Robot monitoring methods and robot systems

Abstract

This system detects changes over time in a robotic system, including robots that travel along a designated path. [Solution] The robot monitoring method acquires information on the rotation of the robot's wheels (drive wheels 61) while the robot (transport robot 6) is traveling along a path 15 within a specific area (building 12). A calculation circuit (controller 69) calculates the distance traveled along the path based on the acquired information. The calculation circuit calculates the actual distance corresponding to the path traveled by the robot. If the difference between the calculated distance traveled and the actual distance is greater than a predetermined threshold, an alert issuer issues an alert regarding wear on the robot's wheels.

Description

Technical Field

[0001] The technology disclosed herein relates to a method for monitoring a robot and a robot system.

Background Art

[0002] Patent Document 1 describes a conventional method for managing a moving body. The conventional management method manages an AGV (Automatic Guided Vehicle) as a moving body. The AGV has an external sensor and generates first position information of the AGV from the surrounding environment scanned by the external sensor and a map of the environment. The AGV also generates second position information of the AGV from a measured value of the rotational speed of the drive wheels. The conventional management method determines that the drive wheels are slipping based on the difference between the first position information and the second position information, and reduces the rotational speed of the electric motor when the drive wheels are slipping. The conventional management method can run the AGV while suppressing the slippage of the drive wheels.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a system including a robot that travels within a specific area using wheels, initially, the travel distance of the robot based on the number of rotations of the wheels corresponds to the distance on the map calculated based on the map of the specific area. However, when the operation of the system extends over a long period, due to the temporal change of the entire system including the robot, the deviation between the travel distance and the distance on the map may increase.

Means for Solving the Problems

[0005] The technology disclosed herein relates to a method for monitoring a robot. In the method for monitoring a robot, Information regarding the rotation of the robot's wheels while the robot is traveling along a path within a specific area is acquired. The calculation circuit calculates the distance traveled by the robot along the path based on the acquired information. The calculation circuit calculates the distance on the map corresponding to the path traveled by the robot, based on the map of the specific region. If the difference between the calculated mileage and the distance on the map is greater than a predetermined threshold, the alert issuer will issue an alert regarding wear on the robot's wheels. [Effects of the Invention]

[0006] According to the robot monitoring method described above, wear and tear on the robot's wheels can be determined based on the difference between the calculated distance traveled and the distance on the map. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows a portion of an automobile manufacturing plant where a robotic system has been implemented. [Figure 2] Figure 2 is a rear view of the work area. [Figure 3] Figure 3 is a block diagram of the robot system. [Figure 4] Figure 4 is a block diagram of the transport robot. [Figure 5] Figure 5 shows the wheels of the transport robot. [Figure 6] Figure 6 is a functional block diagram of the transport robot's controller. [Figure 7] Figure 7 is a flowchart related to the control of the transport robot. [Modes for carrying out the invention]

[0008] The following describes a robot management method and an embodiment of the robot system with reference to the drawings. The robot management method and robot system described herein are illustrative examples.

[0009] (Overall structure of the robot system) Figure 1 shows a part of an automobile manufacturing plant where robot system 1 is applied. Figure 2 illustrates a work area 13 in the manufacturing plant where work is performed on the workpiece.

[0010] A manufacturing line 10 is set up in the building 12 of the manufacturing plant. The inside of building 12 is an example of a specific area. In the illustrated example, the manufacturing line 10 is a line where welding, more specifically, spot welding, is performed on the automobile body 11. The workpiece is the body 11.

[0011] A robot system 1 is constructed on the manufacturing line 10. The robot system 1 includes an autonomous mobile transport robot 6, which will be described later. On the manufacturing line 10, the body 11 is transported by the transport robot 6. The work area 13 is the area where the workpieces transported by the transport robot 6 remain to receive work. The work area 13 is part of the manufacturing line 10. In the illustrated example, the manufacturing line 10 has one work area 13. Note that the number of work areas 13 included in the manufacturing line 10 is not limited to a specific number.

[0012] The front, rear, right, left, top, and bottom of the robot system 1 within the work area 13 are defined as follows, relative to the body 11 of the work object. The front-rear direction of the robot system 1 is perpendicular to the plane of Figure 2. The front of the robot system 1 corresponds to the front of the car body 11, and the rear of the robot system 1 corresponds to the rear of the car body 11. As will be described later, the front-rear direction corresponds to the transport direction of the body 11. The right of the robot system 1 is the right side of the plane of Figure 2. The right of the robot system 1 corresponds to the right side of the car body 11. The left of the robot system 1 corresponds to the left side of the car body 11. The left-right direction is perpendicular to the front-rear direction. The top of the robot system 1 is the top of the plane of Figure 2, and the bottom of the robot system 1 is the bottom of the plane. The top and bottom of the robot system 1 correspond to the top and bottom of the car body 11. The up-down direction is perpendicular to the front-rear direction. The above definitions are used to describe the robot system 1 and are not used to limit the structure or configuration of the robot system 1 and the elements contained therein as disclosed herein.

[0013] As shown in Figure 2, work robots 2 and 4 are installed in the work area 13. The work robots 2 and 4 perform spot welding on the body 11 in the work area 13. Note that work robots 2 and 4 are not essential components of the robot system 1.

[0014] Multiple work robots 2 are installed in the work area 13. The multiple work robots 2 are positioned on both the left and right sides of the automobile body 11. On the right side of the body 11, the multiple work robots 2 are arranged in the front-to-back direction of the body 11. Similarly, on the left side of the body 11, the multiple work robots 2 are arranged in the front-to-back direction of the body 11. The work robots 2 perform work on the body 11, which is transported to the work area 13. The work performed by the work robots 2 on the body 11 is welding. Each work robot 2 performs welding at various points on the body 11. The work robots 2 are vertical articulated robots having 5 to 7 axes. As shown in Figure 2, the work robots 2 have a welding gun 21 as an end effector. Note that the work robots 2 are not limited to vertical articulated robots. Also, the number of work robots 2 is not limited to a specific number. Also, the arrangement of the work robots 2 is not limited to a specific arrangement.

[0015] The work robot 4 is a locator 4 that lifts and supports the body 11 while the work robot 2 is working. Multiple locators 4 are installed in the work area 13. The multiple locators 4 are positioned on both the left and right sides of the body 11. The locators 4 are positioned between the work robot 2 and the transport robot 6. Note that the relative arrangement of the work robot 2, locators 4, and transport robot 6 in the work area 13 is not limited to the example in Figure 2. The locator 4 in the example figure is a 3-axis Cartesian robot. The locator 4 has a rod 45 that engages with the body 11. The rod 45 extends horizontally. The tip of the rod 45 engages with the body 11. The locator 4 changes the position of the tip of the rod 45 in the front-back, left-right, and up-down directions.

[0016] The robot system 1 includes one or more transfer robots 6. The transfer robot 6 transfers the workpiece to the work area 13. The transfer robot 6 travels on the flat floor surface 120 (see FIG. 5) of the factory. As shown in FIG. 2, the body 11 is placed on the carriage 14. The transfer robot 6 is located below the carriage 14 and engages with the carriage 14. The transfer robot 6 transfers the body 11 via the carriage 14. Note that the transfer robot 6 may directly support the body 11 without using the carriage 14. Note that the appearance of the transfer robot 6 shown in FIG. 2 is an example. The structure of the transfer robot 6 will be described later.

[0017] FIG. 3 is a block diagram of the robot system 1. The robot system 1 includes a system controller 16. The system controller 16 controls the entire robot system 1. Note that the system controller 16 is not an essential element of the robot system 1.

[0018] The robot system 1 includes a robot controller 17. Note that the robot controller 17 is not an essential element of the robot system 1. The robot controller 17 is electrically connected to the system controller 16. The electrical connection includes a wired or wireless connection. The robot controller 17 is electrically connected to the work robot 2. The robot controller 17 and the work robot 2 are connected one-to-one. The robot system 1 includes the same number of robot controllers 17 as the work robots 2. The robot controller 17 controls the work robot 2. More specifically, the robot controller 17 receives a control signal from the system controller 16 and outputs a control signal to the work robot 2. The work robot 2 receives a control signal from the robot controller 17 and here, performs a welding operation on the body 11.

[0019] The robot system 1 includes a locator controller 18. However, the locator controller 18 is not an essential component of the robot system 1. The locator controller 18 is electrically connected to the system controller 16. This electrical connection includes wired or wireless connections. The locator controller 18 is also electrically connected to a plurality of locators 4. The locator controller 18 controls the locators 4. More specifically, the locator controller 18 receives control signals from the system controller 16 and outputs control signals to the locators 4. The locators 4, upon receiving control signals from the locator controller 18, position and support the body 11 handed over from the transport robot 6 in a predetermined location.

[0020] The robot system 1 includes a control panel 19. However, the control panel 19 is not an essential component of the robot system 1. The control panel 19 is electrically connected to the system controller 16. Electrical connections include wired and wireless connections. The control panel 19 is also electrically connected to one or more transport robots 6.

[0021] The control panel 19 controls the transport robot 6. More specifically, the control panel 19 receives control signals from the system controller 16 and outputs control signals to the transport robot 6.

[0022] (Structure of a transport robot) The transport robot 6 autonomously transports the workpiece (body 11 in the example figure) to the work area 13. The transport robot 6 is, for example, an AGV (Automated Guided Vehicle). As shown by the dashed line in Figure 1, the AGV autonomously travels along a predetermined path 15 to bring the body 11 into the work area 13. The path 15 is set, for example, by magnetic tape placed on the floor surface 120. Multiple transport robots 6 travel along substantially the same path 15. The transport robot 6 has a SLAM (Simultaneous Localization and Mapping) function. With the SLAM function, the transport robot 6 can autonomously travel using a map 661 and a scanner 65, which will be described later.

[0023] Figure 4 shows the structure of the transport robot 6. The structure of the transport robot 6 in Figure 4 is an example of a transport robot 6.

[0024] The transport robot 6 has wheels that roll on the floor surface 120. The wheels include drive wheels 611 and 612, and passive wheels 621 and 622. The drive wheels 611 and 612 are independent. The transport robot 6 is an independently driven transport vehicle. The drive wheel 611 is located on the left side of the middle section of the transport robot 6 in the front-rear direction. The drive wheel 612 is located on the right side of the middle section of the transport robot 6. The axes of rotation of the drive wheels 611 and 612 extend in the left-right direction and are coaxial. The drive wheel 611 is mechanically connected to the motor 631. The drive wheel 612 is mechanically connected to the motor 632. The drive wheels 611 and 612 can rotate independently of each other.

[0025] Motors 631 and 632 are powered by a battery, which is mounted on the transport robot 6. Motors 631 and 632 are the driving source for the transport robot 6. The driving force from motors 631 and 632 is transmitted to the drive wheels 611 and 612, causing them to rotate.

[0026] Motors 631 and 632 each have an encoder 633. The encoder 633 outputs signals related to the rotation of the drive wheels 611 and 612, specifically the direction and speed of rotation of the drive wheels 611 and 612, to a controller 69, which will be described later.

[0027] If drive wheels 611 and 612 rotate in the same direction at the same speed, the transport robot 6 will move in a straight line. If drive wheels 611 and 612 rotate in the same direction at different speeds, the transport robot 6 will change its direction of travel. If drive wheels 611 and 612 rotate in different directions, the transport robot 6 will turn in place, that is, rotate around its vertical axis. In the following explanation, drive wheels 611 and 612 may be collectively referred to as drive wheel 61.

[0028] Figure 5 shows the drive wheel 61. The drive wheel 61 has a tire 60. The tire 60 is in contact with the floor surface 120 and rolls on the floor surface 120. The tire 60 is made of, for example, rubber to increase frictional resistance with the floor surface 120. As the travel distance of the transport robot 6 increases, the tire 60 wears down. As the tire 60 wears down, the diameter of the drive wheel 61 decreases from the initial D0, shown by the dashed line in Figure 5, to D1.

[0029] The driven wheel 621 is located at the center of the front end of the transport robot 6 in the left-right direction. The driven wheel 622 is located at the center of the rear end of the transport robot 6 in the left-right direction. Both the driven wheel 621 and the driven wheel 622 can be rotated. The transport robot 6 may have only one driven wheel.

[0030] The transport robot 6 has a scanner 65. The scanner 65 acquires information about the area around the transport robot 6. The scanner 65 includes, for example, LiDAR (Light Detection and Ranging). The scanner 65 is not limited to LiDAR. The scanner 65 is located at the front end and rear end of the transport robot 6, respectively.

[0031] The transport robot 6 has storage 66. Storage 66 stores various data. The data stored in storage 66 includes a map 661. Storage 66 includes magnetic recording media such as HDDs (Hard Disk Drives), optical recording media such as Blu-ray discs and DVDs (Digital Versatile Discs), and semiconductor recording media such as SSDs (Solid State Drives) or memory cards. The map 661 is a map of the building 12, which includes the manufacturing line 10. The map of the building 12 may be stored in the transport robot 6 in advance. Before transporting the body 11, the transport robot 6 may autonomously travel inside the building 12 and create the map 661 using a scanner 65 while traveling.

[0032] The transport robot 6 has a communication circuit 67. The communication circuit 67 communicates wirelessly with the control panel 19. The communication circuit 67 can receive control signals from the control panel 19. The communication circuit 67 can transmit, for example, the position information of the transport robot 6 to the control panel 19.

[0033] The transport robot 6 has a rotary table 68. The rotary table 68 is located on the top surface of the transport robot 6. The rotary table 68 engages with the body 11 via a trolley 14. The rotary table 68 rotates clockwise and counterclockwise around a vertical axis. The rotary table 68 rotates relative to the body of the transport robot 6. The rotary table 68 has a drive source. The drive source is, for example, an electric motor. The electric motor includes a servo motor or a stepping motor. More specifically, the rotary table 68 has a rotary motor that rotates the rotary table 68 around a vertical axis and a lifting motor that raises and lowers the rotary table 68. When the rotary table 68 rotates while the transport robot 6 is stationary, the body 11 rotates around the vertical axis via the trolley 14. The body 11 can rotate in place without moving in the forward / backward or left / right directions. The drive of the drive wheels 611 and 612 causes the transport robot 6 to rotate in place, and the rotating table 68 also rotates, allowing the orientation of the transport robot 6 to be changed without changing the orientation of the body 11.

[0034] The transport robot 6 has a controller 69. The controller 69 controls the transport robot 6. The controller 69 is electrically connected to motors 631, 632, a scanner 65, storage 66, a communication circuit 67, and a rotary table 68. The controller 69 receives control signals from the system controller 16 through the control panel 19 and the communication circuit 67, and causes the transport robot 6 to perform actions corresponding to the received control signals. The transport robot 6 autonomously travels along a predetermined path 15 to a position specified by the system controller 16, i.e., the work area 13 of the work robot 2. More specifically, the controller 69 outputs travel control signals to motors 631 and 632 that control the rotation speed of the drive wheels 61, thereby controlling the transport robot 6 to travel in a straight line, change direction, or turn (change direction) in place, so that the transport robot 6 autonomously travels to the work area 13. The motors 631 and 632 receive the travel control signals and rotate at a speed corresponding to the travel control signals to drive the drive wheels 61.

[0035] When the transport robot 6 is traveling, the controller 69 directs the transport robot 6 to travel along a predetermined path 15. While the transport robot 6 is traveling, the controller 69 estimates the transport robot 6's own position based on the signal from the scanner 65 and the map 661. Based on its estimated position, the transport robot 6 determines that it has reached the work area 13. As the transport robot 6 autonomously travels to the work area 13 along the path 15, the body 11 is transported to the work area 13.

[0036] (Monitoring of transport robots) The robot system 1 monitors the travel status of the transport robot 6 and issues alerts regarding the environment of the transport robot 6 or the drive wheels 61 of the transport robot 6. Figure 6 illustrates the functional blocks of the controller 69 of the transport robot 6. The controller 69 has a travel distance calculation unit 691 and a map distance calculation unit 692 as functional blocks.

[0037] The distance calculation unit 691 calculates the distance traveled along the path 15 of the transport robot 6 based on information regarding the rotation of the drive wheels 61 of the transport robot 6. Specifically, as shown in Figure 5, the distance traveled is calculated based on the distance traveled per unit time πD0 × n, which is calculated from the initial diameter D0 of the drive wheels 61 and the rotational speed n based on the signal from the encoder 633. The distance traveled calculated by the distance calculation unit 691 is based on so-called odometry.

[0038] The distance calculation unit 691 calculates the distance traveled based on the initial diameter D0 that is stored in advance. When the diameter of the drive wheel 61 decreases to D1 due to wear of the tire 60, the distance the transport robot 6 travels with one rotation of the drive wheel 61 decreases. The number of rotations of the drive wheel 61 required for the transport robot 6 to reach the target point based on its estimated self-position increases. When the diameter of the drive wheel 61 decreases to D1, the distance traveled calculated by the distance calculation unit 691 becomes longer than the distance actually traveled by the transport robot 6. Also, if the drive wheel 61 slips against the floor surface 120, the transport robot 6 does not move even if the drive wheel 61 rotates, so the distance traveled calculated by the distance calculation unit 691 based on the number of rotations of the drive wheel 61 becomes longer than the distance actually traveled by the transport robot 6.

[0039] The path 15 of the transport robot 6 is divided into multiple sections. Figure 1 includes the first section 91, the second section 92, the third section 93, the fourth section 94, the fifth section 95, and the sixth section 96. Note that there are not limited to six sections. The travel distance calculation unit 691 calculates the travel distances DT91, DT92, DT93, DT94, DT95, and DT96 for each section 91, 92, 93, 94, 95, and 96 as the transport robot 6 passes through each section.

[0040] The map distance calculation unit 692 calculates the map distance corresponding to the path 15 traveled by the transport robot 6, based on the transport robot 6's own position estimated using the map 661 and the scanner 65. Each time the transport robot 6 passes through one of the sections 91, 92, 93, 94, 95, or 96, the map distance calculation unit 692 calculates the map distances DM91, DM92, DM93, DM94, DM95, and DM96 for that section. The map distance calculated by the map distance calculation unit 692 is an example of the actual distance corresponding to the path 15 traveled by the transport robot 6. Alternatively, instead of the map distance calculation unit 692 calculating the map distance based on the map 661, the controller 69 may calculate the actual distance traveled by the transport robot 6 from actual measurements.

[0041] The controller 69 has a difference calculation unit 693 as a functional block. The difference calculation unit 693 calculates the difference between the travel distances DT91, DT92, DT93, DT94, DT95, DT96 calculated by the travel distance calculation unit 691 and the map distances DM91, DM92, DM93, DM94, DM95, DM96 calculated by the map distance calculation unit 692. The difference calculation unit 693 calculates the difference between the travel distance and the map distance for each section.

[0042] The controller 69 has a comparison unit 694 as a functional block. The comparison unit 694 compares the difference calculated for each interval with a predetermined threshold. If the difference exceeds the threshold, the comparison unit 694 issues an alert to the control panel 19. The comparison unit 694 is an example of an alert issuer.

[0043] More specifically, the comparison unit 694 determines that the tires 60 of the drive wheels 61 are worn if the section in which the difference exceeds a threshold spans two or more sections. In other words, if the diameter of the drive wheels 61 is smaller than the initial diameter, the distance traveled calculated by the distance traveled calculation unit 691 will be longer than the distance on the map, regardless of which section the transport robot 6 is traveling through. The comparison unit 694 may also determine that the tires 60 of the drive wheels 61 are worn if the section in which the difference exceeds a threshold spans all sections.

[0044] In response, the comparison unit 694 determines that the drive wheel 61 is slipping in a specific section if the section in which the difference exceeds a threshold is a specific section. The specific section may be a single section or multiple non-contiguous sections. The comparison unit 694 may also determine that the drive wheel 61 is slipping in a section in which the difference exceeds a threshold if there is one or more sections in which the difference exceeds a threshold and one or more sections in which the difference does not exceed a threshold.

[0045] As shown in Figure 3, the control panel 19 has a display 191. The control panel 19 receives an alert issued by the transport robot 6 and displays the alert on the display 191. Depending on the alert from the transport robot 6, the display 191 displays an alert regarding wear on the tires 60 of the drive wheels 61, or an alert regarding slippage occurring in a specific section of the path 15. The manager of the robot system 1 replaces the tires 60 of the drive wheels 61 or checks the specific section where slippage is occurring, according to the alert displayed on the display 191.

[0046] Figure 7 is a flowchart showing the control of the transport robot 6. First, in step S1 after starting, the transport robot 6 determines whether it has received a travel instruction from the system controller 16. If it has received a travel instruction, the transport robot 6 travels in step S2.

[0047] In step S3, the transport robot 6 determines whether it has completed traveling one section, and continues traveling in step S2 until it has completed traveling one section.

[0048] If the transport robot 6 completes travel through one section in step S3, in step S4, it stores the odometry information for that section in the storage 66. The odometry information is the distance traveled in that section, calculated by the travel distance calculation unit 691 based on information regarding the rotation of the drive wheels 61. If the transport robot 6 continues to travel after step S4, the process in Figure 7 repeats steps S1, S2, S3, and S4. If the transport robot 6 travels through multiple sections, it stores the odometry information for each of the multiple sections individually. Alternatively, instead of the storage 66 storing the odometry information, or the storage 66 may store the odometry information and the control panel 19 may receive the odometry information from the transport robot 6 and store it as well.

[0049] If no travel instruction is received in step S1, for example, if travel to a location specified by the system controller 16 is completed, the transport robot 6 stops in step S5. Then, in step S6, the transport robot 6 reads the odometry information stored in the storage 66, and in step S7, calculates the difference between the travel distance DT91, DT92, ... and the distance on the map DM91, DM92, ... for each section. Then, in step S8, the transport robot 6 determines whether the difference exceeds a threshold for each section.

[0050] If neither difference exceeds the threshold, the transport robot 6 determines that there is no wear on the tires 60 and no slippage on the drive wheels 61. The process in Figure 7 returns to the start.

[0051] If any difference exceeds a threshold, the transport robot 6 determines in step S9 whether the section where the difference exceeds the threshold is limited to a specific section. If the determination in step S9 is Yes, the transport robot 6 determines that slippage of the drive wheel 61 has occurred in that section and issues an alert in step S10 regarding the confirmation of the environment of the specific section in the route 15. If the determination in step S9 is No, the transport robot 6 determines that the tire 60 of the drive wheel 61 is worn and issues an alert in step S11 regarding the replacement of the tire 60.

[0052] (Effects and Benefits) For example, if the tires 60 of the drive wheels 61 are replaced based on the number of days the transport robot 6 is in use, the tires 60 may be replaced even if they are not worn. Similarly, if the tires 60 of the drive wheels 61 are replaced based on the distance traveled by the transport robot 6, the tires 60 may be replaced even if they are not worn.

[0053] Furthermore, since the transport robot 6 transports workpieces, the rate of wear on the tires 60 varies depending on the weight of the workpieces being transported. If the tires 60 were to be replaced based on the number of days of use or the distance traveled, there is a risk that the timing of tire replacement may be delayed.

[0054] Furthermore, in a robot system 1 equipped with multiple transport robots 6, there may be individual differences in the degree of wear of the tires 60.

[0055] The aforementioned robot system 1 can accurately estimate the wear of the tires 60 of each transport robot 6 by comparing the travel distances DT91, DT92, ... calculated based on so-called odometry information with the map distances DM91, DM92, ... calculated based on the map 661. This allows for the replacement of the tires 60 at an appropriate time.

[0056] Furthermore, the robot system 1 calculates the distance traveled for each section based on odometry information and compares the distance traveled for each section with the distance on the map. Based on this comparison information, the robot system 1 can distinguish between tire wear 60 and slippage of the drive wheels 61 in a specific section. This also enables the replacement of the tires 60 at the appropriate time. In addition, since slippage of the drive wheels 61 in a specific section can be detected, it becomes possible to eliminate the cause of the slippage.

[0057] The AGV (Automated Guided Vehicle) 6 travels along a predetermined path 15. The robot system 1 can accurately compare the distance traveled along path 15 with the map distance corresponding to the path 15 traveled by the AGV 6.

[0058] (modified version) In the flow chart of Figure 7, the transport robot 6, in steps S6 to S11 after stopping its movement, compares the distance traveled along the route 15 with the distance on the map corresponding to the route 15 traveled by the transport robot 6 to determine whether an alert should be issued. The transport robot 6 may also execute steps S6 to S11 each time it passes through a section while traveling.

[0059] Furthermore, the flow in Figure 7 determines slip of the drive wheels 61 in a specific section based on the driving status of one transport robot 6. Slip of the drive wheels 61 in a specific section may also be determined based on the driving status of multiple transport robots 6. For example, if the difference between the driving distance DT91, DT92, ... and the distance on the map DM91, DM92, ... of the first transport robot 6 exceeds a threshold in a certain section, and the difference between the driving distance DT91, DT92, ... and the distance on the map DM91, DM92, ... of the second transport robot 6 also exceeds a threshold in the same section, then there is a high probability that the environment in that section is deteriorating, that is, that a factor causing slip is present in that section. The robot system 1 may also determine whether or not to issue an alert based on the driving status of multiple transport robots 6. The more transport robots 6 there are, the higher the accuracy of determining environmental factors. For example, if the difference between the travel distance DT91, DT92, ... and the distance on the map DM91, DM92, ... of the first transport robot 6 exceeds a threshold in a certain section, while the difference between the travel distance DT91, DT92, ... and the distance on the map DM91, DM92, ... of the second and third transport robots 6 does not exceed a threshold in the same section, then it is possible that a malfunction has occurred in the first transport robot 6, or that a temporary environmental factor has occurred (for example, the scanner 65 detected something in the dark due to the setting sun, or water droplets on the floor dried up quickly, or the first transport robot 6 stepped on a pebble).

[0060] Furthermore, in the robot system 1 described above, the transport robot 6 determines whether or not to issue an alert in steps S6 to S11. The control panel 19 may receive odometry information from the transport robot 6 and determine whether or not to issue an alert in accordance with steps S6 to S11, or the system controller 16 may determine whether or not to issue an alert in accordance with steps S6 to S11.

[0061] Furthermore, in the robot system 1 described above, the display 191 of the control panel 19 displays the alert, but the display of the alert is not limited to the control panel 19. For example, an information terminal (e.g., a tablet) that can communicate with the control panel 19 may receive information from the control panel 19 and display the alert. Alternatively, an information terminal that can communicate with the transport robot 6 may receive information from the transport robot 6 and display the alert. The display on the transport robot 6 may also display the alert. Moreover, the alert is not limited to display; for example, the transport robot 6 may announce the alert by voice.

[0062] The transport robot 6 is not limited to an AGV; for example, it may be an AMR (Autonomous Mobile Robot). The AMR has SLAM functionality. The AMR eliminates the need for magnetic tape on the floor surface 120.

[0063] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, then the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0064] (Aspect) The embodiments described above are specific examples of the following embodiments.

[0065] (Aspect 1) Information regarding the rotation of the robot's (6) wheels (61) while the robot (6) is traveling along a path (15) within a specific area (12) is acquired. The calculation circuit (69) calculates the travel distance (DT91, DT92, ...) of the robot (6) along the path (15) based on the acquired information, The calculation circuit (69) calculates the actual distances (DM91, DM92, ...) corresponding to the path (15) traveled by the robot (6), If the difference between the calculated mileage (DT91, DT92, ...) and the actual mileage (DM91, DM92, ...) is greater than a predetermined threshold, the alert issuer (69) issues an alert regarding wear on the wheels (61) of the robot (6). Method for monitoring robot (6).

[0066] The calculation circuit (69) calculates the travel distance (DT91, DT92, ...) along the path (15) of the robot (6) based on so-called odometry information. The calculation circuit (69) also calculates the actual distance (DM91, DM92, ...) corresponding to the path (15) traveled by the robot (6).

[0067] As the wheels (61) of the robot (6) wear down over time and their diameter becomes smaller than their initial diameter, the distance the robot (6) travels per rotation of the wheels (61) becomes shorter than initially. As a result, the distance traveled (DT91, DT92, ...) becomes longer than the actual distance (DM91, DM92, ...).

[0068] If the difference between the calculated mileage (DT91, DT92, ...) and the actual mileage (DM91, DM92, ...) is greater than a predetermined threshold, the alert issuer (69) issues an alert regarding wheel (61) wear, thereby enabling prompt detection of wheel (61) wear.

[0069] (Aspect 2) The calculation circuit (69) calculates the map distances (DM91, DM92, ...) corresponding to the path (15) traveled by the robot (6) based on the map (661) of the specific region, as the actual distance. A method for monitoring a robot as described in Embodiment 1.

[0070] By using a map of a specific area (661), the calculation circuit (69) can accurately calculate the actual distance traveled by the robot (6).

[0071] (Aspect 3) The robot (6) travels along the first section (91, 92, 93, 94, 95, 96) and the second section (91, 92, 93, 94, 95, 96) of the path (15), The calculation circuit (69) calculates the first travel distance (DT91, DT92, DT93, DT94, DT95, DT96) in the first section (91, 92, 93, 94, 95, 96) and the second travel distance (DT91, DT92, DT93, DT94, DT95, DT96) in the second section (91, 92, 93, 94, 95, 96). A method for monitoring the robot (6) as described in embodiment 1 or 2.

[0072] By calculating the mileage (DT91, DT92, DT93, DT94, DT95, DT96) for each section (91, 92, 93, 94, 95, 96), it is possible to detect wear on the wheels (61).

[0073] (Aspect 4) If the difference between the first travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the first actual distance corresponding to the first section (DM91, DM92, DM93, DM94, DM95, DM96) is greater than a predetermined threshold, and the difference between the second travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the second actual distance corresponding to the second section (DM91, DM92, DM93, DM94, DM95, DM96) is greater than the threshold, the alert issuer (69) issues an alert regarding wear of the wheel (61). A method for monitoring the robot (6) described in Embodiment 3.

[0074] Regardless of the section traveled by the robot (6), if there is a large difference between the travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the actual distance (DM91, DM92, DM93, DM94, DM95, DM96) in multiple sections, it can be determined that the wheels (61) are worn out.

[0075] (Aspect 5) If the difference between the first travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the first actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is greater than the threshold, and the difference between the second travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the second actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is less than or equal to the threshold, or if the difference between the first travel distance (DT91, DT92, If the difference between DT93, DT94, DT95, DT96) and the first actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is less than or equal to the threshold, and the difference between the second travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the second actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is greater than the threshold, the alert issuer (69) issues an alert regarding the environment of the specific area (12). A method for monitoring the robot (6) according to embodiment 3 or 4.

[0076] If there is a large difference between the travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the actual distance (DM91, DM92, DM93, DM94, DM95, DM96) in a specific section, it can be inferred that the cause lies in that specific section (91, 92, 93, 94, 95, 96).

[0077] (Aspect 6) If the difference between the first travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the first actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is greater than the threshold, and the difference between the second travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the second actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is less than or equal to the threshold, the alert indicates that the wheels slipped in the first section (91, 92, 93, 94, 95, 96). If the difference between the first travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the first actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is less than or equal to the threshold, and the difference between the second travel distance (DT91, DT92, DT93, DT94, DT95, DT96) and the second actual distance (DM91, DM92, DM93, DM94, DM95, DM96) is greater than the threshold, the alert is that the wheels slipped in the second section (91, 92, 93, 94, 95, 96). A method for monitoring the robot (6) described in Embodiment 5.

[0078] (Aspect 7) If the difference between the first travel distance (DT91, DT92, ...) and the first actual distance (DM91, DM92, ...) of the robot (6) is greater than the threshold, and the difference between the second travel distance (DT91, DT92, ...) and the second actual distance (DM91, DM92, ...) is less than or equal to the threshold, and the difference between the first travel distance (DT91, DT92, ...) and the first actual distance (DM91, DM92, ...) of the second robot (6) is greater than the threshold, and the difference between the second travel distance (DT91, DT92, ...) and the second actual distance (DM91, DM92, ...) is less than or equal to the threshold, then the alert issuer issues an alert regarding the environment of the first section. If the difference between the first travel distance (DT91, DT92, ...) and the first actual distance (DM91, DM92, ...) of the robot (6) is less than or equal to the threshold, and the difference between the second travel distance (DT91, DT92, ...) and the second actual distance (DM91, DM92, ...) is greater than the threshold, and the difference between the first travel distance (DT91, DT92, ...) and the first actual distance (DM91, DM92, ...) of the second robot (6) is greater than the threshold, and the difference between the second travel distance (DT91, DT92, ...) and the second actual distance (DM91, DM92, ...) is less than or equal to the threshold, then the alert issuer issues an alert regarding the environment of the second section. A method for monitoring the robot (6) as described in embodiment 5 or 6.

[0079] For each of the multiple robots (6), including robot (6) and the second robot (6), if the difference between the first travel distance (DT91, DT92, ...) and the first actual distance (DM91, DM92, ...) is large, there is a high probability that some factor exists in the environment of the first section. The alert issuer issues an alert regarding the environment of the first section.

[0080] Similarly, for each of the multiple robots (6), including robot (6) and the second robot (6), if the difference between the second travel distance (DT91, DT92, ...) and the second actual distance (DM91, DM92, ...) is large, there is a high probability that some factor exists in the environment of the second section. The alert issuer issues an alert regarding the environment of the second section.

[0081] (Pattern 8) The robot (6) autonomously navigates within the specified area (12) while estimating its own position using a map (661) and a scanner (65) that detects the surrounding environment. A method for monitoring a robot (6) as described in any one of embodiments 1 to 7.

[0082] The robot (6) can calculate the actual distance (DM91, DM92, ...) by estimating its own position.

[0083] (Aspect 9) The robot (6) is an AGV that travels according to a predetermined path (15). A method for monitoring the robot (6) described in aspect 8.

[0084] Since the AGV travels along a predetermined route (15), it is possible to compare the distance traveled along the route (15) based on odometry information (DT91, DT92, ...) with the actual distance traveled based on the map (661) (DM91, DM92, ...).

[0085] (Aspect 10) The robot (6) is a transport robot that transports the workpiece (11) in the specific region (12). A method for monitoring the robot (6) as described in aspect 8 or 9.

[0086] The rate of wear on the wheels (61) varies depending on the weight of the workpiece being transported by the robot (6). Comparing the travel distance (DT91, DT92, ...) with the actual distance (DM91, DM92, ...) allows for highly accurate estimation of wheel (61) wear.

[0087] (Aspect 11) A robot (6) having wheels (61) that roll on the floor surface (120) of a specific area (12) and traveling along a path (15) within the specific area (12), A sensor (633) that outputs a signal regarding the rotation of the wheels (61) while the robot (6) is traveling along the path (15), A calculation circuit (69) calculates the distance traveled by the robot (6) along the path (15) based on the signal from the sensor (633), and also calculates the actual distance (DM91, DM92, ...) corresponding to the path (15) traveled by the robot (6), The system includes an alert generator (69) that issues an alert regarding wear on the wheels (61) of the robot (6) when the difference between the calculated mileage (DT91, DT92, ...) and the actual mileage (DM91, DM92, ...) is greater than a predetermined threshold, Robot system (1). [Explanation of Symbols]

[0088] 1. Robot System 11 Body (Work) 12 Buildings (specific areas) 120 floor surface 15 routes 6. Transport robots 61. Drive wheels 633 Encoder (Sensor) 65 Scanners 661 Map 69. Controller (calculation circuit, alert generator) 691 Distance calculation unit (calculation circuit) 692 Map-based distance calculation unit (calculation circuit) 694 Comparison Unit (Alert Generator) Sections 91-96 DM91~DM96 Distance on map DT91~DT96 Mileage

Claims

1. Information regarding the rotation of the robot's wheels while the robot is traveling along a path within a specific area is acquired. The calculation circuit calculates the distance traveled by the robot along the path based on the acquired information. The calculation circuit calculates the actual distance corresponding to the path traveled by the robot. If the difference between the calculated mileage and the actual mileage is greater than a predetermined threshold, the alert issuer will issue an alert regarding wear on the robot's wheels. Methods for monitoring robots.

2. In the robot monitoring method described in claim 1, The calculation circuit calculates the actual distance as the map distance corresponding to the path traveled by the robot, based on the map of the specific region. Methods for monitoring robots.

3. In the robot monitoring method described in claim 1, The robot travels through the first section and the second section of the aforementioned path. The calculation circuit calculates the first travel distance in the first section and the second travel distance in the second section. Methods for monitoring robots.

4. In the robot monitoring method described in claim 3, If the difference between the first travel distance and the first actual distance corresponding to the first section is greater than a predetermined threshold, and the difference between the second travel distance and the second actual distance corresponding to the second section is greater than the threshold, the alert issuer issues an alert regarding the wear of the wheels. Methods for monitoring robots.

5. In the robot monitoring method described in claim 4, If the difference between the first travel distance and the first actual distance is greater than the threshold, and the difference between the second travel distance and the second actual distance is less than or equal to the threshold, or if the difference between the first travel distance and the first actual distance is less than or equal to the threshold, and the difference between the second travel distance and the second actual distance is greater than the threshold, the alert issuer issues an alert regarding the environment of the specific area. Methods for monitoring robots.

6. In the robot monitoring method described in claim 5, If the difference between the first travel distance and the first actual distance is greater than the threshold, and the difference between the second travel distance and the second actual distance is less than or equal to the threshold, the alert indicates that the wheels are slipping in the first section. If the difference between the first travel distance and the first actual distance is less than or equal to the threshold, and the difference between the second travel distance and the second actual distance is greater than the threshold, the alert indicates that the wheels are slipping in the second section. Methods for monitoring robots.

7. In the robot monitoring method according to claim 5 or 6, If the difference between the first travel distance and the first actual distance of the robot is greater than the threshold, and the difference between the second travel distance and the second actual distance is less than or equal to the threshold, and the difference between the first travel distance and the first actual distance of the second robot is greater than the threshold, and the difference between the second travel distance and the second actual distance is less than or equal to the threshold, then the alert issuer issues an alert regarding the environment of the first section. If the difference between the first travel distance and the first actual distance of the robot is less than or equal to the threshold, and the difference between the second travel distance and the second actual distance is greater than the threshold, and the difference between the first travel distance and the first actual distance of the second robot is greater than the threshold, and the difference between the second travel distance and the second actual distance is less than or equal to the threshold, then the alert issuer issues an alert regarding the environment of the second section. Methods for monitoring robots.

8. In the robot monitoring method described in claim 1, The robot autonomously navigates within the specified area while estimating its own position using a map and a scanner that detects the surrounding environment. Methods for monitoring robots.

9. In the robot monitoring method described in claim 8, The robot is an AGV (Automatic Guided Vehicle) that travels according to a predetermined path. Methods for monitoring robots.

10. In the robot monitoring method according to claim 8 or 9, The robot is a transport robot that transports a workpiece in the specified area. Methods for monitoring robots.

11. A robot having wheels that roll on the floor surface of a specific area and that travels along a path within the specific area, A sensor that outputs a signal regarding the rotation of the wheels while the robot is traveling along the path, A calculation circuit that calculates the distance traveled by the robot along the path based on the signal from the sensor, and also calculates the actual distance corresponding to the path traveled by the robot, The system includes an alert issuer that issues an alert regarding wear on the robot's wheels when the difference between the calculated distance traveled and the actual distance traveled is greater than a predetermined threshold. Robot system.

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