JP2002244735A - Autonomous running robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an autonomous running robot running autonomously on the inside of a predetermined running zone and capable of detecting the approach to a boundary line in the predetermined zone beforehand to take a measure for changing over a running direction. SOLUTION: This autonomous running robot detects an end point on an edge 20 which becomes the boundary line of the running zone by an optical sensor 3 while recognizing its own position based on rotation amount of wheels 11 to prepare data base expressing a position of the edge 20 by coordinate data. In the preparation of the data base, the processing for connecting both end points mutually when a distance between two adjacent end points is smaller than a predetermined value is repeated, and when a closed loop is formed by the processings, coordinate data of the closed loop is registered in the data base as coordinate data of the boundary line. Then, running is controlled so that the robot does not deviate from the edge 20 based on the data base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an autonomous traveling robot which autonomously travels inside a predetermined traveling area and exhibits a desired function.

[0002]

2. Description of the Related Art For example, a robot installed on a table in a dining room or living room and running so as not to fall off the table is equipped with an optical sensor for detecting the edge of the table. In general, the robot recognizes that the robot has approached the edge of the table based on the detection signal and changes the traveling direction.

[0003]

However, in a conventional general autonomous traveling robot, traveling is controlled while detecting a boundary of a predetermined traveling area such as an edge of a table. At the time of detection, it has already reached just before the boundary line, and when the traveling speed is high, there is a possibility that the boundary line may be overrun and fall from, for example, a table.

It is an object of the present invention to provide an autonomous traveling robot capable of detecting approaching a boundary of a traveling area in advance and reducing the traveling speed or changing the traveling direction. is there.

[0005]

An autonomous mobile robot according to the present invention includes a position recognition means for recognizing a position of the autonomous mobile robot in an autonomous driving process, and a robot reaching or approaching a boundary of a running area in the autonomous driving process. Detection means for detecting that the vehicle has been driven, first traveling control means for controlling autonomous traveling based on a detection signal obtained from the boundary detection means, and database creation for creating a database representing the position of the boundary line by coordinate data Means, and second traveling control means for controlling traveling based on the created database and the recognition signal from the position recognizing means so as not to deviate from the traveling area. The database creating means, based on the recognition signal obtained from the position recognition means when a detection signal is obtained from the boundary detection means, while detecting the coordinate position of an end point representing a position on or near the boundary line, Adjacent 2
When the distance between the two end points is smaller than a predetermined value, the process of connecting the end points to each other is repeated. When a closed loop is formed by this, the coordinate data of the closed loop is registered in the database as the coordinate data of the boundary line.

In the above-mentioned autonomous mobile robot of the present invention, the autonomous mobile at low speed is performed under the control of the first running control means. In this process, when approaching the boundary of the running area, the position is set to the end point. Detected as coordinate position,
As a result, when a closed loop is formed by a plurality of end points, the closed loop is recognized as the position of the boundary line.

As the distance between the two end points when two adjacent end points are joined, for example, an interval between two wheels constituting a traveling mechanism of the robot can be adopted. If the distance between the two end points is less than this, even if a space exists between the two end points, the space can be straddled by the two wheels, and there is almost no risk of falling.

After the position of the boundary is recognized, autonomous traveling at high speed is performed under the control of the second traveling control means. That is, the approach to the boundary line is detected in advance based on the current position of the vehicle and the position of the boundary line, and measures such as deceleration and turning are performed.

[0009] In a specific configuration, the database creating means creates a bidirectional list including, for a plurality of endpoints connected to each other, coordinate information of each endpoint and connection information of the endpoints. Here, when the newly detected end point X is not adjacent to the end point of any other bidirectional list at a distance equal to or less than the predetermined value, the coordinate information of the newly detected end point X is used as a new bidirectional list. to add. As a result,
If the newly detected end point X is adjacent to one end point A in the bidirectional list at a distance equal to or less than the predetermined value, and there is no end point adjacent to the end point A, the newly detected end point X Is added next to the end point A. As a result, the end point X and the end point A are connected.

The database creating means may be arranged so that the newly detected end point X is adjacent to one end point A in the bidirectional list at a distance equal to or less than the predetermined value.
When the other end point B is adjacent to the end point A, the angle between the vector V (A, X) from the end point A to the end point X and the vector V (A, B) from the end point A to the end point B is 90 degrees. If it exceeds the degree, a connection path from the end point B to the end point X via the end point A is formed, and the vector V (A, X) and the vector V (A, B)
If the angle does not exceed 90 degrees, a connection path from the end point B to the end point A via the end point X is formed. As a result, when a new end point X is to be connected to the two end points A and B already in the connection relation, the connection partner is appropriately selected, and the connection relation between these three end points A, B, and X is determined. You.

The database creation means may be arranged so that the newly detected end point X is adjacent to one end point A in the bidirectional list at a distance equal to or less than the predetermined value.
If the other two end points B and C are adjacent to each other, the end point X
When the distance D (X, B) between the end point B and the end point B is smaller than the distance D (X, C) between the end point X and the end point C, the end point X is interposed between the end points A and B. Form a path and distance D
When (X, B) is larger than the distance D (X, C), the end point A
Between the end point C and the end point C. As a result, the three end points A which are already in the connection relationship,
When the new endpoint X is to be attached to B and C, the binding partner is appropriately selected, and these four endpoints A, B,
The coupling relationship between C and X is determined.

[0012] Further, when the newly detected end point X is added to the bidirectional list, the database creating means may generate the end points D recorded at both ends of all the bidirectional lists.
If there is an adjacent end point D whose distance D (D, X) to the newly detected end point X is equal to or less than the predetermined value, the bidirectional list including the end point D and the newly detected end point X The two-way list including X is connected so that the information of the end point D and the information of the end point X are adjacent to each other. This allows two bidirectional lists to be
Connected to each other via the newly detected end point X,
They will be merged into one bidirectional list.

[0013]

According to the autonomous mobile robot according to the present invention, the approach to the boundary can be detected in advance by creating a database representing the position of the boundary of the running area. It is possible to take measures such as dropping the vehicle or changing the traveling direction.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG.
The autonomous mobile robot (1) according to the present invention is installed on a table (2) and autonomously runs so as not to fall off the table (2). As shown in FIG. The pair of left and right wheels (11) (11) comes out,
Optical sensors (3) for detecting the edge (20) of the table (2) are provided at four positions in front, rear, left and right. In this embodiment, the edge (20) is used as the contour shape of the table (2).
If the tangent at any point on the top is an edge (2
Suppose something that does not intersect with (0).

FIG. 3 shows an autonomous mobile robot according to the present invention.
It shows the drive system of (1), and each wheel (11) has a speed reduction mechanism
Motors (13) are connected via (12), and each motor (13)
Is connected to a rotary encoder (14) for detecting the rotation angle of the wheel (11).

As shown in FIG. 4, a pair of left and right rotary encoders (14) and (14) and four optical sensors (3) (3) (3) (3) are connected to a control circuit (4) comprising a microcomputer. ing. A memory (41) for storing a database described later is connected to the control circuit (4). Control circuit
(4) creates a control signal for controlling the rotation of the pair of left and right motors (13) and (13) by executing a control procedure described later, and supplies the control signal to each motor (13). Thereby, the autonomous mobile robot (1) moves inside the running area, that is, the table (2).
Autonomously runs inside the edge (20) of the vehicle, and performs its intended function.

FIG. 5 shows an edge (20) by the optical sensor (3).
When the optical sensor moves from the position shown in FIG. 3A to the position shown in FIG. 3B, one optical sensor is detected.
(3a) approaches the edge (20) and the optical sensor (3a)
Detects the edge (20). Therefore, the coordinate position of the end point on the edge (20) can be detected based on the current position of the robot at this time and the position of the optical sensor (3a) that has detected the edge (20).

The autonomous mobile robot (1) can recognize its own current position based on signals obtained from the rotary encoders (14) and (14). That is, the autonomous mobile robot (1) has a map of the (xy) coordinate system shown in FIG. 6 in the memory (41), and the center point of both wheels (11) and (11) is the origin ( (0,0), the position and orientation of the axle direction in the x-axis direction and the direction orthogonal to the axle in the y-axis direction are set as the initial state, and the rotary encoder is used in the subsequent autonomous traveling process.
(14) Based on the signal obtained from (14), its own position and orientation are calculated. In the process of autonomous driving, the edge (2
0) When the upper end point X is detected, the coordinate data of the end point is detected.
(x, y) is recognized and registered in the map.

FIG. 7 shows a control circuit of the autonomous mobile robot (1).
(4) represents a control procedure executed during traveling. First, in step S1, a map initialization process is performed.
In the initialization, as described above, the center point of both wheels
(0, 0), the axle direction is set to the x-axis, and the direction orthogonal thereto is set to the y-axis. Next, in step S2, the traveling mode of the autonomous traveling robot is set to the low-speed traveling mode, and in step S3, a predetermined action involving movement is executed. And
In step S4, it is determined whether or not an end point has been detected. If the determination is no, the process returns to step S3 to continue the predetermined action. Thereafter, when it is determined “yes” in step S4, the process proceeds to step S5, where the newly detected end point is set.
(X) is recorded in a database in the memory (41).

Subsequently, in step S6, an end point connection process described later is executed to connect a plurality of end points to each other by end lines. Then, in step S7, it is determined whether or not a closed area is formed by the end points and the end lines. If the determination is NO, the process returns to step S3 to repeat the end point detection and end point combining processing. Thereafter, when it is determined YES in step S7, the process proceeds to step S8, in which a safe area in which the autonomous mobile robot can move is determined, and in step S9, the driving mode is set to the high-speed moving mode. Perform predetermined activities in the safety domain.

FIGS. 8 and 9 show the procedure of the end point combining process, and FIGS. 10 to 17 illustrate a state where a plurality of end points are combined in the database. In the database, as shown in FIG. 10A, data (x, y) indicating the x-coordinate value and the y-coordinate value of one end point is recorded as end point information, and is represented by a bidirectional arrow. The connection state of the two end points is recorded as connection information.
A set of unconnected end points and a plurality of end points connected to each other constitutes one bidirectional list, and map information is represented by a set of a plurality of bidirectional lists.

First, in step S11 of FIG. 8, an end point A closest to the newly detected end point X is searched from the database. For example, in the example of FIG. 10B, the end point A closest to the newly detected end point X is searched. Next, in step S12 of FIG. 8, the distance D (A, X) between the end point A and the end point X is calculated, and the value is larger than the wheel width W (see FIG. 6) of the autonomous mobile robot (1). It is determined whether or not. If the determination is yes here, the process proceeds to step S21 in FIG. 9 to create a new bidirectional list and add the endpoint information X (case). For example, as shown in FIG. 10B, the distance D (A, X) between the newly detected endpoint X and the nearest endpoint A is the wheel width W.
If it is larger than this, the information of the end point X is added to the map information as shown in FIG.

On the other hand, when it is determined NO in step S12 of FIG. 8, the process proceeds to step S13, and the number of the endpoints adjacent to the endpoint A in the bidirectional list L including the information of the endpoint A is zero. Determine whether or not. If the determination is yes here, the process proceeds to step S22 in FIG.
Information of the end point X is added next to the end point A in the bidirectional list L (case). For example, when the distance D (A, X) between the newly detected end point X and the closest end point A is smaller than the wheel width W as shown in FIG. 11B, as shown in FIG. , The information of the end point X is added, and the end point A and the end point X are combined.

If the determination in step S13 of FIG. 8 is NO, the process proceeds to step S14, where the number of the end points B adjacent to the end point A in the bidirectional list L including the information of the end point A is one. Determine if there is. If the determination is yes here, the process proceeds to step S19 and the end point A
The vector V (A, X) from the point A to the end point X and the vector V (A, B) from the end point A to the end point B determine whether the angle formed by the vector is greater than 90 degrees or not. It is determined by whether or not. If the determination is yes here, the process proceeds to step S25 in FIG. 9 to add the information of the end point X to the end on the end point A side in the bidirectional list L.
(Case). For example, as shown in FIG.
When the angle between (A, X) and the vector V (A, B) is larger than 90 degrees, information on the end point X is added next to the end point A as shown in FIG. And A are combined.

On the other hand, if it is determined NO in step S19 of FIG. 8, the process proceeds to step S20, and information of the endpoint X is added between the endpoint A and the endpoint B in the bidirectional list L (case). . For example, as shown in FIG. 13B, the angle between the vector V (A, X) and the vector V (A, B) is 90
If it is smaller than the degree, the end point X is interrupted between the end points A and B, and information on the end point X is added between the end points A and B as shown in FIG.

If NO in step S14 of FIG. 8, it is determined in step S15 that there are two endpoints adjacent to endpoint A in the bidirectional list L including the information of endpoint A, and endpoint B is determined. And C. Then, step S1
6, the distance D (X, B) between the end point X and the end point B is the end point X
It is determined whether the distance is greater than the distance D (X, C) between the point C and the end point C. If the determination is NO here, step S1
7, the information of the endpoint X is added between the endpoint A and the endpoint B in the bidirectional list L (case). For example, as shown in FIG. 14B, the distance D (X,
When B) is shorter than the distance D (X, C) between the end point X and the end point C, the end point X is interrupted between the end points A and B, and FIG.
As shown in (a), information on the end point X is added between the end points A and B.

If the answer is YES in step S16 in FIG. 8, the process proceeds to step S18, where information on the end point X is added between the end points A and C in the bidirectional list (case). For example, as shown in FIG.
When the distance D (X, B) between the end point B and the end point B is longer than the distance D (X, C) between the end point X and the end point C, the end point X is interrupted between the end points A and C. As shown in (a), information on the end point X is added between the end points A and C.

After the combining process in steps S22 and S25 in FIG. 9, the process proceeds to step S23, where the newly detected endpoints D are recorded at both ends of all the bidirectional lists in the database. Distance D to X
It is determined whether or not (D, X) is less than or equal to the wheel width W. If the determination is affirmative, step S2
4, the bidirectional list including the end point X and the bidirectional list including the end point D are combined so that the information of the end points X and D is adjacent (case). For example, when a newly detected end point X is added as shown in FIGS. 16A and 16B, the distance D between the end point X and the end point D of another bidirectional list is determined.
When (D, X) is smaller than the wheel width W, FIG.
As shown in (b), the end points X and D are connected to each other to integrate the two bidirectional lists.

By repeating the above-mentioned end point connection processing, a closed loop is formed by a plurality of end points and end lines as shown in FIG. 18, and a closed region surrounded by the closed loop is formed. Then, the coordinate data of the closed loop is registered in the database as coordinate data of the edge (20) of the table (2), and is used for control for autonomous traveling in the subsequent activities in the safety area.

For example, the autonomous mobile robot (1) has a speed vector V representing the current moving direction and speed at a constant cycle.
When n is detected and the next moving point Q predicted from the velocity vector deviates from the closed loop as shown in FIG. 18, two direction vectors Va and Vb which are candidates for the direction change are obtained, and further deviate from the closed loop. A turning vector Vc having an appropriate speed and direction without fear is determined. As a result, the autonomous mobile robot (1) moves on the table (2) without falling off the table (2) and performs the intended function.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, in the process of autonomous driving, FIG.
When moving from the position of (a) to the position of FIG. 19B and detecting the edge (20) by one optical sensor (3a),
By slightly changing the direction under the control of the wheels (11) and (11) at that position, an operation of detecting the edge (20) by another optical sensor (3b) as shown in FIG. For example, it is possible to detect more end points in a short time and quickly create a database. in this case,
A region in front of the two optical sensors (3a) and (3b) (shown by a hatched region in the figure) can be grasped as a dangerous region.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an operation state of an autonomous mobile robot according to the present invention.

FIG. 2 is a perspective view of the autonomous mobile robot.

FIG. 3 is a diagram illustrating a configuration of a traveling system in the autonomous traveling robot.

FIG. 4 is a block diagram illustrating a configuration of a control system in the autonomous mobile robot.

FIG. 5 is a diagram illustrating an edge detection operation by the autonomous mobile robot.

FIG. 6 is a diagram illustrating a coordinate system set for the autonomous mobile robot.

FIG. 7 is a flowchart showing a control procedure executed by the autonomous mobile robot during running.

FIG. 8 is a flowchart showing a first half of a procedure of an end point joining process in the control procedure.

FIG. 9 is a flowchart showing the latter half of the procedure.

FIG. 10 is a diagram illustrating the structure and physical meaning of data created in the case of the end point combining process.

FIG. 11 is a diagram illustrating the structure and physical meaning of data created in the case of the end point combining process.

FIG. 12 is a diagram for explaining the structure and physical meaning of data created in the case of the end point combining process.

FIG. 13 is a diagram for explaining the structure and physical meaning of data created in the case of the end point combining process.

FIG. 14 is a diagram illustrating the structure and physical meaning of data created in the case of the end point combining process.

FIG. 15 is a diagram illustrating the structure and physical meaning of data created in the case of the end point connection processing.

FIG. 16 is a diagram illustrating the structure and physical meaning of data created by adding end point information in the case of the end point combining process.

FIG. 17 is a diagram illustrating the structure and physical meaning of data created by combining both lists in the case of the end point combining process.

FIG. 18 is a diagram illustrating traveling control of the autonomous traveling robot after a closed loop is formed in the database.

FIG. 19 is a diagram illustrating another method of detecting an end point.

[Explanation of symbols]

 (1) Autonomous mobile robot (11) Wheels (12) Reduction mechanism (13) Motor (14) Rotary encoder (2) Table (20) Edge (3) Optical sensor (4) Control circuit (41) Memory

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C150 AA14 BA03 CA01 CA02 CA04 CA08 DA06 DK02 ED10 ED42 ED52 EF03 EF05 EF11 EF13 EF16 EF33 3C007 AS34 AS36 CS08 HS04 HS27 HT26 KS03 KS12 KS16 KS11 K04 LTKS MS07 MS10 MS22 MT06 MT14 WA16 WA28 WC13 5H301 AA02 AA10 BB14 CC03 FF13 GG08 GG12

Claims (8)

[Claims] 1. A robot which autonomously travels inside a predetermined traveling area, a position recognizing means for recognizing a position of the robot in an autonomous traveling process, and reaches or approaches a boundary of the traveling area in an autonomous traveling process. Detection means for detecting that the vehicle has been driven, first traveling control means for controlling autonomous traveling based on a detection signal obtained from the boundary detection means, and database creation for creating a database representing the position of the boundary line by coordinate data Means, and second traveling control means for controlling traveling based on the created database and the recognition signal from the position recognizing means so as not to deviate from the traveling area. Based on the recognition signal obtained from the position recognition means when the detection signal is obtained from, the coordinates of an end point representing a position on or near the boundary line While detecting the position, when the distance between the two end points adjacent to each other is smaller than a predetermined value, the process of connecting the end points to each other is repeated. When a closed loop is formed by this, the coordinate data of the closed loop is converted to the boundary line. An autonomous mobile robot characterized in that it is registered in a database as coordinate data. 2. The autonomous mobile robot according to claim 1, wherein the database creation unit creates, for a plurality of end points connected to each other, a bidirectional list including coordinate information of each end point and connection information between the end points. 3. When the newly detected end point X is not adjacent to any of the other end points by a distance equal to or less than the predetermined value, the database creating unit adds the coordinate information of the newly detected end point X to a new position. The autonomous mobile robot according to claim 2, which is added as a bidirectional list. 4. The database creation means according to claim 1, wherein the newly detected end point X is adjacent to one end point A in the bidirectional list at a distance equal to or less than the predetermined value, and the end point X adjacent to the end point A is 4. The autonomous mobile robot according to claim 2, wherein when there is no existing point, the newly detected end point X is added next to the end point A. 5. 5. The database creation means according to claim 1, wherein the newly detected end point X is adjacent to one end point A in the bidirectional list at a distance equal to or less than the predetermined value. When two endpoints B are adjacent to each other, the angle between the vector V (A, X) from the endpoint A to the endpoint X and the vector V (A, B) from the endpoint A to the endpoint B exceeds 90 degrees. When the angle V is not 90 degrees, a connection path is formed from the end point B to the end point X via the end point A. When the angle formed by the vector V (A, X) and the vector V (A, B) does not exceed 90 degrees, the end point The autonomous mobile robot according to any one of claims 2 to 4, wherein a connection path from B to an end point A through an end point X is formed. 6. The database creating means according to claim 1, wherein the newly detected end point X is adjacent to one end point A in the bidirectional list at a distance equal to or less than the predetermined value, and When two end points B and C are adjacent to each other and the distance D (X, B) between the end points X and B is smaller than the distance D (X, C) between the end points X and C, A connection path having an end point X interposed between the end points A and B is formed, and a distance D (X,
The autonomous driving according to any one of claims 2 to 5, wherein when B) is larger than the distance D (X, C), a connection path is formed between the end points A and C with the end point X interposed therebetween. robot. 7. When the newly detected end point X is added to the bidirectional list, the database creation means newly detects the end point D among the end points D recorded at both ends of all the bidirectional lists. If the distance D (D, X) to the specified end point X is equal to or less than the predetermined value and there is an adjacent end point D, the end point D
The autonomous driving according to any one of claims 2 to 6, wherein the two-way list including the end point X and the two-way list including the newly detected end point X are connected so that the information of the end point D and the end point X are adjacent to each other. robot. 8. The first travel control means sets a low travel speed in the travel control until the database is created, and the second travel control means sets the travel speed in the travel control after the database is created. Is set to be high.
The autonomous mobile robot according to any one of the above.