Ethercat-based laser control method and system

Abstract

The invention relates to a laser device control method and system based on EtherCAT, the laser device control method is applied to an electric control cabinet in the laser device control system, the laser device control system comprises a target laser device and the electric control cabinet, and the electric control cabinet and the target laser device are in communication connection through EtherCAT; the laser control method comprises the steps of judging whether a cutting process of a target laser is a fly cutting process or not; if the process is a fly cutting process, the duty ratio in the control information sent to the target laser is kept to be 100%, and light emitting of the target laser is controlled through a PMW signal output by a PMW interface of the target laser; and if the process is not the fly cutting process, the PMW signal is kept at a high level, and the light emitting of the target laser is controlled by controlling the duty ratio in the information, so that the problem that the existing scheme is easily interfered is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser cutting, and in particular to a laser control method and system based on EtherCAT. Background Art

[0002] At present, the existing solutions mainly use analog 0~10V and 24V IO signals to control the light emission of the laser, and due to its advantages of low cost and simple implementation, this solution has been widely used in laser control systems.

[0003] However, the above solution has the problem of being easily interfered. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a laser control method and system based on Ethercat, which solves the technical problem of being easily interfered in the prior art.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, an embodiment of the present invention provides a laser control method based on Ethercat, which is applied to an electric control cabinet in a laser control system, wherein the laser control system includes a target laser and an electric control cabinet, and the electric control cabinet and the target laser are connected via EtherCAT communication; the laser control method includes: determining whether the cutting process of the target laser is a fly-cut process; if it is a fly-cut process, maintaining the duty cycle in the control information sent to the target laser at 100%, and controlling the light emission of the target laser through a PMW signal outputted by its PMW interface; if it is not a fly-cut process, maintaining the PMW signal at a high level, and controlling the light emission of the target laser through the duty cycle in the control information.

[0009] In a possible embodiment, the control information includes a laser power value, a red light power value, a cycle value, and a duty cycle.

[0010] In a possible embodiment, the control method further includes: after receiving a light emission pause signal sent by the target laser, controlling to shut down the light emission of the target laser; wherein the light emission pause signal is triggered and generated by the target laser after determining that the target value is greater than a preset threshold, and the target value is calculated based on the signal strength and temperature value of the optical signal detected by the target laser, the optical signal is the optical signal returned from the optical fiber to the laser, and the temperature value is the temperature at the specified optical fiber position.

[0011] In a possible embodiment, the target value is calculated as follows:

[0012]

[0013] In the formula, a represents the target value; D 实 Indicates the signal strength of the optical signal detected by the target laser; D 阈 represents the upper threshold of the signal strength of the optical signal detected by the target laser; w1 represents the first weight value; T 实 Indicates the temperature value detected by the target laser; T 阈 represents the upper limit threshold of the temperature value detected by the target laser; w2 represents the second weight value.

[0014] In one possible embodiment, the electric control cabinet includes a display screen; the control method further includes: after receiving the real-time light output power sent by the target laser, controlling the display screen to display the real-time light output power in real time; wherein the real-time light output power is determined by the product value of the laser value W near the LOE interface inside the cutting head detected by the target laser and the pre-stored power-to-light coefficient ratio K.

[0015] In a possible embodiment, the power-to-light intensity coefficient ratio K is determined during the power calibration process of a new target laser when it leaves the factory.

[0016] In a possible embodiment, the target laser is any one of a plurality of lasers communicatively connected to the electric control cabinet; the control method further comprises: after receiving a pause processing signal sent by the target laser, controlling the target laser to pause processing; wherein the pause processing signal is triggered and generated by the target laser when it is determined that the power difference is less than its own power value, and the power difference is the difference between the maximum power supply value in the current area and the sum of the powers of all the remaining lasers except the target laser among the plurality of lasers.

[0017] In a second aspect, an embodiment of the present invention provides a laser control system, including a target laser and an electric control cabinet, wherein the electric control cabinet and the target laser are connected via EtherCAT communication, and the electric control cabinet is used to execute the Ethercat-based laser control method as described in any one of the first aspects.

[0018] (III) Beneficial effects

[0019] The beneficial effects of the present invention are:

[0020] The embodiment of the present application provides a laser control method and system based on EtherCAT. The laser control system includes a target laser and an electric control cabinet, and the electric control cabinet and the target laser are connected through EtherCAT communication. The electric control cabinet determines whether the cutting process of the target laser is a fly-cutting process. If it is a fly-cutting process, the duty cycle in the control information sent to the target laser is maintained at 100%, and the light emission of the target laser is controlled through the PMW signal output by its PMW interface. If it is not a fly-cutting process, the PMW signal is maintained at a high level, and the light emission of the target laser is controlled by the duty cycle in the control information. Compared with the existing solution, since Ethercat transmission has high reliability and precise signal transmission characteristics, it solves the problem of being easily interfered in the existing solution.

[0021] In order to make the above-mentioned objectives, features and advantages to be achieved by the embodiments of the present application more obvious and understandable, the following specifically cites preferred embodiments and describes them in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of a laser control system provided in an embodiment of the present application is shown;

[0024] Figure 2 A flowchart of a laser control method based on Ethercat provided in an embodiment of the present application is shown;

[0025] Figure 3 A schematic diagram of a fly-cut timing diagram provided in an embodiment of the present application is shown;

[0026] Figure 4 A schematic diagram of a non-flying-cut timing diagram provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0027] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0028] In order to solve the problem of being easily interfered with in the prior art, an embodiment of the present application provides a laser control method and system based on EtherCAT, wherein the laser control system includes a target laser and an electric control cabinet, and the electric control cabinet and the target laser are connected via EtherCAT communication, and the electric control cabinet determines whether the cutting process of the target laser is a flying cutting process. If it is a flying cutting process, the duty cycle in the control information sent to the target laser is maintained at 100%, and the light emission of the target laser is controlled by the PMW signal output by its PMW interface; if it is not a flying cutting process, the PMW signal is maintained at a high level, and the light emission of the target laser is controlled by the duty cycle in the control information. Compared with the existing solution, since Ethercat transmission has high reliability and precise signal transmission characteristics, it solves the problem of being easily interfered with in the existing solution.

[0029] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0030] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of a laser control system provided by an embodiment of the present application. Figure 1 As shown, the laser control system includes a target laser and an electric control cabinet, and the electric control cabinet and the target laser are connected via EtherCAT communication. Specifically:

[0031] The bus solution is adopted, and the traditional analog signal and complex IO communication interface are abandoned. The Ethercat master station is integrated in the electric control cabinet, while the PWM output IO interface and the safety relay IO interface are retained. In addition, the Ethercat slave station is integrated in the electric control cabinet, and the Ethercat master station and the Ethercat slave station are connected through the EtherCAT protocol, and the Ethercat slave station and the beam combining main control board are connected, and the beam combining main control board and n sub-control boards are connected. Among them, n is a preset positive integer.

[0032] It should be noted here that although Figure 1 The description is made by taking one target laser as an example, but those skilled in the art should understand that the electric control cabinet can also establish communication connections with multiple lasers, and the target laser is any one of the multiple lasers.

[0033] It should also be noted here that although Figure 1 The description is made by taking an electric control cabinet as an example, but technicians in this field can also replace it with other laser control terminals, and the embodiments of the present application are not limited to this.

[0034] Further, see Figure 2 , Figure 2 A flow chart of a laser control method based on EtherCAT provided in an embodiment of the present application is shown. Specifically, the laser control method is applied to an electric control cabinet in a laser control system, the laser control system includes a target laser and an electric control cabinet, and the electric control cabinet and the target laser are connected via EtherCAT communication; the laser control method includes:

[0035] Step S210, determining whether the cutting process of the target laser is a flying cutting process.

[0036] Specifically, when the laser emits light, the electric control cabinet will first determine whether it is a flying cutting process. The determination method is to identify whether there is a change in the height of the cutting head between different cutting line segments. If not, it is a flying cutting process.

[0037] Step S220: If it is a flying cutting process, the duty cycle in the control information sent to the target laser is kept at 100%, and the light emission of the target laser is controlled by the PMW signal outputted by its PMW interface.

[0038] It should be understood that the information included in the control information can be set according to actual needs, and the embodiments of the present application are not limited to this.

[0039] Optionally, the Ethercat master station in the electric control cabinet is responsible for transmitting the control information of the electric control cabinet to the Ethercat slave station, and the main information transmitted is shown in Table 1 below.

[0040] Table 1

[0041] Ethercat control information scope Laser power 0～100.00％ Red light power 0～100.00％ cycle 0~50us Duty Cycle 0～100％

[0042] It should also be understood that the specific steps of step S220 can be set according to actual needs, and the embodiments of the present application are not limited to this.

[0043] Specifically, if it is a fly-cut process, the electric control cabinet will keep the duty cycle at 100%. At this time, whether the laser emits light is completely controlled by the PWM signal. The specific timing is as follows: Figure 3 shown.

[0044] Step S230: If it is not a flying cutting process, the PMW signal is kept at a high level, and the light emission of the target laser is controlled by the duty cycle in the control information.

[0045] Specifically, if it is not the fly-cutting process, the electric control cabinet will keep the PWM signal at a high level. At the same time, the beam-combining main control board will automatically generate the corresponding square-wave timing according to the period and duty cycle. At this time, the output frequency of the laser does not联动 with the CNC (Computer Numerical Control) motion system. Whether the laser emits light is controlled by the duty-cycle signal sent by the laser control terminal, and the laser power is the value from 0 to 100.00% received from the bus.

[0046] When the duty cycle > 0 and the PWM signal level is high, the laser can perform the light-emitting action;

[0047] When the duty cycle ≤ 0, the laser will not emit light. When the PWM signal is low, the laser stops emitting light. The specific timing is as Figure 4 shown.

[0048] Therefore, the present application can achieve the purpose of the laser high-frequency switch light control system based on the Ethercat bus, improve the stability and accuracy of the laser, reduce costs, and improve the reliability and stability of the system.

[0049] In addition, the laser control method further includes: after receiving the light-emission pause signal sent by the target laser, controlling to turn off the light emission of the target laser; wherein, the light-emission pause signal is triggered and generated by the target laser after determining that the target value is greater than the preset threshold, and the target value is obtained by calculating based on the signal intensity and temperature value of the optical signal detected by the target laser. The optical signal is the optical signal returned from the optical fiber to the laser, and the temperature value is the temperature at the specified optical fiber position. The specific value of the preset threshold, etc., is set according to actual needs, and the embodiments of the present application are not limited thereto.

[0050] For example, in the case where the laser and the electric control cabinet can be connected through the Ethercat bus, a PD sensor can be built into the laser. The PD sensor can detect the optical signal returned from the optical fiber to the laser, and the signal intensity range is 0 to D max (for example, 0 to 4095). Through experimental measurement, the laser damage threshold is D 阈 , where 0 < D 阈 < D max , and the meaning of this value is that when the value of the returned light > D 阈 , there is a risk of damage to the laser optical path and pump source. The infrared thermopile sensor detects the temperature at the specific optical fiber position, and the temperature range is -T min ~T max (for example, -20°C to 1000°C). Through experimental measurement, the laser damage threshold temperature threshold T threshold is obtained, where -TminC < T threshold < Tmax.

[0051] Based on the above content, the beam combining main control board inside the laser performs signal sampling at a preset period (for example, 1ms, etc.). When a is greater than a preset threshold, the laser's light emission pause signal is triggered, and the signal can be transmitted through the Ethercat bus. After receiving the light emission pause signal, the electric control cabinet stops the CNC movement and turns off the laser's light emission signal. When a is less than or equal to the preset threshold, the laser's light emission start signal is triggered.

[0052] Among them, the calculation formula of the target value a is:

[0053]

[0054] In the formula, a represents the target value; D 实 Indicates the signal strength of the optical signal detected by the target laser; D 阈 represents the upper threshold of the signal strength of the optical signal detected by the target laser; w1 represents the first weight value; T 实 Indicates the temperature value detected by the target laser; T 阈 represents the upper limit threshold of the temperature value detected by the target laser; w2 represents the second weight value.

[0055] Therefore, the present application can reduce the pressure on the components inside the laser when momentary high reflection is detected during the laser cutting process or when high-reflection material processing is continuously performed, thereby extending the service life of the laser.

[0056] In addition, the laser control method further includes: after receiving the real-time optical power sent by the target laser, controlling the display screen to display the real-time optical power in real time; wherein the real-time optical power is determined by the product value of the laser value W near the LOE interface inside the cutting head detected by the target laser and the pre-stored power intensity coefficient ratio K. wherein the power intensity coefficient ratio K is determined in the power calibration process of the target laser when it is newly shipped out of the factory.

[0057] For example, as the laser is used for a longer time, its power will gradually decay, and the scattered light inside the laser through the optical fiber is not accurate. Therefore, this application connects the laser head through the Ethercat bus to detect the laser value near the LOE interface inside the cutting head, and the data update period can be 1ms (of course, it can also be set to other periods according to actual needs). Let this value be W, where W satisfies 0 <W<W max(For example, 65535W, etc.). In addition, when a new laser is shipped from the factory, a power calibration procedure is performed. The logic is that the laser emits light at full power and full duty, collects m sets of w values, and the interval time is 100ms. W = (w1 + w2 + ... wm) / m is obtained. At the same time, the laser output power P is obtained through a standard power meter. At this time, the power intensity coefficient ratio K = P / W is obtained. Among them, m is a preset positive integer, for example, m is 10.

[0058] And, the power intensity coefficient ratio K after calibration will be recorded in the EEPROM of the laser beam combining main control board, so W*K is the actual optical power of the laser. This actual optical power value can be output to the display screen of the electric control cabinet through the Ethercat bus for display.

[0059] In addition, the target laser is any one of the multiple lasers that are communicatively connected to the electric control cabinet; the control method further includes: after receiving a pause processing signal sent by the target laser, controlling the target laser to pause processing; wherein the pause processing signal is triggered by the target laser when it is determined that the power difference is less than its own power value, and the power difference is the difference between the maximum power supply power value in the current area and the sum of the powers of all remaining lasers among the multiple lasers except the target laser.

[0060] For example, each of the multiple lasers can have a built-in ID address, with values ​​from 1 to n representing the first laser to the nth laser, and a communication cycle of 1ms. A sequence is established in the laser beam combining main control board to record the current power values ​​Wn from 1 to n in real time, and store the maximum power supply value Wtotal in the current area. Each laser can send its own power to the electric control cabinet in real time through the Ethercat bus, which is then forwarded by the electric control cabinet, so that each laser can obtain the real-time power of other lasers connected to the electric control cabinet. Where n is a positive integer.

[0061] If the current laser is a, when Wa>Wtotal-(the sum of the powers of all lasers except the current laser a), the laser sends an action pause processing signal through Ethercat. At this time, the electric control cabinet will suspend the current processing and wait until Wa≤Wtotal-(the sum of the powers of all lasers except the current laser a), and then send a start processing signal.

[0062] Therefore, the present application can be used to stagger the light output of multiple lasers when they are running at the same time through the Ethercat bus to prevent impact on the power grid.

[0063] It should be understood that the above-mentioned Ethercat-based laser control method is only exemplary, and those skilled in the art may make various modifications based on the above-mentioned method, and the modified scheme also belongs to the protection scope of this application.

[0064] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0065] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0066] It should be noted that in the claims, any reference numerals placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third, etc., is for convenience of expression only and does not indicate any order. These words may be understood as part of the component name.

[0067] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0068] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after knowing the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0069] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include these modifications and variations.

Claims

1. A laser control method based on Ethercat, characterized in that: The laser control method is applied to an electric control cabinet in a laser control system, wherein the laser control system comprises a target laser and the electric control cabinet, and the electric control cabinet and the target laser are connected via EtherCAT communication; The laser control method comprises: Determining whether the cutting process of the target laser is a flying cutting process; If it is the fly-cut process, the duty cycle in the control information sent to the target laser is kept at 100%, and the light emission of the target laser is controlled by the PMW signal outputted by its PMW interface; If it is not the fly-cut process, the PMW signal is kept at a high level, and the light emission of the target laser is controlled by the duty cycle in the control information.

2. The laser control method according to claim 1, characterized in that: The control information includes a laser power value, a red light power value, a period value and the duty cycle.

3. The laser control method according to claim 1, characterized in that: The control method further comprises: After receiving the light emission pause signal sent by the target laser, the light emission of the target laser is controlled to be turned off; wherein the light emission pause signal is triggered and generated by the target laser after determining that the target value is greater than a preset threshold, and the target value is calculated based on the signal strength and temperature value of the optical signal detected by the target laser, the optical signal is the optical signal returned to the laser from the optical fiber, and the temperature value is the temperature of the specified optical fiber position.

4. The laser control method according to claim 3, characterized in that: The target value is calculated as follows: Wherein, a represents the target value; D 实 represents the signal intensity of the optical signal detected by the target laser; D 阈 represents the upper threshold value of the signal strength of the optical signal detected by the target laser; w1 represents the first weight value; T 实 represents the temperature value detected by the target laser; T 阈 represents the upper limit threshold of the temperature value detected by the target laser; w2 represents the second weight value.

5. The laser control method according to claim 1, characterized in that: The electric control cabinet includes a display screen; the control method further includes: After receiving the real-time light output power sent by the target laser, the display screen is controlled to display the real-time light output power in real time; wherein, the real-time light output power is determined by the product value of the laser value W near the LOE interface inside the cutting head detected by the target laser and the pre-stored power intensity coefficient ratio K.

6. The laser control method according to claim 5, characterized in that: The power intensity coefficient ratio K is determined during the power calibration process of the target laser when it is newly shipped from the factory.

7. The laser control method according to claim 1, characterized in that: The target laser is any one of the multiple lasers that are communicatively connected to the electric control cabinet; the control method further comprises: After receiving a processing pause signal sent by the target laser, the target laser is controlled to pause processing; wherein the processing pause signal is triggered and generated by the target laser when it is determined that the power difference is less than its own power value, and the power difference is the difference between the maximum power supply value in the current area and the power sum of all the remaining lasers among the multiple lasers except the target laser.

8. A laser control system, characterized in that: It comprises a target laser and an electric control cabinet, wherein the electric control cabinet and the target laser are connected via EtherCAT communication, and the electric control cabinet is used to execute the Ethercat-based laser control method according to any one of claims 1 to 7.

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