Work robot system

Abstract

This work robot system comprises: a robot 10 for performing predetermined work on a target part 101 of an article 100 that is being moved by an article transfer device; and a tracking sensor 50 that is used at least for sequentially detecting the position of the target part 101 being moved by the article transfer device when the target part 101 is tracked by a component 110 or a tool that is supported by the robot 10. A control device for the robot 10 is configured to perform: pre-approach control in which the component 110 or the tool is moved to an approach start position where the component 110 or the tool does not interfere with an interferable region 120 of the article 100 being moved by the article transfer device; and tracking control in which the component 110 or the tool disposed at the approach start position is brought close to the target part 101 and the output of the tracking sensor 50 is used to cause the component 110 or the tool to track the target part 101. The interferable region 120 is a region of the article 100 other than the target part 101.

Description

Technical Field

[0001] The present invention relates to a work robot system.

Background Art

[0002] Conventionally, when assembling parts to an article conveyed by a conveying device, the conveying device was often stopped. In particular, when precisely assembling parts to a large article such as an automobile body, it was necessary to stop the conveyance of the article by the conveying device. This sometimes led to a decrease in work efficiency.

[0003] On the other hand, a work robot system is known that includes a conveying device for conveying an article and a robot, and the robot assembles parts to the article while the article is being conveyed by the conveying device. For example, refer to Patent Document 1. In this work robot system, when the article is carried to a predetermined position by the conveying device, the robot approaches the part to the target part of the article, and when the distance between the part and the article becomes less than or equal to a predetermined distance, the robot makes the part follow the target part.

[0004] Also, a work robot system is known that includes a conveying device for conveying an article and a robot, and when the article is carried to a predetermined position by the conveying device, the conveyance of the article by the conveying device is stopped, and the robot performs work on the stopped article. For example, refer to Patent Document 2.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] A first aspect of the present invention is a work robot system comprising: a robot that performs a predetermined operation on a target part of an article being moved by an article moving device; a control device used to control the robot; and a follow sensor used to sequentially detect at least the position of the target part being moved by the article moving device when causing a part or tool supported by the robot to follow the target part, wherein the control device is configured to perform pre-approach control by controlling the robot to move the part or tool to an approach start position that does not interfere with an interferable part of the article being moved by the article moving device; and follow control by controlling the robot to bring the part or tool positioned at the approach start position closer to the target part, and to control the robot using the output of the follow sensor to cause the part or tool to follow the target part being moved by the article moving device, wherein the interferable part is In the direction of movement by the aforementioned article moving device The article When passing through The aforementioned target part Closer to the aforementioned part or tool It is a part of the body. [Means for solving the problem]

[0007] A robot according to a second aspect of the present invention comprises: an arm that performs a predetermined operation on a target part of an article being moved by an article moving device; a control device used to control the arm; and a tracking sensor capable of sequentially detecting at least the position of the target part being moved by the article moving device when causing a part or tool supported by the arm to follow the target part, wherein the control device is configured to perform: pre-approach control by controlling the arm to move the part or tool to an approach start position that does not interfere with any interferable parts of the article being moved by the article moving device; and tracking control by controlling the arm to bring the part or tool positioned at the approach start position closer to the target part, and to control the arm using the output of the tracking sensor to cause the part or tool to follow the target part being moved by the article moving device, wherein the interferable part is In the direction of movement by the aforementioned article moving device The article If it passes through to the aforementioned target part Closer to the aforementioned part or tool It is a part of the body. A control device according to a third aspect of the present invention comprises at least one memory capable of storing a program including at least a robot approach control program and a follow control program, and at least one processor capable of executing the program, wherein the at least one processor acquires information relating to at least the position of a moving article, and based on the position information and the approach control program, moves the part or tool to an approach start position where the interferable portion of the article does not interfere with the part or tool supported by the robot, and after moving to the approach start position, causes the robot to follow the target portion of the article based on the follow control program, wherein the interferable portion is a portion that is closer to the part or tool than the target portion when the article passes in the direction of movement.

[0008] A robot according to a second aspect of the present invention comprises: an arm that performs a predetermined operation on a target part of an article being moved by an article moving device; a control device used to control the arm; and a tracking sensor capable of sequentially detecting at least the position of the target part being moved by the article moving device when causing a part or tool supported by the arm to follow the target part, wherein the control device is configured to perform pre-approach control by controlling the arm to move the part or tool to an approach start position that does not interfere with any interferable parts of the article being moved by the article moving device; and follow-up control by controlling the arm to bring the part or tool positioned at the approach start position closer to the target part, and to control the arm using the output of the tracking sensor to cause the part or tool to follow the target part being moved by the article moving device, wherein the interferable part is a part of the article other than the target part. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic side view of the work robot system of the first embodiment. [Figure 2] This is a schematic plan view of the work robot system of the first embodiment. [Figure 3] This is an example of image data obtained by the sensors of the work robot system of this embodiment. [Figure 4] This is a block diagram of the control device for the work robot system of the first embodiment. [Figure 5] This is a flowchart of an example of processing performed by the control device of the work robot system of the first embodiment. [Figure 6] This is a schematic plan view of the work robot system according to the second embodiment. [Modes for carrying out the invention]

[0010] A work robot system according to the first embodiment will be described below with reference to the drawings. As shown in Figures 1 and 2, the robotic work system of this embodiment includes a transport device (article moving device) 2 for transporting an article 100 to be worked on, a robot 10 that performs a predetermined operation on a target part 101 of the article 100 moved by the transport device 2, a control device 20 for controlling the robot 10, and a detection device 40.

[0011] The detection device 40 acquires data that can identify at least the position of the target part 101 of the article 100 being transported by the transport device 2. The detection device 40 may also acquire data that can identify the position and orientation of the target part 101. In this embodiment, the target part 101 has a plurality of holes 101a. The function of the detection device 40 may be performed by the tracking sensor 50 described later.

[0012] Any device having such a function can be used as the detection device 40. The detection device 40 may be, for example, a two-dimensional camera, a three-dimensional camera, a three-dimensional distance sensor, a sensor that measures the shape by irradiating an object with line light, a photoelectric sensor, etc. In this embodiment, the detection device 40 is a two-dimensional camera installed along the transport route of the transport device 2. The detection device 40 acquires image data of the target part 101 when the target part 101 is within a predetermined range of the field of view, and transmits the image data to the control device 20 as output. The detection device 40 may be a camera or sensor facing downwards, or a camera or sensor facing horizontally, diagonally downwards, etc.

[0013] Image data is data that can identify the position of at least one of multiple target parts 101. The control device 20 may also identify the position of the target part 101 based on the position, shape, etc., of characteristic parts of the article in the image data. Furthermore, the control device 20 can identify the orientation of the target part 101 based on the positional relationship of multiple target parts 101 in the image data. The control device 20 can identify the orientation of the target part 101 based on the position, shape, etc., of characteristic parts in the image data. Characteristic parts may be elements with distinctive features, such as the mark M shown in Figure 3 or the corners of the article 100.

[0014] The article 100 is not limited to a specific type of object, but in this embodiment, as an example, the article 100 is a car body. The conveying device 2 moves the article 100 in one direction by driving a motor 2a, and in this embodiment, the conveying device 2 moves the article 100 toward the right in Figure 1. The motor 2a is equipped with an operating position detection device 2b, which sequentially detects the rotational position and amount of rotation of the output shaft of the motor 2a. The operating position detection device 2b is, for example, an encoder. The detected values ​​of the operating position detection device 2b are transmitted to the control device 20. The conveying device 2 may also be equipped with other components for moving the article 100, such as a belt.

[0015] The target part 101 is the part of the article 100 where the arm 10a of the robot 10 performs a predetermined operation. In the present embodiment, as the predetermined operation, the hand 30 of the robot 10 lifts the component 110, and the robot 10 attaches the attachment part 111 of the component 110 to the target part 101. Thereby, for example, a plurality of shafts 111a extending downward from the attachment part 111 of the component 110 are respectively fitted into a plurality of holes 101a provided in the target part 101 of the article 100. In the present embodiment, in a state where the article 100 continues to move in one direction by the transport device 2, the arm 10a of the robot 10 attaches the attachment part 111 of the component 110 to the target part 101.

[0016] The robot 10 is not limited to a specific type, but a multi-joint robot having six axes can be used. The arm 10a of the robot 10 in the present embodiment includes a plurality of servo motors 11 that respectively drive a plurality of movable parts (see FIG. 4). Each servo motor 11 has an operating position detection device for detecting its operating position, and the operating position detection device is an encoder as an example. The detection value of the operating position detection device is transmitted to the control device 20.

[0017] A hand 30 for carrying the component 110 is attached to the tip of the robot 10. In one example, the hand 30 includes a servo motor 31 that drives the claws (see FIG. 4). The servo motor 31 has an operating position detection device for detecting its operating position, and the operating position detection device is an encoder as an example. The detection value of the operating position detection device is transmitted to the control device 20. As each of the servo motors 11 and 31, various servo motors such as a rotary motor and a linear motor can be used.

[0018] A force sensor 32 is attached to the tip of the robot 10. The force sensor 32 detects forces in the X-axis, Y-axis, and Z-axis directions, for example, as shown in Figures 1 and 3. The force sensor 32 also detects forces around the X-axis, Y-axis, and Z-axis. The force sensor 32 only needs to be capable of detecting the direction and magnitude of the force applied to the hand 30 or the part 110 gripped by the hand 30. For this reason, in this embodiment the force sensor 32 is provided between the robot 10 and the hand 30, but the force sensor 32 may also be provided inside the hand 30, at the base of the arm 10a, on another part of the arm 10a, on the base of the robot 10, etc.

[0019] The tracking sensor 50 is attached to the tip of the robot 10. In one example, the tracking sensor 50 is attached to the wrist flange of the arm 10a, similar to the hand 30. The tracking sensor 50 can be a two-dimensional camera, a three-dimensional camera, a three-dimensional distance sensor, etc. In this embodiment, the tracking sensor 50 is a two-dimensional camera, and the tracking sensor 50 is a sensor that can sequentially acquire image data of the target part 101 as shown in Figure 3, when the target part 101 is within a predetermined range of the field of view. The tracking sensor 50 sequentially transmits image data (output) to the control device 20. The image data is data that can identify at least the position of the target part 101 being transported by the transport device 2. The tracking sensor 50 may also acquire data that can identify the position and orientation of the target part 101.

[0020] Image data is data that can identify the position of at least one of multiple target parts 101. The control device 20 may also identify the position of the target part 101 based on the position, shape, etc., of characteristic parts of the article in the image data. Furthermore, the control device 20 can identify the orientation of the target part 101 based on the positional relationship of multiple target parts 101 in the image data. The control device 20 can identify the orientation of the target part 101 based on the position, shape, etc., of characteristic parts in the image data. Characteristic parts may be elements with distinctive features, such as the mark M shown in Figure 3 or the corners of the article 100.

[0021] The position and orientation of the coordinate system of the tracking sensor 50 and the position and orientation of the coordinate system of the robot 10 are pre-associated within the control device 20. For example, the coordinate system of the tracking sensor 50 is set as the reference coordinate system of the robot 10, which operates based on the operation program 23b. It is possible to associate the reference coordinate system with a coordinate system whose origin is the tool center point (TCP) of the hand 30, a coordinate system whose origin is the reference position of the part 110, and so on.

[0022] As shown in Figure 4, the control device 20 includes a processor 21 having one or more processor elements such as a CPU and a microcomputer, a display device 22, a storage unit 23 having non-volatile storage, ROM, RAM, etc., a plurality of servo controllers 24 corresponding to the servo motors 11 of the robot 10, a servo controller 25 corresponding to the servo motors 31 of the hand 30, and an input unit 26 connected to the control device 20. In one example, the input unit 26 is an input device such as a control panel that can be carried by the user. In some cases, the input unit 26 communicates wirelessly with the control device 20, and in other examples, the input unit 26 is a tablet computer. In the case of a tablet computer, input is performed using a touchscreen function. In some cases, the control panel or tablet computer has a display device 22.

[0023] The memory unit 23 stores the system program 23a, which is responsible for the basic functions of the control device 20. The memory unit 23 also stores the operation program 23b. Furthermore, the memory unit 23 stores the pre-approach control program 23c, the approach control program 23d, the follow control program 23e, and the force control program 23f.

[0024] Based on these programs, the control device 20 transmits control commands to each servo controller 24, 25 to perform predetermined tasks on the item 100. This causes the robot 10 and the hand 30 to perform the predetermined tasks on the item 100. The operation of the control device 20 during this process will be explained with reference to the flowchart in Figure 5.

[0025] First, when the object 100 is detected by the detection device 40 or the tracking sensor 50 (step S1), the control device 20 transmits control commands to the arm 10a and hand 30 based on the pre-approach control program 23c (step S2). As a result, the arm 10a moves the hand 30, which was in a standby position, to the position where the part 110 is placed, the hand 30 grasps the part 110, and the arm 10a moves the part 110 to the approach start position shown in Figure 2. As shown in Figure 2, the approach start position is on the robot 10 side of the boundary line BL.

[0026] Here, the position and orientation of each item 100 on the conveying device 2 will vary. This variation occurs, for example, when each item 100 is placed on the conveying device 2. This variation also occurs when each item 100 on the conveying device 2 moves slightly in an unintended direction due to vibration or the like. As shown in Figure 2, when an item 100 is placed on the conveying device 2 while rotated around its vertical axis, one end 120 in the X direction of the item 100 that is closer to the robot 10 in the Y direction is positioned closer to the robot 10 than the target part 101 in the Y direction.

[0027] One end 120 is a part that can interfere. In Figure 2, the rotation of the article 100 is depicted in an exaggerated manner. When the length of the article 100 is, for example, around 5 m, and the position of the article 100 in the rotational direction about the aforementioned axis varies within a range of about 2°, the position of one end 120 will vary by 10 cm or more, sometimes more than 20 cm, in the Y direction. If the variation in the mounting position in the Y direction is added to this variation, the variation in the position of one end 120 in the Y direction will become even larger.

[0028] In one example, the non-volatile storage, RAM, etc., of the memory unit 23 of the control device 20 stores start position data 23g, which is the coordinate value of the part 110 at the approach start position, the coordinate value of the hand 30, or the coordinate value of the tip of the arm 10a (Figure 4). The start position data 23g is set so that the part 110 does not interfere with the end 120 that is being moved by the transport device 2. In other words, once this setting is made and the part 110 is positioned at the approach start position corresponding to the start position data 23g, as shown in Figure 2, the part 110 will not interfere with the end 120 even if the transport device 2 moves the end 120 until it has passed in front of the part 110. In this embodiment, interference refers to interference that occurs while the end 120 is passing in front of the part 110, as described above.

[0029] In another example, at least one of the following is stored as boundary position data 23h in the non-volatile storage, RAM, etc., of the memory unit 23 of the control device 20: location information of the boundary line BL, information of area AR1 where interference may occur, and information of area AR2 where interference does not occur (Figure 4). As can be seen from Figure 2, the boundary line BL is a line that separates area AR1 where interference may occur from area AR2 where interference does not occur, by one end 120 which is being moved by the transport device 2. With the presence of start position data 23g or boundary position data 23h, part 110 is positioned at the approach start position so as not to come into contact with article 100.

[0030] In this embodiment, it is sufficient to set at least one of the start position data 23g and boundary position data 23h. In one example, the start position data 23g and boundary position data 23h are stored in the storage unit 23 based on input from the user to the input unit 26. In another example, the control device 20 detects or calculates the path of one end 120 that is moved by the transport device 2 using image data from the detection device 40 or the tracking sensor 50. In one example, the path corresponds to the boundary line BL. The control device 20 then sets the start position data 23g and boundary position data 23h based on the result of the detection or calculation, and stores the set start position data 23g and boundary position data 23h in the storage unit 23. The control device 20 may update the start position data 23g and boundary position data 23h each time the next item 100 arrives.

[0031] Based on the pre-approach control program 23c, the control device 20 adjusts the orientation of the part 110 at the approach start position, or the orientation of the part 110 as it moves toward the approach start position, to match the orientation of the target part 101 (step S3). In one example, the control device 20 adjusts the orientation of the part 110 while the part 110 is moving toward the approach start position, or when the part 110 reaches the approach start position. For example, the control device 20 detects the orientation of the target part 101 using image data from the tracking sensor 50 and adjusts the orientation of the part 110 to match the detected orientation.

[0032] The movement route of the article 100 by the conveying device 2 may not be a straight line. Also, the posture of the article 100 on the conveying device 2 may gradually change due to vibration or the like. In these cases, in step S3, the control device 20 may, based on the pre-approach control program 23c, make the posture of the part 110 at the approach start position, or the posture of the part 110 moving toward the approach start position, follow the posture of the target part 101.

[0033] For this tracking control, the control device 20 provides visual feedback using image data sequentially obtained by, for example, the tracking sensor 50. In other examples, the control device 20 uses data sequentially obtained by other cameras, other sensors, etc. Preferably, the starting position data 23g is set so that contact between the part 110 and the article 100 is prevented even when there is a change in the posture of the target part 101, the part 110, and the hand (tool) 30. Depending on the type and shape of the target part 101, the tracking sensor 50, other cameras, and other sensors may be a three-dimensional camera or a three-dimensional distance sensor. With the above configuration, contact between the part 110 and the article 100 at the approach starting position is prevented, while the attachment of the part 110 to the target part 101 is smooth and reliable.

[0034] The control device 20 may change the start position data 23g or boundary position data 23h for the next item 100 to be worked on by the robot 10. For example, when the next item 100 to be worked on arrives, the control device 20 uses the image data to detect the position of one end 120 and changes the start position data 23g or boundary position data 23h using that position, or using that position and the data of the movement route by the transport device 2. Alternatively, when the next item 100 to be worked on arrives, the control device 20 uses the image data to detect the position and orientation of the item 100 or one end 120 and changes the start position data 23g or boundary position data 23h using that position and orientation, or using that orientation and the data of the movement route. This change is performed, for example, before step S2.

[0035] When the starting position data 23g or boundary position data 23h is changed in this way, it prevents the distance between the part 110 and the target part 101 from becoming unnecessarily large at the approach starting position. This is useful for accurately aligning the orientation of the part 110 with the target part 101, as mentioned above.

[0036] The above configuration can also be applied to a work robot system in which robot 10 performs other tasks on article 100, such as processing, assembly, inspection, and observation. Article 100 can be transported by any means of movement, and it is possible to use a robot other than robot 10 as an article moving device. If article 100 is the body or frame of an automobile, the body or frame may be moved by the engine, motor, wheels, etc. mounted thereon. In this case, the engine, motor, wheels, etc. function as an article moving device. Article 100 may also be moved by an AGV (Automated Guided Vehicle) or the like as an article moving device. In these cases, the control device 20 may receive data of the movement route from the control device of another robot, an automobile, an AGV, sensors installed thereon, etc. Alternatively, the control device 20 may calculate the data of the movement route using the sequentially obtained image data.

[0037] Next, the control device 20 transmits a control command to the arm 10a based on the approach control program 23d (step S4). As a result, the arm 10a brings the part 110 closer to the target part 101. Preferably, before step S4, the control device 20 determines whether the target part 101 is positioned in a location where tracking control in step S6 is possible, based on the output of the tracking sensor 50, the other cameras, the other sensors, etc. Then, if the target part 101 is positioned in a location where tracking control is possible, the control device 20 brings the part 110 closer to the target part 101.

[0038] In step S4, the control device 20 may simply move the part 110 toward the target part 101 by a predetermined distance using the arm 10a. In step S4, the control device 20 may use data from the tracking sensor 50, the detection device 40, the other camera, or the other sensor to bring the part 110 closer to the target part 101 using the arm 10a. In this case, the control device 20 may use visual feedback using the data to make the posture of the part 110 approaching the target part 101 follow the posture of the target part 101. In this embodiment, if the other camera or the other sensor is positioned to observe the target part 101 and the part 110 from above, the control in step S4 becomes more accurate.

[0039] In step S4, the control of arm 10a causes part 110 to reach a position and orientation for fitting onto target part 101. As a result, target part 101 is within a certain field of view of the tracking sensor 50, and when the distance between the mounting part 111 of part 110 and target part 101 falls within a reference value (step S5), the control device 20 starts tracking control to make part 110 follow target part 101 based on tracking control program 23e, and starts fitting control to fit the mounting part 111 onto target part 101 based on operation program 23b (step S6).

[0040] In one example, for tracking control based on the tracking control program 23e, the control device 20 provides visual feedback using image data sequentially obtained by the tracking sensor 50. Known visual feedback can be used. In this embodiment, for example, the following two controls can be used to control each of the visual feedbacks. In the two controls, the tracking sensor 50 detects at least the position of the target part 101, and the processor 21 causes the tip of the robot 10 to follow the target part 101 based on the detected position.

[0041] The first control involves positioning the feature portion on the item 100 at a predetermined location within the field of view of the tracking sensor 50, thereby causing the tip of the robot 10 to follow the target portion 101. The second control involves detecting the position of the feature portion of the item 100 in the coordinate system of the robot 10 (position relative to the robot 10), and correcting the operation program 23b using the detected position of the feature portion, thereby causing the tip of the robot 10 to follow the target portion 101.

[0042] In the first control, the control device 20 detects feature portions on the image data sequentially obtained by the tracking sensor 50. Feature portions include the overall shape of the target portion 101, the holes 101a in the target portion 101, and the mark M provided on the target portion 101 (Figure 3). The control device 20 then uses the image data sequentially obtained by the tracking sensor 50 to send a control command to the servo controller 24 to always position the detected feature portion at a predetermined location in the image data so that it is within the range of a reference shape and size. In this case, the tracking sensor 50 is used for sequential detection of the position and orientation of the target unit 101. In another example, the control device 20 uses the image data sequentially obtained by the tracking sensor 50 to send a control command to the servo controller 24 to always position the detected feature portion at a predetermined location in the image data. If the tracking sensor 50 is a three-dimensional camera, a three-dimensional distance sensor, etc., the control device 20 sends a control command to the servo controller 24 to always position the feature portion at a predetermined location in the three-dimensional image data so that it is in a reference orientation.

[0043] In this case, the control device 20 preferably uses a feature portion that is visible to the tracking sensor 50 when mating occurs, rather than a feature portion that becomes invisible to the tracking sensor 50 when mating occurs. Alternatively, the control device 20 can change the feature portion used for tracking control when that feature portion becomes invisible to the tracking sensor 50.

[0044] In the second control, the control device 20 uses image data sequentially obtained by the tracking sensor 50 to detect the actual position of the feature portion on the item 100 relative to the coordinate system of the robot 10. Then, the processor 21 corrects the teaching points of the operation program 23b based on the difference between the position of the feature portion in the operation program 23b and the actual position of the feature portion.

[0045] In this controlled state, the control device 20 starts force control based on the force control program 23f (step S7). As force control, well-known force control methods can be used. In this embodiment, the arm 10a moves the part 110 in a direction away from the force detected by the force sensor 32. The amount of movement is determined by the control device 20 according to the value detected by the force sensor 32.

[0046] For example, when the shaft 111a of the part 110, which is gripped by the hand 30 according to the operation program 23b, begins to engage with the hole 101a of the article 100, if the force sensor 32 detects a force in the opposite direction to the direction of movement by the conveying device 2, the control device 20 performs the tracking control described above and slightly moves the part 110 in the opposite direction to the direction of movement by the conveying device 2. Furthermore, if the force sensor 32 detects a force exceeding a reference value, the control device 20 performs an abnormal response operation.

[0047] Meanwhile, the control device 20 determines whether the mating operation is complete (step S8), and if the mating operation is complete, it sends control commands to the arm 10a and the hand 30 (step S9). As a result, the hand 30 moves away from the part 110 and the hand 30 is moved by the arm 10a to a waiting position or to a location where the next part 110 is stocked.

[0048] A work robot system according to the second embodiment will be described below with reference to Figure 6. In the second embodiment, the article 100 gripped by the hand 30 is used as a tire, and the target part 101 is used as a hub for the front wheel. In the second embodiment, the same reference numerals are used for components as in the first embodiment, and their descriptions are omitted.

[0049] In the second embodiment, steps S1, S2, and S3 of the first embodiment are also performed. Here, the hub for the front wheel is prone to changes in orientation depending on the position of the vehicle's steering wheel, and the orientation of the hub on the transport device 2 is rarely perfectly constant. In step S3, the control device 20 detects the orientation of the target part 101 using image data from the tracking sensor 50 and adjusts the orientation of the part 110 to match the detected orientation. This ensures that the attachment of the part 110 to the target part 101 is smooth and reliable.

[0050] Furthermore, the posture of the hub may change slightly due to vibrations of the article 100 on the transport device 2. In this case, as in the first embodiment, in step S3, the control device 20 may make the posture of the part 110 at the approach start position, or the posture of the part 110 moving toward the approach start position, follow the posture of the target part 101. This is advantageous for ensuring smooth and reliable attachment of the part 110 to the target part 101. Preferably, in the first and second embodiments, the start position data 23g is set so that the part 110 does not enter the area AR1 where interference may occur even if the part 110 is adjusted or follows the attitude of the part 110 at the approach start position. Next, in the second embodiment, steps S4 to S9 are performed in the same manner as in the first embodiment.

[0051] Alternatively, a tool may be supported at the tip of the robot 10, and the robot 10 may perform a predetermined operation using the tool on the target part 101 being transported by the transport device 2. In this case, the tool may be a drill, milling cutter, drill tap, deburring tool, other tools, welding tool, painting tool, sealant application tool, etc. Even in this case, in step S2 the tool is positioned at the approach start position, and in step S3 the orientation of the tool is adjusted to match the orientation of the target part 101. Furthermore, in step S4 the tool is brought closer to the target part 101, and in step S5 when the distance between the tool and the target part 101 is less than or equal to a predetermined value, in step S6 the arm 10a uses the tool to perform operations such as machining, welding, painting, sealing, etc., on the target part 101.

[0052] As described above, in each embodiment, the control device 20 controls the arm 10a to bring the part 110 or tool, which is positioned at the approach start position, closer to the target part 101. The control device 20 also controls the arm 10a using the output of the tracking sensor 50 to make the part 110 or tool follow the target part 101 being moved by the article moving device. Before bringing the part 110 or tool closer to the target part 101, the control device 20 controls the arm 10a to move the part 110 or tool to an approach start position that does not interfere with one end 120 of the article 100 being moved by the transport device 2. Here, the one end 120 is a part of the article other than the target part 101, and is a part that may interfere with the part 110 or tool.

[0053] Many robot systems exist in which the robot 10 and the object moving device are not fully coordinated. In such cases, during the teaching operation of the robot 10, during the test operation of the robot 10 after the teaching operation, or during the operation of the robot 10 in unintended circumstances, the target part 101 may move downstream of the working area of ​​the arm 10a while the arm 10a has positioned the part 110 or tool at the approach start position. Similarly, the target part 101 may move downstream of the working area of ​​the arm 10a while the arm 10a is moving the part 110 or tool to the approach start position. In such cases, the part or tool does not interfere with one end 120 of the object 100 at the approach start position. The teaching and operation of the robot 10 are performed in various situations, but the above configuration is useful for reducing or eliminating contact between the part 110 or tool at the tip of the robot 10 and the object 100.

[0054] In each of the above embodiments, the approach start position is changed using at least one data point of the position and orientation of the article 100 being moved by the article moving device, and data of the article 100's movement route. This prevents the distance between the part 110 and the target part 101 from becoming unnecessarily large at the approach start position. It also makes it possible to precisely align the orientation of the part 110 with the target part 101.

[0055] For example, the movement route of the article 100 by the article moving device may not be a straight line. Also, the posture of the article 100 on the article moving device may gradually change due to vibration or the like. In each of the above embodiments, in the pre-approach control, the posture of the part 110 or tool is made to follow the posture of the target part 101. This configuration prevents contact between the part 110 and the article 100 at the approach start position, while enabling smooth and reliable attachment of the part 110 to the target part 101.

[0056] The control device 20 may send data to the display device 22, the input unit 26 with a display device, the user's computer with a display device, etc., and these display devices may display areas indicating areas AR1 where interference may occur or areas AR2 where interference does not occur. When area displays are displayed on the display device of the user's computer, the computer functions as part of the robotic system. Preferably, along with the area display, displays are made that show the position of the part 110 or tool, the position of the tip of the arm 10a, etc. Normally, the control device 20 that controls the arm 10a recognizes the position of the part 110 or tool and the position of the tip of the arm 10a. This configuration is useful for understanding the movement of the arm 10a by pre-approach control during the teaching operation of the robot 10, during the test operation of the robot 10 after the teaching operation, and during the normal operation of the robot 10.

[0057] Furthermore, the control device 20 may display the approach start position along with the area display on the display device. This configuration is useful for the user to intuitively and reliably understand whether the settings are appropriate.

[0058] The tracking sensor 50 may be attached to the end of another articulated robot having six axes, rather than to the end of the robot 10. In this case, the position and direction of the coordinate system of the tracking sensor 50 are associated with the position and direction of the coordinate system of the robot 10 and the position and direction of the coordinate system of the other articulated robot. The coordinate system of the tracking sensor 50 is then set as the reference coordinate system for the other articulated robot and the robot 10. By controlling the robot 10 based on the control data of the other articulated robot, the visual feedback using the output of the tracking sensor 50 becomes possible.

[0059] Furthermore, the tracking sensor 50 may be fixed above the work area of ​​the robot 10, or it may be supported above the work area of ​​the robot 10 so as to be movable in the X, Y, Z directions, etc. For example, the tracking sensor 50 may be supported so as to be movable in the X and Y directions using an X-direction linear motion mechanism that is movable in the X direction, a Y-direction linear motion mechanism that is supported by the X-direction linear motion mechanism and is movable in the Y direction, and multiple motors. Even in these cases, the visual feedback using the output of the tracking sensor 50 is possible. [Explanation of Symbols]

[0060] 1. Work robot system 2. Conveying device 10 Robots 11 Servo motors 20 Control device 21 processors 22 Display device 23 Memory section 23a System Program 23b Operating Program 23c Pre-Approach Control Program 23d Approach Control Program 23e Follow-up control program 23f Force control program 23g starting position data 23h Boundary position data 26 Input section 30 hands 31 Servo motor 32 Force Sensors 40 Detection device 50 Tracking Sensors 100 goods 101 Target section 101a hole 110 parts 111 Mounting part 111a Shaft

Claims

1. A robot that performs a predetermined task on a target part of an item being moved by an item moving device, A control device used to control the robot, A work robot system comprising: a tracking sensor used for sequentially detecting at least the position of the target part being moved by the object moving device when the robot supports a part or tool to follow the target part, The control device is Pre-approach control involves controlling the robot to move the part or tool to an approach start position that does not interfere with any potentially interfering parts of the article being moved by the article moving device, By controlling the robot, the part or tool positioned at the approach start position is brought closer to the target part, and by controlling the robot using the output of the tracking sensor, the part or tool is made to follow the target part being moved by the item moving device, and tracking control is performed. It is configured to do the following: A robotic work system in which the interferable portion is a portion that is closer to the part or tool than the target portion when the article passes through in the direction of movement by the article moving device.

2. The work robot system according to claim 1, wherein the control device is configured to change the approach start position using at least one data of the position and orientation of the article being moved by the article moving device and data of the article's movement route.

3. The work robot system according to claim 1 or 2, wherein the control device, in the pre-approach control, causes the posture of the part or the tool to follow the posture of the target part.

4. A work robot system according to any one of claims 1 to 3, comprising a display device that displays an area indicating an area where interference may occur with the interferable part moved by the article moving device, or an area where interference does not occur.

5. The work robot system according to claim 4, wherein the approach start position is displayed together with the area display.

6. An arm that performs a predetermined operation on a target part of an item being moved by an item moving device, A control device used to control the arm, A robot comprising: a tracking sensor capable of sequentially detecting at least the position of the object being moved by the object moving device when causing a part or tool supported by the arm to follow the target part, The control device is Pre-approach control involves controlling the arm to move the part or tool to an approach start position where it does not interfere with any potentially interfering parts of the article being moved by the article moving device. The system is configured to perform tracking control, which involves controlling the arm to bring the part or tool positioned at the approach start position closer to the target, and controlling the arm using the output of the tracking sensor to cause the part or tool to follow the target being moved by the item moving device. The robot wherein the interferable portion is a portion that is closer to the part or tool than the target portion when the article passes through in the direction of movement by the article moving device.

7. At least one memory capable of storing a program that includes at least a robot approach control program and a follow control program, The system comprises at least one processor capable of executing the aforementioned program, The aforementioned at least one processor is Obtain information about at least the location of the moving item, Based on the position information and the approach control program, the part or tool is moved to an approach start position where the part or tool supported by the robot does not interfere with the interferable portion of the article. After moving to the approach start position, the robot is made to follow the target part of the article based on the tracking control program. The control device wherein the interferable portion is a portion that is closer to the part or tool than the target portion when the article passes through in the direction of movement.

8. The control device according to claim 7, wherein the at least one processor is configured to change the approach start position using at least one data of the position and orientation of the moving article and data of the movement route of the article.

9. The control device according to claim 7 or 8, wherein the at least one processor causes the posture of the part or the tool to follow the posture of the target part in the control of moving the part or the tool to the approach start position.

10. The control device according to any one of claims 7 to 9, comprising a display device that displays an area indicating an area where interference with the moving interferable part may occur or an area where interference does not occur.

11. The control device according to claim 10, which displays the approach start position together with the area display.

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