JP7281720B2 - Autonomous mobile device and its control method - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to an autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked, and a tracking method thereof.

2. Description of the Related Art A control technique for an autonomous mobile device that detects a target to be tracked using a range sensor or an imaging device such as a camera and moves autonomously while following the target to be tracked is generally known. With the user mounted on such an autonomous mobile device, the follow-up target moves to the destination, so that the user can be moved to the destination without walking.

However, with such technology, the follower needs to face backward in order for the user of the autonomous mobile device and the leader of the follower to communicate with each other during movement. Therefore, there is a problem in terms of safety.

As a technique for solving such a problem, there is a technique for following control of an autonomous mobile device so as to run alongside a tracked object (see, for example, Patent Literature 1).

In Patent Document 1, based on the surrounding environment recognized by a camera, a communication device, etc., the positional relationship between a tracking target and a moving device is determined, and one of a plurality of tracking modes including a side-by-side mode is selected. It is disclosed that follow-up control is performed by

JP 2007-316924 A

In the technology disclosed in Patent Document 1, when the autonomous mobile device is performing follow-up control in the side-by-side mode, if the tracked target tries to change the course to the autonomous mobile device side, the track of the tracked target is changed by the autonomous mobile device. may be inhibited. In such a case, it becomes difficult for the tracked object to smoothly change course. In addition, when the object to be followed moves along a route that passes by the side of an obstacle, the path of the autonomous mobile device may be obstructed by the obstacle, making it difficult to continue the follow-up control.

An object of the present disclosure is to provide an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, and an autonomous mobile device that can smoothly respond to changes in the course of the object to be tracked, and a control method for the same. .

An autonomous mobile device according to one aspect of the present invention is an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, wherein a sign that the target to be tracked is about to change course is detected. a tracked object route estimating unit for estimating a first route that is the changed route of the tracked object; and a route determination unit that determines a second route of the autonomous mobile device to be moved in the following manner, and based on the position of the autonomous mobile device and the first route at the time of detecting the sign, after the tracking target is changed a motion determination unit that determines whether to stop the autonomous mobile device at the position until it starts moving along the route of the motion determination unit, the motion determination unit determining the position and the first route When the minimum value of the distance is equal to or greater than the first distance, it is determined to stop the autonomous mobile device at the position until the tracked object starts moving along the changed course.
An autonomous mobile device according to one aspect of the present invention is an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, wherein a sign that the target to be tracked is about to change course is detected. a tracked object route estimating unit for estimating a first route that is the changed route of the tracked object; and a route determination unit that determines a second route of the autonomous mobile device to be moved in the following manner, and based on the position of the autonomous mobile device and the first route at the time of detecting the sign, after the tracking target is changed a motion determination unit that determines whether to stop the autonomous mobile device at the position until it starts moving along the route of the motion determination unit, the motion determination unit determining the position and the first route When the minimum value of the distance is less than the first distance, it is determined to move the autonomous mobile device to the intersection of the course of the autonomous mobile device before detecting the sign and the second course.
An autonomous mobile device according to one aspect of the present invention is an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, wherein a sign that the target to be tracked is about to change course is detected. a tracked object route estimating unit for estimating a first route that is the changed route of the tracked object; a route determining unit that determines a second route for the autonomous mobile device to move along the second route; until the tracked object starts moving along the changed route based on the position of the autonomous mobile device and the first route when the sign is detected, and the obstacle detection unit that determines whether or not and a motion determination unit that determines whether or not to stop the autonomous mobile device at the position, wherein the route determination unit determines that the obstacle hinders movement when determining that the obstacle exists. and the operation determination unit determines a modified second course by correcting the second course so that the motion determination unit compares the autonomous mobile device with the course of the autonomous mobile device before detecting the sign and the corrected second course. is determined to move to the intersection of

A control method for an autonomous mobile device according to one aspect of the present invention is a control method for an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, wherein the object to be tracked changes course. A state in which a first route, which is a changed route of the tracked object, is estimated when a sign of the tracked object is detected, and the tracked object travels side by side with the tracked object when it is assumed that the tracked object moves along the first route. to determine the second route of the autonomous mobile device for moving with, and based on the position of the autonomous mobile device at the time of detecting the sign and the first route, the tracked object follows the changed route determining whether to stop the autonomous mobile device at the position until it starts moving, and determining whether to stop the autonomous mobile device at the position; is greater than or equal to the first distance, the autonomous mobile device is stopped at the position until the target to be tracked starts moving along the changed route.
A control method for an autonomous mobile device according to one aspect of the present invention is a control method for an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, wherein the object to be tracked changes course. A state in which a first route, which is a changed route of the tracked object, is estimated when a sign of the tracked object is detected, and the tracked object travels side by side with the tracked object when it is assumed that the tracked object moves along the first route. to determine the second route of the autonomous mobile device for moving with, and based on the position of the autonomous mobile device at the time of detecting the sign and the first route, the tracked object follows the changed route determining whether to stop the autonomous mobile device at the position until it starts moving, and determining whether to stop the autonomous mobile device at the position; is less than the first distance, the autonomous mobile device is determined to move to the intersection of the route of the autonomous mobile device before detecting the sign and the second route.
A control method for an autonomous mobile device according to one aspect of the present invention is a control method for an autonomous mobile device that moves while following an object to be tracked while running side by side with the object to be tracked, wherein the object to be tracked changes course. A state in which a first route, which is a changed route of the tracked object, is estimated when a sign of the tracked object is detected, and the tracked object travels side by side with the tracked object when it is assumed that the tracked object moves along the first route. determining a second route for the autonomous mobile device to move along the second route, and determining whether or not there is an obstacle that hinders movement when the autonomous mobile device is assumed to move along the second route. Then, based on the position of the autonomous mobile device and the first route at the time when the sign is detected, the autonomous mobile device is stopped at the position until the target to be tracked starts moving along the changed route. When determining whether or not the obstacle exists, if it is determined that the obstacle exists, the second route is changed so that the obstacle does not hinder movement. When determining a corrected second course and determining whether or not to stop the autonomous mobile device at the position, the autonomous mobile device is adjusted to the course of the autonomous mobile device before the sign is detected and the It is determined to move to the intersection with the modified second course.

Advantageous Effects of Invention According to the present invention, in an autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked, it is possible to smoothly respond to a course change of the target to be tracked.

Diagram for explaining the autonomous mobile device Block diagram for explaining the functional configuration of the information processing unit Block diagram for explaining the functional configuration of the control unit Flowchart showing a control method for an autonomous mobile device FIG. 4 is a diagram for explaining a first operation executed when there is no obstacle on the tentative route and the nearest neighbor distance D _min is less than the threshold distance D3; FIG. 4 is a diagram for explaining a first operation executed when there is no obstacle on the tentative route and the nearest neighbor distance D _min is less than the threshold distance D3; FIG. 4 is a diagram for explaining a first operation executed when there is no obstacle on the tentative route and the nearest neighbor distance D _min is less than the threshold distance D3; FIG. 4 is a diagram for explaining a first operation executed when there is no obstacle on the tentative route and the nearest neighbor distance D _min is less than the threshold distance D3; FIG. 10 is a diagram for explaining a second operation performed when there is no obstacle on the tentative course and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3; FIG. 10 is a diagram for explaining a second operation performed when there is no obstacle on the tentative course and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3; FIG. 10 is a diagram for explaining a second operation performed when there is no obstacle on the tentative course and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3; FIG. 10 is a diagram for explaining a second operation performed when there is no obstacle on the tentative course and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3; A diagram for explaining the third operation performed when an obstacle exists on the tentative course. A diagram for explaining the third operation performed when an obstacle exists on the tentative course. A diagram for explaining the third operation performed when an obstacle exists on the tentative course. A diagram for explaining the third operation performed when an obstacle exists on the tentative course.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, in different drawings, the same reference numerals are given to the same components. In addition, each drawing schematically shows each constituent element as a subject for easy understanding.

<Autonomous mobile device 100>
First, the configuration of the autonomous mobile device 100 according to the first embodiment of the present disclosure will be described. FIG. 1 is a diagram for explaining an autonomous mobile device 100. FIG.

The autonomous mobile device 100 is a device that autonomously moves so as to follow a follow-up target 200 that is a moving object. FIG. 1 shows that both the autonomous mobile device 100 and the object to be followed 200 are moving upward in the plane of the paper (the dashed lines shown in FIG. 1 indicate the paths of the autonomous mobile device 100 and the object to be followed 200). there). A specific example of the autonomous mobile device 100 is, for example, a wheelchair capable of autonomous travel, and is assumed to be ridden by a user. A specific example of the follow target 200 is, for example, a person different from the above-described user or a moving object (such as a vehicle) different from the autonomous mobile device 100 .

In the present embodiment, as shown in FIG. 1, the autonomous mobile device 100 is assumed to run along the left side of the target 200 to be tracked and follow it. However, the present invention is not limited to this, and the autonomous mobile device 100 may run alongside the tracked object 200 on the right side. Further, the autonomous mobile device 100 may have a follow-up mode in which the follow-up target 200 is followed, for example, in addition to the follow-up follow-up mode in which the follow-up target 200 is run on the left or right side of the follow-up target 200 .

Running side by side in the present invention means that the route of the autonomous mobile device 100 and the route of the object to be tracked 200 are parallel, and the route of the autonomous mobile device 100 and the object to be tracked 200 are in a direction perpendicular to the traveling direction of the object to be tracked 200. This means that the autonomous mobile device 100 moves together with the tracked object 200 while the distance from the route of is maintained at a predetermined distance _Dset . That is, the side-by-side running in the present invention is not limited to maintaining a state in which the autonomous mobile device 100 is positioned right and left beside the object 200 to be tracked, but maintains a position shifted forward and backward in the traveling direction from right beside the object 200 to be tracked. Including.

The predetermined distance D _set may be set, for example, to a distance that is shorter than the reach of each other, or a distance that is shorter than the distance that the users can hear each other, and a distance that is farther than a distance that does not hinder their movement.

Returning to the description of FIG. As shown in FIG. 1, the autonomous mobile device 100 includes a main body 1, a pair of driving wheels 2 and a pair of trailing wheels 3, an information processing section 4, a control section 5, an obstacle sensor 6, and a tracking target sensor 7. , and a course change detection sensor 8 .

A pair of driving wheels 2 and a pair of trailing wheels 3 are provided on the side surfaces of the main body 1 or the like. A drive device (not shown) is connected to the drive wheels 2 , and the autonomous mobile device 100 is moved by being driven under the control of the control unit 5 . A drive device (not shown) is, for example, a motor or an internal combustion engine. The trailing wheel 3 is a wheel for balancing the autonomous mobile device 100 so that it does not overturn, and may not be provided as long as the autonomous mobile device 100 can be balanced.

Based on the information from the obstacle sensor 6, the information processing section 4 detects the presence or absence of an obstacle existing around the autonomous mobile device 100, and the position of the obstacle if it exists. The information processing unit 4 also detects the position, moving speed, and orientation of the tracked target 200 as viewed from the autonomous mobile device 100 based on the information from the tracked target sensor 7 and the course change detection sensor 8 . Details of the functional configuration of the information processing unit 4 will be described later.

The control unit 5 controls the operation of the autonomous mobile device 100 based on information obtained from the information processing unit 4 . The details of the functional configuration of the control unit 5 and the processing executed by each functional configuration will be described later.

The obstacle sensor 6 acquires information about obstacles existing around the autonomous mobile device 100 . The information acquired by the obstacle sensor 6 is, for example, image information of the obstacle or the distance from the autonomous mobile device 100 to the surface of the obstacle. The obstacle sensor 6 is arranged, for example, on the front surface of the main body 1 as shown in FIG. The obstacle sensor 6 is composed of, for example, a ranging sensor such as a laser range finder, or an image sensor such as a stereo camera or a TOF (Time-of-Flight) camera. The distance from the autonomous mobile device 100 to the surface of the obstacle may be the distance from the center of the autonomous mobile device 100 to the surface of the obstacle, or the distance from the surface of the autonomous mobile device 100 including the user on board. to the surface of the obstacle.

The tracked object sensor 7 is arranged, for example, on the side surface of the main body 1 of the autonomous mobile device 100 and acquires information about the tracked object 200 . The information acquired by the tracking target sensor 7 is, for example, image information of the tracking target 200 and/or information related to the distance from the autonomous mobile device 100 to the tracking target 200 (hereinafter referred to as tracking target distance).

Similar to the obstacle sensor 6, the tracking target sensor 7 is composed of a ranging sensor such as a laser range finder, or an image sensor such as a stereo camera or a TOF camera. Alternatively, the tracking target sensor 7 may measure the tracking target distance by receiving radio waves or the like wirelessly transmitted from a position notification device such as a beacon attached in advance to the tracking target 200 . The arrangement position of the tracking target sensor 7 is not limited to the side surface of the main body 1. For example, the arrangement position and the sensor arrangement angle can be arbitrarily changed. Or you may make it change an angle suitably.

In the example shown in FIG. 1, the obstacle sensor 6 and the tracking target sensor 7 are provided independently of each other, but one sensor that serves both as the obstacle sensor 6 and the tracking target sensor 7 may be provided. However, in the present embodiment, the traveling direction (forward) of the autonomous mobile device 100 is different from the direction in which the tracked object 200 exists (lateral direction). Therefore, it is preferable that the obstacle sensor 6 and the tracking target sensor 7 are independent.

The course change detection sensor 8 is arranged, for example, on the side surface of the main body 1 of the autonomous mobile device 100, and acquires information for detecting the movement of the tracked object 200 to change the course. Similar to the obstacle sensor 6 or the tracking target sensor 7, the course change detection sensor 8 is composed of a ranging sensor such as a laser range finder, an image sensor such as a stereo camera or a TOF camera, and the like. In the example shown in FIG. 1, the tracking target sensor 7 and the route change detection sensor 8 are provided independently of each other. good.

The information acquired by the course change detection sensor 8 is used by a course change determination section 45 of the information processing section 4 to be described later to determine whether or not the tracked object 200 is about to change course.

In FIG. 1, the follow-up target sensor 7 and the course change detection sensor 8 are provided only on the right side of the main body 1, but the present invention is not limited to this. The tracking target sensor 7 and the course change detection sensor 8 may be provided only on the left side of the main body 1 or on both sides.

<Information processing unit 4>
FIG. 2 is a block diagram for explaining the functional configuration of the information processing section 4. As shown in FIG. As shown in FIG. 2, the information processing unit 4 includes a tracking target detection unit 41, an obstacle detection unit 42, a tracking target position detection unit 43, an obstacle position detection unit 44, a course change determination unit 45, A self-position detection unit 46 is provided.

The tracking target detection unit 41 determines whether or not the tracking target 200 exists around the autonomous mobile device 100 based on the information acquired by the tracking target sensor 7 .

When one sensor serves both as the obstacle sensor 6 and the tracked object sensor 7 , the information obtained from the sensor is a mixture of information about the obstacle and information about the tracked object 200 . Therefore, in such a case, the follow-up object detection unit 41 distinguishes between the obstacle and the follow-up object 200 based on the characteristic information indicating the shape of the follow-up object 200 stored in advance in a storage unit (not shown). good.

Based on the information acquired by the obstacle sensor 6, the obstacle detection unit 42 determines whether or not there is an obstacle around the autonomous mobile device 100, including on the route.

Based on the information acquired by the tracking target sensor 7, the tracking target position detection unit 43 detects the position of the tracking target 200 as seen from the autonomous mobile device 100, that is, the distance from the autonomous mobile device 100 to the tracking target 200, the distance from the autonomous mobile device 100 to the tracking target 200, Information such as the direction in which the object 200 to be followed as viewed from 100, the speed of movement of the object 200 to be followed, and the orientation of the object 200 to be followed is included.

The moving speed (relative speed) of the tracking target 200 may be calculated based on the moving speed of the autonomous mobile device 100 calculated based on, for example, a wheel speed sensor (not shown). Also, the orientation of the object to be tracked 200 may be specified, for example, based on an image from which the front, back, left and right of the object to be tracked 200 can be recognized. An image from which the front, back, left, and right of the object to be tracked 200 can be recognized is an image from which the positions of the face and shoulders can be recognized when the object to be tracked 200 is a person, and a wheel and a seat when the object to be tracked 200 is a vehicle. This is an image in which the positions of

Based on the information acquired by the obstacle sensor 6, the obstacle position detection unit 44 detects the position of the obstacle as seen from the autonomous mobile device 100, the direction of the obstacle as seen from the autonomous mobile device 100, and the position of the obstacle as seen from the autonomous mobile device 100. Identify the distance from 100 to the surface of the obstacle. When a plurality of obstacles exist around the autonomous mobile device 100, the obstacle position detector 44 identifies the positions of all obstacles within a predetermined range as seen from the autonomous mobile device 100, for example.

Based on the information acquired by the course change detection sensor 8, the course change determination unit 45 decides whether or not the tracked object 200 is about to change course. In other words, the course change determination unit 45 determines whether or not a sign of a course change in the tracked object 200 has been detected. Specifically, the route change determination unit 45 stores images of the tracked object 200 before and after the route is changed as viewed from the autonomous mobile device 100 in advance in a storage unit (not shown). By comparing the acquired image with the image in the storage unit, it is possible to determine whether or not a sign of course change has been detected. In addition, a learning model is created in advance by using, as teacher data, images of the tracked object 200 before and after the course is changed, which were acquired in the past. may determine whether or not a sign of course change has been detected.

Furthermore, the course change determination unit 45 identifies the traveling direction of the track target 200 after the course change based on the information acquired by the course change detection sensor 8 . As a method for specifying the traveling direction of the tracked object 200 after the course change, the orientation of the tracked object 200 is detected based on the information (image information) acquired by the course change detection sensor 8, and the traveling direction is determined based on the detected orientation. A method of specifying the number, etc. may be adopted.

The self-position detector 46 detects the current position of the autonomous mobile device 100 itself. The self-position detection unit 46 may detect the self-position using, for example, a GPS (Global Positioning System) or the like, or may estimate the self-position based on data obtained from various sensors.

The information processing unit 4 may be realized in software by executing a program by a computer, or may be realized in hardware such as a dedicated circuit. A computer that implements the information processing section 4 by a program may include, for example, a processor, an output device, a memory, a storage, and a power supply circuit. These components are connected to a bus and can communicate with each other. A processor is an example of a circuit or device with computing power. At least one of a CPU (Central Processing Unit), MPU (Micro Processing Unit), and GPU (Graphics Processing Unit) may be used for the processor, for example.

The functional blocks of the information processing unit 4, that is, the tracking target detection unit 41, the obstacle detection unit 42, the tracking target position detection unit 43, the obstacle position detection unit 44, the course change determination unit 45, and the self position detection unit 46 may be realized by executing a program by one computer. Moreover, each may be realized by independent hardware, or may be realized by executing a program by an independent computer.

<Control unit 5>
FIG. 3 is a block diagram for explaining the functional configuration of the control section 5. As shown in FIG. The control unit 5 includes a route determination unit 51 , a drive control unit 52 , a track target route estimation unit 53 , and an operation determination unit 54 .

The route determination unit 51 is based on the estimated route of the object to be tracked 200 estimated by the object route estimation unit 53 to be described later, the position of the object to be tracked 200 obtained by the information processing unit 4, and information on the positions of obstacles. , determine the course of the autonomous mobile device 100 .

The drive control unit 52 appropriately controls the drive wheels 2 to move the autonomous mobile device 100 .

When the course change determining unit 45 determines that the tracked object 200 is about to change its course, the tracked object route estimation unit 53 transmits information about the changed route and position information of the tracked object 200 to the information processing unit 4 . , and estimates the course of the tracked object 200 after the change. More specifically, the tracked object route estimator 53 detects the direction of the tracked object 200. For example, when it is detected that the direction of the tracked object 200 has changed by θ from the current estimated route, the tracked object 200 is A course in a direction rotated by θ around the current position of the target to be tracked from the current estimated route is estimated as the changed route of the target to be tracked 200 .

Based on the route of the autonomous mobile device 100 determined by the route determining unit 51 and the route estimated by the tracked object route estimating unit 53, the motion determining unit 54 determines the autonomous movement when the tracked object 200 is about to change its route. Determine the behavior of the mobile device 100 . The details of the method of determining the operation of the autonomous mobile device 100 will be described later.

As with the information processing unit 4, the control unit 5 may be realized in software by executing a program by a computer, or may be realized in hardware such as a dedicated circuit. A computer that implements the control unit 5 by a program may exemplarily include a processor, an output device, a memory, a storage, and a power supply circuit. These components are connected to a bus and can communicate with each other.

The route determination unit 51, the drive control unit 52, the track target route estimation unit 53, and the operation determination unit 54 may all be realized by executing a program by one computer. Moreover, each may be realized by independent hardware, or may be realized by executing a program by an independent computer.

In the example shown in FIG. 1, the information processing section 4 and the control section 5 have different configurations, but the present invention is not limited to this. That is, for example, the control by the control unit 5 and the determination by the information processing unit 4 may be performed by the same computer.

<Control of autonomous mobile device 100>
Next, a control method for the autonomous mobile device 100 will be described with reference to FIG. FIG. 4 is a flowchart showing a control method for the autonomous mobile device 100. As shown in FIG.

In step S<b>11 , the control unit 5 causes the autonomous mobile device 100 to follow the object 200 to be followed based on the direction and position of the object 200 to be moved. In order to cause the autonomous mobile device 100 to follow and move along with the target 200 to be followed, the control unit 5 executes the following processing.

That is, the control unit 5 estimates the current position and speed of the object 200 to be tracked, the position of the object 200 to be tracked after a predetermined minute time, and moves a predetermined distance from the estimated position in a direction perpendicular to the traveling direction of the object 200 to be tracked. A position separated by a distance D is set as a target position. Then, the control unit 5 controls the drive control unit 52 so that the autonomous mobile device 100 can reach its target position after a short period of time. And the control part 5 repeats the said control at any time. The moving speed, traveling direction and position of the tracked object 200 are obtained based on the detection result of the tracked object detection unit 41 of the information processing unit 4 described above. obtained by In the following description, a state in which the autonomous mobile device 100 runs side by side with the target 200 to follow and moves is referred to as a side-by-side tracking state.

In step S<b>12 , the control unit 5 causes the route change determination unit 45 to determine whether or not a sign of a change in the route of the object 200 to be tracked has been detected. If it is determined that a sign of a course change of the tracked object 200 has been detected (step S12: YES), the control unit 5 advances the process to step S13. On the other hand, otherwise (step S12: NO), the control unit 5 returns the process to step S11. That is, unless the target 200 to be tracked detects a sign of a course change, the control unit 5 maintains the state in which the autonomous mobile device 100 is running alongside the target 200 to be tracked.

In step S13, the tracking target route estimation unit 53 of the control unit 5 estimates the changed route of the tracking target 200 after the route change based on the detection results of the tracking target detection unit 41 and the tracking target position detection unit 43. . In the following description, the course of the tracked object 200 after the course change estimated in step S13 is referred to as an estimated course. The estimated course is an example of the first course of the present invention.

In step S14, the route determining unit 51 of the control unit 5 determines the estimated route of the object to be tracked 200, the position of the object to be tracked 200 obtained by the information processing unit 4, and the information on the positions of obstacles. Determine 100 tentative routes. The provisional course of the autonomous mobile device 100 means that, when it is assumed that the tracked object 200 after the course change moves along the estimated course estimated in step S13, the parallel running following state is maintained with respect to the tracked object 200 after the course change. It is a new course for For example, the tentative course is determined as a course parallel to the direction of travel of the estimated course of the tracked object 200 and separated by a predetermined distance D _set in a direction perpendicular to the direction of travel of the estimated course. be done. A provisional course is an example of a second course in the present invention.

In step S15, the operation determination unit 54 of the control unit 5 detects an obstacle whose distance to a point on the temporary course of the autonomous mobile device 100 is less than a predetermined threshold distance D2 within a predetermined threshold distance D1 from the current position. Determine if an object exists. The predetermined threshold distances D1 and D2 are preset distances, and D1>D2. In particular, the threshold distance D2 is a distance (for example, about 50 cm) at which a person riding the autonomous mobile device 100 does not come into contact with an obstacle. If it is determined that there is an obstacle on the temporary route (step S15: YES), the controller 5 proceeds to step S113, otherwise (step S15: NO), it proceeds to step S16. In the following description, the existence of an obstacle whose distance from a point on the temporary course of the autonomous mobile device 100 is less than the predetermined threshold distance D2 is simply defined as the existence of an obstacle on the temporary course. and described.

In step S16, the operation determination unit 54 of the control unit 5 calculates the closest distance between a point on the estimated course of the tracking target 200 and the current position of the autonomous mobile device 100 (hereinafter referred to as the closest distance D _min ). Then, it is determined whether or not this nearest neighbor distance _Dmin is equal to or greater than a predetermined threshold distance D3. The predetermined threshold distance D3 is a distance set in advance and is less than the predetermined distance _Dset . The threshold distance D3 is an example of the first distance of the invention. If the nearest neighbor distance D _min is greater than or equal to the threshold distance D3 (step S16: YES), the control unit 5 proceeds to step S18, otherwise (step S16: NO), proceeds to step S17.

As described above, it is determined in step S15 that there is no obstacle whose distance from a certain point on the temporary course is less than the threshold distance D2, and in step S16 the nearest neighbor distance _Dmin is less than the threshold distance D3. If so, the process proceeds to step S17. A case where the nearest neighbor distance D _min is less than the threshold distance D3 is a case where the autonomous mobile device 100 hinders the movement of the tracked object 200 after the course change.

In such a case, in step S17, the operation determination unit 54 of the control unit 5 moves the autonomous mobile device 100 to the intersection I1 between the current route of the autonomous mobile device 100 and the temporary route determined in step S14 ( First operation to be described later) is determined. As a result, it is possible to avoid a situation in which the autonomous mobile device 100 interferes with the movement of the tracked target 200 after the course change.

On the other hand, in step S15, it is determined that there is no obstacle whose distance from a certain point on the temporary course is less than the threshold distance D2, and in step S16, it is determined that the nearest neighbor distance D _min is greater than or equal to the threshold distance D3. If so, the process proceeds to step S18. Note that when the nearest neighbor distance D _min is equal to or greater than the threshold distance D3, the autonomous mobile device 100 does not hinder the movement of the tracked target 200 after the course change.

In such a case, in step S18, the operation determination unit 54 of the control unit 5 determines to stop the autonomous mobile device 100 on the spot until the tracking target 200 starts moving along the changed route. . In addition, the spot means the position of the autonomous mobile device 100 at the time when the sign of the track change of the tracked object 200 is detected.

In step S19, the motion determination unit 54 of the control unit 5 monitors the object to be tracked 200 and determines whether or not it has started to move along the estimated course. If it is determined that the object 200 to be tracked has started moving along the estimated course (step S19: YES), the control unit 5 advances the process to step S110; otherwise (step S19: NO), the process advances to step S112. proceed.

In step S110, the operation determination unit 54 of the control unit 5 controls the drive control unit 52 so that the autonomous mobile device 100 turns on the spot in accordance with the traveling direction of the track target 200 after the course change. As a result, the traveling direction of the autonomous mobile device 100 and the traveling direction of the tracked object 200 match. Note that the turning motion of the autonomous mobile device 100 may be performed, for example, by rotating the pair of drive wheels 2 in opposite directions at the same speed.

In step S<b>111 , the operation determination unit 54 of the control unit 5 determines the future course of the autonomous mobile device 100 to be the provisional course, and causes the autonomous mobile device 100 to transition again to the state of parallel running and following the tracking target 200 .

In step S<b>112 , the operation determination unit 54 of the control unit 5 determines whether or not the autonomous mobile device 100 can maintain the state of following the tracking target 200 . If it is determined that the parallel running tracking state can be maintained (step S112: YES), the control unit 5 returns the process to step S11, otherwise (step S112: NO), ends the process.

Step S113 is a step that is executed when it is determined in step S15 that an obstacle exists on the temporary route. In step S113, the operation determination unit 54 of the control unit 5 corrects the provisional route determined in step S14, and determines a corrected provisional route passing through a position separated from the obstacle by a threshold distance D2 or more.

In step S114, the operation determination unit 54 of the control unit 5 moves the autonomous mobile device 100 to the intersection point I2 between the current route of the autonomous mobile device 100 and the corrected temporary route determined in step S113. This avoids a situation in which the movement of the autonomous mobile device 100 is hindered by obstacles.

In step S<b>115 , the operation determination unit 54 of the control unit 5 determines whether or not the autonomous mobile device 100 can maintain the state of following the tracking target 200 . When determining that the side-by-side tracking state can be maintained (step S115: YES), the operation determination unit 54 returns the process to step S13, otherwise (step S115: NO), ends the process.

With the above-described control, when the tracked object 200 attempts to change its course while the autonomous mobile device 100 is running side-by-side with the tracked object 200, regardless of the presence or absence of obstacles, the changed course of the tracked object 200 is changed. Together, the course of the autonomous mobile device 100 can be determined.

Below, how the autonomous mobile device 100 actually operates under the control described with reference to FIG. 4 will be described with a specific example.

<First Operation: When there is no obstacle and the nearest neighbor distance D _min is less than the threshold distance D3>
First, when there is no obstacle on the temporary course of the autonomous mobile device 100 and the nearest neighbor distance D _min is less than the threshold distance D3, that is, the operation executed in the processing of step S17 in the flowchart of FIG. 1 operation) will be described.

5A to 5D are diagrams for explaining the first operation performed when there is no obstacle on the tentative route and the nearest neighbor distance D _min is less than the threshold distance D3. In FIGS. 5A to 5D, FIGS. 6A to 6D, and FIGS. 7A to 7D, which will be described later, the directions of the autonomous mobile device 100 and the object to be followed 200 are shown with a square on the front side.

FIG. 5A shows the autonomous mobile device 100 that runs alongside and follows a tracking target 200 that is traveling straight ahead. In the example shown in FIG. 5A , the autonomous mobile device 100 moves following the target 200 to the left of the target 200 to be tracked and at a distance _Dset . In FIG. 5A, the current estimated course C _{200_p} of the tracked object 200 and the course C _{100_p} of the autonomous mobile device 100 are indicated by dashed arrows.

FIG. 5B shows a state in which the tracked object 200 that has been moving along the course C _{200_p} is about to change course (processing of step S13 in FIG. 4). In FIG. 5B, the orientation of the tracked object 200 is changed by θ1 with respect to the estimated course C _{200_p} . In such a case, the autonomous mobile device 100 changes the estimated course C 200_n1 after the change of the tracked object 200 from the estimated course C _{200_p} of the tracked object 200 to the direction rotated by θ1 around the current position of the tracked object ₂₀₀ . presume.

Then, the autonomous mobile device 100 calculates the minimum value (nearest distance) D _min of the distance between the changed estimated course C _{200_n1} of the tracking target 200 and the current position of the autonomous mobile device 100 . In the example shown in FIG. 5B, the nearest neighbor distance D _min is less than the threshold distance D3, and when the tracking target 200 moves along the changed course C _{200_n1} , the autonomous mobile device 100 hinders movement. ing.

In such a case, the autonomous mobile device 100 maintains a position separated by a distance D _set from the estimated course C _{200_n1} based on the changed estimated course C _{200_n1} of the tracking target 200. The new course of the autonomous mobile device 100 (Provisional course) C _{100_n1} is determined (process of step S14 in FIG. 4). Then, as shown in FIG. 5C, the autonomous mobile device 100 moves to an intersection point I1 between the current course C _{100_p} and the temporary course C _{100_n1} (process of step S17 in FIG. 4). An arrow A1 illustrated in FIG. 5C is an arrow indicating movement of the autonomous mobile device 100 to the intersection point I1. As shown in FIG. 5C, the position of the intersection point I1 is a position slightly retreated along the initial course C _{100_p} from the position of the autonomous mobile device 100 at the time when the change of course of the tracked object 200 was detected. As a result, it is possible to avoid a situation in which the autonomous mobile device 100 interferes with the movement of the tracked target 200 after the course change.

After that, as shown in FIG. 5D, the autonomous mobile device 100 performs a turning motion so as to face the same direction as the follow target 200 (process of step S110 in FIG. 4). Thereafter, when the tracked object 200 starts moving along the changed estimated course C _{200_n1} , the autonomous mobile device 100 also starts moving along the provisional course C _{100_n1} (process of step S111 in FIG. 4). With such a first operation, even if the object to be followed 200 tries to change the course toward the autonomous mobile device 100 in the side-by-side tracking state, the movement of the object to be followed 200 after changing the course is not hindered. You can keep track.

<Second operation: when there is no obstacle and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3>
Next, when there are no obstacles on the temporary course of the autonomous mobile device 100 and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3, that is, when the process of S18 is executed in the flowchart of FIG. The second operation performed will be described.

6A to 6D are diagrams for explaining the second operation performed when there is no obstacle on the tentative route and the nearest neighbor distance D _min is equal to or greater than the threshold distance D3.

Similar to FIG. 5A, FIG. 6A shows the autonomous mobile device 100 that runs alongside and follows the tracking target 200 that is traveling straight ahead.

FIG. 6B shows a state in which the follow-up target 200 that has been moving along the course C _{200_p} is about to change course (process of step S13 in FIG. 4). In FIG. 6B, the orientation of the tracked object 200 is changed by θ2 with respect to the estimated course C _{200_p} . The autonomous mobile device 100 estimates the changed estimated course C _{200_n2} of the tracked object 200 in a direction rotated by θ2 about the current position of the tracked object 200 from the estimated course C _{200_p} of the tracked object 200 .

Then, the autonomous mobile device 100 calculates the minimum value (nearest distance) D _min of the distance between the changed estimated course C _{200_n2} of the tracking target 200 and the current position of the autonomous mobile device 100 . In the example shown in FIG. 6B, the nearest neighbor distance D _min is equal to or greater than the threshold distance D3, and the autonomous mobile device 100 does not hinder the movement of the tracked object 200 along the changed course C _{200_n2} .

In such a case, the autonomous mobile device 100 maintains a position separated by a distance D _set from the estimated course C _{200_n1 based on the changed estimated course C 200_n2 of} the tracking target 200. The new course of the autonomous mobile device 100 (Provisional course) C _{100_n2} is determined (process of step S14 in FIG. 4). Then, the autonomous mobile device 100 stops at the current position (process of step S18 in FIG. 4).

Thereafter, as shown in FIG. 6D, the autonomous mobile device 100 performs a turning motion so as to face the same direction as the target 200 to be tracked (process of step S110 in FIG. 4). After that, assuming that the tracked object 200 starts moving along the changed estimated course C _{200_n2} , the autonomous mobile device 100 starts moving toward the provisional course C _{100_n2} (process of step S111 in FIG. 4). . An arrow A2 shown in FIG. 6D is an arrow showing an example of movement toward the provisional course C _{100_n2} after the course change. Due to such a second operation, when the track target 200 changes its course in a direction that does not hinder the movement of the autonomous mobile device 100 in the side-by-side tracking state, the autonomous mobile device 100 also moves along with the track change of the track target 200. You can change course smoothly.

In the above description, as an example of the second operation, as shown in FIGS. 6A to 6D, the case where the tracked object 200 changes its course in the direction in which the autonomous mobile device 100 exists has been described. However, even when the tracked object 200 changes course in the opposite direction to the autonomous mobile device 100, the autonomous mobile device 100 may perform the second operation.

<Third Action: When there is an obstacle on the temporary route>
Next, the third operation performed when there is an obstacle on the temporary course of the autonomous mobile device 100, that is, when the process of S113 is executed in the flowchart of FIG. 4 will be described.

7A to 7D are diagrams for explaining the third operation performed when the obstacle 300 exists on the tentative route.

Similar to FIGS. 5A and 6A, FIG. 7A shows the autonomous mobile device 100 that runs alongside and follows the tracking target 200 that is traveling straight ahead.

FIG. 7B shows a state in which the follow-up target 200 that has been moving along the course C _{200_p} is about to change course (process of step S13 in FIG. 4). In FIG. 7B, the orientation of the tracked object 200 is changed by θ3 with respect to the estimated course C _{200_p} . The autonomous mobile device 100 estimates the changed estimated course C _{200_n3} of the tracked object 200 in a direction rotated by θ3 about the current position of the tracked object 200 from the estimated course C _{200_p} of the tracked object 200 .

Then, the autonomous mobile device 100 maintains a position separated by a distance D _set from the estimated course C _{200_n1} based on the changed estimated course C _{200_n3} of the tracked object 200, a new course (provisional course) of the autonomous mobile device 100 ) Determine C _{100_n3} (process of step S14 in FIG. 4). Then, the autonomous mobile device 100 detects that an obstacle 300 exists on the temporary course C _{100_n3} within the threshold distance D1 from the current position (step S15 in FIG. 4: YES). In such a case, since the autonomous mobile device 100 cannot actually move on the temporary route, regardless of whether or not the existence of the autonomous mobile device 100 hinders the movement of the tracked object 200 after changing the route, It becomes necessary to correct the provisional course.

Therefore, as shown in FIG. 7C, the autonomous mobile device 100 determines a corrected temporary course C _{100_n3_r} that passes through a position separated by a threshold distance D2 or more from the detected obstacle 300 based on the temporary course C _{100_n3} ( process of step S113 in FIG. 4). Then, the autonomous mobile device 100 moves to the intersection point I2 between the current course C _{100_p} and the corrected provisional course C _{100_n3_r} (process of step S114 in FIG. 4). As shown in FIG. 7C, the position of the intersection point I2 is a position slightly forward along the initial course C _{100_p} from the position of the autonomous mobile device 100 at the time when the change of course of the tracked object 200 was detected. As a result, it is possible to prevent the autonomous mobile device 100 from contacting the obstacle 300 after the course change.

It should be noted that the movement of the autonomous mobile device 100 moving forward while avoiding the obstacle 300 may be an unpredictable movement for the target 200 to be tracked. Therefore, before performing the forward motion, the autonomous mobile device 100 notifies the follow target 200 of moving forward by means of not shown notification means (audio output from a speaker, lighting or blinking of a lamp, etc.). You may do so.

Then, as shown in FIG. 7D, the autonomous mobile device 100 moves to the intersection point I2. An arrow A3 illustrated in FIG. 7D is an arrow indicating movement of the autonomous mobile device 100 to the intersection point I2. The follow-up target 200 that sees the autonomous mobile device 100 move to the intersection point I2 should notice the need to correct its course. Therefore, after that, the autonomous mobile device 100 re-estimates the changed course of the tracking target 200, and the size of the closest distance D _min between the re-estimated estimated course of the tracking target 200 and the autonomous mobile device 100 Based on this, the process shifts to the above-described first operation or second operation.

<Action/effect>
As described above, the autonomous mobile device 100 according to the embodiment of the present invention is the autonomous mobile device 100 that moves following the target 200 while running side by side with the target 200. A tracked object track estimator 53 that estimates a first track, which is the changed track of the tracked object 200, when a sign that the tracked object 200 is about to change course is detected, and an assumption that the tracked object 200 moves along the first track. A route determining unit 51 that determines a second route for the autonomous mobile device 100 to move while running side by side with the object 200 to be tracked, and the position and first route of the autonomous mobile device 100 at the time of detecting the sign. and a motion determination unit 54 that determines whether to stop the autonomous mobile device 100 at a position until the tracked object 200 starts moving along the changed route, based on .

With such a configuration, when the object to be followed 200 tries to change its course in the parallel running following state, it is possible to smoothly change its own course according to the object to be followed 200 and maintain the parallel running following state. can. Thereby, the convenience of the autonomous mobile device 100 is improved.

Further, according to the autonomous mobile device 100 according to the embodiment of the present invention, the motion determination unit 54 determines that the minimum value D _min of the distance between the position of the autonomous mobile device 100 and the first route at the time of detecting the sign is If the distance is greater than or equal to the first distance D3, the autonomous mobile device 100 is stopped at the position of the autonomous mobile device 100 when the sign is detected until the track target 200 starts moving along the changed route. decide.

With such a configuration, the autonomous mobile device 100 can smoothly change its own course in accordance with the tracked object 200 when the tracked object 200 tries to change its course, and can maintain the parallel running following state. can be done.

Further, according to the autonomous mobile device 100 according to the embodiment of the present invention, the motion determination unit 54 determines that the minimum value D _min of the distance between the position of the autonomous mobile device 100 and the first route at the time of detecting the sign is If the distance is less than the first distance D3, it is determined to move the autonomous mobile device 100 to the intersection of the route of the autonomous mobile device before detecting the sign and the second route.

With such a configuration, when the autonomous mobile device 100 tries to change the course to a course that hinders the movement of the autonomous mobile device 100, the autonomous mobile device 100 moves to a position that does not hinder the movement of the tracking target 200. can be moved. As a result, the tracked object 200 and the autonomous mobile device 100 can smoothly change course.

The autonomous mobile device 100 described above can move side by side with facility staff or family members while the user is on the autonomous mobile device 100, for example, in facilities such as nursing care sites and commercial facilities. This has the effect of increasing communication between users (care recipients) and facility staff or family members (caregivers), and increasing the user's sense of psychological closeness. User satisfaction can be expected.

INDUSTRIAL APPLICABILITY The present invention is useful for an autonomous mobile device that moves autonomously while following an object while running alongside the object.

1 Main Body 2 Drive Wheel 3 Follower Wheel 4 Information Processing Unit 5 Control Unit 6 Obstacle Sensor 7 Followed Object Sensor 8 Course Change Detection Sensor 41 Followed Object Detector 42 Obstacle Detector 43 Followed Object Position Detector 44 Obstacle Position Detector 45 Course change determination section 46 Self-position detection section 51 Course determination section 52 Drive control section 53 Track target course estimation section 54 Motion determination section 100 Autonomous mobile device 200 Track target 300 Obstacle

Claims (6)

An autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked,
a tracked object route estimating unit that estimates a first route, which is the changed route of the tracked object, when a sign that the tracked object is about to change its route is detected;
a route determination unit that determines a second route of the autonomous mobile device for moving in parallel with the object to be tracked, assuming that the object to be tracked moves along the first route;
Based on the position of the autonomous mobile device and the first route at the time when the sign is detected, whether the autonomous mobile device is stopped at the position until the tracking target starts moving along the changed route. an operation determination unit that determines whether
has
When the minimum value of the distance between the position and the first route is greater than or equal to the first distance, the motion determination unit causes the autonomous mobile device to move until the target to be tracked starts moving along the changed route. determining to stop at said position;
Autonomous mobile device. An autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked,
a tracked object route estimating unit that estimates a first route, which is the changed route of the tracked object, when a sign that the tracked object is about to change its route is detected;
a route determination unit that determines a second route of the autonomous mobile device for moving in parallel with the object to be tracked, assuming that the object to be tracked moves along the first route;
Based on the position of the autonomous mobile device and the first route at the time when the sign is detected, whether the autonomous mobile device is stopped at the position until the tracking target starts moving along the changed route. an operation determination unit that determines whether
has
When the minimum value of the distance between the position and the first course is less than the first distance, the motion determination unit sets the autonomous mobile device to the course of the autonomous mobile device before detecting the sign and the determine to move to the intersection with the second path ;
Autonomous mobile device. An autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked,
a tracked object route estimating unit that estimates a first route, which is the changed route of the tracked object, when a sign that the tracked object is about to change its route is detected;
a route determination unit that determines a second route of the autonomous mobile device for moving in parallel with the object to be tracked, assuming that the object to be tracked moves along the first route;
an obstacle detection unit that determines whether or not there is an obstacle that hinders movement when the autonomous mobile device is assumed to move along the second route;
Based on the position of the autonomous mobile device and the first route at the time when the sign is detected, whether the autonomous mobile device is stopped at the position until the tracking target starts moving along the changed route. an operation determination unit that determines whether
has
When determining that the obstacle exists, the course determination unit determines a modified second course by correcting the second course so that the obstacle does not hinder movement,
The motion determination unit determines to move the autonomous mobile device to an intersection of the route of the autonomous mobile device before detecting the sign and the modified second route .
Autonomous mobile device. A control method for an autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked,
estimating a first course, which is the changed course of the tracked object, when a sign that the tracked object is about to change course is detected;
determining a second route of the autonomous mobile device for moving in parallel with the object to be tracked, assuming that the object to be tracked moves along the first route;
Based on the position of the autonomous mobile device and the first route at the time when the sign is detected, whether the autonomous mobile device is stopped at the position until the tracking target starts moving along the changed route. decide whether or not
When determining whether or not to stop the autonomous mobile device at the position, if the minimum value of the distance between the position and the first course is greater than or equal to the first distance, the track after the change of the tracked object. determining to stop the autonomous mobile device at the position until it begins to move along
control method. A control method for an autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked,
estimating a first course, which is the changed course of the tracked object, when a sign that the tracked object is about to change course is detected;
determining a second route of the autonomous mobile device for moving in parallel with the object to be tracked, assuming that the object to be tracked moves along the first route;
Based on the position of the autonomous mobile device and the first route at the time when the sign is detected, whether the autonomous mobile device is stopped at the position until the tracking target starts moving along the changed route. decide whether or not
When determining whether or not to stop the autonomous mobile device at the position, if the minimum value of the distance between the position and the first course is less than the first distance, the autonomous mobile device is set to the predictor. Determine to move to the intersection of the route of the autonomous mobile device before detecting and the second route,
control method. A control method for an autonomous mobile device that moves while following a target to be tracked while running side by side with the target to be tracked,
estimating a first course, which is the changed course of the tracked object, when a sign that the tracked object is about to change course is detected;
determining a second route of the autonomous mobile device for moving in parallel with the object to be tracked, assuming that the object to be tracked moves along the first route;
Determining whether or not there is an obstacle that hinders movement when the autonomous mobile device is assumed to move along the second route,
Based on the position of the autonomous mobile device and the first route at the time when the sign is detected, whether the autonomous mobile device is stopped at the position until the tracking target starts moving along the changed route. decide whether or not
When determining whether or not the obstacle exists, if it is determined that the obstacle exists, a modified second course is determined by correcting the second course so that the obstacle does not hinder movement. death,
When determining whether or not to stop the autonomous mobile device at the position, the autonomous mobile device is moved to an intersection of the course of the autonomous mobile device before detecting the sign and the modified second course. to determine,
control method.

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