JP7508238B2 - A robot system, a control method, a robot, a workbench, a cart, a control program, a recording medium, and a method for manufacturing an article. - Google Patents

Description

The present invention relates to a robot system , a control method , a robot , a workbench, a cart, a control program, a recording medium, and a method for manufacturing an article.

In recent years, cell production methods have become widespread in the manufacturing industry to accommodate the production of a wide variety of products in small quantities. In automated cell production, robots are used to flexibly handle multiple tasks. In one form of automated assembly work using robots, robots are placed on work tables that form cells for one or more tasks, and they assemble specific units within the cell and transfer workpieces between cells in sequence to perform assembly work. In this type of production, various methods are used as measures to be taken when a robot becomes unable to work. For example, one method is to teach multiple robots the work content because the production of a cell stops and affects downstream cells. In addition, as shown in Patent Document 1, a method has been proposed in which teaching data on a workpiece, i.e., the action point, is acquired from an adjacent robot via communication, and converted into the robot coordinates of the substitute robot to substitute for the work performed by the broken robot.

Japanese Patent Application Laid-Open No. 9-44226

In the configuration of Patent Document 1, robotic work such as welding and painting is assumed, and one of the adjacent robots acquires a reference point on the workpiece as teaching data through communication, and recalculates the movement of the replacement robot to perform the robotic work. In the configuration of Patent Document 1, the "reference point" corresponds to the position of a welding spot or a painting spot located on the workpiece. Here, for example, if the original robot and the replacement robot are different models, and if no constraints are imposed, the movement of the original robot and the movement of the replacement robot when accessing the same action point will be completely different. Furthermore, even if the original robot and the replacement robot are the same model, there are individual differences between the two, and it is not necessarily the case that they can operate to access the same action point with exactly the same movement.

Therefore, in tasks where precision is important, such as the insertion of high-precision parts, it may be impossible to substitute by teaching only the final point of action, as in Patent Document 1. In such cases, trajectory teaching through complex teaching work will ultimately be required for each replacement robot. In addition, depending on constraints on the robot trajectory, it is possible that tasks may not actually be performed by replacement robots with model differences or individual differences due to factors such as the range of motion.

In order to deal with problems such as robot failure, if multiple robots are prepared as backup machines, it may be possible to quickly replace the failed machine or rearrange the line. In that case, if the robots are mobile (self-propelled), it may be possible to more quickly replace the failed machine and rearrange the line.

However, even if a backup machine is prepared, when differences in robot models and individual differences are taken into consideration, the above conventional configuration requires time-consuming teaching work on the backup machine. Generally, robot teaching work is performed using a teaching playback method, so production must be stopped and teaching work must be done at each work station for each backup robot. If multiple cells are to be accommodated for high-mix, low-volume production taking into account line reconfiguration, and multiple robots are prepared for backup, teaching work will be required for the number of robots x type of work, which can result in an enormous amount of work.

The objective of the present invention is to enable multiple work robots to be quickly and easily introduced into a production line.

One aspect of the present invention is a robot system including a first robot and a second robot, the robot system further comprising a control unit for controlling operation of the second robot, the control unit acquiring first trajectory information regarding a trajectory corresponding to a task to be performed by the second robot, acquired using the first robot, and difference information of the second robot relative to the first robot, acquiring second trajectory information for controlling the second robot based on the first trajectory information and the difference information, comparing a first position of the first robot based on the first trajectory information with a second position of the second robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the second robot to perform the task based on the corrected second trajectory information , the predetermined condition including an allowable range of a difference between the first position and the second position .

With the above configuration, for example, a work robot deployed for backup purposes can be quickly and easily introduced into the production line.

FIG. 1 is an explanatory diagram showing a configuration of a robot system according to an embodiment of the present invention. 1A and 1B are explanatory diagrams showing an example of recombination of a working robot according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a detailed configuration of a working robot used in the robot system according to the embodiment of the present invention. FIG. 2 is an explanatory diagram showing a detailed configuration of a work table used in the robot system according to the embodiment of the present invention. FIG. 11 is a flowchart showing a flow of control executed by a working robot in which a malfunction has occurred in the robot system according to the embodiment of the present invention. FIG. 2 is a flowchart showing a control flow executed by a substituting working robot in the robot system according to the embodiment of the present invention. FIG. 2 is a flowchart showing a control flow executed by a substituting working robot in the robot system according to the embodiment of the present invention. FIG. 2 is a flowchart showing a flow of control executed by a system control device in a robot system according to an embodiment of the present invention. FIG. 11 is a flowchart illustrating an example of a correction calculation that can be performed in the robot system according to the embodiment of the present invention. FIG. 1 is an explanatory diagram showing an example of the configuration of a robot system according to a different embodiment of the present invention.

The following describes the embodiment of the present invention with reference to the attached drawings. Note that the configuration shown below is merely an example, and those skilled in the art can make appropriate changes to the detailed configuration, for example, without departing from the spirit of the present invention. The numerical values used in this embodiment are merely illustrative reference values. Note that, hereinafter, reference numbers with a suffix "-n" may be used, for example, "work tables 2-1, 2-2". In the example of "work tables 2-1, 2-2", the entire components and the common conceptual configuration may be referred to by a reference number without the suffix "-n", such as "work table 2".

<Embodiment 1>
FIG. 1 shows the overall configuration of a robot system that employs the present invention. This robot system can perform assembly or processing work on a workpiece and manufacture an article from the workpiece. This robot system includes four working robots 1-1 to 1-4 configured as articulated robots of the same configuration. This robot system also includes four work tables 2-1 to 2-4 on which part supply tools 3-1 to 3-4 and work holders 5-1 to 5-4 are arranged. Furthermore, the robot system of this embodiment includes three replacement robots 1-5 to 1-7 of the same configuration as the working robots 1-1 to 1-4. This robot system also includes a system control device 7 that is equipped with wireless and wired communication devices and manages the operation of the robots and the work tables, and a master robot 6 for teaching work that is of the same configuration as the working robots.

For example, in the robot system of FIG. 1, the worktables 2-1 to 2-3 assemble multiple parts onto the subunits 4-1 to 4-3, which are the workpieces, while the worktable 2-4 joins the subunits 4-1 to 4-3 to complete the work. The worktables 2-1 to 2-4 are equipped with corresponding work robots 1-1 to 1-4.

The working robots 1-1 to 1-7 are preferably designed to have the same shape and performance, and are able to replace each other's work. These working robots are connected to the system control device 7 via wireless communication. For example, if working robot 1-4 breaks down, one of the working robots 1-5 to 1-7 will move to the work position on the workbench 2-4, either manually or in response to a command from the system control device 7, and take over the work of working robot 1-4. In addition, a flexible cell configuration can be achieved by increasing or decreasing the number of workbenches, as shown in Figure 2.

In Fig. 2(a), work tables with buffer functions and a robot 1-5 for transporting subunits are placed between work tables 2-1 to 2-3 and work table 2-4, making the configuration flexible in dealing with fluctuations in work time. In addition, the configuration in Fig. 2(b) aims to improve production capacity by increasing the number of work tables 2-1 and 2-4, which take a long time to work on.

The work content to be performed on each of the work tables 2 is taught by the master robot 6 using a teaching/playback method. Then, trajectory control data (teaching data) for generating the robot trajectory required for the work content to be performed on the work table is expressed, for example, in the form of time-series data of the joint angles of the master robot. This trajectory control data for each work table is stored in the corresponding work table. For example, this trajectory control data is stored in a memory unit (e.g., ROM, EEPROM) of a robot controller built into the ECU 26 (Figure 4). The robot controller built into the ECU 26 controls the robot operation of the working robot 1 placed on that work table 2.

As for the master robot 6, a mechanical model of the robot is assumed to have been obtained in advance by methods such as experiments and actual measurements. The mechanical model here refers to data on link parameters, the length of the end effector, the weight of each part of the robot such as the links and end effector, the stiffness values of the links and joints, and the load applied to the tip of the robot arm. Additionally, the link parameters refer to data on the link length, the link twist angle, the distance between links, and the angle between links.

For each working robot, a mechanical model including the above link parameters is obtained in advance by methods such as experiments and actual measurements. The differences between the master robot 6 and each of these link parameters or the entire mechanical model are stored in the memory element 14 (Figure 3) of the working robot 1 as individual difference information for that robot.

Figure 3 is a schematic diagram of the working robot 1. The working robot 1 is mounted on an autonomously moving cart 18, which is a self-propelled cart that can move autonomously in the XY directions together with a coupling mechanism 8. With this configuration, the working robot 1 functions as a self-propelled robot that can move autonomously. The coupling mechanism 8 is included in the connection part with the work table 2, and is a mechanism for mechanically positioning the relative positions of the work table 2 and the working robot 1 when connected to the work table 2. In this embodiment, the coupling mechanism 8 is provided with a cone-shaped protrusion 9 so that the support position of the working robot 1 in the XYZ directions can be freely determined, for example.

The autonomous mobile carriage 18 carrying the working robot 1 is moved, and mechanical alignment is performed by fitting the protrusion 9 into the fitting hole on the workbench 2. This allows the working robot 1 to be positioned in a predetermined relative positional relationship with respect to the workbench 2, and then connected and fixed.

The above configuration makes it possible to reproduce the relative positional relationship between each work platform and the robot even when the working robot 1 is replaced. In FIG. 3, control signals sent and received between the robot controller (robot control unit) on the work platform 2 side are transmitted via the electrical connector 10. Also, the contents of the memory element 14 of the working robot 1, particularly the individual difference information, are sent via the electrical connector 10 to the robot controller of the ECU 26 of the work platform 2. Note that the communication path between the working robot 1 and the work platform 2 does not necessarily have to be a wired connection via an electrical connector as described above, and may be a wireless connection.

The memory element 14 of the working robot 1 stores the differences with the master robot described above, i.e., individual difference information. This individual difference information can be used to correct the teaching points (trajectory control information) stored in the memory unit of the robot controller. The memory element 14 of the working robot 1 can be a ROM, an EEPROM, a flash memory, etc.

The individual difference information of the working robot 1 itself does not necessarily have to be stored in the memory element 14 of the working robot 1. For example, the working robot 1 may be given identification information capable of identifying the individual difference information of the robot, and the robot controller of the ECU 26 of the workbench 2 may acquire the individual difference information identified by the identification information from another location. A method of giving identification information capable of identifying the individual difference information of the working robot 1 may be, for example, a configuration in which a tag or sticker recording the individual difference information as a printed code (character string information, barcode, etc.) is attached to the working robot 1. The individual difference information of such a tag or sticker can be read by a camera arranged on the workbench 2. In addition, in a configuration using the above-mentioned identification information, the individual difference information of the working robot 1 may be stored in any memory unit. For example, the individual difference information of the working robot 1 may be stored in any memory unit accessible from the ECU 26 of the workbench 2, such as a memory unit on the robot controller side that may use the robot, the system control device 7, or any other memory unit.

The driving power of the working robot 1 and the power required for the memory element 14 are supplied from the robot controller of the worktable 2. However, if there is sufficient battery capacity in the autonomous mobile carriage 18 described below, the driving power of the robot 1 and the power required for the memory element 14 may be supplied from the carriage.

In this embodiment, the robot controller that controls the working robot 1 connected to a specific work platform is arranged as part of the ECU 26 of that work platform 2. In this way, a configuration in which a robot controller that holds trajectory control information corresponding to the work content at a specific work platform is arranged at the work platform is a very reasonable configuration. However, the present invention does not prevent the robot controller that controls the working robot 1 connected to a specific work platform from being arranged in a location separate from the ECU 26 of the work platform 2, depending on circumstances related to the system configuration and design. In other words, the location and arrangement of the robot controller that controls the working robot 1 connected to a specific work platform are arbitrary.

In addition, the storage location of the trajectory control information generated using the master (reference) robot does not necessarily have to be the memory element (first memory unit) of the robot controller arranged as a part of the ECU 26 of the work platform 2. For example, this trajectory control information may be stored in a memory unit, such as the ROM, EEPROM, or RAM of the system control device 7, in association with identification information that can identify the work platform on which the work is performed. Furthermore, it is also a very reasonable configuration for each working robot 1 to have a memory element 14 (second memory unit) that stores individual difference information with its own reference robot (master robot). However, the storage location of this individual difference information does not necessarily have to be the robot itself. As long as there is a means for identifying the individual difference information specific to a certain self-propelled working robot 1 when it is attached to a certain work platform 2, the storage location of the individual difference information does not necessarily have to be the second memory unit described above. One example of a means for identifying the individual difference information specific to such a working robot 1 is, for example, the configuration using the barcode described above.

The autonomous mobile cart 18 in FIG. 3 includes an ECU 11, a sensor 13, a communication antenna 15, a battery 17, and a motor 22. The autonomous mobile cart is wirelessly connected to the system control device 7 via the wireless IF 16 and the communication antenna 15. It automatically moves to a work position on a specified work platform in response to a dispatch command from the system control device 7. At that time, the sensor 13 reads the route, and the CPU 12 included in the ECU 11 controls the motor driver 21 to drive the motor 22, thereby moving the cart. A control program for carrying out these controls can be stored in the ROM 19. In addition, a control program describing the control procedures according to the present invention can be stored in a portable optical disk or flash memory, and can be installed in the robot system and updated via these computer-readable recording media.

In addition, the autonomous mobile cart 18 is equipped with a RAM 20, which is used as a work area for the CPU 12 and also for temporarily storing detection information obtained from the sensor 13, calculation results of the CPU 12, etc.

Next, the worktable 2 will be described. FIG. 4 shows the configuration of the worktable 2 in detail. In FIG. 4, it is assumed that the parts are supplied by the parts supply tool 3, and the robot assembles the workpiece 4, which is positioned and held by the workpiece holder 5, using tools 28 and the like. The robot trajectory information taught by the master robot is stored in the ECU 26. The robot controller for driving the working robot 1 can also be built into the ECU 26. This robot controller can control the operation of the working robot 1 via the robot interfaces 23-1, 23-2, or 23-3. One of the external IFs is a power cable 27, and power is supplied to the ECU 26 via this power cable 27. Another of the external IFs can be a wired or wireless communication network for connection to the system control device 7. The system control device 7 manages the operation of the robot and the worktable, and is composed of devices such as a PLC or sequencer.

In FIG. 4, 23 is a robot interface consisting of a mechanical coupling 24 and an electrical connector 25. The mechanical coupling 24 has a conical hole and a locking mechanism, and by fitting with the protrusion 9 on the robot side and fixing it with the locking mechanism, the relative positions of the robot 1 and the work table 2 can be reproduced with good reproducibility. The master robot 6 and each of the working robots 1-1 to 1-7 used during teaching work have the same mechanical couplings positioned relative to the robot coordinates, and by fitting them with the mechanical coupling on the work table side, position reproducibility is guaranteed when they are replaced. Any number of mechanical couplings 24-1, 24-2, 24-3... can be arranged on the work table 2 as mechanical couplings 24.

The electrical connector 25 can be equipped with drive terminals for driving the motors of each joint axis of the robot, sensor terminals for receiving joint angle signals from the robot, and communication terminals for receiving information from a memory element installed on the robot side. These terminals are used to connect when the robot is placed, receive information on individual differences in the robot, correct the robot's trajectory control information recorded in the ECU 26, and use the resulting trajectory data to control the operation of the working robot 1.

Note that multiple robot interfaces 23 can be installed as necessary, and may be installed, for example, on all vertical surfaces of a workbench. In this case, as long as the positional relationship with the workbench is fixed, it does not necessarily have to be placed on the workbench. For example, the bot interface 23 may be placed on the floor surface on which the robot is installed.

Next, we will explain the sequence when replacing one of the working robots 1 due to a malfunction or other reason. Figures 5 to 8 show the control procedures carried out by the working robot 1-1, working robot 1-5, workbench 2-1, and system control device 7 in the robot production system of Figure 1 when, for example, robot 1-1 malfunctions. The control procedures shown in the figures can be written as a control program for a control device such as the CPU of these devices.

In the following, step numbers in the flowcharts of Figures 5 to 8 will be mainly referred to in parentheses. Also, steps marked with an alphabet in Figures 5 to 8 indicate interactions with steps marked with the same alphabet in other figures, mainly communication operations. In such cases, the same alphabet may be used to refer to signals being sent and received in that communication operation.

In the event that any of the work robots fails, in FIG. 7, the workbench 2-1 with the built-in robot controller can detect the failure (S1). If possible, this robot controller performs failure processing (S2), such as retracting the arm, and sends a failure signal A to the system control device 7 (S3). This failure signal A contains information on whether the robot can be relocated and whether it can be replaced (alternative). After sending the failure signal A, the workbench 2-1 waits to receive a placement command (S4).

In FIG. 8, when the system control device 7 receives a failure signal A (S5), it reads from the received signal whether relocation is possible (S6), and if so, issues an evacuation command B to the broken-down work robot 1-1 (S7). If relocation is not possible, it outputs a warning, for example, to prompt an operator to perform manual repair or replacement work (S8).

In FIG. 5, when the working robot 1-1 receives the evacuation command B (S9), it determines whether it can move on its own (S10). Note that the robot's drive system and the drive system for autonomous driving are separate systems, so it is considered rare for them to fail at the same time. If the working robot 1-1 can move on its own, it will evacuate to the evacuation station (S11) and send an evacuation completion signal C to the system control device 7 (S12). If the working robot 1-1 is not able to move on its own, it will issue a warning that it needs to be replaced (S13). In this case, it is possible to resume production by manually removing the broken robot 1-1 and performing a reset operation, for example, from the operation panel (not shown) of the system control device 7, which will output the evacuation completion signal C (S14).

In FIG. 8, when the system controller 7 receives the evacuation completion signal C (S15), it sends a placement command signal D to the waiting work robot 1-5 (S16), and the robot enters a standby state (S17) until it is possible to relocate the robot and resume production. The placement command can include information about the work table 2-1 to which the robot is to be placed and the table's connection position. If the evacuation completion signal C is not returned for a certain period of time, the system controller 7 outputs a warning to notify the worker, manager, etc. that a problem has occurred (S8). This type of warning can be issued, for example, by voice or display output, or by sending an email or message text.

As shown in FIG. 6, the backup work robots 1-5 to 1-7 normally wait to receive a placement command (S18). For example, when a placement command signal D is received from the system control device 7, the work robot 1-5 moves to the work platform 2-1 where it is to be placed (S19) and performs the joining task (S20).

This connection operation is performed by the above-mentioned alignment operation using the protrusion 9 of the working robot 1-5 and the mechanical coupling 24 of the worktable 2-1. At the same time, an electrical connection is established between the working robot 1-5 and the worktable 2-1 via the electrical connector 25 (FIG. 6: S20, S21). Meanwhile, as shown in FIG. 7, when the worktable 2-1 receives a placement command signal D while waiting for a placement command (S4), it performs connection preparation (S21a). In this connection preparation (S21a), the worktable 2-1 performs processing such as releasing the mechanical lock mechanism using the mechanical coupling 24 on the robot interface 23 and cutting off the power supply to prevent malfunction of the electrical connector. After this connection preparation, a connection operation (S20) is performed, and the working robot 1-5 and the worktable 2-1 are mechanically and electrically connected.

After that, a connection check (S22) is performed, and when the connection between the working robot 1-5 and the work platform 2-1 is complete, the newly placed working robot 1-5 transmits correction data E to the robot controller in the ECU 26 of the work platform 2-1 (Fig. 6: S23). The work platform 2-1 receives this correction data E (Fig. 7: S24), and the robot controller built into the ECU 26 performs a correction calculation for the trajectory information using the correction data E and the trajectory control information stored in the robot controller (S25). Details of this correction calculation will be described later. When the correction calculation is completed, the work platform notifies the system control device 7 of a correction completion signal F (S26) and enters a state of waiting for a restart command (S27).

In FIG. 8, when the system control device 7 receives the correction completion signal F, it determines that preparation is complete and sends a production resume signal G to the workbench 2-1 and each associated workbench (S28). The associated workbenches here are the workbenches located upstream and downstream of the workbench 2-1 that have temporarily stopped work. For example, the work buffers and work positions of these workbenches are full. When the workbench 2-1 and each associated workbench receive the production resume signal G (FIG. 7: S27), they resume normal production work (FIG. 7: S29).

Here, we will explain the correction calculation (S25 in Figure 7). Figure 9 shows an example of the flow of this correction calculation S25, and shows a method for correcting one joint angle Θ6 contained in some teaching data. In reality, there are multiple taught joint angles, so the calculation in Figure 9 is repeated for each teaching point.

In S25-1 of FIG. 9, the hand coordinate T6 is calculated from the joint angle teaching data Θ6 of the master robot and the mechanical model MP6 including the link parameters. This step may be calculated in advance when teaching the master robot 6. In S25-2, the tentative hand coordinate T1-5 is calculated from the joint angle teaching data Θ6 of the master robot and the mechanical model MP1-5 including the link parameters of the alternative robot 1-5.

In S25-3, the difference δT between the taught hand coordinate T6 and the tentative hand coordinate T1-5 is found. In S25-4, it is determined whether the found δT is within the allowable range. If δT is within the allowable range and OK, correction ends. If it ends on the first try, the correction amount becomes 0 and the corrected joint angle Θ1-5=Θ6. If it is NG, proceed to S25-7.

In S25-5, the Jacobian matrix J near the joint angle Θ6 is found from the mechanical model MP1-5 of the substitute robot. This Jacobian matrix J is a matrix that expresses the relationship between the joint speed and the hand speed, and if the hand speed matrix is δT and the joint speed matrix is δΘ, then the relationship δT = J δΘ holds. In S25-6, the inverse matrix J-1 of the Jacobian matrix J is found.

In S25-7, a provisional correction amount δΘ is calculated from δT calculated in S25-5 and J-1 calculated in S25-6. In S25-8, a provisional corrected joint angle Θ1-5 is calculated from δΘ calculated in S25-7 and the current joint angle Θ1-5 (the initial value is Θ6). In S25-9, a new hand coordinate T1-5 is calculated from the mechanical model MP1-5 and Θ1-5, and the process returns to S25-3. Then, again in S25-3, the deviation δT is calculated, and in S25-4, it is calculated whether the accuracy is within the allowable range. If the deviation δT is within the allowable range, the convergence calculation is terminated and the joint angle Θ1-5 at that point is adopted as the corrected teaching data. On the other hand, if δT has not reached the allowable value, the process proceeds to S25-7, S25-8, and S25-9 to find a new T1-5, and the process of evaluating the accuracy in S25-4 is repeated until δT falls within the allowable range. The value Θ1-5 of the joint angle when it finally falls within the allowable range becomes the teaching value after correction using the individual difference information of the alternative robot 1-5. Note that a calculation may be performed to determine the number of turns in the convergence calculation in combination with the allowable range to find the correction amount δΘ and the corrected teaching value Θ1-5 that minimizes δT. The calculation shown in FIG. 9 is performed for each joint angle, and the correction of all teaching points is performed for the number of teaching points, and the correction calculation (S25) is completed by storing the correction in the robot controller of the ECU 26 of the workbench 2-1.

According to this embodiment, there is no need to teach the general-purpose robot through teaching playback for each work station. For example, let us assume that there are n types of work and N number of general-purpose robots, and the general-purpose robots can perform all of the work. In the conventional form, teaching work was required (nxN) times, but since only n teaching works are required, the amount of work can be significantly reduced. In this embodiment, work is required to obtain individual difference information for each robot, such as a mechanical model (hereinafter sometimes referred to as calibration work). However, with regard to teaching the work to be performed by the work robot, it is necessary to carry out the work only once for each robot, regardless of the content of the work, and re-teaching work is not required when reusing the robot on a different line.

<Embodiment 2>
In the above-mentioned first embodiment, it was considered to create teaching data as trajectory control information using a real master robot that exists physically. This master robot is like a meter prototype for a working robot. Preferably, it is used only to teach trajectory control information (teaching point data, teaching information) to be stored in the memory unit of the robot controller of the ECU 26 of the workbench, and is stored in a controlled environment such as a constant temperature and humidity environment for other periods. It is considered that the above-mentioned considerations are necessary when using a physical master robot. However, as described below, by using a virtual master robot VR that operates in a virtual environment by computer simulation to teach the master's trajectory control information, it is possible that the handling of the master robot and the trajectory control information will become easier.

Figure 10 shows the configuration of the robot system of this embodiment in a format equivalent to Figure 1 of the above embodiment. In Figure 10, 29 corresponds to a computer (or the virtual environment itself) that realizes a virtual environment configured by the virtual master robot VR, the work table, and physical data M1 to M4 of jigs, etc. The virtual master robot VR is represented by mechanical model data VM including link parameters, etc. The remaining hardware configuration of the work table and working robot is the same as that of the embodiment.

The virtual master robot VR and the worktable to be taught, among worktables 2-1, 2-2, 2-3, or 2-4, are displayed as a three-dimensional animation on the computer 29, and during teaching, the arm and jig can be freely moved according to user input. The user instructs the computer to record the current joint coordinates at a specific point as teaching data. After all teaching points have been input, the computer simulator performs an interference check based on the teaching points set by the user, and adds interpolation points to generate a trajectory. Each of the work trajectories generated in this way is downloaded to the memory unit of the corresponding worktable 2 (for example, the memory unit of a robot controller built into the ECU 26) and recorded.

In addition, for each of the work robots 1-1 to 1-7, mechanical model data such as link parameters similar to those of the virtual master robot VR is obtained in advance, and is recorded in the memory element 14 of each of the robots 1-1 to 1-7, as in embodiment 1.

Even in the above configuration, when the working robot 1 is connected to the work table 2, difference data (individual difference information) between the working robot 1 and the virtual master robot VR, i.e., mechanical model data such as link parameters, is loaded onto the work table 2. Then, for example, a robot controller built into the ECU 26 can correct the trajectory taught by the virtual master robot VR using the difference data (individual difference information) with the virtual master robot VR and the trajectory control information, as in the first embodiment.

According to this embodiment, the master robot is a virtual robot, which has the advantage that the costs of manufacturing and maintaining the robot (e.g. storing it in a constant temperature and humidity environment) are not required. In addition, it is easy to register multiple types of master robots/working robots, and it is possible to use different master robots/working robots depending on the workbench, which may significantly reduce the costs of configuring and operating a robot system.

In the above-mentioned first and second embodiments, the master (reference) robot and the working robot are described as being of the same model and the same configuration. However, the configuration and control procedure of the present invention do not necessarily require that these robots be of the same model and the same configuration. In the above-mentioned configuration, trajectory control information such as teaching point data is corrected and generated using individual difference information between the master (reference) robot and the working robot. With such a configuration, it is possible to implement even when a master (reference) robot and a working robot with different configurations such as joint configurations and link lengths and models are used. In addition, in the above-mentioned various embodiments, the trajectory control information is stored in a memory unit possessed by the work table 2, and the individual difference information is stored in a memory unit of each working robot 1. However, by adding identification information to each piece of information, the trajectory control information and the individual difference information may be stored in the memory unit of the working robot 1, or the trajectory control information and the individual difference information may be stored in the memory unit of the work table 2. In other words, the locations of the first and second storage units that store the orbit control information and the individual difference information do not limit the present invention and may be different from the above example.

The present invention can also be realized by supplying a program that realizes one or more of the functions of the above-mentioned embodiments to a system or device via a network or storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that realizes one or more functions.

The configurations and controls of the various embodiments described above may also be applicable to systems that are made up of devices that do not have names such as "robot devices." For example, the configurations and controls of the embodiments described above may be applied to various machines that can automatically perform movements such as stretching, bending, moving up and down, moving left and right, or turning, or combinations of these movements, based on information stored in the memory device of the control device.

1...working robot, 2...workbench, 3...parts supplying tool, 4...work, 5...workpiece holder, 6...master robot, 7...system control device, 8...coupling mechanism, 11, 26...ECU, 13...sensor, 15...communication antenna, 17...battery, 22...motor, 23...robot interface, 27...power cable, 28...tool, 29...computer.

Claims (33)

A robot system including a first robot and a second robot,
A control unit for controlling an operation of the second robot,
The control unit:
First trajectory information regarding a trajectory corresponding to a task to be performed by the second robot, the first trajectory information being acquired using the first robot;
Acquire difference information of the second robot with respect to the first robot;
acquiring second trajectory information for controlling the second robot based on the first trajectory information and the difference information;
comparing a first position of the first robot based on the first trajectory information with a second position of the second robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the second robot to perform the work based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A robot system comprising: 2. The robot system according to claim 1,
The first robot is a master robot having a configuration corresponding to the second robot,
Using the master robot, a task to be performed by the second robot is set;
The first trajectory information is time series data of angles of joints of the master robot.
A robot system comprising: 2. The robot system according to claim 1,
The first robot is a virtual master robot that operates in a virtual environment by computer simulation and has a form corresponding to the second robot,
Using the virtual master robot, a task to be performed by the second robot is set;
The first trajectory information is time series data of angles of joints of the virtual master robot.
A robot system comprising: 4. The robot system according to claim 1,
the difference information is individual difference information of the second robot with respect to the first robot,
A robot system comprising: The robot system according to claim 4,
the individual difference information is information regarding a difference in a mechanical mechanism between the second robot and the first robot;
A robot system comprising: 6. The robot system according to claim 4,
The individual difference information is at least one of a difference in link parameters, a difference in length of an end effector, a difference in weight of a link or an end effector, a difference in stiffness value of a link or a joint, and a difference in weight applied to a tip between the second robot and the first robot.
A robot system comprising: 7. The robot system according to claim 6,
The link parameter is at least one of a link length, a link twist angle, a link distance, and a link angle.
A robot system comprising: In the robot system according to any one of claims 1 to 7,
The first position is a position at a predetermined portion of the first robot, and the second position is a position at a predetermined portion of the second robot.R,
A robot system characterized by: 9. The robot system according to claim 1 ,
The predetermined condition includes the allowable range and the number of times of switching of the convergence calculation when the second position is obtained.
A robot system comprising: The robot system according to any one of claims 1 to 9,
It is further equipped with a workbench and a cart,
The second robot is disposed on the carriage and performs work on the work table.
A robot system comprising: The robot system according to claim 10,
The control unit:
When an abnormality occurs in the second robot and the second robot in which the abnormality occurs cannot be moved from the worktable, a notification is issued to prompt a user to manually repair or replace the second robot in which the abnormality occurs.
A robot system comprising: The robot system according to claim 11,
The control unit executes the notification using at least one of a voice, a display, an email, and a message text.
A robot system comprising: The robot system according to any one of claims 10 to 12,
The first trajectory information corresponds to a task performed by the second robot on the worktable.
A robot system comprising: The robot system according to any one of claims 10 to 13,
The work table and the cart are positioned relative to each other by a coupling mechanism.
A robot system comprising: 15. The robot system according to claim 10,
The work table and the cart are electrically connected via a connector.
A robot system comprising: 16. The robot system according to claim 10,
The second robot can move by itself using the carriage, and the second robot is moved and placed on the work table.
A robot system comprising: 17. The robot system according to claim 10,
a first storage unit in which the first trajectory information is stored is disposed on the work table;
a second storage unit in which the difference information is stored is disposed on the second robot or the cart;
A robot system comprising: 18. The robot system according to claim 10,
The control unit is disposed on the workbench, the second robot, or the cart.
A robot system comprising: 19. The robot system according to claim 10,
When an abnormality occurs in the second robot, the control unit places a second robot different from the second robot on the work table.
A robot system comprising: 20. The robot system according to claim 1,
Identification information capable of identifying the difference information corresponding to the second robot is given to the second robot, and the control unit acquires the difference information via the identification information.
A robot system comprising: 21. The robot system according to claim 20,
The identification information is a tag or sticker on which a code is recorded.
A robot system comprising: 22. The robotic system according to claim 21,
The code is character string information or a barcode.
A robot system comprising: 23. The robot system according to claim 1,
The control unit is
When the comparison result satisfies the predetermined condition, the operation of the second robot is controlled so as to perform the task without correcting the acquired second trajectory information.
A robot system comprising: A method for manufacturing an article, comprising the steps of: manufacturing an article using a robot system according to any one of claims 1 to 23; A method for controlling a robot system including a first robot and a second robot, comprising:
The robot system includes a control unit that controls an operation of the second robot,
The control unit:
First trajectory information regarding a trajectory corresponding to a task to be performed by the second robot, the first trajectory information being acquired using the first robot;
Acquire difference information of the second robot with respect to the first robot;
acquiring second trajectory information for controlling the second robot based on the first trajectory information and the difference information;
comparing a first position of the first robot based on the first trajectory information with a second position of the second robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the second robot to perform the work based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A control method comprising: A robot,
First trajectory information regarding a trajectory corresponding to a task to be performed by the robot, the trajectory information being acquired using a reference robot;
and acquiring differential information of the robot with respect to the reference robot;
acquiring second trajectory information for controlling the robot based on the first trajectory information and the difference information;
comparing a first position of the reference robot based on the first trajectory information with a second position of the robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the robot to perform the task based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A robot characterized by: A method for controlling a robot, comprising:
First trajectory information regarding a trajectory corresponding to a task to be performed by the robot, the trajectory information being acquired using a reference robot;
and acquiring differential information of the robot with respect to the reference robot;
acquiring second trajectory information for controlling the robot based on the first trajectory information and the difference information;
comparing a first position of the reference robot based on the first trajectory information with a second position of the robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the robot to perform the task based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A control method comprising: A workbench on which a robot performs work,
First trajectory information regarding a trajectory corresponding to a task to be performed by the robot, the trajectory information being acquired using a reference robot;
and acquiring differential information of the robot with respect to the reference robot;
acquiring second trajectory information for controlling the robot based on the first trajectory information and the difference information;
comparing a first position of the reference robot based on the first trajectory information with a second position of the robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the robot to perform the task based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A workbench characterized by: A method for controlling a worktable on which a robot performs work, comprising the steps of:
First trajectory information regarding a trajectory corresponding to a task to be performed by the robot, the trajectory information being acquired using a reference robot;
and acquiring differential information of the robot with respect to the reference robot;
acquiring second trajectory information for controlling the robot based on the first trajectory information and the difference information;
comparing a first position of the reference robot based on the first trajectory information with a second position of the robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the robot to perform the task based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A control method comprising: A cart on which a robot is disposed,
First trajectory information regarding a trajectory corresponding to a task to be performed by the robot, the trajectory information being acquired using a reference robot;
and acquiring differential information of the robot with respect to the reference robot;
acquiring second trajectory information for controlling the robot based on the first trajectory information and the difference information;
comparing a first position of the reference robot based on the first trajectory information with a second position of the robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the robot to perform the task based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A trolley characterized by: A method for controlling a cart on which a robot performs work, comprising the steps of:
First trajectory information regarding a trajectory corresponding to a task to be performed by the robot, the trajectory information being acquired using a reference robot;
and acquiring differential information of the robot with respect to the reference robot;
acquiring second trajectory information for controlling the robot based on the first trajectory information and the difference information;
comparing a first position of the reference robot based on the first trajectory information with a second position of the robot based on the second trajectory information corresponding to the first position, and if a result of the comparison does not satisfy a predetermined condition, correcting the second trajectory information based on the result of the comparison, and controlling the robot to perform the task based on the corrected second trajectory information;
the predetermined condition includes an allowable range of a difference between the first position and the second position.
A control method comprising: A control program for causing a computer to execute the control method according to any one of claims 25, 27, 29, and 31. A computer-readable recording medium storing the control program according to claim 32.

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