Robot control device, robot control method, and robot control program

Abstract

A robot control device is a control device for a robot, and comprises a processor and a memory. The processor, in cooperation with the memory, acquires information pertaining to a selected stop-execution mode, and stops the robot if there is reception of an input corresponding to the information pertaining to the selected stop-execution mode.

Description

Robot control device, robot control method, and robot control program

[0001] The present disclosure relates to a robot control device, a robot control method, and a robot control program.

[0002] In Patent Document 1, in order to safely stop a robot during a power outage or an emergency stop, a discharge circuit is provided for a power supply circuit provided for a motor that drives an industrial robot, and discharges a capacitor provided in the power supply circuit. This discharge circuit includes a first voltage detector that detects the voltage input to the primary side of the power supply circuit, a second voltage detector that detects the voltage on the secondary side of the power supply circuit, a discharge resistor provided in parallel with the power supply circuit on the secondary side of the power supply circuit, a switch element that interrupts the current flowing through the discharge resistor, and power supply control means that executes discharge control to control the switch element so that current flows through the discharge resistor. The power supply control means executes discharge control when the voltage detected by the second voltage detector exceeds the regeneration determination value, and when the voltage on the primary side falls below the power outage determination value in the first voltage detector, executes discharge control after the elapse of the time required for the stop operation of the industrial robot.

[0003] Japanese Unexamined Patent Application Publication No. 2020-209092

[0004] Patent Document 1 describes a discharge circuit that performs discharge control by hardware (for example, a switch element that interrupts current). However, when realizing the stop of a robot by hardware, the placement location of components, the method for realizing the stop of the robot, etc. become fixed, and it is difficult to have flexibility. As a result, it becomes difficult to improve the convenience for the user.

[0005] The present disclosure has been devised in view of the above-described conventional circumstances, and an object thereof is to provide a robot control device, a robot control method, and a robot control program that can have flexibility in means for realizing the stop of a robot when a user wants to stop the robot, for example, during an emergency stop.

[0006] This disclosure provides a robot control device comprising a processor and a memory, wherein the processor cooperates with the memory to acquire information regarding a selected stop execution mode, and stops the robot when it receives an input corresponding to the information regarding the selected stop execution mode.

[0007] Furthermore, this disclosure provides a robot control method that acquires information regarding a selected stop execution mode and stops the robot when it receives an input corresponding to the information regarding the selected stop execution mode.

[0008] Furthermore, this disclosure provides a robot control program that acquires information regarding a selected stop execution mode and instructs a computer to stop the robot when it receives an input corresponding to the information regarding the selected stop execution mode.

[0009] According to this disclosure, for example, when a user wants to stop the robot in an emergency, there is flexibility in the means of stopping the robot.

[0010] A schematic diagram showing the overall robot system according to this embodiment. A block diagram showing the configuration of the robot system according to this embodiment. A diagram showing an example of the internal structure of a safety device according to a comparative example. A block diagram showing an example of the internal structure of a safety device according to this embodiment. A block diagram showing an example of the selection of the emergency stop execution mode according to this embodiment. A flowchart showing an example of the robot control method according to this embodiment.

[0011] Hereinafter, with reference to the drawings as appropriate, each embodiment that specifically discloses the configuration and operation of the robot control device, robot control method, and robot control program relating to this disclosure will be described in detail. However, unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding by those skilled in the art. The attached drawings and the following explanation are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims. In the following explanation, identical configurations will be given the same reference numerals, and redundant explanations will be omitted or the explanations will be simplified, with different content being described each time.

[0012] First, the robot system 100 according to this embodiment will be described with reference to Figures 1 and 2, respectively. Figure 1 is a schematic diagram showing the overall structure of the robot system 100 according to this embodiment. Figure 2 is a block diagram showing the configuration of the robot system 100 according to this embodiment. It goes without saying that the robot system 100 shown in Figure 1 is just one example and is not limited thereto.

[0013] The robot system 100 can be used for various purposes, such as inspecting or mounting parts, or manufacturing equipment or products. The robot system 100 comprises a plurality of robot bodies 1 and a Programmable Logic Controller (PLC 10). Note that the PLC 10 does not necessarily have to be an element of the robot system 100. The robot bodies 1 are connected to the control unit 2 and the input unit 3, respectively, so that various signals can be input and output. The pair of control unit 2 and input unit 3 is provided for one robot body 1 and functions as a robot controller for controlling the operation of the robot body 1. In the robot system 100, there may be one robot body 1 or a plurality of robot bodies 1.

[0014] The control unit 2 comprises a processor 21 and a memory 22. The processor 21 has a safety circuit 211 (see Figure 2). The processor 21 is configured using, for example, a Central Processing Unit (CPU) or a Field Programmable Gate Array (FPGA), and works in cooperation with the memory 22 to perform various processes and controls. Specifically, the processor 21 refers to the programs and data held in the memory 22 and executes those programs to realize various processes or functions that the robot body 1 should perform. Details of the safety circuit 211 will be described later.

[0015] Memory 22 includes, for example, Random Access Memory (RAM) as work memory used when the processor 21 performs various processes or functions, and storage for storing programs and data that define the operation of the processor 21. Data or information generated or acquired by the processor 21 is temporarily stored in the RAM. The storage contains a program that defines the operation of the processor 21. This program may be, for example, a robot control program for stopping or switching the coordination of processing between robots. PLC 10 also has a similar processor and memory.

[0016] Furthermore, the control unit 2 may also include a Light Emission Diode (LED) that can notify the user of an error when one occurs. The LED can represent errors by color, for example, by lighting up green during normal operation and red when an error occurs, or by blinking.

[0017] The input unit 3 accepts input from the user for operation. The input unit 3 may also have a display unit 31, such as a display or touch panel, which may display what kind of error occurred if an error occurs. The input unit 3 is generally a device called a teaching pendant. A teaching pendant is an input operation device used for creating programs for industrial robots or teaching the movements of industrial robots. In other words, a teaching pendant is a type of remote control that allows a robot to virtually or offline perform the same actions as an actual industrial robot, and to memorize the position, angle, and movement of the joints and end caps of the industrial robot's arm. That is, when the robot body 1 and the teaching pendant are connected, the robot body 1 is in teaching mode (i.e., memorizing a new program, etc.) rather than operating mode. However, even when the robot body 1 and the teaching pendant are connected, the robot body 1 may still be capable of performing movements in operating mode.

[0018] The external input device 4 transmits information indicating the robot body 1 has stopped operating to the safety circuit 211, separately from the input unit 3 such as the teaching pendant. Details will be described later.

[0019] The PLC 10 includes a processor and memory, and can control one or more robot bodies 1 by a program that can be modified by the user.

[0020] Multiple robot bodies 1 and the PLC 10 communicate via a network, such as CAN communication. The communication method used may be any wired or wireless communication. Wireless communication here may be communication via a wireless Local Area Network (LAN) such as Wi-Fi (registered trademark), Bluetooth Low Energy (BLE), etc., or communication via Internet of Things (IoT) network communication or protocol such as Matter, Z-Wave, or ZigBee.

[0021] Next, the safety circuit will be described. Figure 3 is a diagram showing an example of the internal structure of a safety device according to a comparative example. Figure 4 is a block diagram showing an example of the internal structure of a safety device according to this embodiment. Figure 5 is a block diagram showing an example of the selection of the emergency stop execution mode according to this embodiment.

[0022] First, as a comparative example, Figure 3, which has a structure for stopping the robot in hardware, will be described. First, as a premise, the input unit 3, such as a teaching pendant, and the control unit 2 are connected by wire. In detail, the cable connected to the input unit 3 is connected to the input terminal provided on the control unit 2. In the comparative example, the teaching pendant is connected to the same input terminal when in teaching mode. The teaching pendant is also equipped with an input button for stopping the robot body 1. On the other hand, when the robot body 1 is in an automatic operation mode, the input unit 3 such as the teaching pendant is not necessary.

[0023] However, since an input device is required to stop the robot body 1, it was necessary to connect an emergency stop box 300, which has an emergency stop button for inputting a stop command, to the input terminal of the control unit 2, to which the input unit 3 is connected by a wire. This required a dedicated emergency stop box 300 because it had to be connected to the same input terminal, making it difficult to have flexibility in the choice of options. It should be noted that the information indicating a stop is not limited to the emergency stop box 300; a regular stop button could also be used.

[0024] In the comparative example, the safety circuit 311, which received information supporting an emergency stop from the emergency stop box 300, safely achieves an emergency stop using a group of safety-controlled relays located in area X of Figure 3. In other words, in the safety circuit 311 of Figure 3, the stop was achieved by hardware.

[0025] Next, with reference to Figure 4, the safety circuit 211 according to this embodiment will be described. The external input device 4 and the safety circuit 211 are preferably connected by wire via the input connector 2111. The input connector 2111 has multiple input terminals. When information (signals) for stopping the operation of the robot body 1 is transmitted from the external input device 4 to the safety circuit 211, the safety circuit 211, having acquired the information (signals), forwards and inputs it to the CPU 2112 and CPU 2113. The CPU 2112 and CPU 2113 each perform safety control and monitor each other. Then, both CPU 2112 and CPU 2113 output information that they output as safety control (for example, signals for starting or stopping the robot body 1) to the control unit 2 and the robot body 1.

[0026] As shown in Figure 5, the external input device 4 can use any stop device, such as emergency stop 1, emergency stop 2, door stop, external enable switch, or protective stop 1. In the display in Figure 5, at least one of the multiple external input devices 4 can be selected as the input device for stop information. Furthermore, any external input device 4 may be input from any of the input terminals of the input connector 2111, which has multiple input terminals. In other words, it is possible to flexibly select which input terminal of the input connector 2111 to use, and the input terminals of the input connector 2111 include options such as negative common input or contact input.

[0027] In the comparative example, a specified input was required, but in this embodiment, the input terminal can be flexibly selected from a negative common input or a contact input. That is, the external input device 4 is connected to multiple input terminals via the input connector 2111, and the input corresponding to the information regarding the selected stop execution mode is input to the processor 21 from one of the selected input terminals. The input corresponding to the information regarding the selected stop execution mode is the input of information to the safety circuit 211 from the external input device 4 to stop the robot body 1, such as an emergency stop.

[0028] Furthermore, the stop execution mode is selected from multiple options. This means that, as mentioned above, if one of the multiple external input devices 4 or multiple input terminals is selected as the stop execution mode, then naturally there will be multiple stop execution modes, and the stop execution mode will be selected from multiple options.

[0029] Furthermore, the processor 21 may be configured to restrict access to functions such as the teaching pendant-less function (switching on or off a mode in which the teaching pendant, which is the input unit 3, is not connected), the selection of input terminals as shown in Figure 5, and the selection of external input devices 4, so that only authorized users can perform these actions.

[0030] Next, the robot control method will be described with reference to Figure 6. Figure 6 is a flowchart showing an example of the robot control method according to this embodiment. The following description may also be a description of the robot control program. The series of processes shown in the flowchart of Figure 6 may be changed in order unless there are any particular restrictions, and are mainly executed by the processor 21 of the control unit 2 working in cooperation with the memory 22.

[0031] First, the processor 21 determines whether the teaching pendantless function is enabled or disabled (ST1). If the teaching pendantless function is disabled (ST1: NO), the processor 21 determines that the robot body 1 is in normal mode (ST2). In this case, the processor 21 may switch either the teaching mode or the operation mode to the other as the normal mode. In other words, the normal mode is an operation mode different from the stop execution mode described later, and may be, for example, the teaching mode or the operation mode used during normal operation. In teaching mode, program creation and teaching operations are performed via the teaching pendant, which is the input unit 3, and teaching is performed or settings are changed.

[0032] If the processor 21 determines that the teaching pendantless function is enabled (ST1: YES), it acquires information regarding the selected stop execution mode (ST3). That is, the processor 21 selects one from each of the multiple external input devices 4 and multiple input terminals and acquires the information regarding the stop execution mode. Naturally, there are multiple emergency stop execution modes. Therefore, the processor 21 acquires information indicating the stop execution mode selected from among the multiple emergency stop execution mode options. After acquiring the information regarding the stop execution mode, the processor 21 determines whether one or more inputs are assigned to emergency stop (ST4). If the processor 21 determines that one or more inputs are not assigned to emergency stop (ST4: NO), it outputs an abnormal state (an example of error information) (ST5). The output may be displayed on the display unit 31 of the input unit 3, for example, to inform the user that there is an abnormal state (error information). Note that the processing in step ST4 is executed only when the teaching pendantless function (i.e., see step ST1) is enabled. On the other hand, when the teach pendantless function is disabled, the processor 21 obtains information about the selected stop execution mode, similar to step ST3.

[0033] If the processor 21 determines that one or more inputs are assigned to emergency stop (ST4: YES), it determines whether the teaching pendant, which is the input unit 3, is actually connected (ST6). If the processor 21 determines that the teaching pendant is actually connected despite the teaching pendant-less function being enabled (ST6: YES), the processor 21 outputs an error message indicating an abnormal state (an example of error information) (ST7). This output may be displayed on the display unit 31 of the input unit 3, for example, to inform the user of the abnormal state (error information).

[0034] If the processor 21 determines that the teaching pendant is not actually connected (ST6: NO), it determines whether or not it has received an input corresponding to the information regarding the selected stop execution mode (ST8). If the processor 21 has not received an input corresponding to the information regarding the selected stop execution mode (ST8: NO), it determines that the robot body 1 is in a state where it can continue to operate in the operating mode with the teaching pendant-less function (ST9). On the other hand, if the processor 21 has received an input corresponding to the information regarding the selected stop execution mode (ST8: YES), it determines that the robot body 1 should be stopped as an emergency stop (ST10).

[0035] Specifically, the processor 21 works in cooperation with the memory 22 to obtain information about the selected stop execution mode (ST3), and if one or more inputs are assigned to emergency stop and an input corresponding to the information about the selected stop execution mode is received (ST4, ST8: both YES), the robot is stopped (ST10). This provides flexibility in the means of stopping the robot when the user wants to stop it, such as in the case of an emergency stop.

[0036] Furthermore, when the teaching pendant, which is the input unit 3, is connected (ST6: YES), the processor 21 outputs error information (ST7) if one or more inputs are assigned to emergency stop and it receives an input corresponding to the information regarding the selected stop execution mode (ST4, ST6: both YES). Also, when the teaching pendant, which is the input unit 3, is not connected (teaching pendantless function) (ST1: YES), the processor 21 acquires information regarding the selected stop execution mode (ST3), and stops the robot (ST10) if it receives an input corresponding to the information regarding the selected stop execution mode (ST8: YES).

[0037] (Note) The following technologies are disclosed based on the descriptions of each embodiment above.

[0038] (Technology 1) A control device (control unit 2) for a robot (robot body 1), comprising a processor (21) and a memory (22), wherein the processor (21) cooperates with the memory (22) to acquire information regarding a selected stop execution mode (ST3), and when it receives an input corresponding to the information regarding the selected stop execution mode (ST6: YES), it stops the robot (ST7).

[0039] This configuration allows for flexibility in how the robot can be stopped, for example, in the event of an emergency stop, when the user wants to stop the robot.

[0040] (Technical 2) The robot control device (control unit 2) described in (Technical 1), wherein the processor (21) outputs error information when it receives an input corresponding to the information regarding the selected stop execution mode while the teaching pendant (input unit 3) is connected.

[0041] This configuration provides flexibility in how to safely stop the robot, for example, when the user wants to stop the robot in an emergency.

[0042] (Technical 3) The robot control device (control unit 2) described in (Technical 1) to (Technical 2), wherein the processor (21) is connected to a plurality of input terminals (input connector 2111), and the input corresponding to the information regarding the selected stop execution mode is input to the processor (21) from any of the plurality of input terminals selected.

[0043] This configuration allows for flexibility in the input terminals, which constitute part of the means for stopping the robot, for example, when a user wants to stop the robot in an emergency.

[0044] (Technology 4) When the teaching pendant (input unit 3) is not connected, the processor (21) acquires information regarding the selected stop execution mode, and stops the robot (robot main body 1) when an input corresponding to the information regarding the selected stop execution mode is received. The robot control device (control unit 2) described in (Technology 1) to (Technology 3).

[0045] With this configuration, even in a mode where the teaching pendant (input unit 3) is not connected, for example, when the user wants to stop the robot such as during an emergency stop, flexibility can be provided in the means for realizing the stop of the robot.

[0046] (Technology 5) The robot control device described in (Technology 4), wherein the processor (21) enables only a user with authority to switch on / off the mode in which the teaching pendant (input unit 3) is not connected.

[0047] With this configuration, while improving security, for example, when the user wants to stop the robot such as during an emergency stop, flexibility can be provided in the means for realizing the stop of the robot.

[0048] (Technology 6) The stop execution mode is selected from a plurality of options. The robot control device (control unit 2) described in (Technology 1) to (Technology 5).

[0049] With this configuration, for example, when the user wants to stop the robot such as during an emergency stop, flexibility can be provided in the stop execution mode for realizing the stop of the robot.

[0050] (Technology 7) A method for controlling a robot (robot main body 1), which acquires information regarding a selected stop execution mode (ST3), and stops the robot (ST7) when an input corresponding to the information regarding the selected stop execution mode is received (ST6: YES). A robot control method.

[0051] With this configuration, for example, when the user wants to stop the robot such as during an emergency stop, flexibility can be provided in the method for realizing the stop of the robot.

[0052] (Technical 8) A robot control program for a robot (robot body 1), which acquires information regarding a selected stop execution mode (ST3), and stops the robot (ST7) when it receives an input corresponding to the information regarding the selected stop execution mode (ST6: YES).

[0053] This configuration allows for flexibility in the program that instructs the computer to stop the robot, for example, in the event of an emergency stop.

[0054] Although various embodiments have been described above with reference to the attached drawings, this disclosure is not limited to such examples. It will be obvious to those skilled in the art that various modifications, alterations, substitutions, additions, deletions, and equivalents can be conceived within the scope of the claims, and these will also be understood to fall within the technical scope of this disclosure. Furthermore, the components of the various embodiments described above can be arbitrarily combined without departing from the spirit of the invention.

[0055] This disclosure is useful as a presentation of a robot control device, a robot control method, and a robot control program that can have flexibility in the means for stopping the robot, for example, in the event of an emergency stop.

[0056] 1 Robot body 2 Control unit 21 Processor 211, 311 Safety circuit 22 Memory 3 Input unit 31 Display unit 4 External input device 10 PLC

Claims

1. A robot control device comprising a processor and a memory, wherein the processor cooperates with the memory to acquire information regarding a selected stop execution mode, and stops the robot when it receives an input corresponding to the information regarding the selected stop execution mode.

2. The robot control device according to claim 1, wherein the processor outputs error information when it receives an input corresponding to the selected stop execution mode information while a teaching pendant is connected.

3. The robot control device according to claim 1 or 2, wherein the processor is connected to a plurality of input terminals, and an input corresponding to the information regarding the selected stop execution mode is input to the processor from any of the plurality of input terminals selected from among them.

4. The robot control device according to claim 1 or 2, wherein the processor acquires information regarding a selected stop execution mode when the teaching pendant is not connected, and stops the robot when it receives an input corresponding to the information regarding the selected stop execution mode.

5. The robot control device according to claim 4, wherein the processor allows only authorized users to switch the mode in which the teaching pendant is not connected on or off.

6. The robot control device according to claim 1 or 2, wherein the stop execution mode is selected from a plurality of options.

7. A robot control method comprising: acquiring information regarding a selected stop execution mode; and stopping the robot when an input corresponding to the information regarding the selected stop execution mode is received.

8. A robot control program that obtains information regarding a selected stop execution mode and instructs a computer to stop the robot when it receives an input corresponding to the information regarding the selected stop execution mode.

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