control device

Abstract

A control device that controls an actuator that moves a moving member possessed by a machine, includes a safety state monitoring section that monitors a safety state of an operator of the machine, a communication circuit that periodically receives state data indicating an operating state of the actuator and is capable of detecting an error in the state data, an actuator control section that controls the actuator and stops it if the number of times of detection of errors by the communication circuit is equal to or greater than a prescribed tolerance value, and a setting circuit that sets the prescribed tolerance value, the setting circuit making the prescribed tolerance value set different between when monitoring by the safety state monitoring section is valid and when it is not valid.

Description

Technical Field

[0001] This disclosure relates to a control device. Background Technology

[0002] Japanese Patent Application Publication No. 2021-82027 discloses a system for ensuring the safety of people from machinery operating in a factory. For input data based on a safety input signal, error detection processing based on CRC (Cyclic Redundancy Check) is performed. If an error is detected, the safety output signal is forcibly switched to OFF. Therefore, it can handle abnormal states such as malfunctions. Summary of the Invention

[0003] The goal is to improve the noise resistance of the machinery while maintaining the safety of operators.

[0004] This disclosure discloses a control device that controls an actuator that moves a moving component of a machine. The device includes: a safety status monitoring unit that monitors the safety status of the operator of the machine; a communication circuit that periodically receives status data representing the operating status of the actuator and is capable of detecting errors in the status data; an actuator control unit that controls and stops the actuator when the number of error detections by the communication circuit exceeds a predetermined tolerance value; and a setting circuit that sets the predetermined tolerance value, and the setting circuit sets the predetermined tolerance value differently depending on whether the monitoring by the safety status monitoring unit is effective or ineffective. Attached Figure Description

[0005] Figure 1 This is a diagram showing an example of the structure of a machine.

[0006] Figure 2A and Figure 2B This is a diagram illustrating an example of receiving status data.

[0007] Figure 3 This is a diagram illustrating the relationship between monitoring by the safety status monitoring department, the opening and closing of safety doors, and the specified tolerance values.

[0008] Figure 4 This is a diagram illustrating an input / output device.

[0009] Figure 5 This is a flowchart illustrating the processing steps for actuator control.

[0010] Figure 6 This is a diagram showing an example of the structure of a machine.

[0011] Figure 7 This is a flowchart illustrating the processing steps for actuator control.

[0012] Figure 8 This is a diagram showing an example of the structure of a machine.

[0013] Figure 9 This is a flowchart illustrating the processing steps for actuator control.

[0014] Figure 10 This is a flowchart illustrating the processing steps for actuator control.

[0015] Figure 11 This is a diagram showing an example of the structure of a machine.

[0016] Figure 12 This is a flowchart illustrating the processing steps for actuator control.

[0017] Figure 13 This is a diagram showing an example of the structure of a machine.

[0018] Figure 14 This is a flowchart illustrating the processing steps for actuator control.

[0019] Figure 15 This is a flowchart illustrating the processing steps for actuator control. Detailed Implementation

[0020] During machine operation, operators sometimes perform certain tasks on the machine. Because the machine has various moving parts that can be moved by various actuators, it is necessary to monitor the safety status of the operators. When monitoring the safety status of the operators is effective, it is preferable to perform various anomaly detection processes to detect abnormalities. As one type of anomaly detection process, for example, CRC can be used to detect errors in the status data representing the operating status of the actuators.

[0021] In the event of a mechanical malfunction, errors in the status data may be detected continuously. To ensure the safety of personnel operating the machinery in such cases, it is preferable to stop the actuators. However, if no mechanical malfunction occurs, but transient noise causes errors in the status data, stopping the actuators every time noise occurs would reduce the machinery's noise immunity and decrease its operating rate; therefore, this is not preferable.

[0022] In other words, if operator safety is a consideration, errors in the status data should be detected sensitively; however, if the machine's noise immunity is a consideration, they should not be detected too sensitively. By stopping the actuator when the number of status data error detections exceeds the specified tolerance, a balance can be struck between operator safety and the machine's noise immunity.

[0023] However, the operating environments of machinery vary greatly. For example, machinery may be used in environments with high frequencies of transient noise. Alternatively, the machinery may operate automatically for extended periods even when no operator is performing any work around or inside it. When the specified tolerance values ​​are fixed and cannot be changed, the machinery's noise immunity decreases, and its operating rate may also decline. Therefore, it is desirable to improve the machinery's noise immunity while ensuring operator safety, based on the operating environment.

[0024] Figure 1 This diagram illustrates an example of the configuration of machine 10. Machine 10 includes a control device 12, an actuator 14, a moving member 16, an input / output device 18, and a motion status sensor 20. The actuator 14 moves the moving member 16. The actuator 14 is, for example, a drive device such as an amplifier or a motor. The moving member 16 is, for example, a worktable, a slide, a saddle, or a robot arm.

[0025] The input / output device 18 is operated by the operator of the machine 10, and may be a keyboard for inputting text, a display for displaying text and graphics, or a touch panel that combines input and output functions. The target stopping distance Lt, described later, is input by the operator through the input / output device 18.

[0026] The motion status sensor 20 generates status data representing the motion status of the actuator 14. The motion status sensor 20 is, for example, a sensor such as an encoder. Therefore, the status data contains information related to the moving speed Vm of the moving member 16, such as information about the number of revolutions of the actuator 14. The motion status sensor 20 periodically sends data frames containing the status data and a CRC code for error detection of the status data to the control device 12. The CRC code is calculated based on the status data.

[0027] At least a portion of the machine 10 is covered by the cover member 10c. Figure 1 In the example shown, the cover member 10c covers the entire machine 10. That is, the actuator 14, the moving member 16, the input / output device 18, and the motion status sensor 20 are all covered by the cover member 10c.

[0028] Safety door 10d is installed on cover member 10c. When an operator is performing a certain operation on machine 10, the operator opens safety door 10d to perform the operation. After the operation is completed, the operator closes safety door 10d. Therefore, when safety door 10d is open, the operator may perform preparatory work, maintenance work, or other work related to machine 10 around or inside machine 10. When safety door 10d is closed, the operator may not be performing any work related to machine 10.

[0029] A sensor for monitoring the safety status of operators of machine 10 is installed on machine 10. In this embodiment, an opening / closing sensor 22 is used as the sensor. The opening / closing sensor 22 detects the opening and closing of safety door 10d and outputs a detection signal showing its detection result to control device 12.

[0030] The control device 12 controls the machine 10. The control device 12 includes an arithmetic unit 30, a storage unit 32, a communication circuit 34, and a setting circuit 36. The arithmetic unit 30 includes a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). That is, the arithmetic unit 30 includes processing circuitry.

[0031] The storage unit 32 includes volatile memory such as RAM (Random Access Memory) and non-volatile memory such as ROM (Read Only Memory) or flash memory. The volatile memory is used as the processor's working memory. The non-volatile memory stores the programs executed by the processor and other necessary information.

[0032] The communication circuit 34 processes data frames containing data transmitted and received between the actuator 14, the input / output device 18, the operation status sensor 20, and the opening / closing sensor 22, and the arithmetic unit 30. The communication circuit 34 includes an error checking circuit, an error counter, and a CRC calculation circuit, none of which are shown in the figure.

[0033] A data frame contains data, a frame header, and a CRC code. When the communication circuit 34 receives data frames from various components, its error checking circuit uses the CRC code to check for errors in the data frames. If no errors are detected in the data frames, the communication circuit 34 transmits the data to the arithmetic unit 30.

[0034] If an error is detected in a data frame, the communication circuit 34 discards the data frame and increments the error counter that counts the number of error detections. In the event of an abnormality in the mechanical components 10 or transient noise, the number of error detections counted by the error counter in the communication circuit 34 may reach a value exceeding the specified tolerance value N. In this case, the communication circuit 34 outputs a notification signal indicating poor communication to the arithmetic unit 30. Furthermore, the specified tolerance value N is a threshold value for the number of error detections counted by the error counter.

[0035] The arithmetic unit 30 transmits the control signal data, used to control and stop the actuator 14, to the communication circuit 34 according to the notification signal. The communication circuit 34 sets the destination in the frame header corresponding to the actuator 14, which is the destination of the data to be transmitted for the control signal. Based on the control signal data and the frame header, the CRC operation circuit of the communication circuit 34 determines the CRC code by performing an operation using a prescribed formula. The communication circuit 34 generates and transmits a data frame by appending the determined CRC code to the data along with the frame header.

[0036] The setting circuit 36 ​​sets the specified tolerance value N in the error counter. The specified tolerance value N is determined by the arithmetic unit 30 as described later. That is, the setting circuit 36 ​​sets the specified tolerance value N determined by the arithmetic unit 30 in the error counter of the communication circuit 34.

[0037] The arithmetic unit 30 includes a safety status monitoring unit 50, an actuator control unit 52, a decision unit 54, a switching unit 56, an input receiving unit 58, and a speed calculation unit 60. The safety status monitoring unit 50, the actuator control unit 52, the decision unit 54, the switching unit 56, the input receiving unit 58, and the speed calculation unit 60 are realized by the arithmetic unit 30 executing the program stored in the storage unit 32.

[0038] At least one of the safety status monitoring unit 50, actuator control unit 52, decision unit 54, switching unit 56, input receiving unit 58 and speed calculation unit 60 can be implemented by integrated circuits such as ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), or electronic circuits containing discrete devices.

[0039] The safety status monitoring unit 50 monitors the safety status of the operators of the machine 10. The actuator control unit 52 controls the actuator 14. The actuator 14 operates or stops according to the control of the actuator control unit 52.

[0040] As described above, when the number of error detections counted by the error counter of the communication circuit 34 reaches a value exceeding the specified tolerance value N, a notification signal indicating poor communication is output from the communication circuit 34 to the arithmetic unit 30. Based on the notification signal, the safety status monitoring unit 50 causes the actuator control unit 52 to generate a control signal for controlling and stopping the actuator 14. The actuator control unit 52 stops the actuator 14 by sending this control signal to the actuator 14 via the communication circuit 34.

[0041] The decision unit 54 determines the specified tolerance value N. If the monitoring of the operator's safety status by the safety status monitoring unit 50 is effective, the decision unit 54 determines the specified tolerance value N as a first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the moving speed Vm of the moving member 16. The target stopping distance Lt of the moving member 16 is input by the operator through the input / output device 18, as described later, and is stored in the storage unit 32. The moving speed Vm of the moving member 16 is calculated by the speed calculation unit 60, as described later.

[0042] If the monitoring of the operator's safety status by the safety status monitoring unit 50 is ineffective, the decision unit 54 will determine the tolerance value N as the second tolerance value N2. The first tolerance value N1 and the second tolerance value N2 are different from each other. Regarding the different first tolerance value N1 and second tolerance value N2, the following will be used Figure 3 This will be discussed later.

[0043] The setting circuit 36 ​​sets the predetermined tolerance value N determined by the determination unit 54 to the error counter of the communication circuit 34. That is, the setting circuit 36 ​​sets the predetermined tolerance value N set to the error counter differently depending on whether the monitoring performed by the safety status monitoring unit 50 is effective or not. Two different types of predetermined tolerance values ​​N can be determined according to the operating environment of the operator using the machine 10. Therefore, depending on the operating environment of the operator using the machine 10, the noise immunity of the machine 10 can be improved while maintaining the safety of the operator.

[0044] The switching unit 56 acquires the detection signal from the opening / closing sensor 22 via the communication circuit 34. Based on the detection signal from the opening / closing sensor 22, the switching unit 56 switches between active and inactive monitoring of the operator's safety status performed by the safety status monitoring unit 50. Thus, monitoring can be switched based on whether the operator is performing work involving the machine 10 in the vicinity or inside the machine 10.

[0045] If the detection signal from the opening / closing sensor 22 indicates that the safety door 10d is open, the switching unit 56 enables the monitoring performed by the safety status monitoring unit 50. If the detection signal from the opening / closing sensor 22 indicates that the safety door 10d is closed, the switching unit 56 disables the monitoring performed by the safety status monitoring unit 50.

[0046] The input receiving unit 58 accepts text and other inputs via the input / output device 18 operated by the operator. When the target stopping distance Lt of the moving member 16 is input via the input / output device 18 operated by the operator, the input receiving unit 58 accepts the input target stopping distance Lt and saves it in the storage unit 32.

[0047] Furthermore, the target stopping distance Lt is the distance at which the moving member 16 must stop after the error checking circuit of the communication circuit 34 initially detects an error in the data frame. As described above, a data frame containing data for controlling the actuator 14 and stopping it is sent from the communication circuit 34 to the actuator 14. The actuator 14 stops based on the data of the control signals contained in the data frame. Along with the stopping of the actuator 14, the moving member 16 also stops and ceases to move.

[0048] That is, the target stopping distance Lt is a target value of the stopping distance Lm from the passing position of the moving member 16 at the time when the error in the data frame is initially detected to the stopping position of the moving member 16 based on the control signal from the arithmetic unit 30 to the actuator 14. The target stopping distance Lt is predetermined by the operator operating the input / output device 18.

[0049] The speed calculation unit 60 calculates the moving speed Vm of the moving member 16 based on the state data periodically received from the operation state sensor 20. The moving speed Vm of the moving member 16 calculated by the speed calculation unit 60 is used, as described above, to calculate the specified tolerance value N by the determination unit 54.

[0050] Figure 2A and Figure 2B This is a diagram illustrating an example of status data reception. In Figure 2A In the example shown, the control device 12 periodically receives status data representing the operating state of the actuator 14 from the motion status sensor 20. Data frames Fs containing the status data are transmitted by the motion status sensor 20 at periods T and received by the communication circuit 34 of the control device 12. The data frame Fs includes a frame header H, data D, and a CRC code C. The status data is contained in the data D.

[0051] exist Figure 2A The example illustrates N data frames Fs#1, Fs#2, Fs#3, ..., Fs#N. Errors in each data frame Fs are checked using the CRC code C of each data frame Fs via the error-checking circuit of communication circuit 34. Figure 2A In the example shown, all N data frames Fs are correctly received by the control device 12. Status data is transmitted to the arithmetic unit 30 of the control device 12 periodically T.

[0052] exist Figure 2B In the example shown, a data frame Fs containing status data is sent from the motion status sensor 20 to the control device 12 at a period T. However, if an error is detected in the data frame Fs by the error checking circuit of the communication circuit 34, the data frame Fs containing the status data is discarded. Each time an error is detected, the error counter increments.

[0053] exist Figure 2B In the example shown, all N data frames Fs#1, Fs#2, Fs#3, ..., Fs#N were detected as having errors. Therefore, the data frame Fs containing status data was discarded N times consecutively, and the error counter incremented the error detection count N times consecutively. The number of error detections reached the specified tolerance value N. A notification signal indicating poor communication was output from the communication circuit 34.

[0054] The safety status monitoring unit 50, having received the notification signal, causes the actuator control unit 52 to generate the aforementioned control signal. The communication circuit 34 generates a data frame Fi by appending a frame header H, which is set to the destination corresponding to the actuator 14, and a CRC code C, determined based on the data D and the frame header H, to the data D of the control signal generated by the actuator control unit 52.

[0055] The communication circuit 34 sends the data frame Fi to the actuator 14. The actuator 14 receives the data frame Fi and acquires the control signal from the actuator control unit 52. The actuator 14 stops according to the control signal.

[0056] In this embodiment, errors in data frames Fs are detected N times consecutively. However, if an error-free data frame Fs is received before N consecutive errors in data frames Fs are detected, the error counter can be reset to zero. Furthermore, the reset timing of the error counter can be set such that the count value of the error counter reaches a predetermined tolerance value N when N out of K consecutive data frames Fs have been detected as errors.

[0057] Figure 3 This diagram illustrates the relationship between the monitoring performed by the safety status monitoring unit 50, the opening and closing of the safety door 10d, and the specified tolerance value N. As described above, when the safety door 10d is open, it is assumed that an operator is performing work involving the machine 10 around or inside the machine 10. In this case, the monitoring of the operator's safety status performed by the safety status monitoring unit 50 becomes effective. The moving speed Vm of the moving member 16 is suppressed to a lower level.

[0058] In the event of a mechanical malfunction occurring while the safety door 10d is open, the actuator 14 stops to ensure the safety of the workers. If the number of error detections of data frame Fs reaches the specified tolerance value N, due to the possibility of a mechanical malfunction, the moving component 16 must stop at a position within a target stopping distance Lt from the position where the error in the aforementioned data frame Fs was initially detected.

[0059] The stopping distance Lm from the passing position of the moving member 16 to the actual stopping position of the moving member 16 is expressed by equation (1) based on the moving speed Vm of the moving member 16, the specified tolerance value N, and the period T. In addition, the offset Q is used in equation (1) taking into account the transmission delay factors of data frame Fs and data frame Fi.

[0060] Lm=(T×N+Q)×Vm・・・(1)

[0061] Therefore, the specified tolerance value N that makes the stopping distance Lm less than the target stopping distance Lt only needs to satisfy equation (2). The maximum specified tolerance value N that satisfies equation (2) is the first tolerance value N1 mentioned above used when the monitoring performed by the safety status monitoring unit 50 is effective. The specified tolerance value N determined by the determination unit 54 as the first tolerance value N1 is set in the error counter by the setting circuit 36. As a result, the safety of workers performing operations involving the machine 10 around or inside the machine 10 can be maintained.

[0062] N<{(Lt / Vm)-Q} / T・・・(2)

[0063] As described above, the target stopping distance Lt is predetermined by the operator operating the input / output device 18. The target stopping distance Lt is set according to the type, purpose, and installation environment of the machine 10. According to equation (2), the smaller the target stopping distance Lt, the smaller the first tolerance value N1. Furthermore, the greater the moving speed Vm of the moving member 16, the smaller the first tolerance value N1.

[0064] As described above, when safety door 10d is closed, it is assumed that no operator is performing any work involving machine 10 around or inside the machine 10. In this case, the monitoring of the operator's safety status by the safety status monitoring unit 50 becomes ineffective. Machine 10 may operate automatically for an extended period in this potentially unmanned environment. The operating environment of machine 10 is diverse; for example, there may be situations where machine 10 operates automatically for extended periods in locations where transient noise is frequently generated. Whenever transient noise occurs, errors in data frame Fs may be detected.

[0065] Thus, during the automatic operation of machine 10, if the specified tolerance value N is determined to be the same as the first tolerance value N1 when an operator is performing work involving machine 10 around or inside machine 10, then the noise immunity of machine 10 may decrease. Therefore, actuator 14 may stop shortly after machine 10 begins automatic operation. If the restarting and stopping of actuator 14 continues frequently thereafter, the operating rate of machine 10 will decrease.

[0066] Therefore, if the monitoring performed by the safety status monitoring unit 50 is ineffective, the specified tolerance value N is determined to be a second tolerance value N2, which is larger than the first tolerance value N1. The specified tolerance value N, which is determined to be the second tolerance value N2, is set in the error counter by the setting circuit 36. As a result, the noise immunity of the machine 10 can be improved while maintaining the safety of the operator, depending on the operating environment of the operator using the machine 10.

[0067] Figure 4 This is a diagram illustrating the input / output device 18. As described above, the operator can input the target stopping distance Lt by operating the input / output device 18. Figure 4 In the example shown, after the message “Please enter the target stopping distance”, there is an input field for the target stopping distance Lt.

[0068] If an operator operates the input / output device 18 and inputs the target stopping distance Lt in the input field, the input receiving unit 58 accepts the input target stopping distance Lt and saves it in the storage unit 32. That is, by accepting the input of the target stopping distance Lt, the target stopping distance Lt is predetermined. Based on this predetermined target stopping distance Lt, the determination unit 54 determines the specified tolerance value N as described above.

[0069] Figure 5 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. This processing step is repeated during the operation of the machine 10.

[0070] When this processing step begins, in step S1, the switching unit 56 determines whether a detection signal from the opening / closing sensor 22 has been acquired via the communication circuit 34. If the result is "yes" in step S1, the processing step proceeds to step S2. If the result is "no" in step S1, the processing step proceeds to step S7. In step S2, the switching unit 56 switches between active and inactive monitoring of the operator's safety status performed by the safety status monitoring unit 50 based on the detection signal acquired in step S1.

[0071] In step S3, the decision unit 54 determines whether the monitoring performed by the safety status monitoring unit 50 is effective. If the result in step S3 is "yes", this process proceeds to step S4. If the result in step S3 is "no", this process proceeds to step S21.

[0072] In step S4, the speed calculation unit 60 determines whether it has received status data from the motion status sensor 20 via the communication circuit 34. If the result is "yes" in step S4, the process proceeds to step S5. If the result is "no" in step S4, the process returns to step S4. In step S5, the speed calculation unit 60 calculates the moving speed Vm of the moving member 16 based on the status data obtained in step S4.

[0073] In step S6, the determination unit 54 determines the predetermined tolerance value N as a first tolerance value N1 based on the target stopping distance Lt stored in the storage unit 32 and the moving speed Vm of the moving member 16 calculated in step S5. In step S21, the determination unit 54 determines the predetermined tolerance value N as a second tolerance value N2.

[0074] In step S7, the safety status monitoring unit 50 determines whether a notification signal indicating poor communication has been received from the communication circuit 34. If the result in step S7 is "yes," the process proceeds to step S8. If the result in step S7 is "no," the process ends.

[0075] In step S8, the safety status monitoring unit 50 causes the actuator control unit 52 to generate a control signal for controlling and stopping the actuator 14. The actuator control unit 52 sends the control signal to the actuator 14 via the communication circuit 34, thereby stopping the actuator 14. When the processing of step S8 is completed, this processing step ends.

[0076] The above embodiments can also be modified as follows. In the following modifications, descriptions that are repeated in the embodiments are omitted.

[0077] (Variation Example 1)

[0078] In the above embodiment, the machine 10 is covered by the cover member 10c. A safety door 10d is provided on the cover member 10c. In this modified example 1, the machine 10 is not covered by the cover member 10c. No safety door 10d is provided. A sensor for monitoring the safety status of the operator of the machine 10 is installed on the machine 10. In this embodiment, the opening / closing sensor 22 is not used; instead, another sensor is used as the sensor.

[0079] Figure 6 This is a diagram showing an example of the configuration of machine 10. (For example...) Figure 6 As shown, a region sensor 80 is arranged around the machine 10. The region sensor 80 is, for example, a light curtain.

[0080] The area sensor 80 detects whether a worker has entered the monitoring area of ​​the machine 10. The area surrounding the machine 10 is preset as the monitoring area of ​​the machine 10 by the area sensor 80. When the area sensor 80 detects that a worker has entered the monitoring area of ​​the machine 10, it outputs a detection signal indicating the detection result to the control device 12. In this modified example 1, the area sensor 80 is used as the sensor to detect whether a worker has entered the monitoring area of ​​the machine 10, but a laser scanner can also be used instead of the area sensor 80.

[0081] The switching unit 56 acquires the detection signal from the area sensor 80 via the communication circuit 34. Based on the detection signal from the area sensor 80, the switching unit 56 switches between active and inactive monitoring of the operator's safety status performed by the safety status monitoring unit 50. Thus, monitoring can be switched based on whether the operator is performing work involving the machine 10 in the vicinity or inside the machine 10.

[0082] Figure 7 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. For use with... Figure 5 The same symbols are assigned to the same steps as those described above, and the explanations are omitted as appropriate.

[0083] When this processing step begins, in step S31, the switching unit 56 determines whether the detection signal of the area sensor 80 has been acquired via the communication circuit 34. If the result is "yes" in step S31, this processing step proceeds to step S2. If the result is "no" in step S31, this processing step proceeds to step S7.

[0084] (Variation Example 2)

[0085] In the above embodiment, if the monitoring of the operator's safety status by the safety status monitoring unit 50 is effective, the determination unit 54 determines a predetermined tolerance value N as a first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the moving speed Vm of the moving member 16. The setting circuit 36 ​​sets the predetermined tolerance value N determined by the determination unit 54 to the error counter of the communication circuit 34.

[0086] In this modified example 2, when the determination unit 54 determines the specified tolerance value N as the first tolerance value N1, the moving speed Vm of the moving member 16 is not used; instead, the monitoring reference speed Vs used to monitor the moving speed Vm of the moving member 16 is used. Therefore, the determination unit 54 can more easily determine the specified tolerance value N as the first tolerance value N1. The setting circuit 36 ​​sets the specified tolerance value N determined by the determination unit 54 in the error counter of the communication circuit 34.

[0087] Figure 8 This is a diagram showing an example of the configuration of machine 10. (Regarding...) Figure 1 Components marked with the same symbol are appropriately omitted from the description. The control device 12 further includes a speed monitoring unit 90. The speed monitoring unit 90 monitors whether the moving speed Vm of the moving component 16 exceeds the monitoring reference speed Vs. In this modified example 2, the specified tolerance value N satisfies equation (3) instead of equation (2). The maximum specified tolerance value N that satisfies equation (3) is the first tolerance value N1 mentioned above used when the monitoring performed by the safety status monitoring unit 50 is effective.

[0088] N<{(Lt / Vs)-Q} / T・・・(3)

[0089] The predetermined tolerance value N, determined by the decision unit 54 as the first tolerance value N1, is set in the error counter by the setting circuit 36. This ensures the safety of personnel performing operations involving the machine 10 around or inside the machine 10. According to equation (3), the smaller the target stopping distance Lt, the smaller the first tolerance value N1. Furthermore, the larger the monitoring reference speed Vs of the moving member 16, the smaller the first tolerance value N1.

[0090] Figure 9 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. For use with... Figure 5 The same symbols are assigned to the steps described above, and the descriptions are omitted as appropriate.

[0091] If "yes" is obtained in step S3, this process proceeds to step S41. In step S41, the decision unit 54 obtains the monitoring reference speed Vs of the moving member 16 from the speed monitoring unit 90. In step S6, the decision unit 54 determines the predetermined tolerance value N as the first tolerance value N1 based on the target stopping distance Lt stored in the storage unit 32 and the monitoring reference speed Vs of the moving member 16 obtained in step S41.

[0092] (Variation Example 3)

[0093] In the above embodiment, if the monitoring of the operator's safety status by the safety status monitoring unit 50 is effective, the determination unit 54 determines a predetermined tolerance value N as a first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the moving speed Vm of the moving member 16. The setting circuit 36 ​​sets the predetermined tolerance value N determined by the determination unit 54 to the error counter of the communication circuit 34.

[0094] In this modified example 3, when the determination unit 54 determines the specified tolerance value N as the first tolerance value N1, the moving speed Vm of the moving member 16 is not used; instead, the predetermined limited speed Vr of the moving member 16 is used. Therefore, the determination unit 54 can more easily determine the specified tolerance value N as the first tolerance value N1. The setting circuit 36 ​​sets the specified tolerance value N determined by the determination unit 54 in the error counter of the communication circuit 34.

[0095] The actuator control unit 52 controls the actuator 14 to move the moving member 16 at a predetermined limit speed Vr or less. The predetermined limit speed Vr is stored in the storage unit 32. In this modified example 3, the specified tolerance value N satisfies equation (4) instead of equation (2). The maximum specified tolerance value N that satisfies equation (4) is the first tolerance value N1 mentioned above used when the monitoring performed by the safety status monitoring unit 50 is effective.

[0096] N<{(Lt / Vr)-Q} / T・・・(4)

[0097] The predetermined tolerance value N, which is determined by the decision unit 54 as the first tolerance value N1, is set in the error counter by the setting circuit 36. This ensures the safety of personnel performing operations involving the machine 10 around or inside the machine 10. According to equation (4), the smaller the target stopping distance Lt, the smaller the first tolerance value N1. Furthermore, the greater the limiting speed Vr of the moving member 16, the smaller the first tolerance value N1.

[0098] Figure 10 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. For use with... Figure 5 The same symbols are assigned to the steps described above, and the descriptions are omitted as appropriate.

[0099] If "yes" is received in step S3, this process proceeds to step S51. In step S51, the determination unit 54 obtains the limit speed Vr of the moving member 16 from the storage unit 32. In step S6, the determination unit 54 determines the specified tolerance value N as the first tolerance value N1 based on the target stopping distance Lt stored in the storage unit 32 and the limit speed Vr of the moving member 16 obtained in step S51.

[0100] (Variation Example 4)

[0101] In the above embodiment, if the monitoring of the operator's safety status by the safety status monitoring unit 50 is effective, the determination unit 54 determines a predetermined tolerance value N as a first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the moving speed Vm of the moving member 16. The setting circuit 36 ​​sets the predetermined tolerance value N determined by the determination unit 54 to the error counter of the communication circuit 34.

[0102] In this variation 4, when the determination unit 54 determines the specified tolerance value N as the first tolerance value N1, the moving speed Vm of the moving member 16 is not used; instead, the acceleration Am of the moving member 16 is used. Therefore, the determination unit 54 can easily determine the specified tolerance value N as the first tolerance value N1 under acceleration control. The setting circuit 36 ​​sets the specified tolerance value N determined by the determination unit 54 in the error counter of the communication circuit 34.

[0103] Figure 11 This is a diagram showing an example of the configuration of machine 10. (Regarding...) Figure 1 Components labeled with the same symbol have their descriptions omitted appropriately. The control device 12 does not have a velocity calculation unit 60 but has an acceleration calculation unit 92. The status data generated by the motion status sensor 20 includes information about the acceleration Am of the moving component 16.

[0104] The acceleration calculation unit 92 calculates the acceleration Am of the moving member 16 based on the state data periodically received from the operation state sensor 20. The acceleration Am of the moving member 16 calculated by the acceleration calculation unit 92 is used by the determination unit 54 to calculate the specified tolerance value N as described above.

[0105] In this variation 4, the tolerance value N is specified to satisfy equation (5) instead of equation (2). The maximum specified tolerance value N that satisfies equation (5) is the first tolerance value N1 mentioned above used when the monitoring performed by the safety status monitoring unit 50 is effective.

[0106] N<{√(2Lt / Am)-Q} / T・・・(5)

[0107] The predetermined tolerance value N, which is determined by the decision unit 54 as the first tolerance value N1, is set in the error counter by the setting circuit 36. This ensures the safety of personnel performing operations involving the machine 10 around or inside the machine 10. According to equation (5), the smaller the target stopping distance Lt, the smaller the first tolerance value N1. Furthermore, the greater the acceleration Am of the moving member 16, the smaller the first tolerance value N1.

[0108] Figure 12 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. For use with... Figure 5 The same symbols are assigned to the steps described above, and the descriptions are omitted as appropriate.

[0109] If "yes" is received in step S4, this process proceeds to step S61. In step S61, the acceleration calculation unit 92 calculates the acceleration Am of the moving member 16 based on the state data obtained in step S4. In step S6, the determination unit 54 determines a predetermined tolerance value N as a first tolerance value N1 based on the target stopping distance Lt stored in the storage unit 32 and the acceleration Am of the moving member 16 calculated in step S61.

[0110] (Variation Example 5)

[0111] In the above-described variation 4, if the monitoring of the operator's safety status by the safety status monitoring unit 50 is effective, the determination unit 54 determines the predetermined tolerance value N as the first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the acceleration Am of the moving member 16. The setting circuit 36 ​​sets the predetermined tolerance value N determined by the determination unit 54 to the error counter of the communication circuit 34.

[0112] In this variation 5, when the determination unit 54 determines the specified tolerance value N as the first tolerance value N1, the acceleration Am of the moving member 16 is not used; instead, the monitoring reference acceleration As used to monitor the acceleration Am of the moving member 16 is used. Therefore, the determination unit 54 can more easily determine the specified tolerance value N as the first tolerance value N1. The setting circuit 36 ​​sets the specified tolerance value N determined by the determination unit 54 in the error counter of the communication circuit 34.

[0113] Figure 13 This is a diagram showing an example of the configuration of machine 10. (Regarding...) Figure 1 or Figure 11Components marked with the same symbol are omitted from the description as appropriate. The control device 12 further includes an acceleration monitoring unit 94. The acceleration monitoring unit 94 monitors whether the acceleration Am of the moving component 16 exceeds the monitoring reference acceleration As. In this modified example 5, the tolerance value N is specified to satisfy equation (6) instead of equation (5). The maximum specified tolerance value N that satisfies equation (6) is the first tolerance value N1 mentioned above used when the monitoring performed by the safety status monitoring unit 50 is effective.

[0114] N<{√(2Lt / As)-Q} / T・・・(6)

[0115] The predetermined tolerance value N, determined by the decision unit 54 as the first tolerance value N1, is set in the error counter by the setting circuit 36. This ensures the safety of personnel performing operations involving the machine 10 around or inside the machine 10. According to equation (6), the smaller the target stopping distance Lt, the smaller the first tolerance value N1. Furthermore, the larger the monitoring reference acceleration As of the moving member 16, the smaller the first tolerance value N1.

[0116] Figure 14 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. For use with... Figure 5 or Figure 12 The same symbols are assigned to the steps described above, and the descriptions are omitted as appropriate.

[0117] If "yes" is obtained in step S3, this process proceeds to step S71. In step S71, the decision unit 54 obtains the monitoring reference acceleration As of the moving member 16 from the acceleration monitoring unit 94. In step S6, the decision unit 54 determines the predetermined tolerance value N as the first tolerance value N1 based on the target stopping distance Lt stored in the storage unit 32 and the monitoring reference acceleration As of the moving member 16 obtained in step S71.

[0118] (Variation Example 6)

[0119] In the above-described variation 4, if the monitoring of the operator's safety status by the safety status monitoring unit 50 is effective, the determination unit 54 determines the predetermined tolerance value N as the first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the acceleration Am of the moving member 16. The setting circuit 36 ​​sets the predetermined tolerance value N determined by the determination unit 54 to the error counter of the communication circuit 34.

[0120] In this variation 6, when the determination unit 54 determines the specified tolerance value N as the first tolerance value N1, the acceleration Am of the moving member 16 is not used; instead, a predetermined limiting acceleration Ar of the moving member 16 is used. Therefore, the determination unit 54 can more easily determine the specified tolerance value N as the first tolerance value N1. The setting circuit 36 ​​sets the specified tolerance value N determined by the determination unit 54 in the error counter of the communication circuit 34.

[0121] The actuator control unit 52 controls the actuator 14 to move the moving member 16 by a predetermined limit acceleration Ar. The predetermined limit acceleration Ar is stored in the storage unit 32. In this modified example 6, the specified tolerance value N satisfies equation (7) instead of equation (5). The maximum specified tolerance value N that satisfies equation (7) is the first tolerance value N1 mentioned above used when the monitoring performed by the safety status monitoring unit 50 is effective.

[0122] N<{√(2Lt / Ar)-Q} / T・・・(7)

[0123] The predetermined tolerance value N, which is determined by the decision unit 54 as the first tolerance value N1, is set in the error counter by the setting circuit 36. This ensures the safety of personnel performing operations involving the machine 10 around or inside the machine 10. According to equation (7), the smaller the target stopping distance Lt, the smaller the first tolerance value N1. Furthermore, the greater the limiting acceleration Ar of the moving member 16, the smaller the first tolerance value N1.

[0124] Figure 15 This is a flowchart illustrating the processing steps of actuator control. This processing step is performed by executing a program stored in the storage unit 32 by the arithmetic unit 30 of the control device 12 after the target stopping distance Lt has been predetermined. For use with... Figure 5 or Figure 12 The same symbols are assigned to the steps described above, and the descriptions are omitted as appropriate.

[0125] If "yes" is obtained in step S3, this process proceeds to step S81. In step S81, the decision unit 54 obtains the limiting acceleration Ar of the moving member 16 from the storage unit 32. In step S6, the decision unit 54 determines the predetermined tolerance value N as the first tolerance value N1 based on the target stopping distance Lt stored in the storage unit 32 and the limiting acceleration Ar of the moving member 16 obtained in step S81.

[0126] (Variation Example 7)

[0127] In the above embodiment, if the monitoring performed by the safety status monitoring unit 50 is effective, the determination unit 54 determines a predetermined tolerance value N as a first tolerance value N1 based on the target stopping distance Lt of the moving member 16 and the moving speed Vm of the moving member 16. The target stopping distance Lt is predetermined. However, the target stopping distance Lt may not be predetermined. As a result, the time spent by the operator to input the target stopping distance Lt by operating the input / output device 18 can be reduced.

[0128] In this variation 7, the movement range of the moving member 16 is predetermined and stored in the storage unit 32. The status data generated by the motion status sensor 20 contains information about the position of the moving member 16. The distance from the passing position of the moving member 16 at the time when the error of the data frame Fs is initially detected to the position of the endpoint of the movement range of the moving member 16 is used as the target stopping distance Lt.

[0129] (Variation Example 8)

[0130] The above variations 1 to 7 can be appropriately combined within the scope of non-contradiction.

[0131] The following notes further disclose the above-described embodiments and variations.

[0132] (Note 1)

[0133] The control device 12 disclosed herein is a control device for controlling the actuator 14 that moves the moving member 16 of the machine 10. It includes: a safety status monitoring unit 50 that monitors the safety status of the operator of the machine; a communication circuit 34 that periodically receives status data indicating the operating status of the actuator and is capable of detecting errors in the status data; an actuator control unit 52 that controls the actuator and stops it when the number of error detections performed by the communication circuit is more than a predetermined tolerance value N; and a setting circuit 36 ​​that sets the predetermined tolerance value, and the setting circuit makes the set predetermined tolerance value different when the monitoring performed by the safety status monitoring unit is effective and when it is ineffective.

[0134] (Note 2)

[0135] As described in Appendix 1, in the case where the monitoring performed by the safety status monitoring unit is ineffective, the setting circuit can set the specified tolerance value to be larger than the case where the monitoring performed by the safety status monitoring unit is effective.

[0136] (Note 3)

[0137] The control device as described in Appendix 1 or 2 may include a switching unit 56, which switches between valid and invalid monitoring performed by the safety status monitoring unit based on detection signals from sensors installed on the machine.

[0138] (Note 4)

[0139] As described in Appendix 3, the sensor may be an opening / closing sensor 22 for detecting the opening and closing of a safety door 10d, which is disposed on a cover member 10c covering at least a portion of the machinery.

[0140] (Note 5)

[0141] As described in Appendix 3, the sensor may be an area sensor 80 that detects whether the operator has entered the monitored area of ​​the machine.

[0142] (Note 6)

[0143] As described in Appendix 3, the sensor may be a laser scanner that detects whether the operator has entered the monitored area of ​​the machine.

[0144] (Note 7)

[0145] As described in any one of Appendix 1 to 6, when the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance Lt that the moving member must stop after the error is detected.

[0146] (Note 8)

[0147] As described in Appendix 7, the control device includes information about the moving speed Vm of the moving member in the status data. The control device further includes a speed calculation unit 60 that calculates the moving speed based on the status data. When the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance and the calculated moving speed.

[0148] (Note 9)

[0149] The control device described in Appendix 7 further includes a speed monitoring unit 90 that monitors whether the moving speed of the moving member exceeds the monitoring reference speed Vs. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance and the monitoring reference speed.

[0150] (Postscript 10)

[0151] As described in Appendix 7, in the control device, the actuator control unit controls the actuator to move the moving member at a predetermined limit speed Vr or less. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance and the limit speed.

[0152] (Postscript 11)

[0153] As described in Appendix 7, the control device includes information about the acceleration Am when the moving member moves. The control device further includes an acceleration calculation unit 92 that calculates the acceleration based on the state data. When the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance and the calculated acceleration.

[0154] (Postscript 12)

[0155] The control device described in Appendix 7 further includes an acceleration monitoring unit 94 that monitors whether the acceleration of the moving member exceeds the monitoring reference acceleration As. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance and the monitoring reference acceleration.

[0156] (Postscript 13)

[0157] As described in Appendix 7, in the control device, the actuator control unit controls the actuator to move the moving member at a predetermined limit acceleration Ar or less. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit can set the specified tolerance value based on the target stopping distance and the limit acceleration.

[0158] (Postscript 14)

[0159] The control device as described in any one of Appendices 8 to 13 further includes an input receiving unit 58 that receives an input of the target stopping distance, and by receiving the input, the target stopping distance can be predetermined.

[0160] Although this disclosure has been described in detail, it is not limited to the various embodiments described above. Various additions, substitutions, modifications, and partial deletions can be made to these embodiments without departing from the spirit of this disclosure, or from the spirit of this disclosure derived from the claims and their equivalents. Furthermore, these embodiments can also be implemented in combination. For example, in the embodiments described above, the order of actions and the order of processes are shown as examples and are not intended to limit the scope. The same applies to instances where numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

[0161] Symbol Explanation

[0162] 10…Mechanical 12…Control Device

[0163] 14…Actuator 16…Moving component

[0164] 18…Input / output device 20…Action status sensor

[0165] 22… Opening / closing sensor 30… Computing unit

[0166] 32…Storage section 34…Communication circuit

[0167] 36… Setting circuit 50… Safety status monitoring unit

[0168] 52…Actuator Control Unit 54…Decision Unit

[0169] 56…Switching unit 58…Input receiving unit

[0170] 60…speed calculation unit 80…area sensor

[0171] 90… Speed ​​monitoring unit 92… Acceleration calculation unit

[0172] 94…Acceleration Monitoring Department.

Claims

1. A control device for controlling an actuator that moves a movable component of a machine, the control device being characterized by comprising: The safety status monitoring unit monitors the safety status of the operators of the machine. A communication circuit that periodically receives status data representing the operating state of the actuator and is capable of detecting errors in the status data; The actuator control unit controls the actuator and stops it when the number of times the error is detected by the communication circuit exceeds a predetermined tolerance value. as well as The setting circuit sets the specified tolerance value. When the monitoring performed by the safety status monitoring unit is effective and when it is ineffective, the setting circuit sets the specified tolerance value differently.

2. The control device as described in claim 1, characterized in that, If the monitoring performed by the safety status monitoring unit is ineffective, the setting circuit sets the specified tolerance value to be larger than if the monitoring performed by the safety status monitoring unit is effective.

3. The control device as described in claim 1 or 2, characterized in that, The device includes a switching unit that switches between valid and invalid monitoring performed by the safety status monitoring unit based on detection signals from sensors installed on the machine.

4. The control device as described in claim 3, characterized in that, The sensor is an opening / closing sensor for detecting the opening and closing of a safety door, which is mounted on a cover member that covers at least a portion of the machinery.

5. The control device as described in claim 3, characterized in that, The sensor is an area sensor that detects whether the operator has entered the monitored area of ​​the machine.

6. The control device as described in claim 3, characterized in that, The sensor is a laser scanner that detects whether the operator has entered the monitored area of ​​the machine.

7. The control device according to any one of claims 1 to 6, characterized in that, If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance at which the moving member must stop after the error is detected.

8. The control device as described in claim 7, characterized in that, The status data includes information about the moving speed of the moving component. The control device further includes a speed calculation unit that calculates the moving speed based on the state data. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance and the calculated moving speed.

9. The control device as described in claim 7, characterized in that, Furthermore, it includes a speed monitoring unit that monitors whether the moving speed of the moving component exceeds a monitoring reference speed. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance and the monitoring reference speed.

10. The control device as claimed in claim 7, characterized in that, The actuator control unit controls the actuator to move the moving member at a predetermined speed below a certain limit. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance and the speed limit.

11. The control device as claimed in claim 7, characterized in that, The status data includes information about the acceleration of the moving component during movement. The control device further includes an acceleration calculation unit that calculates the acceleration based on the state data. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance and the calculated acceleration.

12. The control device as claimed in claim 7, characterized in that, Furthermore, it includes an acceleration monitoring unit that monitors whether the acceleration of the moving component exceeds a monitoring reference acceleration during movement. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance and the monitoring reference acceleration.

13. The control device as claimed in claim 7, characterized in that, The actuator control unit controls the actuator to move the moving member at a predetermined limited acceleration. If the monitoring performed by the safety status monitoring unit is effective, the setting circuit sets the specified tolerance value based on the target stopping distance and the limiting acceleration.

14. The control device as described in any one of claims 8 to 13, characterized in that, Furthermore, it includes an input receiving unit that accepts the input of the target stopping distance. By accepting the input, the target stopping distance is predetermined.

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