Robot system

Abstract

To accurately orient a workpiece to a reference orientation.SOLUTION: A robot system 1 includes: a robot 2 for performing work on a workpiece (body 11) conveyed to a working area 13; a first stopper 101 and a second stopper 102 positioned with a space on a line orthogonal to a reference line 130 along a conveyance direction of the workpiece in the working area; and a conveyance vehicle (AMR 6) for conveying the workpiece to the working area and stopping when a mobile body 60 including the workpiece and the conveyance vehicle are being in contact with the first stopper and the second stopper.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The technology disclosed herein relates to a robot system. [Background technology]

[0002] Patent Document 1 describes a conventional robot system. The conventional robot system is used in an assembly line for automobile bodies. On the assembly line, a side member is assembled to an underbody. The conventional robot system includes a first multi-axis robot and a second multi-axis robot. The first multi-axis robot positions the underbody. The second multi-axis robot welds the underbody and the side member together. The conventional robot system also includes an AGV (Automatic Guided Vehicle) that transports the underbody to an assembly area. The AGV travels along a magnetic tape on the floor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6887738 Summary of the Invention [Problem to be solved by the invention]

[0004] In the work area where the robot performs work on the work, a reference orientation of the work is determined. The reference orientation of the work is the orientation of the work when the robot performs work on the work, and is the orientation in a horizontal plane. The reference orientation of the work is usually the orientation along the transport direction when the work is transported to the work area.

[0005] Robot systems used in automobile production lines are required to accurately adjust the orientation of workpieces, because with long workpieces such as automobile bodies, even a slight deviation in orientation can result in a large deviation in position at the ends of the workpiece.

[0006] In the conventional robot system, a workpiece arriving at the work area may be tilted relative to a reference orientation. This is because the AGV transports the workpiece to the work area. A pair of guide rollers and a positioning device are installed in the work area of ​​the conventional robot system. The pair of guide rollers position the AGV in the width direction, and the positioning device positions the AGV in the front-to-rear direction. The combination of the pair of guide rollers and the positioning device does not allow the workpiece to be accurately oriented in the reference orientation. [Means for solving the problem]

[0007] The technology disclosed herein relates to a robot system. a robot that performs work on the workpiece transported to the work area; a first stopper and a second stopper positioned at an interval on a line perpendicular to a reference line along a conveying direction of the workpiece in the working area; a transport vehicle that transports the workpiece to the work area and stops when a moving body including the workpiece and the transport vehicle abuts against the first stopper and the second stopper; Equipped with. [Effects of the Invention]

[0008] The transport vehicle that transports the workpiece to the work area uses the first stopper and the second stopper to correct the orientation of the workpiece, so the robot system can accurately orient the workpiece in the reference orientation. [Brief explanation of the drawings]

[0009] [Figure 1] Figure 1 shows a robot system applied to an automobile manufacturing line. [Figure 2] Figure 2 shows the robot system. [Figure 3] FIG. 3 is a block diagram of the robot system. [Figure 4]FIG. 4 is a block diagram of an autonomous mobile robot (AMR). [Figure 5] Figure 5 shows a stopper installed in the path of an AMR. [Figure 6] Figure 6 shows the procedure for correcting the tilt of a workpiece using an AMR with a rotary table. [Figure 7] FIG. 7 is a flowchart showing the control procedure of the AMR. [Figure 8] FIG. 8 shows a variation of the AMR. [Figure 9] Figure 9 shows the procedure for correcting the tilt of a workpiece using an AMR that can rotate on the spot. [Figure 10] FIG. 10 shows another variation of the AMR. [Figure 11] FIG. 11 shows yet another variation of the AMR. [Figure 12] FIG. 12 shows the procedure for correcting the tilt of a workpiece by the AMR when the stopper hits the AMR. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of a robot system will be described with reference to the drawings. The robot system described here is an example.

[0011] (Overall structure of the robot system) Fig. 1 is a perspective view of the robot system 1 seen from diagonally above. Fig. 2 is a rear view of the robot system 1 seen from behind. The robot system 1 is applied to a production line 10 in an automobile factory. In the illustrated production line 10, welding, more specifically spot welding, is performed on an automobile body 11.

[0012] The front Fr, rear Rr, right Rt, left Lt, top Up, and bottom Lw of the robot system 1 are defined as follows, with the body 11 that is the work target of the robot system 1 as the reference.

[0013] The front Fr of the robot system 1 is the left rear side in the direction connecting the right front and left rear of the paper in Figure 1. The front Fr of the robot system 1 corresponds to the front of the automobile body 11, and the rear Rr of the robot system 1 corresponds to the rear of the automobile body 11. As will be described later, the front-to-rear direction corresponds to the conveyance direction of the body 11.

[0014] The right side Rt of the robot system 1 is the far right side in the direction connecting the front left and rear right of the paper in FIG. 1. The right side Rt of the robot system 1 corresponds to the right side of the automobile body 11. The left side Lt of the robot system 1 corresponds to the left side of the automobile body 11. The left-right direction is a direction that is horizontally perpendicular to the front-rear direction.

[0015] The top (Up) of the robot system 1 is the top side of the paper in Fig. 1, and the bottom (Lw) of the robot system 1 is the bottom side of the paper. The top and bottom of the robot system 1 correspond to the top and bottom of the automobile body 11. The up-down direction is a direction perpendicular to the front-to-rear direction.

[0016] It should be noted that the above definitions are used to explain the robot system 1, and are not used to limit the structure or configuration of the robot system 1 and the elements included in the robot system 1 disclosed herein.

[0017] The robot system 1 includes a robot 2. The robot 2 performs work on a workpiece transported to a work area 13. The work area 13 is located on a path 15 of the AMR 6, which will be described later, and refers to an area where the workpiece transported by the AMR 6 stays to be worked on by the robot 2. The workpiece of the robot 2 is a body 11. The work that the robot 2 performs on the body 11 is welding.

[0018] The robot 2 is a vertical articulated robot having five to seven axes. As shown in Fig. 2, the robot 2 has a welding gun 21 as an end effector. However, the robot 2 is not limited to a vertical articulated robot.

[0019] The robot system 1 includes a plurality of robots 2. The robot system 1 shown in the figure includes 12 robots 2. The 12 robots 2 are located on either side of the body 11. On the right side of the body 11, six robots 2 are lined up in the front-to-rear direction of the body 11. Similarly, on the left side of the body 11, six robots 2 are lined up in the front-to-rear direction of the body 11. Each robot 2 performs welding at a different location on the body 11. The number of robots 2 in the robot system 1 is not limited to a specific number. Furthermore, the arrangement of the robots 2 in the robot system 1 is not limited to a specific arrangement.

[0020] The robot system 1 is equipped with a locator 4. However, the locator 4 is not an essential element of the robot system 1. As shown by the dashed dotted line in Figure 2, the locator 4 lifts and supports the body 11 while the robot 2 is working. The locator 4 in the illustration is a three-axis Cartesian robot. The locator 4 has a rod 41 that engages with the body 11. The rod 41 extends in the left-right direction. The tip of the rod 41 engages with the body 11. The locator 4 changes the position of the tip of the rod 41 forward / backward, left-right, and up / down.

[0021] The robot system 1 is equipped with a plurality of locators 4. The robot system 1 in the illustration is equipped with eight locators 4. The eight locators 4 are located on the left and right sides of the body 11. On the right side of the body 11, four locators 4 are lined up in the front-to-rear direction of the body 11. As schematically shown in FIG. 5, one of the four locators 4 supports the right front end of the body 11, and one of the four locators 4 supports the right rear end of the body 11. The remaining two locators not shown in FIG. 5 support the right central portion of the body 11, as shown in FIG. 1. Similarly, on the left side of the body 11, the four locators 4 are lined up in the front-to-rear direction of the body 11. As shown in FIG. 5, one of the four locators 4 supports the left front end of the body 11, and one of the four locators 4 supports the left rear end of the body 11. The remaining two units not shown in FIG. 5 support the left central portion of the body 11 as shown in FIG.

[0022] The robot system 1 is equipped with one or more transport vehicles. The transport vehicles transport workpieces to a work area 13. The transport vehicles are autonomous mobile transport robots (AMRs) 6. The AMR 6 travels on a flat floor in a factory. As illustrated in FIG. 2, a body 11 is placed on a carriage 14. The AMR 6 is positioned below the carriage 14 and engages with the carriage 14. The AMR 6 transports the body 11 via the carriage 14. Note that the AMR 6 may directly support the body 11 without using the carriage 14. Note that the appearance of the AMR 6 shown in FIG. 1 or 2 is an example. The structure of the AMR 6 will be described later.

[0023] A mobile body 60 is configured that includes at least the AMR 6 and the body 11 and moves to the work area 13 of the production line 10.

[0024] 3 is a block diagram of the robot system 1. The robot system 1 includes a system controller 16. However, the system controller 16 is not an essential element of the robot system 1. The system controller 16 controls the entire robot system 1.

[0025] The robot system 1 includes a robot controller 17. Note that the robot controller 17 is not an essential element of the robot system 1. The robot controller 17 is electrically connected to the system controller 16. The electrical connection includes a wired or wireless connection. The robot controller 17 is also electrically connected to the robot 2. The robot controller 17 and the robot 2 are connected one-to-one. The robot system 1 includes the same number of robot controllers 17 as the number of robots 2.

[0026] The robot controller 17 controls the robot 2. More specifically, the robot controller 17 receives a control signal from the system controller 16 and outputs a control signal to the robot 2. The robot 2 receives the control signal from the robot controller 17 and performs welding work on the body 11.

[0027] The robot system 1 includes a locator controller 18. However, the locator controller 18 is not an essential element of the robot system 1. The locator controller 18 is electrically connected to the system controller 16. The electrical connection includes a wired or wireless connection. The locator controller 18 is also electrically connected to multiple locators 4. The robot system 1 may include multiple locator controllers 18.

[0028] The locator controller 18 controls the locator 4. More specifically, the locator controller 18 receives a control signal from the system controller 16 and outputs a control signal to the locator 4. The locator 4 receives the control signal from the locator controller 18 and positions and supports the body 11 delivered from the AMR 6 at a predetermined position.

[0029] The robot system 1 is equipped with a sensor 19. The sensor 19 is not an essential element of the robot system 1. The sensor 19 is electrically connected to the system controller 16. The sensor 19 outputs a signal related to the inclination of the body 11 that has arrived at the work area 13 to the system controller 16, as will be described in detail later. The sensor 19 includes an external camera 191. The external camera 191 is positioned above the work area 13, as shown in FIG. 2. The external camera 191 photographs the body 11 positioned in the work area 13 from above. The image captured by the external camera 191 is sent to the system controller 16. The system controller 16 determines the degree of inclination of the body 11 in a horizontal plane based on the image captured by the external camera 191.

[0030] (AMR structure) Figure 4 shows the structure of AMR6. AMR6a in Figure 4 is an example of AMR6.

[0031] The AMR 6a has a plurality of wheels that roll on the floor surface. The wheels include two drive wheels 61 and two steering wheels 62. The two drive wheels 61 are located on the same rotation axis extending in the left-right direction. The drive wheels 61 are, for example, rear wheels. The drive wheels 61 may also be front wheels. The drive wheels 61 are mechanically connected to a motor 63. The motor 63 is driven by power supplied from a battery. The battery is mounted on the AMR 6a. The motor 63 is a driving source for the AMR 6a to travel. The driving force of the motor 63 is transmitted to the drive wheels 61, causing the drive wheels 61 to rotate. The rotation of the drive wheels 61 causes the AMR 6a to travel (see the arrow in Figure 4).

[0032] The steering wheels 62 are, for example, passive wheels. The steering wheels 62 are located on the opposite side of the driving wheels 61 in the fore-and-aft direction of the AMR 6a. The two steering wheels 62 are located on the same rotation axis extending in the left-right direction. The steering wheels 62 are mechanically connected to a steering mechanism 64. The steering mechanism 64 changes the direction of the steering wheels 62 as shown by the arrow in Figure 4. Changing the direction of the steering wheels 62 changes the traveling direction of the AMR 6a. It should be noted that there may be only one steering wheel 62.

[0033] The AMR 6a has a scanner 65. The scanner 65 acquires information about the surroundings of the AMR 6a. The scanner 65 includes, for example, a LiDAR (Light Detection And Ranging). The scanner 65 is not limited to a LiDAR.

[0034] The AMR 6a has a storage 66. The storage 66 stores various data. The data stored in the storage 66 includes map data 661. The map data 661 is map data of the inside of a factory including the production line 10. Before transporting the body 11, the AMR 6a autonomously travels within the factory in advance, and creates the map data 661 using the scanner 65 while traveling. Note that the AMR 6a may obtain the previously created map data 661 from an external source.

[0035] The AMR 6a has a communication circuit 67. The communication circuit 67 communicates wirelessly with the system controller 16. The communication circuit 67 transmits, for example, position information of the AMR 6a to the system controller 16. The communication circuit 67 receives, for example, information regarding the inclination of the body 11 from the system controller 16.

[0036] The AMR 6a has a rotary table 68. The rotary table 68 is located on the upper surface of the AMR 6a. FIG. 6 is a top view of the AMR 6a transporting the body 11. FIG. 6 schematically illustrates the body 11 and the AMR 6a. Note that FIG. 6 does not include the carriage 14. The rotary table 68 rotates clockwise and counterclockwise around a vertical axis on the upper surface of the AMR 6a. The rotary table 68 rotates relative to the main body of the AMR 6a. The rotary table 68 has a drive source. The drive source is, for example, an electric motor. Examples of electric motors include servo motors and stepping motors. More specifically, the rotary table 68 has a rotary motor that rotates the rotary table 68 around the vertical axis and an elevator motor that raises and lowers the rotary table 68. As will be described later, the rotary table 68 rotates when the AMR 6a is stopped. When the rotary table 68 rotates, the body 11 rotates about a vertical axis via the carriage 14. The body 11 rotates in place without moving in the front-rear or left-right directions.

[0037] The AMR 6a has an AMR controller 69. The AMR controller 69 controls the AMR 6a. The AMR controller 69 is electrically connected to the motor 63, the steering mechanism 64, the scanner 65, the storage 66, the communication circuit 67, and the rotary table 68.

[0038] During the creation of the map data 661, the AMR controller 69 creates the map data 661 based on the signal from the scanner 65 while outputting control signals to the motor 63 and the steering mechanism 64 to move the AMR 6a. The AMR controller 69 stores the created map data 661 in the storage 66.

[0039] The AMR controller 69 receives control signals from the system controller 16 via the communication circuit 67, and causes the AMR 6a to perform an operation in accordance with the received control signal. The AMR 6a travels to a position specified by the system controller 16, that is, to the work area 13 of the robot 2. When the AMR 6a travels, the AMR controller 69 sets a route 15 for the AMR 6a based on map data 661. While the AMR 6a is traveling, the AMR controller 69 determines the self-position of the AMR 6a based on the signal from the scanner 65 and the map data 661. The AMR 6a autonomously travels to the specified position along the route 15, and the body 11 is transported to the work area 13.

[0040] (Work area stopper) The robot system 1 is equipped with stoppers 101 and 102. The stoppers include a first stopper 101 and a second stopper 102. As shown in FIG. 5, the first stopper 101 and the second stopper 102 are located in the work area 13. The first stopper 101 and the second stopper 102 protrude upward from a floor surface 151 of the path 15. In the illustrated example, the first stopper 101 and the second stopper 102 are poles. The first stopper 101 and the second stopper 102 are located in front of the moving body 60 in the forward direction of the moving body 60. The first stopper 101 and the second stopper 102 are located spaced apart on a line perpendicular to a reference line 130 along the conveying direction of the body 11. The first stopper 101 is located to the right of the reference line 130, and the second stopper 102 is located to the left of the reference line 130. More precisely, the first stopper 101 and the second stopper 102 are positioned line-symmetrically with respect to the reference line 130. However, the first stopper 101 and the second stopper 102 are not limited to being positioned line-symmetrically with respect to the reference line 130.

[0041] The reference line 130 is a line that represents the orientation of the body 11 when the robot 2 performs welding on the body 11. In other words, the reference line 130 corresponds to the reference orientation of the workpiece. The reference line 130 corresponds to the center line of the body 11 in the vehicle width direction when the robot 2 performs welding on the body 11. The reference line 130 is aligned with the transport direction when the body 11 is transported to the work area 13.

[0042] The moving body 60 moving along the path 15 hits at least one of the first stopper 101 and the second stopper 102. In the example of FIG.

[0043] The first stopper 101 and the second stopper 102 have a lifting mechanism. As shown in the upper diagram of FIG. 5 , the first stopper 101 and the second stopper 102 switch their positions between a first position where they protrude upward from the floor surface 151 of the path 15, and a second position where they do not protrude from the floor surface 151 of the path 15, as shown in the lower diagram of FIG. 5 . The first stopper 101 and the second stopper 102 in the first position interfere with the front of the moving body 60 in the traveling direction. The first stopper 101 and the second stopper 102 in the first position restrict the moving body 60 from moving forward. The first stopper 101 and the second stopper 102 in the second position do not interfere with the moving body 60. The moving body 60 can pass over the first stopper 101 and the second stopper 102.

[0044] 3, the first stopper 101 and the second stopper 102 are electrically connected to the system controller 16. The system controller 16 outputs signals to the first stopper 101 and the second stopper 102 to command them to switch their positions. The first stopper 101 and the second stopper 102 switch their positions between the first position and the second position based on the signals from the system controller 16.

[0045] The first stopper 101 and the second stopper 102 each have a sensor 103. The sensor 103 outputs a signal related to contact or proximity between the moving object 60 and the first stopper 101 or the second stopper 102 to the system controller 16. Various types of well-known sensors can be used for the sensor 103. As described below, the system controller 16 receives the signal from the sensor 103 and notifies the AMR 6 of interference between the moving object 60 and the first stopper 101 or the second stopper 102.

[0046] (AMR control) Next, a characteristic control of the AMR 6a will be described with reference to Figures 6 and 7. This characteristic control relates to the tilt correction of the workpiece by the AMR 6a. When the AMR 6a arrives at the designated work area 13, the orientation of the AMR 6a may be tilted from a predetermined orientation. This is because the AMR 6a does not require a guide, such as a rail, that mechanically engages to regulate the orientation of the AMR 6a. If the orientation of the AMR 6a is tilted, the orientation of the body 11 being transported by the AMR 6a will deviate from the reference line 130. The predetermined orientation of the AMR 6a is the orientation along the ideal forward direction of the AMR 6a when it arrives at the work area 13.

[0047] The AMR 6a can travel while correcting its orientation based on the scan data from the scanner 65. However, if the AMR 6a attempts to accurately correct its orientation while traveling, repeated small corrections to the orientation of the AMR 6a may require a long time for the correction. If the orientation correction takes a long time, it will take a long time to transport the body 11 to the work area 13, reducing production efficiency on the production line 10.

[0048] FIG. 6 shows the procedure for correcting the inclination of the body 11 by the AMR 6a. FIG. 6 shows the work area 13 where the AMR 6a stops, the locators 4 installed in the work area 13, the AMR 6a positioned in the work area 13, the body 11 transported to the work area 13 by the AMR 6a, and the first stopper 101 and second stopper 102 positioned in the first position. For ease of understanding, the locators 4 shown in FIG. 6 are four locators 4 supporting the four corners of the body 11. The work area 13 in FIG. 6 is drawn sufficiently large compared to the size of the body 11. In FIG. 6, the forward direction of the AMR 6a is downward from the top of the page. The up-down direction on the page in FIG. 6 is the ideal orientation of the AMR 6a arriving at the work area 13.

[0049] The AMR 6a that has arrived at the work area 13 is stopped when the moving object 60 hits the first stopper 101 or the second stopper 102. The AMR 6a may be stopped, for example, by receiving a signal output by the sensor 103 of the first stopper 101 or the second stopper 102 via the system controller 16. The AMR 6a may also be stopped based on a sensor mounted on the AMR 6a detecting contact between the moving object 60 and the first stopper 101 or the second stopper 102.

[0050] The moving body 60 shown in the left diagram of Figure 6 is only in contact with the second stopper 102. The AMR 6a is tilted clockwise with respect to the ideal orientation. As the AMR 6a tilts, the body 11 also tilts with respect to the reference line 130. The amount of tilt of the AMR 6a and the body 11 is an angle θ.

[0051] After stopping in the work area 13, the AMR 6a corrects the tilt of the body 11 using the rotary table 68. The AMR 6a obtains information on the tilt direction from the system controller 16.

[0052] Specifically, when the system controller 16 receives only the signal from the sensor 103 of the first stopper 101, it means that the right side of the moving object 60 hit the first stopper 101 first, and the system controller 16 determines that the AMR 6a is tilted counterclockwise. When the system controller 16 receives only the signal from the sensor 103 of the second stopper 102, it means that the left side of the moving object 60 hit the second stopper 101 first, and the system controller 16 determines that the AMR 6a is tilted clockwise, as shown in the left diagram of FIG. 6. When the system controller 16 receives signals from the sensors 103 of the first stopper 101 and the second stopper 102, it means that the moving object 60 hit the first stopper 101 and the second stopper 102, and the system controller 16 determines that the AMR 6a is not tilted.

[0053] When the system controller 16 determines that the AMR 6a is tilted, it transmits a command to correct the body 11 and information on the direction of the tilt to the AMR 6a.

[0054] The AMR 6a receives a command to correct the body 11 and information about the direction of tilt. As shown in the right diagram of FIG. 6, the AMR 6a rotates the body 11 using the rotary table 68 so that the tilt is corrected. The orientation of the body 11 is aligned with the reference line 130. The body 11 abuts against both the first stopper 101 and the second stopper 102.

[0055] Figure 7 is a flowchart showing the control procedure of the AMR 6. In the flow of Figure 7, the order of the steps can be changed as much as possible, some steps can be omitted, and other steps can be added.

[0056] In step S11 after starting, the AMR 6a determines whether or not it has received a travel command from the system controller 16. The AMR 6a remains stopped until it receives a travel command. The travel command includes a destination. In step S12, the AMR 6a that has received the travel command travels toward the destination. The destination includes the work area 13.

[0057] In step S13, the AMR 6a determines whether or not it has arrived at the work area 13 specified by the system controller 16, based on the scan data from the scanner 65 and the map data 661. The AMR 6a continues traveling in step S12 until it arrives at the work area 13.

[0058] When the AMR 6a arrives at the designated work area 13, in step S14, the AMR 6a travels at a slower speed than before. That is, the AMR 6a decelerates. This is to reduce the impact when the moving object 60 hits the first stopper 101 or the second stopper 102. If the first stopper 101 and the second stopper 102 have proximity sensors, the AMR 6a may receive detection signals from the proximity sensors via the system controller 16. Based on the detection signals from the proximity sensors, the AMR 6a can further reduce its speed before the moving object 60 hits the first stopper 101 or the second stopper 102.

[0059] After arriving at the designated work area 13, the AMR 6a may decelerate after receiving a detection signal from the proximity sensor.

[0060] In step S15, the AMR 6a determines whether the moving object 60 has hit the first stopper 101 or the second stopper 102. If the moving object 60 has not hit the first stopper 101 or the second stopper 102, the AMR 6a continues traveling at a low speed in step S14. If the moving object 60 has hit the first stopper 101 or the second stopper 102, the AMR 6a stops in step S16.

[0061] In step S17, the AMR 6a determines based on a signal from the system controller 16 whether the moving object 60 has hit the first stopper 101 or not.

[0062] If the moving object 60 hits the first stopper 101, the AMR 6a determines in step S18 whether the moving object 60 hits the second stopper 102 or not.

[0063] In step S18, if the movable body 60 is not hitting the second stopper 102, the movable body 60 is hitting only the first stopper 101. In step S19, the AMR 6a corrects the tilt of the body 11 using the rotary table 68. If the movable body 60 is hitting only the first stopper 101, the body 11 is tilted counterclockwise in FIG. 6 with respect to the reference line 130, so the rotary table 68 rotates the body 11 in a first direction. The first direction corresponds to the clockwise direction in FIG. 6.

[0064] After step S19, the AMR 6a returns to step S17. If the moving object 60 hits the first stopper 101 in step S17 and hits the second stopper 102 in step S18, the orientation of the body 11 is along the reference line 130, and the process in FIG. 7 proceeds to step S112.

[0065] On the other hand, if the moving object 60 does not hit the first stopper 101 in step S17, the AMR 6a determines in step S110 whether the moving object 60 hits the second stopper 102. If the moving object 60 does not hit the second stopper 102, the moving object 60 does not hit either the first stopper 101 or the second stopper 102, and the process in FIG. 7 returns to step S15.

[0066] In step S110, if the moving body 60 is in contact with the second stopper 102, the moving body 60 is in contact only with the second stopper 102. In step S111, the AMR 6a corrects the tilt of the body 11 using the rotary table 68. If the moving body 60 is in contact only with the second stopper 102, the body 11 is inclined clockwise in FIG. 6 relative to the reference line 130, so the rotary table 68 rotates the body 11 in the second direction. The second direction corresponds to the counterclockwise direction in FIG. 6.

[0067] After step S111, the AMR 6a returns to step S17. If the moving object 60 hits the first stopper 101 in step S17 and hits the second stopper 102 in step S18, the orientation of the body 11 is along the reference line 130, and the process in FIG. 7 proceeds to step S112.

[0068] In step S112, the AMR 6a sends a signal indicating that the shutdown has been completed to the system controller 16. The process of FIG. 7 returns to step S11.

[0069] When the system controller 16 receives a stop completion signal from the AMR 6a, it commands the locator 4 to support the body 11. As shown in the right diagram of FIG. 6, the locator 4 adjusts the position of the rod 41 in the front-to-rear and left-to-right directions, and then engages the tip of the rod 41 with the body 11 to support the body 11. In other words, the locator 4 lifts the body 11 from the carriage 14, as shown by the dashed line in FIG. 2. Once the support of the body 11 is complete, the system controller 16 commands the robot 2 to weld the body 11. The robot 2 performs welding on the body 11 in accordance with the command.

[0070] In addition, when supporting the body 11, the locator 4 may adjust the position of the body 11 in the left-right direction and the front-rear direction.

[0071] While the robot 2 is performing welding, the AMR 6a waits for a travel command from the system controller 16 in step S11.

[0072] Furthermore, if the moving body 60 is in contact with both the first stopper 101 and the second stopper 102 when the AMR 6a stops in steps S15 and S16, the AMR 6a does not perform the tilt correction in steps S19 or S111, but instead sends a stop completion signal to the system controller 16 in step S112.

[0073] (Action and effect) The AMR 6 does not require a running guide. As shown in Figure 1 or 2, a production line 10 equipped with the AMR 6 has the advantage of not requiring the pits required in conventional production lines for laying body transport rails and body elevators. Another advantage is that, because the floor in the factory is flat, the production line 10 equipped with the AMR 6 can easily accommodate layout changes.

[0074] Furthermore, using an AMR6 in the production line 10 enables production adjustments by adjusting the number of AMR6s, thereby realizing flexible operation of the production line 10.

[0075] The robot system 1 can correct the orientation of the body 11 using the rotary table 68 of the AMR 6a after the AMR 6a arrives at the work area 13. The robot system 1 can use the AMR 6a to align the orientation of the body 11 with the reference line 130 with high accuracy.

[0076] The AMR 6 does not need to precisely adjust the orientation of the AMR 6a while traveling to the work area 13 or immediately before stopping in the work area 13 in order to align the orientation of the body 11 with the reference line 130. The AMR 6a can quickly move to the work area 13. Furthermore, because the rotary table 68 rotates the body 11 about the vertical axis, the orientation of the body 11 can be quickly and accurately corrected. After arriving at the work area 13, the AMR 6a can quickly hand over the body 11 to the locator 4. The robot system 1 reduces the time required to transport the body 11, thereby improving the production efficiency of the production line 10.

[0077] The use of the stoppers 101, 102 makes it possible to accurately position the body 11 at a reference position in the fore-and-aft direction in the work area 13. The reference position in the fore-and-aft direction is the position of the body 11 in the fore-and-aft direction when the robot 2 performs welding on the body 11. The use of the two stoppers, the first stopper 101 and the second stopper 102, makes it possible to both align the orientation of the body 11 with the reference line 130 and to position the fore-and-aft direction position of the body 11 at the reference position.

[0078] Correction of the orientation of the body 11 by the locator 4 can be omitted because the AMR 6 corrects the orientation of the body 11. A small robot such as a three-axis Cartesian robot can be used as the locator 4. A small locator 4 can suppress interference with the robot 2 in a spatially limited area such as the work area 13. The robot system 1 has the advantage that the range of motion of the robot 2 is not limited by the locator 4.

[0079] (AMR Variation 1) FIG. 8 shows an AMR 6b according to a modified example. The AMR 6b in FIG. 8 is an example of an AMR 6. The AMR 6b differs from the AMR 6a in its drive configuration. The AMR 6b does not have a steering mechanism 64. The AMR 6b has two independent drive wheels 611, 612. The AMR 6b is an independently driven transport vehicle.

[0080] The drive wheel 611 is located on the right side of the middle part of the AMR 6b in the front-to-rear direction. The drive wheel 612 is located on the left side of the middle part of the AMR 6b. The rotation axes of the drive wheels 611 and 612 extend in the left-to-right direction and are coaxial.

[0081] The AMR 6b has a passive wheel 621 and a passive wheel 622. The passive wheel 621 is located in the center of the front end of the AMR 6b in the left-right direction. The passive wheel 622 is located in the center of the rear end of the AMR 6b in the left-right direction. The passive wheels 621 and 622 can each change direction. The AMR 6b may have a single passive wheel.

[0082] The AMR 6b has motors 631 and 632 as driving sources for traveling. Motor 631 is mechanically connected to drive wheel 611. Motor 632 is mechanically connected to drive wheel 612. Drive wheel 611 and drive wheel 612 can rotate independently of each other. If drive wheel 611 and drive wheel 612 rotate in the same direction at the same rotation speed, the AMR 6b moves straight. If drive wheel 611 and drive wheel 612 rotate in the same direction at different rotation speeds, the AMR 6b turns.

[0083] When the drive wheels 611 and 612 rotate in different directions, the AMR 6b turns on the spot, that is, rotates around a vertical axis. When the drive wheels 611 rotate in the forward direction and the drive wheels 612 rotate in the reverse direction, the AMR 6b rotates counterclockwise in Fig. 8. When the drive wheels 611 rotate in the reverse direction and the drive wheels 612 rotate in the forward direction, the AMR 6b rotates clockwise in Fig. 8. The AMR 6b, which does not have a rotary table 68, can correct the inclination of the body 11 by turning on the spot.

[0084] FIG. 9 shows the procedure for correcting the inclination of the body 11 using the AMR 6, which can rotate on the spot. As described above, after the AMR 6 enters the work area 13, the moving body 60 comes to a stop when it hits the first stopper 101 or the second stopper 102. After stopping, the AMR 6 receives a command to correct the body 11 and information on the direction of the inclination from the system controller 16. As shown in the right diagram of FIG. 9, the AMR 6 rotates on the spot so that the body 11 hits both the first stopper 101 and the second stopper 102. If the orientation of the body 11 is along the reference line 130, the locator 4 supports the body 11. The robot 2 performs welding on the body 11.

[0085] The control procedure for the AMR 6b that can turn on the spot follows the flow shown in Figure 7. In step S19 or S111, the AMR 6b corrects the tilt of the body 11 by turning on the spot, instead of correcting the tilt of the body 11 using the rotary table 68.

[0086] (AMR Variation 2) Fig. 10 shows an AMR 6c according to a modified example. The AMR 6c in Fig. 10 is an example of an AMR 6. Like the AMR 6b, the AMR 6c can turn on the spot. The drive configuration of the AMR 6c differs from that of the AMR 6b.

[0087] The AMR 6c has Mecanum wheels 711, 712, 713, and 714, which are drive wheels. The Mecanum wheels 711, 712, 713, and 714 are located at the four corners of the AMR 6c. The rotation axes of the Mecanum wheels 711, 712, 713, and 714 extend in the left-right direction. Note that the arrangement of the Mecanum wheels 711, 712, 713, and 714 is just an example. The AMR 6c may have three Mecanum wheels. The three Mecanum wheels are arranged so that the rotation axes intersect with each other at a single point.

[0088] The AMR6c has motors 631, 632, 633, and 634. Motor 631 is connected to Mecanum wheel 711, and motor 632 is connected to Mecanum wheel 712. Motor 633 is connected to Mecanum wheel 713, and motor 634 is connected to Mecanum wheel 714. The four Mecanum wheels 711, 712, 713, and 714 can rotate independently.

[0089] By rotating the two Mecanum wheels 711, 713 located to the right of the AMR 6c in the forward direction and the two Mecanum wheels 712, 714 located to the left of the AMR 6c in the backward direction, the AMR 6c can turn on the spot in the counterclockwise direction in Figure 10. By rotating the two Mecanum wheels 712, 714 located to the left of the AMR 6c in the forward direction and the two Mecanum wheels 711, 713 located to the right of the AMR 6c in the backward direction, the AMR 6c can turn on the spot in the clockwise direction in Figure 10.

[0090] The procedure for correcting the tilt of the body 11 by the AMR 6c is shown in Fig. 9. The AMR 6c is controlled in the same manner as the AMR 6b, according to the flowchart of Fig. 7.

[0091] (AMR Variation 3) Fig. 11 shows an AMR 6d according to a modified example. The AMR 6d in Fig. 11 is an example of an AMR 6. The AMR 6d can turn on the spot, similar to the AMR 6b or AMR 6c. The drive configuration of the AMR 6d differs from that of the AMR 6b and AMR 6c.

[0092] The AMR 6d has omni-wheels 715, 716, 717, and 718, which are drive wheels. The omni-wheel 715 and the omni-wheel 716 are located on the left and right sides of the center of the AMR 6d in the front-to-rear direction. The rotation axes of the two omni-wheels 715 and 716 extend in the left-to-right direction and are located on the same axis. The omni-wheel 717 and the omni-wheel 718 are located on the front and back sides of the center of the AMR 6d in the left-to-right direction. The rotation axes of the two omni-wheels 717 and 718 extend in the front-to-rear direction and are located on the same axis. Note that the arrangement of the omni-wheels 715, 716, 717, and 718 is one example. The AMR 6d may have three omni-wheels. The three omni-wheels are arranged so that their rotation axes intersect with each other at a single point.

[0093] The AMR 6 has motors 635, 636, 637, and 638. The motor 635 is connected to the omni-wheel 715, and the motor 636 is connected to the omni-wheel 716. The motor 637 is connected to the omni-wheel 717, and the motor 638 is connected to the omni-wheel 718. The four omni-wheels 715, 716, 717, and 718 can rotate independently.

[0094] When the omni-wheels 715 and 716 are stopped and the omni-wheels 717 and 718 are rotated in the forward or reverse direction, the AMR 6d can turn on the spot in the clockwise or counterclockwise direction.

[0095] The procedure for correcting the tilt of the body 11 by the AMR 6d is shown in Fig. 9. The AMR 6d is controlled in accordance with the flowchart of Fig. 7, similar to the AMR 6b or AMR 6c.

[0096] (Other variations) The first stopper 101 and the second stopper 102 may interfere with the AMR 6 instead of the body 11. Fig. 12 shows the procedure for correcting the tilt of the body 11 by the AMR 6 when the first stopper 101 and the second stopper 102 hit the AMR 6. The AMR 6 is an AMR 6b, 6c, or 6d that can turn on the spot.

[0097] After entering the work area 13, the AMR 6 hits the first stopper 101 or the second stopper 102 and stops. After stopping, the AMR 6 receives a correction command for the body 11 and information on the tilt direction from the system controller 16. As shown in the right diagram of FIG. 12 , the AMR 6 rotates on the spot so that the AMR 6 hits both the first stopper 101 and the second stopper 102. When the AMR 6 hits both the first stopper 101 and the second stopper 102, the orientation of the body 11 becomes aligned with the reference line 130. The locator 4 supports the body 11 oriented along the reference line 130. The robot 2 performs welding on the body 11.

[0098] In addition, when the first stopper 101 and the second stopper 102 come into contact with the AMR 6, the sensors 103 of the first stopper 101 and the second stopper 102 can be omitted. The AMR 6 may have a sensor that detects interference with the first stopper 101 or the second stopper 102. The AMR 6 can correct the orientation of the body 11 based on the detection signal of the sensor without receiving a correction command from the system controller 16.

[0099] The first stopper 101 and the second stopper 102 are not limited to having a lifting mechanism. The first stopper 101 and the second stopper 102 may have a mechanism for switching their positions between a first position where they stand upright and protrude upward from the floor surface 151 of the path 15 so as to interfere with the moving body 60, and a second position where they are reclined so as not to interfere with the moving body 60.

[0100] The first stopper 101 and the second stopper 102 are not limited to poles. There are no limitations on the structure of the first stopper and the second stopper as long as they have a structure that can restrict the forward movement of the moving body 60 by interfering with the moving body 60.

[0101] When the moving object 60 hits the first stopper 101 or the second stopper 102 and the AMR 6 stops, the system controller 16 may acquire the amount of tilt of the AMR 6 and the body 11 relative to the reference line 130, i.e., the angle θ. The system controller 16 may determine the angle θ based on an image captured by the external camera 191, which image shows the body 11 positioned in the work area 13. The determination of the angle θ based on the image can be performed using known image processing technology. The system controller 16 can transmit a correction command for the body 11 and information about the angle θ to the AMR 6. Note that the information about the angle θ may also include information about the direction of tilt of the body 11.

[0102] Upon receiving the correction command for the body 11 and the information on the angle θ, the AMR 6 rotates the body 11 using the rotary table 68 or turns on the spot to rotate the body 11 so that the angle θ becomes zero. The orientation of the body 11 is aligned with the reference line 130.

[0103] The use of the sensor 19 outside the AMR 6 enables the robot system 1 to obtain accurate information about the tilt of the body 11 in the work area 13. The robot system 1 can correct the tilt of the body 11 with high accuracy using a simple system.

[0104] The number of external cameras 191 is not limited to one, and may be two or more. Multiple cameras may be installed at appropriate positions. The system controller 16 may determine the angle θ of the body 11 based on a composite image obtained by combining images captured by the multiple cameras.

[0105] The external camera 191 may be attached to the robot 2 instead of being fixed to the factory building, as shown in FIG.

[0106] Furthermore, the AMR 6 may have one or more cameras instead of or in addition to the external camera 191. The system controller 16 or the AMR 6 may determine the angle θ of the body 11 using an image captured by the camera of the AMR 6.

[0107] The system controller 16 may determine the angle θ of the body 11 based on measurement signals from one or more distance measuring sensors instead of images captured by a camera. The one or more distance measuring sensors are installed at appropriate locations in the work area 13. The one or more distance measuring sensors may be attached to the locator 4, for example. The one or more distance measuring sensors measure the distance to a moving object 60 stopped in the work area 13. Various types of known sensors can be used as the distance measuring sensor 194. The system controller 16 can determine the angle θ of the body 11 based on measurement signals from the multiple distance measuring sensors 194.

[0108] The swivel-in-place AMR 6b, 6c, or 6d shown in Figures 8, 10, or 11 may include the rotary table 68 of the AMR 6a of Figure 4. The combination of the swivel-in-place AMR 6b, 6c, or 6d with the rotary table 68 allows the orientation of the AMR 6b, 6c, or 6d to be changed without changing the orientation of the body 11.

[0109] The robot system 1 may include an AGV as a transport vehicle. Like an AMR, an AGV may tilt from a predetermined orientation when stopped in the work area 13. The control for correcting the tilt of the body 11 described above can be applied to an AGV.

[0110] The system controller 16 may be omitted from the robot system 1. The robot system 1 may achieve the above-described control by mutual communication between the robot controller 17, the locator controller 18, and the AMR 6.

[0111] The robot system 1 may include an articulated robot that supports the body 11 instead of the locator 4 or in addition to the locator 4.

[0112] The configurations in each example of the AMR6 described above can be mutually applied to each example of the AMR6, individually or in combination with other configurations, within a reasonable range.

[0113] It should be noted that the work performed by the robot system 1 disclosed herein in the manufacturing line 10 is not limited to welding. Furthermore, the workpiece that the robot system 1 acts on is not limited to the automobile body 11. Furthermore, the robot system 1 is not limited to application to the automobile manufacturing line 10.

[0114] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0115] (Aspect) The above-described embodiment is a specific example of the following aspects.

[0116] (Aspect 1) a robot (2) that performs work on a workpiece (11) transported to a work area (13); In the working area (13), a first stopper (101) and a second stopper (102) are positioned at an interval on a line perpendicular to a reference line (130) along a conveying direction of the work (11); a transport vehicle (6) that transports the workpiece (11) to the work area (13) and stops when a moving body (60) including the workpiece (11) and the transport vehicle (6) hits the first stopper (101) and the second stopper (102); A robot system (1) comprising:

[0117] The robot system (1) can use the transport vehicle (6) to accurately align the orientation of the workpiece (11) in the work area (13) with the reference line (130).

[0118] The robot system (1) can also easily and accurately correct the tilt of the workpiece (11) using the first stopper (101) and the second stopper (102).

[0119] (Aspect 2) The transport vehicle (6a) has a rotary table (68) that rotates the work (11) around a vertical axis, The transport vehicle (6a) stops when the workpiece (11) hits at least one of the first stopper (101) and the second stopper (102), The robot system (1) according to aspect 1, wherein the rotary table (68) rotates the workpiece (11) so that the workpiece (11) hits both the first stopper (101) and the second stopper (102) after the transport vehicle (6a) stops.

[0120] The rotary table 68 rotates the workpiece 11 around a vertical axis, allowing for quick and accurate correction of the orientation of the workpiece 11. The robot system 1 can reduce the time required to transport the workpiece 11, including positioning the workpiece 11, on a production line.

[0121] (Aspect 3) The transport vehicles (6b, 6c, 6d) rotate around vertical axes, The robot system (1) according to aspect 1, wherein the transport vehicle (6b, 6c, 6d) stops with the moving body (60) hitting at least one of the first stopper (101) and the second stopper (102), and after stopping, the transport vehicle (6b, 6c, 6d) turns so that the moving body (60) hits both the first stopper (101) and the second stopper (102).

[0122] The transport vehicles (6b, 6c, 6d) rotate the workpiece (11) around the vertical axis by turning on the spot, thereby quickly and accurately correcting the orientation of the workpiece (11). The robot system (1) can reduce the time required to transport the workpiece (11), including positioning the workpiece (11).

[0123] (Aspect 4) The robot system (1) according to any one of aspects 1 to 3, wherein the transport vehicle (6) decelerates before hitting the first stopper (101) or the second stopper (102) in the working area (13).

[0124] The deceleration of the transport vehicle (6) reduces the impact when the moving body (60) hits the first stopper (101) and the second stopper (102).

[0125] (Aspect 5) A robot system (1) according to any one of aspects 1 to 4, wherein the first stopper (101) and the second stopper (102) switch positions between a first position in which they are located on the path (15) of the moving body (60) and interfere with the moving body (60), and a second position in which they are retracted from the path (15) and do not interfere with the moving body (60).

[0126] The moving body (60) that has arrived at the work area (13) and has completed work on the workpiece (11) by the robot (2) can leave the work area (13) without being interfered with by the first stopper (101) and the second stopper (102).

[0127] (Aspect 6) The robot system (1) according to any one of aspects 1 to 5, wherein the transport vehicle is an autonomous transport robot (6a, 6b, 6c, 6d).

[0128] The autonomous mobile transport robots (6a, 6b, 6c, 6d) can transport the workpieces (11) to the work area (13) by traveling on a flat floor. No pit is required for transporting the workpieces (11). The use of the autonomous mobile transport robots (6a, 6b, 6c, 6d) also has the advantage of being able to easily accommodate changes in the layout of the production line.

[0129] The autonomous mobile transfer robots (6a, 6b, 6c, 6d) do not need to precisely adjust the orientation of the workpiece (11) while transferring the workpiece (11) to the work area (13). This is because the autonomous mobile transfer robots (6a, 6b, 6c, 6d) correct the orientation of the workpiece (11) in the work area (13). The autonomous mobile transfer robots (6a, 6b, 6c, 6d) can quickly move to the work area (13). The robot system (1) can reduce the time required to transfer the workpiece (11), including positioning the workpiece (11).

[0130] (Aspect 7) The robot system (1) according to any one of aspects 1 to 6, further comprising a locator (4) located in the work area (13) and supporting the workpiece (11) delivered from the transport vehicle (6) while the robot (2) is working.

[0131] Since the transport vehicle (6) corrects the orientation of the workpiece (11), the need for the locator (4) to correct the orientation of the workpiece (11) can be omitted. The robot system can employ a small locator (4). If the locator (4) is small, interference between the locator (4) and the robot (2) in the work area (13) is suppressed. Furthermore, the small size of the locator (4) is advantageous for expanding the range of motion of the robot (2). [Explanation of symbols]

[0132] 1. Robot System 11 Body (work) 13 Work Area 101 First stopper 102 Second stopper 130 Reference Line 2. Robot 4 Locators 6 AMR (transport vehicle) 6a AMR (transport vehicle) 6b AMR (transport vehicle) 6c AMR (transport vehicle) 6d AMR (transport vehicle) 60 Mobile 68 Rotating Table

Claims

1. a robot that performs work on the workpiece transported to the work area; a first stopper and a second stopper positioned at an interval on a line perpendicular to a reference line along a conveying direction of the workpiece in the working area; a transport vehicle that transports the workpiece to the work area and stops when a moving body including the workpiece and the transport vehicle abuts against the first stopper and the second stopper; A robot system comprising:

2. 2. The robot system according to claim 1, The transport vehicle has a rotary table that rotates the workpiece around a vertical axis, the transport vehicle stops in a state where the workpiece hits at least one of the first stopper and the second stopper, The rotary table rotates the workpiece so that the workpiece hits both the first stopper and the second stopper after the transport vehicle stops.

3. 2. The robot system according to claim 1, The transport vehicle rotates around a vertical axis, The transport vehicle stops when the moving body hits at least one of the first stopper and the second stopper, and after stopping, the transport vehicle rotates so that the moving body hits both the first stopper and the second stopper.

4. 4. The robot system according to claim 2, A robot system, wherein the transport vehicle decelerates before hitting the first stopper or the second stopper in the work area.

5. 2. The robot system according to claim 1, The robot system, wherein the first stopper and the second stopper switch positions between a first position where they are located on the path of the moving body and interfere with the moving body, and a second position where they are retracted from the path and do not interfere with the moving body.

6. 2. The robot system according to claim 1, The robot system, wherein the transport vehicle is an autonomous transport robot.

7. 2. The robot system according to claim 1, The robot system further includes a locator that is positioned in the work area and supports the workpiece delivered from the transport vehicle while the robot is working.

Images