Control system, communication device, and control method

Abstract

The control system includes: a calculation unit that executes an application program and calculates a first command value and a second command value; a signal output unit that outputs a control signal including a first command value in accordance with a control cycle signal indicating a synchronization reference; a communication unit that transmits, in accordance with a control cycle signal, a frame including a second command value in any communication mode that directly or indirectly uses a clock signal; a measurement unit that measures a time indicating a timing at which transmission of a frame is started from a synchronization reference indicated by the control cycle signal; and an adjustment unit that changes the cycle length of at least a part of the clock signal on the basis of the measured time.

Description

Technical Field

[0001] The invention relates to a control system, a communication device and a control method. Background Art

[0002] When controlling various devices, various fluctuations (jitters) may become a major cause of error. For example, Japanese Patent Application Laid-Open No. 2000-078875 (Patent Document 1) discloses a technique for reducing jitters caused by precision errors of phase detectors in servo control using a phase-synchronized loop.

[0003] Jitter may occur not only in detection devices such as phase detectors, but also in communications between devices. For example, Japanese Patent Application Laid-Open No. 2006-127514 (Patent Document 2) discloses a modular numerical control device capable of transmitting synchronization information with low jitter.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-078875

[0007] Patent Document 2: Japanese Patent Application Publication No. 2006-127514 Summary of the invention

[0008] Problems to be solved by the invention

[0009] In a system in which a plurality of mechanisms are controlled by a common control device, it is necessary to synchronize the control of the respective mechanisms with each other. The above-mentioned prior art documents do not take such a subject into consideration at all.

[0010] An object of the present invention is to provide a technology for improving control accuracy in a system that outputs a plurality of instruction values ​​using different transmission methods.

[0011] Means for solving problems

[0012] A control system of one example of the present invention includes: a calculation unit that executes an application to calculate a first instruction value and a second instruction value; a signal output unit that outputs a control signal including the first instruction value in accordance with a control cycle signal indicating a synchronization reference; a communication unit that sends a frame including the second instruction value in accordance with the control cycle signal in any communication method that directly or indirectly uses a clock signal; a measuring unit that measures a time indicating the timing of starting frame transmission from the synchronization reference indicated by the control cycle signal; and an adjustment unit that changes the cycle length of at least a portion of the clock signal based on the measured time.

[0013] According to this configuration, a frame including the second command value can be transmitted at a predetermined arbitrary timing relative to the timing at which the control signal including the first command value is outputted according to the control cycle signal. Even if there is a difference between the response time of the device operating according to the first command value and the response time of the device operating according to the second command value, synchronization between the devices can be achieved by adjusting the timing.

[0014] The measuring unit may measure the time based on the control cycle signal and the synchronization signal that changes at every predetermined cycle of the clock signal. According to this configuration, the timing of starting transmission of the frame including the second command value can be measured appropriately.

[0015] The measuring unit may also include: a first detecting unit that detects a pulse edge included in the control cycle signal; and a second detecting unit that detects a pulse edge included in the synchronization signal. According to this structure, by detecting the pulse edge included in the control cycle signal and the synchronization signal, the time indicating the timing of the start of frame transmission can be measured.

[0016] Alternatively, the adjustment unit determines the number of cycles for changing the period length of the clock signal so that the measured time matches the predetermined reference time. According to this configuration, the control of the timing adjustment can be facilitated by using the number of cycles required to match the measured time with the predetermined reference time.

[0017] The adjustment unit may determine the direction of changing the cycle length of the clock signal based on the magnitude relationship between the measured time and the reference time. According to this configuration, the direction of changing the cycle length of the clock signal can be easily determined.

[0018] Alternatively, the upper limit of the number of cycles of the clock signal whose cycle length is changed may be predetermined within one cycle of the control cycle signal. According to this configuration, by limiting the time width of the adjustment timing in each cycle of the control cycle signal, it is possible to avoid any influence on the frame communication.

[0019] The frame may correspond to a predetermined number of cycles of the clock signal. According to this configuration, the frame is composed of a predetermined number of cycles of the clock signal, so that the timing of transmitting the frame can be directly controlled by changing the cycle length of the clock signal.

[0020] According to another example of the present invention, a communication device is provided, which is connected to a calculation unit that executes an application program to calculate a first instruction value and a second instruction value, and a control unit that outputs a control signal including the first instruction value according to a control cycle signal indicating a synchronization reference. The communication device includes: a communication unit that transmits a frame including the second instruction value in accordance with the control cycle signal in any communication method that directly or indirectly uses a clock signal; a measuring unit that measures a time indicating a timing for starting frame transmission from the synchronization reference indicated by the control cycle signal; and an adjustment unit that changes the cycle length of at least a portion of the clock signal based on the measured time.

[0021] Another example of a control method of the present invention includes the following steps: executing an application to calculate a first instruction value and a second instruction value; outputting a control signal including the first instruction value according to a control cycle signal representing a synchronization reference; sending a frame including the second instruction value according to the control cycle signal in any communication method that directly or indirectly uses a clock signal; measuring a time indicating the timing of starting frame transmission from the synchronization reference indicated by the control cycle signal; and changing the cycle length of at least a portion of the clock signal based on the measured time.

[0022] Effects of the Invention

[0023] According to an aspect of the present invention, it is possible to improve control accuracy in a system that outputs a plurality of command values ​​using different transmission methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram showing a configuration example of a control system according to the present embodiment.

[0025] Figure 2 It is a schematic diagram showing a main hardware configuration example of the control system according to the present embodiment.

[0026] Figure 3 It is a schematic diagram showing a hardware configuration example related to transmission of a mirror control signal in the control system according to the present embodiment.

[0027] Figure 4 It is a timing chart showing a specific example of the mirror control signal of the control system according to the present embodiment.

[0028] Figure 5 This is a schematic diagram for explaining problems that may occur in the related technology of this embodiment.

[0029] Figure 6 This is a diagram for explaining a process of adjusting the timing of outputting a mirror control signal in the control system of the present embodiment.

[0030] Figure 7It is a schematic diagram showing the functional structure in the laser control unit of the control system according to the present embodiment.

[0031] Figure 8 It is a flowchart showing the processing procedure for adjusting the timing of the output mirror control signal in the control system according to the present embodiment.

[0032] Fig. 9 It is a diagram for explaining an operation example for absorbing the influence of jitter in the control system according to the present embodiment.

[0033] Fig.10 It is a diagram for explaining an operation example for absorbing the influence of jitter in the control system according to the present embodiment.

[0034] Fig.11 It is a diagram for explaining an operation example when the set time is changed in the control system according to the present embodiment.

[0035] Fig.12 It is a schematic diagram showing an example of the user interface screen displayed on the operation display device of the control system according to the present embodiment.

[0036] Fig.13 It is a schematic diagram showing another example of the hardware structure related to the transmission of the mirror control signal of the control system according to the present embodiment.

[0037] Fig.14 It is for explaining Fig.13 a diagram showing the method for generating the mirror control signal shown. Detailed Embodiment

[0038] The embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated.

[0039] <A. Application Example>

[0040] First, an example of the scenario to which the present invention is applied will be described.

[0041] Figure 1 It is a schematic diagram showing an example of the structure of the control system 1 according to the present embodiment. In Figure 1 as a typical example, an example of a laser processing system is shown, but the application of the present invention is not limited in any way.

[0042] The control system 1 performs laser processing such as drilling, cutting, and marking on the workpiece 4 disposed on the XY table 20. More specifically, the control system 1 includes a control device 10, an XY table 20, a laser 30, and a galvanometer mirror 40.

[0043] The laser processing of the workpiece 4 combines the adjustment of the workpiece position by the XY table 20 and the adjustment of the irradiation position of the laser light generated by the laser 30 by the galvanometer mirror 40. The displacement amount of the position adjustment of the workpiece 4 by the XY table 20 is relatively large, and the response time is relatively long. In contrast, the displacement amount of the irradiation position adjustment by the galvanometer mirror 40 is relatively small, and the response time is relatively short.

[0044] The control device 10 includes a main control unit 100 , a stage control unit 200 , and a laser control unit 300 .

[0045] The control device 10 may be connected to an operation display device 400 , and the operation display device 400 may output a command to the control device 10 in accordance with a user operation and output a calculation result in the control device 10 .

[0046] The main control unit 100 is equivalent to executing the application program 110 (see Figure 2 ) is a computing unit. The application program 110 is arbitrarily created according to the control target mechanism and the workpiece 4. The main control unit 100 executes the application program 110 and periodically calculates the command values ​​for the XY table 20, the laser 30, and the galvanometer mirror 40. The execution result (command value) obtained by the main control unit 100 executing the application program 110 is output from the table control unit 200 and the laser control unit 300.

[0047] The stage control unit 200 includes a signal output unit that outputs a stage control signal 520 (control signal) including a command value (first command value) for the XY stage 20. More specifically, the stage control unit 200 is connected to the XY stage 20 via a control line 52, and outputs the stage control signal 520 for driving the XY stage 20.

[0048] The XY table 20 includes a plate 22 on which the workpiece 4 is placed, and a servo motor 24 and a servo motor 26 for driving the plate 22. Figure 1 In the example shown, the servo motor 24 displaces the plate 22 in the X-axis direction, and the servo motor 26 displaces the plate 22 in the Y-axis direction.

[0049] The workbench control signal 520 from the workbench control unit 200 is provided to the servo driver 23 and the servo driver 25 (see Figure 2 ).

[0050] The laser control unit 300 is an example of a communication device, is connected to the laser 30 via a control line 53 , and outputs a laser control signal 530 for instructing the laser 30 to turn on or off.

[0051] In addition, the laser control unit 300 includes a communication unit that transmits a mirror control signal 540 (frame) including a command value (second command value) for the galvanometer mirror 40 in any communication method that directly or indirectly uses a clock signal. More specifically, the laser control unit 300 is connected to the galvanometer mirror 40 via a communication line 54 and outputs a mirror control signal 540 for indicating the irradiation position of the galvanometer mirror 40.

[0052] The galvanometer mirror 40 includes an X-axis scanning mirror 43, a Y-axis scanning mirror 45, and a lens 47. The light irradiated from the laser 30 propagates in the order of the lens 47, the Y-axis scanning mirror 45, and the X-axis scanning mirror 43 and is projected onto the XY stage 20.

[0053] The angle of the reflecting surface of the X-axis scanning mirror 43 is adjusted by an X-axis scanning motor 42, and the angle of the reflecting surface of the Y-axis scanning mirror 45 is adjusted by a Y-axis scanning motor 44. The relative distance between the lens 47 and the laser 30 is adjusted by a Z-axis scanning motor 46.

[0054] Here, the stage control signal 520 and the laser control signal 530 are electrical signals. The XY stage 20 and the laser 30 operate according to the level (potential or voltage) or change in level of the electrical signal. In contrast, the mirror control signal 540 is a communication signal obtained by modulating data representing the irradiation position.

[0055] In the control system 1, it is necessary to synchronize the adjustment of the workpiece position by the XY stage 20 with the adjustment of the irradiation position by the galvanometer mirror 40. On the other hand, the method of transmitting the command value is different between the stage control signal 520 and the laser control signal 530 and the mirror control signal 540.

[0056] This embodiment provides a solution for achieving more accurate synchronization even in the presence of such differences in the command value transmission method.

[0057] <B. Hardware Structure Example of Control System 1>

[0058] Next, a hardware structure example of the control system 1 of this embodiment will be described.

[0059] Figure 2 is a schematic diagram showing a main hardware structure example of the control system 1 of this embodiment. As described above, the control device 10 includes a main control unit 100, a stage control unit 200, and a laser control unit 300.

[0060] The main control unit 100 includes a processor 102, a main memory 104, a memory 106, and a bus controller 112 as main components.

[0061] The memory 106 is composed of an SSD (Solid State Disk), a flash memory, or the like, and stores, for example, a system program 108 for providing a basic program execution environment and an application program 110 arbitrarily created according to a purpose.

[0062] Typically, the processor 102 is composed of a CPU (Central Processing Unit), an MPU (Micro-Processing Unit), etc., reads out a system program 108 and an application program 110 stored in a memory 106, and executes them in a main memory 104, thereby achieving overall control of the control system 1.

[0063] The main control unit 100 is electrically connected to the stage control unit 200 and the laser control unit 300 via the internal bus 114. The bus controller 112 mediates data communication via the internal bus 114.

[0064] In addition, a structural example is shown in which the required processing is provided by executing a program by the processor 102, but part or all of the provided processing can also be implemented using a dedicated hardware circuit (for example, an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array), etc.).

[0065] The table control unit 200 generates and outputs a table control signal 520 to be provided to the servo driver 23 and the servo driver 25. More specifically, the table control unit 200 includes an axis control operation unit 210 and an output interface circuit 220.

[0066] The axis control calculation unit 210 obtains the command value calculated by the main control unit 100 executing the application program 110, and generates data to be provided to the servo driver 23 and the servo driver 25. The axis control calculation unit 210 is implemented by a calculation circuit composed of, for example, a processor, ASIC, or FPGA.

[0067] The axis control operation unit 210 has a periodic signal generator 212. The periodic signal generator 212 generates a control periodic signal 510 representing a synchronization reference between the table control unit 200 and the laser control unit 300. For example, the control periodic signal 510 is a signal that changes in a pulse shape and may include a pulse edge (rising or falling) as a synchronization reference.

[0068] The output interface circuit 220 is equivalent to a signal output unit, and outputs a table control signal 520 including a command value according to the control cycle signal 510. More specifically, the output interface circuit 220 generates the table control signal 520 provided to the servo driver 23 and the servo driver 25 according to the data generated by the axis control operation unit 210. The output interface circuit 220 outputs or updates the table control signal 520 at each timing determined based on the synchronization reference indicated by the control cycle signal 510.

[0069] The table control signal 520 may also be an electrical signal obtained by modulating information such as displacement, speed, angular velocity, etc. in each control cycle through PWM (Pulse Width Modulation).

[0070] The axis control calculation unit 210 and the output interface circuit 220 may also be implemented by a single ASIC or FPGA.

[0071] The laser control unit 300 generates and outputs a laser control signal 530 to be supplied to the laser 30 and a laser control signal 530 to be supplied to the galvanometer mirror 40. More specifically, the laser control unit 300 includes a laser control operation unit 310, an output interface circuit 314, and a communication interface circuit 316.

[0072] The laser control operation unit 310 obtains the command value calculated by the main control unit 100 executing the application program 110, and generates data to be provided to the laser 30 and the galvanometer mirror 40. The laser control operation unit 310 is implemented by a calculation circuit composed of a processor, ASIC, FPGA, etc.

[0073] The laser control operation unit 310 generates a laser control signal 530 and a mirror control signal 540 in synchronization with the control cycle signal 510 from the stage control unit 200. The laser control operation unit 310 has a clock generator 312 that generates a clock signal ( Figure 3 As will be described later, the clock generator 312 is capable of changing the cycle length of the clock signal.

[0074] The output interface circuit 314 outputs the laser control signal 530 including the command value according to the control period signal 510. More specifically, the output interface circuit 314 generates the laser control signal 530 provided to the laser 30 according to the data generated by the laser control arithmetic unit 310. As the laser control signal 530, an electric signal having two levels of on / off can be used. The output interface circuit 314 outputs or updates the laser control signal 530 at each timing determined based on the synchronization reference indicated by the control period signal 510.

[0075] The communication interface circuit 316 corresponds to the communication unit and transmits a frame including the command value in any communication method that directly or indirectly uses the clock signal according to the control period signal 510. More specifically, the communication interface circuit 316 communicates with the galvanometer mirror 40 and transmits the frame including the command value to the galvanometer mirror 40. The communication interface circuit 316 starts the transmission of the frame at each timing determined based on the synchronization reference indicated by the control period signal 510.

[0076] The communication between the communication interface circuit 316 and the galvanometer mirror 40 can use, for example, the XY2-100 protocol (a method of specifying the scanning angle range with 16-bit precision), the SL2-100 protocol (a method of specifying the scanning angle range with 20-bit precision), etc. In addition, not limited to the communication protocols specific to such galvanometer mirrors or galvanometer scanners, it can be applied to any communication method that directly or indirectly uses the clock signal.

[0077] In addition, the laser control arithmetic unit 310, the output interface circuit 314, and the communication interface circuit 316 can also be implemented by a single ASIC or FPGA.

[0078] <C. Mirror control signal 540>

[0079] Next, the structure related to transmitting the mirror control signal 540 (frame) via the communication line 54 will be described.

[0080] Figure 3 It is a schematic diagram showing an example of the hardware structure related to the transmission of the mirror control signal 540 of the control system 1 of the present embodiment. Figure 3 An example in which the XY2-100 protocol is adopted as the protocol for transmitting the mirror control signal 540 is shown. The XY2-100 protocol is classified as clock-synchronous serial communication that directly uses the clock signal.

[0081] Refer to Figure 3, in the case of adopting the XY2-100 protocol, the mirror control signal 540 includes the X-axis scanning instruction angle 543 (XDATA), the Y-axis scanning instruction angle 544 (Y DATA), and the Z-axis scanning instruction angle 545 (Z DATA) as the information transmitted from the laser control unit 300 to the galvanometer mirror 40. In addition, the mirror control signal 540 also includes the XY-axis current value 546 (XY STATUS) and the Z-axis current value 547 (ZSTATUS) as the information transmitted from the galvanometer mirror 40 to the laser control unit 300.

[0082] In addition, the mirror control signal 540 also includes a clock signal 541 (CLOCK) and a synchronization signal 542 (SYNC).

[0083] The communication interface circuit 316 includes a driver circuit for transmitting and receiving each signal.

[0084] Figure 4 is a timing chart showing a specific example of the mirror control signal 540 of the control system 1 of the present embodiment. Refer to Figure 4 , as each scanning instruction angle (X-axis scanning instruction angle 543, Y-axis scanning instruction angle 544, Z-axis scanning instruction angle 545), each bit constituting the frame 548 is sequentially sent out synchronously with the clock signal 541. Similarly, as each current value (XY-axis current value 546 and Z-axis current value 547), each bit constituting the frame 549 is sequentially sent out synchronously with the clock signal 541.

[0085] The synchronization signal 542 indicates the timing of sending the scanning instruction angle and the current value. In Figure 4 In the example shown, the scanning instruction angle and the current value each consist of 20 bits to form a frame. In this way, the frame corresponds to a predetermined number of cycles of the clock signal 541.

[0086] In Figure 4 In the example shown, 1 piece of information is transmitted in 20 cycles (cycles) of the clock signal 541. The clock signal 541 is, for example, a pulse signal of 2 MHz (1 cycle is 500 ns), so 1 frame is transmitted every 10 μs.

[0087] In this way, the communication interface circuit 316 of the laser control unit 300 outputs the mirror control signal 540 using a frame corresponding to a specified number of cycles of the clock signal 541.

[0088] <D. Problems and Solutions Related to Synchronization>

[0089] Next, the problems that may occur in the related art of the present embodiment and the solutions to these problems will be described.

[0090] Figure 5 This is a schematic diagram for explaining problems that may occur in the related technology of this embodiment. Figure 5 (A) shows an example of a timing diagram in the related art. Figure 5 (B) shows an example of a timing chart in this embodiment.

[0091] Reference Figure 5 (A), the control device 10 uses the pulse edge (e.g., rising edge) included in the control period signal 510 as a synchronization reference to output or update the worktable control signal 520 and the mirror control signal 540. In addition, regarding the laser control signal 530, the control period signal 510 can also be used as a synchronization reference to be output (or updated).

[0092] For example, after the pulse edge of the control period signal 510 is generated at time t1, the stage control signal 520 and the mirror control signal 540 are output at time t2. The response time of the galvanometer mirror 40 is shorter than the response time of the XY stage 20, so the irradiation position of the galvanometer mirror 40 reaches the target position first. That is, when the stage control signal 520 and the mirror control signal 540 are output at the same timing, there may be a deviation between the adjustment of the workpiece position by the XY stage 20 and the adjustment of the irradiation position by the galvanometer mirror 40.

[0093] Reference Figure 5 (B), in this embodiment, at least the timing of outputting the mirror control signal 540 can be adjusted relative to the synchronization reference (pulse edge) shown in the control cycle signal 510. Figure 5 In the example shown in (B), at time t2, the stage control signal 520 is output, and at the subsequent time t3, the mirror control signal 540 is output.

[0094] By adjusting the output timing of the mirror control signal 540 (ie, the frame transmission timing), the timing when the workpiece position of the XY stage 20 reaches the target position and the timing when the irradiation position of the galvanometer mirror 40 reaches the target position can be made consistent.

[0095] The mirror control signal 540 can adjust the output timing in units of frames, for example. In this case, the resolution of the timing adjustment is the frame length (10μs in the above example). Depending on the response time of the XY table 20, it can be the resolution of the frame length, and in the present embodiment, the output timing is adjusted in units of frames according to the cycle length of the clock signal. The cycle length of the clock signal can be changed, for example, in units of 10ns, which becomes the resolution of the timing adjustment. That is, by changing the cycle length of the clock signal, the resolution of the timing adjustment can be refined by about 1000 times (from 10μs units to 10ns units).

[0096] Figure 6 This is a diagram for explaining a process of adjusting the timing of outputting the mirror control signal 540 in the control system 1 of the present embodiment.

[0097] Figure 6 (A) shows an example of a case where the mirror control signal 540 is output 1000 ns after the synchronization reference (rise) indicated by the control cycle signal 510 . Figure 6 (B) shows an example of a case where the output of the mirror control signal 540 starts 1050ns after the synchronization reference (rise) shown in the control cycle signal 510. Hereinafter, the time from the synchronization reference shown in the control cycle signal 510 to the start of output of the mirror control signal 540 is referred to as "setup time". That is, the setup time refers to the time from the synchronization reference shown in the control cycle signal 510 to the start of frame transmission.

[0098] The cycle length of the control cycle signal 510 maintains an integer multiple relationship with the cycle length (standard) of the clock signal 541. That is, the cycle length of the control cycle signal 510 is set to an integer multiple of the cycle length of the clock signal 541.

[0099] For example, assuming that the cycle length of the control cycle signal 510 is 100 μs (= 100,000 ns) and the cycle length (standard) of the clock signal 541 is 500 ns. In this example, the cycle length of the control cycle signal 510 is 200 times the cycle length (standard) of the clock signal 541. In addition, the cycle length of the control cycle signal 510 can be set arbitrarily.

[0100] In addition, assuming that the cycle length of the clock signal 541 can be changed from 500 ns to 490 ns and 510 ns in increments of 10 ns, the setting time can be set in units of 10 ns based on the adjustment time width (10 ns) of the clock signal 541.

[0101] For example, the setting range of the setting time may be 0.5 μs to 9 μs, and the setting unit of the setting time may be 10 to 20 ns.

[0102] In the control system 1, the time from the synchronization reference indicated by the control cycle signal 510 to the initial fall of the synchronization signal 542 is measured. Hereinafter, the measured time is referred to as the "measurement time". The measurement time is equivalent to the time obtained by subtracting the period length of one cycle of the clock signal 541 from the synchronization reference indicated by the control cycle signal 510 to the start of frame transmission. That is, the measurement time is an example of the time indicating the timing of starting frame transmission from the synchronization reference indicated by the control cycle signal 510. In addition, the time until the initial rise of the synchronization signal 542 may also be measured.

[0103] The time from the fall to the rise of the synchronization signal 542 is equivalent to one cycle of the clock signal 541. Therefore, it is sufficient to control the time obtained by subtracting the cycle length (standard) of the clock signal 541 from the set time to match the measured time. Hereinafter, the time obtained by subtracting the cycle length (standard) of the clock signal 541 from the set time is referred to as the "reference time".

[0104] exist Figure 6 In the example shown in (A), the set time is 1000 ns and the reference time is calculated to be 500 ns. With respect to the reference time, the measured time is 500 ns, so the measured time is consistent with the reference time. That is, the mirror control signal 540 is output at a timing that matches the setting.

[0105] On the other hand, Figure 6 In the example shown in (B), the set time is 1050ns and the reference time is calculated to be 550ns. If the measured time is 500ns relative to the reference time, it is 50ns less than the reference time. That is, the output timing of the mirror control signal 540 is advanced by 50ns.

[0106] Therefore, in order to delay the output timing of the mirror control signal 540 by 50 ns, the cycle length of the clock signal 541 is changed. As described above, the cycle length of the clock signal 541 can be changed to 490 ns and 510 ns. Therefore, according to the time length to be delayed, the cycle of the clock signal 541 is extended by a predetermined number of cycles.

[0107] exist Figure 6 In the example shown in (B), the cycle length of the clock signal 541 is changed to 510ns (adjustment period) in 5 cycles. During this adjustment period, the phase of the clock signal 541 is delayed by 50ns. As a result, at least after the next rise of the synchronization signal 542, the mirror control signal 540 is output at a timing that meets the setting.

[0108] In this way, the control system 1 evaluates the deviation of the output timing of the mirror control signal 540 for each synchronization reference of the control cycle signal 510, and when it is determined that adjustment is necessary, changes the cycle length of the clock signal 541 according to the length of the deviation.

[0109] Figure 7 Schematic diagram showing the functional configuration of the laser control unit 300 of the control system 1 according to the present embodiment. Figure 7 In addition to the clock generator 312 , the laser control unit 300 further includes a reference time calculation unit 320 , pulse edge detection units 322 , 324 , a measurement unit 326 , and an adjustment unit 328 .

[0110] The reference time calculation unit 320 calculates the reference time based on the set time and the cycle length (standard) of the clock signal 541. More specifically, the reference time calculation unit 320 calculates the reference time by subtracting the cycle length (standard) of the clock signal 541 from the set time.

[0111] The pulse edge detection unit 322 detects a pulse edge (rising edge) included in the control cycle signal 510 .

[0112] The pulse edge detection unit 324 detects a pulse edge (falling edge) included in the synchronization signal 542 .

[0113] The measuring unit 326 outputs the measured time as an example of the time indicating the timing of starting the frame transmission from the synchronization reference indicated by the control cycle signal 510. The measuring unit 326 measures the time based on the control cycle signal 510 and the synchronization signal 542 that changes in each predetermined cycle of the clock signal 541. More specifically, the measuring unit 326 measures the time from when the pulse edge detection unit 322 detects the rise of the control cycle signal 510 to when the pulse edge detection unit 324 detects the fall of the synchronization signal 542.

[0114] Adjustment unit 328 changes the cycle length of at least a portion of clock signal 541 based on the time (measurement time) measured by measurement unit 216. Adjustment unit 328 determines the number of cycles for changing the cycle length of clock signal 541 so that the measurement time matches a predetermined reference time.

[0115] More specifically, the adjustment unit 328 determines the number of cycles to be included in the adjustment period and the adjustment direction based on the difference between the reference time and the measured time. For example, the direction of extending the cycle length of the clock signal 541 can be set to "positive", and the direction of shortening can be set to "negative". In this way, the adjustment unit 328 determines the direction of changing the cycle length of the clock signal 541 based on the magnitude relationship between the measured time of the measuring unit 216 and the reference time.

[0116] If applied to Figure 6 In the example shown in (B), the adjustment unit 328 decides to adjust the clock signal 541 in the "positive" direction for 5 cycles.

[0117] Figure 8 This is a flowchart showing a processing procedure for adjusting the timing of outputting the mirror control signal 540 in the control system 1 of the present embodiment. Figure 8 Each of the steps shown is typically executed by the laser control operation unit 310 of the laser control unit 300 .

[0118] Reference Figure 8The laser control unit 300 determines whether a pulse edge (rising edge) of the control cycle signal 510 is detected (step S100). If a pulse edge of the control cycle signal 510 is not detected ("No" in step S100), the process of step S100 is repeated.

[0119] When the pulse edge of the control cycle signal 510 is detected ("Yes" in step S100), the laser control unit 300 determines whether the pulse edge (falling edge) of the synchronization signal 542 is detected (step S102). If the pulse edge of the synchronization signal 542 is not detected ("No" in step S102), the process of step S102 is repeated.

[0120] When the pulse edge of the synchronization signal 542 is detected (Yes in step S102 ), the laser control unit 300 measures the time from the detection of the rising edge of the control cycle signal 510 to the detection of the falling edge of the synchronization signal 542 (step S104 ).

[0121] In this way, the laser control unit 300 measures the time (measured time) indicating the timing at which the transmission of the frame starts from the synchronization reference indicated by the control cycle signal 510 .

[0122] The laser control unit 300 calculates the difference between the measured time and the set time (step S106 ). Then, the laser control unit 300 determines whether the calculated difference is zero (step S108 ).

[0123] If the calculated difference is not zero ("No" in step S108), the laser control unit 300 determines the number of cycles and the adjustment direction to be included in the adjustment period based on the calculated difference (step S110). Then, the laser control unit 300 determines whether the pulse edge (rising edge) of the synchronization signal 542 is detected (step S112). If the pulse edge of the synchronization signal 542 is not detected ("No" in step S112), the process of step S112 is repeated.

[0124] When the pulse edge of the synchronization signal 542 is detected (Yes in step S112), the laser control unit 300 changes the cycle length of the clock signal 541 by the determined number of cycles (step S114). Next, the laser control unit 300 restores the cycle length of the clock signal 541 to its original value (step S116).

[0125] In this way, the laser control unit 300 changes the cycle length of at least a part of the clock signal 541 based on the measured time.

[0126] Then, the processing after step S100 is repeated.

[0127] If the calculated difference is zero (Yes in step S108), the processes after step S100 are repeatedly skipped.

[0128] <E. Operation Example>

[0129] Next, the operation example of the control system 1 will be described.

[0130] (e1: Influence of Jitter)

[0131] Jitter sometimes occurs in the cycle length of the control period signal 510. For example, the jitter generated in the control period signal 510 is several hundred ppm (Part Par Million: one in a million) of the cycle length of the control period signal 510, and the circuit jitter generated in the transceiver circuit of the control period signal 510 is about several tens of ns.

[0132] In the control system 1, even if the cycle length of the control period signal 510 fluctuates, the deviation of the output timing of the mirror control signal 540 can be adjusted.

[0133] Fig. 9 and Fig.10 are diagrams for explaining the operation example for absorbing the influence of jitter in the control system 1 of the present embodiment. Fig. 9 shows the operation example when the cycle length of the control period signal 510 becomes longer, Fig.10 shows the operation example when the cycle length of the control period signal 510 becomes shorter.

[0134] Referring to Fig. 9 , assume that the time length between the time T1 and the time T2, which is the rising timing of the control period signal 510, has become 10 ns longer due to jitter. As a result, the time (measurement time 352) from the rise of the control period signal 510 at time T2 to the fall of the synchronization signal 542 is 490 ns. If the set time 350 is 1000 ns and the reference time 351 is 500 ns, the difference 353 (measurement time 352 - reference time 351) is -10 ns. That is, it means that the timing is 10 ns ahead of the reference time 351.

[0135] To eliminate this difference 353, during the adjustment period, a clock signal 541 with a cycle length extended by one cycle is generated. The number of cycles to be generated during the adjustment period corresponds to the adjustment cycle number 354. At this time, the adjustment cycle number 354 is set to 1.

[0136] That is, the cycle length of the clock signal 541 immediately after the rise of the synchronization signal 542 is set to 510 ns. The cycle length of the subsequent clock signal 541 returns to the standard 500 ns.

[0137] Reference Fig.10 , assuming that the time length between time T1 and time T2, which are the rising timing of the control cycle signal 510, is shortened by 10ns due to jitter. As a result, the time (measurement time 352) from the rise of the control cycle signal 510 at time T2 to the fall of the synchronization signal 542 is 510ns. If the time 350 is set to 1000ns and the reference time 351 is 500ns, the difference 353 (measurement time 352-reference time 351) is +10ns. That is, it means that the timing is delayed by 10ns relative to the reference time 351.

[0138] In order to eliminate the difference 353, a clock signal 541 having a cycle length shortened by one cycle is generated during the adjustment period. At this time, the adjustment cycle number 354 is set to 1.

[0139] That is, the cycle length of the clock signal 541 immediately after the rise of the synchronization signal 542 is set to 490 ns. The cycle length of the clock signal 541 thereafter returns to the standard 500 ns.

[0140] As described above, the cycle length of the clock signal 541 immediately after the synchronization signal 542 rises is changed according to the difference 353. If the difference 353 (measured time 352-reference time 351) is a negative value, the cycle length of the synchronization signal 542 is changed to +10ns, and if the difference 353 is a positive value, the cycle length of the synchronization signal 542 is changed to -10ns. In addition, the number of cycles for changing the cycle length is determined according to the size of the difference 353.

[0141] (e2: Change of setting time)

[0142] Next, an operation example in which the setting time is changed during the output of the mirror control signal 540 will be described.

[0143] Fig.11 This is a diagram for explaining an operation example when the set time is changed in the control system 1 of the present embodiment. Fig.11 An operation example is shown in which the set time 350 is changed from 1000 ns to 2000 ns between time T11 and time T12.

[0144] Reference Fig.11 , the time from the rise of the control cycle signal 510 at time T11 to the fall of the synchronization signal 542 at time t11 (measured time 352) is 500ns, and the reference time 351 is 500ns, so the difference 353 is zero. As a result, the cycle length of the clock signal 541 is maintained at the standard 500ns between time T11 and time T12.

[0145] Between time T11 and time T12 (interval P1), when the setting time 350 is changed from 1000ns to 2000ns, at time T12, the reference time 351 is changed to 1500ns. The time (measurement time 352) from the rise of the control cycle signal 510 at time T12 to the fall of the synchronization signal 542 at time t12 is 500ns, so the difference 353 (measurement time 352-reference time 351) is -1000ns. In order to eliminate the difference 353, the clock signal 541 with the extended cycle length is determined to require 100 cycles. At this time, the adjustment cycle number 354 is set to 100.

[0146] Then, when the synchronization signal 542 rises immediately after time t12, a clock signal 541 having a cycle length of 510 ns is continuously generated. However, within one cycle of the control cycle signal 510, an upper limit value of the number of cycles of the clock signal 541 whose cycle length is changed may be set. Fig.11 In the example shown, 10 cycles are set as the upper limit. That is, the synchronization performance of one cycle of the control cycle signal 510 is 100ns. Therefore, after the synchronization signal 542 rises, when the cycle length of the clock signal 541 generated by 10 cycles is changed to 510ns, the cycle length of the clock signal 541 returns to the standard 500ns.

[0147] As a result, between time T12 and time T13, the output timing is adjusted by 10 ns×10 cycles=100 ns.

[0148] Next, the time (measured time 352) from when the control cycle signal 510 rises at time T13 to when the synchronization signal 542 falls at time t13 is 600 ns (delayed by 100 ns from 500 ns), so the difference 353 is -900 ns. In order to eliminate this difference 353, the adjustment cycle number 354 is set to 90.

[0149] Similar to the period from time T11 to time T12, after the synchronization signal 542 rises, when the clock signal 541 with a cycle length changed to 510 ns is generated for 10 cycles, the cycle length of the clock signal 541 returns to the standard 500 ns.

[0150] Similarly, the output timing of the mirror control signal 540 is adjusted by 100 ns for each cycle of the control cycle signal 510. As a result, the output timing of the mirror control signal 540 is adjusted to the set 2000 ns through 10 cycles (interval P2) of the control cycle signal 510.

[0151] Then, the cycle length of the clock signal 541 is maintained at the standard 500 ns (interval P3).

[0152] In addition, in Fig.11 the example shown, the upper limit value of the clock signal 541 whose cycle length can be changed can be arbitrarily set. Additionally, it is also possible not to set the upper limit value of the clock signal 541 whose cycle length can be changed.

[0153] (e3: Summary)

[0154] In the control system 1, in order not to affect the frame transmission synchronized with the clock signal 541, the number of clock signals 541 generated in each cycle of the control period signal 510 is made constant, and the cycle length of the clock signal 541 is gradually changed. As a result, the phase of the clock signal 541 with respect to the control period signal 510 is adjusted. By adjusting the phase, the output timing of the mirror control signal 540 can be arbitrarily changed with high resolution.

[0155] <F. User Interface>

[0156] Next, an example of the user interface provided to the control system 1 will be described. Typically, the user inputs settings for implementing the above-described processing via the operation display device 400 connected to the control device 10.

[0157] Fig.12 is a schematic diagram showing an example of the user interface screen 450 displayed on the operation display device 400 of the control system 1 of the present embodiment. Fig.12 An example of the user interface screen used when adjusting the output timing of the mirror control signal 540 is shown.

[0158] Referring to Fig.12 , the user interface screen 450 accepts the settings required for the above-described processing.

[0159] The user interface screen 450 includes: an input unit 452 that accepts the setting of the cycle length of the control period signal 510; a display unit 454 that displays the current output timing; an input unit 456 that accepts the setting of the changed output timing; a display unit 458 that displays the adjustment period required to change the output timing; and a setting reflection button 460.

[0160] The user pre-enters the cycle length of the control period signal 510 into the input unit 452. The operation display device 400 displays the currently set output timing on the display unit 454.

[0161] When the user wants to change the currently set output timing, the changed output timing is input into the input unit 456.

[0162] The operation display device 400 calculates the period required for adjusting the output timing based on the period length of the set control period signal 510, the current output timing, the changed output timing, and the synchronization performance, etc.

[0163] More specifically, the operation display device 400 calculates the number of cycles of the control period signal required for adjusting the output timing based on the change time of the output timing and the time width (synchronization performance) that can be adjusted in one cycle of the control period signal 510. In addition, a margin can be set in advance. For example, if the margin is 2, twice the calculated number of cycles is determined as the required period.

[0164] Finally, when the user selects the setting reflection button 460, the displayed setting content is sent to the control device 10.

[0165] The user uses the user interface screen 450 as described above to adjust the output timing of the galvanometer control signal 540 while observing the results of laser processing of the workpiece 4, etc.

[0166] <G. Other Embodiments>

[0167] In the above description, an example using the XY2-100 protocol is mainly described, but this solution can be applied to a communication method that indirectly uses a clock signal.

[0168] Fig.13 It is a schematic diagram showing another hardware structure example related to the transmission of the galvanometer control signal 540 of the control system 1 of the present embodiment. Fig.13 An example of using the SL2-100 protocol as the protocol for transmitting the galvanometer control signal 540 is shown. The SL2-100 protocol is classified as a clock asynchronous serial communication that indirectly uses a clock signal.

[0169] Refer to Fig.13 In the case of using the SL2-100 protocol, the galvanometer control signal 540 includes input data 551 (XY-IN) regarding the X-axis and Y-axis, output data 552 (XY-OUT) regarding the X-axis and Y-axis, input data 553 (Z-IN) regarding the Z-axis, and output data 554 (Z-OUT) regarding the Z-axis, as information transmitted from the laser control unit 300 to the galvanometer mirror 40.

[0170] In addition, the galvanometer control signal 540 does not include a clock signal (CLOCK) and a synchronization signal (SYNC).

[0171] Fig.14 It is for explaining Fig.13 The generation method of the galvanometer control signal 540 shown. As Fig.14As shown in (A) of FIG. , the mirror control signal 540 is composed of temporally continuous frames. A prescribed number (e.g., 192) of frames constitute one channel state block. Each frame contains two sub-frames. Each sub-frame contains a preamble at the beginning.

[0172] As Fig.14 shown in (B) of FIG. , the mirror control signal is composed of biphase mask data generated by modulating binary data using a clock signal. The cycle length of the clock signal used to generate the biphase mask data is adjusted by the above method. That is, by adjusting the cycle length of the clock signal, the length of each frame or each sub-frame is extended, and synchronization with the control period signal 510 can be achieved.

[0173] In this way, even in a communication method that indirectly uses a clock signal, synchronization between the control period signal 510 and the mirror control signal 540 can be maintained.

[0174] <H. Supplementary Note>

[0175] The above-described embodiment includes the following technical ideas.

[0176] [Structure 1]

[0177] A control system, wherein the control system has:

[0178] An arithmetic unit (100) that executes an application program (110) to calculate a first instruction value and a second instruction value;

[0179] A signal output unit (200; 220) that outputs a control signal (520) including the first instruction value in accordance with a control period signal (510) indicating a synchronization reference;

[0180] A communication unit (300; 316) that transmits a frame (540) including the second instruction value in any communication method that directly or indirectly uses a clock signal (541) in accordance with the control period signal;

[0181] A measurement unit (322, 324, 326) that measures the time indicating the timing of starting the transmission of the frame from the synchronization reference indicated by the control period signal; and

[0182] An adjustment unit (328) that changes the cycle length of at least a part of the clock signal based on the measured time.

[0183] [Structure 2]

[0184] In the control system described in Structure 1,

[0185] The measuring unit measures the time based on the control cycle signal and a synchronization signal that changes at every predetermined cycle of the clock signal.

[0186] [Structure 3]

[0187] In the control system described in Structure 2,

[0188] The measuring unit comprises:

[0189] a first detection unit (322) for detecting a pulse edge included in the control period signal; and

[0190] A second detection unit (324) detects a pulse edge included in the synchronization signal.

[0191] [Structure 4]

[0192] In the control system described in any one of structures 1 to 3,

[0193] The adjustment unit determines the number of cycles for changing the period length of the clock signal so that the measured time matches a predetermined reference time.

[0194] [Structure 5]

[0195] In the control system described in Structure 4,

[0196] The adjustment unit determines a direction of changing the cycle length of the clock signal based on a magnitude relationship between the measured time and the reference time.

[0197] [Structure 6]

[0198] In the control system described in any one of structures 1 to 5,

[0199] Within one cycle of the control cycle signal, an upper limit value of the number of cycles of the clock signal whose cycle length is changed is predetermined.

[0200] [Structure 7]

[0201] In the control system described in any one of structures 1 to 6,

[0202] The frame corresponds to a predetermined number of cycles of the clock signal.

[0203] [Structure 8]

[0204] A communication device (300) is connected to a calculation unit (100) that executes an application program (110) to calculate a first instruction value and a second instruction value, and a control unit (200) that outputs a control signal (520) including the first instruction value according to a control cycle signal (510) indicating a synchronization reference, wherein the communication device (300) comprises:

[0205] a communication unit (316) for transmitting a frame (540) including the second instruction value in accordance with the control cycle signal by any communication method using a clock signal directly or indirectly;

[0206] a measuring unit (322, 324, 326) for measuring a time indicating a timing at which transmission of the frame starts from a synchronization reference indicated by the control cycle signal; and

[0207] An adjustment unit (328) changes the cycle length of at least a part of the clock signal based on the measured time.

[0208] [Structure 9]

[0209] A control method, wherein the control method has the following steps:

[0210] Step (100), executing an application program (110) to calculate a first instruction value and a second instruction value;

[0211] Step (200), outputting a control signal (520) including the first command value according to a control period signal (510) indicating a synchronization reference;

[0212] Step (316), sending a frame (540) including the second command value in accordance with the control cycle signal by any communication method using a clock signal directly or indirectly;

[0213] Steps (S100 to S104), measuring a time indicating a timing of starting transmission of the frame from a synchronization reference indicated by the control cycle signal; and

[0214] Steps (S110 to S116) of changing the cycle length of at least a portion of the clock signal based on the measured time.

[0215] The embodiments disclosed this time should be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0216] Description of symbols

[0217] 1: control system; 4: workpiece; 10: control device; 20: XY table; 22: plate; 23, 25: servo drive; 24, 26: servo motor; 30: laser; 40: galvanometer mirror; 42: X-axis scanning motor; 43: axis scanning mirror; 44: Y-axis scanning motor; 45: Y-axis scanning mirror; 46: Z-axis scanning motor; 47: lens; 52, 53: control line; 54: communication line; 100: main control unit; 102: processor; 104: main memory; 106: storage; 108: system program; 110: application program; 112: bus controller; 114: internal bus; 200: workbench control unit; 210: axis control operation unit; 212: periodic signal generator; 216, 326: measurement unit; 220, 314: output interface circuit; 300: laser control unit; 310: laser control operation unit; 312: clock generator; 3 16: Communication interface circuit; 320: Reference time calculation unit; 322, 324: Pulse edge detection unit; 328: Adjustment unit; 350: Setting time; 351: Reference time; 352: Measurement time; 353: Difference; 354: Adjustment cycle number; 400: Operation display device; 450: User interface screen; 452, 456: Input unit; 454, 458: Display unit; 460: Setting reflection button; 510: Control cycle signal; 5 20: workbench control signal; 530: laser control signal; 540: reflector control signal; 541: clock signal; 542: synchronization signal; 543: X-axis scanning command angle; 544: Y-axis scanning command angle; 545: Z-axis scanning command angle; 546: axis current value; 547: Z-axis current value; 548, 549: frame; 551, 553: input data; 552, 554: output data; P1, P2, P3: interval.

Claims

1. A control system, wherein: The control system has: a calculation unit that executes the application program to calculate the first command value and the second command value; a signal output unit that outputs a control signal including the first command value according to a control period signal indicating a synchronization reference; a communication unit that transmits a frame including the second command value in accordance with the control period signal by any communication method that directly or indirectly uses a clock signal; a measuring unit that measures a time indicating a timing at which transmission of the frame starts from a synchronization reference indicated by the control period signal; as well as An adjustment unit changes a cycle length of at least a portion of the clock signal based on the measured time.

2. The control system according to claim 1, wherein: The measuring unit measures the time based on the control cycle signal and a synchronization signal that changes at every predetermined cycle of the clock signal.

3. The control system according to claim 2, wherein: The measuring unit comprises: a first detection unit configured to detect a pulse edge included in the control period signal; and The second detection unit detects a pulse edge included in the synchronization signal.

4. The control system according to any one of claims 1 to 3, wherein: The adjustment unit determines the number of cycles for changing the period length of the clock signal so that the measured time matches a predetermined reference time.

5. The control system according to claim 4, wherein: The adjustment unit determines a direction of changing the cycle length of the clock signal based on a magnitude relationship between the measured time and the reference time.

6. The control system according to any one of claims 1 to 5, wherein: Within one cycle of the control cycle signal, an upper limit value of the number of cycles of the clock signal whose cycle length is changed is predetermined.

7. The control system according to any one of claims 1 to 6, wherein: The frame corresponds to a predetermined number of cycles of the clock signal.

8. A communication device connected to a calculation unit that executes an application program to calculate a first instruction value and a second instruction value, and a control unit that outputs a control signal including the first instruction value according to a control period signal indicating a synchronization reference, wherein: The communication device has: a communication unit that transmits a frame including the second command value in accordance with the control period signal by any communication method that directly or indirectly uses a clock signal; a measuring unit that measures a time indicating a timing at which transmission of the frame starts from a synchronization reference indicated by the control period signal; as well as An adjustment unit changes a cycle length of at least a portion of the clock signal based on the measured time.

9. A control method, wherein: The control method has the following steps: executing the application program to calculate the first instruction value and the second instruction value; outputting a control signal including the first command value according to a control period signal indicating a synchronization reference; According to the control cycle signal, a frame including the second command value is transmitted by any communication method using a clock signal directly or indirectly; measuring a time indicating a timing at which transmission of the frame starts from a synchronization reference indicated by the control period signal; as well as Based on the measured time, a cycle length of at least a portion of the clock signal is changed.

Images