JP7169474B1 - Conveying device, control method, and control program - Google Patents

Abstract

A technique for dealing with vibration of an object for position awareness is provided. An object for position recognition is provided within a range affected by vibrations caused by the operation of the machine tool and outside the machining area of the machine tool. A conveying device capable of conveying an object using the object as a reference includes a camera and a control unit for controlling the conveying device. The control unit outputs a photographing instruction to the camera while the object is included in the photographing field of the camera, acquires a first image showing the object from the camera, and vibrates the object based on the first image. A process of recognizing the state and a predetermined process corresponding to the vibration state are executed. [Selection drawing] Fig. 3

Description

The present disclosure relates to a conveying device, control method, and control program.

There is a demand for unmanned production systems in factories and the like. In order to realize unmanned operation, the development of transport devices is underway. The conveying device carries unprocessed workpieces and tools into the machine tools, and collects workpieces and used tools that have been machined by the machine tools.

In order for the transfer device to work accurately with respect to the machine tool, the transfer device needs to periodically correct its posture. Regarding the correction technique, Japanese Patent Application Laid-Open No. 2021-035708 (Patent Document 1) discloses a robot capable of correcting the working posture. The robot is provided with a camera. The robot uses a camera to photograph an identification figure for posture correction provided inside the machine tool, and corrects the working posture of the robot based on the positional relationship between the camera and the identification figure.

Japanese Patent Application Laid-Open No. 2021-035708

An object for position recognition, such as the identification figure, vibrates under the influence of the operation of the machine tool. If the object for position recognition is photographed while the object is vibrating, the transport device cannot accurately correct its working posture. Therefore, techniques for dealing with vibrations of objects for position awareness are desired. Note that Patent Document 1 does not disclose anything about the vibration of the identification figure.

An example of the present disclosure provides a conveying device capable of conveying a conveyed article with reference to an object for position recognition. The object is provided within a range affected by vibrations caused by the operation of the machine tool and outside the machining area of the machine tool. The transport device includes a camera and a controller for controlling the transport device. The control unit outputs a photographing instruction to the camera while the object is included in the photographing field of the camera, acquires a first image of the object from the camera, and acquires the first image from the camera. Based on this, a process of recognizing the vibration state of the object and a predetermined process corresponding to the vibration state are executed.

In one example of the present disclosure, the transport device further includes a transport robot configured to hold the transported object. The predetermined process is a process of causing the transport robot to transport the article based on the position of the object in the first image when the vibration state indicates that the object is not vibrating. obtaining from the camera a second image, different from the first image, depicting the object when the vibration state indicates that the object is vibrating.

In one example of the present disclosure, the first image is obtained by outputting a photographing instruction to the camera while the transport robot is driven to a predetermined first posture. The second image is obtained from the camera by outputting a photographing instruction while the transport robot is driven to a predetermined second posture. The second attitude is different from the first attitude.

In an example of the present disclosure, the process of acquiring the first image from the camera is a process of acquiring the plurality of first images from the camera by outputting a photographing instruction to the camera at a predetermined first cycle. including. The process of acquiring the second image from the camera includes a process of acquiring the plurality of second images from the camera by outputting a photographing instruction to the camera at a predetermined second cycle. The second period is different from the first period.

In one example of the present disclosure, the predetermined process includes outputting a warning indicating that the machine tool is vibrating when the vibration state indicates that the object is vibrating.

In one example of the present disclosure, the process of acquiring the first image from the camera is performed while the machine tool is processing a workpiece.

Another example of the present disclosure provides a control method for a transport device capable of transporting a transport object with reference to a position recognition object. The object is provided within a range affected by vibrations caused by the operation of the machine tool and outside the machining area of the machine tool. The transport device includes a camera. The control method comprises the steps of: outputting a photographing instruction to the camera while the object is included in the photographing field of view of the camera; acquiring from the camera a first image showing the object; Based on this, a step of recognizing the vibration state of the object and a step of executing a predetermined process according to the vibration state are executed.

Another example of the present disclosure provides a control program for a conveying device capable of conveying a conveyed object on the basis of an object for position recognition. The object is provided within a range affected by vibrations caused by the operation of the machine tool and outside the machining area of the machine tool. The transport device includes a camera. The control program outputs a photographing instruction to the camera while the object is included in the photographing field of view of the camera to the transport device, and acquires a first image of the object from the camera; Based on the first image, a step of recognizing the vibration state of the object and a step of executing a predetermined process according to the vibration state are executed.

The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings.

It is a figure which shows the external appearance of a conveying apparatus. FIG. 10 is a diagram showing a state in which a camera of a conveying device is photographing tags for position recognition; It is a figure which shows a mode that the camera of a conveying apparatus is imaging|photographing the tag attached to the machine tool. It is a figure which shows a mode that a conveying apparatus carries out a workpiece|work from a machine tool. It is a figure which shows the outline of the internal structure of a traveling main body. It is a figure which shows an example of the hardware constitutions of a conveying apparatus. It is a figure which shows an example of the functional structure of a conveying apparatus. FIG. 3 is a diagram showing a three-dimensional map as an example; FIG. 10 is a diagram showing an example of how the tag shooting mode is changed; FIG. 10 is a diagram showing another example of changing the shooting mode of a tag; FIG. 4 is a diagram schematically showing posture correction processing of a transport robot; 4 is a flow chart showing control processing of the conveying device. It is a figure which shows the conveying apparatus according to a modification.

Hereinafter, each embodiment according to the present invention will be described with reference to the drawings. In the following description, identical parts and components are given identical reference numerals. Their names and functions are also the same. Therefore, detailed description of these will not be repeated. In addition, each embodiment and each modified example described below may be selectively combined as appropriate.

<A. Conveying device 100>
First, the conveying device 100 will be described with reference to FIG. FIG. 1 is a diagram showing the appearance of the conveying device 100. As shown in FIG.

The transport device 100 transports objects such as workpieces and tools to a predetermined location such as a machine tool. Further, the conveying device 100 unloads a conveyed object from a predetermined place such as a machine tool.

As shown in FIG. 1 , the carrier device 100 includes a wheel-driven traveling body 10 and a carrier robot 13 . Traveling body 10 includes cover 110 .

A laser sensor 105 is provided inside the cover 110 . The laser sensor 105 is configured to irradiate laser light while rotating and to receive reflected light of the laser light. Thereby, the laser sensor 105 measures the distance to the surrounding object. Based on the measurement result of the laser sensor 105, the conveying device 100 controls the traveling of the traveling body 10 such as the forward direction R, the backward direction B, the right-turn direction, and the left-turn direction.

The transport robot 13 is provided on the traveling main body 10, for example. The transport robot 13 is, for example, an arm robot. The transfer robot 13 as an arm robot includes arms AR1 to AR4 and an end effector 125. As shown in FIG.

One end of arm AR1 is connected to traveling body 10 . The other end of arm AR1 is connected to one end of arm AR2. The other end of arm AR2 is connected to one end of arm AR3. The other end of arm AR3 is connected to one end of arm AR4. An end effector 125 is provided at the other end of the arm AR4. The end effector 125 is configured to be able to hold a work or tool.

The arm AR2 is configured to be rotatable by a motor about a connection shaft with the arm AR1. The arm AR3 is configured to be rotatable by a motor about the axis of rotation connected to the arm AR2. The arm AR4 is configured to be rotatable by a motor about the axis of rotation connected to the arm AR3.

Further, the transport robot 13 is provided with a camera 107 . In the example of FIG. 1, camera 107 is provided on end effector 125 . The camera 107 may be a CCD (Charge Coupled Device) camera, an infrared camera (thermography), or another type of camera.

Note that the camera 107 does not necessarily have to be provided on the transport robot 13 . Camera 107 may be provided on cover 110 of traveling body 10, for example.

Further, on the traveling main body 10, an installation table 109 for a conveyed object is provided. In the example of FIG. 1, a work W is shown as the transported object. The transport robot 13 grips the work W on the installation table 109 and moves the work W to a specified location. Alternatively, the transport robot 13 picks up the work W from a specified location and places the work W on the installation table 109 .

Note that although FIG. 1 describes the transport robot 13 as an arm robot, the transport robot 13 is not limited to an arm robot. As an example, the transport robot 13 may be an autoloader.

<B. Posture Correction Processing Using Tag TG>
Next, posture correction processing using the position recognition tag TG will be described with reference to FIG. FIG. 2 is a diagram showing how the camera 107 of the transport device 100 photographs the tag TG for position recognition.

The carrier device 100 compares the position and orientation recognized within the carrier device 100 with the correct values at a predetermined location, and corrects the position and orientation of the carrier device 100 based on the comparison result. As a result, the conveying apparatus 100 eliminates the error between the internally recognized position and orientation and the actual position and orientation.

The “position/orientation” referred to in this specification is defined as at least one of the position and the angle of a part that constitutes the transport apparatus 100 . As an example, the position and orientation are defined by at least one of the position of the traveling body 10 , the orientation of the traveling body 10 , the angles of the arms of the transfer robot 13 , and the position of the end effector 125 of the transfer robot 13 .

The transport device 100 uses a position recognition tag TG, for example, to correct its own position and orientation. The tag TG is, for example, an AR (Augmented Reality) marker such as AprilTag. A two-dimensional barcode is attached to the tag TG. White or black squares are arranged in a matrix on the two-dimensional barcode. In the example of FIG. 2, the black squares are hatched.

The transport device 100 moves to a preset position and causes the transport robot 13 to take a preset posture at a predetermined timing such as before starting work or during work. After that, the transport device 100 causes the camera 107 to photograph the tag TG, and recognizes the position and orientation of the tag TG in the image.

Next, the transport device 100 transforms the specified position and orientation indicated by the image-based coordinate system into the position and orientation indicated by the predetermined coordinate system based on a predetermined coordinate conversion formula. The predetermined coordinate system may be, for example, a marker coordinate system based on the tag TG, a robot coordinate system based on the transport robot 13, or a world coordinate system based on the traveling body 10. It may be a coordinate system.

After that, the transport device 100 recognizes the error between the position and orientation indicated by the predetermined coordinate system and the preset correct value. Subsequently, the transport apparatus 100 corrects the target position preset based on the correct value with the error, and drives the transport robot 13 toward the corrected target position.

<C. Overview of Vibration Recognition Processing>
Next, the process of recognizing the vibration state of the tag TG will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 is a diagram showing how the camera 107 of the transport device 100 is photographing the tag TG attached to the machine tool 200. As shown in FIG. FIG. 4 is a diagram showing how the conveying device 100 unloads the workpiece W from the machine tool 200. As shown in FIG.

The machine tool 200 is a concept that includes various devices having a function of machining a work. Machine tool 200 may be a horizontal machining center or a vertical machining center. Alternatively, machine tool 200 may be a lathe, an additional processing machine, or other cutting or grinding machine.

Machine tool 200 includes cover 230 . The cover 230 is also called a splash guard, forms an appearance of the machine tool 200, and defines a machining area AR for the workpiece W. As shown in FIG.

The cover 230 is provided with a door DR. Door DR is, for example, a sliding door. The door DR may be configured to be openable and closable by a drive source such as a motor, or may be configured to be manually openable and closable.

Machine tool 200 vibrates during operation. Operations involving vibration include, for example, processing of the workpiece W, opening and closing operations of the door DR, transportation of chips of the workpiece W, and the like. Chips are conveyed by, for example, a chip conveying device (not shown) provided in machine tool 200 .

The tag TG is provided outside the processing area AR. As an example, tag TG is provided on cover 230 of machine tool 200 . When the tag TG is provided outside the processing area AR, the transport device 100 can photograph the tag TG even while the workpiece W is being processed. As a result, the transport device 100 can correct the position and orientation of itself before the processing of the work W is completed, and can start the processing of transporting the work W immediately after the processing of the work W is completed. As a result, the time required for transporting the work W is shortened.

On the other hand, the tag TG may vibrate as the machine tool 200 operates. When the transporting device 100 photographs the vibrating tag TG, the transporting device 100 cannot accurately correct its own position and orientation. Therefore, when the tag TG is provided within a range affected by vibration caused by the operation of the machine tool 200 and outside the machine tool 200, the transport device 100 recognizes the vibration state of the tag TG. , a process corresponding to the vibration state is executed.

More specifically, the transport device 100 outputs a photographing instruction to the camera 107 while the tag TG is included in the field of view CR of the camera 107 . As a result, the transport device 100 acquires an image of the tag TG (hereinafter also referred to as “tag image”) from the camera 107 . Next, the transport device 100 recognizes the vibration state of the tag TG based on the acquired tag image. A method of recognizing the vibration state will be described later. After that, the transport device 100 executes predetermined processing according to the vibration state of the tag TG.

When determining that the tag TG is not vibrating, the transport device 100 uses the tag image used in the vibration recognition process for the position and orientation. That is, the transport device 100 recognizes the position of the tag TG in the tag image, and causes the transport robot 13 to transport the workpiece W based on the position. In the example of FIG. 4 , the transport device 100 unloads the machined work W from the machining area AR of the machine tool 200 .

On the other hand, when the transport device 100 determines that the tag TG is vibrating, the transport device 100 acquires from the camera 107 a tag image different from the tag image used in the vibration recognition process. Then, the transport device 100 recognizes the vibration state of the tag TG again based on the other tag image.

The transport device 100 repeatedly executes the tag image acquisition process and the vibration state recognition process until the vibration of the tag TG stops. After that, the transport device 100 corrects its own position and orientation using the tag image captured when the vibration of the tag TG stops.

In this way, the transport device 100 discards the tag image obtained while the tag TG is vibrating, and uses the tag image obtained while the tag TG is not vibrating to determine its own position and orientation. to correct. Thereby, the transport device 100 can recognize the position of the workpiece W accurately.

<D. Configuration of Traveling Body 10>
Next, the traveling body 10 shown in FIG. 1 will be described with reference to FIG. FIG. 5 is a diagram showing an outline of the internal structure of the traveling body 10. As shown in FIG.

As shown in FIG. 5, the traveling body 10 includes a frame 11, a first wheel section 15 functioning as a front wheel, and a second wheel section 35 functioning as a rear wheel.

The frame 11 has an appropriate notched space when viewed from the top so that a necessary structure can be arranged, and has a structure in which the inside is hollow in order to reduce the weight.

The first wheel portion 15 and the second wheel portion 35 are connected to the frame 11 with a predetermined space therebetween along the forward direction R or the backward direction B. As shown in FIG.

The first wheel portion 15 is composed of a first left wheel portion 16 provided on the left side when viewed from the back of the conveying device 100 and a right front wheel portion 25 provided on the right side when viewed from the back of the conveying device 100. .

The first left wheel section 16 includes a first left support arm 17 provided on the left side surface of the frame 11 , a left front wheel 19 and a left drive wheel 21 . A left front wheel 19 and a left drive wheel 21 are rotatably supported on both ends of a first left support arm 17 about horizontal rotary shafts 20 and 22 perpendicular to the running direction of the conveying device 100 .

The right front wheel section 25 includes a first right support arm 26 provided on the right side surface of the frame 11 , a right front wheel 28 and a right drive wheel 30 . A right front wheel 28 and a right drive wheel 30 are rotatably supported on both ends of a first right support arm 26 about horizontal rotary shafts 29 and 31 orthogonal to the running direction of the conveying device 100 .

The first right support arm 26 is supported by a support shaft 27 provided on the right side surface of the frame 11 and is swingable within a vertical plane along the running direction of the conveying device 100 . Similarly, the first left support arm 17 is supported by a support shaft 18 provided on the left side surface of the frame 11 and is swingable within a vertical plane along the running direction of the conveying device 100 .

In this example, the left front wheel 19 and the right front wheel 28 are driven wheels, and the left drive wheel 21 and the right drive wheel 30 are drive wheels in the traveling direction of the conveying device 100 . A motor 23 is connected to the left drive wheel 21 via a reduction gear 24 provided on the first left support arm 17, and the left drive wheel 21 is driven by the motor 23 to rotate. Similarly, the right drive wheel 30 is connected to a motor 32 via a reduction gear 33 provided on the first right support arm 26, and the right drive wheel 30 is driven by the motor 32 to rotate.

The second wheel portion 35 includes a second support arm 36 provided on the rear side of the frame 11 in the running direction of the conveying device 100 . The second support arm 36 is supported by a support shaft 37 provided on the rear side surface of the frame 11 and is swingable within a vertical plane perpendicular to the running direction of the transport device 100 . The second support arm 36 has a left rear wheel 38 and a right rear wheel 40 rotatably supported at both ends thereof about horizontal rotary shafts 39 and 41 perpendicular to the traveling direction of the conveying device 100 . Prepare. Thus, the second wheel portion 35 has a pair of wheels (the left rear wheel 38 and the right rear wheel 40) configured to be swingable within a plane perpendicular to the running direction of the conveying device 100. As shown in FIG. The left rear wheel 38 and the right rear wheel 40 are driven wheels.

The left front wheel 19, the right front wheel 28, the left rear wheel 38, and the right rear wheel 40 have the same configuration, and are composed of, for example, omni wheels. In this case, the left front wheel 19 can move in the direction of rotation by rotating about the rotation shaft 20, and is slidable in the horizontal direction intersecting the rotation shaft 20 and the direction of rotation.

<E. Hardware Configuration of Conveying Device 100>
Next, with reference to FIG. 6, the hardware configuration of the conveying device 100 will be described. FIG. 6 is a diagram showing an example of the hardware configuration of the transport device 100. As shown in FIG.

The conveying apparatus 100 includes a control circuit 101 (control unit), a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, a communication interface 104, a laser sensor 105, motor driving devices 106 and 108, and storage device 120 . These components are connected to the bus BS.

The control circuit 101 is composed of, for example, at least one integrated circuit. Integrated circuits include, for example, at least one CPU (Central Processing Unit), at least one GPU (Graphics Processing Unit), at least one ASIC (Application Specific Integrated Circuit), at least one FPGA (Field Programmable Gate Array), or It can be configured by a combination of As an example, the control circuit 101 is a PLC (Programmable Logic Controller).

The control circuit 101 controls the operation of the conveying apparatus 100 by executing various programs such as a control program 122 and an operating system. The control circuit 101 reads the control program 122 from the storage device 120 or the ROM 102 to the RAM 103 based on the reception of the instruction to execute the control program 122 . The RAM 103 functions as a working memory and temporarily stores various data necessary for executing the control program 122 .

A LAN (Local Area Network), an antenna, and the like are connected to the communication interface 104 . The conveying apparatus 100 realizes wireless communication or wired communication with external devices via the communication interface 104 . The external equipment includes, for example, a server (not shown), a user terminal (not shown) for operating the transport apparatus 100, and the like. The user terminal is, for example, a tablet terminal, a smartphone, or the like. The user can control traveling of the conveying apparatus 100 via the user terminal.

The laser sensor 105 is configured to irradiate laser light while rotating and to receive reflected light of the laser light. As a result, the laser sensor 105 outputs two-dimensional distance data representing the distance to the surrounding object for each angle.

More specifically, the laser sensor 105 is composed of an irradiation section, a mirror, and a light receiving section. The irradiation unit irradiates the mirror with a laser beam. The mirror is rotatable by a motor and reflects laser light in each direction. Thereby, the laser sensor 105 emits laser light in each direction. When an object is around the laser sensor 105 , the laser light is reflected by the object and returns to the laser sensor 105 . The laser sensor 105 receives the reflected light at its light receiving portion.

A laser sensor 105 receives reflected light from an object and calculates the distance to the object. As an example, the laser sensor 105 calculates the distance from the laser sensor 105 to the object based on the time from the irradiation of the laser light to the reception of the reflected light of the laser light. Typically, the laser sensor 105 calculates the distance to the object by multiplying the speed of light by the time. The laser sensor 105 outputs two-dimensional distance data representing the distance for each angle by associating the distance with the irradiation angle of the laser light.

Preferably, the laser sensor 105 is provided on the traveling body 10 so that the irradiation surface of the laser light is inclined with respect to the horizontal plane. The transport device 100 can measure the surrounding three-dimensional shape by scanning the surroundings while moving.

The motor driving device 106 controls the rotation of the motors 23 and 32 (see FIG. 5) according to control commands from the control circuit 101 . The control commands include, for example, forward rotation commands for the motors 23 and 32, reverse rotation commands for the motors 23 and 32, rotation speeds for the motors 23 and 32, and the like. For the motors 23 and 32, for example, stepping motors or servo motors are employed.

The motor driving device 108 controls the rotation of each motor provided in the transport robot 13 according to the control command from the control circuit 101 . The motor is provided at each joint of the transport robot 13 . The motor is, for example, a servomotor. An encoder is provided on the rotating shaft of the servomotor. The encoder feeds back the position of the servomotor, the rotational speed of the servomotor, the cumulative number of rotations of the servomotor, and the like to the motor driver 108 . The motor driving device 108 controls the position and orientation of the transport robot 13 based on the output value of the encoder.

The storage device 120 is, for example, a storage medium such as a hard disk or flash memory. The storage device 120 stores a control program 122 for controlling travel of the transport device 100, a three-dimensional map 124 that defines the travel route of the transport device 100, control parameters 126 related to driving the transport device 100, and the like. The storage location of the control program 122, the three-dimensional map 124, and the control parameters 126 is not limited to the storage device 120, but may be storage areas of the control circuit 101 (eg, cache memory, etc.), ROM 102, RAM 103, external devices (eg, server ), etc.

Also, the control program 122 may be provided as a part of an arbitrary program, not as a standalone program. In this case, the transport device 100 cooperates with an arbitrary program to implement various processes according to the present embodiment. Even a program that does not include such a part of modules does not deviate from the gist of control program 122 according to the present embodiment. Furthermore, some or all of the functions provided by control program 122 may be implemented by dedicated hardware. Furthermore, the transport apparatus 100 may be configured in a form such as a so-called cloud service in which at least one server executes part of the processing of the control program 122 .

<F. Functional Configuration of Conveying Device 100>
Next, the functional configuration of the conveying device 100 will be described with reference to FIGS. 7 to 11. FIG. FIG. 7 is a diagram showing an example of the functional configuration of the conveying device 100. As shown in FIG.

As shown in FIG. 7 , the control circuit 101 of the conveying device 100 includes a map generation section 152 , a travel control section 154 , a vibration determination section 162 and an execution section 164 . These functions will be described in turn below.

(F1. Map generator 152)
First, functions of the map generator 152 shown in FIG. 7 will be described.

The map generator 152 generates a three-dimensional map 124 representing the space around the transport device 100 based on the two-dimensional distance data D sequentially acquired from the laser sensor 105 while the transport device 100 is driven.

The three-dimensional map 124 is generated by SLAM (Simultaneous Localization and Mapping) technology, for example. The three-dimensional map 124 is information generated for specifying the position of the transport device 100 and is information indicating the positions of stationary objects at the travel location of the transport device 100 . The stationary objects are, for example, walls, shelves, machine tools, and the like.

The three-dimensional map 124 is generated, for example, by the user manually operating the carrier device 100 using a user terminal. In this case, an operation signal corresponding to the user's operation is transmitted to the control circuit 101 via the communication interface 104, and the control circuit 101 outputs a command to the motor driving device 106 according to the operation signal. to control the running of the At this time, the control circuit 101 maps the positions of the objects around the conveying device 100 on the three-dimensional map 124 based on the two-dimensional distance data D input from the laser sensor 105 and the position of the conveying device 100. . The position of the conveying device 100 is specified based on the driving information of the motor driving device 106, for example. Thus, in the three-dimensional map 124, information indicating the presence or absence of an object is associated with each of the three-dimensional coordinate values (x, y, z). Also, in the three-dimensional map 124, object types may be associated.

FIG. 8 is a diagram showing a three-dimensional map 124 as an example. For convenience of explanation, FIG. 8 shows the three-dimensional map 124 as a two-dimensional map.

The three-dimensional map 124 shows, for example, a map inside a factory. As an example, the three-dimensional map 124 defines the positions of the machine tools 200A and 200B, the positions of the obstacles 230A and 230B, the traveling route 240 of the transfer device 100, and the positions of the tags TGA and TGB.

The transport device 100 continues the work transport operation by, for example, repeating movement between the positions PA and PB along the travel route 240 . As an example, the transport device 100 performs a work loading operation from the machine tool 200A to the transport device 100 at the position PA, and performs a work unloading work from the transport device 100 to the machine tool 200B at the position PB.

The transport device 100 moves the tag TGA into a photographable range before starting work on the machine tool 200A. After that, the transport device 100 photographs the tag TGA using the camera 107 and corrects the position and orientation of the transport device 100 based on the tag image obtained from the camera 107 . After that, the transport device 100 starts working on the machine tool 200A.

Similarly, the transport device 100 moves the tag TGB into a photographable range before starting work on the machine tool 200B. After that, the transport device 100 takes an image of the tag TGB using the camera 107 and corrects the position and orientation of the transport device 100 based on the tag image obtained from the camera 107 . After that, the transport device 100 starts working on the machine tool 200B.

In the above description, an example in which the transport device 100 transports the work between the positions PA and PB has been described, but the content of the work performed by the transport device 100 is not particularly limited. As an example, the transport device 100 may transport tools instead of workpieces.

Also, instead of the machine tool 200A, a stocker for storing workpiece materials may be provided. Similarly, instead of the machine tool 200B, a stocker for storing workpiece materials may be provided. In this case, the transfer device 100 transfers the work to the stocker instead of the machine tools 200A and 200B. The tags TGA and TGB may be provided in the stocker, or may be provided in the vicinity of the stocker.

(F2. Running control unit 154)
Next, functions of the travel control unit 154 shown in FIG. 7 will be described. The travel control unit 154 is a functional module for controlling travel of the conveying device 100 .

The travel control unit 154 identifies the current position of the transport device 100 by comparing the two-dimensional distance data D input from the laser sensor 105 and the three-dimensional map 124 . By specifying the current position, the control circuit 101 causes the transport device 100 to travel along a predetermined route on the three-dimensional map 124 .

Further, the travel control unit 154 detects obstacles around the conveying device 100 based on the two-dimensional distance data D sequentially acquired from the laser sensor 105 while the conveying device 100 is being driven. The traveling of the conveying device 100 is controlled so as to avoid collision. The obstacles include, for example, moving objects such as people and other transport devices 100, and stationary objects such as walls and shelves.

The travel control unit 154 controls travel of the conveying device 100 so that it travels along a predetermined route on the three-dimensional map 124 while no obstacle is detected. On the other hand, when an obstacle is detected, the travel control unit 154 controls travel of the conveying device 100 so as to avoid collision with the obstacle.

As an example, when the distance to the obstacle is equal to or greater than a predetermined distance, the travel control unit 154 controls travel of the conveying device 100 so as to avoid the obstacle. On the other hand, when the distance to the obstacle is less than the predetermined distance, the traveling control unit 154 stops traveling of the conveying device 100 .

(F3. Vibration determination unit 162)
9 and 10, the function of vibration determining section 162 shown in FIG. 7 will be described.

The vibration determination unit 162 outputs a shooting instruction to the camera 107 while the tag TG is included in the shooting field of the camera 107 described above. As an example, the vibration determination unit 162 determines that the conveying device 100 has reached a pre-registered location on the three-dimensional map 124 and that the conveying device 100 has been driven to a predetermined posture. , tag TG is included in the field of view of the camera 107 .

The vibration determination unit 162 acquires a tag image showing the tag TG from the camera 107 by outputting a photographing instruction to the camera 107, and recognizes the vibration state of the tag TG based on the tag image. As an example, the vibrating state includes "vibrating" indicating that the tag TG is vibrating and "non-vibrating" indicating that the tag TG is not vibrating. Note that the types of the vibrating state are not limited to two, "vibrating" and "non-vibrating". As an example, the type of vibration state may be one, or may be classified into three or more depending on the vibration intensity of the tag TG.

Further, the vibration determination unit 162 may determine the vibration state of the tag TG from one tag image, or may determine the vibration state of the tag TG from a plurality of tag images.

In one aspect, the vibration determination unit 162 determines the vibration state of the tag TG from one tag image. When the tag TG is vibrating, the edge portion in the tag image is blurred. Focusing on this point, the vibration determination unit 162 applies an edge filter (differential filter) to the tag image to generate an edge image from the tag image. As an example, each pixel in the edge image represents the result of subtracting the pixel values of adjacent pixels in the tag image. The vibration determination unit 162 integrates each pixel value in the edge image and calculates the integration result as the vibration intensity. Preferably, the vibration determination unit 162 removes edge information other than the tag portion, and calculates the vibration intensity using only the edge information of the tag portion.

The vibration determination unit 162 determines that the vibration state of the tag TG is "non-vibrating" when the vibration intensity calculated from the edge image is equal to or less than a predetermined value. On the other hand, when the vibration intensity calculated from the edge image exceeds the predetermined value, the vibration determination unit 162 determines that the vibration state of the tag TG is "vibrating".

In another aspect, the vibration determination unit 162 determines the vibration state of the tag TG from two or more tag images. In this case, the vibration determination unit 162 generates a difference image by subtracting time-series tag images having consecutive shooting timings. When the tag TG is vibrating, the position of the tag in the tag image changes, so the difference image shows the fluctuation of the tag TG. The vibration determination unit 162 integrates each pixel value in the difference image, and calculates the integration result as the vibration intensity. Preferably, the vibration determination unit 162 removes image information other than the tag portion, and calculates the vibration intensity using only the image information of the tag portion.

The vibration determination unit 162 determines that the vibration state of the tag TG is "non-vibrating" when the vibration intensity calculated from the difference image is equal to or less than a predetermined value. On the other hand, when the vibration intensity calculated from the difference image exceeds the predetermined value, the vibration determination unit 162 determines that the vibration state of the tag TG is "vibrating".

Typically, the vibration determination unit 162 repeats the tag image acquisition process and the vibration determination process using the tag image until the vibration state of the tag TG changes from "vibrating" to "non-vibrating". Run. Preferably, the shooting mode of the tag TG is changed each time the acquisition process and the vibration determination process are executed.

An example of a method for changing the shooting mode will be described below. Further, hereinafter, the one or more tag images used for the N-th (N: natural number) vibration determination will also be referred to as image IM1, and the one or more tag images used for the N+1-th vibration determination will also be referred to as image IM2.

FIG. 9 is a diagram showing an example of how the shooting mode of the tag TG is changed. As shown in FIG. 9 , the vibration determination unit 162 drives the transport robot 13 so that it assumes a predetermined first posture, and outputs a photographing instruction to the camera 107 . The first posture is represented by, for example, at least one of the angle of each arm of the transfer robot 13 and the position of the end effector 125 of the transfer robot 13 . The first attitude is, for example, predefined in the control parameters 126 described above.

The vibration determination unit 162 acquires an image IM1 of the tag TG by outputting a photographing instruction to the camera 107 while the transport robot 13 is driven to the first posture. After that, the vibration determination unit 162 uses the acquired image IM1 to determine the vibration state of the tag TG.

When the vibration determination unit 162 determines that the vibration state of the tag TG is “non-vibrating”, the vibration determination unit 162 outputs the image IM1 to the execution unit 164 . On the other hand, when the vibration determination unit 162 determines that the vibration state of the tag TG is "vibrating", it discards the image IM1. After that, the vibration determination unit 162 drives the transport robot 13 so that it assumes a predetermined second posture different from the first posture, and outputs a photographing instruction to the camera 107 .

Thereby, the camera 107 photographs the tag TG in the second posture different from the first posture. The second posture is represented by, for example, at least one of the angle of each arm of the transfer robot 13 and the position of the end effector 125 of the transfer robot 13 . The second attitude is predefined, for example, in the control parameters 126 described above.

Vibration determination unit 162 obtains image IM2 of tag TG from a different direction or different position by outputting a photographing instruction to camera 107 while transport robot 13 is driven to the second posture. After that, the vibration determination unit 162 uses the acquired image IM2 to determine the vibration state of the tag TG.

In this way, in the example of FIG. 9, the image IM1 is obtained by outputting a photographing instruction to the camera 107 while the transport robot 13 is driven to the predetermined first posture. For the image IM2, a photographing instruction is output in a state in which the transport robot 13 is driven to a predetermined second posture. This allows the vibration determination unit 162 to recognize the vibration state using tag images captured under various conditions. As a result, the vibration determination unit 162 can more accurately determine the vibration state of the tag TG.

FIG. 10 is a diagram showing another example of changing the photographing mode of the tag TG. As shown in FIG. 10, vibration determination unit 162 outputs a photographing instruction to camera 107 at a predetermined cycle ΔT1 (first cycle). The period ΔT1 is predefined, for example, in the control parameters 126 mentioned above. A period ΔT1 indicates, for example, a time interval per unit shooting.

The vibration determination unit 162 obtains a plurality of images IM1 of the tag TG by causing the camera 107 to photograph the tag TG at a cycle ΔT1. After that, the vibration determination unit 162 determines the vibration state of the tag TG using the plurality of acquired images IM1.

When the vibration determination unit 162 determines that the vibration state of the tag TG is “non-vibrating”, the vibration determination unit 162 outputs the image IM1 to the execution unit 164 . On the other hand, when the vibration determination unit 162 determines that the vibration state of the tag TG is "vibrating", the multiple images IM1 are discarded. Further, the vibration determination unit 162 outputs a photographing instruction to the camera 107 at a predetermined cycle ΔT2 (second cycle) different from the cycle ΔT1. A period ΔT2 indicates a time interval per unit of imaging. Period ΔT2 is predefined, for example, in control parameters 126 described above.

The vibration determination unit 162 obtains a plurality of images IM2 of the tag TG by outputting a photographing instruction to the camera 107 while the transport robot 13 is driven at the period ΔT2. After that, the vibration determination unit 162 determines the vibration state of the tag TG using the plurality of acquired images IM2.

In this way, in the example of FIG. 10, the plurality of images IM1 are obtained by outputting a photographing instruction to the camera 107 at the period ΔT1, and the plurality of images IM2 are obtained by outputting the photographing instruction to the camera 107 at the period ΔT2. is obtained by When the vibration cycle of the tag TG is the same as the imaging cycle of the camera 107 or M times the vibration cycle (M: natural number), even if the tag TG is vibrating, the position of the tag TG in the tag image may not change. On the other hand, if the shooting cycle is changed while the tag TG is vibrating, the position of the tag TG in the tag image will change more reliably. This allows the vibration determination unit 162 to more accurately recognize the vibration state of the tag TG.

Note that the photographing instruction to the camera 107 is output while the machine tool 200 is processing the workpiece. In other words, the photographing instruction to the camera 107 is output regardless of whether the machine tool 200 is processing the workpiece. As a result, the transport device 100 can correct the position and orientation of itself before the processing of the work W is completed, and can start the processing of transporting the work immediately after the processing of the work is completed. As a result, the time required for transporting the work is shortened.

(F4. Execution unit 164)
Next, referring to FIG. 11, functions of the execution unit 164 shown in FIG. 7 will be described.

Execution unit 164 executes a predetermined process according to the vibration state determined by vibration determination unit 162 . As an example, the execution unit 164 discards tag images for which the vibrating state of the tag TG is determined to be “vibrating”, and discards tag images for which the vibrating state of the tag TG is determined to be “non-vibrating”. is used to correct the posture of the transport robot 13 .

11A and 11B are diagrams schematically showing the attitude correction processing of the transport robot 13. FIG. The image IMA shown in FIG. 11 is a tag image in which it is determined that the vibrating state of the tag TG is "non-vibrating". The execution unit 164 corrects the posture of the transport robot 13 using the image IMA.

More specifically, the execution unit 164 uses existing image processing libraries such as ARToolKit and OpenCV to recognize the position and orientation of the tag TG within the image IMA. A reference image for searching the tag TG from the image IMA is stored in advance in the storage device 120 or the like. Next, the execution unit 164 transforms the position and orientation of the tag TG in the image IMA into the position and orientation of the tag TG in the real world based on a predetermined coordinate transformation formula. The predetermined coordinate conversion formula is estimated based on the positional relationship between the camera 107 and the tag TG. The execution unit 164 compares the position and orientation of the tag TG in the real world with the preset position and orientation as target values.

The position and orientation as target values are stored in advance by teaching the transfer robot 13 . The teaching process is manually set by a user using a user terminal for operating the transport apparatus 100, for example.

The execution unit 164 corrects the position and orientation of the transport device 100 so that the recognized position and orientation of the tag TG match the position and orientation as the target value. In this manner, the execution unit 164 can more accurately correct the position and orientation of the transport apparatus 100 by using the image IMA acquired during non-vibration.

In the above description, the processing executed when it is determined that the vibration state of the tag TG is “non-vibrating” has been described. configured to perform processing.

As an example, the process issues a warning (hereinafter also referred to as "vibration warning") indicating that the machine tool 200 is vibrating when the vibration state of the tag TG indicates that the tag TG is vibrating. Including processing to output.

The output mode of the vibration warning is arbitrary. As an example, the conveying device 100 is provided with a light source, and the execution unit 164 outputs a vibration warning by causing the light source to emit light. As another example, the conveying apparatus 100 is provided with a speaker, and the execution unit 164 outputs the vibration warning by outputting sound from the speaker. As still another example, the conveying apparatus 100 is provided with a display, and the execution unit 164 outputs a vibration warning by displaying a message on the display. As yet another example, execution unit 164 outputs a vibration warning by sending a notification to other terminals such as machine tool 200 and a server.

Further, when the vibration state of the tag TG is “vibrating”, there is a possibility that unexpected vibration such as chatter vibration is occurring in the machine tool 200 . Chatter vibration is vibration of a tool that occurs unintentionally during machining of a workpiece. In this case, execution unit 164 outputs a vibration warning and regards the work machined by machine tool 200 as being in an inspection mode. The execution unit 164 drives the transport device 100 so as to transport the inspection target work to a place different from the place where the normally processed work is stored.

<G. Flowchart>
Next, with reference to FIG. 12, the control flow of the conveying device 100 will be described. FIG. 12 is a flow chart showing control processing of the conveying device 100 .

The processing shown in FIG. 12 is implemented by the control circuit 101 of the conveying apparatus 100 executing the control program 122 described above. In other aspects, part or all of the processing may be performed by circuit elements or other hardware.

In step S110, the control circuit 101 determines whether or not a transport command for the transported object has been received. The transport command includes, for example, a command to carry in a transported object to machine tool 200 and a command to carry out a transported object from machine tool 200 . If the control circuit 101 determines that it has received a command to correct the position and orientation of the transport device 100 (YES in step S110), it switches the control to step S112. Otherwise (NO in step S110), control circuit 101 executes the process of step S110 again.

In step S112, the control circuit 101 functions as the travel control unit 154 described above, and drives the travel main body 10 so that the conveying device 100 moves to a preset position. The preset positions are defined, for example, in the three-dimensional map 124 described above.

In step S114, the control circuit 101 causes the transport robot 13 to take a preset posture based on the fact that the transport device 100 has moved to the preset position. The preset attitude is defined, for example, in the control parameters 126 described above. The posture is defined, for example, by the angle of each arm of the transfer robot 13 . The tag TG is included in the field of view of the camera 107 by the transport robot 13 taking a preset posture.

In step S<b>116 , the control circuit 101 outputs a photographing instruction to the camera 107 while the tag TG is included in the field of view of the camera 107 and acquires the tag image from the camera 107 .

In step S120, the control circuit 101 functions as the above-described vibration determination unit 162, and determines whether or not the vibration state of the tag TG is non-vibration based on the tag image acquired in step S116. Since the method for determining the vibration state is as described above, the description thereof will not be repeated. When the control circuit 101 determines that the vibrating state of the tag TG is non-vibrating (YES in step S120), it switches the control to step S122. Otherwise (NO in step S120), control circuit 101 switches control to step S130.

In step S122, the control circuit 101 functions as the execution unit 164 described above, recognizes the position and orientation of the tag TG in the tag image, and estimates the position and orientation of the tag TG in the real world based on the position and orientation. Next, the control circuit 101 corrects the position and orientation of the transport device 100 so that the estimated position and orientation of the tag TG approaches a preset target value.

At step S<b>124 , the control circuit 101 starts the work specified in the control program 122 . An example of the work includes a work of loading a transported object into the machine tool 200 and a work of unloading the transported object from the machine tool 200 .

In step S130, the control circuit 101 functions as the vibration determination unit 162 described above, and determines whether or not the vibration intensity of the tag TG is lower than a predetermined threshold. Since the method for calculating the vibration intensity is as described above, the description thereof will not be repeated. When the control circuit 101 determines that the vibration intensity of the tag TG is lower than the predetermined threshold (YES in step S130), it switches the control to step S132. Otherwise (NO in step S130), control circuit 101 switches control to step S134.

In step S132, the control circuit 101 changes the shooting mode of the tag TG. The photographing mode includes, for example, the posture of the transport robot 13 and the photographing cycle of the camera 107 . The control circuit 101 executes the process of step S116 again after the shooting mode of the tag TG is changed.

In step S134, the control circuit 101 functions as the execution unit 164 described above and outputs a warning indicating that the machine tool 200 is vibrating (that is, a vibration warning). Since the output mode of the vibration warning is as described above, the description thereof will not be repeated.

<H. Variation>
Next, referring to FIG. 13, a conveying device 100A according to a modified example will be described. FIG. 13 is a diagram showing a conveying device 100A according to a modification.

The conveying device 100 shown in FIG. 1 described above had a traveling body 10 . On the other hand, a conveying device 100A according to this modified example includes a support body 10A instead of the traveling body 10. As shown in FIG. Other configurations of the transporting device 100 are the same as those of the transporting device 100A described above, and thus other descriptions will not be repeated below.

As shown in FIG. 13, the transport device 100A includes a support 10A and a transport robot 13. As shown in FIG.

The support 10A is fixed with respect to the ground. That is, the support 10A does not have a self-propelled function and is immovable.

In this modification, the machine tool 200 described above is installed within the working range of the transfer robot 13 . As an example of work contents, the transfer robot 13 carries a work placed on a tray into the machine tool 200 . As another example of the work content, the transport robot 13 carries out the object to be transported from the machine tool to a tray.

The function of the vibration determination unit 162 and the function of the execution unit 164 described above can also be implemented in such a transport device 100A that is fixed to the ground.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

10 Traveling Main Body 10A Support Body 11 Frame 13 Transfer Robot 15 First Wheel Section 16 First Left Wheel Section 17 First Left Support Arm 18 Support Shaft 19 Left Front Wheel 20 Rotational Axis 21 Left Drive wheel 22 rotating shaft 23 motor 24 speed reducer 25 right front wheel part 26 first right supporting arm 27 supporting shaft 28 right front wheel 29 rotating shaft 30 right driving wheel 31 rotating shaft 32 motor 33 Reduction gear 35 Second wheel section 36 Second support arm 37 Support shaft 38 Left rear wheel 39 Rotating shaft 40 Right rear wheel 41 Rotating shaft 100 Transfer device 100A Transfer device 101 Control circuit 102 ROM, 103 RAM, 104 communication interface, 105 laser sensor, 106 motor drive device, 107 camera, 108 motor drive device, 109 installation table, 110 cover, 120 storage device, 122 control program, 124 three-dimensional map, 125 end effector, 126 control parameter, 152 map generation unit, 154 travel control unit, 162 vibration determination unit, 164 execution unit, 200 machine tool, 200A machine tool, 200B machine tool, 230 cover, 230A obstacle, 230B obstacle, 240 traveling route.

Claims (8)

A conveying device capable of conveying a conveyed object with reference to a position recognition object provided on a cover forming the appearance of a machine tool ,
a traveling body configured to be able to travel;
a transport robot configured to hold the transported object and provided on the traveling main body;
a camera provided on the transport robot ;
A control unit for controlling the conveying device,
The control unit
The moving body is moved to a predetermined position where the object is included in the field of view of the camera, the transport robot is placed in a predetermined first posture, and the object is photographed in the first time series . a process of acquiring an image from the camera;
a process of recognizing the vibration intensity of the object based on the differential image of the time-series first images;
and a predetermined process according to whether the vibration intensity exceeds a predetermined value . The predetermined processing is
a process of causing the transport robot to transport the object based on the position of the object in one of the time-series first images when the vibration intensity is equal to or less than the predetermined value ;
and acquiring, from the camera, a second image that is different from the time-series first image and that captures the object, when the vibration intensity exceeds the predetermined value. A conveying device as described. the second image is obtained from the camera by outputting a photographing instruction while the transport robot is driven to a predetermined second posture;
3. The conveying apparatus according to claim 2, wherein said second orientation is different from said first orientation. The process of acquiring the time-series first image from the camera is a process of acquiring the time -series first image from the camera by outputting a photographing instruction to the camera at a predetermined first cycle. including
The process of acquiring the second image from the camera includes a process of acquiring a plurality of the second images from the camera by outputting a photographing instruction to the camera at a predetermined second cycle,
3. The conveying apparatus according to claim 2, wherein said second period is different from said first period. 3. The transport according to claim 1, wherein said predetermined processing includes processing for outputting a warning indicating that said machine tool is vibrating when said vibration intensity exceeds said predetermined value. Device. The conveying apparatus according to any one of claims 1 to 5, wherein the process of acquiring the time-series first images from the camera is executed while the machine tool is processing a workpiece. A control method for a conveying device capable of conveying a conveyed object with reference to a position recognition object provided on a cover forming the appearance of a machine tool ,
The conveying device is
a traveling body configured to be able to travel;
a transport robot configured to hold the transported object and provided on the traveling main body;
A camera provided on the transport robot ,
The control method is
The moving body is moved to a predetermined position where the object is included in the field of view of the camera, the transport robot is placed in a predetermined first posture, and the object is photographed in the first time series . acquiring an image from the camera;
a step of recognizing the vibration intensity of the object based on the difference image of the time-series first images;
and executing a predetermined process according to whether the vibration intensity exceeds a predetermined value . A control program for a conveying device capable of conveying a conveyed object with reference to a position recognition object provided on a cover forming the appearance of a machine tool ,
The object is provided on a cover forming the appearance of a machine tool ,
The conveying device is
a traveling body configured to be able to travel;
a transport robot configured to hold the transported object and provided on the traveling main body;
A camera provided on the transport robot ,
The control program causes the transport device to:
The moving body is moved to a predetermined position where the object is included in the field of view of the camera, the transport robot is placed in a predetermined first posture, and the object is photographed in the first time series . acquiring an image from the camera;
a step of recognizing the vibration intensity of the object based on the difference image of the time-series first images;
and executing a predetermined process according to whether the vibration intensity exceeds a predetermined value .

Images