METHOD AND SYSTEM FOR SUPERVISION OF A SCAN OF AN ENERGY BEAM

Abstract

A method for supervision of a scan of an energy beam includes the following steps: providing an apparatus configured to provide the energy beam and a scanner to scan the energy beam, the scanner having two mirrors; operating the apparatus and the scanner such that the energy beam is provided while it is scanned according to a predetermined scanning pattern; determining, at least one processor of a computer device or system, an actual scanning pattern of the energy beam, when both the apparatus and the scanner are operated, by processing measurements provided by encoders of the two mirrors; and comparing, the at least one processor, the actual scanning pattern with a predetermined threshold area. A system for supervision of a scan of an energy beam includes an apparatus to provide the energy beam and a scanner to scan the laser beam, the scanner having two mirrors, each having at least an encoder; and a computing device or system with at least one processor.

Claims

1. A method for supervision of a scan of an energy beam, the method including the following steps: providing an apparatus configured to provide the energy beam providing a scanner configured to scan the energy beam, the scanner comprising a first mirror and a second mirror, and operating the apparatus and the scanner such that the energy beam is provided while it is scanned according to a predetermined scanning pattern, determining, by at least one processor of a computer device or system, an actual scanning pattern of the energy beam, while both the apparatus and the scanner are operated, by processing measurements provided by encoders of the first mirror and the second mirror, comparing, by the at least one processor, the actual scanning pattern with a predetermined threshold area, and determining, by the at least one processor, whether the scan of the energy beam is anomalous based on the comparison.

2. The method of claim 1, wherein the predetermined threshold area or a majority thereof does not comprise an expected scanning pattern; and determining whether the scan of the energy beam is anomalous comprises determining that the scan is anomalous when at least part of the actual scanning pattern is outside of the predetermined threshold area.

3. The method of claim 1, wherein the predetermined threshold area comprises an expected scanning pattern; and determining whether the scan of the energy beam is anomalous comprises determining that the scan is anomalous when at least part of the actual scanning pattern is inside of the predetermined threshold area.

4. The method of claim 1, further comprising at least one of: indicating, when it is determined that the scan of the energy beam is anomalous, that an object that was processed by the apparatus is incorrectly processed; and/or stopping the apparatus when it is determined that the scan of the energy beam is anomalous.

5. The method of claim 1, wherein the encoders of the first mirror and the second mirror provide the measurements with a frequency equal to or greater than 10 kHz.

6. The method of claim 1, wherein the scanner is operated such that each of a maximum angular coverage in a first direction and a maximum angular coverage in a second direction is greater than 0° and equal to or less than 20°, the first direction being perpendicular to the second direction.

7. The method of claim 6, wherein each maximum angular coverage is equal to or less than 5°.

8. The method of claim 6, wherein each maximum angular coverage is equal to or less than 1°.

9. The method of claim 1, further including the following steps: obtaining data indicative of the actual scanning pattern being different from the predetermined scanning pattern, and modifying the predetermined scanning pattern based on the data indicative of the actual scanning pattern.

10. A system for supervision of a scan of an energy beam, comprising: an apparatus configured to provide the energy beam; a scanner configured to scan the energy beam, the scanner comprising a first mirror and a second mirror, each mirror comprising at least one encoder, the scanner and the apparatus being configured to provide the energy beam while it is scanned according to a predetermined scanning pattern; and a computing device or system comprising at least one processor; the at least one processor is configured to: determine an actual scanning pattern of the energy beam, when both the apparatus and the scanner are operated, by processing measurements provided by the encoders of the first mirror and the second mirror; compare the actual scanning pattern with a predetermined threshold area; and determine whether the scan of the energy beam is anomalous based on the comparison.

11. The system of claim 10, wherein the predetermined threshold area or a majority thereof does not comprise an expected scanning pattern; and wherein the at least one processor is configured to determine whether the scan of the energy beam is anomalous by determining that it is anomalous when at least part of the actual scanning pattern is outside of the predetermined threshold area.

12. The system of claim 10, wherein the predetermined threshold area comprises an expected scanning pattern; and wherein the at least one processor is configured to determine whether the scan of the energy beam is anomalous by determining that it is anomalous when at least part of the actual scanning pattern is inside of the predetermined threshold area.

13. The system of claim 10, wherein the at least one processor is further configured to at least one of: indicate, when it determines that the scan of the energy beam is anomalous, that an object that was processed by the apparatus is incorrectly processed; and/or to stop the apparatus when it determines that the scan of the energy beam is anomalous.

14. The system of claim 10, wherein the encoders of the first mirror and the second mirror are configured to provide the measurements with a frequency equal to or greater than 10 kHz.

15. The system of claim 10, wherein the at least one processor is further configured to obtain data indicative of the actual scanning pattern being different from the predetermined scanning pattern; and to modify the predetermined scanning pattern based on the data indicative of the actual scanning pattern.

16. The system of claim 10, wherein the scanner is operated such that each of a maximum angular coverage in a first direction and a maximum angular coverage in a second direction is greater than 0° and equal to or less than 20°, the first direction being perpendicular to the second direction.

17. The system of claim 16, wherein each maximum angular coverage is equal to or less than 5°.

18. The system of claim 16, wherein each maximum angular coverage is equal to or less than 1°.

19. A computer-readable storage medium comprising instructions which, when executed by a computing device or system, cause the computing device or system to perform the steps of: operating an apparatus and a scanner such that an energy beam thereof is provided while it is scanned with the scanner according to a predetermined scanning pattern; determining an actual scanning pattern of the energy beam, when both the apparatus and the scanner are operated, by processing measurements provided by encoders of a first mirror and a second mirror of the scanner; comparing the actual scanning pattern with a predetermined threshold area; determining whether a scan of the energy beam is anomalous based on the comparison.

20. The computer-readable storage medium of claim 19, wherein the instructions further cause the computing device or system to perform the steps of: obtaining data indicative of the actual scanning pattern being different from the predetermined scanning pattern; modifying the predetermined scanning pattern based on the data indicative of the actual scanning pattern.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] To complete the description and in order to provide for a better understanding of the disclosure, a set of drawings is provided. Said drawings form an integral part of the description and illustrate embodiments of the disclosure, which should not be interpreted as restricting the scope of the disclosure, but just as examples of how the disclosure can be carried out. The drawings comprise the following figures:

[0070] FIG. 1 illustratively shows a system with an apparatus configured to provide an energy beam and intended to have the energy beam scanned according to a predetermined scanning pattern.

[0071] FIGS. 2A-2D illustratively show how the predetermined scanning pattern of FIG. 1 changes as the energy beam is to be scanned.

[0072] FIG. 3 illustratively shows the system of FIG. 1 with its expected scanning pattern.

[0073] FIGS. 4A-4D illustratively show how the expected scanning pattern of FIG. 3 changes as the predetermined scanning pattern of FIGS. 2A-2D changes.

[0074] FIG. 5 illustratively shows differences between a predetermined scanning pattern and an expected scanning pattern.

[0075] FIGS. 6-8 illustratively show predetermined threshold areas according to the present disclosure.

[0076] FIG. 9 illustratively shows a comparison between an actual scanning pattern and the predetermined threshold area of FIG. 8.

[0077] FIG. 10 diagrammatically shows a system in accordance with an embodiment.

[0078] FIGS. 11-12 diagrammatically show methods in accordance with embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

[0079] FIG. 1 illustratively shows a system with an apparatus 2 intended to have the energy beam 3a, 3b thereof scanned according to a predetermined scanning pattern 8.

[0080] The system comprises: the apparatus for radiating a laser beam 2, the apparatus including a laser source (not illustrated) for providing the laser beam 3a; a scanner 4 with mirrors (not illustrated) for scanning the laser beam 3b on a surface 51 of an object 50, such as a cylindrical journal of a crankshaft having an oil lubrication hole 52; a computing device 6; and a housing 5 within which the apparatus 2 and the computing device 6 may be both included.

[0081] The computing device 6 operates the apparatus 2 so that it provides the laser beam 3a, and also operates the scanner 4 so that the mirrors thereof scan the laser beam 3b in the working area, and more particularly, on the surface 51 of the object 50 such that a laser spot 7 is thereon. The computing device 6 commands the scanner 4 to scan the laser beam 3b according to the predetermined scanning pattern 8 (shown with dashed lines for illustrative purposes only) that is or may be changed while the object 50 is processed. To this end, the computing device 6 is connected to apparatus 2, so as to be communicatively coupled therewith, and to the scanner 4, for instance with cables 67 and 68. In operation of the system, the laser apparatus 2 and the scanner 4 may move with respect to the object 50 to be processed, or the object 50 to be processed moves with respect to the laser apparatus 2 and the scanner 4.

[0082] When the laser beam 3b is scanned at a high speed, such as, for example at a speed that repeats the predetermined scanning pattern 30 or more times per second, preferably 50 or more times, and even more preferably between 90 and 120 (both endpoints being included in the range) times per second, an effective laser spot is provided that makes possible to process the object 50 more accurately as the energy deposited on the object may be better controlled. Accordingly, even though the predetermined scanning pattern 8 is shown static, the entire surface 51 of the object 50 may be e.g. hardened with the apparatus 2 and, thus, the laser beam 3b is to be scanned according to the predetermined scanning pattern 8 at different parts of the surface 51, for instance by superimposing a movement to the predetermined scanning pattern 8 so as to have a predetermined scanning trajectory or by generating a relative movement between the object 50 and the apparatus 2 or the scanner 4. Further, the predetermined scanning pattern 8 may be changed while irradiating the different parts of the surface 51 so that the energy is deposited thereon as desired, as exemplarily illustrated in FIGS. 2A-2D.

[0083] FIGS. 2A-2D illustratively show, in two dimensions, how the predetermined scanning pattern 8 of FIG. 1 changes as the laser beam is to be scanned. The arrows superimposed on the predetermined scanning pattern 8a-8c represent a direction in which the laser beam is to be scanned so as to follow the pattern; it is readily apparent that different directions for scanning the laser beam are possible within the scope of the present disclosure.

[0084] FIG. 2A shows the first predetermined scanning pattern 8a commanded to the scanner 4 for scanning the laser beam 3b. The first scanning pattern 8a resembles the number eight in digital form (i.e. straight lines and sharp change of directions).

[0085] FIG. 2B shows the second predetermined scanning pattern 8b commanded to the scanner 4 as the laser beam 3b could reach the oil lubrication hole 52 to the predetermined scanning trajectory. In order not to irradiate the oil lubrication hole 52, the second predetermined scanning pattern 8b has two endpoints 9a, 9b at which the laser beam is scanned so as to go backwards, as seen in FIG. 2C in which when the laser beam reaches the second endpoint 9b, the laser beam is scanned in reverse direction until it reaches the first endpoint 9a, where it is reversed again, and so on and so forth.

[0086] As the laser beam advances owing to the predetermined scanning trajectory, the oil lubrication hole 52 falls within the third predetermined scanning pattern 8c, which is equal to the first predetermined scanning pattern 8a. The laser beam may be scanned without reversing the direction as occurred with the second predetermined scanning pattern 8b. FIG. 3 illustratively shows the system of FIG. 1 with the laser beam 3a, 3b being scanned according to an expected scanning pattern 18.

[0087] Albeit the scanner 4 is commanded to scan the laser beam 3b according to the predetermined scanning pattern 8, which in this example changes as described with reference to FIGS. 2A-2D, the scanner 4 is unable to scan it accurately and, thus, the laser spot 7 may follow a pattern similar to the expected scanning pattern 18.

[0088] There are many factors that influence the capability of the scanner 4 to actually scan the laser beam 3b according to the desired scanning pattern (the predetermined scanning pattern 8 of FIGS. 1 and 2A-2D), such as the weight of the mirrors, the moment of inertia of the mirrors, the rotating speeds of the mirrors, and the maximum angular coverage (in both directions, only the maximum angular coverage 90 in one direction being represented with dotted lines for the sake of clarity) or maximum angular area coverage that the scanner 4 is configured to cover. Hence, the expected scanning pattern 18 features curvilinear lines and smooth corners.

[0089] FIGS. 4A-4D illustratively show, in two dimensions, how the expected scanning pattern of FIG. 3 changes as the predetermined scanning pattern 8a-8c of FIGS. 2A-2D changes.

[0090] The scanner 4 is commanded to scan according to the predetermined scanning patterns 8a-8c of FIGS. 2A-2D, however the laser spot 7 is expected to follow the pattern illustrated in FIGS. 4A-4D.

[0091] The first expected scanning pattern 18a, shown in FIG. 4A, is a continuous pattern meanwhile the oil lubrication hole 52 is outside of it. The second expected scanning pattern 18b, shown in both FIGS. 4B-4C, makes the laser beam to stop at first and second endpoints 19a, 19b (so that oil lubrication hole 52 is not irradiated) and go in the reverse direction every time one of these endpoints 19a, 19b is reached. The third expected scanning pattern 18c is equal to the first expected scanning pattern 18a as illustrated in FIG. 4D.

[0092] FIG. 5 illustratively shows, in two dimensions, differences between a predetermined scanning pattern 10 and an expected scanning pattern 20.

[0093] As it can be appreciated, the expected scanning pattern 20 has curvilinear lines and rounded corners whereas the predetermined scanning pattern 10, according to which the scanner is operated, has straight lines and sharp corners forming 90° angles. The arrows superimposed on the predetermined scanning pattern 10 and the expected scanning pattern 20 represent a direction in which the laser beam is to be scanned so as to follow the pattern. It is readily apparent that different directions for scanning the laser beam are possible within the scope of the present disclosure.

[0094] FIG. 6 illustratively shows, in two dimensions, a predetermined threshold area 30-32 according to the present disclosure.

[0095] The predetermined threshold area 30-32 is illustrated superimposed on the predetermined scanning pattern 10 and the expected scanning pattern 20 for the sake of clarity only. The predetermined threshold area 30-32 comprises a plurality of areas that are not connected one to each other. The predetermined threshold area may be defined in a number of ways. For example, each area of the plurality of areas may be defined based on the predetermined scanning pattern 10, or more preferably based on the expected scanning pattern 20 since the pattern that the laser beam is expected to follow is generally regarded as the normal operation of the scanner; in the latter case, if the expected scanning pattern 20 is defined by statistically determining the likeliness with which the laser beam deviates when scanned according to the predetermined scanning pattern 10, the predetermined threshold area 30-32 may be defined for scanning deviations that amount to less than a certain value, for example less than 20%, or less than 10%, or less than 5% of a Gaussian distribution of the scanned laser beam. The predetermined threshold area 30-32 may be made larger or smaller depending on the allowed or tolerated margin of error of the scan, accordingly the determination that the scan of the laser beam is anomalous will allow more or less error.

[0096] The actual scanning pattern, that is, the pattern that the laser beam actually follows is compared with the predetermined threshold area 30-32. In this case, it is desirable that the actual scanning pattern or at least part thereof (preferably, a majority of the actual scanning pattern) is outside of the predetermined threshold area 30-32 because the predetermined threshold area represents excessive deviation of the actual scanning pattern.

[0097] If the actual scanning pattern coincides with the expected scanning pattern 20, which hardly ever happens, no part of the actual scanning pattern falls within the predetermined threshold area 30-32. This means that in order to determine that a scan of a laser beam is anomalous, instantaneous determinations (i.e. it is enough that, according to at least one processed measurement, the actual scanning pattern is within the predetermined threshold area 30-32 at one time instant to determine that the scan is anomalous) or ranged determinations (i.e. the actual scanning pattern is within the predetermined threshold area 30-32 at a plurality of time instants, according to a plurality of measurements, to determine that the scan is anomalous) may be carried out.

[0098] Ranged determinations are generally preferred since occasional errors in the scan may occur without existing a problem in the scanner that would result in further errors, or that would result in frequent or continuous anomalous scans. Depending on the number of occasional errors over a period of time or over a range of comparisons, or depending on the percent of occasional errors with respect to a range of comparisons (e.g. at least 3% of the comparisons of a range of comparisons being inside or outside of the predetermined threshold area, in this case inside of the predetermined threshold area; other exemplary values may be, e.g. at least 5%, at least 7%, at least 10%, etc.), it may be indicated that the object is not correctly processed yet the laser apparatus and the scanner are not stopped so that further objects may be processed.

[0099] In these and in other embodiments, the range of comparisons may include: a number of comparisons within a scanning trajectory (which may include a single scanning pattern, a number of repetitions of a scanning pattern, a plurality of scanning patterns, etc.), a number of comparisons in one single scanning pattern, a number of comparisons in a number of scanning pattern repetitions, etc. Preferably, the number of comparisons comprises a number of consecutive comparisons, that is, comparisons of consecutive points of the actual scanning trajectory with the predetermined threshold area.

[0100] FIG. 7 illustratively shows, in two dimensions, a predetermined threshold area 33 according to the present disclosure.

[0101] The predetermined threshold area 33 is illustrated superimposed on the predetermined scanning pattern 10 and the expected scanning pattern 20 for the sake of clarity only. The predetermined threshold area 33 may be defined in a number of ways. For example, it may be defined based on the predetermined scanning pattern 10, or more preferably based on the expected scanning pattern 20. The predetermined threshold area 33 may be made larger or smaller depending on the allowed or tolerated margin of error of the scan.

[0102] The actual scanning pattern is compared with the predetermined threshold area 33. In this case, it is desirable that at least part of the actual scanning pattern (preferably, a majority of the actual scanning pattern) is outside of the predetermined threshold area 33 because the predetermined threshold area represents excessive deviation of the actual scanning pattern.

[0103] In this case, however, the predetermined threshold area 33 comprises area in the center overlapping both the predetermined scanning pattern 10 and the expected scanning pattern 20 (in other examples it could overlap only one of these, for example the predetermined scanning pattern 10). It is expected and desired (according to the predetermined scanning pattern 10) that the laser spot of the laser beam irradiates a surface of an object in this center-most area.

[0104] In order to determine that a scan of a laser beam is anomalous, it is carried out a ranged determination because at some time instants the laser spot is expected to be within the predetermined threshold area 33. Accordingly, it is determined that the scan is anomalous if a number of comparisons or a percent of comparisons (with respect to a range of comparisons) of the actual scanning pattern and the predetermined threshold area 33 exceeds a predetermined threshold value.

[0105] The predetermined threshold value may be established based upon a frequency with which encoders of the mirrors of the scanner provide measurements to the computing device or system carrying out the comparisons and determinations of whether the scan is anomalous, and also based upon the number of commanded repetitions of the predetermined scanning pattern 10 per second (something which influences the rotating speeds of the mirrors of the scanner). From the frequency and the number of commanded repetitions it can be determined how many comparisons may be carried out per repetition, and how many times the actual scanning pattern will be expected to be within the predetermined threshold area 33 due to the overlap between said area 33 and the expected scanning pattern 20. Therefore, the predetermined threshold value should be greater than the number of times the actual scanning pattern will be expected to be within the predetermined threshold area 33 so as to determine a possibly anomalous scan.

[0106] In comparison with the predetermined threshold area 30-32 of FIG. 6, the predetermined threshold area 33 of FIG. 7 may be less preferable because it lacks an area at the outer-most part of the expected scanning pattern 20 (such as the area 30 of FIG. 6). Such area at the outer-most part is convenient for determining that a scan entailing a greater risk for the safety of people is anomalous, mainly because a laser beam being aimed at said outer-most part may be aimed further away from the expected scanning pattern 20 and, therefore, out from the working area.

[0107] In some other embodiments, the predetermined threshold area only comprises area at the outer-most part of the expected scanning pattern 20 (such as the area 30 of FIG. 6). Also, in some other embodiments, the predetermined threshold area may be provided as the areas 31, 32 of FIG. 6 that do not overlap the expected scanning pattern 20 and/or the predetermined scanning pattern 10. In such embodiments, the determination that a scan of a laser beam is anomalous may be carried out either as instantaneous determinations (because the expected scanning pattern 20 does not overlap the area 30, or the areas 31, 32 forming the predetermined threshold area) or as ranged determinations.

[0108] FIG. 8 illustratively shows, in two dimensions, a predetermined threshold area 35 according to the present disclosure.

[0109] The predetermined threshold area 35 is illustrated superimposed on the predetermined scanning pattern 10 and the expected scanning pattern 20 for the sake of clarity only. The predetermined threshold area 35 may be defined in a number of ways. For example, it may be defined based on the predetermined scanning pattern 10, or more preferably based on the expected scanning pattern 20. The predetermined threshold area 35 may be made larger or smaller depending on the allowed or tolerated margin of error of the scan.

[0110] The actual scanning pattern is compared with the predetermined threshold area 35. In this case, it is desirable that the actual scanning pattern or at least part thereof (preferably, a majority of the actual scanning pattern) is inside of the predetermined threshold area 35 because the predetermined threshold area represents lack of deviation of the actual scanning pattern.

[0111] The determination that a scan of a laser beam is anomalous is carried out either as instantaneous determinations or as ranged determinations, depending on which one or more than one comparison should be outside of the predetermined threshold area 35 to determine that the actual scanning pattern has deviated and, therefore, the scan may be anomalous. When the predetermined scanning pattern and the expected scanning pattern changes during the processing of objects, for instance as described with reference to FIGS. 2A-2D and 4A-4D, the predetermined threshold areas also change so that the comparison between the actual scanning pattern and the predetermined threshold area corresponds. By way of example, if the second predetermined scanning pattern 8b and the second expected scanning pattern 18b are considered, the predetermined threshold area will be influenced by the endpoints 9a, 9b, 19a, 19b and, thus, the actual scanning pattern during that part of the processing will have to be outside of the predetermined threshold area (if the area is defined as in FIGS. 6-7) or inside of the predetermined threshold area (if the area is defined as in FIG. 8) with regards to the position of the oil lubrication hole 52.

[0112] Even though the expected scanning pattern 20 has been represented as a line, the same may be in some cases represented as a line having a thickness (thus, having an area) which illustrates where the spot of the energy beam is expected to be when the expected scanning pattern 20 is defined by means of a statistical determination. The thickness may be selected based, for example, on the standard deviation of a normal distribution.

[0113] FIG. 9 illustratively shows, in two dimensions, a comparison between an actual scanning pattern 25 and the predetermined threshold area 35 of FIG. 8.

[0114] The encoders of the mirrors of the scanner sense the absolute position of the mirrors within the scanner, the angle of the mirrors, or the movement of the mirrors. The values sensed are then processed by a computing device or system for determining the actual scanning pattern 25 of a laser beam. The actual scanning pattern 25 is then compared with the predetermined threshold area 35 to determine whether the scan is anomalous.

[0115] As it may be observed in FIG. 9, there are two portions 26a, 26b of the actual scanning pattern 25 that fall outside from the predetermined threshold area 35. Depending on the criteria for determining that the scan is anomalous (e.g. number of points or percent of points outside from the predetermined threshold area 35), the existence of such two portions 26a, 26b may result in the determination that the scan is in fact anomalous, or that it is not anomalous (i.e. a greater percent or number of points must be out from the predetermined threshold area 35). Accordingly, if it is established that one or two points are enough to determine that the scan is anomalous, in the example of FIG. 9 it would be determined that the scan is in fact anomalous; if it is more than two points, depending on the number of points in the portions 26a, 26b the same determination could be made.

[0116] Even though the actual scanning pattern 25 illustrated is shown as a continuous line, it is readily apparent that the measurements provided by the encoders are discrete, thus the actual scanning pattern 25 determined by the computing device or system is a cloud of discrete points rather than a continuous line. Each point of the cloud of points may be compared with the predetermined threshold area 35. The computing device or system may, in some embodiments, connect consecutive discrete points to provide a continuous actual scanning pattern 25 in order to make the comparison, however this is normally not necessary.

[0117] FIG. 10 diagrammatically shows a system 200 in accordance with an embodiment.

[0118] The system 200 comprises a computing device or system 60, a laser apparatus 2 with a laser source (not illustrated) for providing a laser beam with a power over e.g. 1 kW, for instance 2 kW, 3 kW, 5 kW, etc. and less than e.g. 20 kW, such as 15 kW or 10 kW, and a scanner 4. The computing device or system 60 is connected to the laser apparatus 2 and the scanner 4, for example with means such as cables 67, 68, or through a programmable logic controller in turn connected to the laser apparatus 2 and/or the scanner 4, or with Ethernet connections through a switch or router, etc.

[0119] The scanner 4 comprises a first mirror 42, a second mirror 44, at least a first encoder 46 that senses and provides measures of the first mirror 42, and at least a second encoder 48 that senses and provides measures of the second mirror 44. The first and second mirrors 42, 44 scan the laser beam provided by the laser apparatus according to scanning patterns or trajectories.

[0120] The computing device or system 60 comprises at least one processor 62, at least one memory 64, and means 66 for transmitting and receiving data. The computing device or system 60 may comprise input means and user interfaces that enable an operator to adjust and control the operation of the computing device or system 60, something which may also be carried out remotely by transmitting data to and receiving data from the computing device or system 60 through the means 66.

[0121] The at least one processor 62, together with the at least one memory 64 and the means 66, processes measurements provided by the at least first and second encoders 46, 48 so as to determine the actual scanning pattern of the laser beam as scanned, compares the actual scanning pattern with a predetermined threshold area (that may include a plurality of areas not connected one to each other), and determines whether the scan is anomalous. Further, the at least one processor 62 may operate the laser apparatus 2 and/or the scanner 4 so as to change the laser beam provided, e.g. the power thereof, the diameter of the laser spot, etc. and/or the scan of the laser beam, e.g. the predetermined scanning pattern, the rotating speeds of the mirrors, etc.

[0122] In the present disclosure, the computing device or system 60 may be a single device, i.e. a computing device; or it may be a plurality of computing devices that are communicatively coupled, i.e. a computing system, each of which carries out one or more computing operations, or all computing devices carry out one or more computing operations in a distributed manner.

[0123] FIG. 11 diagrammatically shows a method 100 in accordance with an embodiment.

[0124] The method 100 comprises a step of providing 102 an apparatus (for example, the apparatus 2 of FIGS. 1, 3, 10) configured to provide an energy beam, e.g. a laser beam, that is to be scanned with a scanner. The method 100 further comprises a step of providing 104 a scanner (for example, the scanner 4 of FIGS. 1, 3, 10) configured to scan the energy beam provided by the apparatus.

[0125] The method 100 further comprises a step of operating 106 the apparatus and the scanner such that the energy beam is provided while it is scanned according to a predetermined scanning pattern. In some embodiments, this step is carried out by at least one processor of a computing device or system (for example, the computing device 6 of FIGS. 1, 3 or the computing device or system 60 of FIG. 10).

[0126] The method 100 further comprises a step of determining 108 an actual scanning pattern (for example, the actual scanning pattern 25 of FIG. 9) of the energy beam, when both the apparatus and the scanner are operated, by processing measurements provided by encoders of a first mirror and a second mirror of the scanner. This step is carried out by the at least one processor of the computing device or system.

[0127] The method 100 further comprises a step of comparing 110 the actual scanning pattern with a predetermined threshold area (for example, any of the predetermined threshold areas 30-33, 35 of FIGS. 6-9). This step is carried out by the at least one processor of the computing device or system.

[0128] The method 100 may further comprise a step of determining 112 that the scan of the energy beam is anomalous if at least part of the actual scanning pattern is inside or outside of the predetermined threshold area. This step is carried out by the at least one processor of the computing device or system.

[0129] FIG. 12 diagrammatically shows a method 101 in accordance with an embodiment.

[0130] The method 101 comprises the same steps of method 100 of FIG. 11, and further comprises one or both of the following steps: indicating 114, if it is determined 112 that the scan of the energy beam is anomalous, that an object that was processed by the apparatus is incorrectly processed; and stopping 116 the apparatus for emitting an energy beam if it is determined 112 that the scan of the energy beam is anomalous. In some embodiments, these steps may be carried out by the at least one processor of the computing device or system.

[0131] In some embodiments, the method comprises: obtaining data indicative of the actual scanning pattern being different from the predetermined scanning pattern, and modifying the predetermined scanning pattern based on said data. This may involve reprogramming, thus optimizing, the system based on the data indicative of the actual scanning pattern, for example by instructing the scanner to operate more in accordance with the actual scanning pattern, that is to say, by providing to the scanner new instructions that better correspond to the actual operation of the scanner than original instructions.

[0132] The data indicative of the actual scanning pattern can, for example, comprise data originating from encoders of the scanner 4, for example, encoders indicative of the real movements of the mirrors or similar of the scanner. Thus, once the real movement followed by the mirrors is detected, the corresponding data can be used to optimize the operation of the scanner 4 so as to operate not according to the predetermined scanning pattern 10, but according to the actual scanning pattern, or according to a more or less similar scanning pattern. Thus, the system including the scanner 4 can end up being programmed in a manner that better reflects the actual operation of the scanner 4. Thereby, the scanner can be subjected to less operational stress when operated. This serves to minimize the risk of damage to the scanner 4 or to operational failures of the type that tend to appear when a scanner 4 is operated at its operational limits, for example, forced to follow a scanning pattern including abrupt changes at a high speed. The steps of obtaining data indicative of the actual scanning pattern being different from the predetermined scanning pattern, and modifying the predetermined scanning pattern based on the data indicative of the actual scanning pattern, can be repeated several times, such as as often as deemed possible, until a desired conformity between the programmed (predetermined) scanning pattern and the actual scanning pattern followed by the energy beam has been reached, so as to ensure that the system with scanner ends up being programmed in a manner that substantially coincides with its actual operation, thereby minimizing the operational stresses. Albeit embodiments have been described in which laser beams are scanned according to an exemplary predetermined scanning pattern, it is readily apparent that laser beams may be scanned according to other different scanning patterns and which also fall within the scope of the present disclosure. By way of example, upon determining an expected scanning pattern as herein disclosed when the scanner scans an energy beam according to a predetermined scanning pattern, the scanner may be commanded to scan an energy beam with a predetermined scanning pattern defined on the basis of the determined expected scanning pattern; accordingly, the scanner can be subjected to less operational stress when operated yet an expected scanning pattern and one or more predetermined threshold areas are then determined for the operation of the machine as herein disclosed.

[0133] In this text, the terms “actual scanning pattern” and “actual scanning trajectory” refer to the scanning pattern and the scanning trajectory, respectively, as determined based on the processed measurements. Therefore, errors in the processing made result in the determination of a scanning pattern and a scanning trajectory different from the actually followed by the laser beam and the laser spot thereof, as it will be readily apparent to the person skilled in the art. Accordingly, these terms could as well be referred to as, for example but without limitation, “determined scanning pattern” and “determined scanning trajectory”, respectively.

[0134] In this text, the term “comprises” and its derivations (such as “comprising”, etc.) should not be understood in an excluding sense, that is, these terms should not be interpreted as excluding the possibility that what is described and defined may include further elements, steps, etc.

[0135] On the other hand, the disclosure is obviously not limited to the specific embodiment(s) described herein, but also encompasses any variations that may be considered by any person skilled in the art (for example, as regards the choice of materials, dimensions, components, configuration, etc.), within the general scope of the disclosure as defined in the claims.