Working robot
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- MAKITA CORP
- Filing Date
- 2023-08-31
- Publication Date
- 2026-08-05
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] The technology disclosed in this specification relates to a working robot. [Background technology]
[0002] Patent Document 1 discloses a work robot that is used in a work area where a wire is installed, and performs work while moving based on the wire magnetic field generated around the wire. The work robot includes a robot body, a moving unit that moves the robot body, a working unit supported by the robot body, a magnetic sensor supported by the robot body, and a control unit. The control unit is configured to be capable of executing a work operation in which the working unit performs work while moving the robot body with the moving unit. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2016-207158 A Summary of the Invention [Problem to be solved by the invention]
[0004] For example, when an electric signal is no longer applied to the wire due to a power outage, the wire magnetic field is no longer generated, and the wire magnetic field is no longer detected by the magnetic sensor. Usually, when the wire magnetic field is no longer detected by the magnetic sensor during the execution of a work operation, the work operation is interrupted. However, depending on the positional relationship between the magnetic sensor and the wire, the wire magnetic field may not be detected by the magnetic sensor even though the wire magnetic field is generated. In this case, even if the work operation is interrupted, it is preferable to immediately resume the work operation. If a situation continues in which the wire magnetic field is generated but the wire magnetic field is not detected by the magnetic sensor, the work operation cannot be resumed at all, and there is a risk that the work by the work robot will not proceed smoothly. This specification provides a technology that allows the work by the work robot to proceed smoothly. [Means for solving the problem]
[0005] The working robot disclosed in this specification is used in a work area where a wire is installed, and performs work while moving based on a wire magnetic field generated around the wire. The working robot includes a robot body, a moving unit that moves the robot body, a working unit supported by the robot body, a magnetic sensor supported by the robot body, and a control unit. The control unit is configured to be capable of executing a work operation in which the working unit performs work while moving the robot body by the moving unit. The control unit is configured to be capable of executing an operation interruption process that interrupts the work operation when a predetermined operation interruption condition is satisfied during the execution of the work operation, a first magnetic field search process that causes the robot body to move in a first straight direction by a first distance after the operation interruption process and determines whether the wire magnetic field has been detected by the magnetic sensor, and an operation resumption process that resumes the work operation when the wire magnetic field is detected by the magnetic sensor after the work operation is interrupted by the operation interruption process.
[0006] Even when it is expected that the magnetic sensor will not detect the wire magnetic field, the magnetic sensor may detect the wire magnetic field by changing the positional relationship between the magnetic sensor and the wire. According to the above configuration, when the operation interruption condition is satisfied (when it is expected that the magnetic sensor will not detect the wire magnetic field), the control unit can attempt to detect the wire magnetic field by the magnetic sensor while changing the positional relationship between the magnetic sensor and the wire. This can prevent a situation in which the magnetic sensor does not detect the wire magnetic field even though the wire magnetic field is generated from continuing. In addition, when the magnetic sensor detects the wire magnetic field while the work operation is interrupted, the control unit can automatically resume the work operation. This allows the work operation to be resumed without the user's help, allowing the work by the work robot to proceed smoothly. [Brief description of the drawings]
[0007] [Figure 1] 1A to 1C are diagrams illustrating an example of use of a robotic lawnmower 2 according to an embodiment. [Diagram 2] FIG. 2 is a left side view of the robotic lawnmower 2 according to the embodiment. [Diagram 3] FIG. 2 is a rear view of the robotic lawnmower 2 according to the embodiment. [Figure 4] FIG. 1 is a schematic configuration diagram of a robotic lawnmower 2 according to an embodiment. [Diagram 5] 3 is a diagram showing the arrangement of a plurality of magnetic sensors 38 of the robotic lawnmower 2 according to the embodiment. FIG. [Figure 6] 5A to 5C are diagrams showing examples of magnetic signals observed by a plurality of magnetic sensors 38 of the robotic lawnmower 2 according to the embodiment. [Figure 7] 4 is a diagram showing an example of a signal model SM stored in a memory 24 of the robotic lawnmower 2 according to the embodiment. FIG. [Figure 8] 11 is a diagram showing a wire magnetic field M generated around a wire 112 according to an embodiment, and a change in strength of the wire magnetic field M in the vertical direction. [Figure 9] 5 is a flowchart of a process executed by a control unit 8 of a robotic lawnmower 2 according to an embodiment. [Figure 10] FIG. 13 is a diagram showing a state in which each of a plurality of magnetic sensors 38 of the robotic lawnmower 2 according to the embodiment is located directly above a wire 112 (ie, at the boundary of the working area WA). [Figure 11] 10 is a diagram showing how the robotic lawnmower 2 according to the embodiment operates according to the process shown in FIG. 9. FIG. [Figure 12] 10 is a diagram showing how the robotic lawnmower 2 according to the embodiment operates according to the process shown in FIG. 9. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] Representative and non-limiting examples of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing the preferred examples of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed can be used separately or together with other features and inventions to provide further improved work robots.
[0009] In addition, the combinations of features and steps disclosed in the following detailed description are not essential for implementing the present invention in the broadest sense, but are specifically described only to illustrate representative embodiments of the present invention. Furthermore, the various features of the following representative embodiments and the various features described in the claims do not have to be combined in the exact manner of the embodiments described herein or in the order listed in order to provide additional and useful embodiments of the present invention.
[0010] All features described in the specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.
[0011] In one or more embodiments, the operation interruption condition may include the wire magnetic field being no longer detected by the magnetic sensor.
[0012] In the above configuration, even if a wire magnetic field is generated, if the wire magnetic field is not detected by the magnetic sensor, the operation interruption condition is met and the work operation is interrupted. However, when the operation interruption condition is met, the control unit can attempt to detect the wire magnetic field while changing the positional relationship between the magnetic sensor and the wire. This makes it possible to prevent a situation in which the wire magnetic field is generated but not detected by the magnetic sensor from continuing.
[0013] In one or more embodiments, the work robot may include a plurality of the magnetic sensors. The operation interruption condition may include a condition in which the wire magnetic field is no longer detected by a predetermined number or more of the plurality of the magnetic sensors. The predetermined number may be more than half of the total number of the plurality of the magnetic sensors.
[0014] The strength of the wire magnetic field generated around the wire in the vertical direction is almost zero directly above or directly below the wire. Therefore, when the magnetic sensor is configured to observe a vertical magnetic field (magnetic field in the vertical direction), if the magnetic sensor is directly above the wire, the wire magnetic field will not be detected by the magnetic sensor. There is a technology that uses this property to determine that the magnetic sensor is directly above the wire when the wire magnetic field is not detected by the magnetic sensor. Considering this technology, even if some of the multiple magnetic sensors do not detect the wire magnetic field, if the number of magnetic sensors that do not detect the wire magnetic field is small, it is considered that the probability that the wire magnetic field is generated is high. If a series of processes following the operation interruption process are executed even in this case, the work operation will be unnecessarily interrupted, and the work by the work robot will not proceed smoothly. According to the above configuration, when the number of magnetic sensors that do not detect the wire magnetic field is large, the operation interruption condition is established and a series of processes following the operation interruption process are executed. When the number of magnetic sensors that do not detect the wire magnetic field is small, the operation interruption condition is not established and a series of processes following the operation interruption process are not executed. Therefore, the series of processes following the operation interruption process are executed only when the probability of the wire magnetic field being generated is low, so that unnecessary interruptions of the work operation can be suppressed, allowing the work by the work robot to proceed more smoothly.
[0015] In one or more embodiments, the wire magnetic field may include a wire magnetic signal generated by applying a predetermined electric signal to the wire. The control unit may store a signal model of the wire magnetic signal in advance. The control unit may determine that the wire magnetic field is detected by the magnetic sensor when a magnetic signal observed by the magnetic sensor matches or is similar to the signal model of the wire magnetic signal.
[0016] According to the above configuration, it is possible to determine, by simple means, whether or not the wire magnetic field has been detected by the magnetic sensor.
[0017] In one or more embodiments, the control unit may identify a moving direction of the robot body before interrupting the work operation, and may set the opposite direction of the identified moving direction as the first straight direction in the first magnetic field search process.
[0018] In an example in which an area surrounded by a wire is defined as the working area of a working robot, the magnetic sensor may reach directly above the wire, and the magnetic sensor may no longer detect the wire magnetic field, resulting in the operation interruption condition being satisfied. In this case, since the robot body is considered to be located near the boundary of the working area, if the robot body is moved randomly in the first magnetic field search process executed thereafter, the robot body may go outside the working area. According to the above configuration, in the first magnetic field search process, the control unit moves the robot body so as to return it to the position just before the operation interruption condition is satisfied. Since the magnetic sensor should have detected the wire magnetic field until just before the operation interruption condition is satisfied, it is considered that the robot body was within the working area. Therefore, since the robot body can be moved toward the inside of the working area, it is possible to prevent the robot body from going outside the working area.
[0019] In one or more embodiments, the control unit may be configured to further execute a second magnetic field search process in which, after the first magnetic field search process, the moving unit moves the robot body a second distance in a second straight-line direction opposite to the first straight-line direction, and determines whether the wire magnetic field is detected by the magnetic sensor.
[0020] According to the above configuration, after the first magnetic field search process, the magnetic sensor can try to detect the wire magnetic field again while changing the positional relationship between the magnetic sensor and the wire, which makes it possible to more reliably resolve a situation in which the magnetic sensor cannot detect the wire magnetic field even though the wire magnetic field is generated.
[0021] In one or more embodiments, the control unit may not perform the second magnetic field search process if the wire magnetic field is detected in the first magnetic field search process, and may perform the second magnetic field search process if the wire magnetic field is not detected in the first magnetic field search process.
[0022] According to the above configuration, when a wire magnetic field is detected in the first magnetic field search process, the control unit can omit the second magnetic field search process and immediately resume work operation, which allows the work robot to proceed more smoothly with its work.
[0023] In one or more embodiments, the second distance may be the same distance as the first distance.
[0024] If the work operation is resumed from a location different from the location where the work operation was interrupted, there is a risk that the work operation will end with an area where the work robot is not working (an unworked area) remaining. According to the above configuration, the position of the robot body when the second magnetic field search process ends is hardly displaced from the position of the robot body when the work operation was interrupted. Therefore, by resuming the work operation after the second magnetic field search process ends, the work operation can be resumed from the area where the work operation was interrupted. This makes it possible to prevent the work operation from ending with an unworked area remaining.
[0025] In one or more embodiments, the second distance may be less than the first distance.
[0026] There are cases where the magnetic sensor reaches directly above the wire, and the magnetic sensor no longer detects the wire magnetic field, and the operation interruption condition is established. In this case, if the position of the robot body when the second magnetic field search process is completed has not been displaced at all from the position of the robot body when the magnetic sensor no longer detects the wire magnetic field, the magnetic sensor will be directly above the wire again. Therefore, even if the wire magnetic field is detected in the first magnetic field search process or the second magnetic field search process, the wire magnetic field may not be detected by the magnetic sensor after the second magnetic field search process is completed. As a result, even if the work operation is resumed, the work operation will be immediately interrupted, and the work by the work robot may not proceed smoothly. According to the above configuration, the position of the robot body when the second magnetic field search process is completed can be displaced from the position of the robot body when the magnetic sensor no longer detects the wire magnetic field. Therefore, it is possible to prevent the magnetic sensor from being directly above the wire when the second magnetic field search process is completed. As a result, if a wire magnetic field is generated, the wire magnetic field can be detected by the magnetic sensor even after the second magnetic field search process is completed. Therefore, since it is possible to prevent the work operation from being interrupted immediately after it is resumed, the work by the work robot can proceed smoothly.
[0027] In one or more embodiments, the first distance may be a distance of 1000 mm or less.
[0028] If the robot body is moved significantly after the magnetic sensor no longer detects the wire magnetic field, there is a risk that the robot body may end up in an unintended location (for example, a location where there is an obstacle). With the above configuration, it is possible to prevent the robot body from moving significantly after the magnetic sensor no longer detects the wire magnetic field. This makes it possible to prevent the robot body from ending up in an unintended location.
[0029] In one or more embodiments, the first distance may be less than or equal to a full length of the work robot.
[0030] If the robot body is moved significantly after the magnetic sensor no longer detects the wire magnetic field, there is a risk that the robot body may end up in an unintended location (for example, a location where there is an obstacle). With the above configuration, it is possible to prevent the robot body from moving significantly after the magnetic sensor no longer detects the wire magnetic field. This makes it possible to prevent the robot body from ending up in an unintended location.
[0031] In one or more embodiments, the control unit may be further configured to execute a notification process for notifying an occurrence of an abnormality via a notification interface. The control unit may execute the notification process when a predetermined time has elapsed since the first magnetic field search process was ended without the operation resumption process being executed.
[0032] According to the above configuration, when the magnetic sensor still does not detect the wire magnetic field even after the first magnetic field search process and the work operation is not resumed, it is possible to notify the user of this fact.
[0033] In one or more embodiments, the control unit may be further configured to execute a notification process for notifying an occurrence of an abnormality via a notification interface. The control unit may execute the notification process when a predetermined time has elapsed since the second magnetic field search process was completed without the operation resumption process being executed.
[0034] According to the above configuration, when the magnetic sensor still does not detect the wire magnetic field even after the first magnetic field search process and the second magnetic field search process, and the work operation is not resumed, it is possible to notify the user of this.
[0035] In one or more embodiments, the working unit may include a cutting blade for cutting grass. The working robot may function as an autonomously mobile robotic lawnmower.
[0036] According to the above configuration, the lawn mowing work by the robotic lawnmower can proceed smoothly.
[0037] (Example) As shown in FIG. 1, the working robot of this embodiment is, for example, a robotic lawnmower 2 used within a site 100 where a lawn is laid. The site 100 is provided with, for example, a house 102, a pond 104, a road 106, and a fence 108. Also installed within the site 100 are a charging station 110 connected to an external power source (for example, a commercial power source) and a wire 112 that defines a working area WA of the robotic lawnmower 2. The working area WA here is the area surrounded by the wire 112. The working area WA of the robotic lawnmower 2 is divided into a main area MA that includes the charging station 110, and a sub-area SA that does not include the charging station 110. The robotic lawnmower 2 can detect the position of the wire 112 and move autonomously without straying from the working area WA (main area MA in the example of FIG. 1) in which the robotic lawnmower 2 is located. This allows the robotic lawnmower 2 to perform lawn mowing work while moving over the lawn, avoiding the house 102, the pond 104, the road 106, and the fence 108.
[0038] The overall length of the robotic lawnmower 2 is, for example, within a range of 500 mm to 1000 mm, and is 700 mm in this embodiment. The overall width of the robotic lawnmower 2 is, for example, within a range of 300 mm to 600 mm, and is 560 mm in this embodiment. The overall height of the robotic lawnmower 2 is, for example, within a range of 200 mm to 300 mm, and is 270 mm in this embodiment.
[0039] 2, 3, and 4, the robotic lawnmower 2 includes a robot body 4, a power supply unit 6, a control unit 8, an operation unit 10, a display unit 11, a moving unit 12, a working unit 14, a detection unit 16, a communication unit 50, and an alarm unit 52. The power supply unit 6, the control unit 8, the operation unit 10, the display unit 11, the moving unit 12, the working unit 14, the detection unit 16, the communication unit 50, and the alarm unit 52 are each supported by the robot body 4.
[0040] The power supply unit 6 shown in FIG. 4 is capable of supplying power to each component of the robotic lawnmower 2 via a power supply circuit 26 of the control unit 8. The power supply unit 6 includes a rechargeable battery 18, such as a lithium-ion battery, and a charging interface 20 that electrically connects to the battery 18. The nominal capacity of the battery 18 is, for example, 5.0 Ah. The nominal voltage of the battery 18 is, for example, 18 V. The robotic lawnmower 2 can be docked to a charging station 110 (see FIG. 1) via the charging interface 20. When the robotic lawnmower 2 is docked to the charging station 110, the battery 18 can be charged by power supplied from the charging station 110. The charging method for the battery 18 may be wired charging. Specifically, the battery 18 may be charged in a state in which a terminal provided on the charging station 110 and a terminal provided on the charging interface 20 are connected to each other. Alternatively, the charging method for the battery 18 may be wireless charging. Specifically, the battery 18 may be charged by causing a power transmitting coil provided in the charging station 110 to generate an induced electromotive force in a power receiving coil provided in the charging interface 20.
[0041] The control unit 8 includes a processor 22, a memory 24, and a power supply circuit 26. The memory 24 includes a ROM, a RAM, etc. The memory 24 stores a program for autonomously controlling the robotic lawnmower 2. The processor 22 is configured to autonomously control the robotic lawnmower 2 in accordance with the program stored in the memory 24. The memory 24 also stores settings related to the robotic lawnmower 2 (e.g., the mowing height of the lawn). The settings related to the robotic lawnmower 2 include settings related to the operation mode of the robotic lawnmower 2. The operation mode of the robotic lawnmower 2 is set to one of a number of modes including a main area compatible mode corresponding to the main area MA (see FIG. 1) and a sub-area compatible mode corresponding to the sub-area SA (see FIG. 1).
[0042] The operation unit 10 is provided, for example, on the outer surface of the robot body 4 (see FIG. 2), and includes switches and the like that can be operated by the user. The user can perform various operations related to the robotic lawnmower 2 via the operation unit 10. The various operations referred to here include, for example, operations to switch the main power supply of the robotic lawnmower 2 on / off, operations to input instructions for the robotic lawnmower 2, and operations to change settings related to the robotic lawnmower 2.
[0043] The display unit 11 includes, for example, a display (not shown) that displays characters and images, and a light source device that uses the chromaticity and blinking pattern of light to indicate the status of the robotic lawnmower 2. The status of the robotic lawnmower 2 here includes, for example, a state in which the battery 18 is charging, or a state in which an abnormality has occurred in the robotic lawnmower 2.
[0044] The moving unit 12 includes a pair of casters 28L, 28R, a pair of drive wheels 30L, 30R, and a pair of moving motors 32L, 32R. The moving motors 32L, 32R are, for example, brushless DC motors. The drive wheels 30L, 30R are connected to the output shafts of the moving motors 32L, 32R, respectively. As shown in FIG. 2 and FIG. 3, the robot lawnmower 2 is placed on the ground G with the casters 28L, 28R and the drive wheels 30L, 30R in contact with the ground G. The moving unit 12 can move the robot body 4 forward, backward, and turn by operating the moving motors 32L, 32R (see FIG. 4) to rotate the drive wheels 30L, 30R. In this embodiment, the direction perpendicular to the ground G, that is, the direction from the ground G toward the robot body 4 is defined as the upward direction, and the direction from the robot body 4 toward the ground G is defined as the downward direction. The direction perpendicular to the up-down direction, from driving wheel 30R toward driving wheel 30L, is defined as the left direction, and the direction from driving wheel 30L toward driving wheel 30R is defined as the right direction. The direction perpendicular to the up-down direction and the left-right direction, from driving wheels 30L, 30R toward casters 28L, 28R is defined as the front direction, and the direction from casters 28L, 28R toward driving wheels 30L, 30R is defined as the rear direction.
[0045] As shown in FIG. 2, the working unit 14 includes a cutting blade 34 and a work motor 36. The cutting blade 34 is a rotary blade formed in a substantially circular disk shape. The work motor 36 is, for example, a brushless DC motor. The work motor 36 is supported by the robot body 4 with its output shaft tilted from front to rear as it moves from top to bottom. The cutting blade 34 is connected to the output shaft of the work motor 36. The working unit 14 can cut the grass by operating the work motor 36 to rotate the cutting blade 34.
[0046] As shown in FIG. 4, the detection unit 16 includes a plurality of magnetic sensors 38 and a battery voltage detection circuit 42.
[0047] As shown in FIG. 5, the plurality of magnetic sensors 38 includes four magnetic sensors 38a, 38b, 38c, and 38d. The magnetic sensor 38a is disposed at the front left part of the robot body 4. The magnetic sensor 38b is disposed at the front center part of the robot body 4. The magnetic sensor 38c is disposed at the front right part of the robot body 4. The magnetic sensor 38d is disposed at the rear center part of the robot body 4. The plurality of magnetic sensors 38 are, for example, Hall sensors. Each of the plurality of magnetic sensors 38 is configured to observe the change over time in the strength of the vertical magnetic field (magnetic field in the up-down direction) as a magnetic signal as shown in FIG. 6(a) or FIG. 6(b), and output the observation result to the control unit 8 (see FIG. 4).
[0048] 4 is configured to detect the voltage value of the battery 18 and output it to the control unit 8. This allows the control unit 8 to grasp the voltage value of the battery 18.
[0049] The communication unit 50 is, for example, an interface for connecting to the Internet via a base station (not shown) for mobile communications (3G, 4G, 5G, etc.) or a router (not shown) installed in the house 102. The control unit 8 can perform wireless communication with a communication terminal (e.g., a smartphone) owned by the user via the communication unit 50. This enables the control unit 8 to notify the communication terminal owned by the user that an abnormality has occurred in the robotic lawnmower 2, etc.
[0050] The warning sound unit 52 includes, for example, a buzzer (not shown). The warning sound unit 52 can notify the user that an abnormality has occurred in the robotic lawnmower 2 by emitting a sound.
[0051] The following describes the lawnmowing operation executed by the control unit 8 (specifically, the processor 22).
[0052] The lawnmowing operation is the main operation of the robotic lawnmower 2. The lawnmowing operation is started, for example, when the power of the robotic lawnmower 2 is turned on and an instruction to start the lawnmowing operation is given via the operation unit 10. When the lawnmowing operation is started, the control unit 8 confirms that there is no abnormality in the robotic lawnmower 2, and then starts the lawnmowing work with the robotic lawnmower 2. That is, the control unit 8 drives the driving wheels 30L, 30R with the moving motors 32L, 32R while driving the cutting blade 34 with the working motor 36, thereby cutting the grass. Also, when the operation mode of the robotic lawnmower 2 is set to the main area compatible mode, the control unit 8 returns the robot body 4 to the charging station 110 (see FIG. 1) when the remaining charge of the battery 18 decreases, and charges the battery 18. The control unit 8 ends the lawnmowing operation when a predetermined operation end condition is met. The operation end condition here includes, for example, that the elapsed time since the start of the lawnmowing operation reaches a time preset by the user.
[0053] A predetermined electric signal is applied from the charging station 110 to the wire 112 shown in FIG. 1. As a result, a magnetic field (wire magnetic field M) including a magnetic signal (wire magnetic signal) corresponding to the predetermined electric signal is generated around the wire 112. A signal model SM of the wire magnetic signal as shown in FIG. 7 is stored in advance in the memory 24 (see FIG. 4). The control unit 8 (see FIG. 4) is configured to determine whether or not this signal model SM and a magnetic signal observed by each of the multiple magnetic sensors 38 (see FIG. 5) match or are similar during the lawn mowing operation. As a method for determining whether or not two signals match or are similar, for example, correlation analysis is used. For example, when a magnetic signal as shown in FIG. 6(a) is observed by the magnetic sensor 38, the magnetic signal is determined to be similar to the signal model SM shown in FIG. 7. On the other hand, when a magnetic signal as shown in FIG. 6(b) is observed by the magnetic sensor 38, the magnetic signal is determined to be neither similar nor match the signal model SM shown in FIG. 7. In this embodiment, when a magnetic signal that matches or is similar to the signal model SM is observed by the magnetic sensor , the control unit 8 determines that the magnetic sensor has detected the wire magnetic field M.
[0054] As shown in FIG. 8, the wire magnetic field M is generated so as to surround the wire 112 according to the right-hand rule. As a result, the direction of the wire magnetic field M generated inside the working area WA and the direction of the wire magnetic field M generated outside the working area WA are opposite to each other. That is, the phase of the wire magnetic signal generated inside the working area WA and the phase of the wire magnetic signal generated outside the working area WA are opposite to each other. By utilizing this property, when the wire magnetic field M is detected by the magnetic sensor 38 (see FIG. 5), the control unit 8 (see FIG. 4) identifies whether the magnetic sensor 38 is inside or outside the working area WA based on the phase of the magnetic signal observed by the magnetic sensor 38. Also, directly above the wire 112 (i.e., the boundary of the working area WA), the strength of the wire magnetic field M in the vertical direction is almost zero. Therefore, when the magnetic sensor 38 is directly above the wire 112 (i.e., the boundary of the working area WA), the wire magnetic field M is not detected by the magnetic sensor 38. Using this property, when the wire magnetic field M is no longer detected by the magnetic sensor 38, the control unit 8 determines that the magnetic sensor 38 is at the boundary of the working area WA. For each of the multiple magnetic sensors 38, the control unit 8 specifies whether the magnetic sensor 38 is located inside, at the boundary, or outside the working area WA, and thereby specifies the positional relationship between the robot body 4 (see FIG. 5) and the wire 112. Based on the specified positional relationship between the robot body 4 and the wire 112, the control unit 8 moves the robot body 4 so that the robot body 4 does not deviate from the working area WA. In the graph shown in FIG. 8, the horizontal axis represents the distance D between the wire 112 and the magnetic sensor 38 in the front-rear and left-right directions, and the vertical axis represents the strength H of the magnetic field detected by the magnetic sensor 38.
[0055] However, if the wire 112 is broken or if an electric signal is no longer applied to the wire 112 due to a power outage or the like, the wire magnetic field M will no longer be generated. If the wire magnetic field M is no longer generated, the magnetic sensor 38 will no longer be able to detect the wire magnetic field M regardless of whether the magnetic sensor 38 is inside, on the boundary, or outside the work area WA. As a result, the control unit 8 will no longer be able to identify the positional relationship between the robot body 4 and the wire 112. To prepare for such a situation, the control unit 8 repeatedly executes the process shown in FIG. 9 during the lawnmowing operation.
[0056] In S2, the control unit 8 judges whether or not a predetermined operation interruption condition is satisfied. The operation interruption condition is, for example, a condition under which it is estimated that the wire magnetic field M is not being generated, and in this embodiment, it is a condition under which the wire magnetic field M is not detected by three or more of the four magnetic sensors 38a, 38b, 38c, and 38d. If the operation interruption condition is not satisfied (if NO), S2 is repeatedly executed. If the operation interruption condition is satisfied, the process proceeds to S4.
[0057] In S4, the control unit 8 interrupts the ongoing lawnmowing operation. Specifically, the control unit 8 stops the movement motors 32L, 32R and the work motor 36. After S4, the process proceeds to S6.
[0058] In S6, the control unit 8 operates the movement motors 32L and 32R to move the robot body 4 forward or backward by the first distance. At this time, the control unit 8 identifies the movement direction of the robot body 4 before the mowing operation was interrupted in S4, and moves the robot body 4 in the opposite direction to the identified movement direction. For example, if the robot body 4 was moving forward before the mowing operation was interrupted in S4, the control unit 8 moves the robot body 4 backward in S6, and if the robot body 4 was moving backward before the mowing operation was interrupted in S4, the control unit 8 moves the robot body 4 forward in S6. The first distance is set to a distance of 1000 mm or less and less than the total length of the robotic lawnmower 2. In this embodiment, the first distance is set to 100 mm. After S6, the process proceeds to S8.
[0059] In S8, the control unit 8 judges whether or not the wire magnetic field M has been detected by the magnetic sensors 38a, 38b, 38c, 38d while the robot body 4 was being moved in S6. Specifically, the control unit 8 judges whether or not the number of the magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, 38d has become two or more. If the number of the magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, 38d has not become two or more (if NO), the process proceeds to S10.
[0060] In S10, the control unit 8 operates the movement motors 32L and 32R to move the robot body 4 forward or backward by the second distance. At this time, the control unit 8 moves the robot body 4 in the opposite direction to the movement direction of the robot body 4 in S6. For example, if the control unit 8 moves the robot body 4 forward in S6, it moves the robot body 4 backward in S8, and if the control unit 8 moves the robot body 4 backward in S6, it moves the robot body 4 forward in S8. The second distance is set to 1000 mm or less, the total length of the robot lawnmower 2 or less, and less than the first distance. In this embodiment, the second distance is set to 50 mm. After S10, the process proceeds to S12.
[0061] In S12, the control unit 8 judges whether or not the wire magnetic field M has been detected by the magnetic sensors 38a, 38b, 38c, 38d while the robot body 4 was being moved in S10. Specifically, the control unit 8 judges whether or not the number of the magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, 38d has become two or more. If the number of the magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, 38d has not become two or more (if NO), the process proceeds to S14.
[0062] In S14, the control unit 8 causes the robot body 4 to wait at that location with the movement motors 32L, 32R and the work motor 36 stopped. After S14, the process proceeds to S16.
[0063] In S16, the control unit 8 determines whether or not the wire magnetic field M has been detected by the magnetic sensors 38a, 38b, 38c, and 38d. Specifically, the control unit 8 determines whether or not the number of magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, and 38d is two or more. If the number of magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, and 38d is not two or more (if NO), the process proceeds to S18.
[0064] In S18, the control unit 8 determines whether the time that has elapsed since the start of standby in S14 is equal to or greater than a predetermined time (e.g., 15 minutes). If the time that has elapsed since the start of standby in S14 is less than the predetermined time (if NO), the process returns to S16. If the time that has elapsed since the start of standby in S14 is equal to or greater than the predetermined time (if YES), the process proceeds to S20.
[0065] In S20, the control unit 8 operates the display unit 11 and the alarm unit 52 provided on the robot body 4 to notify the occurrence of an abnormality by sound or light. Alternatively, the control unit 8 may communicate with a communication terminal (e.g., a smartphone) owned by the user via the communication unit 50 and notify the communication terminal of the occurrence of an abnormality. For example, the control unit 8 may display a message indicating the occurrence of an abnormality on the communication terminal owned by the user. Note that the abnormality here specifically means that the wire magnetic field M is not detected by the magnetic sensor 38. After S20, the process shown in FIG. 9 ends.
[0066] If it is determined in S8, S12, or S16 that the number of magnetic sensors 38 that detect the wire magnetic field M among the four magnetic sensors 38a, 38b, 38c, 38d is two or more (YES), the process proceeds to S22. In S22, the control unit 8 resumes the lawnmowing operation that was interrupted in S4. Specifically, the control unit 8 operates the travel motors 32L, 32R and the work motor 36 to resume lawnmowing work by the robotic lawnmower 2. After S22, the process shown in FIG. 9 ends.
[0067] For example, as shown in FIG. 10, when each of the multiple magnetic sensors 38 is directly above the wire 112 (i.e., at the boundary of the working area WA), even if the wire magnetic field M (see FIG. 8) is generated, each of the multiple magnetic sensors 38 will not detect the wire magnetic field M. In this situation, the operation interruption condition is met, and the lawnmowing operation is interrupted. If the robot body 4 is made to wait without moving after the lawnmowing operation is interrupted, the situation in which each of the multiple magnetic sensors 38 is directly above the wire 112 cannot be resolved, and therefore the wire magnetic field M may never be detected by each of the multiple magnetic sensors 38. In this case, the lawnmowing operation is never resumed, and the lawnmowing operation by the robot lawnmower 2 may not proceed smoothly. In contrast, according to the process shown in FIG. 9, after the lawnmowing operation is interrupted, for example, the robot body 4 can be moved backward as shown in FIG. 11, while attempting to detect the wire magnetic field M by the multiple magnetic sensors 38. Thereafter, the robot body 4 can be moved forward as shown in FIG. 12, while attempting to detect the wire magnetic field M by the multiple magnetic sensors 38. As a result, the situation where each of the magnetic sensors 38 is directly above the wire 112 is resolved, so that if the wire magnetic field M is generated, each of the magnetic sensors 38 detects the wire magnetic field M and lawnmowing operation is resumed. Therefore, according to the process shown in Figure 9, lawnmowing work by the robotic lawnmower 2 can proceed smoothly.
[0068] However, if the wire 112 is broken or the like and the wire magnetic field M is no longer generated, the magnetic sensors 38 will not be able to detect the wire magnetic field M even if an attempt is made to detect the wire magnetic field M using the multiple magnetic sensors 38 while moving the robot body 4. For this reason, once the wire magnetic field M is no longer generated, the magnetic sensors 38 will continue to be unable to detect the wire magnetic field M. According to the process shown in Fig. 9, if the magnetic sensors 38 continue to be unable to detect the wire magnetic field M, a notification is issued that an abnormality has occurred. Therefore, when the wire magnetic field M is no longer generated, the user can be made aware of this.
[0069] (Modification) The working robot may be a robot other than the robotic lawnmower 2. For example, the working robot may be a robot vacuum cleaner equipped with a brush and / or a suction mechanism for collecting debris such as dust. In this case, the work motor 36 may be used as a motor for driving the brush and / or the suction mechanism. The working robot may also be a rebar binding robot equipped with a rebar binding mechanism for binding the intersections of multiple rebars. In this case, the work motor 36 may be used as a motor for driving the rebar binding mechanism.
[0070] A power cord connected to an external power source (e.g., a commercial power source) may be attached to the robotic lawnmower 2. In this case, the robotic lawnmower 2 may be configured to operate using power supplied from the external power source via the power cord.
[0071] The robotic lawnmower 2 does not have to be equipped with the battery 18. Instead, a rechargeable battery pack such as a lithium-ion battery may be detachably attached to the robot body 4. In this case, the robotic lawnmower 2 may be configured to operate using power supplied from the battery pack.
[0072] The robotic lawnmower 2 does not have to perform work while moving within the work area WA surrounded by the wire 112. For example, the robotic lawnmower 2 may perform work while moving along the wire 112. In this case, the control unit 8 may calculate the distance between the magnetic sensor 38 and the wire 112 based on the strength of the wire magnetic field M detected by the magnetic sensor 38, and move the robot body 4 so that the magnetic sensor 38 does not move away from the wire 112.
[0073] In S6 of the process shown in Fig. 9, instead of moving the robot body 4 forward or backward, the control unit 8 may rotate the drive wheels 30L, 30R at different speeds to turn (or rotate) the robot body 4 to the left or right. Alternatively, in S6 of the process shown in Fig. 9, the control unit 8 may rotate the drive wheels 30L, 30R at equal speeds to move the robot body 4 forward or backward, and then rotate the drive wheels 30L, 30R at different speeds to turn (or rotate) the robot body 4 to the left or right. Also, in S10 of the process shown in Fig. 9, instead of moving the robot body 4 forward or backward, the control unit 8 may rotate the drive wheels 30L, 30R at different speeds to turn (or rotate) the robot body 4 to the left or right. Alternatively, in S10 of the process shown in FIG. 9, the control unit 8 may rotate the drive wheels 30L, 30R at equal speeds to move the robot body 4 forward or backward, and then rotate the drive wheels 30L, 30R at different speeds to turn (or rotate) the robot body 4 to the left or right.
[0074] The moving unit 12 may further include a steering mechanism that rotates each of the drive wheels 30L, 30R around an axis along the up-down direction. The steering mechanism may allow the rotation axes of the drive wheels 30L, 30R to be arranged along a direction different from the left-right direction (for example, the front-rear direction). In this case, in S6 and S10 of the process shown in FIG. 9, the control unit 8 may use the steering mechanism to arrange the rotation axes of the drive wheels 30L, 30R along the front-rear direction, and then rotate the drive wheels 30L, 30R at equal speeds. This may cause the robot body 4 to move straight left or right.
[0075] The moving unit 12 may be equipped with other moving mechanisms (e.g., crawlers, side steppers) instead of the casters 28L, 28R and the drive wheels 30L, 30R. The side stepper here is a mechanism for moving the robot body 4 in the left-right direction. When the moving unit 12 is equipped with a side stepper, the control unit 8 may drive the side stepper in S6 and S10 of the process shown in FIG. 9 to move the robot body 4 straight to the left or right.
[0076] The operation interruption condition may be a condition different from that of the embodiment. For example, the operation interruption condition may be that the wire magnetic field M is no longer detected by all of the four magnetic sensors 38a, 38b, 38c, and 38d. In this case, the control unit 8 may determine YES in S8, S12, and S16 of the process shown in FIG. 9 when the wire magnetic field M is detected by one or more magnetic sensors 38. The operation interruption condition may be that the wire magnetic field M is no longer detected by two or more magnetic sensors 38 out of the four magnetic sensors 38a, 38b, 38c, and 38d. In this case, the control unit 8 may determine YES in S8, S12, and S16 of the process shown in FIG. 9 when the wire magnetic field M is detected by three or more magnetic sensors 38.
[0077] 9, the control unit 8 may skip S8 and execute S10 after S6. That is, the control unit 8 may be configured to move the robot body 4 again regardless of whether the wire magnetic field M is detected by the magnetic sensor 38 while the robot body 4 is being moved in S6.
[0078] 9, when the determination in S8 is NO, the control unit 8 may skip S10 and S12 and execute S12. That is, the control unit 8 may be configured not to move the robot body 4 until the wire magnetic field M is detected by the magnetic sensor 38 after interrupting the lawnmowing operation and moving the robot body 4 by the first distance.
[0079] 9, when the determination in S12 is NO, the control unit 8 may skip S14, S16, and S18 and execute S20. That is, when the magnetic sensor 38 does not detect the wire magnetic field M even though the robot body 4 has been moved, the control unit 8 may immediately notify the occurrence of an abnormality without waiting.
[0080] 9, the control unit 8 does not have to notify the occurrence of an abnormality in S20. Instead, the control unit 8 may turn off the main power supply of the robotic lawnmower 2.
[0081] The total number of magnetic sensors 38 included in the robotic lawnmower 2 may be four or more, or may be less than four. In this case, the operation interruption condition may be that the wire magnetic field M is no longer detected by the majority of the magnetic sensors 38. Furthermore, the control unit 8 may determine YES in S8, S12, and S16 of the process shown in Fig. 9 if the wire magnetic field M is detected by half or more of the magnetic sensors 38.
[0082] The travel distance (first distance) of the robot body 4 in S6 of the process shown in FIG. 9 may be set to a distance different from that in the embodiment. For example, the first distance may be set to a distance exceeding 1000 mm, or may be set to a distance exceeding the overall length of the robotic lawnmower 2. Also, the travel distance (second distance) of the robot body 4 in S10 may be set to a distance different from that in the embodiment. For example, the first distance may be set to a distance exceeding 1000 mm, or may be set to a distance exceeding the overall length of the robotic lawnmower 2, or may be set to a distance equal to or greater than the first distance. For example, the second distance may be set to the same distance as the first distance.
[0083] The movement direction of the robot body 4 in S6 of the process shown in Fig. 9 does not have to be the opposite direction to the movement direction of the robot body 4 before the mowing operation was interrupted in S4. For example, the control unit 8 may randomly determine whether to move the robot body 4 forward or backward in S6. Also, the movement direction of the robot body 4 in S10 does not have to be the opposite direction to the movement direction of the robot body 4 in S6. For example, the control unit 8 may randomly determine whether to move the robot body 4 forward or backward in S10.
[0084] (Features of the embodiment) As described above, in one or more embodiments, the robotic lawnmower 2 is used on site 100 (an example of a work site) on which wire 112 is installed, and performs work while moving based on wire magnetic field M generated around wire 112. The robotic lawnmower 2 comprises a robot body 4, a moving unit 12 that moves the robot body 4, a working unit 14 supported by the robot body 4, a magnetic sensor 38 supported by the robot body 4, and a control unit 8. The control unit 8 is configured to be capable of performing a lawnmowing operation (an example of a work operation) in which the working unit 14 performs work while moving the robot body 4 with the moving unit 12. The control unit 8 is configured to execute an operation interruption process (see S2 and S4 in the process shown in FIG. 9) that interrupts the lawnmowing operation when a predetermined operation interruption condition is met during lawnmowing operation; after the operation interruption process, the moving unit 12 causes the robot body 4 to move straight forward or backward (an example of a first straight direction) a first distance, and a first magnetic field search process (see S6 and S8 in the process shown in FIG. 9) that determines whether or not the wire magnetic field M is detected by the magnetic sensor 38; and an operation resume process (see S22 in the process shown in FIG. 9) that resumes the lawnmowing operation if the wire magnetic field M is detected by the magnetic sensor 38 after the lawnmowing operation is interrupted by the operation interruption process.
[0085] Even when it is expected that the magnetic sensor 38 will not detect the wire magnetic field M, the magnetic sensor 38 may detect the wire magnetic field M by changing the positional relationship between the magnetic sensor 38 and the wire 112. According to the above configuration, when the operation interruption condition is met (when it is expected that the magnetic sensor 38 will not detect the wire magnetic field M), the control unit 8 can attempt to detect the wire magnetic field M by the magnetic sensor 38 while changing the positional relationship between the magnetic sensor 38 and the wire 112. This can prevent a situation in which the magnetic sensor 38 does not detect the wire magnetic field M even though the wire magnetic field M is generated from continuing. In addition, when the magnetic sensor 38 detects the wire magnetic field M while the lawnmowing operation is interrupted, the control unit 8 can automatically resume the lawnmowing operation. This allows the lawnmowing operation to be resumed without the user's help, allowing the robotic lawnmower 2 to smoothly proceed with the work.
[0086] In one or more embodiments, the operation interruption condition includes the wire magnetic field M being no longer detected by the magnetic sensor 38 .
[0087] In the above configuration, even if the wire magnetic field M is generated, if the magnetic sensor 38 cannot detect the wire magnetic field M, the operation interruption condition is met and the lawnmowing operation is interrupted. However, when the operation interruption condition is met, the control unit 8 can attempt to detect the wire magnetic field M while changing the positional relationship between the magnetic sensor 38 and the wire 112. This makes it possible to prevent a situation in which the wire magnetic field M is generated but the magnetic sensor 38 cannot detect it from continuing.
[0088] In one or more embodiments, the robotic lawnmower 2 includes four magnetic sensors 38a, 38b, 38c, and 38d (examples of multiple magnetic sensors). The operation interruption condition includes a situation in which the wire magnetic field M is no longer detected by a predetermined number (three) or more of the magnetic sensors 38 out of the four magnetic sensors 38a, 38b, 38c, and 38d. The predetermined number (three) is more than half (two) of the total number (four) of the multiple magnetic sensors 38.
[0089] The strength of the wire magnetic field M generated around the wire 112 in the vertical direction is almost zero directly above or directly below the wire 112. Therefore, when the magnetic sensor 38 is configured to observe a vertical magnetic field, if the magnetic sensor 38 is directly above the wire 112, the wire magnetic field M will not be detected by the magnetic sensor 38. Using this property, there is a technique for determining that the magnetic sensor 38 is directly above the wire 112 when the wire magnetic field M is not detected by the magnetic sensor 38. Considering this technique, even if some of the multiple magnetic sensors 38 do not detect the wire magnetic field M, if the number of magnetic sensors 38 that do not detect the wire magnetic field M is small, it is considered that the probability that the wire magnetic field M is generated is high. If a series of processes following the operation interruption process are executed even in this case, the lawn mowing operation will be unnecessarily interrupted, and the work by the robotic lawnmower 2 will not proceed smoothly. According to the above configuration, when there are many magnetic sensors 38 that do not detect the wire magnetic field M, the operation interruption condition is established and a series of processes following the operation interruption process are executed. If there are only a small number of magnetic sensors 38 that do not detect the wire magnetic field M, the operation interruption condition is not met and the series of processes following the operation interruption process are not executed. Therefore, the series of processes following the operation interruption process are executed only when the probability that the wire magnetic field M is being generated is low, which prevents the lawnmower from being unnecessarily interrupted. This allows the robotic lawnmower 2 to perform its work more smoothly.
[0090] In one or more embodiments, the wire magnetic field M includes a wire magnetic signal generated by applying a predetermined electric signal to the wire 112. The control unit 8 pre-stores a signal model SM of the wire magnetic signal. The control unit 8 determines that the wire magnetic field M has been detected by the magnetic sensor 38 when the magnetic signal observed by the magnetic sensor 38 matches or is similar to the signal model SM of the wire magnetic signal.
[0091] According to the above configuration, it is possible to determine whether or not the wire magnetic field M is detected by the magnetic sensor 38 by simple means.
[0092] In one or more embodiments, the control unit 8 identifies the moving direction of the robot body 4 before the lawnmowing operation was interrupted, and sets the direction opposite to the identified moving direction as the first straight direction in the first magnetic field search process.
[0093] In an example in which the area surrounded by the wire 112 is defined as the working area WA of the robot lawnmower 2, the magnetic sensor 38 may reach directly above the wire 112, and the wire magnetic field M may no longer be detected by the magnetic sensor 38, resulting in the operation interruption condition being satisfied. In this case, since the robot body 4 is considered to be located near the boundary of the working area WA, if the robot body 4 is moved randomly in the first magnetic field search process executed thereafter, the robot body 4 may go outside the working area WA. According to the above configuration, in the first magnetic field search process, the control unit 8 moves the robot body 4 so as to return it to the position immediately before the operation interruption condition is satisfied. Since the wire magnetic field M should have been detected by the magnetic sensor 38 until immediately before the operation interruption condition was satisfied, it is considered that the robot body 4 was within the working area WA. Therefore, since the robot body 4 can be moved toward the inside of the working area WA, it is possible to prevent the robot body 4 from going outside the working area WA.
[0094] In one or more embodiments, the control unit 8 is configured to further execute a second magnetic field search process (see S10, S12 of the process shown in FIG. 9) in which, after the first magnetic field search process, the moving unit 12 moves the robot body 4 in a straight line a second distance in a backward or forward direction (an example of a second straight line direction opposite to the first straight line direction) and determines whether or not the wire magnetic field M is detected by the magnetic sensor 38.
[0095] According to the above configuration, after the first magnetic field search process, it is possible to try detecting the wire magnetic field M by the magnetic sensor 38 again while changing the positional relationship between the magnetic sensor 38 and the wire 112. This makes it possible to more reliably resolve a situation in which the wire magnetic field M is generated but is not detected by the magnetic sensor 38.
[0096] In one or more embodiments, the control unit 8 does not perform the second magnetic field search process if the wire magnetic field M is detected in the first magnetic field search process, and performs the second magnetic field search process if the wire magnetic field M is not detected in the first magnetic field search process.
[0097] With the above configuration, if the wire magnetic field M is detected in the first magnetic field search process, the control unit 8 can omit the second magnetic field search process and immediately resume mowing operation. This allows the robotic lawnmower 2 to perform its work more smoothly.
[0098] In one or more embodiments, the second distance is the same distance as the first distance.
[0099] If the lawnmowing operation is resumed from a location different from the location where the lawnmowing operation was interrupted, there is a risk that the lawnmowing operation will end with an area (an unworked area) remaining where the robot lawnmower 2 has not performed work. With the above configuration, the position of the robot body 4 when the second magnetic field search process ends is hardly displaced from the position of the robot body 4 when the lawnmowing operation was interrupted. Therefore, by resuming the lawnmowing operation after the second magnetic field search process ends, it is possible to resume the lawnmowing operation from the area where the lawnmowing operation was interrupted. This makes it possible to prevent the lawnmowing operation from ending with an unworked area remaining.
[0100] In one or more embodiments, the second distance is less than the first distance.
[0101] There are cases where the magnetic sensor 38 reaches directly above the wire 112, and the magnetic sensor 38 no longer detects the wire magnetic field M, and the operation interruption condition is established. In this case, if the position of the robot body 4 when the second magnetic field search process is completed has not shifted at all from the position of the robot body 4 when the magnetic sensor 38 no longer detects the wire magnetic field M, the magnetic sensor 38 will again be directly above the wire 112. Therefore, even if the wire magnetic field M is detected in the first magnetic field search process or the second magnetic field search process, the wire magnetic field M may not be detected by the magnetic sensor 38 after the second magnetic field search process is completed. As a result, even if the lawn mowing operation is resumed, the lawn mowing operation will be immediately interrupted, and the work by the robot lawnmower 2 may not proceed smoothly. According to the above configuration, the position of the robot body 4 when the second magnetic field search process is completed can be shifted from the position of the robot body 4 when the magnetic sensor 38 no longer detects the wire magnetic field M. Therefore, it is possible to prevent the magnetic sensor 38 from being directly above the wire 112 when the second magnetic field search process is completed. As a result, if the wire magnetic field M is generated, the magnetic sensor 38 can detect the wire magnetic field M even after the second magnetic field search process has ended. This prevents the lawnmowing operation from being interrupted immediately after it is resumed, allowing the robotic lawnmower 2 to perform its work smoothly.
[0102] In one or more embodiments, the first distance is a distance of 1000 mm or less.
[0103] If the robot body 4 is moved significantly after the magnetic sensor 38 no longer detects the wire magnetic field M, there is a risk that the robot body 4 may end up in an unintended location (for example, a location where an obstacle is present). With the above configuration, it is possible to prevent the robot body 4 from moving significantly after the magnetic sensor 38 no longer detects the wire magnetic field M. This makes it possible to prevent the robot body 4 from ending up in an unintended location.
[0104] In one or more embodiments, the first distance is less than or equal to the overall length of the robotic lawnmower 2 .
[0105] If the robot body 4 is moved significantly after the magnetic sensor 38 no longer detects the wire magnetic field M, there is a risk that the robot body 4 may end up in an unintended location (for example, a location where an obstacle is present). With the above configuration, it is possible to prevent the robot body 4 from moving significantly after the magnetic sensor 38 no longer detects the wire magnetic field M. This makes it possible to prevent the robot body 4 from ending up in an unintended location.
[0106] In one or more embodiments, the control unit 8 is further configured to be capable of executing a notification process (see S20 of the process shown in FIG. 9 ) for notifying, via the display unit 11, the alarm unit 52, and / or the communication unit 50 (an example of a notification interface), that the wire magnetic field M is not detected by the magnetic sensor 38 (an example of an abnormality has occurred). The control unit 8 executes the notification process if 15 minutes (an example of a predetermined time) have passed since the end of the first magnetic field search process without the operation resumption process being executed.
[0107] According to the above configuration, if the wire magnetic field M is not detected by the magnetic sensor 38 even after the first magnetic field search process and the lawnmowing operation is not resumed, it is possible to notify the user of this.
[0108] In one or more embodiments, the control unit 8 is further configured to be capable of executing a notification process (see S20 of the process shown in FIG. 9 ) for notifying, via the display unit 11, the alarm unit 52, and / or the communication unit 50 (an example of a notification interface), that the wire magnetic field M is not detected by the magnetic sensor 38 (an example of an abnormality has occurred). The control unit 8 executes the notification process if 15 minutes (an example of a predetermined time) have passed since the end of the second magnetic field search process without the operation resumption process being executed.
[0109] According to the above configuration, if the wire magnetic field M is not detected by the magnetic sensor 38 and the lawnmowing operation is not resumed even after the first magnetic field search process and the second magnetic field search process have been performed, the user can be notified of this.
[0110] In one or more embodiments, the working unit 14 includes a cutting blade 34 for cutting the grass. The working robot functions as a robotic lawnmower 2 that is capable of autonomous movement.
[0111] According to the above configuration, the lawnmower 2 can smoothly carry out lawnmowing work. [Explanation of symbols]
[0112] 2: robot lawnmower, 4: robot body, 6: power supply unit, 8: control unit, 10: operation unit, 11: display unit, 12: moving unit, 14: working unit, 16: detection unit, 18: battery, 20: charging interface, 22: processor, 24: memory, 26: power supply circuit, 28L: caster, 28R: caster, 30L: driving wheel, 30R: driving wheel, 32L: moving motor, 32R: moving motor, 34: cutting blade, 36: working motor data, 38: magnetic sensor, 38a: magnetic sensor, 38b: magnetic sensor, 38c: magnetic sensor, 38d: magnetic sensor, 42: battery voltage detection circuit, 50: communication unit, 52: alarm unit, 100: site, 102: house, 104: pond, 106: road, 108: fence, 110: charging station, 112: wire, G: ground, M: wire magnetic field, MA: main area, SA: sub area, SM: signal model, WA: work area
Claims
1. A work robot used in a workplace where wires are installed, which moves and performs tasks based on the wire magnetic field generated around the wires, The robot body and A moving unit for moving the robot body, The robot body is supported by a work section, A magnetic sensor supported by the robot body, It includes a control unit, The control unit is configured to perform work operations, in which the robot body is moved by the moving unit while the work unit performs the work. The control unit, while performing the operation, If the predetermined conditions for interrupting operation are met, an operation interruption process is performed to interrupt the aforementioned work operation, After the aforementioned operation interruption process, the moving unit moves the robot body in a straight line for a first distance in the first straight-line direction, A first magnetic field search process that determines whether or not the wire magnetic field has been detected in the magnetic sensor, A work robot configured to perform an operation restart process to resume the work operation if the wire magnetic field is detected in the magnetic sensor after the work operation has been interrupted by the operation interruption process.
2. The working robot according to claim 1, wherein the operation interruption condition includes the wire magnetic field no longer being detected in the magnetic sensor.
3. It is equipped with multiple magnetic sensors, The aforementioned operation interruption condition includes the failure to detect the wire magnetic field in a predetermined number or more of the magnetic sensors among the plurality of magnetic sensors. The work robot according to claim 1, wherein the predetermined number is greater than half the total number of the multiple magnetic sensors.
4. The wire magnetic field includes a wire magnetic signal generated when a predetermined electrical signal is applied to the wire. The control unit has previously stored the signal model of the wire magnetic signal, The work robot according to claim 1, wherein the control unit determines that the wire magnetic field has been detected in the magnetic sensor when the magnetic signal observed in the magnetic sensor and the signal model of the wire magnetic signal match or are similar.
5. The work robot according to claim 1, wherein the control unit identifies the direction of movement of the robot body before interrupting the work operation, and sets the direction opposite to the identified direction of movement as the first straight-line direction in the first magnetic field search process.
6. The work robot according to claim 1, wherein the control unit is configured to, after the first magnetic field search process, move the robot body by a second distance in a second straight-line direction opposite to the first straight-line direction using the moving unit, and further execute a second magnetic field search process to determine whether or not the wire magnetic field has been detected by the magnetic sensor.
7. The work robot according to claim 6, wherein the control unit does not execute the second magnetic field search process if the wire magnetic field is detected in the first magnetic field search process, and executes the second magnetic field search process if the wire magnetic field is not detected in the first magnetic field search process.
8. The work robot according to claim 6, wherein the second distance is the same as the first distance.
9. The work robot according to claim 6, wherein the second distance is shorter than the first distance.
10. The work robot according to claim 1, wherein the first distance is a distance of 1000 mm or less.
11. The work robot according to claim 1, wherein the first distance is a distance less than or equal to the total length of the work robot.
12. The control unit is configured to further perform notification processing via a notification interface to notify that an abnormality has occurred. The work robot according to claim 1, wherein the control unit executes the notification process if a predetermined time has elapsed since the completion of the first magnetic field search process without the operation restart process being executed.
13. The control unit is configured to further perform notification processing via a notification interface to notify that an abnormality has occurred. The work robot according to claim 6, wherein the control unit executes the notification process if a predetermined time has elapsed since the completion of the second magnetic field search process without the operation restart process being executed.
14. The aforementioned work unit is equipped with a cutting blade for cutting grass, The work robot according to claim 1, which functions as an autonomously mobile robotic lawnmower.