Robot system and method for controlling robot system

Abstract

A robot system (100) comprises: a robot (10); a working unit (20) that performs work on a workpiece (200); and a control unit (30) which communicates via a real-time field network (N) capable of guaranteeing real-time communication conforming to Ethernet standards, and which controls the work performed on the workpiece (200) by the working unit (20) on the basis of information relating to the amount of relative movement of the working unit (20) with respect to the workpiece (200) due to the movement of the working unit (20) or the workpiece (200) disposed on the robot.

Description

Robot system and method for controlling a robot system

[0001] This disclosure relates to a robot system and a method for controlling a robot system.

[0002] Conventionally, robot systems are known. Such a robot system is disclosed, for example, in Japanese Patent Application Laid-Open No. 2013-166185.

[0003] Japanese Patent Application Laid-Open No. 2013-166185 discloses a robot system including a robot including a plurality of joints, a control device that performs control to move the robot, and an imager provided at a tip of the robot that images an inspection target. In this robot system, when the tip of the robot moves to a preset position, the control device transmits an imaging command signal to cause the imager to image the inspection target.

[0004] Japanese Patent Application Laid-Open No. 2013-166185

[0005] In Japanese Patent Application Laid-Open No. 2013-166185, when the tip of the robot moves to a preset position, the control device transmits an imaging command signal to cause the imager to image the inspection target. Therefore, when the number of positions for performing operations such as imaging increases, it is necessary to preset many positions, and the setting work for setting the positions for performing operations becomes complicated. Therefore, when performing an operation while relatively moving a working unit such as an imager with respect to a workpiece by a robot, it is desired to suppress the complication of the setting work.

[0006] This disclosure has been made to solve the above problems, and provides a robot system and a method for controlling a robot system capable of suppressing complication of setting work when performing an operation while relatively moving a working unit with respect to a workpiece by a robot.

[0007] The robot system according to the first aspect of this disclosure comprises a robot, a work unit that performs work on a workpiece, and a control unit that communicates via a real-time field network capable of guaranteeing real-time communication in accordance with Ethernet standards, and controls the work performed on the workpiece by the work unit based on information regarding the relative movement of the work unit to the workpiece due to the movement of the workpiece or the work unit positioned on the robot.

[0008] The robot system according to the first aspect of this disclosure, as described above, communicates via a real-time field network that can guarantee the real-time nature of communication in accordance with the Ethernet standard, and includes a control unit that controls the work performed on the workpiece based on information regarding the relative movement of the workpiece to the workpiece due to the movement of the workpiece or work unit placed on the robot. As a result, the work performed on the workpiece can be controlled based on information regarding the relative movement of the work unit to the workpiece, so that work can be performed on the workpiece without having to pre-set all work positions. Consequently, when the robot performs work while moving the work unit relative to the workpiece, the complexity of the setup process can be suppressed.

[0009] The second aspect of this disclosure provides a method for controlling a robot system, comprising: communicating via a real-time field network capable of guaranteeing real-time communication in accordance with the Ethernet standard; and controlling the work performed on a workpiece by a work unit based on information regarding the relative movement of the work unit relative to the workpiece, due to the movement of the work unit positioned on the robot or the work unit that performs work on the workpiece.

[0010] The second aspect of this disclosure provides a robot system control method that, as described above, involves communication via a real-time field network capable of guaranteeing real-time communication in accordance with the Ethernet standard, and controlling the work performed on the workpiece by the workpiece unit based on information regarding the relative movement of the workpiece unit relative to the workpiece, due to the movement of the workpiece unit or the workpiece unit positioned on the robot. As a result, the work performed on the workpiece by the workpiece unit can be controlled based on information regarding the relative movement of the workpiece unit, so that work can be performed on the workpiece without having to pre-set all work positions. Consequently, it is possible to provide a robot system that can suppress the complexity of the setup process when the robot performs work while moving the workpiece unit relative to the workpiece.

[0011] According to this disclosure, as described above, when a robot performs work while moving the work unit relative to the workpiece, it is possible to suppress the complexity of the setup process.

[0012] This figure shows a first example of a robot system according to the first embodiment. This figure shows a second example of a robot system according to the first embodiment. This figure shows a schematic of a robot according to the first embodiment. This is a block diagram of a robot according to the first embodiment. This figure illustrates a first example of relative movement of the work unit of the robot system according to the first embodiment. This figure illustrates a second example of relative movement of the work unit of the robot system according to the first embodiment. This figure shows an example of work performed by the work unit of the robot system according to the first embodiment in comparison with a comparative example. This figure illustrates a first example of control of work performed by the work unit on a workpiece by the robot system according to the first embodiment. This figure illustrates a second example of control of work performed by the work unit on a workpiece by the robot system according to the first embodiment. This figure illustrates a third example of control of work performed by the work unit on a workpiece by the robot system according to the first embodiment. This figure illustrates an example of a signal generated by the robot system according to the first embodiment. This figure shows a robot system according to the second embodiment. This figure shows a coating unit as a work unit of the robot system according to the second embodiment. This figure illustrates work control considering the timing difference between the timing at which work control of the robot system according to the second embodiment is performed by the work unit control unit and the timing at which work is performed by the coating unit as a work unit. This figure illustrates the application of a coating material when the timing difference between the timing at which the robot system's work is controlled by the work unit control unit and the timing at which the coating unit performs work is not considered. This figure shows the current position, first predicted position, and second predicted position of the robot on a predetermined movement trajectory of the robot system according to the second embodiment. This figure illustrates the application of a coating material when the timing difference between the timing at which the robot system's work is controlled by the work unit control unit and the timing at which the coating unit performs work is considered. This figure shows the work unit of the robot system according to a modified version of the first and second embodiments.

[0013] The embodiments of this disclosure will be described below with reference to the drawings.

[0014] [First Embodiment] (Configuration of the Robot System) The configuration of the robot system 100 according to the first embodiment will be described with reference to Figures 1 to 11. The robot system 100 performs work on the workpiece 200.

[0015] Figure 1 shows a first example of a robot system 100. The robot system 100 shown in Figure 1 comprises a robot 10, a work unit 20 that performs work on a workpiece 200, and a control unit 30 that controls the robot 10 and the work unit 20. The control unit 30 includes a master control unit 41, a robot control unit 51, and a work unit control unit 61. The robot system 100 also comprises a master device 40 including the master control unit 41, a robot control device 50 including the robot control unit 51, and a work unit control device 60 including the work unit control unit 61. The master device 40, the robot control device 50, and the work unit control device 60 are connected to each other via a real-time field network N that can guarantee real-time communication in accordance with the Ethernet standard.

[0016] Robot 10 is, for example, an industrial or medical robot. Robot 10 operates using AC power supplied from an external source. For example, robot 10 is a vertical articulated robot. Robot 10 includes a base portion 11 and an arm portion 12 connected to the base portion 11. The arm portion 12 has multiple joints. Each of the multiple joints has a servo motor as a drive source. A work section 20 is positioned at the tip of the arm portion 12. Robot 10 moves the work section 20 relative to the workpiece 200 by driving the multiple joints of the arm portion 12.

[0017] As shown in Figure 3, the arm 12 of the robot 10 includes six joints 12a, 12b, 12c, 12d, 12e, and 12f, and links 13a, 13b, 13c, 13d, and 13e connecting each joint. Furthermore, as shown in Figure 4, each of the six joints 12a to 12f is provided with a motor 14 consisting of a servo motor, a reduction gear 15 that reduces the rotational speed of the motor 14 and outputs the driving force of the motor 14 to the corresponding link, and an encoder 16 that detects the rotational position of each joint.

[0018] Each of the six joints 12a to 12f rotates under the drive of the motor 14.

[0019] The first axis joint 12a is connected to the base portion 11. The joint 12a rotates the link 13a around the rotation axis A1 relative to the base portion 11. The second axis joint 12b rotates the link 13b relative to the link 13a around the rotation axis A2, which is perpendicular to the rotation axis A1.

[0020] The third joint 12c rotates link 13c relative to link 13b around a rotation axis A3 that is parallel to the rotation axis A2. The fourth joint 12d rotates link 13d relative to link 13c around a rotation axis A4 that is perpendicular to the rotation axis A3.

[0021] The fifth joint 12e rotates link 13e relative to link 13d around a rotation axis A5 perpendicular to the rotation axis A4. The sixth joint 12f rotates the work section 20 relative to link 13e around a rotation axis A6 perpendicular to the rotation axis A5.

[0022] The work unit 20 performs operations on the workpiece 200. The work unit 20 includes, for example, at least one of the following: an imaging unit, a three-dimensional shape measurement unit, a distance measuring sensor, a coating unit, an adhesive unit, a spraying unit, a welding unit, a sewing unit, an ultrasonic flaw detection unit, an eddy current flaw detection unit, a tapping inspection unit, a peeling laser irradiation unit, a hardening UV (Ultra Violet) irradiation unit, and a laser cleaning unit.

[0023] The work unit 20 performs operations on the workpiece 200 while moving relative to the workpiece 200. For example, the imaging unit includes at least one of a line camera and an area camera. The imaging unit as a line camera captures a line-shaped image while moving relative to the workpiece 200. The imaging unit as an area camera captures a rectangular image while moving relative to the workpiece 200. The three-dimensional shape measurement unit includes a laser profile sensor. The three-dimensional shape measurement unit as a laser profile sensor projects laser light onto the workpiece 200 while moving relative to the workpiece 200 to perform imaging and measures the three-dimensional shape of the workpiece 200 by the light section method.

[0024] The distance measuring sensor measures the distance to each position on the workpiece 200 while moving relative to the workpiece 200. The coating unit applies the coating material to the workpiece 200 while moving relative to the workpiece 200. The coating material is a liquid or paste such as adhesive, sealant, reagent, paint, solder, mortar, cement, or concrete. Alternatively, the coating material may be a filament used in a 3D printer, such as resin / plastic, metal, or carbon short fiber.

[0025] The adhesive unit applies an adhesive to the workpiece 200 while moving relative to the workpiece 200. The adhesive is, for example, a sealant, a sticker, or tape. The spraying unit sprays an adhesive onto the workpiece 200 while moving relative to the workpiece 200. The spray is, for example, a liquid such as an adhesive, a chemical, or a paint. The welding unit welds the workpiece 200 while moving relative to the workpiece 200. The sewing unit sews the workpiece 200 while moving relative to the workpiece 200.

[0026] The ultrasonic flaw detection unit moves relative to the workpiece 200, irradiating the workpiece 200 with ultrasonic waves and detecting the reflected ultrasonic waves to detect defects in the workpiece 200. The eddy current flaw detection unit moves relative to the workpiece 200, bringing a coil to which alternating current is applied close to the workpiece 200, and detecting the generated eddy currents to detect defects in the workpiece 200. The impact sound inspection unit strikes the workpiece 200 with a hammer and detects the generated sound to detect defects in the workpiece 200. The peeling laser irradiation unit moves relative to the workpiece 200, irradiating the workpiece 200 with laser light to peel off any peeled material from the workpiece 200. The peeled material is, for example, an oxide film and UV-curing resin. The curing UV irradiation unit moves relative to the workpiece 200, irradiating the workpiece 200 with UV light to cure the UV-curing resin on the workpiece 200. The laser cleaning unit moves relative to the workpiece 200 and irradiates the workpiece 200 with laser light to laser clean it. For example, the laser cleaning unit may perform laser cleaning such as removing metal surface oxide films or peeling off UV-cured resins.

[0027] The master device 40 is a computer that manages the robot system 100. The master device 40 includes a master control unit 41. The master control unit 41 includes a memory for storing programs and a processor for executing programs. The master control unit 41 functions as a master in a master-slave real-time field network N in which multiple slaves are connected to one master. The master control unit 41 communicates with each device connected to the real-time field network N via the real-time field network N.

[0028] The robot control device 50 is a computer that controls the robot 10. The robot control device 50 includes a robot control unit 51. The robot control unit 51 includes a memory for storing programs and a processor for executing programs. The robot control unit 51 functions as a slave in the real-time field network N. The robot control unit 51 communicates with each device connected to the real-time field network N via the real-time field network N.

[0029] The robot control unit 51 controls the movement of the robot 10. Specifically, the robot control unit 51 controls the movement of the robot 10 by controlling the power supplied to the motors provided at each joint of the robot 10. The robot control unit 51 also receives instructions (teaching) of the robot 10's movements from the user and controls the robot 10 to perform the movements based on the teaching. Specifically, the robot control unit 51 receives the position and orientation of the robot 10's control points and calculates the movement of each joint of the robot 10. The robot control unit 51 also controls the movement of the robot 10 based on the detected values ​​of the encoders 16 at each joint. The robot control unit 51 may also receive an automatically generated movement trajectory and control the robot 10 to perform movements based on the automatically generated movement trajectory.

[0030] The work unit control device 60 is a computer that controls the work unit 20. The work unit control device 60 includes a work unit control unit 61. The work unit control unit 61 includes a memory for storing programs and a processor for executing programs. The work unit control unit 61 functions as a slave in the real-time field network N. The work unit control unit 61 communicates with each device connected to the real-time field network N via the real-time field network N.

[0031] The work unit control unit 61 controls the work performed on the work unit 20 by the work unit 20. If the work unit 20 is an imaging unit acting as a line camera or area camera, the work unit control unit 61 controls the imaging performed by the work unit 20. Specifically, the work unit control unit 61 controls the timing of imaging of the work unit 20 by the work unit 20.

[0032] When the work unit 20 is a three-dimensional shape measurement unit acting as a laser profile sensor, the work unit control unit 61 controls the projection of laser light and the imaging of laser light by the work unit 20. Specifically, the work unit control unit 61 controls the timing of imaging of the work unit 200 by the work unit 20.

[0033] If the work unit 20 is a distance measuring sensor, the work unit control unit 61 controls the timing of measurement of the workpiece 200 by the work unit 20. If the work unit 20 is a coating unit, the work unit control unit 61 controls the timing and amount of coating applied by the work unit 20.

[0034] If the work unit 20 is an adhesive unit, the work unit control unit 61 controls the timing and amount of adhesive applied by the work unit 20. If the work unit 20 is a spray unit, the work unit control unit 61 controls the timing and amount of spray applied by the work unit 20.

[0035] If the work unit 20 is a welding unit, the work unit control unit 61 controls the timing and amount of welding performed by the work unit 20. If the work unit 20 is a sewing unit, the work unit control unit 61 controls the timing of sewing performed by the work unit 20.

[0036] If the work unit 20 is an ultrasonic flaw detection unit, the work unit control unit 61 controls the timing of ultrasonic emission and detection by the work unit 20. If the work unit 20 is an eddy current flaw detection unit, the work unit control unit 61 controls the timing of eddy current generation by the work unit 20. If the work unit 20 is a tapping inspection unit, the work unit control unit 61 controls the timing of tapping generation by the work unit 20. If the work unit 20 is a peeling laser irradiation unit, the work unit control unit 61 controls the timing of laser light irradiation by the work unit 20. If the work unit 20 is a hardening UV irradiation unit, the work unit control unit 61 controls the timing of UV light irradiation by the work unit 20. If the work unit 20 is a laser cleaning unit, the work unit control unit 61 controls the timing of laser light irradiation by the work unit 20.

[0037] Figure 2 shows a second example of the robot system 100. Referring to Figure 2, a robot system 100 in which the work unit control device 60 does not support the real-time field network N will be described. The robot system 100 shown in Figure 2 comprises a robot 10, a work unit 20, and a control unit 30. The control unit 30 includes a master control unit 41, a robot control unit 51, a work unit control unit 61, and a communication conversion control unit 71. The robot system 100 comprises a master device 40 including the master control unit 41, a robot control device 50 including the robot control unit 51, a work unit control device 60 including the work unit control unit 61, and a communication conversion device 70 including the communication conversion control unit 71. The master device 40, the robot control device 50, and the communication conversion device 70 are connected to each other via the real-time field network N. The communication conversion device 70 and the work unit control device 60 are connected to each other using a communication format other than the communication format of the real-time field network N, such as a serial communication format such as RS422. Detailed explanations of aspects similar to those of the robot system 100 shown in Figure 1 will be omitted, and the differences will be explained in detail.

[0038] The communication conversion device 70 is a device that converts communication formats. The communication conversion device 70 includes a communication conversion control unit 71. The communication conversion control unit 71 includes a memory for storing programs and a processor for executing programs. The communication conversion control unit 71 functions as a slave in the real-time field network N. The communication conversion control unit 71 communicates with each device connected to the real-time field network N via the real-time field network N.

[0039] The communication conversion control unit 71 performs control to convert data in a communication format other than that of the real-time field network N. Specifically, the communication conversion control unit 71 converts the data in a communication format of the real-time field network N acquired from the master control unit 41 into data in a serial communication format, such as RS422, used between the communication conversion control unit 71 and the work unit control unit 61, and outputs it to the work unit control unit 61.

[0040] The work unit control unit 61 of the work unit control device 60 does not function as a slave in the real-time field network N. The work unit control unit 61 communicates with the communication conversion control unit 71 using a communication format other than that of the real-time field network N, such as a serial communication format like RS422. In addition, the work unit control unit 61 communicates with each device connected to the real-time field network N via the communication conversion control unit 71.

[0041] The real-time field network N is a field network that performs periodic communication. In periodic communication, data for controlling the robot system 100, such as information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200, and information regarding the trigger for work performed by the work unit 20 on the workpiece 200, is transmitted and received between the master and the slave. For example, the real-time field network N is EtherCAT®. The data is exchanged between the master and the slave in the form of an Ethernet frame.

[0042] The real-time field network N has a time synchronization function. The time synchronization function includes a distribute clock function. In the distribute clock function, a reference clock is supplied from a slave that has the function of supplying a reference clock that serves as the time standard to the master, and the reference clock is transmitted from the master to each slave, thereby synchronizing the local clocks of the master and each slave to the reference clock. In addition, since the reference clock arrives at each slave with a slight delay, the distribute clock function measures and corrects the communication delay from the reference clock. As a result, it is possible to achieve a very short jitter of 1 μs or less at each slave. The slave that has the function of supplying the reference clock may be any of the robot control unit 51, the work unit control unit 61, and the communication conversion control unit 71, or it may be a control unit separate from the robot control unit 51, the work unit control unit 61, and the communication conversion control unit 71.

[0043] The real-time field network N has an on-the-fly processing function that reads and writes to addressed data. In the on-the-fly processing function, the master transmits data in the format of an Ethernet frame, and each slave reads and writes to the data addressed to it and transmits the data to the next slave. The last slave sends back the data that has been read and written as needed to the master. Because the on-the-fly processing function enables efficient transmission and reception of data between the master and slaves, it is possible to achieve a control cycle of very short less than 100 μs.

[0044] For example, the master control unit 41 transmits data specifying the address of the robot control unit 51 so as to write information such as the relative movement amount of the working unit 20 with respect to the workpiece 200. In this case, the robot control unit 51 writes to the data received with information such as the relative movement amount of the working unit 20 with respect to the workpiece 200. Thereby, it is possible to transmit information regarding the relative movement amount of the working unit 20 with respect to the workpiece 200 to the master control unit 41. Also, if there is a command from the master control unit 41, not only information regarding the relative movement amount of the working unit 20 with respect to the workpiece 200, but also information regarding the relative speed of the working unit 20 with respect to the workpiece 200, three-dimensional coordinate information, pulse number and pulse frequency information, etc. can be transmitted to the master control unit 41. Also, it is possible to transmit information on each joint angle from the servo software to the master control unit 41 at high speed. And it is also possible to calculate the relative movement amount and three-dimensional position on the master control unit 41 side based on the information on each joint angle and transmit it from the master control unit 41 to each slave. Note that, unlike the first embodiment, when the robot control unit 51 functions as a master, the robot control unit 51 calculates the relative movement amount and three-dimensional position and transmits it from the master control unit 41 to each slave. Also, for example, the master control unit 41 transmits data specifying the address of the working unit control unit 61 or the communication conversion control unit 71 so as to read information on the trigger for the work by the working unit 20 with respect to the workpiece 200. In this case, the working unit control unit 61 or the communication conversion control unit 71 reads from the data received with information on the trigger for the work by the working unit 20 with respect to the workpiece 200.

[0045] (Control of Work) Here, in the first embodiment, the control unit 30 controls the work by the working unit 20 on the workpiece 200 based on information regarding the relative movement amount of the working unit 20 with respect to the workpiece 200 due to the movement of the working unit 20 arranged on the robot 10. Specifically, the control unit 30 controls the work by the working unit 20 on the workpiece 200 for each relative movement amount of the working unit 20 with respect to the workpiece 200 based on the information regarding the relative movement amount of the working unit 20 with respect to the workpiece 200. The control unit 30 causes the working unit 20 to perform work for each fixed movement amount.

[0046] When the working unit 20 is an imaging unit as a line camera or an area camera, the control unit 30 controls so that imaging is performed by the working unit 20 for each fixed movement amount of the working unit 20. When the working unit 20 is a three-dimensional shape measurement unit as a laser profile sensor, the control unit 30 controls so that projection of laser light and imaging of laser light are performed for each fixed movement amount of the working unit 20.

[0047] When the working unit 20 is a distance measurement sensor, the control unit 30 controls so that the distance to the workpiece 200 is measured for each fixed movement amount of the working unit 20. When the working unit 20 is an application unit, the control unit 30 controls so that a fixed amount of coating material is applied for each fixed movement amount of the working unit 20.

[0048] When the working unit 20 is an attachment unit, the control unit 30 controls so that a fixed amount of attachment is attached for each fixed movement amount of the working unit 20. When the working unit 20 is a spraying unit, the control unit 30 controls so that a fixed amount of spray is sprayed for each fixed movement amount of the working unit 20.

[0049] When the working unit 20 is a welding unit, the control unit 30 controls so that a fixed amount of welding is performed for each fixed movement amount of the working unit 20. When the working unit 20 is a sewing unit, the control unit 30 controls so that a fixed amount of sewing is performed for each fixed movement amount of the working unit 20.

[0050] When the working unit 20 is an ultrasonic flaw detection unit, the control unit 30 controls so that ultrasonic waves are transmitted for flaw detection for each fixed movement amount of the working unit 20. When the working unit 20 is an eddy current flaw detection unit, the control unit 30 controls so that eddy currents are generated for flaw detection for each fixed movement amount of the working unit 20. When the working unit 20 is a percussion inspection unit, the control unit 30 controls so that percussion inspection is performed for each fixed movement amount of the working unit 20. When the working unit 20 is a peeling laser irradiation unit, the control unit 30 controls so that laser light is irradiated for each fixed movement amount of the working unit 20. When the working unit 20 is a curing UV irradiation unit, the control unit 30 controls so that UV light is irradiated for each fixed movement amount of the working unit 20. When the working unit 20 is a laser cleaning unit, the control unit 30 controls so that laser light is irradiated for each fixed movement amount of the working unit 20.

[0051] The relative movement of the work unit 20 with respect to the workpiece 200 is obtained based on the movement of the control point TCP (see Figure 5), which controls the movement of the robot 10. The control point TCP is set to the working position of the work unit 20 relative to the workpiece 200.

[0052] If the work unit 20 is either an imaging unit as a line camera or an area camera, or a 3D shape measurement unit as a laser profile sensor, the control point TCP is set to the focal position of the work unit 20's imaging. If the work unit 20 is a distance measuring sensor, the control point TCP is set to the distance measuring position of the work unit 20.

[0053] If the work section 20 is a coating section, the control point TCP is set to the coating position of the work section 20. If the work section 20 is an adhesive section, the control point TCP is set to the adhesive position of the work section 20. If the work section 20 is a welding section, the control point TCP is set to the welding position of the work section 20. If the work section 20 is a sewing section, the control point TCP is set to the sewing position of the work section 20. If the work section 20 is either an ultrasonic testing section or an eddy current testing section, the control point TCP is set to the testing position of the work section 20. If the work section 20 is a tapping test section, the control point TCP is set to the tapping test position of the work section 20. If the work section 20 is a peeling laser irradiation section, the control point TCP is set to the laser light irradiation position. If the work section 20 is a curing UV irradiation section, the control point TCP is set to the UV light irradiation position. If the work unit 20 is a laser cleaning unit, the control point TCP is set to the laser beam irradiation position.

[0054] For example, as shown in Figure 5, the robot control unit 51 moves the work unit 20 in a curved relative position to the work unit 200 along the surface of the work unit 200 using the robot 10. Alternatively, for example, the robot control unit 51 moves the work unit 20 relative to the work unit 200 which is curved in the vertical direction using the robot 10. In this case, the work unit control unit 61 controls the work unit 20 to perform work for each movement amount L1 of the control point TCP.

[0055] Furthermore, as shown in Figure 6, for example, the robot control unit 51 moves the work unit 20 in a curved manner relative to the robot 10 along a work position on the workpiece 200 that has a curved section. In this case, the work unit control unit 61 controls the work unit 20 to perform work for each movement amount L2 of the control point TCP. For example, if the work unit 20 is a coating unit, the work unit control unit 61 controls the work unit 20 to dispense a coating amount V1 for each movement amount L2 of the work unit 20. In addition, the work unit control unit 61 controls the discharge stroke for dispensing the coating to be a constant amount for each movement amount L2 of the work unit 20, regardless of the relative movement speed of the work unit 20. As a result, as shown in the embodiment in Figure 7(A), it is possible to apply the coating to both straight and curved sections at a constant rate. On the other hand, in the comparative example shown in Figure 7(B), the coating is applied at a constant discharge rate regardless of the relative movement speed of the work unit 20. In this case, the discharge rate of the coating increases in the curved section, and a large amount of coating is applied in the curved section. As a result, uneven application of the coating occurs in both straight and curved sections.

[0056] Figures 8 and 9 show an example of controlling the work performed on a workpiece 200 by the work unit 20 of the robot system 100 shown in Figure 1.

[0057] As shown in Figures 8 and 9, the master control unit 41 controls the work unit control unit 61 to output a trigger based on information regarding the relative movement amount of the work unit 20 relative to the workpiece 200 obtained from the robot control unit 51. Specifically, the master control unit 41 controls the work unit control unit 61 to output a trigger so that the work unit 20 performs work on the workpiece 200 for each relative movement amount of the work unit 20 relative to the workpiece 200, based on information regarding the relative movement amount of the work unit 20 relative to the workpiece 200 obtained from the robot control unit 51. The work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the trigger obtained from the master control unit 41. Specifically, the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 for each relative movement amount of the work unit 20 relative to the workpiece 200, based on the trigger obtained from the master control unit 41.

[0058] More specifically, the robot control unit 51 performs control to acquire information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 based on the actual movement of the work unit 20, or to acquire information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 based on a movement command from the robot 10. At each control cycle of the real-time field network N, the robot control unit 51 performs control to output the latest information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 to the master control unit 41 by writing information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 to the data output from and returned to the master control unit 41. The information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 includes the relative movement amount of the work unit 20 with respect to the workpiece 200.

[0059] The master control unit 41 controls the work unit control unit 61 to output a trigger, based on the information regarding the relative movement amount of the work unit 20 relative to the work unit 200 obtained from the robot control unit 51, so that the work unit 20 performs work on the work unit 200 at regular intervals. The master control unit 41 controls the work unit control unit 61 to output a trigger by sending data containing trigger information, specifying the address of the work unit control unit 61 to read the trigger information, at the control cycle in which it has determined to output a trigger.

[0060] The work unit control unit 61 reads trigger information from the received data and, based on the triggers obtained from the master control unit 41, controls the work performed by the work unit 20 on the workpiece 200 at regular intervals. In this case, for example, as shown in Figure 8, the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the rising and falling edges of a single-phase pulse, based on the triggers obtained from the master control unit 41. Alternatively, for example, as shown in Figure 9, the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the rising edges of pulses in multiple phases. Figure 9 shows an example in which the work performed by the work unit 20 on the workpiece 20 is controlled by the rising edges of pulses in two phases, A phase and B phase.

[0061] For example, if the work unit 20 performs work on the workpiece 200 every time it moves 0.1 mm relative to the workpiece 200, let's assume that in the first control cycle shown on the far left in Figures 8 and 9, the work unit 20 moves 0.1 mm relative to the workpiece 200. In this case, in the control cycle following the first control cycle, shown second from the left in Figures 8 and 9, data containing trigger information is generated and transmitted. Then, in the control cycle following the control cycle in which the data containing trigger information was generated, shown third from the left in Figures 8 and 9, the work unit 20 performs work on the workpiece 200. By controlling the work performed by the work unit 20 on the workpiece 200 using a real-time field network N, the control cycle becomes 100 μs or less and the jitter becomes 1 μs or less. Therefore, it is possible to make the difference between the timing of outputting the trigger to have the work unit 20 perform work on the workpiece 200 and the timing of the work unit 20 actually performing work on the workpiece 200 very short, less than 101 μs. Furthermore, if the control cycle is further shortened due to improved processing capacity, it will be possible to achieve even shorter delays. Note that when controlling the work performed by the work unit 20 on the workpiece 200 without using the real-time field network N, the timing difference will be several milliseconds.

[0062] Figure 10 shows an example of controlling the work performed on a workpiece 200 by the work unit 20 of the robot system 100 shown in Figure 2. Note that detailed explanations of points similar to those in the examples shown in Figures 8 and 9 will be omitted, and the differences will be explained primarily.

[0063] As shown in Figure 10, the master control unit 41 controls the communication conversion control unit 71 to output a trigger based on information regarding the relative movement amount of the work unit 20 relative to the workpiece 200, which is obtained from the robot control unit 51. Specifically, the master control unit 41 controls the communication conversion control unit 71 to output a trigger so that the work unit 20 performs work on the workpiece 200 for each relative movement amount of the work unit 20 relative to the workpiece 200, based on information regarding the relative movement amount of the work unit 20 relative to the workpiece 200, which is obtained from the robot control unit 51. The work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the trigger obtained from the master control unit 41 via the communication conversion control unit 71. Specifically, the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 for each relative movement amount of the work unit 20 relative to the workpiece 200, based on the trigger obtained from the master control unit 41 via the communication conversion control unit 71.

[0064] The master control unit 41 controls the communication conversion control unit 71 to output a trigger, based on the relative movement amount of the work unit 20 relative to the work unit 20, which is included in the information on the relative movement amount of the work unit 20 relative to the work unit 200 obtained from the robot control unit 51, so that the work unit 20 performs work on the work unit 200 at regular intervals. The master control unit 41 controls the communication conversion control unit 71 to output a trigger by sending data containing trigger information, specifying the address of the communication conversion control unit 71 to read the trigger information, at the control cycle in which it has determined to output a trigger.

[0065] The communication conversion control unit 71 reads trigger information from the received data, converts the trigger acquired from the master control unit 41 into the communication format used between the communication conversion control unit 71 and the work unit control unit 61, and performs control to output it to the work unit control unit 61. Based on the trigger acquired from the master control unit 41 via the communication conversion control unit 71, the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 at regular intervals.

[0066] In the control example shown in Figure 10, the trigger includes a pulse signal based on information regarding the relative movement of the work unit 20 with respect to the workpiece 200. The work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the pulse signal obtained from the master control unit 41 after conversion via the communication conversion control unit 71.

[0067] The master control unit 41 outputs a variable-frequency pulse signal based on the relative movement of the work unit 20 relative to the workpiece 20 for each relative movement of the work unit 20 relative to the workpiece 200. The master control unit 41 outputs a predetermined pulse signal for each relative movement of the work unit 20 relative to the workpiece 200. For example, as shown in Figure 11, the master control unit 41 generates and outputs a pulse signal based on the relative movement of the work unit 20 at predetermined control cycles. In other words, the master control unit 41 acquires the relative movement of the work unit 20 relative to the workpiece 200 at predetermined control cycles. The master control unit 41 then generates a pulse signal containing a number of pulses corresponding to the acquired relative movement. One pulse is generated for every x mm of relative movement. For example, if the relative movement is 5x mm, five pulses are generated. A pulse is counted as one on its rising edge and one on its falling edge. In other words, a pulse is counted as two due to its rising and falling edges. The frequency of the output pulses is variable, for example, in the range from 0 Hz to several MHz. In other words, as the relative displacement increases, the frequency of the output pulse increases, and as the relative displacement decreases, the frequency of the output pulse decreases.

[0068] In the example shown in Figure 11, the control period is 100 μs, and the amount of movement is acquired at each control period, with a pulse signal output based on the amount of movement. Note that the end-effector movement in Figure 11 represents the cumulative amount of movement from 0 mm. In other words, the difference in end-effector movement from the previous control period is acquired as the relative movement in the current control period. For example, if the end-effector movement in the previous control period was 0.1 mm and the end-effector movement in the current control period is 0.2 mm, the relative movement in the current control period is acquired as 0.1 mm. In the example shown in Figure 11, the pulse resolution is set to 0.1 mm / pulse. In other words, one pulse is output for every 0.1 mm movement. For example, when moving 0.1 mm, the number of output pulses is set to 1, and the pulse frequency is 10 kHz. When moving 0.2 mm, the number of output pulses is set to 2, and the pulse frequency is 20 kHz.

[0069] The master control unit 41 controls the communication conversion control unit 71 to output a pulse signal by sending data containing pulse signal information, specifying the address of the communication conversion control unit 71 to read pulse signal information such as frequency and number of pulses, at the control cycle in which it has determined to output a trigger. The communication conversion control unit 71 converts the pulse signal obtained from the master control unit 41 into the communication format used between the communication conversion control unit 71 and the work unit control unit 61, and controls it to output to the work unit control unit 61. The work unit control unit 61 counts the pulses contained in the pulse signal output from the communication conversion control unit 71 to obtain the relative movement amount of the work unit 20. Then, each time the work unit 20 moves a certain amount, the work unit control unit 61 causes the work unit 20 to perform work on the workpiece 200.

[0070] In addition, in the examples shown in Figures 8 and 9, similar to the example shown in Figure 10, the trigger may include a pulse signal based on information regarding the relative movement of the work unit 20 with respect to the workpiece 200, and the work performed by the work unit 20 on the workpiece 200 may be controlled based on the pulse signal.

[0071] In the example shown in Figure 10, as in the examples shown in Figures 8 and 9, by controlling the work performed by the work unit 20 on the workpiece 200 using a real-time field network N, the control period becomes 100 μs or less and the jitter becomes 1 μs or less. As a result, the time difference between the timing of outputting the trigger to have the work unit 20 perform work on the workpiece 200 and the timing of the work unit 20 actually performing work on the workpiece 200 can be reduced to a very short 101 μs or less.

[0072] (Effects of the First Embodiment) In the first embodiment, as described above, the robot system 100 communicates via a real-time field network N that can guarantee real-time communication in accordance with the Ethernet standard, and includes a control unit 30 that controls the work performed on the workpiece 200 by the work unit 20 based on information regarding the relative movement of the work unit 20 to the workpiece 200 due to the movement of the workpiece 200 or the work unit 20 placed on the robot 10. As a result, the work performed on the workpiece 20 by the work unit 20 can be controlled based on information regarding the relative movement of the work unit 20 to the workpiece 200, so that work can be performed on the workpiece 200 without having to set all work positions in advance. As a result, when the robot 10 performs work while moving the work unit 20 relative to the workpiece 200, the complexity of the setting work can be suppressed.

[0073] Furthermore, even when the relative movement speed of the work unit 20 by the robot 10 is not constant, such as when working on both the straight and curved sections of the workpiece 200, the work unit 20 can perform work on the workpiece 200 at predetermined relative movement intervals. In other words, in work involving complex relative movement such as curved sections, it is difficult to increase the relative movement speed. Therefore, if the goal is to keep the relative movement speed of the work unit 20 constant, the relative movement speed must be reduced even for movements on straight sections where it is possible to increase the relative movement speed. On the other hand, in this disclosure, by performing work on the workpiece 200 at predetermined relative movement intervals rather than by speed, it is not necessary to keep the relative movement speed of the work unit 20 constant. Therefore, the speed can be increased at work positions where it is possible to increase the relative movement speed. This makes it possible to suppress the overall slowing down of the work speed. Furthermore, if the working unit 20 performs a constant operation on the workpiece 200 regardless of the speed, and the relative speed of the working unit 20 is changed, the work performed by the working unit 20 on the workpiece 200 will become denser in curved sections where the relative speed is low compared to straight sections where the relative speed is high. On the other hand, in this disclosure, by performing the operation on the workpiece 200 at predetermined relative movement intervals, it is possible to suppress the denser operation performed by the working unit 20 in positions where the relative speed of the working unit 20 is low compared to positions where the relative speed is high, thereby suppressing unevenness in the work performed by the working unit 20 on the workpiece 200.

[0074] Furthermore, since the work performed by the work unit 20 on the workpiece 200 can be controlled using the real-time field network N, communication delay can be reduced compared to the case where the work performed by the work unit 20 on the workpiece 200 is controlled without using the real-time field network N. As a result, the discrepancy between the timing of outputting a trigger to cause the work unit 20 to perform work on the workpiece 200 and the timing of the work unit 20 actually performing work on the workpiece 200 can be reduced, thereby suppressing the inability of the work unit 20 to perform work on the workpiece 200 with high accuracy due to communication delay.

[0075] Furthermore, in the first embodiment, as described above, the real-time field network N has a time synchronization function that performs time synchronization. By performing time synchronization, differences in control cycles between devices, processing delays, and communication fluctuations can be absorbed and reduced, thus easily reducing communication delays. As a result, it is easy to suppress the inability of the work unit 20 to perform work on the workpiece 200 with high accuracy due to communication delays.

[0076] Furthermore, in the first embodiment, as described above, the time synchronization function includes a distribute clock function. This allows for accurate time synchronization, making it easy to reduce communication delays. As a result, it is easy to suppress situations where the work unit 20 cannot perform work on the workpiece 200 accurately due to communication delays.

[0077] Furthermore, in the first embodiment, as described above, the real-time field network N has an on-the-fly processing function that reads and writes to the addressed data. By reading and writing to the addressed data, communication can be performed efficiently, and communication delay can be easily reduced. As a result, it is easy to suppress the inability of the work unit 20 to perform work on the workpiece 200 with high accuracy due to communication delay.

[0078] Furthermore, in the first embodiment, as described above, the real-time field network N is an Ethernet CAT. By using an Ethernet CAT with a distribute clock function and an on-the-fly processing function, communication delay can be easily reduced, thus easily suppressing the inability of the work unit 20 to perform work on the workpiece 200 with high accuracy due to communication delay.

[0079] Furthermore, in the first embodiment, as described above, the control unit 30 includes a master control unit 41 that communicates via a real-time field network N, a robot control unit 51 that communicates via the real-time field network N and acts as a slave to control the robot 10, and a work unit control unit 61 that communicates via the real-time field network N and acts as a slave to control the work unit 20. The master control unit 41 performs control to output a trigger to the work unit control unit 61 based on information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 obtained from the robot control unit 51, and the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the trigger obtained from the master control unit 41. As a result, the master control unit 41, the robot control unit 51, and the work unit control unit 61 can perform the work performed by the work unit 20 on the workpiece 200 in a manner that is highly synchronized with the relative movement of the work unit 20.

[0080] Furthermore, in the first embodiment, as described above, the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the rising and falling edges of a single-phase pulse, or controls the work performed by the work unit 20 on the workpiece 200 based on the rising edges of pulses of multiple phases, based on a trigger acquired from the master control unit 41. This makes it possible to accurately control the timing of the work performed by the work unit 20 on the workpiece 200, whether the control is performed by a single-phase pulse or by pulses of multiple phases.

[0081] Furthermore, in the first embodiment, as described above, the control unit 30 includes a master control unit 41 that communicates via a real-time field network N, a robot control unit 51 that communicates via the real-time field network N and acts as a slave to control the robot 10, a communication conversion control unit 71 that communicates via the real-time field network N and acts as a slave to convert data in a communication format other than that of the real-time field network N, and a work unit control unit 61 that communicates via the communication conversion control unit 71 and controls the work unit 20. The master control unit 41 performs control to output a trigger to the communication conversion control unit 71 based on information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200 obtained from the robot control unit 51, and the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the trigger obtained from the master control unit 41 after conversion via the communication conversion control unit 71. As a result, even if the work unit control unit 61 does not support the communication format of the real-time field network N, the master control unit 41, robot control unit 51, communication conversion control unit 71, and work unit control unit 61 can perform work on the work unit 200 in a manner that is precisely synchronized with the relative movement of the work unit 20. Furthermore, because the control cycle for trigger output is short, it is possible to quickly respond to changes in pulse frequency and output when acceleration or deceleration of robot movement occurs. Conventionally, there is a delay of several ms, so the faster the acceleration or deceleration of robot movement, the more stretching or shrinking of the captured image occurs when the work unit is an imaging unit, but this can be improved.

[0082] Furthermore, in the first embodiment, as described above, the trigger includes a pulse signal based on information regarding the relative movement amount of the work unit 20 with respect to the workpiece 200, and the work unit control unit 61 controls the work performed by the work unit 20 on the workpiece 200 based on the pulse signal obtained from the master control unit 41 after conversion via the communication conversion control unit 71. As a result, the relative movement amount of the work unit 20 with respect to the workpiece 200 can be easily obtained by counting the pulses of the pulse signal, and the work performed by the work unit 20 on the workpiece 200 can be easily controlled based on the relative movement amount of the work unit 20 with respect to the workpiece 200.

[0083] Furthermore, in the first embodiment, as described above, the work unit 20 includes at least one of the following: an imaging unit, a three-dimensional shape measurement unit, a distance measuring sensor, a coating unit, a bonding unit, a spraying unit, a welding unit, a sewing unit, an ultrasonic flaw detection unit, an eddy current flaw detection unit, a tapping inspection unit, a peeling laser irradiation unit, a hardening UV irradiation unit, and a laser cleaning unit. This allows the imaging unit, three-dimensional shape measurement unit, distance measuring sensor, ultrasonic flaw detection unit, eddy current flaw detection unit, or tapping inspection unit to be moved relative to the workpiece 200, and the workpiece 200 can be imaged, measured, or inspected with each relative movement, thereby enabling accurate acquisition of the condition of the workpiece 200. Furthermore, by moving the coating unit, adhesive unit, spray unit, welding unit, sewing unit, peeling laser irradiation unit, curing UV irradiation unit, or laser cleaning unit relative to the workpiece 200, coating, adhesive, spraying, welding, sewing, laser irradiation, UV irradiation, or laser cleaning can be performed on the workpiece 200 with each relative movement, thus suppressing the occurrence of uneven coating, adhesive, spraying, welding, sewing, laser irradiation, UV irradiation, or laser cleaning on the workpiece 200. In addition, by using a real-time field network N, the workpiece 200 can be imaged, measured, or inspected by an imaging unit, a three-dimensional shape measurement unit, a distance sensor, an ultrasonic flaw detection unit, an eddy current flaw detection unit, or a tapping inspection unit, thus suppressing the inability to perform imaging, measurement, or inspection accurately due to communication delays. Furthermore, by using the real-time field network N, the workpiece 200 can be coated, attached, sprayed, welded, sewn, laser-irradiated, UV-irradiated, or laser-cleaned by the coating unit, adhesive unit, spraying unit, welding unit, sewing unit, peeling laser irradiation unit, curing UV irradiation unit, or laser cleaning unit. This suppresses the possibility of inaccurate coating, attachment, spraying, welding, sewing, laser-irradiated, UV-irradiated, or laser-cleaning due to communication delays.

[0084] [Second Embodiment] The configuration of the robot system 300 according to the second embodiment of the present disclosure will be described with reference to Figures 11 to 17. In the figures, the same reference numerals are used for parts that are the same as those in the robot system 100 according to the first embodiment.

[0085] As shown in Figure 12, the robot system 300 comprises a robot 10, a work unit 320 that performs work on a workpiece 200, and a control unit 330 that controls the robot 10 and the work unit 320.

[0086] As shown in Figure 13, the work unit 320 is a coating unit. The coating unit, as the work unit 320, includes a cylinder 321 into which the coating material is filled, a screw 323 provided inside the cylinder 321 that rotates to discharge the coating material from the coating head 322, and a motor 324 that rotates the screw 323. The coating unit, as the work unit 320, changes the amount of coating material discharged from the coating head 322 by changing the rotation speed of the motor 324, thereby changing the pressure inside the cylinder 321. Due to the viscosity of the coating material, it takes time for the pressure inside the cylinder 321 to change after the rotation speed of the motor 324 is changed. For this reason, as shown in Figure 14, a discrepancy is likely to occur between the timing at which the work unit control unit 61 controls the work performed on the workpiece 200 by the coating unit, as the work unit 320, and the timing at which the work unit 320 actually performs the work on the workpiece 200. In Figure 14, the magnitude of the above discrepancy is defined as time t1.

[0087] As shown in Figure 12, the control unit 330 includes a master control unit 341, a robot control unit 51, and a work unit control unit 61. The robot system 300 also includes a master device 340 including the master control unit 341, a robot control device 350 including the robot control unit 351, and a work unit control device 60 including the work unit control unit 61. The master device 340, the robot control device 350, and the work unit control device 60 are connected to each other via a real-time field network N that can guarantee real-time communication in accordance with the Ethernet standard.

[0088] The master control unit 341 performs control to output a trigger based on information regarding the relative movement amount of the coating unit, which acts as the work unit 320, relative to the workpiece 200. The trigger includes a pulse signal based on information regarding the relative movement amount of the coating unit, which acts as the work unit 320, relative to the workpiece 200. As shown in Figure 11, the pulse signal includes a number of pulses corresponding to the relative movement amount of the coating unit, which acts as the work unit 320, relative to the workpiece 200. In other words, the pulse signal is a signal having a frequency corresponding to the relative movement amount of the coating unit, which acts as the work unit 320, relative to the workpiece 200. Note that in Figure 11, the pulse signal is referred to as a pulse output.

[0089] As shown in Figure 12, the robot control unit 351 controls the movement of the robot 10. A teaching terminal 80 that receives commands to teach the robot 10 movements can be connected to the robot control unit 351.

[0090] The work unit control unit 61 controls the work performed on the workpiece 200 by the coating unit, which acts as the work unit 320, based on a trigger that includes a pulse signal acquired from the master control unit 341. The work unit control unit 61 controls the timing and amount of coating applied by the coating unit, which acts as the work unit 320, according to the number of pulses included in the pulse signal. Specifically, the work unit control unit 61 controls the rotation of the motor 324 of the coating unit, which acts as the work unit 320, by an amount corresponding to the number of pulses included in the pulse signal. In other words, the work unit control unit 61 controls the rotation of the motor 324 of the coating unit, which acts as the work unit 320, by an amount corresponding to the frequency of the pulse signal.

[0091] As shown in Figure 15, in a predetermined movement trajectory T of the robot 10, the relative speed of the work unit 20 with respect to the workpiece 200 in the curved section T1 is smaller than the relative speed of the work unit 20 with respect to the workpiece 200 in the straight section T2. ​​In other words, in a predetermined movement trajectory T of the robot 10, the amount of relative movement of the work unit 20 with respect to the workpiece 200 in the curved section T1 is smaller than the amount of relative movement of the work unit 20 with respect to the workpiece 200 in the straight section T2. ​​Therefore, the master control unit 341 performs control to output a trigger at each control cycle of the real-time field network N so that the amount of coating applied in the curved section T1 of the predetermined movement trajectory T is smaller than the amount of coating applied in the straight section T1 of the predetermined movement trajectory T. However, if there is a discrepancy between the timing at which the work unit control 61 controls the work performed on the workpiece 200 by the coating unit as the work unit 320, the coating material adjusted to the amount applied at the curved section T1 of the predetermined movement trajectory T will be applied at a position past the peak of the curved section T1 of the predetermined movement trajectory T. The predetermined movement trajectory T of the robot 10 is a trajectory that passes through the teaching points taught to the robot 10.

[0092] (Work control that takes into account the time difference between when the work is controlled by the work unit control unit and when the work is performed by the work unit) As shown in Figure 14, the master control unit 341 outputs a trigger t2 minutes earlier, corresponding to the time t1 which is the time difference between when the work unit control unit 61 controls the work performed on the workpiece 200 by the coating unit as the work unit 320 and when the coating unit as the work unit 320 actually performs the work on the workpiece 200. In other words, the master control unit 341 takes into account the time t1 which is the time difference between when the work unit control unit 61 controls the work performed on the workpiece 200 by the coating unit as the work unit 320 and when the coating unit as the work unit 320 actually performs the work on the workpiece 200, and outputs the trigger t2 minutes earlier than when the trigger is not output early. For this reason, the master control unit 341 needs a future predicted value as information regarding the relative movement amount of the coating unit as the work unit 320 relative to the workpiece 200, rather than the current value obtainable from the robot control unit 351. Note that time t2 may be equal to time t1 or slightly different.

[0093] As shown in Figure 16, the master control unit 341 calculates a predicted movement amount L4 as information regarding the relative movement amount of the work unit 320 with respect to the workpiece 200. This L4 is calculated between a first predicted position P1, which is the position that the robot 10 is expected to reach after a predetermined time tp has elapsed from its current position P0 on a predetermined movement trajectory T of the robot 10, and a second predicted position P2, which is the position that the robot 10 is expected to reach one control cycle of the real-time field network N one cycle prior to the first predicted position P1. The predetermined movement trajectory T of the robot 10 is a trajectory that passes through the teaching points taught to the robot 10. The robot control unit 351 moves the robot 10 on the predetermined movement trajectory T based on the teaching points. The control cycle of the real-time field network N is, for example, 100 μs. The predetermined time tp is greater than the control cycle, time t1, and time t2 of the real-time field network N.

[0094] The master control unit 341 calculates the first predicted position P1 and the second predicted position P2 based on the current state of the robot 10 and a dynamic model that models the state of the robot 10 on a predetermined movement trajectory T, using either model predictive control or an extended Kalman filter. Model predictive control is a control method that predicts the future behavior of a controlled object over a finite interval from the present time by having a predictive model, i.e., a controlled object model, such as a step response model, impulse response model, transfer function model, or state equation, inside the controller. In order to perform model predictive control, it is necessary to appropriately capture the dynamic characteristics of the controlled object, i.e., its dynamics, and represent them as a model. Furthermore, in order to perform model predictive control, it is necessary to use the predicted results to determine the control input to be given to the controlled object. In model predictive control, the control input is uniquely determined by solving an optimization problem at each sampling time. The extended Kalman filter is an algorithm used to estimate the state of a system when the system's dynamics or measurement method include nonlinear functions.

[0095] As shown in Figure 14, the master control unit 341 performs control to output a trigger based on the predicted movement amount L4 at a time t2 minutes earlier, corresponding to a time t1, than the time it is predicted that the robot 10 will reach the first predicted position P1 on the predetermined movement trajectory T. As a result, the timing at which the work unit control unit 61 acquires the trigger is earlier, corresponding to the time t1, so that the timing at which the work unit control unit 61 controls the work performed on the workpiece 200 by the coating unit as the work unit 320 is earlier, corresponding to the time t1, so that the timing at which the work performed on the workpiece 200 by the coating unit as the work unit 320 is earlier, corresponding to the time t1, so that that work is performed on the workpiece 200. As a result, as shown in Figure 17, appropriately adjusted coating material is applied over the entire predetermined movement trajectory T.

[0096] As shown in Figure 12, the teaching terminal 80 can accept an operation to set a predetermined time tp. When an operation to set a predetermined time tp is performed on the teaching terminal 80, the master control unit 341 obtains the set predetermined time tp via the teaching terminal 80 and the robot control unit 351.

[0097] Furthermore, the other configurations of the robot system 300 of the second embodiment are the same as those of the robot system 100 according to the first embodiment.

[0098] (Effects of the Second Embodiment) In the second embodiment, as described above, similar to the first embodiment, the robot system 300 communicates via a real-time field network N that can guarantee real-time communication in accordance with the Ethernet standard, and includes a control unit 330 that controls the work performed on the workpiece 200 by the work unit 20 based on information regarding the relative movement of the work unit 320 relative to the workpiece 200 due to the movement of the workpiece 200 or the work unit 320 placed on the robot 10. As a result, similar to the first embodiment, it is possible to suppress the complexity of the setup process when the robot 10 performs work while moving the work unit 320 relative to the workpiece 200.

[0099] Furthermore, in the second embodiment, as described above, the control unit 330 includes a master control unit 341 that communicates via a real-time field network N and performs control to output a trigger based on information regarding the relative movement amount of the work unit 320 with respect to the workpiece 200, and a work unit control unit 61 that controls the work performed on the workpiece 200 by the work unit 320 based on the trigger. The master control unit 341 performs control to output a trigger t2 minutes earlier, corresponding to the time difference between the timing at which the work unit control unit 61 controls the work performed on the workpiece 200 by the work unit 320 and the timing at which the work unit 320 actually performs the work on the workpiece 200. This makes it possible to output the trigger earlier, taking into account the time difference between the timing at which the work unit control unit 61 controls the work performed on the workpiece 200 by the work unit 320 and the timing at which the work unit 320 actually performs the work on the workpiece 200. As a result, it is possible to suppress the inability of the work unit 320 to perform work on the workpiece 200 with high precision, which can be caused by a discrepancy between the timing at which the work unit control unit 61 controls the work on the workpiece 200 by the work unit 320 and the timing at which the work unit 320 actually performs work on the workpiece 200.

[0100] Furthermore, in the second embodiment, as described above, the master control unit 341 calculates a predicted movement amount L4 as information regarding the relative movement amount of the work unit 320 with respect to the workpiece 200, between a first predicted position P1, which is the position that the robot 10 is expected to reach after a predetermined time tp has elapsed from the robot 10's current position P0 on a predetermined movement trajectory T of the robot 10, and a second predicted position P2, which is the position that the robot 10 is expected to reach one control cycle of the real-time field network N one minute before the first predicted position P1. Based on the predicted movement amount L4, the master control unit 341 performs control to output a trigger t2 minutes earlier than the time that the robot 10 is expected to reach the first predicted position P1 on the predetermined movement trajectory T, corresponding to the deviation. This makes it easy to calculate the relative movement amount of the work unit 320 with respect to the workpiece 200 after a predetermined time tp has elapsed from the robot 10's current position P0, based on the first predicted position P1 and the second predicted position P2. As a result, a trigger can be easily output based on information regarding the relative movement amount of the work unit 320 relative to the workpiece 200 after a predetermined time tp has elapsed from the current position P0 of the robot 10.

[0101] Furthermore, in the second embodiment, as described above, the master control unit 341 calculates the first predicted position P1 and the second predicted position P2 based on the current state of the robot 10 and a dynamic model that models the state of the robot 10 on a predetermined movement trajectory T, using either model predictive control or an extended Kalman filter. This allows the master control unit 341 to easily calculate the first predicted position P1 and the second predicted position P2.

[0102] Furthermore, in the second embodiment, as described above, the work unit 320 is a coating unit. Here, when the work unit 20 is a coating unit, there is a tendency for a discrepancy to occur between the timing at which the work unit control unit 61 controls the work performed on the workpiece 200 by the work unit 320 and the timing at which the work unit 320 actually performs the work on the workpiece 200. Therefore, when the work unit 320 is a coating unit, it is particularly effective to output the trigger t2 minutes earlier, corresponding to the discrepancy between the timing at which the work unit control unit 61 controls the work performed on the workpiece 200 by the work unit 320 and the timing at which the work unit 320 actually performs the work on the workpiece 200.

[0103] Furthermore, in the second embodiment, as described above, the control unit 330 includes a robot control unit 351 that controls the robot 10. A teaching terminal 80 that accepts operations for teaching the robot 10 to perform actions can be connected to the robot control unit 351. The teaching terminal 80 can accept operations for setting a predetermined time. When an operation to set a predetermined time is performed on the teaching terminal 80, the master control unit 341 obtains the set predetermined time tp via the teaching terminal 80 and the robot control unit 351. This allows the user to arbitrarily set the predetermined time tp that the master control unit 341 uses when calculating the first predicted position P1 and the second predicted position P2.

[0104] Furthermore, the other effects of the second embodiment are the same as those of the first embodiment described above.

[0105] (Variations) The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the description of the embodiments above, and further includes all modifications (variations) in the sense and scope equivalent to the claims.

[0106] For example, the first and second embodiments described above show examples where the robot is a vertical articulated robot, but the disclosure is not limited thereto. For example, the robot may be a horizontal articulated robot or the like.

[0107] Furthermore, while the first and second embodiments described above show examples in which a work unit is placed at the tip of a robot and the work unit is moved by the robot to move it, thereby moving the work unit relative to the work unit, the present disclosure is not limited thereto. In this disclosure, as shown in the example in Figure 18, a work unit 200 may be provided at the tip of a robot 10, and the work unit 20 and 320 may be moved relative to the work unit 200 by the robot 10 to move the work unit 200. In this case, the work unit 20 and 320 may perform work on the work unit 200 at predetermined movement amounts L3. Also, when a work unit 200 is provided at the tip of a robot 10, an end effector may be provided at the tip of the robot 10, and the work unit 200 may be held by the end effector by gripping or the like.

[0108] Alternatively, the workpiece may be placed at the tip of the robot, and the robot may move the workpiece, thereby moving the workpiece relative to the workpiece. Alternatively, the workpiece and workpiece may be placed at the tip of two robots, respectively, and both the workpiece and workpiece may be moved by the two robots, thereby moving the workpiece relative to the workpiece. Furthermore, when the workpiece is moved by a conveyor, the relative movement of the workpiece relative to the workpiece may be obtained in synchronization with the workpiece being moved by the conveyor. In addition, when the robot moves using an external axis, an AGV (Automated Guided Vehicle), or an AMR (Autonomous Mobile Robot), the relative movement of the workpiece relative to the workpiece may be obtained by taking into account the movement of the robot using the external axis, AGV, or AMR. Furthermore, when the workpiece is moved by a positioner, AGV, AMR, etc., the relative movement of the work unit relative to the workpiece may be obtained by taking into account the movement of the workpiece by the external axis, AGV, AMR, etc. Also, when these are combined, the relative movement of the work unit relative to the workpiece may be obtained.

[0109] Furthermore, while the first and second embodiments described above show examples where the real-time field network is EtherCAT, this disclosure is not limited thereto. For example, the real-time field network may be CC-Link IE Field, DeviceNet, DeviceNet Safety, EtherNet® / IP adapter, Profibus Master, Profibus Slave, PROFINET I / O, or Dual channel PROFINET, etc.

[0110] Furthermore, while the first embodiment described above shows an example of obtaining the relative movement of the workpiece with respect to the workpiece based on the movement of the robot's control point, the disclosure is not limited thereto. In this disclosure, the relative movement of the workpiece with respect to the workpiece may be obtained based on the movement of any position of the robot.

[0111] Furthermore, in the second embodiment described above, the master control unit 341 calculates the first predicted position P1 and the second predicted position P2 based on the current state of the robot 10 and a dynamic model that models the state of the robot 10 on a predetermined movement trajectory T, using either model predictive control or an extended Kalman filter. However, the disclosure is not limited to this. In the disclosure, the master control unit may calculate the first predicted position and the second predicted position using methods other than model predictive control and an extended Kalman filter, such as adaptive control.

[0112] Furthermore, although the second embodiment described above shows the work section 320 as an application section, the disclosure is not limited thereto. In the configuration of the second embodiment described above, the work section may be an adhesive section, a spray section, a welding section, a sewing section, etc.

[0113] Furthermore, in the second embodiment described above, the teaching terminal 80 is capable of receiving an operation to set a predetermined time tp, and the master control unit 341 acquires the set predetermined time tp via the teaching terminal 80 and the robot control unit 351 when an operation to set a predetermined time tp is performed on the teaching terminal 80. However, the disclosure is not limited thereto. In this disclosure, the master control unit may be configured to acquire the set predetermined time from an operation unit other than the teaching terminal when an operation to set a predetermined time is performed on an operation unit other than the teaching terminal.

[0114] Furthermore, in the second embodiment described above, the control unit 330 is shown to include a master control unit 341, a robot control unit 51, and a work unit control unit 61, but the disclosure is not limited thereto. In the configuration of the second embodiment described above, the work unit control device does not correspond to the real-time field network N, as in the configuration of the second example of the first embodiment described above, and the control unit may include a communication conversion control unit that performs control to convert data in the communication format of the real-time field network N acquired from the master control unit and output it to the work unit control unit.

[0115] Furthermore, in the second embodiment described above, the coating unit as the work unit 320 was shown to include a cylinder 321 into which the coating material is filled, a screw 323 provided inside the cylinder 321 and rotating to discharge the coating material inside the cylinder 321 from the coating head 322, and a motor 324 that rotates the screw 323, but the present disclosure is not limited thereto. In the present disclosure, the coating unit as the work unit may have a configuration other than that described above, for example, a configuration including a cylinder into which the coating material is filled, a piston provided inside the cylinder and pressing to discharge the coating material inside the cylinder from the coating head, and a motor that drives the piston.

[0116] Furthermore, while the first and second embodiments described above show examples where the master control unit, robot control unit, and work unit control unit are separate control units, the disclosure is not limited thereto. In this disclosure, two or more of the master control unit, robot control unit, and work unit control unit may be a common control unit.

[0117] The functions of the elements disclosed herein may be implemented using one or more circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), and / or conventional circuits. The functions of the elements disclosed herein may be implemented using one or more circuits or processing circuits, including combinations of general-purpose processors, special-purpose processors, integrated circuits, ASICs, FPGAs, and conventional circuits. One or more circuits or processing circuits may be programmed using one or more programs stored together or individually in one or more memories, or otherwise configured to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. A processor may be a programmed processor that executes programs stored in memory. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions individually or in combination with each other, or hardware programmed to perform the enumerated functions individually or in combination with each other. Hardware may be any hardware disclosed herein that is programmed or configured to perform the enumerated functions. A computer program, including computer instructions, is stored in memory. Computer instructions provide logic and routines that enable the hardware to perform the methods disclosed herein. Hardware includes, for example, processing circuits or circuits. A computer program may be implemented in a known format on computer-readable storage media, computer program products, memory devices, recording media such as CD-ROMs or DVDs, and / or in the memory of FPGAs or ASICs.

[0118] [Embodiments] The exemplary embodiments described above will be understood by those skilled in the art to be specific examples of the following embodiments.

[0119] (Aspect 1) A robot system comprising: a robot; a work unit that performs work on a workpiece; and a control unit that communicates via a real-time field network capable of guaranteeing real-time communication in accordance with the Ethernet standard, and controls the work performed on the workpiece by the work unit based on information regarding the relative movement of the work unit with respect to the workpiece due to the movement of the workpiece or the work unit positioned on the robot.

[0120] (Aspect 2) The robot system according to aspect 1, wherein the real-time field network has a time synchronization function for performing time synchronization.

[0121] (Aspect 3) The robot system according to aspect 2, wherein the time synchronization function includes a distribute clock function.

[0122] (Aspect 4) The robot system according to any one of aspects 1 to 3, wherein the real-time field network has an on-the-fly processing function that reads and writes to addressed data.

[0123] (Aspect 5) The robot system according to any one of aspects 1 to 4, wherein the real-time field network is Ethernet®.

[0124] (Aspect 6) The robot system according to any one of aspects 1 to 5, wherein the control unit includes a master control unit that communicates via the real-time field network, a robot control unit that communicates via the real-time field network and acts as a slave for controlling the robot, and a work unit control unit that communicates via the real-time field network and acts as a slave for controlling the work unit, the master control unit performs control to output a trigger to the work unit control unit based on information regarding the relative movement amount of the work unit with respect to the workpiece obtained from the robot control unit, and the work unit control unit controls the work performed by the work unit on the workpiece based on the trigger obtained from the master control unit.

[0125] (Aspect 7) The robot system according to aspect 6, wherein the work unit control unit controls the work performed by the work unit on the workpiece based on the trigger obtained from the master control unit, by the rising and falling edges of a single-phase pulse, or by the rising edges of pulses of multiple phases.

[0126] (Aspect 8) The robot system according to any one of aspects 1 to 5, wherein the control unit includes: a master control unit that communicates via the real-time field network; a robot control unit that communicates via the real-time field network and acts as a slave to control the robot; a communication conversion control unit that communicates via the real-time field network and acts as a slave to convert data in the communication format of the real-time field network to data in a communication format other than the communication format of the real-time field network; and a work unit control unit that communicates via the communication conversion control unit and controls the work unit, wherein the master control unit performs control to output a trigger to the communication conversion control unit based on information regarding the relative movement amount of the work unit with respect to the work unit obtained from the robot control unit; and the work unit control unit controls the work performed by the work unit on the work unit based on the trigger obtained from the master control unit after conversion via the communication conversion control unit.

[0127] (Aspect 9) The robot system according to aspect 8, wherein the trigger includes a pulse signal based on information regarding the relative movement amount of the work unit with respect to the workpiece, and the work unit control unit controls the work performed by the work unit on the workpiece based on the pulse signal obtained from the master control unit after conversion via the communication conversion control unit.

[0128] (Aspect 10) The robot system according to any one of aspects 1 to 9, wherein the work unit includes at least one of the following: an imaging unit, a three-dimensional shape measurement unit, a distance measuring sensor, a coating unit, a pasting unit, a spraying unit, a welding unit, a sewing unit, an ultrasonic flaw detection unit, an eddy current flaw detection unit, a tapping inspection unit, a peeling laser irradiation unit, a hardening UV irradiation unit, and a laser cleaning unit.

[0129] (Aspect 11) The robot system according to any one of aspects 1 to 5, wherein the control unit includes a master control unit that communicates via the real-time field network and performs control to output a trigger based on information regarding the relative movement amount of the work unit with respect to the workpiece, and a work unit control unit that controls the work performed on the workpiece by the work unit based on the trigger, wherein the master control unit performs control to output the trigger a time period earlier corresponding to the difference between the timing at which the work unit control for the work performed on the workpiece by the work unit and the timing at which the work unit performs the work on the workpiece.

[0130] (Aspect 12) The robot system according to aspect 11, wherein the master control unit calculates a predicted amount of movement between a first predicted position, which is a position on a predetermined movement trajectory of the robot that is expected to be reached after a predetermined time has elapsed from the current position of the robot, and a second predicted position, which is a position that is expected to be reached one control cycle of the real-time field network relative to the first predicted position, as information relating to the relative movement amount of the work unit with respect to the work unit, and controls the robot to output the trigger based on the predicted amount of movement at a time corresponding to the deviation earlier than the time at which the robot is expected to reach the first predicted position on the predetermined movement trajectory.

[0131] (Aspect 13) The robot system according to aspect 12, wherein the master control unit calculates the first predicted position and the second predicted position based on the current state of the robot and a dynamic model that models the state of the robot on the predetermined movement trajectory, using one of model predictive control, extended Kalman filter, or adaptive control.

[0132] (Aspect 14) The robot system according to any one of aspects 11 to 13, wherein the work unit is a coating unit.

[0133] (Aspect 15) The robot system according to any one of aspects 12 to 14, wherein the control unit further includes a robot control unit for controlling the robot, the robot control unit is connectable to a teaching terminal that accepts operations for teaching the robot an action, the teaching terminal is capable of accepting an operation for setting a predetermined time, and the master control unit obtains the set predetermined time via the teaching terminal and the robot control unit when an operation for setting a predetermined time is performed on the teaching terminal.

[0134] (Aspect 16) A method for controlling a robot system, comprising: communicating via a real-time field network capable of guaranteeing real-time communication in accordance with the Ethernet standard; and controlling work performed on a workpiece by a work unit based on information regarding the relative movement of the work unit with respect to the workpiece, due to the movement of the work unit positioned on the robot or the work unit that performs work on the workpiece.

[0135] 10 Robot 20, 320 Work Unit 30, 330 Control Unit 41, 341 Master Control Unit 51, 351 Robot Control Unit 61 Work Unit Control Unit 71 Communication Conversion Control Unit 100, 300 Robot System 200 Work L4 Predicted movement amount N Real-time field network P0 Current position P1 First predicted position P2 Second predicted position T Movement trajectory tp Determined time t2 Time corresponding to the deviation

Claims

1. A robot system comprising: a robot; a work unit that performs work on a workpiece; and a control unit that communicates via a real-time field network capable of guaranteeing real-time communication in accordance with the Ethernet standard, and controls the work performed on the workpiece by the work unit based on information regarding the relative movement of the work unit relative to the workpiece due to the movement of the workpiece or the work unit positioned on the robot.

2. The robot system according to claim 1, wherein the real-time field network has a time synchronization function for performing time synchronization.

3. The robot system according to claim 2, wherein the time synchronization function includes a distribute clock function.

4. The robot system according to claim 1, wherein the real-time field network has an on-the-fly processing function that reads and writes to addressed data.

5. The robot system according to claim 1, wherein the real-time field network is Ethernet®.

6. The robot system according to claim 1, wherein the control unit includes a master control unit that communicates via the real-time field network, a robot control unit that communicates via the real-time field network and acts as a slave for controlling the robot, and a work unit control unit that communicates via the real-time field network and acts as a slave for controlling the work unit, the master control unit performs control by outputting a trigger to the work unit control unit based on information regarding the relative movement amount of the work unit with respect to the workpiece obtained from the robot control unit, and the work unit control unit controls the work performed by the work unit on the workpiece based on the trigger obtained from the master control unit.

7. The robot system according to claim 6, wherein the work unit control unit controls the work performed by the work unit on the workpiece based on the trigger obtained from the master control unit, by the rising and falling edges of a single-phase pulse, or by the rising edges of pulses of multiple phases.

8. The robot system according to claim 1, wherein the control unit includes: a master control unit that communicates via the real-time field network; a robot control unit that communicates via the real-time field network and acts as a slave to control the robot; a communication conversion control unit that communicates via the real-time field network and acts as a slave to convert data in the communication format of the real-time field network into data in a communication format other than the communication format of the real-time field network; and a work unit control unit that communicates via the communication conversion control unit and controls the work unit, wherein the master control unit performs control to output a trigger to the communication conversion control unit based on information regarding the relative movement amount of the work unit with respect to the workpiece obtained from the robot control unit; and the work unit control unit controls the work performed by the work unit on the workpiece based on the trigger obtained from the master control unit after conversion via the communication conversion control unit.

9. The robot system according to claim 8, wherein the trigger includes a pulse signal based on information regarding the relative movement of the work unit with respect to the workpiece, and the work unit control unit controls the work performed by the work unit on the workpiece based on the pulse signal obtained from the master control unit via the communication conversion control unit.

10. The robot system according to claim 1, wherein the work unit includes at least one of the following: an imaging unit, a three-dimensional shape measurement unit, a distance measuring sensor, a coating unit, a pasting unit, a spraying unit, a welding unit, a sewing unit, an ultrasonic flaw detection unit, an eddy current flaw detection unit, a tapping inspection unit, a peeling laser irradiation unit, a hardening UV irradiation unit, and a laser cleaning unit.

11. The robot system according to claim 1, wherein the control unit includes a master control unit that communicates via the real-time field network and performs control to output a trigger based on information regarding the relative movement amount of the work unit with respect to the workpiece, and a work unit control unit that controls the work performed on the workpiece by the work unit based on the trigger, wherein the master control unit performs control to output the trigger a time period earlier corresponding to the difference between the timing at which the work unit control for the work performed on the workpiece by the work unit is performed and the timing at which the work unit performs the work on the workpiece.

12. The robot system according to claim 11, wherein the master control unit calculates a predicted amount of movement between a first predicted position, which is a position on a predetermined movement trajectory of the robot that is expected to be reached after a predetermined time has elapsed from the current position of the robot, and a second predicted position, which is a position that is expected to be reached one control cycle of the real-time field network relative to the first predicted position, as information relating to the relative movement amount of the work unit with respect to the work unit, and controls the robot to output the trigger based on the predicted amount of movement earlier by a time corresponding to the deviation than the time at which the robot is expected to reach the first predicted position on the predetermined movement trajectory.

13. The robot system according to claim 12, wherein the master control unit calculates the first predicted position and the second predicted position based on the current state of the robot and a dynamic model that models the state of the robot on the predetermined movement trajectory, using any of model predictive control, extended Kalman filter, and adaptive control.

14. The robot system according to claim 11, wherein the work unit is a coating unit.

15. The robot system according to claim 12, wherein the control unit further includes a robot control unit for controlling the robot, the robot control unit is connectable to a teaching terminal that accepts operations for teaching the robot an action, the teaching terminal is capable of accepting an operation for setting a predetermined time, and the master control unit obtains the set predetermined time via the teaching terminal and the robot control unit when an operation for setting a predetermined time is performed on the teaching terminal.

16. A method for controlling a robot system, comprising: communicating via a real-time field network capable of guaranteeing real-time communication in accordance with the Ethernet standard; and controlling work performed on a workpiece by a work unit based on information regarding the relative movement of the work unit with respect to the workpiece, due to the movement of the work unit positioned on the robot or the work unit that performs work on the workpiece.

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