WO2022162959A1

WO2022162959A1 - Control system, robot controller, and control method

Info

Publication number: WO2022162959A1
Application number: PCT/JP2021/009582
Authority: WO
Inventors: 征彦仲野; 哲司若年; 誠啓里村; 知行島村
Original assignee: オムロン株式会社
Priority date: 2021-01-27
Filing date: 2021-03-10
Publication date: 2022-08-04
Also published as: JP2022114753A

Abstract

This control system includes: a control device for controlling a control target; a robot controller for controlling a robot; and a network that periodically updates data between the control device and the robot controller. The control device includes a means that periodically transmits correction amounts for a robot trajectory. The robot controller includes a means that calculates command values for each control period, following orders received from the control device, and a means that calculates post-correction command values for each control period on the basis of the aforementioned command values and the correction amounts periodically received from the control device.

Description

Control system, robot controller and control method

The present invention relates to a control system, a robot controller and a control method.

FA (Factory Automation) technology using control devices such as PLCs (Programmable Controllers) is widely used in various production sites. With recent advances in ICT (Information and Communication Technology), controllers can now control robots, machine tools, and the like in addition to conventional sequence control.

For example, Japanese Patent Laying-Open No. 2019-036043 (Patent Document 1) discloses a configuration in which a single control device realizes control calculations according to a plurality of types of programs with different execution formats.

JP 2019-036043 A

For example, assuming a configuration in which a robot performs some processing on a workpiece placed on the XY stage, it is preferable to control the robot in accordance with the movement of the XY stage. One object of the present invention is to provide a technique for more accurately correcting the trajectory of a robot.

A control system according to one aspect of the present invention includes a control device for controlling a controlled object, a robot controller for controlling a robot, and a network for periodically updating data between the control device and the robot controller. include. The controller includes means for periodically transmitting corrections to the trajectory of the robot. The robot controller calculates a command value for each control cycle in accordance with a command received from the control device, and calculates a corrected command value for each control cycle based on the command value and a correction amount periodically received from the control device. and means for calculating

According to this configuration, the robot controller calculates the original command value for each control cycle according to the command received from the control device, and corrects the command value calculated for each control cycle by the correction received from the control device. A command value after correction can be calculated by reflecting the amount. As a result, when the trajectory of the robot is to be arbitrarily corrected, the calculation result of the correction amount in the control device can be reliably reflected without deviating from the control cycle. As a result, even if the trajectory of the robot is arbitrarily corrected, more accurate control can be performed.

The control device may further include means for periodically executing the first user program for calculating the correction amount according to arbitrarily created instructions. According to this configuration, the controller can arbitrarily calculate an arbitrary correction amount to be reflected in the robot.

The first user program may include instructions for periodically transmitting correction amounts for the trajectory of the robot. According to this configuration, the user can easily correct the robot simply by including a predetermined instruction in the first user program.

The command for periodically transmitting the correction amount for the trajectory of the robot may be written in the first user program in the form of a function. According to this configuration, it is possible to easily describe a command for implementing the process of periodically transmitting the correction amount for the trajectory of the robot.

The control device may further include means for sequentially transmitting commands to the robot controller by sequentially executing the second user program. According to this configuration, by including in the second user program a command that defines the original trajectory of the robot, the robot can be operated along the intended trajectory.

The execution cycle of the second user program may be set longer than the execution cycle of the first user program. According to this configuration, the first user program for calculating the correction amount can be executed in a shorter cycle.

The robot controller may be configured to enable or disable calculation of the corrected command value according to specific instructions received from the controller. According to this configuration, it can be used so as to enable the correction to the trajectory of the robot only during an arbitrary period.

The robot controller may further include means for periodically transmitting the state values of the robot. According to this configuration, the control device can acquire the state value of the robot, so that the acquired state value of the robot can be reflected in the calculation of the correction amount.

According to another aspect of the present invention, a robot controller for controlling a robot is provided. The robot controller includes an interface for connecting to a control device for controlling a controlled object via a network. The network is configured such that data is periodically updated between the control device and the robot controller. The robot controller includes means for receiving a correction amount for the trajectory of the robot periodically transmitted from the control device, means for calculating a command value for each control cycle according to a command received from the control device, and receiving the command value from the control device. means for calculating a corrected command value for each control cycle based on the correction amount received periodically.

According to still another aspect of the present invention, a control device for controlling a controlled object, a robot controller for controlling a robot, and a network for periodically updating data between the control device and the robot controller. There is provided a control method in a control system comprising: The control method comprises the steps of: a control device periodically transmitting a correction amount for the trajectory of the robot; a step in which the robot controller calculates a command value for each control cycle according to a command received from the control device; calculating a corrected command value for each control cycle based on the command value and the correction amount periodically received from the control device.

According to the present invention, it is possible to more accurately correct the trajectory of the robot.

1 is a schematic diagram showing a system configuration example of a control system according to an embodiment; FIG. It is a figure which shows the example of application of the control system which concerns on this Embodiment. FIG. 2 is a schematic diagram showing a hardware configuration example of a control device that configures the control system according to the present embodiment; FIG. 3 is a schematic diagram showing a hardware configuration example of a robot controller that configures the control system according to the present embodiment; FIG. 2 is a schematic diagram showing a hardware configuration example of a servo controller that configures the control system according to the present embodiment; FIG. 2 is a schematic diagram showing a hardware configuration example of a support device that configures the control system according to the present embodiment; FIG. 4 is a schematic diagram showing an execution example of a program in the control device according to the embodiment; It is a figure which shows an example of the trajectory control of the robot by the control system which concerns on this Embodiment. FIG. 7 is a diagram showing an example of processing when a correction command is included in an application program in the control system according to the embodiment; FIG. 7 is a diagram showing an example of processing for realizing target trajectory correction of the robot in the control system according to the present embodiment; FIG. 2 is a schematic diagram showing a system configuration corresponding to a program example of the control system according to the present embodiment; FIG. FIG. 12 is a schematic diagram showing an example of an application using the robot shown in FIG. 11; 13 is a diagram showing an example of an application program for realizing the application shown in FIG. 12; FIG. 13 is a diagram showing an example of an IEC program for realizing the application shown in FIG. 12; FIG. FIG. 5 is a diagram showing an example of a function indicating a correction amount reflecting command of the control system according to the embodiment; 4 is a flow chart showing a processing procedure executed by the control device of the control system according to the present embodiment; 4 is a flow chart showing a processing procedure executed by the robot controller of the control system according to the embodiment;

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

<A. Application example>
First, a system configuration example of the control system 1 according to the present embodiment will be described.

FIG. 1 is a schematic diagram showing a system configuration example of a control system 1 according to this embodiment. Referring to FIG. 1, control system 1 includes a control device 100 for controlling a controlled object, a robot controller 250 network-connected to control device 100 via field network 10, and a servo controller 350. .

The control device 100 periodically exchanges data with devices connected to the field network 10 and executes processing as described later. The control device 100 may typically be realized by a PLC (Programmable Logic Controller).

The robot controller 250 is in charge of controlling the robot 200. More specifically, the robot controller 250 functions as an interface with the robot 200, outputs commands for driving the robot 200 in accordance with commands from the control device 100, and obtains state information of the robot 200. and output to the control device 100 .

For the robot 200, any robot such as a vertical articulated robot, a horizontal articulated (scalar) robot, a parallel link robot, or an orthogonal robot can be adopted.

The servo controller 350 is in charge of controlling the servo motor 300. More specifically, servo controller 350 drives servo motor 300 according to a command from control device 100 , acquires state information of servo motor 300 , and outputs the information to control device 100 .

For the field network 10, protocols for industrial networks such as EtherCAT (registered trademark) and EtherNet/IP can be used. When EtherCAT is adopted as the protocol, data can be updated between the control device 100 and devices connected to the field network 10 at regular intervals of several hundred microseconds to several milliseconds, for example.

The control device 100 may be connected to the display device 500 and the server device 600 via the host network 20 . For the upper network 20, a protocol for industrial networks such as EtherNet/IP can be used.

The control device 100 may be connected to a support device 400 for installing user programs (the IEC program 150 and the application program 160, which will be described later) executed by the control device 100 and performing various settings.

FIG. 2 is a diagram showing an application example of the control system 1 according to this embodiment. Referring to FIG. 2 , commands for generating the trajectory of robot 200 are sequentially transmitted from control device 100 to robot controller 250 .

The robot controller 250 calculates a command value for the robot 200 in each control cycle according to commands received from the control device 100 . In parallel, the control device 100 transmits the correction amount for the trajectory of the robot 200 to the robot controller 250 every control cycle. The robot controller 250 calculates the corrected command value for each control cycle based on the command value and the correction amount periodically received from the control device 100 . The robot controller 250 then outputs the corrected command value to the robot 200 .

<B. Hardware configuration example>
Next, an example of hardware configuration of main devices constituting the control system 1 shown in FIGS. 1 and 2 will be described.

(b1: control device 100)
FIG. 3 is a schematic diagram showing a hardware configuration example of the control device 100 that configures the control system 1 according to the present embodiment. Referring to FIG. 3, control device 100 includes processor 102, main memory 104, storage 110, memory card interface 112, host network controller 106, field network controller 108, local bus controller 116, USB and a USB controller 120 that provides a (Universal Serial Bus) interface. These components are connected via processor bus 118 .

The processor 102 corresponds to an arithmetic processing unit that executes control arithmetic, and is composed of a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and the like. Specifically, the processor 102 reads a program stored in the storage 110, develops it in the main memory 104, and executes it, thereby implementing control calculations for the controlled object.

The main memory 104 is composed of volatile storage devices such as DRAM (Dynamic Random Access Memory) and SRAM (Static Random Access Memory). The storage 110 is configured by, for example, a non-volatile storage device such as SSD (Solid State Drive) or HDD (Hard Disk Drive).

The storage 110 stores a system program 1102 for realizing basic functions, an IEC program 150 and an application program 160 created according to the object to be controlled.

The IEC program 150 includes instructions for realizing main control other than the control of the robot 200 in the control system 1. An IEC program 150 may typically include sequence instructions and motion instructions. The IEC program 150 may be written in any language defined by IEC61131-3 defined by the International Electrotechnical Commission (IEC). However, the IEC program 150 may include a program written in a manufacturer's own language other than the language defined by IEC61131-3.

The application program 160 includes instructions for controlling the operation of the robot 200. The application program 160 may include instructions written in a predetermined programming language (for example, programming language for robot control such as V+ language or programming language for NC control such as G code).

The memory card interface 112 accepts a memory card 114, which is an example of a removable storage medium. The memory card interface 112 is capable of reading/writing arbitrary data from/to the memory card 114 .

The host network controller 106 exchanges data with arbitrary information processing devices (such as the display device 500 and the server device 600 shown in FIGS. 1 and 2) via the host network 20 .

The field network controller 108 exchanges data with each device via the field network 10. In the system configuration examples shown in FIGS. 1 and 2, the field network controller 108 may function as a communication master of the field network 10. FIG.

The local bus controller 116 exchanges data with any functional unit 130 included in the control device 100 via the local bus 122 . The functional unit 130 includes, for example, an analog I/O unit responsible for inputting and/or outputting analog signals, a digital I/O unit responsible for inputting and/or outputting digital signals, a counter unit receiving pulses from an encoder, etc. And so on.

The USB controller 120 exchanges data with any information processing device (such as the support device 400) via a USB connection.

(b2: robot controller 250)
FIG. 4 is a schematic diagram showing a hardware configuration example of the robot controller 250 that configures the control system 1 according to this embodiment. Referring to FIG. 4, robot controller 250 includes field network controller 252 and control processing circuit 260 .

The field network controller 252 mainly exchanges data with the control device 100 via the field network 10 . That is, field network controller 252 corresponds to an interface for connecting control device 100 via field network 10 .

The control processing circuit 260 executes arithmetic processing required to drive the robot 200 . As an example, control processing circuitry 260 includes processor 262 , main memory 264 , storage 266 and interface circuitry 270 .

A processor 262 executes control operations for driving the robot 200 . The main memory 264 is composed of, for example, a volatile memory device such as DRAM or SRAM. The storage 266 is configured by, for example, a non-volatile storage device such as SSD or HDD.

A system program 268 for realizing control for driving the robot 200 is stored in the storage 266 . The system program 268 includes instructions for executing control operations related to the operation of the robot 200 and instructions related to interfacing with the robot 200 .

Interface circuit 270 exchanges data with robot 200 .
(b3: servo controller 350)
FIG. 5 is a schematic diagram showing a hardware configuration example of the servo controller 350 that configures the control system 1 according to this embodiment. 5, servo controller 350 includes a field network controller 352, a control processing circuit 360, and a drive circuit 370. FIG.

The field network controller 352 mainly exchanges data with the control device 100 via the field network 10 .

The control processing circuit 360 executes arithmetic processing necessary for controlling the servo motor 300 . As an example, control processing circuitry 360 includes processor 362 , main memory 364 , and storage 366 .

The processor 362 executes control calculations related to the servomotor 300 . The main memory 364 is composed of, for example, a volatile memory device such as DRAM or SRAM. The storage 366 is configured by, for example, a non-volatile storage device such as SSD or HDD.

The storage 366 stores a system program 368 for realizing drive control of the servo motor 300 . The system program 368 includes instructions for executing control calculations related to the operation of the servomotor 300 and instructions related to interfacing with the servomotor 300 .

The drive circuit 370 includes a converter circuit, an inverter circuit, and the like, and according to commands calculated by the control processing circuit 360, generates power of specified voltage, current, and phase, and supplies it to the servo motor 300.

The servomotor 300 is not limited to the name of a servomotor, and may be an induction motor, a synchronous motor, a permanent magnet motor, or a reluctance motor. You may

(b4: support device 400)
The support device 400 that configures the control system 1 according to the present embodiment may be implemented using a general-purpose personal computer as an example.

FIG. 6 is a schematic diagram showing a hardware configuration example of the support device 400 that configures the control system 1 according to the present embodiment. 6, support device 400 includes processor 402 such as a CPU or MPU, main memory 404, input unit 406, display unit 408, storage 410, network controller 416, USB controller 418, and an optical drive 420 . These components are connected via bus 424 .

The processor 402 reads out various programs stored in the storage 410, develops them in the main memory 404, and executes them, thereby developing user programs (IEC programs 150 and application programs 160) executed by the control device 100. Provide processing.

The storage 410 is composed of, for example, non-volatile storage devices such as SSDs and HDDs. The storage 410 typically includes an OS 412, a development program 414 for creating a user program to be executed in the control device 100, debugging the created user program, defining the system configuration, setting various parameters, and the like. is stored. The storage 410 may store necessary programs other than the programs shown in FIG.

The input unit 406 is composed of a keyboard, mouse, etc., and receives user operations. A display unit 408 includes a display, various indicators, a printer, and the like, and outputs processing results from the processor 402 and the like.

A network controller 416 controls the exchange of data with other devices via any network. A USB controller 418 controls data exchange with the control device 100 via a USB connection.

The support device 400 has an optical drive 420, and from a recording medium 422 (for example, an optical recording medium such as a DVD (Digital Versatile Disc)) that stores a computer-readable program non-transitory, The stored program is read and installed in the storage 410 or the like.

The various programs executed by the support device 400 may be installed via the computer-readable recording medium 422, or may be installed by downloading them from a server device on the network. Also, the functions provided by the support device 400 according to the present embodiment may be realized by using some of the modules provided by the OS 412 .

(b5: display device 500)
Display device 500 configuring control system 1 according to the present embodiment may be realized using a general-purpose personal computer as an example. Since the basic hardware configuration example of the display device 500 is well known, detailed description thereof will not be given here.

(b6: server device 600)
Server device 600 that configures control system 1 according to the present embodiment may be implemented using a general-purpose personal computer as an example. Since the basic hardware configuration example of the server device 600 is well known, detailed description thereof will not be given here.

(b7: other forms)
3 to 6 show configuration examples in which one or more processors execute programs to provide necessary functions. It may be implemented using a hardware circuit (for example, ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array)).

<C. Execution of IEC Program and Application Program>
Next, execution of IEC program 150 and application program 160 in control device 100 according to the present embodiment will be described.

FIG. 7 is a schematic diagram showing an example of program execution in the control device 100 according to the present embodiment. FIG. 7 shows an example in which a plurality of tasks are set according to priority, and each task shares resources of the processor 102 according to its priority.

The example shown in FIG. 7 shows an example in which two types of tasks, a high-priority task and a low-priority task, are executed. More specifically, the input/output refresh process 140, the execution process 142 of the IEC program 150, the motion command execution process 144 included in the IEC program 150, and the execution process 146 after interpretation of the application program 160 are performed in the control cycle T1. is executed as a high-priority task of

On the other hand, the process of sequentially interpreting the application program 160 is executed as a low-priority task with an application cycle T2 (>control cycle T1).

The high-priority task is repeatedly executed every control cycle T1. A low-priority task is executed each time a high-priority task is not executed. That is, the execution time of the high-priority task is allocated for each control cycle, and the low-priority task is executed during the time other than the execution time of the high-priority task.

The application program 160 is sequentially interpreted by an interpreter (not shown). The intermediate code generated by the interpreter interpreting the application program 160 is sequentially queued (enqueued) in the buffer 148 . The intermediate code queued in the buffer 148 is referred to each time in the execution process 146 to generate instructions. Thus, the control device 100 includes a function of sequentially transmitting commands to the robot controller 250 by sequentially executing the application program 160 (second user program).

As shown in FIG. 7, the interpretation (interpreter) of the application program 160 is executed in a period longer than the control period T1, and punctuality is not sufficiently ensured. That is, the execution cycle (application cycle T2) of the application program 160 (second user program) is set longer than the execution cycle (control cycle T1) of the IEC program 150 (first user program). However, since the robot controller 250 (FIGS. 1 and 2) normally calculates the command value for each control cycle of the robot controller 250 based on the command transmitted from the control device 100, there is no problem with accuracy. .

<D. Issue>
Next, problems that may arise in executing the program shown in FIG. 7 will be described. As an example, assume processing for performing arbitrary correction (hereinafter also referred to as “target trajectory correction”) for the trajectory of the robot controller 250 .

FIG. 8 is a diagram showing an example of trajectory control of the robot 200 by the control system 1 according to this embodiment. FIG. 8 shows tracking correction of the robot 200 as an example of target trajectory correction. More specifically, when the robot 200 performs predetermined processing on a workpiece placed on the XY stage, there is a case of correcting fluctuations occurring in the XY stage.

In this case, the trajectory of the robot 200 is corrected by a correction amount according to the movement of the XY stage for a configuration that controls the robot 200 according to a predetermined robot trajectory.

Next, an example of a method for realizing target trajectory correction for the robot 200 as shown in FIG. 8 will be described.

FIG. 9 is a diagram showing an example of processing when a correction command is included in the application program 160 in the control system 1 according to this embodiment. Referring to FIG. 9 , application program 160 is executed in control device 100 . FIG. 9 shows the code of the robot program written in V+ language as an example. In the V+ language, each instruction is called a "keyword". In the following, a case where "keyword" is used as an example of "instruction" will be described.

More specifically, the application program 160 includes a MOVES keyword 161, which is an instruction for moving to specified coordinates, and a WHILE instruction 162, which is an instruction for specifying repeat processing. The WHILE command 162 includes a correction amount calculation command 163 and an ALTER keyword 164 instructing correction of the specified correction amount. That is, after the MOVES keyword 161 is transmitted, the calculation of the correction amount and the instruction to correct the correction amount are repeatedly executed until the execution of the MOVES keyword 161 is completed.

When the control device 100 executes the application program 160, the MOVES keyword 161 is first sent to the robot controller 250, and then the ALTER keyword 164 is repeatedly sent.

On the other hand, upon receiving the MOVES keyword 161, the robot controller 250 repeats the command value calculation 281 and the command value output 283 every control cycle T3 of the robot controller 250 because the command requires one or more control cycles T3. Run. The command value calculation 281 is processing (interpolation processing) for calculating a trajectory for the target position p1 associated with the MOVES keyword 161 . By this processing, the command value is output from the robot controller 250 to the robot 200 every control cycle T3. That is, the robot controller 250 calculates a command value for each control period T3 according to a keyword (an example of a command) received from the control device 100. FIG.

In addition, when the robot controller 250 receives the ALTER keyword 164, the correction amount addition 282 is performed using the correction amount 284 included in the ALTER keyword 164. As a result, a command value to which the correction amount 284 is added (or subtracted) is output. The ALTER keyword 164 is an instruction whose execution is completed in one control cycle T3. Therefore, the correction processing for the command value is executed each time the ALTER keyword 164 is received.

However, since the execution cycle of the application program 160 is non-fixed, the transmission cycle of the ALTER keyword 164 is not constant and is not necessarily synchronized with the control cycle T1 of the control device. Therefore, there is a possibility that the execution timing of the correction process in the robot controller 250 varies.

<E. Solution>
Next, a configuration for solving the problems described above will be described.

FIG. 10 is a diagram showing a processing example for realizing target trajectory correction of the robot 200 in the control system 1 according to the present embodiment. Referring to FIG. 10, control device 100 executes IEC program 150 and application program 160 .

In the example shown in FIG. 10, the IEC program 150 includes a correction amount calculation command 151 and a correction amount reflection command 152. Application program 160 includes MOVES keyword 161, which is an instruction for moving to specified coordinates.

As in FIG. 9, the MOVES keyword 161 is first sent to the robot controller 250 by the control device 100 executing the application program 160 . Upon receiving the MOVES keyword 161, the robot controller 250 repeatedly executes command value calculation 281 and command value output 283 every control period T3 of the robot controller 250. FIG.

On the other hand, the control device 100 executes the IEC program 150 every control cycle T1. By executing the IEC program 150 , the correction amount 286 is calculated according to the correction amount calculation command 151 and the correction amount 286 is transmitted to the robot controller 250 according to the correction amount reflection command 152 . That is, the correction amount calculation command 151 corresponds to elements for calculating the correction amount for the trajectory of the robot 200 . Also, the correction amount reflection command 152 corresponds to an element that periodically transmits the correction amount for the trajectory of the robot 200 .

In this way, the control device 100 periodically executes the IEC program 150 (first user program) for calculating the correction amount 286 according to arbitrary created instructions. The IEC program 150 (first user program) includes a correction amount reflection command 152 as a command for periodically transmitting the correction amount 286 for the trajectory of the robot 200 .

The control device 100 and the robot controller 250 are connected via the field network 10 in which data transmission (data update) is performed every communication cycle T4. Therefore, data can be exchanged (exchanged) between the control device 100 and the robot controller 250 every communication cycle T4.

Normally, the control period T1 and the communication period T4 are set to match (control period T1=communication period T4), so the robot controller 250 sets the correction amount 286 calculated by the control device 100 to the control period T1 (or It can be received every communication cycle T4).

Normally, the control cycle T3 of the robot controller 250 is set to be about the same as or longer than the control cycle T1 and the communication cycle T4 (control cycle T3≧control cycle T1, communication cycle T4). The correction amount 286 is updated in a sufficiently early period compared to the period T3.

Therefore, the robot controller 250 can receive the correction amount 286 for the trajectory of the robot 200 periodically transmitted from the control device 100 . Then, the robot controller 250 executes the correction amount addition 282 using the correction amount 286 calculated by the control device 100 for each control cycle. As a result, a command value to which the correction amount 284 is added (or subtracted) is output. That is, the robot controller 250 calculates the corrected command value every control cycle T3 based on the command value and the correction amount 286 periodically received from the control device 100 .

An enable/disable switch 287 is provided on the path through which the correction amount 286 is input to the correction amount addition 282, and is enabled or disabled by the ALTON keyword and ALTOFF keyword, respectively, as described later. be. That is, the robot controller 250 enables or disables calculation of the command value after correction according to a specific keyword (example of command) received from the control device 100 .

As described above, in the control system 1 according to the present embodiment, the target trajectory correction by the robot controller 250 can be reliably performed at each predetermined control cycle T3, and the correction amount calculated by the control device 100 286 can be reflected in the target trajectory correction without substantial delay.

The robot controller 250 periodically transmits state information 288 (the position of each axis of the robot 200, the input/output values of the robot 200, the execution state of commands, etc.) to the control device 100. That is, the robot controller 250 has elements that periodically transmit the state values of the robot 200 . The state information 288 is also transmitted every communication cycle T4. Therefore, the control device 100 can also calculate the correction amount every control cycle T1 based on the state information 288 periodically received from the robot controller 250 . Therefore, the correction amount can be calculated with higher accuracy.

<F. Program example>
Next, a program example of the control system 1 according to this embodiment will be described.

FIG. 11 is a schematic diagram showing a system configuration corresponding to a program example of the control system 1 according to this embodiment. Referring to FIG. 11 , controller 100 is connected via field network 10 to robot controller 250 that controls robot 200 and distance sensor 50 attached to end effector 210 of robot 200 .

The control device 100 can transmit command values to the robot controller 250 and can acquire state information from the robot controller 250 . Also, the control device 100 can acquire the distance measured from the distance sensor 50 .

FIG. 12 is a schematic diagram showing an example of an application using the robot 200 shown in FIG.

With reference to FIG. 12(A), assume a process of maintaining the same distance between the end effector 210 of the robot 200 and the work 40 placed on the base 42 . Such processing is required for applications such as inspection of the workpiece 40 and application to the workpiece 40, for example.

With reference to FIG. 12(B), it is assumed that the distance between the end effector 210 of the robot 200 and the exposed surface such as the workpiece 40 is maintained at the reference distance. In this case, the correction amount is calculated so that the result of adding or subtracting the correction amount to the distance measured by the distance sensor 50 matches the reference distance. That is, the correction amount is calculated for each control cycle such that "reference distance=distance measured by distance sensor 50+correction amount".

FIG. 13 is a diagram showing an example of an application program 160 for realizing the application shown in FIG. Referring to FIG. 13, application program 160 includes an enabling unit 165 for instructing robot controller 250 to enable target trajectory correction, and an initial position moving unit 166 for moving robot 200 to the initial position. , an execution validating unit 167 for validating execution of the correction amount reflection command 152 in the IEC program, an execution waiting unit 168 waiting for the execution of the correction amount reflection command 152 in the IEC program, and the robot 200 are predetermined. It includes a trajectory target commanding unit 169 for operating on the trajectory set and an end processing unit 170 for terminating the processing.

The validation unit 165 includes an ALTON keyword that is a command for validating the target trajectory correction. The robot controller 250 activates the correction amount addition 282 of the target trajectory correction shown in FIG. 10 by receiving the ALTON keyword.

The initial position moving part 166 includes the MOVES keyword, which is an instruction for moving to specified coordinates. Note that the object loc. The initial position is stored in init.

The execution enabler 167 includes an instruction to set the Boolean variable ebool_sp1 to "TRUE".

The execution waiting unit 168 includes an instruction to wait processing until the Boolean variable gStartComp becomes "TRUE" in the IEC program 150. The Boolean variable gStartComp corresponds to the compensation ready flag 158 shown in FIG.

The trajectory target command section 169 includes three MOVES keywords, and is defined to sequentially move to target positions p1, p2, and p3, respectively.

The termination processing unit 170 includes an ALTOFF keyword, which is a command for invalidating the target trajectory correction.

FIG. 14 is a diagram showing an example of an IEC program 150 for realizing the application shown in FIG. Referring to FIG. 14 , IEC program 150 includes activation monitoring instruction 159 for executing activation and monitoring of application program 160 , correction amount calculation instruction 151 , and correction amount reflecting instruction 152 .

The activation monitoring instruction 159 activates the application program 160 and monitors the execution state of the application program 160 when a predetermined condition for operating the robot 200 is satisfied.

The correction amount calculation command 151 uses the reference distance 156 (cBaseDiff) and the current distance 157 (E002_input_Data_1) measured by the distance sensor 50 as the second element (Offset[2]) of the structure Offset indicating the correction amount 155. Contains instructions to compute the difference. The calculation of the correction amount 155 is performed on the condition that the application program running flag 154 indicating that the application program 160 is running is "TRUE".

A correction amount 155 (Offset) calculated by the correction amount calculation command 151 is input to the correction amount reflection command 152 . The correction amount 155 is transmitted to the robot controller 250 by executing the correction amount reflection command 152 . Further, the correction amount reflection command 152 sets the correction preparation completion flag 158 to "TRUE" if the correction amount 155 can be transmitted.

The correction amount reflection command 152 may be in any format, but may adopt a function format as shown in FIG. 14, for example.

FIG. 15 is a diagram showing an example of functions indicating the correction amount reflection command 152 of the control system 1 according to the present embodiment. Referring to FIG. 15, correction amount reflection command 152 includes robot designation 1521, execution designation 1522, and correction amount designation 1523 as inputs. Further, the correction amount reflection command 152 includes, as outputs, a currently selected robot 1524, a correction preparation completion flag 1525, a busy flag 1526, an abort flag 1527, an error flag 1528, and an error ID 1529.

A variable for designating the target robot 200 is set in the robot designation 1521 . A Boolean variable for instructing execution of the correction amount reflection instruction 152 is set in the execution designation 1522 . A variable indicating the correction amount to be transmitted to the robot controller 250 of the target robot 200 is set in the correction amount specification 1523 .

When a structure is used as a variable indicating the correction amount, for example, X-axis correction amount [mm], Y-axis correction amount [mm], Z-axis correction amount [mm], X-axis correction amount [deg ], the Y-axis correction amount [deg], the Z-axis correction amount [deg], and the like. That is, the correction amount may include not only the correction value for a specific axis, but also correction values for each of a plurality of axes.

The selected robot 1524 outputs information for specifying the selected robot 200 . The correction preparation completion flag 1525 outputs information indicating whether or not the target trajectory correction for the selected robot 200 can be executed. From the busy flag 1526, the abort flag 1527, and the error flag 1528, presence/absence of a busy state, presence/absence of an abort occurrence, presence/absence of an error occurrence, and the like are output. The error ID 1529 outputs information for identifying the error that has occurred.

In this way, the correction amount reflection command 152, which is a command for periodically transmitting the correction amount 286 for the trajectory of the robot 200, may be written in the IEC program 150 (first user program) in the form of a function.

By using the IEC program 150 and the application program 160 as described above, the application shown in FIG. 12 can be controlled.

<G. Processing procedure>
Next, processing executed by the control device 100 and the robot controller 250 of the control system 1 according to this embodiment will be described.

FIG. 16 is a flow chart showing a processing procedure executed by the control device 100 of the control system 1 according to this embodiment. FIG. 16A shows the process of executing the IEC program 150 by the control device 100, and FIG. 16B shows the process of executing the application program 160 by the control device 100. FIG. Each step shown in FIGS. 16A and 16B may be implemented by processor 102 of control device 100 executing a program.

The process shown in FIG. 16(A) is repeatedly executed in each control period T1 of the control device 100. Referring to FIG. 16A, control device 100 first executes input/output refresh processing 140 . More specifically, the control device 100 outputs the command value calculated in the previous control cycle (step S100), and acquires the input value used in the current control cycle (step S102). The command value output from control device 100 includes correction amount 286 used for target trajectory correction. Input values obtained by controller 100 include state information 288 from robot controller 250 .

The control device 100 determines whether or not the target trajectory correction can be executed based on the obtained input value and the internally held state value (step S104).

If the target trajectory correction can be executed (YES in step S104), the control device 100 calculates the correction amount 284 used for the target trajectory correction according to the correction amount calculation command 151 (step S106), and the correction amount reflecting command 152 , the calculated correction amount 284 is set (step S108). The set correction amount 284 becomes the command value in the next control cycle T1. Through such procedures, the control device 100 periodically transmits the correction amount 284 for the trajectory of the robot 200 .

The processing shown in FIG. 16(B) is executed sequentially so that one execution is within the application period T2. Referring to FIG. 16B, control device 100 sequentially executes application program 160 to determine whether the content of the target line is a keyword (step S150). If the content of the target line is a keyword (YES in step S150), control device 100 transmits the target keyword to robot controller 250 (step S152).

If the content of the target line is not a keyword (NO in step S150), control device 100 executes the content of the target line and stores the execution result in the target variable (step S154). For example, the target line includes control instructions such as DO-WHILE statements and IF statements.

FIG. 17 is a flow chart showing a processing procedure executed by the robot controller 250 of the control system 1 according to this embodiment. The processing shown in FIG. 17 is repeatedly executed in each control cycle T3 of the robot controller 250. In FIG. Each step shown in FIG. 17 may be implemented by the processor 262 of the robot controller 250 executing a program.

Referring to FIG. 17, robot controller 250 first executes input/output refresh processing. More specifically, the robot controller 250 outputs the command value calculated in the previous control cycle (step S200), and acquires the input value used in the current control cycle (step S202). Output of command values from robot controller 250 includes output of commands to drive robot 200 and transmission of state information 288 including state values of the previous control cycle to control device 100 . The input values acquired by the robot controller 250 include state values of the robot 200 (positions of the axes of the robot 200, input/output values of the robot 200, etc.).

Subsequently, the robot controller 250 determines whether or not any keyword has been received from the control device 100 (step S204). If any keyword has been received from control device 100 (YES in step S204), robot controller 250 stores the received keyword in the buffer (step S206). If no keyword has been received from control device 100 (NO in step S204), the process of step S206 is skipped.

Subsequently, the robot controller 250 determines whether or not some keyword is being executed (step S208). If some keyword is being executed (YES in step S208), robot controller 250 calculates the command value for the current control cycle according to the keyword being executed (step S210). In this manner, the robot controller 250 calculates command values for each control period T3 according to the keyword (an example of command) received from the control device 100 .

If no keyword is being executed (NO in step S208), the robot controller 250 determines whether or not the keyword is stored in the buffer (step S212). If a keyword is stored in the buffer (YES in step S212), robot controller 250 reads the keyword from the buffer (step S214) and calculates a command value according to the read keyword (step S216).

The robot controller 250 determines whether or not target trajectory correction is enabled (step S218). If target trajectory correction is enabled (YES in step S218), robot controller 250 adds the correction amount acquired in step S202 to the command value to calculate a corrected command value (step S220). Thus, the robot controller 250 calculates the corrected command value every control cycle T3 based on the command value and the correction amount 286 periodically received from the control device 100 .

If target trajectory correction is not enabled (NO in step S218), the process of step S220 is skipped.

Finally, the robot controller 250 outputs the command value or the corrected command value to the robot 200 (step S222).

If no keyword is stored in the buffer (NO in step S212), the processing of steps S214 to S222 is skipped.

<H. Note>
The present embodiment as described above includes the following technical ideas.

[Configuration 1]
a control device (100) for controlling a controlled object;
a robot controller (250) for controlling the robot (200);
a network (10) for periodically updating data between the controller and the robot controller;
The control device comprises means (102, 152) for periodically transmitting a correction amount (161) for the trajectory of the robot,
The robot controller is
Means (262, 281) for calculating a command value for each control cycle according to a command received from the control device;
A control system comprising means (262, 282) for calculating a command value after correction in each control cycle based on the command value and a correction amount periodically received from the control device.

[Configuration 2]
2. The control system of arrangement 1, wherein said controller further comprises means for periodically executing a first user program (150) for calculating said correction amount in accordance with arbitrarily constructed instructions.

[Configuration 3]
3. The control system of arrangement 2, wherein the first user program includes instructions (152) for periodically transmitting corrections to the trajectory of the robot.

[Configuration 4]
The control system according to configuration 3, wherein the command for periodically transmitting the correction amount for the trajectory of the robot is written in the first user program in a function format.

[Configuration 5]
The control system according to any one of configurations 2 to 4, wherein the control device further comprises means (102, 160) for sequentially transmitting commands to the robot controller by sequentially executing a second user program. .

[Configuration 6]
The control system according to configuration 5, wherein the execution cycle (T2) of the second user program is set longer than the execution cycle (T1) of the first user program.

[Configuration 7]
7. The system of any one of clauses 1-6, wherein the robot controller is configured to enable or disable (287) calculation of corrected command values according to specific instructions received from the controller. Control system as described.

[Configuration 8]
8. The control system of any one of the preceding arrangements, wherein the robot controller further comprises means for periodically transmitting a state value (288) of the robot.

[Configuration 9]
A robot controller (250) for controlling a robot (200), comprising:
An interface (252) for connecting to a control device (100) for controlling a controlled object via a network (10), wherein in the network, periodic communication is performed between the control device and the robot controller data is configured to be refreshed, and
means for receiving a correction amount (161) to the trajectory of the robot periodically transmitted from the controller;
Means (262, 281) for calculating a command value for each control cycle according to a command received from the control device;
A robot controller comprising means (262, 282) for calculating a command value after correction in each control cycle based on the command value and a correction amount periodically received from the control device.

[Configuration 10]
A control device (100) for controlling a controlled object, a robot controller (250) for controlling a robot (200), and a network ( 10) A control method in a control system (1) comprising
a step in which the control device periodically transmits a correction amount for the trajectory of the robot (S108);
a step in which the robot controller calculates a command value for each control cycle according to the command received from the control device (S210, S216);
A control method comprising a step (S220) in which the robot controller calculates a corrected command value for each control cycle based on the command value and a correction amount periodically received from the control device.

<I. Advantage>
In the control system 1 according to the present embodiment, the robot controller 250 calculates the original command value for each control cycle according to the command received from the control device 100, and calculates the command value calculated for each control cycle. , the corrected command value can be calculated by reflecting the correction amount received from the control device 100 . As a result, when the trajectory of the robot 200 is to be arbitrarily corrected, the calculation result of the correction amount in the control device can be reliably reflected without deviating from the control cycle. As a result, even if the trajectory of the robot is arbitrarily corrected, more accurate control can be performed.

The embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 control system, 10 field network, 20 host network, 40 work, 42 base, 50 distance sensor, 100 control device, 102, 262, 362, 402 processor, 104, 264, 364, 404 main memory, 106 host network controller, 108, 252, 352 field network controller, 110, 266, 366, 410 storage, 112 memory card interface, 114 memory card, 116 local bus controller, 118 processor bus, 120, 418 USB controller, 122 local bus, 130 functional unit, 140 input/output refresh process, 142, 144, 146 execution process, 148 buffer, 150 IEC program, 151 correction amount calculation instruction, 152 correction amount reflection instruction, 154 application program execution flag, 155, 284, 286 correction amount, 156 reference Distance, 157 Current distance, 158 Correction preparation completion flag, 159 Startup monitoring instruction, 160 Application program, 161 MOVES keyword, 162 WHILE instruction, 163 Calculation instruction, 164 ALTER keyword, 165 Validation part, 166 Initial position movement part, 167 Execution Validation unit 168 execution standby unit 169 trajectory target command unit 170 end processing unit 200 robot 210 end effector 250 robot controller 260, 360 control processing circuit 268, 368, 1102 system program 270 interface circuit, 281 command value calculation, 282 correction amount addition, 283 command value output, 287 invalidation switch, 288 status information, 300 servo motor, 350 servo controller, 370 drive circuit, 400 support device, 406 input unit, 408 display unit, 412 OS , 414 development program, 416 network controller, 420 optical drive, 422 recording medium, 424 bus, 500 display device, 600 server device, 1521 robot specification, 1522 execution specification, 1523 compensation amount specification, 1524 selected robot, 1525 compensation ready flag, 1526 busy flag, 1527 abort flag, 1528 error flag, 1529 error ID, T1, T3 control period, T2 application period, T 4　Communication cycle.

Claims

a control device for controlling a controlled object;
a robot controller for controlling the robot;
a network for periodically updating data between the controller and the robot controller;
The control device comprises means for periodically transmitting a correction amount for the trajectory of the robot,
The robot controller is
means for calculating a command value for each control cycle according to a command received from the control device;
A control system comprising means for calculating a command value after correction in each control cycle based on the command value and a correction amount periodically received from the control device.
3. The control system according to claim 1, wherein said controller further comprises means for periodically executing a first user program for calculating said correction amount according to arbitrarily created instructions.
3. The control system according to claim 2, wherein the first user program includes instructions for periodically transmitting a correction amount to the trajectory of the robot.
4. The control system according to claim 3, wherein the command for periodically transmitting the correction amount for the trajectory of the robot is written in the first user program in a function format.
The control system according to any one of claims 2 to 4, wherein the control device further comprises means for sequentially transmitting commands to the robot controller by sequentially executing a second user program.
The control system according to claim 5, wherein the execution cycle of said second user program is set longer than the execution cycle of said first user program.
7. The robot controller according to any one of claims 1 to 6, wherein the robot controller is configured to enable or disable calculation of corrected command values according to specific instructions received from the controller. control system.
The control system according to any one of claims 1 to 7, wherein the robot controller further comprises means for periodically transmitting state values of the robot.
A robot controller for controlling a robot,
An interface for connecting to a control device for controlling a controlled object via a network is provided, and in the network, data is periodically updated between the control device and the robot controller. and
means for receiving a correction amount for the trajectory of the robot periodically transmitted from the control device;
means for calculating a command value for each control cycle according to a command received from the control device;
A robot controller, comprising means for calculating a command value after correction in each control cycle based on the command value and a correction amount periodically received from the control device.
A control method in a control system comprising a control device for controlling a controlled object, a robot controller for controlling a robot, and a network for periodically updating data between the control device and the robot controller. hand,
the controller periodically transmitting a correction amount for the trajectory of the robot;
a step in which the robot controller calculates a command value for each control cycle according to the command received from the control device;
A control method, wherein the robot controller calculates a corrected command value for each control cycle based on the command value and a correction amount periodically received from the control device.