicated by the acquired position information is deteriorated. The reference match score is a match score between the reference image and the main image that are referred to when the control device 2 acquires position information indicating the position of the autonomous mobile body 1 (hereinafter referred to as “reference time”). . The immediately preceding match score is a match score between the reference image and the main image that is referred to when the control device 2 acquires position information indicating the position of the autonomous mobile body 1 immediately before the reference time.

  However, when acquiring the position information indicating the position of the autonomous mobile body 1, the control device 2 in the embodiment acquires the position information indicating the position of the autonomous mobile body 1 using the five reference images. Therefore, the difference between the base match score and the previous match score is larger than the case where the position information indicating the position of the autonomous mobile body 1 is acquired using one reference image, and the acquired position information indicates The accuracy of the position of the autonomous mobile body 1 is improved.

According to experiments, when the conventional control device 2 acquires position information indicating the position of the autonomous mobile body 1 moving on a straight road of about 100 meters, the position indicated by the acquired position information and the actual position are 10 There was a deviation of about 50 centimeters per meter. However, when the control device 2 in the embodiment acquires the position of the autonomous mobile body 1 that moves on a straight road of about 100 meters, the deviation between the position indicated by the acquired position information and the actual position is about 10 meters. It was suppressed to about 10 centimeters.
Further, according to an experiment, the conventional control device 2 has been unable to travel about once every five times because the difference between the position indicated by the acquired position information and the actual position is too large. However, in the control device 2 according to the embodiment, the number of times that the vehicle cannot run because the difference between the position indicated by the acquired position information and the actual position is too large is reduced to once in 20 times.

As described above, the initial reference image selection unit 206 of the control device 2 does not necessarily need to select five reference images, and can select three or more N (N is an odd number of 3 or more) reference images. Any number may be used.
Hereinafter, when the initial reference image selection unit 206 selects N reference images, the first determination condition, the second determination condition, the third determination condition, the fourth determination condition, the fifth determination condition, and the sixth determination condition are set. explain.

  The first determination condition is a condition that all of the following three conditions are satisfied. The first condition is that the selected reference image having the largest match score is a selected reference image having a selected reference image number from (N−1) / 2 + 2 to N. The second condition is that the maximum match score is larger than the score threshold. The third condition is a condition that the movement distance indicated by the movement distance information is shorter than the reference path start point distance at the position where the selected reference image having the selected reference image number of 1 is photographed. When N is 3, the first condition is that the selected reference image with the largest match score is a selected reference image with a selected reference image number of 3.

  The second determination condition is a condition that all of the following two conditions are satisfied. The first condition is that the selected reference image with the largest match score is a selected reference image with selected reference image numbers (N−1) / 2 + 1 to N. The second condition is that the reference path start point distance at the position where the selected reference image with the selected reference image number N is photographed is longer than the moving distance indicated by the moving distance information by X meters or more.

  The third determination condition is a condition that the following two conditions are all satisfied. The first condition is that the maximum match score is smaller than the score threshold. The second condition is that the reference path start point distance at the position where the selected reference image with the selected reference image number N is photographed is longer than the moving distance indicated by the moving distance information by X meters or more.

  The fourth determination condition is a condition that the following two conditions are all satisfied. The first condition is that the selected reference image number of the selected reference image with the largest match score is a selected reference image from (N−1) / 2 + 2 to N. The second condition is that the maximum match score is greater than twice the score threshold. When N is 3, the first condition is that the selected reference image with the largest match score is a selected reference image with a selected reference image number of 3.

  The fifth determination condition is a condition that the following two conditions are all satisfied. The first condition is that the selected reference image number of the selected reference image with the largest match score is a selected reference image from (N−1) / 2 + 2 to N. The second condition is that the movement distance indicated by the movement distance information is X / 2 meters or longer than the reference path start point distance at the position where the selected reference image with the selected reference image number N is photographed. When N is 3, the first condition is that the selected reference image with the largest match score is a selected reference image with a selected reference image number of 3.

  The sixth determination condition is the same condition regardless of N, and is a condition that all the conditions of the first determination condition to the fifth determination condition are not satisfied.

  In addition, the autonomous mobile body 1 and the control apparatus 2 do not necessarily need to be mounted in two housings, and the autonomous mobile body 1 and the control apparatus 2 may be mounted in one housing.

  The first selection condition, the second selection condition, and the third selection condition are examples of the first condition. The first determination condition, the second determination condition, the third determination condition, the fourth determination condition, and the fifth determination condition are examples of the second condition. The score threshold is an example of a first value. The length X meter is an example of the second value.

Note that all or part of the functions of the autonomous mobile body 1 and the control device 2 according to the embodiment include hardware such as ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), and FPGA (Field Programmable Gate Array). It may be realized using. The program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. The program may be transmitted via a telecommunication line.
The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within the scope not departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Autonomous mobile body, 2 ... Control apparatus, 11 ... Communication part, 12 ... Imaging | photography part, 13 ... Drive part, 14 ... Odometry acquisition sensor, 15 ... Mobile body main control part, 21 ... Communication part, 22 ... Input part, DESCRIPTION OF SYMBOLS 23 ... Main control part, 100 ... Autonomous movement system, 200 ... Auxiliary storage device, 201 ... Start instruction acquisition part, 202 ... Movement distance information acquisition part, 203 ... Image acquisition part, 204 ... Obstacle determination part, 205 ... Obstacle Avoidance route acquisition unit, 206 ... initial reference image selection unit, 207 ... reference image selection unit during movement, 208 ... match score acquisition unit, 209 ... determination unit, 210 ... position information acquisition unit, 211 ... movement control unit, 212 ... end point Judgment part

Claims (10)

A moving distance information acquiring unit that includes a shooting unit that captures a subject, and that acquires moving distance information indicating a distance that a moving body that moves along a predetermined path moves on the path;
An image acquisition unit for acquiring image data of an image captured by the imaging unit;
Q images (Q is an integer greater than or equal to 5) previously captured before the moving body starts moving are used as reference images, and the reference image satisfying the first condition among the reference images is used as a selected reference image. A match score that is a value indicating the degree of matching between the M (M is an odd number of 3 or more and less than Q) selected reference images and images acquired by the image acquisition unit after the moving object starts moving is acquired. A match score acquisition unit;
The M selected reference images satisfying the second condition and the selected reference images are taken with a predetermined condition based on the match score acquired by the match score acquisition unit and the movement distance information as a second condition. A position information acquisition unit that acquires position information indicating the position of the mobile body based on the information indicating the position,
In accordance with the position information acquired by the position information acquisition unit, a movement control unit that moves the moving body to a predetermined position according to the position information;
A control device comprising: A number assigned in ascending order from 1 to M in order of increasing reference path start point distance according to the reference path start point distance, with a distance between the position where the selected reference image is taken and the start point of the route as a reference path start point distance When the M is 5 or more, the second condition is that the selected reference image having the largest match score acquired by the match score acquisition unit has the selected reference image number (M− 1) The condition that the reference images are from (2 + 2 + 2) to M, the condition that the maximum value of the match score is larger than the first value, and the movement distance indicated by the movement distance information are the selected reference image number 1 is a condition that all conditions, such as a condition that the distance is shorter than the reference path start point distance at the position where the selected reference image is photographed, and when M is 3, The two conditions are a condition that the selected reference image having the largest match score is the selected reference image having the selected reference image number of 3, and a condition that the maximum value of the match score is larger than a first value. The moving distance indicated by the moving distance information is a condition that at least one of the conditions that the moving distance indicated by the moving distance information is shorter than the distance from the reference path starting point at the position where the selected reference image having the selected reference image number 1 is photographed is not satisfied. ,
The control device according to claim 1. A number assigned to each of the M selected reference images, and a distance between the position where the selected reference image is photographed and the start point of the route is defined as a reference route start point distance according to the reference route start point distance. The second condition is that the selected reference image with the largest match score acquired by the match score acquisition unit is a number assigned in ascending order from 1 to M in ascending order of the reference path start point distance. Is a condition that the selected reference image number is the reference image from (M−1) / 2 + 2 to M, and the reference path start point distance at the position where the selected reference image number of the selected reference image number is M. Is a condition that at least one of the conditions that the moving distance information is longer than the second value is not satisfied,
The control device according to claim 1. A number assigned to each of the M selected reference images, and a distance between the position where the selected reference image is photographed and the start point of the route is defined as a reference route start point distance according to the reference route start point distance. The reference condition number is a number assigned in ascending order from 1 to M in ascending order of the reference path starting point distance, and the second condition is that the maximum value of the match score is smaller than the first value, The condition that the reference path start point distance at the position where the selected reference image with the selected reference image number M is photographed is not satisfied with at least one of the conditions that it is longer than the distance indicated by the movement distance information by a second value or more. Is,
The control device according to claim 1. A number assigned to each of the M selected reference images, and a distance between the position where the selected reference image is photographed and the start point of the route is defined as a reference route start point distance according to the reference route start point distance. When the reference path number is an ascending order from 1 to M in ascending order of the reference path starting point distance, and the M is 5 or more, the second condition is that the selection reference with the largest match score is All of the condition that the selected reference image number of the image is the selected reference image from (M−1) / 2 + 2 to M, and the condition that the maximum value of the match score is greater than twice the first value When the M is 3, the second condition is that the selected reference image having the largest match score is the selected reference image having the selected reference image number 3. That there is And matter, the maximum value of the match score is a condition that at least one is not satisfied with the condition that is greater than twice the first value,
The control device according to claim 1. A number assigned to each of the M selected reference images, and a distance between the position where the selected reference image is photographed and the start point of the route is defined as a reference route start point distance according to the reference route start point distance. The reference path starting point distance is assigned in ascending order from 1 to M as the selected reference image number, the first value is X, and when M is 5 or more, the match score is the maximum. The condition that the selected reference image number of the selected reference image is the selected reference image from (M−1) / 2 + 2 to M, and the distance indicated by the movement distance information is the selection of which the selected reference image number is M. The condition that all the conditions of X / 2 meters or more longer than the reference path start point distance at the position where the reference image is taken is satisfied, and when M is 3, the second condition is ,Previous The selected reference image having the largest match score is the selected reference image having the condition that the selected reference image number is 3 and the distance indicated by the movement distance information is the selected reference image having the selected reference image number M. Is a condition in which at least one of the conditions that the reference path start point distance at the position where the image is taken is longer than X / 2 meters is not satisfied.
The control device according to claim 1. The number assigned to the Q reference images, and the distance between the position where the reference image was taken and the start point of the route is a reference route start point distance, and the reference is made according to the reference route start point distance. The first condition is a condition that the reference image number of the reference image is 1 to M, with the number assigned in ascending order from 1 in ascending order of the route start point distance as the reference image number.
The control device according to any one of claims 1 to 6. The number assigned to the Q reference images, and the distance between the position where the reference image was taken and the start point of the route is a reference route start point distance, and the reference is made according to the reference route start point distance. A number given in ascending order from 1 in ascending order of the route start point distance is used as a reference image number, and the match score is obtained by the match score acquisition unit immediately before the moving body moves to the predetermined position under the control of the movement control unit. Assuming that the reference image numbers of the acquired M selected reference images are from Z + 1 to Z + M (Z is an integer greater than or equal to 0), the first condition is that the match score acquisition unit acquires the match score. It is a condition that the reference image number of the selected reference image is Z + 2 to Z + 2 + M.
The control device according to any one of claims 1 to 7. The number assigned to the Q reference images, and the distance between the position where the reference image was taken and the start point of the route is a reference route start point distance, and the reference is made according to the reference route start point distance. A number given in ascending order from 1 in ascending order of the route start point distance is used as a reference image number, and the match score is obtained by the match score acquisition unit immediately before the moving body moves to the predetermined position under the control of the movement control unit. Assuming that the reference image numbers of the acquired M selected reference images are from Z + 1 to Z + M (Z is an integer greater than or equal to 0), the first condition is that the match score acquisition unit acquires the match score. The reference image number of the selected reference image is a condition that Z + 1 to Z + (M−1) and Z + (M + 1).
The control device according to any one of claims 1 to 7. A moving distance information acquisition step that includes a shooting unit for shooting a subject, and acquires moving distance information indicating a distance that a moving body moving along a predetermined path moves on the path;
An image acquisition step of acquiring image data of an image captured by the imaging unit;
Q images (Q is an integer greater than or equal to 5) previously captured before the moving body starts moving are used as reference images, and the reference image satisfying the first condition among the reference images is used as a selected reference image. Acquire a match score that is a value indicating the degree of coincidence between M (M is an odd number of 3 or more and less than Q) selected reference images and images acquired in the image acquisition step after the movement start time by the moving object. A match score acquisition step,
Taking the predetermined condition based on the match score acquired in the match score acquisition step and the movement distance information as a second condition, the M selected reference images satisfying the second condition and the selected reference images are captured. A position information acquisition step for acquiring position information indicating the position of the mobile body based on the information indicating the position that has been performed;
In accordance with the position information acquired in the position information acquisition step, a movement control step of moving the moving body to a predetermined position according to the position information;
A control method.

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