Mobile robot with robotic arm

Abstract

To provide a mobile robot with a robot arm in which a robot arm is mounted on a vehicle body and a safety protection space is formed by use of a noncontact type sensor so that the safety of the surroundings is secured at the time of traveling of the vehicle body and operating the robot, and it eliminates that the noncontact type sensor becomes a traveling obstacle of the vehicle body.SOLUTION: A mobile robot 1A with a robot arm is given in which a robot arm 11 is mounted on a vehicle body 2 and noncontact type sensors 80A, 80B, 80C are arranged. Detection zones Da, Db, Dc which become a vertical plane are made by the noncontact type sensors 80A, 80B, 80C, a safety protection space Sa of the robot arm 11 is formed by the detection zones Da, Db, and Dc, and the noncontact type sensors 80A, 80B, and 80C are movable in the horizontal direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a mobile robot with a robot arm. [Background technology]

[0002] In order to automate the movement of goods within facilities such as factories, warehouses, and hospitals, the introduction of automated guided vehicles is progressing. As for the method of automatic driving in automated guided vehicles, autonomous mobile automated guided vehicles are becoming mainstream compared to the conventional route guidance type due to recent improvements in information processing capabilities and surrounding information gathering technology. Furthermore, automated guided vehicles are also being equipped with robot arms to automate loading and unloading.

[0003] In the case of a mobile robot with a robot arm (i.e., a mobile robot that runs autonomously with a robot arm mounted on a moving base that realizes the robot's mobility), it is necessary to ensure safety in terms of both the movement of the vehicle body and the movement of the robot arm.

[0004] In relation to this, it has been proposed to provide non-contact type obstacle detection sensors for the carriage, such as ultrasonic sensors and optical sensors, at the front and rear of a moving platform called a transport platform, with detection areas set horizontally, and to provide non-contact type obstacle detection sensors for the arm around the moving platform, pointing diagonally upward, and to set the obstacle detection distance of the obstacle detection sensor for the carriage longer than the obstacle detection distance of the obstacle detection sensor for the arm (Patent Document 1). According to this mobile robot, when obstacles such as people, surrounding objects, and other mobile robots are present ahead in the direction of travel, the obstacle detection sensor for the carriage detects the obstacle before the obstacle detection sensor for the arm detects the obstacle, so that the mobile platform can be stopped before the obstacle detection sensor for the arm detects the obstacle, and further, if the obstacle detection sensor for the carriage detects an obstacle but the obstacle detection sensor for the arm does not detect an obstacle, no safety assurance operation is performed for the robot arm, so that the robot arm can continue to work even after the moving platform has stopped until the obstacle detection sensor for the arm detects an obstacle. Therefore, it is said that the work by the robot arm can be efficiently performed.

[0005] It has also been proposed to use the robot's operating program to restrict the amount by which the robot extends beyond the planar projection range of a movable platform called a mobile cart, as well as to restrict the robot's operating range by using hardware such as partitions surrounding the workbench (Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-300252 [Patent Document 2] JP 2018-111180 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, as described in Patent Document 1, if the detection ranges and directions of the cart obstacle detection sensor and the arm obstacle detection sensor are made different, and the robot arm is allowed to continue working in a state where the cart obstacle detection sensor detects an obstacle but the arm obstacle detection sensor does not detect an obstacle, there is a risk of the robot arm colliding with the obstacle if the obstacle approaches the robot arm quickly, and there is a possibility that a person working around the robot arm may be injured, for example.

[0008] Furthermore, as described in Patent Document 2, even if the operating range of a robot arm is restricted by the amount that it extends beyond the planar projection range of the moving base, it is not possible to prevent people from entering that operating range, and there is a risk of injury to those who enter the operating range.

[0009] In order to ensure safety, it is conceivable to set up the non-contact sensor on the moving platform at a safe distance away from the restricted space in which the robot arm is permitted to operate, forming a safe protected space. In this case, if the detection area of ​​the non-contact sensor that detects the intrusion of an obstacle forms a horizontal plane, a safety distance of 1 to 3 m is normally required to prevent contact between a person and the robot arm, whereas if the detection area forms a vertical plane extending vertically to the floor surface, the safety distance can be shortened to about 0.5 to 1 m.

[0010] However, even if a non-contact sensor is installed on the mobile platform so that the detection area forms a vertical plane, if the non-contact sensor is installed at a safe distance away from the restricted space of the robot arm, the non-contact sensor may become an obstacle to the mobile platform's travel, making it impossible to pass through a passage of the same width as before. Also, when the mobile platform turns a corner, the contact sensor may come into contact with surrounding structures, causing damage to the non-contact sensor and surrounding structures.

[0011] Therefore, the object of the present invention is to provide a technology for a mobile robot having a robot arm mounted on a mobile base, which uses a non-contact sensor to form a safe protection space, thereby ensuring safety for the surroundings when the mobile base is moving or the robot is working, and preventing the non-contact sensor from becoming an obstacle to the movement of the mobile base. [Means for solving the problem]

[0012] The inventor has conceived the idea that in order to enable the mobile robot with a robot arm, which has a robot arm mounted on a car body that serves as a moving base, to move a non-contact sensor so that the detection area for detecting the intrusion of obstacles forms a vertical plane, and to form a safe protected space in that detection area while ensuring safety for the surroundings, it is effective to make the horizontal position of the non-contact sensor movable, and has completed the present invention.

[0013] That is, the present invention provides a mobile robot with a robot arm, the robot arm being mounted on a vehicle body and having a non-contact sensor, The non-contact sensor has a detection area that forms a vertical plane, the detection area forms a safe protection space for the robot arm, and the horizontal position of the non-contact sensor is movable, thereby providing a mobile robot with a robot arm.

[0014] The present invention also provides a method for forming a safeguard space for a mobile robot with a robot arm, the robot arm being mounted on a vehicle body, by using a non-contact sensor provided on the mobile robot with the robot arm, the method comprising the steps of: The detection area of ​​the non-contact sensor is a vertical plane, and the horizontal position of the non-contact sensor is made movable, thereby providing a method for forming a safeguard space in which the size of the safeguard space can be varied.

[0015] In this specification, the "detection area" is not limited to the entire range in which the non-contact sensor itself is capable of detecting the presence of an object, but may be a portion of that entire range that is determined by a user or designer using software or the like. Effect of the Invention

[0016] According to the mobile robot with a robot arm of the present invention, the detection area of ​​the non-contact sensor which forms the safeguard space forms a vertical plane, and furthermore, the horizontal position of the non-contact sensor is movable. Therefore, for example, when the vehicle body is moved while the robot arm is stopped working, if the non-contact sensor is installed near the vehicle body, the non-contact sensor is unlikely to impede the movement of the mobile robot with a robot arm even if the passage width is narrow, and when the vehicle body is stopped and the robot arm is made to work, the non-contact sensor is installed in a position away from the outer periphery of the vehicle body, so that the safety required for the work of the robot arm can be ensured.

[0017] Thus, according to the present invention, a safe protection space can be secured by the non-contact sensor, while preventing the non-contact sensor from becoming an obstacle to the travel of the mobile robot with a robot arm. [Brief description of the drawings]

[0018] [Figure 1A] FIG. 1A is a top view of a mobile robot 1A with a robot arm in which the robot arm is at rest and a non-contact sensor is located near the vehicle body. [Figure 1B] FIG. 1B is a front view of the mobile robot with robot arm 1A in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 1C] FIG. 1C is a side view of the mobile robot with robot arm 1A in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 2A] FIG. 2A is a top view of the mobile robot 1A with a robot arm when the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. [Figure 2B] FIG. 2B is a front view of the mobile robot with robot arm 1A with the robot arm in operation and the non-contact sensor away from the vicinity of the vehicle body. [Figure 2C]FIG. 2C is a side view of the mobile robot with robot arm 1A with the robot arm in operation and the non-contact sensor away from the vicinity of the vehicle body. [Figure 3A] FIG. 3A is a top view of the mobile robot 1A with a robot arm when the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. [Figure 3B] FIG. 3B is a front view of the mobile robot with robot arm 1A with the robot arm in operation and the non-contact sensor away from the vicinity of the vehicle body. [Figure 3C] FIG. 3C is a side view of the mobile robot with robot arm 1A with the robot arm in operation and the non-contact sensor away from the vicinity of the vehicle body. [Figure 4] FIG. 4 is an explanatory diagram of the passage of the mobile robot 1A with a robot arm. [Diagram 5] FIG. 5 is a front view of the mobile robot with robot arm 1A storing an article in a transportation box. [Figure 6A] FIG. 6A is a top view of a mobile robot with a robot arm 1B in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 6B] FIG. 6B is a front view of the mobile robot with robot arm 1B in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 6C] FIG. 6C is a side view of the mobile robot with robot arm 1B in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 7A] FIG. 7A is a top view of a mobile robot 1B with a robot arm when the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. [Figure 7B] FIG. 7B is a front view of mobile robot 1B with a robot arm while the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. [Figure 7C] FIG. 7C is a side view of mobile robot 1B with a robot arm while the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. [Figure 8A]FIG. 8A is a front view of a mobile robot 1C with a robot arm. [Figure 8B] FIG. 8B is a side view of the mobile robot with a robot arm 1C. [Figure 9A] FIG. 9A is a top view of a mobile robot 1D with a robot arm in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 9B] FIG. 9B is a front view of mobile robot 1D with a robot arm in which the robot arm is not performing any work and the non-contact sensor is located near the vehicle body. [Figure 9C] FIG. 9C is a side view of mobile robot 1D with a robot arm in which the robot arm is not in operation and the non-contact sensor is in the vicinity of the vehicle body. [Figure 10A] FIG. 10A is a top view of a mobile robot 1D with a robot arm in which the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. [Figure 10B] FIG. 10B is a front view of mobile robot 1D with a robot arm in operation and the non-contact sensor away from the vicinity of the vehicle body. [Figure 10C] FIG. 10C is a side view of mobile robot 1D with a robot arm in which the robot arm is in operation and the non-contact sensor is away from the vicinity of the vehicle body. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The present invention will now be described in detail with reference to the drawings, in which the same reference numerals denote the same or equivalent components.

[0020] <Overall configuration of a mobile robot with a robot arm> Fig. 1A is a top view of a mobile robot 1A with a robot arm according to an embodiment of the present invention, in which the robot arm is at rest and non-contact sensors 80A, 80B, and 80C are located near the outer periphery of the body, Fig. 1B is a front view thereof, and Fig. 1C is a side view thereof. Also, Fig. 2A is a top view of the mobile robot 1A with a robot arm in a state in which the robot arm is working and non-contact sensors 80A, 80B, and 80C are located away from the body, Fig. 2B is a front view thereof, and Fig. 2C is a side view thereof.

[0021] This mobile robot with a robot arm 1A moves autonomously (i.e., an unmanned guided vehicle) from a waiting point to a work point and performs a specified task at the work point. A dual-arm robot 10 equipped with two vertical articulated robot arms 11 is mounted on the body 2 of the mobile robot with a robot arm 1A. A warning light 14 is provided on the shoulder of the dual-arm robot 10.

[0022] The vehicle body 2 is provided with horizontal movement devices 70A and 70B having sliders 71 capable of moving horizontally from the left and right sides of the vehicle body 2 toward the outside of the vehicle body and returning to their original position, and a horizontal movement device 70C having sliders 71 capable of moving horizontally from the rear of the vehicle body 2 toward the outside of the vehicle body and returning to their original position. These horizontal movement devices 70A, 70B, and 70C are fitted with laser scanners as non-contact sensors 80A, 80B, and 80C so that their detection directions are upward. As a result, the detection areas Da and Db of the non-contact sensors 80A and 80B located on the left and right sides of the vehicle body 2 are vertical planes parallel to the sides of the vehicle body 2, and the detection area Dc of the non-contact sensor 80C on the rear side of the vehicle body 2 is a vertical plane parallel to the rear of the vehicle body. Since the laser scanner can set the detection area in the vertical plane to a predetermined shape, each laser scanner is set so that each detection area Da, Db, and Dc forms a safe protection space Sa for the mobile robot 1A with a robot arm (FIG. 1A).

[0023] In the present invention, the vertical plane is not limited to a plane strictly parallel to the direction of gravity, but may be any plane that is substantially vertical.

[0024] Furthermore, in the present invention, the installation position of the non-contact sensor is not limited to the above example, and can be changed as appropriate depending on the layout of structures around the passageway along which the mobile robot with a robot arm travels and the work area, etc. For example, the detection area of ​​the non-contact sensor can be positioned so as to surround the vehicle body from all four sides, i.e., front, rear, left, right, and front, by providing the slider 71 of the horizontal movement device so as to be movable toward the outside of the vehicle body from all four sides, i.e., front, rear, left, right, and front, of the vehicle body.

[0025] Furthermore, in the present invention, the method of installing the non-contact sensor so that its horizontal position can be moved is not limited to using a horizontal movement device. For example, the non-contact sensor may be attached to a rotating movement device (FIGS. 9A to 10C) as described below.

[0026] A work platform 50 is provided on the vehicle body 2 in front of the dual-arm robot 10. The vehicle body 2 may also be provided with a loading platform, a transport box 60, etc. used for transporting luggage (FIG. 5).

[0027] (Automated Driving System) The vehicle body 2 is equipped with an autonomous driving system that allows the mobile robot 1A with a robot arm to automatically travel through a predetermined passageway to a pick point, a work point, a place point, a waiting point, etc. The method of estimating the self-position in the autonomous moving type and the method of improving the accuracy are not particularly limited, and examples thereof include a laser ranging method, a laser SLAM (Simultaneous Localization And Mapping) method, and an image SLAM method. In addition, it is common to use an LRF (Laser Range Finder), also known as Lidar (Light Detection and Ranging), to detect the position distribution of surrounding objects. As an example of improving the accuracy of the autonomous driving, fixed point correction using RFID, QR Code (registered trademark), magnets, etc. may be performed.

[0028] In the present invention, the automatic driving method is not limited to the autonomous movement method, and may be, for example, a route guidance method, a following method, etc. Among these, the route guidance method may be an electromagnetic guidance method, an optical guidance method, a magnetic guidance method, a magnetic material guidance method, etc., and an appropriate method is selected based on the constraints of the available sensors and floor.

[0029] (Non-contact sensor) As described above, in this embodiment, laser scanners are used as the non-contact sensors 80A, 80B, and 80C, but the type of non-contact sensor is not particularly limited in the present invention. For example, in addition to laser scanners, light curtains, area sensors, ultrasonic sensors, infrared sensors, etc. can be used. From the standpoints of safety and reliability, laser scanners and light curtains are preferable, and further, laser scanners are preferable because they are easy to install since the light emitting position and the light receiving position are roughly the same position, and they can be installed compactly.

[0030] Regarding light curtains and laser scanners, highly reliable devices represented by PLd, PLe, SIL2, SIL3, etc. in the ISO standard and SIL standard are called safety light curtains and safety laser scanners, respectively. In the present invention, it is preferable to use a safety laser scanner as the laser scanner.

[0031] Safety laser scanners generally have the ability to perform horizontal scanning of 270°, including 45° to the left and right, rear, as well as front and side, when radially scanning with a laser beam. In addition, the detection distance can be set as desired, and the shape of the detection area can be determined as desired.

[0032] It is also possible to set multiple detection zones on one safety laser scanner. Several detection zones can be set in advance, and then switched depending on the task of the robot arm. Detection signals for each set detection zone can be output from multiple independent terminals, ensuring high reliability in detecting obstacles in each detection zone.

[0033] In the present invention, the non-contact sensor is attached to the vehicle body so that the detection area of ​​the non-contact sensor forms a vertical plane. That is, the non-contact sensor is attached so that the detection element such as the laser light of a laser scanner or the ultrasonic wave of an ultrasonic sensor scans a vertical plane, or the arrangement surface of the laser light of a laser curtain or the like forms a vertical plane. This is for the following reason. If the detection area forms a horizontal plane, when a person enters the detection area, only the torso of the person is often detected. Therefore, in the calculation of the safety distance (JIS B 9715), it is necessary to take into account the length of the person's arm that extends in the direction of the robot arm, which is the source of danger, and a safety distance of 1 to 3 m is usually required. It is customary to take the length of a person's arm as 0.85 m, and the safety distance is calculated by adding the distance obtained by multiplying the total of the detection time of the sensor and the stop time of the device such as a robot by the approach speed of the person. On the other hand, if the non-contact sensor is installed so that the detection area forms a vertical plane, it becomes unnecessary to take the length of the person's arm into account in the calculation of the safety distance, and the safety distance can be usually shortened to about 0.5 to 1 m.

[0034] By making the detection area a vertical plane in this way, the safety distance can be narrowed compared to when it is a horizontal plane, and the robot arm is less likely to slow down or stop even if a person is close to it. Therefore, by making the detection area a vertical plane, the work efficiency of the robot arm can be improved.

[0035] Here, the safety distance generally refers to the appropriate distance set between a protective structure and a danger zone in order to prevent the upper and lower limbs from reaching the danger zone of machinery (JIS B 9718), and in the case of a mobile robot with a robot arm, it is the distance that makes it possible to make these hazards non-hazardous before a person comes into contact with the robot arm, end effector, or workpiece held by the end effector.

[0036] 2A to 2C, the position obtained by adding a safety distance L to the restricted space Sr is the safeguard space Sa. If an obstacle such as a person enters the safeguard space formed by the non-contact sensor, the robot arm is controlled by a program in the control device of the robot arm so as to slow down or stop the movement. Therefore, the safety of people around the robot arm is guaranteed by being outside the safeguard device.

[0037] The safeguard space is defined as the safeguard of the perimeter (JIS B 8433-1). More specifically, in addition to safeguard devices such as non-contact sensors around the robot arm, the safeguard space is also formed by mechanical guards such as fences and surrounding structures in the work environment.

[0038] The restricted space Sr is a space that is restricted so that the movement of the hazardous robot arm, end effector, and workpiece held by the end effector cannot be exceeded. JIS B 8433-1 defines the restricted space as "a part of the maximum space, and a space restricted by a restricting device that sets a limit that must not be exceeded." Here, the "maximum space" is defined in JIS B 8433-1 as "the space that the robot's moving parts can reach, as determined by the manufacturer, plus the space that the end effector and workpiece can reach."

[0039] The restricted space Sr is formed by restrictions on the robot arm movement imposed by the program of the robot arm's control device and mechanical restrictions. The restrictions on the robot arm movement imposed by the program of the control device are created before the start of work, taking into consideration the shape and size of the robot arm, the size of the workpiece, various work movements, the work environment, etc., so that the robot arm does not come into contact with obstacles such as people, surrounding objects, other autonomous mobile robots, etc.

[0040] To prevent the robot arm from exceeding the restricted space Sr, the position, speed, stopping state, etc. of the robot arm are monitored in real time, and if the robot arm is about to exceed the restricted space, the movement of the robot arm is forcibly stopped.

[0041] In this way, if the program of the robot arm control device that monitors the robot arm by providing a safeguard space Sa and a restricted space Sr is independent of the programs that the robot arm performs various tasks, it is not affected by the programs for each task, which is preferable as it increases reliability.

[0042] The program of the control device that monitors the robot arm is not particularly limited. Examples of commercially available products that can be added to the robot controller include Dual Check Safety (DCS) manufactured by FANUC Corporation, Functional Safety Board DX200 manufactured by Yaskawa Electric Corporation, and Safety Expansion Unit manufactured by Mitsubishi Electric Corporation. Examples of products that are pre-installed in the robot controller include the RC8A controller manufactured by Denso Wave Inc., UNIVERSAL ROBOTS e-Series, and robots CR-7iA, CR-4iA, CR-15iA, CR-7iA, and CR-35iA manufactured by FANUC Corporation. Among these, the robots CR-7iA, CR-4iA, CR-15iA, CR-7iA, CR-35iA, and CRX series manufactured by FANUC Corporation, which are collaborative robots conforming to ISO10218-1 (JIS B 8433-1), are particularly suitable for use.

[0043] In this embodiment, the non-contact sensors 80A, 80B, and 80C are installed as laser scanners with their detection direction facing upward, but laser scanners with their detection direction facing downward may be added. This allows the downward safeguard space to be expanded.

[0044] (warning light) In order to ensure the safety of workers around the robot arm, it is preferable to alert them to the existence of a work space or to intrusion into the safeguarded space by using a warning light 14 or sound. By changing the color of the light emitted by the warning light 14 according to the surrounding conditions, such as the narrowness of the gap with the surroundings or the distance of the worker to the safeguarded space, the surrounding workers can determine the condition of the robot arm 11, and it is possible to prevent the robot arm 11 from slowing down or stopping due to mistakenly approaching the dual-arm robot 10, thereby hindering productivity.

[0045] (horizontal movement device) The horizontal movement devices 70A, 70B, 70C are electrically or pneumatically driven to move the slider 71 to which the non-contact sensors 80A, 80B, 80C are attached, thereby changing the positions of the non-contact sensors 80A, 80B, 80C in the horizontal direction. The horizontal movement devices 70A, 70B, 70C are preferably electrically driven, which allows easy change of the stop positions of the non-contact sensors 80A, 80B, 80C, so that the stop positions can be adjusted arbitrarily depending on the working state of the robot arm 11. The horizontal movement devices 70A, 70B, 70C are preferably equipped with a control device that moves the slider 71 as follows depending on the working state of the robot arm 11.

[0046] That is, while the robot arm 11 is working at high speed, even when the vehicle body 2 is stopped or moving, it takes time to stop the work, so the safety distance becomes long. Therefore, it is preferable to move the sliders 71 of the horizontal movement devices 70A, 70B, 70C in the outward direction of the outer periphery of the vehicle body and position the non-contact type sensors 80A, 80B, 80C away from the outer periphery of the vehicle body in the outward direction. This makes it possible to obtain a sufficiently large safety distance. On the other hand, while the robot arm 11 is working at low speed, it does not take time to stop the work, so the safety distance becomes short. Therefore, the sliders 71 of the horizontal movement devices 70A, 70B, 70C can be moved inward of the vehicle body 2 to bring the non-contact type sensors 80A, 80B, 80C closer to the vehicle body, and while the robot arm 11 is stopped, it can be brought even closer to the vehicle body and positioned near the vehicle body.

[0047] The non-contact sensors 80A, 80B, and 80C may be moved by the robot arm 11, but it is preferable to move them by the slider 71 as described above in order to eliminate the risk that the robot arm 11 or a part of the end effector 20 may go outside the detection area during the movement of the non-contact sensors 80A, 80B, and 80C. The moving device to which the non-contact sensors are attached may be one in which the support 76 of the moving device is rotatable, as in the moving robot 1D with a robot arm of an embodiment described later (FIGS. 9A to 10C).

[0048] (Robot Arm) In this embodiment, as the robot arms 11, vertical multi-joint type robot arms are provided as the left and right arms of the dual-arm robot 10. In the present invention, the robot arm is not limited to this and may be a horizontal multi-joint type, a parallel link type, etc., but by using a vertical multi-joint type, the operating range of the arm can be widened.

[0049] In addition, in the mobile robot with robot arms 1A of this embodiment, as shown in FIG. 1B, the left and right robot arms 11 are attached to a base 12, and the base 12 is attached to the vehicle body 2, but the robot arms may be attached directly to the vehicle body 2 as in the mobile robot with robot arms 1B of the embodiment described later (FIGS. 6A to 7C). When attaching the robot arms 11 to the base 12, it is preferable that the base 12 is horizontally rotatable on the vehicle body 2. This allows various tasks to be performed in front of the robot, regardless of the orientation of the vehicle body 2 of the mobile robot with robot arms 1A, thereby optimizing the tasks. This is also preferable in that the operating range of the robot arms 11 can be expanded.

[0050] The left and right robot arms 11 are mutually monitored, and it is preferable that each part of the arms, such as the arm tips, is controlled so as not to interfere with each other. Usually, the robot arms of a dual-arm robot are monitored by its robot controller. When the left and right robot arms each have an independent controller, they are monitored by a special controller that controls and monitors both of the two controllers. This makes it possible to prevent the left and right robot arms 11 from coming into contact with each other and being damaged when an error occurs in the operation program of the robot arm 11 and the robot arm 11 is made to perform an autonomous operation based on the recognition of an image taken by a camera equipped in the dual-arm robot 10.

[0051] In the present invention, the robot arm is not limited to a dual-arm type. Three or more robot arms may be provided on the robot-armed mobile robot 1A, which enables a wide variety of tasks.

[0052] (End effector) End effectors 20 are provided at the tips of the left and right robot arms 11. The end effectors 20 can be provided with a gripping section capable of gripping an object depending on the material, shape, and work to be performed on the object handled by the mobile robot with a robot arm 1A, an adsorption section capable of adsorbing to the object, a blade for cutting strings binding luggage, and the like.

[0053] Specific examples of tasks include loading and unloading items, aligning items, assembling, screwing, welding, soldering, painting, etc.

[0054] Specific examples of items that the end effector may handle include boxes, sheets such as stacked cardboard, stacks of sheets bound together with string or the like, wood, metal materials, resin materials, bottles, caps, or rolls of film, paper, or nonwoven fabric.

[0055] (Workbench) Work is carried out on the workbench 50. The workbench 50 can be used as a platform on which to place a transport box 60 when storing the item therein (FIG. 5) or removing the item from the transport box. The workbench 50 used can be one that can stably hold the item. There are no particular limitations on the structure of the workbench 50 itself. Examples include flat plate-shaped ones, ones with bars or walls on the left and right, front and back of the plate material to prevent items from falling, ones shaped like a cage or made of a plate with holes, ones with a convex or concave structure on the part where the item is placed to prevent the item from rattling, etc.

[0056] The workbench 50 may be provided with a mechanism for gripping an object, such as an electrically or pneumatically driven chuck, depending on the type of work.

[0057] (Transport box) As will be described in the use example of the mobile robot with a robot arm, the mobile robot with a robot arm 1A can store an item in a transport box 60 by the robot arm 11, and can supply the item in the transport box 60 to a specific location by the robot arm 11 (FIG. 5). The transport box 60 is one that can stably hold the item. One or more transport boxes 60 may be used. The transport box 60 itself is not particularly limited. For example, the shape of the transport box 60 may be a cube, a rectangular parallelepiped, a polygonal columnar box, a cylindrical box, etc. One with or without a lid may be used. The structure of the transport box 60 is also not particularly limited, and it may be foldable or non-foldable. Specific examples of the transport box 60 include a cardboard box, a resin box, and a foldable container case. To prevent the item from rattling, a method such as a box with a convex or concave structure on the part where the item is placed, or a box with a partition plate may be used.

[0058] The items to be transported are not particularly limited, and examples include filled and empty containers such as bottles, jars, bags, tubes, and boxes, as well as books, food products, machine parts, and even assortments of these items.

[0059] (Image Recognition) In the mobile robot with a robot arm 1A of this embodiment, a camera 30 used for image recognition is provided above the base 12 of the dual-arm robot 10, that is, at a position equivalent to the head 13 if the dual-arm robot 10 is considered to be humanoid, and an image recognition system is built into the dual-arm robot 10. Image information captured by the camera 30 is sent to a control program for the robot arm via wire or wirelessly, making it possible to perform advanced movement control of the robot arm 11.

[0060] That is, a mobile robot with a robot arm cannot generally stop precisely at a target stop position, regardless of whether the automatic driving method is a route guidance type, an autonomous guidance type, or a tracking type. Normally, a position error of about ±50 mm occurs. Even if a correction device is used, a position error of about ±10 mm occurs. Examples of this correction device include a sensor that reads a magnetic tape attached to the floor at the target position, and a sensor that detects targets of a particular shape installed around the target position. However, when high precision is required for the positional relationship between the robot arm and the surroundings in loading and unloading, the correction device may interfere with the transfer of the cargo.

[0061] In contrast, an image recognition system recognizes markers and characteristic objects around work points such as loading and unloading, and sends the information to the automatic driving system when the mobile robot with a robot arm 1A reaches the target stopping position. Alternatively, the image recognition system estimates the amount of deviation of the actual stopping position and the amount of deviation of the angle of the mobile robot with a robot arm 1A from the target stopping position, and corrects the operation of the robot arm. This ensures that the desired operation can be performed.

[0062] An image recognition system may be used not only to correct the stopping position of the mobile robot 1A with a robot arm, but also to perform the operations of the robot arm 11, such as loading and unloading, by recognizing objects such as luggage, loading platforms, transport boxes, and workbenches using the image recognition system. The image recognition system may also be used to inspect the barcodes and colors of items. The image recognition system may also be used to improve safety during travel. Meanwhile, a dedicated barcode reader may be used to inspect the barcodes of items.

[0063] There is no particular restriction on the camera 30 or the image recognition system itself used for image recognition. A known image recognition system that processes information on two-dimensional images or three-dimensional images obtained by a stereo camera or the like can be used. In addition, a system that obtains information on the size, orientation, and degree of deformation of a marker from a captured image using augmented reality (AR) and estimates the amount of deviation in the position of the robot arm based on the information may be used. The system is appropriately selected depending on the object to be recognized, the processing time, the cost, and the like. In addition to conventional two-dimensional or three-dimensional image recognition systems, AI image recognition may be used. The method of AI image recognition is not particularly limited. Examples include a machine learning method made by OSARO, and a method that enables recognition by performing a simulation of stacking items in advance for the product Alliom made by AI Cube Co., Ltd.

[0064] The installation position of the camera is not particularly limited. For example, as in the mobile robot 1B with a robot arm of an embodiment described later (FIGS. 6A to 7C), a tall pole-shaped installation tool 31 may be erected on the mobile robot 1B with a robot arm separately from the base 12 of the robot arm 11, and the camera 30 may be installed on the installation tool 31. By raising the installation position of the camera 30, it is possible to check the item from a distance. Therefore, it is possible to reduce image distortion caused by the camera lens, and it is possible to prevent misidentification of the position of the item. Furthermore, since an image can be captured as long as the robot arm 11 does not block the field of view for image recognition, it is possible to perform the calculation for image recognition with plenty of time before the robot arm starts to operate. On the other hand, when an image recognition system is used for the operation of the robot arm such as loading and unloading, the camera may be installed at the tip of the robot arm. In this case, the camera can approach the luggage, making it easier to inspect the luggage, and the installation tool supporting the camera does not restrict the movement of the robot arm.

[0065] (Example of use of a mobile robot with a robotic arm) As an example of use of the mobile robot 1A with a robot arm, an example in which the mobile robot 1A with a robot arm travels through passage A shown in Figure 4 from waiting point P1 to item pick point P2, works on the picked item at work point P3 and places the item for which work has been completed, and then returns to waiting point P1 will be described with reference to Figures 1A to 1C, Figures 2A to 2C, and Figures 3A to 3C.

[0066] As shown in Fig. 4, the mobile robot 1A with a robot arm stopped at a waiting point P1 and the mobile robot 1A with a robot arm moving from the waiting point P1 to a pick point P2 have laser scanners 80A, 80B, and 80C positioned near the vehicle body 2 on the outer periphery of the vehicle body as non-contact sensors, as shown in Figs. 1A to 1C. Each laser scanner 80A, 80B, and 80C forms detection areas Da, Db, and Dc on a vertical plane by radially scanning a vertical plane with a laser beam irradiated upward. These detection areas Da, Db, and Dc form a safety protection space Sa on the left and right side sides and the back side of the mobile robot 1A with a robot arm in a reduced state near the vehicle body. Therefore, the mobile robot 1A with a robot arm can move through narrow passages and make small turns. In particular, it can change direction without colliding with surrounding structures at corners of narrow passages.

[0067] In this embodiment, the robot arm 11 extends the end effector 20 to work on a work target in front of which there is no person, so there is no need to form a safeguarded space with a non-contact sensor, and therefore no detection zone is set by a non-contact sensor in front of the robot arm-equipped mobile robot 1A. Also, since there is no need to actually consider the intrusion of obstacles into the safeguarded space in the floor and ceiling directions, the setting of detection zones by a non-contact sensor in these directions is omitted.

[0068] Normally, in a mobile robot, confirmation of the passage while traveling is performed by a camera (image SLAM) or a laser sensor (laser SLAM) provided on the autonomous mobile robot. In the mobile robot 1A with a robot arm of this embodiment, the camera 30 also faces forward so that it can confirm markers and distinctive objects placed around the passage while traveling.

[0069] At the pick point P2 shown in Fig. 4, the mobile robot 1A with a robot arm picks up a specified item and places it on the workbench 50 to perform a specified task. During the task of the robot arm 11, the safeguard space is set to an expanded position so as to reliably prevent people from entering the restricted space. For this reason, as shown in Figs. 2A to 2C, the sliders 71 of the horizontal movement devices 70A, 70B, and 70C move outward from the vehicle body 2, so that the laser scanners 80A, 80B, and 80C attached to the ends of the sliders 71 move outward from the vicinity of the vehicle body on the outer periphery of the vehicle body and move to positions spaced apart from the right side, left side, and back of the dual-arm robot 10, where the detection direction of the laser light is scanned so that the detection area forms a vertical plane parallel to the right side, left side, and back of the vehicle body 2, forming the safeguard space Sa.

[0070] The boundary of the safeguard space in front of the dual-arm robot 10 is defined by the presence of a wall, and the boundary of the safeguard space on the floor side is defined by the detection zone set below the laser scanners 80A, 80B, and 80C. Also, since there is no need to consider the approach of people above the head of the robot 10, no boundary of the safeguard space is set.

[0071] The distance to which the detection areas of the laser scanners 80A, 80B, 80C on the left, right, and rear of the vehicle body 2 are to be placed from the restricted space Sr is appropriately selected depending on the orientation of the dual-arm robot 10, the work content, the operating speed of the robot arm 11, etc.

[0072] Therefore, on the way from pick point P2 to work point P3, the positions of the laser scanners 80A, 80B, and 80C are set near the vehicle body as shown in Figs. 1A to 1C. In addition, when the left side of the traveling direction of the vehicle body 2 at work point P3 is work area D where parts are picked and the front side is work area E where the article picked at point P2 and the part picked at work point P3 are attached and placed, as shown in Figs. 3A to 3C, the laser scanner 80A on the right side of the traveling direction of the vehicle body 2 and the laser scanner 80C on the rear side are moved to positions away from the vehicle body 2 by the horizontal movement devices 70A and 70C, respectively. This ensures a sufficient safety distance on the left and rear sides of the robot arm 11, and the robot arm 11 can work safely.

[0073] When the item B on which the predetermined work has been performed at the point P2 is transported to the point P3, the item B on which the predetermined work has been performed may be stored in a transport box 60 and transported as shown in FIG.

[0074] On the other hand, if the operating speed of the robot arm 11 at point P3 is slower than that for the picking operation at point P2, the required safety distance will be shorter than the safety distance for the picking operation at point P2, so the amount of movement of the laser scanners 80A, 80C toward the outside of the vehicle body 2 can also be made smaller than that for the picking operation. The mobile robot with a robot arm 1A at point P3 in Figure 4 represents such a state.

[0075] At point P3, the wall surrounding the work area D on the side of the vehicle body 2 forming the safeguard space forms the laser scanner 80B on the side of the work area D, and therefore the laser scanner 80B on the side of the work area D is not used to form the safeguard space. Also, the wall surrounding the work area E on the side of the vehicle body 2 forming the safeguard space forms the laser scanner 80B on the side of the work area E.

[0076] After completing the work at work point P3, horizontal movement devices 70A, 70C are moved inside body 2 to position laser scanners 80A, 80B, 80C near the initial outer periphery of the body, and mobile robot 1A with robotic arms is reversed and heads toward waiting point P1 as shown by the dashed arrow. At this time, the safeguard space has been reduced, so mobile robot 1A with robotic arms can pass through narrow passages and turn around corners with tight tolerances.

[0077] <Transformation of the mobile robot with robot arm> The mobile robot with a robot arm of the present invention can take various forms. For example, as shown in Figs. 6A to 7C, a single vertical articulated robot arm 11 may be fixed to a vehicle body 2 as the robot arm of a mobile robot with a robot arm 1B, and the end effector 20 may have a gripping member 26 suitable for picking up and picking down bottles. This robot arm 11 can be used for placing bottles one by one on a workbench 50 at a loading point, and lowering the bottles one by one to a predetermined position at an unloading point after a predetermined operation. Work such as aligning the bottles may be performed while the bottles are being transported.

[0078] In addition, in this mobile robot with a robot arm 1B, the camera 30 used for image recognition is attached to a tall pole-like installation tool 31 standing up from the vehicle body 2, and is installed at a high position above the workbench 50. This makes it possible to reduce image distortion caused by the camera lens, and to prevent misidentification of the bottle position.

[0079] As non-contact sensors, laser scanners 80A, 80B are attached to horizontal movement devices 70A, 70B having a slider 71 and positioned near the left and right side surfaces of the vehicle body 2, similar to the mobile robot 1A with a robot arm shown in Figures 1A to 3C. A laser scanner 80C attached to a horizontal movement device 70C having a slider 71 is also positioned on the rear side of the vehicle body 2. The detection areas of these laser scanners 80A, 80B, 80C form a vertical plane and form a safe protection space Sa.

[0080] When the robot arm 11 is performing work, depending on the work position, work speed, etc., the horizontal movement devices 70A, 70B, 70C can be used to protrude the slider 71 outside the vehicle body, as shown in Figures 7A to 7C, thereby moving the laser scanners 80A, 80B, 80C horizontally from near the outer periphery of the vehicle body 2 to the outside.

[0081] In the mobile robot with a robot arm 1B shown in Figures 6A to 7C, an end effector 20 having a flexible gripping member suitable for picking up and down various objects may be used. The flexible gripping member is not limited to a specific one, but for example, the mobile robot with a robot arm 1C shown in Figures 8A and 8B has a multi-fingered gripping hand with a rotatable base as the flexible gripping member 27. Other examples of the flexible gripping member 27 include a gripping hand with fingers that can flexibly deform to fit an object, and a suction hand that has one suction part and a pressure part around it so that the periphery can fit the object and stably grip it.

[0082] 8A and 8B, the robot arm 11 of the mobile robot with a robot arm 1C can be used for applications such as loading various items one by one or multiple items at once onto a transportation box 60 on a loading platform 50 at a loading point, and unloading the items one by one or multiple items at once to a predetermined position at an unloading point. The transportation box 60 may be placed on the loading platform 50 on the vehicle body 2, or directly on the vehicle body 2.

[0083] The robot arm 11 may simply lower the transport box 60 containing the article to a predetermined position. When placing the transport box 60 on the platform 50 or lowering it to a predetermined position, the end effector 20 that picks up and drops the article may be used as is, or a different end effector suitable for handling the transport box 60 may be used.

[0084] When the transport box containing the article is lowered to a predetermined position as is, an unloading device (not shown) may be used that is separate from the robot arm 11. The unloading device may be installed on the mobile robot with the robot arm, or may be installed at the unloading position.

[0085] The unloading device is not particularly limited, and one example is a method of dragging the transport box 60 off the mobile robot with robot arm 1C using a vacuum pad or hook attached to the tip of an air cylinder, or lifting it up and lowering it, etc. By using the transport box 60 and the flexible gripping member 27 in this way, the mobile robot with robot arm 1C can be suitably used for the task of assembling small quantities of a wide variety of items into transport boxes, known as bulk picking in a logistics center.

[0086] To make the horizontal positions of the laser scanners 80A, 80B, and 80C movable, a swivel-type moving device 75 may be used, as in the mobile robot with a robot arm 1D shown in Figures 9A to 10C. In this swivel-type moving device 75, one end of a support 76 serves as the center of rotation, and the laser scanners 80A, 80B, and 80C are attached to the other end. As shown in Figures 9A to 9C, when the support 76 is standing, the laser scanners 80A, 80B, and 80C are in the OFF state, and the laser scanners do not form a safety protection space.

[0087] On the other hand, when the robot arm 11 is to perform work, as shown in Figures 10A, 10B and 10C, the support pillar 76 of the swivel-type moving device 75 is rotated to make the support pillar 76 horizontal so that the detection areas of the laser scanners 80A, 80B and 80C form a vertical plane, thereby forming a safety protection space Sa.

[0088] From the standpoint of cost, which allows the drive device to be inexpensive, and from the standpoint of the ability to move the non-contact sensor in a short period of time, it is preferable to move the horizontal position of the non-contact sensor by rotation in this manner, but from the standpoint of setup work, which makes it easy to fine-tune the position of the non-contact sensor, and from the standpoint of safety, which makes it easier for people in the vicinity to predict the direction of sensor movement, it is preferable to move the non-contact sensor horizontally as described above.

[0089] In addition, the present invention can take various forms that make it possible to move the position of the non-contact sensor in the horizontal direction. [Explanation of symbols]

[0090] 1A, 1B, 1C, 1D Mobile robot with robot arm 2. Body 10 Dual-arm robot 11 Robot Arm 12 Base 13 Head 14 Warning light 20 End Effector 26 Clamping member 27 Flexible gripping member 30 Camera 31 Installation tools 50 Work platform, loading platform 60 Carrying Box 70A, 70B, 70C horizontal movement device 71 Slider 75 Swivel type mobile device 76 Pillar 80A, 80B, 80C Non-contact sensors, laser scanners A aisle Da, Db, Dc detection zone L Safety distance P1 Waiting point P2 Pick Point P3 Work site Sa Safety protection space Sr Restricted Space

Claims

1. A mobile robot with a robot arm, the robot arm being mounted on a vehicle body and having a non-contact sensor, The non-contact sensor has a detection area that forms a vertical plane, and the detection area forms a safety protection space for the robot arm; The non-contact type sensor is attached to a slider that can be moved horizontally and returned to its original position on the outer periphery of the vehicle body by an electric horizontal movement device, and the horizontal movement device is equipped with a control device; The control device for the mobile robot with a robot arm horizontally moves the non-contact sensor to a position away from the outer periphery of the vehicle body in an outward direction while the robot arm is performing high-speed work, and while the robot arm is performing low-speed work, moves the non-contact sensor closer to the vehicle body by horizontal movement on the outer periphery of the vehicle body than when the robot arm is performing high-speed work, and while the robot arm is stopped, moves the non-contact sensor even closer to the vehicle body than when the robot arm is performing low-speed work, so that the non-contact sensor is in the vicinity of the vehicle body on the outer periphery of the vehicle body.

2. 2. The mobile robot with a robotic arm according to claim 1, wherein the non-contact sensor is a laser scanner.

3. A method for forming a safeguard space for a mobile robot with a robot arm, the robot arm being mounted on a vehicle body, the method comprising the steps of: forming a safeguard space for the robot arm by using a non-contact sensor provided on the mobile robot with the robot arm, the method comprising the steps of: The non-contact sensor is attached to a slider that can be moved horizontally and returned to its original position by an electric horizontal movement device, so that the detection area of ​​the non-contact sensor is a vertical plane, and the horizontal position of the non-contact sensor can be moved by the horizontal movement device equipped with a control device, thereby making it possible to change the size of the safeguard space; The control device positions the non-contact sensor away from the outer periphery of the vehicle body in an outward direction while the robot arm is working at high speed, positions the non-contact sensor closer to the vehicle body than when the robot arm is working at high speed while the robot arm is working at low speed, and positions the non-contact sensor even closer to the vehicle body when the robot arm is stopped than when the robot arm is working at low speed, thereby forming a safety protection space.

4. The method for forming a safe protected space according to claim 3, wherein a laser scanner is used as the non-contact sensor.

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