Production system

Abstract

A production system capable of causing a robot to follow a workpiece in such a manner that the position of the workpiece does not exceed the movable range of the robot at all times. A production system provided with: a workpiece conveyance device that conveys a workpiece; a robot; and a robot movement device that moves the robot, in which, in the production system, the robot is moved by the robot movement device while the workpiece is being conveyed by the workpiece conveyance device, the robot performs work while following the workpiece, the production system has: a determination section that determines whether the position of the workpiece relative to the robot has exceeded the movable range in which the robot can perform work on the workpiece during the period in which the robot moves while following the workpiece; and a position correction section that, in the case where it is determined by the determination section that the position of the workpiece relative to the robot has exceeded the movable range, controls the drive of at least either one of the workpiece conveyance device and the robot movement device to perform position correction so that the position of the workpiece relative to the robot enters the movable range.

Description

Technical Field

[0001] This invention relates to a production system. Background Technology

[0002] Conventionally, a production system is known that includes a workpiece conveying device, a robot, and a robot moving device that moves the robot along the workpiece conveying device (see, for example, Patent Document 1). In this production system, while a workpiece is being conveyed by the workpiece conveying device, the robot moving device moves synchronously with the workpiece conveying, causing the robot to move at the same speed as the workpiece. The robot performs a prescribed operation on the workpiece while following it.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 8-72764 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] Robots have a defined range of motion for performing tasks on workpieces. Therefore, when a robot's moving mechanism follows a workpiece being transported, it needs to move the robot in a manner that does not cause the workpiece's position relative to the robot to exceed the robot's range of motion.

[0008] The workpiece conveying speed is measured in a specified cycle. The robot's moving mechanism uses this measured conveying speed to move the robot at a speed corresponding to the workpiece's conveying speed. Therefore, during normal operation, the workpiece's position relative to the robot will not exceed the robot's range of motion.

[0009] However, in cases where the workpiece conveying speed measurement is not sent to the robot's mobile device due to some unforeseen problem, or where the workpiece conveying speed changes drastically within a period shorter than the measurement cycle, the following situation may occur: the robot's mobile device becomes unable to properly follow the workpiece, causing the workpiece's position relative to the robot to exceed the robot's range of motion.

[0010] Therefore, a production system is desired that allows the robot to follow the workpiece in a way that ensures the workpiece's position relative to the robot never exceeds the robot's range of motion.

[0011] Solution for solving the problem

[0012] One aspect of this disclosure is a production system comprising: a workpiece conveying device for conveying workpieces; a robot; and a robot moving device for moving the robot. In the production system, while the workpiece is being conveyed by the workpiece conveying device, the robot is moved by the robot moving device, and the robot performs work while following the workpiece. The production system includes: a determination unit that determines whether the position of the workpiece relative to the robot exceeds the operable range of the robot's ability to work on the workpiece during the robot's movement following the workpiece; and a position correction unit that, if the determination unit determines that the position of the workpiece relative to the robot has exceeded the operable range, controls the drive of at least one of the workpiece conveying device and the robot moving device to perform position correction so that the position of the workpiece relative to the robot enters the operable range.

[0013] The effects of the invention

[0014] According to one approach, a production system can be provided that enables a robot to follow a workpiece by ensuring that the position of the workpiece relative to the robot never exceeds the robot's range of motion. Attached Figure Description

[0015] Figure 1 It is a diagram that shows an overview of the production system.

[0016] Figure 2 It is a block diagram representing the structure of a production system.

[0017] Figure 3 It is a block diagram representing the structure of the system control device of the production system.

[0018] Figure 4 This diagram illustrates a robot following a workpiece to perform its tasks.

[0019] Figure 5 This is a diagram illustrating one embodiment of the robot's range of motion relative to a workpiece.

[0020] Figure 6 This is a flowchart illustrating one implementation method of the production system's operation.

[0021] Figure 7 This diagram illustrates the process of performing position correction to bring the workpiece into the robot's range of motion relative to the robot.

[0022] Figure 8 This is a diagram illustrating another implementation of the robot's range of motion relative to a workpiece.

[0023] Figure 9This is a flowchart illustrating other implementations of the production system's operation. Detailed Implementation

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Figures 1 to 3 In this system, production system 1 includes a workpiece conveying device 2 for transporting workpiece W, a robot 3, and a robot moving device 4 for moving the robot 3. Workpiece W is the object of operation for the robot 3. The workpiece conveying device 2 and the robot moving device 4 constitute the production line in production system 1.

[0025] The workpiece conveying device 2 is, for example, a conveyor, and is... Figure 2 The system control device 10 shown drives and controls the workpiece conveying device 2. The workpiece conveying device 2 moves the workpiece W, which is placed on the upper surface, in a straight line along the Dw1-Dw2 direction. The workpiece conveying device 2 can convey the workpiece W in both the Dw1 direction (forward direction) and the Dw2 direction (backward direction).

[0026] The position of workpiece W on workpiece conveying device 2 is determined by... Figure 2 The workpiece position detection unit 5 shown is used for detection. The workpiece position detection unit 5 is, for example, composed of a linear encoder. The position information of the workpiece W detected by the workpiece position detection unit 5 is output to the system control device 10. The system control device 10 measures the conveying speed of the workpiece W based on the position information of the workpiece W at each predetermined cycle time.

[0027] Robot 3 was Figure 2 The robot 3 is driven and controlled by the robot control device 30 shown. The robot 3 is, for example, a vertical multi-joint robot with multiple movable parts. The robot 3 has a hand 32 at the front end of the arm 31 for performing a specified operation on the workpiece W. The robot 3 moves the hand 32 freely on the robot moving device 4 by performing a rotating motion and the extension and retraction motion of the arm 31.

[0028] Installed in hand 32 Figure 2 The camera 33 is shown. Image data captured by the camera 33 is sent to the robot control device 30. The robot control device 30 provides visual feedback based on the images captured by the camera 33. In the visual feedback, the robot control device 30 uses a model obtained by teaching the robot to a workable posture to perform pattern matching and controls the robot 3 to move in a way that makes the detection result close to the position of the model during teaching. Thus, the robot 3 performs a specified operation on the workpiece W using its hand 32 within a specified range of motion.

[0029] The robot moving device 4 is driven and controlled by the system control device 10. The robot moving device 4 causes the robot 3, mounted on the upper surface, to move linearly along a track (not shown) in the Dr1-Dr2 direction. The robot moving device 4 causes the robot 3 to move at a speed corresponding to the conveying speed of the workpiece W measured by the system control device 10. The Dr1-Dr2 direction is, for example, a direction parallel to the conveying direction of the workpiece W, i.e., the Dw1-Dw2 direction. The robot moving device 4 can cause the robot 3 to move in both the Dr1 direction (forward direction) and the Dr2 direction (backward direction).

[0030] The position of robot 3 on robot mobile device 4 is determined by... Figure 2 The robot position detection unit 6 shown is used for detection. The robot position detection unit 6 is, for example, composed of a linear encoder. The position information of the robot 3 detected by the robot position detection unit 6 is output to the system control device 10.

[0031] Figure 2 and Figure 3 The system control device 10 shown controls the overall operation of the production system 1. For example... Figure 4 As shown, the system control device 10 drives the workpiece conveying device 2 to convey the workpiece W in the Dw1 direction at a predetermined speed. While conveying the workpiece W, the system control device 10 drives the robot moving device 4, causing the robot 3 to move in the Dr1 direction, which is the same direction as the workpiece W. At this time, the robot moving device 4 causes the robot 3 to move at a speed corresponding to the conveying speed of the workpiece W, so that the position of the workpiece W relative to the robot 3 is continuously positioned within the predetermined range of motion of the robot 3. During the movement of the robot 3, the system control device 10 drives the robot 3 using the robot control device 30. Thus, the robot 3 moves along with the workpiece W while performing predetermined operations on the workpiece W using its hand 32.

[0032] like Figure 3 As shown, the system control device 10 includes a workpiece conveying device drive unit 11, a robot moving device drive unit 12, a judgment unit 13, and a position correction unit 14. The workpiece conveying device drive unit 11 drives the workpiece conveying device 2. The robot moving device drive unit 12 drives the robot moving device 4.

[0033] When the robot 3 is moving along with the workpiece W, the determination unit 13 inputs the workpiece position detected by the workpiece position detection unit 5 and the robot position detected by the robot position detection unit 6. The determination unit 13 has, in a storage unit (not shown) or elsewhere, information pre-stored regarding the defined range of motion of the robot 3 capable of operating on the workpiece W. Specifically, the range of motion information refers to, for example, information such as the distance at which the workpiece W can move relative to the robot 3. Typically, considering operational stability, this range of motion is set to be smaller than the limit at which the robot 3 becomes completely unable to operate.

[0034] The judgment unit 13 measures the relative position of the workpiece W and the robot 3 based on the input workpiece position and robot position, and determines whether the position of the workpiece W relative to the robot 3 exceeds the prescribed range of motion for the robot 3 to perform operations on the workpiece W. This judgment by the judgment unit 13 is performed over a prescribed period of time, which is shorter than the period of time used to measure the conveying speed of the workpiece W based on the position information detected by the workpiece position detection unit 5. If it is determined that the position has exceeded the range of motion, the judgment unit 13 outputs a signal indicating this to the position correction unit 14.

[0035] If the determination unit 13 determines that the position of the workpiece W relative to the robot 3 has exceeded the operable range of the robot 3, the position correction unit 14 performs position correction by controlling the drive of at least one of the workpiece conveying device 2 and the robot moving device 4, so that the position of the workpiece W relative to the robot 3 enters the operable range of the robot 3.

[0036] In detail, such as Figure 5 As shown, robot 3, which moves in the Dr1 direction following workpiece W being transported in the Dw1 direction, has a defined range of motion. When the moving robot 3 maintains an appropriate position relative to the workpiece W being transported, the workpiece W is positioned within the robot 3's range of motion. As long as the workpiece W is positioned within the range of motion, robot 3 can perform operations on the workpiece W regardless of whether it is positioned at W1, W2, or W3. However, if the workpiece W is positioned at W4 or W5, which are outside the range of motion of the moving robot 3, sometimes robot 3 cannot perform operations on the workpiece W.

[0037] If a signal indicating that the operation range is exceeded is input from the judgment unit 13, the position correction unit 14 controls the drive of at least one of the workpiece conveying device 2 and the robot moving device 4 according to the current positions of the workpiece W and the robot 3, respectively.

[0038] Specifically, for example, at the position of workpiece W relative to robot 3, such as Figure 5 When positioned as shown at a position W4 that moves further toward Dw1 than robot 3, the position correction unit 14 performs any of the following controls to position the workpiece W within the operable range of robot 3.

[0039] (1) Only control the drive unit 11 of the workpiece conveying device to reduce the conveying speed of the workpiece conveying device 2 in conveying the workpiece W.

[0040] (2) Control only the drive unit 11 of the workpiece conveying device to reverse the conveying direction of the workpiece W conveyed by the workpiece conveying device 2 to the Dw2 direction and move a predetermined distance.

[0041] (3) Control only the robot moving device drive unit 12 to increase the moving speed of the robot moving device 4 moving the robot 3.

[0042] (4) Control the workpiece conveying device drive unit 11 to reduce the conveying speed of the workpiece conveying device 2 to convey the workpiece W, and control the robot moving device drive unit 12 to increase the moving speed of the robot moving device 4 to move the robot 3.

[0043] On the other hand, for example, when the position of workpiece W relative to robot 3 is as follows: Figure 5 When positioned as shown at a position W5 further backward in the direction of Dw2 than robot 3, the position correction unit 14 performs any of the following controls to position the workpiece W within the operable range of robot 3.

[0044] (5) Only control the drive unit 11 of the workpiece conveying device to increase the conveying speed of the workpiece conveying device 2 in conveying the workpiece W.

[0045] (6) Control only the robot moving device drive unit 12 to reverse the moving direction of the robot moving device 4 to the Dr2 direction and move a predetermined distance.

[0046] (7) Control only the robot moving device drive unit 12 to reduce the moving speed of the robot moving device 4 moving the robot 3.

[0047] (8) Control the workpiece conveying device drive unit 11 to increase the conveying speed of the workpiece conveying device 2 to convey the workpiece W, and control the robot moving device drive unit 12 to reduce the moving speed of the robot 3 moved by the robot moving device 4.

[0048] The conveying speed and direction of the workpiece conveying device 2 affect the productivity of the production system 1. Therefore, when the position correction unit 14 controls the workpiece W to be positioned within the operable range of the robot 3, it is desirable to perform controls (3), (4), (6), (7), and (8) in the above (1) to (8) control, and more preferably to perform controls (3), (6), and (7) only on the robot moving device 4.

[0049] Next, based on Figure 6 The flowchart illustrates the specific actions of production system 1.

[0050] Robot 3 is positioned at the designated initial work start position on robot moving device 4. After production system 1 starts operating, system control device 10 controls workpiece conveying device drive unit 11 to drive workpiece conveying device 2, causing workpiece W to move in the direction of Dw1 at a preset fixed conveying speed. System control device 10 monitors whether workpiece W has entered the working area of ​​robot 3 via workpiece position detection unit 5. System control device 10 remains on standby until workpiece W enters the working area of ​​robot 3 (steps S1, S2; no).

[0051] If the system control device 10 detects that the workpiece W has entered the working area of ​​the robot 3 (step S2; yes), it controls the robot moving device drive unit 12 to drive the robot moving device 4. As a result, the system control device 10 causes the robot 3 to move in the Dr1 direction at a preset fixed moving speed to follow the workpiece W (step S3).

[0052] Subsequently, as the robot 3 begins to move, the system control device 10 outputs a work start command to the robot control device 30. The robot control device 30 then drives the robot 3 according to the prescribed work procedure. Based on images captured by the camera 33 mounted on the hand 32 of the robot 3, the robot control device 30 drives the arm 31 and hand 32 through visual feedback, performing the prescribed work on the workpiece W while following it (step S4).

[0053] During the movement of robot 3 following workpiece W, system control unit 10, in judgment unit 13, determines whether the position of workpiece W relative to robot 3 has exceeded the operable range of robot 3 capable of performing operations on workpiece W, based on the workpiece position and robot position input from workpiece position detection unit 5 and robot position detection unit 6 (step S5). If it is determined that the position of workpiece W relative to robot 3 has not exceeded the operable range (step S5; no), system control unit 10 determines whether the operation of robot 3 on workpiece W has been completed (step S7). If the operation has not been completed (step S7; no), system control unit 10 returns the processing to the processing from step S5; if the operation has been completed (step S7; yes), the operation of robot 3 on workpiece W ends.

[0054] In step S5 above, if it is determined that the position of workpiece W relative to robot 3 has exceeded the operable range (step S5; Yes), the system control device 10, in the position correction unit 14, controls the drive of at least one of the workpiece conveying device 2 or the robot moving device 4 to perform position correction, so that the position of workpiece W relative to robot 3 enters the operable range (step S6). Figure 6 In the flowchart shown, the position correction unit 14 performs position correction by controlling the robot moving device drive unit 12 to change the moving distance or speed of the robot moving device 4.

[0055] For example, such as Figure 5 As shown, when the workpiece W is positioned at a position W4 that moves further towards Dw1 than the robot 3 relative to the workpiece W, the position correction unit 14 controls the robot movement device drive unit 12, as follows: Figure 7 The robot's moving device 4 is driven in a manner that increases the speed of robot 3 to a predetermined speed, as shown. Additionally, as... Figure 5 As shown, when the workpiece W is positioned at a position W5 that is further backward in the direction of Dw2 than the robot 3, the position correction unit 14 controls the robot moving device drive unit 12 to drive the robot moving device 4 so that the robot 3 moves backward in the direction of Dr2 by a predetermined distance. After position correction, the system control unit 10 proceeds to step S7 to determine whether the operation is completed.

[0056] Furthermore, the specified speed and specified distance are, for example, preset and stored in the position correction unit 14. This speed and distance are not limited to a single value. Multiple speed and distance values ​​can also be set corresponding to the distance between the workpiece W and the robot 3. In this case, the position correction unit 14 can select the optimal speed and distance values ​​for the workpiece W to enter the robot 3's operable range based on the distance between the workpiece W and the robot 3, thereby performing position correction.

[0057] As described above, the production system 1 according to this embodiment includes: a workpiece conveying device 2 for conveying workpiece W; a robot 3; and a robot moving device 4 for moving the robot 3. In this production system 1, while the workpiece W is being conveyed by the workpiece conveying device 2, the robot 3 is moved by the robot moving device 4, and the robot 3 performs work while following the workpiece W. The production system 1 includes: a determination unit 13 that determines whether the position of the workpiece W relative to the robot 3 exceeds the operable range of the robot 3 capable of working on the workpiece W during the period when the robot 3 follows the workpiece W; and a position correction unit 14 that, if the determination unit 13 determines that the position of the workpiece W relative to the robot 3 has exceeded the operable range, controls the drive of at least one of the workpiece conveying device 2 and the robot moving device 4 to perform position correction, so that the position of the workpiece W relative to the robot 3 enters the operable range. Therefore, the robot 3 can follow the workpiece W in a manner that ensures the position of the workpiece W relative to the robot 3 never exceeds the operable range of the robot 3. Consequently, the processing accuracy and productivity of the workpiece W in the production system 1 are improved.

[0058] When the position correction unit 14 performs position correction by moving at least one of the workpiece conveying device 2 and the robot moving device 4 by a predetermined distance, position correction can be easily performed by moving at least one of the workpiece W and the robot 3.

[0059] When the position correction unit 14 performs position correction by changing the speed of at least one of the workpiece conveying device 2 and the robot moving device 4, position correction can be performed quickly by moving at least one of the workpiece W and the robot 3.

[0060] The range of motion of robot 3 determined by the decision unit 13 is not limited to... Figure 5 The range shown can also be as follows: Figure 8As shown, the system has at least two ranges: a first operable range and a second operable range that is larger than the first operable range. In this case, in production system 1, the operable range has at least two ranges: a first operable range and a second operable range that is larger than the first operable range. The position correction unit 14 can, when the determination unit 13 determines that the position of the workpiece W relative to the robot 3 has exceeded the first operable range, control the drive of at least one of the workpiece conveying device 2 and the robot moving device 4 to perform a first position correction so that the position of the workpiece W relative to the robot 3 enters the first operable range. And when the determination unit 13 determines that the position of the workpiece W relative to the robot 3 has exceeded the second operable range, control the drive of at least one of the workpiece conveying device 2 and the robot moving device 4 to perform a second position correction with a correction amount larger than the first position correction so that the position of the workpiece W relative to the robot 3 enters the first operable range.

[0061] The first operable range is the range within which robot 3 can stably and comfortably perform operations on workpiece W. For example, when workpiece W is positioned at... Figure 8 In the positions W10, W21, and W31 shown, robot 3 can perform stable and ample work on workpiece W. The second operable range is the range within which robot 3 can work on workpiece W, but there are concerns that its work efficiency may decrease compared to the first operable range. When workpiece W exceeds the second operable range, for example, robot 3 may sometimes find it difficult or impossible to perform appropriate work on workpiece W due to stroke limits. The operable range is not limited to two operable ranges; three or more operable ranges can also be set.

[0062] The workpiece W is positioned relative to the robot 3 at the following location. Figure 8 In the case of the position W22 where the robot moves further toward Dw1 than the robot 3, since the workpiece W has exceeded the first operable range of the robot 3, the position correction unit 14 performs a first position correction by any of the controls (1) to (4) above, so that the workpiece W is positioned within the first operable range of the robot 3.

[0063] On the other hand, the position of workpiece W relative to robot 3 is configured in Figure 8 When the workpiece W is moved backward in the direction of Dw2, as shown, the position correction unit 14 performs a first position correction by any one of the controls (5) to (8) above, so that the workpiece W is positioned within the first operable range of the robot 3, since the workpiece W has exceeded the first operable range of the robot 3.

[0064] Additionally, the workpiece W is positioned relative to the robot 3 at... Figure 8 In the case of position W41, which is further forward in the direction of Dw1 than robot 3, since workpiece W has exceeded the second operable range of robot 3, position correction unit 14 performs second position correction by any of the control in (1) to (4) above, so that workpiece W is positioned within the first operable range of robot 3.

[0065] Furthermore, the workpiece W is positioned relative to the robot 3 at the following location: Figure 8 In the case of position W51, which is further back in the direction of Dw2 than robot 3, since workpiece W has exceeded the second operable range of robot 3, position correction unit 14 performs second position correction by any of the controls in (5) to (8) above, so that workpiece W is positioned within the first operable range of robot 3.

[0066] The correction amount for the second position correction is larger than that for the first position correction. Specifically, when the position correction parameter is distance, the correction distance for the second position correction is a larger value than that for the first position correction. When the position correction parameter is velocity, the change in correction velocity for the second position correction is a larger value than that for the first position correction.

[0067] Next, based on Figure 9 The flowchart describes the specific actions of the production system 1, where the operable range of robot 3 is set to two ranges: a first operable range and a second operable range.

[0068] Robot 3 is positioned at the designated initial work start position on robot moving device 4. After production system 1 starts operating, system control device 10 controls workpiece conveying device drive unit 11 to drive workpiece conveying device 2, causing workpiece W to move in the direction of Dw1 at a preset fixed conveying speed. System control device 10 monitors whether workpiece W has entered the working area of ​​robot 3 via workpiece position detection unit 5. System control device 10 remains on standby until workpiece W enters the working area of ​​robot 3 (steps S11, S12; no).

[0069] If the system control device 10 detects that the workpiece W has entered the working area of ​​the robot 3 (step S12; yes), it controls the robot moving device drive unit 12 to drive the robot moving device 4. As a result, the system control device 10 causes the robot 3 to move in the Dr1 direction at a preset fixed moving speed to follow the workpiece W (step S13).

[0070] As the robot 3 begins to move, the system control device 10 outputs a work start command to the robot control device 30. The robot control device 30 then drives the robot 3 according to a predetermined work procedure. Based on images captured by a camera 33 mounted on the hand 32 of the robot 3, the robot control device 30 drives the arm 31 and hand 32 through visual feedback, performing the predetermined work on the workpiece W while following it (step S14).

[0071] During the movement of robot 3 following workpiece W, system control unit 10, in judgment unit 13, determines whether the position of workpiece W relative to robot 3 has exceeded the first operable range within which robot 3 can perform operations on workpiece W, based on the workpiece position and robot position input from workpiece position detection unit 5 and robot position detection unit 6 (step S15). If it is determined that the position of workpiece W relative to robot 3 has not exceeded the first operable range (step S15; no), system control unit 10 determines whether the operation of robot 3 on workpiece W has been completed (step S18). If the operation has not been completed (step S18; no), system control unit 10 returns the processing to the processing from step S15; if the operation has been completed (step S18; yes), the operation of robot 3 on workpiece W ends.

[0072] If it is determined in step S15 that the position of workpiece W relative to robot 3 has exceeded the first operable range (step S15; yes), then the system control device 10 determines in the determination unit 13 whether the position of workpiece W relative to robot 3 exceeds the second operable range in which robot 3 can perform operations on workpiece W (step S16).

[0073] In step S16 above, if it is determined that the position of workpiece W relative to robot 3 does not exceed the second operable range (step S16; no), in the position correction unit 14, the drive of at least one of the workpiece conveying device 2 or robot moving device 4 is controlled to perform a first position correction, so that the position of workpiece W relative to robot 3 enters the first operable range (step S17). Figure 9 In the flowchart shown, the position correction unit 14 performs the first position correction by controlling the robot moving device drive unit 12 to change the moving distance or speed of the robot moving device 4.

[0074] In step S16 above, if it is determined that the position of workpiece W relative to robot 3 has exceeded the second operable range (step S16; Yes), in the position correction unit 14, the drive of at least one of the workpiece conveying device 2 or robot moving device 4 is controlled to perform a second position correction with a correction amount greater than the first position correction, so that the position of workpiece W relative to robot 3 enters the first operable range (step S19). Figure 9 In the flowchart shown, the position correction unit 14 changes the moving distance or speed of the robot moving device 4 by controlling the robot moving device drive unit 12 to perform the second position correction.

[0075] After performing the first position correction in step S17 and the second position correction in step S19, the system control device 10 moves to step S18 to determine whether the operation is completed.

[0076] In this way, the operable range determined by the determination unit 13 has at least two ranges: a first operable range and a second operable range that is larger than the first operable range. As a result, the robot 3 can always operate on the workpiece W in a better posture. Consequently, the machining accuracy and productivity of the workpiece W in the production system 1 are further improved.

[0077] Explanation of reference numerals in the attached figures

[0078] 1: Production system; 2: Workpiece conveying device; 3: Robot; 4: Robot moving device; 13: Judgment unit; 14: Position correction unit; W: Workpiece.

Claims

1. A production system, comprising: A workpiece conveying device for conveying workpieces; robot; Robotic moving device, which causes the robot to move; and The control device measures the conveying speed of the workpiece during the first cycle time. In the production system, while the workpiece is being transported by the workpiece conveying device, the robot is moved by the robot moving device, and the robot follows the workpiece while performing its work. The production system has: The determination unit determines, using a second cycle time shorter than the first cycle time, whether the position of the workpiece relative to the robot exceeds the robot's operable range for performing operations on the workpiece during the period when the robot follows the workpiece; and The position correction unit, when the determination unit determines that the position of the workpiece relative to the robot has exceeded the operable range, controls the drive of at least one of the workpiece conveying device and the robot moving device to perform position correction, so that the position of the workpiece relative to the robot enters the operable range. The operable range has at least two ranges: a first operable range and a second operable range that is larger than the first operable range. The position correction unit adjusts the position by a larger amount when the determination unit determines that the position of the workpiece relative to the robot has exceeded the second operable range than when the determination unit determines that the position of the workpiece relative to the robot has exceeded the first operable range.

2. The production system according to claim 1, wherein, The position correction unit performs position correction by moving at least one of the workpiece conveying device and the robot moving device by a pre-specified distance.

3. The production system according to claim 1, wherein, The position correction unit performs position correction by changing the speed of at least one of the workpiece conveying device and the robot moving device.

4. A control device for controlling the actions of a robot, which moves via a robot moving device, to follow a workpiece being transported via a workpiece conveying device while performing operations on that workpiece. The control device measures the conveying speed of the workpiece during the first cycle time. The control device has: The determination unit determines, using a second cycle time shorter than the first cycle time, whether the position of the workpiece relative to the robot exceeds the robot's operable range for performing operations on the workpiece during the period when the robot follows the workpiece; and The position correction unit, when the determination unit determines that the position of the workpiece relative to the robot has exceeded the operable range, controls the drive of at least one of the workpiece conveying device and the robot moving device to perform position correction, so that the position of the workpiece relative to the robot enters the operable range. The operable range has at least two ranges: a first operable range and a second operable range that is larger than the first operable range. The position correction unit adjusts the position by a larger amount when the determination unit determines that the position of the workpiece relative to the robot has exceeded the second operable range than when the determination unit determines that the position of the workpiece relative to the robot has exceeded the first operable range.

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